COX-2 inhibitors and genetic background reduce mammary tumorigenesis in cyclooxygenase-2 transgenic mice

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Cyclooxygenase-2 (COX-2) is overexpressed in human breast cancer, and its inhibitors show antitumor effects.
• Previous studies established COX-2 overexpression as oncogenic, inducing mammary tumors in CD1 mice.
• The FVB/N mouse strain is valuable for studying breast cancer progression.

Purpose of the Study:

• To investigate COX-2-dependent tumor progression in the FVB/N mouse strain.
• To evaluate the efficacy of COX-2 selective inhibitors in a COX-2 transgenic breast cancer model.
• To identify potential genetic modifiers of COX-2-mediated tumorigenesis.

Main Methods:

• Generation of COX-2 transgenic mice in the FVB/N strain.
• Crossing COX-2 transgenic FVB/N mice with C57BL6 mice.
• Treatment of COX-2 transgenic FVB/N mice with celecoxib (COX-2 inhibitor) or SC-560 (COX-1 inhibitor).
• Monitoring tumor size and multiplicity.

Main Results:

• Mammary tumors developed in COX-2 transgenic FVB/N mice after multiple pregnancies.
• Crossing with C57BL6 mice abolished the tumorigenic phenotype despite COX-2 gene induction.
• Celecoxib treatment significantly reduced tumor size and multiplicity in FVB/N mice.
• SC-560 treatment had no significant effect on tumorigenesis.

Conclusions:

• FVB/N mice are a suitable model for studying COX-2-mediated breast cancer progression.
• COX-2 plays a critical role in mammary tumor development and progression.
• Selective COX-2 inhibition demonstrates therapeutic potential for breast cancer.
• This model can aid in identifying interacting genes and novel therapeutic strategies for COX-2-targeted treatments.