Non-coding RNAs in cancer immunotherapy: Predictive biomarkers and targets

BACKGROUND

To date, standardising clinical predictive biomarkers for assessing the response to immunotherapy remains challenging due to variations in personal genetic signatures, tumour microenvironment complexities and epigenetic onco-mechanisms.

MAIN BODY

Early monitoring of key non-coding RNA (ncRNA) biomarkers may help in predicting the clinical efficacy of cancer immunotherapy and come up with standard predictive ncRNA biomarkers. For instance, reduced miR-125b-5p level in the plasma of non-small cell lung cancer patients treated with anti-PD-1 predicts a positive outcome. The level of miR-153 in the plasma of colorectal cancer patients treated with chimeric antigen receptor T lymphocyte (CAR-T) cell therapy may indicate the activation of T-cell killing activity. miR-148a-3p and miR-375 levels may forecast favourable responses to CAR-T-cell therapy in B-cell acute lymphoblastic leukaemia. In cancer patients treated with the GPC3 peptide vaccine, serum levels of miR-1228-5p, miR-193a-5p and miR-375-3p were reported as predictive biomarkers of good response and improved overall survival. Therefore, there is a critical need for further studies to elaborate on the key ncRNA biomarkers that have the potential to predict early clinical responses to immunotherapy.

CONCLUSION

This review summarises important predictive ncRNA biomarkers that were reported in cancer patients treated with different immunotherapeutic modalities, including monoclonal antibodies, small molecule inhibitors, cancer vaccines and CAR-T cells. In addition, a concise discussion on forthcoming perspectives is provided, outlining technical approaches for the optimal utilisation of immunomodulatory ncRNA biomarkers as predictive tools and therapeutic targets.

Higher Tumor Mutation Burden Was a Predictor for Better Outcome for NSCLC Patients Treated with PD-1 Antibodies: A Systematic Review and Meta-analysis

This study was conducted to evaluate the predictive efficacy of tumor mutation burden (TMB) in patients with non-small-cell lung cancer (NSCLC) receiving PD-1 antibodies. Embase, PubMed, Ovid Medline, and the Cochrane Library were systematically searched until May 24, 2020. The keywords included "PD-1," "TMB," and "NSCLC." Overall survival (OS) and progression-free survival (PFS) were summarized and combined using the hazard ratio (HR) and 95% confidence interval. Twenty-one studies with 9883 patients were included in the meta-analysis. The overall relapse rate ranged from 39.3% to 64.3% in the higher TMB group as compared with 0% to 40% in the lower TMB group. The median OS ranged from 2.9 to 23 mo in the higher TMB group as compared with 4.3 to 16.2 mo in the lower TMB group. Patients with a higher TMB had a better OS as compared with patients with a lower TMB (HR = 0.61, P < 0.001). Similarly, a higher TMB was also a good predictor of PFS in patients treated with PD1/PDL1 antibodies (HR = 0.55, P < 0.001). Our results suggest that among NSCLC patients receiving PD1/PDL1 antibodies, patients with higher TMB could have a better survival outcome.