IRE1α-TRAF2-ASK1 complex-mediated endoplasmic reticulum stress and mitochondrial dysfunction contribute to...

Area of Science:

• Oncology
• Molecular Biology
• Cell Biology

Background:

• Bladder urothelial carcinoma (UC) presents a significant global health challenge, with current treatments offering limited impact on patient survival.
• Existing therapies for UC primarily focus on extending recurrence intervals rather than improving overall patient survival rates.

Purpose of the Study:

• To investigate the anti-cancer properties of CXC195 against human UC T24 cells.
• To elucidate the molecular mechanisms underlying CXC195's anti-cancer effects in UC.

Main Methods:

• Cell viability assays were performed to assess the impact of CXC195 on T24 cell growth.
• Apoptosis was evaluated using caspase- and mitochondrial-dependent assays.
• Western blotting and co-immunoprecipitation were employed to analyze protein expression and interactions within ER stress signaling pathways.
• Small interfering RNA (siRNA) was used to knock down IRE1α expression.

Main Results:

• CXC195 significantly inhibited T24 cell growth and induced apoptosis via caspase- and mitochondrial-dependent pathways.
• CXC195 treatment led to the activation of ER stress signaling proteins, including GRP78, CHOP, IRE1α, TRAF2, p-ASK1, and p-JNK.
• Co-immunoprecipitation revealed that IRE1α activation, through the formation of an IRE1α-TRAF2-ASK1 complex, mediated JNK activation.
• Knockdown of IRE1α using siRNA abrogated CXC195-induced apoptosis and the activation of downstream signaling molecules.

Conclusions:

• CXC195 exhibits potent anti-cancer activity against bladder urothelial carcinoma cells.
• The anti-cancer effects of CXC195 are mediated through the induction of ER stress and subsequent activation of the IRE1α-TRAF2-ASK1-JNK signaling pathway.
• These findings offer novel insights into the therapeutic potential of CXC195 for treating human UC.