Abstract C020: Nuclear encoded mitochondrial protein MAGMAS as a potential predictor of taxane sensitivity in advanced prostate cancer patients and differential diagnostic marker of tumor aggressiveness in men of African ancestry
Authors: Duran Alfonso , Whitley Kristen , Santiago Krystal , Das Bhaskar , Casiano Carlos , Almaguel Frankis 
Published: September 2024

Prostate cancer (PCa) is the most commonly diagnosed malignancy and the second leading cause of cancer-related death among men in the United States (U.S.). Strikingly, men of African ancestry (AA) are 1.7 times more likely to be diagnosed with PCa and more than twice as likely to die of PCa than men of European origin (EU). These disparities are driven by socioeconomic, lifestyle, environmental, and biological/genetic factors. Prostate-specific antigen screening is limited in identifying men with aggressive PCa and exposes men to increased harm with minimal reduction in mortality from PCa. Specifically, several studies report that men of AA are considered to have low-risk prostate cancer by clinical parameters, and those who enrolled in active surveillance programs progress to a higher Gleason-grade cancer and high-volume status than men of EA. Also, men of AA in low to moderate-risk groups appear to be at a higher risk for biochemical recurrence after curative-intent treatment. Therefore, there is a need to understand molecular mechanisms underlying PCa aggressiveness in men of AA that are translatable to the clinic as reliable biomarkers and for the development of novel therapeutic targets. Evidence supports that the mitochondria have a fundamental influence on all steps of oncogenesis, including malignant transformation, tumor progression, and treatment resistance. Regarding cancer health disparities, genes encoding mitochondrial complexes involved in oxidative phosphorylation are upregulated to a greater extent in tumor specimens from AA patients than those from EA patients, supporting the rationale for investigating the role of mitochondria in cancer health disparities. This study investigates Magmas, a nuclear-encoded mitochondrial protein, as a potential mitochondrial marker for PCa tumor aggressiveness and a therapeutic target for advanced PCa. Several observations support the rationale for this study: 1) Magmas overexpression in multiple aggressive cancer subtypes, including high-grade prostate, ovarian cancer, and malignant gliomas. 2) AA PCa cell line overexpresses Magmas similar to chemo-resistant PCa cells, whereas the EA cell line is shown to exhibit lower expression. 3) In human cells, overexpression of Magmas suppresses oxidative stress by regulating the reactive oxygen species (ROS) levels. 4) In chemo-resistant PCa cell lines, pharmacological inhibition of Magmas re-sensitized PCa cells to taxane treatment; and 5) non-cytotoxic pharmacological inhibition of Magmas in chemo-resistant PCa cells dramatically reduced clonogenicity potential. We will evaluate the hypothesis that AA PCa tissue will overexpress Magmas and that overexpression will predict tumor aggressiveness, and 2) that pharmacological inhibition of Magmas will overcome treatment resistance in advanced PCa models. The proposed exploratory study is highly relevant as it will reveal the biological basis for race-related differential expression of Magmas, providing critical insights into mitochondrial determinants that contribute to PCa mortality disparities.

Citation Format: Alfonso Duran, Kristen Whitley, Krystal Santiago, Bhaskar Das, Carlos Casiano, Frankis Almaguel. Nuclear encoded mitochondrial protein MAGMAS as a potential predictor of taxane sensitivity in advanced prostate cancer patients and differential diagnostic marker of tumor aggressiveness in men of African ancestry [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C020.