Murine double minute 2 rs2279744 polymorphism and hepatocellular carcinoma risk in East Asians: a meta-analysis

Current evidence on the relationship between murine double minute 2 T309G polymorphism and esophageal cancer susceptibility

The relationship between murine double minute 2 (MDM2) T309G polymorphism and esophageal cancer risk has been discussed with discrepant results. The aim of our study is to investigate the systematic association between the potentially functional MDM2 T309G polymorphism and esophageal cancer risk. Eligible studies were included through searching the databases of PubMed, EMBASE, and Chinese National Knowledge Infrastructure (up to April 2014). The crude odds ratio (OR) and 95% confidence interval (CI) were used to estimate the strength of the association. Six published case-control studies, including 1899 cases and 3016 controls, were identified. Overall, our study suggested that MDM2 T309G polymorphism was significantly associated with increased risk of esophageal cancer (TT vs. GG: OR = 0.77, 95% CI = 0.65-0.90, P = 0.002; T vs. G: OR = 0.88, 95% CI = 0.81-0.96, P = 0.002). In subgroup analyses stratified by source of controls, ethnicity, and quality score assessment, respectively, similar results were obtained (TT vs. GG: OR = 0.65, 95% CI = 0.48-0.89, P = 0.007 for hospital-based studies; T vs. G: OR = 0.90, 95% CI = 0.81-0.99, P = 0.04 for population-based studies; and T vs. G: OR = 0.85, 95% CI = 0.78-0.93, P = 0.004 for Asians). The results of Begg's test and Egger's test did not suggest publication bias in the studies. Therefore, the MDM2 T309G polymorphism may be significantly associated with increased esophageal cancer risk, especially among Asians.

Autoantibody response to murine double minute 2 protein in immunodiagnosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide. Although new therapeutic strategies have been continuously developed and applied to clinical treatment for HCC, the prognosis is still very poor. Thus, early detection of HCC may enhance effective and curative management. In this study, autoantibody responses to MDM2 protein in HCC patient's serum were evaluated by enzyme-linked immunosorbent assay (ELISA) and part sera were evaluated by Western blotting and indirect immunofluorescence assay. Immunohistochemistry (IHC) over tissue array slides was also performed to analyze protein expression of MDM2 in HCC and control tissues. The prevalence of autoantibodies against MDM2 was significantly higher than that in liver cirrhosis (LC), chronic hepatitis (CH), and normal human sera (NHS). The average titer of autoantibodies against MDM2 in HCC serum was higher compared to that in LC, CH, and NHS. A high titer of autoantibodies against MDM2 in ELISA could be observed in the serum in 6 to 9 months before the clinical diagnosis of HCC in the serum of several HCC patients with serial bleeding samples. Our preliminary data indicate that MDM2 and anti-MDM2 system may be a potential biomarker for early stage HCC screening and immunodiagnosis.