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>

Clinical characteristics, diagnosis and treatment of hepatoid adenocarcinoma of the stomach / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the clinical characteristics,diagnosis and treatment of hepatoid adenocarcinoma of the stomach.</p><p><b>METHODS</b>Clinical data of 13 hepatoid adenocarcinomas of the stomach, collected from 201 cases of gastric cancer, were analyzed retrospectively.</p><p><b>RESULTS</b>Of the 201 gastric carcinomas, there were 13 AFP-producing adenocarcinomas of the stomach, the positive rate was 6.5%. Morphologically, the tumor cells formed glandular, medullary and linear structures. Of the 13 hepatoid adenocarcinomas of the stomach, 10 cases were in gastric antrum and 10 cases were poorly differentiated. The metastasis rates of liver and lymph node in hepatoid adenocarcinoma of stomach were higher than those in non-hepatoid adenocarcinoma of stomach. The treatment of hepatoid adenocarcinoma of stomach depended mainly on radical resection, and adjuvant chemotherapy was needed.The prognosis of hepatoid adenocarcinoma of stomach was poor.</p><p><b>CONCLUSION</b>Hepatoid adenocarcinoma of the stomach has its own special tumor biological behavior and poor prognosis. Special attention should be paid to this disease.</p>

Mitotic arrest of gastric cancer cells induced by silencing of STK15 gene / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the role of STK15 in regulating mitosis of gastric cancer cells (MKN45) by gene silencing through RNA interference mechanism.</p><p><b>METHODS</b>RNA interference technique was used to inhibit STK15 expression in MKN45 cells. The expression levels of STK15 mRNA and protein were measured by real-time quantitative RT-PCR and Western blot respectively and cell morphological changes were investigated by reverse microscopy. In addition, cell cycle distribution and cellular proliferation were determined by flow-cytometry and MTT assay respectively. Finally, the mitotic phenotype of MKN45 cells was studied by immunofluorescence staining and confocal microscopy.</p><p><b>RESULTS</b>Silencing of STK15 gene by RNA interference was confirmed by marked decrease of STK15 mRNA and protein levels in the treated MKN45 cells. This silencing correlated with rounding of the cells, decreasing of DNA content in G(2) phase (P < 0.05) and a lowered proliferation index (P < 0.05), along with alterations of mitotic phenotype of MKN45 (P < 0.05).</p><p><b>CONCLUSION</b>STK15 gene may play a key role in regulating cellular mitosis and its inhibition by RNA interference leading to mitosis arrest in MKN45 cells.</p>

Study of growth inhibition of gastric cancer cells by sRNA targeting polo like kinase 1 in vitro and vivo / 中华外科杂志

<p><b>OBJECTIVE</b>To observe the effect of polo like kinase 1 (plk1) gene depletion on the growth of gastric cancer cell line-MKN45 cells in vitro and vivo and discuss the feasibility and effectiveness of arranging plk1 as gene therapeutic target for gastric cancer.</p><p><b>METHODS</b>The plk1 expression of MKN45 cells was inhibited by RNA interference (RNAi). The plk1 mRNA and protein level were measured by real-time quantitative PCR and western blotting, and the change of cell cycle distribution and apoptosis rate were detected by flow-cytometry, and the MKN45 cells proliferation was measured by MTT method. MKN45 cells treated with plk1 siRNA were transplanted subcutaneously in nude mice and their tumorgenesis ability were observed, the plk1 protein levels of the samples from nude mice in different groups were compared.</p><p><b>RESULTS</b>After treatment with plk1 siRNA, plk1 mRNA and protein level decreased obviously in certain time, more MKN45 cells accumulated at G(2)/M (P < 0.05). Apoptosis rate of MKN45 cells treated with plk1 siRNA was higher than that of control cells at 48 h and 72 h (P < 0.05), and MKN45 cells proliferated slowly than control groups (P < 0.05), while the tumorgenesis ability obviously decreased, but the plk1 protein levels of the samples from nude mice in different groups were not different.</p><p><b>CONCLUSIONS</b>siRNA targeting plk1 can inhibit the proliferation of MKN45 cells in vitro and vivo. Plk1 may be a novel therapeutic target for gastric cancer.</p>

Inhibition of serine/threonine kinase 15 gene expression induces apoptosis of gastric cancer cells / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To observe the effect of inhibition of serine/threonine kinase15 (STK15) gene expression on apoptosis induction in gastric cancer cell line-MKN45 and discuss the role of STK15 in viability of gastric cancer cells.</p><p><b>METHODS</b>The STK15 expression was inhibited by chemically synthesized siRNA. The STK15 mRNA and protein level were respectively measured by real-time quantitative PCR and western blotting,the change of cell cycle distribution and apoptosis rate were detected by flow-cytometry, cell morphological change was observed by Hoechst staining,and pro-caspase 3 level was also detected by western blot.</p><p><b>RESULTS</b>After treatment by siRNA targeting STK15 after 48 h, STK15 mRNA and protein level decreased obviously. More MKN45 cells accumulated at G(2)/M phase (P< 0.05). The apoptosis rate of STK15 siRNA treated MKN45 cells was higher than that of control cells(P< 0.05) with the pro-caspase 3 level decreased.</p><p><b>CONCLUSIONS</b>Inhibition of STK15 gene expression may induce apoptosis in MKN45 cells through the pathway of caspase3. STK15 gene play a key role in proliferation and viability of MKN45 cells.</p>

Mitosis arrest caused by inhibition of PLK1 expression in gastric cancer MKN45 cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To observe the effect of polo-like kinase 1 (PLK1) gene depletion on mitosis phenotype and elucidate its vital role in gastric cancer cell line (MKN45) mitosis.</p><p><b>METHODS</b>The PLK1 expression in MKN45 cells was blocked by RNA interference (RNAi), the expression level of PLK1 mRNA and protein were measured by real-time quantitative PCR and Western blot, respectively. The morphological change of microtubules and mitosis phenotype in MKN45 cells were observed by immunofluorescence staining and laser confocal microscopy, the morphological changes of cells were observed by reverse microscopy, the variation of cell cycle distribution was detected by flow-cytometry.</p><p><b>RESULTS</b>After RNAi targeting PLK1, PLK1 mRNA and protein level decreased obviously, the cell microtubules became obscure and lost cohesiveness, the mitosis phenotype also varied substantially (P < 0.05), more gastric cancer cells became rounded and showed G(2) phase cell DNA content (P < 0.05).</p><p><b>CONCLUSION</b>PLK1 gene plays a key role in mitosis and its inhibition can lead to mitosis arrest in MKN45 cells.</p>