Overexpression Of Special AT-rich Sequence Binding Protein 1 Research Articles

Peripheral Blood of Vitiligo Patients-Derived Exosomal MiR-21-5p Inhibits Melanocytes Melanogenesis via Targeting SATB1.

Vitiligo is a common depigmentation disease characterized by progressive destruction and disappearance of epidermal melanocytes. Exosomes have been discovered to regulate the pigment status of melanocytes. We aimed to explore the role of exosomes from peripheral blood of vitiligo patients on melanogenesis. Human melanocytes cell line PIG1 was treated with exosomes from the healthy volunteers or exosomes from the vitiligo patients referred to the Department of Dermatology, Children's Hospital Affiliated to Zhengzhou University, China and transfected with miR-21-5p mimic or inhibitor. Exosome labeling assay was used to assess whether exosomes were absorbed by melanocytes. Melanin content and tyrosinase activity assays were performed to investigate melanogenesis in melanocytes. The levels of melanogenesis-related genes and proteins were detected by RT-qPCR and western blot assays. Dual-luciferase reporter assay was performed to confirm the relationship between miR-21-5p and special AT-rich sequence binding protein-1 (SATB1). Exosomes from peripheral blood of vitiligo patients were transferred into melanocytes and suppressed melanin content, tyrosinase activity and melanogenesis-related genes and proteins levels. Besides, miR-21-5p was highly expressed in exosomes from peripheral blood of vitiligo patients. The results of the gain- and loss-of-function experiments demonstrated that miR-21-5p inhibited the melanogenesis of melanocytes. Furthermore, miR-21-5p inhibitor abolished the inhibitory role of exosomes from peripheral blood of vitiligo patients. Subsequently, miR-21-5p directly targeted SATB1 in melanocytes. Furthermore, overexpression of SATB1 reversed the inhibitory roles of miR-21-5p mimic on melanin content, tyrosinase activity, and melanogenesis-related protein expression. Peripheral blood of vitiligo patients-derived exosomal miR-21-5p inhibited melanocytes melanogenesis via targeting SATB1.

MiR-7-5p inhibits cell migration and invasion in glioblastoma through targeting SATB1.

MicroRNAs (miRNAs/miRs) have been revealed to influence the development and progression of glioblastoma. Although a number of miRNAs are abnormally expressed in glioblastoma it is not clear whether they are a factor associated with glioblastoma pathogenesis. In the present study, miR-7-5p was identified as being aberrantly downregulated in glioblastoma tissues and cell lines. miR-7-5p overexpression significantly decreased the migratory and invasive capacity of the cells, while miR-7-5p silencing had the opposite effect. In addition, a luciferase assay confirmed that special AT rich sequence binding protein 1 (SATB1) was a direct target gene of miR-7-5p in glioblastoma. The overexpression of SATB1 in glioblastoma was revealed to promote cell migration and invasion. In addition, SATB1 overexpression may weaken the inhibitory effect of miR-7-5p on cell migration and invasion. miR-7-5p overexpression reversed the effects of SATB1 on cell migration and invasion in glioblastoma cells. In conclusion, miR-7-5p may be a useful therapeutic target for the diagnosis and treatment of patients with glioblastoma.

Identification of MS4A3 as a reliable marker for early myeloid differentiation in human hematopoiesis

Information of myeloid lineage-related antigen on hematopoietic stem/progenitor cells (HSPCs) is important to clarify the mechanisms regulating hematopoiesis, as well as for the diagnosis and treatment of myeloid malignancies. We previously reported that special AT-rich sequence binding protein 1 (SATB1), a global chromatin organizer, promotes lymphoid differentiation from HSPCs. To search a novel cell surface molecule discriminating early myeloid and lymphoid differentiation, we performed microarray analyses comparing SATB1-overexpressed HSPCs with mock-transduced HSPCs. The results drew our attention to membrane-spanning 4-domains, subfamily A, member 3 (Ms4a3) as the most downregulated molecule in HSPCs with forced overexpression of SATB1. Ms4a3 expression was undetectable in hematopoietic stem cells, but showed a concomitant increase with progressive myeloid differentiation, whereas not only lymphoid but also megakaryocytic-erythrocytic progenitors were entirely devoid of Ms4a3 expression. Further analysis revealed that a subset of CD34+CD38+CD33+ progenitor population in human adult bone marrow expressed MS4A3, and those MS4A3+ progenitors only produced granulocyte/macrophage colonies, losing erythroid colony- and mixed colony-forming capacity. These results suggest that cell surface expression of MS4A3 is useful to distinguish granulocyte/macrophage lineage-committed progenitors from other lineage-related ones in early human hematopoiesis. In conclusion, MS4A3 is useful to monitor early stage of myeloid differentiation in human hematopoiesis.

Tetramerization of SATB1 is essential for regulating of gene expression.

Special AT-rich sequence-binding protein 1 (SATB1) functions as a 'genome organizer' in tumorigenesis. Our previous report showed that SATB1 forms a tetramer through its N-terminal ubiquitin like domain rather than the proposed PDZ domain. In the present study, we aim to illustrate whether this oligomerization is critical to its function as a global repressor of gene expression in vivo. Luciferase and GST pull-down assays demonstrated that disrupting SATB1's tetramerization not only affects the activities of promoters but also influences the recruitment of interaction partners. Furthermore, we developed stable cell lines that overexpressed either the SATB1 tetramer or STAB1 dimer (KWN-AAA) and monitored global gene expression. Gene expression profiling revealed that over 1000 genes were significantly upregulated or downregulated upon the overexpression of SATB1 or the SATB1 (KWN-AAA) mutant. These data implied that SATB1 might regulate gene expression through its different oligomerization state. In conclusion, we inferred that the oligomerization of SATB1 is pivotal to its function of different biological processes.

SATB1 promotes the malignant of human non-Hodgkin lymphoma by activating the ribonucleotide reductase small subunit M2

To explore the role of the special AT rich sequence binding protein-1 (SATB1) and ribonucleotide reductase M2 (RRM2) in enhancing malignant progression of non-Hodgkin lymphoma (NHL). Methods: A total of 42 NHL and 42 chronic lymphadenitis patients were recruited. The protein expressions of SATB1 and RRM2 in cervical lymph nodes were determined by Western blot. After overexpression of SATB1, siSATB1 or siRRM2, the mRNA levels of SATB1 and RRM2 in cells were analyzed via RT-PCR, the cell proliferation was evaluated via MTT and EdU assays, while the migration and invasion of cells were assessed by transwell assays. Results: Compared with chronic lymphadenitis, the expressions of SATB1 and RRM2 in NHL patients were up-regulated. There was positive correlation between SATB1 and RRM2 in NHL patients. RRM2 mRNA level was up-regulated after transfection of SATB1 and down-regulated after transfection of siSATB1. Overexpression of SATB1 increased tumor cell proliferation, migration and invasion, while knockdown of RRM2 reversed those phenomena. Conclusion: SATB1 functions as an oncogene and promotes tumor cell proliferation, migration and invasion by up-regulation of RRM2 in NHL.

Special AT-rich sequence-binding protein-1 participates in the maintenance of breast cancer stem cells through regulation of the Notch signaling pathway and expression of Snail1 and Twist1.

The stem cell populations in cancerous tissues and cell lines vary widely and are often associated with aggressive cases of breast cancer. Despite research on the topic, the mechanism underlying the regulation of the breast cancer stem cell (BCSC) population within tumors remains to be fully elucidated. To investigate the function of special AT-rich sequence-binding protein-1 (SATB1) in the maintenance of the BCSC population, SATB1 was overexpressed with lentivirus in MCF-7 cells or knocked down with shRNA-lentivirus in BT-549 cells. The effects of SATB1 overexpression or knockdown on mammosphere formation, the size of the of BCSC population, cell invasion and tumorigenesis were investigated. Activation of the Notch signaling pathway and expression of Snail1 and Twist1 were also examined in the cells. Overexpression of SATB1 in MCF-7 cells was observed to increase mammosphere formation, the size of the BCSC population, cell invasion and tumorigenesis, accompanied by an increase in the activation of Notch signaling and expression levels of Snail1 and Twist1. Conversely, knockdown of SATB1 in BT-549 cells produced the opposite effects. The results indicated that expression of SATB1 may increase the size of the BCSC population via the activation of the Notch signaling pathway and by increasing expression levels of Snail1 and Twist1.

Overexpression of SATB1 is associated with biologic behavior in human renal cell carcinoma.

Special AT-rich sequence-binding protein-1 (SATB1) has been reported to be aberrantly expressed in various cancers and correlated with the malignant behavior of cancer cells. However, the function of SATB1 in RCC remains unclear. With the combination of immunohistochemistry, western blotting, immunofluorescence, qRT-PCR, and cell proliferation, migration and invasion assays, we found that levels of SATB1 mRNA and protein were dramatically increased in human ccRCC tissues (P<0.001 for both), and upregulation of SATB1 was significantly associated with depth of invasion (P<0.001), lymph node status (P = 0.001) and TNM stage (P = 0.009). SATB1 knockdown inhibited the proliferation, migration and invasion of 786-O cells, whereas SATB1 overexpression promoted the growth and aggressive phenotype of ACHN cells in vitro. Furthermore, SATB1 expression was positively correlated with ZEB2 expression (P = 0.013), and inversely linked to levels of SATB2 and E-cadherin (P = 0.005 and P<0.001, respectively) in ccRCC tissues. Our data provide a basis for the concept that overexpression of SATB1 may play a critical role in the acquisition of an aggressive phenotype for RCC cells through EMT, providing new insights into the significance of SATB1 in invasion and metastasis of ccRCC, which may contribute to fully elucidating the exact mechanism of development and progression of RCC.

Over-expression of the special AT rich sequence binding protein 1 (SATB1) promotes the progression of nasopharyngeal carcinoma: association with EBV LMP-1 expression

BackgroundSpecial AT rich sequence binding protein 1 (SATB1) plays a crucial role in the biology of various types of human cancer. However, the role of SATB1 in human nasopharyngeal carcinoma (NPC) remains unknown. In the present study, we sought to investigate the contribution of aberrant SATB1 expression in the progression of NPC and its association with the Epstein Barr virus (EBV)-encoded latent membrane protein 1 (LMP-1).MethodsImmunohistochemical analysis was performed to detect SATB1 and LMP-1 protein in clinical samples, and the association of SATB1 protein expression with patient clinicopathological characteristics and LMP-1 expression were analyzed. SATB1 expression profiles were evaluated in well-differentiated NPC cell line CNE1, poorly-differentiated CNE2Z, undifferentiated C666-1 and immortalized nasopharyngeal epithelia NP-69 cells using quantitative RT-PCR, western blotting and fluorescent staining. After inhibition the SATB1 expression by using SATB1 specific small interfering RNA in these cell lines, the change of cell proliferation was investigated by western blotting analysis of PCNA (proliferating cell nuclear antigen) expression and CCK-8 assay, and the cell migration was assessed by Transwell migration assay. Finally, the expressions of SATB1 and PCNA were examined in CNE1 cells that forced LMP-1 expression by fluorescent staining and RT-PCR.ResultsImmunohistochemical analysis revealed that SATB1 protein expression was elevated in NPC tissues compared to benign nasopharyngeal tissues (P = 0.005). Moreover, high levels of SATB1 protein expression were positively correlated with clinical stage (P = 0.025), the status of lymph node metastasis (N classification) (P = 0.018), distant metastasis (M classification) (P = 0.041) and LMP-1 expression status (r = 2.35, P < 0.01) in NPC patients. In vitro experiments demonstrated that an inverse relationship between SATB1 expression and NPC differentiation status, with SATB1 weakly expressed in NP-69 cells and CNE1 cells, and significant increasingly expressed in CNE-2Z and C666-1 cells. Targeted knockdown of SATB1 expression obviously attenuated the proliferation and migration of highly SATB1-expressing CNE2Z and C666-1 cells, but not NP-69 and CNE1 cells. Interestingly, forced LMP-1 expression in CNE1 cells led to a surprisingly increasing SATB1 expression and nuclear location, companying with an up-regulated PCNA expression.ConclusionsOur results reveal that EBV LMP-1-mediated over-expression of SATB1 is associated with NPC progression, suggesting SATB1 may represent a promising biomarker and therapeutic target for NPC.

SATB1 Expression Is Associated with Biologic Behavior in Colorectal Carcinoma In Vitro and In Vivo

There is increasing evidence that Special AT-rich sequence-binding protein 1 (SATB1) is aberrantly expressed in several cancers and is correlated with clinicopathologic parameters in these tumors. In this study, we showed over-expression of SATB1 in 80 cases of colorectal cancer and in 3 colorectal cancer cell lines and found expression levels were strongly associated with tumor differentiation and stage. Expression levels of SATB1 protein were higher in poorly-differentiated as compared with well-differentiated cell lines, and both quantity and distribution patterns of SATB1 were associated with tumor differentiation and pTNM stage. Strikingly, we further investigated the effect of down regulation of SATB1 expression on malignant phenotypic features in colorectal cancer cells in vitro, and showed that SABT1 down-regulation negatively affected growth potential, anchorage-independent colony formation and cancer cell invasion, and resulted in increased apoptosis. SATB1 expression was positively associated with the expression of various biological and genetic markers, including Cyclin D1, MMP-2, NF-κB, and PCNA, and was associated with loss of APC and BRAFV600E. These findings suggest that SATB1 is involved in the carcinogenesis, development and progression of colorectal cancer.

Clinicopathologic and prognostic significance of SATB1 in cutaneous malignant melanoma

Special AT-rich sequence-binding protein-1 (SATB1), a new type of gene regulator, has been reported to be expressed in several human cancers and may have malignant potential. However, no data on SATB1 expression and its relationship to tumor progression in cutaneous malignant melanoma (CMM) has yet been reported. We examined the immunohistochemical expression of SATB1 in CMM to determine whether it could serve as a prognostic marker. A total of 97 samples of primary CMM and controls were immunostained for SATB1. The following clinicopathologic variables were evaluated: age, gender, subtype, SATB1 expression, Breslow thickness, Clark level, presence of ulceration, lymph node metastasis, distant metastasis, and survival. Statistical analyses were performed to assess for associations. Several parameters were analyzed for survival using the Kaplan-Meier method and Cox proportional-hazards model. Forty cases (85.1%) of CMM showed positive staining for SATB1 by immunohistochemistry. The intensity of SATB1 staining was significantly higher in CMM than in nevus NV and normal skin (NS) (P < 0.01). High SATB1 expression was significantly correlated with Breslow thickness, Clark level, mortality, presence of ulceration, and lymph node metastasis (P < 0.01). Moreover, Kaplan-Meier analysis revealed that SATB1 overexpression was significantly associated with worse survival (P < 0.01). Further univariate analysis and multivariate regression analysis indicated that SATB1 expression was an independent prognostic marker for CMM (P = 0.03). The overexpression of SATB1 correlated with metastatic potential of CMM and is a novel independent prognostic marker for predicting outcome.

The BCL2 gene is regulated by a special AT-rich sequence binding protein 1-mediated long range chromosomal interaction between the promoter and the distal element located within the 3′-UTR

The 279-bp major breakpoint region (mbr) within the 3′-untranslated region (3′-UTR) of the BCL2 gene is a binding site of special AT-rich sequence binding protein 1 (SATB1) that is well known to participate in the long-range regulation of gene transcription. Our previous studies have revealed that the mbr could regulate BCL2 transcription over a 200-kb distance and this regulatory function was closely related to SATB1. This study is to explore the underlying mechanism and its relevance to cellular apoptosis. With chromosome conformation capture (3C) and chromatin immunoprecipitation (ChIP) assays we demonstrated that the mbr could physically interact with BCL2 promoter through SATB1-mediated chromatin looping, which was required for epigenetic modifications of the promoter, CREB accessibility and high expression of the BCL2 gene. During early apoptosis, SATB1 was a key regulator of BCL2 expression. Inhibition of SATB1 cleavage by treatment of cells with a caspase-6 inhibitor or overexpression of mutant SATB1 that was resistant to caspase-6, inhibited disassembly of the SATB1-mediated chromatin loop and restored the BCL2 mRNA level in Jurkat cells. These data revealed a novel mechanism of BCL2 regulation and mechanistically link SATB1-mediated long-range interaction with the regulation of a gene controlling apoptosis pathway for the first time.

SATB1 is an independent prognostic marker for gastric cancer in a Chinese population

Special AT-rich sequence binding protein 1 (SATB1), a new type of gene regulator, has been reported to express in various human cancers and may associate with the malignant potential. However, there are few data available on SATB1 expression and its relationship to tumor progression in gastric cancer. The current study was designed to examine the SATB1 expression in gastric cancer and to correlate it with clinical outcome. SATB1 expression was studied by qRT-PCR, western blotting and immunohistochemistry, respectively. The correlations between SATB1 expression and clinicopathological factors were statistically analyzed. SATB1 mRNA expression was significantly up-regulated in gastric cancer specimens as compared with that in normal tissues (P<0.001). Overexpression of SATB1 protein was observed in gastric cancer cell lines by western blotting. Fifty-three (44.9%) cases showed positive staining for the SATB1 proteins by immunohistochemistry. The expression of SATB1 mRNA agreed well with the western blotting and immunohistochemical findings (P<0.001). SATB1 expression was positively correlated with age, depth of invasion, lymph node metastasis, distant metastasis and TNM stage. Moreover, Kaplan-Meier analysis revealed that SATB1 overexpression was associated with a significantly worse survival (P<0.001). Further multivariable analysis indicated that SATB1 expression was an independent prognostic indicator for gastric cancer (P=0.023). In summary, overexpression of SATB1 correlated with metastatic potential of human gastric cancer and would be a novel independent prognostic marker for predicting the outcome of gastric cancer.

Abstract 2364: Overexpression of SATB1 (Special AT-Rich Sequence-Binding Protein 1) in prostate cancer potentiates metastatic phenotype

Abstract One of the reasons for the most prostate cancer-related deaths is the growth of secondary tumors due to metastases and not the primary organ-confined carcinoma. Metastasis in cancer cells results in acquiring abilities of increased motility and invasiveness, to home in other parts of the body. The key regulator involved in the control of metastasis genes in prostate cancer is presently unknown. Special AT-rich sequence-binding protein 1 (SATB1) is a transcription factor and functions as genome organizer. SATB1 being a transcription factor tend to bind with AT rich base unpaired sequences of the target gene. SATB1 acquires a “3 D chickenwire” network by forming anchor loops around chromatin, recruits chromatin remodeling complexes on the anchorage sites, and regulates histone modifications by rendering DNA sequences accessible or inaccessible for transcription. Earlier studies suggested the role of SATB1 in breast cancer progression. We aimed to observe the role of SATB1 in prostate cancer progression. We used different grades of human prostate cancer specimens, non tumorigenic and aggressive prostate cancer cells. Immunohistochemical evaluation of SATB1 in prostate cancer specimens of various Gleason grades exhibited significantly increased expression with increase in Gleason grade. A progressive increase in nuclear SATB1 expression was observed as tumor grade increased along with its presence in the cytoplasm. Further, SATB1 protein levels were higher in human prostate cancer cell lines viz. HPV-CA-10, DU145, DUPro, PC-3, PC-3M compared to non-tumorigenic prostate epithelial cells PZ-HPV-7. Nuclear expression of SATB1 was higher in biologically aggressive subclones of prostate cancer cells. Introduction of SATB1 through transient infections into non-tumorigenic PZ-HPV-7 cells increased its invasiveness and migration capabilities, whereas these properties were inhibited by silencing SATB1 through shRNA techniques. Furthermore, knock down of SATB1 caused increased E-cadherin expression and simultaneous reduction in matrix metalloproteinase-9 expression, providing further evidence that SATB1 significantly influences the metastasis process. Taken together, our results suggest that SATB1 is a master regulator of the metastasis process in prostate cancer and, therefore, could be considered as an independent prognostic factor and a potential therapeutic target for prostate cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2364.

A Distal Single Nucleotide Polymorphism Disrupts Development-Dependent Long-Range Transcriptional Regulation of the PU.1 Gene through the Chromatin-Remodeling Protein SATB1 in Acute Myeloid Leukemia.

Expression of the transcription factor PU.1 is dependent on a highly conserved upstream regulatory element (URE) located 14 kilobases upstream of the transcriptional start site. The proximal promoter of PU.1 alone, without this enhancer, displays 100-fold reduced promoter activity and is not capable of driving PU.1 expression in transgenic mice. Targeted disruption of the URE reduces PU.1 expression by 80% and leads to AML in mice. However, the mechanisms mediating the long-range regulatory function of the URE are largely unknown. Here, we identified a binding site of the chromatin-remodeling special AT-rich sequence-binding protein 1 (SATB1). Utilizing EMSA and ChIP, we found that SATB1 binds to the URE in myeloid U937 cells. Luciferase assays demonstrated 7-fold reduced reporter activity upon disruption of the SATB1 site. Lentiviral overexpression of SATB1 in primary murine Lin−, Kit+ progenitor cells led to an upregulation of PU.1 expression. We did not observe this effect in URE−/− progenitors indicating that the PU.1 regulatory function of SATB1 is mediated by the URE. Inhibition of SATB1 by siRNA in U937 cells led to a decrease in PU.1 expression. This inhibitory effect was not seen in myeloid URE−/− cells. To address the question at which stages during myeloid development SATB1 regulates PU.1, we sorted KSL-HSC, CMP, GMP, and MEP of SATB1 knockout mice and determined PU.1 expression levels. Interestingly, PU.1 expression was 88% and 80% reduced in SATB1−/− GMP and MEP, while KSL-HSC and CMP did not show significantly changed PU.1 levels. This finding indicates a stage-specific regulatory function of SATB1 during myelopoiesis. When we sequenced the URE in human individuals with AML we identified a SNP that abates binding of SATB1 and leads to decreased PU.1 expression in GMP and MEP. While the overall frequency of the homozygous SNP was not significantly changed in AML patients compared with healthy controls, this SNP was 2.3-fold more frequent in patients with AML with complex karyotype than in AML with normal karyotype (p<0.05). These findings suggest a role of this SNP in leukemia progression, in that the SNP acts as a modifier and favors a specific AML subtype, complex karyotypic AML. In conclusion, we have shown that the chromatin-remodeling protein SATB1 binds to the URE and acts as a development-dependent long-range transcriptional regulator of the PU.1 gene. Further, we have identified a SNP within this distal enhancer that is associated with a subtype of leukemia and exerts a deleterious effect through remote transcriptional dysregulation in specific progenitor subtypes.

A distal single nucleotide polymorphism alters long-range regulation of the PU.1 gene in acute myeloid leukemia

Targeted disruption of a highly conserved distal enhancer reduces expression of the PU.1 transcription factor by 80% and leads to acute myeloid leukemia (AML) with frequent cytogenetic aberrations in mice. Here we identify a SNP within this element in humans that is more frequent in AML with a complex karyotype, leads to decreased enhancer activity, and reduces PU.1 expression in myeloid progenitors in a development-dependent manner. This SNP inhibits binding of the chromatin-remodeling transcriptional regulator special AT-rich sequence binding protein 1 (SATB1). Overexpression of SATB1 increased PU.1 expression, and siRNA inhibition of SATB1 downregulated PU.1 expression. Targeted disruption of the distal enhancer led to a loss of regulation of PU.1 by SATB1. Interestingly, disruption of SATB1 in mice led to a selective decrease of PU.1 RNA in specific progenitor types (granulocyte-macrophage and megakaryocyte-erythrocyte progenitors) and a similar effect was observed in AML samples harboring this SNP. Thus we have identified a SNP within a distal enhancer that is associated with a subtype of leukemia and exerts a deleterious effect through remote transcriptional dysregulation in specific progenitor subtypes.

The bcl-2 major breakpoint region (mbr) possesses transcriptional regulatory function

The bcl-2 major breakpoint region (mbr), located within the 3′-UTR of the bcl-2 gene, is the site of the most common chromosomal translocation, t(14;18) (q32;q21), which occurs in follicular lymphoma. The mbr forms a triplex DNA structure under physiological conditions and the transcription factor special AT-rich sequence- binding protein 1 (SATB1) binds immediately downstream of the mbr. These observations raise the possibility that the mbr may be involved in regulation of bcl-2 gene expression. We investigated the role of the bcl-2 mbr on reporter gene activity and the relevance of SATB1 to this function in a variety of cell lines. We found that the mbr up-regulated reporter gene expression. Deletion of the 37-bp AT-rich SATB1 binding site abolished the bcl-2 mbr regulation of reporter gene expression. Overexpression of SATB1 enhanced bcl-2 mbr up-regulation of the reporter gene activity. Our data strongly demonstrated that the bcl-2 mbr possessed regulatory function that was related to SATB1.