title: Pifithrin-μ is efficacious against non-small cell lung cancer via inhibition of heat shock protein 70.
abstract: Heat-shock protein (Hsp) 70, known as a pro-survival protein, is aberrantly expressed in several malignancies. The small molecule 2-phenylethyenesulfonamide (PES), also referred to as pifithrin-μ, is known as an HSP70 inhibitor, which exhibits antitumor activities in a variety of cancer cell lines. However, little is known about its effect on non-small cell lung cancer (NSCLC) cell lines. This study aimed to investigate the effect of PES on human NSCLC cell lines A549 and H460, and explore the possible underlying mechanism of action. Cell viability assay by using CCK-8 kits was performed to demonstrate that PES dose- and time-dependently inhibited proliferation of A549 and H460 cells. Wound healing assay and Transwell migration assay results indicated that PES inhibited cell migration of A549 and H460 cells. Flow cytometry results demonstrated that PES resulted in G0/G1 phase cell cycle arrest, and induced apoptosis via a caspase-dependent manner in A549 and H460 cells. Western blotting results suggested that phosphorylation of AKT and ERK was inhibited by PES treatment. In addition, death receptor 4 (DR4) and DR5 were increased by PES treatment. Overexpression of Hsp70 in A549 cells attenuated the growth inhibitory efficiency of PES. Knockdown of Hsp70 in A549 cells enhanced sensitivity of PES to cell growth inhibition, suggesting that the inhibitory effect of PES on cell proliferation is specifically through Hsp70-dependent mechanism. PES and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) exerts a potent synergistic effect on cell proliferation inhibition and induction of apoptosis in A549 and H460 cells. In a mouse xenograft model of lung cancer by A549 cells, PES treatment displayed significant inhibitory effects on tumor growth. All these findings suggest that PES shows antitumor activity against human NSCLC in vitro and in vivo, and therefore may be a promising agent for use to the treatment of NSCLC.
authors.affiliation: Department of Respiratory Medicine, The Second Clinical Medical College, Yangtz University, Jingzhou, Hubei 434020, P.R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Respiratory Medicine, The Second Clinical Medical College, Yangtz University, Jingzhou, Hubei 434020, P.R. China.
authors.forename: Jingping
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Respiratory Medicine, The Second Clinical Medical College, Yangtz University, Jingzhou, Hubei 434020, P.R. China.
authors.forename: Jiahong
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Respiratory Medicine, The Second Clinical Medical College, Yangtz University, Jingzhou, Hubei 434020, P.R. China.
authors.forename: Li
authors.initials: L
authors.lastname: He
authors.affiliation: Department of Respiratory Medicine, The Second Clinical Medical College, Yangtz University, Jingzhou, Hubei 434020, P.R. China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Gong
authors.affiliation: Department of Laboratory Medicine, Jingzhou First People's Hospital, Jingzhou, Hubei 434100, P.R. China.
authors.forename: Cong
authors.initials: C
authors.lastname: Long
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008819:Mice, Nude; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology*; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000494:pharmacology; D023041:Xenograft Model Antitumor Assays
chemical_list: C545747:2-phenylacetylenesulfonamide; D000970:Antineoplastic Agents; D018840:HSP70 Heat-Shock Proteins; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D013449:Sulfonamides; D053221:TNF-Related Apoptosis-Inducing Ligand; C105190:TNFRSF10A protein, human; C505639:TNFRSF10B protein, human; D051057:Proto-Oncogene Proteins c-akt