Adaptive stress response signaling driving treatment resistance and metastasis in cancer

Cancer deaths are driven by two key biological processes: metastasis and treatment resistance. Although these processes are extensively studied as unrelated occurrences, evidence of shared signaling networks suggests common genetic or adaptive events. These pathways will change a therapy-responsive tumour to a resistant and lethal tumour. This occurs in prostate cancer where strategies used to kill tumours induce adaptive responses promoting the emergence of treatment-resistant tumours prone to metastasize. There is limited study of linkages between metastasis and treatment resistance, and Dr. Amina Zoubeidi’s research program will address an important knowledge gap in our understanding of aggressive tumour behavior in prostate cancer. The hope is that this research will translate into novel therapeutic development for prostate and other human cancers.

Zoubeidi’s work will be facilitated by her recent development of novel cell lines and xenograft models of prostate cancer that are resistant to a new generation of the AR pathway inhibitor drugs MDV3100 and abiraterone. These drugs, while recently introduced as therapeutics for patients with castration-resistant prostate cancer, offer survival gains of only four months and promote MDV- or abi-resistance. Zoubeidi has observed that MDV-resistant tumours metastasize whereas the castration-resistant tumours from which they were derived are non-metastatic. These observations suggest that tumours acquire metastatic traits in parallel with drug resistance.

Zoubeidi’s research program will focus on identifying common molecular mechanisms that elicit both metastasis and resistance to this new generation of prostate cancer drugs. Because tumour invasion and resistance dictate treatment outcome, pathways identified with this approach will represent relevant targets that can be inhibited singularly or jointly as more effective therapy. The research program is organized under three themes: the role of sustained AR activation in these processes; mechanisms associated with acquired EMT and their abilities to elicit treatment resistance; and the emergence of cancer cell “stem-ness” as a common mechanism driving treatment resistance and metastasis.