Abstract: PO1856
Role of miR-23b and miR-133a in Apoptosis Control Induced by TRAIL in Lung Adenocarcinoma and Kidney Carcinoma Cell Lines
Session Information
- Cancer and Kidney Diseases: Nephrotoxins, RCC, and More
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Onco-Nephrology
- 1500 Onco-Nephrology
Authors
- Leite, Denise, Universidade Federal de Sao Paulo Escola Paulista de Medicina, Sao Paulo, SP, Brazil
- Maquigussa, Edgar, Universidade Federal de Sao Paulo Escola Paulista de Medicina, Sao Paulo, SP, Brazil
- Boim, Mirian A., Universidade Federal de Sao Paulo Escola Paulista de Medicina, Sao Paulo, SP, Brazil
Background
Lung and kidney cancer are often diagnosed as advanced disease and frequently become resistant to systemic therapies. Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) binds to TRAIL receptor 1 and 2 (TRAILR1/R2) on the cell surface to stimulate apoptosis, making TRAIL apoptotic pathway a promising target for cancer therapy. Cullin-3 ubiquitination is essential to TRAIL receptors activation. However, resistance to TRAIL is an obstacle to achieve an effective anti-tumoral therapy. One of the mechanisms that lead to TRAIL resistance appears to be dependent on translocation, mediated by clathrin (CLTA), of TRAIL receptors to the nucleus. MicroRNAs (miRs)-23b and -133a may have relevant role in TRAIL resistance.
Methods
A549 and CaKi-2 cell lines and their respective controls (MRC-5 and HK2) were used. mRNA expressions of miR-23b, miR-133a, TRAIL-R1/R2, CUL3, CLTA Apaf-1 and KPNA-1 were estimated by RT-qPCR. MTT assay was used to evaluate the effect of TRAIL-induced cytotoxicity. TRAIL receptors celllular distribution was determined by western blot.
Results
Both cell lines were TRAIL resistant on MTT. TRAIL-R1 and TRAIL-R2 were predominantly located in nuclear compartment of A549 cells. TargetScan showed that miR-23b targets CUL3, Apaf-1 and KPNA-1 and miR-133a targets CLTA. MiR-23b expression was upregulated in A549 and CaKi-2 cells. MiR-23b inhibition upregulated CUL3 expression in A549 cells. In contrast, miR-133a was undetectable in both cell lines. TargetScan was used to determinate potential mRNAs targets for miR-23b and miR-133a.
Conclusion
MiR-23b expression was upregulated in A549 and CaKi-2 cells. However, supposed miR-23a target mRNAs were unchanged suggesting no relationship between miR-23a and those molecules. MiR-23b inhibition upregulated CUL3 expression in A549 cells, which could enhance TRAIL receptors activation and sensivity- this will be investigated in next step. In contrast, miR-133a was undetectable raising the hypothesys of an increased capacity of cells to translocate TRAIL receptors to the nucleus via clathrin and thus be resistant to TRAIL. The possible miR-133a ability to reduce clathrin expression may represent a novel approach for control of TRAIL apoptotic pathway and must be further investigated as a TRAIL sensitizing mechanism.