Significance of the Tumor Microenvironment in Liver Cancer Progression

The tumor microenvironment (TME) favors the complex interaction of tumor cells with stromal cells that are recognized to be the regulators of hallmarks of liver cancer growth and metastasis. The most common components of TME include cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), and tumor-associated extracellular matrix (ECM) are involved in facilitating the enhancement of liver cancer and can be exploited as potential targets. In addition, cancer stem cells (CSCs) that are known to regulate tumor initiation and progression are present in the TME. All these accumulated factors of the TME represent the driving force for liver cancer progression. This review is focused on the functions of each of the above-mentioned components of the TME and their roles as potential key players in targeting liver cancer.