Association between cyclin D1 G870A polymorphism and hepatocellular carcinoma risk: a meta-analysis

Association between Cyclin D1 G870A (rs9344) polymorphism and cancer risk in Indian population: meta-analysis and trial sequential analysis

Introduction: Association between Cyclin D1 (CCND1) single nucleotide polymorphism (SNP) rs9344 and cancer risk is paradoxical. Thus, we performed a meta-analysis to explore the association between CCND1 variant and overall cancer risk in Indian population. Methods: Data from 12 published studies including 3739 subjects were collected using Pubmed and Embase. RevMan (Review Manager) 5.3 was used to perform the meta-analysis. OR with 95%CI were calculated to establish the association. Results: Overall, the cumulative findings demonstrated that CCND1 polymorphism (rs9344) was not significantly associated with cancer risk in all the genetic models studied (dominant model: GG vs GA+AA: OR (95%CI) = 0.81 (0.60-1.09), P=0.17; recessive model: GG+GA vs AA: OR (95%CI) = 1.23 (0.96-1.59), P=0.11; co-dominant model: GG vs AA: OR (95%CI) = 1.35 (0.93-1.97), P=0.12; co-dominant model: (GG vs GA: OR (95%CI) = 1.16 (0.85-1.59), P=0.34; allelic model: A vs G: OR (95%CI) = 1.20 (1.14-2.85), P=0.23; allelic model: G vs A: OR (95%CI) = 0.83 (0.62-1.12), P=0.23). Subgroup analysis according to cancer types presented significant association of CCND1 polymorphism and increased breast cancer risk in dominant model (GG vs GA+AA: OR = 2.75, 95%CI = 1.54-4.90, P=0.0006) and allelic model (G vs A: OR = 1.63, 95%CI = 1.22-2.19, P=0.001). An increased esophageal cancer risk in recessive model (GG+GA vs AA: OR = 1.51, 95%CI = 1.05-2.16, P=0.03) and co-dominant model (GG vs AA: OR = 2.51, 95%CI = 1.10-5.71, P=0.03) was detected. A higher risk for colorectal cancer was detected under both the co-dominant models (GG vs AA: OR = 2.46, 95%CI = 1.34-4.51, P=0.004 and GG vs GA: OR = 1.74, 95%CI = 1.14-2.67, P=0.01). However, in case of cervical cancer risk a non-significant association was reported under the recessive model (GG+GA vs AA: OR = 1.52, 95%CI = 0.60-3.90, P=0.38) with reference to CCND1 polymorphism (rs9344). The trial sequential analysis (TSA) showed that the cumulative Z-curve neither crossed the trial sequential monitoring boundary nor reached the required information size (RIS). Thus, present meta-analysis remained inconclusive due to insufficient evidence. Conclusion:CCND1 polymorphism rs9344 may not have a role in overall cancer susceptibility in Indian population. However, this polymorphism acts as a crucial risk factor for breast, esophageal, and colorectal cancer but not for cervical cancer. Future studies with larger sample size are required to draw a reliable conclusion.

The essential role of MTDH in the progression of HCC: a study with immunohistochemistry, TCGA, meta-analysis and in vitro investigation

Recent studies found that metadherin (MTDH) played an essential role in hepatocellular carcinoma (HCC). Nevertheless, the exact function of MTDH in the pathogenesis of HCC was unclarified. In the present study, we aimed to investigate the clinical significance of MTDH in HCC and its effect on HCC cells. Immunohistochemistry (IHC) was performed to detect MTDH expression in HCC tissues. Data from The Cancer Genome Atlas (TCGA) and ONCOMINE was obtained to examine MTDH expression in HCC and its clinical significance. Meta-analysis was conducted to assess the correlation between MTDH expression and both the prognosis (Overall Survival (OS) or Disease-free Survival (DFS)) and clinicopathological features of HCC via STATA 12.0. In vitro experiments were performed to investigate the role of MTDH in cell growth, caspase-3/7 activity and apoptosis in HCC cells. The MTDH staining was remarkably stronger in HCC tissues than in non-cancer tissues from IHC, TCGA and ONCOMINE data. Moreover, MTDH-positive expression was significantly correlated with pathological grade, distant metastasis and hepatitis B virus (HBV) infection by IHC. For meta-analysis, MTDH expression was indicative of poor OS without heterogeneity in HCC patients. Additionally, MTDH expression was correlated with high-grade histological differentiation, non-vascular invasion and metastasis in HCC. In vitro experiments revealed that MTDH could the inhibit cell growth and activate caspase-3/7 activity and apoptosis in the four HCC cell lines. In conclusion, MTDH expression may serve as a novel targeting strategy for HCC due to its clinical significance and oncogenic function in HCC cells.