Gene Summary

Gene:CYP2B6; cytochrome P450 family 2 subfamily B member 6
Aliases: CPB6, EFVM, IIB1, P450, CYP2B, CYP2B7, CYP2B7P, CYPIIB6
Summary:This gene, CYP2B6, encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum and its expression is induced by phenobarbital. The enzyme is known to metabolize some xenobiotics, such as the anti-cancer drugs cyclophosphamide and ifosphamide. Transcript variants for this gene have been described; however, it has not been resolved whether these transcripts are in fact produced by this gene or by a closely related pseudogene, CYP2B7. Both the gene and the pseudogene are located in the middle of a CYP2A pseudogene found in a large cluster of cytochrome P450 genes from the CYP2A, CYP2B and CYP2F subfamilies on chromosome 19q. [provided by RefSeq, Jul 2008]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:cytochrome P450 2B6
Source:NCBIAccessed: 30 August, 2019

Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 30 August 2019 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Risk Factors
  • Breast Cancer
  • Cyclophosphamide
  • Polymorphism
  • Xenobiotics
  • Glutathione Transferase
  • CYP2D6
  • Aryl Hydrocarbon Hydroxylases
  • Messenger RNA
  • Survival Rate
  • Oligonucleotide Array Sequence Analysis
  • Biomarkers, Tumor
  • Doxorubicin
  • Cytochrome P-450 CYP3A
  • Alleles
  • Biotransformation
  • Transplantation Conditioning
  • Liver Cancer
  • Hepatocellular Carcinoma
  • Antineoplastic Agents
  • Single Nucleotide Polymorphism
  • Urinary Bladder
  • Drug Resistance
  • Tamoxifen
  • Transfection
  • Cancer Gene Expression Regulation
  • Genetic Predisposition
  • Gene Expression Profiling
  • Cohort Studies
  • Case-Control Studies
  • Adolescents
  • Cytochrome P-450 CYP2C19
  • Antineoplastic Agents, Alkylating
  • Promoter Regions
  • Cytochrome P-450 Enzyme System
  • Cytochrome P-450 CYP2B6
  • Childhood Cancer
  • Chromosome 19
  • Genotype
  • Enzymologic Gene Expression Regulation
Tag cloud generated 30 August, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (2)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: CYP2B6 (cancer-related)

Zhong X, Huang G, Ma Q, et al.
Identification of crucial miRNAs and genes in esophageal squamous cell carcinoma by miRNA-mRNA integrated analysis.
Medicine (Baltimore). 2019; 98(27):e16269 [PubMed] Free Access to Full Article Related Publications
Esophageal squamous cell carcinoma (ESCC) is a malignancy that severely threatens human health and carries a high incidence rate and a low 5-year survival rate. MicroRNAs (miRNAs) are commonly accepted as a key regulatory function in human cancer, but the potential regulatory mechanisms of miRNA-mRNA related to ESCC remain poorly understood.The GSE55857, GSE43732, and GSE6188 miRNA microarray datasets and the gene expression microarray datasets GSE70409, GSE29001, and GSE20347 were downloaded from Gene Expression Omnibus databases. The differentially expressed miRNAs (DEMs) and differentially expressed genes (DEGs) were obtained using GEO2R. Gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for DEGs were performed by Database for Annotation, Visualization and Integrated Discovery (DAVID). A protein-protein interaction (PPI) network and functional modules were established using the STRING database and were visualized by Cytoscape. Kaplan-Meier analysis was constructed based on The Cancer Genome Atlas (TCGA) database.In total, 26 DEMs and 280 DEGs that consisted of 96 upregulated and 184 downregulated genes were screened out. A functional enrichment analysis showed that the DEGs were mainly enriched in the ECM-receptor interaction and cytochrome P450 metabolic pathways. In addition, MMP9, PCNA, TOP2A, MMP1, AURKA, MCM2, IVL, CYP2E1, SPRR3, FOS, FLG, TGM1, and CYP2C9 were considered to be hub genes owing to high degrees in the PPI network. MiR-183-5p was with the highest connectivity target genes in hub genes. FOS was predicted to be a common target gene of the significant DEMs. Hsa-miR-9-3p, hsa-miR-34c-3p and FOS were related to patient prognosis and higher expression of the transcripts were associated with a poor OS in patients with ESCC.Our study revealed the miRNA-mediated hub genes regulatory network as a model for predicting the molecular mechanism of ESCC. This may provide novel insights for unraveling the pathogenesis of ESCC.

Dusek J, Skoda J, Holas O, et al.
Stilbene compound trans-3,4,5,4´-tetramethoxystilbene, a potential anticancer drug, regulates constitutive androstane receptor (Car) target genes, but does not possess proliferative activity in mouse liver.
Toxicol Lett. 2019; 313:1-10 [PubMed] Related Publications
The constitutive androstane receptor(CAR) activation is connected with mitogenic effects leading to liver hyperplasia and tumorigenesis in rodents. CAR activators, including phenobarbital, are considered rodent non-genotoxic carcinogens. Recently, trans-3,4,5,4´-tetramethoxystilbene(TMS), a potential anticancer drug (DMU-212), have been shown to alleviate N-nitrosodiethylamine/phenobarbital-induced liver carcinogenesis. We studied whether TMS inhibits mouse Car to protect from the PB-induced tumorigenesis. Unexpectedly, we identified TMS as a murine CAR agonist in reporter gene experiments, in mouse hepatocytes, and in C57BL/6 mice in vivo. TMS up-regulated Car target genes Cyp2b10, Cyp2c29 and Cyp2c55 mRNAs, but down-regulated expression of genes involved in gluconeogenesis and lipogenesis. TMS did not change or down-regulate genes involved in liver proliferation or apoptosis such as Mki67, Foxm1, Myc, Mcl1, Pcna, Bcl2, or Mdm2, which were up-regulated by another Car ligand TCPOBOP. TMS did not increase liver weight and had no significant effect on Ki67 and Pcna labeling indices in mouse liver in vivo. In murine hepatic AML12 cells, we confirmed a Car-independent proapoptotic effect of TMS. We conclude that TMS is a Car ligand with limited effects on hepatocyte proliferation, likely due to promoting apoptosis in mouse hepatic cells, while controlling Car target genes involved in xenobiotic and endobiotic metabolism.

Zhang GH, Chen MM, Kai JY, et al.
Molecular profiling of mucinous epithelial ovarian cancer by weighted gene co-expression network analysis.
Gene. 2019; 709:56-64 [PubMed] Related Publications
PURPOSE: In order to identify the molecular characteristics and improve the efficacy of early diagnosis of mucinous epithelial ovarian cancer (mEOC), here, the transcriptome profiling by weighted gene co-expression network analysis (WGCNA) has been proposed as an effective method.
METHODS: The gene expression dataset GSE26193 was reanalyzed with a systematical approach, WGCNA. mEOC-related gene co-expression modules were detected and the functional enrichments of these modules were performed at GO and KEGG terms. Ten hub genes in the mEOC-related modules were validated using two independent datasets GSE44104 and GSE30274.
RESULTS: 11 co-expressed gene modules were identified by WGCNA based on 4917 genes and 99 epithelial ovarian cancer samples. The turquoise module was found to be significantly associated with the subtype of mEOC. KEGG pathway enrichment analysis showed genes in the turquoise module significantly enriched in metabolism of xenobiotics by cytochrome P450 and steroid hormone biosynthesis. Ten hub genes (LIPH, BCAS1, FUT3, ZG16B, PTPRH, SLC4A4, MUC13, TFF1, HNF4G and TFF2) in the turquoise module were validated to be highly expressed in mEOC using two independent gene expression datasets GSE44104 and GSE30274.
CONCLUSION: Our work proposed an applicable framework of molecular characteristics for patients with mEOC, which may help us to obtain a precise and comprehensive understanding on the molecular complexities of mEOC. The hub genes identified in our study, as potential specific biomarkers of mEOC, may be applied in the early diagnosis of mEOC in the future.

Matsuoka S, Tsutsumi Y, Kikuchi R, et al.
Gene Polymorphism of Tacrolimus-Metabolizing Enzymes Associated With Impaired Absorption of Tacrolimus Following Allogeneic Hematopoietic Stem Cell Transplantation: A Case Report.
Transplant Proc. 2019; 51(3):998-1001 [PubMed] Related Publications
OBJECTIVE: To elucidate the mechanisms by which orally administered tacrolimus was not absorbed in a patient following allogeneic hematopoietic stem cell transplantation.
CLINICAL COURSE: A 17-year-old girl with acute myeloid leukemia underwent HLA-haploidentical peripheral blood stem cell transplantation following fludarabine, busulfan, and total-body irradiation. Graft-vs-host disease prophylaxis was post-transplant cyclophosphamide, followed by intravenous tacrolimus and mycophenolate mofetil. When tacrolimus was switched to oral administration, its blood level declined rapidly, resulting in development of acute graft-vs-host disease, which was ameliorated by switching back to intravenous administration.
METHODS/RESULTS: To elucidate if impaired tacrolimus absorption could be related to genetic polymorphism of tacrolimus-metabolizing enzymes, we analyzed gene polymorphisms of cytochrome P450 3A4, cytochrome P450 3A5, and multidrug resistance 1 (MDR1). The patient had wild-type cytochrome P450 3A4 (*1/*1) and variant-type cytochrome P450 3A5 (*3/*3), while MDR1 genes (2677A/G, 3435C/C) were wild-type.
CONCLUSION: Wild-type MDR1 gene product P-glycoprotein expressed in the intestine reduces drug absorption from the gastrointestinal tract and may have contributed to low blood levels of tacrolimus in this patient when tacrolimus was orally administered.

Wu Q, Zhang B, Wang Z, et al.
Integrated bioinformatics analysis reveals novel key biomarkers and potential candidate small molecule drugs in gastric cancer.
Pathol Res Pract. 2019; 215(5):1038-1048 [PubMed] Related Publications
BACKGROUND AND OBJECTIVE: The underlying molecular mechanisms of gastric cancer (GC) have yet not been investigated clearly. In this study, we aimed to identify hub genes involved in the pathogenesis and prognosis of GC.
METHODS: We integrated five microarray datasets from Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) between GC and normal samples were analyzed with limma package. Gene ontology (GO) and KEGG enrichment analysis were performed using DAVID. Then we established the protein-protein interaction (PPI) network of DEGs by the Search Tool for the Retrieval of Interacting Genes database (STRING). The prognostic analysis of hub genes were performed through Gene Expression Profiling Interactive Analysis (GEPIA). Additionally, we used real-time quantitative PCR to validate the expression of hub genes in 5 pairs of tumor tissues and corresponding adjacent tissues. Finally, the candidate small molecules as potential drugs to treat GC were predicted in CMap database.
RESULTS: Through integrating five microarray datasets, a total of 172 overlap DEGs were detected including 79 up-regulated and 93 down-regulated genes. Biological process analysis of functional enrichment showed these DEGs were mainly enriched in digestion, collagen fibril organization and cell adhesion. Signaling pathway analysis indicated that these DEGs played an vital in ECM-receptor interaction, focal adhesion and metabolism of xenobiotics by cytochrome P450. Protein-protein interaction network among the overlap DEGs was established with 124 nodes and 365 interactions. Three DEGs with high degree of connectivity (NID2, COL4A1 and COL4A2) were selected as hub genes. The GEPIA database confirmed that overexpression levels of hub genes were significantly associated with worse survival of patients. Finally, the 20 most significant small molecules were obtained based on CMap database and spiradoline was the most promising small molecule to reverse the GC gene expression.
CONCLUSIONS: Our results indicated that NID2, COL4A1 and COL4A2 could be the potential novel biomarkers for GC diagnosis prognosis and the promising therapeutic targets. The present study may be crucial to understanding the molecular mechanism of GC initiation and progression.

Barooah P, Saikia S, Bharadwaj R, et al.
Role of
Genet Test Mol Biomarkers. 2019; 23(5):325-331 [PubMed] Related Publications

Ye Z, Wang F, Yan F, et al.
Bioinformatic identification of candidate biomarkers and related transcription factors in nasopharyngeal carcinoma.
World J Surg Oncol. 2019; 17(1):60 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The incidence of nasopharyngeal carcinoma (NPC) is rare, but a certain amount of mortality remains in NPC patients. Our study aimed to identify candidate genes as biomarkers for NPC screening, diagnosis, and therapy.
METHODS: We investigated two microarray profile datasets GSE64634 and GSE12452 to screen the potential differentially expressed genes (DEGs) in NPC. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of the DEGs were also performed. A protein-protein interaction (PPI) network of DEGs was constructed by STRING and visualized by Cytoscape software. The associated transcriptional factor regulatory network of the DEGs was also constructed.
RESULTS: A total of 152 DEGs were identified from the GSE64634 and GSE12452 datasets, including 10 upregulated and 142 downregulated genes. Gene functional enrichment analysis indicated that these DEGs were enriched in the cilium movement, antimicrobial humoral response, O-glycan processing, mucosal immune response, carbohydrate transmembrane transporter activity, hormone biosynthetic process, neurotransmitter biosynthetic process, and drug metabolism-cytochrome P450 pathway. Five hub genes (DNALI1, RSPH4A, RSPH9, DNAI2, and ALDH3A1) and one significant module (score = 5.6) were obtained from the PPI network. Key transcriptional factors, such as SPI1, SIN3B, and GATA2, were identified with close interactions with these five hub DEGs from the gene-transcriptional factor network.
CONCLUSIONS: With the integrated bioinformatic analysis, numerous DEGs related to NPC were screened, and the hub DEGs we identified may be potential biomarkers for NPC.

Wang JS, Wang YG, Zhong YS, et al.
Identification of co-expression modules and pathways correlated with osteosarcoma and its metastasis.
World J Surg Oncol. 2019; 17(1):46 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Osteosarcoma is the most common bone tumor that occurs in children.
METHODS: To identify co-expression modules and pathways correlated with osteosarcoma and its clinical characteristics, we performed weighted gene co-expression network analysis (WGCNA) on RNA-seq data of osteosarcoma with 52 samples. Then we performed pathway enrichment analysis on genes from significant modules.
RESULTS: A total of 5471 genes were included in WGCNA, and 16 modules were identified. Module-trait analysis identified that a module involved in microtubule bundle formation, drug metabolism-cytochrome P450, and IL-17 signaling pathway was negatively correlated with osteosarcoma and positively correlated with metastasis; a module involved in DNA replication was positively correlated with osteosarcoma; a module involved in cell junction was positively correlated with metastasis; and a module involved in heparin binding negatively correlated with osteosarcoma. Moreover, expression levels in four of the top ten differentially expressed genes were validated in another independent dataset.
CONCLUSIONS: Our analysis might provide insight for molecular mechanisms of osteosarcoma.

Lin JT, Chan TC, Li CF, et al.
Downregulation of the cytochrome P450 4B1 protein confers a poor prognostic factor in patients with urothelial carcinomas of upper urinary tracts and urinary bladder.
APMIS. 2019; 127(4):170-180 [PubMed] Related Publications
The objective of this study was to examine the expression level of cytochrome P450 4B1 (CYP4B1) protein and its clinical significance in specimens from patients with urothelial carcinomas (UC) including upper tract urothelial carcinoma (UTUC, n = 340) and urinary bladder urothelial carcinoma (UBUC, n = 295). Data mining on public domains identified five potential candidate transcripts which were downregulated in advanced UBUCs, indicating that it might implicate in UC progression. Immunohistochemistry was performed to analyze the CYP4B1 protein levels on 635 tissues from UC patients retrospectively. Immunoexpression of CYP4B1 was further estimated using the H-score method. Correlations between CYP4B1 H-score and important clinicopathological factors, as well as the significance of CYP4B1 expression level for disease-specific and metastasis-free survivals were evaluated. In UTUCs and UBUCs, 118 (34.7%) and 92 (31.2%) patients, respectively, were identified to be of CYP4B1 downregulation. The CYP4B1 expression level was found to be associated with several clinicopathological factors and patient survivals. Downregulation of CYP4B1 protein was correlated to advanced primary tumor (p < 0.001), nodal metastasis (p < 0.001), high histological grade (p = 0.001), vascular invasion (p < 0.001), perineural invasion (p = 0.017) and mitotic rate (p = 0.036) in UTUCs and/or UBUCs. Low CYP4B1 protein level independently predicted inferior disease-specific (p = 0.009; p < 0.001) and metastasis-free (p = 0.035; p < 0.001) survivals in UTUC and UBUC patients. Our findings showed that downregulation of CYP4B1 protein level is an independent unfavorable prognosticator. Loss of the CYP4B1 gene expression may play an important role in UC progression.

Zhang Q, Sun S, Zhu C, et al.
Prediction and analysis of weighted genes in hepatocellular carcinoma using bioinformatics analysis.
Mol Med Rep. 2019; 19(4):2479-2488 [PubMed] Free Access to Full Article Related Publications
The aim of the present study was to identify the differentially expressed genes (DEGs) between primary tumor tissue and adjacent non‑tumor tissue of hepatocellular carcinoma (HCC) samples in order to investigate the mechanisms of HCC. The microarray data of the datasets GSE76427, GSE84005 and GSE57957 were downloaded from the Gene Expression Omnibus database. DEGs were identified using the limma package in the R programming language. Following the intersection of the DEGs screened from the three datasets, 218 genes were selected for further study. A protein‑protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes database. The construction and analysis of modules were performed using Cytoscape and the module with the highest score was selected for further analysis. Gene Ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were conducted for genes involved in the PPI network and the selected subnetwork. The network of the enriched pathways and their associated genes was constructed using Cytoscape. For the genes in the global PPI network, metabolism‑associated pathways were significantly enriched; whereas, for the genes in the subnetwork, 'cell cycle', 'oocyte meiosis' and 'DNA replication' pathways were significantly enriched. To demonstrate the portability and repeatability of the prognostic value of the weighted genes, a validation cohort was obtained from datasets of The Cancer Genome Atlas and Kaplan‑Meier survival analysis was conducted. Evidence is presented that the expression levels of aldehyde dehydrogenase 2 family member, cytochrome P450 family 2 subfamily C member 8, alcohol dehydrogenase 4 (class II), pi polypeptide, alcohol dehydrogenase 1B (class I), β polypeptide and cytochrome P450 family 2 subfamily C member 9 were associated with the overall survival of patients with HCC and that the expression levels of pituitary tumor‑transforming 1, cell division cycle 20, DNA topoisomerase II α and cyclin B2 were negatively associated with the overall survival of patients with HCC. In conclusion, 9 weighted genes, involved in the development and progression of HCC, were identified using bioinformatics and survival analyses.

Yamaguchi M, Hankinson O
2,3,7,8‑tetrachlorodibenzo‑p‑dioxin suppresses the growth of human colorectal cancer cells in vitro: Implication of the aryl hydrocarbon receptor signaling.
Int J Oncol. 2019; 54(4):1422-1432 [PubMed] Free Access to Full Article Related Publications
Human colorectal cancer is the third most common cancer disease with a 5‑year survival rate of 55% in USA in 2016. The investigation to identify novel biomarker factors with molecular classification may provide notable clinical information to prolong the survival of patients with colorectal cancer. The aryl hydrocarbon receptor (AHR) binds the AHR nuclear translocator in the cytoplasm of various types of cells, including liver cells, and then binds to the xenobiotic responsive element on various genes. AHR was initially discovered via its ligand, the polychlorinated hydrocarbon, 2,3,7,8‑tetrachlorodibenzo‑p‑dioxin (TCDD). The present study was undertaken to determine whether TCDD, an agonist of AHR signaling, impacts the growth of RKO human colorectal cancer cells in vitro. Treatment with TCDD (0.1‑100 nM) revealed suppressive effects on colony formation and proliferation of RKO cells, and stimulated death of these cells with subconfluence. These effects of TCDD were abolished by pretreatment with CH223191, an inhibitor of AHR signaling. Western blot analysis demonstrated that TCDD treatment decreased AHR levels and elevated cytochrome P450 family 1 subfamily A member 1 (CYP1A1) levels, indicating a stimulation of AHR signaling. TCDD treatment caused an increase in nuclear factor‑κB p65 and β‑catenin levels, although it did not have an effect on Ras levels. Notably, TCDD treatment increased the levels of p53, retinoblastoma, p21 and regucalcin, which are depressors of carcinogenesis. Additionally, action of TCDD on cell proliferation and death were not revealed in regucalcin‑overexpressing RKO cells, and regucalcin overexpression depressed AHR signaling associated with CYP1A1 expression. Thus, AHR signaling suppresses the growth of colorectal cancer cells, indicating a role as a significant targeting molecule for colorectal cancer.

An D, Song Z, Yi Y, et al.
Oroxylin A, a methylated metabolite of baicalein, exhibits a stronger inhibitory effect than baicalein on the CYP1B1-mediated carcinogenic estradiol metabolite formation.
Phytother Res. 2019; 33(4):1033-1043 [PubMed] Related Publications
Human cytochrome P450 1B1 (CYP1B1)-mediated formation of 4-hydroxyestradiol (4-OHE2) from 17β-estradiol plays an important role in the progression of human breast cancer, while the biotransformation of 17β-estradiol to 2-hydroxyestradiol mediated by cytochrome P450 1A1 (CYP1A1) is considered as a less harmful pathway. In this study, inhibitory effects of flavonoids baicalein and oroxylin A, a metabolite of baicalein in human body, on CYP1A1 and 1B1 activities were investigated in vitro. The inhibition intensities of baicalein and oroxylin A towards CYP1B1 were greater than towards CYP1A1 with a mixed mechanism. In addition, oroxylin A showed a stronger inhibitory effect than baicalein towards the CYP1B1-mediated 17β-estradiol 4-hydroxylation, with the IC

Ruoß M, Damm G, Vosough M, et al.
Epigenetic Modifications of the Liver Tumor Cell Line HepG2 Increase Their Drug Metabolic Capacity.
Int J Mol Sci. 2019; 20(2) [PubMed] Free Access to Full Article Related Publications
Although human liver tumor cells have reduced metabolic functions as compared to primary human hepatocytes (PHH) they are widely used for pre-screening tests of drug metabolism and toxicity. The aim of the present study was to modify liver cancer cell lines in order to improve their drug-metabolizing activities towards PHH. It is well-known that epigenetics is strongly modified in tumor cells and that epigenetic regulators influence the expression and function of Cytochrome P450 (CYP) enzymes through altering crucial transcription factors responsible for drug-metabolizing enzymes. Therefore, we screened the epigenetic status of four different liver cancer cell lines (Huh7, HLE, HepG2 and AKN-1) which were reported to have metabolizing drug activities. Our results showed that HepG2 cells demonstrated the highest similarity compared to PHH. Thus, we modified the epigenetic status of HepG2 cells towards 'normal' liver cells by 5-Azacytidine (5-AZA) and Vitamin C exposure. Then, mRNA expression of Epithelial-mesenchymal transition (EMT) marker SNAIL and CYP enzymes were measured by PCR and determinate specific drug metabolites, associated with CYP enzymes by LC/MS. Our results demonstrated an epigenetic shift in HepG2 cells towards PHH after exposure to 5-AZA and Vitamin C which resulted in a higher expression and activity of specific drug metabolizing CYP enzymes. Finally, we observed that 5-AZA and Vitamin C led to an increased expression of Hepatocyte nuclear factor 4α (HNF4α) and E-Cadherin and a significant down regulation of Snail1 (SNAIL), the key transcriptional repressor of E-Cadherin. Our study shows, that certain phase I genes and their enzyme activities are increased by epigenetic modification in HepG2 cells with a concomitant reduction of EMT marker gene SNAIL. The enhancing of liver specific functions in hepatoma cells using epigenetic modifiers opens new opportunities for the usage of cell lines as a potential liver in vitro model for drug testing and development.

Gaviria-Calle M, Duque-Jaramillo A, Aranzazu M, et al.
Polymorphisms in alcohol dehydrogenase (ADH1) and cytochrome p450 2E1 (CYP2E1) genes in patients with cirrhosis and/or hepatocellular carcinoma
Biomedica. 2018; 38(4):555-568 [PubMed] Related Publications
Introduction: One of the most important risk factors for hepatocellular carcinoma (HCC) is alcohol consumption: Studies in different populations suggest that the risk of liver disease could be associated with genetic variants of the enzymes involved in alcohol metabolism, such as alcohol dehydrogenase (ADH) and cytochrome P450 CYP2E1. Objective: To identify and characterize the allelic variants of ADH1B, ADH1C and CYP2E1 genes in Colombian patients with cirrhosis and/or HCC. Materials and methods: We included samples from patients attending the hepatology unit between 2005-2007 and 2014-2016 of a hospital in Medellin. Samples were genotyped using PCR-RFLP. We compared the results with two control groups and the 1000 Genomes Project database. Results: We collected 97 samples from patients with a diagnosis of cirrhosis and/or HCC. The two main risk factors were chronic alcohol consumption (18.6%) and cholangiopathies (17.5%). The most frequent genotypes in the study population were ADH1B*1/1 (82%), ADH1C*1/1 (59%), and CYP2E1*C/C (84%). Conclusions: This first study of polymorphisms in Colombian patients diagnosed with cirrhosis and/or HCC showed genotypes ADH1B*1/1, ADH1C*1/1 and CYP2E1*C/C as the most frequent. We found no significant differences in the genotype frequency between cases and controls. Further studies are necessary to explore the association between polymorphisms and the risk of end-stage liver disease from alcohol consumption.

Cheng Y, Wang K, Geng L, et al.
Identification of candidate diagnostic and prognostic biomarkers for pancreatic carcinoma.
EBioMedicine. 2019; 40:382-393 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Pancreatic carcinoma (PC) is one of the most aggressive cancers affecting human health. It is essential to identify candidate biomarkers for the diagnosis and prognosis of PC. The present study aimed to investigate the diagnosis and prognosis biomarkers of PC.
METHODS: Differentially expressed genes (DEGs) were identified from the mRNA expression profiles of GSE62452, GSE28735 and GSE16515. Functional analysis and the protein-protein interaction network analysis was performed to explore the biological function of the identified DEGs. Diagnosis markers for PC were identified using ROC curve analysis. Prognosis markers were identified via survival analysis of TCGA data. The protein expression pattern of the identified genes was verified in clinical tissue samples. A retrospective clinical study was performed to evaluate the correlation between the expression of candidate proteins and survival time of patients. Moreover, comprehensive analysis of the combination of multiple genes/proteins for the prognosis prediction of PC was performed using both TCGA data and clinical data. In vitro studies were undertaken to elaborate the potential roles of these biomarkers in clonability and invasion of PC cells.
FINDINGS: In total, 389 DEGs were identified. These genes were mainly associated with pancreatic secretion, protein digestion and absorption, cytochrome P450 drug metabolism, and energy metabolism pathway. The top 10 genes were filtered out following Fisher's exact test. ROC curve analysis demonstrated that TMPRSS4, SERPINB5, SLC6A14, SCEL, and TNS4 could be used as biomarkers for the diagnosis of PC. Survival analysis of TCGA data and clinical data suggested that TMC7, TMPRSS4, SCEL, SLC2A1, CENPF, SERPINB5 and SLC6A14 can be potential biomarkers for the prognosis of PC. Comprehensive analysis show that a combination of identified genes/proteins can predict the prognosis of PC. Mechanistically, the identified genes attributes to clonability and invasiveness of PC cells.
INTERPRETATION: We synthesized several sets of public data and preliminarily clarified pathways and functions of PC. Candidate molecular markers were identified for diagnosis and prognosis prediction of PC including a novel gene, TMC7. Moreover, we found that the combination of TMC7, TMPRSS4, SCEL, SLC2A1, CENPF, SERPINB5 and SLC6A14 can serve as a promising indicator of the prognosis of PC patients. The candidate proteins may attribute to clonability and invasiveness of PC cells. This research provides a novel insight into molecular mechanisms as well as diagnostic and prognostic markers of PC. FUND: National Natural Science Foundation of China [No. 81602646 &81802339], Natural Science Foundation of Guangdong Province [No. 2016A030310254] and China Postdoctoral Science Foundation [No. 2016M600648].

Zhou YX, Fuentes-Creollo G, Ponce F, et al.
No difference in 4-nitroquinoline induced tumorigenesis between germ-free and colonized mice.
Mol Carcinog. 2019; 58(5):627-632 [PubMed] Related Publications
Variations in oral bacterial communities have been linked to oral cancer suggesting that the oral microbiome is an etiological factor that can influence oral cancer development. The 4-nitroquinoline 1-oxide (4-NQO)-induced murine oral and esophageal cancer model is frequently used to assess the effects of preventive and/or therapeutic agents. We used this model to assess the impact of the microbiome on tumorigenesis using axenic (germ-free) and conventionally housed mice. Increased toxicity was observed in germ-free mice, however, no difference in tumor incidence, multiplicity, and size was observed. Transcriptional profiling of liver tissue from germ-free and conventionally housed mice identified 254 differentially expressed genes including ten cytochrome p450 enzymes, the largest family of phase-1 drug metabolizing enzymes in the liver. Gene ontology revealed that differentially expressed genes were enriched for liver steatosis, inflammation, and oxidative stress in livers of germ-free mice. Our observations emphasize the importance of the microbiome in mediating chemical toxicity at least in part by altering host gene expression. Studies on the role of the microbiome in chemical-induced cancer using germ-free animal models should consider the potential difference in dose due to the microbiome-mediated changes in host metabolizing capacity, which might influence the ability to draw conclusions especially for tumor induction models that are dose dependent.

Wang X, Liao X, Yang C, et al.
Identification of prognostic biomarkers for patients with hepatocellular carcinoma after hepatectomy.
Oncol Rep. 2019; 41(3):1586-1602 [PubMed] Free Access to Full Article Related Publications
Hepatocellular carcinoma (HCC) is a lethal malignancy with high morbidity and mortality rates worldwide. The identification of prognosis‑associated biomarkers is crucial to improve HCC patient survival. The present study aimed to explore potential predictive biomarkers for HCC. Differentially expressed genes (DEGs) were analyzed in the GSE36376 dataset using GEO2R. Hub genes were identified and further investigated for prognostic value in HCC patients. A risk score model and nomogram were constructed to predict HCC prognosis using the prognosis‑associated genes and clinical factors. Pearson's correlation was employed to show interactions among hub genes. Gene enrichment analysis was performed to identify detailed biological processes and pathways. A total of 71 DEGs were obtained and seven (ADH4, CYP2C8, CYP2C9, CYP8B1, SLC22A1, TAT and HSD17B13, all adjusted P≤0.05) of the 10 hub genes were identified as prognosis‑related genes for survival analysis in HCC patients, including alcohol dehydrogenase 4 (class II), pi polypeptide (ADH4), cytochrome p450 family 2 subfamily C member 8 (CYP2C8), cytochrome P450 family 2 subfamily C member 9 (CYP2C9), cytochrome P450 family 8 subfamily B member 1 (CYP8B1), solute carrier family 22 member 1 (SLC22A1), tyrosine aminotransferase (TAT) and hydroxysteroid 17‑β dehydrogenase 13 (HSD17B13). The risk score model could predict HCC prognosis and the nomogram visualized gene expression and clinical factors of probability for HCC prognosis. The majority of genes showed significant Pearson's correlations with others (41 Pearson correlations P≤0.01, four Pearson correlations P>0.05). GO analysis revealed that terms such as 'chemical carcinogenesis' and 'drug metabolism‑cytochrome P450' were enriched and may prove helpful to elucidate the mechanisms of hepatocarcinogenesis. Hub genes ADH4, CYP2C8, CYP2C9, CYP8B1, SLC22A1, TAT and HSD17B13 may be useful as predictive biomarkers for HCC prognosis.

Qi Y, Wang L, Wang K, et al.
New mechanistic insights of clear cell renal cell carcinoma from integrated miRNA and mRNA expression profiling studies.
Biomed Pharmacother. 2019; 111:821-834 [PubMed] Related Publications
Differentially expressed (DE) microRNAs (miRNAs) in clear cell renal cell carcinoma (ccRCC) tissues from pooled samples were reported to affect the tumorigenesis and progression of ccRCC. However, systematic studies on the miRNA-mRNA regulatory networks involved in various pathways in all four stages of the disease are lacking. In this study, we applied microarray technology to perform an integrated analysis of the miRNome and transcriptome in ccRCC tissues from patients at different stages of ccRCC. A total of 604 DEmiRNAs and 6892 DEgenes (DEGs) were identified by comparison with corresponding adjacent normal tissues. The pairing of miRNAs with DEGs were searched using validated miRWalk module, and the pairs were confirmed by comparing with DEmiRNAs in our study. Our results demonstrated that different stages of ccRCC had distinct miRNA/mRNA profiles. However, four common pathways (the complement and coagulation cascades, the pathway for the metabolism of xenobiotics by cytochrome P450, the PPAR signaling pathway, and the pathway for aldosterone-regulated sodium reabsorption) were enriched by targets of DEmiRNAs at all stages of ccRCC. We carried out an extensive analysis of data on miR-16, which had the most target genes, and found that its differential expression was validated in The Cancer Genome Atlas dataset. We also verified the correlation between miR-16 expression and target pathways by gene set enrichment analysis and in vitro experiments. High miR-16 level was also associated with shorter survival time in ccRCC. Our work presents a systematic profiling of miRNA, mRNA and pathways regulated by miRNAs in different stages of ccRCC. Our cross-omics results also identify four common pathways that function aberrantly in all stages of the disease. These pathways are likely to be critical in occurrence and progression of ccRCC. These common dysfunctional pathways have the potential to serve as therapeutic targets and diagnostic biomarkers, whereas miRNAs (miR-20, 484, 497) differentially expressed in only stage I tissues and in blood could be used to diagnose early-stage ccRCC patients.

Bezerra LS, Santos-Veloso MAO, Bezerra Junior NDS, et al.
Impacts of Cytochrome P450 2D6 (CYP2D6) Genetic Polymorphism in Tamoxifen Therapy for Breast Cancer.
Rev Bras Ginecol Obstet. 2018; 40(12):794-799 [PubMed] Related Publications
Tamoxifen (TMX) is the main drug used both in pre and postmenopausal women as adjuvant treatment for hormone receptor-positive breast cancer. An important barrier to the use of TMX is the development of drug resistance caused by molecular processes related to genetic and epigenetic mechanisms, such as the actions of cytochrome P450 2D6 (

Qiu J, Du Z, Liu J, et al.
Association between polymorphisms in estrogen metabolism genes and breast cancer development in Chinese women: A prospective case-control study.
Medicine (Baltimore). 2018; 97(47):e13337 [PubMed] Free Access to Full Article Related Publications
We comprehensively identified polymorphisms in estrogen-metabolizing genes that may be associated with breast cancer initiation in Chinese women, via an ongoing prospective case-control study.An ongoing prospective case-control study of 427 female case patients diagnosed with breast cancer from August 2013 to March 2015 and 536 women (case controls) with no prior history of cancer or benign breast tumors was performed. Buccal cell specimens were obtained using the cotton swabbing method. DNA was extracted from the buccal cells using the phenol/chloroform method. Genotype was carried out for 5 single nucleotide polymorphisms (rs4646903, rs1056836, rs1695, rs4970737, and rs4680) using direct sequencing.The polymorphic genotypes of glutathione S-transferase (GSTP1) (P = .044) and catechol-O-methyltransferase (COMT) (P = .008) showed significantly different distributions, while that of cytochrome P450 (CYP1B1) (P = .051) showed a slight difference in distribution between healthy women and patients with breast cancer. Individuals with homozygous variant genotypes for GSTP1 or COMT exhibited a higher risk of developing breast cancer than those with wild-type genotypes; however, for CYP1B1, the homozygous variant genotype was associated with a lower risk, and the heterozygous genotype for these 3 genes was not associated with breast cancer development.An individual's risk of breast cancer is only influenced by the specific combination of risk-associated alleles of COMT and GSTP1, despite the protective effects of the homozygous CYP1B1 genotype revealed by univariate analysis.

Ruiz-Pinto S, Martin M, Pita G, et al.
Pharmacogenetic variants and response to neoadjuvant single-agent doxorubicin or docetaxel: a study in locally advanced breast cancer patients participating in the NCT00123929 phase 2 randomized trial.
Pharmacogenet Genomics. 2018; 28(11):245-250 [PubMed] Related Publications
OBJECTIVES: Taxanes and anthracyclines are widely used in the treatment of breast cancer, although the benefit is limited to a proportion of patients and predictive biomarkers for clinical outcome remain elusive.
PATIENTS AND METHODS: We carried out a pharmacogenetic study in 181 patients with locally advanced breast cancer enrolled in a phase 2 randomized clinical trial (NCT00123929), where patients were randomly assigned to receive neoadjuvant single-agent docetaxel 100 mg/m(2) (n=84) or doxorubicin 75 mg/m(2) (n=97). We studied the association of 226 single nucleotide polymorphisms (SNPs) in 15 key drug biotransformation genes with neoadjuvant pathological tumor response residual cancer burden index to docetaxel and to doxorubicin.
RESULTS: We identified a significant association for rs162561, an intronic SNP located in the cytochrome P450 family 1 subfamily B member 1 (CYP1B1) gene, with tumor response in patients treated with single-agent docetaxel (dominant model: β=1.02, 95% confidence interval=0.49-1.55; P=1.77×10(-4)), and for rs717620, an SNP located in the promoter of the ATP-binding cassette subfamily C member 2 (ABCC2) gene, in patients treated with neoadjuvant doxorubicin (recessive model: β=1.67; 95% confidence interval=0.26-3.11; P=0.02).
CONCLUSION: We identified two polymorphisms in CYP1B1 and ABCC2 associated with tumor pathological response following docetaxel or doxorubicin neoadjuvant monotherapy, respectively. Although further validation is required, these variants could be potential predictive genetic markers for treatment outcome in breast cancer patients.

Valencia-Cervantes J, Huerta-Yepez S, Aquino-Jarquín G, et al.
Hypoxia increases chemoresistance in human medulloblastoma DAOY cells via hypoxia‑inducible factor 1α‑mediated downregulation of the CYP2B6, CYP3A4 and CYP3A5 enzymes and inhibition of cell proliferation.
Oncol Rep. 2019; 41(1):178-190 [PubMed] Free Access to Full Article Related Publications
Medulloblastomas are among the most frequently diagnosed pediatric solid tumors, and drug resistance remains as the principal cause of treatment failure. Hypoxia and the subsequent activation of hypoxia‑inducible factor 1α (HIF‑1α) are considered key factors in modulating drug antitumor effectiveness, but the underlying mechanisms in medulloblastomas have not yet been clearly understood. The aim of the present study was to determine whether hypoxia induces resistance to cyclophosphamide (CPA) and ifosfamide (IFA) in DAOY medulloblastoma cells, whether the mechanism is dependent on HIF‑1α, and whether involves the modulation of the expression of cytochromes P450 (CYP)2B6, 3A4 and 3A5 and the control of cell proliferation. Monolayer cultures of DAOY medulloblastoma cells were exposed for 24 h to moderate (1% O2) or severe (0.1% O2) hypoxia, and protein expression was evaluated by immunoblotting. Cytotoxicity was studied with the MTT assay and by Annexin V/PI staining and flow cytometry. Cell proliferation was determined by the trypan‑blue exclusion assay and cell cycle by propidium iodide staining and flow cytometry. Hypoxia decreased CPA and IFA cytotoxicity in medulloblastoma cells, which correlated with a reduction in the protein levels of CYP2B6, CYP3A4 and CYP3A5 and inhibition of cell proliferation. These responses were dependent on hypoxia‑induced HIF‑1α activation, as evidenced by chemical inhibition of its transcriptional activity with 2‑methoxyestradiol (2‑ME), which enhanced the cytotoxic activity of CPA and IFA and increased apoptosis. Our results indicate that by stimulating HIF‑1α activity, hypoxia downregulates the expression of CYP2B6, CYP3A4 and CYP3A5, that in turn leads to decreased conversion of CPA and IFA into their active forms and thus to diminished cytotoxicity. These results support that the combination of HIF‑1α inhibitors and canonical antineoplastic agents provides a potential therapeutic alternative against medulloblastoma.

Eun HS, Cho SY, Lee BS, et al.
Profiling cytochrome P450 family 4 gene expression in human hepatocellular carcinoma.
Mol Med Rep. 2018; 18(6):4865-4876 [PubMed] Free Access to Full Article Related Publications
Cytochrome P450 family 4 (CYP4) enzymes are known as microsomal omega (ω)-hydroxylases that metabolize fatty acids, eicosanoids, vitamin D and carcinogens. Thus, CYP4 enzymes may influence tumor development and progression. The aim of the present study was to evaluate the CYP4 expression profile in hepatocellular carcinoma (HCC) and its clinical relevance. The present study obtained CYP4 mRNA expression data for 377 HCC cases from The Cancer Genome Atlas cohort and performed Kaplan‑Meier survival, Gene Ontology functional enrichment, and gene set enrichment analysis (GSEA). In addition, the level of CYP4F2 protein expression was evaluated in matched pairs of HCC and non‑tumor tissue samples and the results were correlated with the clinicopathological characteristics of HCC (n=113). HCC survival analyses indicated better overall survival in patients with high CYP4F2, CYP4F12 and CYP4V2 mRNA expression levels; the results for histological grade and Tumor‑Node‑Metastasis stage supported these results. GSEA revealed high levels of CYP4F2, CYP4F12 and CYP4V2 mRNA expression to be negatively correlated with the expression of cell cycle‑associated genes. CYP4F2 protein expression was higher in non‑neoplastic liver tissue than in HCC tissue and positively correlated with favorable pathological tumor stage (I vs. II‑IV; P=0.022) and was a good independent prognostic factor for overall survival (P=0.004). These results demonstrate that the expression levels of the genes CYP4F2, CYP4F12 and CYPV2 are favorable prognostic factors in HCC and suggest the potential predictive diagnostic and prognostic roles of CYP4F2, CYP4F12 and CYPV2 gene expression in HCC.

Yin X, Xiong W, Wang Y, et al.
Association of CYP2E1 gene polymorphisms with bladder cancer risk: A systematic review and meta-analysis.
Medicine (Baltimore). 2018; 97(39):e11910 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Human cytochrome P450 (CYP) is an enzyme responsible for the metabolic activation of many carcinogens, including nitrosamines. CYP2E1 represents a major CYP isoform and is expressed in the human urothelial cells. Recent studies have investigated the association of CYP2E1 gene polymorphisms with bladder cancer risk but have shown contradictory results. Hence, we performed a systematic literature review and meta-analysis to assess the association between CYP2E1 gene polymorphisms and bladder cancer.
METHODS: Systematic literature searches were conducted with PubMed, Excerpt Medica Database, Science Direct/Elsevier, China National Knowledge Infrastructure, and the Cochrane Library up to January 2018 for studies that involved the association of CYP2E1 gene polymorphisms with bladder cancer risk. A meta-analysis was performed with Review Manager and Stata software. Combined odds ratios (ORs) were identified with 95% confidence intervals (CIs) in a random or fixed effects model.
ETHICS: The protocol was approved by the institutional review board of each study center. Written informed consent will be obtained from all patients before registration, in accordance with the Declaration of Helsinki.
RESULTS: Eight studies were identified, including 1733 cases of bladder cancer and 1814 normal controls. Our results illustrated that there are significant associations between CYP2E1 gene polymorphisms and bladder cancer in all genetic models (P < .05). The combined ORs and 95% CIs were as follows for each model: additive model [OR 0.56; 95% CI (0.38-0.82)]; dominant model [OR 0.79; 95% CI (0.67-0.93)]; recessive model [OR 0.61; 95% CI (0.41-0.89)]; codominant model [OR 0.80; 95% CI (0.67-0.96)]; allele model [OR 0.75; 95% CI (0.59-0.95)]. A subgroup study showed that there are also significant associations between CYP2E1 gene polymorphisms and bladder cancer in Asian people. However, there are no significant associations between CYP2E1 gene polymorphisms and bladder cancer in Caucasian populations.
CONCLUSIONS: The present study provides evidence for an association between CYP2E1 gene polymorphisms and bladder cancer progression, and suggests that CYP2E1 gene polymorphisms might be a protective factor against bladder cancer in Asian people. However, studies with larger sample sizes are needed to confirm the correlation between CYP2E1 gene polymorphisms and bladder cancer.

Zeng Y, Shen Z, Gu W, Wu M
Bioinformatics analysis to identify action targets in NCI-N87 gastric cancer cells exposed to quercetin.
Pharm Biol. 2018; 56(1):393-398 [PubMed] Free Access to Full Article Related Publications
CONTEXT: Quercetin exerts antiproliferative effects on gastric cancer. However, its mechanisms of action on gastric cancer have not been comprehensively revealed.
OBJECTIVE: We investigated the mechanisms of action of quercetin against gastric cancer cells.
MATERIALS AND METHODS: Human NCI-N87 gastric cancer cells were treated with 15 μM quercetin or dimethyl sulfoxide (as a control) for 48 h. DNA isolated from cells was sequenced on a HiSeq 2500, and the data were used to identify differentially expressed genes (DEGs) between groups. Then, enrichment analyses were performed for DEGs and a protein-protein interaction (PPI) network was constructed. Finally, the transcription factors (TFs)-DEGs regulatory network was visualized by Cytoscape software.
RESULTS: A total of 121 DEGs were identified in the quercetin group. In the PPI network, Fos proto-oncogene (FOS, degree = 12), aryl hydrocarbon receptor (AHR, degree = 12), Jun proto-oncogene (JUN, degree = 11), and cytochrome P450 family 1 subfamily A member 1 (CYP1A1, degree = 11) with higher degrees highly interconnected with other proteins. Of the 5 TF-DEGs, early growth response 1 (EGR1), FOS like 1 (FOSL1), FOS, and JUN were upregulated, while AHR was downregulated. Moreover, FOSL1, JUN, and Wnt family member 7B (WNT7B) were enriched in the Wnt signaling pathway.
DISCUSSION AND CONCLUSIONS: CYP1A1 highly interconnected with AHR in the PPI network. Therefore, FOS, AHR, JUN, CYP1A1, EGR1, FOSL1, and WNT7B might be targets of quercetin in gastric cancer.

Sasaki S, Urabe M, Maeda T, et al.
Induction of Hepatic Metabolic Functions by a Novel Variant of Hepatocyte Nuclear Factor 4γ.
Mol Cell Biol. 2018; 38(24) [PubMed] Free Access to Full Article Related Publications
Hepatocyte nuclear factor 4α (HNF4α) is a critical factor for hepatocyte differentiation. HNF4α expression is decreased in hepatocellular carcinoma (HCC), which suggests a role in repression of hepatocyte dedifferentiation. In the present study, hepatic expression of HNF4γ was increased in liver-specific

Mazzio EA, Soliman KFA
Whole-transcriptomic Profile of SK-MEL-3 Melanoma Cells Treated with the Histone Deacetylase Inhibitor: Trichostatin A.
Cancer Genomics Proteomics. 2018 Sep-Oct; 15(5):349-364 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Malignant melanoma cells can rapidly acquire phenotypic properties making them resistant to radiation and mainline chemotherapies such as decarbonize or kinase inhibitors that target RAS-proto-oncogene independent auto-activated mitogen-activated protein kinases (MAPK)/through dual specificity mitogen-activated protein kinase (MEK). Both drug resistance and inherent transition from melanocytic nevi to malignant melanoma involve the overexpression of histone deacetylases (HDACs) and a B-Raf proto-oncogene (BRAF) mutation.
MATERIALS AND METHODS: In this work, the effects of an HDAC class I and II inhibitor trichostatin A (TSA) on the whole transcriptome of SK-MEL-3 cells carrying a BRAF mutation was examined.
RESULTS: The data obtained show that TSA was an extremely potent HDAC inhibitor within SK-MEL-3 nuclear lysates, where TSA was then optimized for appropriate sub-lethal concentrations for in vitro testing. The whole-transcriptome profile shows a basic phenotype dominance in the SK-MEL-3 cell line for i) synthesis of melanin, ii) phagosome acidification, iii) ATP hydrolysis-coupled proton pumps and iv) iron transport systems. While TSA did not affect the aforementioned major systems, it evoked a dramatic change to the transcriptome: reflected by a down-regulation of 810 transcripts and up-regulation of 833, with fold-change from -15.27 to +31.1 FC (p<0.00001). Largest differentials were found for the following transcripts: Up-regulated: Tetraspanin 13 (TSPAN13), serpin family i member 1 (SERPINI1), ATPase Na+/K+ transporting subunit beta 2 (ATP1B2), nicotinamide nucleotide adenylyl transferase 2 (NMNAT2), platelet-derived growth factor receptor-like (PDGFRL), cytochrome P450 family 1 subfamily A member 1 (CYP1A1), prostate androgen-regulated mucin-like protein 1 (PARM1), secretogranin II (SCG2), SYT11 (synaptotagmin 11), rhophilin associated tail protein 1 like (ROPN1L); down-regulated: polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3), carbonic anhydrase 14 (CAXIV), BCL2-related protein A1 (BCL2A1), protein kinase C delta (PRKCD), transient receptor potential cation channel subfamily M member 1 (TRPM1), ubiquitin associated protein 1 like (UBAP1L), glutathione peroxidase 8 (GPX8), interleukin 16 (IL16), tumor protein p53 (TP53), and serpin family H member 1 (SERPINH1). There was no change to any of the HDAC transcripts (class I, II and IV), the sirtuin HDAC family (1-6) or the BRAF proto-oncogene v 599 transcripts. However, the data showed that TSA down-regulated influential transcripts that drive the BRAF-extracellular signal-regulated kinase (ERK)1/2 oncogenic pathway (namely PRKCD and MYC proto-oncogene which negatively affected the cell-cycle distribution. Mitotic inhibition was corroborated by functional pathway analysis and flow cytometry confirming halt at the G
CONCLUSION: TSA does not alter HDAC transcripts nor BRAF itself, but down-regulates critical components of the MAPK/MEK/BRAF oncogenic pathway, initiating a mitotic arrest.

Elfaki I, Mir R, Almutairi FM, Duhier FMA
Cytochrome P450: Polymorphisms and Roles in Cancer, Diabetes and Atherosclerosis
Asian Pac J Cancer Prev. 2018; 19(8):2057-2070 [PubMed] Free Access to Full Article Related Publications
Cytochromes P450s (CYPs) constitute a superfamily of enzymes that catalyze the metabolism of drugs and other substances. Endogenous substrates of CYPs include eicosanoids, estradiol, arachidonic acids, cholesterol, vitamin D and neurotransmitters. Exogenous substrates of CYPs include the polycyclic aromatic hydrocarbons and about 80% of currently used drugs. Some isoforms can activate procarcinogens to ultimate carcinogens. Genetic polymorphisms of CYPs may affect the enzyme catalytic activity and have been reported among different populations to be associated with various diseases and adverse drug reactions. With regard of drug metabolism, phenotypes for CYP polymorphism range from ultrarapid to poor metabolizers. In this review, we discuss some of the most clinically important CYPs isoforms (CYP2D6, CYP2A6, CYP2C19, CYP2C9, CYP1B1 and CYP1A2) with respect to gene polymorphisms and drug metabolism. Moreover, we review the role of CYPs in renal, lung, breast and prostate cancers and also discuss their significance for atherosclerosis and type 2 diabetes mellitus.

Pedersen MH, Hood BL, Ehmsen S, et al.
CYPOR is a novel and independent prognostic biomarker of recurrence-free survival in triple-negative breast cancer patients.
Int J Cancer. 2019; 144(3):631-640 [PubMed] Related Publications
Prognostic and predictive biomarkers of disease and treatment outcome are needed to ensure optimal treatment of patients with triple-negative breast cancer (TNBC). In a mass spectrometry-based global proteomic study of 44 formalin-fixed, paraffin-embedded (FFPE) primary TNBC tumors and 10 corresponding metastases, we found that Cytochrome P450 reductase (CYPOR) expression correlated with patient outcome. The correlation between CYPOR expression and outcome was further evaluated in a Danish cohort of 113 TNBC patients using immunohistochemistry and publicly available gene expression data from two cohorts of TNBC and basal-like breast cancer patients, respectively (N = 249 and N = 580). A significant correlation between high CYPOR gene expression and shorter recurrence-free survival (RFS), but not overall survival, was found in the cohort of 249 TNBC patients (p = 0.018, HR = 1.77, 95% CI 1.1-2.85), and this correlation was recapitulated in a cohort of 580 basal-like breast cancer patients (p = 0.018, HR = 1.4, 95% CI 1.06-1.86). High CYPOR protein expression was also associated with shorter RFS in the cohort of 113 TNBC patients (p = 0.017, HR = 2.73, 95% CI 1.20-6.19), particularly those who were lymph node tumor-negative (p = 0.029, HR = 5.22). Multivariate Cox regression analysis identified CYPOR as an independent prognostic factor for shorter RFS in TNBC patients (p = 0.032, HR = 2.19, 95% CI 1.07-4.47). Together, these data suggest high expression of CYPOR as an independent prognostic biomarker of shorter RFS, which could be used to identify patients who should receive more extensive adjuvant treatment and more aggressive surveillance.

Dong Q, Lv C, Zhang G, et al.
Impact of RNA‑binding motif 3 expression on the whole transcriptome of prostate cancer cells: An RNA sequencing study.
Oncol Rep. 2018; 40(4):2307-2315 [PubMed] Related Publications
RNA‑binding motif 3 (RBM3) is a cold‑shock protein that has been previously shown to attenuate cancer stem cell‑like features in prostate cancer (PCa) cells. However, the mechanism underlying RBM3 regulation in PCa cells is largely unknown. The present study investigated the impact of RBM3 expression on the whole transcriptome of PCa cells using high‑throughput RNA sequencing (RNA‑seq). Differentially expressed genes (DEGs) that were identified through RNA‑seq were applied to Gene Ontology (GO), pathway analysis, pathway‑action networks and protein‑protein interaction network analysis. GO and pathway ananlyses showed that RBM3 expression was associated with several metabolism pathways. Combining GO analysis and pathway analysis, certain DEGs, including phospholipase A2 group IIA (PLA2G2A), PLA2G2F, PLA2G4C, endothelin 1, cytochrome P450 family 2 subfamily B member 6, G protein subunit γ5, nitric oxide synthase 3 and CD38 molecule, were shown to be closely associated with RBM3 regulation in PCa cells. Furthermore, the changes in expression of selected genes upon RBM3‑knockdown in RNA‑seq were confirmed by separate reverse transcription‑quantitative‑polymerase chain reaction, validating the results of RNA‑seq. Thus, the present study provides a series of valuable reference genes and pathways for the future study of the pathogenic role of RBM3 in the development of PCa.

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