LINC00612 functions as a ceRNA for miR-214-5p to promote the proliferation and invasion of osteosarcoma in vitro and in vivo

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.

Protosappanin B enhances the chemosensitivity of 5-fluorouracil in colon adenocarcinoma by regulating the LINC00612/microRNA-590-3p/Golgi phosphoprotein 3 axis

BACKGROUND

5-fluorouracil (5-FU) is conventionally used in chemotherapy for colon adenocarcinomas. Acquired resistance of 5-FU remains a clinical challenge in colon cancer, and efforts to develop targeted agents to reduce resistance have not yielded success. Protosappanin B (PSB), the main component of Lignum Sappan extract, is known to exhibit anti-tumor effects. However, whether and how PSB could improve 5-FU resistance in colon cancer have not yet been established. In this study, we aimed to explore the effects and underlying mechanisms of PSB in 5-FU-induced chemoresistance in colon adenocarcinoma.

METHODS

Forty-seven paired colon cancer tissue samples from patients who received 5-FU chemotherapy were collected as clinical samples. Two 5-FU resistant colon cancer cell lines were established for in vitro experiments. Reverse transcription-quantitative PCR (RT-qPCR) was performed to determine the mRNA and microRNA (miRNA) expression levels in colon adenocarcinoma tissues and cell lines. Cell Counting Kit-8 (CCK-8) and flow cytometry assays were performed to evaluate cell proliferation and apoptosis, respectively.

RESULTS

LINC00612 was highly expressed in colon adenocarcinoma samples and 5-FU resistant colon cancer cells. LINC00612 knockdown enhances 5-FU chemosensitivity in 5-FU resistant cells. Notably, PSB treatment attenuated LINC00612 expression in 5-FU resistant colon adenocarcinoma cells. Moreover, PSB treatment reversed the increase in LINC00612-induced 5-FU resistance. Mechanistically, LINC00612 specifically bound to miR-590-3p, which promoted 5-FU resistance in colon adenocarcinoma cells and attenuated the inhibitory effect of LINC00612 on GOLPH3 expression.

CONCLUSION

PSB attenuates 5-FU chemoresistance in colon adenocarcinoma by regulating the LINC00612/miRNA-590-3p/GOLPH3 axis.

Identification of Wnt/β-Catenin- and Autophagy-Related lncRNA Signature for Predicting Immune Efficacy in Pancreatic Adenocarcinoma

Pancreatic cancer is one of the tumors with a poor prognosis. Therefore, it is significant and urgent to explore effective biomarkers for risk stratification and prognosis prediction to promote individualized treatment and prolong the survival of patients with PAAD. In this study, we identified Wnt/β-catenin- and autophagy-related long non-coding RNAs (lncRNAs) and demonstrated their role in predicting immune efficacy for PAAD patients. The univariate and multivariate Cox proportional hazards analyses were used to construct a prognostic risk model based on six autophagy- and Wnt/β-catenin-related lncRNAs (warlncRNAs): LINC01347, CASC8, C8orf31, LINC00612, UCA1, and GUSBP11. The high-risk patients were significantly associated with poor overall survival (OS). The receiver operating characteristic (ROC) curve analysis was used to assess the predictive accuracy of the prognostic risk model. The prediction efficiency was supported by the results of an independent validation cohort. Subsequently, a prognostic nomogram combining warlncRNAs with clinical indicators was constructed and showed a good predictive efficiency for survival risk stratification. Furthermore, functional enrichment analysis demonstrated that the signature according to warlncRNAs is closely linked to malignancy-associated immunoregulatory pathways. Correlation analysis uncovered that warlncRNAs' signature was considerably associated with immunocyte infiltration, immune efficacy, tumor microenvironment score, and drug resistance.

Identification of long non-coding RNA and circular RNA associated networks in cellular stress responses

Mammalian cells employ various adaptive responses to cope with multiple stresses to maintain homeostasis. Functional roles of non-coding RNAs (ncRNAs) in response to cellular stresses have been proposed, and systematical investigations about the crosstalk among distinct types of RNAs are required. Here, we challenged HeLa cells with thapsigargin (TG) and glucose deprivation (GD) treatments to induce endoplasmic reticulum (ER) and metabolic stresses, respectively. Ribosomal RNA (rRNA)-depleted RNA sequencing (RNA-seq) was then performed. Characterization of the RNA-seq data revealed a series of differentially expressed long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) with parallel changes responsive to both stimuli. We further constructed the lncRNA/circRNA-mRNA co-expressing network, competing endogenous RNA (ceRNA) network in the lncRNA/circRNA-miRNA-mRNA axis, and lncRNA/circRNA-RNA binding protein (RBP) interactome map. These networks indicated the potential cis and/or trans regulatory roles of lncRNAs and circRNAs. Moreover, Gene Ontology analysis demonstrated that these identified ncRNAs were associated with several essential biological processes known to be related to cellular stress responses. In conclusion, we systematically established functional regulatory networks of lncRNA/circRNA-mRNA, lncRNA/circRNA-miRNA-mRNA and lncRNA/circRNA-RBP to perceive the potential interactions and biological processes during cellular stresses. These results provided insights in ncRNA regulatory networks of stress responses and the basis for further identification of pivotal factors involved in cellular stress responses.

LincRNA00612 inhibits apoptosis and inflammation in LPS-induced BEAS-2B cells via enhancing interaction between p-STAT3 and A2M promoter

Long non-coding RNAs (lncRNAs) have been reported as key regulators of chronic obstructive pulmonary disease (COPD). This study aimed to figure out the regulatory mechanism as well as the effects of lncRNA00612 (LINC00612) in lipopolysaccharide (LPS)-induced inflammation and apoptosis in BEAS-2B cells. LINC00612 and its co-expressed gene alpha-2-macroglobulin (A2M) were strikingly downregulated in the peripheral venous blood of COPD patients. Overexpressed LINC00612 enhances BEAS-2B cells against apoptosis and inflammatory reactions mediated by LPS, however, an A2M knockdown can attenuate the degree of the enhancement. Bioinformatics analysis revealed putative binding sites between LINC00612, signal transducer and activator of transcription 3 (STAT3) and the A2M promoter, while RNA antisense purification and Chromatin immunoprecipitation were performed to confirm the prediction. Knockdown of LINC00612 impaired the binding of p-STAT3 to the promoter of A2M, which meant that LINC00612 was critical for the binding of STAT3 with the A2M promoter. Therefore, it can be concluded that LINC00612 ameliorates LPS-induced cell apoptosis and inflammation via recruiting STAT3 to bind to A2M. This conclusion will serve as a theoretical foundation for the treatment of COPD.

LINC00536 Promotes Breast Cancer Progression by Regulating ROCK1 via Sponging of miR-214-5p

Accumulating evidence has shown that long noncoding RNAs (lncRNAs) play a significant role in regulating gene expression and participating in the progression of various malignancies. In our study, by analyzing data from The Cancer Genome Atlas (TCGA), LINC00536 was found to be highly expressed in breast cancer (BC) tissues, but its function and clinical significance in BC are still unknown. Therefore, we aimed to explore the role and molecular mechanism of LINC00536 in BC. We collected human BC tissue specimens and validated that LINC00536 was overexpressed in BC tissues. Increased LINC00536 expression was associated with advanced TNM stage, larger tumor diameter, lymph node metastasis and poor prognosis in patients with BC. Univariate and multivariate Cox regression analyses showed that high LINC00536 expression was an independent prognostic risk factor for overall survival in BC patients. Furthermore, quantitative reverse transcription PCR (qRT-PCR) showed that LINC00536 was upregulated in BC cell lines. Then, we confirmed that LINC00536 silencing-inhibited BC cell proliferation, migration, and invasion and led to cell cycle arrest in vitro. Animal experiments showed that knockdown of LINC00536 expression suppressed tumorigenesis in vivo. Mechanistically, LINC00536 serves as a ceRNA for miR-214-5p, increasing the expression of ROCK1, which acts as a tumor promoter in BC. Rescue assays revealed that miR-214-5p inhibition or ROCK1 overexpression could neutralize the suppressive effects of LINC00536 knockdown on cell proliferation, migration and invasion. Our data indicated that LINC00536 accelerates BC progression by regulating the miR-214-5p/ROCK1 pathway, which might provide a new perspective to investigate the development process of BC.

Modulation of immunosuppressive cells and noncoding RNAs as immunotherapy in osteosarcoma

The most common bone cancer is osteosarcoma (OS), which mostly affects children and teenagers. Early surgical resection combined with chemotherapy significantly improves the prognosis of patients with OS. Existing chemotherapies have poor efficacy in individuals with distant metastases or inoperable resection, and these patients may respond better to novel immunotherapies. Immune escape, which is mediated by immunosuppressive cells in the tumour microenvironment (TME), is a major cause of poor OS prognosis and a primary target of immunotherapy. Myeloid-derived suppressor cells, regulatory T cells, and tumour-associated macrophages are the main immunosuppressor cells, which can regulate tumorigenesis and growth on a variety of levels through the interaction in the TME. The proliferation, migration, invasion, and epithelial-mesenchymal transition of OS cells can all be impacted by the expression of non-coding RNAs (ncRNAs), which can also influence how immunosuppressive cells work and support immune suppression in TME. Interferon, checkpoint inhibitors, cancer vaccines, and engineered chimeric antigen receptor (CAR-T) T cells for OS have all been developed using information from studies on the metabolic properties of immunosuppressive cells in TME and ncRNAs in OS cells. This review summarizes the regulatory effect of ncRNAs on OS cells as well as the metabolic heterogeneity of immunosuppressive cells in the context of OS immunotherapies.

miR-129-2 upregulation induces apoptosis and promotes NSCLC chemosensitivity by targeting SOX4

Background

As one of the main causes of death worldwide, the treatment of non‐small‐cell lung cancer (NSCLC) is still unsatisfactory. This study aimed to explore the role of miR‐129‐2 in cell apoptosis and NSCLC chemosensitivity.

Methods

The effect of miR‐129‐2 on NSCLC was investigated using lung cancer cell lines (A549, NCl‐H23, and HCC827), a normal lung cell line (BEAS‐2B), and NSCLC tissues and adjacent healthy tissues. The oncogene SOX4 was verified as the target gene of miR‐129‐2 by luciferase reporter assay and real‐time polymerase chain reaction.

Results

miR‐129‐2 expression was downregulated in NSCLC tissues, NCl‐H23 cells, and A549 cells. miR‐129‐2 upregulation induced apoptosis in NCl‐H23 and A549 cells. miR‐129‐2 upregulation also inhibited NSCLC in a xenograft mouse model, which was related to downregulation of SOX4 expression. Furthermore, miR‐129‐2 and SOX4 were aberrantly expressed in the cisplatin‐resistant lung cancer cell line A549/DDP, and upregulation of miR‐129‐2 expression promoted cisplatin sensitivity in A549/DDP cells.

Conclusions

In conclusion, miR‐129‐2 expression was downregulated in NSCLC tissues and cell lines, and its upregulation induced cell apoptosis and promoted NSCLC chemosensitivity by regulating SOX4. Therefore, miR‐129‐2 can serve as a potential diagnostic and therapeutic target in NSCLC.

Unraveling the roles of miRNAs in regulating epithelial-to-mesenchymal transition (EMT) in osteosarcoma

Osteosarcoma is one of the most prevalent primary bone tumors with a high metastatic and recurrence rate with poor prognosis. MiRNAs are short and non-coding RNAs that could regulate various cellular activities and one of them is the epithelial-to-mesenchymal transition (EMT). Osteosarcoma cells that have undergone EMT would lose their cellular polarity and acquire invasive and metastatic characteristics. Our literature search showed that many pre-clinical and clinical studies have reported the roles of miRNAs in modulating the EMT process in osteosarcoma and compared to other cancers like breast cancer, there is a lack of review article which effectively summarizes the various roles of EMT-regulating miRNAs in osteosarcoma. This review, therefore, was aimed to discuss and summarize the EMT-promoting and EMT-suppressing roles of different miRNAs in osteosarcoma. The review would begin with the discussion on the concepts and principles of EMT, followed by the exploration of the diverse roles of EMT-regulating miRNAs in osteosarcoma. Subsequently, the potential use of miRNAs as prognostic biomarkers in osteosarcoma to predict the likelihood of metastases and as therapeutic agents would be discussed.

Oncogenic functions of ZEB1 in pediatric solid cancers: interplays with microRNAs and long noncoding RNAs

The transcription factor Zinc finger E-box binding 1 (ZEB1) displays a range of regulatory activities in cell function and embryonic development, including driving epithelial-mesenchymal transition. Several aspects of ZEB1 function can be regulated by its functional interactions with noncoding RNA types, namely microRNAs (miRNAs) and long noncoding RNAs (lncRNAs). Increasing evidence indicates that ZEB1 importantly influences cancer initiation, tumor progression, metastasis, and resistance to treatment. Cancer is the main disease-related cause of death in children and adolescents. Although the role of ZEB1 in pediatric cancer is still poorly understood, emerging findings have shown that it is expressed and regulates childhood solid tumors including osteosarcoma, retinoblastoma, neuroblastoma, and central nervous system tumors. Here, we review the evidence supporting a role for ZEB1, and its interplays with miRNAs and lncRNAs, in pediatric cancers.

LncRNA RCAT1 promotes tumor progression and metastasis via miR-214-5p/E2F2 axis in renal cell carcinoma

Renal cell carcinoma is the second malignant tumors in the urinary system with high mortality and morbidity. Increasing evidence suggests that long non-coding RNAs (lncRNAs) play critical roles in tumor development and progression. In the current study, based on the publicly available data obtained from GEO and TCGA database, we identified five prognosis-related lncRNAs with the ability to predict the prognosis of patients with renal cell carcinoma. Among them, the uncharacterized and upregulated lncRNA RCAT1 (renal cancer-associated transcript 1) was identified as the key lncRNA. Our data further revealed that the expression of lncRNA RCAT1 was significantly upregulated in renal cell carcinoma tissues and cells. Gain-of-function and loss-of-function studies showed that lncRNA RCAT1 promoted cell proliferation, migration, and invasion in vitro and in vivo. Furthermore, we verified that lncRNA RCAT1 could abundantly sponge miR-214-5p, which served as a tumor suppressor in renal cell carcinoma. Significantly, miR-214-5p overexpression could attenuate the promotion of cell proliferation and metastasis induced by lncRNA RCAT1. Moreover, we found that E2F2 was a direct target of miR-214-5p, and lncRNA RCAT1 could protect E2F2 from miR-214-5p-mediated degradation. Taken together, our findings suggested that lncRNA RCAT1 could enhance the malignant phenotype of renal cell carcinoma cells by modulating miR-214-5p/E2F2 axis, and lncRNA RCAT1 might be a novel prognostic biomarker and a potential therapeutic target for renal cell carcinoma.

Long non-coding RNA LINC00511 regulates the expression of microRNA-625-5p and activates signal transducers and activators of transcription 3 (STAT3) to accelerate the progression of gastric cancer

This study aimed to investigate the expression, biological function, and downstream mechanism of LINC00511 in gastric cancer (GC). In paired GC samples, LINC00511, miR-625-5p and STAT3 mRNA expression levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR); STAT3 protein expression was detected by immunohistochemical (IHC). The gain-of-function and loss-of-function models were established, and the proliferative and migrative ability of GC cells were measured by CCK-8 and transwell assays, respectively. The regulatory relationship between miR-625-5p and LINC00511 or STAT3 was examined by bioinformatics analysis, luciferase reporter gene assay, qRT-PCR, and western blot. We reported that LINC00511 and STAT3 expressions in GC tissues and cell lines were observably up-regulated, while miR-625-5p expression was inhibited. High expression of LINC00511 could facilitate the proliferation and promote the migration of GC cells. miR-625-5p was proved to be a downstream target of LINC00511, and LINC00511 could induce the expression of STAT3 by inhibiting the expression of miR-625-5p. Additionally, knockdown of LINC00511 suppressed the growth and lung metastases of CRC cells in nude mice. In conclusion, LINC00511 promotes the GC cell proliferation and migration via targeting the miR-625-5p/STAT3 axis, implying that LINC00511 can function as a target for GC therapy.

microRNA-939 Promotes the Vitality of Human Breast Cancer Cells via Inhibition of E2F1/P73 Signaling

We assessed miR-939’s role in breast cancer (BC) and its molecular mechanism. PCR was performed to detect miRNA levels. Correlations between miR-939 and patients’ pathological information were analyzed. After transfection of E2F1 plasmid, P73 plasmid, si-E2F1, si-P73, miR-939 mimic or si-miR-939, cell proliferation and apoptosis were measured. The miR-939 target gene was proved by a luciferase assay. Protein and mRNA levels of E2F1 and P73 were detected by immunoblotting and PCR, and corresponding proliferation or apoptosis were assessed. MiR-939 expression was significantly increased in BC and associated with TNM staging, Ki-67 enhancement, and shorter disease-free survival time. In BC clinical samples, E2F1 expression is negatively correlated with miR-939 expressions. Overexpressing miR-939 stimulated growth but suppressed cell apoptosis. Functional analysis indicated E2F1 is the target gene of miR-939, and overexpression of miR-939 significantly downregulated E2F1 and P73. Silencing of E2F1 or P73 significantly promoted MDA-MB-231 cell proliferation and inhibited apoptosis. Overexpression of E2F1 plasmid or P73 plasmid significantly inhibited MDA-MB-231 cell proliferation but induced apoptosis. Transfection of P73 or E2F1 plasmid abolished miR-939’s effects on proliferation and apoptosis. miR-939 promotes breast cancer progression by downregulation of E2F1 to inhibit P73 pathway, thereby promoting proliferation and inhibiting apoptosis.

LncRNA prostate androgen-regulated transcript 1 (PART 1) functions as an oncogene in osteosarcoma via sponging miR-20b-5p to upregulate BAMBI

Background

Osteosarcoma (OS) is an aggressive bone cancer that most commonly affects adolescents and children. Emerging studies have shown that long noncoding RNA (lncRNA) performs essential roles in the occurrence and development of many tumors. Prostate androgen-regulated transcript 1 (PART 1) has been reported as a tumor oncogene; despite this, the mechanisms underlying its involvement in OS are unclear.

Methods

OS and paired normal tissue samples were obtained, and gene expressions were detected by real time-quantitative polymerase chain reaction (RT-qPCR). The functions of PART 1 in OS cell proliferation, invasion, and migration were determined by Cell Counting Kit-8 (CCK-8) and Transwell assays. Furthermore, the binding sites of PART 1 and miR-20b-5p as well as those between miR-20b-5p and bone morphogenic protein and activin membrane-bound inhibitor homolog (BAMBI) were verified by bioinformatics analysis and dual-luciferase reporter assay.

Results

Our study found obvious overexpression of PART 1 in OS tissues and cells. Furthermore, PART 1 overexpression facilitated OS cell proliferation, invasion, and migration. Further mechanistic investigations revealed that PART 1 could sponge to miR-20b-5p, which was expressed at a low level in OS tissues and cells. Importantly, miR-20b-5p overexpression inhibited OS cell proliferation, invasion, and migration. Additionally, BAMBI was confirmed as a downstream gene of miR-20b-5p, and its expression was reversely modulated by miR-20b-5p and positively modulated by PART 1. Rescue experiments suggested that BAMBI was involved in PART 1-mediated promotion of OS progression.

Conclusions

PART 1 serves as a competing endogenous RNA to promote OS tumorigenesis via its regulation of the miR-20b-5p/BAMBI axis, which may provide a promising therapeutic biomarkers for OS patients.

Silencing ZEB2 Induces Apoptosis and Reduces Viability in Glioblastoma Cell Lines

Background: Glioma is an aggressive type of brain tumor that originated from neuroglia cells, accounts for about 80% of all malignant brain tumors. Glioma aggressiveness has been associated with extreme cell proliferation, invasion of malignant cells, and resistance to chemotherapies. Due to resistance to common therapies, glioma affected patients’ survival has not been remarkably improved. ZEB2 (SIP1) is a critical transcriptional regulator with various functions during embryonic development and wound healing that has abnormal expression in different malignancies, including brain tumors. ZEB2 overexpression in brain tumors is attributed to an unfavorable state of the malignancy. Therefore, we aimed to investigate some functions of ZEB2 in two different glioblastoma U87 and U373 cell lines. Methods: In this study, we investigated the effect of ZEB2 knocking down on the apoptosis, cell cycle, cytotoxicity, scratch test of the two malignant brain tumor cell lines U87 and U373. Besides, we investigated possible proteins and microRNA, SMAD2, SMAD5, and miR-214, which interact with ZEB2 via in situ analysis. Then we evaluated candidate gene expression after ZEB2-specific knocking down. Results: We found that ZEB2 suppression induced apoptosis in U87 and U373 cell lines. Besides, it had cytotoxic effects on both cell lines and reduced cell migration. Cell cycle analysis showed cell cycle arrest in G0/G1 and apoptosis induction in U87 and U373 cell lines receptively. Also, we have found that SAMAD2/5 expression was reduced after ZEB2-siRNA transfection and miR-214 upregulated after transfection. Conclusions: In line with previous investigations, our results indicated a critical oncogenic role for ZEB2 overexpression in brain glioma tumors. These properties make ZEB2 an essential molecule for further studies in the treatment of glioma cancer.

Histone methyltransferase SUV39H2 regulates LSD1-dependent CDH1 expression and promotes epithelial mesenchymal transition of osteosarcoma

OBJECTIVE

Osteosarcoma (OS) is a malignant tumor characterized by the direct production of bone or osteoid tissues by proliferating tumor cells. Suppressor of variegation 3-9 homolog 2 (SUV39H2) is implicated in the occurrence of OS. Therefore, we designed this study to investigate effects of SUV39H2 in OS meditated by the lysine specific demethylase-1/E-cadherin (LSD1/CDH1) axis.

METHODS

Clinical OS tissues and paracancerous tissues were collected for analysis of SUV39H2, LSD1 and CDH1 expression, and Kaplan-Meier survival analysis was applied to test the relationship between SUV39H2 expression and overall survival. Loss- and gain-of-function assays were conducted to determine the roles of SUV39H2, LSD1 and CDH1 in OS epithelial mesenchymal transition (EMT) and migration in OS cells, with quantitation of relevant proteins by immunofluorescence. We confirmed the effects of modulating the SUV39H2/CDH1 axis in a mouse OS tumor model.

RESULTS

SUV39H2 and LSD1 were highly expressed, while CDH1 was downregulated in OS tissues and cells. SUV39H2 expression correlated inversely with overall survival of patients with OS. SUV39H2 positively regulated LSD1 expression, while LSD1 negatively regulated CDH1 expression. SUV39H2 or LSD1 overexpression, or CDH1 silencing promoted migration and EMT, as indicated by reduced E-cadherin and dramatically upregulated Vimentin and N-cadherin of OS cells. SUV39H2 expedited the progression of OS, which was reversed by CDH1 repression in the setting of OS in vitro and in vivo.

CONCLUSIONS

Collectively, our results demonstrate highly expressed SUV39H2 in OS elevates the expression of LSD1 to downregulate CDH1 expression, thereby aggravating OS, providing a potential therapeutic target for treatment of OS.

lncRNA TUSC7 inhibits osteosarcoma progression through the miR‑181a/RASSF6 axis

Osteosarcoma (OS) is one of the most aggressive malignancies, accompanied by an elevated incidence and a decreased rate of healing. Recently, several long non-coding RNAs (lncRNAs) have been reported to be involved in OS progression. Although tumor suppressor candidate 7 (TUSC7) was reported as a novel lncRNA, little is known about its biological functions in OS. The present study was designed to explore whether TUSC7 was involved in the pathological development of OS using various methods, including hematoxylin and eosin staining, Cell Counting Kit-8 assay, colony formation assay and Transwell assay. The present study revealed that TUSC7 expression was downregulated in OS tissues and cell lines compared with in normal tissues and cell lines. Functionally, the current results revealed that overexpression of TUSC7 inhibited OS cell proliferation, migration and invasion, while promoting apoptosis in vitro and in vivo. Next, the subcellular distribution of TUSC7 was examined by nuclear/cytoplasmic RNA fractionation and reverse transcription-quantitative PCR. Mechanistic studies revealed that TUSC7 exerted its role by sponging microRNA (miR)-181a in OS cell lines. Ras association domain family member 6 (RASSF6) was confirmed as a target gene of miR-181a, and the expression levels of RASSF6 were negatively regulated by miR-181a. Additionally, the results of rescue experiments suggested that overexpression of miR-181a neutralized the inhibitory effects of TUSC7 overexpression on OS cells. Overall, the present study demonstrated that the tumor suppressor role of TUSC7 in OS progression was mediated through the miR-181a/RASSF6 axis, which may represent a new therapeutic target for OS.

LncRNA NR_027471 Functions as a ceRNA for miRNA-8055 Leading to Suppression of Osteosarcoma by Regulating the Expression of TP53INP1

Osteosarcoma is a malignancy with high aggressiveness and poor prognosis, which occurs mainly in children. The therapeutic strategy against osteosarcoma includes surgery combined with chemotherapy and radiotherapy. Although the treatment of osteosarcoma has been improved in recent years, there is a large proportion of patients with incurable osteosarcoma. Investigation of the mechanism of osteosarcoma progression would be of great help in discovering therapeutic targets for this disease. Long non-coding RNAs play critical roles in the pathogenesis of different types of cancer. The current study showed that long non-coding RNA NR_027471 was downregulated in osteosarcoma cells. In vitro and in vivo studies indicated that upregulation of NR_027471 impeded the viability, proliferation, and invasion of osteosarcoma, as well as induced cell cycle arrest at G1. In addition, binding of miR-8055 to NR_027471 was demonstrated, thereby influencing the expression of tumor protein p53 inducible nuclear protein 1 (TP53INP1). Knockdown of NR_027471 promoted epithelial–mesenchymal transition by inhibiting E-cadherin and increasing the expression of zinc finger E-box-binding homeobox 1 (ZEB1), Snail, and fibronectin. These results suggested that overexpression of NR_027471 upregulated TP53INP1 by sponging to miR-8055, leading to suppression of osteosarcoma cell proliferation and progression.

Circ-XPR1 promotes osteosarcoma proliferation through regulating the miR-214-5p/DDX5 axis

Circular RNAs (circRNAs) are a new class of RNAs that play an important role in the development of various tumors. However, the expression profile and biological function of circRNAs in osteosarcoma (OS) progression remain unclear. OS-related circRNA expression profiles from the GEO database (GSE96964) were downloaded to identify differentially expressed circRNAs between OS and normal tissues. We identified one upregulated circRNA (Circ-XPR1), and RT-PCR was performed to further confirm the expression abundance in OS tissue. Circ-XPR1 was closely related to overall survival and disease-free survival of OS patients. Knockdown of Circ-XPR1 significantly reduced the proliferation of OS cells. Gain- and loss-of-function studies showed that Circ-XPR1 promoted OS cell proliferation by sponging miR-214-5p to regulate DDX5 expression. Our findings suggested that Circ-XPR1 regulates OS cell proliferation by sponging miR-214-5p to regulate DDX5 expression. Therefore, the Circ-XPR1/miR-214-5p/DDX5 axis may serve as a potential therapeutically relevant target for OS.

microRNA-214 Prevents Traits of Cutaneous Squamous Cell Carcinoma via VEGFA and Bcl-2

BACKGROUND

Dysregulation of microRNA-214 (miR-214) has been indicated in different tumors. The function of miR-214 in cutaneous squamous cell carcinoma (CSCC) is yet to be deciphered. The current study aimed to investigate the specific mechanism underpinning CSCC development with the involvement of miR-214 and its putative targets.

METHODS

Microarray analysis of CSCC and adjacent tissues was carried out to filter the most significant downregulated miRNA. Survival analysis of patients was subsequently implemented, followed by miRNA expression determination in CSCC cells. Gain-of-function assays were performed to evaluate its function on cellular level. The targets of the determined miRNA were predicted and their expression in CSCC and adjacent tissues was evaluated. The targeting relationship was analyzed by dual-luciferase assays. Finally, rescue experiments were conducted.

RESULTS

miR-214 was reduced in CSCC tissues and cells, and the survival of patients harboring overexpression of miR-214 was higher. miR-214 restoration increased CSCC cell apoptosis, while decreased proliferative, invasive and migratory activities. miR-214 interacted with vascular endothelial growth factor A (VEGFA) and B-cell CLL/lymphoma 2 (Bcl-2). VEGFA and Bcl-2, overexpressed in CSCC tissues and cells, were negatively correlated with miR-214. Moreover, VEGFA and Bcl-2 overexpression reversed the anti-tumor phenotypes of miR-214 on CSCC cells. miR-214 disrupted the Wnt/β-catenin pathway through VEGFA and Bcl-2 in the CSCC cells.

CONCLUSION

Our data demonstrates that miR-214 exerts a suppressing role in CSCC. The discovery of novel targets such as miR-214 and VEGFA/Bcl-2 may facilitate the development of therapeutic options.