scholarly journals Repression of BET activity sensitizes oral squamous cell carcinoma to PARP inhibition via inhibiting DNA homologous recombination and immune inhibition

2021 ◽  
Author(s):  
Dongdong Tong ◽  
Xin Zhang ◽  
Fenghe Zhang ◽  
xiaojing Liu

Abstract Objective: To investigate the therapeutic resistance mechanism of oral squamous cell carcinoma (OSCC) to the PARP inhibitor olaparib and explore the combination with the BET inhibitor JQ1 to enhance its treatment effects. Material and Methods: Cell proliferation, apoptosis and cell cycle distribution were evaluated. Levels of relevant factors were determined by quantitative real-time PCR, western blot and immunofluorescence. The effect of the combination treatment on xenograft OSCC mouse model was examined.Results: Cal27 cells were more sensitive to the PARP inhibitor olaparib than Scc25 cells. Functional assays demonstrated that olaparib induced HR repair and upregulated PD-L1 expression, which results in drug resistance of OSCC to olaparib. Variations of these factors in the two cell lines may explain different sensitivity to olaparib. Moreover, the JQ1 BET inhibitor and olaparib synergistically exhibited anti-cancer effects in OSCC in vitro and in vivo and inhibited essential HR repair factors RAD51, BRCA1, and TOPBP1 through the ATR/CHK1 pathway and immune suppression mediated by the PD-L1 pathway.Conclusions: Elevated HR and PD-L1 are involved in resistance mechanisms of OSCC to olaparib, attenuating its anti-tumor effects. Our results suggest that the strong synergistic anti-cancer effects of the combination of olaparib with the JQ1 BET inhibitor in OSCC in vitro and in vivo may be via suppression of the ATR/CHK1-mediated DNA damage response and PD-L1-related immune escape, indicating this combination strategy as a possible therapeutic approach for OSCC.

2016 ◽  
Vol 17 (3) ◽  
pp. 272 ◽  
Author(s):  
Masaaki Yasukawa ◽  
Hisako Fujihara ◽  
Hiroaki Fujimori ◽  
Koji Kawaguchi ◽  
Hiroyuki Yamada ◽  
...  

2020 ◽  
Author(s):  
Xiaojing Liu ◽  
Fenghe Zhang ◽  
Xin Zhang

Abstract Background: To investigate the root cause of therapeutic resistance underlying oral squamous cell carcinoma (OSCC) to the PARP inhibitor olaparib and explore the combination with the BET inhibitor JQ1 to augment its treatment effects.Material and Methods: Cell viability were detected in the study. We also evaluated the expression of a series of factors through quantitative real-time PCR, immunofluorescence and western blot. The effect of combining JQ1 and olaparib in xenograft OSCC mouse model was also examined.Results: The sensitivity of Cal27 cells to olaparib was better than Scc25. Functional assays demonstrated that olaparib induced HR repair and upregulated PD-L1 expression, which results in drug resistance of OSCC to olaparib. Variations of these factors in the two cell lines may explain different sensitivity to olaparib. Moreover, the JQ1 BET inhibitor and olaparib synergistically exhibited anti-cancer effects in OSCC in vitro and in vivo and inhibited essential HR repair factors RAD51, BRCA1, and TOPBP1 through the ATR/CHK1 pathway and immune suppression mediated by the PD-L1 pathway.Conclusions: Elevated HR and PD-L1 are involved in resistance mechanisms of OSCC to olaparib, attenuating its anti-tumor effects. Our results suggest that the strong synergistic anti-cancer activity of combining olaparib with BET inhibitor in OSCC may be via suppression of the ATR/CHK1-mediated DNA damage response and PD-L1-related immune escape, indicating this combination strategy as a possible therapy in OSCC.


2015 ◽  
Vol 35 (1) ◽  
pp. 89-98 ◽  
Author(s):  
LIN QUE ◽  
DAN ZHAO ◽  
XIU-FA TANG ◽  
JI-YUAN LIU ◽  
XIANG-YU ZHANG ◽  
...  

2020 ◽  
Vol 12 (8) ◽  
pp. 1022-1029
Author(s):  
Ming Liu ◽  
Chen Lin ◽  
Xiaoqing Huang ◽  
Yuxiang Lin

Natural flavonoid formononetin (FN) has anticancer effects, but the hydrophobic structure, characteristics of the short half-life in vivo, limiting its clinical wide-ranging application. In this study, FN loaded Pluronic (PF)@folic acid (FA) micelles (FN-PF@FA), were prepared to improve the solubility, bioavailability and targeting. FA coupling PF was prepared by carbodiimide crosslinker chemical method, FN-PF@FA micelles were prepared by modified film hydration method, and compared the antitumor activity of FN loaded micelles with free FN In Vitro. The spherical smooth surface of FN-PF@FA micelles had smaller particle size (112.3±5.3 nm), high encapsulation efficiency (86.14±2.68%), high negative zeta potential (-25.8±0.57 mV), low critical concentration CMC (0.03 mg/mL), and better sustained release profile. In addition, FN-PF@FA micelles have a positive targeting effect on oral squamous cell carcinoma cells (SCC3). In 48 hours, the growth inhibition of 50% (GI50) was 28.6±1.2 μg/mL for FN and 17.4±0.78 μg/mL for FN-PF, the dose dropped by nearly 38.46%. In addition, the GI50 value of FN-PF@FA was 9.5±0.3 μg/mL, 66.43% lower than FN and 44.83% lower than FN-PF. Furthermore, the laser scanning confocal microscopy revealed that the conjugation of FA significantly improves the active targeting ability of micelles. FN-PF@FA micelles have the potential to target the release of anticancer drugs with higher bioavailability, further provides a new avenue for the application of traditional Chinese medicine extract in oral malignant tumor.


2020 ◽  
Vol 11 (12) ◽  
Author(s):  
Ze-nan Zheng ◽  
Guang-zhao Huang ◽  
Qing-qing Wu ◽  
Heng-yu Ye ◽  
Wei-sen Zeng ◽  
...  

AbstractOral squamous cell carcinoma (OSCC) is the most common oral cancer. The molecular mechanisms of this disease are not fully understood. Our previous studies confirmed that dysregulated function of long non-coding RNA (lncRNA) AC007271.3 was associated with a poor prognosis and overexpression of AC007271.3 promoted cell proliferation, migration, invasion, and inhibited cell apoptosis in vitro, and promoted tumor growth in vivo. However, the underlying mechanisms of AC007271.3 dysregulation remained obscure. In this study, our investigation showed that AC007271.3 functioned as competing endogenous RNA by binding to miR-125b-2-3p and by destabilizing primary miR-125b-2, resulted in the upregulating expression of Slug, which is a direct target of miR-125b-2-3p. Slug also inhibited the expression of E-cadherin but N-cadherin, vimentin, and β-catenin had no obvious change. The expression of AC007271.3 was promoted by the canonical nuclear factor-κB (NF-κB) pathway. Taken together, these results suggested that the classical NF-κB pathway-activated AC007271.3 regulates EMT by miR-125b-2-3p/Slug/E-cadherin axis to promote the development of OSCC, implicating it as a novel potential target for therapeutic intervention in this disease.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Fengyuan Guo ◽  
Qingming Tang ◽  
Guangjin Chen ◽  
Jiwei Sun ◽  
Junyi Zhu ◽  
...  

Oral squamous cell carcinoma, one of the most prevalent cancer types in the world, has been confirmed under the influence of a key circadian gene, PER2, whose role has been identified in the development of some other types of cancers. However, the mechanism through which PER2 regulates the progress of OSCC remains largely unknown. In this study, we showed that besides the abnormal expression and subcellular localization of PER2 observed in OSCC tissues and cells as expected, these anomalous changes also existed in the adjacent noncancerous tissues, which was a novel finding in our research. The phase of PER2 rhythmic expression pattern in OSCC cells was later than that in oral keratinocytes in the protein level. In addition, we demonstrated that PER2 played as a resistant factor in the development of OSCC by upregulating TP53 and inhibiting epithelial-mesenchymal transition in vitro and in vivo. Taken together, our results identified that the development of OSCC is closely associated with PER2, the aberrant expression and subcellular localization of which facilitates the malignant progress.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Xiaofeng Qi ◽  
Wengguang Xu ◽  
Junqi Xie ◽  
Yufeng Wang ◽  
Shengwei Han ◽  
...  

Abstract Resistance towards chemotherapy is a common complication in treatment of oral cancers, which leads to treatment failure and poor outcome. In recent years, a growing body of evidence has shown that tumour hypoxia significantly contributes to chemoresistance. Metformin, a widely used oral hypoglycaemic drug, can reportedly potentiate the efficacy of chemotherapeutic drugs in various cancers; however, the underlying mechanisms are intricate and have not been fully understood. In this study, we explored the role of metformin in chemosensitivity of oral squamous cell carcinoma cells (OSCC) to cisplatin both in vitro and in vivo, and attempted to elucidate its possible underlying mechanisms. Encouragingly, we found that metformin synergistically enhanced cisplatin cytotoxicity and reversed the chemoresistance to certain extent. This mechanism could likely be related with inhibition of the NF-κB/HIF-1α signal axis and lead to the downregulation of hypoxia-regulated genes products. Therefore, metformin could serve as a chemosensitiser for cisplatin-based regimens for OSCC, thereby providing a theoretical basis for future use in the treatment of oral cancers.


Sign in / Sign up

Export Citation Format

Share Document