SOX4: Joining the Master Regulators of Epithelial-to-Mesenchymal Transition?

SOX Genes in Spinal Cord Injury: Redefining Neural Stem Cell Regeneration Strategies

The study design is literature review. The sex-determining region Y gene (SRY)-related high mobility group box (HMG)-box (SOX) gene family has primarily been associated with neural development and sex determination and is a key component of human embryonic development. Recent studies on zebrafish models have demonstrated that the unique ability of the latter for central nervous tissue (CNS) repair following injury is largely mediated by SOX genes. Given that efforts aimed at the structural regeneration and functional restoration of neural tissue still represent a major therapeutic challenge in patients suffering CNS injury, these findings have initiated a discussion regarding the development of novel therapeutic strategies for SCI focusing on neural tissue regeneration. Spinal cord injury (SCI), in particular, represents a field that could greatly benefit from studies related to the function of the SOX genes. Neuro-informatics Laboratory, Mayo Clinic, Rochester, MN. A literature review was conducted, with a focus on SOX gene that has been described in the experimental studies of SCI. In this review, the existing evidence linking the SOX gene family to the pathophysiology of SCI is summarized, and future research steps regarding the potential implications of the SOX genes in neurological recovery following SCI are discussed, especially focusing on highlighting potential therapeutic targets. The potential implications of the latter could play a crucial role in future efforts to advance the treatment approaches to SCI.

SOX4 promotes vascular abnormality in glioblastoma and is a novel target to improve drug delivery

Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults with dismal prognosis. Vascular abnormality is a hallmark of GBM, and aggravates diseases progression by increasing hypoxia, inducing life-threaten edema and hindering drug delivery. Nonetheless, the intricate mechanism underlying vascular abnormality remains inadequately understood. Here, we revealed a key role of SOX4 on vascular abnormality in GBM. SOX4 expression was increased in endothelial cells (ECs) from human brain tumors compared with ECs from paired normal brain tissue. Knockdown of SOX4 in mouse brain ECs restrained cell migration and proliferation. Furthermore, in vitro suppression of SOX4 in brain ECs and in vivo conditional knockout of SOX4 in tumor ECs led to the downregulation of genes linked with vascular abnormality. Notably, specific depletion of SOX4 in ECs enhanced drug delivery and sensitive tumor to chemotherapeutic drugs in GBM. Taken together, these results demonstrated that SOX4 is a novel regulator for tumor angiogenesis and vascular abnormality in GBM. Our findings identify SOX4 as a potential vascular therapeutic target to improve drug delivery for GBM treatment.

ALDH and cancer stem cells: Pathways, challenges, and future directions in targeted therapy

Human ALDH comprise 19 subfamilies in which ALDH1A1, ALDH1A3, ALDH3A1, ALDH5A1, ALDH7A1, and ALDH18A1 are implicated in CSC. Studies have shown that ALDH can also be involved in drug resistance and standard chemotherapy regimens are ineffective in treating patients at the stage of disease recurrence. Existing chemotherapeutic drugs eliminate the bulk of tumors but are usually not effective against CSC which express ALDH+ population. Henceforth, targeting ALDH is convincing to treat the patient's post-relapse. Combination therapies that interlink signaling mechanisms seem promising to increase the overall disease-free survival rate. Therefore, targeting ALDH through ALDH inhibitors along with immunotherapies may create a novel platform for translational research. This review aims to fill in the gap between ALDH1 family members in relation to its cell signaling mechanisms, highlighting their potential as molecular targets to sensitize recurrent tumors and bring forward the future development concerning the current progress and draw backs. This review summarizes the role of cancer stem cells and their upregulation by maintaining the tumor microenvironment in which ALDH is specifically highlighted. It discusses the regulation of ALDH family proteins and the crosstalk between ALDH and CSC in relation to cancer metabolism. Furthermore, it establishes the correlation between ALDH involved signaling mechanisms and their specific targeted inhibitors, as well as their functional modularity, bioavailability, and mechanistic role in various cancers.

Expression of SOX4 Significantly Predicts the Risk of Lymph Node Metastasis for Patients With Early-Stage Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma stands as a notably aggressive malignancy within the digestive system. In cases of early esophageal cancer without lymph node metastasis, endoscopic surgical resection offers a viable alternative, often resulting in improved patient quality of life. However, the paucity of methods to preoperatively ascertain lymph node involvement complicates surgical planning. SOX4 gene was previously found to be highly associated with invasive metastasis in our work through single-cell RNA sequencing on 5 paired tumor/peritumor tissues. This research included the collection of 124 tissue samples from 106 patients (106 tumor and 18 lymph node specimens). Samples were methodically arranged into a tissue microarray and treated with immunohistochemical staining. Statistical analysis was conducted to assess the relationship between them. In the univariate analysis, 3 factors were identified as statistically significant in relation to lymph node metastasis: T category (P = .014), vascular invasion (P < .001), and SOX4 intensity (P = .001). Additionally, when evaluating SOX4 intensity alongside other clinical indicators, SOX4 was shown to independently influence lymph node metastasis. Further, the multivariate analysis revealed that vascular invasion (P < .001) and SOX4 intensity (P = .003) were significantly associated with lymph node metastasis, exhibiting hazard ratios of 10.174 and 7.142, respectively. The results of our study indicate that both SOX4 expression and vascular invasion serve as predictors of lymph node metastasis in patients diagnosed with category T1 esophageal squamous cell carcinoma, underscoring the potential utility of SOX4 in prognostic evaluations.

Single-cell transcriptomics enable the characterization of local extension in retinoblastoma

Retinoblastoma (RB) is the most prevalent ocular tumor of childhood, and its extraocular invasion significantly increases the risk of metastasis. Nevertheless, a single-cell characterization of RB local extension has been lacking. Here, we perform single-cell RNA sequencing on four RB samples (two from intraocular and two from extraocular RB patients), and integrate public datasets of five normal retina samples, four intraocular samples, and three extraocular RB samples to characterize RB local extension at the single-cell level. A total of 128,454 qualified cells are obtained in nine major cell types. Copy number variation inference reveals chromosome 6p amplification in cells derived from extraocular RB samples. In cellular heterogeneity analysis, we identified 10, 8, and 7 cell subpopulations in cone precursor like cells, retinoma like cells, and MKI67+ photoreceptorness decreased (MKI67+ PhrD) cells, respectively. A high expression level of SOX4 was detected in cells from extraocular samples, especially in MKI67+ PhrD cells, which was verified in additional clinical RB samples. These results suggest that SOX4 might drive RB local extension. Our study presents a single-cell transcriptomic landscape of intraocular and extraocular RB samples, improving our understanding of RB local extension at the single-cell resolution and providing potential therapeutic targets for RB patients.

Oral tumor heterogeneity, its implications for patient monitoring and designing anti-cancer strategies

Oral cancer tumors occur in the mouth and are mainly derived from oral mucosa linings. It is one of the most common and fatal malignant diseases worldwide. The intratumor heterogeneity (ITH) of oral cancerous tumor is vast, so it is challenging to study and interpret. Due to environmental selection pressures, ITH arises through diverse genetic, epigenetic, and metabolic alterations. The ITH also talks about peri-tumoral vascular/ lymphatic growth, perineural permeation, tumor necrosis, invasion, and clonal expansion/ the coexistence of multiple subclones in a single tumor. The heterogeneity offers tumors the adaptability to survive, induce growth/ metastasis, and, most importantly, escape antitumor therapy. Unfortunately, the ITH is prioritized less in determining disease pathology than the traditional TNM classifications or tumor grade. Understanding ITH is challenging, but with the advancement of technology, this ITH can be decoded. Tumor genomics, proteomics, metabolomics, and other modern analyses can provide vast information. This information in clinics can assist in understanding a tumor's severity and be used for diagnostic, prognostic, and therapeutic decision-making. Lastly, the oral tumor ITH can lead to individualized, targeted therapy strategies fighting against OC.

TGFβ-induced circLTBP2 predicts a poor prognosis in intrahepatic cholangiocarcinoma and mediates gemcitabine resistance by sponging miR-338-3p

BACKGROUND & AIMS

Intrahepatic cholangiocarcinoma (iCCA) is a deadly cancer worldwide with an increasing incidence and limited therapeutic options. Therefore, there is an urgent need to open the field to new concepts for identifying clinically relevant therapeutic targets and biomarkers. Here, we explored the role and the clinical relevance of circular RNA (circRNA) circLTBP2 in iCCA.

METHODS

Transforming growth factor β (TGFβ)-regulated circRNAs were identified by dedicated microarrays in human HuCC-T1 iCCA cell line, and their clinical relevance was evaluated in independent cohorts of patients. Gain and loss of function of circLTBP2 combined with functional tests was performed in vitro and in vivo in mice. RNA pulldown, microRNA sequencing, and RNA immunoprecipitation were performed to explore the sponging activity of circLTBP2.

RESULTS

CircLTBP2 (has_circ_0032603) was identified as a novel TGFβ-induced circRNA in several cholangiocarcinoma cell lines. CircLTBP2 promotes tumour cell proliferation, migration, and resistance to gemcitabine-induced apoptosis in vitro and tumour growth in vivo. Mechanistically, circLTBP2 acts as a competitive RNA regulating notably the activity of the tumour suppressor microRNA miR-338-3p, leading to the overexpression of its pro-metastatic targets. The restoration of miR-338-3p levels in iCCA cells reversed the pro-tumourigenic effects driven by circLTBP2, including the resistance to gemcitabine-induced apoptosis. In addition, circLTBP2 expression predicted a reduced survival, as detected in not only tumour tissues but also serum extracellular vesicles isolated from patients with iCCA.

CONCLUSIONS

CircLTBP2 is a novel effector of the pro-tumourigenic arm of TGFβ and a clinically relevant biomarker easily detected from liquid biopsies in iCCA.

IMPACT AND IMPLICATIONS

Intrahepatic cholangiocarcinoma (iCCA) is an aggressive cancer with limited therapeutic options. Opening the field to new concepts is urgently needed to improve the survival of patients. Here, we evaluated the role and the clinical relevance of circular RNA. We report that TGFβ-induced circLTBP2 contributes to CCA carcinogenesis and may constitute a clinically relevant prognostic biomarker detected in liquid biopsies.

Growth differentiation factor myostatin regulates epithelial-mesenchymal transition genes and enhances invasion by increasing serine protease inhibitors E1 and E2 in human trophoblast cells

Placental insufficiency disorders, including preeclampsia and intrauterine growth restriction, are major obstetric complications that can have devastating effects on both the mother and the fetus. These syndromes have underlying poor placental trophoblast cell invasion into uterine tissues. Placental invasion is controlled by many hormones and growth factors. Myostatin (MSTN) is a transforming growth factor-β superfamily member recognized for its important role in muscle growth control. MSTN has also been shown to be secreted and functioning in the placenta, and its serum and/or placental levels were found to be upregulated in preeclampsia and intrauterine growth restriction. Considering that the mechanistic role of MSTN in placentation remains poorly understood, we hypothesized that MSTN uses ALK4/5-SMAD2/3/4 signaling to increase human trophoblast invasion through a group of epithelial-mesenchymal transition genes including SERPINE2, PAI-1, and SOX4. mRNA sequencing of control and MSTN-treated primary human trophoblast cells (n = 5) yielded a total of 610 differentially expressed genes (false discovery rate <0.05) of which 380 genes were upregulated and 230 were downregulated. These differentially expressed genes were highly enriched in epithelial-mesenchymal transition genes, and a subset including SERPINE2, PAI-1, and SOX4 was investigated for its role in MSTN-induced trophoblast cell invasion. We found that MSTN induced upregulation of SERPINE2 via ALK4/5-SMAD2/3/4 signaling; however, SMAD2 was not involved in MSTN-induced PAI-1 upregulation. SOX4 was involved in MSTN-induced upregulation of SERPINE2, but not PAI-1. Collectively, this study discovers novel molecular mechanisms of MSTN-induced human trophoblast cell invasion and provides insight into the functional consequences of its dysregulation in placental insufficiency disorders.

Tumor-suppressive role of miR-139-5p in angiogenesis and tumorigenesis of ovarian cancer: Based on GEO microarray analysis and experimental validation

This study clarified the possible molecular mechanisms by which the miR-139-5p/SOX4/TMEM2 axis affected angiogenesis and tumorigenesis of ovarian cancer (OC) based on GEO microarray datasets and experimental support. The expression of miR-139-5p and SOX4 was examined in clinical OC samples. Human umbilical vein endothelial cells (HUVECs) and human OC cell lines were included in vitro experiments. Tube formation assay was conducted in HUVECs. The expression of SOX4, SOX4, and VEGF in OC cells was identified using Western blot and immunohistochemistry. Luciferase assays were conducted to validate the targeting relationship between miR-139-5p and SOX4 and between SOX4 and TMEM2. A RIP assay assessed the binding of SOX4 and miR-139-5p. The impact of miR-139-5p and SOX4 on OC tumorigenesis in vivo was evaluated in nude mice. SOX4 was up-regulated, while miR-139-5p was down-regulated in OC tissues and cells. Ectopic miR-139-5p expression or SOX4 knockdown inhibited angiogenesis and tumorigenicity of OC. By targeting SOX4 in OC, miR-139-5p lowered VEGF expression, angiogenesis, and TMEM2 expression. The miR-139-5p/SOX4/TMEM2 axis also reduced VEGF expression and angiogenesis, which might curtail OC growth in vivo. Collectively, miR-139-5p represses VEGF expression and angiogenesis by targeting the transcription factor SOX4 and down-regulating TMEM2 expression, thereby impeding OC tumorigenesis.

Molecular Mechanism of Nucleosome Recognition by the Pioneer Transcription Factor Sox

Pioneer transcription factors (PTFs) have the remarkable ability to directly bind to chromatin to stimulate vital cellular processes. In this work, we dissect the universal binding mode of Sox PTF by combining extensive molecular simulations and physiochemistry approaches, along with DNA footprinting techniques. As a result, we show that when Sox consensus DNA is located at the solvent-facing DNA strand, Sox binds to the compact nucleosome without imposing any significant conformational changes. We also reveal that the base-specific Sox:DNA interactions (base reading) and Sox-induced DNA changes (shape reading) are concurrently required for sequence-specific nucleosomal DNA recognition. Among three different nucleosome positions located on the positive DNA arm, a sequence-specific reading mechanism is solely satisfied at the superhelical location 2 (SHL2). While SHL2 acts transparently for solvent-facing Sox binding, among the other two positions, SHL4 permits only shape reading. The final position, SHL0 (dyad), on the other hand, allows no reading mechanism. These findings demonstrate that Sox-based nucleosome recognition is essentially guided by intrinsic nucleosome properties, permitting varying degrees of DNA recognition.

Suppression of preadipocyte determination by SOX4 limits white adipocyte hyperplasia in obesity

Preadipocyte determination expanding the pool of preadipocytes is a vital process in adipocyte hyperplasia, but the molecular mechanisms underlying this process are yet to be elucidated. Herein, SRY-related HMG box transcription factor 4 (SOX4) was identified as a critical target in response to BMP4- and TGFβ-regulated preadipocyte determination. SOX4 deficiency is sufficient to promote preadipocyte determination in mesenchymal stem cells (MSCs) and acquisition of preadipocyte properties in nonadipogenic lineages, while its overexpression impairs the adipogenic capacity of preadipocytes and converts them into nonadipogenic lineages. Mechanism studies indicated that SOX4 activates and cooperates with LEF1 to retain the nuclear localization of β-catenin, thus mediating the crosstalk between TGFβ/BMP4 signaling pathway and Wnt signaling pathway to regulate the preadipocyte determination. In vivo studies demonstrated that SOX4 promotes the adipogenic-nonadipogenic conversion and suppresses the adipocyte hyperplasia. Together, our findings highlight the importance of SOX4 in regulating the adipocyte hyperplasia in obesity.

Differential expression profiles and functional prediction of circRNA in mice with traumatic heterotopic ossification

Background

Traumatic heterotopic ossification (HO) is an intractable sequela incited by inflammatory insult. To date, the exact molecular mechanisms of traumatic HO formation remain unclear. Recent studies have indicated that circular RNAs (circRNAs) participate in various human skeletal diseases. Although the formation of HO recapitulates many programs during bone development and remodeling, few data are available concerning whether circRNAs could participate in this pathological osteogenesis.

Methods

To investigate the differentially expressed circRNAs (DE-circRNAs) in HO formation, microarray assay was performed to analyze the circRNA expression profile in four pairs of mice HO tissues and normal tissues. Then, qRT-PCR was applied to verify the microarray data. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed the biological functions of the differentially expressed circRNAs target genes. Cytoscape software was used to construct the circRNA-miRNA-mRNA network for circRNAs with different expression levels as well as the target genes.

Results

We demonstrated that 491 circRNAs were significantly differentially expressed in mouse HO tissues by a fold-change ≥ 2 and p-value ≤ 0.05. Among them, the expressions of 168 circRNAs were increased, while 323 were decreased. The expression levels of 10 selected circRNAs were verified successfully by qRT-PCR. GO analysis exhibited that these DE-circRNAs participated in a series of cellular processes. KEGG pathway analysis revealed that multiple upregulated and downregulated pathways were closely related to the DE-circRNAs in HO mice. The circRNA-miRNA-mRNA networks demonstrated that DE-circRNAs may be involved in the pathological osteogenesis of HO through the circRNA-targeted miRNA-mRNA axis.

Conclusion

Our study first demonstrated the expression profiles and predicted the potential functions of DE-circRNAs in mice traumatic HO, which may shed new light on the elucidation of mechanisms as well as provide novel potential peripheral biological diagnostic markers and therapeutic targets for traumatic HO.

Circular RNA hsa_circ_0012673 Promotes Breast Cancer Progression via miR-576-3p/SOX4 Axis

Circular RNAs (circRNAs) have been reported to exert critical roles in human cancers. In this study, we investigated the role and molecular mechanism of hsa_circ_0012673 in breast cancer. Herein, we found that the expression of hsa_circ_0012673 was upregulated in breast cancer tissues and cell lines. Knockdown of hsa_circ_0012673 using RNA interference technique suppressed the proliferation, migration, and invasion of breast cancer cells. Mechanistically, hsa_circ_0012673 sponged miR-576-3p to stabilize SRY-box transcription factor 4 (SOX4), and thereby facilitating breast cancer cell proliferation, migration and invasion. Collectively, our study identified the oncogenic properties of hsa_circ_0012673/miR-576-3p/SOX4 axis in breast cancer, providing potential and exploitable diagnostic and therapeutic molecules for breast cancer.

Amazonian Guarana- and Açai-Conjugated Extracts Improve Scratched Fibroblast Healing and Eisenia fetida Surgical Tail Amputation by Modulating Oxidative Metabolism

Background

Previous studies have suggested that guarana (Paullinia cupana) and açai (Euterpe oleracea) have antioxidant, anti-inflammatory, and proliferative properties, indicating their potential therapeutic action in wound healing. We produced a conjugated guarana-açai (GA) extract and tested its healing action on earthworms (Eisenia fetida) subjected to tail amputation by surgical incision.

Methods

Extract from roasted guarana seeds and fresh açai seed berries was produced. The antioxidant and genoprotective capacity of GA extract was tested. The concentration with the most remarkable healing potential was used in subsequent tests. The last three posterior segments of the clitellate earthworm tail reared under standardized conditions were surgically amputated. Next, topical PBS or GA extract was applied to the surgical wound. The rate of cell migration and tissue regeneration at the local wound site was histologically evaluated after the procedure. Expression of the SOX4 gene that acts in epithelial-to-mesenchymal transition was determined by RT-qPCR.

Results

Sixteen bioactive molecules, including some previously described substances, were identified. All tested concentrations exhibited antioxidant and genoprotective effects. The GA extract accelerated the healing processes as observed through macroscopic and histological analyses and increased expression of SOX4.

Conclusion

The GA extract has a potential role in the healing of surgically induced wounds.

SOX4-mediated FBW7 transcriptional upregulation confers Tamoxifen resistance in ER+ breast cancers via GATA3 downregulation

AIM

Tamoxifen-mediated endocrine therapy has been standard treatment for ER+ breast cancers; however, majority of them acquire resistance leading to disease relapse. Although numerous substrates of E3 ligase FBW7 are known, only a handful of factors that regulate FBW7 expression and function are reported. In particular, there remains a lack of in-depth understanding of FBW7 transcriptional regulation.

MATERIALS AND METHODS

Luciferase reporter assay was performed after cloning full length and truncated FBW7 promoters followed by Chromatin immunoprecipitation assay to validate binding of SOX4 on FBW7 promoter. Transcriptional regulation of FBW7 by SOX4 and their biological consequences with respect to ER+ breast cancer was then evaluated using immunoblotting and other cell based assays.

KEY FINDINGS

SOX4 positively regulates FBW7 at transcriptional level by binding to three putative SOX4 biding sites within 3.1 kb long FBW7 promoter. Analysis of publicly available RNAseq datasets also showed a positive correlation between SOX4 and FBW7 mRNA in cancer cell lines and patient samples. qPCR and Immunoblotting confirmed that transiently or stably expressed SOX4 induced both endogenous FBW7 mRNA and protein levels. Our findings further demonstrated that increased levels of SOX4 and FBW7 in MCF7 mammospheres promoted cancer stemness and tumor cell dormancy. We further showed that both MCF7 mammospheres and MCF^TAMR cells had elevated SOX4 levels which apparently enhanced FBW7 to potentiate GATA3 degradation leading to enhanced stemness, tumor dormancy and Tamoxifen resistance in MCF7^TAMR as well as patients with ER+ breast cancers.

SIGNIFICANCE

Targeting SOX4-FBW7-GATA3 axis may overcome tamoxifen resistance in ER+ breast cancers.

Transcriptional inhibition of miR-486-3p by BCL6 upregulates Snail and induces epithelial-mesenchymal transition during radiation-induced pulmonary fibrosis

Background

Ionizing radiation (IR) can induce pulmonary fibrosis by causing epithelial mesenchymal transition (EMT), but the exact mechanism has not been elucidated. To investigate the molecular mechanism of how radiation induces pulmonary fibrosis by altering miR-486-3p content and thus inducing EMT.

Methods

The changes of miR-486-3p in cells after irradiation were detected by RT-qPCR. Western blot was used to detect the changes of cellular epithelial marker protein E-cadherin, mesenchymal marker N-cadherin, Vimentin and other proteins. The target gene of miR-486-3p was predicted by bioinformatics method and the binding site was verified by dual luciferase reporter system. In vivo experiments, adeno-associated virus (AAV) was used to carry miR-486-3p mimic to lung. Radiation-induced pulmonary fibrosis (RIPF) model was constructed by 25Gy⁶⁰Co γ-rays. The structural changes of mouse lung were observed by HE and Masson staining. The expression of relevant proteins in mice was detected by immunohistochemistry.

Results

IR could decrease the miR-486-3p levels in vitro and in vivo, and that effect was closely correlated to the occurrence of RIPF. The expression of Snail, which induces EMT, was shown to be restrained by miR-486-3p. Therefore, knockdown of Snail blocked the EMT process induced by radiation or knockdown of miR-486-3p. In addition, the molecular mechanism underlying the IR-induced miRNA level reduction was explored. The increased in BCL6 could inhibit the formation of pri-miR-486-3p, thereby reducing the levels of miR-486-3p in the alveolar epithelial cells, which would otherwise promote EMT and contribute to RIPF by targeting Snail.

Conclusion

IR can exacerbate RIPF in mice by activating the transcription factor BCL6, which inhibits the transcription of miR-486-3p and decreases its content, which in turn increases the content of the target gene slug and triggers EMT.

Circular RNA TLK1 Exerts Oncogenic Functions in Hepatocellular Carcinoma by Acting as a ceRNA of miR-138-5p

Mounting evidence has shown that circular RNAs (circRNAs) function as key regulators in carcinogenesis and cancer progression, and this study is aimed at investigating the regulatory functions of circRNA TLK1 (circ-TLK1) in hepatocellular carcinoma (HCC). We observed that circ-TLK1 was highly expressed in HCC samples, and its high expression was closely associated with poor clinicopathological variables of HCC patients. The results of functional experiments revealed that knockdown of circ-TLK1 remarkably inhibited the proliferation, migration, invasion, and EMT of HCC cells, while circ-TLK1 overexpression promoted these malignant behaviors. Moreover, we noted that circ-TLK1 was capable of binding to miR-138-5p and upregulating its target gene, SOX4 in HCC. Based on rescue assays, miR-138-5p inhibition partially suppressed the effects of circ-TLK1 knockdown on the malignant behaviors of HCC cells. In short, this study is the first to indicate that circ-TLK1 functions as an oncogene in HCC progression partly through acting as a ceRNA of miR-138-5p, which may be a promising target for HCC therapy.

SOX4 is a novel phenotypic regulator of endothelial cells in atherosclerosis revealed by single-cell analysis

INTRODUCTION

Atherosclerotic complications represent the leading cause of cardiovascular mortality globally. Dysfunction of endothelial cells (ECs) often initiates the pathological events in atherosclerosis.

OBJECTIVES

In this study, we sought to investigate the transcriptional profile of atherosclerotic aortae, identify novel regulator in dysfunctional ECs and hence provide mechanistic insights into atherosclerotic progression.

METHODS

We applied single-cell RNA sequencing (scRNA-seq) on aortic cells from Western diet-fed apolipoprotein E-deficient (ApoE^-/-) mice to explore the transcriptional landscape and heterogeneity of dysfunctional ECs. In vivo validation of SOX4 upregulation in ECs were performed in atherosclerotic tissues, including mouse aortic tissues, human coronary arteries, and human renal arteries. Single-cell analysis on human aortic aneurysmal tissue was also performed. Downstream vascular abnormalities induced by EC-specific SOX4 overexpression, and upstream modulators of SOX4 were revealed by biochemical assays, immunostaining, and wire myography. Effects of shear stress on endothelial SOX4 expression was investigated by in vitro hemodynamic study.

RESULTS

Among the compendium of aortic cells, mesenchymal markers in ECs were significantly enriched. Two EC subsets were subsequently distinguished, as the 'endothelial-like' and 'mesenchymal-like' subsets. Conventional assays consistently identified SOX4 as a novel atherosclerotic marker in mouse and different human arteries, additional to a cancer marker. EC-specific SOX4 overexpression promoted atherogenesis and endothelial-to-mesenchymal transition (EndoMT). Importantly, hyperlipidemia-associated cytokines and oscillatory blood flow upregulated, whereas the anti-diabetic drug metformin pharmacologically suppressed SOX4 level in ECs.

CONCLUSION

Our study unravels SOX4 as a novel phenotypic regulator during endothelial dysfunction, which exacerbates atherogenesis. Our study also pinpoints hyperlipidemia-associated cytokines and oscillatory blood flow as endogenous SOX4 inducers, providing more therapeutic insights against atherosclerotic diseases.

Genetic and Transcriptional Contributions to Relapse in Normal Karyotype Acute Myeloid Leukemia

To better understand clonal and transcriptional adaptations after relapse in patients with acute myeloid leukemia (AML), we collected presentation and relapse samples from six normal karyotype AML cases. We performed enhanced whole-genome sequencing to characterize clonal evolution, and deep-coverage single-cell RNA sequencing on the same samples, which yielded 142,642 high-quality cells for analysis. Identifying expressed mutations in individual cells enabled us to discriminate between normal and AML cells, to identify coordinated changes in the genome and transcriptome, and to identify subclone-specific cell states. We quantified the coevolution of genetic and transcriptional heterogeneity during AML progression, and found that transcriptional changes were significantly correlated with genetic changes. However, transcriptional adaptation sometimes occurred independently, suggesting that clonal evolution does not represent all relevant biological changes. In three cases, we identified cells at diagnosis that likely seeded the relapse. Finally, these data revealed a conserved relapse-enriched leukemic cell state bearing markers of stemness, quiescence, and adhesion. SIGNIFICANCE: These data enabled us to identify a relapse-enriched leukemic cell state with distinct transcriptional properties. Detailed case-by-case analyses elucidated the complex ways in which the AML genome, transcriptome, and immune microenvironment interact to evade chemotherapy. These analyses provide a blueprint for evaluating these factors in larger cohorts.This article is highlighted in the In This Issue feature, p. 1.

Clinicopathological significance of SOX4 and epithelial-mesenchymal transition markers in patients with laryngeal squamous cell carcinoma

OBJECTIVE

Sex-determining region-Y-related high-mobility-group box 4 (SOX4) is associated with the metastasis and prognosis of many cancer types. However, studies on the role of SOX4 in laryngeal squamous cell carcinoma (LSCC) are few, and hence the mechanism is unclear. Epithelial-mesenchymal transition (EMT) allows neoplastic cells to gain the plasticity and motility required for tumor progression and metastasis. This study aimed to analyze the relationship between SOX4 and EMT, and their relationship with clinicopathological factors and related prognosis.

METHODS

Immunohistochemical staining was used to detect the positive expression of SOX4 protein, EMT-related transcription factor protein, and related marker protein in 127 LSCC tissue samples. At the same time, data on various parameters of clinical pathology and postoperative survival were collected.

RESULTS

The positive expression rate of SOX4 and Slug in LSCC was related to pathological differentiation, Lymph node metastasis (LNM), and pathological TNM of a tumor. The expression rates of ZEB1, E-cadherin, N-cadherin, and β-catenin in LSCC correlated with LNM and pTNM. The expression of SOX4, combined expression of SOX4 and ZEB1, and LNM were independent prognostic factors for the total survival time of patients with LSCC.

CONCLUSIONS

In summary, SOX4 was vital in the LSCC EMT process, which might be mediated by transcription factor ZEB1. SOX4 and ZEB1 might serve as potential biomarkers of metastasis and prognosis, as well as promising therapeutic targets of LSCC.

Transcription factor SOX4 facilitates BMP2-regulated gene expression during invasive trophoblast differentiation

The interplay between growth factors, signaling pathways and transcription factors during placental development is key to controlling trophoblast differentiation. Bone morphogenetic protein 2 (BMP2) has been implicated in trophoblast invasion and spiral artery remodeling during early placental development. However, the molecular mechanisms by which these are accomplished have not been fully elucidated, particularly for transcriptional regulation of key transcription factors. Here, we identified SOX4 as a direct target gene induced by BMP2 in first-trimester placental trophoblasts. Analysis of single-cell RNA-seq data from first-trimester placentas and decidua tissues revealed that SOX4 expression is mainly localized in extravillous trophoblast and decidual stromal cells. Moreover, gain- and loss-of-function approaches demonstrated that SOX4 exerts a pro-invasive role in human trophoblasts, and this effect contributes to BMP2-enhanced trophoblast invasion. Importantly, we found that SOX4 was required for BMP2-induced regulation of a subset of genes associated with cell migration and extracellular matrix organization. We also show that SOX4-dependent regulation of the BMP2 target SERPINE2 occurs via binding of SOX4 to regulatory elements such as enhancers, thereby promoting BMP2-induced trophoblast invasion. In conclusion, these findings uncover a novel mechanism involving SOX4 that shapes the BMP2-regulated transcriptional network during invasive trophoblast development.

E2F1-Induced lncRNA BAIAP2-AS1 Overexpression Contributes to the Malignant Progression of Hepatocellular Carcinoma via miR-361-3p/SOX4 Axis

Currently, plenty of researches have revealed that long noncoding RNAs (lncRNAs) can act as crucial roles during the progression of various tumors, including hepatocellular carcinoma (HCC). Here, we measured the expression of lncRNA BAIAP2 antisense RNA 1(BAIAP2-AS1) as well as its contribution to the developments of HCC. In this study, the expressions of BAIAP2-AS1 and SOX4 were distinctly upregulated in HCC cells and tissues, and high BAIAP2-AS1 may be a novel biomarker for HCC. E2F1 activated BAIAP2-AS1 expression. The silence of BAIAP2-AS1 inhibited the proliferation and metastasis of HepG2 and PLC5 cells. Assays for relationship verification showed that BAIAP2-AS1 regulated the expression of SOX4 and miR-361-3p. Rescue experiments further confirmed the positive interaction between miR-361-3p and BAIAP2-AS1 as well as between miR-361-3p and SOX4. Overall, BAIAP2-AS1 modulated the miR-361-3p/SOX4 axis to promote the development of HCC. Thus, our study offers a potential therapeutic target for treating HCC.

Apobec1 complementation factor overexpression promotes hepatic steatosis, fibrosis, and hepatocellular cancer

The RNA-binding protein Apobec1 complementation factor (A1CF) regulates posttranscriptional ApoB mRNA editing, but the range of RNA targets and the long-term effect of altered A1CF expression on liver function are unknown. Here we studied hepatocyte-specific A1cf-transgenic (A1cf+/Tg), A1cf+/Tg Apobec1-/-, and A1cf-/- mice fed chow or high-fat/high-fructose diets using RNA-Seq, RNA CLIP-Seq, and tissue microarrays from human hepatocellular cancer (HCC). A1cf+/Tg mice exhibited increased hepatic proliferation and steatosis, with increased lipogenic gene expression (Mogat1, Mogat2, Cidea, Cd36) associated with shifts in polysomal RNA distribution. Aged A1cf+/Tg mice developed spontaneous fibrosis, dysplasia, and HCC, and this development was accelerated on a high-fat/high-fructose diet and was independent of Apobec1. RNA-Seq revealed increased expression of mRNAs involved in oxidative stress (Gstm3, Gpx3, Cbr3), inflammatory response (Il19, Cxcl14, Tnfα, Ly6c), extracellular matrix organization (Mmp2, Col1a1, Col4a1), and proliferation (Kif20a, Mcm2, Mcm4, Mcm6), and a subset of mRNAs (including Sox4, Sox9, Cdh1) were identified in RNA CLIP-Seq. Increased A1CF expression in human HCC correlated with advanced fibrosis and with reduced survival in a subset with nonalcoholic fatty liver disease. In conclusion, we show that hepatic A1CF overexpression selectively alters polysomal distribution and mRNA expression, promoting lipogenic, proliferative, and inflammatory pathways leading to HCC.

circRNA hsa_circ_0005909 Predicts Poor Prognosis and Promotes the Growth, Metastasis, and Drug Resistance of Non-Small-Cell Lung Cancer via the miRNA-338-3p/SOX4 Pathway

Background

Circular RNAs (circRNAs) are powerful factors in regulating various cancer behaviors. It has been manifested in previous researches that circular RNA hsa_circ_0005909 (circ_0005909) exhibits a regulatory function in osteosarcoma. However, there are no other studies on whether circ_0005909 displays potential functions on the progression of non-small-cell lung cancer (NSCLC).

Methods

RT-PCR was applied to examine the expression of circ_0005909 in NSCLC. To study the specific behaviors of NSCLC cells after circ_0005909 knockdown, cell counting kit-8 (CCK-8) assays, colony formation assays, Transwell assays, and xenograft tumor model assays were conducted. Bioinformatics and luciferase reporter assays were employed to study the association among circ_0005909, miRNA-338-3p, and SOX4.

Results

In this research, our group firstly showed that circ_0005909 expressions were distinctly increased in NSCLC specimens and cell lines. Clinical studies revealed that high circ_0005909 expressions were associated with poor prognosis of NSCLC patients. Functionally, knockdown of circ_0005909 was observed to suppress the proliferation, metastasis, and drug resistance of NSCLC cells. In the terms of mechanism, circ_0005909 could act as a sponge of miRNA-338-3p, and miRNA-338-3p could target SOX4. In addition, miRNA-338-3p inhibitors reversed the suppressor ability of circ_0005909 silence on NSCLC behaviors.

Conclusions

circ_0005909 promoted the progression of NSCLC via the modulation of the miRNA-338-3p/SOX4 axis, which may be a therapeutic target for NSCLC.

Anaplastic Lymphoma Kinase Overexpression Is Associated with Aggressive Phenotypic Characteristics of Ovarian High-Grade Serous Carcinoma

Deregulated full-length anaplastic lymphoma kinase (ALK) overexpression has been found in some primary solid tumors, but little is known about its role in ovarian high-grade serous carcinoma (HGSC). Herein, we focused on the functional roles of ALK in HGSC. Cytoplasmic ALK immunoreactivity without chromosomal rearrangement and gene mutations was significantly higher in HGSC compared with non-HGSC type ovarian carcinomas, and was significantly associated with several unfavorable clinicopathologic factors and poor prognosis. HGSC cell lines stably overexpressing ALK exhibited increased cell proliferation, enhanced cancer stem cell features, and accelerated cell mobility, whereas these phenotypes were abrogated in ALK-knockdown cells. Expression of the nervous system-associated gene, ELAVL3, and the corresponding protein (commonly known as HuC) was significantly increased in cells overexpressing ALK. There was increased expression of Sox2 and Sox3 (genes associated with the neural progenitor population) in ALK-overexpressing but not ALK-knockdown cells. Furthermore, overexpression of Sox2 or Sox3 enhanced both ALK and ELAVL3 promoter activities, suggesting the existence of ALK/Sox/HuC signaling loops. Finally, ALK overexpression was due to increased expression of neuroendocrine markers, including synaptophysin, CD56, and BCL2, in HGSC tissues. These findings suggest that overexpression of full-length ALK may influence the biological behavior of HGSC through cooperation with ELAVL3 and Sox factors, leading to establishment and maintenance of the aggressive phenotypic characteristics of HGSC.

miR-30a/SOX4 Double Negative Feedback Loop is modulated by Disulfiram and regulates EMT and Stem Cell-like properties in Breast Cancer

Background: Both epithelial-to-mesenchymal transition (EMT) and cancer stem cells play important roles in development and progression of breast cancer. MicroRNA (miR)-30 family members have been reported to be associated with the regulation of EMT and stem cell phenotypes, however, the underlying molecular mechanisms are not well understood.

Methods: miR-30a stable transfectants of breast cancer cell lines were created using a lentiviral system. Bioinformatics analysis was performed to explore miR-30a target genes and SOX4 was selected and identified by dual luciferase reporter assay. The effects of miR-30a and target gene SOX4 on EMT and CSC phenotypes in breast cancer were explored in vitro and in vivo.

Results: Overexpression of miR-30a in breast cancer cells inhibited EMT and CSC phenotypes by targeting SOX4. Luciferase reporter assay confirmed that miR-30a directly targeted 3'UTR of SOX4, and formed a double-negative feedback loop with SOX4. Functional experiments demonstrated that knockdown of SOX4 suppressed EMT and CSC phenotypes of breast cancer cells through TGF-β/SMAD pathway, which was consistent with the inhibitory effects by overexpression of miR-30a. Additionally, we found disulfiram can upregulate miR-30a expression, and high miR-30a expression was associated with a good prognosis in breast cancer patients through TCGA database.

Conclusion: Our findings suggest a novel double-negative loop between miR-30a and SOX4 mediated regulation of EMT and CSC features in breast cancer through TGF-β/SMAD pathway, highlighting a novel therapeutic target for breast cancer.

SOX4 as biomarker in hepatitis B virus-associated hepatocellular carcinoma

Background: Hepatitis B virus infection is associated with liver disease, including cancers. In this study, we assessed the power of sex-determining region Y (SRY)-related high-mobility group (HMG)-box 4(SOX4) gene to predict the clinical course of hepatocellular carcinoma (HCC).

Methods: To evaluate the differential expression of SOX4 and its diagnostic and prognostic potential in HCC, we analyzed the GSE14520 dataset. Stratified analysis and joint-effect analysis were done using SOX4 and clinical factor. We then designed a nomogram for predicting the clinical course of HCC. Differential SOX4 expression and its correlation with tumor stage as well as its diagnostic and prognostic value were analyzed on the oncomine and GEPIA websites. Gene set enrichment analysis was explored as well as candidate gene ontology and metabolic pathways modulated by in SOX4 HCC.

Results: Our analysis revealed that the level of SOX4 was significantly upregulated in tumor issue (P <0.001). This observation was validated through oncomine dataset and MERAV analysis (all P <0.05). Diagnostic receiver operating characteristic (ROC) analysis of SOX4 suggested it has diagnostic potential in HCC (GSE14520 dataset: P <0.001, area under curve (AUC) = 0.782; Oncomine: (Wurmbach dataset) P = 0.002, AUC = 0.831 and (Mas dataset) P <0.001, AUC = 0.947). In addition, SOX4 exhibited high correlation with overall survival of HBV-associated HCC (adjusted P = 0.004, hazard ratio (HR) (95% confidence interval (CI)) = 2.055 (1.261-3.349) and recurrence-free survival (adjusted P = 0.008, HR (95% CI) = 1.721 (1.151-2.574). These observations which were verified by GEPIA analysis for overall survival (P = 0.007) and recurrence-free survival (P= 0.096). Gene enrichment analysis revealed that affected processes included lymphocyte differentiation, pancreatic endocrine pathways, and insulin signaling pathway. SOX4 prognostic value was evaluated using nomogram analysis for HCC 1, 3, and 5-year, survival.

Conclusion: Differential SOX4 expression presents an avenue of diagnosing and predicting clinical course of HCC. In HCC, SOX4 may affect TP53 metabolic processes, lymphocyte differentiation and the insulin signaling pathway.

Clinicopathological significance of SOX4 and epithelial-mesenchymal transition markers in patients with laryngeal squamous cell carcinoma

BACKGROUND AND AIM

Sex-determining region-Y-related high-mobility-group box 4 (SOX4) is associated with the metastasis and prognosis of many cancer types. However, studies on the role of SOX4 in laryngeal squamous cell carcinoma (LSCC) are few, and hence the mechanism is unclear. Epithelial-mesenchymal transition (EMT) allows neoplastic cells to gain the plasticity and motility required for tumor progression and metastasis. This study aimed to analyze the relationship between SOX4 and EMT, and their relationship with clinicopathological factors and related prognosis.

METHODS

Immunohistochemical staining was used to detect the positive expression of SOX4 protein, EMT-related transcription factor protein, and related marker protein in 127 LSCC tissue samples. At the same time, data on various parameters of clinical pathology and postoperative survival were collected.

RESULTS

The positive expression rate of SOX4 and Slug in LSCC was related to pathological differentiation, lymphatic invasion, and pathological tumor node metastasis (TNM) of a tumor. The expression rates of ZEB1, Twist, E-cadherin, N-cadherin, and β-catenin in LSCC correlated with lymphatic invasion and pathological tumor node metastasis. The expression of SOX4, combined expression of SOX4 and ZEB1, and lymphatic invasion were independent prognostic factors for the total survival time of patients with LSCC.

CONCLUSIONS

In summary, SOX4 was vital in the LSCC EMT process, which might be mediated by transcription factor ZEB1. SOX4 and ZEB1 might serve as potential biomarkers of metastasis and prognosis, as well as promising therapeutic targets of LSCC.

IL‑6 plays a crucial role in epithelial‑mesenchymal transition and pro‑metastasis induced by sorafenib in liver cancer

Interleukin‑6 (IL‑6) is involved in various biological responses, including tumor progression, metastasis and chemoresistance. However, the role and molecular mechanism of IL‑6 in the treatment of sorafenib in liver cancer remain unclear. In the present study, through western blot analysis, Transwell assay, flow cytometric assay, ELISA analysis and immunohistochemistry it was revealed that sorafenib promoted metastasis and induced epithelial‑mesenchymal transition (EMT) in liver cancer cells in vitro and in vivo, and significantly increased IL‑6 expression. Endogenous or exogenous IL‑6 affected metastasis and EMT progression in liver cancer cells through Janus kinase 2/signal transducer and activator of transcription 3 (STAT3) signaling. Knocked out IL‑6 markedly attenuated the pro‑metastasis effect of sorafenib and increased the susceptibility of liver cancer cells to it. In conclusion, the present results indicated that IL‑6/STAT3 signaling may be a novel therapeutic strategy for liver cancer.

SOX4 Serves an Oncogenic Role in the Tumourigenesis of Human Breast Adenocarcinoma by Promoting Cell Proliferation, Migration and Inhibiting Apoptosis

BACKGROUND

Breast cancer is among the most common malignant cancers worldwide, and breast adenocarcinoma in glandular tissue cells has excessive metastasis and invasion capability. However, little is known on the molecular process by which this disease develops and progresses.

OBJECTIVE

In this study, we explored the effects of sex-determining region Y-box 4 (SOX4) protein on proliferation, migration, apoptosis and tumourigenesis of breast adenocarcinoma and its possible mechanisms.

METHODS

The SOX4 overexpression or knockdown Michigan Cancer Foundation-7 (MCF-7) cell lines were established. Among the SOX4 overexpression or MCF-7 knockdown cell lines, proliferation, migration ability and apoptosis rate were detected. The expression levels of apoptosis-related proteins (Bax and Cleaved caspase-3) were analysed using Western blot. The effect of SOX4 on tumourigenesis was analysed using the clone formation assay in vitro and tumour xenograft experiment in nude mice.

RESULTS

Compared with the overexpression of control cells, proliferation and migration ability of SOX4 overexpression cells significantly increased, the apoptosis rate significantly decreased in addition to the expression levels of Bax and Cleaved caspase-3 (P < 0.05). Compared with the knockdown of control cells, proliferation and migration ability of SOX4 knockdown cells significantly decreased, and the apoptosis rate and expression levels of Bax and Cleaved caspase-3 significantly increased (P < 0.05). Clone formation and tumour growth abilities of SOX4 overexpression cells were significantly higher than those of the control cells (P < 0.05), whereas SOX4 knockdown cells had the opposite effect.

CONCLUSION

SOX4 plays an oncogenic role in breast adenocarcinoma tumourigenesis by promoting cell proliferation, migration and inhibiting apoptosis. It can be used as a potential molecular target for breast cancer gene therapy.

Integrin αvβ6-TGFβ-SOX4 Pathway Drives Immune Evasion in Triple-Negative Breast Cancer

Cancer immunotherapy shows limited efficacy against many solid tumors that originate from epithelial tissues, including triple-negative breast cancer (TNBC). We identify the SOX4 transcription factor as an important resistance mechanism to T cell-mediated cytotoxicity for TNBC cells. Mechanistic studies demonstrate that inactivation of SOX4 in tumor cells increases the expression of genes in a number of innate and adaptive immune pathways important for protective tumor immunity. Expression of SOX4 is regulated by the integrin αvβ6 receptor on the surface of tumor cells, which activates TGFβ from a latent precursor. An integrin αvβ6/8-blocking monoclonal antibody (mAb) inhibits SOX4 expression and sensitizes TNBC cells to cytotoxic T cells. This integrin mAb induces a substantial survival benefit in highly metastatic murine TNBC models poorly responsive to PD-1 blockade. Targeting of the integrin αvβ6-TGFβ-SOX4 pathway therefore provides therapeutic opportunities for TNBC and other highly aggressive human cancers of epithelial origin.

Hypoxia-sensitive long noncoding RNA CASC15 promotes lung tumorigenesis by regulating the SOX4/β-catenin axis

BACKGROUND

Accumulating evidence has demonstrated that long non-coding RNAs (lncRNAs) are involved in the hypoxia-related cancer process and play pivotal roles in enabling malignant cells to survive under hypoxic stress. However, the molecular crosstalk between lncRNAs and hypoxia signaling cascades in non-small cell lung cancer (NSCLC) remains largely elusive.

METHODS

Firstly, we identified differentially expressed lncRNA cancer susceptibility candidate 15 (CASC15) as associated with NSCLC based on bioinformatic data. The clinical significance of CASC15 in lung cancer was investigated by Kaplan-Meier survival analysis. Then, we modulated CASC15 expression in NSCLC cell lines by RNAi. CCK-8 and transwell assays were carried out to examine the effects of CASC15 on proliferation and migration of NSCLC cells. Upstream activator and downstream targets of CASC15 were validated by luciferase reporter assay, qRT-PCR, Western blotting, and chromatin immunoprecipitation (ChIP). Lastly, RNA in situ hybridization (RNA-ISH) and immunohistochemistry (IHC) were performed to confirm the genetic relationships between CASC15 and related genes in clinical samples.

RESULTS

CASC15 was highly expressed in NSCLC tissues and closely associated with poor prognosis. Loss-of-function analysis demonstrated that CASC15 was essential for NSCLC cell migration and growth. Mechanistic study revealed that CASC15 was transcriptionally activated by hypoxia signaling in NSCLC cells. Further analysis showed that hypoxia-induced CASC15 transactivation was mainly dependent on hypoxia-inducible factor 1α (HIF-1α) and hypoxia response elements (HREs) located in CASC15 promoter. CASC15 promotes the expression of its chromosomally nearby gene, SOX4. Then SOX4 functions to stabilize β-catenin protein, thereby enhancing the proliferation and migration of NSCLC cells. HIF-1α/CASC15/SOX4/β-catenin pathway was activated in a substantial subset of NSCLC patients.

CONCLUSIONS

HIF-1α/CASC15/SOX4/β-catenin axis plays an essential role in the development and progression of NSCLC. The present work provides new evidence that lncRNA CASC15 holds great promise to be used as novel biomarkers for NSCLC. Blocking the HIF-1α/CASC15/SOX4/β-catenin axis can serve as a potential therapeutic strategy for treating NSCLC.

Master regulator genes and their impact on major diseases

Master regulator genes (MRGs) have become a hot topic in recent decades. They not only affect the development of tissue and organ systems but also play a role in other signal pathways by regulating additional MRGs. Because a MRG can regulate the concurrent expression of several genes, its mutation often leads to major diseases. Moreover, the occurrence of many tumors and cardiovascular and nervous system diseases are closely related to MRG changes. With the development in omics technology, an increasing amount of investigations will be directed toward MRGs because their regulation involves all aspects of an organism’s development. This review focuses on the definition and classification of MRGs as well as their influence on disease regulation.

Overexpression of transmembrane protein 2 (TMEM2), a novel hyaluronidase, predicts poor prognosis in pancreatic ductal adenocarcinoma

BACKGROUND

Abnormal metabolism of hyaluronan (HA), a major component of extracellular matrix, is a hallmark of cancer. Our previous studies have shown the importance of enzymes responsible for HA degradation in the aggressive phenotype of pancreatic ductal adenocarcinoma (PDAC). In the present study, we investigated the expression and function of transmembrane protein 2 (TMEM2), a recently identified HA-degrading enzyme, in PDAC.

MATERIALS & METHODS

We used immunohistochemistry to investigate expression patterns of TMEM2 in archival tissues obtained from 100 patients with PDAC who underwent surgical resection from 1982 to 2012. The correlations between TMEM2 expression and clinicopathological variables, including survival, were determined using univariate and multivariate analyses. The effect of TMEM2 on proliferation and migratory ability (measured using transwell cell migration assay) of PDAC cells was determined by TMEM2 knockdown with small-interfering RNA (siRNA).

RESULTS

Immunohistochemical analysis revealed high expression of TMEM2 in 22 (22%) of 100 patients. The overall survival was significantly shorter in patients with high TMEM2 expression than in those with low expression (P = 0.013). Multivariate analysis identified high TMEM2 expression as an independent factor predicting poor prognosis (P = 0.011). Unexpectedly, knockdown of TMEM2 resulted in increased migratory ability of PDAC cells, which was associated with increased expression of KIAA1199, a potent HA-degrading enzyme shown to enhance cell migration.

CONCLUSION

TMEM2 overexpression is associated with poor prognosis in PDAC patients. Targeted disruption of this molecule, however, could enhance the aggressiveness of PDAC cells through a possible interaction with KIAA1199.

Age-induced accumulation of methylmalonic acid promotes tumour progression

From age 65 onwards, the risk of cancer incidence and associated mortality is substantially higher^1–6. Nonetheless, our understanding of the complex relationship between age and cancer is still in its infancy^2,3,7,8. For decades, this link has largely been attributed to increased exposure time to mutagens in older individuals. However, this view does not account for the well-established role of diet, exercise and small molecules that target the pace of metabolic aging^9–12. Here, we show that metabolic alterations that occur with age can render a systemic environment favorable to progression and aggressiveness of tumors. Specifically, we show that methylmalonic acid (MMA), a by-product of propionate metabolism, is significantly up-regulated in the serum of older people, and functions as a mediator of tumor progression. We traced this to MMA’s ability to induce SOX4 and consequently eliciting a transcriptional reprogramming that can endow cancer cells with aggressive properties. Thus, accumulation of MMA represents a novel link between aging and cancer progression, implicating MMA as a novel therapeutic target for advanced carcinomas.

Selective Translation of Cell Fate Regulators Mediates Tolerance to Broad Oncogenic Stress

Human skin tolerates a surprisingly high burden of oncogenic lesions. Although adult epidermis can suppress the expansion of individual mutant clones, the mechanisms behind tolerance to oncogene activation across broader regions of tissue are unclear. Here, we uncover a dynamic translational mechanism that coordinates oncogenic HRAS-induced hyperproliferation with loss of progenitor self-renewal to restrain aberrant growth and tumorigenesis. We identify translation initiator eIF2B5 as a central co-regulator of HRAS proliferation and cell fate choice. By coupling in vivo ribosome profiling with genetic screening, we provide direct evidence that oncogene-induced loss of progenitor self-renewal is driven by eIF2B5-mediated translation of ubiquitination genes. Ubiquitin ligase FBXO32 specifically inhibits epidermal renewal without affecting overall proliferation, thus restraining HRAS-driven tumorigenesis while maintaining normal tissue growth. Thus, oncogene-driven translation is not necessarily inherently tumor promoting but instead can manage widespread oncogenic stress by steering progenitor fate to prolong normal tissue growth.

S-adenosylmethionine in combination with decitabine shows enhanced anti-cancer effects in repressing breast cancer growth and metastasis

Abnormal DNA methylation orchestrates many of the cancer‐related gene expression irregularities such as the inactivation of tumour suppressor genes through hypermethylation as well as activation of prometastatic genes through hypomethylation. The fact that DNA methylation abnormalities can be chemically reversed positions the DNA methylation machinery as an attractive target for anti‐cancer drug development. However, although in vitro studies suggested that targeting concordantly hypo‐ and hypermethylation is of benefit in suppressing both oncogenic and prometastatic functions of breast cancer cells, this has never been tested in a therapeutic setting in vivo. In this context, we investigated the combined therapeutic effects of an approved nutraceutical agent S‐adenosylmethionine (SAM) and FDA‐approved hypomethylating agent decitabine using the MDA‐MB‐231 xenograft model of breast cancer and found a pronounced reduction in mammary tumour volume and lung metastasis compared to the animals in the control and monotherapy treatment arms. Immunohistochemical assessment of the primary breast tumours showed a significantly reduced expression of proliferation (Ki‐67) and angiogenesis (CD31) markers following combination therapy as compared to the control group. Global transcriptome and methylome analyses have revealed that the combination therapy regulates genes from several key cancer‐related pathways that are abnormally expressed in breast tumours. To our knowledge, this is the first preclinical study demonstrating the anti‐cancer therapeutic potential of using a combination of methylating (SAM) and demethylating agent (decitabine) in vivo. Results from this study provide a molecularly founded rationale for clinically testing a combination of agents targeting the epigenome to reduce the morbidity and mortality from breast cancer.

Liquid Biopsy as Novel Tool in Precision Medicine: Origins, Properties, Identification and Clinical Perspective of Cancer's Biomarkers

In recent years, there has been an increase in knowledge of cancer, accompanied by a technological development that gives rise to medical oncology. An instrument that allows the implementation of individualized therapeutic strategies is the liquid biopsy. Currently, it is the most innovative methodology in medical oncology. Its high potential as a tool for screening and early detection, the possibility of assessing the patient’s condition after diagnosis and relapse, as well as the effectiveness of real-time treatments in different types of cancer. Liquid biopsy is capable of overcoming the limitations of tissue biopsies. The elements that compose the liquid biopsy are circulating tumor cells, circulating tumor nucleic acids, free of cells or contained in exosomes, microvesicle and platelets. Liquid biopsy studies are performed on various biofluids extracted in a non-invasive way, and they can be performed both from the blood and in urine, saliva or cerebrospinal fluid. The development of genotyping techniques, using the elements that make up liquid biopsy, make it possible to detect mutations, intertumoral and intratumoral heterogeneity, and provide molecular information on cancer for application in medical oncology in an individualized way in different types of tumors. Therefore, liquid biopsy has the potential to change the way medical oncology could predict the course of the disease.

Serial Xenotransplantation in NSG Mice Promotes a Hybrid Epithelial/Mesenchymal Gene Expression Signature and Stemness in Rhabdomyosarcoma Cells

Serial xenotransplantation of sorted cancer cells in immunodeficient mice remains the most complex test of cancer stem cell (CSC) phenotype. However, we have demonstrated in various sarcomas that putative CSC surface markers fail to identify CSCs, thereby impeding the isolation of CSCs for subsequent analyses. Here, we utilized serial xenotransplantation of unsorted rhabdomyosarcoma cells in NOD/SCID gamma (NSG) mice as a proof-of-principle platform to investigate the molecular signature of CSCs. Indeed, serial xenotransplantation steadily enriched for rhabdomyosarcoma stem-like cells characterized by enhanced aldehyde dehydrogenase activity and increased colony and sphere formation capacity in vitro. Although the expression of core pluripotency factors (SOX2, OCT4, NANOG) and common CSC markers (CD133, ABCG2, nestin) was maintained over the passages in mice, gene expression profiling revealed gradual changes in several stemness regulators and genes linked with undifferentiated myogenic precursors, e.g., SOX4, PAX3, MIR145, and CDH15. Moreover, we identified the induction of a hybrid epithelial/mesenchymal gene expression signature that was associated with the increase in CSC number. In total, 60 genes related to epithelial or mesenchymal traits were significantly altered upon serial xenotransplantation. In silico survival analysis based on the identified potential stemness-associated genes demonstrated that serial xenotransplantation of unsorted rhabdomyosarcoma cells in NSG mice might be a useful tool for the unbiased enrichment of CSCs and the identification of novel CSC-specific targets. Using this approach, we provide evidence for a recently proposed link between the hybrid epithelial/mesenchymal phenotype and cancer stemness.

Long non-coding RNA TGLC15 advances hepatocellular carcinoma by stabilizing Sox4

BACKGROUND

The hepatocellular carcinoma (HCC) belongs to a common malignancy especially in China. Recent data have clarified important roles of long non-coding RNAs (lncRNAs) in HCC. However, the role of a novel intergenic lncRNA termed TGLC15 is still elusive.

METHODS

We screened for novel lncRNAs using lncRNA profiling. TGLC15 expression was quantified by qRT-PCR. In vitro experiments such as migration and viability assays were performed. In vivo implantation experiments were conducted to investigate tumorigenic functions of TGLC15. Combined RNA immunoprecipitation (RIP) and mass spectrometry (MS) were utilized to uncover Sox4 as TGLC15 binding protein.

RESULTS

TGLC15 is significantly overexpressed in tumor tissues and HCC cell lines. Higher TGLC15 levels correlated with advanced malignant characteristics such as TNM stages, tumor size, and metastasis. TGLC15 advanced HCC migration and viability. The in vivo experiments supported that xenograft tumor growth and proliferation were facilitated by TGLC15 overexpression. Mechanistic studies showed that TGLC15 interacted with Sox4 and interaction between TGLC15 and Sox4 could stabilize Sox4 via reduction in proteasome-mediated degradation.

CONCLUSIONS

Collectively, our data have identified a novel lncRNA TGLC15 during HCC development. The TGLC15-Sox4 signaling might be a potential target for pharmaceutical intervention.

LncARSR sponges miR-129-5p to promote proliferation and metastasis of bladder cancer cells through increasing SOX4 expression

Emerging evidences have indicated that long non-coding RNAs (lncRNAs) are potential biomarkers, playing important roles in the development of cancer. LncRNA Activated in RCC with Sunitinib Resistance (lncARSR) is a novel lncRNA that functions as a potential biomarker and is involved in the progression of cancers. However, the clinical significance and molecular mechanism of lncARSR in bladder cancer (Bca) remains unknow. In this study, we discovered that lncARSR was significantly up-regulated in bladder cancer. In addition, increased expression of lncARSR was positively correlated with higher histological grade and larger tumor size. Further experiments demonstrated that suppression of lncARSR attenuated the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) process of Bca cells. Mechanistically, lncARSR was mainly located in the cytoplasm and acted as a miRNA sponge to positively modulate the expression of Sex-determining region Y-related high-mobility-group box transcription factor 4 (SOX4) via sponging miR-129-5p and subsequently promoted the proliferation and metastasis of Bca cells, thus playing an oncogenic role in Bca pathogenesis. In conclusion, our study indicated that lncARSR plays a critical regulatory role in Bca cells and lncARSR may serve as a potential diagnostic biomarker and therapeutic target for bladder cancer.

Discovering master regulators in hepatocellular carcinoma: one novel MR, SEC14L2 inhibits cancer cells

Identification of master regulator (MR) genes offers a relatively rapid and efficient way to characterize disease-specific molecular programs. Since strong consensus regarding commonly altered MRs in hepatocellular carcinoma (HCC) is lacking, we generated a compendium of HCC datasets from 21 studies and identified a comprehensive signature consisting of 483 genes commonly deregulated in HCC. We then used reverse engineering of transcriptional networks to identify the MRs that underpin the development and progression of HCC. After cross-validation in different HCC datasets, systematic assessment using patient-derived data confirmed prognostic predictive capacities for most HCC MRs and their corresponding regulons. Our HCC signature covered well-established liver cancer hallmarks, and network analyses revealed coordinated interaction between several MRs. One novel MR, SEC14L2, exerted an anti-proliferative effect in HCC cells and strongly suppressed tumor growth in a mouse model. This study advances our knowledge of transcriptional MRs potentially involved in HCC development and progression that may be targeted by specific interventions.

ALDH3A1 Overexpression in Melanoma and Lung Tumors Drives Cancer Stem Cell Expansion, Impairing Immune Surveillance through Enhanced PD-L1 Output

Melanoma and non-small-cell lung carcinoma (NSCLC) cell lines are characterized by an intrinsic population of cancer stem-like cells (CSC), and high expression of detoxifying isozymes, the aldehyde dehydrogenases (ALDHs), regulating the redox state. In this study, using melanoma and NSCLC cells, we demonstrate that ALDH3A1 isozyme overexpression and activity is closely associated with a highly aggressive mesenchymal and immunosuppressive profile. The contribution of ALDH3A1 to the stemness and immunogenic status of melanoma and NSCLC cells was evaluated by their ability to grow in 3D forming tumorspheres, and by the expression of markers for stemness, epithelial to mesenchymal transition (EMT), and inflammation. Furthermore, in specimens from melanoma and NSCLC patients, we investigated the expression of ALDH3A1, PD-L1, and cyclooxygenase-2 (COX-2) by immunohistochemistry. We show that cells engineered to overexpress the ALDH3A1 enzyme enriched the CSCs population in melanoma and NSCLC cultures, changing their transcriptome. In fact, we found increased expression of EMT markers, such as vimentin, fibronectin, and Zeb1, and of pro-inflammatory and immunosuppressive mediators, such as NFkB, prostaglandin E2, and interleukin-6 and -13. ALDH3A1 overexpression enhanced PD-L1 output in tumor cells and resulted in reduced proliferation of peripheral blood mononuclear cells when co-cultured with tumor cells. Furthermore, in tumor specimens from melanoma and NSCLC patients, ALDH3A1 expression was invariably correlated with PD-L1 and the pro-inflammatory marker COX-2. These findings link ALDH3A1 expression to tumor stemness, EMT and PD-L1 expression, and suggest that aldehyde detoxification is a redox metabolic pathway that tunes the immunological output of tumors.

Identification of Novel Markers of Prostate Cancer Progression, Potentially Modulated by Vitamin D

Prostate cancer (PCa) is one of the most common cancers in men. The main risk factors associated with the disease include older age, family history of the disease, smoking, alcohol and race. Vitamin D is a pleiotropic hormone whose low levels are associated with several diseases and a risk of cancer. Here, we undertook microarray analysis in order to identify the genes involved in PCa. We analyzed three PCa microarray datasets, overlapped all genes significantly up-regulated, and subsequently intersected the common genes identified with the down-regulated genes transcriptome of LNCaP cells treated with 1α,25(OH)2D3, in order to identify the common genes involved in PCa and potentially modulated by Vitamin D. The analysis yielded 43 genes potentially involved in PCa and significantly modulated by Vitamin D. Noteworthy, our analysis showed that six genes (PRSS8, SOX4, SMYD2, MCCC2, CCNG2 and CD2AP) were significantly modulated. A Pearson correlation analysis showed that five genes out of six (SOX4 was independent), were statistically correlated with the gene expression levels of KLK3, and with the tumor percentage. From the outcome of our investigation, it is possible to conclude that the genes identified by our analysis are associated with the PCa and are potentially modulated by the Vitamin D.

Milk-derived miRNA profiles elucidate molecular pathways that underlie breast dysfunction in women with common genetic variants in SLC30A2

Studies in humans and pre-clinical animal models show milk-derived miRNAs reflect mammary gland function during lactation. The zinc transporter SLC30A2/ZnT2 plays a critical role in mammary gland function; ZnT2-null mice have profound defects in mammary epithelial cell (MEC) polarity and secretion, resulting in sub-optimal lactation. Non-synonymous genetic variation in SLC30A2 is common in humans, and several common ZnT2 variants are associated with changes in milk components that suggest breast dysfunction in women. To identify novel mechanisms through which dysfunction might occur, milk-derived miRNA profiles were characterized in women harboring three common genetic variants in SLC30A2 (D¹⁰³E, T²⁸⁸S, and Exon 7). Expression of ten miRNAs differed between genotypes, and contributed to distinct spatial separation. Studies in breast milk and cultured MECs confirmed expression of ZnT2 variants alters abundance of protein levels of several predicted mRNA targets critical for breast function (PRLR, VAMP7, and SOX4). Moreover, bioinformatic analysis identified two novel gene networks that may underlie normal MEC function. Thus, we propose that genetic variation in genes critical for normal breast function such as SLC30A2 has important implications for lactation performance in women, and that milk-derived miRNAs can be used to identify novel mechanisms and for diagnostic potential.

Development of an oncogenic dedifferentiation SOX signature with prognostic significance in hepatocellular carcinoma

Background

Gradual loss of terminal differentiation markers and gain of stem cell-like properties is a major hall mark of cancer malignant progression. The stem cell pluripotent transcriptional factor SOX family play critical roles in governing tumor plasticity and lineage specification. This study aims to establish a novel SOX signature to monitor the extent of tumor dedifferentiation and predict prognostic significance in hepatocellular carcinoma (HCC).

Methods

The RNA-seq data from The Cancer Genome Atlas (TCGA) LIHC project were chronologically divided into the training (n = 188) and testing cohort (n = 189). LIRI-JP project from International Cancer Genome Consortium (ICGC) data portal was used as an independent validation cohort (n = 232). Kaplan-Meier and multivariable Cox analyses were used to examine the clinical significance and prognostic value of the signature genes.

Results

The SOX gene family members were found to be aberrantly expressed in clinical HCC patients. A five-gene SOX signature with prognostic value was established in the training cohort. The SOX signature genes were found to be closely associated with tumor grade and tumor stage. Liver cancer dedifferentiation markers (AFP, CD133, EPCAM, and KRT19) were found to be progressively increased while hepatocyte terminal differentiation markers (ALB, G6PC, CYP3A4, and HNF4A) were progressively decreased from HCC patients with low SOX signature scores to patients with high SOX signature scores. Kaplan-Meier survival analysis further indicated that the newly established SOX signature could robustly predict patient overall survival in both training, testing, and independent validation cohort.

Conclusions

An oncogenic dedifferentiation SOX signature presents a great potential in predicting prognostic significance in HCC, and might provide novel biomarkers for precision oncology further in the clinic.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-6041-2) contains supplementary material, which is available to authorized users.

SOX4: The unappreciated oncogene

SOX4 is an essential developmental transcription factor that regulates stemness, differentiation, progenitor development, and multiple developmental pathways including PI3K, Wnt, and TGFβ signaling. The SOX4 gene is frequently amplified and overexpressed in over 20 types of malignancies, and multiple lines of evidence support that notion that SOX4 is an oncogene. Its overexpression is due to both gene amplification and to activation of PI3K, Wnt, and TGFβ pathways that SOX4 regulates. SOX4 interacts with multiple other transcription factors, rendering many of its impacts on gene expression context and tissue-specific. Nevertheless, there are common themes that run through many of the effects of SOX4 hyperactivity, such as the promotion of cell survival, stemness, the epithelial to mesenchymal transition, migration, and metastasis. Specific targeting of SOX4 remains a challenge for future cancer research and drug development.

SOX4: Epigenetic regulation and role in tumorigenesis

Sex-determining region Y-related (SRY) high-mobility group box 4 (SOX4) is a member of the group C subfamily of SOX transcription factors and promotes tumorigenesis by endowing cancer cells with survival, migratory, and invasive capacities. Emerging evidence has highlighted an unequivocal role for this transcription factor in mediating various signaling pathways involved in tumorigenesis, epithelial-to-mesenchymal transition (EMT), and tumor progression. During the last decade, numerous studies have highlighted the epigenetic interplay between SOX4-targeting microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and SOX4 and the subsequent modulation of tumorigenesis, invasion and metastasis. In this review, we summarize the current state of knowledge about the role of SOX4 in cancer development and progression, the epigenetic regulation of SOX4, and the potential utilization of SOX4 as a diagnostic and prognostic biomarker and its depletion as a therapeutic target.