High expression of SOX30 is associated with favorable survival in human lung adenocarcinoma

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.

DKK1 affects survival of patients with head and neck squamous cell carcinoma by inducing resistance to radiotherapy and immunotherapy

BACKGROUND

Immune checkpoint inhibitors (ICIs) have been approved to treat various types of tumors, including head and neck squamous cell carcinoma (HNSC). However, most HNSC patients do not respond to ICIs. Radioimmunotherapy has been proposed to enhance the immune response rate in HNSC. Dickkopf-1 (DKK1), a secreted protein, plays important roles in the Wnt signaling pathways. Herein, we aimed to explore the effect of DKK1 on radioimmunotherapy in HNSC.

METHODS

We collected the gene expression profile and clinical information of HNSC patients from TCGA and GEO databases. The immune cell infiltration and immune score were assessed using R package CIBERSORT and ESTIMATE. The level of related pathways and biological processes were analyzed by GSEA. The signature scores of gene sets of interest were calculated by GSVA. We also performed cell viability and apoptosis assay, and clonogenic assay to investigate the radiation sensitivity of HSC-3 cells and CNE-2 cells after silencing DKK1 by siRNA.

RESULTS

We found DKK1 was significantly higher expressed in HNSC, and closely correlated with patients' survival time, especially the patients who received radiotherapy. DKK1-knockdown HSC-3 cells or CNE-2 cells showed a decrease in cell viability and colony formation, and an increase in apoptotic rate after radiation. DKK1^high tumors showed a more immunosuppressive microenvironment with lower infiltration of T cells and higher infiltration of marrow-derived suppressor cells (MDSCs).

CONCLUSION

Our data show that DKK1 can affect both radiotherapy and immunotherapy in HNSC, suggesting that DKK1 can be a potential target for radioimmunology in HNSC.

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.

Prognostic Significance of KIF11 and KIF14 Expression in Pancreatic Adenocarcinoma

Simple Summary

Prognostic markers for survival stratification of patients with pancreatic adenocarcinoma (PAC) are missing yet. Therefore, the primary aim of this study was to assess the expression, clinical associations, and survival implications of KIF11 and KIF14 in PACs. In addition, the genes co-expressed with KIF11 or KIF14 were predicted and functionally annotated. Herein, we found that the expression patterns of KIF11 and KIF14 alter significantly in PACs, at both protein and mRNA levels, and this may be harnessed for patient prognosis. KIF11 and KIF14 could be defined as positive prognostic biomarkers based on the protein-based immunohistochemistry data, while they were associated with adverse prognosis based on the transcriptomic data. We also captured a five-gene prognostic signature and the biology associated with it. The findings of the present study suggest that KIF11 or KIF14 proteins, as well as a new five-gene panel, may serve as potentially useful prognostic biomarkers for PAC.

Abstract

Available biomarkers for pancreatic adenocarcinoma (PAC) are inadequate to guide individual patient prognosis or therapy. Therefore, herein we aimed to verify the hypothesis that differences in the expression of KIF11 and KIF14, i.e., molecular motor proteins being primarily implicated in cell division events could account for the differences in the clinical outcome of PAC patients. In-house immunohistochemistry was used to evaluate the protein expressions of KIF11 and KIF14 in PAC, whereas RNA-seq datasets providing transcript expression data were obtained from public sources. IHC and mRNA results were correlated with clinicopathological features and overall survival (OS). Furthermore, the genes co-expressed with KIF11 or KIF14 were predicted and functionally annotated. In our series, malignant ducts displayed more intense but less abundant KIF11 staining than normal-appearing ducts. The former was also true for KIF14, whereas the prevalence of positive staining was similar in tumor and normal adjacent tissues. Based on categorical immunoreactive scores, we found KIF11 and KIF14 to be frequently downregulated or upregulated in PAC cases, respectively, and those with elevated levels of either protein, or both together, were associated with better prognosis. Specifically, we provide the first evidence that KIF11 or KIF14 proteins can robustly discriminate between patients with better and worse OS, independently of other relevant clinical risk factors. In turn, mRNA levels of KIF11 and KIF14 were markedly elevated in tumor tissues compared to normal tissues, and this coincided with adverse prognosis, even after adjusting for multiple confounders. Tumors with low predicted KIF11 or KIF14 expression were seen to have enrichment for circadian clock, whereas those with high levels were enriched for the genomic instability-related gene set. KIF11 and KIF14 were strongly correlated with one another, and CEP55, ASPM, and GAMT were identified as the main hub genes. Importantly, the combined expression of these five genes emerged as the most powerful independent prognostic indicator associated with poor survival outcome compared to classical clinicopathological factors and any marker alone. In conclusion, our study identifies novel prognostic biomarkers for PAC, which await validation.

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 forkhead box M1 (FOXM1) is a poor prognostic biomarker in lung adenocarcinoma

BACKGROUND

Forkhead box M1 (FOXM1) is closely related to the formation and development of cancer. Because of differences in cellular origin, lung adenocarcinoma (ADC) and lung squamous cell carcinoma (SCC) usually exhibit different signatures. Therefore, it is essential to investigate the abnormalities of FOXM1 in the two subtypes separately.

METHODS

Through the Oncomine and TCGA databases, we investigated the expression of FOXM1 mRNA, its prognostic value and possible mechanisms leading to its dysregulation. Furthermore, networks involving FOXM1 and its significantly altered neighboring genes were identified using the cBioPortal database. GO and KEGG enrichment analyses were performed using DAVID.

RESULTS

Expression of FOXM1 mRNA was higher in lung tumor tissues than in normal tissues, and higher in SCC tissues than in ADC tissues. FOXM1 mRNA expression was correlated with N stage, TNM stage, age, sex and smoking history in ADC, but only correlated with N stage, age and sex in SCC. Survival analysis indicated that high expression of FOXM1 mRNA resulted to poor overall survival (OS) for ADC patients, but not for SCC patients. Cox regression analysis confirmed that FOXM1 mRNA expression was an independent prognostic indicator for ADC patients, and regression analysis identified a moderately positive correlation between FOXM1 mRNA levels and copy number alterations (CNAs), but a weakly negative association with DNA methylation. FOXM1 was mainly involved in cell cycle regulation, G2/M transition, G1/S transition and p53, PI3K-Akt and TGF-beta signaling pathway.

CONCLUSIONS

High expression of FOXM1 mRNA might be an independent biomarker of poor OS in ADC patients.

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.

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.

Cancer progression is mediated by proline catabolism in non-small cell lung cancer

Dysregulated metabolism contributes to cancer initiation and progression, but the key drivers of these pathways are just being discovered. Here, we report a critical role for proline catabolism in non-small cell lung cancer (NSCLC). Proline dehydrogenase (PRODH) is activated to reduce proline levels by the chromatin remodeling factor lymphoid-specific helicase (LSH), an epigenetic driver of NSCLC. PRODH promotes NSCLC tumorigenesis by inducing epithelial to mesenchymal transition (EMT) and IKKα-dependent inflammatory genes, including CXCL1, LCN2, and IL17C. Consistently, proline addition promotes the expression of these inflammatory genes, as well as EMT, tumor cell proliferation, and migration in vitro and tumor growth in vivo, while the depletion or inhibition of PRODH blocks these phenotypes. In summary, we reveal an essential metabolic pathway amenable to targeting in NSCLC.

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.

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.

Identification of TC2N as a novel promising suppressor of PI3K-AKT signaling in breast cancer

Although TC2N has proven to be an oncogene in lung cancer, its biological function and molecular mechanisms in other cancer still remains unclear. Here, we investigate in breast cancer that TC2N expression is sharply overexpressed in breast cancer specimens compared with normal breast specimens, and the low TC2N expression was associated with advanced stage, lymphatic metastasis, larger tumors and shorter survival time. Upregulation of TC2N significantly restrains breast cancer cell proliferation in vitro and tumor growth in vivo. Mechanistically, TC2N blocks AKT signaling in a PI3K dependent and independent way through weakening the interaction between ALK and p55γ or inhibiting the binding of EBP1 and AKT. To sum up, these results unmask an ambivalent role of TC2N in cancer, providing a promising inhibitor for PI3K-AKT signaling.

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.

PTBP1 promotes tumorigenesis by regulating apoptosis and cell cycle in colon cancer

Increased expression of polypyrimidine tract-binding protein 1 (PTBP1) has been observed in human ovarian tumors, glioblastomas, and breast cancer, but its biological roles in tumorigenesis is not fully clear. In the present research, we investigated the biological role of PTBP1 in colon cancer. We found that PTBP1 was overexpressed both in colon cancer cell lines and tissues. Tissue microarray analysis (TMA) indicated that low PTBP1 expression predicted a favorable overall survival for colon cancer patients. Using small interfering RNA technology, we found that down-regulation of PTBP1 significantly inhibited colon cancer cell growth/proliferation, and induced cell cycle arrest as well as apoptosis in vitro. Western blot analysis showed that siRNA PTBP1 could up-regulate the expression of cytoC, p53 and Bax as well as down-regulated p85, p-AKT, cyclinD1, CDK4 and Bcl2 compared to the control. Furthermore, Caspase-3 and PARP1 were activated when PTBP1 is knockdown. This study implies that PTBP1 plays an important role in tumorigenesis of colon 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.

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.

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.

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.

Eight potential biomarkers for distinguishing between lung adenocarcinoma and squamous cell carcinoma

Lung adenocarcinoma (LADC) and squamous cell carcinoma (LSCC) are the most common non-small cell lung cancer histological phenotypes. Accurate diagnosis distinguishing between these two lung cancer types has clinical significance. For this study, we analyzed four Gene Expression Omnibus (GEO) datasets (GSE28571, GSE37745, GSE43580, and GSE50081). We then imported the datasets into the Gene-Cloud of Biotechnology Information online platform to identify genes differentially expressed in LADC and LSCC. We identified DSG3 (desmoglein 3), KRT5 (keratin 5), KRT6A (keratin 6A), KRT6B (keratin 6B), NKX2-1 (NK2 homeobox 1), SFTA2 (surfactant associated 2), SFTA3 (surfactant associated 3), and TMC5 (transmembrane channel-like 5) as potential biomarkers for distinguishing between LADC and LSCC. Receiver operating characteristic curve analysis suggested that KRT5 had the highest diagnostic value for discriminating between these two cancer types. Using the PrognoScan online survival analysis tool and the Kaplan-Meier Plotter, we found that high KRT6A or KRT6B levels, or low NKX2-1, SFTA3, or TMC5 levels correlated with unfavorable prognoses in LADC patients. Further studies will be needed to verify our findings in additional patient samples, and to elucidate the mechanisms of action of these potential biomarkers in non-small cell lung cancer.

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.