The Azzam Lab — Cancer Research

Arsenic-associated carcinogenesis is a major global public health concern affecting millions of people through contaminated drinking water. This type of chronic exposure, including those at low levels, has been associated with the formation of cancer stem cells (CSCs) and transformation of non-stem cells into CSCs. In our study, normal, non-malignant ovarian surface epithelial (OCE0 and fallopian tube epithelial (FNE) cells have been grown in the absence or presence of inorganic arsenic, in the form of sodium arsenite (100nM or 1μM), long-term and assessed for cellular and nuclear alterations, including the detection of Giant Nucleated Cells (GNCs) and Multi-Nucleated Cells (MNCs). These primary cultures have been well-characterized and are grown in their own unique media to phenocopy the cells from their respective tissue of origin. By week 3 of arsenic exposure, there are already phenotypic changes in OCE and FNE cells, including changes in their morphology and the formation of GNCs and MNCs. Therefore, we are interested in determining the type of cell responsible and the plausible mechanism(s) that lead to the formation of GNCs and MNCs.

Breast cancer remains one of the leading causes of cancer deaths worldwide in women. The triple-negative breast cancer (TNBC) subtype is the most aggressive, accounting for 40% of the mortality rate within the first 5 years following diagnosis and accounting for 5% of all cancer-related deaths annually. TNBC is highly invasive, leading to metastasis in approximately 46% of patients, with a median overall survival time of only 10.2 months with current therapies. One of the determining factors contributing to tumor heterogeneity, therapy resistance, and recurrence in TNBCs is the presence of a subpopulation of cells known as breast cancer stem cells (BCSCs), which have self-renewal and tumor-initiating potential. Our group has identified a subset of BCSCs that are CD44+CD24low and exhibit increased resistance to radiation therapy and chemotherapy treatment compared to the CD44+CD24neg population. These findings suggest that CD24 expression may play a role in the metastatic potential of BCSCs. In this project, we are investigating the molecular mechanisms of chemoresistance of CD44+CD24low BCSCs to improve treatment options in TNBC patients.

Glioblastoma (GBM) is the most common malignant primary brain tumor in adults, making up 54% of all gliomas. Despite aggressive surgical resection, radiation, and chemotherapy, GBM remains an incurable tumor with a median survival time of only 15 months. Therefore, there is a critical need to understand the mechanisms responsible for the resistance and recurrence in GBM to develop more efficacious therapies. Translocator protein 18kDa (TSPO), previously known as the peripheral benzodiazepine receptor, is expressed at low levels in the normal brain neuropil but becomes highly expressed in several types of brain cancers including gliomas. Several studies have shown a positive correlation between TSPO expression and grade of malignancy and a negative correlation with survival in glioma patients. In addition, the TSPO gene has several polymorphisms that can alter the stability and folding of the protein. While there is some evidence that TSPO genetic polymorphisms may be associated with certain psychiatric disorders such as bipolar disorder, it is not known whether TSPO polymorphisms may have clinical implications in the detection and treatment of brain tumors. As such, our group recently published a study that showed a significant correlation between the TSPO rs6971 polymorphism with the shorter overall survival and progression-free survival in male GBM patients but not in females. These observations suggest that the TSPO rs6971 polymorphism could be a significant predictor of poor prognosis in GBM, with a potential use as a prognostic biomarker in GBM patients. Therefore, our findings could have a direct impact on prognosis and treatment strategies for male and female glioblastoma patients.

Despite increased efforts in whole genome screening of advanced cancers, much work remains to be done in characterizing germline and somatic mutations with matching, targeted treatments. The implementation of functional precision medicine (FPM)—the integration of ex vivo drug screening (DST) and mutation profiling—can, therefore, provide better treatment options for advanced cancer patients. By partnering with Nicklaus Children’s Hospital, our group has demonstrated the feasibility and efficacy of providing individualized treatments to children with a wide variety of advanced cancers including leukemias, sarcomas, glioblastoma, and more. Our feasibility study demonstrated that ex vivo DST can be performed within a clinically actionable timeframe (median: 7 days) and return between 10-30 treatment options for each patient. Overall, FPM-guided treatment regimens obtained in our clinical trial resulted in encouraging partial and complete responses as compared to the progressive disease in prior or physician’s choice regimens. We have, therefore, expanded our studies to include an observational study on newly diagnosed pediatric sarcoma patients. We also have an observational study on relapsed and/or refractory adult sarcoma patients, which we perform in collaboration with oncologists at Cleveland Clinic Florida in Weston, FL.

Guilarte, T. R., A. N. Rodichkin, J. L. McGlothan, A. M. Acanda De La Rocha, and D. J. Azzam. "Imaging Neuroinflammation with Tspo: A New Perspective on the Cellular Sources and Subcellular Localization." Pharmacol Ther 234 (Jun 2022): 108048. https://dx.doi.org/10.1016/j.pharmthera.2021.108048.

Acanda De La Rocha, A. M., M. Fader, E. R. Coats, P. S. Espinal, V. Berrios, C. Saghira, I. Sotto, R. Shakya, M. Janvier, Z. Khatib, H. Abdella, M. Bittle, C. M. Andrade-Feraud, T. R. Guilarte, J. McCafferty-Fernandez, D. Salyakina, and D. J. Azzam. "Clinical Utility of Functional Precision Medicine in the Management of Recurrent/Relapsed Childhood Rhabdomyosarcoma." JCO Precis Oncol 5 (2021). https://dx.doi.org/10.1200/PO.20.00438.

Troike, K. M., A. M. Acanda de la Rocha, T. J. Alban, M. M. Grabowski, B. Otvos, G. Cioffi, K. A. Waite, J. S. Barnholtz Sloan, J. D. Lathia, T. R. Guilarte, and D. J. Azzam. "The Translocator Protein (Tspo) Genetic Polymorphism A147t Is Associated with Worse Survival in Male Glioblastoma Patients." Cancers 13, no. 18 (Sep 8 2021). https://dx.doi.org/10.3390/cancers13184525.

Blevins, L. K., R. B. Crawford, D. J. Azzam, T. R. Guilarte, and N. E. Kaminski. "Surface Translocator Protein 18 Kda (Tspo) Localization on Immune Cells Upon Stimulation with Lps and in Art-Treated Hiv(+) Subjects." Journal of Leukocyte Biology 110, no. 1 (Jul 2021): 123-40. https://dx.doi.org/10.1002/JLB.3A1219-729RR.

Loth, M. K., S. R. Guariglia, D. B. Re, J. Perez, V. N. de Paiva, J. L. Dziedzic, J. W. Chambers, D. J. Azzam, and T. R. Guilarte. "A Novel Interaction of Translocator Protein 18 Kda (Tspo) with Nadph Oxidase in Microglia." Molecular Neurobiology 57, no. 11 (Nov 2020): 4467-87. https://dx.doi.org/10.1007/s12035-020-02042-w.