Stem cell elimination offers ovarian cancer breakthrough

The medical profession has experienced much difficulty and frustration in detecting and treating ovarian cancer, but researchers at the Yale School of Medicine, Connecticut, believe they have made a major breakthrough. They say eliminating cancer stem cells (CSCs) within a tumor could hold the key to successful treatments.

“We found that stopping the expression of two genes — Lin28 and Oct4 — reduces ovarian cancer cell growth and survival,” said Yingqun Huang, M.D., assistant professor in the Department of Obstetrics, Gynecology and Reproductive Sciences at Yale School of Medicine.

The school reports that ovarian cancer has been challenging to treat because it tends to recur frequently and develop resistance to treatment. Women suffering the disease have been known to present to their doctors with subtle and non-specific symptoms, often resulting in initial misdiagnosis or delays in treatment. Hence the cancer’s moniker of the “disease that whispers.”

“This recurrence and drug resistance may be due to the presence of CSCs within the tumors that have the capacity to reproduce and to differentiate into non-CSC tumor cells that repopulate the tumor mass,” said Huang, who is a member of Yale Stem Cell Center and Yale Cancer Center. “Eliminating these CSCs may be key to successful treatments.”

Huang and her colleagues made the unexpected discovery while studying the functions of stem cell proteins in human embryonic stem cells. They found that a sub-population of ovarian cancer cells express stem cell proteins Lin28 and Oct4. They also found that the two proteins appeared to act together in ovarian cancer tissue cells to produce more advanced tumors. By inhibiting their combined expression the researchers detected a significant decrease in the growth and survival of cancer cells.

To confirm their findings, a larger-scale ovarian cancer study is currently underway.

“We hope we will soon be able to apply this new information to improve outcomes, perhaps by developing better diagnostic markers and treatment strategies that may be useful in customizing treatment for ovarian cancer patients,” said Huang.

The findings will be published in the journal Oncogene by Yale school of medicine researchers. Other Yale authors on the study included Nita Maihle and Shuping Peng.

The study was supported by Connecticut Innovations, the Fannie E. Rippel Foundation and the National Cancer Institute.