[The effect of RABEX-5 downregulation on the chemosensitivity of human breast cancer cells].
OBJECTIVE
To investigate the changes in sensitivity to anthracycline and taxanes of human breast cancer cells after RABEX-5 downregulated.


METHODS
By constructing a lentiviral vector for RNA interference (RNAi) of RABEX-5 gene and transfected into human breast cancer cell line MCF-7 to silence the express of RABEX-5. Real-time PCR and Western blot were used to detect the silencing effect. The changes in sensitivity to chemotherapeutic drugs of MCF-7/RNAi and its negative control cell lines MCF-7/vector were detected by CCK-8 reagent.


RESULTS
Compared with MCF-7 cell and MCF-7/vector cell, the expression of RABEX-5 mRNA and protein was downregulated in MCF-7/RNAi cells. The sensitivity to epirubicin was reduced after downregulating the expression of RABEX-5, the 50% inhibition concentration (IC50) of MCF-7/RNAi [(3.590 0 +/- 0.228 69) microg/mL] was higher than that of MCF-7/Vvector [(1.193 3 +/- 0.187 71) microg/mL, P < 0.05]; while the same effect was not found in docetaxel group, the IC50 were (11.162 7 +/- 0.210 26) microg/mL and (10.536 7 +/- 0.430 97) microg/mL, respectively (P > 0.05).


CONCLUSIONS
Downregulation of RABEX-5 can induce chemoresistance to epirubicin in human breast cancer cell MCF-7; while its effect on sensitivity to docetaxel is not significant. This study can provide a theoretical basis for future research RABEX-5 in the individualized treatment of breast cancer.
Department of Endocrine and Breast Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
Xiang
X
Zhang
Department of Endocrine and Breast Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
Hong-Yuan
HY
Li
Department of Endocrine and Breast Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
Jie
J
Min
Department of Endocrine and Breast Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
Yan
Y
Li
Department of Endocrine and Breast Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
Qiang
Q
Liu
Department of Endocrine and Breast Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
Xin-Jie
XJ
Liang
D018943:Anthracyclines / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D015536:Down-Regulation; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005260:Female; D005822:Genetic Vectors / Q000235:genetics; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D034622:RNA Interference; D043823:Taxoids / Q000494:pharmacology; D014162:Transfection
D018943:Anthracyclines; D000970:Antineoplastic Agents; D020662:Guanine Nucleotide Exchange Factors; C108382:RABGEF1 protein, human; D043823:Taxoids