The studies were carried out on nude mice bearing human colorectal carcinoma SW480 cell line xenografts to evaluate the chemotherapeutic potential of selenium containing compounds such as sodium selenite (SSe) and selenomethionine (SeMet). Three doses of anticancer drugs were used, including 0.1 mg/kg/day SSe (LSSe), 2 mg/kg/day SSe (HSSe), and 2 mg/kg/day SeMet. We explored the anticancer effect of SSe and SeMet administered by IP injection for 21 days. We observed the pathologic changes and the cell apoptosis in tumor tissue by HE staining and TUNNEL assay after HSSe and SeMet treatment. GSH level and antioxidant enzyme GPX activity in tumor tissues were assessed. In addition, Western blotting was used to detect the expression of apoptosis-related proteins. The results suggested that HSSe and SeMet had significantly inhibited tumor growth in vivo. We also observed the pathologic changes and cell apoptosis in tumor tissues after HSSe and SeMet treatment. GSH level was a bit increased but the GPX activity was reduced. Moreover, SSe and SeMet treatment downregulated the expression of the protein Bcl-xL, increased the expression of Bax, Bad, and Bim, and activated caspase-9. SSe and SeMet may be the selective, low-toxic anticancer agents to treat human colorectal carcinoma cancer.

The aim of the present study was to explore the existence of known or candidate drug-target genes that are upregulated in colorectal cancer (CRC) and may serve as novel prognostic factors or therapeutic targets for this type of malignancy. An in silico analysis was conducted using the Oncomine tool to compare the expression levels of a list of drug-target genes between cancerous and normal tissues in 6 independent CRC cohorts retrieved from the Oncomine database. Phosphoserine aminotransferase 1 (PSAT1) was identified as the top-ranked upregulated gene in CRC tumors, and was highly expressed in patients with chemoresistant disease. Subsequently, the expression of PSAT1 was further experimentally validated using immunohistochemistry in an independent cohort of CRC specimens. The immunohistochemistry results demonstrated that PSAT1 was overexpressed in the CRC tissues compared with the normal colorectal tissues, which was consistent with the previous in silico analysis. Furthermore, PSAT1 overexpression was associated with response to irinotecan, 5-fluorouracil and leucovorin chemotherapy, and with shorter survival time, and retained significance as an independent prognostic factor for CRC when subjected to the multivariate analysis with a Cox's proportional hazards model. Therefore, the present results implicate PSAT1 as a potential prognostic biomarker and a promising therapeutic target for CRC. Targeted PSAT1 inhibition in the treatment of CRC warrants further investigation.

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BackgroundNodal, a TGF-β-related embryonic morphogen, is involved in multiple biologic processes. However, the expression of Nodal in hepatocellular carcinoma (HCC) and its correlation with tumor angiogenesis, epithelial-mesenchymal transition, and prognosis is unclear.MethodsWe used real-time PCR and Western blotting to investigate Nodal expression in 6 HCC cell lines and 1 normal liver cell line, 16 pairs of tumor and corresponding paracarcinomatous tissues from HCC patients. Immunohistochemistry was performed to examine Nodal expression in HCC and corresponding paracarcinomatous tissues from 96 patients. CD34 and Vimentin were only examined in HCC tissues of patients mentioned above. Nodal gene was silenced by shRNA in MHCC97H and HCCLM3 cell lines, and cell migration and invasion were detected. Statistical analyses were applied to evaluate the prognostic value and associations of Nodal expression with clinical parameters.ResultsNodal expression was detected in HCC cell lines with high metastatic potential alone. Nodal expression is up-regulated in HCC tissues compared with paracarcinomatous and normal liver tissues. Nodal protein was expressed in 70 of the 96 (72.9%) HCC tumors, and was associated with vascular invasion (P = 0.000), status of metastasis (P = 0.004), AFP (P = 0.049), ICGR15 (indocyanine green retention rate at 15 min) (P = 0.010) and tumor size (P = 0.000). High Nodal expression was positively correlated with high MVD (microvessal density) (P = 0.006), but not with Vimentin expression (P = 0.053). Significantly fewer migrated and invaded cells were seen in shRNA group compared with blank group and negative control group (P<0.05). High Nodal expression was found to be an independent factor for predicting overall survival of HCC.ConclusionsOur study demonstrated that Nodal expression is associated with aggressive characteristics of HCC. Its aberrant expression may be a predictive factor of unfavorable prognosis for HCC after surgery.