Associations between three XRCC1 polymorphisms and hepatocellular carcinoma risk: A meta-analysis of case-control studies

Association of XRCC1 p. Arg194Trp gene polymorphism with the risk of hepatocellular carcinoma in HCV Egyptian population: A pilot case-control study

Background: Hepatocellular carcinoma (HCC) is the most common and fatal primary liver cancer. Genetic variants of DNA repair systems can reduce DNA repair capability and increase HCC risk. Objectives: This study aimed to examine, in Egyptian hepatitis C virus (HCV) patients, the relationship between the X-ray repair cross-complementing group 1 (XRCC1) rs1799782 single nucleotide polymorphism (SNP) and HCC susceptibility. Methods: We included 100 adult HCV-positive patients with HCC and 100 adult HCV-positive patients with liver cirrhosis as pathological controls. XRCC1 rs1799782 SNP genotyping was done in both groups using quantitative real-time PCR (qPCR). The distribution of genotypes in patients and controls was compared using several inheritance models. Results: We found that the CT genotype, when analyzed under both the co-dominant (OR (95 % CI): 2.147 (1.184-3.893), p = .012) and the over-dominant (OR (95 % CI): 2.055 (1.153-3.660), p = .015) models, as well as the combined CT and TT genotypes under the dominant model (OR (95 % CI) of 1.991 (1.133-3.497), p = .017), were associated with increased susceptibility to HCC. The frequency of the T allele was higher among HCC participants (32%) compared to those with cirrhosis (23.5%) and carrying the T allele increased the risk of HCC by 1.532 times, however, these associations did not reach statistical significance (p-values >0.05). Moreover, the variant T allele was associated with worse clinical manifestations and laboratory results among the HCC group, but AFP levels were not affected significantly. Conclusions: Egyptians with XRCC1 rs1799782 SNP may have a higher risk of HCV-related HCC. More extensive multi-center prospective investigations must confirm this association.

The critical role of circular RNAs in drug resistance in gastrointestinal cancers

Nowadays, drug resistance (DR) in gastrointestinal (GI) cancers, as the main reason for cancer-related mortality worldwide, has become a serious problem in the management of patients. Several mechanisms have been proposed for resistance to anticancer drugs, including altered transport and metabolism of drugs, mutation of drug targets, altered DNA repair system, inhibited apoptosis and autophagy, cancer stem cells, tumor heterogeneity, and epithelial-mesenchymal transition. Compelling evidence has revealed that genetic and epigenetic factors are strongly linked to DR. Non-coding RNA (ncRNA) interferences are the most crucial epigenetic alterations explored so far, and among these ncRNAs, circular RNAs (circRNAs) are the most emerging members known to have unique properties. Due to the absence of 5' and 3' ends in these novel RNAs, the two ends are covalently bonded together and are generated from pre-mRNA in a process known as back-splicing, which makes them more stable than other RNAs. As far as the unique structure and function of circRNAs is concerned, they are implicated in proliferation, migration, invasion, angiogenesis, metastasis, and DR. A clear understanding of the molecular mechanisms responsible for circRNAs-mediated DR in the GI cancers will open a new window to the management of GI cancers. Hence, in the present review, we will describe briefly the biogenesis, multiple features, and different biological functions of circRNAs. Then, we will summarize current mechanisms of DR, and finally, discuss molecular mechanisms through which circRNAs regulate DR development in esophageal cancer, pancreatic cancer, gastric cancer, colorectal cancer, and hepatocellular carcinoma.

Genetic polymorphisms in DNA repair genes and hepatocellular carcinoma risk

Hepatocellular carcinoma (HCC) is one of the most frequent types of tumors worldwide. Its occurrence and development have been related to various risk factors, such as chronic infection with hepatitis B or C viruses and alcohol addiction. DNA repair systems play a critical role in maintaining the integrity of the genome. Defects in these systems have been related to increased susceptibility to various types of cancer. Multiple genetic polymorphisms in genes of DNA repair systems have been reported that may affect DNA repair capacity (DRC) and modulate risk to cancer. Several studies have been conducted to assess the role of polymorphisms of DNA repair genes on the HCC risk. Identifying these polymorphisms and their association with HCC risk may help to improve prevention and treatment strategies. In this study, we review investigations that evaluated the association between genetic polymorphisms of DNA repair genes and risk of HCC.

Identification of Ten Core Hub Genes as Potential Biomarkers and Treatment Target for Hepatoblastoma

Background

This study aimed to systematically investigate gene signatures for hepatoblastoma (HB) and identify potential biomarkers for its diagnosis and treatment.

Materials and Methods

GSE131329 and GSE81928 were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between hepatoblastoma and normal samples were identified using the Limma package in R. Then, the similarity of network traits between two sets of genes was analyzed by weighted gene correlation network analysis (WGCNA). Cytoscape was used to visualize and select hub genes. PPI network of hub genes was construed by Cytoscape. GO enrichment and KEGG pathway analyses of hub genes were carried out using ClueGO. The random forest classifier was constructed based on the hub genes using the GSE131329 dataset as the training set, and its reliability was validated using the GSE81928 dataset. The resulting core hub genes were combined with the InnateDB database to identify the innate core genes.

Results

A total of 4244 DEGs in HB were identified. WGCNA identified four modules that were significantly correlated with the disease status. A total of 114 hub genes were obtained within the top 20 genes of each node rank. 6982 relation pairs and 3700 nodes were contained in the PPI network of 114 hub genes. GO enrichment and KEGG pathway analyses of hub genes were focused on MAPK, cell cycle, p53, and other crucial pathways involved in HB. A random forest classifier was constructed using the 114 hub genes as feature genes, resulting in a 95.5% true positive rate when classifying HB and normal samples. A total of 35 core hub genes were obtained through the mean decrease in accuracy and mean decrease Gini of the random forest model. The classification efficiency of the random forest model was 81.4%. Finally, CDK1, TOP2A, ADRA1A, FANCI, XRCC1, TPX2, CCNB2, CDK4, GLYATL1, and CFHR3 were identified by cross-comparison with the InnateDB database.

Conclusion

Our study established a random forest classifier that identified 10 core genes in HB. These findings may be beneficial for the diagnosis, prediction, and targeted therapy of HB.

Comprehensive analysis of the correlation between base-excision repair gene SNPs and esophageal squamous cell carcinoma risk in a Chinese Han population

This study sought to assess the relationship between single nucleotide polymorphisms (SNPs) affecting DNA base-excision repair (BER) genes and esophageal squamous cell carcinoma (ESCC) risk in a Han Chinese population. Genes screened for such SNPs included 8-oxoguanine DNA glycosylase (OGG1), apurinic/apyrimidinic endonuclease 1 (APE1) and X-ray repair cross-complementing group 1 protein (XRCC1). Blood samples that had been collected in a prospective manner were used for DNA extraction, with all DNA samples then being subjected to PCR-restriction fragment length polymorphism genotyping for BER gene SNPs, including APE1 Asp148Glu and -141T/G, OGG1 Ser326Cys, and XRCC1 Arg399Gln. The relationship between these SNPs and ESCC risk was then assessed, with the comparability of the case and control groups being enhanced via propensity score matching (PSM). This study initially included 642 healthy controls and 321 ESCC patients, with PSM optimization leading to a final analyzed total of 311 matched subjects per group (311 total). Factors associated with elevated ESCC risk in this analysis included advanced age, being male and smoking. We further identified that the XRCC1 399 Gln/Gln genotype was associated with a significant reduction in ESCC risk prior to propensity matching (odds ratio=0.48; 95% CI: 0.23-1.00; P<0.05), although this did not remain true following matching. For the remaining analyzed SNPs, no significant associations between genotype and ESCC risk were detected prior to or following propensity matching. A multivariate analysis incorporating patient age, sex, smoking status and drinking status failed to detect any relationship between the four tested genotypes and ESCC risk. In conclusion, being male, a smoker or of advanced age was associated with an elevated ESCC risk. However, we did not detect any significant relationship between ESCC risk and BER polymorphisms in XRCC1, OGG1, APE1 or the APE1 promoter region in a Han Chinese population.

Molecular Bases of Drug Resistance in Hepatocellular Carcinoma

The poor outcome of patients with non-surgically removable advanced hepatocellular carcinoma (HCC), the most frequent type of primary liver cancer, is mainly due to the high refractoriness of this aggressive tumor to classical chemotherapy. Novel pharmacological approaches based on the use of inhibitors of tyrosine kinases (TKIs), mainly sorafenib and regorafenib, have provided only a modest prolongation of the overall survival in these HCC patients. The present review is an update of the available information regarding our understanding of the molecular bases of mechanisms of chemoresistance (MOC) with a significant impact on the response of HCC to existing pharmacological tools, which include classical chemotherapeutic agents, TKIs and novel immune-sensitizing strategies. Many of the more than one hundred genes involved in seven MOC have been identified as potential biomarkers to predict the failure of treatment, as well as druggable targets to develop novel strategies aimed at increasing the sensitivity of HCC to pharmacological treatments.