Macrophage Flipping from Foe to Friend: A Matter of Interest in Breast Carcinoma Heterogeneity Driving Drug Resistance

Tumor heterogeneity within various cancer types including breast carcinoma is pivotal in the manifestations of tumor hallmarks. Tumor heterogeneity is seen as a common landscape where intra-tumoral components including cellular and non-cellular factors create an interface with outside environment that leads to the unique identity of a specific cancer type. Among various contributors to tumor heterogeneity, cellular heterogeneity immensely plays a role in drug resistance and relapse of cancer. Within cellular heterogeneity of tumor, tumor-associated macrophages (TAMs) are the pro-tumor type of immune cells that promote growth, metastasis and drug resistance in breast carcinoma and other cancer types. Revealing the molecular aspects of TAMs can provide a breakthrough to remove therapeutics blockade to existing drugs and this understanding in future will pave the way for a new class of cancer immunotherapeutic. This review addresses current understanding of the role of TAMs in breast carcinoma hallmarks and clarifies the current scenario of pre-clinical drugs directed to tame pro-cancer TAMs.