Spotlight on a Researcher – Dr. Jean Latimer

Jean Latimer, Ph.D. is a cancer research scientist and an Associate Professor at NSU’s College of Pharmacy. Dr. Latimer also serves as the Director of NSU AutoNation Institute for Breast Cancer Research and Care.

Prior to joining NSU in 2011, Dr. Latimer was an Assistant Professor at the University of Pittsburgh Cancer Institute and conducted research as an independent researcher at the university’s Hillman Cancer Institute. She was also an Adjunct Professor at the Bayer School of Natural and Environmental Sciences at Duquesne University in Pittsburgh. She attended Cornell University for her Bachelor of Arts degree. Following her undergraduate Dr. Latimer received her PhD from SUNY Roswell Park Cancer Institute. After her PhD she pursued postdoctoral research at University of California, San Francisco with embryologist Roger Pedersen and DNA repair biochemist James Cleaver.

Dr. Latimer’s research has resulted in over 30 publications and two patents. She has also authored two books, “Mammography and Beyond: Developing Technologies for the Early Detection of Breast Cancer” (2001) and “Pathways to Breast Cancer: A Case Study for Innovation in Chemical Safety Evaluation” (2010). Currently she leads a team of researchers at NSU and her research is primarily focused on studying DNA damage in human breast tissue due to environmental causes. Some major areas of her lab’s research interest include DNA Repair, stem cells, breast cancer etiology, environmental causes of cancer, genomic instability, and mutation in breast tissue.

Currently, there are several therapies available for breast cancer. However, malignant cells often develop resistance to commonly used chemotherapeutic agents resulting in significant reduction of clinical efficacy. Dr. Latimer’s lab has been conducting research to develop a more efficient therapeutic agent for treating breast malignancies that can overcome this drug resistance. For multiple chemotherapy agents, such as cisplatin and doxorubicin, the mode of action is through targeting DNA of the cancer cells. These chemotherapeutic compounds result in genomic damage and lead to apoptosis of cancer cells. Although this is an effective mechanism of attacking cancer cells, it has a drawback. Cancer cells have a highly active DNA repair pathway that can counter the effect of these chemotherapeutic agents by repairing the drug-induced damages to the genome of cancer cells. This reversal of DNA damage results in resistance to drugs and increases probability of tumor recurrence. One of the major DNA repair mechanisms associated with this resistance to genotoxic cancer drugs is the Nucleotide Excision Repair (NER) pathway. Moreover, NER is significantly enhanced in late-stage breast malignancies comparative to healthy breast tissue or Stage I breast cancer. Therefore, NER is considered a significant reason for clinical resistance to genotoxic anticancer agents in late-stage breast cancer and is a current focus of Dr. Latimer’s work.

NER activity has also been shown to be a predictor of early relapse in certain cancers. Researchers in Dr. Latimer’s lab investigated the association between NER gene expression with drug resistance and relapse in pediatric acute lymphoblastic leukemia (ALL). The findings of this research published in a peer-reviewed article in BMC Medical Genomics showed that NER gene expression among patients relapsing early was significantly higher than over that of the late relapsing group even at diagnosis. Dr. Latimer and other authors of this research article evaluated the relative expression of the 20 canonical genes associated with NER. The data from this research show that increased expression of NER genes is an underlying mechanism of both the initial drug resistance (early relapsers) and eventual relapse in ALL (late relapsers).

 

 

Considering this important role played by NER in resistance to genotoxic anticancer compounds, Dr. Latimer explored the possibility of combining NER regulating or suppressing agent with currently used genotoxic chemotherapy drugs to enhance efficacy in treating breast cancer. To achieve this aim, researchers at Dr. Latimer’s lab implemented novel methods to suppress or inhibit the NER mechanism by inhibiting expression of genes crucial for this process. The researchers applied microRNA compositions for regulating or suppressing functional capacity of NER in breast cancer cells by targeting three genes essential for NER pathway.

Scientific findings from assays on breast cancer cells reported by Dr. Latimer have shown that NER dysregulation is associated with breast cancer and gain of NER function is linked with cancer progression. The application of specific microRNA for suppressing NER in malignant cells makes them more vulnerable to chemotherapeutic agents. To identify the ideal microRNA, researchers at NSU evaluated 800 microRNAs for their possible involvement in NER function. Through these efforts, the researchers in Dr. Latimer’s lab identified and applied a specific microRNA sequence that demonstrated efficacy against three different late-stage breast cancer cell lines. The targeted therapeutic application of this microRNA can be aimed at inhibiting or suppressing genes that are essential for NER function in malignant cells. This invention offers a method of NER regulation in breast cancer, and potentially can be used as the platform for developing new therapeutic procedures for increased clinical efficacy for treating late-stage breast tumors with highly proficient NER function and resistance to existing genotoxic chemotherapy regimens.

The research being conducted in Dr. Latimer’s lab at NSU AutoNation Institute for Breast Cancer Research and Care has resulted in multiple peer-reviewed publications and has significant academic value. Moreover, these findings have substantial therapeutic potential in treating cancer. Considering the possible clinical and commercial value of Dr. Latimer’s research, NSU’s Office of Technology Transfer (OTT) worked with her to apply for a patent for protecting the intellectual property associated with this invention. Currently, Dr. Latimer’s invention related to the use of NER for treatment of cancer is available for licensing (https://www.nova.edu/ott/industry-partners/index.html) through NSU’s OTT so that it can be further developed for commercialization.

In addition to being a researcher, inventor, and teacher, Dr. Latimer has received multiple scholarships, fellowships, and awards, including the Hillman Scholar Award from the University of Pittsburgh Cancer Institute and the U.S. Department of Defense Concept Award for Breast Cancer Research. Dr. Latimer’s dedication and efforts in the field of cancer biology have enabled her to make significant contributions toward a better understanding of the underlying causes and development of therapeutics for treating cancer. As an important member of the NSU community she continues to serve students, conduct research, and develop new inventions that will positively impact the lives of patients.