Influence of polymorphisms in the Wnt/β-catenin pathway genes on hepatocellular carcinoma risk in a Chinese Han population

Associations Between Single Nucleotide Polymorphisms of Hypoxia-Related Genes and Capsule Formation in Hepatocellular Carcinoma

Purpose

Tumor capsule is an independent prognostic factor for patients with hepatocellular carcinoma (HCC) and used increasingly to guide clinical decision-making. Considering the genetic complexity for capsule formation and its potential association with hypoxia, the significance of the polymorphisms of hypoxia-related genes in capsule formation and HCC prognosis remains to be elucidated.

Patients and Methods

Peripheral blood samples from HCC patients were collected in this study. Single nucleotide polymorphism (SNP) genotyping was conducted by the iPLEX chemistry on a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (Sequenom, Inc.). The demographic and clinical data for the patients were obtained through medical chart review and/or consultation with the treating physicians. SPSS 25.0, R 4.1.1, and PLINK toolset were used to perform statistical analysis.

Results

A total of 183 patients were enrolled, including 88 patients assigned to the capsule group and 95 to the non-capsule group. SLC2A1 rs841858 T allele, SLC2A1 rs2297977 T allele, STAT1 rs1547550 C allele, and STAT1 rs34997637 G allele were associated with significantly increased risk of capsule formation. The genotypes of SLC2A1 rs841858, SLC2A1 rs2297977, STAT1 rs34997637, and STAT1 rs1914408 were significantly associated with the formation of HCC capsule. The polymorphisms of STAT1 rs2066802, STAT1 rs12693591, and HIF1A rs2057482 showed close relationship with the prognosis of HCC patients in the capsule group, while the genotype distributions of CTNNB1 rs4135385, IFNG rs1861494, and SERPINE1 rs2227631 were closely related to the survival of patients in the non-capsule group. Further haplotype analysis suggested that SLC2A1 block 1 and STAT1 block 2 were related to the susceptibility of HCC capsule.

Conclusion

The polymorphisms of the hypoxia-related genes (HIF1A, SERPINE1, IFNG, STAT1, CTNNB1, and SLC2A1) were correlated with the formation of HCC capsule. Several SNPs in these genes also showed association with HCC prognosis except SLC2A1. Further functional studies are warranted to explore the underlying mechanisms.

CTNNB1 polymorphism (rs121913407) in circulating tumor DNA (ctDNA) in Egyptian hepatocellular carcinoma patients

Background

Hepatocellular carcinoma (HCC) represents the sixth most common cancer worldwide and the fourth in Egypt. Persistent inflammation and specific somatic mutations in driving genes play a major role in the development of HCC. One of these somatic mutations is CTNNB1 mutations with subsequent activation of β-catenin in HCC, associated with a risk of malignant transformation. In this study, we investigate the clinical utility of peripheral blood circulating tumor DNA (ctDNA) CTNNB1 (rs121913407) in HCC patients compared to pathological chronic hepatitis C virus (HCV) patients and healthy controls.

Methods

Our study is a case-control study at the Ain Shams Centre for Organ Transplantation, Ain Shams University Hospitals, enrolling twenty-eight adult HCC patients (twelve early HCC patients and sixteen advanced HCC patients), ten patients with chronic hepatitis C as a disease control group, and ten healthy controls. We collected plasma and stored at −80 °C. We detected mutations in the gene locus CTNNB1 rs121913407 by real-time PCR.

Results

All of our studied cases (early and advanced HCC) in addition to HCV and healthy control groups were CTNNB1 wild (TT) genotype. There was statistical significant difference between early and late cases of HCC as regards AFP and AST.

Conclusions

None of our recruited subjects showed CTNNB1 rs121913407 gene mutation. Further studies on larger number of patients are needed to clarify and confirm the clinical utility of CTNNB1 single-nucleotide polymorphism in the pathogenesis of HCC related to HCV in Egyptian population.

Investigation of CTNNB1 gene mutations and expression in hepatocellular carcinoma and cirrhosis in association with hepatitis B virus infection

Hepatitis B virus (HBV), along with Hepatitis C virus chronic infection, represents a major risk factor for hepatocellular carcinoma (HCC) development. However, molecular mechanisms involved in the development of HCC are not yet completely understood. Recent studies have indicated that mutations in CTNNB1 gene encoding for β-catenin protein lead to aberrant activation of the Wnt/ β-catenin pathway. The mutations in turn activate several downstream genes, including c-Myc, promoting the neoplastic process. The present study evaluated the mutational profile of the CTNNB1 gene and expression levels of CTNNB1 and c-Myc genes in HBV-related HCC, as well as in cirrhotic and control tissues. Mutational analysis of the β-catenin gene and HBV genotyping were conducted by direct sequencing. Expression of β-catenin and c-Myc genes was assessed using real-time PCR. Among the HCC cases, 18.1% showed missense point mutation in exon 3 of CTNNB1, more frequently in codons 32, 33, 38 and 45. The frequency of mutation in the hotspots of exon 3 was significantly higher in non-viral HCCs (29.4%) rather than HBV-related cases (12.7%, P = 0.021). The expression of β-catenin and c-Myc genes was found upregulated in cirrhotic tissues in association with HBV infection. Mutations at both phosphorylation and neighboring sites were associated with increased activity of the Wnt pathway. The results demonstrated that mutated β-catenin caused activation of the Wnt pathway, but the rate of CTNNB1 gene mutations was not related to HBV infection. HBV factors may deregulate the Wnt pathway by causing epigenetic alterations in the HBV-related HCC.

Variations in the Wnt/β-Catenin Pathway Key Genes as Predictors of Cervical Cancer Susceptibility

Background

Cervical cancer is the fourth most common and fatal tumor among women worldwide. The Wnt/β-catenin signaling pathway was etiologically involved in the cervical cancer model. Herein, we aimed to investigate whether germline genetic variations within the Wnt/β-catenin pathway can be genetic risk factors of cervical cancer.

Patients and Methods

A total of 305 samples (147 patients, 158 controls) were included. Eight genetic variations located in APC (rs454886), GSK3β (rs3755557), CTNNB1 (rs11564475, rs1798802, rs3864004, rs2293303, and rs4135385), and TCF7L2 (rs7903146) were genotyped via Sanger sequencing. The χ² test and non-conditional logistic regression were used in the single-locus analysis. Gene–gene interactions and haplotype construction in case–control samples were performed by the GMDR method and Haploview software, respectively.

Results

The frequency of CTNNB1 rs1798802 GA+AA genotype was significantly lower in cervical cancer patients adjusted for age (OR=0.626, 95% CI=0.398–0.984). The mutant alleles of rs3864004 (A) and rs2293303 (T) located in CTNNB1 showed 1.513 (1.038–2.207), and 1.654 (1.020–2.683) fold increased risk of cervical cancer, respectively. Haplotype analysis showed no association between haplotypes of the CTNNB1 gene and cervical cancer risk. No significant contribution of interactions among genes in the Wnt pathway was identified.

Conclusion

We concluded that the genetic variants in the CTNNB1 gene might contribute to the development of cervical cancer.

Apoptotic protease activating factor-1 negatively regulates Wnt signaling in hepatocellular carcinoma

The current study aims to evaluate the mechanism of apoptotic protease activating factor-1 (Apaf-1) in hepatocellular carcinoma (HCC) cells by verifying the regulation of the wnt/beta-catenin signaling pathway via Apal-1. Our data showed that transfection with Ad-Apaf-1 could inhibit the activity of a lymphoid enhancer factor (LEF) luciferase plasmid activated by β-catenin. Overexpressing Apaf-1 could suppress the β-catenin-induced LEF luciferase activity in a dose-dependent manner. Western blot assays demonstrated that the overexpression of Apaf1 significantly suppressed the expression of Wnt/β-catenin signaling-related proteins. Further study demonstrated that Apaf-1 suppressed HepG2 cell migration, invasion, and viability. Knocking down the expression of Apaf-1 activated the wnt/β-catenin pathway in HepG2 cells. In contrast, silencing β-catenin decreased the activation of wnt/β-catenin, even in the presence of si-Apaf-1. Cell cycle distribution analysis demonstrated a decrease in the number of cells in the G0/G1 phase in the Apaf-1 silencing group. In contrast, knocking down the expression of β-catenin increased the number of cells in the G0/G1 phase, even in the presence of si-Apaf-1. In summary, the Apaf-1-mediated suppression of HepG2 cell malignancy is achieved by inhibiting the wnt/β-catenin pathway.