Immune checkpoint inhibitors in non-small-cell lung cancer: current status and future directions.

Since 2015, immunotherapies, especially immune checkpoint inhibitors (ICIs), have made great breakthroughs in non-small-cell lung cancer (NSCLC). Among them, nivolumab, pembrolizumab and atezolizumab have been granted US Food and Drug Administration approval for NSCLC. It is imperative to combine ICIs with chemotherapy, radiotherapy, antivascular therapy and targeted therapy. But in the bright future, there are two problems. One is how to use biomarkers to select the beneficiaries. The other is how to achieve a balance between drug effectiveness and safety. There are now seven drugs targeting the programmed death-1/programmed death ligand-1 (PD-1/PD-L1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) pathways that have been or are expected to enter clinical treatment. This review focuses on these drugs and summarizes clinical trials that have been reported or that ongoing ones have already entered the recruiting state.

Endostar enhances the antitumor effects of radiation by affecting energy metabolism and alleviating the tumor microenvironment in a Lewis lung carcinoma mouse model.

Lung cancer is a leading cause of morbidity and mortality. Previous studies have identified that an improvement in treatment efficacy was achieved using Endostar; however, the role of Endostar in lung cancer remains poorly understood. The present study investigated whether the enhanced antitumor effects of Endostar in combination with radiation involved changes in the metabolism and microenvironment in non-small cell lung cancer. A Lewis lung carcinoma mouse model was used, including the control, Endostar (ES), radiotherapy (RT) and Endostar plus radiotherapy (ES + RT) groups. The tumor inhibition rates and growth were described based on changes in tumor volume. In addition, ultraviolet enzymatic analysis was performed to determine the lactate level and reverse transcription-polymerase chain reaction was used to measure the mRNA expression of lactate dehydrogenase (LDH). A Meph-3 pH meter was used to detect the ranges of tumor interstitial tissue pH, and immunohistochemical analysis was adopted to examine hypoxia within the tumor microenvironment. The tumor inhibition rate of the ES + RT group was significantly higher compared with the other three groups (P<0.05). Following treatment, the lactate levels decreased in all three treatment groups compared with the control, particularly in the ES + RT group (P<0.05). Reduced LDH expression and hypoxic fraction in the tumor microenvironment were also observed in the ES + RT group (P<0.05). Furthermore, changes from acidic to alkaline pH in the tumor microenvironment were detected in the ES + RT group. The present study suggested that Endostar is involved in the regulation of metabolism and tumor microenvironment hypoxia, which may be responsible for the enhanced antitumor effect of Endostar in combination with radiotherapy.