MicroRNA-431 serves as a tumor inhibitor in breast cancer through targeting FGF9

Upregulation of FGF9 and NOVA1 in cancer-associated fibroblasts promotes cell proliferation, invasion and migration of triple negative breast cancer

Cancer-associated fibroblasts (CAFs) play a pivotal role in cancer progression. This study aimed to explore the roles of CAFs-derived Fibroblast growth factor 9 (FGF9) and Neuro-oncological ventral antigen 1 (NOVA1) in triple negative breast cancer (TNBC) progression. MDA-MB-231 and BT-549 cells were cocultured with CAF conditioned-medium (CAF-CM) or normal fibroblasts conditioned-medium (NF-CM). MTT, EdU, colony formation, wound healing, transwell migration, and invasion assays were employed to determine cell proliferation, migration and invasion, respectively. Western blot and RT-qPCR were carried out to examine the protein and mRNA expression of FGF9 and NOVA1. Xenograft tumor experiments were conducted to evaluate the effects of CAFs, FGF9, and NOVA1 on tumor growth in vivo. Our results showed that CAFs significantly promoted the proliferation, invasion, and migration of TNBC cells. FGF9 and NOVA1 were significantly upregulated in TNBC CAFs, tissues and cells. CAF-CM also could increase the expression of FGF9 and NOVA1 in TNBC cells. Knockdown of FGF9 or NOVA1 could hamper cell proliferation, invasion, migration, and EMT of TNBC cells. Moreover, CAFs with FGF9/NOVA1 knockdown also could inhibit TNBC progression. Besides, CAFs significantly accelerated tumor growth in vivo, which was blocked by FGF9/NOVA1 knockdown in nude mice. In conclusion, our results indicated the tumor-promoting role of CAFs in TNBC progression. FGF9 and NOVA1 upregulation in CAFs induced cell proliferation, migration and invasion in vitro, and facilitated tumor growth in vivo in TNBC development.

FBXL19‑AS1 promotes the progression of nasopharyngeal carcinoma by acting as a competing endogenous RNA to sponge miR‑431 and upregulate PBOV1

Long non‑coding RNAs (lncRNAs) have been shown to function as crucial regulators in the progression of various types of cancer, including nasopharyngeal carcinoma (NPC). The aim of the present study was to investigate the mechanisms underlying the role of the FBXL19‑AS1/microRNA (miR)‑431/prostate and breast cancer overexpressed 1 (PBOV1) axis in the progression of NPC. The expression levels of FBXL19‑AS1, miR‑431 and PBOV1 were assessed by reverse transcription‑quantitative PCR. The Cell Counting Kit‑8 assay was utilized to detect cell viability. Cell migration and invasion were determined using a Transwell assay. The associations between FBXL19‑AS1 and miR‑431 or miR‑431 and PBOV1 were verified via bioinformatics analysis, dual‑luciferase and RNA‑binding protein immunoprecipitation assays. It was demonstrated that the expression levels of FBXL19‑AS1 and PBOV1 were upregulated in NPC tissues and cells, whereas miR‑431 expression was downregulated. FBXL19‑AS1 directly interacted with miR‑431. FBXL19‑AS1 silencing inhibited the viability, migration and invasion of C666‑1 and SUNE1 cells, whereas these effects could be alleviated by suppressing miR‑431. miR‑431 could target the 3'‑untranslated region of PBOV1. Overexpression of PBOV1 neutralized the miR‑431‑mediated suppression of NPC progression. Moreover, FBXL19‑AS1 could regulate PBOV1 by sponging miR‑431 in NPC cells. In conclusion, the lncRNA FBXL19‑AS1 accelerated NPC progression via the miR‑431/PBOV1 axis, suggesting that it may serve as a potential therapeutic target for patients with NPC.

Identification of circRNA circ-CSPP1 as a potent driver of colorectal cancer by directly targeting the miR-431/LASP1 axis

Colorectal cancer (CRC) is the third most common malignancy worldwide. Circular RNAs (circRNAs) have been implicated in cancer biology. The purpose of the current work is to investigate the precise parts of circRNA centrosome and spindle pole-associated protein 1 (circ-CSPP1) in the progression of CRC. Our data showed that circ-CSPP1 was significantly overexpressed in CRC tissues and cells. The knockdown of circ-CSPP1 attenuated cell proliferation, migration, invasion and promoted apoptosis in vitro and weakened tumor growth in vivo. circ-CSPP1 directly targeted miR-431, and circ-CSPP1 knockdown modulated CRC cell progression in vitro via upregulating miR-431. Moreover, LIM and SH3 protein 1 (LASP1) was a functional target of miR-431 in modulating CRC cell malignant progression. Furthermore, circ-CSPP1 in CRC cells functioned as a posttranscriptional regulator on LASP1 expression by targeting miR-431. Our present study identified the oncogenic role of circ-CSPP1 in CRC partially by the modulation of the miR-431/LASP1 axis, providing evidence for circ-CSPP1 as a promising biomarker for CRC management.

Circ_0001367 inhibits glioma proliferation, migration and invasion by sponging miR-431 and thus regulating NRXN3

Many studies have reported that circular RNAs play a vital role in the malignant progression of human cancers. However, the role and underlying mechanism of circRNAs in the development of gliomas have not been fully clarified. In this study, we found that circ_0001367 was downregulated in glioma tissues and showed a close correlation with glioma patient survival. Functional assays demonstrated that upregulation of circ_0001367 could suppress the proliferation, migration and invasion of glioma cells in vitro and inhibit glioma growth in vivo. Furthermore, bioinformatics analysis, luciferase reporter assay and RNA immunoprecipitation assay indicated that circ_0001367 can serve as a sponge for miR-431 and that miR-431 acts as an oncogene by regulating neurexin 3 (NRXN3). In addition, rescue experiments verified that circ_0001367 could regulate both the expression and function of NRXN3 in a miR-431-dependent manner. In conclusion, circ_0001367 functions as an suppressor in glioma by targeting the miR-431/NRXN3 axis and may be a promising therapeutic target against gliomas.