SRY-Related Transcription Factors in Head and Neck Squamous Cell Carcinomas: In Silico Based Analysis.

Head and neck squamous cell carcinoma (HNSCC) is the sixth leading cancer and the fifth cause of cancer-related deaths worldwide with a poor 5-year survival. SOX family genes play a role in the processes involved in cancer development such as epithelial-mesenchymal transition (EMT), the maintenance of cancer stem cells (CSCs) and the regulation of drug resistance. We analyzed the expression of SOX2-OT, SOX6, SOX8, SOX21, SOX30 and SRY genes in HNSCC patients using the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets, to assess their biological role and their potential utility as biomarkers. We demonstrated statistically significant differences in expression between normal and primary tumor tissues for SOX6, SOX8, SOX21 and SOX30 genes and pointed to SOX6 as the one that met the independent diagnostic markers criteria. SOX21 or SRY alone, or the panel of six SRY-related genes, could be used to estimate patient survival. SRY-related genes are positively correlated with immunological processes, as well as with keratinization and formation of the cornified envelope, and negatively correlated with DNA repair and response to stress. Moreover, except SRY, all analyzed genes were associated with a different tumor composition and immunological profiles. Based on validation results, the expression of SOX30 is higher in HPV(+) patients and is associated with patients' survival. SRY-related transcription factors have vast importance in HNSCC biology. SOX30 seems to be a potential biomarker of HPV infection and could be used as a prognostic marker, but further research is required to fully understand the role of SOX family genes in HNSCC.

Forkhead box A2-mediated lncRNA SOX2OT up-regulation alleviates oxidative stress and apoptosis of renal tubular epithelial cells by promoting SIRT1 expression in diabetic nephropathy.

BACKGROUND: Renal tubular injury is the main feature of diabetic nephropathy (DN). We intend to investigate the function and related mechanisms of lncRNA SOX2 overlapping transcript (SOX2OT) in high glucose (HG)-induced oxidative stress and apoptosis of renal tubular epithelial cells (RTECs). METHODS: To construct diabetes models, the human kidney-2 (HK-2) cells were treated with HG (30 mM), and mice were injected with streptozotocin. The levels of intracellular and mitochondrial reactive oxygen species (ROS) were assessed by dihydroethidium staining and MitoSox staining. The cell apoptosis was assessed by flow cytometry and TUNEL staining. Levels of serum creatinine, blood urea nitrogen (BUN), Urinary ACR, and oxidative stress marker 8-hydroxy-2'-deoxyguanosine (8-OHdG) were detected by relevant kits. In addition, fluorescence in situ hybridization staining, RNA-pull down, RNA immunoprecipitation (RIP), co-immunoprecipitation (co-IP), dual-luciferase reporter gene assay and chromatin immunoprecipitation (ChIP) were also executed. RESULTS: Levels of SOX2OT and silent information regulator 1 (SIRT1) were down-regulated in HG-cultured HK-2 cells. Overexpressing SOX2OT reduced intracellular and mitochondrial ROS levels and cell apoptosis in vitro. Moreover, SOX2OT overexpression also reduced serum creatinine, BUN, urinary ACR, 8-OHdG, renal tubular injury markers KIM1 and NGAL, ROS levels, and cell apoptosis in vivo. In addition, SOX2OT promoted SIRT1 expression by suppressing its ubiquitination. Besides, interference with SIRT1 reversed the inhibitory effect of SOX2OT overexpression on HG-induced oxidative stress and apoptosis. Forkhead box A2 (Foxa2) levels were up-regulated in HG-cultured HK-2 cells. Foxa2 could bind to the SOX2OT promoter and suppress its expression. Furthermore, interfering with SOX2OT reversed the inhibitory effect of Foxa2 interference on HG-induced oxidative stress and apoptosis. CONCLUSION: Foxa2-mediated SOX2OT up-regulation reduced oxidative stress and apoptosis of RTECs by promoting SIRT1 expression, thus alleviating the progression of DN.

Silencing of Long noncoding RNA SOX2-OT relieves myocardial ischemia/reperfusion injury through up-regulating microRNA-146a-5p.

PURPOSE: Long noncoding RNAs (lncRNAs) are involved in the development of myocardial ischemia/reperfusion injury (MIRI). In this study, we aimed to explore the regulatory effect and mechanism of lncRNA SOX2-OT in MIRI. METHODS: The expression levels of SOX2-OT and miR-146a-5p in OGD/R-treated H9C2 cells and in myocardial tissues of MIRI rats were measured by qRT-PCR. Cell viability was detected by MTT assay. The levels of IL-1ß, IL-6, TNF-α, MDA, and SOD were measured by ELISA. The target relationship between SOX2-OT and miR-146a-5p was predicted by LncBase, and subsequently confirmed by DLR assay. The effects of SOX2-OT silencing on myocardial apoptosis and function were further validated in MIRI rats. RESULTS: The expression of SOX2-OT was increased in OGD/R-treated H9C2 cells and myocardial tissues of MIRI rats. Silencing of SOX2-OT increased the viability and inhibited the inflammation and oxidative stress of OGD/R-treated H9C2 cells. SOX2-OT negatively regulated its target miR-146a-5p. Inhibition of miR-146a-5p reversed the effects of sh-SOX2-OT on increasing the viability, and on inhibiting the inflammation and oxidative stress of OGD/R-treated H9C2 cells. In addition, silencing of SOX2-OT alleviated myocardial apoptosis and improved myocardial function in MIRI rats. CONCLUSIONS: Silencing of SOX2-OT relieved the apoptosis, inflammation, and oxidative stress of myocardial cells via up-regulating miR-146a-5p, contributing to the remission of MIRI (Fig. 28, Ref. 33).

LncRNA SOX2OT facilitates LPS-induced inflammatory injury by regulating intercellular adhesion molecule 1 (ICAM1) via sponging miR-215-5p.

AIM: Long non-coding RNA SOX2 overlapping transcript (SOX2OT) is closely related to heart failure and myocardial damage. We attempted to investigate its role in endotoxin lipopolysaccharide (LPS) injury in cardiomyocytes. MATERIALS & METHODS: Cell viability, apoptosis rate, and levels of pro-inflammatory cytokines and apoptosis- and oxidative stress-related proteins were measured by MTS assay kit, flow cytometry, western blotting, and commercial kits. Physical interactions were confirmed by dual-luciferase report assay and RNA immunoprecipitation assay. RESULTS: Silencing SOX2OT and reinforcing miRNA (miR)-215-5p protected human AC16 cardiomyocytes from LPS-induced oxidative and inflammatory injuries by inhibiting intercellular adhesion molecule 1 (ICAM1). SOX2OT directly interacted with miR-215-5p, and miR-215-5p could target ICAM1. CONCLUSION: Inhibiting SOX2OT/miR-215-5p/ICAM1 axis might be a possible approach to treat myocardial damage. LAY ABSTRACT: Lipopolysaccharide (LPS) is an endotoxin from some bacteria including Escherichia coli, and it can cause inflammation in different tissues/cells including myocardia/cardiomyocytes, resulting in diseases such as myocarditis, cardiomyopathy, and cardiac hypertrophy. The underlying mechanism was not completely clarified, but known to include the dysregulation of non-coding RNAs. Herein, we demonstrated the biological role of long non-coding RNA SOX2 overlapping transcript (SOX2OT) in LPS-infected cardiomyocytes. Eventually, we found that inhibiting the expression of SOX2OT could mitigate LPS-induced a series of injuries in human cardiomyocytes, and SOX2OT interacts with a microRNA named as miR-215-5p. Besides, restoring miR-215-5p elicited similar effects to SOX2OT knockdown. Collectively, we concluded that SOX2OT binding to miR-215-5p might protect cardiomyocytes from LPS infection through regulating an important protein named ICAM1. This study suggested SOX2OT/miR-215-5p might be novel potential treatment targets in bacterial infection-related myocardial damages.

Diagnostic and prognostic significance of lncRNA SOX2-OT in patients with carotid atherosclerosis.

BACKGROUND: This paper aimed to analyze IncRNA SOX2-OT expression in patients with carotid atherosclerosis and to elucidate the predictive significance of SOX2-OT on carotid atherosclerosis. METHODS: The levels of SOX2-OT from 185 participants were tested. The relationship between CIMT levels and SOX2-OT expression was examined by Pearson analysis. The clinical value of SOX2-OT was investigated by the ROC curve, K-M curve, and COX regression analysis. The comparison of SOX2-OT expression between patients with good prognosis and poor prognosis was also performed. RESULTS: The expression of SOX2-OT was augmented in the patients with carotid atherosclerosis and was correlated with the level of CIMT. The high level of SOX2-OT might be a risk factor for carotid atherosclerosis. An enhancement of SOX2-OT expression was found in patients with poor prognosis. SOX2-OT might be an independent prognostic biomarker. CONCLUSIONS: SOX2-OT was upregulated in patients with carotid atherosclerosis and might be a predictive indicator in the progression of carotid atherosclerosis.

LncRNA SOX2OT alleviates mesangial cell proliferation and fibrosis in diabetic nephropathy via Akt/mTOR-mediated autophagy.

BACKGROUND: Accumulating evidences have demonstrated that long non-coding RNAs (lncRNAs) are involved in the pathophysiology of diabetic nephropathy (DN). lncRNA SOX2OT plays an essential role in many diseases, including diabetes. Herein, we aim to investigate the underlying mechanism of lncRNA SOX2OT in DN pathogenesis. METHODS: Streptozotocin-induced DN mouse models and high glucose-induced mouse mesangial cells were constructed to examine the expression pattern of lncRNA SOX2OT. The activation of autophagy was evaluated using immunohistochemistry, immunofluorescence and western blot analysis, respectively. SOX2OT overexpressing plasmid was applied to further verify the functional role of SOX2OT in DN pathogenesis. CCK-8 and EDU assays were performed to the proliferation of mesangial cells. Additionally, rapamycin, the inhibitor of mTOR signaling, was used to further clarify whether SOX2OT controls DN development through Akt/mTOR pathway. RESULTS: lncRNA SOX2OT was markedly down-regulated both in streptozotocin-induced DN mice and high glucose-induced mouse mesangial cells. Moreover, overexpression of lncRNA SOX2OT was able to diminish the suppression of autophagy and alleviate DN-induced renal injury. Functionally, CCK-8 and EDU assays indicated that lncRNA SOX2OT overexpression significantly suppressed the proliferation and fibrosis of mesangial cells. Additionally, an obvious inhibition of Akt/mTOR was also observed with lncRNA SOX2OT overexpression, which was then further verified in vivo. CONCLUSION: In summary, we demonstrated that lncRNA SOX2OT alleviates the pathogenesis of DN via regulating Akt/mTOR-mediated autophagy, which may provide a novel target for DN therapy.

CRISPR/Cas9-mediated gene editing on Sox2ot promoter leads to its truncated expression and does not influence neural tube closure and embryonic development in mice.

Sox2 overlapping transcript (Sox2ot) is a long non-coding RNA (lncRNA), which harbors one of the major regulators of pluripotency, the Sox2 gene, in its intronic region. Sox2ot is primarily expressed in the developing neuroepithelium. However, its role in neural tube closure and embryonic development remains unclear. To investigate if Sox2ot is required for neural tube closure and embryonic development, Sox2ot promoter was deleted by CRISPR-Cas9 genome editing technology to prevent Sox2ot gene expression in mice. We designed 9 guide RNAs to specifically target the Sox2ot promoter and 3 gRNAs induced gene editing on the promoter of the Sox2ot gene in cells transfected with Cas9 mRNA and gRNAs. Then, these gRNAs and Cas9 mRNA were injected into mouse zygotes and implanted into pseudopregnant mice. A Sox2ot promoter-deleted mouse line was identified with complete deletion of promoter as well as deletion of exon 1 and exon 2. Sox2ot transcript was truncated with a lack of exon 1 and exon 2 in Sox2ot promoter-deleted mice. Furthermore, neural tube closure and embryonic development were checked at E9.5, E10.5, E14.5, E17.5 and after-birth (P2) and we did not find any failure of neural tube closure and aberrant embryonic development in Sox2ot promoter-deleted mice. Thus, our study demonstrated that CRISPR-Cas9 gene editing in Sox2ot promoter leads to its truncated expression and does not influence neural tube closure and embryonic development.

Long Non-Coding RNA SOX2 Overlapping Transcript Aggravates H9c2 Cell Injury via the miR-215-5p/ZEB2 Axis and Promotes Ischemic Heart Failure in a Rat Model.

Heart failure is a common cardiovascular disease, which has been regarded as one of the highest health care costs with high morbidity and mortality in the western countries. Long noncoding RNAs have been widely reported to regulate the initiation or progression of cardiovascular diseases. However, the specific role of SOX2 overlapping transcript (SOX2-OT) in ischemic heart failure remains uncharacterized. The present study aimed to explore the function and mechanism of SOX2-OT in ischemic heart failure. The starBase website was used to predict potential miRNAs or target mRNAs. Western blot assay was implemented to test collagen protein levels. Functional assays were conducted to evaluate the effects of SOX2-OT on H9c2 cell viability and apoptosis. RNA pull down and luciferase reporter assays were used to confirm the combination between miR-215-5p and SOX2-OT. We found out that SOX2-OT level was increased by oxygen glucose deprivation/reoxygenation treatment in H9c2 cells. Silencing of SOX2-OT ameliorated cell injury by promoting cell viability, inhibiting cell apoptosis and reducing productions of collagens. Mechanistically, miR-215-5p was confirmed to bind with SOX2-OT after prediction and screening. In addition, we discovered that miR-215-5p negatively regulated zinc finger E-box binding homeobox 2 (ZEB2) protein level by directly binding with ZEB2 3' untranslated region. Finally, we verified that SOX2-OT aggravated cell injury by targeting ZEB2 in H9c2 cells. In conclusion, SOX2-OT aggravated heart failure in vivo and promoted H9c2 cell injury via the miR-215-5p/ZEB2 axis in vitro, implying a novel insight into heart failure treatment.

lncRNA SOX2-OT ceRNA network enhances the malignancy of long-term PM2.5-exposed human bronchial epithelia.

Exposure to fine particulate matter (PM2.5) in outdoor air is carcinogenic and associated with the development of lung cancer; however, the underlying mechanism remains unclear. In the present study, the profiles of lncRNA, microRNA and mRNA expression profiles in human bronchial epithelia (HBE) following exposure to PM2.5, diesel exhaust particles (DEPs), or aluminum oxide nanoparticles (Al2O3 NPs) were explored by microarray to reveal the lncRNA-microRNA-mRNA network participating in the malignant transformation of HBE cells following long-term PM2.5 exposure. The results showed that lncRNA SOX2 overlapping transcript (SOX2-OT) was significantly induced in HBE cells exposed to PM2.5, DEPs, or Al2O3 NPs, acting as a sponge to microRNA-345-5p, which subsequently increased the expression levels of epidermal growth factor receptor (EGFR). EGFR is a therapeutic target in non-small cell lung cancer. Here, we found that SOX2-OT is an upstream trigger of EGFR in HBE cells during long-term PM2.5 exposure. Importantly, SOX2-OT knockdown effectively reduced the colony formation and migration capacities of HBE cells, compared to the wild type control. Collectively, SOX2-OT/microRNA-345-5p/EGFR is a ceRNA mechanism underlying the malignant transformation of bronchial epithelia exposed to PM2.5, which improves our understanding of the association between ambient PM2.5 exposure and the development of lung cancer.

Long non-coding RNA Sox2 overlapping transcript (SOX2OT) promotes multiple myeloma progression via microRNA-143-3p/c-MET axis.

Long non-coding RNA Sox2 overlapping transcript (SOX2OT) was reported to be involved in progression of multiple cancers. However, the role and mechanism of SOX2OT in multiple myeloma (MM) has yet to be unravelled. In the present study, elevated SOX2OT levels are reported in MM cell lines and patient samples as compared to normal plasma cells (nPCs) and healthy donors, respectively. Knock-down of SOX2OT led to a significant inhibition of cell proliferation, arrested cells at G0/G1 phase and induced cell apoptosis in MM samples in vitro, as well as slowed the growth of tumours in vivo. Additionally, our data indicated that SOX2OT functioned as a competing endogenous RNA (ceRNA) in MM cells that regulated miR-144-3p expression. Repression of miR-144-3p reversed the inhibition of MM development due to SOX2OT knock-down. Our data also revealed that SOX2OT regulated the expression of the cellular-mesenchymal to epithelial transition factor (c-MET, a known target of miR-143-3p) by functioning as a sponge of miR-144-3p in MM samples. These data support that SOX2OT promotes MM progression through regulating the miR-144-3p/c-MET axis, suggesting that SOX2OT might be as a potential therapeutic target for MM.

Long non-coding RNA SOX2OT promotes the stemness phenotype of bladder cancer cells by modulating SOX2.

BACKGROUND: Accumulating evidence indicates that long non-coding RNAs (lncRNAs) are potential biomarkers and key regulators of tumour development and progression. SOX2 overlapping transcript (SOX2OT) is a novel lncRNA that acts as a potential biomarker and is involved in the development of cancer and cancer stem cells. However, the clinical significance and molecular mechanism of SOX2OT in bladder cancer are still unknown. METHODS: The expression level of SOX2OT was determined by RT-qPCR in a total of 106 patients with urothelial bladder cancer and in different bladder cancer cell (BCC) lines. Bladder cancer stem cells (BCSCs) were isolated from BCCs using flow cytometry based on the stem cell markers CD44 and ALDH1. Loss-of-function experiments were performed to investigate the biological roles of SOX2OT in the stemness phenotype of BCSCs. Comprehensive transcriptional analysis, RNA FISH, dual-luciferase reporter assays and western blots were performed to explore the molecular mechanisms underlying the functions of SOX2OT. RESULTS: SOX2OT was highly expressed in bladder cancer, and increased SOX2OT expression was positively correlated with a high histological grade, advanced TNM stage and poor prognosis. Further experiments demonstrated that knockdown of SOX2OT inhibited the stemness phenotype of BCSCs. Moreover, inhibition of SOX2OT delayed xenograft tumour growth and decreased metastases in vivo. Mechanistically, we found that SOX2OT was mainly distributed in the cytoplasm and positively regulated SOX2 expression by sponging miR-200c. Furthermore, SOX2 overexpression reversed the SOX2OT silencing-induced inhibition of the BCSC stemness phenotype. CONCLUSION: This study is the first to demonstrate that SOX2OT plays an important regulatory role in BCSCs and that SOX2OT may serve as a potential diagnostic biomarker and therapeutic target in bladder cancer.

Long noncoding RNA SOX2OT promotes the proliferation of pancreatic cancer by binding to FUS.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant tumors has one of the worst prognoses, and the role of long noncoding RNAs (lncRNAs) in the biological and pathological processes of pancreatic cancer, including tumor cell proliferation, is a popular topic in tumor research. Our previous study revealed the correlation between high levels of the lncRNA-SOX2OT (SOX2OT) with poor survival outcomes. Cell Counting Kit-8, EdU, Flow cytometry and Colony formation assays as well as Xenograft growth of PDAC cells in mice were used for the detection of PDAC cells proliferation progression. Fluorescence in situ hybridization, RNA-binding protein pulldown and RNA immunoprecipitation assays were also used to identify the putative mechanisms of SOX2OT participating in the tumor progression. SOX2OT and its potential downstream targets were verified by Western blot and quantitative real-time polymerase chain reaction (qRT-PCR). SOX2OT was confirmed to promote the proliferation of PDAC cells. It was found to directly physically bind to FUS and we also demonstrated that FUS protein stability was affected by binding with SOX2OT and FUS could suppressed PDAC tumor by regulating cell cycle-associated factors CCND1 and p27. Our findings suggest that SOX2OT may act as a tumor promoter in PDAC through physically binding FUS and regulating its downstream cell cycle-associated factors CCND1 and p27. It may serve as an effective target for antitumor treatment for pancreatic cancer.

Knockdown of long non-coding RNA SOX2OT downregulates SOX2 to improve hippocampal neurogenesis and cognitive function in a mouse model of sepsis-associated encephalopathy.

BACKGROUND: Aberrant hippocampal neurogenesis is an important pathological feature of sepsis-associated encephalopathy. In the current study, we examined the potential role of the long noncoding RNA (lncRNA) sex-determining region Y-box 2 (SOX2) overlapping transcript (SOX2OT), a known regulator of adult neurogenesis in sepsis-induced deficits in hippocampal neurogenesis and cognitive function. METHODS: Sepsis was induced in adult C57BL/6 J male mice by cecal ligation and perforation (CLP) surgery. Randomly selected CLP mice were transfected with short interfering RNAs (siRNAs) against SOX2OT or SOX2, or with scrambled control siRNA. Cognitive behavior was tested 8-12 days post-surgery using a Morris water maze. Western blotting and RT-qPCR were used to determine expression of SOX2, Ki67, doublecortin (DCX), nestin, brain lipid-binding protein, and glial fibrillary acidic protein (GFAP) in the hippocampus. The number of bromodeoxyuridine (BrdU)+/DCX+ cells, BrdU+/neuronal nuclei (NeuN)+ neurons, and BrdU+/GFAP+ glial cells in the dentate gyrus were assessed by immunofluorescence. RESULTS: CLP mice showed progressive increases in SOX2OT and SOX2 mRNA levels on days 3, 7, and 14 after CLP surgery, accompanied by impaired cognitive function. Sepsis led to decrease in all neuronal markers in the hippocampus, except GFAP. Immunofluorescence confirmed the decreased numbers of BrdU+/DCX+ cells and BrdU+/NeuN+ neurons, and increased numbers of BrdU+/GFAP+ cells. SOX2OT knockdown partially inhibited the effects of CLP on levels of SOX2 and neuronal markers, neuronal populations in the hippocampus, and cognitive function. SOX2 deficiency recapitulated the effects of SOX2OT knockdown. CONCLUSION: SOX2OT knockdown improves sepsis-induced deficits in hippocampal neurogenesis and cognitive function by downregulating SOX2 in mice. Inhibiting SOX2OT/SOX2 signaling may be effective for treating or preventing neurodegeneration in sepsis-associated encephalopathy.

LncRNA SOX2OT/Smad3 feedback loop promotes myocardial fibrosis in heart failure.

Long noncoding RNA SOX2OT is associated with myocardial fibrosis (MF) in heart failure (HF). This article aims to investigate the role of SOX2OT in MF. We constructed HF mouse models by subcutaneous injection of isoprenaline (ISO). Cardiac fibroblasts (CFs) were treated with ISO to induce MF.Hematoxylin-eosin, Masson, and Sirius-red staining were used to identify myocardial injury and collagen deposition in heart tissues. The relationship among SOX2OT, miR-138-5p, TGF-ß1, and Smad3 were evaluated by chromatin immunoprecipitation and luciferase reporter assay. The gene and protein expression were verified by quantitative real-time PCR and western blot. We found that SOX2OT was up-regulated in HF mice and ISO-induced CFs. SOX2OT knockdown reduced myocardial injury and collagen deposition in HF mice. The expression of collagen I, α-SMA, TGF-ß1, and p-Smad3 were inhibited by SOX2OT down-regulation in HF mice and ISO-induced CFs. Furthermore, TGF-ß1 was a target gene of miR-138-5p and indirectly regulated by SOX2OT. SOX2OT promoted MF in HF by activating TGF-ß1/Smad3, and then Smad3 interacted with the SOX2OT promoter and formed a positive feedback loop. In conclusion, our work verifies that SOX2OT/Smad3 feedback loop promotes MF in HF. Thus, SOX2OT is potentially a novel therapeutic target for MF in HF.

LncRNA promoted inflammatory response in ischemic heart failure through regulation of miR-455-3p/TRAF6 axis.

OBJECTIVES: Ischemic heart failure (IHF) is the most common cause of death globally. Growing evidence shows abnormal expression of long non-coding RNAs in heart failure patients. This study aims to investigate the effect of sex-determining region Y-box 2 (SOX2) overlapping transcript (SOX2-OT) on the regulation of the inflammatory response in ischemic heart failure. METHODS: IHF rat and oxygen and glucose deprivation (OGD) cell models were established. qRT-PCR was employed to investigate the expression of SOX2-OT. ELISA, western blot and cell viability/apoptosis assays were performed to assess the effects of SOX2-OT. Online software program was used to identify miRNAs that target SOX2-OT, followed by validation using RNA pull-down. Potential targets of miRNAs were searched, and examined by immunoblotting, qRT-PCR and luciferase reporter assay. RESULTS: SOX2-OT was up-regulated in IHF and OGD. Knockdown of SOX2-OT promoted cell proliferation, decreased apoptosis rate and cell oxidative damage, and ameliorated inflammatory response. SOX2-OT contains binding sites for miR-455-3p, miR-5586-3p and miR-1252-5p. RNA pull-down confirmed the binding ability between SOX2-OT and miR-455-3p. TRAF6 is a direct target of miR-455-3p. Moreover, the regulatory activity of SOX2-OT on inflammatory response was partially through its negative regulation of miR-455-3p, which directly regulates TRAF6. Down-regulation of SOX2-OT improved myocardial dysfunction in IHF rat. CONCLUSIONS: Our results reveal that SOX2-OT may be a driver of IHF through repression of miR-455-3p, and miR-455-3p alleviates IHF by targeting TRAF6. Therefore, SOX2-OT/miR-455-3p/TRAF6 may be a potential target for advanced therapeutic strategy for IHF.

LncRNA SOX2-OT regulates proliferation and metastasis of nasopharyngeal carcinoma cells through miR-146b-5p/HNRNPA2B1 pathway.

Nasopharyngeal carcinoma (NPC) is an aggressive malignancy with a high mortality on account of its frequent metastasis and poor prognosis. An extensive body of investigations has proven that long noncoding RNAs are implicated in a variety of biological processes. Although SOX2-OT has been reported to play an oncogenic role in osteosarcoma, the mechanism of SOX2-OT-driven NPC progression is still obscure. The aim of this study was to elucidate the biological function of SOX2-OT and the related possible mechanism in NPC. In our study, SOX2-OT was notably elevated in NPC samples and cells. Further, a high expression level of SOX2-OT was correlated with poor clinical outcomes of NPC. Results from loss-of-function experiments suggested that knockdown of SOX2-OT repressed cell proliferation, arrested cell cycle, facilitated cell apoptosis, and inhibited cell metastasis of NPC. To further investigate the molecular mechanism of SOX2-OT, miR-146b-5p was found to directly bind to SOX2-OT, which mediated the role of SOX2-OT in NPC tumorigenesis. In addition, HNRNPA2B1 was a target of miR-146b-5p and SOX2-OT modulated the expression of HNRNPA2B1 through competitively binding to miR-146b-5p. At last, we discovered that SOX2-OT regulated NPC progression by targeting miR-146b-5p/HNRNPA2B1 pathway, which may provide more innovative targets for the treatment of patients with NPC.

Long noncoding RNA SOX2-OT facilitates prostate cancer cell proliferation and migration via miR-369-3p/CFL2 axis.

Accepted as crucial participators in human malignancies, long noncoding RNAs (lncRNAs) have been proven to exert significant function on the complicated processes of cancer progression. Although existing investigations have revealed the oncogenic role of lncRNA SOX2 overlapping transcript (SOX2-OT) in different kinds of cancers, such as osteosarcoma and cholangiocarcinoma, the potential role of it in prostate cancer (PC) is poorly understood. This study was the first attempt to decipher the underlying regulatory mechanism of SOX2-OT in PC. According to the data from this study, SOX2-OT expression was conspicuously elevated in PC tissues and cells. Silenced SOX2-OT could repress PC cell proliferation and migration. Besides, mechanism assays manifested that SOX2-OT bound with miR-369-3p and negatively correlated with miR-369-3p in PC. Additionally, miR-369-3p was confirmed to elicit suppressive impact on PC progression. What's more, cofilin 2 (CFL2) was testified to be a downstream target gene of miR-369-3p. Final rescue tests uncovered that CFL2 upregulation or miR-369-3p inhibition could largely restore SOX2-OT knockdown-mediated function on PC progression. To sum up, SOX2-OT accelerates cell proliferation and migration by targeting miR-369-3p/CFL2 axis in PC.

Long noncoding RNA SOX2-OT facilitates laryngeal squamous cell carcinoma development by epigenetically inhibiting PTEN via methyltransferase EZH2.

Long noncoding RNAs (lncRNAs) play important roles in the initiation and progression of various cancers, including laryngeal squamous cell carcinoma (LSCC). Recently, lncRNA Sox2 overlapping transcript (SOX2-OT) has been identified as an oncogene in various cancers. However, the functional role and the regulatory mechanism of SOX2-OT in LSCC remains unclear. In this study, we found that SOX2-OT expression was increased and negatively correlated with PTEN expression in LSCC tissues. Furthermore, SOX2-OT overexpression promoted LSCC cell proliferation, migration, invasion, and suppressed cell apoptosis in vitro, as well as facilitated the in vivo tumorigenicity. By contrast, SOX2-OT silencing exerted the opposite effect. Mechanically, SOX2-OT interacted with EZH2 and recruited EZH2 to induce H3K27me3 and epigenetically inhibited PTEN expression in LSCC cells. Additionally, EZH2 silencing and PTEN overexpression significantly abrogated the SOX2-OT overexpression-mediated promotion of LSCC cell malignant behavior. Collectively, our findings demonstrate that SOX2-OT inhibits PTEN expression to facilitate LSCC development through EZH2-mediated H3K27me3. © 2019 IUBMB Life, 71(9):1230-1239, 2019.

LncRNA SOX2OT alleviates the high glucose-induced podocytes injury through autophagy induction by the miR-9/SIRT1 axis.

OBJECTIVES: Podocytes injury is a major contributor to the progression of diabetic nephropathy (DN). This study aims to investigate the role of long non-coding RNA SOX2OT in the high glucose (HG)-induced injury of human podocytes cells (HPCs) and the underlying mechanism. METHODS: HPCs proliferation and apoptosis were examined using MTT assay and flow cytometry assay, respectively. The protein levels of SIRT1 and autophagy-associated proteins (Beclin-1, LC3-II, Atg7, and p62) were determined using western blot. The interactions among SOX2OT, miR-9, and SIRT1 were investigated using luciferase activity assay. RESULTS: SOX2OT overexpression significantly alleviated the HG-induced HPCs injury and induced autophagy, which was abrogated by the autophagy inhibitor 3-MA and SIRT1 knockdown. Mechanistically, SOX2OT acted as a ceRNA by sponging miR-9 to facilitate SIRT1, and thus induce autophagy. CONCLUSION: SOX2OT overexpression alleviates the HG-induced podocytes injury through autophagy induction by the miR-9/SIRT1 axis.

Long noncoding RNA SOX2OT contributes to gastric cancer progression by sponging miR-194-5p from AKT2.

Gastric cancer (GC) is a highly malignant cancer with poor prognosis. Long non-coding RNA (LncRNA) may play an important role in tumor progression. Our present study aimed to explore the effect of LncRNA SOX2OT on GC progression. We observed that SOX2OT was overexpressed in GC tissues and cell lines. Overexpressed SOX2OT promoted cell proliferation and metastasis of GC cells (SGC-7901, TMK-1) and the phosphorylation of AKT2 as well, while knockdown of SOX2OT reversed these effects. Besides that, miR-194-5p was predicted to be a target of SOX2OT and decreased expression of miR-194-5p was observed in GC tissues and cell lines. Overexpressed miR-194-5p counteracted the promoting role of SOX2OT on cell proliferation and invasion of GC cells. Moreover, AKT2 was predicted to be a target of miR-194-5p. The expression of AKT2 was negatively regulated by miR-194-5p while positively regulated by SOX2OT. Overexpressed AKT2 also promoted GC cell proliferation and invasion. Our in vitro experiments suggested that SOX2OT promoted cell proliferation and metastasis of GC cells via sponging miR-194-5p from AKT2. Finally, our in vivo experiments indicated that overexpressed SOX2OT promoted GC tumor growth and metastasis in nude mice. Taken together, our present study suggested that SOX2OT contributed to GC progression via sponging miR-194-5p from AKT2 both in vitro and in vivo. The SOX2OT-miR-194-5p-AKT2 axis may provide a new perspective for treatment of GC.