ABSTRACT
Protein phosphatase, Mg2+/Mn2+ dependent, 1D (PPM1D) has been associated with carcinogenesis. The present study investigated PPM1D expression as a potential biomarker in colorectal cancer (CRC). PPM1D expression was assessed using immunohistochemistry in 368 patients with CRC. The correlation between PPM1D expression, clinicopathological features and prognosis was analyzed. PPM1D small interfering (si)RNA-induced PPM1D silencing was performed in CRC cell lines to assess the effect of PPM1D on tumor cell proliferation and invasion in vitro. A total of 68.48% (252/368) of the CRC samples displayed high PPM1D expression. By contrast, only 9.24% (34/368) of the matched non-cancerous tissue samples exhibited high PPM1D expression. High PPM1D expression was correlated with node metastasis (P=0.0024), distant metastasis (P<0.001) and TNM stage (P=0.0016). Kaplan-Meier survival analysis revealed that patients with low PPM1D expression had significantly longer survival than those with high PPM1D expression (P=0.012). Moreover, multivariate analyses demonstrated that high PPM1D expression was an independent prognostic factor for overall survival (hazard ratio = 0.24; 95% confidence interval, 0.13-0.86; P=0.004). Furthermore, PPM1D gene silencing was found to significantly reduce the proliferation and invasion of CRC cells in vitro. These findings suggest a role for PPM1D as a prognostic marker and potential therapeutic target in CRC.
ABSTRACT
In 2013, the World Health Organization reported the first case of human infection with a new influenza A (H7N9) virus in China. This has caused damage and panic within certain areas in China. Therefore, analysis of this virus with bioinformatics technology is very necessary. Neuraminidase (NA) is one of the most important antigens of the influenza virus and an important target for anti-flu drugs. In this study, the nucleotide and protein sequences of NA gene of A/H7N9 influenza viruses were retrieved from the NCBI database, and MEGA 5.0 software was employed to construct a phylogenetic tree based on the nucleotide coding sequence; BioEdit software was used to align the nucleotide and protein sequences of NA and calculate the homologies of nucleotides and amino acids and then to analyze the important mutation sites of NA gene. The results demonstrated that the spread of influenza virus H7N9 showed certain geographical and temporal relations. The H7N9 virus isolated from China in 2013 belonged to Euroasiatic serotype, and its NA stalk region hadobvious variation, which may be one of the reasons that this virus infects human. These analyses may be very helpful for understanding the evolutionary relationship and mutation trend of A/H7N9 influenza viruses.
