ABSTRACT
Objective: To investigate the expression of long non-coding RNA (LncRNA) KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) in ovarian cancer tissues, and to explore the effect of LncRNA KCNQ1OT1 on the resistance of ovarian cancer cells to cisplatin (DDP). Methods: The expression of LncRNA KCNQ1OT1 in ovarian cancer specimens from the DDP sensitive and insensitive patients, ovarian cancer tissues and their matched paracancerous normal tissues, DDP-resistant SKOV3/DDP cells and parental SKOV3 cells, different human ovarian cancer cell lines (OVCAR3, OVCAR5, OVCAR8, SKOV3, A2780 and PA-1) and immortalized ovarian epithelial cell lines (OSE, IOSE120T and IOSE398) was detected by real-time fluorescent quantitative PCR. Two pairs of short hairpin RNA (shRNA) targeting LncRNA KCNQ1OT1 (shRNA1 and shRNA2) and their negative control shRNA (NC shRNA) were synthesized and cloned into lentivirus vector PLKO.1/puro, respectively. The recombinant plasmids were transfected into 293T cells, and the lentiviruses were packaged and infected into the ovarian cancer SKOV3/DDP cells. Then the expression of LncRNA KCNQ1OT1 was detected by real-time fluorescent quantitative PCR. The proliferation and cell cycle of SKOV3/ DDP cells after infection with lentivirus were detected by MTT and FCM method, respectively. The half maximal inhibitory concentration (IC50) value of DDP in SKOV3/DDP cells was calculated. The expressions of multidrug resistance 1 (MDR1) protein and mRNA in SKOV3/ DDP cells after infection with lentivirus were detected by real-time fluorescent quantitative PCR and Western blotting, respectively. Results: The expression level of LncRNA KCNQ1OT1 in ovarian cancer tissues of DDPinsensitive patients was higher than that of DDP-sensitive patients (P < 0.05). The expression level of LncRNA KCNQ1OT1 in ovarian cancer tissues was higher than that in the matched paracancerous tissues (P < 0.05). The expression level of LncRNA KCNQ1OT1 in SKOV3/ DDP cells was higher than that in SKOV3 cells (P < 0.05). The expression level of LncRNA KCNQ1OT1 in human ovarian cancer cell line OVCAR3, OVCAR5, OVCAR8, SKOV3, A2780 and PA-1 was higher than that in immortalized ovarian epithelial cell line OSE, IOSE120T and IOSE398 (all P < 0.05). After the lentivirus containing LncRNA KCNQ1OT1 shRNA was constructed and infected into SKOV3/DDP cells, the expression of LncRNA KCNQ1OT1 was obviously decreased (P < 0.05). LncRNA KCNQ1OT1 knockdown inhibited the proliferation of SKOV3/DDP cells (P < 0.05), and blocked cell cycle in G0/G1 phase (P < 0.05), decreased the IC50 value of DDP in SKOV3/DDP cells (P < 0.05), and down-regulated the expression levels of MDR1 protein and mRNA in SKOV3/DDP cells (both P < 0.05). Conclusion: The expression level of LncRNA KCNQ1OT1 in ovarian cancer tissues from DDPinsensitive patients is obviously high. LncRNA KCNQ1OT1 knockdown can significantly enhance the sensitivity of SKOV3/DDP cells to DDP.
ABSTRACT
Objective: To investigate the reversal effect of DHA (docosahexaenoic acid) on ADR (adriamycin)-induced multidrug resistance of human gastric cancer SGC-7901 cells. Methods: Human gastric cancer SGC-7901 cells were cultured in vitro and treated with either DHA or ADR alone or in combination for 24 h. The cell proliferation was detected by MTT method. The cell morphology was observed under an inverted microscope. The apoptotic rate was examined by FCM (flow cytometry). The cellular level of ADR was detected by laser scanning confocal microscopy and HPLC (high-performance liquid chromatography). The expression levels of MDR (multidrug resistance protein)-associated P-glycoprotein p-170 mRNA and protein were detected by RT-PCR and Western blotting, respectively. Results: The findings revealed that when DHA was given in combination with ADR, DHA significantly inhibited the growth of SGC-7901 cells. An increased number of dead cells and a higher apoptotic rate were observed. The intracellular accumulation of ADR was increased by 2.1-fold. The intracellular expressions of p-170 mRNA and protein were decreased (P < 0.05). Conclusion: DHA may enhance the sensitivity of gastric cancer SGC-7901 cells to ADR, so it can increase the antitumor effect of ADR. Copyright © 2012 by TUMOR.
ABSTRACT
Objective To investigate the expression of multidrug resistance protein such as multidrug resistance-associated protein 1 (MRP1),lung-resistance related protein (LRP), P-glycoprotein (Pgp),glutathione s-transferase (GST-π) and topoismerase Ⅱ (TOPO Ⅱ ) in hepatocellular carcinoma (HCC), which would be supplied for the clinical chemotherapy of HCC. Methods Twenty-six cases of HCC who underwent hepatectomy were enrolled and immunohistochemical (IHC) staining was carried out on all specimens for the detection of expression of MRP1,LRP,Pgp,GST-πand TOPO Ⅱ and the data was analyzed by image analysis system. Results The expression of five multidrug resistance protein in HCC tissue were significantly higher than those in adjacent tissue beyond cancer (P ＜0.05). The significant differences were found in the expression of Pgp,TOPO Ⅱ and GST-π between HCC tissue and distant metastasis (P ＜ 0.05 ). The expression of the five multidrug resistance protein in poorly differentiated HCC tissue was higher than that in well-differentiated tissue,while the significant difference was only found in the expression of TOPO Ⅱ (P ＜ 0.05 ). The significant association was not found between the expressions of five multidrug resistance protein in HCC tissue and the size of tumor,AFP, the portal vein tumor thrombus,hepatic cirrhosis and liver function. Conclusions Five multidrug resistance protein overexpression in various degrees in HCC tissue, which relates to some biological behavior of the cancer. Combined detection is of much benefit to the choice of the drug of chemotherapy and to the prediction of prognosis.