Asperuloside Inhibits Bladder Cancer Cell Migration and Proliferation by Downregulating ATF6 Signalling Pathway and...

This study aimed to determine whether asperuloside (ASP) inhibits the proliferation and invasion of bladder cancer (BLCA) cells and its ability to undergo epithelial-mesenchymal transition (EMT) by downregulating activating transcription factor 6 (ATF6) signalling.

The expression levels of ATF6 and EMT markers were assessed in tumor and surrounding normal tissues obtained from patients with BLCA. In vitro, T24 BLCA cells were transfected with the ATF6 plasmid or a control vector, treated with different concentrations of ASP (0, 1, 3 and 5 mM) and then treated with 5 mM ASP. We examined cell growth, apoptosis (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay), migration and invasion (Transwell), EMT markers (E-cadherin, N-cadherin and Snail) and inflammatory cytokines (interleukin-6 (IL-6), C-C motif ligand 2 (CCL2) and C-X-C motif chemokine ligand 10 (CXCL10)) using Western blot, quantitative real-time polymerase chain reaction (qRT-PCR) and functional assays.

BLCA tissues had significantly higher levels of ATF6 than nearby normal tissues (p < 0.01). ASP treatment decreased cell invasion and migration in a dose-dependent manner (p < 0.05) and markedly increased apoptosis in T24 cells (p < 0.05). E-cadherin was upregulated and N-cadherin and Snail proteins were downregulated (p < 0.05) as a result of changes in the expression of EMT markers. In addition, ASP decreased inflammatory cytokine levels of IL-6, CCL2 and CXCL10 messenger RNA (mRNA) (p < 0.01 vs. control). ATF6 overexpression partially counteracted these effects, confirming ATF6's function in mediating ASP's biological effects.

In T24 BLCA cells, ASP inhibits ATF6, which prevents apoptosis resistance and migration and alters the expression of inflammatory genes and EMT markers. According to these findings, ASP is a promising natural substance that targets the endoplasmic reticulum (ER) stress-ATF6 axis in BLCA. It has a unique multi-target capability that allows it to simultaneously control inflammation, tumour proliferation and metastasis, providing a therapeutic advantage over conventional single-target agents.