SET Binding Factor Research Articles

Knockdown of long non-coding RNA SBF2-AS1 inhibits calcium oxalate-induced HK-2 cell injury by regulating the miR-302e/NLRP3 pathway.

Long non-coding ribose nucleic acids (lncRNAs) have been implicated in the development of nephrolithiasis. The study aims to investigate the interplay of lncRNA SBF2-AS1 (SETbinding factor 2 antisense RNA 1) and NLR family pyrin domain containing 3 (NLRP3) in regulating the calcium oxalate monohydrate (COM)-induced human kidney HK-2 cell injury. HK-2 cells were treated with COM (100µg/mL) to create a cellular model of kidney injury. Gene and protein expression was assessed by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) and Western blot. Proliferation and apoptosis rates, as well as levels of malondialdehyde (MDA), lactate dehydrogenase (LDH), superoxide dismutase (SOD), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 were measured. Additionally, potential miRNAs interacting with SBF2-AS1 and NLRP3 were predicted utilizing the starBase and TargetScan databases. The interference of SBF2-AS1 resulted in increased cell proliferation and SOD levels in HK-2 cells after COM induction. SBF2-AS1 silencing also reduced COM-induced cell death and inflammatory cytokine production by down-regulating NLRP3 protein expression. Conversely, forced upregulation of NLRP3 abrogated the effect of SBF2-AS1 interference. Notably, SBF2-AS1 interference on COM-induced oxidative stress and COM-induced cellular damage was rescued by antioxidant, indicating the involvement of oxidative burden in COM-induced damage. miR-302e acted as a mediator miRNA linking the functional association of SBF2-AS1 and NLRP3. Silencing SBF2-AS1 promoted miR-302e level and miR-302e reduced NLRP3 expression in HK-2 cells to protect against COM-induced damage. In summary, these findings suggest that downregulation of lncRNA SBF2-AS1 can potentially protect HK-2 cells from COM-induced injury by modulating the miR-302e/NLRP3 pathway.

YBX1/lncRNA SBF2-AS1 interaction regulates proliferation and tamoxifen sensitivity via PI3K/AKT/MTOR signaling in breast cancer cells.

Y-box binding protein 1 (YBX1) is a multifunctional oncoprotein that can interact with several long non-coding RNAs (lncRNAs)to regulate metastasis in malignancies including breast cancer (BC). In the present study, we demonstrated the association of YBX1 with oncogenic lncRNA SBF2-AS1 (SET-binding factor 2 antisense RNA 1) via PI3K/AKT/mTOR signaling to regulate BC cell proliferation. We further explored the involvement of the YBX1/SBF2-AS1/PI3K/AKT/mTOR axis in the restoration of tamoxifen (TAM) sensitivity. YBX1-SBF2-AS1 association was predicted in silico and verified by RNA immunoprecipitation (RIP)-qPCR assay. Transfection experiments, Real-time RT PCR, Western blots, Phospho AKT/mTOR antibody array kit, and cell proliferation/apoptosis assays were employed to detect the YBX1/SBF2-AS1/ PI3K/AKT/mTOR axis and its effects upon TAM treatment in vitro. We identified that the YBX1 protein specifically binds to lncRNA SBF2-AS1. Our transfection experiments in MCF-7 and MDA-MB-468 cells with SBF2-AS1 silenced or overexpressed YBX1 plasmids, and their negative controls revealed that YBX1 regulates the expression of SBF2-AS1 by forming a positive feedback loop for its activation. We further demonstrated YBX1-SBF2-AS1 association exerts its effects on cell proliferation via PI3K/AKT/mTOR signaling pathway. Furthermore, we observed an increase in TAM sensitivity in BC cells after the knockdown of YBX1-SBF2-AS1 marked by decreased cell proliferation through disruption of the PI3K/AKT/mTOR axis. Our study has identified a novel YBX1/SBF2-AS1/PI3K/AKT/mTOR regulatory axis which may serve as a potential target to improve the effectiveness and efficacy of TAM treatment in BC.

Knockdown of LncRNA SBF2-AS1 Inhibited Gastric Cancer Tumorigenesis via the Wnt/LRP5 Signaling Pathway.

This investigation aimed to uncover the impact of a long noncoding RNA, SET-binding factor 2 antisense RNA1 (SBF2-AS1) on the malignant progression of gastric cancer (GC) and to further explore its underlying mechanism. SBF2-AS1 expression was quantified by qRT-PCR in GC cell lines and GC tissues. In vitro loss-of-function studies of SBF2-AS1, accompanied by flow cytometry, CCK-8, and cell invasion tests, were applied to elucidate the impact of SBF2-AS1 on the tumor progression of GC cells. Finally, Western blotting and a luciferase assay were used to detect WNT/LRP5 signaling pathway activation. SBF2-AS1 was aberrantly expressed in GC cell lines (p<0.05) and GC tissues (p<0.05). Cell invasive and proliferative capabilities were inhibited via SBF2-AS1 knockdown, resulting in apoptosis of NCI-N87 and MKN74 cells. Additionally, online database analysis uncovered a positive correlation between SBF2-AS1 and the Wnt/LRP5 signaling pathway (p<0.05). SBF2-AS1 knockdown blocked the Wnt/LRP5 signaling pathway, whereas the effects of SBF2-AS1 knockdown on the malignant genotype of MKN74 as well as NCI-N87 cells were partially restored by triggering the Wnt/ LRP5 signaling pathway. High expression of SBF2-AS1 was found in GC, the malignant progression of which was repressed via SBF2-AS1 knockdown by inhibiting the Wnt/LRP5 signaling pathway.

A (GCC) repeat in SBF1 reveals a novel biological phenomenon in human and links to late onset neurocognitive disorder

The human SBF1 (SET binding factor 1) gene, alternatively known as MTMR5, is predominantly expressed in the brain, and its epigenetic dysregulation is linked to late-onset neurocognitive disorders (NCDs), such as Alzheimer’s disease. This gene contains a (GCC)-repeat at the interval between + 1 and + 60 of the transcription start site (SBF1-202 ENST00000380817.8). We sequenced the SBF1 (GCC)-repeat in a sample of 542 Iranian individuals, consisting of late-onset NCDs (N = 260) and controls (N = 282). While multiple alleles were detected at this locus, the 8 and 9 repeats were predominantly abundant, forming > 95% of the allele pool across the two groups. Among a number of anomalies, the allele distribution was significantly different in the NCD group versus controls (Fisher’s exact p = 0.006), primarily as a result of enrichment of the 8-repeat in the former. The genotype distribution departed from the Hardy–Weinberg principle in both groups (p < 0.001), and was significantly different between the two groups (Fisher’s exact p = 0.001). We detected significantly low frequency of the 8/9 genotype in both groups, higher frequency of this genotype in the NCD group, and reverse order of 8/8 versus 9/9 genotypes in the NCD group versus controls. Biased heterozygous/heterozygous ratios were also detected for the 6/8 versus 6/9 genotypes (in favor of 6/8) across the human samples studied (Fisher’s exact p = 0.0001). Bioinformatics studies revealed that the number of (GCC)-repeats may change the RNA secondary structure and interaction sites at least across human exon 1. This STR was specifically expanded beyond 2-repeats in primates. In conclusion, we report indication of a novel biological phenomenon, in which there is selection against certain heterozygous genotypes at a STR locus in human. We also report different allele and genotype distribution at this STR locus in late-onset NCD versus controls. In view of the location of this STR in the 5′ untranslated region, RNA/RNA or RNA/DNA heterodimer formation of the involved genotypes and alternative RNA processing and/or translation should be considered.

LncRNA SBF2-AS1: A Budding Star in Various Cancers.

Long non-coding RNA (lncRNA) is a new kind of RNA with a length of over 200 nucleotides. Current frontiers revealed that lncRNAs implicate in various tumor progression, including tumorigenesis, proliferation, migration, invasion, metastasis, and angiogenesis. Recently discovered long non-coding RNA SETbinding factor 2 antisense RNA 1 (lncRNA SBF2-AS1), an oncogenic antisense RNA to SBF2, locates at 11p15.1 locus and is 2708 nt long. Accumulating evidence has demonstrated that lncRNA SBF2-AS1 participates in the progression of the various tumor, including pathogenesis, diagnosis, treatment, and prognosis of acute myeloid leukemia (AML), breast cancer (BC), cervical cancer (CC), clear cell renal cell carcinoma (ccRCC), colorectal cancer (CRC), diffuse large B-cell lymphoma (DLBCL), esophageal squamous cell carcinoma (ESCC), gastric cancer (GC), glioma, glioblastoma (GBM), hepatocellular carcinoma (HCC), lung cancer (LC), lung adenocarcinoma (LUAD), non-small cell lung cancer (NSCLC), osteosarcoma (OS), pancreatic cancer (PC), papillary thyroid cancer (PTC), small cell lung cancer (SCLC). Therefore, we summarized the underlying mechanisms of lncRNA SBF2-AS1 in various cancers to utilize its therapeutic function in target-selective treatment modalities.

LncRNA SBF2-AS1 Facilitates Nonsmall Cell Lung Cancer Progression by Targeting miR-520a-3p.

Background Long noncoding RNA (lncRNA) SET-binding factor 2 (SBF2) antisense RNA1 (SBF2-AS1), which acts as an oncogene in various cancers, can promote tumors progression. The study aimed to explore the role and molecular mechanism of SBF2-AS1 in nonsmall cell lung cancer (NSCLC). Methods qRT-PCR was introduced to detect SBF2-AS1 and miR-520a-3p expression in NSCLC. The effects of SBF2-AS1 and miR-520a-3p on the proliferation, migration, and invasion of NSCLC cells were assessed through cell counting kit-8 (CCK-8) and transwell assay. Furthermore, the relationship of SBF2-AS1 and miR-520a-3p was verified by the RNA immunoprecipitation (RIP) assay, dual-luciferase assay, and Spearman correlation analysis. Results In NSCLC tissues, SBF2-AS1 was highly expressed, while miR-520a-3p expression has decreased. The overall survival of NSCLC patients with high SBF2-AS1 expression was lower. SBF2-AS1 silencing repressed the proliferation, migration, and invasion of NSCLC cells. SBF2-AS1 directly interacted with miR-520a-3p, and a negative relationship was observed between their expression levels in NSCLC tissues. More importantly, the suppression of SBF2-AS1 silencing on the proliferation, migration, and invasion in NSCLC cells was counteracted by miR-520a-3p inhibition. Conclusion SBF2-AS1 accelerated the proliferation, migration, and invasion of NSCLC cells via mediating miR-520a-3p, thus promoting NSCLC progression.

The impact of SBF2 on taxane-induced peripheral neuropathy.

Taxane-induced peripheral neuropathy (TIPN) is a devastating survivorship issue for many cancer patients. In addition to its impact on quality of life, this toxicity may lead to dose reductions or treatment discontinuation, adversely impacting survival outcomes and leading to health disparities in African Americans (AA). Our lab has previously identified deleterious mutations in SET-Binding Factor 2 (SBF2) that significantly associated with severe TIPN in AA patients. Here, we demonstrate the impact of SBF2 on taxane-induced neuronal damage using an ex vivo model of SBF2 knockdown of induced pluripotent stem cell-derived sensory neurons. Knockdown of SBF2 exacerbated paclitaxel changes to cell viability and neurite outgrowth while attenuating paclitaxel-induced sodium current inhibition. Our studies identified paclitaxel-induced expression changes specific to mature sensory neurons and revealed candidate genes involved in the exacerbation of paclitaxel-induced phenotypes accompanying SBF2 knockdown. Overall, these findings provide ex vivo support for the impact of SBF2 on the development of TIPN and shed light on the potential pathways involved.

Silencing of SBF2-AS1 inhibits cell growth and invasion by sponging microRNA-338-3p in serous ovarian carcinoma.

Long noncoding RNA SET-binding factor 2 (SBF2) antisense RNA 1 (AS1) is associated with the growth and metastasis of multiple cancer types, but its biological roles in serous ovarian carcinoma (SOC) remain unclear. In this study, the aberrant upregulation of SBF2-AS1 is detected in SOC after analysis of differentially expressed genes between SOC tissues and normal fallopian tubes from the public Gene Expression Omnibus (GEO) database. We determine that knockdown of SBF2-AS1 inhibits SOC cell proliferation and invasion by sponging miR-338-3p. MiR-338-3p acts as a tumor suppressor in SOC, and E26 transformation specific-1 (ETS1) is identified as a potential target of miR-338-3p regulation. Furthermore, SBF2-AS1 could modulate ETS1 by operating as a competing endogenous RNA for miR-338-3p. This finding elucidates a new mechanism for SBF2-AS1 in SOC development and provides a potential target for SOC therapeutic intervention.

Distinct roles for the Charcot-Marie-Tooth disease-causing endosomal regulators Mtmr5 and Mtmr13 in axon radial sorting and Schwann cell myelination.

The form of Charcot-Marie-Tooth type 4B (CMT4B) disease caused by mutations in myotubularin-related 5 (MTMR5; also called SET binding factor 1, SBF1) shows a spectrum of axonal and demyelinating nerve phenotypes. This contrasts with the CMT4B subtypes caused by MTMR2 or MTMR13 (SBF2) mutations, which are characterized by myelin outfoldings and classic demyelination. Thus, it is unclear whether MTMR5 plays an analogous or distinct role from that of its homolog, MTMR13, in the peripheral nervous system (PNS). MTMR5 and MTMR13 are pseudophosphatases predicted to regulate endosomal trafficking by activating Rab GTPases and binding to the phosphoinositide 3-phosphatase MTMR2. In the mouse PNS, Mtmr2 was required to maintain wild-type levels of Mtmr5 and Mtmr13, suggesting that these factors function in discrete protein complexes. Genetic elimination of both Mtmr5 and Mtmr13 in mice led to perinatal lethality, indicating that the two proteins have partially redundant functions during embryogenesis. Loss of Mtmr5 in mice did not cause CMT4B-like myelin outfoldings. However, adult Mtmr5-/- mouse nerves contained fewer myelinated axons than control nerves, likely as a result of axon radial sorting defects. Consistently, Mtmr5 levels were highest during axon radial sorting and fell sharply after postnatal day seven. Our findings suggest that Mtmr5 and Mtmr13 ensure proper axon radial sorting and Schwann cell myelination, respectively, perhaps through their direct interactions with Mtmr2. This study enhances our understanding of the non-redundant roles of the endosomal regulators MTMR5 and MTMR13 during normal peripheral nerve development and disease.

The Clinical Prognostic Value of lncRNA SBF2-AS1 in Cancer Patients: A Meta-Analysis.

Background:The mortality and recurrence of patients with cancer is of high prevalence. SET-binding factor 2 (SBF2) antisense RNA1 (lncRNA-SBF2-AS1) is a promising long non-coding RNA. There is increasing evidence that SBF2-AS1 is abnormally expressed in various tumors and is associated with cancer prognosis. However, the identification of the effect of lncRNA SBF2-AS1 in tumors remains necessary.Materials and Methods:Up to November 2, 2020, electronic databases, including PubMed, Cochrane Library, EMBASE, Medline, and Web of Science, were searched. The results were evaluated by pooled odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs).Results:A total of 11 literatures on cancer patients were included for the present meta-analysis. The combined results revealed that high expression of SBF2-AS1 was significantly associated with unfavorable overall survival (OS) (HR = 1.48, 95% CI: 1.34-1.62, P < 0.00001) in a variety of cancers. In additional, the increase in SBF2-AS1 expression was also correlated with tumor size ((larger vs. smaller) OR = 2.34, 95% CI: 1.47-3.70, P = 0.0003), advanced TNM stage ((III/IV vs. I/II) OR = 2.78, 95% CI: 1.75-4.41, P < 0.0001), lymph node metastasis ((Positive vs. Negative) OR = 3.06, 95% CI: 1.93-4.86, P < 0.00001), and histological grade ((poorly vs. well/moderately) OR = 2.58, 95% CI: 1.47-4.52, P = 0.001) in patients with cancer. Furthermore, The Cancer Genome Atlas (TCGA) dataset valuated that SBF2-AS1 was upregulated in a variety of tumors, and predicted the worse prognosis.Conclusions:Our results of this meta-analysis demonstrate that high SBF2-AS1 expression may become a potential target for predicting the prognosis of human cancers.

Prognostic Value of Immune-Related lncRNA SBF2-AS1 in Diffuse Lower-Grade Glioma.

LncRNA SET-binding factor 2 (SBF2) antisense RNA1 (SBF2-AS1) has been proven to play an oncogenic role in various types of tumors, but the prognostic role of SBF2-AS1 in tumors, especially in diffuse lower-grade glioma (LGG), is still unclear. Here, we aimed to investigate the prognostic value of SBF2-AS1 in LGG. The LGG expression profiles from The Cancer Genome Atlas (TCGA, n = 524) and Chinese Glioma Genome Atlas (CGGA, n = 431) were mined by Kaplan-Meier analysis, Cox regression analysis, Chi-square test and GSEA analysis. Through Kaplan-Meier analysis, we found the prognosis of LGG patients with high expression of SBF2-AS1 were worse than that of patients with low expression (Log Rank P < 0.001). Cox analysis showed SBF2-AS1 was an independent prognostic factor for poorer overall survival in LGG (P < 0.05). SBF2-AS1 was found to be significantly related to IDH mutation status and SBF2-AS1 was highly expressed in IDH wildtype group. GSEA analysis obtained a total of 126 GO terms and 6 KEGG pathways that were significantly enriched in SBF2-AS1 high expression phenotype (NOM P value < 0.05). We found these 126 GO terms and KEGG pathways were mainly related to immunity. In conclusion, lncRNA SBF2-AS1 expression is an immune-related lncRNA associated with unfavorable overall survival in LGG. SBF2-AS1 could be a reliable prognostic biomarker for patients with LGG.

Long noncoding RNAs SET-binding factor 2-antisense RNA1 promotes cell growth through targeting miR-431-5p/CDK14 axis in human papillary thyroid cancer.

Papillary thyroid cancer (PTC) is a frequent thyroid malignancy. With the significant regulatory role in tumor progression, more attention has been employed to investigate mechanism of long noncoding RNAs (lncRNAs) in progression of PTC. We prospectively explored the mechanism whereby lncRNA SET-binding factor 2-antisense RNA1 (SBF2-AS1) is implicated in pathogenesis of PTC. First, differentially expressed SBF2-AS1 between PTC and normal adjacent thyroid tissues was determined, and result indicated a higher SBF2-AS1 expression in PTC tissues than adjacent normal tissues. Moreover, highly SBF2-AS1 expression predicted a poor prognosis in PTC patients. Second, SBF2-AS1 overexpression promoted cell viability and cycle of PTC, while inhibited cell apoptosis. However, SBF2-AS1 downregulation reduced viability and cycle, while promoted cell apoptosis. Moreover, SBF2-AS1 could bind with miR-431-5p and showed negative correlation with miR-431-5p in PTC patients. Furthermore, miR-431-5p bind with cyclin-dependent kinase (CDK) 14 and showed negative correlation with CDK14 in PTC patients. Finally, overexpression of CDK14 counteracted with the inhibitory role of SBF2-AS1 downregulation on cell viability, cycle, and apoptosis of PTC. In conclusion, SBF2-AS1 exhibited oncogenic property in PTC, and knockdown of SBF2-AS1 could be a therapeutic strategy for PTC.

Genetic Factors Associated with Toe Walking in Children

The article describes genetic factors associated with toe walking in children. Association of gait abnormality with variants in genes listed below is shown: PMP22 (peripheral myelin protein 22), EGR2 (early growth response protein 2), AIFM1 (apoptosis inducing factor mitochondria associated 1), MORC2 (member of the Microrchidia family CW-type zinc finger 2), DHTKD1 (dehydrogenase E1 and transketolase domain containing 1), GDAP1 (ganglioside induced differentiation associated protein 1), KIF1B (kinesin family member 1B), FGD4 (FYVE, RhoGEF and PH domain containing 4), SBF2 (SET binding factor 2), SH3TC2 (SH3 domain and tetratricopeptide repeats 2), NAGLU (N-acetyl-alpha-glucosaminidase), NEFL (neurofilament light) и PRX (periaxin). Genetic testing of patients with toe walking is crucial for accurate diagnostics of this pathology as well as clinical examination.

Down-regulated lncRNA SBF2-AS1 in M2 macrophage-derived exosomes elevates miR-122-5p to restrict XIAP, thereby limiting pancreatic cancer development.

Evidence has indicated that M2 macrophages promote the progression of cancers, but few focus on the ability of M2 macrophage‐derived exosomes in pancreatic cancer (PC). This study aims to explore how M2 macrophages affect malignant phenotypes of PC through regulating long non‐coding RNA SET‐binding factor 2 antisense RNA 1 (lncRNA SBF2‐AS1)/microRNA‐122‐5p (miR‐122‐5p)/X‐linked inhibitor of apoptosis protein (XIAP) axis. THP‐1 cells were transformed into M1 macrophages by lipopolysaccharide and interferon‐γ treatment, and into M2 macrophages after interleukin‐4 treatment. The PANC‐1 PC cell line with the largest lncRNA SBF2‐AS1 expression was selected, and M2 macrophage‐derived exosomes were isolated and identified. A number of assays were applied for the examination of lncRNA SBF2‐AS1 expression, PC cell biological functions and subcellular localization of lncRNA SBF2‐AS1. XIAP expression was detected, along with the interaction among lncRNA SBF2‐AS1, miR‐122‐5p and XIAP. M2 macrophage exosomal lncRNA SBF2‐AS1 expression's effects on the tumorigenic ability of PANC‐1 cells in nude mice were also investigated. M2 macrophage‐derived exosomes promoted progression of PC cells. Overexpressed lncRNA SBF2‐AS1 promoted progression of PC cells. LncRNA SBF2‐AS1 was found to act as a competing endogenous RNA to repress miR‐122‐5p and up‐regulate XIAP. Constrained lncRNA SBF2‐AS1 in M2 macrophage‐derived exosomes contributed to restraining tumorigenic ability of PC cells. Collectively, our study reveals that constrained lncRNA SBF2‐AS1 in M2 macrophage‐derived exosomes increases miR‐122‐5p expression to restrain XIAP expression, which further inhibits PC progression.

Down-regulated lncRNA SBF2-AS1 inhibits tumorigenesis and progression of breast cancer by sponging microRNA-143 and repressing RRS1

BackgroundRecently, the roles of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in human diseases have been unveiled, this research was conducted to explore the impacts of lncRNA SET-binding factor 2-antisense RNA1 (SBF2-AS1), miR-143 and resistance to ralstonia solanacearum 1 (RRS1) on breast cancer (BC) development.MethodsThe expression of SBF2-AS1, miR-143 and RRS1 in BC tissues, as well as in MDA-MB-231 and MCF-7 cell lines were assessed. Subsequently, the cells were transfected with miR-143 mimics or/and silenced or overexpressed SBF2-AS1 plasmids, and their negative controls. Then the proliferation, colony formation ability, cell cycle arrest, apoptosis, invasion and migration of the cells were assessed through gain- and loss-of-function experiments. Furthermore, the tumor growth, ki-67 expression and apoptosis in vivo were observed by subcutaneous tumorigenesis in nude mice. Binding relation between SBF2-AS1 and miR-143, and that between miR-143 and RRS1 were confirmed.ResultsSBF2-AS1 and RRS1 were amplified, while miR-143 was reduced in BC tissues and cells. Reduced SBF2-AS1 and elevated miR-143 could repress the proliferation, invasion and migration via restraining RRS1 expression. Moreover, knockdown of SBF2-AS1 up-regulated miR-143 to promote the apoptosis of BC cells by downregulating RRS1, resulting in a prohibitive effect on the tumorigenesis and progression of BC. Results of in vivo experiments indicated that the inhibited SBF2-AS1 and overexpressed miR-143 could restrict BC cell proliferation and promote apoptosis, and decelerate tumor growth in xenografts.ConclusionWe have discovered in this study that down-regulated SBF2-AS1 could inhibit tumorigenesis and progression of BC by up-regulation miR-143 and repressing RRS1, which provides basic therapeutic considerations for a novel target against BC.

Overexpression of long non-coding RNA SBF2-AS1 promotes cell progression in esophageal squamous cell carcinoma (ESCC) by repressing miR-494 to up-regulate PFN2 expression.

Esophageal squamous cell carcinoma (ESCC) is an intractable esophageal cancer caused by smoking, alcohol consumption and nutritional deficiencies. Recently, long non-coding RNA SET-binding factor 2 antisense RNA 1 (SBF2-AS1) was validated as an oncogene in multiple cancers. However, the mechanism of SBF2-AS1 in ESCC progression is poorly understood. In the present research, we found that the expression of SBF2-AS1 and PFN2 was up-regulated, while miR-494 was down-regulated in ESCC tumors and cells using quantitative real-time polymerase chain reaction (qRT-PCR). 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay and transwell assay demonstrated that silencing of SBF2-AS1 suppressed proliferation, migration and invasion. Moreover, western blot showed that SBF2-AS1 deletion also inhibited epithelial to mesenchymal transition (EMT) by detecting MMP9, Vimentin and E-cadherin protein expression. We confirmed that miR-494 was a target of SBF2-AS1 by luciferase reporter system, RIP and RNA pull-down assay. In addition, miR-494 inhibitor reversed the repression induced by SBF2-AS1 silencing on ESCC cell proliferation, migration, invasion and EMT. Furthermore, PFN2 was negatively regulated by miR-494. Besides, restoration of PFN2 inversed the inhibition effects on cell proliferation, migration, invasion and EMT induced by SBF2-AS1 silencing in ESCC. In conclusion, SBF2-AS1 contributed to cell proliferation, migration, invasion and EMT in ESCC by enhancing PFN2 expression via sponging miR-494, providing promising biomarkers for ESCC diagnosis and treatment.

Long non-coding RNA SBF2-AS1 promotes hepatocellular carcinoma progression through regulation of miR-140-5p-TGFBR1 pathway

A growing number of studies has suggested that long non-coding RNAs (lncRNAs) exert essential roles in the development and progression of hepatocellular carcinoma (HCC). However, the roles of lncRNA and its molecular mechanism in HCC are largely unknown. In the present study, the functions and molecular mechanisms of a novel lncRNA, SET-binding factor 2 (SBF2) antisense RNA1 (SBF2-AS1), were investigated in HCC tissues and cell lines. We found that the expression levels of SBF2-AS1 were significantly up-regulated in HCC tissues and correlated with poor prognosis. SBF2-AS1 knockdown could inhibit the proliferation of HCC cells and attenuate the development of HCC tumor in vivo. Moreover, wound healing and Transwell assays revealed that down-regulation of SBF2-AS1 suppressed the migration and invasion of HCC cells by modulating epithelial-mesenchymal transition (EMT) ability. Mechanistically, we observed that SBF2-AS1 served as a competing endogenous RNA (ceRNA) of miR-140–5p. Subsequently, transforming growth factor beta receptor 1 (TGFBR1) was certified as a direct target of miR-140–5p and enforcing SBF2-AS1 expression elevated TGFBR1 expression in HCC. Taken together, our study suggested that SBF2-AS1 modulated TGFBR1 through sponging miR-140–5p in HCC development and progression indicating that SBF2-AS1 might be further chosen as a potential anticancer therapeutic target and a promising prognostic biomarker for HCC.

Upregulated long non-coding RNA SBF2-AS1 promotes proliferation in esophageal squamous cell carcinoma.

Esophageal cancer is one of the most common types of malignant tumors located within the digestive system, with >50% of esophageal cancer cases worldwide occurring in China. Recent studies have demonstrated that long non-coding RNAs (lncRNAs) are frequently dysregulated in cancer; however, few lncRNAs have been characterized in esophageal squamous cell carcinoma (ESCC). In the present study, a novel lncRNA, SET-binding factor 2 (SBF2) antisense RNA1 (SBF2-AS1) was exhibited in ESCC. Expression levels of SBF2-AS1 in ESCC and adjacent non-cancerous tissues were detected using the reverse transcription-quantitative polymerase chain reaction. SBF2-AS1 was knocked down, and proliferation, migration, invasion, apoptosis and the cell cycle were examined in ESCC cells. Results identified that SBF2-AS1 was significantly upregulated in ESCC compared with adjacent non-cancerous tissues (fold increase, 8.82; P=0.023). The SBF2-AS1 expression level was significantly increased in patients who had a smoking (9.927 vs. 4.507; P=0.030) and/or drinking (10.938 vs. 4.232; P=0.032) history. Patients with a large tumor size exhibited increased SBF2-AS1 expression (≥4 vs. <4 cm, 14.898 vs. 5.435; P=0.018). Patients with advanced ESCC exhibited increased upregulation of SBF2-AS1 [tumor-node-metastasis (TNM) I-II vs. TNM III-IV, 1.302 vs. 15.475; P<0.01]. SBF2-AS1 was also silenced using small interfering RNA. Cell proliferative and invasive ability were significantly inhibited (P<0.05) following SBF2-AS1 silencing, the cell cycle was arrested in the G2 phase; however, there was no significant difference in the proportion of apoptotic cells. Gene Set Enrichment Analysis revealed that genes associated with cell cycle biological processes, including the cancer suppressor gene cyclin-dependent kinase 1A (CDKN1A), were significantly associated with SBF2-AS1 in ESCC tissues. Further validation confirmed that CDKN1A expression levels were increased in ECA-109 cells following SBF2-AS1 silencing. The results of the present study demonstrate that SBF2-AS1 is significantly upregulated in ESCC, and that silencing of SBF2-AS1 inhibits the proliferative and invasive ability of ESCC cells. SBF2-AS1 may be a novel biomarker and therefore a potential therapeutic target for ESCC.

Low expression of microRNA-1908 predicts a poor prognosis for patients with ovarian cancer.

MicroRNAs (miRs) serve important roles in cancer genesis and progression. The expression of miR-1908 has been reported in a number of types of cancer; however, the clinical significance of miR-1908 in human ovarian cancer (OC) remains unclear. A total of 491 patients with OC from The Cancer Genome Atlas project cohort were selected and divided into two groups according to the median expression level of miR-1908. Univariate and multivariate analyses, using the Kaplan-Meier method and Cox regression, were performed to identify the characteristics that predict OC prognosis. Bioinformatics tools were used to identify potential targets of miR-1908. It was identified that the low expression of miR-1908 is associated with a poor prognosis for OC (P<0.05). The potential target genes of miR-1908 included podocan-like 1, JunB AP-1 transcription factor subunit, homeobox B8, SET binding factor 1 and sirtuin 2; high expression of these five genes additionally predicted a poor prognosis. These results suggest that miR-1908 may be a suitable target for the development of novel approaches in OC diagnosis and therapy in the future.

Abstract IA09: Impact of genetically determined race on outcomes in E5103

Abstract Background: African Americans (AAs) have inferior breast cancer outcomes. AAs have a higher percentage of the poor prognosis triple negative breast cancer subtype and also have inferior relative benefit from chemotherapy when compared to other races. While some of the disparity may be due to socio-economic factors, the underlying biology of the tumor may also play a pivotal role. Using ancestry informative markers, we have evaluated race-specific outcomes and various therapy-induced side effects in the adjuvant breast cancer trial, E5103. We have further explored the roles of germline genetic biomarkers to predict the increased risk for the most common chemotherapy induced toxicity; taxane-induced peripheral neuropathy (TIPN) in AAs. Methods: E5103 was a phase III adjuvant breast cancer trial that randomized 4,994 patients with node-positive or high risk node-negative breast cancer to intravenous doxorubicin and cyclophosphamide every 2 or 3 weeks for four cycles followed by 12 weeks of weekly paclitaxel alone (Arm A) or to the same chemotherapy with either concurrent bevacizumab (Arm B) or concurrent plus sequential bevacizumab (Arm C). Germline (blood) DNA and clinical data were available from 3394 patients across all arms. Genome-wide analyses were performed in these patients and race was determined by principle components analysis (PCA). Clinical outcome and the occurrence of therapy-induced toxicities were compared in genetically defined AAs against other races. Germline biomarkers were evaluated to predict the risk of TIPN in AAs through a genome wide association study (for common variants) and through whole exome sequencing (for rare variants). Results: PCA determined 386 AAs among 3394 available patients from E5103. Compared to other races, AA patients had an inferior disease free survival. AAs were also more likely to experience the most common, severe side effects from each of the agents used in E5103, including: CTCAE v 4.0 grade 3-4 TIPN (p=2.4 × 10-11; OR=2.9) and grade 3-4 bevacizumab induced hypertension (p=0.002; OR=1.6). Despite a small number of events, the same trend was observed for anthracycline induced congestive heart failure (p=0.08, OR=1.8). The genome wide study identified several germline biomarkers that impacted the risk of TIPN specific to AAs. Specifically, a SNP in FCAMR demonstrated a trend toward decreased risk of grade 2-4 TIPN in AAs (p-value=2.8 × 10-7). Whole exome sequencing revealed an association between deleterious rare variants in SET binding factor 2 (SBF2) with a marked increased risk of grade 3-4 TIPN in AAs (p-value=4.35 × 10-6). Conclusion: AA breast cancer patients had an inferior DFS and were more likely to experience bevacizumab-induced hypertension, TIPN, and anthracycline-induced congestive heart failure compared with other races in E5103. Germline biomarkers for predicting the risk of TIPN, pending validation in independent trials, can drastically impact counseling patients for the likelihood of this toxicity. Citation Format: Bryan Paul Schneider. Impact of genetically determined race on outcomes in E5103. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr IA09.