PMID- 25946033 OWN - NLM STAT- MEDLINE DCOM- 20160425 LR - 20220310 IS - 1932-6203 (Electronic) IS - 1932-6203 (Linking) VI - 10 IP - 5 DP - 2015 TI - Immunomodulatory Protein from Ganoderma microsporum Induces Pro-Death Autophagy through Akt-mTOR-p70S6K Pathway Inhibition in Multidrug Resistant Lung Cancer Cells. PG - e0125774 LID - 10.1371/journal.pone.0125774 [doi] LID - e0125774 AB - Chemoresistance in cancer therapy is an unfavorable prognostic factor in non-small cell lung cancer (NSCLC). Elevation of intracellular calcium level in multidrug resistant (MDR) sublines leads to sensitization of MDR sublines to cell death. We demonstrated that a fungal protein from Ganoderma microsporum, GMI, elevates the intracellular calcium level and reduces the growth of MDR subline via autophagy and apoptosis, regardless of p-glycoprotein (P-gp) overexpression, in mice xenograft tumors. In addition, we examined the roles of autophagy in the death of MDR A549 lung cancer sublines by GMI, thapsigargin (TG) and tunicamycin (TM) in vitro. Cytotoxicity of TG was inhibited by overexpressed P-gp. However, TM-induced death of MDR sublines was independent of P-gp level. Combinations of TG and TM with either docetaxel or vincristine showed no additional cytotoxic effects on MDR sublines. TG- and TM-mediated apoptosis of MDR sublines was demonstrated on Annexin-V assay and Western blot and repressed by pan-caspase inhibitor (Z-VAD-FMK). Treatment of MDR sublines with TG and TM also augmented autophagy with accumulation of LC3-II proteins, breakdown of p62 and formation of acidic vesicular organelles (AVOs). Inhibition of ATG5 by shRNA silencing significantly reduced autophagy and cell death but not apoptosis following TG or TM treatment. GMI treatment inhibited the phosphorylation of Akt/S473 and p70S6K/T389. Interestingly, the phosphorylation of ERK was not associated with GMI-induced autophagy. We conclude that autophagy plays a pro-death role in acquired MDR and upregulation of autophagy by GMI via Akt/mTOR inhibition provides a potential strategy for overcoming MDR in the treatment of lung cancers. FAU - Chiu, Ling-Yen AU - Chiu LY AD - Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan. FAU - Hu, Ming-E AU - Hu ME AD - Department of Anatomy, School of Medicine, Chung Shan Medical University, Taichung, Taiwan. FAU - Yang, Tsung-Ying AU - Yang TY AD - Division of Chest Medicine, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan. FAU - Hsin, I-Lun AU - Hsin IL AD - Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan. FAU - Ko, Jiunn-Liang AU - Ko JL AD - Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan; Department of Medical Oncology and Chest Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan. FAU - Tsai, Kan-Jen AU - Tsai KJ AD - School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan. FAU - Sheu, Gwo-Tarng AU - Sheu GT AD - Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan; Department of Medical Oncology and Chest Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20150506 PL - United States TA - PLoS One JT - PloS one JID - 101285081 RN - 0 (ATG5 protein, human) RN - 0 (ATP Binding Cassette Transporter, Subfamily B, Member 1) RN - 0 (Amino Acid Chloromethyl Ketones) RN - 0 (Antineoplastic Agents) RN - 0 (Autophagy-Related Protein 5) RN - 0 (Fungal Proteins) RN - 0 (Microtubule-Associated Proteins) RN - 0 (RNA, Small Interfering) RN - 0 (Taxoids) RN - 0 (benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone) RN - 11089-65-9 (Tunicamycin) RN - 15H5577CQD (Docetaxel) RN - 5J49Q6B70F (Vincristine) RN - 67526-95-8 (Thapsigargin) RN - EC 2.7.1.1 (MTOR protein, human) RN - EC 2.7.11.1 (Proto-Oncogene Proteins c-akt) RN - EC 2.7.11.1 (Ribosomal Protein S6 Kinases, 70-kDa) RN - EC 2.7.11.1 (TOR Serine-Threonine Kinases) SB - IM MH - ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism MH - Amino Acid Chloromethyl Ketones/pharmacology MH - Animals MH - Antineoplastic Agents/*therapeutic use MH - Apoptosis/*drug effects MH - Autophagy/*drug effects MH - Autophagy-Related Protein 5 MH - Carcinoma, Non-Small-Cell Lung/*drug therapy MH - Cell Line, Tumor MH - Docetaxel MH - Drug Resistance, Multiple MH - Drug Resistance, Neoplasm MH - Fungal Proteins/*therapeutic use MH - Ganoderma MH - Humans MH - Lung Neoplasms/*drug therapy MH - Male MH - Medicine, Chinese Traditional MH - Mice MH - Mice, Inbred NOD MH - Microtubule-Associated Proteins/genetics MH - Proto-Oncogene Proteins c-akt/antagonists & inhibitors MH - RNA Interference MH - RNA, Small Interfering MH - Ribosomal Protein S6 Kinases, 70-kDa/antagonists & inhibitors MH - TOR Serine-Threonine Kinases/antagonists & inhibitors MH - Taxoids/therapeutic use MH - Thapsigargin/therapeutic use MH - Tunicamycin/therapeutic use MH - Vincristine/therapeutic use MH - Xenograft Model Antitumor Assays PMC - PMC4422711 COIS- Competing Interests: The authors have declared that no competing interests exist. EDAT- 2015/05/07 06:00 MHDA- 2016/04/26 06:00 PMCR- 2015/05/06 CRDT- 2015/05/07 06:00 PHST- 2014/06/18 00:00 [received] PHST- 2015/03/26 00:00 [accepted] PHST- 2015/05/07 06:00 [entrez] PHST- 2015/05/07 06:00 [pubmed] PHST- 2016/04/26 06:00 [medline] PHST- 2015/05/06 00:00 [pmc-release] AID - PONE-D-14-27200 [pii] AID - 10.1371/journal.pone.0125774 [doi] PST - epublish SO - PLoS One. 2015 May 6;10(5):e0125774. doi: 10.1371/journal.pone.0125774. eCollection 2015.