Research IndicatorsGraph generated 31 August 2019 using data from PubMed using criteria.
Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic. Tag cloud generated 31 August, 2019 using data from PubMed, MeSH and CancerIndex
Specific Cancers (6)
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).
OMIM, Johns Hopkin University
Referenced article focusing on the relationship between phenotype and genotype.
International Cancer Genome Consortium.
Summary of gene and mutations by cancer type from ICGC
Cancer Genome Anatomy Project, NCI
COSMIC, Sanger Institute
Somatic mutation information and related details
GEO Profiles, NCBI
Search the gene expression profiles from curated DataSets in the Gene Expression Omnibus (GEO) repository.
Latest Publications: HEBP1 (cancer-related)
Most expression quantitative trait locus (eQTL) studies to date have been performed in heterogeneous tissues as opposed to specific cell types. To better understand the cell-type-specific regulatory landscape of human melanocytes, which give rise to melanoma but account for <5% of typical human skin biopsies, we performed an eQTL analysis in primary melanocyte cultures from 106 newborn males. We identified 597,335
Giri B, Dey S, Das T, et al.Chronic hyperglycemia mediated physiological alteration and metabolic distortion leads to organ dysfunction, infection, cancer progression and other pathophysiological consequences: An update on glucose toxicity.
Biomed Pharmacother. 2018; 107:306-328 [PubMed
] Related Publications
Chronic exposure of glucose rich environment creates several physiological and pathophysiological changes. There are several pathways by which hyperglycemia exacerbate its toxic effect on cells, tissues and organ systems. Hyperglycemia can induce oxidative stress, upsurge polyol pathway, activate protein kinase C (PKC), enhance hexosamine biosynthetic pathway (HBP), promote the formation of advanced glycation end-products (AGEs) and finally alters gene expressions. Prolonged hyperglycemic condition leads to severe diabetic condition by damaging the pancreatic β-cell and inducing insulin resistance. Numerous complications have been associated with diabetes, thus it has become a major health issue in the 21st century and has received serious attention. Dysregulation in the cardiovascular and reproductive systems along with nephropathy, retinopathy, neuropathy, diabetic foot ulcer may arise in the advanced stages of diabetes. High glucose level also encourages proliferation of cancer cells, development of osteoarthritis and potentiates a suitable environment for infections. This review culminates how elevated glucose level carries out its toxicity in cells, metabolic distortion along with organ dysfunction and elucidates the complications associated with chronic hyperglycemia.
Metabolic reprogramming of the tumor microenvironment is recognized as a cancer hallmark. To identify new molecular processes associated with tumor metabolism, we analyzed the transcriptome of bulk and flow-sorted human primary non-small cell lung cancer (NSCLC) together with
Mander S, You DJ, Park S, et al.Nafamostat mesilate negatively regulates the metastasis of triple-negative breast cancer cells.
Arch Pharm Res. 2018; 41(2):229-242 [PubMed
] Related Publications
Triple-negative breast cancer (TNBC) lacking of oestrogen receptor, progesterone receptor, and epidermal growth factor receptor type 2 is a highly malignant disease which results in a poor prognosis and rare treatment options. Despite the use of conventional chemotherapy for TNBC tumours, resistance and short duration responses limit the treatment efficacy. Therefore, a need exists to develop a new chemotherapy for TNBC. The aim of this study was to examine the anti-cancer effects of nafamostat mesilate (NM), a previously known serine protease inhibitor and highly safe drug on breast cancer cells. Here, we showed that NM significantly inhibits proliferation, migration, and invasion in MDA-MB231 cells, induces G2/M phase cell-cycle arrest, and inhibits the expression of cyclin-dependent kinase 1 (CDK1). Exposure of MDA-MB231 cells to NM also resulted in decreased transcription factor activities accompanied by the regulated phosphorylation of signalling molecules and a decrease in metalloproteinases, the principal modulators of the extracellular environment during cancer progression. Especially, inhibition of TGFβ-stimulated Smad2 phosphorylation and subsequent metastasis-related gene expression, and downregulation of ERK activity may be pivotal mechanisms underlying inhibitory effects of NM on NM inhibits lung metastasis of breast cancer cells and growth of colonized tumours in mice. Taken together, our data revealed that NM inhibits cell growth and metastasis of TNBC cells and indicated that NM is a multi-targeted drug that could be an adjunct therapy for TNBC treatment.
Peng C, Zhu Y, Zhang W, et al.Regulation of the Hippo-YAP Pathway by Glucose Sensor O-GlcNAcylation.
Mol Cell. 2017; 68(3):591-604.e5 [PubMed
] Related Publications
The Hippo pathway is crucial in organ size control and tissue homeostasis, with deregulation leading to cancer. An extracellular nutrition signal, such as glucose, regulates the Hippo pathway activation. However, the mechanisms are still not clear. Here, we found that the Hippo pathway is directly regulated by the hexosamine biosynthesis pathway (HBP) in response to metabolic nutrients. Mechanistically, the core component of Hippo pathway (YAP) is O-GlcNAcylated by O-GlcNAc transferase (OGT) at serine 109. YAP O-GlcNAcylation disrupts its interaction with upstream kinase LATS1, prevents its phosphorylation, and activates its transcriptional activity. And this activation is not dependent on AMPK. We also identified OGT as a YAP-regulated gene that forms a feedback loop. Finally, we confirmed that glucose-induced YAP O-GlcNAcylation and activation promoted tumorigenesis. Together, our data establish a molecular mechanism and functional significance of the HBP in directly linking extracellular glucose signal to the Hippo-YAP pathway and tumorigenesis.
Aberrant metabolism in hexosamine biosynthetic pathway (HBP) has been observed in several cancers, affecting cellular signaling and tumor progression. However, the role of O-GlcNAcylation, a post-translational modification through HBP flux, in apoptosis remains unclear. Here, we found that hyper-O-GlcNAcylation in lung carcinoma cells by O-GlcNAcase inhibition renders the cells to apoptosis resistance to cisplatin (CDDP). Profiling of various key regulatory proteins revealed an implication of either p53 or c-Myc in the apoptosis regulation by O-GlcNAcylation, independent of p53 status. Using co-immunoprecipitation and correlation analyses, we found that O-GlcNAcylation of p53 under certain cellular contexts, i.e. high p53 activation, promotes its ubiquitin-mediated proteasomal degradation, resulting in a gain of oncogenic and anti-apoptotic functions. By contrast, O-GlcNAcylation of c-Myc inhibits its ubiquitination and subsequent proteasomal degradation. Gene manipulation studies revealed that O-GlcNAcylation of p53/c-Myc is in part a regulator of CDDP-induced apoptosis. Accordingly, we classified CDDP resistance by hyper-O-GlcNAcylation in lung carcinoma cells as either p53 or c-Myc dependence based on their molecular targets. Together, our findings provide novel mechanisms for the regulation of lung cancer cell apoptosis that could be important in understanding clinical drug resistance and suggest O-GlcNAcylation as a potential target for cancer therapy.
Khan GJ, Gao Y, Gu M, et al.TGF-β1 Causes EMT by Regulating N-Acetyl Glucosaminyl Transferases via Downregulation of Non Muscle Myosin II-A through JNK/P38/PI3K Pathway in Lung Cancer.
Curr Cancer Drug Targets. 2018; 18(2):209-219 [PubMed
] Related Publications
BACKGROUND: Epithelial to mesenchymal transition (EMT) is a major determinant of cancer metastasis and is closely linked with TGF-β1. Intracellular proteins, including E. Cadherin, N. Cadherin and Vimentin are directly related to EMT that affect cell migration and adhesion; on the other hand, non muscle myosin (NM) has a central role in cytokinesis, migration and adhesion.
OBJECTIVE: We aimed to explore the association of EMT and metastasis with TGF-β1 through regulation of non-muscle myosin II-A (NMII-A) and its interaction with Hexosamine Biosynthesis Pathway (HBP).
METHOD: Protein expression changes were assessed by western blotting and immunofluorescent staining while transcription level changes were assessed by qRT-PCR. EMT was assessed by phenotypic analysis, wound healing, proliferation and transwell migration assay in vitro while in vivo studies were conducted in BALB/c nude mice for lung orthotopic and tail vein metastasis models.
RESULTS: We demonstrated that regulation of JNK/ P38/PI3K by TGF-β1 led to down expression of NMII-A which promoted EMT and lung cancer metastasis. This down expression of NMII-A conversely upregulated the expression of Core 2 N-acetyl Glucosaminyl Transferase mucin type (C2GnT-M) and further facilitated up-regulation and down-regulation of N-acetylglucosaminyltransferase (GnT) -V and -III respectively; moreover, NMII-A K.D cells showed 3 times more tendency to migrate towards brain in vivo.
CONCLUSION: The study reports a novel pathway through which NMII-A negatively regulates EMT and metastasis via up regulation of C2GnT-M, GnT-V and down expression of GnT-III. These findings of lung cancer may further be required to study other cancer types.
Zhang W, Yin G, Dai J, et al.Chemoprevention by Quercetin of Oral Squamous Cell Carcinoma by Suppression of the NF-κB Signaling Pathway in DMBA-treated Hamsters.
Anticancer Res. 2017; 37(8):4041-4049 [PubMed
] Related Publications
BACKGROUND/AIM: The aim of this study was to investigate the effects of the flavonoid quercetin on chemoprevention of oral squamous cell carcinoma (OSCC). The study involved molecular signaling pathways in 7,12-dimethylbenz(a) anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis.
MATERIALS AND METHODS: DMBA (0.5%) was painted at the right buccal pouches of hamsters for 14 weeks to induce carcinoma. DMBA-treated hamsters received simultaneous doses of quercetin. Animals without DMBA induction were used as normal controls. The incidence of OSCC and the severity of pre-malignant lesions were determined histologically. Apoptosis in the pouch tissue was determined by TUNEL staining. The mRNA and protein expression of NF-κB p50 and p65, as well as Bcl-2 and Bax genes were analyzed using RT-PCR and Western blotting, respectively.
RESULTS: Quercetin, at various doses, significantly reduced OSCC incidence and severity of hyperplasia and dysplasia compared to the DMBA-induction-only group (p<0.01). Apoptosis was induced by quercetin treatment compared to the DMBA-induction-only group (p<0.01). mRNA and protein expression of NF-κB p50, p65 as well as Bcl-2 genes were significantly suppressed by quercetin at high doses compared to DMBA induction only (p<0.05). However, mRNA and protein expression of the Bax gene was increased by quercetin treatment at medium and high doses, compared to the DMBA-induction-only group (p<0.05). Quercetin significantly reduced body-weight loss compared to the DMBA-induction-only group (p<0.05).
CONCLUSION: Quercetin reduced tumor incidence and induced apoptosis through modulation of NF-κB signaling and its target genes Bcl-2 and Bax in the DMBA-induced carcigenesis hamster model, suggesting the potential of quercetin as a candidate for OSCC chemoprevention.
Kyrochristos ID, Glantzounis GK, Ziogas DE, et al.From Clinical Standards to Translating Next-Generation Sequencing Research into Patient Care Improvement for Hepatobiliary and Pancreatic Cancers.
Int J Mol Sci. 2017; 18(1) [PubMed
] Free Access to Full Article Related Publications
Hepatobiliary and pancreatic (HBP) cancers are associated with high cancer-related death rates. Surgery aiming for complete tumor resection (R0) remains the cornerstone of the treatment for HBP cancers. The current progress in the adjuvant treatment is quite slow, with gemcitabine chemotherapy available only for pancreatic ductal adenocarcinoma (PDA). In the advanced and metastatic setting, only two targeted drugs have been approved by the Food & Drug Administration (FDA), which are sorafenib for hepatocellular carcinoma and erlotinib for PDA. It is a pity that multiple Phase III randomized control trials testing the efficacy of targeted agents have negative results. Failure in the development of effective drugs probably reflects the poor understanding of genome-wide alterations and molecular mechanisms orchestrating therapeutic resistance and recurrence. In the post-ENCODE (Encyclopedia of DNA Elements) era, cancer is referred to as a highly heterogeneous and systemic disease of the genome. The unprecedented potential of next-generation sequencing (NGS) technologies to accurately identify genetic and genomic variations has attracted major research and clinical interest. The applications of NGS include targeted NGS with potential clinical implications, while whole-exome and whole-genome sequencing focus on the discovery of both novel cancer driver genes and therapeutic targets. These advances dictate new designs for clinical trials to validate biomarkers and drugs. This review discusses the findings of available NGS studies on HBP cancers and the limitations of genome sequencing analysis to translate genome-based biomarkers and drugs into patient care in the clinic.
Pancreatic cancer is one of the most lethal of all types of cancer, with the 5-year survival rate ranging only at 6-7%. The aberrant glucose metabolism is one of the hallmarks of cancer cells, and as a branch of glucose metabolism, hexosamine biosynthesis pathway (HBP) has been reported to play a critical role in the insulin resistance and progression of cancer. Glutamine:fructose-6-phosphate amidotransferase (GFAT1) is the rate-limiting enzyme of the HBP; nevertheless, the prognostic value of GFAT1 in pancreatic cancer remains elusive. In this study, we found that the expression of GFAT1 was increased in pancreatic cancer samples compared to peri-tumor tissues. High expression of GFAT1 was positively associated with lymph node metastasis, pTNM stage and shorter overall survival (OS) in pancreatic cancer patients. GFAT1 was identified as an independent prognosticator for OS, and combining GFAT1 expression with pTNM stage generated a predictive nomogram, which showed better prognostic efficiency for OS in patients with pancreatic cancer. In summary, high GFAT1 expression is identified as an independent predictor of adverse clinical outcome in our small number of pancreatic cancer patients, and the practical prognostic nomogram model may help clinicians in decision making and the design of clinical studies.
Pham LV, Bryant JL, Mendez R, et al.Targeting the hexosamine biosynthetic pathway and O-linked N-acetylglucosamine cycling for therapeutic and imaging capabilities in diffuse large B-cell lymphoma.
Oncotarget. 2016; 7(49):80599-80611 [PubMed
] Free Access to Full Article Related Publications
The hexosamine biosynthetic pathway (HBP) requires two key nutrients glucose and glutamine for O-linked N-acetylglucosamine (O-GlcNAc) cycling, a post-translational protein modification that adds GlcNAc to nuclear and cytoplasmic proteins. Increased GlcNAc has been linked to regulatory factors involved in cancer cell growth and survival. However, the biological significance of GlcNAc in diffuse large B-cell lymphoma (DLBCL) is not well defined. This study is the first to show that both the substrate and the endpoint O-GlcNAc transferase (OGT) enzyme of the HBP were highly expressed in DLBCL cell lines and in patient tumors compared with normal B-lymphocytes. Notably, high OGT mRNA levels were associated with poor survival of DLBCL patients. Targeting OGT via small interference RNA in DLBCL cells inhibited activation of GlcNAc, nuclear factor kappa B (NF-κB), and nuclear factor of activated T-cells 1 (NFATc1), as well as cell growth. Depleting both glucose and glutamine in DLBCL cells or treating them with an HBP inhibitor (azaserine) diminished O-GlcNAc protein substrate, inhibited constitutive NF-κB and NFATc1 activation, and induced G0/G1 cell-cycle arrest and apoptosis. Replenishing glucose-and glutamine-deprived DLBCL cells with a synthetic glucose analog (ethylenedicysteine-N-acetylglucosamine [ECG]) reversed these phenotypes. Finally, we showed in both in vitro and in vivo murine models that DLBCL cells easily take up radiolabeled technetium-99m-ECG conjugate. These findings suggest that targeting the HBP has therapeutic relevance for DLBCL and underscores the imaging potential of the glucosamine analog ECG in DLBCL.
Baba AB, Kowshik J, Krishnaraj J, et al.Blueberry inhibits invasion and angiogenesis in 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral squamous cell carcinogenesis in hamsters via suppression of TGF-β and NF-κB signaling pathways.
J Nutr Biochem. 2016; 35:37-47 [PubMed
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Aberrant activation of oncogenic signaling pathways plays a pivotal role in tumor initiation and progression. The purpose of the present study was to investigate the chemopreventive and therapeutic efficacy of blueberry in the hamster buccal pouch (HBP) carcinogenesis model based on its ability to target TGF-β, PI3K/Akt, MAPK and NF-κB signaling and its impact on invasion and angiogenesis. Squamous cell carcinomas were induced in the HBP by 7,12-dimethylbenz[a]anthracene (DMBA). The effect of blueberry on the oncogenic signaling pathways and downstream events was analyzed by quantitative real-time PCR and immunoblotting. Experiments with the ECV304 cell line were performed to explore the mechanism by which blueberry regulates angiogenesis. Blueberry supplementation inhibited the development and progression of HBP carcinomas by abrogating TGF-β and PI3K/Akt pathways. Although blueberry failed to influence MAPK, it suppressed NF-κB activation by preventing nuclear translocation of NF-κB p65. Blueberry also modulated the expression of the oncomiR miR-21 and the tumor suppressor let-7. Collectively, these changes induced a shift to an anti-invasive and anti-angiogenic phenotype as evidenced by downregulating matrix metalloproteinases and vascular endothelial growth factor. Blueberry also inhibited angiogenesis in ECV304 cells by suppressing migration and tube formation. The results of the present study suggest that targeting oncogenic signaling pathways that influence acquisition of cancer hallmarks is an effective strategy for chemointervention. Identification of modulatory effects on phosphorylation, intracellular localization of oncogenic transcription factors and microRNAs unraveled by the present study as key mechanisms of action of blueberry is critical from a therapeutic perspective.
Zhou F, Huo J, Liu Y, et al.Elevated glucose levels impair the WNT/β-catenin pathway via the activation of the hexosamine biosynthesis pathway in endometrial cancer.
J Steroid Biochem Mol Biol. 2016; 159:19-25 [PubMed
] Related Publications
Endometrial cancer (EC) is one of the most common gynecological malignancies in the world. Associations between fasting glucose levels (greater than 5.6mmol/L) and the risk of cancer fatality have been reported. However, the underlying link between glucose metabolic disease and EC remains unclear. In the present study, we explored the influence of elevated glucose levels on the WNT/β-catenin pathway in EC. Previous studies have suggested that elevated concentrations of glucose can drive the hexosamine biosynthesis pathway (HBP) flux, thereby enhancing the O-GlcNAc modification of proteins. Here, we cultured EC cell lines, AN3CA and HEC-1-B, with various concentrations of glucose. Results showed that when treated with high levels of glucose, both lines showed increased expression of β-catenin and O-GlcNAcylation levels; however, these effects could be abolished by the HBP inhibitors, Azaserine and 6-Diazo-5-oxo-l-norleucine, and be restored by glucosamine. Moreover the AN3CA and HEC-1-B cells that were cultured with or without PUGNAc, an inhibitor of the O-GlcNAcase, showed that PUGNAc increased β-catenin levels. The results suggest that elevated glucose levels increase β-catenin expression via the activation of the HBP in EC cells. Subcellular fractionation experiments showed that AN3CA cells had a higher expression of intranuclear β-catenin in high glucose medium. Furthermore, TOP/FOP-Flash and RT-PCR results showed that glucose-induced increased expression of β-catenin triggered the transcription of target genes. In conclusion, elevated glucose levels, via HBP, increase the O-GlcNAcylation level, thereby inducing the over expression of β-catenin and subsequent transcription of the target genes in EC cells.
UNLABELLED: Conventional wisdom ascribes metabolic reprogramming in cancer to meeting increased demands for intermediates to support rapid proliferation. Prior models have proposed benefits toward cell survival, immortality, and stress resistance, although the recent discovery of oncometabolites has shifted attention to chromatin targets affecting gene expression. To explore further effects of cancer metabolism and epigenetic deregulation, DNA repair kinetics were examined in cells treated with metabolic intermediates, oncometabolites, and/or metabolic inhibitors by tracking resolution of double-strand breaks (DSB) in irradiated MCF7 breast cancer cells. Disrupting cancer metabolism revealed roles for both glycolysis and glutaminolysis in promoting DSB repair and preventing accelerated senescence after irradiation. Targeting pathways common to glycolysis and glutaminolysis uncovered opposing effects of the hexosamine biosynthetic pathway (HBP) and tricarboxylic acid (TCA) cycle. Treating cells with the HBP metabolite N-acetylglucosamine (GlcNAc) or augmenting protein O-GlcNAcylation with small molecules or RNAi targeting O-GlcNAcase each enhanced DSB repair, while targeting O-GlcNAc transferase reversed GlcNAc's effects. Opposing the HBP, TCA metabolites including α-ketoglutarate blocked DSB resolution. Strikingly, DNA repair could be restored by the oncometabolite 2-hydroxyglutarate (2-HG). Targeting downstream effectors of histone methylation and demethylation implicated the PRC1/2 polycomb complexes as the ultimate targets for metabolic regulation, reflecting known roles for Polycomb group proteins in nonhomologous end-joining DSB repair. Our findings that epigenetic effects of cancer metabolic reprogramming may promote DNA repair provide a molecular mechanism by which deregulation of metabolism may not only support cell growth but also maintain cell immortality, drive therapeutic resistance, and promote genomic instability.
IMPLICATIONS: By defining a pathway from deregulated metabolism to enhanced DNA damage response in cancer, these data provide a rationale for targeting downstream epigenetic effects of metabolic reprogramming to block cancer cell immortality and overcome resistance to genotoxic stress.
Arqués O, Chicote I, Puig I, et al.Tankyrase Inhibition Blocks Wnt/β-Catenin Pathway and Reverts Resistance to PI3K and AKT Inhibitors in the Treatment of Colorectal Cancer.
Clin Cancer Res. 2016; 22(3):644-56 [PubMed
] Related Publications
PURPOSE: Oncogenic mutations in the KRAS/PI3K/AKT pathway are one of the most frequent alterations in cancer. Although PI3K or AKT inhibitors show promising results in clinical trials, drug resistance frequently emerges. We previously revealed Wnt/β-catenin signaling hyperactivation as responsible for such resistance in colorectal cancer. Here we investigate Wnt-mediated resistance in patients treated with PI3K or AKT inhibitors in clinical trials and evaluate the efficacy of a new Wnt/tankyrase inhibitor, NVP-TNKS656, to overcome such resistance.
EXPERIMENTAL DESIGN: Colorectal cancer patient-derived sphere cultures and mouse tumor xenografts were treated with NVP-TNKS656, in combination with PI3K or AKT inhibitors.We analyzed progression-free survival of patients treated with different PI3K/AKT/mTOR inhibitors in correlation with Wnt/β-catenin pathway activation, oncogenic mutations, clinicopathological traits, and gene expression patterns in 40 colorectal cancer baseline tumors.
RESULTS: Combination with NVP-TNKS656 promoted apoptosis in PI3K or AKT inhibitor-resistant cells with high nuclear β-catenin content. High FOXO3A activity conferred sensitivity to NVP-TNKS656 treatment. Thirteen of 40 patients presented high nuclear β-catenin content and progressed earlier upon PI3K/AKT/mTOR inhibition. Nuclear β-catenin levels predicted drug response, whereas clinicopathologic traits, gene expression profiles, or frequent mutations (KRAS, TP53, or PIK3CA) did not.
CONCLUSIONS: High nuclear β-catenin content independently predicts resistance to PI3K and AKT inhibitors. Combined treatment with a Wnt/tankyrase inhibitor reduces nuclear β-catenin, reverts such resistance, and represses tumor growth. FOXO3A content and activity predicts response to Wnt/β-catenin inhibition and together with β-catenin may be predictive biomarkers of drug response providing a rationale to stratify colorectal cancer patients to be treated with PI3K/AKT/mTOR and Wnt/β-catenin inhibitors.
Itkonen HM, Engedal N, Babaie E, et al.UAP1 is overexpressed in prostate cancer and is protective against inhibitors of N-linked glycosylation.
Oncogene. 2015; 34(28):3744-50 [PubMed
] Related Publications
Prostate cancer is the second most common cause of cancer-associated deaths in men, and signaling via a transcription factor called androgen receptor (AR) is an important driver of the disease. Consequently, AR target genes are prominent candidates to be specific for prostate cancer and also important for the survival of the cancer cells. Here we assess the levels of all hexosamine biosynthetic pathway (HBP) enzymes in 15 separate clinical gene expression data sets and identify the last enzyme in the pathway, UDP-N-acetylglucosamine pyrophosphorylase 1 (UAP1), to be highly overexpressed in prostate cancer. We analyzed 3261 prostate cancers on a tissue microarray and found that UAP1 staining correlates negatively with Gleason score (P=0.0039) and positively with high AR expression (P<0.0001). Cells with high UAP1 expression have 10-fold increased levels of the HBP end-product, UDP-N-acetylglucosamine (UDP-GlcNAc). UDP-GlcNAc is essential for N-linked glycosylation occurring in the endoplasmic reticulum (ER) and high UAP1 expression associates with resistance against inhibitors of N-linked glycosylation (tunicamycin and 2-deoxyglucose) but not with a general ER stress-inducing agent, the calcium ionophore A23187. Knockdown of UAP1 expression re-sensitized cells towards inhibitors of N-linked glycosylation, as measured by proliferation and activation of ER stress markers. Taken together, we have identified an enzyme, UAP1, which is highly overexpressed in prostate cancer and protects cancer cells from ER stress conferring a growth advantage.
Yan Z, Wang J, Wang C, et al.miR-96/HBP1/Wnt/β-catenin regulatory circuitry promotes glioma growth.
FEBS Lett. 2014; 588(17):3038-46 [PubMed
] Related Publications
We found that miR-96 is overexpressed in glioma, and its level inversely correlates with the survival of patients. The reduction in miR-96 abundance suppresses the proliferation and colony formation of glioma cells. The tumorigenicity of U-87 MG cells is reduced by miR-96 silencing. miR-96 contributes to the activation of Wnt/β-catenin pathway in glioma cells. HMG-box transcription factor 1 (HBP-1), a Wnt/β-catenin pathway inhibitor, is suppressed by miR-96. The reactivation of Wnt/β-catenin signaling causes an increase in the proliferation of glioma cells, and a decrease in miR-96 expression. On the other hand, HBP1 silencing promotes miR-96 expression. Collectively, miR-96 contributes to the progression of glioma by enhancing the activation of the Wnt/β-catenin pathway, and the miR-96/HBP1/Wnt/β-catenin regulatory circuitry promotes the proliferation of glioma cells.
O-linked β-N-acetylglucosamine (O-GlcNAc) is a regulatory post-translational modification of intracellular proteins. The dynamic and inducible cycling of the modification is governed by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) in response to UDP-GlcNAc levels in the hexosamine biosynthetic pathway (HBP). Due to its reliance on glucose flux and substrate availability, a major focus in the field has been on how O-GlcNAc contributes to metabolic disease. For years this post-translational modification has been known to modify thousands of proteins implicated in various disorders, but direct functional connections have until recently remained elusive. New research is beginning to reveal the specific mechanisms through which O-GlcNAc influences cell dynamics and disease pathology including clear examples of O-GlcNAc modification at a specific site on a given protein altering its biological functions. The following review intends to focus primarily on studies in the last half decade linking O-GlcNAc modification of proteins with chromatin-directed gene regulation, developmental processes, and several metabolically related disorders including Alzheimer's, heart disease and cancer. These studies illustrate the emerging importance of this post-translational modification in biological processes and multiple pathophysiologies.
Väänänen RM, Lilja H, Kauko L, et al.Cancer-associated changes in the expression of TMPRSS2-ERG, PCA3, and SPINK1 in histologically benign tissue from cancerous vs noncancerous prostatectomy specimens.
Urology. 2014; 83(2):511.e1-7 [PubMed
] Free Access to Full Article Related Publications
OBJECTIVE: To investigate whether messenger ribonucleic acid (mRNA) expression of TMPRSS2-ERG fusion gene, a suggested prostate cancer (PCa) biomarker, was specific to cancerous lesions alone and to study the expression of SPINK1 and PCA3 mRNAs in the same cohort to also explore the proposed mutual exclusivity of TMPRSS2-ERG and SPINK1 expression.
METHODS: Levels of 2 TMPRSS2-ERG transcripts, PCA3, and SPINK1 mRNAs were measured with highly standardized reverse transcription quantitative polymerase chain reaction assays in cystoprostatectomy specimens from 19 patients with invasive bladder cancer and 174 radical prostatectomy (RP) samples (88 histologically benign prostate [HBP] tissues and 86 from cancerous lesions) from 87 patients with clinically localized PCa.
RESULTS: Expression of TMPRSS2-ERG transcripts was detected in 45 of 88 (51%) HBP tissues from RP specimens and more frequently (57 of 86, 66%) found in cancerous lesions. In contrast, TMPRSS2-ERG expression was detected in only 2 of 19 (11%) cystoprostatectomy specimens, both with incidental PCa foci elsewhere in the gland. Similar trends of changes in the expression of PCA3 and SPINK1 were present in HBP tissue from RP compared with cystoprostatectomy specimens.
CONCLUSION: Although the expression of TMPRSS2-ERG, SPINK1, and PCA3 mRNA is higher or more frequently found in cancerous lesions, HBP tissues from patients with clinically localized PCa manifest molecular, mRNA level changes that are absent in cystoprostatectomy specimens lacking incidental PCa foci or infrequent in cystoprostatectomy specimens containing incidental PCa. If this finding is replicated, these molecular assays could be used to inform men with negative biopsy results about the likelihood of cancerous lesions in unsampled regions and hence the need for repeat biopsy.
Puig I, Chicote I, Tenbaum SP, et al.A personalized preclinical model to evaluate the metastatic potential of patient-derived colon cancer initiating cells.
Clin Cancer Res. 2013; 19(24):6787-801 [PubMed
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PURPOSE: Within the aim of advancing precision oncology, we have generated a collection of patient-derived xenografts (PDX) characterized at the molecular level, and a preclinical model of colon cancer metastasis to evaluate drug-response and tumor progression.
EXPERIMENTAL DESIGN: We derived cells from 32 primary colorectal carcinomas and eight liver metastases and generated PDX annotated for their clinical data, gene expression, mutational, and histopathological traits. Six models were injected orthotopically into the cecum wall of NOD-SCID mice in order to evaluate metastasis. Three of them were treated with chemotherapy (oxaliplatin) and three with API2 to target AKT activity. Tumor growth and metastasis progression were analyzed by positron emission tomography (PET).
RESULTS: Patient-derived cells generated tumor xenografts that recapitulated the same histopathological and genetic features as the original patients' carcinomas. We show an 87.5% tumor take rate that is one of the highest described for implanted cells derived from colorectal cancer patients. Cecal injection generated primary carcinomas and distant metastases. Oxaliplatin treatment prevented metastasis and API2 reduced tumor growth as evaluated by PET.
CONCLUSIONS: Our improved protocol for cancer cell engraftment has allowed us to build a rapidly expanding collection of colorectal PDX, annotated for their clinical data, gene expression, mutational, and histopathological statuses. We have also established a mouse model for metastatic colon cancer with patient-derived cells in order to monitor tumor growth, metastasis evolution, and response to treatment by PET. Our PDX models could become the best preclinical approach through which to validate new biomarkers or investigate the metastatic potential and drug-response of individual patients.
Prostate cancer is the second most common cause of cancer-associated deaths in men and signalling via a transcription factor called androgen receptor (AR) is an important driver of the disease. Androgen treatment is known to affect the expression and activity of other oncogenes including receptor tyrosine kinases (RTKs). In this study we report that AR-positive prostate cancer cell-lines express 50% higher levels of enzymes in the hexosamine biosynthesis pathway (HBP) than AR-negative prostate cell-lines. HBP produces hexosamines that are used by endoplasmic reticulum and golgi enzymes to glycosylate proteins targeted to plasma-membrane and secretion. Inhibition of O-linked glycosylation by ST045849 or N-linked glycosylation with tunicamycin decreased cell viability by 20%. In addition, tunicamycin inhibited the androgen-induced expression of AR target genes KLK3 and CaMKK2 by 50%. RTKs have been shown to enhance AR activity and we used an antibody array to identify changes in the phosphorylation status of RTKs in response to androgen stimulation. Hormone treatment increased the activity of Insulin like Growth Factor 1-Receptor (IGF-1R) ten-fold and this was associated with a concomitant increase in the N-linked glycosylation of the receptor, analyzed by lectin enrichment experiments. Glycosylation is known to be important for the processing and stability of RTKs. Inhibition of N-linked glycosylation resulted in accumulation of IGF-1R pro-receptor with altered mobility as shown by immunoprecipitation. Confocal imaging revealed that androgen induced plasma-membrane localization of IGF-1R was blocked by tunicamycin. In conclusion we have established that the glycosylation of IGF-1R is necessary for the full activation of the receptor in response to androgen treatment and that perturbing this process can break the feedback loop between AR and IGF-1R activation in prostate cells. Achieving similar results selectively in a clinical setting will be an important challenge in the future.
Itkonen HM, Minner S, Guldvik IJ, et al.O-GlcNAc transferase integrates metabolic pathways to regulate the stability of c-MYC in human prostate cancer cells.
Cancer Res. 2013; 73(16):5277-87 [PubMed
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Metabolic disruptions that occur widely in cancers offer an attractive focus for generalized treatment strategies. The hexosamine biosynthetic pathway (HBP) senses metabolic status and produces an essential substrate for O-linked β-N-acetylglucosamine transferase (OGT), which glycosylates and thereby modulates the function of its target proteins. Here, we report that the HBP is activated in prostate cancer cells and that OGT is a central regulator of c-Myc stability in this setting. HBP genes were overexpressed in human prostate cancers and androgen regulated in cultured human cancer cell lines. Immunohistochemical analysis of human specimens (n = 1987) established that OGT is upregulated at the protein level and that its expression correlates with high Gleason score, pT and pN stages, and biochemical recurrence. RNA interference-mediated siliencing or pharmacologic inhibition of OGT was sufficient to decrease prostate cancer cell growth. Microarray profiling showed that the principal effects of OGT inhibition in prostate cancer cells were related to cell-cycle progression and DNA replication. In particular, c-MYC was identified as a candidate upstream regulator of OGT target genes and OGT inhibition elicited a dose-dependent decrease in the levels of c-MYC protein but not c-MYC mRNA in cell lines. Supporting this relationship, expression of c-MYC and OGT was tightly correlated in human prostate cancer samples (n = 1306). Our findings identify HBP as a modulator of prostate cancer growth and c-MYC as a key target of OGT function in prostate cancer cells.
Cancer cell metabolic reprogramming includes a shift in energy production from oxidative phosphorylation to less efficient glycolysis even in the presence of oxygen (Warburg effect) and use of glutamine for increased biosynthetic needs. This necessitates greatly increased glucose and glutamine uptake, both of which enter the hexosamine biosynthetic pathway (HBP). The HBP end product UDP-N-acetylglucosamine (UDP-GlcNAc) is used in enzymatic post-translational modification of many cytosolic and nuclear proteins by O-linked β-N-acetylglucosamine (O-GlcNAc). Here, we observed increased HBP flux and hyper-O-GlcNAcylation in human pancreatic ductal adenocarcinoma (PDAC). PDAC hyper-O-GlcNAcylation was associated with elevation of OGT and reduction of the enzyme that removes O-GlcNAc (OGA). Reducing hyper-O-GlcNAcylation had no effect on non-transformed pancreatic epithelial cell growth, but inhibited PDAC cell proliferation, anchorage-independent growth, orthotopic tumor growth, and triggered apoptosis. PDAC is supported by oncogenic NF-κB transcriptional activity. The NF-κB p65 subunit and upstream kinases IKKα/IKKβ were O-GlcNAcylated in PDAC. Reducing hyper-O-GlcNAcylation decreased PDAC cell p65 activating phosphorylation (S536), nuclear translocation, NF-κB transcriptional activity, and target gene expression. Conversely, mimicking PDAC hyper-O-GlcNAcylation through pharmacological inhibition of OGA suppressed suspension culture-induced apoptosis and increased IKKα and p65 O-GlcNAcylation, accompanied by activation of NF-κB signaling. Finally, reducing p65 O-GlcNAcylation specifically by mutating two p65 O-GlcNAc sites (T322A and T352A) attenuated the induction of PDAC cell anchorage-independent growth. Our data indicate that hyper-O-GlcNAcylation is anti-apoptotic and contributes to NF-κB oncogenic activation in PDAC.
Priyadarsini RV, Nagini SQuercetin suppresses cytochrome P450 mediated ROS generation and NFκB activation to inhibit the development of 7,12-dimethylbenz[a]anthracene (DMBA) induced hamster buccal pouch carcinomas.
Free Radic Res. 2012; 46(1):41-9 [PubMed
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Increased production of reactive oxygen species (ROS) has long been recognized to play a pivotal role in carcinogenesis. Quercetin, a naturally occurring dietary flavonoid is known for its ROS scavenging properties. The present study was designed to investigate the chemopreventive and chemotherapeutic effects of quercetin based on cytochrome P450 (CYP) mediated ROS generation, ROS-induced cellular damage and activation of the NFκB signalling circuit during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. Administration of quercetin inhibited the development of DMBA-induced HBP carcinomas by impairing CYP-mediated ROS production via downregulation of the expression of CYP1A1 and CYP1B1, and upregulation of antioxidant defences. Attenuation of ROS generation by quercetin in turn abrogated NFκB signalling by preventing the phosphorylation and degradation of IκB, nuclear translocation of NFκB and transactivation of its target genes associated with cell proliferation and apoptosis evasion. Thus dietary flavonoids such as quercetin that can block ROS generation and inhibit the redox regulated transcription factor NFκB, by virtue of their antioxidant potential are promising candidates for future antioxidant-based anticancer regimens.
Glucosamine, a naturally occurring amino monosaccharide, has been reported to play a role in the regulation of apoptosis more than half century. However the effect of glucosamine on tumor cells and the involved molecular mechanisms have not been thoroughly investigated. Glucosamine enters the hexosamine biosynthetic pathway (HBP) downstream of the rate-limiting step catalyzed by the GFAT (glutamine:fluctose- 6-phosphate amidotransferase), providing UDPGlcNAc substrates for O-linked β-N-acetylglucosamine (O-GlcNAc) protein modification. Considering that O-GlcNAc modification of proteasome subunits inhibits its activity, we examined whether glucosamine induces growth inhibition via affecting proteasomal activity. In the present study, we found glucosamine inhibited proteasomal activity and the proliferation of ALVA41 prostate cancer cells. The inhibition of proteasomal activity results in the accumulation of ubiquitinated proteins, followed by induction of apoptosis. In addition, we demonstrated that glucosamine downregulated proteasome activator PA28γ and overexpression of PA28γ rescued the proteasomal activity and growth inhibition mediated by glucosamine. We further demonstrated that inhibition of O-GlcNAc abrogated PA28γ suppression induced by glucosamine. These findings suggest that glucosamine may inhibit growth of ALVA41 cancer cells through downregulation of PA28γ and inhibition of proteasomal activity via O-GlcNAc modification.
Tu Y, Kim JSSelective gene transfer to hepatocellular carcinoma using homing peptide-grafted cationic liposomes.
J Microbiol Biotechnol. 2010; 20(4):821-7 [PubMed
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Gene delivery that provides targeted delivery of therapeutic genes to the cells of a lesion enhances therapeutic efficacy and reduces toxic side effects. This process is especially important in cancer therapy when it is advantageous to avoid unwanted damage to healthy, normal cells. Incorporating cancer-specific ligands that recognize receptors overexpressed on cancer cells can increase selective binding and uptake and, as a result, increase targeted transgene expression. In this study, we investigated whether a peptide capable of homing to hepatocellular carcinoma (HCC) could facilitate targeted gene delivery by cationic liposomes. This homing peptide (HBP) exhibited selective binding to a human hepatocarcinoma cell line, HepG2, at a concentration ranging from 5 to 5,000 nM. When conjugated to a cationic liposome, HBP substantially increased cellular internalization of plasmid DNA to increase transgene expression in HepG2 cells. In addition, there was no significant enhancement in gene transfer detected for other human cell lines tested including THLE-3, AD293, and MCF-7 cells. Therefore, we demonstrate that HBP provides targeted gene delivery to HCC by cationic liposomes.
Caldwell SA, Jackson SR, Shahriari KS, et al.Nutrient sensor O-GlcNAc transferase regulates breast cancer tumorigenesis through targeting of the oncogenic transcription factor FoxM1.
Oncogene. 2010; 29(19):2831-42 [PubMed
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Cancer cells upregulate glycolysis, increasing glucose uptake to meet energy needs. A small fraction of a cell's glucose enters the hexosamine biosynthetic pathway (HBP), which regulates levels of O-linked beta-N-acetylglucosamine (O-GlcNAc), a carbohydrate posttranslational modification of diverse nuclear and cytosolic proteins. We discovered that breast cancer cells upregulate the HBP, including increased O-GlcNAcation and elevated expression of O-GlcNAc transferase (OGT), which is the enzyme catalyzing the addition of O-GlcNAc to proteins. Reduction of O-GlcNAcation through RNA interference of OGT in breast cancer cells leads to inhibition of tumor growth both in vitro and in vivo and is associated with decreased cell-cycle progression and increased expression of the cell-cycle inhibitor p27(Kip1). Elevation of p27(Kip1) was associated with decreased expression and activity of the oncogenic transcription factor FoxM1, a known regulator of p27(Kip1) stability through transcriptional control of Skp2. Reducing O-GlcNAc levels in breast cancer cells decreased levels of FoxM1 protein and caused a decrease in multiple FoxM1-specific targets, including Skp2. Moreover, reducing O-GlcNAcation decreased cancer cell invasion and was associated with the downregulation of matrix metalloproteinase-2, a known FoxM1 target. Finally, pharmacological inhibition of OGT in breast cancer cells had similar anti-growth and anti-invasion effects. These findings identify O-GlcNAc as a novel mechanism through which alterations in glucose metabolism regulate cancer growth and invasion and suggest that OGT may represent novel therapeutic targets for breast cancer.
Ko SY, Chang KW, Lin SC, et al.The repressive effect of green tea ingredients on amyloid precursor protein (APP) expression in oral carcinoma cells in vitro and in vivo.
Cancer Lett. 2007; 245(1-2):81-9 [PubMed
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In a hamster model of N-methyl-N-benzylnitrosamine (MBN)-induced oral carcinogenesis, the incidence of buccal pouch (HBP) carcinomas in MBN-treated hamsters (17.8+/-7.5) was significantly higher than MBN-treated hamsters given tea (10.8+/-3.9) (P<0.05). Amyloid precursor protein (APP) expression was also significantly increased in MBN-induced HBP carcinomas but was significantly reduced by tea intake (P<0.0001). Furthermore, APP expression and secretion by OECM-1 oral squamous cell carcinoma cells was inhibited by a major polyphenolic ingredient of green tea, (-)-epigallocatechin gallate, in a dose-dependent manner. Thus, APP might promote oral carcinogenesis, whereas green tea ingredients might diminish it by down-regulating APP.