Gene Summary

Gene:APRT; adenine phosphoribosyltransferase
Aliases: AMP, APRTD
Summary:Adenine phosphoribosyltransferase belongs to the purine/pyrimidine phosphoribosyltransferase family. A conserved feature of this gene is the distribution of CpG dinucleotides. This enzyme catalyzes the formation of AMP and inorganic pyrophosphate from adenine and 5-phosphoribosyl-1-pyrophosphate (PRPP). It also produces adenine as a by-product of the polyamine biosynthesis pathway. A homozygous deficiency in this enzyme causes 2,8-dihydroxyadenine urolithiasis. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:adenine phosphoribosyltransferase
Source:NCBIAccessed: 31 August, 2019


What does this gene/protein do?
Show (19)
Pathways:What pathways are this gene/protein implicaed in?
Show (1)

Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 31 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.

  • Amino Acid Sequence
  • Phenotype
  • Neoplastic Cell Transformation
  • Cancer DNA
  • Neoplasm Proteins
  • Chromosome 8
  • Adenine Phosphoribosyltransferase
  • Neurofibromatosis 1
  • Oxidative Stress
  • Molecular Sequence Data
  • Colorectal Cancer
  • DNA Methylation
  • alpha 1-Antitrypsin
  • Hypoxanthine Phosphoribosyltransferase
  • Polyamines
  • Ultraviolet Rays
  • Messenger RNA
  • Drug Resistance
  • Transcriptome
  • Adenocarcinoma
  • Genetic Markers
  • Xanthine Dehydrogenase
  • Cultured Cells
  • Stomach Cancer
  • Cell Line
  • Skin Cancer
  • Base Sequence
  • DNA Repair
  • Gene Deletion
  • Chromosome 16
  • Mutation
  • Restriction Mapping
  • Two-Dimensional Difference Gel Electrophoresis
  • Temozolomide
  • Cancer Gene Expression Regulation
  • Genetic Variation
  • Mutagenesis
  • Signal Transduction
  • Loss of Heterozygosity
Tag cloud generated 31 August, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (3)

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: APRT (cancer-related)

Guo Y
Clinical significance of serum MicroRNA-203 in patients with acute myeloid leukemia.
Bioengineered. 2019; 10(1):345-352 [PubMed] Related Publications
This study aimed to detect serum miR-203 expression levels in AML and explore its potential clinical significance. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was performed to measure the serum miR-203 levels in 134 patients with AML and 70 healthy controls. The results demonstrated that serum miR-203 expression was significantly reduced in AML patients compared with healthy controls. Receiver operating characteristic curve (ROC) analysis revealed miR-203 could distinguish AML cases from normal controls. Low serum miR-203 levels were associated with worse clinical features, as well as poorer overall survival and relapse free survival of AML patients. Moreover, multivariate analysis confirmed low serum miR-203 expression to be an independent unfavorable prognostic predictor for AML. The bioinformatics analysis showed that the downstream genes and pathways of miR-203 was closely associated with tumorigenesis. Downregulation of miR-203 in AML cell lines upregulated the expression levels of oncogenic promoters such as CREB1, SRC and HDAC1. Thus, these findings demonstrated that serum miR-203 might be a promising biomarker for the diagnosis and prognosis of AML.

Ni Y, Schmidt KR, Werner BA, et al.
Death effector domain-containing protein induces vulnerability to cell cycle inhibition in triple-negative breast cancer.
Nat Commun. 2019; 10(1):2860 [PubMed] Free Access to Full Article Related Publications
Lacking targetable molecular drivers, triple-negative breast cancer (TNBC) is the most clinically challenging subtype of breast cancer. In this study, we reveal that Death Effector Domain-containing DNA-binding protein (DEDD), which is overexpressed in > 60% of TNBCs, drives a mitogen-independent G1/S cell cycle transition through cytoplasm localization. The gain of cytosolic DEDD enhances cyclin D1 expression by interacting with heat shock 71 kDa protein 8 (HSC70). Concurrently, DEDD interacts with Rb family proteins and promotes their proteasome-mediated degradation. DEDD overexpression renders TNBCs vulnerable to cell cycle inhibition. Patients with TNBC have been excluded from CDK 4/6 inhibitor clinical trials due to the perceived high frequency of Rb-loss in TNBCs. Interestingly, our study demonstrated that, irrespective of Rb status, TNBCs with DEDD overexpression exhibit a DEDD-dependent vulnerability to combinatorial treatment with CDK4/6 inhibitor and EGFR inhibitor in vitro and in vivo. Thus, our study provided a rationale for the clinical application of CDK4/6 inhibitor combinatorial regimens for patients with TNBC.

Minuesa G, Albanese SK, Xie W, et al.
Small-molecule targeting of MUSASHI RNA-binding activity in acute myeloid leukemia.
Nat Commun. 2019; 10(1):2691 [PubMed] Free Access to Full Article Related Publications
The MUSASHI (MSI) family of RNA binding proteins (MSI1 and MSI2) contribute to a wide spectrum of cancers including acute myeloid leukemia. We find that the small molecule Ro 08-2750 (Ro) binds directly and selectively to MSI2 and competes for its RNA binding in biochemical assays. Ro treatment in mouse and human myeloid leukemia cells results in an increase in differentiation and apoptosis, inhibition of known MSI-targets, and a shared global gene expression signature similar to shRNA depletion of MSI2. Ro demonstrates in vivo inhibition of c-MYC and reduces disease burden in a murine AML leukemia model. Thus, we identify a small molecule that targets MSI's oncogenic activity. Our study provides a framework for targeting RNA binding proteins in cancer.

Hu Q, Ye Y, Chan LC, et al.
Oncogenic lncRNA downregulates cancer cell antigen presentation and intrinsic tumor suppression.
Nat Immunol. 2019; 20(7):835-851 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
How tumor cells genetically lose antigenicity and evade immune checkpoints remains largely elusive. We report that tissue-specific expression of the human long noncoding RNA LINK-A in mouse mammary glands initiates metastatic mammary gland tumors, which phenotypically resemble human triple-negative breast cancer (TNBC). LINK-A expression facilitated crosstalk between phosphatidylinositol-(3,4,5)-trisphosphate and inhibitory G-protein-coupled receptor (GPCR) pathways, attenuating protein kinase A-mediated phosphorylation of the E3 ubiquitin ligase TRIM71. Consequently, LINK-A expression enhanced K48-polyubiquitination-mediated degradation of the antigen peptide-loading complex (PLC) and intrinsic tumor suppressors Rb and p53. Treatment with LINK-A locked nucleic acids or GPCR antagonists stabilized the PLC components, Rb and p53, and sensitized mammary gland tumors to immune checkpoint blockers. Patients with programmed ccll death protein-1(PD-1) blockade-resistant TNBC exhibited elevated LINK-A levels and downregulated PLC components. Hence we demonstrate lncRNA-dependent downregulation of antigenicity and intrinsic tumor suppression, which provides the basis for developing combinational immunotherapy treatment regimens and early TNBC prevention.

Zhao J, Lee EE, Kim J, et al.
Transforming activity of an oncoprotein-encoding circular RNA from human papillomavirus.
Nat Commun. 2019; 10(1):2300 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
Single-stranded circular RNAs (circRNAs), generated through 'backsplicing', occur more extensively than initially anticipated. The possible functions of the vast majority of circRNAs remain unknown. Virus-derived circRNAs have recently been described in gamma-herpesviruses. We report that oncogenic human papillomaviruses (HPVs) generate circRNAs, some of which encompass the E7 oncogene (circE7). HPV16 circE7 is detectable by both inverse RT-PCR and northern blotting of HPV16-transformed cells. CircE7 is N

Mehta A, Patel BM
Therapeutic opportunities in colon cancer: Focus on phosphodiesterase inhibitors.
Life Sci. 2019; 230:150-161 [PubMed] Related Publications
Despite novel technologies, colon cancer remains undiagnosed and 25% of patients are diagnosed with metastatic colon cancer. Resistant to chemotherapeutic agents is one of the major problems associated with treating colon cancer which creates the need to develop novel agents targeting towards newer targets. A phosphodiesterase is a group of isoenzyme, which, hydrolyze cyclic nucleotides and thereby lowers intracellular levels of cAMP and cGMP leading to tumorigenic effects. Many in vitro and in vivo studies have confirmed increased PDE expression in different types of cancers including colon cancer. cAMP-specific PDE inhibitors increase intracellular cAMP that leads to activation of effector molecules-cAMP-dependent protein kinase A, exchange protein activated by cAMP and cAMP gated ion channels. These molecules regulate cellular responses and exert its anticancer role through different mechanisms including apoptosis, inhibition of angiogenesis, upregulating tumor suppressor genes and suppressing oncogenes. On the other hand, cGMP specific PDE inhibitors exhibit anticancer effects through cGMP dependent protein kinase and cGMP dependent cation channels. Elevation in cGMP works through activation of caspases, suppression of Wnt/b-catenin pathway and TCF transcription leading to inhibition of CDK and survivin. These studies point out towards the fact that PDE inhibition is associated with anti-proliferative, anti-apoptotic and anti-angiogenic pathways involved in its anticancer effects in colon cancer. Thus, inhibition of PDE enzymes can be used as a novel approach to treat colon cancer. This review will focus on cAMP and cGMP signaling pathways leading to tumorigenesis and the use of PDE inhibitors in colon cancer.

Hu Y, Chen CH, Ding YY, et al.
Optimal control nodes in disease-perturbed networks as targets for combination therapy.
Nat Commun. 2019; 10(1):2180 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
Most combination therapies are developed based on targets of existing drugs, which only represent a small portion of the human proteome. We introduce a network controllability-based method, OptiCon, for de novo identification of synergistic regulators as candidates for combination therapy. These regulators jointly exert maximal control over deregulated genes but minimal control over unperturbed genes in a disease. Using data from three cancer types, we show that 68% of predicted regulators are either known drug targets or have a critical role in cancer development. Predicted regulators are depleted for known proteins associated with side effects. Predicted synergy is supported by disease-specific and clinically relevant synthetic lethal interactions and experimental validation. A significant portion of genes regulated by synergistic regulators participate in dense interactions between co-regulated subnetworks and contribute to therapy resistance. OptiCon represents a general framework for systemic and de novo identification of synergistic regulators underlying a cellular state transition.

Liu K, Newbury PA, Glicksberg BS, et al.
Evaluating cell lines as models for metastatic breast cancer through integrative analysis of genomic data.
Nat Commun. 2019; 10(1):2138 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
Cell lines are widely-used models to study metastatic cancer although the extent to which they recapitulate the disease in patients remains unknown. The recent accumulation of genomic data provides an unprecedented opportunity to evaluate the utility of them for metastatic cancer research. Here, we reveal substantial genomic differences between breast cancer cell lines and metastatic breast cancer patient samples. We also identify cell lines that more closely resemble the different subtypes of metastatic breast cancer seen in the clinic and show that surprisingly, MDA-MB-231 cells bear little genomic similarities to basal-like metastatic breast cancer patient samples. Further comparison suggests that organoids more closely resemble the transcriptome of metastatic breast cancer samples compared to cell lines. Our work provides a guide for cell line selection in the context of breast cancer metastasis and highlights the potential of organoids in these studies.

Cheng YH, Chen YC, Lin E, et al.
Hydro-Seq enables contamination-free high-throughput single-cell RNA-sequencing for circulating tumor cells.
Nat Commun. 2019; 10(1):2163 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
Molecular analysis of circulating tumor cells (CTCs) at single-cell resolution offers great promise for cancer diagnostics and therapeutics from simple liquid biopsy. Recent development of massively parallel single-cell RNA-sequencing (scRNA-seq) provides a powerful method to resolve the cellular heterogeneity from gene expression and pathway regulation analysis. However, the scarcity of CTCs and the massive contamination of blood cells limit the utility of currently available technologies. Here, we present Hydro-Seq, a scalable hydrodynamic scRNA-seq barcoding technique, for high-throughput CTC analysis. High cell-capture efficiency and contamination removal capability of Hydro-Seq enables successful scRNA-seq of 666 CTCs from 21 breast cancer patient samples at high throughput. We identify breast cancer drug targets for hormone and targeted therapies and tracked individual cells that express markers of cancer stem cells (CSCs) as well as of epithelial/mesenchymal cell state transitions. Transcriptome analysis of these cells provides insights into monitoring target therapeutics and processes underlying tumor metastasis.

Malik N, Yan H, Moshkovich N, et al.
The transcription factor CBFB suppresses breast cancer through orchestrating translation and transcription.
Nat Commun. 2019; 10(1):2071 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
Translation and transcription are frequently dysregulated in cancer. These two processes are generally regulated by distinct sets of factors. The CBFB gene, which encodes a transcription factor, has recently emerged as a highly mutated driver in a variety of human cancers including breast cancer. Here we report a noncanonical role of CBFB in translation regulation. RNA immunoprecipitation followed by deep sequencing (RIP-seq) reveals that cytoplasmic CBFB binds to hundreds of transcripts and regulates their translation. CBFB binds to mRNAs via hnRNPK and enhances translation through eIF4B, a general translation initiation factor. Interestingly, the RUNX1 mRNA, which encodes the transcriptional partner of CBFB, is bound and translationally regulated by CBFB. Furthermore, nuclear CBFB/RUNX1 complex transcriptionally represses the oncogenic NOTCH signaling pathway in breast cancer. Thus, our data reveal an unexpected function of CBFB in translation regulation and propose that breast cancer cells evade translation and transcription surveillance simultaneously through downregulating CBFB.

Weissmiller AM, Wang J, Lorey SL, et al.
Inhibition of MYC by the SMARCB1 tumor suppressor.
Nat Commun. 2019; 10(1):2014 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
SMARCB1 encodes the SNF5 subunit of the SWI/SNF chromatin remodeler. SNF5 also interacts with the oncoprotein transcription factor MYC and is proposed to stimulate MYC activity. The concept that SNF5 is a coactivator for MYC, however, is at odds with its role as a tumor-suppressor, and with observations that loss of SNF5 leads to activation of MYC target genes. Here, we reexamine the relationship between MYC and SNF5 using biochemical and genome-wide approaches. We show that SNF5 inhibits the DNA-binding ability of MYC and impedes target gene recognition by MYC in cells. We further show that MYC regulation by SNF5 is separable from its role in chromatin remodeling, and that reintroduction of SNF5 into SMARCB1-null cells mimics the primary transcriptional effects of MYC inhibition. These observations reveal that SNF5 antagonizes MYC and provide a mechanism to explain how loss of SNF5 can drive malignancy.

Zheng KB, Xie J, Li YT, et al.
Knockdown of CERB expression inhibits proliferation and migration of glioma cells line U251.
Bratisl Lek Listy. 2019; 120(4):309-315 [PubMed] Related Publications
BACKGROUND: Glioma is a type of tumor that occurs in the brain and accounts for almost 30 % of all brain and central nervous system tumors and 80 % of all malignant brain tumors. In this study, we investigate the role of cAMP response element-binding protein (CREB) in the progression of glioma.
METHODS: Tissue samples from glioma patients were collected and examined for expression of CREB and its correlation with tumor grades. CREB was then knocked down via siRNA to see if reduced expression of CREB affects cell proliferation and migration. Factors involved in cell cycles, adhesion and apoptosis were examined as well. Moreover, CRESP/CAS9 mediated knockout of CREB was conducted and athymic Nude mice model was used to investigate CREB's role in vivo.
RESULTS: The evaluated expression level of CREB in glioma patients was correlated with tumor grades. Knockdown of CREB via siRNA in glioma cell line U251 significantly inhibited the proliferation and migration of tumor cells. Moreover, CyclinD1 and Bcl-2 expression were reduced, as well as phosphorylation of IRK1/2 and AKT. Additionally, knockout of CREB via CRESP/CAS9 inhibited tumor formation of U251 cells in athymic Nude mice model.
CONCLUSIONS: In conclusion, our data suggest that over expression of CREB may contribute to progression of glioma and knockdown of CREB expression may serve as a novel target for therapy (Tab. 1, Fig. 6, Ref. 25).

Chen MK, Peng CC, Maner RS, et al.
Geniposide ameliorated fluoxetine-suppressed neurite outgrowth in Neuro2a neuroblastoma cells.
Life Sci. 2019; 226:1-11 [PubMed] Related Publications
AIM: Fluoxetine (FXT), a selective serotonin reuptake inhibitor (SSRI), is one of the most common psychiatric medications clinically prescribed; while over-produced serotonin may suppress neurite development. The role of major iridoids like geniposide (GPS) and genipin (GNP) from Gardenia jasminoides Ellis fruit (family Rubiaceae) in ameliorating the anti-neurite outgrowth effect of FXT is poorly understood. In this study, the effects of these iridoids on FXT-suppressed neurite outgrowth in Neuro2a neuroblastoma cells were investigated.
MAIN METHODS: Neuro2a cells were treated with FXT and GPS. The effect of GPS-FXT co-treatment on neurite outgrowth was observed using inverted phase-contrast microscope imaging system, while neurite outgrowth markers - microtubule-associated protein-2 (MAP2) and growth-associated protein 43 (GAP43) were analyzed using RT-PCR, Western blot and immunofluorescence staining. The transcription factor-cAMP response element binding (CREB), and signaling pathways - mitogen-activated protein kinase (MAPK) and protein kinase B/mammalian target of rapamycin (AKT/mTOR) were also analyzed with the help of Western blot.
KEY FINDINGS: The results showed that FXT decreased the neurite outgrowth in Neuro2a cells and also downregulated gene and protein expression of MAP2 and GAP43. It also downregulated the protein expression of phosphorylated-CREB, MAPK, and AKT/mTOR signaling pathways. In contrast, GPS counteracted the effects of FXT. GPS-FXT co-treatment increased the percentage of neurite-bearing cells by 3.6-fold at 200 μM as compared to FXT treatment only.
SIGNIFICANCE: This study has provided the possible molecular mechanism showing how FXT exerted its detrimental side-effects on the neurite differentiation, and via the same mechanism how GPS attenuated these side effects.

Zou Y, Chen M, Zhang S, et al.
TRPC5‑induced autophagy promotes the TMZ‑resistance of glioma cells via the CAMMKβ/AMPKα/mTOR pathway.
Oncol Rep. 2019; 41(6):3413-3423 [PubMed] Related Publications
Temozolomide (TMZ) is the first choice chemotherapy agent against glioblastoma, but the TMZ chemotherapy resistance has restricted the clinical application. Although autophagy is considered an adaptive response for cell survival under the pressure of chemotherapy and associated with chemotherapy resistance, its initiator and the precise molecular mechanism remains unknown. In the present study, it was determined that TMZ increases the transient receptor potential cation channel subfamily C member 5 (TRPC5) protein expression and the basal autophagy level, and the upregulation of autophagy is mediated by TRPC5 in glioma cells. Additionally, knockdown of TRPC5 upregulated the chemotherapy sensitivity in vitro and in vivo. Furthermore, TRPC5‑small interfering RNA and pharmacological inhibition indicated that the Ca2+/calmodulin dependent protein kinase β (CaMKKβ)/AMP‑activated protein kinase α (AMPKα)/mechanistic target of rapamycin kinase (mTOR) pathway mediates cell survival autophagy during TMZ treatment. In addition, TMZ‑resistant U87/TMZ cells retained a high basal autophagy level, while silence of TRPC5 expression or inhibition of autophagy reversed TMZ resistance. Thus, the present study revealed that TRPC5, an initiator of autophagy, upregulated TMZ resistance via the CaMKKβ/AMPKα/mTOR pathway and this indicated a novel therapeutic site for drug resistance in glioma chemotherapy.

Wu Y, Xie Z, Chen J, et al.
Circular RNA circTADA2A promotes osteosarcoma progression and metastasis by sponging miR-203a-3p and regulating CREB3 expression.
Mol Cancer. 2019; 18(1):73 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
BACKGROUND: As a subclass of noncoding RNAs, circular RNAs (circRNAs) have been demonstrated to play a critical role in regulating gene expression in eukaryotes. Recent studies have revealed the pivotal functions of circRNAs in cancer progression. However, little is known about the role of circTADA2A, also named hsa_circ_0043278, in osteosarcoma (OS).
METHODS: CircTADA2A was selected from a previously reported circRNA microarray comparing OS cell lines and normal bone cells. QRT-PCR was used to detect the expression of circTADA2A in OS tissue and cell lines. Luciferase reporter, RNA immunoprecipitation (RIP), RNA pull-down and fluorescence in situ hybridization (FISH) assays were performed to confirm the binding of circTADA2A with miR-203a-3p. OS cells were stably transfected with lentiviruses, and Transwell migration, Matrigel invasion, colony formation, proliferation, apoptosis, Western blotting, and in vivo tumorigenesis and metastasis assays were employed to evaluate the roles of circTADA2A, miR-203a-3p and CREB3.
RESULTS: Our findings demonstrated that circTADA2A was highly expressed in both OS tissue and cell lines, and circTADA2A inhibition attenuated the migration, invasion and proliferation of OS cells in vitro as well as tumorigenesis and metastasis in vivo. A mechanistic study revealed that circTADA2A could readily sponge miR-203a-3p to upregulate the expression of CREB3, which was identified as a driver gene in OS. Furthermore, miR-203a-3p inhibition or CREB3 overexpression could reverse the circTADA2A silencing-induced impairment of malignant tumor behavior.
CONCLUSIONS: CircTADA2A functions as a tumor promoter in OS to increase malignant tumor behavior through the miR-203a-3p/CREB3 axis, which could be a novel target for OS therapy.

Liu D, Qiao X, Ge Z, et al.
IMB0901 inhibits muscle atrophy induced by cancer cachexia through MSTN signaling pathway.
Skelet Muscle. 2019; 9(1):8 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
BACKGROUND: Cancer cachexia as a metabolic syndrome can lead to at least 25% of cancer deaths. The inhibition of muscle atrophy is a main strategy to treat cancer cachexia. In this process, myostatin (MSTN) can exert a dual effect on protein metabolism, including inhibition of protein biosynthesis and enhancement of protein degradation. In this study, we will test the effect on muscle atrophy induced by cancer cachexia of IMB0901, a MSTN inhibitor.
METHODS: Two high-throughput screening models against MSTN were developed. By screening, IMB0901, 2-((1-(3,4-dichlorophenyl)-1H-pyrazolo [3,4-d] pyrimidin-4-yl) amino) butan-1-ol, was picked out from the compound library. The in vitro cell model and the C26 animal model of muscle atrophy induced by cancer cachexia were used to determine the pharmacological activity of IMB0901. Whether IMB0901 could inhibit the aggravating effect of doxorubicin on muscle wasting was examined in vitro and in vivo.
RESULTS: IMB0901 inhibited the MSTN promoter activity, the MSTN signaling pathway, and the MSTN positive feedback regulation. In atrophied C2C12 myotubes, IMB0901 had a potent efficiency of decreasing MSTN expression and modulating MSTN signaling pathway which was activated by C26-conditioned medium (CM). In C2C12 myotubes, the expressions of three common myotube markers, myosin heavy chain (MyHC), myogenic differentiation 1 (MyoD), and myogenin (MyoG), were downregulated by CM, which could be efficiently reversed by IMB0901 via reduction of ubiquitin-mediated proteolysis and enhancement of AKT/mTOR-mediated protein synthesis. In the C26 animal model, IMB0901 mitigated the weight loss of body, quadricep and liver, and protected the quadriceps cell morphology. Furthermore, IMB0901 decreased the expression of two E3 ligases Atrogin-1 and MuRF-1 in the quadriceps in vivo. At the cellular level, IMB0901 had no influence on anti-tumor effect of three chemotherapeutic agents (cisplatin, doxorubicin, and gemcitabine) and lowered doxorubicin-induced upregulation of MSTN in C2C12 myotubes. IMB0901 did not affect the inhibitory effect of doxorubicin on C26 tumor and delayed the weight loss of muscle and adipose tissue caused by C26 tumor and doxorubicin.
CONCLUSIONS: IMB0901 inhibits muscle atrophy induced by cancer cachexia by suppressing ubiquitin-mediated proteolysis and promoting protein synthesis. These findings collectively suggest that IMB0901 is a promising leading compound for the management of muscle atrophy induced by cancer cachexia.

Pasha M, Sivaraman SK, Frantz R, et al.
Metformin Induces Different Responses in Clear Cell Renal Cell Carcinoma Caki Cell Lines.
Biomolecules. 2019; 9(3) [PubMed] Article available free on PMC after 03/12/2019 Related Publications
Clear cell renal cell carcinoma (ccRCC) is the most common and lethal form of urological cancer diagnosed globally. Mutations of the von Hippel-Lindau

Huang Y, Wang J, Jia P, et al.
Clonal architectures predict clinical outcome in clear cell renal cell carcinoma.
Nat Commun. 2019; 10(1):1245 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
The genetic landscape of clear cell renal cell carcinoma (ccRCC) had been investigated extensively but its evolution patterns remained unclear. Here we analyze the clonal architectures of 473 patients from three different populations. We find that the mutational signatures vary substantially across different populations and evolution stages. The evolution patterns of ccRCC have great inter-patient heterogeneities, with del(3p) being regarded as the common earliest event followed by three early departure points: VHL and PBRM1 mutations, del(14q) and other somatic copy number alterations (SCNAs) including amp(7), del(1p) and del(6q). We identify three prognostic subtypes of ccRCC with distinct clonal architectures and immune infiltrates: long-lived patients, enriched with VHL but depleted of BAP1 mutations, have high levels of Th17 and CD8

Ma S, Liu W, Zhang A, et al.
Identification of a PRKAR1A mutation (c.491_492delTG) in familial cardiac myxoma: A case report.
Medicine (Baltimore). 2019; 98(11):e14866 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
RATIONALE: Cardiac myxoma is the most common cardiac neoplasm. Currently, there are not many reports on familial cardiac myxoma. Herein, we reported 2 first-degree relatives with left atrial myxoma.
PATIENT CONCERNS: A 20-year-old female was admitted in our hospital for lapsing into a coma for 24 hours, and was diagnosed with recurrent left atrial cardiac myxoma. The patient's father also had a history of cardiac myxoma.
DIAGNOSIS: The patient was diagnosed with left atrial myxoma using transthoracic echocardiography (TTE). Whole exome sequencing (WES) identified a p.Val164Aspfs (c.491-492delTG) mutation in the cAMP-dependent protein kinase A (PKA) regulatory (R) subunit 1 (PRKAR1A) gene for both the proband and her father, but not in her uncle and brother, who had not shown manifestation of cardiac myxoma by the time of this report.
INTERVENTIONS: The myxoma resection was performed following the standard procedure of open chest surgery.
OUTCOMES: The tumor was successfully removed along with the tuberculum. The patient recovered well and was discharged home. No recurrence occurred during 1-year follow-up.
LESSONS: Our findings suggest that PRKAR1A mutation (c.491_492delTG) may be associated with cardiac myxoma, and genetic counseling and specific locus mutation tests may contribute to assessing the risk of cardiac myxoma.

Liu CH, Ge YL, Wu NJ, Jin XP
Hyperglycemia and Hypokalemia in a 16-Year-Old Overweight Female Patient Misdiagnosed with Cushing Syndrome at First and Ultimately Diagnosed with Carney Complex Proven by PRKAR1A Gene Test: a Case Report and Literature Review.
Clin Lab. 2019; 65(3) [PubMed] Related Publications
BACKGROUND: Here we report on a 16-year-old female patient with typical Cushingoid features who was admitted because of purple striae, menostasis, and microsomia for 1 year, and laboratory tests showed hyperglycemia and hypokalemia.
METHODS: For diagnosis, we employed a hormone test, abdominal and pituitary computed tomography scan, ultrasonography to detect endocrine and cardiocutaneous lesions. DNA sequencing to detect PRKAR1A gene mutation to make differential diagnosis for Cushing Syndrome.
RESULTS: Hormone test revealed hypercortisolism, images demonstrated right adrenal nodular hyperplasia and hyperparathyroid hyperplasia. DNA sequencing analysis revealed a heterozygous C.680 G>A substitution in PRKAR1A.
CONCLUSIONS: We describe here an atypical Carney Complex (CNC) patient magnified Cushing Syndrome with a nonsense mutation in the PRKAR1A gene, which cannot sustain the diagnosis except for the RKAR1A gene sequencing for analysis.

Tang KD, Liu J, Russell PJ, et al.
Gamma-Tocotrienol Induces Apoptosis in Prostate Cancer Cells by Targeting the Ang-1/Tie-2 Signalling Pathway.
Int J Mol Sci. 2019; 20(5) [PubMed] Article available free on PMC after 03/12/2019 Related Publications
Emerging evidence suggests that gamma-tocotrienol (γ-T3), a vitamin E isomer, has potent anti-cancer properties against a wide-range of cancers. γ-T3 not only inhibited the growth and survival of cancer cells in vitro, but also suppressed angiogenesis and tumour metastasis under in vivo conditions. Recently, γ-T3 was found to target cancer stem cells (CSCs), leading to suppression of tumour formation and chemosensitisation. Despite its promising anti-cancer potential, the exact mechanisms responsible for the effects of γ-T3 are still largely unknown. Here, we report the identification of Ang-1 (Angiopoietin-1)/Tie-2 as a novel γ-T3 downstream target. In prostate cancer cells, γ-T3 treatment leads to the suppression of Ang-1 at both the mRNA transcript and protein levels. Supplementing the cells with Ang-1 was found to protect them against the anti-CSC effect of γ-T3. Intriguingly, inactivation of Tie-2, a member receptor that mediates the effect of Ang-1, was found to significantly enhance the cytotoxic effect of γ-T3 through activation of AMP-activated protein kinase (AMPK) and subsequent interruption of autophagy. Our results highlighted the therapeutic potential of using γ-T3 in combination with a Tie-2 inhibitor to treat advanced prostate cancer.

Kang M, Park SH, Park SJ, et al.
p44/42 MAPK signaling is a prime target activated by phenylethyl resorcinol in its anti-melanogenic action.
Phytomedicine. 2019; 58:152877 [PubMed] Related Publications
BACKGROUND: Melanin plays a crucial role in protecting human skin against exposure to ultraviolet (UV) radiation. However, its overproduction induces hyperpigmentation disorders of the skin.
PURPOSE: To investigate effects of phenylethyl resorcinol as one resorcinol derivative on melanogenesis and its mechanisms using B16F10 mouse melanoma cells and human epidermal melanocytes.
METHODS: Effects of phenylethyl resorcinol on melanogenesis and its mechanism of action were examined using several in vitro assays (i.e., cell survival, melanin content, cellular tyrosinase activity, real-time PCR analysis, luciferase-reporter assay, Western blot analysis, and ELISAs for cyclic AMP (cAMP), protein kinase A (PKA), cAMP response element binding (CREB) protein, and mitogen-activated protein kinases (MAPKs)).
RESULTS: Phenylethyl resorcinol reduced both melanin content and tyrosinase activity in these cells. Phenylethyl resorcinol also suppressed tyrosinase activity in cell-free tyrosinase enzyme assay. Although phenylethyl resorcinol decreased mRNA levels of tyrosinase and tyrosinase-related protein (TRP)-2, it did not affect mRNA levels of melanogenic gene microphthalmia-associated transcriptional factor (MITF) or TRP-1. Phenylethyl resorcinol had no effects on cAMP signaling or NF-κB signaling based on results of cyclic AMP response element (CRE)-luciferase reporter assay, cAMP production, protein kinase A (PKA) activity, Western blot assays for phosphorylated CRE-binding protein (CREB), NF-κB-luciferase reporter assay, and Western blot assays for phosphorylated NF-κB. However, phenylethyl resorcinol induced activation of activator protein-1 (AP-1) signaling. Specifically, phenylethyl resorcinol increased AP-1 reporter activity and increased phosphorylation of p44/42 MAPK, but not p38 MAPK or c-Jun N-terminal kinase (JNK). MEK1/2 and Src, upstream molecules of p44/42 MAPK were also phosphorylated by phenylethyl resorcinol. In addition, phenylethyl resorcinol-induced decreases in melanin content, tyrosinase activity, and MITF protein levels were attenuated by PD98059, a p44/42 MAPK inhibitor.
CONCLUSION: These data indicate that the anti-melanogenic activity of phenylethyl resorcinol is mediated by activation of p44/42 MAPK, indicating that phenylethyl resorcinol may be a potential therapeutic agent for treating hyperpigmentation skin disorders.

Ku KE, Choi N, Oh SH, et al.
Src inhibition induces melanogenesis in human G361 cells.
Mol Med Rep. 2019; 19(4):3061-3070 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
The Src kinase family (SKF) includes non‑receptor tyrosine kinases that interact with many cellular cytosolic, nuclear and membrane proteins, and is involved in the progression of cellular transformation and oncogenic activity. However, there is little to no evidence on the effect of SKF or its inhibitors on melanogenesis. Therefore, the present study investigated whether C‑terminal Src kinase inhibition can induce melanogenesis and examined the associated signaling pathways and mRNA expression of melanogenic proteins. First, whether stimulators of melanogenesis, such as ultraviolet B and α‑melanocyte‑stimulating hormone, can dephosphorylate Src protein was evaluated, and the results revealed that SU6656 and PP2 inhibited the phosphorylation of Src in G361 cells. Src inhibition by these chemical inhibitors induced melanogenesis in G361 cells and upregulated the mRNA expression levels of melanogenesis‑associated genes encoding microphthalmia‑associated transcription factor, tyrosinase‑related protein 1 (TRP1), TRP2, and tyrosinase. In addition, Src inhibition by small interfering RNA induced melanogenesis and upregulated the mRNA expression levels of melanogenesis‑associated genes. As the p38 mitogen‑activated protein kinase (MAPK) and cyclic adenosine monophosphate response element binding (CREB) pathways serve key roles in melanogenesis, the present study further examined whether Src mediates melanogenesis via these pathways. As expected, Src inhibition via SU6656 or PP2 administration induced the phosphorylation of p38 or CREB, as determined by western blotting analysis, and increased the levels of phosphorylated p38 or CREB, as determined by immunofluorescence staining. In addition, the induced pigmentation and melanin content of G361 cells by Src inhibitors was significantly inhibited by p38 or CREB inhibitors. Taken together, these data indicate that Src is associated with melanogenesis, and Src inhibition induces melanogenesis via the MAPK and CREB pathways in G361 cells.

Yang Q, Yu W, Han X
Overexpression of microRNA‑101 causes anti‑tumor effects by targeting CREB1 in colon cancer.
Mol Med Rep. 2019; 19(4):3159-3167 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
Accumulating evidence has demonstrated that aberrantly expressed microRNAs (miRNAs) are involved in the initiation and progression of numerous types of human cancer. Although a number of miRNAs have been demonstrated to be associated with the diagnosis, progression and prognosis of colon cancer, the function of miRNA‑101 (miR‑101) in colon cancer remains unclear, and the molecular mechanisms underlying the effects of miR‑101 in colon cancer require further investigation. The present study investigated the role of miR‑101 in colon cancer, and the results suggested that miR‑101 expression levels were significantly decreased in colorectal carcinoma tissues and in three types of colorectal cancer cell lines. Furthermore, overexpression of miR‑101 inhibited cell proliferation and migration in HT29 cells. The transcription factor cAMP responsive element binding protein 1 (CREB1) was identified to be a direct target of miR‑101 using a luciferase reporter assay, reverse transcription‑quantitative polymerase chain reaction analysis and western blot assay. miR‑101 overexpression in tumor xenografts in vivo decreased the expression levels of proliferating cell nuclear antigen and CREB1, and suppressed tumor growth. The present results suggested that miR‑101 may serve a role in colon cancer by directly targeting CREB1. Collectively, the present study may contribute to the development of improved diagnosis and prognostics for colon cancer.

Bai L, Zhang S, Zhou X, et al.
Brain-derived neurotrophic factor induces thioredoxin-1 expression through TrkB/Akt/CREB pathway in SH-SY5Y cells.
Biochimie. 2019; 160:55-60 [PubMed] Related Publications
Brain-derived neurotrophic factor (BDNF) is one of the neurotrophic factors that are vital to the survival and proliferation of neuron. Thioredoxin-1 (Trx-1) is a redox regulating protein and plays various roles in regulating transcript factors and inhibiting apoptosis. It has been reported that Trx-1 is required for nerve growth factor-mediated signal transduction and neurite outgrowth, and is involved in synaptic protein expression induced by BDNF. However, the molecular mechanism on BDNF inducing Trx-1 expression has not been fully verified. The present study investigated the expression of Trx-1 after treatment with BDNF in SH-SY5Y cells. We first demonstrated that cell viability and the expression of Trx-1 were increased by BDNF in SH-SY5Y cells, which were inhibited by the tyrosine kinase B (TrkB) inhibitor, K252a, and the phosphatidylinositol 3-kinase (PI3-K) inhibitor, LY294002. Moreover, BDNF increased the activity of cAMP response element-binding protein (CREB) through TrkB/PI3-K/Akt pathway. Whereas the expression of Trx-1 induced by BDNF was suppressed by CREB siRNA. Thus, our data suggest that BDNF induces the expression of Trx-1 through the TrkB/Akt/CREB pathway.

Bai J, Jhaney I, Daniel G, Watkins Bruner D
Pilot Study of Vaginal Microbiome Using QIIME 2™ in Women With Gynecologic Cancer Before and After Radiation Therapy.
Oncol Nurs Forum. 2019; 46(2):E48-E59 [PubMed] Related Publications
OBJECTIVES: To characterize the vaginal microbiome using QIIME 2™ (Quantitative Insights Into Microbial Ecology 2) in women with gynecologic cancer.
SAMPLE & SETTING: 19 women with gynecologic cancer before and after radiation therapy at a comprehensive cancer center in Atlanta, Georgia.
METHODS & VARIABLES: This pilot study analyzed vaginal microbiome communities using a microbiome analysis pipeline, beginning with 16S rRNA gene sequencing and processing through use of a bioinformatics pipeline to downstream microbial statistical analysis.
RESULTS: The findings showed the methods to be robust, and most women with gynecologic cancer showed depletion of Lactobacillus. Compared to those pre-radiation therapy, women post-radiation therapy showed higher abundances of Mobiluncus, Atopobium, and Prevotella but lower abundances of Lactobacillus, Gardnerella, and Peptostreptococcus, which are associated with bacterial vaginosis.
IMPLICATIONS FOR NURSING: This study presents the fundamentals of human microbiome data collection and analysis methods to inform nursing science. Assessing the vaginal microbiome provides a potential pathway to develop interventions to ameliorate dysbiosis of the vaginal microbiome.

Won SY, Park JJ, Shin EY, Kim EG
PAK4 signaling in health and disease: defining the PAK4-CREB axis.
Exp Mol Med. 2019; 51(2):11 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
p21-Activated kinase 4 (PAK4), a member of the PAK family, regulates a wide range of cellular functions, including cell adhesion, migration, proliferation, and survival. Dysregulation of its expression and activity thus contributes to the development of diverse pathological conditions. PAK4 plays a pivotal role in cancer progression by accelerating the epithelial-mesenchymal transition, invasion, and metastasis. Therefore, PAK4 is regarded as an attractive therapeutic target in diverse types of cancers, prompting the development of PAK4-specific inhibitors as anticancer drugs; however, these drugs have not yet been successful. PAK4 is essential for embryonic brain development and has a neuroprotective function. A long list of PAK4 effectors has been reported. Recently, the transcription factor CREB has emerged as a novel effector of PAK4. This finding has broad implications for the role of PAK4 in health and disease because CREB-mediated transcriptional reprogramming involves a wide range of genes. In this article, we review the PAK4 signaling pathways involved in prostate cancer, Parkinson's disease, and melanogenesis, focusing in particular on the PAK4-CREB axis.

Jia D, Lu M, Jung KH, et al.
Elucidating cancer metabolic plasticity by coupling gene regulation with metabolic pathways.
Proc Natl Acad Sci U S A. 2019; 116(9):3909-3918 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
Metabolic plasticity enables cancer cells to switch their metabolism phenotypes between glycolysis and oxidative phosphorylation (OXPHOS) during tumorigenesis and metastasis. However, it is still largely unknown how cancer cells orchestrate gene regulation to balance their glycolysis and OXPHOS activities. Previously, by modeling the gene regulation of cancer metabolism we have reported that cancer cells can acquire a stable hybrid metabolic state in which both glycolysis and OXPHOS can be used. Here, to comprehensively characterize cancer metabolic activity, we establish a theoretical framework by coupling gene regulation with metabolic pathways. Our modeling results demonstrate a direct association between the activities of AMPK and HIF-1, master regulators of OXPHOS and glycolysis, respectively, with the activities of three major metabolic pathways: glucose oxidation, glycolysis, and fatty acid oxidation. Our model further characterizes the hybrid metabolic state and a metabolically inactive state where cells have low activity of both glycolysis and OXPHOS. We verify the model prediction using metabolomics and transcriptomics data from paired tumor and adjacent benign tissue samples from a cohort of breast cancer patients and RNA-sequencing data from The Cancer Genome Atlas. We further validate the model prediction by in vitro studies of aggressive triple-negative breast cancer (TNBC) cells. The experimental results confirm that TNBC cells can maintain a hybrid metabolic phenotype and targeting both glycolysis and OXPHOS is necessary to eliminate their metabolic plasticity. In summary, our work serves as a platform to symmetrically study how tuning gene activity modulates metabolic pathway activity, and vice versa.

Lu CC, Chiang JH, Tsai FJ, et al.
Metformin triggers the intrinsic apoptotic response in human AGS gastric adenocarcinoma cells by activating AMPK and suppressing mTOR/AKT signaling.
Int J Oncol. 2019; 54(4):1271-1281 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
Metformin is commonly used to treat patients with type 2 diabetes and is associated with a decreased risk of cancer. Previous studies have demonstrated that metformin can act alone or in synergy with certain anticancer agents to achieve anti‑neoplastic effects on various types of tumors via adenosine monophosphate‑activated protein kinase (AMPK) signaling. However, the role of metformin in AMPK‑mediated apoptosis of human gastric cancer cells is poorly understood. In the current study, metformin exhibited a potent anti‑proliferative effect and induced apoptotic characteristics in human AGS gastric adenocarcinoma cells, as demonstrated by MTT assay, morphological observation method, terminal deoxynucleotidyl transferase dUTP nick end labeling and caspase‑3/7 assay kits. Western blot analysis demonstrated that treatment with metformin increased the phosphorylation of AMPK, and decreased the phosphorylation of AKT, mTOR and p70S6k. Compound C (an AMPK inhibitor) suppressed AMPK phosphorylation and significantly abrogated the effects of metformin on AGS cell viability. Metformin also reduced the phosphorylation of mitogen‑activated protein kinases (ERK, JNK and p38). Additionally, metformin significantly increased the cellular ROS level and included loss of mitochondrial membrane potential (ΔΨm). Metformin altered apoptosis‑associated signaling to downregulate the BAD phosphorylation and Bcl‑2, pro‑caspase‑9, pro‑caspase‑3 and pro‑caspase‑7 expression, and to upregulate BAD, cytochrome c, and Apaf‑1 proteins levels in AGS cells. Furthermore, z‑VAD‑fmk (a pan‑caspase inhibitor) was used to assess mitochondria‑mediated caspase‑dependent apoptosis in metformin‑treated AGS cells. The findings demonstrated that metformin induced AMPK‑mediated apoptosis, making it appealing for development as a novel anticancer drug for the treating gastric cancer.

Hardy S, Kostantin E, Wang SJ, et al.
Magnesium-sensitive upstream ORF controls PRL phosphatase expression to mediate energy metabolism.
Proc Natl Acad Sci U S A. 2019; 116(8):2925-2934 [PubMed] Article available free on PMC after 03/12/2019 Related Publications
Phosphatases of regenerating liver (PRL-1, PRL-2, and PRL-3, also known as PTP4A1, PTP4A2, and PTP4A3) control magnesium homeostasis through an association with the CNNM magnesium transport regulators. Although high PRL levels have been linked to cancer progression, regulation of their expression is poorly understood. Here we show that modulating intracellular magnesium levels correlates with a rapid change of PRL expression by a mechanism involving its 5'UTR mRNA region. Mutations or CRISPR-Cas9 targeting of the conserved upstream ORF present in the mRNA leader derepress PRL protein synthesis and attenuate the translational response to magnesium levels. Mechanistically, magnesium depletion reduces intracellular ATP but up-regulates PRL protein expression via activation of the AMPK/mTORC2 pathway, which controls cellular energy status. Hence, altered PRL-2 expression leads to metabolic reprogramming of the cells. These findings uncover a magnesium-sensitive mechanism controlling PRL expression, which plays a role in cellular bioenergetics.

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