Role of therapeutic agents on repolarisation of tumour-associated macrophage to halt lung cancer progression

Tumour-associated macrophages (TAMs) represent as much as 50% of the solid mass in different types of human solid tumours including lung, breast, ovarian and pancreatic adenocarcinomas. The tumour microenvironment (TME) plays an important role in the polarisation of macrophages into the M1 phenotype, which is tumour-suppressive, or M2 phenotype, which is tumour promoting. Preclinical and clinical evidences suggest that TAMs are predominantly of the M2 phenotype that supports immune suppression, tumour growth, angiogenesis, metastasis and therapeutic resistance. Hence, significant attention has been focussed on the development of strategies for the modification of TAMs to halt lung cancer progression. The promotion of repolarisation from the M2 to the M1 subtype, or the prevention of M2 polarisation of TAMs in the stromal environment is potential approaches to reduce progression and metastasis of lung cancer. The focus of this article is an introduction to the development and evaluation of therapeutic agents that may halt lung cancer progression via the manipulation of macrophage polarisation. This article will address recent advances in the therapeutic efficacy of nanomedicine exploiting surface functionalisation of nanoparticles and will also consider future perspectives.