microRNA-20b-5p overexpression combing Pembrolizumab potentiates cancer cells to radiation therapy via repressing programmed death-ligand 1

Abstract

Radiation therapy (RT) is widely applied in cancer treatment. The sensitivity of tumor cells to RT is the key to the treatment. This study probes the role and mechanism of miR-20b-5p in Pembrolizumab’s affecting the radiosensitivity of tumor cells. After Pembrolizumab treatment or cell transfection (miR-20b-5p mimics and miR-20b-5p inhibitors), tumor cells (NCI-H460 and ZR-75-30) were exposed to RT. The sensitivity of NCI-H460 and ZR-75-30 to RT was evaluated by monitoring cell proliferation and apoptosis. The dual-luciferase reporter assay and RNA immunoprecipitation (RIP) were adopted to evaluate the binding relationship between miR-20b-5p and CD274 (PD-L1). The xenograft model was established in nude mice to examine the mechanism of action of Pembrolizumab in vivo . Our outcomes exhibited that either Pembrolizumab treatment or miR-20b-5p overexpression potentiated radiosensitivity of tumor cells. Overexpressing miR-20b-5p enhanced radiosensitization of Pembrolizumab in vivo and in vitro by targeting PD-L1 and inactivating PD-L1/PD1. Overall, miR-20b-5p overexpression combined with Pembrolizumab potentiated cancer cells’ sensitivity to RT by repressing PD-L1/PD1. Abbreviations Akt: serine/threonine kinase 1; cDNA: complementary DNA; CO 2 : carbon dioxide; EDTA: Ethylene Diamine Tetraacetic Acid; ENCORI: The Encyclopedia of RNA Interactomes; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; IGF2BP2: insulin like growth factor 2 mRNA binding protein 2; IHC: Immunohistochemistry; LncRNA MALAT1: Long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1; miRNAs: MicroRNAs; Mt: Mutant type; MTT: 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide; NC: negative control; NR2F2: nuclear receptor subfamily 2 group F member 2; NSCLC: non-small cell lung cancer; OD: optical density; PBS: phosphate-buffered saline; PD-L1: Programmed death-ligand 1; PD-1: programmed death 1; PI3K: phosphatidylinositol 3-kinase; qRT-PCR: Quantitative reverse transcription-polymerase chain reaction; RIP: RNA immunoprecipitation; RIPA: Radio Immunoprecipitation Assay; RRM2: ribonucleotide reductase regulatory subunit M2; RT: Radiation therapy; U6: U6 small nuclear RNA; V: volume; WB: Western blot; Wt: wild type; x ± sd: mean ± standard deviation.

Comprehensive analysis of microRNA (miRNA) in cancer cells

“…Today, microRNAs are widely used in cancer treatment and radiation therapy (RT). The results have shown that the high expression of miR-20b-5p in tumor cells makes these cells more sensitive to radiation therapy, which has led to an increase in the efficiency of this treatment method [42]. Xiang et al showed that miR-139-5p in bone marrow mesenchymal stem cells (BMSCs) delays tumorigenesis and metastasis of bladder cancer cells in vivo by inactivating the p21 factor [43].…”

The effect and mechanism of miR-30e-5p targeting SNAI1 to regulate epithelial-mesenchymal transition on pancreatic cancer

“…The formula of calculating cells using cell count plates: the cell numbers in the per milliliter cell suspension = total cell numbers in the four big squares/4 * 10,000. The cell survival fraction = Experimental groups (OD)/Control groups (OD) [ 22 , 24 ].…”

Long noncoding RNA regulatory factor X3- antisense RNA 1 promotes non-small cell lung cancer via the microRNA-577/signal transducer and activator of transcription 3 axis

“…After the membranes were flushed with tap water, cell numbers were calculated with an inverted microscope (magnification: ×200; Olympus Corporation). All other steps of the migration experiment were the same as the invasion experiment except that Matrigel was not used [ 23 ].…”