Knockdown of lncRNA LINC00662 suppresses malignant behaviour of osteosarcoma cells via competition with miR-30b-3p to regulate ELK1 expression

Osteosarcoma in a ceRNET perspective

Osteosarcoma (OS) is the most prevalent and fatal type of bone tumor. It is characterized by great heterogeneity of genomic aberrations, mutated genes, and cell types contribution, making therapy and patients management particularly challenging. A unifying picture of molecular mechanisms underlying the disease could help to transform those challenges into opportunities.This review deeply explores the occurrence in OS of large-scale RNA regulatory networks, denominated "competing endogenous RNA network" (ceRNET), wherein different RNA biotypes, such as long non-coding RNAs, circular RNAs and mRNAs can functionally interact each other by competitively binding to shared microRNAs. Here, we discuss how the unbalancing of any network component can derail the entire circuit, driving OS onset and progression by impacting on cell proliferation, migration, invasion, tumor growth and metastasis, and even chemotherapeutic resistance, as distilled from many studies. Intriguingly, the aberrant expression of the networks components in OS cells can be triggered also by the surroundings, through cytokines and vesicles, with their bioactive cargo of proteins and non-coding RNAs, highlighting the relevance of tumor microenvironment. A comprehensive picture of RNA regulatory networks underlying OS could pave the way for the development of innovative RNA-targeted and RNA-based therapies and new diagnostic tools, also in the perspective of precision oncology.

LncRNA SNHG25 Predicts Poor Prognosis and Promotes Progression in Osteosarcoma via the miR-497-5p/SOX4 Axis

BACKGROUND

Osteosarcoma is a disease that primarily affects adolescents with skeletal immaturity. LncRNAs are abnormally expressed and correlated with osteosarcoma patients' prognosis. We identified aberrant expression of LncRNA SNHG25 (small nucleolar RNA host gene 25) in osteosarcoma and analyzed the molecular mechanisms by which it regulates osteosarcoma progression.

METHODS

The expression levels of SNHG25 in tumour specimens and cells were measured by RTqPCR. Loss-of-function assays were conducted to investigate the functional role of SNHG25 in vitro and in vivo. Bioinformatic predictions, dual-luciferase reporter assays, and western blotting were performed to explore the possible underlying mechanisms.

RESULTS

SNHG25 was highly expressed in osteosarcoma cells and tissues. The Kaplan-Meier curve showed that the survival rate of patients with high SNHG25 expression was significantly lower than those with low SNHG25 expression. Functional studies have indicated that inhibition of SNHG25 suppresses cell proliferation, migration, and invasion, while promoting apoptosis. SNHG25 knockdown suppresses osteosarcoma tumour growth in vivo. SNHG25 functions as a sponge for miR-497-5p in osteosarcoma cells. The level of SNHG25 was negatively correlated with that of miR-497-5p. The proliferation, invasion, and migration of osteosarcoma cells were restored by transfection of the miR-497-5p inhibitor in the SNHG25 knockdown group.

CONCLUSION

SNHG25 was determined to function as an oncogene by promoting osteosarcoma cell proliferation, invasion, and migration through the miR-497-5p/SOX4 axis. Upregulation of SNHG25 expression indicated poor prognosis in patients with osteosarcoma, which showed that SNHG25 may serve as a potential therapeutic target and prognostic biomarker in osteosarcoma.

hsa_circ_0005991 promotes epithelial-mesenchymal transition by regulating miR-30b-3p/Cdc42EP1 axis in ovary endometriosis

Endometriosis is a common gynecological disease with an enigmatic pathogenesis. This work explored the function of hsa_circ_0005991 in ovarian endometriosis. High-throughput RNA-Seq was conducted in five matched ectopic (EC) and eutopic (EU) samples. Further, several types of cell function experiments were conducted. According to bioinformatics analysis, a competing endogenous RNA network was established. It included 5 circRNAs, 13 miRNAs, and 551 mRNAs. The expression levels of hsa_circ_0005991 and Cdc42EP1 were significantly elevated, while miR-30b-3p was reduced in the EC group. Upregulation of hsa_circ_0005991 raised Cdc42EP1 levels, induced EMT, and boosted Ishikawa cell proliferation, migration, and invasion. hsa_circ_0005991 knockdown indicated the opposite effects. When co-transfected with miR-30b-3p mimics or inhibitors, these effects could be reversed, respectively. Western blot assays showed alterations of EMT markers in EC samples. hsa_circ_0005991/miR-30b-3p/Cdc42EP1 axis promotes the EMT process in endometriosis, which may offer a theoretical foundation for the mechanism exploration and therapy of this disease.

The 8q24 region hosts miRNAs altered in biospecimens of colorectal and bladder cancer patients

BACKGROUND

The 8q24 locus is enriched in cancer-associated polymorphisms and, despite containing relatively few protein-coding genes, it hosts the MYC oncogene and other genetic elements connected to tumorigenesis, including microRNAs (miRNAs). Research on miRNAs may provide insights into the transcriptomic regulation of this multiple cancer-associated region.

MATERIAL AND METHODS

We profiled all miRNAs located in the 8q24 region in 120 colorectal cancer (CRC) patients and 80 controls. miRNA profiling was performed on cancer/non-malignant adjacent mucosa, stool, and plasma extracellular vesicles (EVs), and the results validated with The Cancer Genome Atlas (TCGA) data. To verify if the 8q24-annotated miRNAs altered in CRC were dysregulated in other cancers and biofluids, we evaluated their levels in bladder cancer (BC) cases from the TCGA dataset and in urine and plasma EVs from a set of BC cases and healthy controls.

RESULTS

Among the detected mature miRNAs in the region, 12 were altered between CRC and adjacent mucosa (adj. p < 0.05). Five and four miRNAs were confirmed as dysregulated in the CRC and BC TCGA dataset, respectively. A co-expression analysis of tumor/adjacent tissue data from the CRC group revealed a correlation between the dysregulated miRNAs and CRC-related genes (PVT1 and MYC) annotated in 8q24 region. miR-30d-5p and miR-151a-3p, altered in CRC tissue, were also dysregulated in stool of CRC patients and urine of BC cases, respectively. Functional enrichment of dysregulated miRNA target genes highlighted terms related to TP53-mediated cell cycle control.

CONCLUSIONS

Altered expression of 8q24-annotated miRNAs may be relevant for the initiation and/or progression of cancer.

A pan-cancer analysis of the prognostic value of long non-coding RNA LINC00662 in human cancers

Background: Numerous studies have revealed that the long non-coding RNA LINC00662 is irregularly expressed in various cancers, as well as is correlated with cancer development and progression. Nevertheless, the clinical value of LINC00662 remains controversial. Hence, we explored the correlation of LINC00662 with cancer prognosis through meta-analysis and bioinformatics analysis. Methods: From the beginning through 12 March 2022, we searched for correlational studies on Web of Science, Embase, PubMed and The Cochrane Library. We used pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) to determine the significance of studies on survival outcomes and clinicopathological aspects in human cancers. Additionally, the Gene Expression Profiling Interactive Analysis (GEPIA) database was employed to confirm our findings. Results: Our meta-analysis of 14 studies comprising a total of 960 cancer patients revealed that LINC00662 overexpression was correlated with poor overall survival (HR = 1.91, 95% CI 1.49-2.45, p < 0.001) in cancer patients and relapse-free survival (HR = 2.12, 95% CI 1.19-3.76, p = 0.010) in hepatocellular carcinoma patients. The correlation between LINC00662 and OS was further supported by the results of subgroup analyses according to cancer type, follow-up time, HR availability, and NOS score. In addition, LINC00662 overexpression predicted advanced tumor stage (OR = 4.23, 95% CI 2.50-7.17, p < 0.001), larger tumor size (OR = 1.49, 95% CI 1.11-1.99, p = 0.008), earlier lymph node metastasis (OR = 2.40, 95% CI 1.25-4.59, p = 0.008), and earlier distant metastasis (OR = 4.78, 95% CI 2.57-8.88, p < 0.001). However, there were no statistically significant differences in age (OR = 1.16, 95% CI 0.90-1.51, p = 0.246), gender (OR = 1.10, 95% CI 0.79-1.53, p = 0.578), or differentiation grade (OR = 1.53, 95% CI 0.71-3.33, p = 0.280). Conclusion: LINC00662 expression upregulation is associated with poor prognosis and advanced clinicopathological features in patients with multiple tumors. LINC00662 may serve as a biomarker for the diagnosis and treatment of patients with tumors.

Oncogenic roles of LINC01234 in various forms of human cancer

Abnormal expression of long non-coding RNAs (lncRNAs) plays an essential role in various malignant neoplasia. As a newly identified lncRNA, LINC01234 is abnormally expressed in several types of cancers and promotes the development of cancers. Accumulating evidence indicates that overexpression of LINC01234 is associated with poor clinical outcomes. Moreover, LINC01234 modulates many cellular events as a putative proto-oncogene, including proliferation, migration, invasion, apoptosis, cell cycle progression, and EMT. In terms of molecular mechanism, LINC01234 regulates gene expression by acting as ceRNA, participating in signaling pathways, interacting with proteins and other molecules, and encoding polypeptide. It reveals that LINC01234 may serve as a potential biomarker for cancer diagnosis, treatment, and prognosis. This review summarizes the expression pattern, biological function, and molecular mechanism of LINC01234 in human cancer and discusses its potential clinical utility.

The interaction between ETS transcription factor family members and microRNAs: A novel approach to cancer therapy

In cancer biology, ETS transcription factors promote tumorigenesis by mediating transcriptional regulation of numerous genes via the conserved ETS DNA-binding domain. MicroRNAs (miRNAs) act as posttranscriptional regulators to regulate various tumor-promoting or tumor-suppressing factors. Interactions between ETS factors and miRNAs regulate complex tumor-promoting and tumor-suppressing networks. This review discusses the progress of ETS factors and miRNAs in cancer research in detail. We focused on characterizing the interaction of the miRNA/ETS axis with competing endogenous RNAs (ceRNAs) and its regulation in posttranslational modifications (PTMs) and the tumor microenvironment (TME). Finally, we explore the prospect of ETS factors and miRNAs in therapeutic intervention. Generally, interactions between ETS factors and miRNAs provide fresh perspectives into tumorigenesis and development and novel therapeutic approaches for malignant tumors.

Downregulation of hsa-miR-30b-3p Inhibits the Oncogenicity of Lung Adenocarcinoma by Targeting the METTL7B Gene

Objective

Lung adenocarcinoma (LUAD) is one of the malignant tumors with the highest morbidity and mortality rates worldwide. Although surgery-based combination therapy can greatly improve the prognosis of LUAD patients, the overall outcome is still poor, and there is an urgent need to develop new and effective treatment alternatives for LUAD. The microRNA (miRNA) miR-30b-3p is a typical multifunctional miRNA that has been reported to promote the development of various malignancies. In this study, we investigated the effects of miR-30b-3p on the biological properties of LUAD and the possible mechanisms involved to provide new ideas for the development of more effective treatment options for LUAD.

Methods

Fluorescence quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the expression of miR-30b-3p and its target METTL7B gene in tumor tissues and adjacent noncancerous lung tissues of LUAD patients and to determine their correlation. The effect of miR-30b-3p on the biological properties of LUAD was investigated, after transfection of miR-30b-3p mimics or scramble miRNA (negative control) in LUAD cells, using various approaches, including by measuring cell proliferation using CCK-8 and Edu assays, cell invasion by Transwell assay, and apoptosis and cell cycle distribution by flow cytometry. Additionally, rescue assays were performed to verify the effect of METTL7B on miR-30b-3p function.

Results

In LUAD patients, low expression of miR-30b-3p and high expression of METTL7B in tumor tissues were significantly and negatively correlated with those in adjacent noncancerous lung tissues of the LUAD patients. It was also found that miR-30b-3p inhibits the proliferation and invasion of LUAD cells, promotes apoptosis, and changes the cell cycle distribution. METTL7B is a target gene of miR-30b-3p. METTL7B overexpression significantly reversed the biological effects of miR-30b-3p overexpression, including inhibition of cell proliferation and invasion, promotion of apoptosis, and alteration of the cell cycle distribution.

Conclusions

The miR-30b-3p alters the biology of LUAD by negatively regulating METTL7B expression, indicating the importance of the miR-30b-3p/METTL7B pathway in the development of LUAD.