Sylvester Researchers Develop Technique for Growing Ovarian Cancer Cell Lines in Long-Term Culture

Tan A. Ince, MD, PhD

A team of researchers at the Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine has developed a technique for growing ovarian cancer cell lines that mimic the original tumor in long-term cultures. The technique offers hope for quickly advancing precision medicine applications for a variety of cancers by enabling clinicians to test therapies on cells from a patient’s own tumor in the laboratory, thus identifying the most targeted therapy for that patient.

The results of the research, which was led by Tan A. Ince, MD, PhD, associate professor of pathology, Scientific Director of Sylvester’s Live Tumor Culture Core and Tissue Bank Core Facility, and Director of the Tumor Stem Cell Division at the Interdisciplinary Stem Cell Institute, have been published online in the journal Nature Communications in an article entitled “Characterization of Twenty-Five Ovarian Tumour Cell Lines that Phenocopy Primary Tumours.”

The key to Ince’s research is his development of a mixture of essential nutrients in liquid form, commonly referred to as a “cell culture medium,” that permits cells taken from a patient tumor to replicate in a Petri dish and become a permanent cell line faithful to the characteristics of the original tumor over a long period of time in the laboratory. Using the novel medium, his laboratory has developed 25 unique lines using ovarian cancer tumor cells from 26 patients. To achieve this result, with only one failure, is unprecedented.

Ince also sent the cell lines to researchers at several top cancer research institutions, who became co-authors of the journal article, and their findings matched those attained in Ince’s laboratory.

“Standard cell culture media contain 40 to 50 ingredients,” said Ince, who was both first author and corresponding author for the article. “Because they are unable to support living cells on their own, they are supplemented with tissue extracts, feeder layers, anti-apoptic drugs and serum.”

Only a rare minority of cancers are able to grow as cell lines in these media, and when they do, they are often very different at the molecular level from the tumor of origin.

“The medium I have developed over years of experimentation contains more than 80 ingredients that provide all the essential nutrients for maintaining basic cellular metabolism without undefined supplements,” said Ince. “It has enabled us to routinely establish cell lines from diverse subtypes with greater than 95 percent efficiency. Importantly, the 25 new ovarian tumor cell lines retain the genomic landscape, histopathology and molecular features of the original tumors.

“Furthermore, the molecular profile and drug response of these cell lines correlate with distinct groups of primary tumors with different outcomes. Thus tumor cell lines derived using this new methodology represent a significantly improved new platform to study human tumor pathophysiology and response to therapy. I consider this to be some of the most important work that will ever come out of my lab.”

“Dr. Ince’s decades of investment in cancer research are paying off in very important ways for patients with cancer,” said Stephen D. Nimer, M.D., Director of Sylvester Comprehensive Cancer Center, which has provided financial support for Ince’s work. “These cell lines are incredibly valuable because they allow researchers in the field to study the amazing diversity that is routinely seen in each patient’s cancer. This work contributes significantly to our efforts to develop personalized medicine approaches at Sylvester, which will benefit our patients and others around the world.”

“This is the ultimate way to target cancer,” said Ince. “We foresee that this approach can one day be used for personalized oncology, where the in vitro drug-sensitivity profile of each patient’s tumor can be assessed in real time and this information can be used to guide treatment decisions.”

It also will help avoid unnecessary side effects from standard chemotherapy treatments that may prove ineffective.

“Dr. Ince and his colleagues have created a paradigm shift, by demonstrating the ability to grow the majority of human ovarian cancers in long-term culture,” said Richard J. Cote, M.D., Professor and Joseph R. Coulter Chair of the Department of Pathology, professor of biochemistry and molecular biology, Chief of Pathology at Jackson Memorial Hospital, and Director of BioNIUM. “There is no doubt that this technology will become an essential tool in cancer research, and I expect it will become a standard in the application of precision medicine as a critical element in determining the best therapy for the individual patient.”

Ince calls the first 25 cell lines a proof of concept, noting that in a clinical setting, he would make a new cell line for each patient.

“With standard technology, you could do this for only one patient out of 100 who walks through your doors,” he said. “Any technology that applies to 1 percent of patients is not viable, practically or scientifically. Our success rate is 95 percent plus. That puts us for the first time in the clinical application ballpark range, and that’s what we were trying to prove with this paper. It’s no longer research; it’s ready for clinical implementation.”

The next steps involve expanding their methodology to other cancer types such as breast, lung, pancreas, colon and prostate cancers — small pilot studies are already in progress using different media optimized for these tumors to determine the individual response of patients to various cancer drugs.

Moving forward, the real challenge will be unfavorable funding environment starting in 2008 with the financial crisis. “In this case clinical trials are not years away, we’ve done the science and ready to initiate clinical trials; the only thing lacking is funding” Ince said. “It is easier said than done, but this technology could be useful to somebody next month with the right grant or philanthropic support.”

Meanwhile, the cell lines that Ince and his team developed are being made available through the non-profit Live Tumor Culture Core at UM, which is providing cancer cell lines at cost to researchers around the world.

“Dr. Ince’s Pharmacology background, medical training and expertise have uniquely positioned him to develop a potentially groundbreaking approach to the treatment of cancer,” said Norma Sue Kenyon, Ph.D., Martin Kleiman Professor of Surgery, Microbiology and Immunology, and Biomedical Engineering at the Diabetes Research Institute, Chief Innovation Officer and Vice Provost for Innovation at the University of Miami. “U Innovation has been working to determine how best to make this technology available to patients.”

Miller School co-authors in the Nature Communications article were Peter Buchwald, Ph.D., associate professor in the Department of Molecular and Cellular Pharmacology; Senior Research Associates Aurea D. Sousa and Michelle A. Jones; Post-Doctoral Fellows Bin Wang and Abigail E. Witt; and Research Associate Zhanna Kozhekbaeva.