IRE1α-XBP1s pathway promotes prostate cancer by activating c-MYC signaling

Area of Science:

• Oncology
• Molecular Biology
• Cellular Biology

Background:

• Endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) are implicated in cancer.
• The precise molecular mechanisms linking UPR to cancer and therapeutic strategies remain unclear.

Purpose of the Study:

• To investigate the role of the IRE1α-XBP1s pathway in prostate cancer (PCa).
• To evaluate the therapeutic potential of targeting this pathway in PCa.

Main Methods:

• Utilized an IRE1α RNase-specific inhibitor (MKC8866) in preclinical PCa models.
• Performed global transcriptomic analysis to assess pathway activity.
• Correlated XBP1-specific gene expression signatures with PCa prognosis.

Main Results:

• MKC8866 demonstrated significant inhibition of PCa tumor growth as monotherapy and synergistic effects with existing drugs.
• IRE1α-XBP1s pathway activity was found to be essential for c-MYC signaling in PCa.
• Established a direct link between UPR activation and oncogene expression, with XBP1s regulating c-MYC.
• An XBP1-specific gene signature strongly correlated with PCa patient prognosis.

Conclusions:

• The IRE1α-XBP1s signaling pathway is a critical regulator in prostate cancer.
• Targeting IRE1α-XBP1s represents a promising novel therapeutic strategy for prostate cancer.
• Understanding the UPR-oncogene link provides new avenues for cancer treatment development.