The prognostic value of long noncoding RNA Sox2ot expression in various cancers: A systematic review and meta-analysis

Long non-coding RNA as a potential diagnostic and prognostic biomarker in melanoma: A systematic review and meta-analysis

Recently, long noncoding RNAs (lncRNAs) have been applied as biomarkers for melanoma patients. In this systematic review and meta-analysis, we investigated the diagnostic and prognostic value of lncRNAs. We used the keywords 'lncRNA' and 'melanoma' to search databases for studies published before June 14th, 2023. The specificity, sensitivity and AUC were utilized to assess diagnostic accuracy and the prognostic value was assessed using overall survival, progression-free survival and disease-free survival hazard ratios. After screening 1191 articles, we included seven studies in the diagnostic evaluation section and 17 studies in the prognosis evaluation section. The Reitsma bivariate model estimated a cumulative sensitivity of 0.724 (95% CI: 0.659-0.781, p < 0.001) and specificity of 0.812 (95% CI: 0.752-0.859, p < 0.001). The pooled AUC was 0.780 (95% CI: 0.749-0.811, p < 0.0001). The HR for overall survival was 2.723 (95% CI: 2.259-3.283, p < 0.0001). Two studies reported an HR for overall survival less than one, with an HR of 0.348 (95% CI: 0.200-0.607, p < 0.0002). The HR for progression-free survival was 2.913 (95% CI: 2.050-4.138, p < 0.0001). Four studies reported an HR less than one, with an HR of 0.457 (95% CI: 0.256-0.817). The HR for disease-free survival was 2.760 (95% CI: 2.009-3.792, p < 0.0001). In conclusion, the expression of lncRNAs in melanoma patients affects survival and prognosis. LncRNAs can also be employed as diagnostic biomarkers.

N6-methyladenine-mediated aberrant activation of the lncRNA SOX2OT-GLI1 loop promotes non-small-cell lung cancer stemness

Despite the advent of precision medicine and immunotherapy, mortality due to lung cancer remains high. The sonic hedgehog (SHH) cascade and its key terminal factor, glioma-associated oncogene homolog 1 (GLI1), play a pivotal role in the stemness and drug resistance of lung cancer. Here, we investigated the molecular mechanism of non-canonical aberrant GLI1 upregulation. The SHH cascade was upregulated in stem spheres and chemo-resistant lung cancer cells and was accountable for drug resistance against multiple chemotherapy regimens. GLI1 and the long non-coding RNA SOX2OT were positively regulated, and the GLI1-SOX2OT loop mediated the proliferation of parental and stem-like lung cancer cells. Further mechanistic investigation revealed that SOX2OT facilitated METTL3/14/IGF2BP2-mediated m6A modification and stabilization of the GLI1 mRNA. Additionally, SOX2OT upregulated METTL3/14/IGF2BP2 by sponging miR-186-5p. Functional analysis corroborated that GLI1 acted as a downstream target of METTL3/14/IGF2BP2, and GLI1 silencing could block the oncogenicity of lung cancer stem-like cells. Pharmacological inhibition of the loop remarkably inhibited the oncogenesis of lung cancer cells in vivo. Compared with paired adjacent normal tissues, lung cancer specimens exhibited consistently upregulated GLI1/SOX2OT/METTL3/14/IGF2BP2. The m6A-modified GLI1-SOX2OT loop may serve as a potential therapeutic target and prognostic predictor for lung cancer therapy and diagnosis in the clinic.

SOX2-OT induced by PAI-1 promotes triple-negative breast cancer cells metastasis by sponging miR-942-5p and activating PI3K/Akt signaling

Triple-negative breast cancer (TNBC) has an aggressive biological behavior and poor outcome. Our published study showed that PAI-1 could induce the migration and metastasis of TNBC cells. However, the underlying mechanism by which PAI-1 regulates TNBC metastasis has not been addressed. Here, we demonstrated that PAI-1 is high expressed in TNBC and promotes TNBC cells tumorigenesis. Using microarray analysis of lncRNA expression profiles, we identified a lncRNA SOX2-OT, which is induced by PAI-1 and could function as an oncogenic lncRNA in TNBC. Mechanistic analysis demonstrated that SOX2-OT acts as a molecular sponge for miR-942-5p to regulate the expression of PIK3CA, ultimately leading to activating PI3K/Akt signaling pathway and promoting TNBC metastasis. Taken together, our findings suggest that SOX2-OT regulates PAI-1-induced TNBC cell metastasis through miR-942-5p/PIK3CA signaling and illustrate the great potential of developing new SOX2-OT-targeting therapy for TNBC patients.

Long non-coding RNA MIR31HG as a prognostic predictor for malignant cancers: A meta- and bioinformatics analysis

Background

The possible regulatory mechanism of MIR31HG in human cancers remains unclear, and reported results of the prognostic significance of MIR31HG expression are inconsistent.

Methods

The meta‐analysis and related bioinformatics analysis were conducted to evaluate the role of MIR31HG in tumor progression.

Results

The result showed that high MIR31HG expression was not related to prognosis. However, in the stratified analysis, we found that the overexpression of MIR31HG resulted in worse OS, advanced TNM stage, and tumor differentiation in respiratory system cancers. Moreover, our results also found that MIR31HG overexpression was related to shorter OS in cervical cancer patients and head and neck tumors. In contrast, the MIR31HG was lower in digestive system tumors which contributed to shorter overall survival, advanced TNM stage, and distant metastasis. Furthermore, the bioinformatics analysis showed that MIR31HG was highly expressed in normal urinary bladder, small intestine, esophagus, stomach, and duodenum and low in colon, lung, and ovary. The results obtained from FireBrowse indicated that MIR31HG was highly expressed in LUSC, CESC, HNSC, and LUAD and low in STAD and BLCA. Gene Ontology analysis showed that the co‐expressed genes of MIR31HG were most enriched in the biological processes of peptide metabolism and KEGG pathways were most enriched in Ras, Rap1, and PI3K‐Akt signaling pathway.

Conclusion

MIR31HG may serve as a potential biomarker in human cancers.

Long Noncoding RNA SOX2-OT: Regulations, Functions, and Roles on Mental Illnesses, Cancers, and Diabetic Complications

SRY-box transcription factor 2 (SOX2) overlapping transcript (SOX2-OT) is an evolutionarily conserved long noncoding RNA. Its intronic region contains the SOX2 gene, the major regulator of the pluripotency of embryonic stem cells. The human SOX2-OT gene comprises multiple exons and has multiple transcription start sites and generates hundreds of transcripts. Transcription factors (IRF4, AR, and SOX3), transcriptional inhibitors (NSPc1, MTA3, and YY1), and miRNAs (miR-211 and miR-375) have been demonstrated to control certain SOX2-OT transcript level at the transcriptional or posttranscriptional levels. Accumulated evidence indicates its crucial roles in the regulation of the SOX2 gene, miRNAs, and transcriptional process. Restricted expression of SOX2-OT transcripts in the brain results in the association between SOX2-OT single nucleotide polymorphisms and mental illnesses such as schizophrenia and anorexia nervosa. SOX2-OT is notably elevated in tumor tissues, and a high level of SOX2-OT is well correlated with poor clinical outcomes in cancer patients, leading to the establishment of its role as an oncogene and a prognostic or diagnostic biomarker for cancers. The emerging evidence supports that SOX2-OT mediates diabetic complications. In summary, SOX2-OT has diversified functions and could be a therapeutic target for various diseases.

Clinicopathological Implication of Long Non-Coding RNAs SOX2 Overlapping Transcript and Its Potential Target Gene Network in Various Cancers

Background

SOX2 overlapping transcript (SOX2-OT) produces alternatively spliced long non-coding RNAs (lncRNA). Previous studies of the prognostic role of SOX2-OT expression met with conflicting results. The aim of this study was to properly consider the prognostic role of SOX2-OT expression in several cancers. In addition, the regulative mechanism of SOX2-OT is explored.

Methods

PubMed, EMBASE, and Cochrane Library and The Cancer Genome Atlas (TCGA) database were comprehensively explored to recover pertinent studies. We conducted an extensive inquiry to verify the implication of SOX2-OT expression in cancer patients by conducting a meta-analysis of 13 selected studies. Thirty-two TCGA databases were used to analyze the connection between SOX2-OT expression and both the overall survival (OS) and clinicopathological characteristics of cancer patients using R and STATA 13.0. Trial sequential analysis (TSA) was adopted in order to compute the studies' power.

Results

Thirteen studies involving 1172 cancer patients and 32 TCGA cancer types involving 9676 cancer patients were eventually selected. Elevated SOX2-OT expression was significantly related to shorter OS (HR = 2.026, 95% CI: 1.691-2.428, P < 0.0001) and disease-free survival (DFS) (HR = 2.554, 95% CI: 1.261-5.174, P = 0.0092) in cancer patients. Meanwhile, TSA substantiated adequate power to demonstrate the relationship between SOX2-OT expression and OS. The cancer patients with elevated SOX2-OT expression were more likely to have advanced clinical stage (RR = 1.468, 95% CI: 1.106-1.949, P = 0.0079), earlier lymphatic metastasis (P = 0.0005), earlier distant metastasis (P < 0.0001), greater tumor size (P < 0.0001), and more extreme tumor invasion (P < 0.0001) compared to those with low SOX2-OT expression. Meta-regression and subgroup analysis revealed that follow-up time, sample type, and tumor type could significantly contribute to heterogeneity for survival outcomes. The follow-up time could significantly explain heterogeneity for tumor, node, metastasis (TNM) stage. Furthermore, up to 500 validated target genes were distinguished, and the gene oncology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses demonstrated that the validated targets of SOX2-OT were substantially enriched in cell adhesion, mRNA binding, and mRNA surveillance pathways.

Conclusions

Elevated expression of SOX2-OT predicted a poor OS and DFS. Overexpression of SOX2-OT was correlated with more advanced tumor stage, earlier lymphatic metastasis, earlier distant metastasis, larger tumor size, and deeper tumor invasion. SOX2-OT-mediated cell adhesion, mRNA binding, or mRNA surveillance could be intrinsic mechanisms for invasion and metastasis.

Role of lncRNA-ATB in ovarian cancer and its mechanisms of action

This study aimed to elucidate the role of long non-coding RNA activated by transforming growth factor-β (lncRNA-ATB) in ovarian cancer and its underlying mechanisms of action. Expression levels of lncRNA-ATB in ovarian cancer cell line SKOV3 and in a healthy human ovarian cell line were compared using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The results indicated that lncRNA-ATB was expressed at significantly higher levels in SKOV3 cells compared with the healthy cell line. After downregulation of lncRNA-ATB expression in SKOV3 cells using lncRNA-ATB-short hairpin RNA, cell proliferation, apoptosis, invasion and migration were assessed using Cell counting kit-8, Live Dead staining, Transwell assay and wound healing assay, respectively. RT-qPCR and western blotting were used to quantify the expression of signal transducer and activator of transcription 3 (STAT3), phosphorylated (p)-STAT3, and the additional epithelial to mesenchymal transition (EMT)-related proteins E-cadherin and vimentin in SKOV3 cells. LncRNA-ATB downregulation significantly reduced SKOV3 cell proliferation, invasion and migration, promoted apoptosis, decreased the expression of p-STAT3 and vimentin, and increased E-cadherin expression. Taken together, these results suggest that lncRNA-ATB downregulation can inhibit ovarian cancer cell proliferation, invasion and migration, and promote cell apoptosis. Lnc-RNA-ATB may therefore be a new target for ovarian cancer treatment.

Differential expression of long non-coding RNA SOX2OT in gastric adenocarcinoma

BACKGROUND

Gastric cancer (GC) is the third leading cause of cancer-related death in the world. Dysfunction of long noncoding RNAs (lncRNAs) in cancers, especially those with role in pluripotency, are approved by increasing evidence.

OBJECTIVE

SOX2 overlapping transcript (SOX2OT) lncRNA, is aberrantly expressed in different cancers; however its role in gastric cancer is still controversial.

MATERIALS AND METHODS

In this study, the expression of SOX2OT was evaluated in 33 matched pair tumor and non-tumor gastric samples and AGS and MKN45 gastric and NTERA2 embryonic carcinoma cell lines by real time PCR.

RESULTS

Our finding revealed a significant decrease in the expression of SOX2OT in gastric tumor samples compared to their matched non-tumor samples (P= 0.05) and also a lower expression in high grade compared to low grade of gastric malignancy. As we expected SOX2OT expression showed higher expression in NT2 compared to AGS and MKN45 cell lines.

CONCLUSION

Simultaneous expression of SOX2 and SOX2OT was reported in some cancers. Regarding to the decreased expression of SOX2OT in the present study in concurrent with downregulation of SOX2 in our previous study, it seems that SOX2OT plays a tumor suppressor role in GC and may be useful biomarker for diagnosis of GC.

Retracted: Long Noncoding RNA SOX2OT Accelerates the Carcinogenesis of Wilms' Tumor Through ceRNA Through miR-363/FOXP4 Axis

REFERENCES

ATCC. www.lgcstandards-atcc.org/Products/All/CRL-1441.aspx?geo_country=it Memorial Sloan Kettering Cancer Cancer. https://www.mskcc.org/research-advantage/support/technology/tangiblematerial/sk-nep-1-human-ewing-sarcoma-cell-line.

Long non-coding RNA activated by TGF-β expression in cancer prognosis: A meta-analysis

BACKGROUND

Recently, long non-coding RNA activated by transforming growth factor beta (TGF-β) (lncRNA ATB) was shown to be useful in cancer prognosis, however, its prognostic value in human cancer has been inconsistent. Our study aimed to explore the prognostic role of lncRNA ATB expression in cancer prognosis.

METHODS

PubMed, Embase, and Cochrane Library databases were thoroughly searched to retrieve studies focusing on the prognostic role of lncRNA ATB expression in cancer, and meta-analysis was performed.

RESULTS

A total of 15 studies were included into this meta-analysis. High lncRNA ATB expression was significantly related to shorter overall survival (OS) (HR = 2.44, 95%CI = 1.98-3.01, P < 0.01), recurrence-free survival (RFS) (HR = 1.85, 95%CI = 1.42-2.40, P < 0.01), disease-free survival (DFS) (HR = 3.61, 95%CI = 2.45-5.33, P < 0.01), and progression-free survival (PFS) (HR = 2.97, 95%CI = 2.12-4.16, P < 0.01) when compared with low lncRNA ATB expression in cancer. Moreover, Patients with high lncRNA ATB expression tended to have worse tumor differentiation (P < 0.01), more advanced clinical stage (P < 0.01), deeper tumor invasion (P < 0.01), earlier distant metastases (P = 0.02), lymph node metastases (P = 0.04), and vascular invasion (P < 0.01) when compared with those with low lncRNA ATB expression.

CONCLUSIONS

High lncRNA ATB expression was significantly associated with worse prognosis in cancer. LncRNA ATB expression could be used as a prognostic biomarker for human cancer.