Natural Killer Cells Show Memory and Potent Attack Against Ovarian Cancer, New Research Finds

Researchers from Karolinska Institutet have uncovered a remarkable property of a specific subtype of natural killer (NK) cells, known as adaptive NK cells, which can recognize and remember ovarian tumor cells. Published in the journal Cancer Immunology Research, this breakthrough suggests that these cells can remember tumor-specific signals, infiltrate ovarian tumors, and collaborate with other components of the immune system to effectively destroy cancer cells. This discovery could lead to the development of innovative immunotherapies for ovarian cancer, a disease that is often difficult to treat successfully.

Natural killer cells are a crucial part of the immune system, acting as frontline defenders by identifying and eliminating virally infected and cancerous cells without prior exposure. Traditionally regarded as innate immune cells lacking memory, this study challenges that perception by demonstrating that adaptive NK cells can develop tumor-specific immune memory. The research involved analyzing human immune cells and ovarian tumor tissues using advanced RNA and gene expression techniques at the single-cell level. These insights reveal that adaptive NK cells not only remember past encounters with tumor cells but also actively respond to and combat ovarian cancer.

Dhifaf Sarhan, a senior lecturer at Karolinska Institutet and lead researcher, emphasizes the therapeutic potential of these findings. "Our results indicate that enhancing the activity and number of adaptive NK cells could significantly improve treatment outcomes for patients with ovarian cancer," she notes. She further states that the study opens new avenues for immunotherapy development by redefining the roles of NK cells and their capacity for immune memory.

The team’s future plans include developing methods to boost the presence and function of adaptive NK cells in patients, ultimately progressing to clinical trials to assess their efficacy in improving survival rates. This research paves the way for more effective cancer immunotherapies, especially for those with hard-to-treat ovarian tumors.

For more detailed information, see the original study: Yizhe Sun, et al. Adaptive NK Cells Exhibit Tumour-Specific Immune Memory and Cytotoxicity in Ovarian Cancer (2025).