Introduction: The mammalian target of rapamycin (mTOR) is a vital effect factor in regulating cell growth, survival and autophagy via direct interaction with mTORC1 (mTOR complex 1) and mTORC2 (mTOR complex 2). The mTOR signaling pathway is abnormally activated in prostate cancer and may play an important role in prostate cancer progression and drug resistance.The purpose of this study was to investigate the effects of mTORC1/2 dual inhibitor AZD2014 on docetaxel-sensitive and resistant human prostate cancer cell lines.
Methods: In vitro, using Dimethyl sulfoxide(DMSO) and rapamycin as controls,the effects of AZD2014 on the activation state of mTOR signaling pathway in docetaxel-sensitive (C4-2?CWR22Rv1)and resistant (C4-2-Doc-R? CWR22Rv1-Doc-R)human prostate cancer cell lines were examined by Western blot.The effects of AZD2014 on cell proliferation, cell cycle and cell apoptosis were detected by CCK8 assay, flow cytometry and apoptosis assay.The effects of AZD2014 on cell invasion, migration, autophagy and EMT were determined by Transwell assay, wound healing assay, Acidic vesicular organelles staining assay, immunofluorescence and Western blot assay.
Results: We found that in docetaxel-sensitive and resistant human prostate cancer cell lines, rapamycin only inhibited the phosphorylation of 4EBP1 but had no significant effect on the AKT phosphorylation level; AZD2014 could inhibite 4EBP1 phosphorylation more strongly than rapamycin and can significantly inhibit the phosphorylation of AKT.Meanwhile, AZD2014 lead to more profound apoptosis, proliferation suppression, cell cycle arrest and autophagy in all PCa cells when compared with rapamycin. Moreover, AZD2014 was more effcacious than rapamycin in inhibiting the migration, invasion and EMT progression of all PCa cells.
Conclusions: These data highlight an important role for AZD2014 in the regulation of multiple biological functions in PCa and indicate the potential more effcacious antitumor ability of AZD2014 than rapamycin. AZD2014 is a potent dual inhibitor of mTORC1 and mTORC2 that simultaneously blocks mTORC1/2 signaling in docetaxel-sensitive and resistant human prostate cancer cell lines and prevents feedback activation of AKT signaling, thus showing significant anti-tumor effects, including inhibition of proliferation, induction of apoptosis, cycle arrest and autophagy, inhibition of migration , invasion and EMT.This study provides a reliable theoretical basis for the clinical application of AZD2014 in both docetaxel-sensitive and resistant human prostate cancer. Source of
Funding: National Natural Science Foundation(NO.81770755,81570683)