Role of vitamin K-dependent protein Gas6 in the expression of endothelial cell adhesion molecule-1 and chemokines induced by Porphyromonas gingivalis lipopolysaccharide / 北京大学学报(医学版)

OBJECTIVE@#Growth-arrest-specific protein 6 (Gas6) is a vitamin K-dependent protein and involved in cell proliferation, survival, adhesion and migration . Also it has been shown to play an important role in the inflammatory response .The aim of present study was to investigate the role of Gas6 in the process of the expression of adhesion molecules and chemokines of human umbilical vein endothelial cells (HUVECs) induced by Porphyromonas gingivalis lipopolysaccharide(P.g-LPS).@*METHODS@#After up-regulation and down-regulation of the expression of Gas6, the vascular endothelial cells were stimulated with 1 mg/L P.g-LPS for 3 h and 24 h. Real-time quantitative polymerase chain reaction(real-time PCR) was taken to detect the expression of the cell adhesion molecules:intercellular adhesion molecule-1 (ICAM-1) and E-selectin, as well as chemokines:interleukin-8 (IL-8) and monocyte chemoattractant protein 1 (MCP-1). Wound healing assay was taken to observe the migration ability of endothelium cells in different groups.@*RESULTS@#After 3 h of P.g-LPS stimulation, the expression of adhesion molecules and chemokine in the down-regulation group was not significantly different from that in the control group,while in the up-regulation group the decrease of E-selectin, ICAM-1, IL-8 and MCP-1 was 81%±0%, 47%±3%, 76% ± 3%, 26% ± 6% respectively. After 24 h of P.g-LPS stimulation, the expression of adhesion molecules and chemokine in down-regulation group was significantly higher than that in control group (2.06±0.07, 1.99±0.11, 3.14±0.15, 1.84±0.03 flod), while these molecules in the down-regulation group was significantly lower than in the control group (29%±1%, 62%±3%, 69%±1%, 41%±2%). Differences were statistically significant (P<0.01). Wounding healing assay showed that down-regulation of Gas6 enhanced migration ability of endothelial cells while up-regulation of Gas6 weakened this ability,which was consistent with the trend of real-time PCR result.@*CONCLUSION@#Down-regulation of the Gas6 gene enhanced the expression of ICAM-1, E-selectin, IL-8 and MCP-1 in HUVECs after P.g- LPS stimulating, while up-regulaiton of the Gas6 gene weakened the expression of ICAM-1, E-selectin, IL-8 and MCP-1 in HUVECs after P.g-LPS stimulating,suggesting that Gas6 may play a role in the process of endothelial cell adhesion.

Significance of TSLC1 gene methylation and TSLC1 protein expression in the progression of cervical lesions / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the expression and significance of tumor suppressor in lung cancer 1 (TSLC1) gene methylation, the expression of TSLC1 protein in cervix cancer and precancerous lesions as well as their relationship with HR-HPV DNA infection.</p><p><b>METHODS</b>The clinicopathological data of 92 cases of different cervical lesions during March 2011 to August 2012 treated in our hospital were collected. There were pathologically confirmed 10 cases of normal cervix, 26 cases of cervical intraepithelial neoplasia (CIN) I, 20 cases of CIN II, 15 cases of CIN III, and 21 cases of cervical cancer. Methylation-specific polymerase chain reaction (MSP) was used to detect the TSLC1 gene methylation status in cervical lesions, immunohistochemistry (SP) was used to detect the expressions of TSLC1 protein in cervical lesions, and the second generation hybrid capture (HC2) method was used to detect the high-risk HPV in cervical lesions.</p><p><b>RESULTS</b>The expression rate of TSLC1 gene methylation in normal cervical tissue, CIN I, CIN II, CIN III and SCC were 10.0%, 30.8%, 55.0%, 60.0%, 66.7%, respectively, showing a statistically significant difference (P = 0.004). The positive expression rate of TSLC1 protein in normal cervical tissue, CIN I, CIN II, CIN III and SCC were 100.0%, 80.8%, 65.0%, 33.3%, and 23.8%, respectively, with a significant difference (P = 0.004). In the progression from CIN to invasive cervical cancer, there was no significant correlation between TSLC1 gene methylation and HR-HPV DNA infection (P = 0.919), TSLC1 protein expression and HR-HPV DNA infection (P = 0.664). The correlation analysis showed a negative correlation between TSLC1 gene methylation and TSLC1 protein expression (r = -0.674, P < 0.001).</p><p><b>CONCLUSIONS</b>TSLC1 gene promoter methylation may be an early event in the cervical carcinogenesis, become an early sensitive marker, and serve the early prevention and prognostic prediction for cervical cancer.</p>

The relationship between the TSLC1 silencing and DNA methylation in human lung cancer cells / 中国肺癌杂志

<p><b>BACKGROUND AND OBJECTIVE</b>The expression of TSLC1 is downregulated or abrogated in many kinds of tumors, and its downregulation is highly associated with DNA hypermethlyation. The aim of this study is to explore the relationship between TSLC1 silencing and DNA methylation of its promoter region in lung cancer cells.</p><p><b>METHODS</b>We detected the expression pattern of TSLC1 in human normal lung tissue and three lung cancer cell lines (A549, NCI-H446 and Calu-3) by semi-quantitative RT-PCR and Real-time PCR. Then we detected the status of DNA methylation in TSLC1 promoter region with bisulfite sequencing in above normal lung tissue and lung cancer cell lines. After treatment of above cell lines with the inhibitor of DNA methyltransferase 5-Aza-2-deoxycytidine (5-Aza-dC), we detected the expression change of TSLC1 by Real-time PCR before and after the treatment of 5-Aza-dC.</p><p><b>RESULTS</b>There was no methylation in TSLC1 promoter region in normal lung tissue and A549 cell line in which TSLC1 expressed; while there was DNA hypermethylation in TSLC1 promoter region in NCI-H446 and Calu-3 cell lines in which TSLC1 was abrogated, also the expression of TSLC1 in NCI-H446 and Calu-3 cell lines could be restored after treatment of 5-Aza-dC.</p><p><b>CONCLUSION</b>The silencing of TSLC1 in lung cancer cells is due to the hypermethylation of its promoter region.</p>

The growth inhibition effects of TSLC1 gene on human hepatocyte carcinoma cell line HepG2 / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To study the effects of tumor suppressor in lung cancer-1 (TSLC1) on human hepatocyte carcinoma cell line HepG2.</p><p><b>METHODS</b>A full length of TSLC1 cDNA was amplified from RNA of normal human liver cells by RT-PCR, and it was cloned into a pCI-neo expression vector and transfected into human hepatocellular carcinoma cell line HepG2. The HepG2 cells transfected with this plasmid (experimental group) and those treated with pCI-neo vector (control group) and without any treatment (blank group) were compared. Cell morphology was studied microscopically and cell growth was analyzed with MTT assay. FACSort flow cytometry analysis was performed to assess the cell cycle distribution and apoptosis.</p><p><b>RESULTS</b>A stable cell line expressing TSLC1 protein was successfully established. Morphologically, cells of the experimental group were tightly aggregated when compared with those of the control and blank groups. The growth of TSLC1-transfected cells was significantly suppressed in vitro compared with those of the control and blank groups. The amount of G0-G1 cells was 63.66%+/-3.83% (P less than 0.01) in the experimental group, while those of the control and blank groups were 47.45%+/-0.91% and 54.47%+/-0.96% respectively. The amount of S phase cells in the experimental group, 22.90%+/-6.04%, was significantly lower (P less than 0.05) than that of the control group (36.58%+/-0.61%) and the blank group (33.61%+/-2.99%), which suggested a G0-G1 cell cycle arresting. The number of cells in early and late phase apoptosis (17.09%+/-0.20% and 16.11%+/-0.40% respectively) were significantly higher than those of the control and blank groups (P less than 0.01).</p><p><b>CONCLUSIONS</b>TSLC1 strongly inhibits the growth of HepG2 cells in vitro and induces apoptosis of the cells, suggesting that TSLC1 may have a tumor suppressor function in HCC.</p>

The study on methylation of gene IGSF4 promoter in acute leukemia cells / 中国实验血液学杂志

To study whether gene IGSF4 was inactived by methylation in leukocytic cells, expression of IGSF4 was examined before and after treatment with demethylating agent in U937, Molt4 and HL-60 leukemia cell lines by means of RT-PCR. The methylation of promoter in U937, Molt4 and HL-60 cells as well as 21 acute leukemia patients was analyzed by MS-PCR. The results showed that methylation of IGSF4 promoter was inactived and could be reversed by treatment with a demethylating agent in U937, Molt4 and HL-60 cell. IGSF4 promoter methylation was detected in 57.1% of acute leukemia patients. There is no difference in incidence of IGSF4 promoter methylation between acute myelocytic leukemia and acute lymphocytic leukemia. In conclusion, IGSF4 is frequently inactived in acute leukemia and is a good candidate for the leukemia suppressor gene. As a normal suppressor gene, it may play an important role in inhibiting the development of leukemia, and the methylation of gene IGSF4 may be a good index in monitoring relapse of leukemia.