scholarly journals A Novel Low-Risk Germline Variant in the SH2 Domain of the SRC Gene Affects Multiple Pathways in Familial Colorectal Cancer

2021 ◽  
Vol 11 (4) ◽  
pp. 262
Author(s):  
Diamanto Skopelitou ◽  
Beiping Miao ◽  
Aayushi Srivastava ◽  
Abhishek Kumar ◽  
Magdalena Kuświk ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Susceptibility ◽  
In Silico Analysis ◽  
Missense Variant ◽  
Sh2 Domain ◽  
Colorectal Carcinogenesis ◽  
Mrna Levels ◽  
Potential Marker ◽  
Src Gene ◽  
Predisposition Genes

Colorectal cancer (CRC) shows one of the largest proportions of familial cases among different malignancies, but only 5–10% of all CRC cases are linked to mutations in established predisposition genes. Thus, familial CRC constitutes a promising target for the identification of novel, high- to moderate-penetrance germline variants underlying cancer susceptibility by next generation sequencing. In this study, we performed whole genome sequencing on three members of a family with CRC aggregation. Subsequent integrative in silico analysis using our in-house developed variant prioritization pipeline resulted in the identification of a novel germline missense variant in the SRC gene (V177M), a proto-oncogene highly upregulated in CRC. Functional validation experiments in HT-29 cells showed that introduction of SRCV177M resulted in increased cell proliferation and enhanced protein expression of phospho-SRC (Y419), a potential marker for SRC activity. Upregulation of paxillin, β-Catenin, and STAT3 mRNA levels, increased levels of phospho-ERK, CREB, and CCND1 proteins and downregulation of the tumor suppressor p53 further proposed the activation of several pathways due to the SRCV177M variant. The findings of our pedigree-based study contribute to the exploration of the genetic background of familial CRC and bring insights into the molecular basis of upregulated SRC activity and downstream pathways in colorectal carcinogenesis.

scholarly journals A Novel Low-Risk Germline Variant in the SH2 Domain of the SRC Gene Affects Multiple Pathways in Familial Colorectal Cancer

2021 ◽  
Author(s):  
Diamanto Skopelitou ◽  
Beiping Miao ◽  
Aayushi Srivastava ◽  
Abhishek Kumar ◽  
Magdalena Kuświk ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Susceptibility ◽  
In Silico Analysis ◽  
Missense Variant ◽  
Sh2 Domain ◽  
Colorectal Carcinogenesis ◽  
Beta Catenin ◽  
Mrna Levels ◽  
Potential Marker ◽  
Src Gene

Colorectal cancer (CRC) shows one of the largest proportions of familial cases among different malignancies, but only 5-10% of all CRC cases are linked to mutations in established predisposition genes. Thus, familial CRC constitutes a promising target for the identification of novel, high- to moderate-penetrance germline variants underlying cancer susceptibility by next generation sequencing. In this study, we performed whole genome sequencing on 3 members of a family with CRC aggregation. Subsequent integrative in silico analysis using our in-house developed variant prioritization pipeline resulted in the identification of a novel germline missense variant in SRC gene (V177M), a proto-oncogene highly upregulated in CRC. Functional validation experiments in HT-29 cells showed that introduction of SRCV177M resulted in increased cell proliferation and enhanced protein expression of phospho-SRC (Y419), a potential marker for SRC activity. Upregulation of paxillin, β-Catenin and STAT3 mRNA levels, increased levels of phospho-ERK, CREB and CCND1 proteins and downregulation of the tumor suppressor p53 further proposed the activation of several pathways due to the SRCV177M variant. The findings of our pedigree-based study contribute to the exploration of the genetic background of familial CRC and bring insights into the molecular basis of upregulated SRC activity and downstream pathways in colorectal carcinogenesis.

scholarly journals The Survivin −31 Snp in Human Colorectal Cancer Correlates with Survivin Splice Variant Expression and Improved Overall Survival

2010 ◽  
Vol 33 (5-6) ◽  
pp. 177-189 ◽  
Author(s):  
Anna G. Antonacopoulou ◽  
Konstantina Floratou ◽  
Vasiliki Bravou ◽  
Anastasia Kottorou ◽  
Fotinos-Ioannis Dimitrakopoulos ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Overall Survival ◽  
Splice Variant ◽  
Splice Variants ◽  
Colorectal Carcinogenesis ◽  
Clinicopathological Parameters ◽  
Mrna Levels ◽  
Colorectal Carcinomas ◽  
Tissue Samples ◽  
Survivin Protein

Background: Survivin is involved in the regulation of cell division and survival, two key processes in cancer. The majority of studies on survivin in colorectal cancer (CRC) have focused on protein expression and less is known about the expression of survivin splicing variants or survivin gene polymorphisms in CRC. In the present study, the mRNA levels of the five known isoforms of survivin as well as survivin protein were assessed in matched normal and neoplastic colorectal tissue. Moreover, the 9386C/T and −31G/C polymorphisms were investigated.Methods: Quantitative RT-PCR was used to assess mRNA levels in fresh/frozen tissue samples. Protein levels were immunohistochemically evaluated on formalin-fixed paraffin-embedded tissue sections. Individuals were genotyped using real time PCR.Results: Expression of all 5 survivin splice variants as well as survivin protein was elevated in colorectal carcinomas compared to normal tissue. Specific splice variant expression differentially correlated with clinicopathological parameters. Furthermore, both snps correlated with splice variant levels or their ratios in colorectal carcinomas while the −31G/C snp may be related to CRC development and improved overall survival.Conclusion: Our results support a role of survivin in colorectal carcinogenesis while the −31G/C snp may constitute a marker of survival.

scholarly journals Inhibitory effect of selenomethionine on carcinogenesis in the model of human colorectal cancer in vitro and its link to the Wnt/β-catenin pathway.

2018 ◽  
Vol 65 (3) ◽  
Author(s):  
Edyta Korbut ◽  
Agata Ptak-Belowska ◽  
Tomasz Brzozowski
Keyword(s):  
Colorectal Cancer ◽  
Cancer Cells ◽  
Colorectal Carcinogenesis ◽  
Mrna Levels ◽  
Human Colorectal Cancer ◽  
Bax Protein ◽  
Colorectal Cancer Cells ◽  
Gsk 3Β ◽  
Ht 29

Selenium compounds have been implicated as anticancer agents; however, the mechanism of their inhibitory action against cancer development has not been extensively investigated. The constitutive activation of the Wnt/β-catenin pathway is a central event in colorectal carcinogenesis. In this pathway, the excessive cell proliferation is initiated by the generation of β-catenin followed by overexpression of proto-oncogenes such as c-Myc. It is believed that under physiological conditions the level of c-Myc is efficiently controlled by accessibility of β-catenin protein through the process of phosphorylation by glycogen synthase kinase 3β (GSK-3β). Here, we determined whether selenomethionine (SeMet) can inhibit cell growth and affect the Wnt/β-catenin pathway in HT-29 human colorectal cancer cells in vitro. The effective cytotoxic doses of SeMet have been selected after 48 h of incubation of this compound with colorectal cancer HT-29 cell line. The MTT assay was used to assess cell viability and the protein and mRNA levels of β-catenin and c-Myc were determined by Western blotting and qPCR, respectively. The SeMet potently inhibited growth of HT-29 cells, significantly decreased the β-catenin protein and mRNA concentration, down-regulated the c-Myc gene expression and up-regulated pro-apoptotic Bax protein expression. Moreover, SeMet increased the level of GSK-3β phosphorylated at serine 9 (S9) and significantly increased the level of β-catenin phosphorylated at S33 and S37. We conclude that SeMet suppresses the growth of HT-29 colorectal cancer cells by the mechanism linked to the Wnt/β-catenin pathway, however, the degradation of β-catenin may occur independently of GSK-3β catalytic activity and its phosphorylation status.

scholarly journals Whole Exome Sequencing Identifies Novel Germline Variants of SLC15A4 Gene as Potentially Cancer Predisposing in Familial Colorectal Cancer

2021 ◽  
Author(s):  
Diamanto Skopelitou ◽  
Aayushi Srivastava ◽  
Beiping Miao ◽  
Abhishek Kumar ◽  
Dagmara Dymerska ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Familial Aggregation ◽  
Familial Cancer ◽  
Missense Variant ◽  
Upstream Region ◽  
Germline Variants ◽  
Whole Exome ◽  
Predisposition Genes

About 15% of colorectal cancer (CRC) patients have first-degree relatives affected by the same malignancy. However, for most families the cause of familial aggregation of CRC is unknown. In order to identify novel high-to-moderate penetrant germline variants underlying CRC susceptibility, we performed whole exome sequencing (WES) on four CRC cases and two unaffected family members of a Polish family without any mutation in known CRC predisposition genes. After WES, we used our in-house developed Familial Cancer Variant Prioritization Pipeline and identified two novel variants in the solute carrier family 15 member 4 (SLC15A4) gene. The heterozygous missense variant, p. Y444C, was predicted to affect the phylogenetically conserved PTR2/POT domain and to have a deleterious effect on the function of the encoded peptide/histidine transporter. The other variant was located in the upstream region of the same gene (GRCh37.p13, 12_129308531_C_T; 43bp upstream of transcription start site, ENST00000266771.5) and it was annotated to affect the promoter region of SLC15A4 as well as binding sites of 17 different transcription factors. Our findings of two distinct variants in the same gene may indicate a synergistic up-regulation of SLC15A4 as the underlying genetic cause and implicate this gene for the first time in genetic inheritance of familial CRC.

scholarly journals β-Catenin Regulation in Sporadic Colorectal Carcinogenesis: Not as Simple as APC

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Ernst Fredericks ◽  
Gill Dealtry ◽  
Saartjie Roux
Keyword(s):  
Colorectal Cancer ◽  
Protein Expression ◽  
Statistical Significance ◽  
Inhibitory Effect ◽  
Colorectal Carcinogenesis ◽  
Sporadic Colorectal Cancer ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
Peroxisome Proliferator Activated Receptor ◽  
Cox 2

Background. The wnt/APC/β-catenin pathway is a critical initiator in colorectal carcinogenesis in both hereditary and sporadic colorectal cancer (CRC). The progression of this process remains incompletely understood, although inflammation is pivotal. Drivers of inflammation are elevated in malignant tissue and have been shown to regulate β-catenin expression. Interleukin-17A (IL-17A) is protumorigenic at elevated levels via COX-2 stimulation. Elevated peroxisome proliferator-activated receptor γ (PPARγ) expression has reduced risk of carcinogenesis and good overall prognosis in established CRC. Activation of PPARγ has inhibitory effect on β-catenin. Methods. Using qPCR and IHC, we compared β-catenin, PPARγ, COX-2, and IL-17A in the colonic mucosa of patients with sporadic CRC, inflammatory bowel disease (IBD), and irritable bowel syndrome (IBS), against a normal control population. Results. β-catenin mRNA and protein expression progressively increased from the Normal group, through IBS and IBD reaching statistical significance in CRC. COX-2 mRNA levels increased similarly with statistical significance in IBD and CRC. However, COX-2 protein expression was inverted with significant expression in the Normal and IBS groups and reduced levels in IBD and CRC. PPARγ mRNA expression was unchanged in IBD and CRC but was significantly elevated in the IBS. IL-17A mRNA was significantly reduced in IBS and CRC but unchanged in IBD. There were no differences in all parameters tested in the Normal and IBS groups. Conclusion. β-catenin is confirmed as a major driver of colorectal carcinogenesis but is controlled by many more players other than APC. Elevated levels of PPARγ may have an anticarcinogenic effect. The role of COX-2 expression, especially its posttranscriptional regulation in colorectal cancer, needs further elucidation.

scholarly journals TP73 G4C14-A4T14 polymorphism and cancer susceptibility: evidence from 36 case–control studies

2018 ◽  
Vol 38 (6) ◽  
Author(s):  
Jialin Meng ◽  
Shuo Wang ◽  
Meng Zhang ◽  
Song Fan ◽  
Li Zhang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cervical Cancer ◽  
In Silico ◽  
Cancer Susceptibility ◽  
Meta Analysis ◽  
In Silico Analysis ◽  
Case Control ◽  
Genetic Models ◽  
Case Control Studies ◽  
Silico Analysis

G4C14-A4T14 polymorphism of TP73 gene has been reported with a potential association in cancer risks through affected cell homeostasis; however the results were not consistent. We performed a comprehensive meta-analysis to explore the associations between G4C14-A4T14 polymorphism and cancer susceptibility. Extensive retrieve was performed in PubMed, EMBASE, Google Scholar, Web of Science, Wanfang database and CNKI database up to May 20, 2018. Odds ratios (ORs) and 95% confidence intervals (CIs) were conducted to evaluate the overall strength of the associations in five genetic models, as well as in subgroup analyses. Q-test, false-positive report probability analysis and trial sequential analysis, Egger’s test and Begg’s funnel plot were applied to evaluate the robustness of the results. In silico analysis was managed to demonstrate the relationship of TP73 expression correlated with cancer tissues. Finally, 36 case–control studies with a total of 9493 cancer cases and 13,157 healthy controls were enrolled into the meta-analysis. The pooled results present a significantly higher risk of G4C14-A4T14 polymorphism in all the five genetic models, as well as in the subgroups of Caucasian, cervical cancer, colorectal cancer, H-B subgroup and comfort to Hardy–Weinberg equilibrium subgroup. In silico analysis revealed that the expression of TP73 in cervical cancer tissue is higher than it in corresponding normal tissue, as well as in cervical cancer. All in all, TP73 G4C14-A4T14 polymorphism causes an upgrade cancer risk, especially in Caucasian population. G4C14-A4T14 polymorphism might be a potential biomarker for judging the tumorigenesis of cervical cancer and colorectal cancer.

A Tale of Two Colons and Two Cancers

Swiss Surgery ◽  
2003 ◽  
Vol 9 (1) ◽  
pp. 3-7 ◽  
Author(s):  
Gervaz ◽  
Bühler ◽  
Scheiwiller ◽  
Morel
Keyword(s):  
Colorectal Cancer ◽  
Colon Cancer ◽  
Adjuvant Chemotherapy ◽  
Splenic Flexure ◽  
Chromosomal Instability ◽  
Proximal Colon ◽  
Colorectal Carcinogenesis ◽  
Physiological Data ◽  
Central Hypothesis ◽  
Group Stratification

The central hypothesis explored in this paper is that colorectal cancer (CRC) is a heterogeneous disease. The initial clue to this heterogeneity was provided by genetic findings; however, embryological and physiological data had previously been gathered, showing that proximal (in relation to the splenic flexure) and distal parts of the colon represent distinct entities. Molecular biologists have identified two distinct pathways, microsatellite instability (MSI) and chromosomal instability (CIN), which are involved in CRC progression. In summary, there may be not one, but two colons and two types of colorectal carcinogenesis, with distinct clinical outcome. The implications for the clinicians are two-folds; 1) tumors originating from the proximal colon have a better prognosis due to a high percentage of MSI-positive lesions; and 2) location of the neoplasm in reference to the splenic flexure should be documented before group stratification in future trials of adjuvant chemotherapy in patients with stage II and III colon cancer.

Regulation of microRNAs in Inflammation-Associated Colorectal Cancer: A Mechanistic Approach

2020 ◽  
Vol 20 ◽  
Author(s):  
Sridhar Muthusami ◽  
Ilangovan Ramachandran ◽  
Sneha Krishnamoorthy ◽  
Yuvaraj Sambandam ◽  
Satish Ramalingam ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Molecular Mechanisms ◽  
Colorectal Carcinogenesis ◽  
Model Systems ◽  
Necrosis Factor Alpha ◽  
Multi Stage ◽  
Mechanistic Approach ◽  
Tnf Α ◽  
Factor Alpha

: The development of colorectal cancer (CRC) is a multi-stage process. The inflammation of the colon as in inflammatory bowel disease (IBD) such as ulcerative colitis (UC) or Crohn’s disease (CD) is often regarded as the initial trigger for the development of CRC. Many cytokines such as tumor necrosis factor alpha (TNF-α) and several interleukins (ILs) are known to exert proinflammatory actions, and inflammation initiates or promotes tumorigenesis of various cancers, including CRC through differential regulation of microRNAs (miRNAs/miRs). miRNAs can be oncogenic miRNAs (oncomiRs) or anti-oncomiRs/tumor suppressor miRNAs, and they play key roles during colorectal carcinogenesis. However, the functions and molecular mechanisms of regulation of miRNAs involved in inflammation-associated CRC are still anecdotal and largely unknown. Consolidating the published results and offering perspective solutions to circumvent CRC, the current review is focused on the role of miRNAs and their regulation in the development of CRC. We have also discussed the model systems adapted by researchers to delineate the role of miRNAs in inflammation-associated CRC.

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