Association of complement components with risk of colorectal cancer: A systematic review and meta-analysis.

BACKGROUND: Complement components could contribute to the tumor microenvironment and the systemic immune response. Nevertheless, their role in colorectal cancer (CRC) remains a contentious subject. AIM: To elucidate the relationship between complement components and CRC risk and clinical characteristics. METHODS: Searches were conducted in PubMed, the Cochrane Library, and the China National Knowledge Infrastructure database until June 1, 2023. We included cohort studies encompassing participants aged ≥ 18 years, investigating the association between complement components and CRC. The studies were of moderate quality or above, as determined by the Agency for Healthcare Research and Quality. The meta-analysis employed fixed-effects or random-effects models based on the I² test, utilizing risk ratio (RR) and their corresponding 95% confidence interval (CI) for outcomes. Sensitivity and subgroup analyses were performed to validate the robustness of the collective estimates and identify the source of heterogeneity. RESULTS: Data from 15 studies, comprising 1631 participants that met the inclusion criteria, were included in the meta-analysis. Our findings indicated that protein levels of cluster of differentiation 46 (CD46) (RR = 3.66, 95%CI: 1.75-7.64, P < 0.001), CD59 (RR = 2.86, 95%CI: 1.36-6.01, P = 0.005), and component 1 (C1) (RR = 5.88, 95%CI: 1.75-19.73, P = 0.004) and serum levels of C3 (standardized mean difference = 1.82, 95%CI: 0.06-3.58, P = 0.040) were significantly elevated in patients with CRC compared to healthy controls. Strong expression of CD55 or CD59 was associated with a higher incidence of lymph node metastasis, whereas strong CD46 expression correlated with a higher incidence of tumor differentiation compared to low CD46 expression (P < 0.05 for all). Although specific pooled results demonstrated notable heterogeneity, subgroup analyses pointed to regional differences as the primary source of inconsistency among the studies. CONCLUSION: Our analysis underscores that increased levels of specific complement components are associated with a heightened risk of CRC, emphasizing the potential significance of monitoring elevated complement component levels.

Role and mechanism of circ-PRKCI in hepatocellular carcinoma.

BACKGROUND: The circular RNA circ-PRKCI is an endogenous non-coding RNA that forms a covalently closed ring after reverse splicing, which plays a key role in the occurrence and development of multiple digestive system tumors. AIM: To investigate the role and mechanism of circ-PRKCI in the occurrence and development of hepatocellular carcinoma (HCC). METHODS: This study used real-time polymerase chain reaction to detect the expression of circ-PRKCI in tumor tissues, tumor adjacent tissues, and blood in patients with HCC and other digestive system tumor cells. A series of functional tests were performed to explore whether circ-PRKCI affects the growth of HCC cells and what is its mechanism in HCC. Meanwhile, fluorescence in situ hybridization was used to detect the subcellular localization of circ-PRKCI. Survival analysis was performed to predict the correlation between circ-PRKCI and the prognosis of HCC. Chi-square test and t-test were performed for statistical analyses. RESULTS: The level of circ-PRKCI was significantly higher in HCC tissues than in tumor adjacent tissues, and in HCC cell lines than in cells lines of esophageal, liver, stomach, and colon cancers. A series of functional tests showed that circ-PRKCI substantially inhibited cell apoptosis and promoted cell invasion. It was found that circ-PRKCI can act as the sponge of miRNA-545 to reduce the expression of AKT3 protein. Moreover, the result of survival analysis showed that circ-PRKCI target gene E2F7 can reduce liver cancer patients' survival rate. And clinical data suggested that the distribution of circ-PRKCI rose with the depth of invasion, lymph node metastasis, distant metastasis, and TNM stage, indicating that circ-PRKCI may affect the survival and prognosis of patients with HCC by regulating E2E7. CONCLUSION: This study explores the role and mechanism of circ-PRKCI in HCC, which provides a new research direction and theoretical basis for the treatment of HCC.

[Association between LMP2/LMP7 gene polymorphism and the infection of hepatitis B virus].

OBJECTIVE: To elucidate whether the antigen-processing gene (LMP2/LMP7) polymorphisms could influence the infection of hepatitis B virus. METHODS: Genomic DNA of 176 patients infected with HBV and 208 healthy volunteers were extracted from the peripheral blood leukocytes. Polymorphisms of LMP genes in HBV patients were determined by polymerase chain reaction-restriction fragment length polymorphism (RFLP), the controls by DNA sequencing. We used the software PHASE1.0 to construct the haplotypes of every individual. At last the unconditional Logistic regression model was used to analyze the statistical association of genotypes or haplotypes in two groups adjusted by gender and age. RESULTS: The distributions of LMP2 genes between cases and controls did not differ. However, LMP7 gene frequency in patients was higher than that in controls [odds ratio 2.11(95% confidence interval 1.36-3.26); 2.66 (95% confidence interval 1.17-6.02), heterogenous or homologous respectively]. Similarly, we found the haplotype combinated by R-K had a significant difference in two groups [odds ratio 1.81 (95% confidence interval 1.19-2.76)]. CONCLUSION: These findings suggest that polymorphisms of LMP2/LMP7 gene is one of the important host factors which independently affect on the infection of hepatitis B virus.