KRAS mutation coupled with p53 loss is sufficient to induce ovarian carcinosarcomas in mice

Area of Science:

• Oncology
• Gynecologic Oncology
• Cancer Biology

Background:

• Ovarian carcinosarcoma is a rare and highly lethal gynecologic malignancy.
• The underlying pathogenesis and biological drivers of ovarian carcinosarcoma remain poorly understood.
• Endometriosis is a potential precursor, but its role in malignant transformation is unclear.

Purpose of the Study:

• To establish a novel transgenic mouse model for studying ovarian carcinosarcoma.
• To investigate the role of K-ras mutation and p53 deletion in ovarian cancer development.
• To explore the potential link between endometriosis and ovarian carcinosarcoma pathogenesis.

Main Methods:

• Development of a K-ras^G12D p53^loxP/loxP transgenic mouse model.
• Induction of K-ras mutation and p53 deletion in ovarian surface epithelium.
• Histopathological analysis of induced ovarian lesions and tumors.
• Confirmation of K-ras^G12D role in MCAS and PA-1 ovarian cancer cell lines.

Main Results:

• K-ras mutation and p53 deletion induced ovarian lesions with hyperproliferation and endometrioid glandular morphology.
• Double mutant ovaries developed high-grade, poorly differentiated ovarian carcinosarcomas.
• Tumors exhibited rapid metastasis to abdominal organs (liver, spleen, kidney).
• K-ras^G12D overexpression increased proliferation, migration, and invasion in ovarian cancer cells.

Conclusions:

• The developed mouse model accurately recapitulates ovarian carcinosarcoma histomorphology and metastatic potential.
• K-ras^G12D mutation and p53 loss are critical drivers of ovarian carcinosarcoma.
• The model provides insights into the probable mechanism of malignant transformation in endometriosis-associated ovarian cancer.