Long non-coding RNA CRNDE exacerbates NPC advancement mediated by the miR-545-5p/CCND2 axis

Abstract

Background Previous studies indicated CRNDE to have a pivotal part within tumorigenesis. Notwithstanding, precise details on CRNDE activities within NPC are still uncertain. The investigation described in this article served to focus in greater depth on the mechanistics regarding CRNDE, together with all associated regulatory networks, on nasopharyngeal carcinoma (NPC) and its treatment possibilities. Methods Quantitative real-time polymerase chain reaction (RT-qPCR) analyzed CRNDE, miR-545-5p and CCND2 expression within NPCs and representative cell lineages. CCK-8 cell counting-, EdU-, wound-healing-/transwell-assays analyzed cellular proliferation, migrative, together with invasive properties. Apoptosis/cell cycle progression were scrutinized through flow cytometry. Dual-luciferase reporter assays validated CRNDE/miR-545-5p/CCND2 interplay. Proteomic expression of apoptosis-related protein, EMT-related protein and CCND2 protein were evaluated through Western blotting. In addition, Ki67 expression was evaluated through immunohistochemical staining. The effect of CRNDE in vivo was assessed by nude murine xenograft model studies. Results This study demonstrated up-regulated expression of CRNDE and CCND2 within NPC tissues/cell lines. Meanwhile, miR-545-5p was down-regulated. CRNDE knock-down or miR-545-5p over-expression drastically reduced NPC proliferative, migrative and invasive properties, promoted apoptosis/altered cell cycle, and inhibited CCND2 expression. However, miR-545-5p down-regulation had opposing effects. All inhibiting functions generated by CRNDE down-regulation upon NPC progression could be counterbalanced or synergistically exacerbated, depending on miR-545-5p down-regulation or up-regulation, respectively. Multiple-level investigations revealed CRNDE to serve as a sponge for miR-545-5p, and can target CCND2 within NPCs. Conclusions CRNDE increases CCND2 expression by competitive binding with miR-545-5p, thus accelerating the development of NPC. This provides potential therapeutic targets and prognostic markers against NPC.

Current and future perspectives on the regulation and functions of miR-545 in cancer development

“…Five lncRNA/miR-545-5p/PCG axes promote cancer progression, including CRNDE/miR-545-5p/CCND2 in nasopharyngeal carcinoma (NPC), 44 NR2F2-AS1/miR-545-5p/MET in LC, 45 LncRP5/miR-545-5p/PTP4A1 in OC, 46 CRNDE/miR-545-5p/TIM-3 in OSCC, 47 and LINC00342/miR-545-5p/MDM2 in CRC. 48 …”

“… 39 In CRC, miR-545-3p arrests the cell cycle at the G 1 phase by targeting CDK4. 12 miR-545-5p targets CCND2 44 in NPC, causing G 0 /G 1 phase arrest in the cell line.…”

“…MiR-545-5p inhibits EMT in NPC cells by targeting CCND2, which prevents the reduction of E-cadherin and the replacement of the cytokeratin cytoskeleton with vimentin. 44 Additionally, miR-545-5p downregulates biliverdin reductase by targeting c-Met, thereby inhibiting EMT in NSCLC cells. 45…”

“…In contrast, research has shown that miR-545-3p can promote cancer cell invasion and migration by targeting three genes: LUZP1 in GBM/LGG, 4 SMAD7 in HCC, 28 and MT1M in HCC. 53 Additionally, miR-545-5p promotes cancer cell invasion and migration by targeting six genes: CCND2 in NPC, 44 SSFA2 in LC, 36 c-MET in NSCLC, 45 CNPY2 in GC, 61 MDM2 in CRC, 48 and DIMT1 in SaOS. 9 …”