SOX30, a novel epigenetic silenced tumor suppressor, promotes tumor cell apoptosis by transcriptional activating p53 in lung cancer

Multifaceted roles and functions of SOX30 in human cancer

SRY-box transcription factor 30 (SOX30) participates in tumor cell apoptosis in lung cancer. The occurrence of somatic SOX30 mutations, the expression signature of SOX30 in normal and cancer tissues, the correlation of SOX30 with immune cells and immune-related genes, and the clinical significance of SOX30 in various cancers have stimulated interest in SOX30 as a potential cancer biomarker. SOX30 influences drug sensitivity and tumor immunity in specific cancer types. In this review, we have comprehensively summarized the latest research on the role of SOX30 in cancer by combining bioinformatics evidence and a literature review. We summarize recent research on SOX30 in cancer regarding somatic mutations, trials, transcriptome analysis, clinical information, and SOX30-mediated regulation of malignant phenotypes. Additionally, we report on the diagnostic value of SOX30 mRNA expression levels across different cancer types. This review on the role of SOX30 in cancer progression may provide insights into possible research directions for SOX30 in cancer and a theoretical basis for guiding future studies.

SOX on tumors, a comfort or a constraint?

The sex-determining region Y (SRY)-related high-mobility group (HMG) box (SOX) family, composed of 20 transcription factors, is a conserved family with a highly homologous HMG domain. Due to their crucial role in determining cell fate, the dysregulation of SOX family members is closely associated with tumorigenesis, including tumor invasion, metastasis, proliferation, apoptosis, epithelial-mesenchymal transition, stemness and drug resistance. Despite considerable research to investigate the mechanisms and functions of the SOX family, confusion remains regarding aspects such as the role of the SOX family in tumor immune microenvironment (TIME) and contradictory impacts the SOX family exerts on tumors. This review summarizes the physiological function of the SOX family and their multiple roles in tumors, with a focus on the relationship between the SOX family and TIME, aiming to propose their potential role in cancer and promising methods for treatment.

Role of Epigenetics for the Efficacy of Cisplatin

The clinical utility of the chemotherapeutic agent cisplatin is restricted by cancer drug resistance, which is either intrinsic to the tumor or acquired during therapy. Epigenetics is increasingly recognized as a factor contributing to cisplatin resistance and hence influences drug efficacy and clinical outcomes. In particular, epigenetics regulates gene expression without changing the DNA sequence. Common types of epigenetic modifications linked to chemoresistance are DNA methylation, histone modification, and non-coding RNAs. This review provides an overview of the current findings of various epigenetic modifications related to cisplatin efficacy in cell lines in vitro and in clinical tumor samples. Furthermore, it discusses whether epigenetic alterations might be used as predictors of the platinum agent response in order to prevent avoidable side effects in patients with resistant malignancies. In addition, epigenetic targeting therapies are described as a possible strategy to render cancer cells more susceptible to platinum drugs.

Clinical Significance of SOX10 Expression in Human Pathology

The embryonic development of neural crest cells and subsequent tissue differentiation are intricately regulated by specific transcription factors. Among these, SOX10, a member of the SOX gene family, stands out. Located on chromosome 22q13, the SOX10 gene encodes a transcription factor crucial for the differentiation, migration, and maintenance of tissues derived from neural crest cells. It plays a pivotal role in developing various tissues, including the central and peripheral nervous systems, melanocytes, chondrocytes, and odontoblasts. Mutations in SOX10 have been associated with congenital disorders such as Waardenburg-Shah Syndrome, PCWH syndrome, and Kallman syndrome, underscoring its clinical significance. Furthermore, SOX10 is implicated in neural and neuroectodermal tumors, such as melanoma, malignant peripheral nerve sheath tumors (MPNSTs), and schwannomas, influencing processes like proliferation, migration, and differentiation. In mesenchymal tumors, SOX10 expression serves as a valuable marker for distinguishing between different tumor types. Additionally, SOX10 has been identified in various epithelial neoplasms, including breast, ovarian, salivary gland, nasopharyngeal, and bladder cancers, presenting itself as a potential diagnostic and prognostic marker. However, despite these associations, further research is imperative to elucidate its precise role in these malignancies.

Integrated Multi-Omic Analysis Reveals Immunosuppressive Phenotype Associated with Poor Outcomes in High-Grade Serous Ovarian Cancer

High-grade serous ovarian cancer (HGSOC) is characterized by a complex genomic landscape, with both genetic and epigenetic diversity contributing to its pathogenesis, disease course, and response to treatment. To better understand the association between genomic features and response to treatment among 370 patients with newly diagnosed HGSOC, we utilized multi-omic data and semi-biased clustering of HGSOC specimens profiled by TCGA. A Cox regression model was deployed to select model input features based on the influence on disease recurrence. Among the features most significantly correlated with recurrence were the promotor-associated probes for the NFRKB and DPT genes and the TREML1 gene. Using 1467 transcriptomic and methylomic features as input to consensus clustering, we identified four distinct tumor clusters-three of which had noteworthy differences in treatment response and time to disease recurrence. Each cluster had unique divergence in differential analyses and distinctly enriched pathways therein. Differences in predicted stromal and immune cell-type composition were also observed, with an immune-suppressive phenotype specific to one cluster, which associated with short time to disease recurrence. Our model features were additionally used as a neural network input layer to validate the previously defined clusters with high prediction accuracy (91.3%). Overall, our approach highlights an integrated data utilization workflow from tumor-derived samples, which can be used to uncover novel drivers of clinical outcomes.

Identification of novel genes by targeted exome sequencing in Retinoblastoma

BACKGROUND

Retinoblastoma (RB) is initiated by mutation in both alleles of RB1 gene. However, few cases may occur even in the absence of RB1 mutation suggesting the role of genes other than RB1.

METHODOLOGY

The current study was planned to utilize targeted exome sequencing in Indian RB patients affected with unilateral non-familial RB. 75 unilateral RB patients below 5 years of age were enrolled. Genomic DNA was extracted from blood and tumor tissue. From peripheral blood DNA, all coding and exon/intron regions were amplified using PCR and direct sequencing. Cases which did not harbor pathogenic variants in peripheral blood DNA were further screened for mutations in their tumor tissue DNA using targeted exome sequencing. Three pathogenicity prediction tools (Mutation Taster, SIFT, and PolyPhen-2) were used to determine the pathogenicity of non-synonymous variations. An in-house bioinformatics pipeline was devised for the mutation screening by targeted exome sequencing. Protein modeling studies were also done to predict the effect of the mutations on the protein structure and function.

RESULTS

Using the mentioned approach, we found two novel variants (g.69673_69674insT and g.48373314C>A) in RB1 gene in peripheral blood DNA. We also found novel variants in eight genes (RB1, ACAD11, GPR151, KCNA1, OTOR, SOX30, ARL11, and MYCT1) that may be associated with RB pathogenesis.

CONCLUSION

The present study expands our current knowledge regarding the genomic landscape of RB and also highlights the importance of NGS technologies to detect genes and novel variants that may play an important role in cancer initiation, progression, and prognosis.

The emerging role of miR-653 in human cancer

MicroRNAs (miRNAs) refer to a family of non-coding RNA with ~22 nucleotides in length. A high number of studies show evidence that deregulation in miRNAs expression could be implicated in the processes of many pathologies such as cancer, hypoxia, and stroke. Herein, we aimed to summarize the miR-653 expression level and molecular mechanisms through which it functions in human cancer. It was found that variations in miR-653 expression are linked to tumor aggressiveness and unfavorable prognosis in human cancer, and it plays an inhibitory effect in some types of cancer, such as breast, cervical, liver, renal, and lung cancers. In contrast, it plays an acceleratory impact in some other cancers, such as bladder and prostate cancers. In gastric cancer, the role played by miR-653 is still controversial and will need to be elucidated in future studies. Future studies could definitely establish targeting miR-653 as a novel strategy in human cancer, from diagnosis to effective treatment.

SOX30 Overexpression Reflects Tumor Invasive Degree, Lymph Node Metastasis and Predicts Better Survival in Colorectal Cancer Patients: A Long-Term Follow-Up Cohort Study

Aims

Sex-determining region Y-box containing gene 30 (SOX30) takes part in the progression of several cancers, while its clinical engagement in colorectal cancer (CRC) is obscure. Therefore, this study aimed to explore the association of SOX30 with clinicopathological features and prognosis in CRC patients.

Methods

Tumor and adjacent noncancerous specimens of 195 CRC patients who received resection were acquired. Furthermore, an immunohistochemistry assay was performed to detect SOX30 protein expression in these specimens; meanwhile, SOX30 mRNA expression was determined by reverse transcription-quantitative polymerase chain reaction assay in 95 out of 195 specimens. Moreover, clinical characteristics and survival data (follow-up duration median (range): 71.0 (7.0-95.0) months) of CRC patients were gathered.

Results

SOX30 protein and mRNA expressions were both decreased in CRC tumor tissue compared to adjacent tissue (both P < 0.001). Furthermore, a negative correlation was found in tumor SOX30 protein expression with tumor size (P = 0.049), lymph node (LYN) metastasis (P = 0.018), T stage (P = 0.001), N stage (P = 0.034), and TNM stage (P = 0.001); tumor SOX30 mRNA expression was also negatively correlated with LYN metastasis (P = 0.001), T stage (P = 0.019), N stage (P = 0.004), and TNM stage (P < 0.001). Furthermore, tumor SOX30 protein expression was positively correlated with overall survival (OS) (P = 0.017), while tumor SOX30 mRNA expression was not correlated with OS (P = 0.070). Multivariate Cox’s regression analysis illustrated that tumor SOX30 protein high expression was an independent factor for favorable OS (hazard ratio: 0.525, P = 0.034).

Conclusions

SOX30 has potential as a biomarker for the progression and prognostication of CRC, which might improve the management of CRC.

MPDZ as a novel epigenetic silenced tumor suppressor inhibits growth and progression of lung cancer through the Hippo-YAP pathway

MPDZ also named MUPP1 is involved in signal transduction mediated by the formation of protein complexes. However, the expression regulation, clinical significance, potential function, and mechanism of this gene in lung cancer remain unclear. Methylation status of MPDZ was measured by methylation-specific PCR and bisulfite genomic sequencing. Kaplan-Meier and Cox regression analyses were performed to identify the prognostic value of MPDZ. The tumor suppressing effects of MPDZ were determined in vitro and in vivo. The target molecules and signaling pathway that mediated the function of MPDZ were also identified. MPDZ methylation was identified in 61.2% of primary lung cancer tissues and most lung cancer cell lines but not in normal lung tissues. MPDZ expression was significantly downregulated in lung cancer tissues and negatively associated with DNA hypermethylation, and attenuated MPDZ expression predicted a poor outcome. Furthermore, MPDZ overexpression prominently dampened cell growth, migration, and invasion of tumor cells. Conversely, MPDZ knockdown promoted cell proliferation, migration, and invasion in vitro and in vivo. Moreover, MPDZ deficiency promotes tumor metastasis and reduces the survival of MPDZ knockout mice. Importantly, MPDZ promotes tumor suppressor ability that depends on the Hippo pathway-mediated repression of YAP. MPDZ activates the phosphorylation of YAP (Ser127) and inhibits YAP expression through stabilizing MST1 and interaction with LATS1. We first identified and validated that MPDZ methylation and expression could be a good diagnostic marker and independent prognostic factor for lung cancer. MPDZ functions as a tumor suppressor by inhibiting cell proliferation, migration, and invasion through regulating the Hippo-YAP signaling pathway.

Identification of SRY-box 30 as an age-related essential gatekeeper for male germ-cell meiosis and differentiation

Although important factors governing the meiosis have been reported in the embryonic ovary, meiosis in postnatal testis remains poorly understood. Herein, we first report that SRY‐box 30 (Sox30) is an age‐related and essential regulator of meiosis in the postnatal testis. Sox30‐null mice exhibited uniquely impaired testis, presenting the abnormal arrest of germ‐cell differentiation and irregular Leydig cell proliferation. In aged Sox30‐null mice, the observed testicular impairments were more severe. Furthermore, the germ‐cell arrest occurred at the stage of meiotic zygotene spermatocytes, which is strongly associated with critical regulators of meiosis (such as Cyp26b1, Stra8 and Rec8) and sex differentiation (such as Rspo1, Foxl2, Sox9, Wnt4 and Ctnnb1). Mechanistically, Sox30 can activate Stra8 and Rec8, and inhibit Cyp26b1 and Ctnnb1 by direct binding to their promoters. A different Sox30 domain required for regulating the activity of these gene promoters, providing a “fail‐safe” mechanism for Sox30 to facilitate germ‐cell differentiation. Indeed, retinoic acid levels were reduced owing to increased degradation following the elevation of Cyp26b1 in Sox30‐null testes. Re‐expression of Sox30 in Sox30‐null mice successfully restored germ‐cell meiosis, differentiation and Leydig cell proliferation. Moreover, the restoration of actual fertility appeared to improve over time. Consistently, Rec8 and Stra8 were reactivated, and Cyp26b1 and Ctnnb1 were reinhibited in the restored testes. In summary, Sox30 is necessary, sufficient and age‐associated for germ‐cell meiosis and differentiation in testes by direct regulating critical regulators. This study advances our understanding of the regulation of germ‐cell meiosis and differentiation in the postnatal testis.

Homeobox-A13 acts as a functional prognostic and diagnostic biomarker via regulating P53 and Wnt signaling pathways in lung cancer

BACKGROUND

The prognosis of lung cancer patients is poor without useful prognostic and diagnostic biomarker. To search for novel prognostic and diagnostic markers, we previously found homeobox-A13 (HOXA13) as a promising candidate in lung cancer.

OBJECTIVE

To determine the precisely clinical feature, prognostic and diagnostic value, possible role and mechanism of HOXA13.

METHODS

Gene-expression was explored by real-time quantitative-PCR, western-blot and tissue-microarray. The associations were analyzed by Chi-square test, Kaplan-Meier and Cox-regression. The roles and mechanisms were evaluated by MTS, EdU, transwell, xenograft tumor and luciferase-reporter assays.

RESULTS

HOXA13 expression is increased in tumors, and correlated with age of patients. HOXA13 expression is associated with unfavorable overall survival and relapse-free survival of patients in four cohorts. Interestingly, HOXA13 has different prognostic significance in adenocarcinoma (ADC) and squamous-cell carcinoma (SCC), and is a sex- and smoke-related prognostic factor only in ADC. Importantly, HOXA13 can serve as a diagnostic biomarker for lung cancer, especially for SCC. HOXA13 can promote cancer-cell proliferation, migration and invasion in vitro, and facilitate tumorigenicity and tumor metastasis in vivo. HOXA13 acts the oncogenic roles on tumor growth and metastasis by regulating P53 and Wnt/β-catenin signaling activities in lung cancer.

CONCLUSIONS

HOXA13 is a new prognostic and diagnostic biomarker associated with P53 and Wnt/β-catenin signaling pathways.

The Role of Noncoding RNAs in the Regulation of Anoikis and Anchorage-Independent Growth in Cancer

Cancer is a global health concern, and the prognosis of patients with cancer is associated with metastasis. Multistep processes are involved in cancer metastasis. Accumulating evidence has shown that cancer cells acquire the capacity of anoikis resistance and anchorage-independent cell growth, which are critical prerequisite features of metastatic cancer cells. Multiple cellular factors and events, such as apoptosis, survival factors, cell cycle, EMT, stemness, autophagy, and integrins influence the anoikis resistance and anchorage-independent cell growth in cancer. Noncoding RNAs (ncRNAs), such as microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), are dysregulated in cancer. They regulate cellular signaling pathways and events, eventually contributing to cancer aggressiveness. This review presents the role of miRNAs and lncRNAs in modulating anoikis resistance and anchorage-independent cell growth. We also discuss the feasibility of ncRNA-based therapy and the natural features of ncRNAs that need to be contemplated for more beneficial therapeutic strategies against cancer.

Anti-Cancer Effect of Melatonin via Downregulation of Delta-like Ligand 4 in Estrogen-Responsive Breast Cancer Cells

BACKGROUND

The Notch signaling pathway has a key role in angiogenesis and Delta - Like Ligand 4 (DLL4) is one of the main ligands of Notch involved in cell proliferation in sprouting vessels.

OBJECTIVE

In this study, we aimed to evaluate the expression of DLL4 in primary breast tumors and to examine the effect of melatonin on DLL4 expression in vitro.

METHODS

Eighty-five breast tumor and paired adjacent non-tumor tissue samples were collected. Apoptosis assay was performed on breast cancer cells to evaluate melatonin effects. Western blot and quantitative RT-PCR were used to measure DLL4 expression. Then, we investigated the effect of melatonin on the expression of DLL4 in four breast cancer cell lines at RNA and protein levels. We also performed a probabilistic neural network analysis to study genes closely associated with DLL4 expression.

RESULTS

Our results showed a significantly higher expression of DLL4 in tumor tissues compared to non-tumor tissues (P = 0.027). Melatonin treatment substantially attenuated DLL4 expression in BT474 and MCF-7 cells, but not in SK-BR-3 and MDA-MB-231 cells. Also, melatonin induced apoptosis in all four cell lines. Network analysis revealed a set of 15 genes that had close association and interaction with DLL4. DLL4 was overexpressed in breast cancer tissues as compared to the non-tumor tissues.

CONCLUSION

It can be concluded that melatonin treatment attenuated DLL4 expression only in estrogen- responsive breast cancer cells and is able to induce apoptosis in breast cancer cells.

Role of SOX Protein Groups F and H in Lung Cancer Progression

Simple Summary

The expression of SOX proteins has been demonstrated in many tissues at various stages of embryogenesis, where they play the role of transcription factors. The SOX18 protein (along with SOX7 and SOX17) belongs to the SOXF group and is mainly involved in the development of the cardiovascular system, where its expression was found in the endothelium. SOX18 expression was also demonstrated in neoplastic lines of gastric, pancreatic and colon adenocarcinomas. The prognostic role of SOX30 expression has only been studied in lung adenocarcinomas, where a low expression of this factor in the stromal tumor was associated with a worse prognosis for patients. Because of the complexity of non-small-cell lung cancer (NSCLC) development, the role of the SOX proteins in this malignancy is still not fully understood. Many recently published papers show that SOX family protein members play a crucial role in the progression of NSCLC.

Abstract

The SOX family proteins are proved to play a crucial role in the development of the lymphatic ducts and the cardiovascular system. Moreover, an increased expression level of the SOX18 protein has been found in many malignances, such as melanoma, stomach, pancreatic breast and lung cancers. Another SOX family protein, the SOX30 transcription factor, is responsible for the development of male germ cells. Additionally, recent studies have shown its proapoptotic character in non-small cell lung cancer cells. Our preliminary studies showed a disparity in the amount of mRNA of the SOX18 gene relative to the amount of protein. This is why our attention has been focused on microRNA (miRNA) molecules, which could regulate the SOX18 gene transcript level. Recent data point to the fact that, in practically all types of cancer, hundreds of genes exhibit an abnormal methylation, covering around 5–10% of the thousands of CpG islands present in the promoter sequences, which in normal cells should not be methylated from the moment the embryo finishes its development. It has been demonstrated that in non-small-cell lung cancer (NSCLC) cases there is a large heterogeneity of the methylation process. The role of the SOX18 and SOX30 expression in non-small-cell lung cancers (NSCLCs) is not yet fully understood. However, if we take into account previous reports, these proteins may be important factors in the development and progression of these malignancies.

High expression of SRY-box transcription factor 30 associates with well differentiation, absent lymph node metastasis and predicts longer survival in nonsmall-cell lung cancer patients

The present study aimed to investigate SRY-box transcription factor 30 (SOX30) expression in nonsmall-cell lung cancer (NSCLC) tumor tissues and adjacent noncancerous tissues, and further explore the correlation of tumor SOX30 expression with clinical characteristics and survival profiles in patients with NSCLC.Totally, 365 patients with NSCLC who underwent resection were screened, and SOX30 expression was detected in their tumor tissues and adjacent noncancerous tissues via immunohistochemistry (IHC) assay, which was assessed by a semiquantitative method considering the multiplying staining intensity score and staining density score. According to the tumor SOX30 expression, patients were categorized as tumor SOX30 low (IHC score ≤3) and high (IHC score 4-12) patients, the latter were further divided into tumor SOX30 high+ (IHC score 4-6), high++ (IHC score 7-9), and high+++ (IHC score 10-12) patients.SOX30 was downregulated in NSCLC tumor tissues compared with adjacent noncancerous tissues. Meanwhile, tumor SOX30 high expression associated with well differentiation, absent lymph node metastasis, decreased TNM stage, but did not associated with age, gender, history of smoke and drink, hypertension, hyperlipidemia, diabetes, tumor size, or carcinoembryonic antigen level. Both accumulating disease-free survival and overall survival were the longest in tumor SOX30 high+++ patients, followed by tumor SOX30 high++ patients, and tumor SOX30 high+ patients, and the shortest in tumor SOX30 low patients. Besides, tumor SOX30 high expression was an independent predictor for longer disease-free survival and overall survival.Tumor SOX30 exhibits the potential to be a novel biomarker for survival prediction of patients with NSCLC.

SOX30 confers a tumor suppressive effect in acute myeloid leukemia through inactivation of Wnt/β-catenin signaling

Recent studies suggested SRY-related high mobility group box 30 (SOX30) as a candidate tumor-promoter or tumor-inhibitor in multiple tumor types. Yet, the detailed role of SOX30 in acute myeloid leukemia (AML) has not been well studied. The present research was designed to investigate the detailed relevance of SOX30 in AML. The data of our study indicated that SOX30 expression was markedly downregulated in AML cells, a pattern associated with its hypermethylation. SOX30 overexpression caused a marked reduction in AML cell proliferation and colony formation, but it promoted AML cell apoptosis. By contrast, SOX30 depletion by small interfering RNA (siRNA)-mediated gene silencing had the opposite effect. Moreover, SOX30 overexpression markedly decreased β-catenin expression, a change that led to inactivation of Wnt/β-catenin pathway. Notably, restoration of β-catenin expression partially reversed SOX30-mediated tumor suppressive effect in AML cells. In an AML-derived mouse xenograft model, SOX30 overexpression remarkably retarded the tumor growth in vivo. Overall, these data of the study suggest a tumor-inhibition role of SOX30 in AML, and highlight a key role of SOX30/Wnt/β-catenin axis in the progression of AML.

LHX3 is an advanced-stage prognostic biomarker and metastatic oncogene in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a common cancer and exhibits high morbidity and mortality in the world. We recently identified LHX3 as a preferentially expressed gene with a possible involvement in HCC.

OBJECTIVE

To determine the expression, clinical relevance, prognostic significance and functions of LHX3 in HCC.

MATERIALS AND METHODS

LHX3 expression was assessed in 190 cancerous and 40 adjacent non-cancerous tissues by PCR, western blot and immunohistochemistry. Associations between LHX3 expression and clinicopathological characteristics of patients were investigated. Correlations between LHX3 expression and overall survival of patients were analyzed by Kaplan-Meier and Cox-regression methods. Functional roles of LHX3 were evaluated by transwell assays.

RESULTS

LHX3 expression is significantly increased in carcinoma tissues, and associated with clinical stage and metastasis of patients. LHX3 expression is much higher in the advanced-stage patients than the early-stage patients, and is sharply increased in metastasic patients. High LHX3 expression is associated with unfavorable overall survival, and is an independent prognostic factor of patients. Moreover, LHX3 is an unfavorable and independent prognostic factor unique to advanced-stage patients. Knockdown expression of LHX3 obviously inhibits tumor cell migration and invasion.

CONCLUSION

LHX3 is an advanced-stage prognostic biomarker, and acts as a new potential metastatic oncogene in HCC.

Correlation of sex-determining region Y-box 30 with tumor characteristics and its prognostic value in breast cancer

Objective

Sex‐determining region Y‐box 30 (SOX30) suppresses progression of several cancers, whereas its role in breast cancer is unclear. Therefore, we aimed to determine the correlation of SOX30 with tumor characteristics and prognosis in breast cancer patients.

Methods

The tumor samples of 510 breast cancer patients who underwent resection were obtained, and SOX30 expression was analyzed by immunohistochemistry. Clinical characteristics, disease‐free survival (DFS), and overall survival (OS) of breast cancer patients were recorded.

Results

There were 368 breast cancer patients in SOX30 low‐expression group and 142 in SOX30 high‐expression group. SOX30 was negatively correlated with tumor size (P = .010), tumor (T) stage (P < .001), node (N) stage (P = .001), and tumor, node, metastasis (TNM) stage (P < .001) in breast cancer patients. For prognosis, patients in SOX30 high‐expression group had prolonged DFS (P = .011) and OS (P = .002); moreover, increased SOX30 grade (assessed by semi‐quantitative scoring method assessment) was correlated with better DFS (P = .015) and OS (P = .014). Univariate Cox's regression analysis disclosed that SOX30 high expression was correlated with enhanced DFS (P = .012, hazard ratio (HR) = 0.582) and OS (P = .002, HR = 0.389); however, multivariate Cox's regression analysis revealed that SOX30 could not independently predict DFS (P = .224, HR = 0.766) or OS (P = .087, HR = 0.582) in breast cancer patients, indicating it might interact with other independent predictive factors (such as pathological differentiation, T stage, and N stage) to influence DFS and OS in breast cancer patients.

Conclusion

Sex‐determining region Y‐box 30 is a potential prognostic biomarker in breast cancer, which might contribute to the better outcome of breast cancer patients.

SOX30, a target gene of miR-653-5p, represses the proliferation and invasion of prostate cancer cells through inhibition of Wnt/β-catenin signaling

BACKGROUND

Sex-determining region Y-box containing gene 30 (SOX30) is a newly identified tumor-associated gene in several types of cancer. However, whether SOX30 is involved in the development and progression of prostate cancer remains unknown. This study investigated the potential role of SOX30 in prostate cancer.

METHODS

Prostate cancer cell lines and a normal prostate epithelial cell line were used for the experiments. The expression of SOX30 was determined using quantitative real-time PCR and western blot analysis. The malignant cellular behaviors of prostate cancer were assessed using the Cell Counting Kit-8, colony formation and Matrigel invasion assays. The miRNA-mRNA interaction was validated using the dual-luciferase reporter assay.

RESULTS

SOX30 expression was lower in cells of prostate cancer lines than in cells of the normal prostate epithelial line. Its overexpression repressed the proliferation and invasion of prostate cancer cells. SOX30 was identified as a target gene of microRNA-653-5p (miR-653-5p), which is upregulated in prostate cancer tissues. MiR-653-5p overexpression decreased SOX30 expression, while its inhibition increased SOX30 expression in prostate cancer cells. MiR-653-5p inhibition also markedly restricted prostate cancer cell proliferation and invasion. SOX30 overexpression or miR-653-5p inhibition significantly reduced β-catenin expression and downregulated the activation of Wnt/β-catenin signaling. SOX30 knockdown significantly reversed the miR-653-5p inhibition-mediated inhibitory effect on the proliferation, invasion and Wnt/β-catenin signaling in prostate cancer cells.

CONCLUSIONS

These results reveal a tumor suppressive function for SOX30 in prostate cancer and confirmed the gene as a target of miR-653-5p. SOX30 upregulation due to miR-653-5p inhibition restricted the proliferation and invasion of prostate cancer cells, and this was associated with Wnt/β-catenin signaling suppression. These findings highlight the importance of the miR-653-5p-SOX30-Wnt/β-catenin signaling axis in prostate cancer progression.

One-Step Self-Assembly of Multifunctional DNA Nanohydrogels: An Enhanced and Harmless Strategy for Guiding Combined Antitumor Therapy

DNA nanostructure-based drug delivery system (DDS) has become an advanced therapeutic strategy for cancer because of its unsurpassed editability, intrinsic biodegradability, and tunable multifunctionality. An intelligent DNA nanosystem integrating targeting, immunostimulation, and chemotherapy was constructed based on unmethylated cytosine-phosphate-guanine oligonucleotides (CpG ODNs) DNA nanohydrogels (CpG-MUC1-hydrogel). By facile one-step self-assembly, the cross-shaped DNAs (C-DNAs) assembled from pH-responsive I-motif sequences and targeted MUC1 aptamer-immunoadjuvant CpG-fused sequences (CpG-MUC1) were integrated into DNA nanohydrogels with controllable size by the hybridization of DNA linkers. Subsequently, DOX was successively intercalated into the base pairs of CpG-MUC1-hydrogel, resulting in CpG-MUC1-hydrogel/Dox that would disassemble and release DOX and CpGs at acidic conditions. After MUC1-mediated internalization, CpG-MUC1-hydrogel/Dox dissociated in the endo/lysosomes and induced favorable apoptosis of tumor cells. Afterward, liberated CpGs triggered vast cytokine secretion from immune cells which elicited potent immune response against malignancy. Notably, CpG-MUC1-hydrogel induced an apoptosis effect on MCF-7 cells via significantly increasing the Bax/Bcl₂ ratios and a higher level of tumor necrosis factor (TNF-α) on RAW264.7 cells than naked CpGs. Our results demonstrated that self-assembled CpG-MUC1-hydrogel represented an attractive DDS for precise delivery, potent immunostimulating activity, and considerable combination efficiency with few adverse effects, which is expected to make breakthroughs in clinical translation.

Epigenetic Inactivation of SOX30 Is Associated with Male Infertility and Offers a Therapy Target for Non-obstructive Azoospermia

Non-obstructive azoospermia (NOA) is the most severe form of male infertility. However, the etiology of NOA is largely unknown, resulting in a lack of clinical treatments. Here, we performed a comparative genome-wide profiling of DNA methylation and identified SOX30 as the most notably hyper-methylated gene at promoter in testicular tissues from NOA patients. This hyper-methylation at promoter of SOX30 directly causes its silencing of expression in NOA. The reduced levels of SOX30 expression are correlated with severity of NOA disease. Deletion of Sox30 in mice uniquely impairs testis development and spermatogenesis with complete absence of spermatozoa in testes leading to male infertility, but does not influence ovary development and female fertility. The pathology and testicular size of Sox30 null mice highly simulate those of NOA patients. Re-expression of Sox30 in Sox30 null mice at adult age reverses the pathological damage of testis and restores the spermatogenesis. The re-presented spermatozoa after re-expression of Sox30 in Sox30 null mice have the ability to start a pregnancy. Moreover, the male offspring of Sox30 re-expression Sox30 null mice still can father children, and these male offspring and their children can live normally more than 1 year without significant difference of physical appearance compared with wild-type mice. In summary, methylated inactivation of SOX30 uniquely impairs spermatogenesis, probably causing NOA disease, and re-expression of SOX30 can successfully restore the spermatogenesis and actual fertility. This study advances our understanding of the pathogenesis of NOA, offering a promising therapy target for NOA disease.

Diverse pathogenetic roles of SOX genes in acute myeloid leukaemia and their therapeutic implications

Acute myeloid leukaemia (AML) is a heterogeneous group of diseases with diverse pathogenetic pathways. When treated uniformly with conventional chemotherapy and allogeneic haematopoietic stem cell transplantation (HSCT), it showed variable clinical outcome and prognosis. Members of the SOX [Sry-related high-mobility group (HMG) box] gene family are involved in diverse embryonic and oncogenic processes. The roles of SOX genes in AML are not entirely clear but emerging evidence, including that arising from studies in solid-cancers, showed that SOX genes can function as tumour suppressors or oncogenes and may be involved in key pathogenetic pathways in AML involving C/EBPα mutations, activation of β-catenin/Wnt and Hedgehog pathways and aberrant TP53 signals. Recent data based on genomics and proteomics have identified key interactions between SOX genes and partnering proteins of pathogenetic significance. The observations illustrated the principles and feasibilities of developing lead molecules of potential therapeutic values. Studying the diverse pathogenetic roles of SOX genes in AML may shed lights to the heterogeneity of AML and generate information that can be translated into novel therapeutic strategies.

Diagnostic and prognostic value of the BEX family in lung adenocarcinoma

Previous studies have demonstrated that members of the brain-expressed X-linked (BEX) family participate in a wide range of biological functions in normal and tumor tissues. However, their role and clinical significance in lung adenocarcinoma (LUAD) remains unclear. The present study investigated The Cancer Genome Atlas data and revealed that the BEX family was downregulated in LUAD tissues compared with adjacent non-cancerous tissues. Additionally, analysis of LUAD cohorts from the Oncomine database revealed similar results. Furthermore, the expression of BEX members was significantly decreased in several LUAD cell lines compared with normal lung epithelial cells in vitro. The aforementioned data mining and in vitro results suggested that the BEX family may be involved in the development of LUAD. Furthermore, receiver operating characteristic curve analysis revealed that BEX members exhibited high sensitivity and specificity for the diagnosis of patients with LUAD. The low expression levels of BEX1, BEX4 and BEX5 were associated with certain pathologic features, particularly in advanced LUAD. Survival analysis demonstrated that BEX members, particularly BEX4, were involved in the prognosis of patients with LUAD at early and late clinical stages. The results obtained in the current study suggested that BEX members may serve as potential tumor biomarkers for the diagnosis and prognosis of patients with LUAD.

Epigenetic silencing of ALX4 regulates microcystin-LR induced hepatocellular carcinoma through the P53 pathway

Recent studies have shown that microcystin-LR (MC-LR) is one of the principal factors that cause liver cancer. Previously we have found that Aristaless-like Homeobox 4 (ALX4) was differentially expressed in MC-LR-induced malignant transformed L02 cells. However, the expression regulation, role and molecular mechanism of ALX4 during the process of liver cancer induced by MC-LR are still unclear. The expression of ALX4 was detected by quantitative reverse-transcription PCR and Western blot in MC-LR induced malignantly transformed cell and rat models. Methylation status of ALX4 promoter region was evaluated by methylation-specific PCR and bisulfite genomic sequencing. The anti-tumor effects of ALX4 on MC-LR induced liver cancer were identified in vitro and in vivo. ALX4 expression was progressively down-regulated in MC-LR-induced malignantly transformed L02 cells and the MC-LR exposed rat models. ALX4 promoter regions were highly methylated in malignantly transformed cells, while treatment with demethylation agent 5-aza-dC significantly increased ALX4 expression. Functional studies showed that overexpression of ALX4 inhibits cell proliferation, migration, invasion and metastasis in vitro and in vivo, blocks the G1/S phase and promotes the apoptosis. Conversely, knockdown of ALX4 promotes cell proliferation, migration and invasion. Mechanism study found that ALX4 exerts its antitumor function through the P53 pathway, C-MYC and MMP9. More importantly, ALX4 expression level showed a negative relation with serum MC-LR levels in patients with hepatocellular carcinoma. Our results suggested that ALX4 was inactivated by DNA methylation and played a tumor suppressor function through the P53 pathway in MC-LR induced liver cancer.

SOX30 methylation correlates with disease progression in patients with chronic myeloid leukemia

Background

Our previous study has reported that aberrant SOX30 methylation was associated with poor prognosis in AML, and it correlated with disease progression in MDS. Herein, we further determined SOX30 methylation and its clinical significance in the other myeloid malignance - chronic myeloid leukemia (CML).

Methods

SOX30 methylation was examined by real-time quantitative methylation-specific PCR and bisulfite sequencing PCR, whereas SOX30 expression was detected by real-time quantitative PCR.

Results

SOX30 methylation was identified in 11% (10/95) CML patients. SOX30 methylation was associated with lower hemoglobin and platelets (P=0.006 and 0.032, respectively). Importantly, significant differences were observed in the distributions of clinical stages and cytogenetics (P=0.006 and 0.002, respectively). The frequency of SOX30 methylation in chronic phase (CP) stage occurred with lowest frequency (4/74, 5%), higher in accelerated phase (AP) stage (1/7, 14%), and the highest in blast crisis (BC) stage (12/31, 39%). In addition, SOX30 methylated patients tended to have a higher level of BCR-ABL transcript than SOX30 non-methylated patients (P=0.063). In two paired CML patients, SOX30 methylation showed lower density in CP stage (19% and 17%, respectively), and was significantly increased in BC stage (89% and 69%, respectively) during disease progression. Additionally, SOX30 methylated CML patients presented a lower SOX30 transcript level than SOX30 non-methylated CML patients (P=0.046).

Conclusion

Our study revealed that SOX30 methylation correlated with disease progression in chronic myeloid leukemia.

Plakophilin-2 accelerates cell proliferation and migration through activating EGFR signaling in lung adenocarcinoma

BACKGROUND

Plakophilin 2 (PKP2), encodes a plakophilin protein that belongs to the member of desmosomal proteins. It has been reported that high expression of PKP2 is associated with several types of cancer in humans. However, the role of PKP2 in lung cancer remains obscure.

METHODS

PKP2 expression was investigated in non-small cell lung cancer (NSCLC) tissues and non-tumor tissues by performing immunohistochemistry on a tissue microarray and using The Cancer Genome Atlas (TCGA) database. Kaplan-Meier survival analysis and multivariate Cox-regression analysis were performed to identify the clinical significance of PKP2. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), colony formation, Transwell and xenograft tumor growth/ metastasis assays were conducted to evaluate the biological function of PKP2 in vitro and in vivo. Gene set enrichment analysis (GSEA), WB and immunoprecipitation (IP) assay were utilized to explore the potential downstream signaling pathway and molecule mechanism of PKP2 in lung adenocarcinoma (LUAD).

RESULTS

Analysis of PKP2 expression and clinicopathological parameters reveals a significant correlation of PKP2 expression with gender (n = 1020, P < 0.001) and histological type (n = 1020, P < 0.001). Subsequently, our results demonstrated that high PKP2 expression is not associated with poor survival in different gender of lung cancer patients, and is an unfavorable and independent prognostic biomarker for LUAD patients, but not for LUSC patients. Gene set enrichment analysis (GSEA) revealed that PKP2 expression is positively associated with EGFR signaling in LUAD. Further, in vitro and in vivo assays revealed that PKP2 promotes cell proliferation, migration and invasion through activating EGFR signaling pathway in LUAD cells.

CONCLUSION

Our study provides the basis for further investigation of the function and molecular mechanism by which upregulation of PKP2 promotes the development and progression of LUAD. PKP2 may serve as a potential target for anticancer therapies.

JAM3 functions as a novel tumor suppressor and is inactivated by DNA methylation in colorectal cancer

Purpose

JAM3, an adhesion and transmigration regulatory element, is abundantly expressed in intestinal epithelial cells. However, its expression and function in colorectal cancer (CRC) remain unknown. In this study, we explored its epigenetic mechanism and biological role in CRC.

Patients and methods

Bioinformatics analysis was used to analyze the expression and methylation level of JAM3 in CRC. Methylation and expression status of JAM3 were then validated by quantitative methylation-specific PCR (qMSP) and quantitative PCR in tissues, plasma samples, and cell lines. Flow cytometry, Western blot, transwell, siRNA, colony formation, and transfection were used to evaluate the biological function of JAM3.

Results

We initially found that JAM3 was frequently methylated and downregulated in CRC based on bioinformatics tools. qMSP validation showed that the methylation levels of JAM3 were increased in 75% (18/24) of CRC tissues, 61% (11/18) plasma samples, and all four CRC cell lines and were significantly associated with tumor stage in CRC tissues. Moreover, JAM3 was downregulated in primary CRC tissues, plasma samples, and CRC cell lines as compared with that in nonmalignant controls, although its expression could be recovered after demethylation treatment. Restoration of JAM3 repressed CRC cell viability, colony formation, and migration. In addition, siRNA-mediated depletion of JAM3 in NCM460 cells improved the clonogenicity and migration capability, whereas it suppressed cell apoptosis and cell-cycle arrest. These functional effects were accompanied with alterations of several epithelial cell markers, including E-cadherin, vimentin, phosphor-β-catenin (ser552), and TJP1, which were responsible for epithelial–mesenchymal transition.

Conclusion

The findings indicated that JAM3 may be a novel tumor suppressor gene with epigenetic reduction in CRC and can be used as a potential noninvasive biomarker for CRC diagnosis.

The role of SOX family members in solid tumours and metastasis

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

SOX30 is a prognostic biomarker and chemotherapeutic indicator for advanced-stage ovarian cancer

New potential biomarkers and therapeutic targets for ovarian cancer should be identified. The amplification in chromosomal region 5q31-5q35.3 exhibits the strongest correlation with overall survival (OS) of ovarian cancer. SOX30 coincidentally located at this chromosomal region has been determined as a new important tumor suppressor. However, the prognostic value, role and mechanism of SOX30 in ovarian cancer are unexplored. Here, we reveal that SOX30 is frequently overexpressed in ovarian cancer tissues and is associated with clinical stage and metastasis of ovarian cancer patients. High SOX30 expression predicts better OS and acts as an independent prognostic factor in advanced-stage patients, but is not associated with OS in early-stage patients. Based on the survival analyses, the advanced-stage patients with high SOX30 expression can receive platin- and/or taxol-based chemotherapy, whereas they should not receive chemotherapy containing gemcitabine or topotecan. Functionally, SOX30 strongly inhibits tumor cell migration and invasion in intro and suppresses tumor metastasis in vivo. SOX30 regulates some markers (E-CADHERIN, FIBRONECTIN, N-CADHERIN and VIMENTIN) and prevents the characteristics of epithelial-mesenchymal transition (EMT). SOX30 transcriptionally regulates the expression of E-CADHERIN, FIBRONECTIN and N-CADHERIN by binding to their promoters. Restoration of E-CADHERIN and/or N-CADHERIN when overexpressing SOX30 significantly reduces the anti-metastatic role of SOX30. Indeed, chemotherapy treatment containing platin or gemcitabine combined with SOX30 expression influences tumor cell metastasis and the survival of nude mice differently, which is closely associated with EMT. In conclusion, SOX30 antagonizes tumor metastasis by preventing EMT process that can be used to predict survival and incorporated into chemotherapeutics of advanced-stage ovarian cancer patients.

SOX30 specially prevents Wnt-signaling to suppress metastasis and improve prognosis of lung adenocarcinoma patients

BACKGROUND

Different histological subtypes of non-small cell lung cancer (NSCLC) show different molecular characteristics and responses to therapeutic strategy. Identification of specific gene, clarification of its special roles and molecular mechanisms are crucial for developing new therapeutic approach for particular subtype patients.

METHODS

Surgical specimens of 540 NSCLC patients were recruited. Immunohistochemistry was used to detect SOX30 expression, and correlations with clinical parameters were analyzed. Functional experiments and gene ontology analysis were performed to investigate roles of SOX30. Network analysis, TOP/FOP-Flash assays, luciferase reporter assays and ChIP-PCR assays were performed to determine the mechanism. Survival analyses were calculated by Kaplan-Meier and Cox regression. Recovery experiment was investigated the importance of the target of SOX30.

RESULTS

SOX30 expression is closely associated with histological types of NSCLC, and metastasis of adenocarcinoma (ADC) patients but not of squamous cell carcinoma (SCC) patients. SOX30 strongly inhibits cancer cell migration and invasion in ADC cell lines, whrereas not affects cell migration and invasion in SCC cell lines. The genes associated with SOX30 preferentially enrich in metastasis process and Wnt-signaling in only ADC patients. Consistently, SOX30 is negatively associated with the expression of Wnt-signaling and metastasis-related gene CTNNB1 (β-catenin) in ADC, but not in SCC. At the molecular level, SOX30 represses Wnt-signaling by directly transcriptional inhibition of CTNNB1 in ADC, and also not in SCC. In the clinical, SOX30 is a favorable and independent prognostic factor in ADC patients, whereas is an unfavorable and independent prognostic factor in SCC patients. Moreover, SOX30 expression is a double face early-stage prognostic biomarker in ADC and SCC patients. In addition, forcible restoration of CTNNB1 indeed can inhibit the anti-metastatic role of SOX30 in ADC patients.

CONCLUSIONS

In early-stage ADC patients, elevated SOX30 expression inhibits tumor-metastasis by directly binding to CTNNB1 promoter resulting in a favorable prognosis of these patients. However, in early-stage SCC patients, SOX30 has no inhibitory role on tumor-metastasis due to not binding to CTNNB1 promoter leading to an unfavorable prognosis of the patients. This study highlights a special role and prognostic value of SOX30 in ADC, providing a novel therapeutic target for particular subtype NSCLC patients.

MicroRNA-645 represses hepatocellular carcinoma progression by inhibiting SOX30-mediated p53 transcriptional activation

Amount of evidence demonstrate that aberrant microRNAs (miRNAs) are involved in tumorigenesis and progression in hepatocellular carcinoma (HCC). Among them, miR-645 is recently recognized as cancer-related miRNA and its significance in HCC remains largely unknown. In this study, we reported for the first that miR-645 expression was markedly elevated in HCC tissues and cell lines, and its up-regulation was associated with malignant clinical features, including tumor size and venous infiltration and poor prognosis. Our data revealed that miR-645 promoted cell proliferation, colony formation and inhibited apoptosis by gain- and loss-of function experiments in vitro. In vivo assays showed that miR-645 overexpression enhanced tumor growth. Moreover, miR-645 directly bound to the SOX30 3'-UTR and post-transcriptionally repressed SOX30 expression in HCC cells. Furthermore, miR-645 inversely correlated with SOX30 expression in HCC tissues. Restoration of SOX30 expression at least partially abolished the biological effects of miR-645 on HCC cells. SOX30 regulated HCC progression through aberrant activation of p53 by directly binding to its promoter. Taken together, this research supports the first evidence that miR-645 exerts an oncogenic role in HCC progression and may be a therapeutic target for HCC treatment.

TC2N, a novel oncogene, accelerates tumor progression by suppressing p53 signaling pathway in lung cancer

The protein containing the C2 domain has been well documented for its essential roles in endocytosis, cellular metabolism and cancer. Tac2-N (TC2N) is a tandem C2 domain-containing protein, but its function, including its role in tumorigenesis, remains unknown. Here, we first identified TC2N as a novel oncogene in lung cancer. TC2N was preferentially upregulated in lung cancer tissues compared with adjacent normal lung tissues. High TC2N expression was significantly associated with poor outcome of lung cancer patients. Knockdown of TC2N markedly induces cell apoptosis and cell cycle arrest with repressing proliferation in vitro, and suppresses tumorigenicity in vivo, whereas overexpression of TC2N has the opposite effects both in vitro and in vivo. Using a combination of TCGA database and bioinformatics, we demonstrate that TC2N is involved in regulation of the p53 signaling pathway. Mechanistically, TC2N attenuates p53 signaling pathway through inhibiting Cdk5-induced phosphorylation of p53 via inducing Cdk5 degradation or disrupting the interaction between Cdk5 and p53. Moreover, the blockade of p53 attenuates the function of TC2N knockdown in the regulation of cell proliferation and apoptosis. In addition, downregulated TC2N is involved in the apoptosis of lung cancer cells induced by doxorubicin, leading to p53 pathway activation. Overall, these findings uncover a role for the p53 inactivator TC2N in regulating the proliferation and apoptosis of lung cancer cells. Our present study provides novel insights into the mechanism of tumorigenesis in lung cancer.

Identification and validation of SRY-box containing gene family member SOX30 methylation as a prognostic and predictive biomarker in myeloid malignancies

Background

Methylation-associated SOX family genes have been proved to be involved in multiple essential processes during carcinogenesis and act as potential biomarkers for cancer diagnosis, staging, prediction of prognosis, and monitoring of response to therapy. Herein, we revealed SOX30 methylation and its clinical implication in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS).

Results

In the discovery stage, we identified that SOX30 methylation, a frequent event in AML, was negatively associated with SOX30 expression and correlated with overall survival (OS) and leukemia-free survival (LFS) in cytogenetically normal AML among SOX family members from The Cancer Genome Atlas (TCGA) datasets. In the validation stage, we verified that SOX30 methylation level was significantly higher in AML even in MDS-derived AML compared to controls, whereas SOX30 hypermethylation was not a frequent event in MDS. SOX30 methylation was inversely correlated with SOX30 expression in AML patients. Survival analysis showed that SOX30 hypermethylation was negatively associated with complete remission (CR), OS, and LFS in AML, where it only affected LFS in MDS. Notably, among MDS/AML paired patients, SOX30 methylation level was significantly increased in AML stage than in MDS stage. In addition, SOX30 methylation was found to be significantly decreased in AML achieved CR when compared to diagnosis time and markedly increased in relapsed AML when compared to the CR population.

Conclusions

Our findings revealed that SOX30 methylation was associated with disease progression in MDS and acted as an independent prognostic and predictive biomarker in AML.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0523-y) contains supplementary material, which is available to authorized users.

Decreased expression of SRY-box containing gene 30 is related to malignant phenotypes of human bladder cancer and correlates with poor prognosis

Background

In human pulmonary malignancies, the SRY-box containing gene 30 (SOX30) is a known cancer-suppressing gene. Nevertheless, its molecular role and clinical effects remains unknown in bladder cancer.

Methods

SOX30 mRNA expression was quantified in bladder cancer tissue, paired adjacent normal tissue, and cell lines with qRT-PCR. SOX30 protein expression in BC tissue and cell lines was evaluated via western blotting and immunohistochemistry. In addition, the clinical and prognostic significance of SOX30 in BC were assessed using Kaplan-Meier analysis. Furthermore, we measured cell migration and invasion, cell proliferation and cell apoptosis by means of a Transwell assay, cell counting kit-8 along with flow cytometry, respectively.

Results

Expression levels of SOX30 were markedly lower in BC cells and tumor tissues than in adjacent noncancerous tissues. Moreover, clinicopathological analyses showed that low SOX30 expression was positively related to an advanced tumor, node, and metastasis (TNM) stage. Furthermore, low SOX30 expression conferred reduced survival rates (P < 0.05). Functional analyses revealed that SOX30 overexpression attenuated cell proliferation, invasion, and migration, while promoting apoptosis in BC cells.

Conclusions

SOX30 displays tumor suppressive behavior, warranting future investigations into its therapeutic potential in the treatment of BC.

SOX30 is a key regulator of desmosomal gene suppressing tumor growth and metastasis in lung adenocarcinoma

Background

The expression of desmosomal genes in lung adenocarcinoma and lung squamous carcinoma is different. However, the regulatory mechanism of desmosomal gene expression in lung adenocarcinoma and lung squamous carcinoma remains unknown.

Methods

The correlation between expression of desmosomal gene expression and SOX30 expression were analyzed by bioinformatics. The expression of SOX30, DSP, JUP and DSC3 were detected in lung cancer cell lines, lung tissues of mice and patients’ tissues by qPCR, WB, Immunofluorescence and Immunohistochemistry. A chromatin Immunoprecipitation assay was used to investigate the mechanisms of the SOX30 regulation on desmosomal gene expression. In vitro proliferation, migration and invasion assays, and an in vivo nude mice model were utilized to assess the important role of desmosomal genes on SOX30-induced tumor suppression. A WB assay and TOP/FOP flash reporter assay was used to investigate the downstream pathway regulated by the SOX30-desmosomal gene axis. A chemical carcinogenic model of SOX30-knockout mice was generated to confirm the role of the SOX30-desmosomal gene axis in tumorigenesis.

Results

The expression of desmosomal genes were upregulated by SOX30 in lung adenocarcinoma but not in lung squamous carcinoma. Further mechanism studies showed that SOX30 acts as a key transcriptional regulator of desmosomal genes by directly binding to the ACAAT motif of desmosomal genes promoter region and activating their transcription in lung adenocarcinoma. Knockdown of the expression of related desmosomal genes by miRNA significantly attenuated the inhibitory effect of SOX30 on cell proliferation, migration and invasion in vitro and on tumor growth and metastasis in vivo. In addition, knockout of SOX30 promotes lung tumor development and loss the inhibition of desmosomal genes on downstream Wnt and ERK signal in urethane-induced lung carcinogenesis in SOX30-knockout mice.

Conclusions

Overall, these findings demonstrate for the first time that SOX30 acts as a master switch of desmosomal genes, inhibits lung adenocarcinoma cell proliferation, migration and invasion by activating the transcription of desmosomal genes. This study provides novel insights on the regulatory mechanism of desmosomal genes in lung adenocarcinoma.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0778-3) contains supplementary material, which is available to authorized users.

Role of the SOX18 protein in neoplastic processes

There is a high demand for anticancer drugs due to the fact that the chemotherapeutics currently used have numerous side effects, which lowers the patient's quality of life. However, the latest antibody therapies are extremely expensive, hence the requirement to identify novel, equally effective but low-toxic treatments that have limited side effects. As a result of this, a number of research centres around the world are attempting to identify novel molecular markers that could be effective targets for anticancer therapy in the future. The SOX18 protein has been suggested to be a significant diagnostic and prognostic marker in various types of cancer. SRY-related HMG-box 18 (SOX18) is an important transcription factor involved in the development of cardiovascular and lymphatic vessels during embryonic development. In addition, it is involved in the progression of atherosclerosis and wound-healing processes. It has been observed that its level is higher in a number of cancer types, including melanoma, pancreas, stomach, liver, breast, lung, ovarian and cervical cancer. Furthermore, an association between a high expression of SOX18 in gastric cancer stromal cells and a poor prognosis has been demonstrated. The literature indicates how complex the pathogenesis of cancer is. Knowing the molecular basis of the pathogenesis of the tumor will allow for the effective use of targeted therapy, which may result in a higher success in treating patients. It is therefore important to identify novel and effective therapies as well as new proteins that could be potential markers. The SOX18 family, represented by the SOX18 protein, seems to be in this respect a promising element in modern anticancer therapy.

SOX30 Inhibits Tumor Metastasis through Attenuating Wnt-Signaling via Transcriptional and Posttranslational Regulation of β-Catenin in Lung Cancer

Although high mortality of lung cancer is greatly due to distant metastasis, the mechanism of this metastasis remains unclear. Here, we investigate in lung cancer that SOX30 is sharply under-expressed in metastatic tumors compared with non-metastatic tumors, and suppresses plenty of metastasis related processes or pathways. SOX30 strongly inhibits tumor cell metastasis in vitro and in vivo. Sox30 deficiency promotes lung metastasis in Sox30^−/− mice and this uncontrollable lung-metastasis is re-inhibited upon Sox30 re-expression. Mechanistically, SOX30 diminishes Wnt-signaling via directly transcriptional repressing β-catenin or interacting with β-catenin to compete with TCF for binding to β-catenin. The carboxyl-terminus of SOX30 is required for attenuating β-catenin transcriptional activity, whereas the amino-terminus of SOX30 is required for its interaction with β-catenin protein. Enhance of β-catenin attenuates the anti-metastatic role of SOX30. Moreover, Sox30 deficiency promotes tumor metastasis and reduces survival of mice. In addition, nuclear SOX30 expression is closely associated with metastasis and represents a favorable independent prognostic biomarker of lung cancer patients. Altogether, these results highlight an important role and mechanism of SOX30 in lung cancer metastasis, providing a potential therapeutic target for anti-metastasis.

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SOX30 is closely associated with lung cancer metastasis, and strongly inhibits cancer cell metastasis in vitro and in vivo.

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SOX30 suppresses cancer metastasis via transcriptional repressing β-catenin or competing with TCF for β-catenin binding.

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SOX30 deficiency promotes tumor long-distance metastasis and reduces overall survival of mice and lung cancer patients.

The high mortality of lung cancer is largely due to distant-metastases. However, the mechanism of this metastasis remains unclear. Here, we demonstrate that SOX30 strongly inhibits lung cancer metastasis in vitro and in vivo. As an important metastatic suppressor, SOX30 prevents long-distant metastases and causes fine prognosis inhibiting Wnt-signaling via transcriptional repressing β-catenin or competing with TCF for interaction with β-catenin. This study provides useful information for effective therapies against tumor-metastasis. Considering key role of β-catenin in tumor-metastasis and ineffective treatment using inhibitors against β-catenin, it is a potential choice to suppress Wnt/β-catenin activity via targeting the upstream SOX30.

ALX4, an epigenetically down regulated tumor suppressor, inhibits breast cancer progression by interfering Wnt/β-catenin pathway

Background

ALX4 is a paired-like homedomain transcription factor mainly expressed in the mesenchymal compartment of variety of developing tissues, but its functions, regulation mechanisms and clinical values in breast cancer remains unclear.

Methods

The expression of ALX4 in breast cancer cell lines and patients’ tissues were detected by RT-PCR, qPCR and western blot. Furthermore TCGA database was applied to confirm these results. MSP and BSP methods were used to assess the methylation of ALX4 promoter region. In vitro proliferation, metastasis and in vivo nude mice model were used to evaluate the anti-tumor effect of ALX4 on breast cancer cell lines. Luciferase reporter assay, western blot and TCGA database were used to investigate the tumor suppression mechanisms of ALX4. TMA of 142 breast patients was generated to evaluate the clinical significance of ALX4.

Results

Expression analysis revealed that ALX4 expression is down regulated in breast cancer cell lines and tissues. MSP study showed that the promoter region of ALX4 was hyper-methylated 100% (3/3) in breast cancer cell lines and 69.44% (75/108) in primary breast tumors tissues while 0% (0/8) in normal breast tissues. 5-aza-dc de-methylation treatment restored ALX4 expression in breast cancer cell lines. Functional studies showed that ectopic expression of ALX4 in breast cancer cells inhibited cell proliferation, metastasis in vitro and in vivo. Mechanism study found that ALX4 exerted its anti-tumor function by suppressing the Wnt/β-catenin pathway through promoting the phosphorylation degradation of β-catenin in a GSK3β dependent manner. Clinically multivariate analysis showed that ALX4 expression was an independent favorable prognostic factor in breast cancer patients.

Conclusions

We reveal for the first time that ALX4 acts as a novel functional tumor suppressor inactivated by DNA methylation and is an independent prognostic factor in breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s13046-017-0643-9) contains supplementary material, which is available to authorized users.

SOX14 activates the p53 signaling pathway and induces apoptosis in a cervical carcinoma cell line

SOX14 is a member of the SOX family of transcription factors mainly involved in the regulation of neural development. Recently, it became evident that SOX14 is one of four hypermethylated genes in cervical carcinoma, considered as a tumor suppressor candidate in this type of malignancy. In this paper we elucidated the role of SOX14 in the regulation of malignant properties of cervical carcinoma cells in vitro. Functional analysis performed in HeLa cells revealed that SOX14 overexpression decreased viability and promoted apoptosis through altering the expression of apoptosis related genes. Our results demonstrated that overexpression of SOX14 initiated accumulation of p53, demonstrating potential cross-talk between SOX14 and the p53 signaling pathway. Further analysis unambiguously showed that SOX14 triggered posttranslational modification of p53 protein, as detected by the significantly increased level of phospho-p53 (Ser-15) in SOX14-overexpressing HeLa cells. Moreover, the obtained results revealed that SOX14 activated p53 protein, which was confirmed by elevated p21^Waf1/Cip1, a well known target gene of p53. This study advances our understanding about the role of SOX14 and might explain the molecular mechanism by which this transcription factor could exert tumor suppressor properties in cervical carcinoma.

HOXA13 is associated with unfavorable survival and acts as a novel oncogene in prostate carcinoma

AIM

To investigate the clinical relevance and functional role of HOXA13 in prostate cancer Methods: PCR, western blot and immunohistochemistry were performed to determine the expression. Kaplan-Meier and Cox regression survival analyses investigated the clinical relevance. Cell viability, flow cytometry and transwell assays were used to determine the functional roles.

RESULTS

HOXA13 expression is sharply increased in carcinoma tissues and is significantly associated with poor prognosis of prostate cancer patients. Interestingly, nucleus not cytoplasm HOXA13 expression is associated with unfavorable survival of the patients. Furthermore, nucleus HOXA13 expression represents an unfavorable and independent prognosis factor of histological grade 2 or Gleason grade <8 patients. Functionally, forced expression of HOXA13 obviously promotes tumor cell proliferation, migration and invasion, whereas inhibits tumor cell apoptosis.

CONCLUSION

HOXA13 is an unfavorable prognostic factor and a novel oncogene for prostate cancer.

LHX6, An Independent Prognostic Factor, Inhibits Lung Adenocarcinoma Progression through Transcriptional Silencing of β-catenin

Introduction: Our previous study identified LIM homeobox domain 6 (LHX6) as a frequently epigenetically silenced tumor-suppressor gene in lung cancer. However, its clinical value has never been evaluated, and the in-depth anti-tumor mechanism remains unclear.

Methods: Public database was used for lung cancer, lung adenocarcinoma and lung squamous carcinoma patients and tissue microarray data was used for lung adenocarcinoma patients to study prognostic outcome of LHX6 expression by Kaplan-Meier and Cox-regression analysis. In vitro proliferation, metastasis and in vivo nude mice model were used to evaluate the anti-tumor effect of LHX6 on lung adenocarcinoma cell lines. The mechanisms were explored using western blot, TOP/FOP flash assays and luciferase reporter assays. LHX6 expression and clinical stages data were collected from The Cancer Genome Atlas database (TCGA).

Results: Expression of LHX6 was found to be a favorable independent prognostic factor for overall survival (OS) of total lung adenocarcinoma patients (P=0.014) and patients with negative lymph nodes status (P=0.014) but not related the prognostic outcome of lung squamous cell carcinoma patients. The expression status of LHX6 significantly correlated to histological grade (P<0.01), tumor size (P=0.026), lymph node status (P=0.039) and clinical stages (P<0.01) of lung adenocarcinoma patients. Functionally, LHX6 inhibited the proliferation and metastasis of lung adenocarcinoma cells in vitro and in vivo. Furthermore, LHX6 suppressed the Wnt/β-catenin pathway through transcriptionally silencing the expression of β-catenin, and the promoter region (-1161 bp to +27 bp) was crucial for its inhibitory activity.

Conclusions: Our data indicate that the expression of LHX6 may serve as a favorable prognostic biomarker for lung adenocarcinoma patients and provide a novel mechanism of LHX6 involving in the tumorigenesis of lung adenocarcinoma.

Ski regulates Smads and TAZ signaling to suppress lung cancer progression

Ski, the transforming protein of the avian Sloan-Kettering retrovirus, displays both pro- and anti-oncogenic activities in human cancer. The mechanisms underlying these conflicting observations have not been fully understood. Herein, we investigated the mechanism underlying the tumor suppressor activity of Ski. To investigate the effect of Ski re-activation on TGF-β and Hippo/TAZ pathway, we measured its effect on the endogenous Smad target genes (PAI-1 and P15^INK4B ) and TAZ target gene CTGF. The results revealed that Ski exerted its inhibitory activity in TGF-β1/Smad signaling pathway. Ski inhibited TAZ by increasing their phosphorylation by Lats2 and did not alter the localization of TAZ. Ski inhibited lung cancer growth and invasion. Ski methylation correlated with decreased mRNA expression in human lung cancer cell lines. Thus, Ski inhibited the function of TGF-β and TAZ through multiple mechanisms in human lung cancer.

LHX3 is an early stage and radiosensitivity prognostic biomarker in lung adenocarcinoma

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. We previously identified LHX3 as a new preferentially expressed gene in NSCLC. In the present study, we sought to determine its expression, the clinical relevance and the functional roles in NSCLC. LHX3 expression is sharply increased in carcinoma tissues compared to non-carcinoma tissues. Relational analysis reveals a significant association between LHX3 expression and clinical stage (n=172, P=0.032) or radiotherapy (n=167, P=0.022) of patients. LHX3 expression is much higher in the patients at advanced stages (stage III–IV) than in the patients at early stages (stage I–II, P=0.0304), and LHX3 expression is remarkably increased in the patients with radiotherapy treatment (P=0.0002). Survival analyses indicate that LHX3 is associated with unfavorable survival (n=180, P=0.002) and represents an independent prognostic factor [hazard ratio (HR)=1.834, P=0.004] of the NSCLC patients. Furthermore, LHX3 is associated with unfavorable overall survival (n=866, P=0.004) and represents an independent prognostic factor (HR=2.36, P=0.000) in lung adenocarcinoma (ADC) patients, but is not associated with overall survival of squamous cell carcinoma (SCC) patients (n=524, P=0.27). Further analyses found that LHX3 is an early-stage (n=94, P=0.003) and radiosensitivity (n=45, P=0.002) prognostic factor in ADC patients. The patients without radiotherapy have a significantly prolonged survival compared to those with radiotherapy (P=0.0069). Further functional studies show that forced expression of LHX3 in lung cancer cells obviously promotes cell proliferation and invasion, whereas inhibits cell apoptosis. In summary, LHX3 is an early-stage and radiosensitivity prognostic biomarker, and a novel potential oncogene in ADC.

MicroRNA-645 is an oncogenic regulator in colon cancer

Despite advances in early diagnosis and the development of molecularly targeted therapy, curative treatment of colon cancer once it has metastasized is yet to be accomplished. This is closely associated with deregulated CRC cell proliferation and resistance to apoptosis. Here we reveal that upregulation of microRNA-645 (miR-645) through DNA copy number gain is responsible for enhanced proliferation and resistance to apoptosis in colon cancer. MiR-645 was upregulated in most colon cancer tissues related to adjacent normal mucosa. This appeared to be associated with amplification of a section of chromosome 20q13.13, where miR-645 is located. Inhibition of miR-645 reduced proliferation and enhanced sensitivity to apoptosis triggered by the chemotherapeutic drugs 5-fluorouracil and cisplatin in CRC cells, and retarded colon cancer xenograft growth. Conversely, overexpression of miR-645 in normal colon epithelial cells enhanced proliferation and triggered anchorage-independent cell growth. Although SRY-related HMG-box 30 (SOX30) was identified as a miR-645 target, its expression was only partially affected by miR-645, suggesting that miR-645 is a fine-tuning mechanism of SOX30 expression. Moreover, overexpression of SOX30 only moderately inhibited promotion of CRC cell proliferation by miR-645, indicating that miR-645 may have more targets that contribute to its pro-proliferation effect in colon cancer. Together, this study reveals that miR-645 can regulate oncogenesis in colon cancer with SOX30 being one of its targets.

Pregnane X receptor is associated with unfavorable survival and induces chemotherapeutic resistance by transcriptional activating multidrug resistance-related protein 3 in colorectal cancer

Background

Although chemotherapy represents a predominant anti-cancer therapeutic modality, drug treatment efficacy is often limited due to the development of resistant tumor cells. The pregnane X receptor (PXR) affects chemotherapeutic effects by regulating targets involved in drug metabolism and transportation, but the regulatory mechanism is poorly understood.

Methods

Oxaliplatin (L-OHP) content in tumor cells was analyzed by mass cytometry. The roles of PXR on cancer cell proliferation, apoptosis and tumor growth with L-OHP-treated were investigated by MTS, colony formation, flow cytometry and xenograft tumor assays. Luciferase reporter, Chromatin-immunoprecipitation and Site-directed mutagenesis were evaluated the mechanisms. The PXR and multidrug resistance-related protein 3 (MRP3) expressions were examined by western blot, RT-PCR or immunohistochemistry of TMA. Kaplan-Meier and Cox regression were adopted to analyze the prognostic value of PXR in colorectal cancer (CRC).

Results

PXR over-expression significantly increased oxaliplatin (L-OHP) transport capacity with a reduction of its content and repressed the effects of L-OHP on tumour cell proliferation and apoptosis. Conversely, PXR knockdown augments L-OHP-mediated cellular proliferation and apoptosis. Moreover, PXR significantly reduced the therapeutic effects of L-OHP on tumor growth in nude mice. Further studies indicated a positive correlation between PXR and MRP3 expression and this finding was confirmed in two independent cohorts. Significantly increased MRP3 expression was also found in PXR over-expressing cell lines. Mechanistically, PXR could directly bind to the MRP3 promoter, activating its transcription. The PXR binding sites were determined to be at -796 to -782bp (CTGAAGCAGAGGGAA) and the key binding sites were the “AGGGA” (-787 to -783bp) on the MRP3 promoter. Accordingly, blockade of MRP3 diminishes the effects on drug resistance of PXR. In addition, PXR expression is significantly associated with poor overall survival and represents an unfavorable and independent factor for male or stage I + II CRC patient prognosis.

Conclusions

PXR is a potential biomarker for predicting outcome and activates MRP3 transcription by directly binding to its promoter resulting in an increased L-OHP efflux capacity, and resistance to L-OHP or platinum drugs in CRC. Our work reveals a novel and unique mechanism of drug resistance in CRC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-017-0641-8) contains supplementary material, which is available to authorized users.

Role of connexin 43 in cadmium-induced proliferation of human prostate epithelial cells

Connexins (Cxs), the subunits of gap junction channels, are involved in many physiological processes. Aberrant control of Cxs and gap junction intercellular communication may contribute to many diseases, including the promotion of cancer. Cd exposure is associated with increased risk of human prostate cancer and benign prostatic hyperplasia. The roles of Cxs in the effects of Cd on the prostate have, however, not been reported previously. In this study, the human prostate epithelial cell line RWPE-1 was exposed to Cd. A low dose of Cd stimulated cell proliferation along with a lower degree of gap junction intercellular communication and an elevated level of the protein Cx43. Cd exposure increased the levels of intracellular Ca²⁺ and phosphorylated Cx43 at the Ser368 site. Knockdown of Cx43 using siRNA blocked Cd-induced proliferation and interfered with the Cd-induced changes in the protein levels of cyclin D1, cyclin B1, p27^Kip1 (p27) and p21^Waf1/Cip1 (p21). The increase in Cx43 expression induced by Cd was presumably mediated by the androgen receptor, because it was abolished upon treatment with the androgen receptor antagonist, flutamide. Thus, a low dose of Cd promotes cell proliferation in RWPE-1, possibly mediated by Cx43 expression through an effect on cell cycle-associated proteins. Cx43 might be a target for prostatic diseases associated with Cd exposure. Copyright © 2017 John Wiley & Sons, Ltd.

Overexpression of miR-26b-5p regulates the cell cycle by targeting CCND2 in GC-2 cells under exposure to extremely low frequency electromagnetic fields

The increasing prevalence of extremely low frequency electromagnetic fields (ELF-EMFs) exposure has raised considerable public concern regarding the potential hazardous effects of ELF-EMFs on male reproductive function. Increasing evidence indicates that miRNAs are necessary for spermatogenesis and male fertility. However, the regulation of miRNA expression and the roles of miRNAs in response to ELF-EMFs remain unclear. In our study, mouse spermatocyte-derived GC-2 cells were intermittently exposed to a 50 Hz ELF-EMF for 72 h (5 min on/10 min off) at magnetic field intensities of 1 mT, 2 mT and 3 mT. MiR-26b-5p was differentially expressed in response to different magnetic field intensities of ELF-EMFs. The host gene CTDSP1 showed an unmethylation status in GC-2 cells at different magnetic field intensities of ELF-EMF exposure. MiR-26b-5p had no significant, obvious influence on the cell viability, apoptosis or cell cycle of GC-2 cells. However, the overexpression of miR-26b-5p significantly decreased the percentage of G0/G1 phase cells and slightly increased the percentage of S phase cells compared to the sham group that was exposed to a 50 Hz ELF-EMF. Computational algorithms identified Cyclin D2 (CCND2) as a direct target of miR-26b-5p. MiR-26b-5p and a 50 Hz ELF-EMF altered the expression of CCND2 at both the mRNA and protein levels. Overexpressed miR-26b-5p in GC-2 cells can change the mRNA expression of CCND2 following 50 Hz ELF-EMF at 3 mT. These findings demonstrate that miR-26b-5p could serve as a potential biomarker following 50 Hz ELF-EMF exposure, and miR-26b-5p-CCND2-mediated cell cycle regulation might play a pivotal role in the biological effects of ELF-EMFs.