LncRNA SOX2 Overlapping Transcript Research Articles

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.

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). 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. 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. 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 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.

Long non-coding RNA Sox2OT promotes coronary microembolization-induced myocardial injury by mediating pyroptosis.

ObjectiveAs a common complication of coronary microembolization (CME), myocardial injury (MI) implies high mortality. Long non‐coding RNAs (lncRNAs) are rarely studied in CME‐induced MI. Herein, this study intended to evaluate the role of lncRNA Sox2 overlapping transcript (Sox2OT) in CME‐induced MI.MethodsThe CME rat models were successfully established by injection of microemboli. Rat cardiac functions and MI were observed by ultrasonic electrocardiogram, HE staining, and HBFP staining. Functional assays were utilized to test the inflammatory responses, oxidative stress, and pyroptosis using reverse transcription quantitative polymerase chain reaction, Western blotting, immunohistochemistry, immunofluorescence, and ELISA. Dual‐luciferase reporter gene assay and RNA immunoprecipitation were conducted to clarify the targeting relations between Sox2OT and microRNA (miRNA)‐23b and between miR‐23b and toll‐like receptor 4 (TLR4).ResultsRat CME disrupted the cardiac functions and induced inflammatory responses and oxidative stress, and activated the nuclear factor‐kappa B (NF‐κB) pathway and pyroptosis (all P < 0.05). An NF‐κB inhibitor downregulated the NF‐κB pathway, reduced pyroptosis, and relieved cardiomyocyte injury and pyroptosis. Compared with the sham group (1.05 ± 0.32), lncRNA Sox2OT level (4.41 ± 0.67) in the CME group was elevated (P < 0.05). Sox2OT acted as a competitive endogenous RNA (ceRNA) of miR‐23b to regulate TLR4. Silencing of Sox2OT favoured miR‐23b binding to 3′UTR of TLR4 mRNA leading to suppressed TLR4‐mediated NFKB signalling and pyroptosis in myocardial tissues harvested from CME rat models. In addition, miR‐23b overexpression could supplement the cytosolic miR‐23b reserves to target TLR‐4 and partially reverse Sox2OT‐mediated pyroptosis in LPS‐treated H9C2 cells.ConclusionsThis study supported that silencing Sox2OT inhibited CME‐induced MI by eliminating Sox2OT/miR‐23b binding and down‐regulating the TLR4/NF‐κB pathway. This investigation may provide novel insights for the treatment of CME‐induced MI.

A novel lncRNA SOX2OT promotes the malignancy of human colorectal cancer by interacting with miR-194-5p/SOX5 axis

Long noncoding RNAs (lncRNAs) show emerging roles in colorectal cancer (CRC) development and are considered to be involved in the potential mechanism of tumor malignancy. While Sox2 overlapping transcript (SOX2OT) has been implicated in the progression of multiple cancers, its role in CRC remains to be explored. In this study, in situ hybridization (ISH) and qRT-PCR were performed to establish the functional relationships between SOX2OT and CRC deranged in CRC tissue and cells. Subsequently, SOX2OT shRNAs vectors were transfected into CRC cells to performed loss-of-function assays to detect the potential role of SOX2OT on proliferation and metastasis in vitro and vivo. The results showed SOX2OT was an oncogene that was up-regulated in human CRC tissues and cell lines. SOX2OT silencing suppressed cell proliferation, migration, and invasion in CRC cells in vitro, and inhibited tumorigenesis in the mouse xenografts. Bioinformatic predictive analysis coupled with the dual-luciferase reporter, RNA immunoprecipitation (RIP), and functional rescue assay elucidated the mechanistic network of the SOX2OT-miR-194-5p-SOX5 axis in CRC. Mechanistically, SOX2OT acted as a competing endogenous RNA (ceRNA) to upregulate SOX5 by sponging miR-194-5p. Downregulated SOX2OT boosted miR-194-5p expression, thus decreased the protein level of SOX5, which suppresses tumorgenesis of CRC.

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.

LncRNA SOX2-OT regulates AKT/ERK and SOX2/GLI-1 expression, hinders therapy, and worsens clinical prognosis in malignant lung diseases.

The involvement of LncRNA SOX2-overlapping transcript (SOX2-OT), SOX2, and GLI-1 transcription factors in cancer has been well documented. Nonetheless, it is still unknown whether co-expressed SOX2-OT/SOX2 or SOX2-OT/SOX2/GLI-1 axes are epigenetically/transcriptionally involved in terms of resistance to oncology therapy and in poorer clinical outcomes for patients with lung cancer. We evaluated the role of SOX2-OT/SOX2 and SOX2-OT/SOX2/GLI-1 axes using RT-qPCR, western blot, immunofluorescence analyses, gene silencing, cellular cytotoxic, and ChIP-qPCR assays on human cell lines, solid lung malignant tumors, and normal lung tissue. We detected that the SOX2-OT/SOX2/GLI-1 axis promotes resistance to tyrosine kinase inhibitor (TKI)-erlotinib and cisplatin-based therapy. Evidence from this study show that SOX2-OT modulates the expression/activation of EGFR-pathway members AKT/ERK. Further, both SOX2-OT and GLI-1 genes are epigenetically regulated at their promoter sequences, in an LncRNA SOX2-OT-dependent manner, mainly through modifying the enrichment of the activation histone mark H3K4me3/H3K27Ac, versus the repressive histone mark H3K9me3/H3K27me3. In addition, we identified that inhibition of SOX2-OT and reduced expression of SOX2/GLI-1 sensitizes lung cancer cells to EGFR/TKI-erlotinib or cisplatin-based treatment. Finally, we show that high co-expression of SOX2-OT/SOX2 transcripts and SOX2/GLI-1 proteins appears to correlate with a poor clinical prognosis and lung malignant phenotype. Collectively, these results present evidence that LncRNA SOX2-OT modulates an orchestrated resistance mechanism, promoting poor prognosis and human lung malignancy through genetic, epigenetic, and post-translational mechanisms.

LncRNA SOX2OT Knockdown Alleviates Lipopolysaccharide-Induced Damage of PC12 Cells by Regulating miR-331-3p/Neurod1 Axis

Long noncoding RNAs (lncRNAs) serve as crucial regulators in the pathogenesis of spinal cord injury (SCI). However, the role of lncRNA SOX2 overlapping transcript (SOX2OT) in SCI remains to be well revealed. An SCI rat model was established and assessed by the Basso-Beattie-Bresnahan (BBB) method. An SCI PC12 cell model was established through lipopolysaccharide (LPS) treatment. Quantitative real-time polymerase chain reaction assay was used for SOX2OT, miR-331-3p, and neurogenic differentiation 1 (Neurod1) mRNA levels. Cell counting kit-8 assay and flow cytometry analysis were performed for cell viability and apoptosis, respectively. Enzyme-linked immunosorbent assay was performed for the levels of inflammatory cytokines. The production of superoxide dismutase and malondialdehyde was determined with relevant kits. Dual-luciferase reporter and RNA immunoprecipitation assays were conducted for the relationships among SOX2OT, miR-331-3p, and Neurod1. Western blot assay was employed for protein levels. SOX2OT was elevated in SCI rat and cell models. SOX2OT knockdown relieved the injury of SCI in SCI rat model. Moreover, the suppressive role in PC12 cell viability and the promotional roles in apoptosis, inflammation, and oxidative stress mediated by LPS were all restored by silencing SOX2OT. For mechanism analysis, SOX2OT was identified as a sponge of miR-331-3p to positively regulate Neurod1 expression. Inhibition of miR-331-3p reversed the effect of SOX2OT knockdown on LPS-induced PC12 damage. Overexpression of miR-331-3p protected PC12 cells from LPS-induced damage by binding to Neurod1. In addition, SOX2OT knockdown relieved PC12 cell injury by inactivation of Janus kinase-signal transducer and activator of transcription pathway. SOX2OT promoted PC12 cell injury through modulating miR-331-3p/Neurod1 axis and activating Janus kinase-signal transducer and activator of transcription pathway.

LncRNA SOX2OT rs9839776 Polymorphism Reduces Sepsis Susceptibility in Southern Chinese Children.

BackgroundSepsis in children is one of the main causes of death in pediatric intensive care units (PICUs); however, the pathogenesis of sepsis is not fully clear. Previous studies revealed that many genetic variations were related to sepsis susceptibility. A long non-coding RNA SOX2 overlapping transcript (SOX2OT) may play a role in mitochondrial homeostasis and antioxidative activity, but the relationship between the lncRNA SOX2OT polymorphism and sepsis susceptibility has not been reported.MethodsIn this study, 474 pediatric sepsis patients and 678 healthy controls were recruited from southern China. After genotyping, the strength of the associations was evaluated through odds ratios (ORs) and 95% confidence intervals (CIs).ResultsThe SOX2OT rs9839776 T allele was associated with decreased susceptibility to sepsis in southern Chinese children (TT/CT vs CC adjusted OR = 0.778, 95% CI = 0.610–0.992; P = 0.0431). Moreover, the difference in susceptibility was greater in children of age >60 months (adjusted OR = 0.458, 95% CI = 0.234–0.896; P = 0.0225), survivors (adjusted OR = 0.758, 95% CI = 0.585–0.972; P = 0.0358), males (adjusted OR = 0.655, 95% CI = 0.479–0.894; P = 0.0077) and the sepsis subgroup (adjusted OR = 0.548, 95% CI = 0.343–0.876; P = 0.0120).ConclusionThe rs9839776 T allele may contribute to decreased sepsis risk in Chinese children. Future studies with a larger sample size are needed to verify these results.

LncRNA SOX2OT affects cervical cancer cell growth, migration and invasion by regulating SOX2

ABSTRACT Long non-coding RNA (lncRNA) SOX2 overlapping transcript (SOX2OT) has been shown to play an oncogenic role in diverse cancers, generating eight transcript variants. SOX2 is located in the third intron of SOX2OT. However, the biological function of SOX2OT in cervical cancer and implication with SOX2 remain to be further explored. In this study, we screened the expression pattern of different SOX2OT transcript variants in cervical cancer cells. Interestingly, both high-expression levels of SOX2OT transcript 7 (SOX2OT-7) and SOX2 were detected in C-33A (HPV−) and SiHa (HPV16+) cells. Thus, C-33A and SiHa cells were conducted to investigate the effects of SOX2OT on cell growth, migration and invasion. Finally, rescue experiments were performed to confirm the role of SOX2 in SOX2OT-mediated regulation of cervical cancer progression. The results showed that knockdown of SOX2OT suppressed cell viability, arrested cell cycle and ameliorated migration and invasion ability of C-33A and SiHa cells. Ectopic expression of SOX2OT-7 exacerbated cervical cancer cell proliferation, migration and invasion. In addition, we found that the expression levels and protein stability of SOX2 were positively regulated by SOX2OT. Inhibition of SOX2 could block the malignant phenotypes of C-33A and SiHa cells by SOX2OT-7. In conclusion, these findings indicate that lncRNA SOX2OT contributes to the growth, migration and invasion of cervical cancer cells by modulating SOX2. Importantly, we demonstrate that the transcript SOX2OT-7 may be a novel and promising biomarker for both HPV− and HPV16+ cervical cancer.

The lncRNA SOX2OT rs9839776 C>T Polymorphism Indicates Recurrent Miscarriage Susceptibility in a Southern Chinese Population.

Genetic susceptibility may be involved in the onset of recurrent miscarriage. Previous studies have shown that some genetic polymorphisms that regulate cell migration are associated with susceptibility to recurrent miscarriage. The SOX2 overlapping transcript (SOX2OT) may regulate the migration and invasion of multiple tumor cells and is related to susceptibility to various diseases. However, whether lncRNA SOX2OT polymorphisms are related to recurrent miscarriage susceptibility is unclear. Therefore, we investigated the relationship between the lncRNA SOX2OT rs9839776 C>T polymorphism and recurrent miscarriage susceptibility. We recruited 570 subjects with recurrent miscarriage and 578 healthy control subjects from a population in southern China and used the TaqMan method for genotyping. We found a significant association between the rs9839776 CT genotype in the SOX2OT gene and an increased risk for recurrent miscarriage (CT vs CC: adjusted OR = 1.357, 95%CI = 1.065 − 1.728, P = 0.0134). However, we did not observe any significant associations between the recurrent miscarriage risk and the number of miscarriages in different age groups. In conclusion, our study indicated that the rs9839776 CT genotype may contribute to an increased risk of recurrent miscarriage in the southern Chinese population and that rs9839776 may act as a prognostic biomarker in recurrent miscarriage patients. However, an experiment-based study with a larger sample size should be performed to confirm these results.

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.

Circulating long noncoding RNA act as potential novel biomarkers for diagnosis and prognosis of non-small cell lung cancer.

Lung cancer is the first leading cause of cancer deaths worldwide. Non‐small cell lung cancer (NSCLC) is the most common type of lung cancer. Increasing evidence shows that long noncoding RNA (lncRNA) are capable of modulating tumor initiation, proliferation and metastasis. In the present study, we aimed to evaluate whether circulating lncRNA could be used as biomarkers for diagnosis and prognosis of NSCLC. Expression profiles of 14 lncRNA selected from other studies were validated in 20 pairs of tissues by quantitative real‐time PCR, and the dysregulated lncRNA thus identified were further validated in serum samples from two independent cohorts along with three tumor makers (CEA, CYFRA21‐1, and SCCA). Receiver‐operating characteristic analysis was utilized to estimate the diagnostic efficiency of the candidate lncRNA and tumor markers. Importantly, we observed an association between lncRNA expression and overall survival (OS) rate of NSCLC. The expressions of SOX2 overlapping transcript (SOX2OT) and ANRIL were obviously upregulated in NSCLC tissues and serum samples compared with normal controls (P < 0.01). Based on the data from the training set, we next used a logistic regression model to construct an NSCLC diagnostic panel consisting of two lncRNA and three tumor markers. The area under the curve of this panel was 0.853 (95% confidence interval = 0.804–0.894, sensitivity = 77.1%, specificity = 79.2%), and this was distinctly superior to any biomarker alone (all at P < 0.05). Similar results were observed in the validation set. Intriguingly, Kaplan–Meier analysis demonstrated that low expressions of SOX2OT and ANRIL were both associated with higher OS rate (P = 0.008 and 0.017, respectively), and SOX2OT could be used as an independent prognostic factor (P = 0.036). Taken together, our study demonstrated that the newly developed diagnostic panel consisting of SOX2OT, ANRIL, CEA, CYFRA21‐1, and SCCA could be valuable in NSCLC diagnosis. LncRNA SOX2OT and ANRIL might be ideal biomarkers for NSCLC prognosis.

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.

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.