Cep70 drives taxol drug resistance through regulating the acetylation α-tubulin to reduce microtubule stability / 中国医师杂志

ABSTRACT

Objective To explore the Cep70 by adjusting the stability of acetylated alpha tubulin,participate in breast cancer drug resistance mechanisms.Methods (1) In order to induce taxol drug resistance cell line Michigan cancer foundation-7 (MCF-7)/pac,high-dose shock treatments taxol MCF-7 was used for 6 months,until the cells can grow in 3.5 μmol/L of paclitaxel.(2) The 3-(4,5-dimenthylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) method was used to detect inhibition rate by taxol to MCF-7 and MCF-7/pac cell.(3) Immunofluorescence and Western blot were used to test acetylated alpha-tubulin and Cep70 expression levels in MCF-7 and MCF-7/pac cells.(4) Chemical intervention was used to acetylate apha-tubulin expression,Western blot and polymerase chain reaction (PCR) were used to detect the change of acetylated alpha-tubulin and Cep70 in MCF-7 and MCF-7/pac groups.Flow cytometry and Western blot were used to detect the change of cell cycle.Results (1) IC50 of MCF-7 and MCF-7/pac was 22.47 μ mol/L and 31.38 μmol/L,respectively.(2) Immunofluorescence and Western blot results showed that the expression of acetylation of alpha-tubulin in resistant MCF-7 cell/pac was obviously decreased.(3) Real time polymerase chain reaction (RT-PCR) and Western blot showed Cep70 expression was consistent of acetylation of alpha-tubulin.(4) After incubation with paclitaxel for 24 hours,the expressions of acetylation of alpha-tubulin and Cep70 in MCF-7 and MCF-7/pac were increased,but the extent of MCF-7 cell was much higher.Instead,incubation with nocodazole after 24 hours,the acetylation of alpha-tubulin and Cep70 in MCF-7 and MCF-7/pac cells were obviously lowered.(5) After paclitaxel intervention,compared to the same group MCF-7 cells,the G2 phase ratio in MCF-7/pac cells was lower.In addition,given nocodazole after the intervention,compared to the same group MCF-7 cells,the ratio of G2 phase in MCF-7 cell/pac was significantly decreased.Conclusions Cep70 decreased the expression of the acetylated alpha-tubulin,reduced the stability of microtubules,which could be an important mechanism of taxol drug resistance.