SOX2 Overlapping Transcript Expression Research Articles

Long non-coding RNA SOX2-OT enhances cancer biological traits via sponging to tumor suppressor miR-122-3p and miR-194-5p in non-small cell lung carcinoma

The oncogenic role of long non-coding RNA SOX2 overlapping transcript (SOX2-OT) has been demonstrated as a miRNA decay system that sponges tumor suppressor miRNA, including miR-122-3p in glioblastoma and miR-194-5p in glioblastoma, gastric, and colorectal cancers. However, the molecular function of SOX2-OT remains unknown in most cancers, including lung cancer. In the current study, we aimed to evaluate the downstream regulatory function of SOX2-OT in A549 and Calu-3 lung cancer cell lines. We knocked down SOX2-OT expression using an RNA interference system, which significantly decreased expression in A549 and Calu-3 cells. The expression of down-regulating miRNAs (miR-122-3p and miR-194-5p) was evaluated, revealing increased expression of miR-122-3p and miR-194-5p. Additionally, the expression of miRNAs downstream mRNA, including FOXO1 (Forkhead Box O1) and FOXA1 (Forkhead Box O1), changed. Recently, critical roles of FOXO1 and FOXA1 proteins in pathways involved in proliferation, metastasis and apoptosis have been demonstrated. Downstream changes in cellular traits were assessed using MTT, flow cytometry, metastasis and apoptosis assays. These assessments confirmed that the biological behaviors of lung cancer cells were influenced after SOX2-OT knockdown. In summary, the present study highlights the oncogenic role of SOX2-OT through the regulation of miR-122-3p/FOXO1 and miR-194-5p/FOXA1 pathways.

SOX2 Overlapping Transcript (SOX2-OT) Enhances the Lung Cancer Malignancy Through Interaction with miR-194-5p/SOX5 Axis.

Lung cancer is one of the most common types of cancer and a leading cause of cancer-related deaths worldwide. Therefore, it is useful to know the biomarkers involved in the malignancy of lung cancer. This study aimed to show that SOX2-OT as a long non-coding RNA (IncRNA) regulates gene expression via the SOX2-OT/miR-194-5p/SOX5 axis molecular pathway in lung cancer. A549 cells transfected with siRNA-SOX2-OT and the expression of SOX2-OT and miR-194-5p genes were analyzed by real-time PCR before and after transfection. In addition, the expression of the B-catenin, MMP9, phosphorylated and activated STAT3 (p-STAT3), SOX5, and VEGF proteins before and after transfection was investigated by Western blotting. After using siRNA-SOX2-OT, an increase in the expression of miR-194-5p and a decrease in the expression of B-catenin, SOX5, p-STAT3 activated STAT3, VEGF, and MMP9 proteins was observed. According to the results of the present study, an increase in SOX2-OT in lung cancer seems to stimulate the expression of beta-catenin, SOX5, MMP9, and VEGF thus support the malignancy of lung cancer cells.

Silencing of long non-coding RNA SOX2-overlapping transcript relieves myocardial ischemia/reperfusion injury through up-regulating miRNA-146a-5p.

Long non-coding 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-overlapping transcript (SOX2-OT) in MIRI. The viability of oxygen and glucose deprivation/reperfusion (OGD/R)-treated H9c2 cells was detected by MTT assay. The levels of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, malondialdehyde (MDA), and superoxide dismutase (SOD) were measured by ELISA. The target relationship between SOX2-OT and miR-146a-5p was predicted by LncBase, and subsequently confirmed by Dual luciferase reporter assay. The effects of SOX2-OT silencing on myocardial apoptosis and function were further validated in MIRI rats. 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. Silencing of miR-146a-5p reversed the effects of sh-SOX2-OT on OGD/R-treated H9c2 cells. In addition, silencing of SOX2-OT also alleviated myocardial apoptosis and improved myocardial function in MIRI rats. 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.

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

AimLong 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 & methodsCell 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. ResultsSilencing 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. ConclusionInhibiting SOX2OT/miR-215-5p/ICAM1 axis might be a possible approach to treat myocardial damage. Lay abstractLipopolysaccharide (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.

Expression of SOX2OT, DANCR and TINCR long non‑coding RNAs in papillary thyroid cancer and its effects on clinicopathological features.

Long non-coding RNAs (lncRNAs) are molecules that are >200 base pairs long and do not encode a protein. However, they perform important roles in regulating gene expression. Recent studies have revealed that the changes in the expressions of lncRNAs serve a role in the development and metastases of a number of types of cancer. A number of studies have been published on the association of SOX2 overlapping transcript (SOX2OT), differentiation antagonizing non-protein coding RNA (DANCR) and tissue differentiation-induced non-coding RNA (TINCR) expression with various types of cancer. However, researchers have not yet studied their roles in papillary thyroid cancer or at least, those roles are not clarified. The aim of the present study was to investigate the expression and clinical significance of SOX2OT, DANCR and TINCR in papillary thyroid cancer (PTC). A total of 102 patients with PTC were included in the present study. Reverse transcription-quantitative PCR method was used to determine the relative gene expression levels of lncRNAs and then the relationship between expressions of lncRNAs and clinical characteristics of the subjects was analyzed in detail. Expression levels of SOX2OT (P=0.016) and DANCR (P=0.017) increased in the tumor samples in contrast to the normal tissues. No significant difference was observed in the expression level of TINCR (P=0.298). In addition, SOX2OT expression was associated with micro carcinoma (P<0.001), tumor size (P=0.010) and primary tumor (P=0.006), while DANCR expression was associated with age (P=0.030) and micro carcinoma (P=0.004). The findings of the present study indicated that DANCR may contribute to the development of PTC while SOX2OT may contribute to both the development and progression of PTC.

SOX2OT Long Noncoding RNA Is Regulated by the UPR in Oestrogen Receptor-Positive Breast Cancer

Endoplasmic reticulum (ENR) stress perturbs cell homeostasis and induces the unfolded protein response (UPR). In breast cancer, this process is activated by oestrogen deprivation and is associated with tamoxifen resistance. We present evidence that the transcription factor SOX2 and the long noncoding RNA SOX2 overlapping transcript (SOX2OT) are upregulated in oestrogen receptor-positive (ER+) breast cancer and in response to oestrogen deprivation. We examined the effect of the UPR on SOX2 and SOX2OT expression and the effect of SOX2OT on UPR pathways in breast cancer cell lines. The induction of the UPR by thapsigargin or glucose deprivation upregulates SOX2OT expression. This upregulation is also shown with the anti-oestrogen 4OH-tamoxifen and mTOR inhibitor everolimus in ER + breast cancer cells that are sensitive to oestrogen deprivation or everolimus treatment. SOX2OT overexpression decreased BiP and PERK expression. This effect of SOX2OT overexpression was confirmed on BiP and PERK pathway by q-PCR. Our results show that a long noncoding RNA regulates the UPR and evince a new function of SOX2OT as a participant of ENR stress reprogramming of breast cancer cells.

Long noncoding RNA SOX2OT silencing alleviates cerebral ischemia-reperfusion injury via miR-135a-5p-mediated NR3C2 inhibition

ObjectiveThis study is aimed to investigate the role of the long noncoding RNA SOX2 overlapping transcript (SOX2OT) in cerebral ischemia-reperfusion injury (CIRI) and the underlying regulatory mechanisms. MethodsThe oxygen-glucose deprivation/reoxygenation (OGD/R)-treated PC12 cells and middle cerebral artery occlusion/reperfusion (MCAO/R)-treated rats were established to simulate CIRI condition in vitro and in vivo. Quantitative real-time polymerase chain reaction was performed to detect the expression of SOX2OT, microRNA-135a-5p (miR-135a-5p), and nuclear receptor subfamily 3 group C member 2 (NR3C2). The cell viability and apoptosis were analyzed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assays. The levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), and reactive oxygen species (ROS) or interleukin (IL)-1β and IL-6 were used to evaluate the oxidative stress or inflammation. Dual-luciferase reporter assay was conducted to validate the interactions among SOX2OT, miR-135a-5p, and NR3C2. Additionally, neurological deficit scores (NDS), infarct volume, and brain edema were used to assess brain impairments in vivo. ResultsThe expression of SOX2OT and NR3C2 was increased, while miR-135a-5p was decreased in OGD/R-treated PC12 cells. SOX2OT silencing repressed the levels of LDH, MDA, ROS, IL-1β, IL-6, reduced the numbers of TUNEL positive cells, and elevated viability and SOD level in OGD/R-treated PC12 cells. Besides, SOX2OT targeted miR-135a-5p, and miR-135a-5p targeted NR3C2. Both miR-135a-5p downregulation and NR3C2 upregulation reversed the suppressive effects of SOX2OT knockdown on oxidative stress, apoptosis, and inflammation of OGD/R-treated PC12 cells. Furthermore, injection of sh-SOX2OT reduced the NDS, cerebral infarct, and cerebral edema in MCAO/R-treated rats. ConclusionsSilencing of SOX2OT attenuated CIRI via regulation of the miR-135a-5p/NR3C2 axis, which may provide a novel therapeutic target for CIRI.

Long Noncoding RNA SOX2-OT Knockdown Inhibits Proliferation and Metastasis of Prostate Cancer Cells Through Modulating the miR-452-5p/HMGB3 Axis and Inactivating Wnt/β-Catenin Pathway.

Background: Recent studies have proven that abnormal expression of long noncoding RNAs (lncRNAs) often contributes to growth and invasion of cancer cells. The purpose of this study was to investigate the biological function and regulatory mechanism of lncRNA SOX2 overlapping transcript (SOX2-OT) in prostate cancer (PCa) progression. Materials and Methods: The expression of SOX2-OT, microRNA-452-5p (miR-452-5p), and high mobility group box 3 (HMGB3) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Flow cytometry was performed to determine the cell cycle distribution. Western blot assay was conducted to measure the protein levels of cyclin D1, p21, p27, E-cadherin, vimentin, and N-cadherin. The interaction between miR-452-5p and SOX2-OT or HMGB3 was predicted by bioinformatics analysis and verified by dual-luciferase reporter assay and RNA immunoprecipitation assay. The mice xenograft model was established to investigate the role of SOX2-OT in vivo. Results: SOX2-OT and HMGB3 were upregulated, whereas miR-452-5p was downregulated in PCa tissues and cells. Knockdown of SOX2-OT inhibited PCa cell growth and metastasis. MiR-452-5p could directly bind to SOX2-OT and its knockdown reversed the inhibitory effects of SOX2-OT interference on growth and metastasis of PCa cells. HMGB3 was a direct target of miR-452-5p and its knockdown weakened the promotive effects of miR-452-5p silence on growth and metastasis of PCa cells. Moreover, HMGB3 expression was inversely regulated by miR-452-5p and positively modulated by SOX2-OT. Furthermore, SOX2-OT activated the Wnt/β-catenin signaling pathway through increasing HMGB3 expression. Finally, SOX2-OT knockdown hindered tumor growth in vivo by regulating miR-452-5p/HMGB3 axis. Conclusions: SOX2-OT downregulation limited PCa cell growth and metastasis by regulating miR-452-5p/HMGB3 axis and inactivating Wnt/β-catenin signaling pathway, which might offer lncRNA-directed diagnosis and therapy for PCa.

SOX2OT Long Noncoding RNA Is Regulated by the UPR in Oestrogen Receptor-Positive Breast Cancer

Endoplasmic reticulum (ER) stress perturbs cell homeostasis and induces the unfolded protein response (UPR). In breast cancer, this process is activated by oestrogen deprivation and is associated with tamoxifen resistance. We present evidence that the transcription factor SOX2 and the long noncoding RNA SOX2 overlapping transcript (SOX2OT) are up-regulated in oestrogen receptor-positive (ER+) breast cancer and in response to oestrogen deprivation. We examined the effect of the UPR on SOX2 and SOX2OT expression, and the effect of SOX2OT on UPR pathways in breast cancer cell lines. The induction of the UPR by thapsigargin or glucose deprivation up-regulates SOX2OT expression. This up-regulation is also shown with the anti-oestrogen 4OH-tamoxifen and mTOR inhibitor everolimus in ER + breast cancer cells that are sensitive to oestrogen deprivation or everolimus treatment. SOX2OT overexpression decreased BiP and PERK expression. This effect of SOX2OT overexpression was confirmed on BiP and PERK pathway by q-PCR. Our results show that a long noncoding RNA regulates the UPR and evince a new function of SOX2OT as a participant of ER stress reprogramming of breast cancer cells.

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

BackgroundAccumulating 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.MethodsThe 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.ResultsSOX2OT 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.ConclusionThis 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 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.

Circulating long non-coding RNA GAS5 and SOX2OT as potential biomarkers for diagnosis and prognosis of non-small cell lung cancer.

Early diagnosis of non-small cell lung cancer (NSCLC) is essential for patient treatment and prognosis. Long noncoding RNA (lncRNA) have potential roles in tumor initiation and differentiation. The objective of this study was to investigate whether the circulating lncRNA, growth arrest-specific transcript 5 (GAS5) and SOX2 overlapping transcript (SOX2OT), could be used as noninvasive biomarkers for NSCLC diagnosis. Moreover, we aimed at evaluating the association between lncRNA and the clinicopathological features of NSCLC in order to predict the cancer prognosis. The results showed significant downregulation of GAS5 expression and upregulation of SOX2OT in NSCLC patients compared with controls (P<0.001). Furthermore, the expression level of GAS5 was declined in stage IV of NSCLC, but SOX2OT expression was increased sharply in stages III and IV. The expression levels of lncRNAs were used to distinguish NSCLC patients from control with an area under curve of 0.81 (sensitivity 82.5% and specificity 80%) for GAS5 and 0.73 (sensitivity 76.3% and specificity 78.6%) for SOX2OT. The combination of GAS5 and SOX2OT showed differentiation NSCLC patients from controls with increased sensitivity (83.8) and specificity (81.4). In conclusion, the newly developed diagnostic panel involving of circulating GAS5 and SOX2OT could be perfect biomarker for diagnosis and prognosis of NSCLC.

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.

NSPc1 polycomb protein complex binds and cross‑talks to lncRNAs in glioma H4 cells.

Recently, emerging evidence shows that a number of long non‑coding RNAs (lncRNAs) recruit polycomb group (PcG) proteins to specific chromatin loci to silence relevant gene expression. In the present study, we provided evidence that lncRNA candidates, selected by bioinformatic analysis and nervous system polycomb 1 (NSPc1), a key polycomb repressive complex 1 (PRC1) member, were highly expressed in glioma H4 cells in contrast to that noted in non‑cancerous cells. RNA binding protein immunoprecipitation (RIP) assays demonstrated that metastasis associated lung adenocarcinoma transcript 1 (MALAT1), SOX2 overlapping transcript (SOX2OT) and maternally expressed 3 (MEG3) among the 8 candidates bound to the NSPc1 protein complex in glioma H4 cells. Furthermore, overexpression of NSPc1 caused a decrease in the expression of MALAT1 and MEG3 and increased expression of SOX2OT, while NSPc1 downregulation caused the levels of all three genes to increase. Meanwhile, suppression of the expression of MALAT1 increased the expression levels of mRNA and protein of NSPc1, whereas downregulation of the expression of SOX2OT decreased NSPc1 expression. Moreover, a significant decrease in cell growth and increased cell apoptosis were observed in the transfected H4 cells by MTT assay and flow cytometric analysis. The results showed that the reduced co‑expression between NSPc1 and MALAT1/SOX2OT decreased the proliferation and promoted the death of H4 cells more obviously than the respectively decrease in expression of NSPc1, MALAT1 and SOX2OT. Remarkably, the influence of a simultaneously decreased expression of NSPc1 and SOX2OT on promoting cell apoptosis was more obvious than the total effect of the separate downregulation of NSPc1 and SOX2OT on accelerating cell death. However, that impact was partially counteracted in the silencing of the co‑expression of MALAT1 and NSPc1. Furthermore, they cooperated to affect transcription of p21 and OCT4.Briefly, these data suggest NSPc1 polycomb protein complex binding and cross‑talk to lncRNAs in glioma H4 cells, offering new insight into the important function of polycomb protein complex and lncRNA interactions in glioma cells and provide a novel view of potential biomarkers and targets for the diagnosis and therapy of glioma.

The SOX2OT/miR-194-5p axis regulates cell proliferation and mobility of gastric cancer through suppressing epithelial-mesenchymal transition.

Recent studies reported that long noncoding RNAs (LncRNAs) were involved in tumorigenesis of various human cancer types, including gastric cancer (GC) through targeting microRNAs (miRNAs/miRs). The present study investigated the biological functions of LncRNA SOX2 overlapping transcript (SOX2OT)/miR-194-5p axis and its underlying mechanism in the tumor progression of GC. The results showed that relative expression of LncRNA SOX2OT was highly upregulated while the expression of miR-194-5p was down-regulated in GC tissues and cell lines (MGC-803, SGC-7901, MKN-74). Knockdown of SOX2OT inhibited cell proliferation, invasion and migration of GC cells (MGC803, MKN-74) through reducing epithelial-mesenchymal transition (EMT). Moreover, miR-194-5p was predicted to be one of the targets of SOX2OT through bioinformatics analysis and was verified by luciferase reporter assay. miR-194-5p expression was negatively regulated by SOX2OT expression in GC cells and miR-194-5p inhibitor was found to counteract the inhibitory effects of SOX2OT short hairpin (sh)RNA on cell proliferation and mobility through enhancing EMT in GC cells. Taken together, the in vitro experiments revealed that knockdown of SOX2OT inhibited cell proliferation and mobility through suppressing EMT via targeting miR-194-5p in GC. In addition, results from in vivo experiments showed that knockdown of SOX2OT suppressed GC tumor growth and matrix metalloproteinase (MMP)-2 and MMP-9 expression through inhibiting EMT. Besides that, relative expression of miR-194-5p was increased in sh-SOX2OT group compared with sh-NC group. In summary, our study elucidated that the SOX2OT/miR-194-5p axis participated in the tumor progression of GC through regulation of EMT both in vitro and in vivo. Hence, targeting the SOX2OT/miR-194-5p axis may aid in establishing novel strategies for therapy of GC.

Long noncoding RNA Sox2 overlapping transcript (SOX2OT) promotes non-small-cell lung cancer migration and invasion via sponging microRNA 132 (miR-132).

BackgroundLong noncoding RNA (lncRNA) Sox2 overlapping transcript (SOX2OT) has been reported to be upregulated in various types of cancers, including non-small-cell lung cancer (NSCLC). However, the biological role and underlying mechanism of SOX2OT activity in NSCLC remain largely unknown. This study aims to investigate the function and possible molecular mechanisms of SOX2OT in NSCLC.Materials and methodsQuantitative real-time polymerase chain reaction was used to detect SOX2OT expression, and cellular proliferation, migration, and invasion were measured using cell counting kit-8, wound healing, and Transwell invasion assays, respectively. Western blotting was used to determine protein expression. Starbase 2.0 and luciferase reporter assay were utilized to identify the molecular target of SOX2OT.ResultsHere, we discovered that SOX2OT was markedly upregulated in NSCLC tissues and cell lines. Knockdown of SOX2OT inhibited the proliferation, migration, invasion, and epithelial–mesenchymal transition (EMT) process in NSCLC cells. Moreover, we explored the regulatory mechanism of SOX2OT and found that SOX2OT directly bound microRNA 132 (miR-132) in NSCLC cells. Importantly, miR-132 inhibition partially reversed the SOX2OT knockdown-mediated inhibitory effect on cell proliferation, migration, invasion, and EMT process. We also found that SOX2OT could regulate zinc finger E-box-binding homeobox 2 (a target of miR-132) expression, which played crucial roles in tumor cell proliferation and invasion.ConclusionThese findings indicated that SOX2OT was a noncoding oncogene that exerted important regulatory functions in NSCLC via sponging miR-132 and might represent a novel strategy for overcoming this disease.

LncRNA SOX2-OT is a novel prognostic biomarker for osteosarcoma patients and regulates osteosarcoma cells proliferation and motility through modulating SOX2.

Long noncoding RNA (LncRNA) SOX2 overlapping transcript (SOX2-OT) has been shown to serve an oncogenic role in human lung cancer, hepatocellular carcinoma, and gastric cancer. However, the clinical significance and biological function of lncRNA SOX2-OT in osteosarcoma are still unclear. LncRNA SOX2-OT expression was measured in osteosarcoma tissues and cell lines. Loss-of-function and gain-of-function studies were performed to observe the effects of lncRNA SOX2-OT on osteosarcoma cells proliferation, migration, invasion, and expressions of cancer stem cell biomarker. The relationship between lncRNA SOX2-OT and SOX2 was analyzed in osteosarcoma tissues and cells. Rescued-function studies were conducted to confirm the role of SOX2 in the regulation of lncRNA SOX2-OT in osteosarcoma cells migration, invasion, and expression of cancer stem cell biomarkers. In our results, lncRNA SOX2-OT expression was increased in osteosarcoma tissues and cell lines, and associated with malignant status and overall survival in osteosarcoma patients. LncRNA SOX2-OT regulated osteosarcoma cells proliferation, migration, invasion, and expression of cancer stem cell biomarkers. LncRNA SOX2-OT positively regulated SOX2 expression in osteosarcoma cells and positively associated with SOX2 expression in osteosarcoma tissues. The rescued-function studies suggested that SOX2 is necessary for lncRNA SOX2-OT induced osteosarcoma cells migration, invasion, and expression of cancer stem cell biomarkers. In conclusion, lncRNA SOX2-OT is a prognostic biomarker for osteosarcoma patients and serves an oncogenic role to regulate osteosarcoma cells migration, invasion, and expression of cancer stem cell biomarkers. © 2017 IUBMB Life, 69(11):867-876, 2017.

Transcriptional role of androgen receptor in the expression of long non-coding RNA Sox2OT in neurogenesis.

The complex architecture of adult brain derives from tightly regulated migration and differentiation of precursor cells generated during embryonic neurogenesis. Changes at transcriptional level of genes that regulate migration and differentiation may lead to neurodevelopmental disorders. Androgen receptor (AR) is a transcription factor that is already expressed during early embryonic days. However, AR role in the regulation of gene expression at early embryonic stage is yet to be determinate. Long non-coding RNA (lncRNA) Sox2 overlapping transcript (Sox2OT) plays a crucial role in gene expression control during development but its transcriptional regulation is still to be clearly defined. Here, using Bicalutamide in order to pharmacologically inactivated AR, we investigated whether AR participates in the regulation of the transcription of the lncRNASox2OTat early embryonic stage. We identified a new DNA binding region upstream of Sox2 locus containing three androgen response elements (ARE), and found that AR binds such a sequence in embryonic neural stem cells and in mouse embryonic brain. Our data suggest that through this binding, AR can promote the RNA polymerase II dependent transcription of Sox2OT. Our findings also suggest that AR participates in embryonic neurogenesis through transcriptional control of the long non-coding RNA Sox2OT.

The Effect of MicroRNA-375 Overexpression, an Inhibitor of Helicobacter pylori-Induced Carcinogenesis, on lncRNA SOX2OT.

BackgroundHelicobacter pylori is a major human pathogenic bacterium in gastric mucosa. Although the association between gastric cancer and H. pylori has been well-established, the molecular mechanisms underlying H. pylori-induced carcinogenesis are still under investigation. MicroRNAs (miRNAs) are small noncoding RNAs that modulate gene expression at the posttranscriptional level. Recently, studies have revealed that miRNAs are involved in immune response and host cell response to bacteria. Also, microRNA-375 (miR-375) is a key regulator of epithelial properties that are necessary for securing epithelium-immune system cross-talk. It has been recently reported that miR-375 acts as an inhibitor of H. pylori-induced gastric carcinogenesis. There are few reports on miRNA-mediated targeting long noncoding RNAs (lncRNAs).ObjectivesThis study aimed to examine the possible effect of miR-375 as an inhibitor of H. pylori-induced carcinogenesis on the expression of lncRNA SOX2 overlapping transcript (SOX2OT) and SOX2, a master regulator of pluripotency of cancer stem cells.Materials and MethodsIn a model cell line, NT-2 was transfected with the constructed expression vector pEGFP-C1 contained miR-375. The RNA isolations and cDNA synthesis were performed after 48 hours of transformation. Expression of miR-375 and SOX2OT and SOX2 were quantified using real-time polymerase chain reaction and compared with control cells transfected with pEGFP-C1-Mock clone. Cell cycle modification was also compared after transfections using the flow cytometry analysis.ResultsFollowing ectopic expression of miR-375, SOX2OT and SOX2 expression analysis revealed a significant decrease in their expression level (P < 0.05) in NT-2 cells compared to the control. Cell cycle analysis following ectopic expression of miR-375 in the NT-2 cells using propidium iodine staining revealed significant extension in sub-G1 cell cycle.ConclusionsThis is the first report to show down-regulation of SOX2OT and SOX2 following induced expression of miR-375. This finding may suggest expression regulation potential between different classes of ncRNAs, for example between miR-375 and SOX2OT. This data not only extends our understanding of possible ncRNA interactions in cancers but also may open novel investigation lines towards elucidation of molecular mechanisms controlling H. pylori inflammation and carcinogenesis.

Long non-coding RNA SOX2OT: expression signature, splicing patterns, and emerging roles in pluripotency and tumorigenesis.

SOX2 overlapping transcript (SOX2OT) is a long non-coding RNA which harbors one of the major regulators of pluripotency, SOX2 gene, in its intronic region. SOX2OT gene is mapped to human chromosome 3q26.3 (Chr3q26.3) locus and is extended in a high conserved region of over 700 kb. Little is known about the exact role of SOX2OT; however, recent studies have demonstrated a positive role for it in transcription regulation of SOX2 gene. Similar to SOX2, SOX2OT is highly expressed in embryonic stem cells and down-regulated upon the induction of differentiation. SOX2OT is dynamically regulated during the embryogenesis of vertebrates, and delimited to the brain in adult mice and human. Recently, the disregulation of SOX2OT expression and its concomitant expression with SOX2 have become highlighted in some somatic cancers including esophageal squamous cell carcinoma, lung squamous cell carcinoma, and breast cancer. Interestingly, SOX2OT is differentially spliced into multiple mRNA-like transcripts in stem and cancer cells. In this review, we are describing the structural and functional features of SOX2OT, with an emphasis on its expression signature, its splicing patterns and its critical function in the regulation of SOX2 expression during development and tumorigenesis.