MiR-216b inhibits osteosarcoma cell proliferation, migration, and invasion by targeting Forkhead Box M1

Comprehensive bioinformatics analysis reveals the oncogenic role of FoxM1 and its impact on prognosis, immune microenvironment, and drug sensitivity in osteosarcoma

Osteosarcoma, a highly malignant bone tumor primarily affecting adolescents, presents a significant challenge in cancer therapy due to its resistance to chemotherapy. This study explores the multifaceted impact of the transcription factor FoxM1 on osteosarcoma, shedding light on its pivotal role in tumor progression, immune microenvironment modulation, and drug response. Utilizing publicly available datasets from the Gene Expression Omnibus (GEO) and Therapeutically Applicable Research To Generate Effective Treatments (TARGET) databases, we conducted an in-depth bioinformatics analysis. Our findings illuminate the far-reaching implications of FoxM1 in osteosarcoma, emphasizing its significance as a potential therapeutic target. Differential expression analysis and Gene Set Enrichment Analysis (GSEA) revealed FoxM1's influence on critical pathways related to apoptosis, cell cycle regulation, and DNA repair. Notably, FoxM1 expression correlated with poor clinical outcomes in osteosarcoma patients, highlighting its prognostic relevance. Additionally, FoxM1 was found to modulate the immune microenvironment within tumor tissues, impacting immune cell infiltration, immunomodulators, immune checkpoints, and chemokines. Furthermore, a prognostic model based on FoxM1-coexpressed genes demonstrated its effectiveness in predicting patient survival. Drug sensitivity analysis indicated FoxM1's association with drug response, potentially guiding personalized treatment approaches. Hub gene screening identified RAB23 as a key target regulated by FoxM1, with RAB23 shown to influence osteosarcoma cell growth. This study also confirmed FoxM1's overexpression in osteosarcoma tissues compared to normal tissues, and its association with clinicopathological characteristics, including clinical stage, pathological type, and lung metastasis. In conclusion, FoxM1 emerges as a central player in the pathogenesis of osteosarcoma, impacting gene expression, immune responses, and therapeutic outcomes. This comprehensive analysis deepens our understanding of FoxM1's role in osteosarcoma and offers potential avenues for improved diagnosis and treatment.

Identification of m7G Methylation-Related miRNA Signature Associated with Survival and Immune Microenvironment Regulation in Uterine Corpus Endometrial Carcinoma

Background. N7-methylguanosine (m7G) has been implicated in the development of cancer. The role of m7G-related miRNAs in the survival prediction of UCEC patients has not been investigated. Current research was the first to construct an m7G-related miRNA model to accurately predict the survival of patients with uterine corpus endometrial carcinoma (UCEC) and to explore immune cell infiltration and immune activity in the tumor microenvironment. Methods. RNA-seq data and clinical information of UCEC patients were derived from The Cancer Genome Atlas (TCGA) database. Using the TargetScan online database, we predicted miRNAs linked to the m7G-related genes and identified miRNAs which were significantly associated with the survival in UCEC patients and constructed a risk scoring model. The TCGA-UCEC cases were scored according to the risk model, and the high- and low-risk groups were divided by the median risk value. Gene enrichment analysis and immune cell infiltration and immune function analysis were performed using “clusterProfiler” and “GSVA” packages in R. Results. The survival prediction model consisted of 9 miRNAs, namely, hsa-miR-1301, hsa-miR-940, hsa-miR-592, hsa-miR-3170, hsa-miR-876, hsa-miR-215, hsa-miR-934, hsa-miR-3920, and hsa-miR-216b. Survival of UCEC patients in the high-risk group was worse than that in the low-risk group ( $p<0.001$ ). The receiver operating characteristic (ROC) curve showed that the model had good predictive performance, and the area under the curve was 0.800, 0.690, and 0.705 for 1-, 3-, and 5-year survival predictions, respectively. There were differences in the degree of immune cell infiltration and immune activity between the low-risk and high-risk groups. The expression levels of the identified differentially expressed genes correlated with the susceptibility to multiple anticancer drugs. Conclusions. The survival prediction model constructed based on 9 m7G-related miRNAs had good predictive performance.

MicroRNA-216b regulates cell proliferation, invasion and cycle progression via interaction with cyclin T2 in gastric cancer

Gastric cancer has become the second most common malignant tumor in the world, revealing the molecular mechanism of gastric cancer development is essential for the treatment of gastric cancer and improvement of prognosis. Recent studies have shown that microRNAs may play a carcinogenic or tumor-suppressive role in many types of cancer. It has been detected that miR-216b is down-regulated in many cancer types, indicating that miR-216b can be used as a prognostic marker for these particular types of cancer. However, the effect of miR-216b on gastric cancer remains unclear. In the present study, miR-216 was observed to be significantly down-regulated in cancer tissues compared to normal tissues, and the level of miR-216b in various gastric cancer cell lines was decreased. In addition, miR-216b overexpression inhibits proliferation, migration, invasion, cell cycle and apoptosis of gastric cancer cells. We further verified that the inhibitory effect of miR-216b on proliferation and invasion of gastric cancer cells is mediated by cyclin T2. Overexpression of cyclin T2 can reverse the anti-cancer effect of miR-216b mimics. The results further enriched the mechanism of miR-216b in the development and progression of gastric cancer.

The Role of Forkhead Box Family in Bone Metabolism and Diseases

Forkhead box (Fox) family, an evolutionarily conserved family of transcription factors carrying the "Forkhead" motif, plays an indispensable role in human health and disease. Fox family genes are involved in cell differentiation, proliferation and apoptosis, embryonic development, aging, glucose and lipid metabolism, and immune regulation. The regulatory role of the Fox family in the context of bone metabolism and orthopedic diseases is an emerging research hotspot. In this review, we highlight the major molecular mechanisms underlying the regulatory role of Fox factors in bone metabolism, bone development, bone homeostasis, and bone diseases associated with inhibition or upregulation of Fox factors. In addition, we discuss the emerging evidence in the realm of Fox factor-based therapeutics.

Thiostrepton and miR-216b synergistically promote osteosarcoma cell cytotoxicity and apoptosis by targeting FoxM1

Osteosarcoma is a common primary bone cancer that there are currently no effective treatment strategies for. Forkhead box M1 (FoxM1) is key in the development of osteosarcoma, and microRNA (miR)-216b serves an antitumor role by targeting FoxM1. Moreover, thiostrepton (TST), a natural thiazole antibiotic, induces antitumor effects and specifically targets FoxM1. Therefore, the present study investigated whether thiostrepton and miR-216b synergistically inhibited osteosarcoma cells by targeting FoxM1. The MTT assay, reverse transcription-quantitative PCR, a dual-luciferase reporter assay and flow cytometry were performed. Compared with the human osteoblast cell line hFOB1.19, miR-216b expression was significantly downregulated in the osteosarcoma cell lines U2OS, MG63 and Saos-2. By contrast, FoxM1 expression was significantly upregulated in osteosarcoma cell lines compared with the hFOB1.19 cell line. The results indicated that miR-216b targeted the 3′-untranslated region of FoxM1. Moreover, the results suggested that miR-216b cooperated with TST to decrease cell cytotoxicity and increase cell apoptosis. In addition, miR-216b cooperated with TST to increase Bax expression and decrease Bcl-2 expression. In conclusion, the combination of TST and miR-216b synergistically promoted osteosarcoma cell cytotoxicity and apoptosis by targeting FoxM1. Therefore, the present study suggested that the combination of TST and miR-216b may serve as a promising therapeutic strategy for osteosarcoma.

FoxM1 is Upregulated in Osteosarcoma and Inhibition of FoxM1 Decreases Osteosarcoma Cell Proliferation, Migration, and Invasion

Background

Osteosarcoma (OS) is a highly aggressive bone malignancy that is mostly diagnosed in children and young adults. Increasing evidence indicates that the transcription factor Forkhead Box M1 (FoxM1) plays a key role in the pathogenesis of various tumors. However, the function of FoxM1 in OS has not been clearly elucidated.

Methods

In the present study, we first analyzed the expressions of FoxM1 in human OS and myositis ossificans (MO, included as a control) tissues by immunohistochemistry. To investigate the functional significance of FoxM1 in OS tumorigenesis, we examined the effects of FoxM1 downregulation in MG-63 and HOS-MNNG cells by either short hairpin RNA (shRNA)-mediated gene silencing or treatment with thiostrepton, a specific FoxM1 inhibitor.

Results

FoxM1 was detected in 82.1% (55/67) of OS vs only 10% (2/20) of MO samples. High expressions of FoxM1 were also detected in three human OS cell lines (HOS-MNNG, MG-63, and U-2OS). FoxM1 downregulation significantly reduced MG-63 and HOS-MNNG cell proliferation, migration, and invasion as well as cell cycle arrest in the G2/M phase and increased apoptotic cell death.

Conclusion

The present study demonstrated the critical role of FoxM1 in the pathogenesis of OS. Therefore, FoxM1 may serve as a potential therapeutic target for the treatment of OS.

microRNA-216b enhances cisplatin-induced apoptosis in osteosarcoma MG63 and SaOS-2 cells by binding to JMJD2C and regulating the HIF1α/HES1 signaling axis

Background

Although cisplatin-based chemotherapy represents the standard regimen for osteosarcoma (OS), OS patients often exhibit treatment failure and poor prognosis due to chemoresistance to cisplatin. Emerging research has highlighted the tumor suppressive properties of microRNAs (miRNAs or miRs) in various human cancers via the inhibition of the histone demethylase jumonji domain containing protein 2C (JMJD2C). As a coactivator for hypoxia-inducible factor 1α (HIF1α), JMJD2C targets hairy and enhancer of split-1 (HES1) gene. Hence, the current study aimed to elucidate the role of miR-216b in OS cell cisplatin resistance to identify the underlying mechanism of miR-216b regulating the JMJD2C//HIF1α/HES1 signaling.

Methods

Tumor and paracancerous tissues were collected from OS patients to determine the expression patterns of miR-216b and JMJD2C. After ectopic expression and knockdown experiments in the OS cells, CCK-8 assay and flow cytometry were employed to determine cell viability and apoptosis. The interaction of miR-216b, JMJD2C, HIF1α and HES1 was subsequently determined by dual luciferase reporter, co-immunoprecipitation (IP) and ChIP-qPCR assays. In vivo experiments were conducted to further verify the role of the miR-216b in the resistance of OS cells to cisplatin.

Results

miR-216b expression was reduced in the OS tissues, as well as the MG63 and SaOS-2 cells. Heightened miR-216b expression was found to be positively correlated with patient survival, and miR-216b further enhanced cisplatin-induced apoptosis of MG63 and SaOS-2 cells. Mechanistically, miR-216b inhibited JMJD2C expression by binding to its 3’UTR. Through interaction with HIF1α, JMJD2C removed the H3K9 methylation modification at the HES1 promoter region, leading to upregulation of HES1 in vitro. Furthermore, miR-216b was observed to increase the tumor growth in nude mice in the presence of cisplatin treatment. HES1 overexpression weakened the effects of miR-216b in MG63 and SaOS-2 cells and in nude mouse xenografts.

Conclusion

Overall, miR-216b enhanced the sensitivity of OS cells to cisplatin via downregulation of the JMJD2C/HIF1α/HES1 signaling axis, highlighting the capacity of miR-216b as an adjunct to cisplatin chemotherapy in the treatment of OS.

Differential Expression of miRNAs in Hypoxia ("HypoxamiRs") in Three Canine High-Grade Glioma Cell Lines

Dogs with spontaneous high-grade gliomas increasingly are being proposed as useful large animal pre-clinical models for the human disease. Hypoxia is a critical microenvironmental condition that is common in both canine and human high-grade gliomas and drives increased angiogenesis, chemo- and radioresistance, and acquisition of a stem-like phenotype. Some of this effect is mediated by the hypoxia-induced expression of microRNAs, small (~22 nucleotides long), non-coding RNAs that can modulate gene expression through interference with mRNA translation. Using an in vitro model with three canine high-grade glioma cell lines (J3T, SDT3G, and G06A) exposed to 72 h of 1.5% oxygen vs. standard 20% oxygen, we examined the global “hypoxamiR” profile using small RNA-Seq and performed pathway analysis for targeted genes using both Panther and NetworkAnalyst. Important pathways include many that are well-established as being important in glioma biology, general cancer biology, hypoxia, angiogenesis, immunology, and stem-ness, among others. This work provides the first examination of the effect of hypoxia on miRNA expression in the context of canine glioma, and highlights important similarities with the human disease.

Growth hormone receptor promotes osteosarcoma cell growth and metastases

Osteosarcoma (OS) is the primary bone malignancy in children and adolescents, with a high incidence of lung metastasis and poor prognosis. Here, we report that growth hormone receptor (GHR) is overexpressed in OS samples compared with osteofibrous dysplasia. We subsequently demonstrated that GHR knockdown inhibited colony formation, promoted cell apoptosis and decreased the number of cells at G2/M phase in 143B and U2OS cells. Furthermore, knockdown of GHR inhibited tumor growth in vivo. Together, these findings indicate that GHR modulates cell proliferation and metastasis through the phosphoinositide 3‐kinase/AKT signaling pathway and may be suitable for use as a putative biomarker of OS.