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

Reprint of: Fibroblast Growth Factor 6

Fibroblast Growth Factor 6 (FGF6), also referred to as HST2 or HBGF6, is a member of the Fibroblast Growth Factor (FGF), the Heparin Binding Growth Factor (HBGF) and the Heparin Binding Secretory Transforming Gene (HST) families. The genomic and protein structure of FGF6 is highly conserved among varied species, as is its expression in muscle and muscle progenitor cells. Like other members of the FGF family, FGF6 regulates cell proliferation, differentiation, and migration. Specifically, it plays key roles in myogenesis and muscular regeneration, angiogenesis, along with iron transport and lipid metabolism. Similar to others from the FGF family, FGF6 also possesses oncogenic transforming activity, and as such is implicated in a variety of cancers.

Linc00265 in human disease: A comprehensive analysis of its implications in human disease pathobiology and therapeutic prospect

Linc00265, a long intergenic non-coding RNA, has garnered significant research attention due to its involvement in various human diseases, particularly cancer. It exhibits tissue-specific and dysregulated expression across multiple cancer types, including blood malignancies, colorectal, gastric, bladder, osteosarcoma, and hepatocellular carcinoma. This dysregulation is often associated with tumor aggressiveness, metastasis, and poor prognosis. Moreover, aberrant expression of Linc00265 has been reported in inflammation-related diseases such as osteoarthritis and sepsis. Mechanistically, Linc00265 acts as a competing endogenous RNA (CeRNA), sequestering specific microRNAs and thereby modulating their downstream targets. Additionally, it influences critical signaling pathways by mediating the key effectors within these pathways. Importantly, the dysregulation of Linc00265 shows promising potential as a diagnostic and prognostic biomarker in several human diseases. This review aims to comprehensively analyze the expression patterns, regulatory mechanisms, and potential biomarker roles of Linc00265 in human diseases, with a particular focus on cancer. By elucidating the functional implications of Linc00265, we can deepen our understanding of its roles in human diseases, potentially paving the way for novel therapeutic interventions in disease management.

The FGF6 amplification mutation plays an important role in the progression and treatment of malignant meningioma

Meningioma is a benign tumor with slow growth and long course. However, patients with recurrent malignant meningioma still face a lack of effective treatment. Here, we report a rare case of primary mediastinal malignant meningioma with lung and bone metastases, who benefited from the treatment of apatinib (≥33 months) and anlotinib (until the publication date). Retrospective molecular analysis revealed the frequent amplification of FGF6 in primary and metastatic lesions. Then we constructed the FGF6 over-expressed IOMM-LEE and CH157MN malignant meningioma cell lines, and in vitro and vivo experiments showed that overexpression of FGF6 can promote the proliferation, migration and invasion of malignant meningioma cells. Based on the Western analysis, we revealed that FGF6 can promote the phosphorylation of FGFR, AKT, and ERK1/2, which can be inhibited by anlotinib. Together, we were the first to verify that overexpression of FGF6 promotes the progression of malignant meningiomas by activating FGFR/AKT/ERK1/2 pathway and pointed out that anlotinib may effectively inhibit the disease progression of patients with FGF6 amplification.

Fibroblast Growth Factor 6

Fibroblast Growth Factor 6 (FGF6), also referred to as HST2 or HBGF6, is a member of the Fibroblast Growth Factor (FGF), the Heparin Binding Growth Factor (HBGF) and the Heparin Binding Secretory Transforming Gene (HST) families. The genomic and protein structure of FGF6 is highly conserved among varied species, as is its expression in muscle and muscle progenitor cells. Like other members of the FGF family, FGF6 regulates cell proliferation, differentiation, and migration. Specifically, it plays key roles in myogenesis and muscular regeneration, angiogenesis, along with iron transport and lipid metabolism. Similar to others from the FGF family, FGF6 also possesses oncogenic transforming activity, and as such is implicated in a variety of cancers.

Identification of EGFR as an essential regulator in chondrocytes ferroptosis of osteoarthritis using bioinformatics, in vivo, and in vitro study

Objective

The mechanisms of chondrocytes ferroptosis in osteoarthritis (OA) have not yet been fully elucidated. This study aimed to identify key ferroptosis related genes (FRGs) involved in chondrocytes ferroptosis.

Methods

LASSO, SVM-RFE, and receiver operating characteristic curve (ROC) were performed to screen key differentially expressed FRGs (DEFRGs). Functional analyses were conducted using GO, and KEGG analyses. Unsupervised clustering analysis was used to identify ferroptosis related patterns. The CeRNA network was constructed to predict the upstream miRNAs and lncRNAs. Finally, we validated the role of EGFR in chondrocytes ferroptosis using in vivo and in vitro experiments.

Results

A total of 42 DEFRGs were identified between OA and normal cartilages. GO and KEGG analyses indicated that these DEFRGs were significantly engaged in ferroptosis related biological processes and pathways, such as cellular response to oxidative stress, positive regulation of programmed cell death, MAPK and PI3K-Akt signaling pathways. Moreover, four key DEFRGs, including ACSF2, AURKA, EGFR, and KLHL24, were considered as potential biomarkers of OA. Moreover, two distinct ferroptosis related patterns were determined, and a total of 882 differentially expressed genes were identified which might participate in extracellular matrix degradation and inflammatory response. In addition, the CeRNA network showed that EGFR could be competitively regulated by 3 lncRNAs and 4 miRNAs. Significantly, the expression of EGFR was downregulated in human OA cartilages, OA mouse model, and erastin induced chondrocytes. EGFR inhibition could induce the occurrence of chondrocytes ferroptosis and ECM degradation which could be reversed by the addition of Ferrostatin-1.

Conclusion

Our study has identified ACSF2, AURKA, EGFR, and KLHL24 as ferroptosis-related biomarkers in OA. Furthermore, we have conducted a preliminary investigation into the role of EGFR in regulating chondrocytes ferroptosis. These findings offer novel insights into the molecular mechanisms underlying OA.

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.

Placental circadian lincRNAs and spontaneous preterm birth

Long non-coding RNAs (lncRNAs) have a much higher cell- and/or tissue-specificity compared to mRNAs in most cases, making them excellent candidates for therapeutic applications to reduce off-target effects. Placental long non-coding RNAs have been investigated in the pathogenesis of preeclampsia (often causing preterm birth (PTB)), but less is known about their role in preterm birth. Preterm birth occurs in 11% of pregnancies and is the most common cause of death among infants in the world. We recently identified that genes that drive circadian rhythms in cells, termed molecular clock genes, are deregulated in maternal blood of women with spontaneous PTB (sPTB) and in the placenta of women with preeclampsia. Next, we focused on circadian genes-correlated long intergenic non-coding RNAs (lincRNAs, making up most of the long non-coding RNAs), designated as circadian lincRNAs, associated with sPTB. We compared the co-altered circadian transcripts-correlated lincRNAs expressed in placentas of sPTB and term births using two published independent RNAseq datasets (GSE73712 and GSE174415). Nine core clock genes were up- or downregulated in sPTB versus term birth, where the RORA transcript was the only gene downregulated in sPTB across both independent datasets. We found that five circadian lincRNAs (LINC00893, LINC00265, LINC01089, LINC00482, and LINC00649) were decreased in sPTB vs term births across both datasets (p ≤ .0222, FDR≤.1973) and were negatively correlated with the dataset-specific clock genes-based risk scores (correlation coefficient r = -.65 ∼ -.43, p ≤ .0365, FDR≤.0601). Gene set variation analysis revealed that 65 pathways were significantly enriched by these same five differentially expressed lincRNAs, of which over 85% of the pathways could be linked to immune/inflammation/oxidative stress and cell cycle/apoptosis/autophagy/cellular senescence. These findings may improve our understanding of the pathogenesis of spontaneous preterm birth and provide novel insights into the development of potentially more effective and specific therapeutic targets against sPTB.

Long Intergenic Noncoding RNA00265 Enhances Cell Viability and Metastasis via Targeting miR-485-5p/USP22 Axis in Osteosarcoma

Osteosarcoma is one of the bone malignancies in children and adolescents. Long noncoding RNAs (lncRNAs) have been demonstrated to participate in osteosarcoma development and progression. Linc00265 has been shown to involve in osteosarcoma oncogenesis; however, the underlying mechanism is largely unclear. In this study, we investigated the function of linc00265 in osteosarcoma cells, including cell viability, migration and invasion. Moreover, we elucidated mechanistically the involvement of linc00265 in osteosarcoma. We found that linc00265 overexpression promoted viability, migration and invasion of osteosarcoma cells. Notably, linc00265 sponged miR-485-5p and increased the expression of USP22, one target of miR-485-5p, in osteosarcoma cells. Strikingly, linc00265 exerted its oncogenic function via regulating miR-485-5p and USP22 in osteosarcoma. Taken together, targeting linc00265 is a promising approach for treating osteosarcoma patients.