Impact of the APE1 Redox Function Inhibitor E3330 in Non-Small Cell Lung Cancer Cells Exposed to Cisplatin: Increased Cytotoxicity and Impairment of Cell Migration and Invasion

Abstract

Elevated expression levels of the apurinic/apyrimidinic endonuclease 1 (APE1) have been correlated with the more aggressive phenotypes and poor prognosis of non-small cell lung cancer (NSCLC). This study aimed to assess the impact of the inhibition of the redox function of APE1 with E3330 either alone or in combination with cisplatin in NSCLC cells. For this purpose, complementary endpoints focusing on cell viability, apoptosis, cell cycle distribution, and migration/invasion were studied. Cisplatin decreased the viability of H1975 cells in a time- and concentration-dependent manner, with IC50 values of 9.6 µM for crystal violet assay and 15.9 µM for 3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. E3330 was clearly cytotoxic for concentrations above 30 µM. The co-incubation of E3330 and cisplatin significantly decreased cell viability compared to cisplatin alone. Regarding cell cycle distribution, cisplatin led to an increase in sub-G1, whereas the co-treatment with E3330 did not change this profile, which was then confirmed in terms of % apoptotic cells. In addition, the combination of E3330 and cisplatin at low concentrations decreased collective and chemotactic migration, and also chemoinvasion, by reducing these capabilities up to 20%. Overall, these results point to E3330 as a promising compound to boost cisplatin therapy that warrants further investigation in NSCLC.

Small-molecule inhibition of APE1 induces apoptosis, pyroptosis, and necroptosis in non-small cell lung cancer

“…The knockdown of APE1 by RNA interference has been shown to induce apoptosis in human cancer cell lines 51 . Our data indicated that NO.0449-0145 treatment induced cell apoptosis in both A549 and NCI-H460 cells, consistent with the results reported for other APE1 inhibitors, such as APX3330, which induced apoptosis in multiple tumor cell lines 14 , 17 . Intriguingly, we also observed some NO.0449-0145 treated cells characterized by cytoplasmic swelling and plasma membrane bubbles, followed by plasma membrane rupture and the subsequent loss of intracellular contents.…”

“…Elevated DNA repair activity has been correlated with cisplatin resistance 5 . A previous study showed that the co-incubation cells with APX3330 and cisplatin significantly decreased cell viability compared with cisplatin alone 17 . Our study showed that NO.0449-0145 treatment alone was able to overcome cisplatin resistance in A549-DDP cell and sensitize A549-DDP cells to cisplatin treatment, implying that the inhibition of APE1 by a small-molecule inhibitor may be used to overcome chemotherapeutic resistance in lung cancer treatment.…”

“…Furthermore, APX3330 treatment effectively reversed the epithelial‐to‐mesenchymal transition (EMT) phenotype and further sensitized cells to epidermal growth factor receptor (EGFR)‐TKIs 34 . In addition, APX3330 increased the cisplatin-induced cytotoxicity and impairment of cell migration and invasion in NSCLC cells, indicating that APX3330 might represent a promising compound for boosting cisplatin therapy 17 . However, the application of APE1 endonuclease inhibitors for NSCLC therapy remains limited.…”

Role of Base Excision Repair Pathway in the Processing of Complex DNA Damage Generated by Oxidative Stress and Anticancer Drugs

“…Several APE1 inhibitors have been generated and explored, which can specifically target either AP site cleavage activity [methoxyamine and APE1 inhibitor compound III (API3)] or redox regulation function (E3330 and Gossypol/AT101) of human enzyme (reviewed in Laev et al, 2017). A recent study demonstrated that the combination of cisplatin treatment with inhibition of the redox function of APE1 by E3330 decreased migration and invasion of lung cancer cells (Manguinhas et al, 2020). Another study showed that APE1 redox inhibitors in combination with cisplatin inhibit proliferation of bladder cancer cells more efficiently than cisplatin alone (Fishel et al, 2019).…”

Curcumin Resuscitate Gliadin Induced Oxidative Damage And Altered Cellular Responses In Human Intestinal Cells Via Cross-Talk Between The Transcription Factor Nrf-2 And Multifunctional Protein APE1

“…In the present study, the elevated level of 8-oxo-dG was found in both the cell lines HCT-116 and HT-29 after the treatment of gliadin which was signi cantly masked by the pre-treatment of curcumin.Abasic sites, the DNA damage which is created by oxidative stress is mainly repaired via BER pathway by using APE1 enzyme along with other BER enzymes. APE1 is a multifunctional enzyme, along with its role in DNA base repair, cleaving of AP sites, it also helps in maintaining the cellular redox homeostasis by interacting and activating many key transcription factors like Nrf-2, AP-1, NF-κB, p53, HIF1α and others(Sarkar et al 2017;Thakur et al 2018;Manguinhas et al 2020). In the present study transcriptional and translational levels (expression pro ling) of APE1, endonuclease activity and its redox function were performed in HCT-116 and HT-29 cells in the presence of gliadin, curcumin and their combinations.…”