ABSTRACT
BACKGROUND@#Gastric cancer (GC) is one of the most globally prevalent cancers in the world. The pathogenesis of GC has not been fully elucidated, and there still lacks effective targeted therapeutics. The influence of altered kinesin superfamily protein 22 (KIF22) expression in GC progression is still unclearly. The aim of this study was to investigate the KIF22 effects on GC and related mechanisms.@*METHODS@#Gastric carcinoma tissues and matching non-cancerous tissues were collected from patients with GC who have accepted a radical gastrectomy in Lanzhou University Second Hospital from May 2013 to December 2014. The expression of KIF22 was examined in GC of 67 patients and 20 para-carcinoma tissues by immunochemical staining. The relationship between the expression of KIF22 and clinicopathologic characteristics was next investigated in the remaining 52 patients except for 15 patients who did not complete follow-up for 5 years. Cell viability was performed via 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) test and colony formation assay in the MGC-803 and BGC-823 GC cells. Cell scratch and trans-well invasion assay was performed to assess migration ability in the MGC-803 and BGC-823 GC cells. Gene set enrichment analysis (GSEA) pathway enrichment analysis was performed to explore the potential functions. Cell cycle was detected by flow cytometry. In addition, the two GC cell lines were used to elucidate the underlying mechanism of KIF22 in GC in vitro via assessing the effects on mitogen-activated protein kinase and extracellular regulated protein kinases (MAPK/ERK) signal transduction pathway-related expressions by Western blotting assays. The differences were compared by t tests, one-way analysis of variance, and Chi-squared tests.@*RESULTS@#The study showed that KIF22 was up-regulated in GC, and KIF22 high expression was significantly related to differentiation degree (χ = 12.842, P = 0.002) and poorly overall survivals. GSEA pathway enrichment analysis showed that KIF22 was correlated with the cell cycle. Silence of KIF22 decreased the ability of the proliferation and migration in gastric cells, induced G1/S phase cell cycle arrest via regulating the MAPK-ERK pathways.@*CONCLUSIONS@#KIF22 protein level was negatively correlated with prognosis. KIF22 knockdown might inhibit proliferation and metastasis of GC cells via the MAPK-ERK signaling pathway.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the inhibitory effect of dehydroepaimdrosterone (DHEA) on the growth of transplanted Morris hepatomas (7288CTC) in vivo in rats.</p><p><b>METHODS</b>21 Buffalo rats were randomly devided into 4 groups, including one blank control group (n = 5), one group for tumor-bearing control (n = 6), and 2 experimental groups with DHEA (n = 6) or DHEA-s (n = 4). DHEA or DHEA-s was fed to the rats for 4 weeks immediately after Morris hepatomas (7288CTC) was implanted in both flanks. Phenotypes of the spleen lymphocytes were examined by flow cytometry, Akt and PTEN expression in tumor cells was detected by Western blot and immunohistochemistry.</p><p><b>RESULTS</b>Tumor weights of DHEA treated group were less than those of the control (P less than 0.05), the inhibitory rate was 43%. The results of Western blot and immunohistochemistry showed that in DHEA tumor group,the expression of phosphorilated Akt protein was decreased, the expression of PTEN was enhanced, the percentage of CD3 positive cells and the ratio of CD4/CD8 were increased (P less than 0.05).</p><p><b>CONCLUSION</b>DHEA can inhibit tumor growth, possibly via the inhibition of the Akt signaling pathway as well as modulating the immune function.</p>