Effects of 5-Aza-dC on KISS1 gene expression and the abilities of invasion and migration of human colorectal cancer cell line HCT116 / 肿瘤

Objective: To investigate the effects of methylation of KISS1 gene promoter and KISS1 expression on biological characteristics of colorectal cancer HCT116 cells induced by methyltransferase inhibitor 5-aza-2′-deoxycytidine (5-Aza-dC). Methods: The promoter methylation status of KISS1 gene and its mRNA and protein expressions in HCT116 cells were detected by methylation-specific PCR, real-time fluorogenic quantitative-PCR and Western blotting, respectively; after treatment with 5-Aza-dC in vitro. The abilities of invasion and migration of HCT116 cells were detected by Transwell assay, and the cell proliferation was detected by Cell Counting Kit-8 (CCK-8). Results: The demethylation of KISS1 promoter was induced after treatment with 5-Aza-dC. The expressions of KISS1 mRNA and protein in HCT116 cells were significantly increased in a dose-dependent manner after treatment with different doses of 5-Aza-dC for 5 days as compared with those without treatment with 5-Aza-dC (P 0.05). The abilities of invasion and migration of HCT116 cells after 5-Aza-dC treatment were also reduced (P < 0.05). Conclusion: The DNA methyltransferase inhibitor 5-Aza-dC can reverse the methylation of KISS1 promoter, and reduce the abilities of invasion and migration of HCT116 cells by up-regulating the expression of KISS1. Copyright© 2014 by TUMOR.

Kiss-1 gene expression after radiation and its association with proliferation and apoptosis in colorectal cancer cells / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the change of expression level of metastasis suppressor gene Kiss-1 in the colorectal cancer cell line SW480 after radiation, and to determine its association with the proliferation and apoptosis of SW480 cells.</p><p><b>METHODS</b>SW480 cells were divided into control group (0 Gy) and study groups (2, 4, 6, 8 Gy). Cells in the study groups were irradiated by 6-MV X-ray radiation for 48 hours. Immunohistochemistry and real-time PCR methods were used to investigate the influence of radiation on Kiss-1 gene expression of SW480. Colony formation assay was used to detect the proliferation of SW480. Flow cytometry-Annexin- V/PI assay was used to observe the change of the apoptosis rate.</p><p><b>RESULTS</b>Compared with the control group, Kiss-1 protein expression increased after radiation of 6, 8 Gy (P<0.05), but no significant changes were observed after radiation of 2, 4 Gy(P>0.05). Kiss-1 gene mRNA level increased after radiation of 2, 4, 6 Gy, while no obvious change was observed for 8 Gy radiation. The apoptosis rates increased for 4, 6, 8 Gy radiation(P<0.05), however, there was no significant difference for 2 Gy radiation (P<0.05).</p><p><b>CONCLUSION</b>Radiation may increase Kiss-1 gene expression in SW480 cells, which results in decreases proliferation and increases apoptosis in residual surviving cells.</p>

Influencing factors related to lymphatic metastasis of T2 rectal carcinoma / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To study the risk factors associated with lymphatic metastasis of T2 rectal carcinoma.</p><p><b>METHODS</b>A consecutive series of 122 patients with T2 rectal cancer who underwent radical surgery in the First Affiliated Hospital of Fujian Medical University from 2006 to 2011 were included for retrospective analysis. Risk factors associated with lymphatic metastasis were investigated.</p><p><b>RESULTS</b>The rate of lymph node metastasis was 21.3% (26/122). Distance to anal verge(P<0.05), morphological type(P<0.05), histological type(P<0.05), tumor differentiation(P<0.05), and depth of invasion(P<0.05) were risk factors for lymph node metastasis in T2 rectal cancer by univariate analysis. The depth of invasion remained statistically significant by multivariate analysis. The rate of lymph node metastasis was 13%(7/54) in patients with shallow muscularis propria involvement, and 28%(19/68) in those with deep muscularis involvement.</p><p><b>CONCLUSION</b>For T2 rectal cancer with shallow muscularis involvement, the risk of lymph node metastasis is low and transanal excision should be considered.</p>