title: [The effect of ginkgolic acids on multidrug resistance in oral squamous cell carcinoma].
abstract: OBJECTIVE
  Carboplatin (CBP)-resistant cell line (Tca8113/CBP) and pingyangmycin (PYM)-resistant cell line (Tca8113/PYM) were established in vitro. Ginkgolic acids' influence over multidrug resistance (MDR) of drug-resistant cells was discussed by ginkgolic acids coupled with chemotherapy drugs.
  
  
  METHODS
  The expression of P-glycoprotein (P-gp) was detected by immunohistochemistry. MTT assay was applied to ascertain the resistance index of drug-resistant cells. The effect of different concentrations of ginkgolic acids on the proliferation of drug-resistant cells and parental cell was measured by MTT assay. Making sure the non-toxic concentration of ginkgolic acids and observing the reversal effect of ginkgolic acids on drug-resistant cells. Resistance index was redetermined by MTT assay after ginkgolic acids coupled with chemotherapy drugs induced the cell lines for some time.
  
  
  RESULTS
  Immunohistochemistry showed that P-gp positive expression rate of drug-resistant cells was significantly higher than parental cells. The non-toxic concentration of ginkgolic acids which was determined by MTT assay was 10 microg x mL(-1). The reversal folds of Tca8113/CBP cell line to CBP and Tca8113/PYM cell line to PYM were 2.94 and 2.43 respectively. Before coupled with ginkgolic acids, the resistance indices of Tca8113/CBP and Tca8113/PYM cell lines were 3.24 and 11.9 respectively. When ginkgolic acids was added with chemotherapy drugs for some time, the resistance indices of Tca8113/CBP and Tca8113/PYM cell lines were 2.18 and 4.43 respectively.
  
  
  CONCLUSIONS
  This experiment successfully induced the drug-resistant cell lines of Tca8113/CBP and Tca8113/PYM. The method of chemotherapy drugs coupled with ginkgolic acids further confirmed the effect on proliferation of Tca8113/CBP and Tca8113/PYM cell lines was reducing. Non-toxic concentration of ginkgolic acids can partially reverse the drug resistance of Tca8113/ CBP and Tca8113/PYM cell lines. Furthermore, MDR level of drug-resistant cells decreased somewhat when they were induced by ginkgolic acids coupled with chemotherapy drugs for some time.
authors.affiliation: State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Chen-Chen
authors.initials: CC
authors.lastname: Zhou
authors.forename: Yun
authors.initials: Y
authors.lastname: Feng
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Dai
authors.forename: Jiao
authors.initials: J
authors.lastname: Chen
authors.forename: Si-Xiu
authors.initials: SX
authors.lastname: Chen
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Li
authors.forename: Yu-Rong
authors.initials: YR
authors.lastname: Liu
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D001761:Bleomycin / Q000031:analogs & derivatives; D002294:Carcinoma, Squamous Cell; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D006801:Humans; D009062:Mouth Neoplasms; D012459:Salicylates
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D012459:Salicylates; D001761:Bleomycin; C112485:ginkgolic acid; C025703:bleomycetin