SOX1 inhibits breast cancer cell growth and invasion through suppressing the Wnt/β-catenin signaling pathway

Tumor suppressor function of RBMS3 overexpression in EOC associated with immune cell infiltration

Objectives

Epithelial ovarian cancer (EOC) is considered to be a prevalent female malignancy with both high incidence and mortality. It is reported that RNA-binding protein 3 (RBMS3) executives a tumor suppressor function in different cancers. This investigation was designed to examine the expression of RBMS3 in epithelial ovarian cancer, the effects on EOC cells, and its connection to immune cells that infiltrate tumors in the EOC microenvironment.

Methods

The expression levels of RBMS3 in EOC tissues as well as their correlations with immune cell infiltration and clinical outcome were examined using bioinformatics approaches. Western blotting as well as immunohistochemistry were carried out to determine the protein levels in EOC tissues. In addition, qRT-PCR was employed to look at the expression of the mRNA. The role of RBMS3 in EOC cells was investigated, and an RBMS3 lentiviral vector was developed. The effects of RBMS3 on subcutaneous tumor development, the proliferation protein Ki-67, the tumor angiogenesis indicator CD31, and its function in controlling the tumor immune microenvironment were evaluated by in vivo tests.

Results

There was a considerable decrease in RBMS3 expression in EOC tissues, which was linked to a poor prognosis for patients and the infiltration of multiple immune cell. Given immunohistochemical studies, tissues with increased RBMS3 expression had decreased markers of myeloid-derived suppressor cells, regulatory T cells, and M2 macrophages, whereas M1 macrophage markers were elevated. RBMS3 appears to suppress the capabilities of proliferating, invading, and migrating in EOC cells according to in vitro tests, whereas tumors overexpressing RBMS3 developed more slowly in syngeneic mouse models. The overexpression of RBMS3 led to a decline in the levels of Ki-67 protein and CD31. Additionally, it showed a negatively correlation with markers of regulatory T cell, myeloid-derived suppressor cell, and M2 macrophage but a positive correlation with markers of M1 macrophage.

Conclusions

The findings revealed that elevated RBMS3 expression plays a tumor suppressor role in EOC and was connected to patient survival in EOC. The studies conducted in vitro and in vivo demonstrated a link between RBMS3 expression and the infiltration of certain immune cells, indicating a function for RBMS3 in the immunosuppressive tumor microenvironment and its promising efficiency as a novel target for immunotherapy against EOC.

MicroRNA-155 and cancer metastasis: Regulation of invasion, migration, and epithelial-to-mesenchymal transition

Among the leading causes of death globally has been cancer. Nearly 90% of all cancer-related fatalities are attributed to metastasis, which is the growing of additional malignant growths out of the original cancer origin. Therefore, a significant clinical need for a deeper comprehension of metastasis exists. Beginning investigations are being made on the function of microRNAs (miRNAs) in the metastatic process. Tiny non-coding RNAs called miRNAs have a crucial part in controlling the spread of cancer. Some miRNAs regulate migration, invasion, colonization, cancer stem cells' properties, the epithelial-mesenchymal transition (EMT), and the microenvironment, among other processes, to either promote or prevent metastasis. One of the most well-conserved and versatile miRNAs, miR-155 is primarily distinguished by overexpression in a variety of illnesses, including malignant tumors. It has been discovered that altered miR-155 expression is connected to a number of physiological and pathological processes, including metastasis. As a result, miR-155-mediated signaling pathways were identified as possible cancer molecular therapy targets. The current research on miR-155, which is important in controlling cancer cells' invasion, and metastasis as well as migration, will be summarized in the current work. The crucial significance of the lncRNA/circRNA-miR-155-mRNA network as a crucial regulator of carcinogenesis and a player in the regulation of signaling pathways or related genes implicated in cancer metastasis will be covered in the final section. These might provide light on the creation of fresh treatment plans for controlling cancer metastasis.

SOX1 acts as a tumor hypnotist rendering nasopharyngeal carcinoma cells refractory to chemotherapy

SOX1, a well-known tumor suppressor, delays malignant progression in most cancer types. However, high expression of SOX1 in late-stage head and neck squamous cell carcinoma leads to poor prognosis. In this study, we show that SOX1 induces nasopharyngeal carcinoma (NPC) cells to enter a quiescent state. Using a model that mimics therapeutic resistance and tumor recurrence, a subpopulation of SOX1-induced NPC cells is refractory to paclitaxel, a cell cycle-specific chemotherapy drug. These cells maintain a quiescent state with decreased translational activity and down-regulated cell growth potential. However, once SOX1 expression is decreased, the NPC cells recover and enter a proliferative state. The chemotherapy resistance induced by SOX1 can not pass to next generation, as the cells that undergo re-proliferation become sensitive to paclitaxel again. Moreover, SOX1 directly binds to the promoter region of the MYC gene, leading to transcriptional suppression. When switching to a paclitaxel-free culture environment, the cells with decreased levels of SOX1 re-express MYC, resulting in increased abundance of proliferative cancer cells. Our study presents an evolutionary trade-off between tumor growth and chemoresistance orchestrated by SOX1-MYC in NPC. Basing on the dynamic role of SOX1 in different stages of cancer development, SOX1 would be regarded as a "tumor hypnotist".

Identifying C1QB, ITGAM, and ITGB2 as potential diagnostic candidate genes for diabetic nephropathy using bioinformatics analysis

Background

Diabetic nephropathy (DN), the most intractable complication in diabetes patients, can lead to proteinuria and progressive reduction of glomerular filtration rate (GFR), which seriously affects the quality of life of patients and is associated with high mortality. However, the lack of accurate key candidate genes makes diagnosis of DN very difficult. This study aimed to identify new potential candidate genes for DN using bioinformatics, and elucidated the mechanism of DN at the cellular transcriptional level.

Methods

The microarray dataset GSE30529 was downloaded from the Gene Expression Omnibus Database (GEO), and the differentially expressed genes (DEGs) were screened by R software. We used Gene Ontology (GO), gene set enrichment analysis (GSEA), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis to identify the signal pathways and genes. Protein-protein interaction (PPI) networks were constructed using the STRING database. The GSE30122 dataset was selected as the validation set. Receiver operating characteristic (ROC) curves were applied to evaluate the predictive value of genes. An area under curve (AUC) greater than 0.85 was considered to be of high diagnostic value. Several online databases were used to predict miRNAs and transcription factors (TFs) capable of binding hub genes. Cytoscape was used for constructing a miRNA-mRNA-TF network. The online database 'nephroseq' predicted the correlation between genes and kidney function. The serum level of creatinine, BUN, and albumin, and the urinary protein/creatinine ratio of the DN rat model were detected. The expression of hub genes was further verified through qPCR. Data were analyzed statistically using Student's t-test by the 'ggpubr' package.

Results

A total of 463 DEGs were identified from GSE30529. According to enrichment analysis, DEGs were mainly enriched in the immune response, coagulation cascades, and cytokine signaling pathways. Twenty hub genes with the highest connectivity and several gene cluster modules were ensured using Cytoscape. Five high diagnostic hub genes were selected and verified by GSE30122. The MiRNA-mRNA-TF network suggested a potential RNA regulatory relationship. Hub gene expression was positively correlated with kidney injury. The level of serum creatinine and BUN in the DN group was higher than in the control group (unpaired t test, t = 3.391, df = 4, p = 0.0275, r = 0.861). Meanwhile, the DN group had a higher urinary protein/creatinine ratio (unpaired t test, t = 17.23, df = 16, p < 0.001, r = 0.974). QPCR results showed that the potential candidate genes for DN diagnosis included C1QB, ITGAM, and ITGB2.

Conclusions

We identified C1QB, ITGAM and ITGB2 as potential candidate genes for DN diagnosis and therapy and provided insight into the mechanisms of DN development at transcriptome level. We further completed the construction of miRNA-mRNA-TF network to propose potential RNA regulatory pathways adjusting disease progression in DN.

Transcription factor SOX3 upregulated pro-apoptotic genes expression in human breast cancer

BACKGROUND

Sex-determining region Y-box 3 (SOX3) protein, a SOX transcriptions factors group, has been identified as a key regulator in several diseases, including cancer. Downregulation of transcriptions factors in invasive ductal carcinoma (IDC) can interfere in neoplasia development, increasing its aggressiveness. We investigated SOX3 protein expression and its correlation with apoptosis in the MDA-MB-231 cell line, as SOX3 and Pro-Caspase-3 immunoexpression in paraffin-embedded invasive ductal carcinoma tissue samples from patients (n = 27). Breast cancer cell line MDA-MD-231 transfected with pEF1-SOX3 + and pEF1-Empty vector followed by cytotoxicity assay (MTT), Annexin-V FITC PI for apoptosis percentage assessment by flow cytometry, qPCR for apoptotic-related gene expression, immunofluorescence, and immunohistochemistry to SOX3 immunolocalization in culture cells, and paraffin-embedded invasive ductal carcinoma tissue samples.

RESULTS

Apoptotic rate was higher in cells transfected with pEF1-SOX3 + (56%) than controls (10%). MDA-MB-231 transfected with pEF1-SOX3 + presented upregulation of pro-apoptotic mRNA from CASP3, CASP8, CASP9, and BAX genes, contrasting with downregulation antiapoptotic mRNA from BCL2, compared to non-transfected cells and cells transfected with pEF1-empty vector (p < 0.005). SOX3 protein nuclear expression was detected in 14% (4/27 cases) of ductal carcinoma cases, and pro-Caspase-3 expression was positive in 50% of the cases.

CONCLUSION

Data suggest that SOX3 transcription factor upregulates apoptosis in breast cancer cell line MDA-MB-231, and has a down nuclear expression in ductal carcinoma cases, and need to be investigated as a tumor suppressor protein, and its loss of expression and non-nuclear action turn the cells resistant to apoptosis. Further studies are necessary to understand how SOX3 protein regulates the promoter regions of genes involved in apoptosis.

Coexistence of anti-SOX1 and anti-GABAB receptor antibodies with paraneoplastic limbic encephalitis presenting with seizures and memory impairment in small cell lung cancer: A case report

Purpose

Paraneoplastic neurological syndromes associated with autoantibodies are rare diseases that cause abnormal manifestations of the nervous system. Early diagnosis of paraneoplastic neurological syndromes paves the way for prompt and efficient therapy.

Case report

we reported a 56-year-old man presenting with seizures and rapidly progressive cognitive impairment diagnosed as paraneoplastic limbic encephalitis (PLE) with anti-SRY-like high-mobility group box-1 (SOX-1) and anti-γ-aminobutyric acid B (GABAB) receptor antibodies and finally confirmed by biopsy as small cell lung cancer (SCLC). At the first admission, brain magnetic resonance imaging (MRI) showed no abnormal signal in bilateral hippocampal regions and no abnormal enhancement of enhanced scan. The serum anti-GABAB receptor antibody was 1:100 and was diagnosed as autoimmune encephalitis (AE). The computed tomography (CT) scans of the chest showed no obvious tumor signs for the first time. Although positron emission tomography-computed tomography (PET-CT) revealed hypermetabolism in the para mid-esophageal, the patient and his family declined to undertake a biopsy. The patient improved after receiving immunoglobulin, antiepileptic therapy, and intravenous methylprednisolone (IVMP) pulse treatment. However, after 4 months, the symptoms reappeared. Brain MRI revealed abnormal signals in the hippocampal regions. Reexamination of the cerebral fluid revealed anti-GABAB receptor and anti-SOX-1 antibodies, which contributed to the diagnosis of PLE. SCLC was found in a para mid-esophageal pathological biopsy. Antiepileptic medications and immunoglobulin were used to treat the patient, and the symptoms were under control.

Conclusion

Our findings increase the awareness that patients with limbic encephalitis with cognitive dysfunction and epileptic seizures should be enhanced to detect latent malignancy. Our case also highlights the importance of anti-SOX1 antibodies in the detection of underlying neoplasm, particularly SCLC. Our findings raise awareness of the cognitive impairment seen by patients with limbic encephalitis.

Smartly responsive DNA-miRNA hybrids packaged in exosomes for synergistic enhancement of cancer cell apoptosis

Endogenous and exogenous tumor-related microRNAs (miRNAs) are considered promising tumor biomarkers and tumor therapeutic agents. In this work, we propose a miRNA self-responsive drug delivery system (miR-SR DDS), which enables the association between endogenous and exogenous miRNAs, so as to achieve a smart responsive and synergistic drug delivery. The miR-SR DDS consists of DNA-miRNA hybrids of let-7a and the complementary DNA of miR-155, which was packaged in exosomes. In response to the overexpressed miR-155 in breast cancer cells, the hybrids disintegrate and release let-7a and the complementary DNA of miR-155 to inhibit the expression of HMGA1 and relieve the inhibition of SOX1, respectively. Under the dual-targeted gene regulation, results show that the growth, migration and invasion of breast cancer cells can be synergistically inhibited through the Wnt/β-catenin signaling pathway. The concept and successful practice of the miR-SR DDS can be used as a reference for the development of miRNA drugs.

Understanding the function and regulation of Sox2 for its therapeutic potential in breast cancer

Sox family of transcriptional factors play essential functions in development and are implicated in multiple clinical disorders, including cancer. Sox2 being their most prominent member and performing a critical role in reprogramming differentiated adult cells to an embryonic phenotype is frequently upregulated in multiple cancers. High Sox2 levels are detected in breast tumor tissues and correlate with a worse prognosis. In addition, Sox2 expression is connected with resistance to conventional anticancer therapy. Together, it can be said that inhibiting Sox2 expression can reduce the malignant features associated with breast cancer, including invasion, migration, proliferation, stemness, and chemoresistance. This review highlights the critical roles played by the Sox gene family members in initiating or suppressing breast tumor development, while primarily focusing on Sox2 and its role in breast tumor initiation, maintenance, and progression, elucidates the probable mechanisms that control its activity, and puts forward potential therapeutic strategies to inhibit its expression.

Construction of miRNA-mRNA-TF Regulatory Network for Diagnosis of Gastric Cancer

Gastric cancer (GC), as an epidemic cancer worldwide, has more than 1 million new cases and an estimated 769,000 deaths worldwide in 2020, ranking fifth and fourth in global morbidity and mortality. In mammals, both miRNAs and transcription factors (TFs) play a partial role in gene expression regulation. The mRNA expression profile and miRNA expression profile of GEO database were screened by GEO2R for differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs). Then, DAVID annotated the functions of DEGs to understand the functions played in biological processes. The prediction of potential target genes of miRNA and key TFs of mRNA was performed by mipathDB V2.0 and CHEA3, respectively, and the gene list comparison was performed to look for overlapping genes coregulated by key TFs and DEMs. Finally, the obtained miRNAs, TF, and overlapping genes were used to construct the miRNA-mRNA-TF regulatory network, which was verified by RT-qPCR. 76 upregulated DEGs, 199 downregulated DEGs, and 3 upregulated miRNAs (miR-199a-3p/miR-199b-3p, miR-125b-5p, and miR-199a-5p) were identified from the expression profiles of mRNA (GSE26899, GSE29998, GSE51575, and GSE13911) and miRNA (GSE93415), respectively. Through database prediction and gene list comparison, it was found that among the 199 downregulated DEGs, 61, 71, and 69 genes were the potential targets of miR-199a-3p/miR-199b-3p, miR-125b-5p, and miR-199a-5p, respectively. 199 downregulated DEGs were used as the gene list for the prediction of key TFs, and the results showed that RFX6 ranked the highest. The potential target overlap genes of miR-199a-3p/miR-199b-3p, miR-125b-5p, and miR-199a-5p were 4 genes (SH3GL2, ATP4B, CTSE, and SORBS2), 7 genes (SLC7A8, RNASE4, ESRRG, PGC, MUC6, Fam3B, and FMO5), and 6 genes (CHGA, PDK4, TMPRSS2, CLIC6, GPX3, and PSCA), respectively. Finally, we constructed a miRNA-mRNA-TF regulatory network based on the above 17 mRNAs, 3 miRNAs, and 1 TF and verified by RT-qPCR and western blot results that the expression of RFX6 was downregulated in GC tissues. These identified miRNAs, mRNAs, and TF have a certain reference value for further exploration of the regulatory mechanism of GC.

Cervical cancer progression is regulated by SOX transcription factors: Revealing signaling networks and therapeutic strategies

Cervical cancer is the fourth common gynecologic cancer and is considered as second leading cause of death among women. Various strategies are applied in treatment of cervical cancer including radiotherapy, chemotherapy and surgery. However, cervical cancer cells demonstrate aggressive behavior in advanced phases, requiring novel strategies in their elimination. On the other hand, SOX proteins are transcription factors capable of regulating different molecular pathways and their expression varies during embryogenesis, disease development and carcinogenesis. In the present review, our aim is to reveal role of SOX transcription factors in cervical cancer. SOX transcription factors play like a double-edged sword in cancer. For instance, SOX9 possesses both tumor-suppressor and tumor-promoting role in cervical cancer. Therefore, exact role of each SOX members in cervical cancer has been discussed to direct further experiments for revealing other functions. SOX proteins can regulate proliferation and metastasis of cervical cancer cells. Furthermore, response of cervical cancer cells to chemotherapy and radiotherapy is tightly regulated by SOX transcription factors. Different downstream targets of SOX proteins such as Wnt signaling, EMT and Hedgehog have been identified. Besides, upstream mediators such as microRNAs, lncRNAs and circRNAs can regulate SOX expression in cervical cancer. In addition to pre-clinical studies, role of SOX transcription factors as prognostic and diagnostic tools in cervical cancer has been shown.

SOX14 hypermethylation as a tumour biomarker in cervical cancer

BACKGROUND

The association between SOX14 and cancer has been reported. The aim of this study was to identify and validate the potential value of SOX14 methylation in the early detection of cervical cancer.

METHODS

First, we extracted the data for SOX14 methylation and expression within cervical cancer from The Cancer Genome Atlas (TCGA) database and analysed them via UALCAN, Wanderer, MEXPRESS and LinkedOmics. Subsequently, according to the bioinformatics findings, primers and probes were designed for the most significantly differentiated methylation CpG site and synthesized for methylation-specific PCR (MSP) and quantitative methylation-specific PCR (QMSP) to verify SOX14 methylation in both cervical tissuses and liquid-based cell samples. Eventually, the clinical diagnostic efficacy of SOX14 methylation in the normal, cervical intraepithelial neoplasia, and cancer groups was analysed by ROCAUC.

RESULTS

Pooled analysis demonstrated that SOX14 methylation levels were significantly increased in cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) compared to normal tissues (P < 0.001). Both the verification and validation cohorts indicated that the methylation level and the positive rate of SOX14 gradually increased with increasing severity from normal to cancer samples (P < 0.01). When the cut-off value was set as 128.45, the sensitivity and specificity of SOX14 hypermethylation in the diagnosis of cervical cancer were 94.12 and 86.46%, respectively. When taken as a screening biomarker (>CINII), the sensitivity was 74.42% and the specificity was 81.48%, with a cut-off value of 10.37.

CONCLUSION

SOX14 hypermethylation is associated with cervical cancer and has the potential to be a molecular biomarker for the screening and early diagnosis of cervical cancer.

DNA methylation association with stage progression of head and neck squamous cell carcinoma

Head and Neck Squamous Cell Carcinoma (HNSCC) is the sixth most common cancer worldwide, which accounts for approximately 6% of all cases and is responsible for an estimated 2% of all cancer deaths. Despite progress in the treatment of squamous cell carcinomas, survival rates remain low. It is a fact that epigenetic modifications have numerous associations with biological processes and complex diseases such as cancer. Hence, a more systematic approach is needed to provide potential screening targets and have an effective therapy method. This study developed a workflow to analyze HM450 methylation arrays with mRNA expression profiles that identified novel signatures of epigenetic regulators for tumor progression. We identified differentially expressed genes and differentially methylated regions and the correlation between associated genes to identify epigenetic modifications underlying regulation roles. We have taken the differentiation direction of expressions into account during the integration of gene expression and DNA methylation modification to detect epigenetic regulators of core genes of tumor-stage progression. Enrichment analysis of selected key genes provides better insight into their functionality. Thus, we have investigated gene copy number alteration and mutations to filter differentially expressed genes, including some members of the fibroblast growth factor family and cyclin-dependent kinase inhibitor family with other potential known regulators. Our analysis has revealed the list of 61 commercial methylation probes positively correlated with 31 differentially expressed genes, which can be associated with HNSC metastasis stages. Most of these genes have already reported potential epigenetic regulators, and their role in cancer progression was studied. We suggest these selected probes of DNA methylation as potential targets of the epigenetic regulators in revealed genes that have displayed significant genetic and epigenetic modification behavior during cancer stage progression and tumor metastasis.

The role of SOX family transcription factors in gastric cancer

Gastric cancer (GC) is a leading cause of death worldwide. GC is the third-most common cause of cancer-related death after lung and colorectal cancer. It is also the fifth-most commonly diagnosed cancer. Accumulating evidence has revealed the role of signaling networks in GC progression. Identification of these molecular pathways can provide new insight into therapeutic approaches for GC. Several molecular factors involved in GC can play both onco-suppressor and oncogene roles. Sex-determining region Y (Sry)-box-containing (SOX) family members are transcription factors with a well-known role in cancer. SOX proteins can bind to DNA to regulate cellular pathways via a highly conserved domain known as high mobility group (HMG). In the present review, the roles of SOX proteins in the progression and/or inhibition of GC are discussed. The dual role of SOX proteins as tumor-promoting and tumor-suppressing factors is highlighted. SOX members can affect upstream mediators (microRNAs, long non-coding RNAs and NF-κB) and down-stream mediators (FAK, HIF-1α, CDX2 and PTEN) in GC. The possible role of anti-tumor compounds to target SOX pathway members in GC therapy is described. Moreover, SOX proteins may be used as diagnostic or prognostic biomarkers in GC.

In Silico Identification of SOX1 Post-Translational Modifications Highlights a Shared Protein Motif

The transcription factor SOX1 is a key regulator of neural stem cell development, acting to keep neural stem cells (NSCs) in an undifferentiated state. Postnatal expression of Sox1 is typically confined to the central nervous system (CNS), however, its expression in non-neural tissues has recently been implicated in tumorigenesis. The mechanism through which SOX1 may exert its function is not fully understood, and studies have mainly focused on changes in SOX1 expression at a transcriptional level, while its post-translational regulation remains undetermined. To investigate this, data were extracted from different publicly available databases and analysed to search for putative SOX1 post-translational modifications (PTMs). Results were compared to PTMs associated with SOX2 in order to identify potentially key PTM motifs common to these SOXB1 proteins, and mapped on SOX1 domain structural models. This approach identified several putative acetylation, phosphorylation, glycosylation and sumoylation sites within known functional domains of SOX1. In particular, a novel SOXB1 motif (xKSExSxxP) was identified within the SOX1 protein, which was also found in other unrelated proteins, most of which were transcription factors. These results also highlighted potential phospho-sumoyl switches within this SOXB1 motif identified in SOX1, which could regulate its transcriptional activity. This analysis indicates different types of PTMs within SOX1, which may influence its regulatory role as a transcription factor, by bringing changes to its DNA binding capacities and its interactions with partner proteins. These results provide new research avenues for future investigations on the mechanisms regulating SOX1 activity, which could inform its roles in the contexts of neural stem cell development and cancer.

SOX1 Promoter Hypermethylation as a Potential Biomarker for High-Grade Squamous Intraepithelial Neoplasia Lesion and Cervical Carcinoma: A Meta-Analysis With Trial Sequential Analysis

Background: DNA methylation has been widely assessed as a potential biomarker for the early detection of cervical cancer (CC). Herein, we assessed the associations of SOX1 promoter hypermethylation with squamous intraepithelial lesion and CC.

Methods: Published studies and genome-wide methylation datasets were searched from electronic databases (up to April 2019). The associations of SOX1 hypermethylation with high-grade squamous intraepithelial lesion (HSIL) and CC risks were evaluated by odds ratios (ORs) and 95% confidence intervals (CIs). The summary receiver operator characteristic test was used to assess the diagnostic value of the SOX1 promoter hypermethylation of CC and intraepithelial neoplasia type III or worse (CIN3+). Trial sequential analysis (TSA) was performed to evaluate the stability of results and estimate the required information size (RIS).

Results: In this meta-analysis of 17 published studies, the SOX1 methylation rates increased among low-grade SIL (LSIL, 27.27%), HSIL (40.75%), and CC (84.56%) specimens. Compared with control specimens, SOX1 promoter hypermethylation progressively increased the risk of HSIL by 4.20-fold (p < 0.001) and CC by 41.26-fold (p < 0.001). The pooled sensitivity of SOX1 methylation was estimated to be 0.85 (95% CI: 0.81–0.88) in differentiating patients with CC, corresponding to a specificity of 0.72 (95% CI: 0.69–0.75) and an area under the curve (AUC) of 0.93. Furthermore, the pooled sensitivity of SOX1 methylation was estimated to be 0.75 (95% CI: 0.72–0.78) in differentiating patients with CIN3+, corresponding to a specificity of 0.71 (95% CI: 0.69–0.73) and an AUC of 0.84. The pooled results of TCGA and GEO datasets showed that all CpG sites in SOX1 were associated with CC and 16 of 19 CpG sites were associated with HSIL. The results of TSA illustrated that the size was sufficient and significant associations were observed.

Conclusion: This meta-analysis indicated that SOX1 promoter hypermethylation might have a potential value in the clinical diagnosis of CC and CIN3+.

Cancer and SOX proteins: New insight into their role in ovarian cancer progression/inhibition

Transcription factors are potential targets in disease therapy, particularly in cancer. This is due to the fact that transcription factors regulate a variety of cellular events, and their modulation has opened a new window in cancer therapy. Sex-determining region Y (SRY)-related high-mobility group (HMG) box (SOX) proteins are potential transcription factors that are involved in developmental processes such as embryogenesis. It has been reported that abnormal expression of SOX proteins is associated with development of different cancers, particularly ovarian cancer (OC). In the present review, our aim is to provide a mechanistic review of involvement of SOX members in OC. SOX members may suppress and/or promote aggressiveness and proliferation of OC cells. Clinical studies have also confirmed the potential of transcription factors as diagnostic and prognostic factors in OC. Notably, studies have demonstrated the relationship between SOX members and other molecular pathways such as ST6Ga1-I, PI3K, ERK and so on, leading to more complexity. Furthermore, SOX members can be affected by upstream mediators such as microRNAs, long non-coding RNAs, and so on. It is worth mentioning that the expression of each member of SOX proteins is corelated with different stages of OC. Furthermore, their expression determines the response of OC cells to chemotherapy. These topics are discussed in this review to shed some light on role of SOX transcription factors in OC.

The MRTF-A/miR-155/SOX1 pathway mediates gastric cancer migration and invasion

Background

Gastric cancer (GC) is the leading cause of death worldwide and is closely related to metastasis. MRTF-A is one of the most well-characterized genetic markers in cancer. However, the mechanism whereby MRTF-A mediate gastric cancer (GC) tumorigenesis is not fully clear. Increasing evidence has confirmed that miRNA dysregulation is involved in MRTF-A-mediated tumorigenesis, supporting their potential as therapeutic targets for cancer. Although miR-155 has been reported as an upregulated miRNA, the interplay between miR-155 and MRTF-A-mediated gastric cancer progression remain largely elusive.

Methods

Real-time PCR was performed to determine miR-155 expression after transfected with MRTF-A encoding plasmids and siRNA. Potential target genes were identified by Western blot and luciferase reporter assay. Chip assay was proved that MRTF-A binds in the promoter region of miR-155. Transwell assay and Scratch-healing migration assay was used to investigate the role of MRTF-A and SOX1 in gastric cancer cell migration and invasion.

Results

MRTF-A can interact with the miR-155 promoter to promote histone acetylation and RNA polymerase II recruitment via the Wnt-β-catenin pathway. miR-155 promotes gastric cancer cell migration by suppressing SOX1 expressiom by targeting its 3′UTR in vitro and in vivo. MRTF-A inhibited the inhibitory effects of SOX1 on gastric cancer cell migration by promoting the express -ion of miR-155.

Conclusion

Our data therefore provide important and novel insights into how the MRTF-A/miR-155/SOX1 pathway mediates migration and invasion in GC.

SOX1 promotes differentiation of nasopharyngeal carcinoma cells by activating retinoid metabolic pathway

Undifferentiation is a key feature of nasopharyngeal carcinoma (NPC), which presents as a unique opportunity for intervention by differentiation therapy. In this study, we found that SOX1 inhibited proliferation, promoted differentiation, and induced senescence of NPC cells, which depended on its transcriptional function. RNA-Seq-profiling analysis showed that multiple undifferentiated markers of keratin family, including KRT5, KRT13, and KRT19, were reduced in SOX1 overexpressed NPC cells. Interestingly, gene ontology (GO) analysis revealed genes in SOX1 overexpressed cells were enriched in extracellular functions. The data of LC/MS untargeted metabolomics showed that the content of retinoids in SOX1 overexpressed cells and culture medium was both higher than that in the control group. Subsequently, we screened mRNA level of genes in retinoic acid (RA) signaling or metabolic pathway and found that the expression of UDP-glucuronosyltransferases was significantly decreased. Furtherly, UGT2B7 could rescue the differentiation induced by SOX1 overexpression. Inhibition of UGTs by demethylzeylasteral (T-96) could mimic SOX1 to promote the differentiation of NPC cells. Thus, we described a mechanism by which SOX1 regulated the differentiation of NPC cells by activating retinoid metabolic pathway, providing a potential target for differentiation therapy of NPC.

Connection between SOX7 Expression and Breast Cancer Prognosis

Background

SOX7 exerts a repressing effect against tumors and imposes vital influences on malignancies. Our research discussed the importance of SOX7 in breast cancer prognoses.

Material/Methods

SOX7 mRNA expression in breast cancer tissues samples and matched adjacent normal controls of breast cancer patients was measured by quantitative real-time-polymerase chain reaction (qRT-PCR). The relationship of SOX7 with clinicopathological characteristics were analyzed via chi-square test. The association of SOX7 levels with clinical outcomes was evaluated adopting the Kaplan-Meier method and multivariate Cox proportional hazards regression model.

Results

SOX7 mRNA degree of expression exhibited a declining tendency in breast cancer tissue compared to paired bordering normal tissue specimens (P<0.001). In addition, the reduced SOX7 degree of expression had a strong correlation to larger cancer mass dimension (P=0.006) and lymph node metastasis (P=0.001). Survival analysis revealed that the overall survival (OS) time was much shorter among cases harboring low SOX7 degree of expression compared to high degree of expression (P=0.005). Moreover, SOX7 expression alone could predict OS among breast cancer patients (hazard ratio=3.956, 95% confidence interval=1.330–11.772, P=0.013).

Conclusions

SOX7 expression was downregulated in breast cancer tissues, and it could function as a useful prognostic marker in breast cancer.

Emerging Role of SOX Proteins in Breast Cancer Development and Maintenance

The SOX genes encode a family of more than 20 transcription factors that are critical regulators of embryogenesis and developmental processes and, when aberrantly expressed, have been shown to contribute to tumor development and progression in both an oncogenic and tumor suppressive role. Increasing evidence demonstrates that the SOX proteins play essential roles in multiple cellular processes that mediate or contribute to oncogenic transformation and tumor progression. In the context of breast cancer, SOX proteins function both as oncogenes and tumor suppressors and have been shown to be associated with tumor stage and grade and poor prognosis. Experimental evidence demonstrates that a subset of SOX proteins regulate critical aspects of breast cancer biology including cancer stemness and multiple signaling pathways leading to altered cell proliferation, survival, and tumor development; EMT, cell migration and metastasis; as well as other tumor associated characteristics. This review will summarize the role of SOX family members as important mediators of tumorigenesis in breast cancer, with an emphasis on the triple negative or basal-like subtype of breast cancer, as well as examine the therapeutic potential of these genes and their downstream targets.

The role of SOX family members in solid tumours and metastasis

Cancer is a heavy burden for humans across the world with high morbidity and mortality. Transcription factors including sex determining region Y (SRY)-related high-mobility group (HMG) box (SOX) proteins are thought to be involved in the regulation of specific biological processes. The deregulation of gene expression programs can lead to cancer development. Here, we review the role of the SOX family in breast cancer, prostate cancer, renal cell carcinoma, thyroid cancer, brain tumours, gastrointestinal and lung tumours as well as the entailing therapeutic implications. The SOX family consists of more than 20 members that mediate DNA binding by the HMG domain and have regulatory functions in development, cell-fate decision, and differentiation. SOX2, SOX4, SOX5, SOX8, SOX9, and SOX18 are up-regulated in different cancer types and have been found to be associated with poor prognosis, while the up-regulation of SOX11 and SOX30 appears to be favourable for the outcome in other cancer types. SOX2, SOX4, SOX5 and other SOX members are involved in tumorigenesis, e.g. SOX2 is markedly up-regulated in chemotherapy resistant cells. The SoxF family (SOX7, SOX17, SOX18) plays an important role in angio- and lymphangiogenesis, with SOX18 seemingly being an attractive target for anti-angiogenic therapy and the treatment of metastatic disease in cancer. In summary, SOX transcription factors play an important role in cancer progression, including tumorigenesis, changes in the tumour microenvironment, and metastasis. Certain SOX proteins are potential molecular markers for cancer prognosis and putative potential therapeutic targets, but further investigations are required to understand their physiological functions.

Knockdown of long non-coding RNA CCAT2 suppressed proliferation and migration of glioma cells

Long non-coding RNA colon cancer-associated transcript 2 (CCAT2) is commonly investigated in a number of cancers. However, little is known of its expression and biological function in glioma biology. In the current study, we used quantitative real-time PCR (qRT-PCR) to determine the expression of CCAT2 in glioma tissues. We found that expression of CCAT2 was up-regulated in glioma tissues and significantly correlated with the advanced tumor stage (III/IV). Functional assays in vitro and in vivo demonstrated that knockdown of CCAT2 could inhibit proliferation, cell cycle progression and migration of glioma cells. Further analysis indicated the effect of CCAT2 knockdown on glioma cell phenotype through inhibiting Wnt/β-catenin signal pathway activity. Thus, our study provides evidence that CCAT2 may function as a potential biomarker for glioma.

Expression of a SOX1 overlapping transcript in neural differentiation and cancer models

SOX1 is a member of the SOXB1 subgroup of transcription factors involved in early embryogenesis, CNS development and maintenance of neural stem cells. The structure and regulation of the human SOX1 locus has been less studied than that of SOX2, another member of the SOXB1 subgroup for which an overlapping transcript has been reported. Here we report that the SOX1 locus harbours a SOX1 overlapping transcript (SOX1-OT), and describe expression, splicing variants and detection of SOX1-OT in different stem and cancer cells. RT-PCR and RACE experiments were performed to detect and characterise the structure of SOX1-OT in neuroprogenitor cultures and across different cancer cell lines. SOX1-OT was found to present a complex structure including several unannotated exons, different transcript variants and at least two potential transcription start sites. SOX1-OT was found to be highly expressed in differentiated neural stem cells across different time points of differentiation, and its expression correlated with SOX1 gene expression. Concomitant expression of SOX1 and SOX1-OT was further observed in several cancer cell models. While the function of this transcript is unknown, the regulatory role reported for other lncRNAs strongly suggests a possible role for SOX1-OT in regulating SOX1 expression, as previously observed for SOX2. The elucidation of the genetic and regulatory context governing SOX1 expression will contribute to clarifying its role in stem cell differentiation and tumorigenesis.

Oncogenic activity of SOX1 in glioblastoma

Glioblastoma remains the most common and deadliest type of brain tumor and contains a population of self-renewing, highly tumorigenic glioma stem cells (GSCs), which contributes to tumor initiation and treatment resistance. Developmental programs participating in tissue development and homeostasis re-emerge in GSCs, supporting the development and progression of glioblastoma. SOX1 plays an important role in neural development and neural progenitor pool maintenance. Its impact on glioblastoma remains largely unknown. In this study, we have found that high levels of SOX1 observed in a subset of patients correlate with lower overall survival. At the cellular level, SOX1 expression is elevated in patient-derived GSCs and it is also higher in oncosphere culture compared to differentiation conditions in conventional glioblastoma cell lines. Moreover, genetic inhibition of SOX1 in patient-derived GSCs and conventional cell lines decreases self-renewal and proliferative capacity in vitro and tumor initiation and growth in vivo. Contrarily, SOX1 over-expression moderately promotes self-renewal and proliferation in GSCs. These functions seem to be independent of its activity as Wnt/β-catenin signaling regulator. In summary, these results identify a functional role for SOX1 in regulating glioma cell heterogeneity and plasticity, and suggest SOX1 as a potential target in the GSC population in glioblastoma.

RBMS3 Inhibits the Proliferation and Metastasis of Breast Cancer Cells

RBMS3, a gene encoding a glycine-rich RNA-binding protein, belongs to the family of c-Myc gene single-strand binding proteins (MSSP). Recently, several reports have provided evidence that RBMS3 was deregulated in a diverse range of solid tumors and played a critical role in tumor progression. However, it remains unclear whether RBMS3 inhibits the progression of human breast cancer. Thus, the aim of this study was to investigate the role of RBMS3 in breast cancer and explore the underlying mechanism in breast cancer progression. Our results showed, for the first time, that the expression of RBMS3 at both the mRNA and protein levels was significantly downregulated in human breast cancer tissues and cell lines. In addition, RBMS3 overexpression dramatically suppressed the proliferation, migration, and invasion of breast cancer cells in vitro and attenuated tumor growth in vivo. Furthermore, we observed that RBMS3 greatly inhibited the protein expression of β-catenin, cyclin D1, and c-Myc in breast cancer cells. In summary, we have shown that RBMS3 inhibited the proliferation and tumorigenesis of breast cancer cells, at least in part, through inactivation of the Wnt/β-catenin signaling pathway. Thus, RBMS3 may be a potential treatment target for breast cancer.

Secreted frizzled-related protein 2-mediated cancer events: Friend or foe?

Secreted frizzled-related protein (SFRP)2, an identified member of the SFRPs family of molecules, is often methylated in human cancers and its down-regulation is closely related to Wnt signaling activity and tumor progression. Although the blocker of the Wnt signaling has not been fully used in clinical trial, interest has been further enhanced by the realization of SFRPs' potential as targets to modulate Wnt signaling and cancer cell growth. Emerging evidence showed that SFRP2 was an anti-oncogene, however, a steady flow of research has indicated that it may also have tumor promotion effects in some cancer types. Furthermore, SFRP2 methylation was shown to accelerate cancer cell invasion and growth in tumor progression. In this review, we define recent understanding of the diverse roles of SFRP2 in tumorigenesis, and it might promote the development of novel drugs for curing cancer by targeting SFRP2.