This study investigates why some ovarian cancer cells stop responding to cisplatin, a commonly used chemotherapy drug, by focusing on the role of a protein called MMP3. They found that cisplatin-resistant ovarian cancer cells have much higher levels of MMP3 than cisplatin-sensitive ones. When they reduce MMP3 levels using molecular tools, the resistant cells become less able to survive, grow, or invade, especially when combined with cisplatin treatment. They also looked at the changes in many genes and proteins when MMP3 is reduced, showing that many pathways related to cell cycle control, death (apoptosis), metabolism, stress responses, and the structure around cells are affected. In mouse models, targeting MMP3 together with cisplatin led to slower tumor growth compared to treatments alone. The research suggests that MMP3 contributes to multiple processes that allow cancer cells to resist treatment, and that targeting MMP3 may improve response to cisplatin in ovarian cancer.