A research team at Bundang CHA Hospital has found the mechanism of recurring and metastatic ovarian cancer, different from general ovarian cancer tissue, by genetic analysis, providing the possibility of developing a stem cell-based therapy.
In general ovarian cancer tissues, cells proliferate and exchange signals actively with their surroundings. However, the cell cycle and signaling system were inhibited in ovarian cancer cells involved in metastasis and recurrence.
The research team, led by Professors Park Hyun and An Hee-jung of Gynecologic Cancer Center at Bundang CHA Hospital, found that the stem cells remained dormant in the cancer cell spheroid. Cancer cell spheroid spreads when it grows in other organs and relapses when the remaining part develops after surgery or chemotherapy.
The research team extracted cells from tumor tissue of patients with ovarian cancer and made a spheroid to identify mechanisms involved in metastasis and recurrence.
The researchers then used the ovarian cancer cell spheroid to measure the degree of expression of major genes micro ribonucleic acid (RNA), including transcription factors.
The result showed that the ovarian cancer cells involved in metastasis and relapse were distinctly different from the original cancer cells. Transcription factors, such as Early Growth Response 1 (EGR1), MYC, and miR-130a-3p, which regulate cancer cells' genes, were also expressed in unusual ways.
These transcription factors actively regulated several genes to reduce cells from proliferating and sending signals. MYC, known to grow tumors, was less expressed, and EGR1, which inhibits tumors, was overly expressed.
“We have confirmed that metastasis and recurrence are caused by cells with significantly different characteristics from normal ovarian cancer cells in this study,” Professor Park said. “Existing therapies that focus on inhibiting proliferation cannot prevent metastasis and recurrence of ovarian cancer. Therefore, treating intractable ovarian cancer requires an understanding of the nature of stem cells and the tumor's surrounding environment.”
The study was published on the latest issue of an international journal, Ovarian Cancer Research.