Special AT-rich Sequence Binding Protein 1 Expression Research Articles

Oncogenic Role of SATB2 In Vitro: Regulator of Pluripotency, Self-Renewal, and Epithelial-Mesenchymal Transition in Prostate Cancer.

Special AT-rich sequence binding protein-2 (SATB2) is a nuclear matrix protein that binds to nuclear attachment regions and is involved in chromatin remodeling and transcription regulation. In stem cells, it regulates the expression of genes required for maintaining pluripotency and self-renewal and epithelial-mesenchymal transition (EMT). In this study, we examined the oncogenic role of SATB2 in prostate cancer and assessed whether overexpression of SATB2 in human normal prostate epithelial cells (PrECs) induces properties of cancer stem cells (CSCs). The results demonstrate that SATB2 is highly expressed in prostate cancer cell lines and CSCs, but not in PrECs. Overexpression of SATB2 in PrECs induces cellular transformation which was evident by the formation of colonies in soft agar and spheroids in suspension. Overexpression of SATB2 in PrECs also resulted in induction of stem cell markers (CD44 and CD133), pluripotency-maintaining transcription factors (cMYC, OCT4, SOX2, KLF4, and NANOG), CADHERIN switch, and EMT-related transcription factors. Chromatin immunoprecipitation assay demonstrated that SATB2 can directly bind to promoters of BCL-2, BSP, NANOG, MYC, XIAP, KLF4, and HOXA2, suggesting SATB2 is capable of directly regulating pluripotency/self-renewal, cell survival, and proliferation. Since prostate CSCs play a crucial role in cancer initiation, progression, and metastasis, we also examined the effects of SATB2 knockdown on stemness. SATB2 knockdown in prostate CSCs inhibited spheroid formation, cell viability, colony formation, cell motility, migration, and invasion compared to their scrambled control groups. SATB2 knockdown in CSCs also upregulated the expression of E-CADHERIN and inhibited the expression of N-CADHERIN, SNAIL, SLUG, and ZEB1. The expression of SATB2 was significantly higher in prostate adenocarcinoma compared to normal tissues. Overall, our data suggest that SATB2 acts as an oncogenic factor where it is capable of inducing malignant changes in PrECs by inducing CSC characteristics.

Correlations of special AT-rich sequence binding protein 2 and chitinase-3-like protein-1 with sensitivity to paclitaxel chemotherapy for gastric cancer

Abstract Background: Our objective was to examine the associations between special AT-rich sequence binding protein 2 (SATB2) and chitinase-3-like protein-1 (CHI3L1) and the responsiveness to paclitaxel treatment in individuals with gastric cancer. Methods: From March 2018 to October 2020, our hospital collected gastric cancer samples along with adjacent gastric mucosal tissues located more than 5 cm away from the cancerous margin. These samples were obtained from 90 patients who underwent chemotherapy regimens containing paclitaxel. To assess the rates of positive expression of CHI3L1 and SATB2 in gastric cancer and adjacent tissues, the immunohistochemical streptavidin-peroxidase (SP) technique was utilized. Results: The positive expression rate of CHI3L1 was higher in gastric cancer tissues compared to adjacent tissues, while the positive expression rate of SATB2 was lower (P<0.05). Risk factors that influenced the positive expression of CHI3L1 in gastric cancer tissues included the level of differentiation, tumor-node-metastasis (TNM) stage, and the presence of lymph node metastasis (OR>1, P<0.05). Additionally, the positive expression of SATB2 was also affected by TNM stage and lymph node metastasis, which were identified as risk factors (OR>1, P<0.05). In gastric cancer tissues, there was a negative correlation observed between the expressions of CHI3L1 and SATB2 (r<0, P<0.05). According to the analysis results of Kendall’s tau-b (K), it was found that the presence of CHI3L1 had an inverse relationship with the responsiveness to paclitaxel-based chemotherapy in gastric cancer (r=-0.498, P=0.000), while SATB2 exhibited a positive correlation with the sensitivity (r=0.513, P=0.000). During the 3-year follow-up after chemotherapy, the survival rate was 55.55% (50/90). Conclusions: The findings indicate a strong correlation between SATB2 and CHI3L1 with the TNM stage, lymph node metastasis, response to paclitaxel-based chemotherapy, and the overall survival rate of individuals.

Upregulation of ubiquitin carboxy‑terminal hydrolase 47 (USP47) in papillary thyroid carcinoma exvivo and reduction of tumor cell malignant behaviors after USP47 knockdown by stabilizing SATB1 expression invitro.

Aberrant ubiquitination contributes to cancer development, including thyroid carcinoma. The present study assessed the expression of ubiquitin carboxy-terminal hydrolase 47 (USP47) and underlying molecular events in the development of papillary thyroid carcinoma (PTC). The effects of USP47 on PTC cell invasion and migration were analyzed by Transwell assays, while. the effects of USP47 and SATB1on PTC cell gene expression and changes in tumor cell metabolism were assayed by reverse transcription-quantitative PCR, western bolt, or ELISA, respectively. The expression of USP47 mRNA and protein was upregulated in PTC tissue and associated with the PTC tumor size. Knockdown of USP47 expression in PTC cell lines (TPC-1 and K1), decreased the cell proliferation mobility and invasion capacities, whereas USP47 overexpression in these cell lines showed an inverse effect and promoted cell glycolysis and glutamine metabolism. Moreover, expression of special AT-rich sequence-binding protein-1 (SATB1) was high in PTC tissue and was associated with USP47 expression. SATB1 expression promoted tumor cell glycolysis and glutamine metabolism, while USP47 protein bound to and deubiquitinated SATB1 to increase its intracellular levels, thus promoting glycolysis and glutamine metabolism. USP47 promotion of PTC development may be due to its stabilization of SATB1 protein, suggesting that targeting the USP47/SATB1 signaling axis may serve as a therapeutic intervention for PTC.

SATB2 Cytoplasmic Expression is Characteristic of a Subset of Ovarian Stromal Cells and Sex Cord Stromal Tumors.

Special AT-rich sequence-binding protein 2 (SATB2) is a nuclear transcription factor that shows consistent nuclear staining in colorectal adenocarcinoma and osteosarcoma. Following the observation of cytoplasmic staining with this marker in luteinized ovarian stromal cells, we studied the expression of SATB2 in ovarian stromal cells, various types of follicular cysts, and sex cord-stromal tumors. Eighty-five cases were stained for SATB2. Ovarian hilar Leydig cells (n = 12), luteinized stromal cells (n = 10), corpora lutea (n = 4), luteinized follicular cysts (n = 4), and stromal hyperthecosis (n = 6) exhibited consistent, usually diffuse, granular cytoplasmic staining. In addition, Leydig cell tumors (n = 1) and steroid cell tumors (n = 4) showed diffuse cytoplasmic staining. SATB2 also exhibited cytoplasmic staining in most Sertoli-Leydig cell tumors (n = 16) and gynandroblastomas (n = 3) confined to the Leydig cell component. Adult granulosa cell tumors (n = 14), juvenile granulosa cell tumors (n = 3), sex cord tumors with annular tubules (n = 3), cellular fibromas (n = 3), sclerosing stromal tumors (n = 1), and thecomas (n = 1) were negative apart from cytoplasmic staining in associated luteinized stromal cells. SATB2 cytoplasmic staining has not been previously described in these lesions but is characteristic of a variety of ovarian stromal cells and sex cord-stromal tumors, in particular, those exhibiting luteinization or a Leydig or steroid cell component. SATB2 staining may be of value in identifying luteinized or Leydig cells when these are morphologically inconspicuous.

Microfracture technique combined with mesenchymal stem cells inducer represses miR-708-5p to target special at-rich sequence-binding protein 2 to drive cartilage repair and regeneration in rabbit knee osteoarthritis

Knee osteoarthritis (KOA) is a degenerative joint illness which leads to knee pain and functional limitation. In this study, we combined microfracture surgery with kartogenin (KGN), a small bioactive molecule used to promote the differentiation of mesenchymal stem cells (MSCs), and explored its impact on cartilage repair and possible latent mechanisms of action. The research offers a brand-new idea for the clinical cure of KOA. The microfracture technique in combination with KNG treatment was performed on a rabbit model of KOA. Animal behaviour was evaluated after the intra-articular injection of miR-708-5p and Special AT-rich sequence binding protein 2 (SATB2) lentiviruses. Later, the expression of the tumour necrosis factor α (TNF-α) and interleukin- 1 (IL-1), the pathology of synovial tissue and cartilage tissue, and the positive cartilage type II collagen, MMP-1, MMP-3 and TIMP-1 were detected. Finally, a luciferase assay was conducted to verify the interaction of miR-708-5p and SATB2. Our results showed that miR-708-5p was elevated in the rabbit KOA model; however, the expression of SATB2 was reduced. Meanwhile, the microfracture technology combined with MSCs inducer KGN drove cartilage repair and regeneration in rabbit KOA by repressing the miR-708-5p expression. We also found that miR-708-5p directly targeted the SATB2 mRNA to regulate its expression. Furthermore, our data urged that elevating miR-708-5p or restraining SATB2 may reverse the therapeutic effect of the microfracture technique combined with MSCs inducer on rabbit KOA. Microfracture technique combined with MSCs inducer represses miR-708-5p to target SATB2 to drive cartilage repair and regeneration in rabbit KOA. This indicates that the microfracture technique combined with MSCs inducers is supposed to be an effective latent method for osteoarthritis cure.

Proteomic analysis identifies argininosuccinate synthetase 1 and special AT-rich sequence binding protein 1 as reliable markers for the immunohistochemical distinction between WHO types A and B3 thymomas.

The reliable classification of type A versus type B3 thymomas has prognostic and therapeutic relevance, but can be problematic due to considerably overlapping morphology. No immunohistochemical markers aiding in this distinction have been published so far. We identified and quantified numerous differentially expressed proteins using an unbiased proteomic screen by mass spectrometry in pooled protein lysates from three type A and three type B3 thymomas. From these, candidates were validated in a larger series of paraffin-embedded type A and B3 thymomas. We identified argininosuccinate synthetase 1 (ASS1) and special AT-rich sequence binding protein 1 (SATB1) as highly discriminatory between 34 type A and 20 type B3 thymomas (94% sensitivity, 98% specificity and 96% accuracy). Although not the focus of this study, the same markers also proved helpful in the diagnosis of type AB (n = 14), B1 (n = 4) and B2 thymomas (n = 10). Mutually exclusive epithelial expression of ASS1 in 100% of type B3 thymomas and ectopic nuclear expression of SATB1 in 92% of type A thymomas support the distinction between type A and type B3 thymomas with 94% sensitivity, 98% specificity and 96% accuracy.

SATB1 Chromatin Loops Regulate Megakaryocyte/Erythroid Progenitor Expansion by Facilitating HSP70 and GATA1 Induction.

Diamond Blackfan anemia (DBA) is an inherited bone marrow failure syndrome associated with severe anemia, congenital malformations, and an increased risk of developing cancer. The chromatin-binding special AT-rich sequence-binding protein-1 (SATB1) is downregulated in megakaryocyte/erythroid progenitors (MEPs) in patients and cell models of DBA, leading to a reduction in MEP expansion. Here we demonstrate that SATB1 expression is required for the upregulation of the critical erythroid factors heat shock protein 70 (HSP70) and GATA1 which accompanies MEP differentiation. SATB1 binding to specific sites surrounding the HSP70 genes promotes chromatin loops that are required for the induction of HSP70, which, in turn, promotes GATA1 induction. This demonstrates that SATB1, although gradually downregulated during myelopoiesis, maintains a biological function in early myeloid progenitors.

Immunohistochemical Expression Profile of SATB2 in Colorectal Adenocarcinoma and Association with Clinicopathological Parameters

Introduction: Colorectal carcinoma is the third most common cancer worldwide. Several clinicopathological parameters act as prognostic factors in colorectal carcinoma, but only a few are helpful in predicting the treatment outcome. Therefore, there is a need for better prognostic markers which also aids in assessing treatment benefits in colorectal carcinoma patients. Special AT Rich Sequence Binding Protein 2 (SATB2) is a highly specific marker for colorectal tissue. Decreased expression of SATB2 is also associated with poor prognosis in colorectal carcinoma. Aim: To analyse the histomorphology, immunohistochemical expression profile of SATB2 and association with clinicopathological parameters in colorectal adenocarcinoma. Materials and Methods: The cross-sectional study included 84 cases of colorectal carcinoma received in the Department of Pathology, SRM Medical College Hospital and Research Centre, Kattankulathur, Chennai, Tamil Nadu, India, in the period between April 2021 to September 2022. Both biopsy and resected specimens were included in the study. Relevant clinical data was collected. Histological diagnosis, grading and staging of the tumour was done using Haematoxylin and Eosin (H&E) slides as described and tabulated. Immunohistochemistry (IHC) for SATB2 and was done and expression profile compared with the clinicopathological parameters to assess prognostic significance. Data was analysed using software-Statistical Package for Social Sciences (SPSS, version 23.0). Results: Out of the 84 cases, 42 were biopsy and 42 resected specimens. Mean age of the patients in the study was 57.9 years. Patients were predominantly males (n=51, 60.7%) with a male:female ratio of 1.54:1. Of the 84 cases, 40.5% (n=34) had tumour located in the rectum. Majority of the cases were moderately differentiated adenocarcinoma (n=48, 57.1%). Predominantly, stage III tumours (n=33, 39.3%) were noted. Out of the tumours showing decreased expression of SATB2, 55% (n=22) were left-sided tumours, metastasis was seen in 60% (n=24 cases), 37.5% of cases (n=9) showed lymphovascular invasion, and 55% (n=22) had a stage III tumour. Conclusion: The present study results indicate that a decrease in SATB2 expression is associated with presence of lymphovascular invasion, perineural invasion, regional and distant metastasis and a higher pathological stage which signifies poor prognosis in colorectal carcinoma. These aid the physician for risk stratification of patients and enable personalised treatment choices including adjuvant chemotherapy in high-risk groups.

Diagnostic accuracy of SATB2 in identifying primary and metastatic colorectal carcinoma: a comparative immunohistochemical study.

Special AT-rich sequence-binding protein 2 (SATB2) is a new marker that could identify the colonic origin, but whether its expression is preserved in metastatic colorectal carcinomas (CRCs) remains unclear. This study was designed to investigate SATB2 validity in the identification of CRC either alone or in combination with caudal-type homeobox 2 (CDX2) and/or cytokeratin 20 (CK20). Moreover, we examined the concordance of SATB2 expression in primary CRC and paired metastatic specimen. Immunohistochemical expression of SATB2, CDX2 and CK20 was evaluated in primary CRC, 50 paired metastatic CRC and 80 non-CRC specimens. This study demonstrated that the ideal SATB2 cut-off value for recognising colonic from non-colonic origin was 10%. SATB2 was more sensitive and specific than CK20. However, it was more specific but less sensitive than CDX2. Analysing the combined markers expression, SATB2 and CDX2 combination revealed better sensitivity, specificity and larger area under curve compared to SATB2 alone, CDX2 alone and combined CDX2 and CK20. Moreover, SATB2 was able to retain its expression at the metastatic sites. SATB2 was totally concordant between primary CRC and their paired metastatic sites (concordance rate = 100%) with perfect level of agreement. SATB2 could be considered as an accurate diagnostic marker of primary and metastatic CRC. SATB2 and CDX2 is the best combination serving the highest sensitivity and specificity in detection of CRC.

Special AT-rich sequence-binding protein 2 (SATB2) in the differential diagnosis of osteogenic and non-osteogenic bone and soft tissue tumors.

BackgroundThe diagnosis of osteosarcoma (OSA) depends on clinicopathological and radiological correlation. A biopsy is considered the gold standard for OSA diagnosis. However, since OSA is a great histological mimicker, diagnostic challenges exist. Immunohistochemistry (IHC) can serve as an adjunct for the histological diagnosis of OSA. Special AT-rich sequence-binding protein 2 (SATB2) was recently described as a reliable adjunct immunohistochemical marker for the diagnosis of OSA.MethodsWe investigated the IHC expression of SATB2 in 95 OSA and 100 non-osteogenic bone and soft tissue tumors using a monoclonal antibody (clone EPNCIR30A). The diagnostic utility of SATB2 and correlation with clinicopathological parameters were analyzed.ResultsSATB2 IHC was positive in 88 out of 95 cases (92.6%) of OSA and 50 out of 100 cases (50.0%) of primary non-osteogenic bone and soft tissue tumors. Of the 59 bone tumors, 37 cases (62.7%) were positive for SATB2, and of the 41 soft tissue tumors, 13 cases (31.7%) were positive for SATB2. The sensitivity of SATB2 as a diagnostic test was 92.6%, specificity 50%, positive predictive value 63.8%, and negative predictive value 87.7%.ConclusionsAlthough SATB2 is a useful diagnostic marker for OSA, other clinical, histological and immunohistochemical features should be considered for the interpretation of SATB2.

Special AT-Rich Sequence-Binding Protein 1 Supports Survival and Maturation of Naive B Cells Stimulated by B Cell Receptors.

Epigenetic mechanisms underpin the elaborate activities of essential transcription factors in lymphocyte development. Special AT-rich sequence-binding protein 1 (SATB1) is a chromatin remodeler that orchestrates the spatial and temporal actions of transcription factors. Previous studies have revealed the significance of SATB1 in T cell lineage. However, whether and how SATB1 controls B cell lineage development is yet to be clarified. In this study, we show that SATB1 is an important factor during splenic B cell maturation. By analyzing SATB1/Tomato reporter mice, we determined the dynamic fluctuation of SATB1 expression in the B cell lineage. Although SATB1 expression decreased to minimal levels during B cell differentiation in the bone marrow, it resurged markedly in naive B cells in the spleen. The expression was dramatically downregulated upon Ag-induced activation. Splenic naive B cells were subdivided into two categories, namely SATB1high and SATB1-/low, according to their SATB1 expression levels. SATB1high naive B cells were less susceptible to death and greater proliferative than were SATB1-/low cells during incubation with an anti-IgM Ab. Additionally, SATB1high cells tended to induce the expression of MHC class II, CD86, and CD83. Accordingly, naive B cells from B lineage-specific SATB1 conditional knockout mice were more susceptible to apoptosis than that in the control group upon anti-IgM Ab stimulation in vitro. Furthermore, conditional knockout mice were less capable of producing Ag-specific B cells after immunization. Collectively, our findings suggest that SATB1 expression increases in naive B cells and plays an important role in their survival and maturation.

Elevated Expression of SATB1 Predicts Unfavorable Clinical Outcomes in Colon Adenocarcinoma.

Special AT-rich sequence-binding protein 1 (SATB1) belongs to the chromatin-remodeling protein which regulates different genes expression. High expression of SATB1 was found to be associated with the development of certain carcinomas. However, the functions of SATB1 in colon adenocarcinoma (CAC) remains unclear yet. Our study aims to investigate the potential role of SATB1 in CAC and whether it is associated with the unfavorable symptoms of CAC patients. The expression pattern of SATB1 was measured in CAC samples and adjacent noncancerous samples through quantitative real-time polymerase chain reaction and immunohistochemistry staining. We performed univariate and multivariate analyses to evaluate the clinical role of SATB1 in enrolled patients. The Kaplan-Meier analyses and log-rank tests were carried out to assess the clinicopathologic characteristics. The effect of SATB1 in human colon cancer cells was examined through cellular experiments. The expression level of SATB1 in CAC tissues was significantly elevated compared with adjacent control tissues. High expression of SATB1 in tumor tissue was found to be associated with lymph node metastasis and advanced TNM stage. Higher SATB1 level in CAC patients indicated a worse 5-year survival time. Moreover, high SATB1 was defined as an independent poor prognostic factor. Cellular experiments showed that inhibition of the SATB1 protein level in human colon cells could suppress the migration and invasion capabilities. Our findings revealed that high expression of SATB1 was significantly correlated with the poor clinical features and prognosis of CAC patients. It indicated that SATB1 might serve as a potential prognostic predictor and novel drug target for CAC treatment.

SATB2 is expressed in neuroendocrine carcinoma of the uterine cervix.

Neuroendocrine carcinoma (NEC) of the uterine cervix is less characterized than neuroendocrine neoplasms of other sites such as of the digestive system and the lung. Special AT-rich sequence-binding protein 2 (SATB2) recently emerged as a marker of well-differentiated neuroendocrine tumors of the lower gastrointestinal (GI) tract. Among NECs, SATB2 is more frequently expressed in cutaneous Merkel cell carcinoma than in NEC of other anatomical sites. In our study, we performed an immunohistochemical study of SATB2 in 16 NECs of the uterine cervix, where the expression of these markers is still undefined. SATB2 was expressed in 12/16 cervical NECs (75%), with 7/16 cases (44%) showing SATB2 positivity in ≥ 50% of cells. In 7 cervical NECs associated with a non-neuroendocrine component, the expression of SATB2 was restricted to the neuroendocrine component. SATB2 was positive in all cases that expressed CDX2 (n = 7) and TTF1 (n = 5), with no evident association with p16 and p53. Our study demonstrated that SATB2 is often expressed in NECs of the uterine cervix. This information should be taken into account when assessing the origin of a NEC.

Comprehensive clinicopathologic, molecular, and immunologic characterization of colorectal carcinomas with loss of three intestinal markers, CDX2, SATB2, and KRT20.

Caudal-type homeobox 2 (CDX2), special AT-rich sequence-binding protein 2 (SATB2), and keratin 20 (KRT20) are frequently used as intestinal epithelium-specific markers in immunohistochemical studies. However, subsets of colorectal carcinomas (CRCs) show loss of these markers. We analyzed The Cancer Genome Atlas data to explore molecular correlates of CDX2, SATB2, and KRT20 genes in 390 CRCs. The decreased mRNA expression of each of the three genes commonly correlated with microsatellite instability-high (MSI-H), CpG island methylator phenotype-high (CIMP-H), BRAF/RNF43 mutations, consensus molecular subtype 1, and high tumor mutational burden. The downregulation of CDX2 or SATB2 was dependent on both MSI-H and CIMP-H, whereas that of KRT20 was more dependent on MSI-H than on CIMP-H. Next, we evaluated the immunohistochemical expression of CDX2, SATB2, and KRT20 in 436 primary CRCs. In contrast to RNA-level expression, decreased expression of CDX2 and SATB2 was more dependent on CIMP-H than on MSI-H. However, consistent with RNA-level expression, decreased expression of KRT20 was more dependent on MSI-H than on CIMP-H. CIMP-H and lymphatic invasion were consistently associated with both CDX2 loss and SATB2 loss in CRCs, regardless of MSI status. In microsatellite stable CRCs, CDX2 loss correlated with BRAF mutation, whereas SATB2 loss was associated with KRAS mutations and decreased T-cell infiltration. Cases with concurrent loss of all three markers were found exclusively in MLH1-methylated MSI-H/CIMP-H CRCs. In conclusion, MSI-H and/or CIMP-H are major common correlates of decreased CDX2/SATB2/KRT20 expression in CRCs, but the specific features associated with the loss of each marker are different in CRCs.

Expression of SATB1 is a prognostic indicator for survival in diffuse large B-cell lymphoma patients.

Special AT-rich Sequence-binding Protein-1 (SATB1) and Matrix Attachment Region-binding Protein were associated with high tumor stage, tumor recurrence, tumor-related death and indicating a poor prognosis. The association between SATB1 and diffuse large B-cell lymphoma (DLBCL) has been discussed controversially. Thence, this study anticipated probing the expression of SATB1 in DLBCL and the relationships with clinic pathological features and prognosis. 180 cases of DLBCL tissues and 180 cases of chronic Lymphadenitis tissues in Para-carcinoma of DLBCL patients were collected in Guigang City People's Hospital, Guangxi, China, from August 2010 to December 2018. Here, the expression pattern of SATB1 in patients was examined by the method of streptomycin peroxides biotin (SP) immunohistochemical and analyzed the relationship of SATB1 with clinical pathological features and patient prognosis. DLBCL carcinoma tissues expression SATB1 was significantly higher than chronic lymphadenitis tissues (p < 0.05), and the expression of SATB1 was not correlated with age, B symptoms and the ECOG status of patients (p> 0.05), but correlated with tumor stage, serum level of LDH, extranodal involvement, and IPI score (p < 0.05). Kaplan-Meier curves and multivariate analysis showed that SATB1 is an independent factor affecting progression-free survival time and overall survival time. SATB1 participates in and affects the occurrence and development of DLBCL and influences their prognosis. It has broad prospects for improving prognosis evaluation, feasibility, molecular treatment intention and allocation of the most appropriate therapy.

Exploring new molecules that regulate hematopoietic stem cells and early stages of lymphoid hematopoiesis: the functional significance of ESAM and SATB1

Hematopoietic stem cells (HSCs) possess multilineage differentiation capability, which sustains the production of blood and immune cells throughout life. However, the precise mechanisms by which HSCs initiate differentiation toward a particular lineage and the factors that attenuate their lymphopoietic potential with aging are yet to be elucidated. Our group has investigated this issue for over two decades. We initially developed a method for segregating early lymphoid progenitors from HSCs and identified two molecules: endothelial cell-selective adhesion molecule (ESAM), highly expressed in HSCs, and special AT-rich sequence binding protein 1 (SATB1), expressed in early lymphoid progenitors. ESAM marks HSCs across species, including humans. In addition to its significance in stress-induced hematopoiesis, ESAM is also useful in identifying features of human acute myeloid leukemia stem cells. Further, we determined the role of SATB1 in the early HSC differentiation processes toward the lymphoid lineage. Remarkably, SATB1 expression in HSCs significantly decreased with aging, whereas its exogenous induction in aged HSCs rejuvenated their lymphopoietic potential. Furthermore, SATB1-expressing HSCs demonstrated robust lymphopoietic and long-term reconstituting capability, whereas HSCs without SATB1 skewed toward the myeloid lineage. Thus, our continuing research has revealed the significance of ESAM and SATB1 in the fundamental biology of HSCs.

SATB1 enhances gastric cancer progression and metastasis via upregulation of CLIP4/DZIP1/ PRICKLE2 axis in gastric cancer patients

SATB1 (Special AT-rich sequence binding protein 1) plays key role in chromatin remodeling and geneexpression. SATB1 has been shown to promote invasion, migration and metastasis. However, the underlying molecular mechanisms, function and clinicopathological features of SATB1 in gastric cancer (GC) remains poorly understood. Here, we show that SATB1 plays critical role in GC progression. SATB1 upregulates in GC patients’ samples and shows co-apmlification with a subset of oncogenic proteins (PRICKLE2, ZEB1, CBWX7, WWTR1, ENAH, DZIP1, IGSF11, ZSCAN18, GFRA2, GFRA1, FGFR1, HDAC4, GHR, TIMP3, CLIP4, TAGLN and ILK) in different subtypes of GC. SATB1 shows positive correlation with GC promoting oncogenes and enhances the expression of metastasis associated genes in GC samples to potentiate GC progression. SATB1 enhances WNT/NOTCH signaling axis in GC samples. In contrast, STAB1 suppresses a network of tumor suppressor genes in GC samples. Moreover, SATB1 expression negatively correlates with GC patient’s survival. Importantly, we found that SATB1 co-amplified genes CLIP4, DZIP1 and PRICKLE2 independently involve in GC progression. Overexpression of CLIP4, DZIP1 and PRICKLE2 show poor survival rates in GC patients. DZIP1 empowers AKT3/FGF2/FGFR1 and CXCR3/CXCR6 in GC patients. PRICKLE2 enhances GC progression by targeting FGFR1/NOTCH3/WNT4 signaling. Taken together, these results identified novel roles of SATB1, CLIP4, DZIP1 and PRICKLE2 in the GC invasion, migration and metastasis using cancer bioinformatics approach. These results highlights clinical significance of SATB1, CLIP4, DZIP1 and PRICKLE2 in GC patients and furthermore, these proteins may serve as prognostic markers in GC. These results also provide SATB1, CLIP4, DZIP1 and PRICKLE2 as potential chemotherapeutic targets in treatment of gastric cancer patients.

Small Interfering RNA-Mediated Knockdown of SATB1 Increases Cell Proliferation through NF-κb Activation in Acute Myeloid Leukemia

Background: Special AT-rich sequence-binding protein 1(SATB1) is a chromatin-remodeling protein that has been shown to regulate gene expressions and aberrant cell growth in different types of cancer. Up-regulation of SATB1 is linked with progression and metastasis of tumors. It is also reported that SATB1 is involved in the differentiation of hematopoietic lineages. However, less is known about the association between SATB1 and hematology malignancy. We previously reported that SATB1 expressions were decreased in T cell leukemia/lymphoma (T-ALL), and knockdown of SATB1 significantly enhanced invasiveness of Jurkat cell through the activation of Wnt/β-catenin signaling pathway in vitro. The contrary roles of SATB1 in solid organ tumors and hematology malignancy may provide hints to study the function of SATB1. Here, we investigated the role of SATB1 in acute myeloid leukemia (AML).Methods: To characterize SATB1 mRNA and protein expression in AML, we performed qRT-PCR and Western blot on peripheral blood mononuclear cells (PBMCs) from 52 newly diagnosed AML patients, as well as AML cell lines NB4, HEL, THP-1 and HL-60. Stable HL-60 cell lines with knockdown of SATB1 by shRNAs sequences (HL-60 SATB1-shRNA1 and HL-60 SATB1-shRNA2) were established. CCK-8 cell proliferation assay and flow cytometric analysis were performed to evaluate the cell proliferation and cell cycle. The invasiveness of HL-60 SATB1-shRNAs and HL-60 CTR cells was analyzed and compared by transwell assay. In order to study the role of SATB1 in vivo, murine model was established using HL-60 SATB1-shRNAs treated nude mice and tumorigenicity was comopared by tumor size. After demonstrating the association between SATB1 knockdown and tumorigenicity in vitro and in vivo, we next investigated NF-κB, AKT and MAPK signaling pathways by western blot.Results:l. SATB1 expression was significantly lower in AML patients than normal controls, which is similar to what we found in T-ALL patients. SATB1 expression was different before and after treatment, especially after complete remission (CR) of AML. Increased SATB1 expression was associated with better clinical outcome. We further investigated the roles of SATB1 on AML cells by shRNAs mediated knockdown of SATB1. Knockdown of SATB1 promoted the proliferation of HL-60 SATB1 shRNA1 cells and HL-60 SATB1 shRNA2 cells compared to the control. However, the transwell assay did not show increased invasiveness in SATB1 depleted HL-60 cells. The in vivo experiment showed that tumor size and weight in SATB1 knockdown mice were significantly increased compared to the control mice. In the mechanism study, we investigated NF-κB, AKT and MAPK signaling pathways by western blot. We found that the expression of NF-κB p65 in HL60 SATB1-shRNAs cells was increased, which suggested that SATB1 regulated AML cell growth via the activation of NF-κB signaling pathway.Conclusions: Impairment of SATB1 is associated with AML. SATB1 expressions were decreased in AML. Knockdown of SATB1 promoted cell proliferation and tumorigenicity of AML via the activation of NF-κB signaling pathway. DisclosuresNo relevant conflicts of interest to declare.

Expression of SATB2 in Acute Myeloid Leukemia and Its Prognostic Significance

Background: Human special AT-rich sequence-binding protein-2 (SATB2) is a novel DNA binding protein, which is involved in regulating gene expression. Recent studies conducted to evaluate the clinical significance of SATB2 in multiple malignant carcinomas, and have yielded controversial results. The purpose of this study is to investigate the expression status of SATB2 and its prognostic significance in AML patients.Methods: Total RNA was extracted from bone marrow or plasma of 87 patients with AML and 21 health volunteers. The expression of SATB2 was examined by Realtime quantitative PCR. The relationship of SATB2 expression and other clinicopathological charactors and its prognosis significance were statistically analyzed.Results: The relative expression of SATB2 was significantly up-regulated in AML patients (median value 0.061, range: 0.007-0.328) in comparison to those of healthy volunteers (median value 0.033, range: 0.008-0.077; P < 0.001) , and SATB2 expression level was much lower in patients who had achieved CR (median value 0.005, range: 0.001-0.006;P < 0.001) compared with newly diagnosed AML patients(median value 0.010, range: 0.002-0.027;P < 0.001).Furthermore, the expression of SATB2 was markedly associated with gender(P =0.043), WBC count(P =0.001), platelet count (P =0.025), BM blast count (P = 0.007) and Complete Remission (P < 0.001). Patients with higher SATB2 expression had a relatively poor overall survival(OS) (P = 0.009) and short disease-free survival(DFS) (P < 0.001). Moreover, SATB2 expression was an independent prognostic factors for both OS (P = 0.001) and DFS (P = 0.006).Conclusions: SATB2 was significantly up-regulated in AML patients in comparison to healthy donors. Patients who had achieved CR usually had a lower level of SATB 2 expression compared with newly diagnosed AML patients. The over-expression of SATB2 is associated with poor prognosis in AML patients, and was an independent prognostic factor for both OS and DFS. DisclosuresNo relevant conflicts of interest to declare.

SATB2 Expression in Uterine Sarcoma: A Multicenter Retrospective Study.

Uterine sarcomas represent a clinical challenge because of their difficult diagnosis and the poor prognosis of certain subtypes. The aim of this study was to evaluate the expression of the special AT-rich sequence-binding protein 2 (SATB2) in endometrial stromal sarcoma (ESS) and other types of uterine sarcoma by immunohistochemistry. We studied the expression of SATB2 on 71 full tissue sections of endometrial stromal nodule, low-grade ESS, uterine leiomyomas and leiomyosarcoma, undifferentiated uterine sarcoma, adenosarcoma, and carcinosarcoma samples. Nuclear SATB2 expression was then evaluated in an extended sample set using a tissue microarray, including 78 additional uterine tumor samples. Overall, with a cut-off of ≥10% of tumor cell staining as positive, the nuclear SATB2 score was negative in all endometrial stromal nodule samples (n=10) and positive in 83% of low-grade ESS samples (n=29/35), 40% of undifferentiated uterine sarcoma (n=4/10), 13% of leiomyosarcoma (n=2/16), 14% of adenosarcoma (n=3/22), and 8% carcinosarcoma (n=2/25) samples. Furthermore, in ESS patients, direct comparison of nuclear SATB2 scores with clinicopathologic parameters and other reported biomarkers such as progesterone receptor and estrogen receptor showed that nuclear SATB2 was associated with PR expression and a decreased risk of disease-specific death (odds ratio=0.06, 95% confidence interval=0.04-0.81, P=0.04). Our data suggest that SATB2 could be a marker with relative sensitivity (83%) for distinguishing between endometrial stromal nodule and ESS with potential prognostic value.