ABSTRACT
Objective Trihostatin A (TSA) is a histone deacetylase inhibitor of oxime salts, which has certain anti-tumor activity. This article mainly investigates the molecular mechanism of TSA inhibiting cell proliferation through p-AKT/p-mTOR pathway in gastric cancer cells. Methods Gastric cancer cell line-SGC-7901 were treated with TSA of different concentrations, and the inhibition rate of TSA on the cells was detected by MTT assay. The cells were divided into control group (without any treatment), TSA-treated group (200ng/ml TSA), p-AKT covering group (200 ng/mL TSA+8 μg/mL SC79) and autophagy inhibition group (5 mmol/mL 3-methyladenine+200 ng/mL TSA). The protein expression distribution of Lc3 in control and TSA group were detected by cell immunofluorescence staining. The relative expression levels of p-AKT, p-mTOR and autophagy related proteins Lc3 and P62 in control group, TSA group and p-AKT covering group were detected by Western blot. The proliferation of cells in control group, TSA group, p-AKT covering group and autophagy inhibition group were measured by EdU and cell count assay. Results After 24h of treatment, Lc3 in TSA group formed a large number of granular aggregates in the cytoplasm, and the fluorescence distribution changed from the initial diffuse to dense. The TSA group showed a significant reduction in green fluorescence compared with the control group in the EdU experiment. The expression levels of p-AKT in the control group, TSA group and the autophagy inhibition group were 1.78±0.19, 0.92±0.03 and 1.71±0.19, respectively, and Lc3 were 0.21±0.01, 0.79±0.06 and 0.55±0.10, respectively. Compared with the control group, the relative expression level of p-AKT in the TSA group all decreased, while the expression level of Lc3 increased (P <0.05). p-mTOR in the three groups was 0.80±0.16, 0.45±0.04 and 0.98±0.16, respectively. Compared with the control group, the relative expression level of p-mTOR in the TSA group all decreased (P <0.05). P62 in the three groups was 1.17±0.15, 0.48±0.08 and 0.77±0.10, respectively. Compared with the control group, the relative expression level of P62 in the TSA group all decreased (P<0.05). Compared with the TSA group, p-AKT, p-mTOR and P62 expression in the p-AKT covering group increased (P<0.05), while Lc3 expression decreased (P<0.05). Compared with the control group, the inhibition effect of cell growth curve was the most obvious in the TSA group, while the cell growth curve of p-AKT covering group and autophagy inhibition group showed a partial recovery compared with the TSA group. Conclusion TSA can promote autophagy by inhibiting p-AKt/p-mTOR pathway, thus inhibiting the proliferation of gastric cancer cells.
ABSTRACT
Objective Gastric cancer is the most common cancer in the world. In China, Patients with gastric cancer are mostly treated with platinum-based chemotherapy. Programmed cell death 4 (PDCD4) was found as an important proapoptosis recently, the aim of the present study was to investigate the role of PDCD4 reversed the apoptosis induced by cisplatin in gastric cancer cell. The study will provide the target marker for treatment and diagnosis of cisplatin resistance in gastric cancer.Methods Stable transfection with pCMV-PDCD4 vector into human cisplatin resistance gastric cancer cell line-SGC7901/DDP; the cells were divided into control group, over-expression group, control with cisplatin group, over-expression with cisplatin group for following experiments. Hoechst dying with immunofluorescence and flow cytometry were used to measure the cell apoptosis in vitro; Real-time PCR was used to detect the mRNA expression levels of PDCD4, and the protein levels of PDCD4, pAK, pGSK3β, BCL-2 and Bak were detected by Western blot. The cells were divided into vector group, PDCD4 group, PDCD4 with activator group for detect the level of PARP(C) by Western blot.Results Compared with control group, the Results of real-time PCR and western blot were showed the level of PDCD4 was augmented in over-expression group (also in the over-expression with cisplatin group), which was indicated stable transfection with PDCD4 was successful. Immunofluorescence (with hoechst dying) and flow cytometry demonstrated that PDCD4 facilitated cell apoptosis exposed to cisplatin. PDCD4 overexpression attenuated the protein levels of pAkt, pGSK3β and BCL-2, but increased the protein levels of BAK. Furthermore, incubation with SC-79 (the activator of Akt) reversed cell apoptosis induced by PDCD4.Conclusion Overexpression of PDCD4 promotes the apoptosis induced by cisplatin through pAKT/pGSK3β pathway, which is favorable to reverse cisplatin resistance in gastric cancer.
ABSTRACT
<p><b>OBJECTIVE</b>To isolate fetal DNA from maternal plasma and examine its fetal origin.</p><p><b>METHODS</b>Fetal DNA in maternal plasma was isolated from 150 samples in the first trimester and mid-trimester of pregnancy, respectively. Real-time fluorescence quantitative polymerase chain reaction PCR (FQ-PCR) was used to determine sex-determining region Y (SRY) gene on Y chromosome.</p><p><b>RESULTS</b>Eighty-two women in the first trimester and 90 women in the mid-trimester carried male fetuses,70 and 90 samples of them were positive, respectively. The mean concentrations were (58.82+/-20.90) copies/ml and (152.08+/-62.61) copies/ml. The results of FQ-PCR were negative in the women who carried female fetuses.</p><p><b>CONCLUSION</b>The results show that fetal SRY gene can be found at a time as early as 42 days of gestation in maternal plasma by the use of FQ-PCR. The number of fetal DNA increases with gestational age. The real-time FQ-PCR is of great value in the non-invasive prenatal diagnosis.</p>