title: HSPA6 augments garlic extract-induced inhibition of proliferation, migration, and invasion of bladder cancer EJ cells; Implication for cell cycle dysregulation, signaling pathway alteration, and transcription factor-associated MMP-9 regulation.
abstract: Although recent studies have demonstrated the anti-tumor effects of garlic extract (GE), the exact molecular mechanism is still unclear. In this study, we investigated the molecular mechanism associated with the inhibitory action of GE against bladder cancer EJ cell responses. Treatment with GE significantly inhibited proliferation of EJ cells dose-dependently through G2/M-phase cell cycle arrest. This G2/M-phase cell cycle arrest by GE was due to the activation of ATM and CHK2, which appears to inhibit phosphorylation of Cdc25C (Ser216) and Cdc2 (Thr14/Tyr15), this in turn was accompanied by down-regulation of cyclin B1 and up-regulation of p21WAF1. Furthermore, GE treatment was also found to induce phosphorylation of MAPK (ERK1/2, p38MAPK, and JNK) and AKT. In addition, GE impeded the migration and invasion of EJ cells via inhibition of MMP-9 expression followed by decreased binding activities of AP-1, Sp-1, and NF-κB motifs. Based on microarray datasets, we selected Heat shock protein A6 (HSPA6) as the most up-regulated gene responsible for the inhibitory effects of GE. Interestingly, overexpression of HSPA6 gene resulted in an augmentation effect with GE inhibiting proliferation, migration, and invasion of EJ cells. The augmentation effect of HSPA6 was verified by enhancing the induction of G2/M-phase-mediated ATM-CHK2-Cdc25C-p21WAF1-Cdc2 cascade, phosphorylation of MAPK and AKT signaling, and suppression of transcription factor-associated MMP-9 regulation in response to GE in EJ cells. Overall, our novel results indicate that HSPA6 reinforces the GE-mediated inhibitory effects of proliferation, migration, and invasion of EJ cells and may provide a new approach for therapeutic treatment of malignancies.
authors.affiliation: Department of Food Science and Nutrition, Jeju National University, Jeju, South Korea.
authors.forename: Seung-Shick
authors.initials: SS
authors.lastname: Shin
authors.affiliation: Department of Food and Nutrition, Chung-Ang University, Anseong, South Korea.
authors.forename: Jun-Hui
authors.initials: JH
authors.lastname: Song
authors.affiliation: Department of Food and Nutrition, Chung-Ang University, Anseong, South Korea.
authors.forename: Byungdoo
authors.initials: B
authors.lastname: Hwang
authors.affiliation: Department of Food and Nutrition, Chung-Ang University, Anseong, South Korea.
authors.forename: Dae-Hwa
authors.initials: DH
authors.lastname: Noh
authors.affiliation: Department of Food and Nutrition, Chung-Ang University, Anseong, South Korea.
authors.forename: Sung Lyea
authors.initials: SL
authors.lastname: Park
authors.affiliation: Department of Urology, Chungbuk National University, Cheongju, Chungbuk, South Korea.
authors.forename: Won Tae
authors.initials: WT
authors.lastname: Kim
authors.affiliation: Department of Food Science and Nutrition, Jeju National University, Jeju, South Korea.
authors.forename: Sung-Soo
authors.initials: SS
authors.lastname: Park
authors.affiliation: Department of Urology, Chungbuk National University, Cheongju, Chungbuk, South Korea.
authors.forename: Wun-Jae
authors.initials: WJ
authors.lastname: Kim
authors.affiliation: Department of Food and Nutrition, Chung-Ang University, Anseong, South Korea.
authors.forename: Sung-Kwon
authors.initials: SK
authors.lastname: Moon
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D064447:Checkpoint Kinase 2 / Q000378:metabolism; D005737:Garlic / Q000737:chemistry*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D020935:MAP Kinase Signaling System; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D010936:Plant Extracts / Q000494:pharmacology*; D001749:Urinary Bladder Neoplasms / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D018840:HSP70 Heat-Shock Proteins; C544598:HSPA6 protein, human; D010936:Plant Extracts; D064447:Checkpoint Kinase 2; C578634:CHEK2 protein, human; C579270:MMP9 protein, human; D020780:Matrix Metalloproteinase 9