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.

Medicinal Plants Used in Traditional Management of Cancer in Uganda: A Review of Ethnobotanical Surveys, Phytochemistry, and Anticancer Studies

“…Diallyl thiosulfinate (allicin) (4), diallyl sulfide (DAS) (5), diallyl disulfide (DADS) (6), diallyl trisulfide (DATS) (7), E-ajoene (8), Z-ajoene (9), S-allyl-cysteine (SAC) (10), and S-allyl-cysteine sulfoxide (alliin) (11) [60] Extracts exhibited an antiproliferative effect on human cancer cell lines, including liver (HepG2), colon (Caco2), prostate (PC-3), and breast (MCF-7) cancer cells [61]. Extracts induced G2/M-phase cell cycle arrest in EJ bladder cancer cells [62]. DATS suppressed the proliferation of SGC-7901 gastric cancer cells [63] SAC induced cell cycle arrest in A2780 human epithelial ovarian cancer cells [64].…”

APC-activated long noncoding RNA inhibits colorectal carcinoma pathogenesis through reduction of exosome production

“…These findings indicate that lncRNA-APC1 might interact with Rab5b mRNA. Next, to test whether lncRNA-APC1 regulates the stability of Rab5b mRNA, we treated DLD-1 and SW480 cells with α-amanitin to block RNA polymerase II-mediated new RNA synthesis microarray, we first measured the expression of the factors HSPA6 and PPM1B, both of which can inhibit the MAPK pathway (31)(32)(33)(34). qRT-PCR data confirmed a significant decrease in the expression of both HSPA6 and PPM1B in HUVECs treated with exosomes derived from lncRNA-APC1-silenced HCT116 cells ( Figure 11B).…”

Identification of the anticancer effects of a novel proteasome inhibitor, ixazomib, on colorectal cancer using a combined method of microarray and bioinformatics analysis

“…Although the function of HSPA6 remains far more to be elucidated due to limited researches, a recent study has demonstrated that HSPA6 augmented garlic extract-induced inhibition of proliferation, migration, and invasion of bladder cancer cells. 32 In that study, HSPA6 was the most highly upregulated gene in bladder cancer EJ cells after garlic extract treatment. 32 Overexpression of HSPA6 has been verified to enhance the G2/M phase cell cycle arrest and the inhibition of matrix metallopeptidase 9 enzyme activity induced by garlic extract.…”