OTU deubiquitinase 4 is silenced and radiosensitizes non-small cell lung cancer cells via inhibiting DNA repair

Abstract

Background Radiotherapy is becoming one major therapeutics for non-small cell lung cancer (NSCLC). Identifying novel radiosensitizers will greatly increase the efficacy of radiotherapy and benefit more patients. OTU deubiquitinase 4 (OTUD4) has been reported involved in DNA damage repair pathways and could be a potential target for chemotherapy therapy. This study aimed to investigate the roles of OTUD4 in regulation of radiosensitivity of NSCLC via modulating DNA repair. Methods The expression of OTUD4, γ-H2Ax and ATM/CHK2/p53 pathway-related signaling molecules were detected by Western blotting and QRT-PCR. The methylation of OTUD4 promoter was investigated by 5-aza-deoxycytidine treatment, methylation-specific PCR and bisulfite genomic sequencing assays. Radiosensitivity was assessed by the clonogenic formation assay. Cell cycle, cell apoptosis were analyzed by flow cytometry. DNA damage and repair were determined by comet assay, γ-H2Ax foci staining and flow cytometry. Results OTUD4 is dramatically downregulated in NSCLC and its downregulation significantly correlates with poor prognosis of NSCLC patients. Promoter hypermethylation is responsible for the loss of OTUD4 expression in NSCLC cells. Overexpression of OTUD4 increases radiosensitivity of NSCLC cells exhibiting as impaired clonogenic formation ability, enhanced cell cycle arrest and increased cell apoptosis. Moreover, molecular mechanism study reveals that OTUD4 radiosensitizs NSCLC cells via ATM/CHK2/P53 signaling and inhibiting homology-directed repair of DNA double strand breaks induced by ionizing radiation. Conclusions This study uncovers a tumor-suppressing role of OTUD4 and that OTUD4 is a potential radiosensitizer for NSCLC. Electronic supplementary material The online version of this article (10.1186/s12935-019-0816-z) contains supplementary material, which is available to authorized users.

DNMT1 facilitates proliferation and metastasis of breast cancer cells by promoting MEG3 promoter methylation in MEG3/miR-494-3p/OTUD4 regulatory axis

“…This indicated that miR-494-3p targeted down-regulated the expression of OTUD4. OTUD4 has been found to be lowly expressed in non-small cell lung cancer and was able to inhibit the proliferation of cancer cells 28 . In addition, alkylation damage which is critical for cancer chemotherapy can be regulated by OTUD4 29 , but the mechanism of OTUD4 in breast cancer has not been reported.…”

Current Landscape of Epigenetics in Lung Cancer: Focus on the Mechanism and Application

“…At present, with the development of high-throughput technology and the deepening of molecular targeting technology research, in addition to these traditional predictors, abnormal epigenetic molecular markers, such as DNA methylation and noncoding RNA, can also be used for prognosis prediction. Wu et al [81] showed that OTUD4 (OTU deubiquitinase 4) is silenced by promoter methylation and that its downregulation correlates with poor prognosis in NSCLC. Li et al [82] found that four methylation-driven genes, GCSAM, GPR75, NHLRC1, and TRIM58, could serve as prognostic indicators for LUSC.…”

Quercetin radiosensitizes non‐small cell lung cancer cells through the regulation of miR‐16‐5p/WEE1 axis

“…Radiotherapy is one of the main treatments used in the management of advanced non‐small cell lung cancer (NSCLC) . During radiotherapy, ionizing radiation rays destroy the DNA of tumor cells, thereby suppressing their proliferation and inducing their apoptosis . Unfortunately, multiple factors lead to radiation resistance in tumor cells, while the increase in the radiation dose will also increase the risk of radiotherapy‐related complications, such as radiation pneumonitis and radiation pulmonary fibrosis .…”

“…1,2 During radiotherapy, ionizing radiation rays destroy the DNA of tumor cells, thereby suppressing their proliferation and inducing their apoptosis. 3 Abbreviations: 3'-UTR, 3'-untranslated region; DMEM, Dulbecco modified Eagles' medium; FBS, fetal bovine serum; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; miR-NC, miRNA negative control; miRNAs/miRs, microRNAs; NSCLC, non-small cell lung cancer cells; PI, propidium iodide; qRT-PCR, quantitative real-time PCR; WEE1, WEE1 G2 checkpoint kinase.…”