Cancer du rein et radiothérapie : radiorésistance et au-delà

Up-Regulation of miR-26a-5p Inhibits E2F7 to Regulate the Progression of Renal Carcinoma Cells

Background

Metastasis is the main cause of renal cell carcinoma (RCC) tumor death, and effective inhibition of RCC metastasis is an essential means to meliorate the prognosis of RCC patients. MicroRNAs (miRs) have been proved to be stable and important biomarkers for several malignancies. This study is therefore set out to explore the metastasis-related miR and its mechanism in RCC.

Methods

The expression of miR- 26a -5p in RCC was analyzed using the expression profile in the Cancer Genome Atlas (TCGA). MiR-26a-5p and E2F transcription factor 7 (E2F7) in RCC patients were detected by qRT-PCR. Cell Counting Kit-8 (CCK-8) was adopted to assess cell proliferation, Transwell was utilized to evaluate migration and invasion, and flow cytometry (FC) was used to determine apoptosis. Mouse cell-derived and patient-derived xenotransplantation models were established to evaluate the effect of miR-26a-5p on tumor growth and metastasis in vivo. The molecular mechanism of miR-26a-5p was analyzed by dual-luciferase reporter (DLR) gene analysis, qRT-PCR, and Western blot (WB) both in vivo and in vitro.

Results

MiR-26a-5p was reduced in renal carcinoma cells and may serve as a biomarker for renal cancer metastasis and prognosis. MiR-26a-5p up-regulation inhibited migration and invasion in renal cell lines and tumor metastasis in vivo. Bioinformatics target prediction and RNA-seq results showed that E2F7 was among the targets of miR-26a-5p and was significantly inhibited by miR-26a-5p in vivo and in vitro.

Conclusion

MiR-26a-5p presents low expression in RCC and promotes RCC cell apoptosis and prevents cells from proliferating and invading by targeting E2F7, which is a promising therapeutic target for RCC.

[Radiotherapy of oligometastases: Sequences and interactions with systemic therapies, example of kidney cancer]

This article is a review of the literature that aims to clarify the place of systemic and locoregional treatments, with a focus on radiotherapy and surgery in the management of patients with oligometastatic kidney cancer. We have selected articles of interest published in Medline indexed journals. We have also analysed the related guidelines: National Comprehensive Cancer Network (NCCN) 2019, European Association of Urology (EAU) 2019, European Society of Medical Oncology (ESMO) 2019, Association française d'urologie (Afu) 2018 as well as some abstracts of international congresses. The main treatments evaluated were surgery and radiotherapy. We defined the different scenarios conventionally encountered in clinical practice. The evolution of systemic therapies (increased overall survival and response rate) is likely to increase the number of patients potentially accessible to locoregional treatments. The complete analysis of the literature underlines the place of locoregional treatments whatever the scenarios mentioned. Data on stereotactic radiotherapy found a local control rate consistently above 70% in all studies with a maintained response and positive impact on overall survival and progression-free survival. The improvement of overall survival by sequential use of the various therapeutic classes confirms the need for optimization of locoregional treatments in the model of oligometastatic kidney cancer. The dogma of radioresistance must definitely be set aside with current irradiation techniques.