One of the greatest challenges in cancer therapeutics lies in the ability of tumor cells to easily evade immune surveillance and rapidly develop chemoresistance. However, a recent study led by Dr. Xiaoping Chen at the Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences reported a surprising finding that Plasmodium falciparum, the causative agent for malaria, could induce the apoptosis of cancer cells by invoking a series of immune defense mechanisms. The suspicion began when Dr. Chen noticed an apparent inverse correlation between cancer mortality and malaria incidence. This relationship was confirmed in subsequent investigations that eliminated the possible interference from confounding factors such as differences in life expectancy, socioeconomic status, etc. The group then successfully replicated the antitumor effect of the parasite in a murine model, in which they confirmed that the infection could significantly inhibit cancer growth and metastasis. Detailed mechanistic studies suggested that the lethality of Plasmodium falciparum toward tumor could be attributed to its ability to trigger cytokine release from immune cells such as NK cells and DC cells. The induced immune response to the parasitic infection in turn nullified the immune evasion of the tumor cells. Even more fascinating is the observation that Plasmodium falciparum-infected erythrocytes secreted abundant miRNAs that could suppress angiogenesis in cancer tissues by inducing the apoptosis of vascular endothelial cells. Dr. Chen’s group is currently evaluating the clinical relevance of these experimental results.
