Ursolic acid-downregulated long noncoding RNA ASMTL-AS1 inhibits renal cell carcinoma growth via binding to HuR and reducing vascular endothelial growth factor expression.

It has been reported ursolic acid (UA), one of the naturally abundant pentacyclic triterpenes, possesses a wide range of biological activities including anti-inflammatory, anti-atherosclerotic, and anticancer properties. Renal cell carcinoma (RCC) is a severe malignancy due to its asymptomatically spreading ability. Our study aimed to investigate the role and molecular mechanism of UA in RCC. RCC cell proliferation, migration, invasion, and angiogenesis were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, Transwell, and tube formation assays. Xenograft tumor models were established to confirm the role of UA and long noncoding RNA ASMTL antisense RNA 1 (ASMTL-AS1) in vivo. Expression levels of ASMTL-AS1 and vascular endothelial growth factor (VEGF) were measured using reverse transcriptase quantitative polymerase chain reaction and western blot analysis. The interaction probabilities of ASMTL-AS1 or VEGF with RNA-binding protein human antigen R (HuR) were verified by RNA immunoprecipitation experiment. The half-life period of messenger RNA (mRNA) was determined using actinomycin D. UA inhibited RCC cell growth in vivo and tumorigenesis in vitro. ASMTL-AS1 was highly expressed in RCC cell lines. Of note, UA downregulated ASMTL-AS1 expression, and overexpressed ASMTL-AS1 reversed the UA-induced suppression on RCC cell migration, invasion, and tube formation. Additionally, ASMTL-AS1 bound to HuR to maintain the stability of VEGF mRNA. Rescue experiments showed that the suppressed malignancy of RCC cells mediated by ASMTL-AS1 knockdown was counteracted by overexpression of VEGF. Moreover, silenced ASMTL-AS1 inhibited RCC tumor growth and metastasis in vivo. The obtained data suggest UA as a promising therapeutic agent to attenuate the development of RCC via regulation of the targeted molecules.

Silencing of FGF6 hampers aerobic glycolysis and angiogenesis in bladder cancer by regulating PI3K/Akt and MAPK signaling pathways.

Metabolic abnormalities and uncontrolled angiogenesis are two vital features of malignant tumors. Although fibroblast growth factor 6 (FGF6) is known to promote the proliferation and migration of bladder cancer (BC) cells, its influences on aerobic glycolysis and angiogenesis in BC remain unclear. Gene expression at messenger RNA and protein levels were examined by reverse transcription-quantitative polymerase chain reaction and Western blot analyses, respectively. Lactate production and glucose uptake in BC cells were evaluated by performing aerobic glycolysis assays. A vasculogenic mimicry assay was executed for assessing the angiogenesis of BC cells. The viability, migration, and angiogenesis of human umbilical vein endothelial cells (HUVECs) cocultured with supernatants of BC cells were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, wound healing assay, and tube formation assay. It was found that FGF6 displayed a high level in BC cell lines. Silencing of FGF6 reduced the levels of lactate production, glucose uptake, and the expression of angiogenic factors and glycolytic enzymes in BC cells, which also inhibited the viability and migration of HUVECs. In addition, FGF6 depletion or aerobic glycolysis inhibitor 2-deoxy-d-glucose treatment decreased the total branching length and intersection number of both BC cells and HUVECs. Moreover, glucose or lactate treatment reversed FGF6-induced suppression of cell viability, migration, tube formation, and vasculogenic mimicry. The activation of the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) and mitogen-activated protein kinase (MAPK) signaling pathways was blocked by silenced FGF6. Furthermore, PI3K/Akt inhibitor (LY2940002) and p38-MAPK inhibitor (SB203580) inhibited the levels of aerobic glycolysis-related proteins. In conclusion, FGF6 knockdown suppressed aerobic glycolysis, thereby inhibiting angiogenesis in BC via regulation of the PI3K/Akt and MAPK signaling pathways.

LINC00265 promotes the viability, proliferation, and migration of bladder cancer cells via the miR-4677-3p/FGF6 axis.

BACKGROUND: Bladder cancer (BCa) is a common genitourinary malignancy with higher incidence in males. Long intergenic non-protein coding RNA 265 (LINC00265) is identified as an oncogene in many malignancies, while its role in BCa development remains unknown. PURPOSE: To explore the functions and mechanism of LINC00265 in BCa. RESEARCH DESIGN: Reverse transcription quantitative polymerase chain reaction was performed to examine LINC00265 expression in BCa cells. Cell counting kit-8 assays, colony formation assays, TdT-mediated dUTP Nick-End Labeling assays, and Transwell assays were conducted to examine BCa cell viability, proliferation, apoptosis, and migration. Luciferase reporter assays and RNA immunoprecipitation assays were carried out to explore the binding capacity between miR-4677-3p and messenger RNA fibroblast growth factor 6 (FGF6) (or LINC00265). Xenograft tumor model was established to explore the role of LINC00265 in vivo. RESULTS: LINC00265 was highly expressed in BCa cells. LINC00265 knockdown inhibited xenograft tumor growth and BCa cell viability, proliferation and migration while enhancing cell apoptosis. Moreover, LINC00265 interacted with miR-4677-3p to upregulate the expression of FGF6. FGF6 overexpression reversed the suppressive effect of LINC00265 knockdown on malignant phenotypes of BCa cells. CONCLUSIONS: LINC00265 promotes the viability, proliferation, and migration of BCa cells by binding with miR-4677-3p to upregulate FGF6 expression.