Immunotherapy against programmed death-1/programmed death ligand 1 in hepatocellular carcinoma: Importance of molecular variations, cellular heterogeneity, and cancer stem cells

摘要

Hepatocellular carcinoma(HCC)is a heterogeneous malignancy related to diverse etiological factors.Different oncogenic mechanisms and genetic variations lead to multiple HCC molecular classifications.Recently,an immune-based strategy using immune checkpoint inhibitors(ICIs)was presented in HCC therapy,especially with ICIs against the programmed death-1(PD-1)and its ligand PD-L1.However,despite the success of anti-PD-1/PD-L1 in other cancers,a substantial proportion of HCC patients fail to respond.In this review,we gather current information on biomarkers of anti-PD-1/PD-L1 treatment and the contribution of HCC heterogeneity and hepatic cancer stem cells(CSCs).Genetic variations of PD-1 and PD-L1 are associated with chronic liver disease and progression to cancer.PD-L1 expression in tumoral tissues is differentially expressed in CSCs,particularly in those with a close association with the tumor microenvironment.This information will be beneficial for the selection of patients and the management of the ICIs against PD-1/PD-L1.