SOX4 regulates proliferation and apoptosis of human ovarian granulosa-like tumor cell line KGN through the Hippo pathway

The proliferation and apoptosis of ovarian granulosa cells are important for folliculogenesis. As a transcription factor, SRY-box transcription factor 4 (SOX4) has important roles in regulating cellular proliferation and apoptosis. Nonetheless, the regulatory mechanisms of SOX4 on proliferation and apoptosis of granulosa cells remain elusive. Therefore, a stably overexpressed SOX4 ovarian granulosa cell line KGN was generated by lentivirus encapsulation. We observed that overexpression of SOX4 inhibits apoptosis, promotes proliferation and migration of KGN cells. Comparative analysis of the transcriptome revealed 868 upregulated and 696 downregulated DEGs in LV-SOX4 in comparison with LV-CON KGN cell lines. Afterward, further assessments were performed to explore the possible functions about these DEGs. The data showed their involvement in many biological processes, particularly the Hippo signaling pathway. Moreover, the expression levels of YAP1, WWTR1, WTIP, DLG3, CCN2, and AMOT, which were associated with the Hippo signaling pathway, were further validated by qRT-PCR. In addition, the protein expression levels of YAP1 were markedly elevated, while p-YAP1 were notably reduced after overexpression of SOX4 in KGN cells. Thus, these results suggested that SOX4 regulates apoptosis, proliferation and migration of KGN cells, at least partly, through activation of the Hippo signaling pathway, which might be implicated in mammalian follicle development.

Investigating the Cell Origin and Liver Metastasis Factors of Colorectal Cancer by Single-Cell Transcriptome Analysis

Background

Colorectal cancer (CRC) is one of the deadliest causes of death by cancer worldwide. Liver metastasis (LM) is the main cause of death in patients with CRC. Therefore, identification of patients with the greatest risk of liver metastasis is critical for early treatment and reduces the mortality of patients with colorectal cancer liver metastases.

Methods

Initially, we characterized cell composition through single-cell transcriptome analysis. Subsequently, we employed copy number variation (CNV) and pseudotime analysis to delineate the cellular origins of LM and identify LM-related epithelial cells (LMECs). The LM-index was constructed using machine learning algorithms to forecast the relative abundance of LMECs, reflecting the risk of LM. Furthermore, we analyzed drug sensitivity and drug targeted gene expression in LMECs and patients with a high risk of LM. Finally, functional experiments were conducted to determine the biological roles of metastasis-related gene in vitro.

Results

Single-cell RNA sequencing analysis revealed different immune landscapes between primary CRC and LM tumor. LM originated from chromosomal variants with copy number loss of chr1 and chr6p and copy number gain of chr7 and chr20q. We identified the LMECs cluster and found LM-associated pathways such as Wnt/beta-catenin signaling and KRAS signaling. Subsequently, we identified ten metastasis-associated genes, including SOX4, and established the LM-index, which correlates with poorer prognosis, higher stage, and advanced age. Furthermore, we screened two drugs as potential candidates for treating LM, including Linsitinib_1510, Lapatinib_1558. Immunohistochemistry results demonstrated significantly elevated SOX4 expression in tumor samples compared to normal samples. Finally, in vitro experiments verified that silencing SOX4 significantly inhibited tumor cell migration and invasion.

Conclusion

This study reveals the possible cellular origin and driving factors of LM in CRC at the single cell level, and provides a reference for early detection of CRC patients with a high risk of LM.

The roles and mechanisms of TGFB1 in acute myeloid leukemia chemoresistance

Relapsed or Refractory (R/R) Acute Myeloid Leukemia (AML) patients usually have very poor prognoses, and drug-resistance is one of the major limiting factors. In this study, we aimed to explore the functions of Transforming Growth Factor-β1 (TGFB1) in AML drug-resistance. First, TGFB1 levels in serum and bone marrow are higher in R/R patients compared with newly diagnosed patients, this phenomenon could be due to different sources of secreted TGFB1 according to immunohistochemistry of marrow biopsies. Similarly, TGFB1 expression in AML drug-resistant cell lines is higher than that in their parental cell lines, and blocking the TGFB signaling pathway by specific inhibitors decreased resistance to chemotherapeutic agents. On the other hand, exogenous TGFB1 can also promote AML parental cells senescence and chemotherapy resistance. Next, we found SOX4 level is upregulated in drug-resistant cells, and parental cells treated with exogenous TGFB1 induced upregulation of SOX4 levels. Interference of SOX4 expression by siRNA diminished the TGFB1-induced sensitivity to chemotherapeutic agents. Finally, we conduct metabolomic analysis and find Alanine, aspartate and glutamate metabolism pathway, and Glycerophospholipid metabolism pathway are decreased after inhibiting TGFB signaling pathway or interfering SOX4 expression. This study concludes that TGFB1 level in R/R AML patients and drug-resistant strains is significantly increased. Blocking the TGFB signaling pathway can enhance the chemosensitivity of drug-resistant cells by suppressing SOX4 expression and metabolic reprogramming.

Unraveling the role of CD24 in Hepatocellular carcinoma: Involvement of inactivated Hippo signaling and SOX4-mediated regulation

Hepatocellular carcinoma (HCC) is a prevalent type of liver cancer, and CD24 gene is reportedly involved in HCC progression. However, the precise regulatory mechanisms of CD24 in HCC remain unclear. In this study, we established a primary HCC mouse model and observed that CD24, induced by inactivation of the Hippo pathway, was highly expressed in HCC. Using a systematic molecular and genomic approach, we identified the Hippo-YAP1-SOX4 pathway as the mechanism through which YAP1 induces CD24 upregulation in HCC cells. CD24 knockdown significantly attenuated YAP1 activation-induced HCC. These findings shed light on the link between CD24 and HCC progression, particularly in the Hippo-inactivated subclass of HCC. Therefore, CD24 may serve as a potential target for specific treatment of this HCC subclass.

PTPRO inhibition ameliorates spinal cord injury through shifting microglial M1/M2 polarization via the NF-κB/STAT6 signaling pathway

Spinal cord injury (SCI) induces severe neuroinflammation, and subsequently neurological dysfunction. Activated microglia are critical for modulation of neuroinflammation. Protein tyrosine phosphatase receptor type O (PTPRO), a member of protein tyrosine phosphatases (PTPs), exerts a pro-inflammatory role in multiple human diseases; however, its role in SCI remains unclarified. Here, a T7 spinal cord compression injury model was established in Sprague-Dawley (SD) rats, and PTPRO expression was upregulated in injured spinal cord and microglia after SCI. Microglia M1 and M2 polarization in vitro were induced using LPS/IFN-γ and IL-4, respectively. PTPRO expression was elevated in M1-polarized microglia, and PTPRO downregulation mediated by PTPRO shRNA (shPTPRO) decreased CD86+ cell proportion, iNOS, TNF-α, IL-1β, and IL-6 levels, and p65 phosphorylation. PTPRO was downregulated in M2 microglia, and PTPRO upregulation by PTPRO overexpression plasmid (OE-PTPRO) reduced CD206+ cell percentage, Arg-1, IL-10, and TGF-β1 levels and STAT6 phosphorylation. Mechanistically, the transcription factor SOX4 elevated PTPRO expression and its promoter activity. SOX4 overexpression enhanced M1 polarization and p65 phosphorylation, while its knockdown promoted M2 polarization and STAT6 phosphorylation. PTPRO might mediate the function of SOX4 in BV2 microglia polarization. Furthermore, lentivirus-mediated downregulation of PTPRO following SCI improved locomotor functional recovery, demonstrated by elevated BBB scores, incline angle, consistent hindlimb coordination, and reduced lesion area and neuronal apoptosis. PTPRO downregulation promoted microglia M2 polarization, NF-κB inactivation and STAT6 activation after injury. In conclusion, PTPRO inhibition improves spinal cord injury through facilitating M2 microglia polarization via the NF-κB/STAT6 signaling pathway, which is probably controlled by SOX4.

[Retracted] MicroRNA‑338‑3p functions as tumor suppressor in breast cancer by targeting SOX4

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that the GAPDH control western blotting assay data shown in Figs. 5D and 6B, the cell‑cycle data in Fig. 4A, the cell apoptotic data in Fig. 4B and the Transwell cell invasion assay in Fig. 3B were strikingly similar to data appearing in different form in other articles written by different authors at different research institutes that had either already been published elsewhere prior to the submission of this paper to International Journal of Oncology, or were under consideration for publication at around the same time. In view of the fact that certain of these data had already apparently been published previously, the Editor of International Journal of Oncology has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [International Journal of Oncology 47: 1594‑1602, 2015; DOI: 10.3892/ijo.2015.3114].

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.

METTL3-mediated m6A modification of SOX4 regulates osteoblast proliferation and differentiation via YTHDF3 recognition

N6-methyladenosine (m6A), the most prevalent internal modification in mRNA, is related to the pathogenesis of osteoporosis (OP). Although methyltransferase Like-3 (METTL3), an m6A transferase, has been shown to mitigate OP progression, the mechanisms of METTL3-mediated m6A modification in osteoblast function remain unclear. Here, fluid shear stress (FSS) induced osteoblast proliferation and differentiation, resulting in elevated levels of METTL3 expression and m6A modification. Through Methylated RNA Immunoprecipitation Sequencing (MeRIP-seq) and Transcriptomic RNA Sequencing (RNA-seq), SRY (Sex Determining Region Y)-box 4 (SOX4) was screened as a target of METTL3, whose m6A-modified coding sequence (CDS) regions exhibited binding affinity towards METTL3. Further functional experiments demonstrated that knockdown of METTL3 and SOX4 hampered osteogenesis, and METTL3 knockdown compromised SOX4 mRNA stability. Via RNA immunoprecipitation (RIP) assays, we further confirmed the direct interaction between METTL3 and SOX4. YTH N6-Methyladenosine RNA Binding Protein 3 (YTHDF3) was identified as the m6A reader responsible for modulating SOX4 mRNA and protein levels by affecting its degradation. Furthermore, in vivo experiments demonstrated that bone loss in an ovariectomized (OVX) mouse model was reversed through the overexpression of SOX4 mediated by adeno-associated virus serotype 2 (AAV2). In conclusion, our research demonstrates that METTL3-mediated m6A modification of SOX4 plays a crucial role in regulating osteoblast proliferation and differentiation through its recognition by YTHDF3. Our research confirms METTL3-m6A-SOX4-YTHDF3 as an essential axis and potential mechanism in OP.

Inhalable dry powders of microRNA-laden extracellular vesicles prepared by thin-film freeze-drying

Extracellular vesicles (EVs) are endogenous vesicles that comprise a variety of submicron vesicular structures. Among these, exosomes have been widely investigated as delivery systems for small and large molecules. Herein, the thin-film freeze-drying technology was utilized to engineer aerosolizable dry powders of miR-335-laden induced EVs (iEV-335) generated in B cells for potential delivery into the lung to treat primary lung cancer and/or pulmonary metastases. The size distribution, structure, and morphology of iEV-335 were preserved after they were subjected to thin-film freeze-drying with the proper excipients. Importantly, iEV-335, in liquid or reconstituted from thin-film freeze-dried powders, were equally effective in downregulating SOX4 gene expression in LM2 human triple-negative mammary cancer cells. The iEV-335 dry powder compositions showed mass median aerodynamic diameters (MMAD) of around 1.2 µm with > 60 % of the emitted doses had an MMAD of ≤ 3 µm, indicating that the powders can potentially achieve efficient deposition within the alveolar region following oral inhalation, which is desirable for treatment of primary lung cancer and pulmonary metastases. Overall, it is concluded that it is feasible to apply thin-film freeze-drying to prepare aerosolizable dry powders of iEVs for pulmonary delivery.

Landscape of Constitutional SOX4 Variation in Human Disorders

SOX proteins are transcription factors which play a role in regulating the development of progenitor cells and tissue differentiation. Twenty members are known, clustered in eight groups named A through H and sharing a common DNA-binding domain called the HMG (high-mobility-group) box. Eleven of the SOX genes have been associated with genetic disorders so far, covering a broad spectrum of developmental diseases. SOX4 is a single-exon gene and belongs to the SOXC group, together with SOX11 and SOX12. SOX4 variants have been recently described to cause a highly penetrant but heterogeneous disorder, with a phenotypic spectrum ranging from mild developmental delays and learning difficulties to intellectual disabilities with congenital anomalies. Nineteen pathogenic variants have been reported to date, generally de novo, heterozygous, and inactivating, either stop-gain or missense, the latter ones primarily targeting the HMG domain. Further, a bi-allelic variant was reported in a single consanguineous family. Copy number variants leading to whole gene deletion or duplication are rare and not clearly associated with any neurodevelopmental disorder. Many open questions remain regarding the definition of variants of unknown significance, a possible role of missense variants outside the HMG domain, genotype-phenotype correlation, the range of phenotypic spectrum and modifying factors, and treatment options.

SOX4 reversibly induces phenotypic changes by suppressing the epithelial marker genes in human keratinocytes

BACKGROUND

SOX4 is a transcription factor belonging to the SOX (Sry-related High Mobility Group [HMG] box) family and plays a pivotal role in various biological processes at various stages of life. SOX4 is also expressed in the skin in adults and has been reported to be involved in wound healing, tumor formation, and metastasis.

METHODS AND RESULTS

In this study, we investigated the role of SOX4 in keratinocyte phenotypic changes. We generated a SOX4-overexpressing keratinocyte cell line that expresses SOX4 in a doxycycline (DOX)-inducible manner. DOX treatment induced a change from a paving stone-like morphology to a spindle-like morphology under microscopic observation. Comprehensive gene analysis by RNA sequencing revealed increased expression of genes related to anatomical morphogenesis and cell differentiation as well as decreased expression of genes related to epithelial formation and keratinization, suggesting that SOX4 induced EMT-like phenotype in keratinocytes. Differentially expressed genes (DEGs) obtained by RNA-seq were confirmed using qRT-PCR. DOX-treated TY-1 SOX4 showed a decrease in the epithelial markers (KRT15, KRT13, KRT5, and CLDN1) and an increase in the mesenchymal marker FN1. Protein expression changes by Western blotting also showed a decrease in the epithelial marker proteins keratin 15, keratin 13, and claudin 1, and an increase in the mesenchymal marker fibronectin. Removal of DOX from DOX-treated cells also restored the epithelial and mesenchymal markers altered by SOX4.

CONCLUSION

Our results indicate that SOX4 reversibly induces an EMT-like phenotype in human keratinocytes via suppression of epithelial marker genes.

The SOX4/EZH2/SLC7A11 signaling axis mediates ferroptosis in calcium oxalate crystal deposition-induced kidney injury

Epigenetic regulation is reported to play a significant role in the pathogenesis of various kidney diseases, including renal cell carcinoma, acute kidney injury, renal fibrosis, diabetic nephropathy, and lupus nephritis. However, the role of epigenetic regulation in calcium oxalate (CaOx) crystal deposition-induced kidney injury remains unclear. Our study demonstrated that the upregulation of enhancer of zeste homolog 2 (EZH2)-mediated ferroptosis facilitates CaOx-induced kidney injury. CaOx crystal deposition promoted ferroptosis in vivo and in vitro. Usage of liproxstatin-1 (Lip-1), a ferroptosis inhibitor, mitigated CaOx-induced kidney damage. Single-nucleus RNA-sequencing, RNA-sequencing, immunohistochemical and western blotting analyses revealed that EZH2 was upregulated in kidney stone patients, kidney stone mice, and oxalate-stimulated HK-2 cells. Experiments involving in vivo EZH2 knockout, in vitro EZH2 knockdown, and in vivo GSK-126 (an EZH2 inhibitor) treatment confirmed the protective effects of EZH2 inhibition on kidney injury and ferroptosis. Mechanistically, the results of RNA-sequencing and chromatin immunoprecipitation assays demonstrated that EZH2 regulates ferroptosis by suppressing solute carrier family 7, member 11 (SLC7A11) expression through trimethylation of histone H3 lysine 27 (H3K27me3) modification. Additionally, SOX4 regulated ferroptosis by directly modulating EZH2 expression. Thus, this study demonstrated that SOX4 facilitates ferroptosis in CaOx-induced kidney injury through EZH2/H3K27me3-mediated suppression of SLC7A11.

CircHDAC9 regulates myocardial ischemia-reperfusion injury via miR-671-5p/SOX4 signaling axis

BACKGROUND

Myocardial ischemia-reperfusion (I/R), a harmful process in the treatment of cardiovascular diseases, can cause secondary damage to the cardiac tissues. Circular RNAs (circRNAs) are important regulators in a number of cardiac disorders. However, the role of circHDAC9 in myocardial I/R injury has not been clarified.

METHODS

Human cardiac myocytes (HCMs) were treated with hypoxia/reoxygenation (H/R) and mice were subjected to I/R. Quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) was used to analyze the expression of circHDAC9, miR-671-5p, and SOX4, and western blot was used to detect SOX4 protein. The binding relationship among circHDAC9, miR-671-5p, and SOX4 was confirmed by RNA pull-down, luciferase, and RNA immunoprecipitation (RIP) assays. The effects of circHDAC9/miR-671-5p/SOX4 axis on the apoptosis, oxidative stress and inflammation were evaluated in both myocardial I/R injury models.

RESULTS

The expression of circHDAC9 and SOX4 was noticeably elevated, whereas miR-671-5p expression was downregulated in both myocardial I/R injury models. circHDAC9 knockdown significantly reduced the apoptosis, activities of caspase-3 and caspase-9, ROS intensity, MDA activity, and concentrations of TNF-α, IL-1β, and IL-6, but increased the viability and SOD activity in H/R-treated HCMs. Suppression of circHDAC9 dramatically reduced the levels of circHDAC9 and SOX4, while enhanced miR-671-5p expression in H/R-treated HCMs. CircHDAC9 functioned via sponging miR-671-5p to regulate SOX4 expression in vitro. Additionally, silencing of circHDAC9 improved the pathological abnormalities and cardiac dysfunction, and reduced the apoptosis, oxidative stress and inflammation in mice with myocardial I/R injury.

CONCLUSIONS

Inhibition of circHDAC9 significantly improved myocardial I/R injury by regulating miR-671-5p/SOX4 signaling pathway.

SOX4 is a pivotal regulator of tumorigenesis in differentiated thyroid cancer

The SOX family consists of about 20 transcription factors involved in embryonic development, reprogramming, and cell fate determination. In this study, we demonstrated that SOX4 was significantly upregulated in differentiated thyroid cancer. Immunohistochemical analysis revealed that high SOX4 expression was associated with papillary histology, extrathyroidal extension, lymph node metastasis, and advanced disease stage. Patients whose tumors exhibited high SOX4 expression had a shorter recurrence-free survival, though significance was lost in multivariate Cox regression analysis. SOX4 silencing in thyroid cancer cells slowed cell growth, attenuated clonogenicity, and suppressed anoikis resistance. Additionally, SOX4 knockdown impeded xenograft tumor growth in nude mice. Knockdown of SOX4 expression was accompanied by reduced phosphorylation of AKT and ERK. Furthermore, CRABP2 expression correlated with SOX4 expression, and SOX4 silencing decreased CRABP2 expression and its downstream effectors such as integrin β1 and β4. These results indicate that SOX4 has both prognostic and therapeutic implications in differentiated thyroid cancer, and targeting SOX4 may modulate tumorigenic processes in the thyroid.

PHRF1 Promotes Cell Invasion by Modulating SOX4 Expression in Colorectal Cancer HCT116-p53-/- Cells

BACKGROUND/AIM

PHD and RING finger domain-containing protein 1 (PHRF1) ubiquitinates TGIP (TG-interacting protein) and redistributes cPML (cytoplasmic variant of PML) to the cytoplasm to enhance TGF-β signaling by. It is unclear whether PHRF1 affects invasion and survival when both mutations of the activated oncogene Kras and inactivation of the tumor suppressor p53 are present.

MATERIALS AND METHODS

We knockout PHRF1 expression using Crispr-Cas9 editing in HCT116-p53-/- (KrasG13D/p53-/-) cells and analyzed the expression profile in HCT116-p53-/-PHRF1-/- cells.

RESULTS

In contrast to lung cancer A549 (KrasG12S/p53wt) cells, the expression of Zeb1, a transcription factor for epidermal-mesenchymal transition (EMT), was not affected in PHRF1-knockout HCT116 p53-/- cells. Instead, SOX4 displayed a significant contribution to the impaired invasion in HCT116-p53-/-PHRF1-/- cells. Mechanistically, the C-terminal SRI domain of PHRF1 was required for both transwell invasion and SOX4 expression. The reintroduction of SOX4 into HCT116-p53-/- PHRF1-/- cells partially restored their invasive capability.

CONCLUSION

This study sheds light on the role of PHRF1 in the invasion of colorectal cancer HCT116-p53-/- cells, which harbor the oncogenic KrasG13D mutation and lack p53. These findings provide novel insights regarding the role of PHRF1 in invasion by modulating SOX4 expression in colorectal cancer HCT116-p53-/- cells.

miRNA-381 regulates renal cancer stem cell properties and sunitinib resistance via targeting SOX4

Cancer stem cells (CSCs) are crucial in the pathogenesis of human cancers. Existing studies reported that microRNA (miRNA) modulates the stemness of CSCs. We discovered that renal cell CSCs have suppressed miR-381. Suppression of miR-381 promotes renal cell tumorigenesis and CSC-like properties. Furthermore, the forced expression of miR-381 prevents the renal cell tumorigenesis and CSC-like properties. Mechanistically, renal cell CSCs have been found to interact with SOX4 through miR-381 directly. miR-381 inhibits renal cell CSC-like properties and tumorigenesis via downregulating SOX4. Examination of the patient-derived xenografts (PDX) and patient cohorts reveals that miR-381 may be able to forecast the advantages of Sunitinib in RCC patients. Moreover, the introduction of SOX4 could reverse the sensitivity of miR-381 overexpression RCC cells to Sunitinib-induced cell apoptosis. These results indicated that miR-381 is critical in renal cell CSC-like properties and tumorigenesis, making it the ideal therapeutic target for RCC.

SOX4 as a potential therapeutic target for pathological cardiac hypertrophy

Pathological cardiac hypertrophy can lead to heart failure, making its prevention crucial. SOX4, a SOX transcription factor, regulates tissue growth and development, although its role in pathological cardiac hypertrophy is unclear. We found that the SOX4 expression was elevated in hypertrophic hearts and angiotensin II (Ang II)-treated neonatal rat cardiomyocytes (NRCMs), and knocking down the SOX4 expression in NRCMs and mouse hearts significantly reduced the hypertrophic response. Mechanistically, SOX4 can bind to the SIRT3 promoter, inhibit SIRT3 transcription and expression, and thus affect downstream MnSOD acetylation levels, leading to abnormal increases in ROS and oxidative stress levels and promoting the occurrence of cardiac hypertrophy. In conclusion, this study identified a new role for SOX4 in regulating cardiac hypertrophy, and decreasing SOX4 expression may be a potential treatment for pathological cardiac hypertrophy.

Pan-Cancer Analysis and Experimental Validation of SOX4 as a Potential Diagnosis, Prognosis, and Immunotherapy Biomarker

INTRODUCTION

SOX4 plays an important role in tumorigenesis and cancer progression. The role of SOX4 in pan-cancer and its underlying molecular mechanism in liver hepatocellular carcinoma (LIHC) are not fully understood. In this study, a comprehensive analysis and experimental validation were performed to explore the function of SOX4 across tumor types.

METHODS

Raw data in regard to SOX4 expression in malignant tumors were downloaded from the TCGA and GTEx databases. The expression levels, prognostic values, genetic mutation, and DNA promoter methylation of SOX4 across tumor types were explored via systematic bioinformatics analysis. The ceRNA regulatory network, immune characteristics, and prognostic models were analyzed in LIHC. Finally, we conducted in vitro experiments including Western blotting, cell proliferative assay, trypan blue staining, and fluorescence microscopy to further explore the function of SOX4 in LIHC.

RESULTS

SOX4 expression was significantly upregulated in 24 tumor types. SOX4 expression level was strongly associated with unfavorable prognoses, genetic mutations, and DNA methylation levels across different tumor types. Especially in LIHC, LINC00152/hsa-miR-139-3p/SOX4 was identified as a crucial ceRNA network. Moreover, this study also provides insight into the roles of SOX4 expression in immune cell infiltration, macrophage polarization, immune subtype, molecular subtype, and immunomodulators, as well as the tumor immune microenvironment (TIME)-related prognosis, in LIHC. The study established six favorable prognostic models to predict LIHC prognosis based on the SOX4-associated genes. Finally, lenvatinib treatment can increase the expression of SOX4 in hepatocellular carcinoma cells and lead to drug resistance. Silencing SOX4 can effectively eliminate the drug resistance caused by lenvatinib treatment and inhibit the proliferation of cancer cells.

CONCLUSIONS

This study highlights that SOX4 may serve as a promising therapeutic target for tumor treatment.

Circ_103128 is associated with the tumorigenesis of medulloblastoma

BACKGROUND & AIMS

Medulloblastoma (MB) is a primary malignant tumor of the brain. They are categorized as WHO grade IV neoplasms, and mostly occur in children. The traditional therapy for MB is surgery, followed by radiation and chemotherapy, but the clinical outcome is still poor and has a high possibility of recurrence. The mechanism underlying the development of MB should be further investigated to develop novel therapeutic strategies.

METHODS

Research has demonstrated that circRNAs contribute to tumorigenesis, but the functional mechanism of circRNAs in MB has not been fully explored and remains vague. The differentially expressed circRNAs between MB and normal cerebellar tissues were analyzed based on the microarray expression profiles to characterize the potential mechanism of circRNAs in MB.

RESULTS

The results revealed that circRNA_103128 was highly expressed in MB, and cellular and animal experiments were performed to verify its tumorigenic effect in MB. Furthermore, a bioinformatics analysis and literature review previous literature were performed, confirming miR-129-5p as a target gene downstream of circRNA_103128. In addition, SOX4 was predicted to be a downstream target protein of miR-129-5p. Subsequently, miR-129-5p expression was inhibited, which revealed the regulatory mechanism of circRNA_103128. The latter promotes MB cell growth, migration, and invasion by the sponge effect of miR-129-5p, thereby affecting the expression of SOX4.

CONCLUSIONS

This study is the first to systematically demonstrate that circRNA_103128 may play an important regulatory role in MB through a sponge effect with miR-129 -5p, which affects SOX4 expression and regulates tumorigenesis and tumor cell development in MB.

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.

SOX4-SMARCA4 complex promotes glycolysis-dependent TNBC cell growth through transcriptional regulation of Hexokinase 2

Tumor cells rely on increased glycolytic capacity to promote cell growth and progression. While glycolysis is known to be upregulated in the majority of triple negative (TNBC) or basal-like subtype breast cancers, the mechanism remains unclear. Here, we used integrative genomic analyses to identify a subset of basal-like tumors characterized by increased expression of the oncogenic transcription factor SOX4 and its co-factor the SWI/SNF ATPase SMARCA4. These tumors are defined by unique gene expression programs that correspond with increased tumor proliferation and activation of key metabolic pathways, including glycolysis. Mechanistically, we demonstrate that the SOX4-SMARCA4 complex mediates glycolysis through direct transcriptional regulation of Hexokinase 2 (HK2) and that aberrant HK2 expression and altered glycolytic capacity are required to mediate SOX4-SMARCA4-dependent cell growth. Collectively, we have defined the SOX4-SMARCA4-HK2 signaling axis in basal-like breast tumors and established that this axis promotes metabolic reprogramming which is required to maintain tumor cell growth.

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.

IL-17 induces non-small cell lung cancer metastasis via GCN5-dependent SOX4 acetylation enhancing MMP9 gene transcription and expression

Interleukin-17 (IL-17), a potent proinflammatory cytokine, can trigger the metastasis of non-small cell lung cancer (NSCLC). However, the underlying mechanism involved in IL-17-induced NSCLC cell metastasis remains unclear. In this study, we found that not only the expression of IL-17, IL-17RA, and/or general control nonrepressed protein 5 (GCN5), SRY-related HMG-BOX gene 4 (SOX4), and matrix metalloproteinase 9 (MMP9) was increased in the NSCLC tissues and in the IL-17-stimulated NSCLC cells, but also IL-17 treatment could enhance NSCLC cell migration and invasion. Further mechanism exploration revealed that IL-17-upregulated GCN5 and SOX4 could bind to the same region (-915 to -712 nt) of downstream MMP9 gene promoter driving its gene transcription. In the process, GCN5 could mediate SOX4 acetylation at lysine 118 (K118, a newly identified site) boosting MMP9 gene expression as well as cell migration and invasion. Moreover, the SOX4 acetylation or MMP9 induction and metastatic nodule number in the lung tissues of the BALB/c nude mice inoculated with the NSCLC cells stably infected by corresponding LV-shGCN5 or LV-shSOX4, LV-shMMP9 plus IL-17 incubation were markedly reduced. Overall, our findings implicate that NSCLC metastasis is closely associated with IL-17-GCN5-SOX4-MMP9 axis.

Choline Regulates SOX4 through miR-129-5p and Modifies H3K27me3 in the Developing Cortex

Choline availability regulates neural progenitor cell proliferation and differentiation in the developing cerebral cortex. Here, we investigated the molecular mechanism underlying this process and demonstrated that choline regulates the transcription factor SOX4 in neural progenitor cells. Specifically, we found that low choline intake during neurogenesis reduces SOX4 protein levels, causing the downregulation of EZH2, a histone methyltransferase. Importantly, we demonstrate that low choline is not involved in SOX4 protein degradation rate and established that protein reduction is caused by aberrant expression of a microRNA (miR-129-5p). To confirm the role of miR-129-5p, we conducted gain-of-function and loss-of-function assays in neural progenitor cells and demonstrated that directly altering miR-129-5p levels could affect SOX4 protein levels. We also observed that the reduction in SOX4 and EZH2 led to decreased global levels of H3K27me3 in the developing cortex, contributing to reduced proliferation and precocious differentiation. For the first time, to our knowledge, we demonstrate that a nutrient, choline, regulates a master transcription factor and its downstream targets, providing a novel insight into the role of choline in brain development.

LncRNA SNHG25 predicts poor prognosis and promotes progression in osteosarcoma via the miR-497-5p/SOX4 axis

BACKGROUND

Osteosarcoma is a disease that primarily affects adolescents with skeletal immaturity. LncRNAs are abnormally expressed and correlated with osteosarcoma patients' prognosis. We identified aberrant expression of LncRNA SNHG25 (small nucleolar RNA host gene 25) in osteosarcoma and analyzed the molecular mechanisms by which it regulates osteosarcoma progression.

METHODS

The expression levels of SNHG25 in tumour specimens and cells were measured by RT-qPCR. Loss-of-function assays were conducted to investigate the functional role of SNHG25 in vitro and in vivo. Bioinformatic predictions, dual-luciferase reporter assays, and western blotting were performed to explore the possible underlying mechanisms.

RESULTS

SNHG25 was highly expressed in osteosarcoma cells and tissues. The Kaplan-Meier curve showed that the survival rate of patients with high SNHG25 expression was significantly lower than those with low SNHG25 expression. Functional studies have indicated that inhibition of SNHG25 suppresses cell proliferation, migration, and invasion, while promoting apoptosis. SNHG25 knockdown suppresses osteosarcoma tumour growth in vivo. SNHG25 functions as a sponge for miR-497-5p in osteosarcoma cells. The level of SNHG25 was negatively correlated with that of miR-497-5p. The proliferation, invasion, and migration of osteosarcoma cells were restored by transfection of the miR-497-5p inhibitor in the SNHG25 knockdown group.

CONCLUSION

SNHG25 was determined to function as an oncogene by promoting osteosarcoma cell proliferation, invasion, and migration through the miR-497-5p/SOX4 axis. Upregulation of SNHG25 expression indicated poor prognosis in patients with osteosarcoma, which showed that SNHG25 may serve as a potential therapeutic target and prognostic biomarker in osteosarcoma.

METTL3-mediated ALDH m6 A methylation regulates the malignant behavior of BMI1+ HNSCC stem cells

OBJECTIVES

To reveal the effect and mechanism of methyltransferase-like 3 (METTL3) on cancer stem cells (CSCs) of head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

First, we analyzed 14-HNSCC-patients' scRNA-seq dataset and TCGA dataset of HNSCC. Then, Mettl3 knockout or overexpression mice models were studied via tracing and staining technologies. In addition, we took flow cytometry sorting and sphere formation assays to observe tumorigenicity and used cell transfection and western blotting to verify target protein expression levels. Furthermore, methylated RNA immunoprecipitation sequencing (MeRIP-seq) and MeRIP-quantitative real-time PCR (MeRIP-qPCR) were taken to identify the mechanism of Mettl3 regulating Bmi1⁺ CSCs in HNSCC.

RESULTS

Due to SOX4 transcriptional regulation, METTL3 regulated the malignant behavior of BMI1⁺ HNSCC stem cells through cell division pathway. The progression and malignancy of HNSCC were decreased after Mettl3 knocked-out, while increased after Mettl3 knocked-in in Bmi1⁺ CSCs in vivo. Knockdown of Mettl3 inhibited stemness properties of CSCs in vitro. Mechanically, Mettl3 mediated the m⁶ A modification of ALDH1A3 and ALDH7A1 mRNA in Bmi1⁺ HNSCC CSCs.

CONCLUSION

Regulated by SOX4, METTL3-mediated ALDH m⁶ A methylation regulates the malignant behavior of BMI1⁺ HNSCC CSCs through cell division pathway.

miR-2053 inhibits the growth of ovarian cancer cells by downregulating SOX4

Ovarian cancer is one of the major gynaecological malignancies and a leading cause of cancer-related deaths worldwide. Dysregulation of miR-2053 has been reported in numerous types of cancer; however, its function in ovarian cancer remains largely unknown. In our study, the roles of miR-2053 during the development of ovarian cancer were investigated. miR-2053 expression was examined in ovarian cancer specimens and cells. Furthermore, the detailed functions and downstream targets of miR-2053 were identified. Briefly, the levels of miR-2053 were assessed in ovarian cancer tissues and paired non-cancerous samples, as well as in ovarian cancer cells using reverse transcription-quantitative polymerase chain reaction. The proliferation of cells was determined by cell counting kit-8 kit, and the levels of PCNA were also examined using immunostaining. Cell migration and invasion were evaluated using Transwell assay, and E-cad expression was assessed by immunostaining. In addition, cell apoptosis was determined by flow cytometry, and the expression of cleaved caspase-3 was examined using western blotting. The results revealed the downregulation of miR-2053 in ovarian cancer tissues and cells. Moreover, miR-2053 mimics suppressed the proliferation, migration, and invasion of ovarian cancer cells, while cell apoptosis was promoted. In addition, SOX4 was a putative downstream molecule of miR-2053 in ovarian cancer. Furthermore, SOX4 is involved in miR-2053-regulated growth and metastasis of ovarian cancer cells. In summary, miR-2053 and its novel target SOX4 could serve essential roles during tumour development of ovarian cancer, more importantly, miR-2053/SOX4 axis may be novel candidate for targeted therapy for patients with ovarian cancer.

Expanding the Immunophenotypic Spectrum of Neoplastic and Reactive Plasmacytoid Dendritic Cells

OBJECTIVES

Targeted therapies for blastic plasmacytoid dendritic cell neoplasm (BPDCN) have presented a diagnostic dilemma for differentiating residual BPDCN from reactive plasmacytoid dendritic cells (pDCs) because these conditions have a similar immunoprofile, necessitating discovery of additional diagnostic markers.

METHODS

Fifty cases of BPDCN involving bone marrow (26/50) and skin (24/50) as well as other hematologic malignancies (67) and nonneoplastic samples (37) were included. Slides were stained using a double-staining protocol for the following immunohistochemical marker combinations: TCF4/CD123, TCF4/CD56, SOX4/CD123, and IRF8/CD123.

RESULTS

The nuclear marker SOX4 is expressed in neoplastic pDCs; in our cohort, SOX4/CD123 showed 100% sensitivity and 98% specificity in distinguishing BPDCN from reactive pDCs and other neoplasms. TCF4/CD56 had a 96% sensitivity and 100% specificity for BPDCN. IRF8 is a nonspecific marker that is positive in BPDCN and pDCs as well as other myeloid malignancies.

CONCLUSIONS

The novel immunohistochemical combination SOX4/CD123 distinguishes BPDCN, including CD56-negative BPDCN, from both reactive pDCs and other neoplasms. Because of their high diagnostic sensitivity and specificity, the double-staining marker combinations TCF4/CD123, TCF4/CD56, and SOX4/CD123 can be used to confirm lineage in BPDCN cases and detect minimal/measurable residual disease in tissue specimens.

Exosomes from adipose-derived stem cells inhibits skin cancer progression via miR-199a-5p/SOX4

Although miR-199a-5p is linked to the development of numerous cancers, its regulatory role in skin cancer is unclear. In this work, the impact of miR-199a-5p produced by adipose-derived stem cells on malignant melanoma skin cancer was investigated.30 pair tumor tissues and adjacent tissues were obtained from skin cancer patients. Adipose-derived stem cell (ADSCs) were isolated from adipose tissues harvested from healthy subjects. The mRNA relative expression was evaluated via qRT-PCR. Cell proliferation ability was measured via CCK-8 assay. Apoptosis was evaluated via flow cytometry. The connection between miR-199a-5p and SOX4 was confirmed via luciferase reporter assay. Western blot was conducted to evaluate protein expression. MiR-199a-5p was higher expressed in ADSCs exosomes and was lower expressed in skin cancer tissues and cells. ADSCs-derived exosomes inhibited cell invasion of skin cancer. MiR-199a-5p inhibitor enhanced cell viability and invasion. In addition, miR-199a-5p inhibitor suppressed cell apoptosis. MiR-199a-5p NC transfected ADSCs inhibited cell viability and invasion while miR-199a-5p mimic transfected ADSCs further inhibited cell viability and invasion. In addition, miR-199a-5p NC transfected ADSCs enhanced cell apoptosis while miR-199a-5p mimic transfected ADSCs further enhanced cell apoptosis. Luciferase supported the targetscan prediction that miR-199a-5p might control SOX4 expression. SOX4 expression was noticeably lower in the miR-199a-5p mimic group.Exosomes from adipose-derived stem cells inhibited skin cancer progression via miR-199a-5p/SOX4.

circGRAMD1B contributes to migration, invasion and epithelial-mesenchymal transition of lung adenocarcinoma cells via modulating the expression of SOX4

Lung adenocarcinoma (LUAD) represents the subtype of non-small-cell lung cancer (NSCLC), with the high morbidity over the world. Mounting studies have highlighted the important roles of circular RNAs (circRNA) in cancers, including LUAD. This study mainly focused on revealing the role of circGRAMD1B and its relevant regulatory mechanism in LUAD cells. RT-qPCR and Western blot were conducted to detect the expression of target genes. Function assays were performed to determine the effect of related genes on migration, invasion, and epithelial-mesenchymal transition (EMT) of LUAD cells. Mechanism analyses were conducted to figure out the specific mechanism with regard to circGRAMD1B and its downstream molecules as well. Based on the experimental results, circGRAMD1B was upregulated in LUAD cells and promoted the migration, invasion, and EMT of LUAD cells. Mechanically, circGRAMD1B sponged miR-4428 to upregulate the expression of SOX4. In addition, SOX4 activated the expression of MEX3A at the transcriptional level, thereby modulating PI3K/AKT pathway to facilitate LUAD cell malignant behaviors. In conclusion, circGRAMD1B is discovered to modulate miR-4428/SOX4/MEX3A axis to further activate PI3K/AKT pathway, finally boosting migration, invasion, and EMT of LUAD cells.

SOXC Transcription Factors as Diagnostic Biomarkers and Therapeutic Targets for Arthritis

Osteoarthritis (OA) and rheumatoid arthritis (RA) are two common disorders that disrupt the quality of life of millions of people. These two chronic diseases cause damage to the joint cartilage and surrounding tissues of more than 220 million people worldwide. Sex-determining region Y-related (SRY) high-mobility group (HMG) box C, SOXC, is a superfamily of transcription factors that have been recently shown to be involved in various physiological and pathological processes. These include embryonic development, cell differentiation, fate determination, and autoimmune diseases, as well as carcinogenesis and tumor progression. The SOXC superfamily includes SOX4, SOX11, and SOX12, all have a similar DNA-binding domain, i.e., HMG. Herein, we summarize the current knowledge about the role of SOXC transcription factors during arthritis progression and their potential utilization as diagnostic biomarkers and therapeutic targets. The involved mechanistic processes and signaling molecules are discussed. SOX12 appears to have no role in arthritis, however SOX11 is dysregulated and promotes arthritic progression according to some studies but supports joint maintenance and protects cartilage and bone cells according to others. On the other hand, SOX4 upregulation during OA and RA was documented in almost all studies including preclinical and clinical models. Molecular details have indicated that SOX4 can autoregulate its own expression besides regulating the expression of SOX11, a characteristic associated with the transcription factors that protects their abundance and activity. From analyzing the currently available data, SOX4 seems to be a potential diagnostic biomarker and therapeutic target of arthritis.

Novel Variants of SOX4 in Patients with Intellectual Disability

SOX4 is a transcription factor with pleiotropic functions required for different developmental processes, such as corticogenesis. As with all SOX proteins, it contains a conserved high mobility group (HMG) and exerts its function via interaction with other transcription factors, such as POU3F2. Recently, pathogenic SOX4 variants have been identified in several patients who had clinical features overlapping with Coffin-Siris syndrome. In this study, we identified three novel variants in unrelated patients with intellectual disability, two of which were de novo (c.79G>T, p.Glu27*; c.182G>A p.Arg61Gln) and one inherited (c.355C>T, p.His119Tyr). All three variants affected the HMG box and were suspected to influence SOX4 function. We investigated the effects of these variants on transcriptional activation by co-expressing either wildtype (wt) or mutant SOX4 with its co-activator POU3F2 and measuring their activity in reporter assays. All variants abolished SOX4 activity. While our experiments provide further support for the pathogenicity of SOX4 loss-of-function (LOF) variants as a cause of syndromic intellectual disability (ID), our results also indicate incomplete penetrance associated with one variant. These findings will improve classification of novel, putatively pathogenic SOX4 variants.

PLAC8 contributes to the malignant behaviors of cervical cancer cells by activating the SOX4-mediated AKT pathway

Cervical cancer (CC) is the primary cancer-related cause of morbidity and mortality in women. Previous studies have shown that placenta-specific 8 (PLAC8) has different functions in multiple malignancies. This study aimed to explore the function and regulatory mechanism of PLAC8 in CC. Bioinformatics and immunohistochemical analyses demonstrated that PLAC8 was significantly upregulated in CC tissues compared with normal tissues. Gain/loss-of-function experiments showed that siRNA-mediated knockdown of PLAC8 suppressed cell migration and invasion, while PLAC8 overexpression promoted cell motility. Moreover, PLAC8 was revealed to affect the epithelial-mesenchymal transition (EMT) process by upregulating epithelial (E)-cadherin and decreasing the expression of mesenchymal markers of EMT, including vimentin, zinc finger E-box binding homeobox 1 (ZEB1), neural (N)-cadherin, matrix metalloproteinase-9 (MMP-9), and MMP-2 in PLAC8-silenced cells. PLAC8 activated the AKT pathway, as proven by the downregulation of p-AKT_Ser473 and p-AKT_Thr308 expression after PLAC8 knockdown. Furthermore, PLAC8 overexpression upregulated the expression of sex-determining region Y-related high-mobility group box transcription factor 4 (SOX4), which is reported to mediate the activation of the AKT pathway, and SOX4 deficiency reversed the cellular functions caused by PLAC8 overexpression. Overall, the present study indicates that PLAC8 may facilitate CC development by activating the SOX4-mediated AKT pathway, suggesting that PLAC8 may serve as a potential biomarker for CC treatment.

CircCCNB1 Knockdown Blocks the Progression of Cervical Cancer by Acting as Competing Endogenous RNA in the miR-370-3p/SOX4 Pathway

OBJECTIVE

Cervical cancer is one of the leading causes of cancer-related death in women, which has been shown to be associated with the deregulation of circular RNAs (circRNAs). The aim of this study was to determine the role of circRNA cyclin B1 (circCCNB1) in cervical cancer.

METHODS

The expression of circCCNB1, microRNA-370-3p (miR-370-3p), and SRY-box transcription factor 4 (SOX4) mRNA was detected by quantitative real-time PCR (qPCR). Functional experiments, including colony formation assay, EdU assay, transwell assay and flow cytometry assay, were performed. Lactate production and glucose uptake were examined to assess glycolysis metabolism. The protein levels of glycolysis-related markers and SOX4 were detected by western blot. The interaction between miR-370-3p and circCCNB1 or SOX4 was verified by dual-luciferase reporter, RIP, and pull-down assay. Xenograft assay was performed to monitor the role of circCCNB1 in animal models.

RESULTS

CircCCNB1 was highly expressed in cervical cancer tissues and cells (squamous cell carcinoma and adenocarcinoma cells). The knockdown of circCCNB1 inhibited cell proliferation, migration, invasion and glycolysis metabolism, and induced cell apoptosis. CircCCNB1 functioned as miR-370-3p sponge to suppress miR-370-3p expression and function. Moreover, circCCNB1 inhibited the expression of miR-370-3p to increase the expression of SOX4. MiR-370-3p inhibition reversed the effects of circCCNB1 knockdown and thus promoted cell proliferation, migration, invasion and glycolysis. SOX4 overexpression reversed the effects of miR-370-3p restoration and thus promoted cell proliferation, migration, invasion and glycolysis.

CONCLUSION

CircCCNB1 knockdown blocks cervical cancer development by targeting the miR-370-3p/SOX4 pathway.

SOX4 Mediates ATRA-Induced Differentiation in Neuroblastoma Cells

Neuroblastoma (NB), which is considered to be caused by the differentiation failure of neural crest cells, is the most common extracranial malignant solid tumor in children. The degree of tumor differentiation in patients with NB is closely correlated with the survival rate. To explore the potential targets that mediate NB cell differentiation, we analyzed four microarray datasets from GEO, and the overlapping down- or upregulated DEGs were displayed using Venn diagrams. SOX4 was one of the overlapping upregulated DEGs and was confirmed by RT-qPCR and Western blot in ATRA-treated NGP, SY5Y, and BE2 cells. To clarify whether SOX4 was the target gene regulating NB cell differentiation, the correlation between the expression of SOX4 and the survival of clinical patients was analyzed via the R2 database, SOX4 overexpression plasmids and siRNAs were generated to change the expression of SOX4, RT-qPCR and Western blot were performed to detect SOX4 expression, cell confluence or cell survival was detected by IncuCyte Zoom or CCK8 assay, immunocytochemistry staining was performed to detect cells' neurites, and a cell cycle analysis was implemented using Flow cytometry after PI staining. The results showed that the survival probabilities were positively correlated with SOX4 expression, in which overexpressing SOX4 inhibited NB cell proliferation, elongated the cells' neurite, and blocked the cell cycle in G1 phase, and that knockdown of the expression of SOX4 partially reversed the ATRA-induced inhibition of NB cell proliferation, the elongation of the cells' neurites, and the blocking of the cell cycle in the G1 phase. These indicate that SOX4 may be a target to induce NB cell differentiation.

[Retracted] Upregulation of microRNA‑25‑3p inhibits proliferation, migration and invasion of osteosarcoma cells in vitro by directly targeting SOX4

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the cell migration assay data shown in Figs. 3B and 5C were strikingly similar to data that had appeared in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a satisfactory reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 16: 4293‑4300, 2017; DOI: 10.3892/mmr.2017.7103].

LncRNA CASC9 activated by STAT3 promotes the invasion of breast cancer and the formation of lymphatic vessels by enhancing H3K27ac-activated SOX4

Numerous long noncoding RNAs (lncRNAs) are abnormally expressed in breast cancer (BC), but the underlying mechanisms remain large unknown. Here, we aimed to investigate the functions and mechanisms of lncRNA cancer susceptibility candidate 9 (CASC9) in BC. Western blotting and quantitative real-time PCR (qRT-PCR) were performed to assess gene and protein expression, respectively. The proliferative and metastatic abilities of BC cells were tested by cell counting kit-8 and transwell assays, respectively. The formation of lymphatic vessels was detected by tube formation assay. Chromatin immunoprecipitation (ChIP) and dual luciferase reporter assays were performed to verify molecular interactions. CASC9 was found to be highly expressed in BC tissues and cell lines, and ectopic overexpression was positively associated with tumor volume, TNM stage, and lymph node metastasis. In addition, CASC9 silencing significantly inhibited the proliferation and invasion of BC cells, as well as BC-associated invasion and formation of lymphatic vessels of human dermal lymphatic endothelial cells. Mechanical studies demonstrated that CASC9 could be transcriptionally activated by STAT3 and elevate SOX4 expression by enhancing the acetylation of its promoter region. Our results illustrated that STAT3-activated CASC9 served as a tumor-promoting gene involved in promoting BC invasion and BC-associated formation of lymphatic vessels by upregulating SOX4 through altering H3K27ac level. This finding elucidated a new underlying network of CASC9 in the metastasis of BC.

Single-cell atlas of craniogenesis uncovers SOXC-dependent, highly proliferative, and myofibroblast-like osteodermal progenitors

The mammalian skull vault is essential to shape the head and protect the brain, but the cellular and molecular events underlying its development remain incompletely understood. Single-cell transcriptomic profiling from early to late mouse embryonic stages provides a detailed atlas of cranial lineages. It distinguishes various populations of progenitors and reveals a high expression of SOXC genes (encoding the SOX4, SOX11, and SOX12 transcription factors) early in development in actively proliferating and myofibroblast-like osteodermal progenitors. SOXC inactivation in these cells causes severe skull and skin underdevelopment due to the limited expansion of cell populations before and upon lineage commitment. SOXC genes enhance the expression of gene signatures conferring dynamic cellular and molecular properties, including actin cytoskeleton assembly, chromatin remodeling, and signaling pathway induction and responsiveness. These findings shed light onto craniogenic mechanisms and SOXC functions and suggest that similar mechanisms could decisively control many developmental, adult, pathological, and regenerative processes.

Angelozzi and colleagues establish a detailed transcriptomic atlas of mouse embryonic craniogenesis and use mutant mice to show that SOXC (SOX4, SOX11, and SOX12 transcription factors) critically support osteogenesis and dermogenesis by promoting the expression of dynamic cellular and molecular properties of progenitor populations. SOXC could similarly affect many other processes.

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.

USP20 regulates the stability of EMT transcription factor SOX4 and influences colorectal cancer metastasis

BACKGROUND

Colorectal cancer (CRC) is a familiar malignancy accompanied by higher morbidity and mortality. The deubiquitination enzyme USP20 has been discovered to be one key factor in several cancers progression. SOX4 is a critical transcription factor to regulate the expression of various genes, and participates into the occurrence and progression of cancers. In this study, it was aimed to illustrate the role of USP20 and the regulatory relationship between USP20 and SOX4 in CRC.

METHODS

The protein expressions of USP20, SOX4, E-cadherin, N-cadherin, Snail and slug were tested through western blot. The cell proliferation ability was verified through CCK-8 assay. The migration and invasion abilities were detected through Transwell assay. The mRNA expression of SOX4 was confirmed through RT-qPCR. The interaction between USP20 and SOX4 was notarized through Co-IP assay.

RESULT

Our study demonstrated that USP20 displayed higher expression, and facilitated CRC progression through regulating cell proliferation, migration, invasion and EMT process markers. USP20 was found to modulate SOX4 protein expression. Next, it was verified that USP20 regulated SOX4 degradation through deubiquitination. Finally, through rescue assays, we revealed that USP20 mediated SOX4 expression to accelerate CRC progression.

CONCLUSIONS

In this study, USP20 regulated the stability of EMT transcription factor SOX4 and aggravated colorectal cancer metastasis. This finding might highlight the function of USP20 in the treatment of CRC.

LEM domain containing 1 (LEMD1) transcriptionally activated by SRY-related high-mobility-group box 4 (SOX4) accelerates the progression of colon cancer by upregulating phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway

Colon cancer is a highly malignant tumor in the digestive system. LEM domain containing 1 (LEMD1) is supposed to be a survival marker of poor prognosis in colon cancer. We aimed to explore the role and mechanism of LEMD1 in colon cancer progression. GEPIA database analyzed LEMD1 expression in colon cancer tissues and prognosis of colon cancer patients. LEMD1 expression in tumor cells was tested by RT-qPCR and western blotting. Proliferation of colon cancer cells was estimated by CCK-8 and colony formation assays. Transwell and wound healing assays were used to appraise the cell invasion and migration. Meanwhile, tube formation assays were used to evaluate angiogenesis. The possible binding sites between SRY-related high-mobility-group box 4 (SOX4) and LEMD1 were predicted by JASPAR database. Besides, SOX4 expression in colon cancer tissues and the correlation between SOX4 and LEMD1 were examined using the GEPIA database. Luciferase reporter and ChIP assays were used to verify the interaction between SOX4 and LEMD1. The expression of proteins in PI3K/Akt signaling was evaluated by western blotting. LEMD1 was overexpressed in colon cancer tissues and cells and associated with poor prognosis. Functionally, LEMD1 deficiency impeded the proliferation, migration, invasion and angiogenesis of colon cancer cells. Additionally, SOX4 had a positive correlation with LEMD1 and could bind to LEMD1 promoter. Rescue assays validated that SOX4 elevation reversed the suppressive role of LEMD1 deletion in the development of colon cancer and the expression of p-PI3K and p-AKT. Collectively, LEMD1 induced by SOX4 drove the progression of colon cancer by activating PI3K/Akt signaling.

Human mesenchymal stem cell derived exosomes inhibit the survival of human melanoma cells through modulating miR-138-5p/SOX4 pathway

Melanoma, a skin cancer derived from malignant melanocytes, is characterized by high aggressiveness and mortality. However, its exact etiology is unknown. Recently, the roles of exosomes and exosomal microRNAs (miRNAs) in the progression and therapy of various disorders, including melanoma, have gained attention. We investigated the impact of miR-138-5p from exosomes released by human mesenchymal stem cells (HMSCs) on the pathogenesis of melanoma. We isolated exosomes from HMSCs (HMSC-exos) by ultracentrifugation and verified them by specific biomarkers and transmission electron microscopy. We used CCK8, flow cytometry, quantitative real-time PCR (qRT-PCR), and Western blots to investigate cell proliferation, apoptosis, and mRNA and protein levels, respectively. Additionally, we used luciferase assays to examine the relationship between miR-138-5p and SOX4. Administration of HMSC-exos dramatically repressed the growth of melanoma cells. Elevated miR-138-5p levels in HMSC-exos were linked to increased cell apoptosis, and miR-138-5p downregulation had the opposite effects on cells. SOX4 was targeted by miR-138-5p through direct binding to the SOX4 3'UTR. In melanoma tissues, miR-138-5p was downregulated, and SOX4 was upregulated and was negatively correlated. MiR-138-5p plays a crucial role in melanoma progression. The negative regulation of SOX4 transcription mediates the function of miR-138-5p. These findings provide a novel concept of melanoma pathogenesis and identify a valuable target (miR-138-5p/SOX4 axis) in treating this disease.

Circular RNA hsa_circ_0000277 promotes tumor progression and DDP resistance in esophageal squamous cell carcinoma

Background

Circular RNAs (circRNAs) are well-known regulators of cancer progression and chemoresistance in various types of cancers. This study was performed to investigate the function of hsa_circ_0000277 in esophageal squamous cell carcinoma (ESCC).

Methods

RNA levels were analyzed via the reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Cell Counting Kit-8 (CCK-8) assay was applied to determine cell proliferation and half maximal inhibitory concentration (IC50) of cisplatin (DDP). Colony formation ability was evaluated by colony formation assay. Cell cycle and apoptosis were measured using flow cytometry. RNA immunoprecipitation (RIP), pull-down assay and dual-luciferase reporter assays were performed for target interaction analysis. The protein levels were determined through western blot. Xenograft models were established for researching hsa_circ_0000277 function in vivo.

Results

Hsa_circ_0000277 expression was increased in ESCC cells and tissues, and it had important clinical significance. Downregulation of hsa_circ_0000277 repressed ESCC cell proliferation, colony formation, cell cycle, and DDP resistance. Hsa_circ_0000277 acted as a microRNA-873-5p (miR-873-5p) sponge and Sry-related high-mobility group box 4 (SOX4) was validated as a target of miR-873-5p. Moreover, hsa_circ_0000277/miR-873-5p axis and miR-873-5p/SOX4 axis regulated ESCC cell progression and DDP resistance. Hsa_circ_0000277/miR-873-5p axis activated SOX4/Wnt/β-catenin signaling pathway. Hsa_circ_0000277 facilitated tumorigenesis and DDP resistance by miR-873-5p/SOX4 axis in vivo.

Conclusion

These findings unraveled that hsa_circ_0000277 promoted ESCC progression and DDP resistance via miR-873-5p/SOX4/Wnt/β-catenin axis, showing a specific molecular mechanism of carcinogenesis and chemoresistance in ESCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09241-9.

SOX4-activated lncRNA MCM3AP-AS1 aggravates osteoarthritis progression by modulating miR-149-5p/Notch1 signaling

OBJECTIVE

To clarify the expression and underlying network of long non-coding RNA (lncRNA) MCM3AP-AS1 in osteoarthritis (OA).

METHODS

Human articular cartilage samples, OA model rats and IL-1β-treated C28/I2 cells were used in this study. The expression changes of genes and proteins were assessed by real-time quantitative PCR (qRT-PCR) and western blot. Cell viability, apoptosis, autophagy and extracellular matrix (ECM) degradation were assessed by Cell Counting Kit-8 (CCK-8), immunohistochemistry (IHC), flow cytometry, immunofluorescence and western blot assays, respectively. Molecule interactions were validated by dual luciferase and Chromatin immunoprecipitation (ChIP) assays. H&E staining was used to detect the pathological changes of cartilage.

RESULTS

MCM3AP-AS1 was upregulated in OA patients and IL-1β-induced chondrocytes. Knockdown of MCM3AP-AS1 enhanced autophagy, while alleviated ECM degradation and cartilage injury. Mechanistically, overexpression of SOX4 boosted the transcription of MCM3AP-AS1. Moreover, MCM3AP-AS1 functioned as a molecular sponge or epigenetic regulator of miR-149-5p to facilitate Notch1 expression. Functional rescue experiments showed that either inhibition of miR-149-5p nor ectopic expression of Notch1 dramatically weakened the biological impacts of MCM3AP-AS1 silencing.

CONCLUSION

These finding demonstrated that SOX4-activated MCM3AP-AS1 aggravated OA progression by modulating autophagy and ECM degradation via targeting miR-149-5p/Notch1 axis. These data supported that inhibition of MCM3AP-AS1 might be a potential treatment strategy of OA.

miR-129-2 upregulation induces apoptosis and promotes NSCLC chemosensitivity by targeting SOX4

Background

As one of the main causes of death worldwide, the treatment of non‐small‐cell lung cancer (NSCLC) is still unsatisfactory. This study aimed to explore the role of miR‐129‐2 in cell apoptosis and NSCLC chemosensitivity.

Methods

The effect of miR‐129‐2 on NSCLC was investigated using lung cancer cell lines (A549, NCl‐H23, and HCC827), a normal lung cell line (BEAS‐2B), and NSCLC tissues and adjacent healthy tissues. The oncogene SOX4 was verified as the target gene of miR‐129‐2 by luciferase reporter assay and real‐time polymerase chain reaction.

Results

miR‐129‐2 expression was downregulated in NSCLC tissues, NCl‐H23 cells, and A549 cells. miR‐129‐2 upregulation induced apoptosis in NCl‐H23 and A549 cells. miR‐129‐2 upregulation also inhibited NSCLC in a xenograft mouse model, which was related to downregulation of SOX4 expression. Furthermore, miR‐129‐2 and SOX4 were aberrantly expressed in the cisplatin‐resistant lung cancer cell line A549/DDP, and upregulation of miR‐129‐2 expression promoted cisplatin sensitivity in A549/DDP cells.

Conclusions

In conclusion, miR‐129‐2 expression was downregulated in NSCLC tissues and cell lines, and its upregulation induced cell apoptosis and promoted NSCLC chemosensitivity by regulating SOX4. Therefore, miR‐129‐2 can serve as a potential diagnostic and therapeutic target in NSCLC.

Circular RNA circ_0000518 promotes breast cancer progression through the microRNA-1225-3p/SRY-box transcription factor 4 pathway

This work is designed to probe the functions and mechanisms of circ_0000518 in breast cancer (BC). qRT-PCR was performed to evaluate the circ_0000518, miR-1225-3p and Sry‑Related HMG box 4 (SOX4) mRNA expression in BC tissues and cells. After circ_0000518 was overexpressed in MDA-MB-468 cells, and circ_0000518 was knocked down in BT549 cells, CCK-8 test, and EdU assay were performed to measure the viability and growth of MDA-MB-468 and BT549 cells. Wound healing experiment was executed to determine the migration of BC cells. The invasion of cells was studied by the Transwell assay. Bioinformatics analysis, dual-luciferase reporter gene assay, qRT-PCR and Western blot were applied to predict and verify the binding sites between circ_0000518 and miR-1225-3p, miR-1225-3p and SOX4 mRNA. Pearson's correlation analysis was utilized to evaluate the correlations among circ_0000518 expression, miR-1225-3p expression, and SOX4 mRNA expression in BC specimens. It was revealed that, circ_0000518 and SOX4 mRNA expression levels were up-modulated in BC tissues, while miR-1225-3p expression was down-modulated in BC tissues than that in adjacent tissues. Circ_0000518 overexpression or inhibition of miR-1225-3p remarkably enhanced the growth, migration as well as invasion of BC cells in vitro, whereas circ_0000518 knockdown or miR-1225-3p overexpression worked oppositely. Circ_0000518 was identified as a molecular sponge of miR-1225-3p, and it can up-regulate SOX4 mRNA expression via repressing miR-1225-3p. In conclusion, circ_0000518 is oncogenic in BC and functions through miR-1225-3p/SOX4 axis.

hsa_circ_0000218/hsa-miR-139-3p/SOX4 regulatory feedback circuit influences the proliferation and apoptosis of gastric cancer cells

Previous studies have reported that circular (circ)RNAs serve an important role in cancer progression, but the effects of hsa_circRNA_0000218 (circ_0000218) and its potential underlying mechanism in gastric cancer (GC) are not completely understood. In the present study, dual luciferase reporter and RNA pull down assays were performed to detect the relationship between microRNA (miR)-139-3p and circ_0000218, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect circ_0000218, miR-139-3p and SRY-box transcription factor 4 (SOX4) mRNA expression levels in GC and GES-1 cells. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometry were used to detect cell proliferation and apoptosis, respectively. Western blotting was performed to assess cleaved-Caspase3 and Caspase3 expression levels in GC cells. circ_0000218 and SOX4 were highly expressed, whereas miR-139-3p was lowly expressed in GC cells. Moreover, circ_0000218 negatively regulated miR-139-3p in GC cells. circ_0000218 knockdown inhibited GC cell proliferation, promoted apoptosis and enhanced cleaved-Caspase3 expression in GC cells, whereas miR-139-3p knockdown reversed these effects. miR-139-3p overexpression inhibited proliferation and induced apoptosis in GC cells, but these effects were reversed by SOX4 overexpression. Collectively, the present study demonstrated that circ_0000218 upregulated SOX4 via downregulating miR-139-3p to promote GC progression.

Long noncoding RNA NR2F1-AS1 stimulates the tumorigenic behavior of non-small cell lung cancer cells by sponging miR-363-3p to increase SOX4

Long noncoding RNA (lncRNA), specifically the upregulation of lncRNA NR2F1 antisense RNA 1 (NR2F1-AS1), has been involved in the progression of non-small cell lung cancer (NSCLC), but the mechanisms that underlie this remain unclear. In this study, the expression of NR2F1-AS1, miR-363-3p, and SOX4 was assessed in NSCLC cells. A loss-of-function assay was used to measure the tumorigenicity of NSCLC cells. The glycolysis and glutamine metabolism of NSCLC cells was also measured via extracellular acidification rate, consumption of glucose and glutamine, and production of lactate and ATP. The relationships among NR2F1-AS1, miR-363-3p, and SOX4 were detected via dual-luciferase reporter assay. HK-2, GLS1, and SOX4 levels were also analyzed. We found that both NSCLC tissues and cells had higher levels of NR2F1-AS1. Silencing of NR2F1-AS1 inhibited the tumorigenicity of cells in vitro and reduced the glycolysis and glutamine metabolism of NSCLC cells. Regarding its mechanism, NR2F1-AS1 positively regulated the SOX4 level by sponging miR-363-3p. Furthermore, miR-363-3p inhibition or SOX4 overexpression reversed the repressing role of sh-NR2F1-AS1 in the tumorigenicity of NSCLC cells. In summary, NR2F1-AS1 promotes the tumorigenicity of NSCLC cells by regulating miR-363-3p/SOX4.