MiR-17-5p/RRM2 Regulated Gemcitabine Resistance in Lung Cancer A549 Cells

Abstract

Background To investigate the roles of miR-17-5p/RRM2 in A549/G+. Methods Cell survival was analyzed by CCK8 kit and clone formation experiment; The mRNA expression level was detected by qRT-PCR, and the protein level was compared by Western blotting; And flow cytometry for cell cycle detection; The target gene of miR-17-5p was verified by double luciferase activity experiment. Results CCK8 assay displayed that miR-17-5p’s overexpression can let A549/G + cells turn into sensitive ones; in turn, in the case of inhibition of expression, miR-17-5p can make A549/G- cells turn into resistance ones. And similar results were obtained in cell clone formation experiment. Cell cycle analysis showed that miR-17-5p’s overexpression increased the number of G1 phase cells and reduced the number of S phase cells in A549/G + cells; Conversely, lowing expression level of miR-17-5p yielded the opposite results in A549/G- cells. Western blot results showed that when miR-17-5p was expressed highly, the expression levels of cell cycle related proteins, CCNE1, CCNA2 and P21 decreased in A549/G + cells; Conversely, inhibition of miR-17-5p expression yielded the opposite results too in A549/G- cells. Western blot analysis of signal pathway proteins and the results showed that PTEN and PI3K expressed higher, but p-PTEN expressed lower in A549/G + cells. After miR-17-5p overexpressed in A549/G + cells, the level of p-PTEN increased, and the level of p-AKT decreased; when miR-17-5p expressed low in A549/G-cells, the expression of p-PTEN and p-AKT were opposite. The dual-luciferase experiment demonstrated that RRM2 was the target gene of miR-17-5p. The restorative experiments of RRM2 verified it. Conclusion This article suggested that the miR-17- 5p/RRM2 axis could adjust gemcitabine-resistance in A549 cells and might associate with p-PTEN/PI3K/AKT signal pathway.

β‐elemene enhances cisplatin sensitivity of non‐small cell lung cancer cells via the miR‐17‐5p/STAT3 axis

“…Another limitation of the present work is the lack of in vivo data, and animal experiments may make our conclusion more convincing. Finally, miR‐17‐5p is associated with drug resistance of NSCLC, while the expression characteristics of miR‐17‐5p in NSCLC are indeed controversial (Chatterjee et al., 2014; Ma et al., 2023; Zhang et al., 2017). In this case, the expression pattern of miR‐17‐5p in NSCLC patients, especially the patients with cisplatin resistance, should be examined in the following work.…”

“…Moreover, the miRNA 17 family targets transforming growth factor β receptor 2 in NSCLC cells, and reduces cisplatin resistance in NSCLC cells (Jiang et al., 2014). Another study reports that, miR‐17‐5p sensitize A549 cells to gemcitabine via regulating RRM2 (Ma et al., 2023). In this work, miR‐17‐5p is revealed to be markedly down‐modulated in cisplatin‐resistant NSCLC cells, and β‐elemene facilitates miR‐17‐5p expression, and miR‐17‐5p overexpression increases cisplatin sensitivity of NSCLC‐resistant cells.…”

“…Additionally, STAT3 overexpression partially counteracts the effects of β-elemene on cisplatin-resistant NSCLC cells. Considering miR-17-5p and STAT3 pathway are closely associated with chemoresistance of cancer cells (Chatterjee et al, 2014;Jiang et al, 2014;Laurino et al, 2023;Ma et al, 2023;Sun et al, 2019;Yang et al, 2023;Wang & Ji, 2018), and in this study we observe that β-elemene upregulates the expression of miR-17-5p and represses the expression of STAT3, we conclude that β-elemene sensitizes NSCLC cells to cisplatin via modulating miR-17-5p/STAT3 axis, and this is a different mechanism compared with the previous report (Yao et al, 2014). It should be emphasized, cancer cells' resistance to Platinum chemotherapeutic drugs is caused by multiple mechanisms, and modulated by various signal pathways, such as the activation of PI3K/Akt pathway, pentose phosphate pathway, abnormal epigenetic modifications et al (Giacomini et al, 2020;Navaei et al, 2022;Zhang et al, 2014).…”

RRM2‑mediated Wnt/β‑catenin signaling pathway activation in lung adenocarcinoma: A potential prognostic biomarker

“…Recent studies have indicated that RRM2, an oncogene, plays a critical role in the proliferation, migration, invasion, and drug resistance of breast cancer cells, small cell lung cancer cells, renal clear cell carcinoma cells, and pancreatic cancer cells (29)(30)(31)(32). In lung adenocarcinoma, suppression of RRM2 also inhibits the proliferation, migration and invasive ability of lung adenocarcinoma cells (33)(34)(35)(36). However, there is still limited research on the specific mechanism of action of RRM2 in lung adenocarcinoma.…”

“…Regarding the downstream mechanisms of RRM2 in lung adenocarcinoma, Ma et al (34) discovered that RRM2 may influence the sensitivity of A549 cells to gemcitabine by modulating the phosphorylated phosphatase and tensin homolog/PI3K/AKT signaling pathway. Another study demonstrated that suppression of RRM2 expression not only inhibits the malignant behavior of lung adenocarcinoma cells but also synergistically enhances the efficacy of radiotherapy in inducing cell death (35).…”