ABSTRACT
AIM:To investigate the expression of microRNA-193b(miR-193b) in the cervical tissues, and fur-ther to explore the effect of silencing miR-193b on diamminedichloroplatinum ( DDP)-treated HeLa cell viability.METH-ODS:The expression levels of miR-193b in different cervical tissues were examined by qPCR.After transfection of miR-193b-inhibitor, the cell migration was determined by Transwell assay, the sensitivity of HeLa cells to DDP was measured by MTT assay, the protein levels of phosphate and tension homology deleted on chromsome ten ( PTEN), protein kinase B (Akt), p-Akt and p-glycoprotein(P-gp) were determined by Western blot.RESULTS:The mRNA level of miR-193b was significantly increased in the cervical cancer tissues compared with normal cervical tissues ( P<0.05) .Knockdown of miR-193b obviously inhibited migration and enhanced sensitivity to DDP of HeLa cells (P<0.05).Additionally, after transfec-tion of miR-193b-inhibitor, the expression of PTEN was increased, whereas the protein levels of p-Akt and P-gp were de-creased (P<0.05).CONCLUSION:miR-193b is highly expressed in the cervical cancer tissues.Inhibition of miR-193b augments the sensitivity to DDP of HeLa cells, at least in part, through PTEN-PI3K/Akt signaling pathway.
ABSTRACT
[ ABSTRACT] AIM:To study the effect of rapamycin ( Rap) on the proliferation, invasion, adhesion, apoptosis and autophagy of human adenocarcinoma A549 and resistant A549/DDP cells treated with cis-diamminedichloroplatinum ( DDP) .METHODS: Human adenocarcinoma A549 and resistant A549/DDP cell lines were cultured.The inhibitory effects of Rap alone or combined with DDP on A549 and resistant A549/DDP cells were detected by MTT assay.The in vitro invasion abilities of the 2 cell lines treated with Rap alone or combined with DDP were detected by Transwell methods. The in vitro adhesion abilities of the 2 cell lines treated with Rap alone or combined with DDP were detected by adhesion experiments.The apoptosis of A549 and resistant A549/DDP cells induced by Rap alone or combined with DDP was ana-lyzed by flow cytometry.The cell autophagy marker proteins beclin-1 and LC3 in A549 and resistant A549/DDP cells trea-ted with Rap alone or combined with DDP were detected by Western blotting.RESULTS:Compared with Rap or DDP a-lone group, the combination of Rap and DDP significantly inhibited the proliferation, invasion and adhesion of A549 and resistant A549/DDP cells in vitro, and promoted the cell apoptosis and autophagy marker proteins beclin-1 and LC3 expres-sion ( all P<0.05) .CONCLUSION:Rap enhances the effect of DDP through promoting the cell autophagy, thereby in-hibiting the proliferation, invasion and adhesion of A549 and resistant A549/DDP cells and inducing the cell apoptosis with a synergistic effect.
ABSTRACT
Experiments have been carried out with C3H mouse fibrosarcoma (FSa II) to determine the effect of different sequence and time intervals between irradiation and administration of cis-diamminedichloroplatinum(cia-DDP) with gross tumors (6 mm in diameter), microscopic tumors (3 days after transplantation of 103 cells) and cells in culture. The drug was administered either 24, 12, 8, 4, 2, 1, 0.5 hour before irradiation, immediately before irradiation, or 0.5, 1, 2, 4, 8, 12, 24 hours after irradiation. In case of in vivo studies, tumor growth delay was used as an end point. Clonogenic cell surviving fraction was used for in vivo studies. Tumor growth delay for gross tumor after 10 Gy radiation plus 10 mg/kg cis-DDP ranged from 0.3 to 10.66 days and the enhancement ratio ranged from 1.37 to 2.23. The most effective combination was whets cis-DDP was given 4 hours before irradiation. Tumor growth delay for microscopic tumor after 5 Gy of radiation and 5 mg/kg of cia-DDP ranged from 3.55 to 11.98 days with enhancement ratio from 2.05 to 6.92. Microscopic tumors showed response significantly greater than additive in every time interval and the most effective treatments were when cis-DDP was given 2 and 1 hour before irradiation. In in vitro experiment, the surviving fraction after 6 Gy of radiation and 1 hour exposure to 4 mu cia-DDP fluctuated as a function of time between treatments, but the difference between maximum and minimum surviving fractions was very small. According to the above results the sequence and time interval between irradiation and chemotherapy is very critical especially for the management of microscopic tumors as in the case of postoperative adiuvant treatment.