Expression and significance of SATB1 in the development of breast cancer

MicroRNA-409 regulates the proliferation and invasion of breast cancer cell lines by targeting special AT-rich sequence-binding protein 1 (SATB1)

This study aims to determine the cellular functions and clinical significance of microRNA-409 (miR-409) in breast cancer by targeting special AT-rich sequence-binding protein 1 (SATB1). Breast cancer tissues and adjacent normal tissues, breast cancer cell lines (MDA-MB-453, MDA-MB-231, BT-549, BR3, and MCF-7) were used. miR-409 mimics, miR-409 inhibitor, SATB1, and siSATB1 were transiently transduced into cancer cells independently or together. RT-qPCR, Western blot, Cell Counting Kit-8 (CCK8), and Transwell assays were carried out to analyze the expression, cellular proliferation, and invasion. The results showed that the expression of miR-409 in breast cancer tissues is lower than that in adjacent tissues. The application of a target prediction algorithm predicts that the candidate gene regulated by miR-409 may be SATB1. The expression level of miR-409 in MDA-MB-453 cells is lower, while in BT-549 cells it is higher, when compared with MDA-MB-231, BR3, and MCF-7. The proliferation rate and invasive ability of MDA-MB-453 cells transfected with the miR-409 mimic was significantly lower than that of the miRNA negative control (miR-NC) cells, while the proliferation rate and invasive ability of BT-549 cells transfected with the miR-409 inhibitor were significantly increased. Cell proliferation and invasion of miR-409 mimic and SATB1 co-transfected MDA-MB-453 cells increased compared with that of miR-409 mimic-transfected cells, while miR-409 inhibitor and siSATB1 co-transfected BT-549 cells showed the opposite result. All these results indicated that miR-409 regulates breast cancer proliferation and invasion by targeting SATB1 and might be a potential therapeutic target for the treatment of breast cancer.

FOXA1 Suppresses SATB1 Transcription and Inactivates the Wnt/β-Catenin Pathway to Alleviate Diabetic Nephropathy in a Mouse Model

OBJECTIVE

Diabetic nephropathy (DN) represents the most common diabetic complication that may lead to end-stage renal disease. This work focused on the effect of FOXA1 on the DN development and the molecular mechanism.

METHODS

A mouse model of DN was induced by high-fat diets and streptozotocin. The concentrations of blood glucose and urinary protein in mice, and the pathological changes in mouse kidney tissues were determined. A podocyte cell line MPC-5 was treated with high glucose (HG) to mimic a DN-like condition in vitro. FOXA1 and SATB1 were overexpressed in HG-treated MPC-5 cells and in DN mice to explore their effects on cell proliferation and apoptosis, and on pathological changes in mouse kidney tissues. The binding relationship between FOXA1 and STAB1 was predicted and validated. Activation of the Wnt/β-catenin pathway was detected.

RESULTS

FOXA1 was poorly expressed in the kidney tissues of DN mice. Overexpression of FOXA1 reduced the concentrations of fasting blood glucose and 24-h urinary protein in mice. It also suppressed the accumulation of glomerular mesangial matrix and hyperplasia of glomerular basement membrane, and reduced collagen deposition and interstitial fibrosis in mouse kidney. Also, FOXA1 reduced HG-induced apoptosis of MPC-5 cells. FOXA1 bound to the promoter region of SATB1 for transcription suppression. Overexpression of SATB1 activated the Wnt/β-catenin pathway and blocked the protective roles of FOXA1 in DN mice and in HG-treated MPC-5 cells.

CONCLUSION

This study demonstrated that FOXA1 transcriptionally suppresses SATB1 expression and inactivates the Wnt/β-catenin signaling pathway, thereby inhibiting podocyte apoptosis and DN progression.

The Role of SATB1 in Tumour Progression and Metastasis

Carcinogenesis is a long-drawn, multistep process, in which metastatic spread is an unequivocal hallmark of a poor prognosis. The progression and dissemination of epithelial cancers is commonly thought to rely on the epidermal-mesenchymal transition (EMT) process. During EMT, epithelial cells lose their junctions and apical-basal polarity, and they acquire a mesenchymal phenotype with its migratory and invasive capabilities. One of the proteins involved in cancer progression and EMT may be SATB1 (Special AT-Rich Binding Protein 1)-a chromatin organiser and a global transcriptional regulator. SATB1 organizes chromatin into spatial loops, providing a "docking site" necessary for the binding of further transcription factors and chromatin modifying enzymes. SATB1 has the ability to regulate whole sets of genes, even those located on distant chromosomes. SATB1 was found to be overexpressed in numerous malignancies, including lymphomas, breast, colorectal, prostate, liver, bladder and ovarian cancers. In the solid tumours, an elevated SATB1 level was observed to be associated with an aggressive phenotype, presence of lymph node, distant metastases, and a poor prognosis. In this review, we briefly describe the prognostic significance of SATB1 expression in most common human cancers, and analyse its impact on EMT and metastasis.

Dietary DHA/EPA supplementation ameliorates diabetic nephropathy by protecting from distal tubular cell damage

The aim was to explore the influence of experimental diabetes mellitus type 1 (DM1) and potential protective/deleterious effects of different dietary n-6/n-3 PUFA ratios on renal phospholipid composition and pathological changes caused by DM1. Male Wistar rats were injected with 55 mg/kg streptozotocin or citrate buffer (control group). Control (C) and diabetic groups (STZ) were fed with n-6/n-3 ratio of ≈ 7, STZ + N6 with n-6/n-3 ratio ≈ 60 and STZ + DHA with n-6/n-3 ratio of ≈ 1 containing 16% EPA and 19% DHA. Tissues were harvested 30 days after DM1 induction. Blood and kidneys were collected and analysed for phospholipid fatty acid composition, pathohystological changes, ectopic lipid accumulation and expression of VEGF, NF-kB and special AT-rich sequence-binding protein-1 (SATB1). Pathological changes were studied also by using transmission electron microscopy, after immunostaining for VEGF. Substantial changes in renal phospholipid fatty acid composition resulted from DM1 and dietary PUFA manipulation. Extensive vacuolization of distal tubular cells (DTCs) was found in DM1, but it was attenuated in the STZ + DHA group, in which the highest renal NF-kB expression was observed. The ectopic lipid accumulation was observed in proximal tubular cells (PTCs) of all diabetic animals, but it was worsened in the STZ + N6 group. In DM1, we found disturbance of VEGF-transporting vesicular PTCs system, which was substantially worsened in STZ + DHA and STZ + N6. Results have shown that the early phase of DN is characterized with extent damage and vacuolization of DTCs, which could be attenuated by DHA/EPA supplementation. We concluded that dietary fatty acid composition can strongly influence the outcomes of DN.

Prognostic and Clinicopathological Significance of SATB1 in Colorectal Cancer: A Meta-Analysis

Background: A large number of studies have reported the aberrant expression of special AT-rich sequence binding protein 1 (SATB1) in colorectal cancer (CRC). However, the role of SATB1 in CRC is still controversial. Therefore, we performed this meta-analysis to elucidate the prognostic and clinical value of SATB1 in CRC patients.

Methods: We searched Web of Science, EMBASE and PubMed entirely in January 2018 to identify related articles. Pooled Hazard ratio (HR) was adopted to evaluate the prognostic value of SATB1 in CRC and odd ratio (OR) was used to assess the clinicopathological significance of SATB1 in CRC.

Results: Ten eligible studies containing 7 on prognosis and 9 on clinicopathological characteristics were finally included in the present meta-analysis. Results revealed that patients with high expression of SATB1 tended to have shorter overall survival (OS) (pooled HR: 1.64, 95% CI: 1.04–2.57). Besides, we also discovered that the expression of SATB1 was associated with histologic grade (OR = 1.88, 95% CI: 1.06–3.34), distant metastasis (OR = 1.43, 95% CI: 1.11–1.85) and lymph node metastasis (OR = 1.50, 95% CI: 1.03–2.19).

Conclusion: Broadly speaking, our meta-analysis demonstrated that high expression level of SATB1 was related to poor prognosis in CRC patients.

SATB1 in Malignant T Cells

Deficient expression of SATB1 hampers thymocyte development and results in inept T-cell lineages. Recent data implicate dysregulated SATB1 expression in the pathogenesis of mycosis fungoides, the most frequent variant of cutaneous T-cell lymphoma. Here, we report on a disease stage-associated decrease of SATB1 expression and an inverse expression of STAT5 and SATB1 in situ. STAT5 inhibited SATB1 expression through induction of microRNA-155. Decreased SATB1 expression triggered enhanced expression of IL-5 and IL-9 (but not IL-6 and IL-32), whereas increased SATB1 expression had the opposite effect, indicating that the microRNA-155 target SATB1 is a repressor of IL-5 and IL-9 in malignant T cells. In accordance, inhibition of STAT5 and its upstream activator JAK3 triggered increased SATB1 expression and a concomitant suppression of IL-5 and IL-9 expression in malignant T cells. In conclusion, we provide a mechanistic link between the proto-oncogenic JAK3/STAT5/microRNA-155 pathway, SATB1, and cytokines linked to CTCL severity and progression, indicating that SATB1 dysregulation is involved in cutaneous T-cell lymphoma pathogenesis.

Prognostic significance of SATB1 in gastrointestinal cancer: a meta-analysis and literature review

Background

The special AT-rich sequence-binding proteins 1 (SATB1) is a major regulator involved in cell differentiation. It has been shown that SATB1 acts as an oncogenic regulator. The clinical and prognostic significance of SATB1 in gastrointestinal cancer remains controversial. The purpose of this study is to conduct a systematic review and meta-analysis to elucidate the impact of SATB1 in gastrointestinal cancer.

Results

A total of 3174 gastrointestinal cancer patients from 15 studies were included. The correlation between SATB1 expression and OS or RFS was investigated in 12 and 5 studies respectively. The results of meta-analysis showed that SATB1 overexpression is inversely correlated with OS (combined HR: 1.79, p = 0.0003) and RFS (combined HR: 2.46, p < 0.0001). In subgroup analysis, SATB1 expression is significantly correlated with poor prognosis in gastrointestinal cancer in Asian population. SATB1 expression is associated with stage, invasion depth, lymph node metastasis and distant metastasis.

Methodology

Published studies with data on overall survival (OS) and/or relapse free survival (RFS) and SATB1 expression were searched from Cochrane Library, PubMed and Embase (up to Dec 30, 2016). The outcome measurement is hazard ratio (HR) for OS or RFS related with SATB1 expression. Two reviewers independently screened the literatures, extracted the data and performed meta-analysis using RevMan 5.3.0 software. The combined HRs were calculated by fixed- or random-effect models.

Conclusions

The results of this meta-analysis suggest that SATB1 overexpression is related to advanced stage, lymph node metastasis and distant metastasis. SATB1 overexpression is a marker indicating poor prognosis in gastrointestinal cancer.

Expression of SATB1 and E-cad in tissues of patients with endometrial carcinoma and the relationship with clinicopathological features

The expression of special AT-rich sequence binding protein 1 (SATB1) and E-cadherin (E-cad) in tissues of patients with endometrial carcinoma and the relationships with clinicopathological features were investigated. One hundred and four cases of carcinoma tissues and 104 cases of para-carcinoma tissues of patients pathologically diagnosed as endometrial carcinoma in Affiliated Hospital of Jining Medical University (Jining, China) from August 2015 to August 2016 were selected. The expressions of SATB1 and E-cad in tissues was detected via streptavidin peroxidase biotin (SP) immunohistochemical method, and the relationship with clinicopathological features of patients was analyzed. SATB1 was positively expressed in 71 out of 104 cases of endometrial carcinoma tissues (the expression rate was 68.27%) and in 25 out of 104 cases of para-carcinoma tissues (the expression rate was 24.03%). The expression of SATB1 in endometrial carcinoma tissues was significantly higher than that in para-carcinoma tissues (P<0.05). E-cad was positively expressed in 60 out of 104 cases of carcinoma tissues (the expression rate was 57.6%) and 95 out of 104 cases of para-carcinoma tissues (the positive expression rate was 91.3%) (P<0.05). The expression of SATB1 and E-cad in endometrial carcinoma tissues was not associated with the menopausal status or age of patients (P>0.05), but correlated with the histological grade of endometrial carcinoma, depth of tumor invasion, lymph node metastasis and tumor lymph node metastasis (TNM) staging (P<0.05). In conclusion, SATB1 and E-cad play important roles in the occurrence and development of endometrial carcinoma, which are of great significance to the potential therapeutic target and prognosis estimation of endometrial carcinoma.

High expression of special AT-rich sequence binding protein-1 predicts esophageal squamous cell carcinoma relapse and poor prognosis

Previous studies of the roles of special AT-rich sequence binding protein-1 (SATB1) in the development and progression of cancer have suggested that SATB1 promotes cancer cell metastasis. The aim of the present study is to evaluate the role of SATB1 in the progression and prognosis of esophageal squamous cell carcinoma (ESCC). ESCC tissues were collected from 102 patients and SATB1 mRNA expression was measured by reverse transcription-quantitative polymerase chain reaction. The association between expression of SATB1 mRNA with clinicopathological features and prognosis was assessed, and the prognosis of ESCC was evaluated using Kaplan-Meier survival curves. In the 102 ESCC tissues, SATB1 mRNA expression correlated with the clinical tumor node metastasis stage (P<0.05), but not with any other clinicopathological features (including age, gender, tumor differentiation grade, adjuvant radio/chemotherapy, or the consumption of alcohol and use of cigarettes) (P>0.05). The disease-free survival (DFS) and overall survival (OS) of patients with high SATB1 expression was decreased compared with those with low SATB1 expression. The present study indicated that SATB1 mRNA expression was associated with the postoperative recurrent and poor prognosis in ESCC. SATB1 may be a novel marker for predicting the recurrent and worse prognosis of ESCC.

Downregulation of SATB1 increases the invasiveness of Jurkat cell via activation of the WNT/β-catenin signaling pathway in vitro

Special AT-rich sequence-binding protein-1 (SATB1) is critical for genome organizer that reprograms chromatin organization and transcription profiles, and associated with tumor growth and metastasis in several cancer types. Many studies suggest that SATB1 overexpression is an indicator of poor prognosis in various cancers, such as breast cancer, malignant cutaneous melanoma, and liver cancer. However, their expression patterns and function values for adult T cell leukemia (ATL) are still largely unknown. The aim of this study is to examine the levels of SATB1 in ATL and to explore its function and mechanisms in Jurkat cell line. Here, we reported that SATB1 expressions were decreased in ATL cells (p < 0.001) compared with normal controls. Knockdown of SATB1 expression significantly enhanced invasion of Jurkat cell in vitro. Furthermore, knockdown of SATB1 gene enhances β-catenin nuclear accumulation and transcriptional activity and thus may increase the invasiveness of Jurkat cell through the activation of Wnt/β-catenin signaling pathway in vitro.