OBJECTIVE To investigate the effect and mechanism of miR-152-3p on the resistance to paclitaxel(PTX)of PTX-resistant ovarian cancer cells(A2780T cells).METHODS ① Ovarian cancer parent cells(A2780 cells)and A2780T cells were treated with PTX(1.875,3.75,7.5,17 and 23 μmol·L-1)for 48 h.Cell viability was evaluated by MTT assay,and the 50%inhibitory concentration(IC50)and drug resistance index of A2780T cells were calculated.Western blotting was used to detect the expres-sions of resistance protein P-glycoprotein(P-gp),multidrug resistance related protein 1(MRP1)and adenosine triphosphate binding transporter G superfamily member 2(ABCG2).② Real-time fluorescent quantita-tive PCR(RT-qPCR)was used to detect the expressions of miR-152-3p in A2780 and A2780T cells.The lipid-mediated transient transfection technique was employed to transfect the miR-152-3p inhibitor to reduce miR-152-3p expression in A2780T cells(miR-152-3p inhibitor group),while the negative control(miR-152-3p NC)group was established.RT-qPCR was used to detect transfection efficiency,and the MTT method,scratch experiment,and flow cytometry were used to investigate the effects of the trans-fecting miR-152-3p inhibitor on survival,migration and apoptosis of A2780T cells.Western blotting was used to detect the protein expressions of Bax and Bcl-2 in A2780T cells.③ Bioinformatics analysis of databases including miRDB,Targetscan,miRWalk,and Starbase predicted the target genes of miR-152-3p that were verified by Western blotting to detect the protein expression of PTEN in A2780T cells of the miR-152-3p inhibitor and miR-152-3p NC groups,and RT-qPCR to detect the PTEN mRNA expression in A2780 and A2780T cells.Then,the lipid-mediated transient transfection technique was used to transfect PTEN siRNA to silence PTEN expression in A2780T cells(PTEN siRNA group).The siRNA negative control(siRNA NC)group was established.RT-qPCR was used to detect transfection efficiency,the MTT method was employed to measure the survival rate and IC50 value,and Western blotting was used to assess the protein expressions of P-gp,MRP1,and ABCG2 in A2780T cells after silencing PTEN expression.RESULTS ①After treatment with PTX,the cell survival rates were decreased in A2780 and A2780T cells(P<0.05),and the resistance index of A2780T cells was 2.8.Compared with A2780 cells,the protein expressions of P-gp and MRP1 and ABCG2 were highly expressed in A2780T cells(P<0.05,P<0.01).② RT-qPCR showed that the expression of miR-152-3p in A2780T cells was higher than that of A2780 cells(P<0.01).Compared with the miR-152-3p NC group,A2780T cell viability(P<0.05,P<0.01)and cell migration capability(P<0.05)were significantly inhibited,while the apoptosis rate increased(P<0.01)in miR-152-3p inhibitor group.Moreover,the protein expression of Bax was increased(P<0.01),but Bcl-2 decreased(P<0.05).③ Bioinformatics analysis suggested that PTEN was a target gene of the miR-152-3p,and the verified results showed that the PTEN protein expression in A2780T cells of the miR-152-3p inhibitor group was lower than that of the miR-152-3p NC group(P<0.05),and PTEN mRNA expression in A2780T cells was higher than that in A2780 cells(P<0.01).After silencing the expression of PTEN in A2780T cells,the cell viability was significantly reduced(P<0.05,P<0.01),while the IC50 value was reduced(P<0.01)compared with the siRNA NC group.In addition,the protein expressions of P-gp,MRP1 and ABCG2 were decreased(P<0.05,P<0.01).CONCLUSION miR-152-3p is highly expressed in A2780T cells,and down-regulation of its expression may inhibit proliferation and migration,prompt apoptosis and reduce the resistance to PTX of A2780T cells,which is made possible by inhibiting expression of its target gene PTEN.

Objective To evaluate the effect of thoracic paravertebral nerve block (TPVB) on postoperative chronic pain in patients undergoing thoracic surgery.Methods One hundred and forty patients of both sexes,aged 25-64 yr,with body mass index of 18-24 kg/m2,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,scheduled for elective thoracoscopic radical resection of lung cancer,were divided into 2 groups (n=70 each) using a random number table method:control group (group C) and TPVB group (group P).Two-point (T4,6) TPVB was performed on the affected side under ultrasound guidance before anesthesia induction,and 0.5％ ropivacaine 20 ml was injected into each puncture site in group P.Sufentanil 0.1 μg/kg was intravenously injected at 10 min before the end of operation in group C.Analgesic pump was connected at the end of operation in two groups,and patient-controlled intravenous analgesia was performed with sufentanil.The patients were followed up after operation.Sufentanil 0.1 μg/kgwas intravenously injected when visual analogue scale score ≥4.The total consumption of sufentanil and the number of requirements for rescue analgesia were recorded at 48 h after operation in both groups.The patients were followed up to 2 months by telephone after operation,the occurrence of postoperative chronic pain was recorded,and the effect of pain on daily life and grade of treatment measures were evaluated.Results Compared with group C,the total consumption of sufentanil and the number of requirements for rescue analgesia were significantly reduced,and the impact of postoperative chronic pain on daily life and grade of treatment measures for pain were decreased in group P (P＜0.05).There was no significant difference in the incidence of postoperative chronic pain between the two groups (P＞ 0.05).Conclusion Although TPVB cannot reduce the incidence of postoperative chronic pain,it can relieve the degree of postoperative chronic pain in patients undergoing thoracic surgery.