Sharks RX Spring 2015 Magazine

COLLEGE OF PHARMACY r 17 triple-negative, but only about 17 percent in European white women, mostly descendants of Ashkenazi Jews. Hispanic women also manifest triple-negative breast cancer, but not as frequently as African American women. Latimer’s and Grant’s recent paper showing that DNA repair is very high in the heart and undetectable in the brain (as well as six other tissues) illustrates this ability using murine tissues. Two NSU pharmacy students, Vongai Majekwana and Yashira Pabon-Padin, participated in this study and were authors on the paper. Environmental, Cultural Factors Latimer’s laboratory has approximately 125 breast tissue cell lines that she created from patients—including normal tissue derived from women who had breast reduction surgeries, and tumor lines—including 13 triple-negative tumors fromEuropean white and African American patients. Her goal is to use these cultures for drug development and discovery. “We’re interested in studying ancestral diversity in breast development and breast cancer,” she said. Latimer and Grant recently teamed up with Jose Lopez, Ph.D., from the NSU Oceanographic Center, in a project to look at the impact of the Deepwater Horizon oil spill on normal breast cultures and on shrimp that humans consume. “Environmental exposure is a significant contributor to 85 percent of all breast cancers,” said Latimer. For 2014–2015, Latimer and her College of Pharmacy team— which includes Grant and graduate students Manasi Pimpley, Omar Ibrahim, and Homood As Sobeai—received a President’s Faculty Research and Development Grant to further their development of a unique method of using cultural human breast epithelial cells, both normal and malignant. “We propose to use nontumor-adjacent cell explants as the basis for development of an assay that tests environ- mental chemicals directly for the ability to ‘transform’ breast cells into malignancy,” she explained in her abstract. The new test will inexpensively establish that a chemical can “transform” a human breast epithelial cell to malig- nancy in culture, according to the abstract. “Cancer is dealt with by the medical community after it has already developed. Our research is driven by defeating it, and part of defeating it is to find out the causes and how to prevent it,” she said. Her research at NSU is an extension of the work she began years ago in Pittsburgh. There, Latimer, Grant, and a team of researchers determined that breast cancers that arise sporadically, rather than through inheritance of certain genes, start with defects of DNA repair mechanisms. The study, published in 2010 in the Proceedings of the National Academy of Sciences, showed that potent chemotherapy drugs that target DNA in later-stage cancers could be an effective way to treat the earliest of breast tumors. The research also found that breast cells do not repair everyday damage to DNA as well as other tissues, such as skin, so the breast is a particularly vul- nerable tissue to environmental toxins. This has led to new research exploring ways to improve the cells’ protective abilities, with the hope of reducing the number of breast cancer cases. “DNA repair is a process that occurs 24 hours a day, seven days a week in the nucleus of every one of your cells, to reverse DNA damage,” Latimer said. The damage can occur because of exposure to radiation, chemicals, and other environmental factors, she added. “The more this damage occurs, the more likely these cells are to become a cancer cell,” but most take 30 years or more to develop, she said. Another important area of their research involves tumor stem cells, which are more resistant to treatment than tumor cells. “If you kill the stem cells, the tumor will peter out, because without stem cells it cannot live. We’re working on an approach that doctors are waiting for,” Grant said. “We scientists are the ultimate purveyors of hope,” Latimer said. “We believe in what we’re doing.” The couple’s 13-year-old daughter, Schaefer (her grandmother’s maiden name), attends NSU’s University School. Latimer has told Schaefer that if her friends ask what her parents do, “she should say we work for mankind. We’ve told her she doesn’t have to be a scientist, but she has to do something to help mankind.” n