Long non-coding RNA LINC00525 interacts with miR-31-5p and miR-125a-5p to act as an oncogenic molecule in spinal chordoma

LINC00525 enhances ZNF460-regulated CD24 expression through the sponge miR-125a-5p to promote malignant progression of breast cancer

INTRODUCTION

CD24 is a highly glycosylated glycosylphosphatidylinositol anchored membrane protein that plays an important role in tumor progression. The aim of this study was to investigate the effect of abnormal expression of CD24 on the proliferation, migration and invasion of breast cancer (BC) cells, and the molecular mechanism of regulating CD24 expression in breast cancer.

METHODOLOGY

The bioinformatics method was used to predict the expression level of CD24 in BC and its relationship with the occurrence and development of BC. IHC, RT-qPCR and WB were used to detect the expression of CD24 in BC tissues and cells. The proliferation of CD24 was evaluated by CCK-8 and colony formation assay, and the migration and invasion of CD24 were evaluated by wound healing and transwell. In addition, the effect of CD24 on the malignancy of BC in vivo was further evaluated by subcutaneous tumorigenesis assay. Molecular mechanisms were measured by luciferase reporter assays, biotin-labeled miRNA pull-down assay, RIP, and western blotting.

RESULTS

The results show that CD24 is highly expressed in breast cancer tissues and cell lines, and knockdown of CD24 in vivo and in vitro can inhibit the proliferation, migration and invasion of BC cells. Mechanistically, the transcription factor ZNF460 promotes its expression by binding to the CD24 promoter, and the expression of ZNF460 is regulated by miR-125a-5p, which inhibits its expression by targeting the 3'UTR of ZNF460. In addition, LINC00525 acts as a ceRNA sponge to adsorb miR-125a-5p and regulate its expression.

CONCLUSIONS

Overexpression of CD24 is involved in the development and poor prognosis of BC, which can be used as a potential target for the treatment of BC and provide a theoretical basis for the treatment of BC.

LINC00525 promotes tumour growth and epithelial-mesenchymal transition as an oncogene in oral squamous cell carcinoma

OBJECTIVE

Oral squamous cell carcinoma (OSCC) is the most common malignant tumour in the oral cavity. OSCC is aggressive and prone to metastasis; it is associated with high mortality and short survival. In this study, we investigated the function of the long non-coding RNA LINC00525 in OSCC progression and the molecular mechanisms through in vitro and in vivo experiments.

MATERIALS AND METHODS

CCK8 assay was used to detect the effect of LINC00525 on cell viability; transwell migration and invasion assays and scratch assay were used to examine the role of LINC00525 in cell migration and invasion. Flow cytometry, RT-PCR and western blot were used to detect apoptosis indexes. Tumorigenic effects were investigated using mouse xenograft tumour models.

RESULTS

LINC00525 was associated with OSCC survival and prognosis. LINC00525 knockdown decreased cell viability and epithelial-mesenchymal transition (EMT) properties and increased apoptosis and also shortened the cell cycle of OSCC cells in vitro. The downregulation of LINC00525 reduced the growth of OSCC tumour in vivo. LINC00525 can regulate OSCC cells via the apoptotic signalling pathway.

CONCLUSION

Our results indicate that LINC00525 exhibits oncogenic functions in OSCC. LINC00525 may be a new promising and potential target for the treatment of OSCC.

The role of tumor immune microenvironment in chordoma: promising immunotherapy strategies

Chordoma is a rare malignant bone tumor with limited therapeutic options, which is resistant to conventional chemotherapy and radiotherapy, and targeted therapy is also shown with little efficacy. The long-standing delay in researching its mechanisms of occurrence and development has resulted in the dilemma of no effective treatment targets and no available drugs in clinical practice. In recent years, the role of the tumor immune microenvironment in driving tumor growth has become a hot and challenging topic in the field of cancer research. Immunotherapy has shown promising results in the treatment of various tumors. However, the study of the immune microenvironment of chordoma is still in its infancy. In this review, we aim to present a comprehensive reveal of previous exploration on the chordoma immune microenvironment and propose promising immunotherapy strategies for chordoma based on these characteristics.

XIST sponges miR-320d to promote chordoma progression by regulating ARF6

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XIST was highly expressed in chordoma tissues.

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XIST knockdown inhibited chordoma progression by downregulating ARF6.

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MiR-320d inhibited the malignant behaviors of chordoma cells.

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XIST positively upregulated ARF6 expression via sponging miR-320d in chordoma cells.

Background

Long non-coding RNAs (lncRNAs) have been demonstrated to play important roles in various tumors, including chordoma. The purpose of this study was to investigate the role and mechanism of lncRNA X-inactive specific transcript (XIST) in chordoma.

Methods

RNA levels and protein levels were measured by real-time quantitative polymerase chain reaction (RT‑qPCR) and western blot assay, respectively. Cell proliferation was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 5-ethynyl-2′-deoxyuridine (EdU) assay and colony formation assay. Tanswell assay was used to examine cell migration and invasion. Cellular glycolysis was examined via the measurement of extracellular acidification rate (ECAR) and lactate production. The interaction between microRNA-320d (miR-320d) and XIST or ADP-ribosylation factor 6 (ARF6) was predicted by bioinformatics analysis and verified by a dual-luciferase reporter and RNA-pull down assays. The xenograft tumor model was used to explore the biological function of XIST in vivo.

Results

XIST was overexpressed in chordoma tissues. XIST knockdown suppressed chordoma cell proliferation, migration, invasion, and glycolysis. XIST acted as a sponge of miR-320d. Moreover, miR-320d overexpression inhibited the proliferation, migration, invasion, and glycolysis of chordoma cells. ARF6 was a direct target of miR-320d, and XIST upregulated ARF6 expression via sponging miR-320d. Furthermore, overexpression of ARF6 reversed the inhibitory effects of XIST knockdown on chordoma cell proliferation, migration, invasion, and glycolysis. Importantly, XIST silencing blocked xenograft tumor growth in vivo.

Conclusion

XIST knockdown inhibited chordoma progression via regulating the miR-320d/ARF6 axis, providing a novel insight into chordoma pathogenesis.

Dysregulated Epigenetics of Chordoma: Prognostic Markers and Therapeutic Targets

Chordoma is a rare, slow-growing sarcoma that is locally aggressive, and typically resistant to conventional chemo- and radiotherapies. Despite its low incidence, chordoma remains a clinical challenge because therapeutic options for chordoma are limited, and little is known about the molecular mechanisms involved in resistance to therapies. Furthermore, there are currently no established predictive or prognostic biomarkers to follow disease progression or treatment. Whole-genome sequencing of chordoma tissues has demonstrated a low-frequency mutation rate compared to other cancers. This has generated interest in the role of epigenetic events in chordoma pathogenesis. In this review, we discuss the current understanding of the epigenetic drivers of chordoma and their potential applications in prognosis and the development of new therapies.

LncRNA LINC00525 activates HIF-1α through miR-338-3p / UBE2Q1 / β-catenin axis to regulate the Warburg effect in colorectal cancer

Warburg effect is considered to be related to the malignancy of tumor cells under hypoxic conditions, but the underlying mechanism remains unknown. In this article, it has been reported that lncRNA LINC00525 is a hypoxia-responsive lncRNA and is essential for hypoxia-enhanced glycolysis. It was found that LINC00525 was up-regulated, and promoted cell proliferation in colorectal cancer in vitro and in vivo. In colorectal cancer cells, hypoxia increasedLINC00525 expression, whereas knocking down LINC00525 reduced hypoxia-enhanced glycolysis. For specific molecular mechanisms, it was found that LINC00525 promoted UBE2Q1 expression by binding miR-338-3p, and UBE2Q1-stabilized β-catenin enhances hypoxia-enhanced glycolysis by activating HIF-1α. In conclusion, these findings showed that LINC00525 was essential for hypoxia-enhanced glycolysis; its mechanism was related to activating HIF-1α through miR-338-3p/UBE2Q1/β-catenin axis in colorectal cancer cells.