Colorectal Cancer Susceptibility Research Articles

Apparition of germline mutation c.1395-1397del of MUTYH in Algerian consanguineous family with colorectal cancer

MUTYH is a glycosylase that removes adenine opposite 8-oxoguanine (OG) during base-excision repair of DNA. Variants of MUTYH defective in functional activity lead to MUTYH-associated polyposis (MAP), autosomal recessive predisposition to colorectal cancer (CRC). MAP combines clinical features with other hereditary CRC syndromes, and exhibits phenotypic overlap, particularly with Lynch syndrome (LS). To determine the impact of MUTYH mutations in colorectal adenomas and cancer susceptibility, this prospective objective screens the MUTYH gene in seventeen Eastern Algerian families with clinically suspected LS but without mismatch repair (MMR) mutations. Methods: We examined the presence of the mutations in the probands and their relatives using direct sequencing of the entire coding region of the MUTYH gene. Results: The biallelic and monoallelic pathogenic MUTYH mutations, c.1395_1397del, were discovered in a consanguineous family with CRC and gastric cancer as a novel finding in our Eastern Algerian population. Conclusion: High rates of consanguinity in Algerian population increase the risk of CRC caused by biallelic mutations in the MUTYH gene. In our families, the LS and MAP phenotypes might coexist.

Benzo[a]pyrene exposure affects colorectal cancer susceptibility by regulating ERβ-mediated LINC02977 transcription

Environmental pollutants known as polycyclic aromatic hydrocarbons (PAHs) are produced through the incomplete combustion of organic material. While PAHs have been investigated as genotoxicants, they can also operate through nongenotoxic pathways in estrogen-dependent malignancies, such as breast, cervical and ovarian cancer. However, whether PAHs induce colorectal cancer (CRC) risk through estrogenic effects is still illusive. Here, we systematically investigated the abnormal expression and activation of estrogen receptor beta (ERβ) regulated by PAHs in CRC as well as the underlying mechanisms of ERβ-mediated CRC risk. Based on the 300 plasma samples from CRC patients and healthy controls detected by GC–MS/MS, we found that the plasma concentrations of benzo[a]pyrene (BaP) were significantly higher in CRC cases than in healthy controls, with significant estrogenic effects. Moreover, histone deacetylase 2 (HDAC2)-induced deacetylation of the promoter decreases ERβ expression, which is associated with poor overall survival and advanced tumor stage. The study also revealed that BaP and estradiol (E2) had different carcinogenic effects, with BaP promoting cell proliferation and inhibiting apoptosis, while E2 had the opposite effects. Additionally, this study mapped ERβ genomic binding regions by performing ChIP-seq and ATAC-seq and identified genetic variants of rs1411680 and its high linkage disequilibrium SNP rs6477937, which were significantly associated with CRC risk through meta-analysis of two independent Chinese population genome-wide association studies comprising 2,248 cases and 3,173 controls and then validation in a large-scale European population. By integrating data from functional genomics, we validated the regulatory effect of rs6477937 as an ERβ binding-disrupting SNP that mediated allele-specific expression of LINC02977 in a long-range chromosomal interaction manner, which was found to be highly expressed in CRC tissues. Overall, this study suggests that the different active effects on ERβ by PAHs and endogenous E2 may play a crucial role in the development and progression of CRC and highlights the potential of targeting ERβ and its downstream targets for CRC prevention and treatment.

Nonsense suppression induces read-through of a novel BMPR1A variant in a Chinese family with hereditary colorectal cancer.

BMPR1A-mediated signaling transduction plays an essential role in intestinal growth. Variations of BMPR1A lead to a rare autosomal dominant inherited juvenile polyposis syndrome (JPS) with high probability of developing into colorectal cancer (CRC). Nonsense and frameshift variations, generating premature termination codons (PTCs), are the most pathogenic variants in the BMPR1A gene. This study aimed to investigate the molecular genetic etiology in a Chinese family with three generations of CRC. Pathogenic variants of 18 known CRC susceptibility genes were examined in a Chinese CRC family through multigene panel testing using the next-generation sequencing platform. The candidate gene variant was validated in the family members by Sanger sequencing. Potential biological functions of the gene variant were further investigated in the RKO colon cancer cell line. A novel nonsense variant (c.1114A>T, p.Lys372*) of BMPR1A was identified in the CRC family. This variant generated a PTC at the kinase domain and caused nonsense-mediated mRNA decay. Read-through inducing reagents G418 and PTC124 partially restored BMPR1A expression and its following signaling pathway. The identification of the novel BMPR1A variant enriched the genotype-phenotype spectrum of BMPR1A. Meanwhile, our finding also provided support for future PTC-targeting therapy for BMPR1A-mediated JPS and CRC.

Association of genetic polymorphism of glutathione S-transferases with colorectal cancer susceptibility in snuff (Naswar) addicts.

The current study aimed to investigate the relationship between polymorphisms in detoxifying (GSTM1, GSTT1, and GSTP1) genes and their association with colorectal cancer (CRC) in tobacco addicts of Pashtun ethnicity. Polymorphisms in the selected genes were genotyped in a case-control study consisting of 100 histologically confirmed male CRC patients and 100 birth-year and gender-matched healthy controls using the PCR-RFLP method. The GSTM1 null, and GSTT1 null genotypes were significantly contributed to the risk of CRC in the cases (OR= 3.131, 95% CI: 1.451-6.758, P = 0.004, and OR= 3.541, 95% CI: 1.716-7.306, P = 0.001, respectively), whereas the association observed for GSTP1 Val/Val (1.139, 95% CI: 0.356-3.644, P = 0.826) did not show statistical significance. The combined GSTM1 null and GSTT1 null showed a 41-fold increased risk (95% CI: 4.945-351.950, P = 0.001), while, the combined GSTM1 null and GSTP1 Ile/Val or Val/Val variant genotypes exhibited about 3-fold (95% CI: 1.196-7.414, P = 0.019) increased risk to CRC. Similarly, the combined GSTT1 null and GSTP1 Ile/Val or Val/Val variant genotypes showed about a 3-fold (95% CI: 1.285-8.101, P = 0.013) increased risk of CRC. In the combination of three GST genotypes, the GSTM1 null, GSTT1 null, and GSTP1 Ile/Val or Val/Val variant genotypes demonstrated a more than a 22-fold (95% CI: 2.441-212.106, P = 0.006) increased risk of CRC. Our findings suggest that GSTM1 and GSTT1 polymorphism and its combination with GSTP1 may be associated with CRC susceptibility in the Naswar addicted Pashtun population of Khyber Pakhtunkhwa, Pakistan.

Polymorphisms of CD44 rs187115 as a Predictive Biomarker in Early Colorectal Cancer Diagnostic.

Introduction: Colorectal cancer (CRC) has exhibited an increasing incidence worldwide in recent years, underscoring the importance of early diagnosis methods. This study aimed to assess the influence of CD44 gene polymorphism rs187115 on CRC susceptibility. Material and Methods: The study encompassed 470 CRC patients and 165 healthy controls. Genotyping of all biological blood samples was conducted using the TaqMan assay on the ABI 7500 Real Time PCR System (Applied Biosystems, USA). Results: The genotyping revealed that carriers of the variant G allele, including the genotypes AG and GG, exhibited a heightened risk of CRC occurrence, with an odds ratio (OR) of 1.89 (95% confidence interval [CI] = 1.57-1.97; p = 0.047) compared to those carrying the AA genotype. Conclusions: The findings underscore the potential utility of CD44 rs187115 polymorphisms as a novel predictive biomarker for CRC prognosis.

A GENOME-WIDE ASSOCIATION STUDY IN A ROMANIAN COLORECTAL CANCER COHORT IDENTIFIES GENETIC MARKERS ASSOCIATED WITH SUSCEPTIBILITY TO SARS-COV-2 INFECTIONS

Colorectal cancer ranks second in the incidence of cancer deaths worldwide. Our objectives are to identify genetic markers associated with colorectal cancer susceptibility using a genome-wide association study and to evaluate the identified genetic markers in the context of associated SARS-CoV-2 infections in the Romanian population. The study population consisted of 576 unrelated histopathologically confirmed colorectal cancer (CRC) cases and 1,069 controls consisting of patients admitted for medical conditions, excluding cancer. The DNA was extracted from buccal swab samples and analyzed by deCODE Genetics (Reykjavik, Iceland). We used the NHGRI catalog database to identify 85 unique variants from a systematic literature review for variants associated with CRC. Two of the tested variants in the Romanian GWAS reached genomewide significance (p-value lower than 5 × 10-8), but one of them did not match the other criteria. The top three markers were located on chr3, and the following two were located on chr2 and chr12, respectively. The Romanian GWAS results for CRC were compared to established markers linked to the measurement of COVID-19 symptoms. This allowed us to identify loci that may be useful in the future for assessing prognosis, treatment, and outcomes. We confirmed that established colorectal cancer SNPs are linked to colorectal cancer risk in the Romanian population while also examining the potential genetic connections between colorectal cancer predisposition and SARS-CoV-2 infection and symptoms.

The Variant Allele Frequency of CTLA-4 rs11571317 (-658 C/T) Polymorphism With Colorectal Cancer Susceptibility in the Saudi Population and Other Ethnic Groups.

The single nucleotide polymorphisms (SNPs) in the promoter region of the cytotoxic T-lymphocyte antigen-4 (CTLA-4) gene are directly associated with the progression and onset of various human cancers. These SNPs are important prognostic biomarkers for the prediction and early onset of cancer risk. The variant frequency of the CTLA-4 rs11571317 (-658 C/T) polymorphism may be affecting the various ethnic groups differently. In the present study, the allelic frequency distribution of -658 C/T polymorphism was assessed in the population of Saudi Arabia and compared with other world populations. The data from different cancers were extracted from case-control studies in the various ethnic groups by using PubMed (MEDLINE) and similar web databases. The frequency of CTLA-4 rs11571317 (-658 C/T) variant allele (T) was observed to be 25.5% and different frequencies were found significant for India (p = 0.001), USA (p = 0.03), and China (p = 0.04), when the prevalence of Saudi Arabian population was compared to that of other population groups. The current finding reveals that there is a distinct pattern of CTLA-4 rs11571317 (-658 C/T) polymorphism variant allele in the populations of Saudi Arabia, may be because of the differences in ethnicity. The observed findings can help in the assessment of the risk for the population harboring the risk allele of rs11571317 (-658 C/T) SNP and towardtheir subsequent susceptibility to cancer.

Assessment of HER1 (rs11543848) and HER2 (rs1136201) polymorphism and their association with colorectal cancer susceptibility in Khyber Pakhtunkhwa, Pakistan.

Colorectal cancer (CRC) is a widespread malignancy characterized by uncontrolled growth in the colon or rectum and remains a leading cause of cancer-related mortality globally. Various genes polymorphisms have been linked with the risk of CRC, but our study aimed to investigate the association between HER1 (rs11543848) and HER2 (rs1136201) polymorphisms with the risk of CRC in the Khyber Pakhtunkhwa (KPK) population of Pakistan. The association of the selected polymorphisms (rs11543848 and rs1136201) with CRC risk has been investigated in various ethnic groups, but their impact remains unexplored in Pakistan, particularly within the KPK population, highlighting the need of the study in this region. In this study 120 CRC patients and 120 healthy controls were enrolled. The DNA was extracted from the blood by salting-out method and genotyping was done using ARMS-PCR. Our investigations provided convincing evidence of a strong association between HER1 (rs11543848) and the risk of CRC. Both the genotypes heterozygous GA (OR = 2.07, CI = 1.18 to 3.64, P = 0.01) and homozygous AA (OR = 6.22, CI = 2.56 to 15.08, P = 0.0001) showed higher risk and significant association with the CRC risk. Similarly, heterozygous genotype AG of HER2 (rs1136201) was significantly associated (OR = 3.16, 95% CI = 1.78 to 5.58, P = 0.0001) while mutant genotype GG showed higher risk but non-significant association (OR = 3.23, 95% CI = 0.84 to 12.43, P = 0.08) with CRC patients. HER1 (rs11543848) demonstrated a significant association (P = 0.003) with the age at diagnosis in CRC patients, while HER2 (rs1136201) showed a non-significant association (P = 0.434). Both the SNPs were non-significantly associated with gender (P = 0.793 and 0.117), metastasis (P = 0.582 and 0.129), location of the tumor (P = 0.555 and 0.993), tumor grade (P = 0.290 and 0.920), tumor size (P = 0.535 and 0.289) and stages of cancer (P = 0.892 and 0.352). In conclusion, both the polymorphisms rs11543848 and rs1136201 displayed susceptibility with CRC in the KPK population. However, further investigations are recommended while using whole exome sequencing on a larger sample size for more precise results.

Association study for the role of MMP8 gene polymorphisms in Colorectal cancer susceptibility

BackgroundColorectal cancer (CRC) is one of the most common malignant tumors, influenced by several genetic loci in its clinical phenotypes. The aim of this study was to determine the relationship between the MMP8 gene polymorphism and CRC risk in the Chinese Han population.MethodThis study recruited 688 CRC patients and 690 healthy controls. The relationship between MMP8 polymorphism and CRC susceptibility was assessed by calculating the odds ratio (OR) and 95% confidence interval (CI) after stratifying by age, gender, body mass index (BMI), smoking, and alcohol consumption under a multi-genetic model.ResultsMMP8 rs3740938 was associated with increased CRC predisposition (p = 0.016, OR = 1.24, 95% CI: 1.04–1.48), and this association was detected particularly in subjects aged > 60 years, females, people with BMI > 24 kg/m2, smokers, and drinkers. Moreover, rs3740938 was found to be associated with the pathological type of rectal cancer.ConclusionsOur results first displayed that rs3740938 in MMP8 was a risk factor for CRC predisposition. This finding may provide a new biological perspective for understanding the role of the MMP8 gene in CRC pathogenesis.

High Norepinephrine State Induces Growth of Colorectal Cancer Cells via ADP-Ribosyltransferase 1 in Type 2 Diabetes Mellitus.

Patients with type 2 diabetes mellitus have a higher susceptibility for colorectal cancer and poorer prognosis, but the mechanism is still unknown. Here, we investigated the effect of ADP-ribosyltransferase 1 (ART1) on the growth of colorectal cancer in an animal model of diabetes with high norepinephrine status, as well as the potential mechanism. We evaluated the size and weight of transplanted CT26 cell tumors with different ART1 expression levels in a mouse model of diabetes, as well as the survival time. CCK8 and flow cytometry were used to evaluate the growth of CT26 cells in vitro. Western blot was performed to analyze differentially expressed proteins in the ART1-modulated pathway. High levels of norepinephrine and ART1 favored the proliferation of CT26 cells in vitro and in vivo. Moreover, inhibition of norepinephrine-dependent proliferation was observed in ART1-silenced CT26 cells compared to those with normal ART1 expression. Following reduction of the serum norepinephrine level by surgery, the size and weight of transplanted CT26 cell tumors was significantly reduced compared to non-operated and sham-operated mice. Furthermore, the expression of ART1, mTOR, STAT3, and p-AKT protein in the tumor tissue of diabetic mice was higher than in non-diabetic mice. Following reduction of the norepinephrine level by renal denervation (RD), expression of the proliferation-related proteins mTOR, STAT3, p-AKT protein decreased, but no change was seen for ART1 expression. At the same concentration of norepinephrine, ART1 induced the expression of p-AKT, mTOR, STAT3, CyclinD1 and c-myc in CT26 cells in vitro. We conclude that faster growth of colorectal cancer in high norepinephrine conditions requires the expression of ART1, and that high ART1 expression may be a novel target for the treatment of diabetes-associated colorectal cancer.

Genetic variants in hypoxia-inducible factor pathway are associated with colorectal cancer risk and immune infiltration.

Hypoxia-inducible factor (HIF) pathway genes influence tumorigenesis and immune status. However, the associations between genetic variants in hypoxia-related genes and colorectal cancer risk and the immune status of hypoxia-associated genes in colorectal cancer have not been systematically characterized. The associations between genetic variants and colorectal cancer risk were evaluated in Chinese, Japanese and European populations using logistic regression analysis. The relationships between target genes and tumour immune infiltration were predicted by Tumour Immune Estimation Resource (TIMER). We found that rs34533650 in EPAS1 was associated with colorectal cancer risk (OR = 1.43, 95% CI = 1.20-1.70, P(FDR) = 8.35 × 10-4 ), and this finding was validated in two independent populations (Japanese: OR = 1.07, 95% CI = 1.01-1.15, p = 3.38 × 10-2 ; European: OR = 1.11, 95% CI = 1.03-1.19, p = 6.04 × 10-3 ). EPAS1-associated genes were enriched in immune-related pathways. In addition, we found that EPAS1 copy number variation (CNV) was associated with the degree of infiltration of immune cells and observed correlations between EPAS1 expression and immune cell infiltration levels in colorectal cancer. These results highlight that genetic variants of hypoxia-related genes play roles in colorectal cancer risk and provide new insight that EPAS1 might be a promising predictor of colorectal cancer susceptibility and immune status.

SMAD7 gene polymorphisms and their influence on patients with colorectal cancer

ABSTRACT Colorectal cancer (CRC) is a prevalent malignant tumor, and its pathogenesis is still not fully understood. Studies have shown that SMAD7 gene polymorphisms can affect CRC susceptibility, but the results have been inconsistent and require additional confirmation. Our study aimed to evaluate the effect of SMAD7 variants on the risk of CRC in the Chinese Han population. A total of five single nucleotide polymorphisms (SNPs) in SMAD7 were genotyped among 696 CRC patients and 696 healthy participants using the MassARRAY iPLEX platform. SNPs were evaluated for their associations with CRC using logistic regression analysis under multiple genetic models. The false-positive report probability (FPRP) analysis was used to validate the positive findings. Our study indicated that rs11874392 showed an increased association with CRC risk (odds ratio, 1.31; 95% confidence interval, 1.04–1.67; p = 0.024). Stratified analysis showed that rs11874392 might increase the risk of CRC in females (OR = 1.70, p = 0.028), individuals with smoking (OR = 1.87, p = 0.026), and drinking (OR = 1.38, p = 0.027). The rs11874392 was found to be related to an elevated risk of rectal cancer (OR = 1.73, p = 0.003), but not with colon cancer. FPRP analysis demonstrated that all of these associations were statistically significant (FPRP <0.2). Additionally, rs11874392 was the strongest predictive model for CRC. This study provides evidence that the SMAD7 rs11874392 is related to an increased susceptibility to CRC.

Assessing the Feasibility of a Faith-Based Colorectal Cancer Education and Screening Intervention for Latino Men in Pennsylvania.

Introduction: Limited health knowledge, literacy, engagement in preventive health services, participation in health promotion behaviors, and cultural factors place Latino men at high risk for colorectal cancer (CRC). This pilot study aimed to determine the feasibility and acceptability of a faith-based cancer education intervention focusing on Latino men between 45 and 74 years old. Methods: This pilot study used a single group pre- and post-intervention research design to compare changes in knowledge, perceived benefit of screening, perceived susceptibility and severity of CRC, and the completion of CRC screening after the intervention. Results: In this study, Latino men were willing to participate in a CRC educational intervention supported by a faith-based institution. The participants had limited knowledge about CRC, yet most recognized that screening is beneficial and that getting CRC is serious. Sixty percent of the participants completed the fecal immunochemical screening test, which showed that the intervention impacted the screening uptake among this group. Conclusion: The findings of this study support the further development of faith-based interventions focusing on Latino men.

Cis-vaccinic acid, Dibutyl-Cyanamide and 9, 12-Octadecadienoic acid from pistachio (Pistachia vera) seed coat (PSCE) induced nuclear damage and cytotoxicity in human colon cancer HT-115 cells

Current strategy for colorectal cancer (CRC) therapy like regular intake of non-steroidal anti-inflammatory drugs (NSAIDs) may reduce the risk of developing CRC but they induce the regression of adenomas. Even the CRC management technique include colectomy, have not yet been proven to reduce mortality. The present study aimed to reduce the susceptibility of CRC via controlling cellular oxidative stress, inflammation and caspase depended apoptosis in HT-115 human colorectal cancer cells using pistachio seed coat extract as nutritional therapy. Increasing concentrations of pistachio seed coat ethyl acetate extract (PSCE) were applied to HT-115 cells, which were incubated for 24 h and 48 h. The IC50 values were 14 mg/dl after 24 h, and and 7.5 mg/dl after 48 h. Acridine orange/ ethidium bromide staining confirmed the presence of 32% early apoptotic, 27% pre-apoptotic, 12% apoptotic, and 6% necrotic cells after 48 h. PSCE at 14 mg/dl significantly increased the antioxidant capacity via the expression of CYP1A and GSK3β, and decreased inflammatory agents via decreasing NF-κb, TNF-α, COX-2 and PGE-2 expression three-fold after 48 h. The expression of the tumor suppression related genes p53 and mdm2, and the apoptosis related genes Bax, Bcl-2, Caspase 3, p21, and PCNA levels increased one-fold, and levels of mdm2, Bcl-2 and PCNA decreased after PME treatment of 48 h. PSCE effectively controlled colon cancer cell proliferation via the caspase-dependent mitochondrial mediated apoptotic pathway.&#x0D; Keywords: Pistachia vera, cytotoxicity, human colon cancer, Cis-Vaccininc acid, apoptosis

Identification and characterization of colorectal-cancer-associated SNPs on the SMAD7 locus.

Genome-wide association studies have identified SMAD7 as a colorectal cancer (CRC) susceptibility gene. However, its underlying mechanism has not yet been characterized. This study screened functional SNPs (fSNPs) related to colorectal cancer through Reel-seq and obtained regulatory proteins on functional SNPs. The candidate fSNPs on the SMAD7 locus were screened by Reel-seq method. Eight SNPs such as rs8085824 were identified as functional SNPs by luciferase reporter assay and EMSA, SDCP-MS and AIDP-WB revealed that HNRNPK can specifically bind to the rs8085824-C allele. The knockdown of HNRNPK by RNAi proved that HNRNPK could affect cell function by regulating SMAD7. Eight functional SNPs was found on the SMAD7 locus in linkage disequilibrium (LD) with R2 > 0.8, i.e., rs12953717, rs7227023, rs34007497, rs58920878, rs8085824, rs4991143, rs4939826, and rs7227023. We also identified allele-imbalanced binding of HNRNPK to rs8085824, H1-3 to rs12953717, THOC6 to rs7227023, and DDX21 to rs58920878. Further functional analysis revealed that these proteins are the regulatory proteins that modulate the expression of SMAD7 in the human colorectal cancer cell line DLD1. In particular, we discovered that siRNA knockdown of HNRNPK inhibits cell proliferation and cell clonal formation by downregulating SMAD7, as the decreased cell proliferation and cell clonal formation in the siRNA HNRNPK knockdown cells was restored by SMAD7 overexpression. Our findings reveal a mechanism which underlies the contribution of the fSNP rs8085824 on the SMD7 locus to CRC susceptibility.

TCF21 rs2327429 and TCF21 rs12190287 are associated with colorectal cancer in a Chinese population.

Aims: TCF21 is considereda tumor suppressor gene. This work was designed to explore the associations between TCF21 polymorphisms and colorectal cancer (CRC) susceptibility. Methods: A case-control study was designed with 421patients with CRCand 469 non-CRC controls. Six tagging single-nucleotide polymorphisms (rs2327429 T>C, rs2327430 T>C, rs2327433 A>G, rs12190287 C>G, rs7766238 G>A andrs4896011 T>A) were genotyped byligase detection reaction of PCR. Results: TCF21 rs2327429 and rs12190287 polymorphisms were associated with CRC susceptibility in aChinese Han population. Conclusion: rs2327429 and rs12190287 polymorphisms may be predictive ofCRC susceptibility in Chinese Han populations.

The association of TP53 (Arg72Pro) rs1042522 C&gt;G polymorphism and colorectal cancer susceptibility in Duhok individuals

The association of TP53 (Arg72Pro) rs1042522 C&gt;G polymorphism and colorectal cancer susceptibility in Duhok individuals

Novel insights into genetic susceptibility for colorectal cancer from transcriptome-wide association and functional investigation.

Transcriptome-wide association studies have been successful in identifying candidate susceptibility genes for colorectal cancer (CRC). To strengthen susceptibility gene discovery, we conducted a large transcriptome-wide association study and an alternative splicing transcriptome-wide association study in CRC using improved genetic prediction models and performed in-depth functional investigations. We analyzed RNA-sequencing data from normal colon tissues and genotype data from 423 European descendants to build genetic prediction models of gene expression and alternative splicing and evaluated model performance using independent RNA-sequencing data from normal colon tissues of the Genotype-Tissue Expression Project. We applied the verified models to genome-wide association studies (GWAS) summary statistics among 58 131 CRC cases and 67 347 controls of European ancestry to evaluate associations of genetically predicted gene expression and alternative splicing with CRC risk. We performed in vitro functional assays for 3 selected genes in multiple CRC cell lines. We identified 57 putative CRC susceptibility genes, which included the 48 genes from transcriptome-wide association studies and 15 genes from splicing transcriptome-wide association studies, at a Bonferroni-corrected P value less than .05. Of these, 16 genes were not previously implicated in CRC susceptibility, including a gene PDE7B (6q23.3) at locus previously not reported by CRC GWAS. Gene knockdown experiments confirmed the oncogenic roles for 2 unreported genes, TRPS1 and METRNL, and a recently reported gene, C14orf166. This study discovered new putative susceptibility genes of CRC and provided novel insights into the biological mechanisms underlying CRC development.

Association of miR-149 T>C and miR-196a2 C>T Polymorphisms with Colorectal Cancer Susceptibility: A Case-Control Study.

The principal aim of the current study was to investigate the relationship between miR-149 T>C (rs2292832) and miR-196a2 C>T (rs11614913) small non-coding RNA polymorphisms and the risk of developing CRC in the Azerbaijani population. The study included 120 patients diagnosed with CRC and 125 healthy individuals. Peripheral blood samples were collected from all the subjects in EDTA tubes and DNA extraction was performed by salting out. Polymorphisms were determined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. While comparing without gender distinction no statistical correlation was found between the heterozygous TC (OR = 0.66; 95% CI = 0.37-1.15; p = 0.142), mutant CC (OR = 1.23; 95% CI = 0.62-2.45; p = 0.550), and mutant C (OR = 1.03; 95% CI = 0.72-1.49; p = 0.859) alleles of the miR-149 gene and the CT (OR = 1.23; 95% CI = 0.69-2.20; p = 0.485), mutant TT (OR = 1.29; 95% CI = 0.67-2.47; p = 0.452), and mutant T (OR = 1.17; 95% CI = 0.82-1.67; p = 0.388) alleles of the miR-196a2 gene and the risk of CRC. However, among women, miR-149 TC (OR = 0.43; 95% CI = 0.19-1.01; p = 0.048) correlated with a reduced risk of CRC, whereas miR-196a2 CT (OR = 2.77; 95% CI = 1.13-6.79; p = 0.025) correlated with an increased risk of CRC. Our findings indicated that miR-149 T>C (rs2292832) might play a protective role in the development of CRC in female patients, whereas the miR-196a2 (rs11614913) polymorphism is associated with an increased risk of CRC in women in the Azerbaijani population, highlighting the importance of gender dimorphism in cancer etiology.

Functional analysis of CTLA4 promoter variant and its possible implication in colorectal cancer immunotherapy.

Colorectal cancer (CRC) is a prevalent cancer, ranking as the third most common. Recent advances in our understanding of the molecular causes of this disease have highlighted the crucial role of tumor immune evasion in its initiation and progression. CTLA4, a receptor that acts as a negative regulator of T cell responses, plays a pivotal role in this process, and genetic variations in CTLA4 have been linked to CRC susceptibility, prognosis, and response to therapy. We conducted a case-control study involving 98 CRC patients and 424 controls. We genotyped the CTLA4 c.-319C > T variant (rs5742909) and performed an association analysis by comparing allele frequencies between the patients and controls. To assess the potential functional impact of this variant, we first performed an In Silico analysis of transcription factor binding sites using Genomatix. Finally, to validate our findings, we conducted a luciferase reporter gene assay using different cell lines and an electrophoretic mobility shift assay (EMSA). The case-control association analysis revealed a significant association between CTLA4 c.-319C > T and CRC susceptibility (p = 0.023; OR 1.89; 95% CI = 1.11-3.23). Genomatix analysis identified LEF1 and TCF7 transcription factors as specific binders to CTLA4 c.-319C. The reporter gene assay demonstrated notable differences in luciferase activity between the c.-319 C and T alleles in COS-7, HCT116, and Jurkat cell lines. EMSA analysis showed differences in TCF7 interaction with the CTLA4 C and T alleles. CTLA4 c.-319C > T is associated with CRC susceptibility. Based on our functional validation results, we proposed that CTLA4 c.-319C > T alters gene expression at the transcriptional level, triggering a stronger negative regulation of T-cells and immune tumoral evasion.