Research IndicatorsGraph generated 12 March 2017 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 12 March, 2017 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: SRC (cancer-related)
BACKGROUND: Systemic toxicity of chemotherapeutic agents and the challenges associated with targeting metastatic tumors are limiting factors for current lung cancer therapeutic approaches. To address these issues, plant-derived bioactive components have been investigated for their anti-cancer properties because many of these agents are non-toxic to healthy tissues. Enterolactone (EL) is a flaxseed-derived mammalian lignan that has demonstrated anti-migratory properties for various cancers, but EL has not been investigated in the context of lung cancer, and its anticancer mechanisms are ill-defined. We hypothesized that EL could inhibit lung cancer cell motility by affecting the FAK-Src signaling pathway.
METHODS: Non-toxic concentrations of EL were identified for A549 and H460 human lung cancer cells by conducting 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-Dephenyltetrazolium Bromide (MTT) assays. The anti-migratory and anti-invasive potential of EL for lung cancer cell lines was determined by scratch wound healing and Matrigel® invasion assays. Changes in filamentous actin (F-actin) fiber density and length in EL-treated cells were determined using phalloidin-conjugated rhodamine dye and fluorescent microscopy. Vinculin expression in focal adhesions upon EL treatment was determined by immunocytochemistry. Gene and protein expression levels of FAK-Src signaling molecules in EL-treated lung cancer cells were determined using PCR arrays, qRT-PCR, and western blotting.
RESULTS: Non-toxic concentrations of EL inhibited lung cancer cell migration and invasion in a concentration- and time-dependent manner. EL treatment reduced the density and number of F-actin fibers in lung cancer cell lines, and reduced the number and size of focal adhesions. EL decreased phosphorylation of FAK and its downstream targets, Src, paxillin, and decreased mRNA expression of cell motility-related genes, RhoA, Rac1, and Cdc42 in lung cancer cells.
CONCLUSIONS: Our data suggest that EL suppresses lung cancer cell motility and invasion by altering FAK activity and subsequent activation of downstream proteins needed for focal adhesion formation and cytoskeletal rearrangement. Therefore, administration of EL may serve as a safe and complementary approach for inhibiting lung tumor cell motility, invasion, and metastasis.
Kelley MJ, Jha G, Shoemaker D, et al.Phase II Study of Dasatinib in Previously Treated Patients with Advanced Non-Small Cell Lung Cancer.
Cancer Invest. 2017; 35(1):32-35 [PubMed
] Related Publications
The Src pathway in activated in about one-third of non-small cell lung cancer (NSCLC) tumors. Dasatinib has Src-inhibitor activity. We examined the activity of dasatinib in 37 patients with advanced, previously treated NSCLC. Among the 29 patients who underwent pre-treatment biopsy for RNA biomarker analysis, 25 were treated with dasatinib 70 mg twice daily. There were no responses. Five patients discontinued treatment due to toxicity. Three patients had minor biopsy-related pneumothoraces. Given the lack of responses, no biomarkers were analyzed. Dasatinib 70 mg twice daily does not have activity nor is it well tolerated in unselected patients with advanced stage, previously treated NSCLC.
Lu KH, Chen PN, Hsieh YH, et al.3-Hydroxyflavone inhibits human osteosarcoma U2OS and 143B cells metastasis by affecting EMT and repressing u-PA/MMP-2 via FAK-Src to MEK/ERK and RhoA/MLC2 pathways and reduces 143B tumor growth in vivo.
Food Chem Toxicol. 2016; 97:177-186 [PubMed
] Related Publications
Many natural flavonoids have cytostatic and apoptotic properties; however, we little know whether the effect of synthetic 3-hydroxyflavone on metastasis and tumor growth of human osteosarcoma. Here, we tested the hypothesis that 3-hydroxyflavone suppresses human osteosarcoma cells metastasis and tumor growth. 3-hydroxyflavone, up to 50 μM without cytotoxicity, inhibited U2OS and 143B cells motility, invasiveness and migration by reducing matrix metalloproteinase (MMP)-2 and urokinase-type plasminogen activator (u-PA) and also impaired cell adhesion to gelatin. 3-hydroxyflavone significantly reduced p-focal adhesion kinase (FAK) Tyr397, p-FAK Tyr925, p-steroid receptor coactivator (Src), p-mitogen/extracellular signal-regulated kinase (MEK)1/2, p-myosin light chain (MLC)2 Ser19, epithelial cell adhesion molecule, Ras homolog gene family (Rho)A and fibronectin expressions. 3-hydroxyflavone also affected the epithelial-mesenchymal transition (EMT) by down-regulating expressions of Vimentin and α-catenin with activation of the transcription factor Slug. In nude mice xenograft model and tail vein injection model showed that 3-hydroxyflavone reduced 143B tumor growth and lung metastasis. 3-hydroxyflavone possesses the anti-metastatic activity of U2OS and 143B cells by affecting EMT and repressing u-PA/MMP-2 via FAK-Src to MEK/ERK and RhoA/MLC2 pathways and suppresses 143B tumor growth in vivo. This may lead to clinical trials of osteosarcoma chemotherapy to confirm the promising result in the future.
Yan Q, Wang F, Miao Y, et al.Sex-determining region Y-box3 (SOX3) functions as an oncogene in promoting epithelial ovarian cancer by targeting Src kinase.
Tumour Biol. 2016; 37(9):12263-12271 [PubMed
] Related Publications
Ovarian cancer is one of the most common cancers which cause female mortality. The knowledge of ovarian cancer initiation and progression is critical to develop new therapeutic strategies to treat and prevent it. Recently, SOX3 has been reported to play a pivotal role in tumor progression. However, the clinical significance of SOX3 in human ovarian cancer remains elusive, and the identity of SOX3 in ovarian cancer initiation, progression, and the related underlying mechanism is unknown. In this study, we showed that SOX3 expression increased from benign and borderline to malignant ovarian tumors. Subsequently, we found that overexpression of SOX3 in EOC cells promoted proliferation, migration, and invasion, while restrained apoptosis and adhesion of ovarian cancer cells. In contrast, silencing of SOX3 gained the opposite results. Finally, we discovered SOX3 targeted Src kinase in EOC cells. These data imply that SOX3, acting as an oncogene in EOC, is not only a crucial factor in the carcinogenesis but also a promising therapeutic target for EOC.
Panagopoulos I, Gorunova L, Viset T, Heim SGene fusions AHRR-NCOA2, NCOA2-ETV4, ETV4-AHRR, P4HA2-TBCK, and TBCK-P4HA2 resulting from the translocations t(5;8;17)(p15;q13;q21) and t(4;5)(q24;q31) in a soft tissue angiofibroma.
Oncol Rep. 2016; 36(5):2455-2462 [PubMed
] Free Access to Full Article Related Publications
We present an angiofibroma of soft tissue with the karyotype 46,XY,t(4;5)(q24;q31),t(5;8;17)(p15;q13;q21)/46,XY,t(1;14)(p31;q32)/46,XY. RNA‑sequencing showed that the t(4;5)(q24;q31) resulted in recombination of the genes TBCK on 4q24 and P4HA2 on 5q31.1 with generation of an in‑frame TBCK‑P4HA2 and the reciprocal but out‑of‑frame P4HA2‑TBCK fusion transcripts. The putative TBCK‑P4HA2 protein would contain the kinase, the rhodanese‑like domain, and the Tre‑2/Bub2/Cdc16 (TBC) domains of TBCK together with the P4HA2 protein which is a component of the prolyl 4‑hydroxylase. The t(5;8;17)(p15;q13;q21) three‑way chromosomal translocation targeted AHRR (on 5p15), NCOA2 (on 8q13), and ETV4 (on 17q21) generating the in‑frame fusions AHRR‑NCOA2 and NCOA2‑ETV4 as well as an out‑of‑frame ETV4‑AHRR transcript. In the AHRR‑NCOA2 protein, the C‑terminal part of AHRR is replaced by the C‑terminal part of NCOA2 which contains two activation domains. The NCOA2‑ETV4 protein would contain the helix‑loop‑helix, PAS_9 and PAS_11, CITED domains, the SRC‑1 domain of NCOA2 and the ETS DNA‑binding domain of ETV4. No fusion gene corresponding to t(1;14)(p31;q32) was found. Our findings indicate that, in spite of the recurrence of AHRR‑NCOA2 in angiofibroma of soft tissue, additional genetic events (or fusion genes) might be required for the development of this tumor.
Dadhania V, Zhang M, Zhang L, et al.Meta-Analysis of the Luminal and Basal Subtypes of Bladder Cancer and the Identification of Signature Immunohistochemical Markers for Clinical Use.
EBioMedicine. 2016; 12:105-117 [PubMed
] Free Access to Full Article Related Publications
BACKGROUND: It has been suggested that bladder cancer can be divided into two molecular subtypes referred to as luminal and basal with distinct clinical behaviors and sensitivities to chemotherapy. We aimed to validate these subtypes in several clinical cohorts and identify signature immunohistochemical markers that would permit simple and cost-effective classification of the disease in primary care centers.
METHODS: We analyzed genomic expression profiles of bladder cancer in three cohorts of fresh frozen tumor samples: MD Anderson (n=132), Lund (n=308), and The Cancer Genome Atlas (TCGA) (n=408) to validate the expression signatures of luminal and basal subtypes and relate them to clinical follow-up data. We also used an MD Anderson cohort of archival bladder tumor samples (n=89) and a parallel tissue microarray to identify immunohistochemical markers that permitted the molecular classification of bladder cancer.
FINDINGS: Bladder cancers could be assigned to two candidate intrinsic molecular subtypes referred to here as luminal and basal in all of the datasets analyzed. Luminal tumors were characterized by the expression signature similar to the intermediate/superficial layers of normal urothelium. They showed the upregulation of PPARγ target genes and the enrichment for FGFR3, ELF3, CDKN1A, and TSC1 mutations. In addition, luminal tumors were characterized by the overexpression of E-Cadherin, HER2/3, Rab-25, and Src. Basal tumors showed the expression signature similar to the basal layer of normal urothelium. They showed the upregulation of p63 target genes, the enrichment for TP53 and RB1 mutations, and overexpression of CD49, Cyclin B1, and EGFR. Survival analyses showed that the muscle-invasive basal bladder cancers were more aggressive when compared to luminal cancers. The immunohistochemical expressions of only two markers, luminal (GATA3) and basal (KRT5/6), were sufficient to identify the molecular subtypes of bladder cancer with over 90% accuracy.
INTERPRETATION: The molecular subtypes of bladder cancer have distinct clinical behaviors and sensitivities to chemotherapy, and a simple two-marker immunohistochemical classifier can be used for prognostic and therapeutic stratification.
FUNDING: U.S. National Cancer Institute and National Institute of Health.
Tomar T, de Jong S, Alkema NG, et al.Genome-wide methylation profiling of ovarian cancer patient-derived xenografts treated with the demethylating agent decitabine identifies novel epigenetically regulated genes and pathways.
Genome Med. 2016; 8(1):107 [PubMed
] Free Access to Full Article Related Publications
BACKGROUND: In high-grade serous ovarian cancer (HGSOC), intrinsic and/or acquired resistance against platinum-containing chemotherapy is a major obstacle for successful treatment. A low frequency of somatic mutations but frequent epigenetic alterations, including DNA methylation in HGSOC tumors, presents the cancer epigenome as a relevant target for innovative therapy. Patient-derived xenografts (PDXs) supposedly are good preclinical models for identifying novel drug targets. However, the representativeness of global methylation status of HGSOC PDXs compared to their original tumors has not been evaluated so far. Aims of this study were to explore how representative HGSOC PDXs are of their corresponding patient tumor methylome and to evaluate the effect of epigenetic therapy and cisplatin on putative epigenetically regulated genes and their related pathways in PDXs.
METHODS: Genome-wide analysis of the DNA methylome of HGSOC patients with their corresponding PDXs, from different generations, was performed using Infinium 450 K methylation arrays. Furthermore, we analyzed global methylome changes after treatment of HGSOC PDXs with the FDA approved demethylating agent decitabine and cisplatin. Findings were validated by bisulfite pyrosequencing with subsequent pathway analysis. Publicly available datasets comprising HGSOC patients were used to analyze the prognostic value of the identified genes.
RESULTS: Only 0.6-1.0 % of all analyzed CpGs (388,696 CpGs) changed significantly (p < 0.01) during propagation, showing that HGSOC PDXs were epigenetically stable. Treatment of F3 PDXs with decitabine caused a significant reduction in methylation in 10.6 % of CpG sites in comparison to untreated PDXs (p < 0.01, false discovery rate <10 %). Cisplatin treatment had a marginal effect on the PDX methylome. Pathway analysis of decitabine-treated PDX tumors revealed several putative epigenetically regulated pathways (e.g., the Src family kinase pathway). In particular, the C-terminal Src kinase (CSK) gene was successfully validated for epigenetic regulation in different PDX models and ovarian cancer cell lines. Low CSK methylation and high CSK expression were both significantly associated (p < 0.05) with improved progression-free survival and overall survival in HGSOC patients.
CONCLUSIONS: HGSOC PDXs resemble the global epigenome of patients over many generations and can be modulated by epigenetic drugs. Novel epigenetically regulated genes such as CSK and related pathways were identified in HGSOC. Our observations encourage future application of PDXs for cancer epigenome studies.
Yu ZS, Song XH, Gan HM, et al.Activation of Src tyrosine kinase in esophageal carcinoma cells in different regulatory environments and corresponding occurrence mechanism.
Genet Mol Res. 2016; 15(3) [PubMed
] Related Publications
This study aims at observing the expression of activated Src tyrosine kinase in esophageal squamous cell carcinoma (ESCC), and exploring the relationship of Src tyrosine kinase with the occurrence and progression of ESCC. Immunohistochemistry, immunofluorescence, and immunoblotting are employed to investigate the expression of Src tyrosine kinase in the ESCC tissue. Cellular immunofluorescence is used to measure the expression of activated Src tyrosine kinase in TE1 and TE9 cell lines of human ESCC tissues and EPC1-htert and EPC2-htert cell lines of esophageal epithelial cells. Src tyrosine kinase is overexpressed in ESCC tissue and underexpressed in normal esophageal mucosa. Furthermore, it is overexpressed in the TE1 and TE9 cell lines of human ESCC tissue and underexpressed in the EPC1-htert and EPC2-htert cell lines of esophageal epithelial cells. Src tyrosine kinase shows a higher expression in human ESCC tissue than in normal esophageal mucosa. The difference is statistically significant (P < 0.05). The activation of Src tyrosine kinase plays an important role in the occurrence and development of ESCC.
Aim. We aim to identify protein kinases involved in the pathophysiology of papillary thyroid carcinoma (PTC) in order to provide potential therapeutic targets for kinase inhibitors and unfold possible molecular mechanisms. Materials and Methods. The gene expression profile of GSE27155 was analyzed to identify differentially expressed genes and mapped onto human protein kinases database. Correlation of kinases with PTC was addressed by systematic literature search, GO and KEGG pathway analysis. Results. The functional enrichment analysis indicated that "mitogen-activated protein kinases pathway" expression was extremely enriched, followed by "neurotrophin signaling pathway," "focal adhesion," and "GnRH signaling pathway." MAPK, SRC, PDGFRa, ErbB, and EGFR were significantly regulated to correct these pathways. Kinases investigated by the literature on carcinoma were considered to be potential novel molecular therapeutic target in PTC and application of corresponding kinase inhibitors could be possible therapeutic tool. Conclusion. SRC, MAPK, and EGFR were the most important differentially expressed kinases in PTC. Combined inhibitors may have high efficacy in PTC treatment by targeting these kinases.
Xu L, Tong X, Zhang S, et al.ASPP2 suppresses stem cell-like characteristics and chemoresistance by inhibiting the Src/FAK/Snail axis in hepatocellular carcinoma.
Tumour Biol. 2016; 37(10):13669-13677 [PubMed
] Related Publications
Hepatocellular carcinoma (HCC) is the third leading cause of death in cancer patients worldwide. Understanding the molecular pathogenesis of HCC recurrence and chemoresistance is key to improving patients' prognosis. In this study, we report that downregulation of ASPP2, a member of the ankyrin-repeat-containing, SH3-domain-containing, and proline-rich-region-containing protein (ASPP) family, bestowed HCC cells with stem-like properties and resistance to chemotherapy, including the expansion of side population fractions, formation of hepatospheroids, expression of stem cell-associated genes, loss of chemosensitivity, and increased tumorigenicity in immunodeficient mice. An expression profiling assay revealed that ASPP2 specifically repressed focal adhesion kinase (FAK)/Src/extracellular signal regulated kinase (ERK) signaling. ASPP2 does this by physically interacting with C-terminal Src kinase (CSK) and stimulating its kinase activity, which eventually leads to activator protein 1 (AP1)-mediated downregulation of Snail expression. In addition, pharmacologic inhibition of Src attenuated the effects of ASPP2 deficiency. Our findings present functional and mechanistic insight into the critical role of ASPP2 in the inhibition of HCC stemness and drug resistance and may provide a new strategy for therapeutic combinations to treat HCC.
BACKGROUND: Triple negative breast cancer (TNBC) is high-risk due to its rapid drug resistance and recurrence, metastasis, and lack of targeted therapy. So far, no molecularly targeted therapeutic agents have been clinically approved for TNBC. It is imperative that we discover new targets for TNBC therapy.
OBJECTIVES: A large volume of cancer genomics data are emerging and advancing breast cancer research. We may integrate different types of TNBC genomic data to discover molecular targets for TNBC therapy.
DATA SOURCES: We used publicly available TNBC tumor tissue genomic data in the Cancer Genome Atlas database in this study.
METHODS: We integratively explored genomic profiles (gene expression, copy number, methylation, microRNA [miRNA], and gene mutation) in TNBC and identified hyperactivated genes that have higher expression, more copy numbers, lower methylation level, or are targets of miRNAs with lower expression in TNBC than in normal samples. We ranked the hyperactivated genes into different levels based on all the genomic evidence and performed functional analyses of the sets of genes identified. More importantly, we proposed potential molecular targets for TNBC therapy based on the hyperactivated genes.
RESULTS: Some of the genes we identified such as FGFR2, MAPK13, TP53, SRC family, MUC family, and BCL2 family have been suggested to be potential targets for TNBC treatment. Others such as CSF1R, EPHB3, TRIB1, and LAD1 could be promising new targets for TNBC treatment. By utilizing this integrative analysis of genomic profiles for TNBC, we hypothesized that some of the targeted treatment strategies for TNBC currently in development are more likely to be promising, such as poly (ADP-ribose) polymerase inhibitors, while the others are more likely to be discouraging, such as angiogenesis inhibitors.
LIMITATIONS: The findings in this study need to be experimentally validated in the future.
CONCLUSION: This is a systematic study that combined 5 different types of genomic data to molecularly characterize TNBC and identify potential targets for TNBC therapy. The integrative analysis of genomic profiles for TNBC could assist in identifying potential new therapeutic targets and predicting the effectiveness of a targeted treatment strategy for TNBC therapy.
Zhao Z, Zhang X, Wen L, et al.Steroid receptor coactivator-3 is a pivotal target of gambogic acid in B-cell Non-Hodgkin lymphoma and an inducer of histone H3 deacetylation.
Eur J Pharmacol. 2016; 789:46-59 [PubMed
] Related Publications
Gambogic acid (GA), the active ingredient from gamboges, has been verified as a potent anti-tumor agent in many cancer cells. Nevertheless, its function in lymphoma, especially in B-cell Non-Hodgkin lymphoma (NHL), remains unclear. Amplification and/or overexpression of steroid receptor coactivator-3 (SRC-3) have been detected in multiple tumors and have confirmed its critical roles in carcinogenesis, progression, metastasis and therapy resistance in these cancers. However, no clinical data have revealed the overexpression of SRC-3 and its role in B-cell NHL. In this study, we demonstrated the anti-tumor effects of GA, which included cell growth inhibition, G1/S phase cell cycle arrest and apoptosis in B-cell NHL. We also verified that SRC-3 was overexpressed in B-cell NHL in both cell lines and lymph node samples from patients. The overexpressed SRC-3 was a central drug target of GA, and its down-regulation subsequently modulated down-stream gene expression, ultimately contributing to apoptosis. Silencing SRC-3 decreased the expression of Bcl-2, Bcl-6 and cyclin D3, but not of NF-κB and IκB-α. GA treatment did not inhibit the activation of AKT signaling pathway, but induced the deacetylation of histone H3 at lysine 9 and lysine 27. Down-regulated SRC-3 was observed to interact with more HDAC1 to mediate the deacetylation of H3. As the component of E3 ligase, Cullin3 was up-regulated and mediated the degradation of SRC-3. Our results demonstrate that GA is a potent anti-tumor agent that can be used for therapy against B-cell NHL, especially against those with an abundance of SRC-3.
Sun L, Wang D, Li X, et al.Extracellular matrix protein ITGBL1 promotes ovarian cancer cell migration and adhesion through Wnt/PCP signaling and FAK/SRC pathway.
Biomed Pharmacother. 2016; 81:145-51 [PubMed
] Related Publications
Despite the advances in cancer treatment and the progresses in tumor biological, ovarian cancer remains a bad situation. In current study, we found a novel extracellular matrix protein, ITGBL1, which is highly expressed in ovarian cancer tissues by immunohistochemistry examination. The expression pattern of ITGBL1 in malignant tissues inspired us to investigate its role in ovarian cancer progression. Both loss- and gain-function assays revealed that ITGBL1 could promote ovarian cancer cell migration and adhesion. As it's a secreted protein, we further used recombinant ITGBL1 protein treated cancer cells and found that ITGBL1 promotes cell migration and adhesion in a concentration dependent manner. Furthermore, we found that ITGBL1 not only influences the activity of Wnt/PCP signaling but also affects FAK/src pathway in vitro. Taken together, our results suggest that highly expressed ITGBL1 could promotes cancer cell migration and adhesion in ovarian cancer and as a secreted protein, ITGBL1 might be a novel biomarker for ovarian cancer diagnosis.
Somatic mutations have been extensively characterized in breast cancer, but the effects of these genetic alterations on the proteomic landscape remain poorly understood. Here we describe quantitative mass-spectrometry-based proteomic and phosphoproteomic analyses of 105 genomically annotated breast cancers, of which 77 provided high-quality data. Integrated analyses provided insights into the somatic cancer genome including the consequences of chromosomal loss, such as the 5q deletion characteristic of basal-like breast cancer. Interrogation of the 5q trans-effects against the Library of Integrated Network-based Cellular Signatures, connected loss of CETN3 and SKP1 to elevated expression of epidermal growth factor receptor (EGFR), and SKP1 loss also to increased SRC tyrosine kinase. Global proteomic data confirmed a stromal-enriched group of proteins in addition to basal and luminal clusters, and pathway analysis of the phosphoproteome identified a G-protein-coupled receptor cluster that was not readily identified at the mRNA level. In addition to ERBB2, other amplicon-associated highly phosphorylated kinases were identified, including CDK12, PAK1, PTK2, RIPK2 and TLK2. We demonstrate that proteogenomic analysis of breast cancer elucidates the functional consequences of somatic mutations, narrows candidate nominations for driver genes within large deletions and amplified regions, and identifies therapeutic targets.
Feng W, Li HC, Xu K, et al.SHCBP1 is over-expressed in breast cancer and is important in the proliferation and apoptosis of the human malignant breast cancer cell line.
Gene. 2016; 587(1):91-7 [PubMed
] Related Publications
BACKGROUND: SHC SH2-binding protein 1, a member of Src homolog and collagen homolog (Shc) family, has been recently identified in different contexts in unbiased screening assays. It has been reported to be over-expressed in several malignant cancers.
METHODS: Immunohistochemistry of SHCBP1 on 128 breast cancer tissues and adjacent normal tissues were used to evaluate the prognostic significance of SHCBP1. Survival analyses were performed by Kaplan-Meier method. CRISPR/CAS9 method was used to knockout SHCBP1 expression. CRISPR/CAS9 technology was used to knockout SHCBP1 in 2 breast cancer cell lines. MTT assay, BrdU assay, colony formation assay, cell cycle assay and apoptosis analysis in MCF-7 and MDA-MB-231 cell lines were carried out to evaluate the effects of SHCBP1 on breast cancer in vitro.
RESULTS: Immunohistochemical analysis revealed SHCBP1 was significantly up-regulated in breast cancer tissues compared with adjacent normal tissues (82 of 128, 64%). Over-expressed SHCBP1 was correlated with advanced clinical stage and poorer survival. Ablation of SHCBP1 inhibited the proliferation in vitro. SHCBP1 knockout increased cyclin-dependent kinase inhibitor p21, and decreased the Cyclin B1 and CDK1.
CONCLUSION: Our study suggests SHCBP1 is dysregulated expressed in breast cancer and plays a critical role in cancer progression, which can be a potential prognosis predictor of breast cancer.
Increasing evidence has revealed that miR-199a-5p is actively involved in tumor invasion and metastasis as well as in the decline of breast cancer tissues. In this research, overexpression of miR-199a-5p weakened motility and invasion of breast cancer cells MCF-7 and MDA-MB-231. Upregulation of Ets-1 increased breast cancer cell invasion, but the mechanism by which miR-199a-5p modulates activation of Ets-1 in breast cancer was not clarified. We investigated the relationship between miR-199a-5p and Ets-1 on the basis of 158 primary breast cancer case specimens, and the results showed that Ets-1 expression was inversely correlated with endogenous miR-199a-5p. Overexpression of miR-199a-5p reduced the mRNA and protein levels of Ets-1 in MCF-7 and MDA-MB-231 cells, whereas anti-miR-199a-5p elevated Ets-1. siRNA-mediated Ets-1 knockdown phenocopied the inhibition invasion of miR-199a-5p in vitro. Moreover, luciferase reporter assay revealed that miR-199a-5p directly targeted 3'-UTR of Ets-1 mRNA. This research revealed that miR-199a-5p could descend the levels of β1 integrin by targeting 3'-UTR of Ets-1 to alleviate the invasion of breast cancer via FAK/Src/Akt/mTOR signaling pathway. Our results provide insight into the regulation of β1 integrin through miR-199a-5p-mediated Ets-1 silence and will help in designing new therapeutic strategies to inhibit signal pathways induced by miR-199a-5p in breast cancer invasion.
Chen YJ, Lin KN, Jhang LM, et al.Gallic acid abolishes the EGFR/Src/Akt/Erk-mediated expression of matrix metalloproteinase-9 in MCF-7 breast cancer cells.
Chem Biol Interact. 2016; 252:131-40 [PubMed
] Related Publications
Several studies have revealed that natural compounds are valuable resources to develop novel agents against dysregulation of the EGF/EGFR-mediated matrix metalloproteinase-9 (MMP-9) expression in cancer cells. In view of the findings that EGF/EGFR-mediated MMP-9 expression is closely related to invasion and metastasis of breast cancer. To determine the beneficial effects of gallic acid on the suppression of breast cancer metastasis, we explored the effect of gallic acid on MMP-9 expression in EGF-treated MCF-7 breast cancer cells. Treatment with EGF up-regulated MMP-9 mRNA and protein levels in MCF-7 cells. EGF treatment induced phosphorylation of EGFR and elicited Src activation, subsequently promoting Akt/NFκB (p65) and ERK/c-Jun phosphorylation in MCF-7 cells. Activation of Akt/p65 and ERK/c-Jun was responsible for the MMP-9 up-regulation in EGF-treated cells. Gallic acid repressed the EGF-induced activation of EGFR and Src; furthermore, inactivation of Akt/p65 and ERK/c-Jun was a result of the inhibitory effect of gallic acid on the EGF-induced MMP-9 up-regulation. Over-expression of constitutively active Akt and MEK1 or over-expression of constitutively active Src eradicated the inhibitory effect of gallic acid on the EGF-induced MMP-9 up-regulation. A chromosome conformation capture assay showed that EGF induced a chromosomal loop formation in the MMP-9 promoter via NFκB/p65 and AP-1/c-Jun activation. Treatment with gallic acid, EGFR inhibitor, or Src inhibitor reduced DNA looping. Taken together, our data suggest that gallic acid inhibits the activation of EGFR/Src-mediated Akt and ERK, leading to reduced levels of p65/c-Jun-mediated DNA looping and thus inhibiting MMP-9 expression in EGF-treated MCF-7 cells.
Gastric cancer, which is the most common malignant gastrointestinal tumor, has jumped to the third leading cause of cancer-related mortality worldwide. It is of great importance to identify novel and potent drugs for gastric cancer treatment. P21-activated kinase 4 (PAK4) has emerged as an attractive target for the development of anticancer drugs in consideration of its vital functions in tumorigenesis and progression. In this paper, we reported that GL-1196, as a small molecular compound, effectively suppressed the proliferation of human gastric cancer cells through downregulation of PAK4/c-Src/EGFR/cyclinD1 pathway and CDK4/6 expression. Moreover, GL-1196 prominently inhibited the invasion of human gastric cancer cells in parallel with blockage of the PAK4/LIMK1/cofilin pathway. Interestingly, GL-1196 also inhibited the formation of filopodia and induced cell elongation in SGC7901 and BGC823 cells. Taken together, these results provided novel insights into the potential therapeutic strategy for gastric cancer.
Goel RK, Lukong KEUnderstanding the cellular roles of Fyn-related kinase (FRK): implications in cancer biology.
Cancer Metastasis Rev. 2016; 35(2):179-99 [PubMed
] Related Publications
The non-receptor tyrosine kinase Fyn-related kinase (FRK) is a member of the BRK family kinases (BFKs) and is distantly related to the Src family kinases (SFKs). FRK was first discovered in 1993, and studies pursued thereafter attributed a potential tumour-suppressive function to the enzyme. In recent years, however, further functional characterization of the tyrosine kinase in diverse cancer types suggests that FRK may potentially play an oncogenic role as well. Specifically, while ectopic expression of FRK suppresses cell proliferation and migration in breast and brain cancers, knockdown or catalytic inhibition of FRK suppresses these cellular processes in pancreatic and liver cancer. Such functional paradox is therefore evidently exhibited in a tissue-specific context. This review sheds light on the recent developments emerged from investigations on FRK which include: (a) a review of the expression pattern of the protein in mammalian cells/tissues, (b) underlying genomic perturbations and (c) a mechanistic function of the enzyme across different cellular environments. Given its functional heterogeneity observed across different cancers, we also discuss the therapeutic significance of FRK.
Kundu M, Mahata B, Banerjee A, et al.Ganglioside GM2 mediates migration of tumor cells by interacting with integrin and modulating the downstream signaling pathway.
Biochim Biophys Acta. 2016; 1863(7 Pt A):1472-89 [PubMed
] Related Publications
The definitive role of ganglioside GM2 in mediating tumor-induced growth and progression is still unknown. Here we report a novel role of ganglioside GM2 in mediating tumor cell migration and uncovered its mechanism. Data shows differential expression levels of GM2-synthase as well as GM2 in different human cancer cells. siRNA mediated knockdown of GM2-synthase in CCF52, A549 and SK-RC-26B cells resulted in significant inhibition of tumor cell migration as well as invasion in vitro without affecting cellular proliferation. Over-expression of GM2-synthase in low-GM2 expressing SK-RC-45 cells resulted in a consequent increase in migration thus confirming the potential role GM2 and its downstream partners play in tumor cell migration and motility. Further, treatment of SK-RC-45 cells with exogenous GM2 resulted in a dramatic increase in migratory and invasive capacity with no change in proliferative capacity, thereby confirming the role of GM2 in tumorigenesis specifically by mediating tumor migration and invasion. Gene expression profiling of GM2-synthase silenced cells revealed altered expression of several genes involved in cell migration primarily those controlling the integrin mediated signaling. GM2-synthase knockdown resulted in decreased phosphorylation of FAK, Src as well as Erk, while over-expression and/or exogenous GM2 treatment caused increased FAK and Erk phosphorylation respectively. Again, GM2 mediated invasion and Erk phosphorylation is blocked in integrin knockdown SK-RC-45 cells, thus confirming that GM2 mediated migration and phosphorylation of Erk is integrin dependent. Finally, confocal microscopy suggested co-localization while co-immunoprecipitation and surface plasmon resonance (SPR) confirmed direct interaction of membrane bound ganglioside, GM2 with the integrin receptor.
Baek SH, Ko JH, Lee H, et al.Resveratrol inhibits STAT3 signaling pathway through the induction of SOCS-1: Role in apoptosis induction and radiosensitization in head and neck tumor cells.
Phytomedicine. 2016; 23(5):566-77 [PubMed
] Related Publications
BACKGROUND: Signal transducer and activator of transcription 3 (STAT3) is persistently activated in squamous cell carcinoma of the head and neck (SCCHN) and can cause uncontrolled cellular proliferation and division.
HYPOTHESIS: Thus, its targeted abrogation could be an effective strategy to reduce the risk of SCCHN. Resveratrol is known for its anti-cancer efficacy in a variety of cancer models.
STUDY DESIGN: The effect resveratrol on STAT3 activation, associated protein kinases, phosphatases, cellular proliferation and apoptosis was investigated.
METHODS: We evaluated the effect of resveratrol on STAT3 signaling cascade and its regulated functional responses in SCCHN cells.
RESULTS: We found that HN3 and FaDu cells expressed strongly phosphorylated STAT3 on both tyrosine 705 and serine 727 residues as compared to other SCCHN cells. The phosphorylation was completely suppressed by resveratrol in FaDu cells, but not substantially in HN3 cells. STAT3 suppression was mediated through the inhibition of activation of upstream JAK2, but not of JAK1 and Src kinases. Treatment with the protein tyrosine phosphatase (PTP) inhibitor pervanadate reversed the resveratrol-induced down-regulation of STAT3, thereby indicating a critical role for a PTP. We also found that resveratrol induced the expression of the SOCS-1 protein and mRNA. Further, deletion of SOCS-1 gene by siRNA suppressed the induction of SOCS-1, and reversed the inhibition of STAT3 activation. Resveratrol down-regulated various STAT3-regulated gene products, inhibited proliferation, invasion, as well as induced the cell accumulation in the sub-G1 phase and caused apoptosis. Beside, this phytoalexin also exhibited the enhancement of apoptosis when combined with ionizing radiation treatment.
CONCLUSION: Our results suggest that resveratrol blocks STAT3 signaling pathway through induction of SOCS-1, thus attenuating STAT3 phosphorylation and proliferation in SCCHN cells.
Pelosi G, Pellegrinelli A, Fabbri A, et al.Deciphering intra-tumor heterogeneity of lung adenocarcinoma confirms that dominant, branching, and private gene mutations occur within individual tumor nodules.
Virchows Arch. 2016; 468(6):651-62 [PubMed
] Related Publications
While pulmonary adenocarcinoma (ADC) is morphologically heterogeneous, little is known about intra-tumor gene mutation heterogeneity (ITH). We therefore subjected 20 ADC nodules, 5 mutated for EGFR and 5 for KRAS, 5 with an ALK translocation, and 5 wild type (WT) for these alterations, to unsupervised next-generation sequencing of tumor regions from diverse architectural patterns. When 2 or more different gene mutations were found in a single tumor, this fulfilled the criteria for ITH. In the 84 studied tumor regions with diverse architecture, 71 gene mutations and 34 WT profiles were found. ITH was observed in 9/15 (60 %) ADC, 3 with an EGFR, 3 with a KRAS, and 3 with an ALK aberration, as reflected in 5, 6, and 9 additional mutations, respectively, detected in these tumors. EGFR mutations were observed in 21/22 and KRAS mutations in 18/22 tumor regions, suggesting that they appear early and have a driver role (dominant or trunk mutations). Branching mutations (in EZH2, PIK3CA, TP53, and EGFR exon 18) occurred in two or more regions, while private mutations (in ABL1, ALK, BRAF, HER2, KDR, LKB1, PTEN, MET, SMAD4, SMARCB1, and SRC) were confined to unique tumor samples of individual lesions, suggesting that they occurred later on during tumor progression. Patients with a tumor showing branching mutations ran a worse clinical course, independent of confounding factors. We conclude that in ADC, ITH exists in a pattern suggesting spatial and temporal hierarchy with dominant, branching, and private mutations. This is consistent with diverse intra-tumor clonal evolution, which has potential implications for patient prognosis or development of secondary therapy resistance.
Cell-cell adhesion protein αE-catenin inhibits skin squamous cell carcinoma (SCC) development; however, the mechanisms responsible for this function are not completely understood. We report here that αE-catenin inhibits β4 integrin-mediated activation of SRC tyrosine kinase.SRCis the first discovered oncogene, but the protein substrate critical for SRC-mediated transformation has not been identified. We found that YAP1, the pivotal effector of the Hippo signaling pathway, is a direct SRC phosphorylation target, and YAP1 phosphorylation at three sites in its transcription activation domain is necessary for SRC-YAP1-mediated transformation. We uncovered a marked increase in this YAP1 phosphorylation in human and mouse SCC tumors with low/negative expression of αE-catenin. We demonstrate that the tumor suppressor function of αE-catenin involves negative regulation of the β4 integrin-SRC signaling pathway and that SRC-mediated phosphorylation and activation of YAP1 are an alternative to the canonical Hippo signaling pathway that directly connect oncogenic tyrosine kinase signaling with YAP1.
Zhao R, Jiang W, Li X, et al.Anaplastic lymphoma kinase (ALK) gene alteration in gastric signet ring cell carcinoma.
Cancer Biomark. 2016; 16(4):569-74 [PubMed
] Related Publications
BACKGROUND: This study was aimed to investigating the frequency of Anaplastic lymphoma kinase (ALK) alterations in patients with gastric signet ring cell carcinoma (SRC) and the correlations between ALK alterations and the clinical-pathological features.
METHODS: The expression of ALK protein was first determined in paraffin-embedded tissue specimens (FFPE) from 177 pathologically confirmed SRC patients by Ventana Immunohistochemistry (IHC). Then patients with ALK positive detected by IHC were assayed in ALK rearrangement by Fluorescence in Situ Hybridization (FISH).
RESULTS: We assessed 4 of 177 cases (2.3%) as positive by IHC. 3 of the 4 patients had T4 tumors and positive nodal status, and 1 of them had metastasis. All of them were HER2 negative. All of the 4 patients were positive for ALK rearrangement using the standard criteria of FISH.
COUCLUSION: Our analysis showed that about 2.3% of Chineses SRC patients treated in our hospital were ALK positive. Ventana IHC and FISH were both of the reliable approaches in SRC patients. Patients with ALK positive seemed to have deep infiltrated and positive lymph nodes and HER2 negative.
BACKGROUND: 8000 cases of renal cancer are diagnosed each year in the UK, with a five-year survival rate of 50%. Treatment options are limited; a potential therapeutic target is the Src family kinases (SFKs). SFKs have roles in multiple oncogenic processes and promote metastases in solid tumours. The aim of this study was to investigate SFKs as potential therapeutic targets for clear cell renal cell carcinoma (ccRCC).
METHODS: SFKs expression was assessed in a tissue microarray consisting of 192 ccRCC patients with full clinical follow-up. SFK inhibitors, dasatinib and saracatinib, were assessed in early ccRCC cell lines, 786-O and 769-P and a metastatic ccRCC cell line, ACHN (± Src) for effects on protein expression, apoptosis, proliferation and wound healing.
RESULTS: High nuclear expression of Lyn and the downstream marker of activation, paxillin, were associated with decreased patient survival. Conversely, high cytoplasmic expression of other SFK members and downstream marker of activation, focal adhesion kinase (FAK) were associated with increased patient survival. Treatment of non-metastatic 786-O and 769-P cells with dasatinib, dose dependently reduced SFK activation, shown via SFK (Y(419)) and FAK (Y(861)) phosphorylation, with no effect in metastatic ACHN cells. Dasatinib also increased apoptosis, while decreasing proliferation and migration in 786-O and 769-P cell lines, both in the presence and absence of Src protein.
CONCLUSIONS: Our data suggests that nuclear Lyn is a potential therapeutic target for ccRCC and dasatinib affects cellular functions associated with cancer progression via a Src kinase independent mechanism.
Massari F, Ciccarese C, Santoni M, et al.Metabolic phenotype of bladder cancer.
Cancer Treat Rev. 2016; 45:46-57 [PubMed
] Related Publications
Metabolism of bladder cancer represents a key issue for cancer research. Several metabolic altered pathways are involved in bladder tumorigenesis, representing therefore interesting targets for therapy. Tumor cells, including urothelial cancer cells, rely on a peculiar shift to aerobic glycolysis-dependent metabolism (the Warburg-effect) as the main energy source to sustain their uncontrolled growth and proliferation. Therefore, the high glycolytic flux depends on the overexpression of glycolysis-related genes (SRC-3, glucose transporter type 1 [GLUT1], GLUT3, lactic dehydrogenase A [LDHA], LDHB, hexokinase 1 [HK1], HK2, pyruvate kinase type M [PKM], and hypoxia-inducible factor 1-alpha [HIF-1α]), resulting in an overproduction of pyruvate, alanine and lactate. Concurrently, bladder cancer metabolism displays an increased expression of genes favoring the pentose phosphate pathway (glucose-6-phosphate dehydrogenase [G6PD]) and the fatty-acid synthesis (fatty acid synthase [FASN]), along with a decrease of AMP-activated protein kinase (AMPK) and Krebs cycle activities. Moreover, the PTEN/PI3K/AKT/mTOR pathway, hyper-activated in bladder cancer, acts as central regulator of aerobic glycolysis, hence contributing to cancer metabolic switch and tumor cell proliferation. Besides glycolysis, glycogen metabolism pathway plays a robust role in bladder cancer development. In particular, the overexpression of GLUT-1, the loss of the tumor suppressor glycogen debranching enzyme amylo-α-1,6-glucosidase, 4-α-glucanotransferase (AGL), and the increased activity of the tumor promoter enzyme glycogen phosphorylase impair glycogen metabolism. An increase in glucose uptake, decrease in normal cellular glycogen storage, and overproduction of lactate are consequences of decreased oxidative phosphorylation and inability to reuse glucose into the pentose phosphate and de novo fatty acid synthesis pathways. Moreover, AGL loss determines augmented levels of the serine-to-glycine enzyme serine hydroxymethyltransferase-2 (SHMT2), resulting in an increased glycine and purine ring of nucleotides synthesis, thus supporting cells proliferation. A deep understanding of the metabolic phenotype of bladder cancer will provide novel opportunities for targeted therapeutic strategies.
Park JE, Park B, Chae IG, et al.Carnosic acid induces apoptosis through inactivation of Src/STAT3 signaling pathway in human renal carcinoma Caki cells.
Oncol Rep. 2016; 35(5):2723-32 [PubMed
] Related Publications
Carnosic acid (CA), the major bioactive compound of Rosmarinus officinalis L., has been reported to possess anti-inflammatory and anticancer activities. However, the molecular mechanisms underlying the anticancer effects of CA remain poorly understood. In the present study, we investigated that CA significantly reduced the viability of human renal carcinoma Caki cells. CA-induced apoptosis was connected with the cleavage of caspase-9, -7 and -3, and that of PARP. Moreover, CA increased the expression of pro-apoptotic protein Bax and diminished the expression of anti-apoptotic protein Bcl-2 and Bcl-xL, thereby releasing cytochrome c into the cytosol. Treatment with CA in Caki cells also induced the expression of p53 and its target gene product, p27, through down-regulation of Murine double minute-2 (Mdm2). Furthermore, CA generated reactive oxygen species (ROS), and pretreatment with ROS scavenger N-acetyl cysteine (NAC) abrogated CA-induced cleavage of PARP and expression of p53. One of the key oncogenic signals is mediated through signal transducer and activator of transcription-3 (STAT3), which promotes abnormal cell proliferation. Incubation of cells with CA markedly diminished the phosphorylation of STAT3 and its upstream, Src, and reduced the expression of STAT3 responsive gene products, such as D-series of cyclins and survivin. Taken together, the present study revealed that CA induced apoptosis in Caki cells by induction of p53 and suppression of STAT3 signaling.
Transmitochondrial cybrids and multiple OMICs approaches were used to understand mitochondrial reprogramming and mitochondria-regulated cancer pathways in triple-negative breast cancer (TNBC). Analysis of cybrids and established breast cancer (BC) cell lines showed that metastatic TNBC maintains high levels of ATP through fatty acid β oxidation (FAO) and activates Src oncoprotein through autophosphorylation at Y419. Manipulation of FAO including the knocking down of carnitine palmitoyltransferase-1A (CPT1) and 2 (CPT2), the rate-limiting proteins of FAO, and analysis of patient-derived xenograft models confirmed the role of mitochondrial FAO in Src activation and metastasis. Analysis of TCGA and other independent BC clinical data further reaffirmed the role of mitochondrial FAO and CPT genes in Src regulation and their significance in BC metastasis.
Kim C, Baek SH, Um JY, et al.Resveratrol attenuates constitutive STAT3 and STAT5 activation through induction of PTPε and SHP-2 tyrosine phosphatases and potentiates sorafenib-induced apoptosis in renal cell carcinoma.
BMC Nephrol. 2016; 17:19 [PubMed
] Free Access to Full Article Related Publications
BACKGROUND: Signal transducers and activators of transcription (STAT) proteins are critical transcription factor that are aberrantly activated in various types of malignancies, including renal cell carcinoma (RCC).
METHODS: We investigated the effect of resveratrol (RES), an edible polyphenol phytoalexin on STAT3 and STAT5 activation cascade in both Caki-1 and 786-O RCC cell lines.
RESULTS: We found that RES suppressed both constitutive STAT3 (tyrosine residue 705 and serine residue 727) and STAT5 (tyrosine residue 694 and 699) activation, which correlated with the suppression of the upstream kinases (JAK1, JAK2, and c-Src) in RCC. Also, RES abrogated DNA binding capacity and nuclear translocation of these two transcription factors. RES-induced an increased expression of PTPε and SHP-2 and the deletion of these two genes by small interfering RNA abolished the ability of RES to inhibit STAT3 activation, suggesting the critical role of both PTPε and SHP-2 in its possible mechanism of action. Moreover, RES induced S phase cell cycle arrest, caused induction of apoptosis, loss of mitochondrial membrane potential, and suppressed colony formation in RCC. We also found that RES downregulated the expression of STAT3/5-regulated antiapoptotic, proliferative, and metastatic gene products; and this correlated with induction of caspase-3 activation and anti-invasive activity. Beside, RES potentiated sorafenib induced inhibitory effect on constitutive STAT3 and STAT5 phosphorylation, apoptotic effects in 786-O cells, and this correlated with down-regulation of various oncogenic gene products.
CONCLUSION: Overall, our results suggest that RES is a blocker of both STAT3 and STAT5 activation and thus may exert potential growth inhibitory effects against RCC cells.
Siiskonen SJ, Zhang M, Li WQ, et al.A Genome-Wide Association Study of Cutaneous Squamous Cell Carcinoma among European Descendants.
Cancer Epidemiol Biomarkers Prev. 2016; 25(4):714-20 [PubMed
] Article available free on PMC
after 01/04/2017 Related Publications
BACKGROUND: No GWAS on the risk of cutaneous squamous cell carcinoma (SCC) has been published. We conducted a multistage genome-wide association study (GWAS) to identify novel genetic loci for SCC.
METHODS: The study included 745 SCC cases and 12,805 controls of European descent in the discovery stage and 531 SCC cases and 551 controls of European ancestry in the replication stage. We selected 64 independent loci that showed the most significant associations with SCC in the discovery stage (linkage disequilibrium r(2) < 0.4) for replication.
RESULTS: Rs8063761 in the DEF8 gene on chromosome 16 showed the strongest association with SCC (P = 1.7 × 10(-9) in the combined set; P = 1.0 × 10(-6) in the discovery set and P = 4.1 × 10(-4) in the replication set). The variant allele of rs8063761 (T allele) was associated with a decreased expression of DEF8 (P = 1.2 × 10(-6)). Besides, we validated four other SNPs associated with SCC in the replication set, including rs9689649 in PARK2 gene (P = 2.7 × 10(-6) in combined set; P = 3.2 × 10(-5) in the discovery; and P = 0.02 in the replication), rs754626 in the SRC gene (P = 1.1 × 10(-6) in combined set; P = 1.4 × 10(-5) in the discovery and P = 0.02 in the replication), rs9643297 in ST3GAL1 gene (P = 8.2 × 10(-6) in combined set; P = 3.3 × 10(-5) in the discovery; and P = 0.04 in the replication), and rs17247181 in ERBB2IP gene (P = 4.2 × 10(-6) in combined set; P = 3.1 × 10(-5) in the discovery; and P = 0.048 in the replication).
CONCLUSION: Several genetic variants were associated with risk of SCC in a multistage GWAS of subjects of European ancestry.
IMPACT: Further studies are warranted to validate our finding and elucidate the genetic function of these variants. Cancer Epidemiol Biomarkers Prev; 25(4); 714-20. ©2016 AACR.