Therapeutic drugs and drug delivery systems targeting stromal cells for cancer therapy: a review.

Tumour microenvironment provides the 'soil' for tumour growth. Besides tumour cells, there are also numbers of stromal cells, extracellular matrix and other components in the tumour microenvironment. In the past years, kinds of ligands and markers specifically high-expressed on the surface of the tumour stromal cells have been explored, which can be used as the therapeutic targets for cancer treatment. Recently, the antitumor drugs by targeting stromal cells, including small-molecular inhibitor and large-molecular monoclonal antibody, have been widely discovered and applied in clinic attributed to their specific targeting ability. Moreover, the targeted drug delivery system also paid more and more attentions due to their desired profiles in increased accumulation at tumour sites, enhanced antitumor ability and less toxicity and side effects. Therefore, it is of great significance to find and construct drug delivery systems targeting tumour stromal cells. In this review, we discussed the widely recognised therapeutic targets on tumour stromal cells, besides, the current status on the targeting drugs as well as the drug delivery systems were also highlighted.