Inducing cells apoptosis has always been considered one way to cure cancer. However, according to the latest research, it may not be that simple. Through the study on lymphoma and melanoma, scientists from UK has found that apoptotic cells could accelerate the growth of cancer cells and the assemble and vasculogenesis of tumor-associated macrophages TAM. The study was published in Current Biology.

Cells undergoing apoptosis are known to modulate their tissue microenvironments. By acting on phagocytes, notably macrophages, apoptotic cells inhibit immunological and inhibit immunological and inflammatory responses and promote trophic signaling pathways. Paradoxically, because of their potential to cause death of tumor cells and thereby militate against malignant disease progression, both apoptosis and tumor-associated macrophages(TAMs) are often associated with poor prognosis in cancer.

In this study, researchers demonstrate that apoptotic tumor cells promote coordinated tumor growth, angiogenesis, and accumulation of TAMs in aggressive B cell lymphomas. Through unbiased “in situ transcriptomics” analysis-gene expression profiling of laser-captured TAMs to establish their activation signature in situ. They show that these cells are activated to signal via multiple tumor-promoting reparatory, trophic, angiogenic, tissue remodeling, and anti-inflammatory pathways.

The research also shows that apoptotic lymphoma cells help drive this signature. Furthermore, they demonstrate that ,upon induction of apoptosis, lymphoma cells not only activate expression of the tumor-promoting matrix metalloproteinases MMP2 and MMP12 in macrophages but also express and process these MMPs directly.

These results have important implications for understanding the fundamental biology of cell death, its roles in malignant disease, and the broader consequences of apoptosis-inducing anti-cancer therapy.

Reference:

Ford C A, Petrova S, Pound J D, et al. Oncogenic Properties of Apoptotic Tumor Cells in Aggressive B Cell Lymphoma[J]. Current Biology, 2015, 25(5): 577-588.