Predicting prognosis and immune status in sarcomas by identifying necroptosis-related lncRNAs

BACKGROUND

Sarcomas are a type of highly heterogeneous malignant tumors originating from mesenchymal tissues. Necroptosis is intricately connected to the oncogenesis and progression of tumors. The main goal of this research is to assess the prognostic value of necroptosis-related lncRNAs (NRlncRNAs) in sarcomas and to develop a risk model based on NRlncRNAs to evaluate prognostic and immune status of the sarcomas.

METHODS

We screened NRlncRNAs using the gene co-expression network, developed a prognostic risk model of sarcomas, and then verified the model. Following that, various bioinformatics analysis algorithms were employed to analyze the distinct characteristics of patients of the risk model. Furthermore, the function and regulatory mechanism of NRlncRNA SNHG6 in sarcomas were investigated through osteosarcoma cell experiments, such as qRT-PCR, Western blot, CCK-8, clone formation, and transwell assay.

RESULTS

We successfully developed a NRlncRNAs-related prognostic risk model and screened 5 prognosis-related NRlncRNAs, with SNGH6 being the most significant for prognosis of patients. According to results, the significant differences exist in prognosis, clinical characteristics, and tumor immune status among patients of the risk model. The experiments of osteosarcoma cells demonstrated that NRlncRNA SNHG6 knockdown significantly attenuated the cells' proliferation, migration, and invasion. qRT-PCR and WB results showed that SNHG6 regulated AXL and AKT signaling.

CONCLUSIONS

We have developed an innovative investigation on NRlncRNAs, which can serve as a reference for diagnosis, therapy, and prognosis of sarcomas. Additionally, we demonstrated that NRlncRNA SNHG6 regulated AXL and AKT signaling in osteosarcoma cells and the proliferation, migration, and invasion of tumor cells.

Long non-coding RNAs - SNHG6 emerge as potential marker in colorectal cancer

Colorectal cancer (CRC) ranks among the leading cancers in terms of incidence and mortality in the Western world. Currently, there are no sufficient diagnostic markers that would enable an early diagnosis and efficient therapy. Unfortunately, a significant number of new CRC cases is detected in late stages, with distant metastases, therefore, new therapeutic approaches, which would alleviate the prognosis for advanced stages of CRC, are highly in demand. SNHG6 belongs to the group of long non-coding RNAs, which are a larger entity of RNAs consisting of >200 nucleotides. SNHG6 is expressed mainly in the cell cytoplasm, where it acts as a regulator of numerous processes: modulation of crucial protein hubs; sponging miRNAs and upregulating the expression of their target mRNAs; and interacting with various cellular pathways including TGF-β/Smad and Wnt/β-catenin. SNHG6 is an oncogene, substantially overexpressed in CRC tissues and cancerous cell lines as compared to healthy samples. Its overexpression is associated with higher grade, lymphovascular invasion and tumor size. Taking into consideration the role of SNHG6 in the colorectal tumorigenesis, invasion and metastasis, we summarized its role in CRC and conclude that it could serve as a potential biomarker in CRC diagnosis and prognosis assessment.

Expression of selected long non-coding RNAs in gastric cancer cells treated with coumarin: Possible mechanisms for anti-cancer activity

Long non-coding RNAs (lncRNAs) can be utilized as prognostic indicators of gastric cancer since they can affect several cancer-related processes. Coumarin is a natural product with some useful anti-cancer properties. Here, we measured the expression of selected lncRNAs (RuPAR, SNHG6, CASC11, and their targets, miR-340-5p, p21, E-cadherin, and CDK1) in AGS gastric cancer cells treated with coumarin. MTT test has been utilized for assessing the AGS cells' cell viability after exposure to coumarin. The expression of the lncRNAs (RuPAR, SNHG6, and CASC11) and miR-340-5p was evaluated via qRT-PCR. Western blot analysis has been utilized to determine changes in p21, E-cadherin, and CDK1 expression. Coumarin decreased AGS viability in a dose-dependent manner. The coumarin treated cells had lower levels of the mRNAs known to be targets of lncRNAs SNHG6 and CASC11 compared to control. Additionally, the coumarin group had increased levels of lncRNA RuPAR expression when compared with the control group. Some lncRNA targets, including p21, E-cadherin, and CDK1, showed lower expression in the coumarin group compared to the control by Western blotting. Coumarin could be a promising pharmacological candidate to be included in gastric cancer treatment regimens because it modulates lncRNAs and their targets.

LncRNA SNHG6 role in clinicopathological parameters in cancers

RNA sequencing has revealed that a substantial portion of the human genome undergoes transcription, yet a minimal fraction of these transcripts translates into proteins. LncRNAs, RNA molecules less than 200 nt in length, once deemed as transcriptional noise, have now emerged as crucial regulators of numerous cellular processes. This review focuses on the lncRNA SNHG6, aiming to elucidate its biogenesis, the pivotal roles it plays, and its mechanisms in facilitating the hallmarks of cancer. A comprehensive literature review and analysis were undertaken to delve into the biogenesis of SNHG6, its roles in cellular processes, and the mechanisms through which it contributes to the hallmarks of cancer. SNHG6 is a notable lncRNA, observed to be overexpressed in various cancer types; its perturbation has been linked to tumor progression, emphasizing its significance in oncogenesis. This lncRNA contributes to a range of cellular aberrations, influencing transcriptional, post-transcriptional, and epigenetic processes of mRNA, ultimately driving cancerous transformations. LncRNA SNHG6 serves as a potential biomarker and therapeutic target due to its association with tumorigenesis. Understanding its mechanism and role in cancer can pave the way for novel diagnostic and therapeutic strategies.

A short peptide encoded by long non-coding RNA small nucleolar RNA host gene 6 promotes cell migration and epithelial-mesenchymal transition by activating transforming growth factor-beta/SMAD signaling pathway in human endometrial cells

BACKGROUND

Endometrial dysfunction is closely correlated with the development of multiple severe gynecological disorders including intrauterine adhesion. Accumulating evidence supports that some long non-coding RNAs (lncRNAs) have peptide-coding potential. In this text, the peptide-coding ability of lncRNA SNHG6 was examined. Also, the effects of an SNHG6-encoded peptide on the viability and migration of human endometrial stromal cells (hESCs) and human endometrial epithelial cells (hEECs) and related molecular mechanisms were explored.

METHODS

The peptide-encoding potential of SNHG6 was predicted by FuncPEP and getorf databases and validated by western blot assay. Cell viability was tested by cell counting kit-8 assay. Cell migratory ability was examined by wound healing and transwell migration assays. Protein levels of genes were measured by western blot assay.

RESULTS

Prediction analysis suggested that SNHG6 had the potential peptide-coding ability and multiple open-reading frames (ORFs). Western blot validated that SNHG6 ORF#1 and ORF#2 could translate into short peptides. SNHG6 ORF#2 overexpression facilitated cell migration and epithelial-mesenchymal transition (EMT) in hESCs and hEECs, while these effects were abrogated by transforming growth factor-beta (TGF-β)/SMAD signaling inhibitor GW788388. Moreover, GW788388 inhibited the increase of p-SMAD2 and p-SMAD3 levels induced by SNHG6 ORF#2 in hESCs. SNHG6 ORF#2-encoded peptide did not influence endometrial stromal and epithelial cell viability.

CONCLUSIONS

LncRNA SNHG6 ORF#1 and ORF#2 could translate into small peptides and SNHG6 ORF#2 overexpression promoted cell migration and EMT by activating the TGF-β/SMAD pathway in hESCs and hEECs, suggesting the potential roles of SNHG6-encoded peptides in the development of endometrial stromal and epithelial cells and related gynecological diseases.

LncRNA SNHG6 promotes glycolysis reprogramming in hepatocellular carcinoma by stabilizing the BOP1 protein

Metabolic reprogramming is an important feature in tumor progression. Long noncoding RNA's (lncRNA) small nucleolar RNA host gene 6 (SNHG6) acts as a proto-oncogene in hepatocellular carcinoma (HCC) but its role in glycolysis is mostly unknown. The role of SNHG6 and Block of proliferation 1 (BOP1) on glycolysis is assessed by glucose uptake, lactate production, oxygen consumptive rate (OCR) and extracellular acidification rate (ECAR) and glycolytic enzyme levels. The regulatory effect of SNHG6 on BOP1 protein was confirmed by Western blotting, MS2 pull-down, RNA pull-down, and RIP assay. SNHG6 and BOP1 levels were increased in HCC tissues and cells. SNHG6 and BOP1 were prognostic factors in HCC patients and significantly correlated to TP53 mutant and tumor grade. SNHG6 promoted proliferation, inhibited apoptosis, enhanced glucose uptake and lactate production, decreased OCR, and increased ECAR in HCC cell lines. SNHG6 could bind the BOP1 protein and enhance its stability. BOP1 overexpression rescued the change of proliferation, apoptosis, and glycolysis in HCCLM3 and SMMC-7721 cells. Our data indicate that SNHG6 accelerates proliferation and glycolysis and inhibits the apoptosis of HCC cell lines by binding the BOP1 protein and enhancing its stability. Both SNHG6 and BOP1 are promising prognostic and therapeutic markers in HCC.

Silencing of LncRNA SNHG6 protects trophoblast cells through regulating miR-101-3p/OTUD3 axis in unexplained recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is a gestational disease with complex pathogenesis, and trophoblast cells are closely involved in the pathogenesis of RSA. This study aimed to explore the regulatory effects and mechanisms of SNHG6 on trophoblast cells. The expression of SNHG6, miR-101-3p, and OTUD3 were detected in villous tissues from patients with unexplained RSA and normal pregnant women with induced abortion by qRT-PCR. The target relationships between miR-101-3p and SNHG6/OTUD3 were confirmed by dual-luciferase reporter assay. The viability, migration, and apoptosis of trophoblast cells were measured by MTT, wound healing, and flow cytometry assays, respectively. Western blot was performed to detect the protein expression of OTUD3, Ki-67, Bax, and Bcl-2. The results showed that SNHG6 and OTUD3 were up-regulated, and miR-101-3p was down-regulated in RSA patients. MiR-101-3p was a target of SNHG6, and OTUD3 was a target of miR-101-3p. There were negative correlations between the expression of miR-101-3p and OTUD3/SNHG6 in RSA patients. In addition, both SNHG6 silencing and miR-101-3p overexpression could increase cell viability and migration, decrease cell apoptosis, up-regulate Ki-67 and Bcl-2, and down-regulate Bax in HTR-8/SVneo cells. The effects of SNHG6 silencing on HTR-8/SVneo cells were reversed by miR-101-3p silencing or OTUD3 overexpression. To sum up, silencing of SNHG6 enhanced the viability and migration, and inhibited the apoptosis of trophoblast cells through regulating miR-101-3p/OTUD3. SNHG6/miR-101-3p/OTUD3 may be potential targets for the prevention of unexplained RSA.

Abnormal pattern of vitamin D receptor-associated genes and lncRNAs in patients with bipolar disorder

BACKGROUND

Bipolar disorder (BD) is a multifactorial condition. Several signaling pathways affect development of this disorder. With the purpose of exploring the role of vitamin D receptor (VDR) signaling in this disorder, we measured expression of selected mRNA coding genes and long non-coding RNAs (lncRNAs) in this pathway in patients versus normal subjects.

METHODS

We measured expression of VDR-associated lncRNAs and mRNAs (SNHG6, MALAT1, Linc00511, Linc00346, VDR and CYP27B1) in the peripheral blood of BD patients vs. healthy individuals.

RESULTS

Expression of SNHG6 was significantly higher in cases vs. controls (Posterior beta = 1.29, P value < 0.0001. Subgroup analysis by sex revealed significant results in both subgroups (P value < 0.0001 and P value = 0.023 for males and females, respectively). Expression of CYP27B1 was up-regulated in cases vs. controls (Posterior beta = 0.415, P < 0.0001). Such pattern was also detected among males (P < 0.0001), but not females (P = 0.419). Similarly, MALAT1 and Linc00346 were up-regulated in total cases vs. controls (Posterior beta = 0.694, P < 0.0001 and Posterior beta = 0.4, P = 0.012, respectively) and in male cases compared with male controls (Posterior beta = 0.712, P < 0.0001 and Posterior beta = 0.41, P value = 0.038, respectively). Expression of VDR was up-regulated in total cases compared with controls (Posterior beta = 0.683, P value = 0.001). Finally, expression of Linc00511 was not different between groups. MALAT1, SNHG6, CYP27B1, VDR and Linc00346 had AUC values of 0.95, 0.94, 0.91, 0.85 and 0.83 in differentiation of male patients from controls, respectively.

CONCLUSION

The current study suggests VDR-associated genes as possible markers for BD.

LncRNA SNHG6 facilitates cell proliferation, migration, invasion and EMT by upregulating UCK2 and activating the Wnt/β-catenin signaling in cervical cancer

Cervical cancer is a most prevalent gynecological malignancy around the world. Long non-coding RNAs (lncRNAs) are recognized as crucial players in the cellular activities of diverse cancers including cervical cancer. We aimed to reveal the biological function of lncRNA small nucleolar RNA host gene 6 (SNHG6) in cervical cancer. Our findings illuminated that SNHG6 expression was elevated in cervical cancer tissues and cell lines, and highly expressed SNHG6 was associated with poor outcome in patients with cervical cancer. Moreover, knockdown of SNHG6 repressed cervical cancer development via inhibiting cell proliferation and migration and accelerating cell apoptosis. Further, SNHG6 was a sponge of miR-485-3p and uridine-cytidine kinase 2 (UCK2) was the functional target of miR-485-3p. SNHG6 increased UCK2 expression by binding with miR-485-3p in cervical cancer cells. The rescue experiments showed that SNHG6 contributed to malignant phenotypes of cervical cancer cells by the miR-485-3p/UCK2 axis. Additionally, SNHG6 activated the Wnt/β-catenin pathway to enhance the proliferative and migratory ability of cervical cancer cells. Overall, this work revealed that SNHG6 promoted malignant behaviors of cervical cancer cells by binding with miR-485-3p to regulate UCK2 and activating the Wnt/β-catenin pathway, which may offer a beneficial direction to treat cervical cancer.

A Review on the Role of Small Nucleolar RNA Host Gene 6 Long Non-coding RNAs in the Carcinogenic Processes

Being located on 17q25.1, small nucleolar RNA host gene 6 (SNHG16) is a member of SNHG family of long non-coding RNAs (lncRNA) with 4 exons and 13 splice variants. This lncRNA serves as a sponge for a variety of miRNAs, namely miR-520a-3p, miR-4500, miR-146a miR-16–5p, miR-98, let-7a-5p, hsa-miR-93, miR-17-5p, miR-186, miR-302a-3p, miR-605-3p, miR-140-5p, miR-195, let-7b-5p, miR-16, miR-340, miR-1301, miR-205, miR-488, miR-1285-3p, miR-146a-5p, and miR-124-3p. This lncRNA can affect activity of TGF-β1/SMAD5, mTOR, NF-κB, Wnt, RAS/RAF/MEK/ERK and PI3K/AKT pathways. Almost all studies have reported oncogenic effect of SNHG16 in diverse cell types. Here, we explain the results of studies about the oncogenic role of SNHG16 according to three distinct sets of evidence, i.e., in vitro, animal, and clinical evidence.

Transcriptomic Analysis in Multiple Myeloma and Primary Plasma Cell Leukemia with t(11;14) Reveals Different Expression Patterns with Biological Implications in Venetoclax Sensitivity

Simple Summary

The growing interest in BCL2 inhibitors for the treatment of multiple myeloma (MM) has led to the need for biomarkers that are able to predict patient’s sensitivity to the drug. The presence of the chromosomal translocation t(11;14) in MM is mainly associated with sensitivity to venetoclax and good prognosis. The incidence of t(11;14) largely increases in primary Plasma Cell Leukemia (pPCL) in association with an unfavorable outcome. Currently, data concerning pPCL sensitivity to venetoclax are virtually absent. In this context, we investigated the transcriptome of MM and pPCL with t(11;14), evidencing that the two clinical entities are likely responsive to venetoclax based on different molecular programs, thus prompting further studies to elucidate better novel potential predictive biomarkers.

Abstract

Mechanisms underlying the pathophysiology of primary Plasma Cell Leukemia (pPCL) and intramedullary multiple myeloma (MM) need to be further elucidated, being potentially relevant for improving therapeutic approaches. In such a context, the MM and pPCL subgroups characterized by t(11;14) deserve a focused investigation, as the presence of the translocation is mainly associated with sensitivity to venetoclax. Herein, we investigated a proprietary cohort of MM and pPCL patients, focusing on the transcriptional signature of samples carrying t(11;14), whose incidence increases in pPCL in association with an unfavorable outcome. In addition, we evaluated the expression levels of the BCL2-gene family members and of a panel of B-cell genes recently reported to be associated with sensitivity to venetoclax in MM. Moreover, transcriptional analysis of lncRNAs in the two clinical settings led to the identification of several differentially expressed transcripts, among which the SNGH6 deregulated lncRNA might be relevant in the pathogenesis and prognosis of pPCL with t(11;14). Overall, our data suggest that MMs and pPCLs with t(11;14) might be responsive to venetoclax based on different molecular programs, prompting further studies to elucidate better novel potential predictive biomarkers.

Upregulation of VDR-associated lncRNAs in Schizophrenia

Vitamin D receptor (VDR) signaling has been found to contribute to the pathology of numerous neuropsychiatric diseases including schizophrenia. Notably, VDR signaling has a functional relationship with many long non-coding RNAs (lncRNAs) such as SNHG6, LINC00346 and LINC00511. We calculated expression of these lncRNAs in the venous blood of patients with schizophrenia versus healthy individuals. Expression of SNHG6 was significantly higher in cases versus controls (posterior beta = 0.552, adjusted P value < 0.0001). This pattern of expression was detected in both men (posterior beta = 0.556, adjusted P value < 0.0001) and women (posterior beta = 0.31, adjusted P value = 0.005). Expression of LINC00346 was also higher in cases versus controls (posterior beta = 0.497, adjusted P value < 0.0001) and in distinct sex-based comparisons (posterior beta = 0.451, adjusted P value = 0.009 among men and posterior beta = 0.214, P value = 0.004 among women). Expression of LINC00511 was higher in cases versus controls (posterior beta = 0.318, adjusted P value = 0.01). While sex-based comparisons revealed significant difference in expression of LINC00511 among female subgroups (posterior beta = 0.424, adjusted P value = 0.016), such comparison showed no difference among male cases and male controls (adjusted P value = 0.295). The expression levels of SNHG6 distinguished patients with schizophrenia from controls, with AUC = 0.932. LINC00346 and LINC00511 distinguished between the two groups with AUC values of 0.795 and 0.706, respectively. Therefore, these lncRNAs might be used as markers for schizophrenia.

Long Non-Coding RNA SNHG6 Supports Glioma Progression Through Upregulation of Notch1, Sox2, and EMT

Gliomas, particularly the advanced grade glioblastomas, have poor 5-year survival rates and worse outcomes. lncRNAs and EMT have been extensively studied in gliomas but the disease progression remains poorly understood. SNHG6 has been shown to affect glioma cell proliferation but its effect on EMT of glioma cells along with its effect on disease progression is not known. We screened four glioma cell lines; H4, A172, U87MG, and SW088 and grouped them based on high vs. low SNHG6 expression. Transfections with SNHG6 specific siRNA resulted in induction of apoptosis of high SNHG6 expressing A172 and U87MG cells. This was accompanied by inhibition of EMT and downregulation of EMT-modulating factor Notch1, β-catenin activity and the cancer stem cell marker Sox2. The regulation was not found to be reciprocal as silencing of Notch1 and Sox2 failed to affect SNHG6 levels. The levels of SNHG6 and Notch1 were also found elevated in Grade IV glioma patients (n = 4) relative to Grade II glioma patients (n = 5). These results identify SNHG6 and Notch1 as valid targets for glioma therapy.

lncRNA SNHG6 promotes hepatocellular carcinoma progression by interacting with HNRNPL/PTBP1 to facilitate SETD7/LZTFL1 mRNA destabilization

The lncRNA SNHG6 (small nucleolar RNA host gene 6) plays vital roles in tumorigenesis and the progression of hepatocellular carcinoma (HCC). However, the regulatory mechanisms of SNHG6 are largely unknown. In this study, we identified, via quantitative proteomics, specific cytoskeleton-associated proteins and enzyme modulators to be potential targets of SNHG6. SNHG6 reduced the mRNA levels of lysine methyltransferase, SET domain containing 7 (SETD7) and leucine zipper transcription factor-like 1 (LZTFL1) by posttranscriptional destabilization. Silencing of SETD7 or LZTFL1 reversed the suppressive effects of SNHG6 knockdown on HCC progression. Heterogeneous nuclear ribonucleoprotein L (HNRNPL) and polypyrimidine tract binding protein 1 (PTBP1) were identified as SNHG6-interacting proteins that bind to SETD7 or LZTFL1 mRNA. Forced expression of SNHG6 led to HNRNPL being competitively adsorbed by SNHG6, thereby removing its stabilizing effect on SETD7. Concurrently, the functional SNHG6-PTBP1 complex facilitated the degradation of LZTFL1 mRNA in hepatoma cells. These results indicated that SNHG6 promotes HCC progression by functioning as a "decoy plus guide" for HNRNPL and PTBP1 to facilitate mRNA decay of SETD7 and LZTFL1, thereby serving as a novel therapeutic target for HCC.

Evaluation of expression of VDR-associated lncRNAs in COVID-19 patients

BACKGROUND

Coronavirus disease 2019 (COVID-19) has been shown to cause serious health problems among them is the Acute Respiratory Distress syndrome (ARDS). Vitamin D receptor (VDR) signaling possibly partakes in the pathophysiology of this devastating complication.

METHODS

In the current project, we have appraised expression levels of VDR, CYP27B1 and a number of associated lncRNAs in the circulation of COVID-19 patients versus healthy subjects using real-time PCR method.

RESULTS

Expression of SNHG6 was considerably lower in COVID-19 patients compared with control subjects (Ratio of mean expression (RME) = 0.22, P value = 7.04E-05) and in both female and male COVID-19 patients compared with sex-matched unaffected individuals (RME = 0.32, P value = 0.04 and RME = 0.16, P value = 0.000679683, respectively). However, its expression was similar among ICU-hospitalized and non-ICU patients. Similarly, expression of SNHG16 was lower in in COVID-19 patients compared with controls (RME = 0.20, P value = 5.94E-05) and in both female and male patients compared with sex-matched controls (RME = 0.32, P value = 0.04 and RME = 0.14, P value = 0.000496435, respectively) with no significant difference among ICU-hospitalized and non-ICU hospitalized patients. Expression of VDR was lower in COVID-19 patients compared with controls (RME = 0.42, P value = 0.04) and in male patients compared with male controls (RME = 0.27, P value = 0.02). Yet, expression of VDR was statistically similar between female subgroups and between ICU-hospitalized and non-ICU hospitalized patients. Expression levels CYP27B, Linc00511 and Linc00346 were similar among COVID-19 patients and healthy subjects or between their subgroups. Significant correlations have been detected between expression levels of VDR, CYP27B and SNHG6, SNHG16, Linc00511 and Linc00346 lncRNAs both among COVID-19 patients and among healthy controls with the most significant ones being SNHG6 and SNHG16 (r = 0.74, P value = 3.26e-17 and r = 0.81, P = 1.54e-22, respectively).

CONCLUSION

Combination of transcript levels of VDR, CYP27B and SNHG6, SNHG16, Linc00511 and Linc00346 could differentiate patients from controls with AUC = 0.76, sensitivity = 0.62 and specificity = 0.81. The current data potentiate SNHG6, SNHG16 and VDR as possible contributors in COVID-19 infection but not in the severity of ARDS.

Expression Analysis of VDR-Related LncRNAs in Autism Spectrum Disorder

Vitamin D receptor (VDR) signaling has been reported to affect neurodevelopment, thus participating in the risk of autism spectrum disorder (ASD). We have measured expression amounts of VDR, CYP27B1, and two related long non-coding RNAs, namely SNHG6 and LINC00511, in the circulation of ASD patients compared with normal controls. Expression of CYP27B1 was remarkably higher in ASD cases compared with controls (posterior beta = 2.38, SE = 0.46, adjusted P value < 0.0001, 95% credible interval (CrI) for beta = [1.49, 3.27]). Level of SNHG6 was lower in ASD cases compared with controls (posterior beta = - 0.791, SE = 0.24, adjusted P value = 0.029, 95% CrI for beta = [- 1.27, - 0.33]). Expression levels of VDR and LINC00511 were similar between ASD cases and controls (P values = 0.97 and 0.46, respectively). Expressions of VDR, CYP27B1, SNHG6, and LINC00511 were not correlated with age of children. However, significant correlations were perceived between expressions of CYP27B1 and LINC00511 (r = 0.47, P < 0.0001), VDR and CYP27B1 (r = 0.42, P < 0.0001), and VDR and SNHG6 (r = 0.32, P < 0.0001). Therefore, these results imply dysregulation of a number of VDR-related genes in ASD patients.

LncRNA SNHG6 promotes breast cancer progression and epithelial-mesenchymal transition via miR-543/LAMC1 axis

PURPOSE

Breast cancer (BC) is the most prevalent cancer in women with an estimated incidence of 10% and the leading cause of mortality due to its heterogenous property and high metastasis rate. Development of novel therapy is very necessary and requires an understanding of molecular mechanisms. We investigated the function of SNHG6/miR-543/LAMC1 axis in BC.

METHODS

Human BC tissues were obtained from diagnosed patients. BC cell lines and normal breast cells were used. QRT-PCR and Western blotting were employed to measure expression levels of SNHG6, miR-543, LAMC1, EMT-related proteins, and PI3K/AKT pathway. Dual-luciferase assay was performed to validate interactions of SNHG6/miR-543 and miR-543/LAMC1. Colony formation assay, flow cytometry, scratch wound healing assay, and transwell assay were utilized to assess the proliferation, apoptosis, migration, and invasion of BC cells. Nude mouse xenograft model was used the evaluate the function of SNHG6/miR-543 in tumor growth in vivo.

RESULTS

SNHG6 and LAMC1 were elevated, but miR-543 was reduced in BC tissues and cells. SNHG6 interacted directly with miR-543, while miR-543 targeted LAMC1. Knockdown of SNHG6 suppressed BC cell proliferation, migration, invasion, EMT, and PI3K/AKT pathway, but promoted cell apoptosis, while miR-543 inhibitor or overexpression of LAMC1 reversed those effects. Overexpression of LAMC1 also blocked the effects of miR-543 on BC cell proliferation, migration, invasion, and EMT. Knockdown of SNHG6 restrained BC growth in vivo, while miR-543 inhibitor inhibited that suppression.

CONCLUSION

SNHG6 promoted EMT and BC cell proliferation and migration by acting as a miR-543 sponge and disinhibiting LAMC1/PI3K/AKT pathway. SNHG6/miR-543/LAMC1 axis could serve as candidates for the development of therapeutic strategies for BC.

LncRNA-SNHG6 promotes the progression of hepatocellular carcinoma by targeting miR-6509-5p and HIF1A

Background

Accumulating evidences have been reported that long noncoding RNAs play crucial roles in the progression of hepatocellular carcinoma (HCC). SnoRNA host gene 6 (SNHG6) is believed to be involved in several human cancers, but the specific molecular mechanism of SNHG6 in HCC is not well studied.

Methods

In this study, we experimentally down-regulated the SNHG6 in two hepatocellular carcinoma cell lines in vitro, and then measured the proliferation, migration and invasion abilities and the apoptotic levels. Also, we performed the xenograft assay to investigate the function of SNHG6 during the tumor growth in vivo.

Results

We found SNHG6 was highly expressed in HCC tissues. Next, using Hep3B and Huh7 cells, we confirmed knockdown of SNHG6 reduced the proliferation, migration and invasion abilities in vitro. Also, by bioinformatics analysis, further molecular and cellular experiments, we found miR-6509-5p bound to SNHG6 directly, and the expression level of HIF1A was regulated through SNHG6/miR-6509-5p axis. Finally, we found that down-regulation of SNHG6 dramatically reduced the tumor growth ability of Huh7 cells in vivo.

Conclusions

We concluded that SNHG6/miR-6509-5p/HIF1A axis functioned in the progression of hepatocellular carcinoma, and could be the promising therapeutic targets during the development of hepatocellular carcinoma drugs.

Silencing of SNHG6 alleviates hypoxia/reoxygenation-induced cardiomyocyte apoptosis by modulating miR-135a-5p/HIF1AN to activate Shh/Gli1 signalling pathway

OBJECTIVES

To examine the effects of small nucleolar RNA host gene 6 (SNHG6) on apoptosis during myocardial ischemic/reperfusion (I/R) injury and its potential molecular mechanisms.

METHODS

In vitro model of I/R was built through exposing mouse HL-1 cardiomyocytes to hypoxia/reoxygenation (H/R) treatment. Quantitative real-time polymerase chain reaction assays were performed to determine gene expression. Cell Counting Kit-8, flow cytometric and western blot assays were conducted to detect cell viability, apoptosis and protein expression. Lactate dehydrogenase (LDH) activity was examined by a commercial detection kit. Dual-luciferase gene reporter and RNA immunoprecipitation experiments were applied for determining the interaction between the molecules.

KEY FINDINGS

SNHG6 expression was increased in H/R-challenged cardiomyocytes. Depletion of SNHG6 protected against H/R-induced cardiomyocytes apoptosis. SNHG6 could sponge miR-135a-5p to inhibit its expression. Down-regulation of miR-135a-5p reversed the anti-apoptotic effect caused by SNHG6 knockdown in H/R-induced cardiomyocytes. Hypoxia inducible factor 1 subunit alpha inhibitor (HIF1AN) was identified as a direct target of miR-135a-5p, and knockdown of HIF1AN relieved H/R-induced cardiomyocytes apoptosis. Silencing of SNHG6 activated Shh/Gli1 signalling pathway by regulating miR-135a-5p/HIF1AN. Furthermore, inactivation of Shh/Gli signalling abolished the anti-apoptotic effects of SNHG6 knockdown in H/R-induced cardiomyocytes.

CONCLUSIONS

SNHG6 serves as a sponge for miR-135a-5p to promote HIF1AN expression and inactivate Shh/Gli1 signalling, eventually aggravating H/R-induced apoptosis in cardiomyocytes.

LncRNA SNHG6 Promotes Wilms' Tumor Progression Through Regulating miR-429/FRS2 Axis

Background: Long noncoding RNA (lncRNA) small nucleolar RNA host gene 6 (SNHG6) has been reported to be an oncogene in a variety of cancers. However, the role of SNHG6 and its associated mechanisms in Wilms' tumor progression remain largely unknown. Methods: The expression of SNHG6, microRNA-429 (miR-429), and FGF receptor substrates 2 (FRS2) messenger RNA (mRNA) was detected by quantitative real-time polymerase chain reaction. Cell proliferation was analyzed through 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and plate colony assay. The apoptosis was assessed by flow cytometry. Cell glycolytic metabolism was analyzed through detecting the lactate dehydrogenase activity, glucose uptake, lactate production, and ATP level. The target relationship between miR-429 and SNHG6 or FRS2 was predicted by miRcode or Starbase and then validated by dual-luciferase reporter assay and RNA pull-down assay. Murine xenograft model was established to validate the function of SNHG6 in vivo. Results: The level of SNHG6 was elevated in Wilms' tumor tissues and cells, and SNHG6 played an oncogenic role to promote the proliferation and glycolysis and restrain the apoptosis of Wilms' tumor cells. MiR-429 was identified as a target of SNHG6, and miR-429 interference partly reversed the inhibitory effects induced by SNHG6 silencing on the malignant behaviors of Wilms' tumor cells. FRS2 mRNA bound to miR-429 in Wilms' tumor cells. SNHG6 upregulated the expression of FRS2 through acting as a sponge of miR-429. MiR-429-induced influences in Wilms' tumor cells were largely counteracted by the overexpression of FRS2. SNHG6 silencing suppressed the Wilms' tumor growth through miR-429/FRS2 axis in vivo. Conclusion: SNHG6 accelerated Wilms' tumor progression through regulating miR-429/FRS2 signaling in vitro and in vivo.

Long noncoding RNA SNHG6 promotes carcinogenesis by enhancing YBX1-mediated translation of HIF1α in clear cell renal cell carcinoma

Recent studies have showed that Small nucleolar RNA host genes (SNHGs) acted as a subset of long noncoding RNAs (lncRNAs) have critical roles in human cancer carcinogenesis. However, the biological functions of SNHGs in clear cell renal cell carcinoma (ccRCC) have not been fully investigated. In this study, we screened an oncogenic lncRNA termed SNHG6 using RNA-Seq data of ccRCC from The Cancer Genome Atlas (TCGA). Quantitative real-time PCR was then used to demonstrate the expression of SNHG6 in ccRCC tissues. SNHG6 overexpression is highly associated with malignant features in patients and is a prognostic indicator. SNHG6 significantly promotes ccRCC cell proliferation and metastasis in vitro and in vivo. Mechanistic investigations identified that SNHG6 exerts oncogenic effects by interacting with YBX1, and then, enhancing HIF1α translation. Taken together, SNHG6 promotes ccRCC progression by binding YBX1 and may serve as a novel molecular target for ccRCC therapy.

Downregulation of long noncoding RNA SNHG6 rescued propofol-induced cytotoxicity in human induced pluripotent stem cell-derived cardiomyocytes

Background

Propofol (PPF) overdose is a rare but lethal condition, which may lead to severe cardiac failure. In this study, we established an in vitro PPF-induced cardiac cytotoxicity model, and investigate the functional role of long non-coding RNA (lncRNA) small nucleolar RNA host gene 6 (SNHG6).

Methods

Human induced pluripotent stem cell-derived cardiomyocytes (HiPSC-CMs) were exposed to PPF in vitro. PPF-induced cytotoxic effects were measured. PPF-induced SNHG6 expression change in HiPSC-CMs were monitored by qRT-PCR. SNHG6 was downregulated in HiPSC-CMs to examine its role in PPF-induced cardiac cytotoxicity. The expression of competing endogenous RNA (ceRNA) candidate of SNHG6, human microRNA-186-5p (hsa-miR-186-5p) was also investigated in PPF-exposed HiPSC-CMs. Functions of hsa-miR-186-5p were further investigated in PPF-exposed and SNHG6-downregulated HiPSC-CMs.

Results

PPF induced significant cytotoxicity, as well as SNHG6 upregulation in HiPSC-CMs. SNHG6 downregulation had rescuing effects on PPF-induced cardiac cytotoxicity. Dual-luciferase activity assay confirmed that hsa-miR-186-5p was the ceRNA candidate of SNHG6. QRT-PCR showed hsa-miR-186-5p expression was reversely correlated with SNHG6 in PPF-exposed HiPSC-CMs. Suppressing hsa-miR-186-5p reduced the rescuing effects of SNHG6-downregulation on PPF-induced cardiac cytotoxicity.

Conclusions

SNHG6/hsa-miR-186-5p can modulate PPF-induced cardiac cytotoxicity in HiPSC-CMs, and thus may be a future drug target to prevent PPF infusion syndrome.

Long non-coding RNA SNHG6 increases JAK2 expression by targeting the miR-181 family to promote colorectal cancer cell proliferation

BACKGROUND

Long non-coding RNA (lncRNA) small nucleolar RNA host gene 6 (SNHG6) exerts a regulatory role in cancer biology, although its detailed functions and mechanisms in colorectal cancer (CRC) still remain unclear.

METHODS

A quantitative reverse transcriptase-polymerase chain reaction was implemented to investigate the expression of SNHG6, miR-181 family and Janus kinase 2 (JAK2) in CRC tissues and cell lines. The proliferation of CRC cells was detected by a cell counting kit-8 assay, and the apoptosis of CRC cells was determined by flow cytometry analysis. The interaction of the miR-181 family with SNHG6 or with the 3'-untranslated region of JAK2 was validated by the luciferase reporter gene method. The effects of SNHG6 and the miR-181 family on JAK2 expression were analyzed by western blotting.

RESULTS

SNHG6 was significantly up-regulated in CRC samples. The knockdown of SNHG6 reduced the proliferation of CRC cells and promoted the apoptosis, whereas the over-expression of SNHG6 had the opposite effect. SNHG6 could bind with all the four members of the miR-181 family, and expression in miR-181 family members was significantly down-regulated in CRC samples. SNHG6 expression was negatively correlated with the miR-181 family member expression in CRC samples. Moreover, over-expressed SNHG6 significantly counteracted the inhibitory effect of miR-181 mimics on CRC cell proliferation, as well as the promoting effect on apoptosis. Furthermore, SNHG6 over-expression and knockdown can promote and inhibit JAK2 expression, respectively, and miR-181 family member function is opposite to that of SNHG6 by repressing JAK2.

CONCLUSIONS

SNHG6 can exert a cancer-promoting effect in CRC by targeting miR-181 family members and up-regulating JAK2.

LncRNA SNHG6 Induces Epithelial-Mesenchymal Transition of Pituitary Adenoma Via Suppressing MiR-944

Background:

Pituitary adenoma (PA) is a common primary brain tumor with invasive properties. Despite that long noncoding RNA (lncRNA) small nucleolar RNA host gene 6 (SNHG6) exerts oncogenic function in cancer cells and that miR-944 inhibits epithelial–mesenchymal transition (EMT) of cancer cells are well documented, few studies have explored the function and mechanism of SNHG6 and miR-944 in invasive pituitary adenoma (IPA).

Materials and Methods:

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expressions of SNHG6 and miR-944 in PA samples. Human PA cell line HP75 was used as a cell model. The biological effects of SNHG6 and miR-944 on HP75 cells were investigated with cell counting kit-8 (CCK-8) assay, Transwell assay, and scratch healing assay in vitro, respectively. Markers of EMT, including E-cadherin and vimentin, were detected by Western blot. Interactions between SNHG6 and miR-944, miR-944 and RAB11A were determined by bioinformatics analysis, qRT-PCR, and dual luciferase reporter assay.

Results:

SNHG6 was significantly upregulated in IPA samples, whereas miR-944 was downregulated. SNHG6 markedly promoted viability, migration, invasion, and EMT of PA cells, whereas miR-944 transfection had the opposite effects. SNHG6 could downregulate miR-944, and there was a negative correlation between SNHG6 expression and miR-944 expression in IPA samples. Besides, it was confirmed that miR-944 could pair with the 3′-untranslated region of RAB11A and repress its expression.

Conclusions:

This study authenticates that the SNHG6/miR-994/RAB11A axis plays a crucial role in regulating proliferation, migration, invasion, and EMT of IPA cells. SNHG6 and miR-994 can serve as novel valuable therapeutic targets for IPA.

LncRNA SNHG6 promotes LMO3 expression by sponging miR-543 in glioma

Small nucleolar RNA host gene 6 (SNHG6) was a newly discovered long non-coding RNA, which was involved in the occurrence and development of a variety of cancers and was on the rise in human cancers. However, the molecular mechanism of SNHG6 in glioma required further investigation. The levels of SNHG6, microRNA-543 (miR-543) and LIM-only protein 3 (LMO3) were detected in glioma tissues and cells by quantitative real-time polymerase chain reaction. We examined cell proliferation and apoptosis rate by methylthiazolyldiphenyl-tetrazolium bromide and flow cytometry assays, respectively. Transwell assay was used to measure cell migration and invasion. The target relationships were predicted by StarBase v.2.0 and TargetScan and confirmed by dual-luciferase reporter assay. Spearman's test was adopted for expression correlation of SNHG6, miR-543 and LMO3 in tissues. The protein expression level of LMO3 was assessed by western blot. We found that SNHG6 was obviously upregulated in glioma tissues and cells. SNHG6 knockdown significantly repressed glioma cell proliferation, migration and invasion, and induced apoptosis. Additionally, SNHG6 directly targeted miR-543 and their expression was negatively correlated in glioma tissues. And miR-543 targeted LMO3 and their expression was also inversely correlated. We found that silencing LMO3 also inhibited the progression of glioma cells. Importantly, SNHG6 could competitively sponging miR-543 thereby modulating LMO3 in glioma cells. SNHG6 served as an oncogene and played a vital role in glioma development through miR-543/LMO3 axis.

LncRNA SNHG6 enhances the radioresistance and promotes the growth of cervical cancer cells by sponging miR-485-3p

Background

Cervical cancer (CC) is the one of most common malignant gynecological tumors, which is characterized with the high mortality and recurrence rate. Previous studies have elucidated the oncogenic role of small nucleolar RNA host gene 6 (SNHG6) in some types of human cancers, whereas it is unclear whether it functions as an oncogene in CC. This study was aimed at unveiling the role of SNHG6 in CC.

Methods

qRT-PCR analysis was implemented to evaluate the expression levels of SNHG6, miR-485-3p and STYX in CC cells. RNA pull down assay and luciferase reporter assay were conducted to verify the interaction between miR-485-3p and SNHG6 or STYX. Functional assays, such as colony formation assay, JC-1 assay and TUNEL assay were applied to detect the biological behaviors of CC cells. The resistance of CC cells to radiation was evaluated by colony formation assay.

Results

SNHG6 was expressed at a high level in CC cells. Silenced SNHG6 suppressed cell proliferation but promoted cell apoptosis. Additionally, silenced SNHG6 could sensitize CC cells to radiation treatment. miR-485-3p could bind to both SNHG6 and STYX. Knockdown of miR-485-3p or overexpression of STYX could abolish the effects of SNHG6 silencing on CC cell growth.

Conclusions

LncRNA SNHG6 enhances the radioresistance of CC cells and promotes CC cell growth by sponging miR-485-3p to release STYX.

Long non-coding RNA SNHG6 regulates the sensitivity of prostate cancer cells to paclitaxel by sponging miR-186

Background

Chemo-resistance is one of the main obstacles in the treatment of prostate cancer (PCa). Long non-coding RNA small nucleolar RNA host gene 6 (SNHG6) is involved in the chemo-resistance of various tumors. We aim to survey the role and underlying molecular mechanism of SNHG6 in PCa resistance to paclitaxel (PTX).

Methods

The expression of SNHG6 and miR-186 was detected using quantitative real time polymerase chain reaction (qRT-PCR). The proliferation, migration, invasion, and apoptosis of PTX-resistant PCa cells were determined via 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), transwell assay, or flow cytometry assay. Protein levels of CyclinD1, matrix metalloproteinase 9 (MMP9), Vimentin, E-cadherin, Cleaved-caspase-3 (Cleaved-casp-3) Cleaved-caspase-9 (Cleaved-casp-9), Multidrug Resistance associated Protein 1 (MRP1), and multidrug resistance-1 (MDR1) were assessed by western blot analysis. The relationship between SNHG6 and miR-186 were confirmed by dual-luciferase reporter assay. The role of SNHG6 in vivo was confirmed by xenograft tumor model.

Results

SNHG6 expression was increased and miR-186 expression was reduced in drug-resistant PCa tissues and cells. SNHG6 knockdown elevated PTX-resistant PCa cells sensitivity to PTX in vitro and in vivo, and repressed proliferation, migration, and invasion of PTX-resistant PCa cells in vitro. Importantly, SNHG6 acted as a sponge of miR-186. Furthermore, miR-186 downregulation reversed SNHG6 silencing-mediated cell sensitivity to PTX, proliferation, migration, and invasion in PTX-resistant PCa cells.

Conclusions

SNHG6 knockdown elevated the sensitivity of PTX-resistant PCa cells to PTX by sponging miR-186, indicating that SNHG6 might be a therapeutic target for PCa.

The prognostic value of lncRNA SNHG6 in cancer patients

Background

Although tremendous improvement has been seen in cancer diagnosis and treatment, its morbidity and mortality is still high due to lack of ideal biomarkers. An increasing number of studies have demonstrated that the expression of lncRNA small nucleolar RNA host gene 6 (SNHG6) has significantly negative correlation with various cancer prognosis. The present meta-analysis was aimed to clarify the potential of clinical application of SNHG6 in cancers.

Methods

A detailed literature review was conducted by searching through PubMed and Web of Science databases. The expression level of SNHG6, clinicopathological features and survival outcomes were extracted from eligible studies. Pooled analysis was performed with a DerSimonian-Laird random-effect model. The results were further validated through the Cancer Genome Atlas (TCGA) dataset.

Results

Five studies with a total of 487 cases were finally included in this meta-analysis. The results demonstrated that a high expression of SNHG6 was significantly associated with an increased risk of poor overall survival (OS) in cancer patients (HR = 2.06, 95% CI 1.56–2.73). Similar results from the TCGA dataset further confirmed our findings.

Conclusions

Overexpressed SNHG6 was significantly associated with poor prognosis in various cancers. Therefore, SNHG6 may become a novel molecular target for treatment and prognostic evaluation.

SPI1-induced upregulation of lncRNA SNHG6 promotes non-small cell lung cancer via miR-485-3p/VPS45 axis

More and more researches have proved that long noncoding RNAs (lncRNAs) are vital regulators and biological participants in human cancers [1-5]. SnoRNA host gene 6 (SNHG6) was found to have an effect on the early stage and tumorigenesis in many cancers [6-10]. However, the expression of SNHG6 and its role of in non-small cell lung cancer (NSCLC) still need to be investigated. This work aims to investigate the expression and its biological role in NSCLC. In our study, the expression of SNHG6 was abnormally high in NSCLC tissues and cells. The negative impact of SNHG6 expression on the overall survival of patients with NSCLC was analyzed with Kaplan Meier method. Functionally, loss of SNHG6 expression led to the inhibition on the growth, migration and invasion of NSCLC cells. Mechanistically, miR-485-3p was necessary for the regulatory relation between SNHG6 and VPS45. More importantly, SPI1 could promote the expression of SNHG6 via transcriptionally activation. In conclusion, we proved that SPI1/SNHG6/miR-485-3p/VPS45 axis exerted oncogenic role in the cellular process of NSCLC cells.

Long noncoding RNA SNHG6 mainly functions as a competing endogenous RNA in human tumors

Increased expression of the small nucleolar RNA host gene 6 (SNHG6) has been reported in different cancers, such as hepatocellular carcinoma, colorectal cancer, and lung cancer. The high expression level of SNHG6 is associated with tumor progression and poor prognosis. This paper provides an overview of recent studies on the oncogenic role and potential clinical utilities of SNHG6. Upregulated SNHG6 arrests tumor cell cycle and reduces apoptosis but promotes migration, invasion, metastasis, epithelial-mesenchymal transition (EMT), and chemoresistance in tumors. Mechanically, SNHG6 primarily sponges tumor suppressor microRNA (miRNA), functioning as a competing endogenous RNA. Once sponged, miRNA is unable to degrade, silence, or hamper the translation of its downstream, mostly oncogenic genes, ultimately driving cancer-related processes. Thus, SNHG6 might serve as a biomarker for cancer diagnosis and prognosis.

LncRNA SNHG6 plays an oncogenic role in colorectal cancer and can be used as a prognostic biomarker for solid tumors

Small nucleolar RNA host gene 6 (SNHG6) has been recognized as an oncogene in numerous cancers and overexpression of SNHG6 was found to promote colorectal cancer (CRC). Hence, we performed a meta-analysis to examine the clinical importance of the long noncoding RNA (lncRNA) SNHG6. Moreover, comprehensive identification of RNA-binding proteins-mass spectrometry (ChIRP-MS) was conducted to explore the carcinogenic mechanism of lncRNA SNHG6 in CRC. Fourteen studies conducted on 1,139 patients were included in this meta-analysis. We also constructed the protein-protein interactive (PPI) network in string based on the ChIRP-MS results and cytoscape was used to identify core modules in the PPI network, which were then analyzed using the bioinformatics websites, cancer single-cell state atlas (CancerSEA) and G:profilter. The clinical outcomes of the meta-analysis indicated that higher expression of SNHG6 was related with a poorer survival outcome (overall survival: hazard ratio (HR) = 1.92; 95% confidence interval [Cl]: 1.48, 2.49; p < .0001; disease-free survival: HR = 1.84; 95% Cl: 1.02, 3.34; p = .044), higher tumor stage (odds ratio [OR] = 3.35; 95% Cl: 2.57, 4.37; p < .0001), distant metastasis (OR = 1.83; 95% Cl: 1.11, 2.99; p = .017) and lymph node metastasis (OR = 1.33; 95% Cl: 0.93, 1.89; p = .119). The ChIRP-MS results showed that core Module 1 of the PPI was significant in ribosomes and core Module 2 was mainly related to spliceosomes and messenger RNA processing. In conclusion, a higher expression of SNHG6 was found to be associated with a poorer survival outcome, high tumor stage, and distant metastasis in various solid tumors. SNHG6 was also found to be able to affect the processes of transcription and translation to promote CRC.

Long Noncoding RNA SNHG6 Promotes Proliferation and Inhibits Apoptosis in Non-small Cell Lung Cancer Cells by Regulating miR-490-3p/RSF1 Axis

Background: Nonsmall cell lung cancer (NSCLC) is a malignant cancer type and has developed into the leading cause of cancer-related death worldwide. Small nucleolar RNA host gene 6 (SNHG6) has been identified as an oncogene in multiple cancers. However, the functions of SNHG6 in tumorigenesis and progression of NSCLC are still poorly understood. Materials and Methods: The expression of SNHG6, miR-490-3p, and remodeling and spacing factor 1 (RSF1) in NSCLC tumors and cells was measured by quantitative real-time polymerase chain reaction. The correlation between miR-490-3p and SNHG6 or RSF1 was analyzed by Pearson's correlation coefficient. Luciferase reporter assay was employed for verifying the interaction between miR-490-3p and SNHG6 or RSF1. Cell viability was examined by 3-(4, 5)-dimethylthiazole-2-y1)-2, 5-biphenyl tetrazolium bromide (MTT) assay. Cell apoptosis was evaluated by flow cytometry and Western blot, respectively. Protein expression of RSF1, Bcl-2, Bax, and cleaved caspase-3 (cleaved casp-3) was detected by Western blot assay. Xenograft mice models were established by subcutaneously injecting H460 cells stably transfected with sh-SNHG6 and sh-NC. Results: SNHG6 and RSF1 expression were upregulated, whereas miR-490-3p was downregulated in NSCLC tumors and cell lines compared with normal tissues and cells. Pearson's correlation coefficient analysis indicated that miR-490-3p was correlated with SNHG6 and RSF1 inversely. Then, luciferase reporter assay confirmed the interaction between miR-490-3p and SNHG6 or RSF1. More importantly, the rescue experiments clarified that miR-490-3p inhibitor could relieve SNHG6 silencing-mediated inhibition on proliferation and promotion on apoptosis in NSCLC. In addition, the authors discovered that SNHG6 promoted cell progression by regulating miR-490-3p/RSF1 axis. However, SNHG6 knockdown hindered tumor growth in vivo by regulating RSF1 by targeting miR-490-3p. Conclusion: The authors demonstrated that SNHG6 promoted proliferation and inhibits apoptosis in NSCLC by regulating miR-490-3p/RSF1 axis, representing promising targeted therapeutic strategies against NSCLC.

Long non-coding RNA SNHG6 promotes the growth and invasion of non-small cell lung cancer by downregulating miR-101-3p

BACKGROUND

The aim of this study was to determine the function of long non-coding RNA small nucleolar RNA host gene 6 (SNHG6) in non-small cell lung cancer (NSCLC) and its underlying mechanisms.

METHODS

The association of SNHG6 or miR-101-3p with clinicopathological characteristics and prognosis in patents with NSCLC was assessed by TCGA dataset. Cell proliferation and invasion were evaluated by MTT and Transwell assays and SNHG6-specific binding with miR-101-3p was verified by bioinformatic analysis, luciferase gene report and RNA immunoprecipitation assays. qRT-PCR and Western blot was used to assess the effects of SNHG6 on the expression of miR-101-3p and chromodomain Y like (CDYL) in NSCLC cells. A xenograft tumor model in vivo was established to observe the effects of SNHG6 knockdown on tumor growth.

RESULTS

We found that increased expression of SNHG6 was associated with pathological stage and lymph node infiltration, and acted as an independent prognostic factor of tumor recurrence in patients with NSCLC. Silencing SNHG6 expression repressed cell growth and invasion in vitro and in vivo, but overexpression of SNHG6 reversed these effects. Furthermore, SNHG6 was identified to act as a sponge of miR-101-3p, which could reduce cell proliferation and attenuate SNHG6-induced CDYL expression. Low expression of miR-101-3p or high expression of CDYL was related to poor survival in patients with NSCLC.

CONCLUSIONS

Our findings demonstrated that lncRNA SNHG6 contributed to the proliferation and invasion of NSCLC by downregulating miR-101-3p.

Long noncoding RNA SNHG6 promotes proliferation and angiogenesis of cholangiocarcinoma cells through sponging miR-101-3p and activation of E2F8

Cholangiocarcinoma (CCA) development is an extremely complex process with alterations occurring in numerous genes. SNHG6, a validated lncRNA, has been reported to regulate the expression of multiple tumor-related genes in hepatocellular carcinoma, colorectal cancer and breast cancer. Here, we elucidated the function and possible molecular mechanisms of SNHG6 in human CCA cells. Our results proved that the expression SNHG6 was upregulated in CCA tissues and cell lines. Ectopic expression of SNHG6 promoted cell proliferation, cell cycle progression, migration, and angiogenesis in CCA cells, whereas knockdown of SNHG6 repressed these cellular processes. Further mechanistic studies revealed that SNHG6 could compete with the transcription factor E2F8 to bind with miR-101-3p, thus affecting E2F8 expression. Taken together, these results provided a comprehensive analysis of the role of SNHG6 in CCA cells and offered important clues to understand the key roles of competing endogenous RNA (ceRNA) mechanisms in human cholangiocarcinoma.

Long Noncoding RNA SNHG6 Functions as an Oncogene in Non-Small Cell Lung Cancer via Modulating ETS1 Signaling

Background

Non-small cell lung cancer (NSCLC) is a great threat to human health and the biology of the NSCLC still remains largely unknown. Aberrantly expressed long non-coding RNA (lncRNA) Small nucleolar RNA host gene 6 (SNHG6) was involved in the tumorigenesis and progression of various cancers. The aim of this study is to investigate the roles of SNHG6 in NSCLC.

Methods

qRT-PCR and Western blot assays were applied to detect gene expressions. Cell proliferation and migration assays were used to analyze the gene functions. Luciferase reporter assay, RNA Immunoprecipitation assay and Chromatin immunoprecipitation assay were performed to investigate the molecular mechanism.

Results

We found that SNHG6 expression was significantly increased in NSCLC tissues and cell lines and its high expression was correlated with malignant features of NSCLC. In in vitro assays, knockdown of SNHG6 significantly depressed the proliferation vitality and migration activity of NSCLC cells. Research on mechanisms revealed that SNHG6 exerted its tumorigenesis role by promoting ETS1 expression via competitively binding with miR-944 and miR-181d-5p. We also demonstrated that ETS1 enhanced the expression of WIPF1 via binding to its promoter and SNHG6 could thereby regulate the expression of ETS1 target genes including WIPF1, MMP2 and MMP9.

Conclusion

Our study illustrates that SNHG6 is an oncogene in NSCLC and involved in NSCLC tumorigenesis by regulating ETS1 signaling via miR-944 and miR-181d-5p.

Prognostic and clinicopathological significance of SNHG6 in human cancers: a meta-analysis

Background

Recently, accumulating evidence has suggested that the aberrant expression of SNHG6 exists in a variety of tumors and has a correlation with poor clinical outcomes across cancer patients. Considering the inconsistent data among published studies, we aim to assess the prognostic effect of SNHG6 on malignancies.

Methods

We retrieved relevant publications in Web of Science, Embase, MEDLINE, PubMed and Cochrane Library based on predefined selection criteria, up to October 1, 2019. Pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were utilized to evaluate the correlation between SNHG6 and overall survival (OS), recurrence-free survival (RFS) and progression-free survival (PFS) as well as clinicopathology.

Results

In total, 999 patients from 14 articles were enrolled in our meta-analysis. The results revealed that augmented SNHG6 expression was significantly correlated with poor OS (HR = 2.20, 95% CI = 1.76–2.75, P < 0.001) and RFS (HR = 3.10, 95% CI = 1.90–5.07, P < 0.001), but not with PFS (HR = 2.11, 95% CI = 0.82–5.39, P = 0.120). In addition to lung cancer and ovarian cancer, subgroup analysis showed that the prognostic value of SNHG6 across multiple tumors was constant as the tumor type, sample size, and methods of data extraction changed. Moreover, cancer patients with enhanced SNHG6 expression were prone to advanced TNM stage (OR = 3.31, 95% CI = 2.46–4.45, P < 0.001), distant metastasis (OR = 4.67, 95% CI = 2.98–7.31, P < 0.001), lymph node metastasis (OR = 2.59, 95% CI = 1.41–4.77, P = 0.002) and deep tumor invasion (OR = 3.75, 95% CI = 2.10–6.69, P < 0.001), but not associated with gender, histological grade and tumor size.

Conclusions

SNHG6 may serve as a promising indicator in the prediction of prognosis and clinicopathological features in patients with different kinds of tumors.

SNHG6 modulates oxidized low-density lipoprotein-induced endothelial cells injury through miR-135a-5p/ROCK in atherosclerosis

BACKGROUND

Plenty of long non-coding RNAs (lncRNAs) play vital roles in the progression of atherosclerosis. Small nucleolar RNA host gene 6 (SNHG6) is a well known lncRNA that is aberrantly high expressed in atherosclerosis patients. However, its function and basic mechanism in atherosclerosis events have not been well clarified.

METHODS

The expression patterns of SNHG6, miR-135a-5p, ROCK1 and ROCK2 in clinical samples and cells were detected by RT-qPCR assays. Cell Counting Kit-8 (CCK-8), flow cytometry assays, ELISA and reactive oxygen species (ROS) and malondialdehyde (MDA) detection, were performed to assess cell viability, apoptosis, inflammation and oxidative stress, respectively. Western blot analysis was carried out to examine the protein levels of Bax, Bcl-2, and SNHG6. Luciferase reporter and RIP assays were used to confirm the true interaction between SNHG6 and miR-135a-5p, or miR-135a-5p and ROCK.

RESULTS

The levels of SNHG6, ROCK1 and ROCK2 were notably increased and miR-135a-5p was decreased in atherosclerosis patients and oxidized low-density lipoprotein (ox-LDL)-treated HUVECs. Knockdown of SNHG6 alleviated ox-LDL-induced injury of HUVECs, while this effect was partly reversed by miR-135a-5p inhibitor. Moreover, overexpression of ROCKs aggravated miR-135a-5p-alleviated atherosclerosis cell injury. SNHG6 contributed to ROCK expression through sequestering miR-135a-5p as a molecular sponge.

CONCLUSION

SNHG6 functions as a promoter in atherosclerosis events by targeting miR-135a-5p/ROCK axis in ox-LDL-stimulated HUVECs. This finding will help to develop a novel therapeutic strategy for atherosclerosis.

Expression analysis of vitamin D receptor-associated lncRNAs in epileptic patients

Vitamin D has been vastly acknowledged as a neuroactive steroid controlling neurodevelopment. As it exerts its functions through activation of vitamin D receptor (VDR), several studies have assessed the role of VDR in brain function. More recently, a number of long non-coding RNAs (lncRNAs) have been recognized that alter expression of VDR. In the current study, we evaluated expression of four VDR-related lncRNAs (LINC00511, LINC00346, SNHG6 and SNHG16) in peripheral blood of 40 epileptic patients and 39 healthy subjects using quantitative real time PCR method. The relative expression levels of SNHG16 and LINC00511 were higher in epileptic patients compared with healthy subjects. For SNHG16, the difference was only significant between male patients and male controls, while LINC00511 had the opposite pattern. The results of Quantile regression model showed significant associations between SNHG6 and SNHG16 expressions and gender (P values of 0.027 and 0.009 respectively). Significant correlations were detected between expression levels of SNHG6 and SNHG16 (r = 0.32, P = 0.004), SNHG6 and LINC00346 (r = 0.37, P = 0.001), SNHG16 and LINC00346 (r = 0.30, P = 0.007) as well as SNHG16 and LINC00511 (r = 0.29, P = 0.009). Expression of LINC00346 was inversely correlated with vitamin D levels only in male epileptic patients (r = -0.58, P = 0.011). Expression of SNHG6 was correlated with vitamin D levels in male controls but no other subgroups (r = 0.51, P = 0.044). Based on the results of ROC curve analysis, SNHG16 had the diagnostic power of 0.86 in male subjects. Taken together, the current study provides evidences for dys-regulation of VDR-related lncRNAs in epileptic patients. The clinical significance of these finding should be explored in future studies.

lncRNA SNHG6 functions as a ceRNA to up-regulate c-Myc expression via sponging let-7c-5p in hepatocellular carcinoma

Emerging evidence has revealed that dysregulation of lncRNAs correlate with the development and progression of hepatocellular carcinoma (HCC). In the present study, we globally investigated the expression of SNHG6 in 31 cancer type, and we found that SNHG6 was highly expressed in various cancers, especially in HCC. High expression of SNHG6 was associated with progression and poor prognosis in patients with HCC. Gain of function and loss of function assays showed that SNHG6 promoted HCC cell proliferation. Gene Set Enrichment Analysis (GSEA) and correlation analysis suggested that SNHG6 positively correlated with c-Myc and its downstream targets. Ectopic overexpression of SNHG6 markedly increased the expression of c-Myc and its downstream targets, whereas silencing SNHG6 had the opposite effect on the expression of c-Myc and its downstream targets. Mechanistic assays revealed that SNHG6 acted as a competing endogenous RNA (ceRNA) to sponge let-7c-5p and thereby modulating the depression of c-Myc by let-7c-5p. Taken together, SNHG6 promotes HCC cell proliferation via competitively binding let-7c-5p in hepatocellular carcinoma.

LncRNA SNHG6 promotes chemoresistance through ULK1-induced autophagy by sponging miR-26a-5p in colorectal cancer cells

Background

Chemotherapy resistance is one of the main causes of recurrence in colorectal cancer (CRC) patients and leads to poor prognosis. Long noncoding RNAs (lncRNAs) have been reported to regulate chemoresistance. We aimed to determine the role of the lncRNA small nucleolar RNA host gene 6 (SNHG6) in CRC cell chemoresistance.

Methods

Cell drug sensitivity tests and flow cytometry were performed to analyze CRC cell chemoresistance. Animal models were used to determine chemoresistance in vivo, and micro RNA (miRNA) binding sites were detected by dual-luciferase reporter assays. Bioinformatics analysis was performed to predict miRNAs binding to SNHG6 and target genes of miR-26a-5p. SNHG6/miR-26a-5p/ULK1 axis and autophagy-related proteins were detected by qRT-PCR and western blotting. Furthermore, immunofluorescence was employed to confirm the presence of autophagosomes.

Results

SNHG6 enhanced CRC cell resistance to 5-fluorouracil (5-FU), promoted autophagy, inhibited 5-FU-induced apoptosis, and increased 5-FU resistance in vivo. Bioinformatics analysis showed that miR-26a-5p might bind to SNHG6 and target ULK1, and dual-luciferase reporter assays confirmed this activity. qRT-PCR and western blotting showed that SNHG6 was able to negatively regulate miR-26a-5p but correlated positively with ULK1.

Conclusion

SNHG6 may promote chemoresistance through ULK1-induced autophagy by sponging miR-26a-5p in CRC cells.

LncRNA SNHG6 functions as a ceRNA to regulate neuronal cell apoptosis by modulating miR-181c-5p/BIM signalling in ischaemic stroke

Long non‐coding RNAs (lncRNAs) play important roles in the pathogenesis of brain and neurodegenerative disorders. As far as we know, the functions and potential mechanisms of small nucleolar RNA host gene 6 (SNHG6) in ischaemic stroke have not been explored. This study aimed to examine the functional role of SNHG6 in the ischaemic stroke. Middle cerebral artery occlusion (MCAO) in mice and the oxygen glucose deprivation (OGD)‐induced injury in neuronal cells were applied to mimic ischaemic stroke. TTC staining, quantitative real‐time PCR, cell apoptosis assay, caspase‐3 activity assay, Western blot, RNA immunoprecipitation and luciferase reporter assay were performed to evaluate the function and possible mechanisms of SNHG6 in the pathogenesis of ischaemic stroke. The results show that SNHG6 expression was significantly increased both OGD‐induced neuronal cells and MCAO model mice. In vitro results showed that inhibition of SNHG6 increased cell viability, inhibited cell apoptosis and caspase‐3 activity in OGD‐induced neuronal cells. Consistently, knockdown of SNHG6 reduced brain infarct size and improved neurological scores in the MCAO mice. Mechanistic study further revealed that SNHG6 functioned as a competing endogenous RNA (ceRNA) for miR‐181c‐5p, which in turn repressed its downstream target of Bcl‐2 interacting mediator of cell death (BIM) and inhibiting cell apoptosis. This study revealed a novel function of SNHG6 in the modulating neuronal apoptosis in the ischaemic stroke model, and the role of SNHG6 in the regulating of neuronal apoptosis was at least partly via targeting miR‐181c‐5p/BIM signalling pathway.

Up-regulation of SNHG6 activates SERPINH1 expression by competitive binding to miR-139-5p to promote hepatocellular carcinoma progression

We aimed to assess the roles of small nucleolar RNA host gene 6 (SNHG6) in hepatocellular carcinoma (HCC) progression, and establish the lncRNA-miRNA-mRNA regulation mechanism for HCC therapy. SNHG6 is one of the host genes in small nucleolar RNAs (snoRNAs), which make a difference in the development of human cancers. SERPINH1 is a gene encoding a member of the serpin superfamily of serine proteinase inhibitors with miRNA predicted by TargetScan and DIANA Tools. SNHG6, serpin family H member 1 (SERPINH1) and miR-139-5p expression levels in HCC tissues and cells were determined by quantitative real-time PCR (qRT-PCR). Migration and invasion of HCC cells were measured by transwell assay. Cell cycle analysis was determined by using flow cytometry. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and colony formation assay were performed for cell viability analysis. The expression of SERPINH1 was detected by qRT-PCR and western blot. Dual-luciferase reporter gene assay was conducted to identify the targeted relationship between miR-139-5p and SNHG6, as well as SERPINH1 and miR-139-5p. The positive regulation between SNHG6 and SERPINH1 was demonstrated in this study. In contrast, miR-139-5p was significantly down-regulated in HCC cells, the inhibition of miR-139-5p promotes the proliferation of HCC cells, and accelerated the cell cycle of HCC cells. Our study demonstrated the co-expression of SNHG6 and SERPINH1 in HCC cells for the first time, which revealed that SNHG6 could serve as a novel oncogene for the HCC therapy by its regulation.

Long non-coding RNA SNHG6 promotes cell proliferation and migration through sponging miR-4465 in ovarian clear cell carcinoma

Dysregulation of small nucleolar RNA host gene 6 (SNHG6) exerts critical oncogenic effects and facilitates tumourigenesis in human cancers. However, little information about the expression pattern of SNHG6 in ovarian clear cell carcinoma (OCCC) is available, and the contributions of this long non‐coding RNA to the tumourigenesis and progression of OCCC are unclear. In the present study, we showed via quantitative real‐time PCR that SNHG6 expression was abnormally up‐regulated in OCCC tissues relative to that in unpaired normal ovarian tissues. High SNHG6 expression was correlated with vascular invasion, distant metastasis and poor survival. Further functional experiments demonstrated that knockdown of SNHG6 in OCCC cells inhibited cell proliferation, migration and invasion in vitro as well as tumour growth in vivo. Moreover, SNHG6 functioned as a competing endogenous RNA (ceRNA), effectively acting as a sponge for miR‐4465 and thereby modulating the expression of enhancer of zeste homolog 2 (EZH2). Taken together, our data suggest that SNHG6 is a novel molecule involved in OCCC progression and that targeting the ceRNA network involving SNHG6 may be a treatment strategy in OCCC.

Silencing of SNHG6 induced cell autophagy by targeting miR-26a-5p/ULK1 signaling pathway in human osteosarcoma

Background

lncRNAs have been proved to play crucial parts in various human cytopathology and cell physiology, including tumorigenesis. Down-regulated lncRNAs SNHG6 have shown great cell proliferation inhibitory effects in cancer development. Here we investigated how SNHG6 effected human osteosarcoma (OS) development and progression. Methods: Reverse transcription-quantitative PCR was performed to detect SNHG6 mRNA level in both OS tissues and cell lines. MTT and colony formation assays were used to determine the growth impact of SNHG6. Wound healing and trans-well assay were performed to measure the invasion effect of SNHG6. Western blotting were utilized to dissect molecular mechanisms.

Results

We identified SNHG6 as a lncRNAs that significantly up-regulated in OS tissues and cells, patients with high SNHG6 expression suffered more malignant metastasis and shorter survival times. Furthermore, silencing of SNHG6 in OS significantly inhibited OS cell growth, weakened cell invasion capacity, arrested cell cycle at G0/G1 phase, and induced cell apoptosis. Additionally, mechanism assays suggested that SNHG6 could competitively sponging miR-26a-5p thereby regulating ULK1, and induced cell apoptosis and autophagy by targeting caspase3 and ATF3. Conclusions: Our findings demonstrated that SNHG6 acted as an oncogene in osteosarcoma cells through regulating miR-26a-5p/ULK1 at a post-transcriptional level. SNHG6 might serve as a candidate prognostic biomarker and a target for novel therapies of osteosarcoma patients.

SNHG6 is upregulated in primary breast cancers and promotes cell cycle progression in breast cancer-derived cell lines

BACKGROUND

Long non-coding RNAs (lncRNAs) are known as RNAs that do not encode proteins and that are more than 200 nucleotides in size. Previously, it has been found that LncRNAs play crucial roles in normal cellular processes, including proliferation and apoptosis. A growing body of evidence suggests that lncRNAs may also play regulatory roles in the initiation, progression and metastasis of various malignancies, including breast cancer. SNHG6 is a lncRNA that has previously been found to contribute to the initiation and progression of hepatocellular and gastric carcinomas. In this study, the clinical significance of SNHG6 expression in breast cancer was investigated.

METHODS

SNHG6 expression in primary breast cancer tissues was assessed using RT-qPCR. The functional role of SNHG6 was investigated using RNAi-mediated silencing and exogenous overexpression in breast cancer-derived cells. MTT, colony formation, cell cycle, apoptosis and senescence assays were used to determine the impact of SNHG6 expression on breast cancer-derived cells. The effect of SNHG6 on the migration and epithelial-to-mesenchymal transition (EMT) of breast cancer-derived cells was determined using scratch wound healing and immunofluorescence assays, respectively.

RESULTS

We found that the expression of SNHG6 was significantly upregulated in primary high-grade and progesterone receptor (PR)-positive breast tumours. Additional siRNA-based experiments revealed that SNHG6 silencing led to G1 cell cycle arrest in SK-BR-3 and MDA-MB-231 breast cancer-derived cells. Moreover, we found that SNHG6 silencing led to suppressed breast cancer cell proliferation by inducing apoptosis and senescence. Our data also indicate that SNHG6 may contribute to the migration and EMT of breast cancer cells.

CONCLUSIONS

Our results indicate that lncRNA SNHG6 is involved in breast cancer development and may be considered as a potential biomarker for the diagnosis, prognosis and treatment of breast cancer.

Upregulation of long non-coding RNA SNHG6 promote esophageal squamous cell carcinoma cell malignancy and its diagnostic value

AIM

To investigate the expression of lncRNA SNHG6 in esophageal squamous cell carcinoma (ESCC), the biological function of SNHG6 in ESCCs, and evaluate its diagnostic value in ESCC.

METHODS

SNHG6 expression in tissues and cells was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The effect of SNHG6 on the cell proliferation, migration and invasion was detected by CCK-8 assay and transwell assay, respectively.

RESULTS

SNHG6 expression was upregulated in ESCC tissues and ESCCs. Upregulated SNHG6 expression was correlated with prognosis, lymph node metastasis, distant metastasis and TNM stage of ESCC patients. SNHG6 promoted the abilities of cell proliferation, migration and invasion in ESCCs, knockdown of SNHG6 reversed these effects. SNHG6 might serve as an independently diagnostic biomarker for lymph node metastasis, distant metastasis and TNM stage.

CONCLUSION

SNHG6 may exert oncogenic function in ESCC and may be a potential diagnostic marker for this cancer.

Long noncoding RNA SNHG6 functions as a competing endogenous RNA by sponging miR-181a-5p to regulate E2F5 expression in colorectal cancer

Background

Long noncoding RNAs (lncRNAs) have been identified as a novel class of regulators implicated in diverse biological processes in human cancers. Currently, evidence have shown that SNHG6, a cancer-associated lncRNA, exerts critical functions in gastric cancer and hepatocellular carcinoma; however, its role in colorectal cancer (CRC) remains unclear.

Methods

The expression of SNHG6 was determined by quantitative real-time PCR in CRC tissues and cells. SNHG6 was downregulated by using RNAi technology. Cell proliferation was examined by MTT and clone formation assays. Cell migration and invasion were determined by wound healing and transwell assays. Fluorescence in situ hybridization assays were performed to examine subcellular localization of SNHG6 in CRC cells. Fluorescence reporter and Western blot assays were used to explore the potential mechanisms of SNHG6 in CRC progression.

Results

In this study, we found that SNHG6 was significantly upregulated in CRC tissues and cell lines, compared with normal tissues and normal colorectal epithelial cell line NCM460, respectively. High expression of SNHG6 was positively correlated with tumor size, advanced TNM stage, and distant metastasis. Survival analyses revealed that SHNG6 was significantly associated with poor clinical outcomes and could serve as an independent prognostic factor. Loss-of-function studies demonstrated that SNHG6 knockdown inhibited CRC cell proliferation, induced G0/G1 arrest, promoted apoptosis, suppressed CRC cell migration and invasion, and restrained tumor growth. Mechanistic investigations showed that SNHG6 acted as a competing endogenous RNA for miR-181a-5p and attenuated the inhibitory effect of miR-181a-5p on E2F5.

Conclusion

Taken together, these results demonstrated that SNHG6 plays a crucial role in CRC progression via miR-181a-5p/E2F5 axis. Therefore, SNHG6 may serve as a prognostic and therapeutic biomarker in CRC.

lncRNA SNHG6 regulates EZH2 expression by sponging miR-26a/b and miR-214 in colorectal cancer

BACKGROUND

Abnormal expression of long non-coding RNAs (lncRNAs) has been found in almost all human tumors, providing numerous potential diagnostic biomarkers, prognostic biomarkers, and therapeutic targets.

METHODS

We analyzed RNA sequencing data to explore abnormally expressed lncRNAs in colorectal cancer (CRC). The functions of small nucleolar RNA host gene 6 (SNHG6) were investigated through in vitro and in vivo assays (CCK-8 assay, colony formation assay, flow cytometry assay, EdU assay, wound healing assay, transwell assay, and xenograft model). The mechanism of action of SNHG6 was explored through bioinformatics, RNA fluorescence in situ hybridization, luciferase reporter assay, RNA pull-down assay, chromatin immunoprecipitation assay, and RNA immunoprecipitation assay.

RESULTS

We identified aberrantly expressed lncRNAs in CRC. We found that elevated SNHG6 expression was associated with poor prognosis and CRC progression. We also demonstrated that the high SNHG6 expression was partly due to DNA copy number gains and SP1 induction. Functional studies showed that SNHG6 promoted CRC cell growth, migration, and invasion both in vitro and in vivo. Mechanistically, we found that SNHG6 expressed predominantly in the cytoplasm. SNHG6 could interact with miR-26a, miR-26b, and miR-214 and regulate their common target EZH2.

CONCLUSIONS

Our study elucidated that SNHG6 acted as an oncogene in CRC, which might serve as a novel target for CRC diagnosis and therapy.

LncRNA SNHG6 promotes proliferation, invasion and migration in colorectal cancer cells by activating TGF-β/Smad signaling pathway via targeting UPF1 and inducing EMT via regulation of ZEB1

Background: Long noncoding RNAs (lncRNAs) are non-protein coding transcripts longer than 200 nucleotides in length. They drive many important cancer phenotypes through their interactions with other cellular macromolecules including DNA, RNA and protein. Recent studies have identified numerous lncRNAs active in colorectal cancer (CRC). The lncRNA small nucleolar RNA host gene 6 (SNHG6) has been reported to have an oncogenic role in multiple cancers. However, the biological role and mechanism of SNHG6 in the tumorigenesis of CRC has not been reported in-deep. Methods: The Cancer Genome Atlas (TCGA) database and GEO database were used to identify SNHG6 expression in different human cancers and explore the relationship between SNHG6 expression and patient prognosis using Kaplan-Meier method analysis. SNHG6 expression in 77 pairs of clinical CRC tissues and different CRC cell lines were analyzed by quantitative real-time PCR (qRT-PCR). A CCK-8 assay was used to assess cell proliferation, transwell assay to detect the cell metastasis, and tumor growth was investigated with a nude mice model in vivo. Whether UPF1 and ZEB1 are downstream targets of SNHG6 was verified by bioinformatics target gene prediction, qRT-PCR and western blot. Results: TCGA data showed that SNHG6 was significantly upregulated in colorectal cancer samples in comparison with healthy data samples (P < 0.01). CRC patients with high levels of SNHG6 had a significantly shorter overall survival than those with low levels of SNHG6 (P = 0.0162). qRT-PCR confirmed that the expression of SNHG6 was significantly upregulated in CRC tissues and cell lines. Upregulation of SNHG6 expression induced RKO and HCT116 cell proliferation as well as RKO cell metastasis, while downregulation of SNHG6 expression supressed the proliferation and metastasis of RKO cells and tumor growth in vivo. UPF1 was upregulated and ZEB1 was decreased when SNHG6 knockdown, regulating the TGF-β/Smad pathway and inducing EMT respectively. Conclusions: SNHG6 may play an oncogenic role in CRC cells by activating TGF-β/Smad signaling pathway via targeting of UPF1 and inducing EMT via regulating ZEB1. This could be a prognostic biomarker and therapeutic target for CRC.

Assessment of functional variants and expression of long noncoding RNAs in vitamin D receptor signaling in breast cancer

Purpose

Vitamin D receptor (VDR) signaling pathway is implicated in the pathogenesis of breast cancer.

Patients and methods

We selected VDR-associated long noncoding RNAs (lncRNAs) through an in silico analysis of available microarray and RNA-sequencing data and assessed their expression in 75 breast tumor samples and their adjacent noncancerous tissues (ANCTs). We also genotyped two functional polymorphisms within VDR gene in all patients.

Results

VDR, MALAT1, and LINC00511 were significantly upregulated in tumoral tissues compared with ANCTs (fold change [FC] =1.85, P=0.03; FC =1.54, P=0.04; and FC =4.75, P=0.000, respectively). In patients younger than 55 years, significant associations were found between expression levels of both SNHG16 and LINC00511 genes and nuclear grade (P=0.03), expression of LINC00346 and tubule formation (P=0.01), expression of both SNHG16 and SNHG6 genes and family history of cancer (P=0.01 and 0.03, respectively), as well as expression of VDR and progesterone receptor status (P=0.03). We detected significant correlations between expression levels of VDR and SNHG16 in both tumoral tissues and ANCTs. The TT genotype of FokI polymorphism was associated with the higher expression levels of VDR. FokI variants were associated with expression levels of both MALAT1 and SNHG16 in ANCTs (P=0.01 and 0.03, respectively). CdxII variants were associated with expression levels of SNHG16 in ANCTs. A significant correlation was found between FC values of SNHG16 expression and vitamin D levels.

Conclusion

The present study provides further evidence for the contribution of VDR signaling and the related lncRNAs in the pathogenesis of breast cancer and introduces some novel lncRNAs as putative molecules in the interactive functional network of VDR signaling in breast cancer.