SATB2 overexpression promotes oral squamous cell carcinoma progression by up-regulating NOX4

Astragaloside IV inhibits nasopharyngeal carcinoma progression by suppressing the SATB2/Wnt signaling axis

Astragaloside IV (AS-IV), a major bioactive component of Astragalus membranaceus, exhibits anti-cancer and anti-inflammatory properties. However, its precise role in nasopharyngeal carcinoma (NPC) remains unclear. This study investigated the effects of AS-IV on NPC progression and its relationship with Special AT-rich binding protein-2 (SATB2), a diagnostic marker for NPC. AS-IV treatment reduced NPC cell viability in a dose-dependent manner, as assessed by CCK-8 assays. Functional experiments, including transwell, immunofluorescence, and flow cytometry assays, demonstrated that AS-IV inhibited cell migration, invasion, and autophagy while promoting apoptosis. Western blot analysis showed that SATB2 expression was significantly elevated in NPC cells, particularly in C666-1 and HK-1 cells. Overexpression of SATB2 partially reversed AS-IV's inhibitory effects on NPC progression. Further analysis revealed that AS-IV suppressed the Wnt signaling pathway by downregulating SATB2 expression, while SATB2 overexpression restored Wnt pathway activation. This effect was reversed upon treatment with the Wnt pathway inhibitor DKK-1. In vivo, AS-IV administration inhibited tumor growth in a nude mouse subcutaneous xenograft model, reduced Ki-67 positivity, and lowered LC3B expression, indicating decreased proliferation and autophagy. However, these effects were diminished upon SATB2 overexpression. These findings suggest that AS-IV exerts anti-tumor effects in NPC by downregulating SATB2 and suppressing Wnt pathway activation, highlighting its potential as a therapeutic agent for NPC.

Highlights

Astragaloside IV (AS-IV) reduces nasopharyngeal carcinoma (NPC) cell vitality, suppresses cell migration, invasion and autophagy, and fosters apoptosis.SATB2 exhibits notably high levels in NPC cells.Overexpression of SATB2 counteracts the inhibition of NPC malignant progression by AS-IV.AS-IV impedes NPC progression by decreasing SATB2 and thereby hindering the Wnt pathway.AS-IV deters NPC tumor growth in nude mice.

SATB2 promotes radiation resistance of esophageal squamous cell carcinoma by regulating epithelial-to-mesenchymal transition via the Wnt/β-catenin pathway

Purpose

Radioresistance remains a predominant factor contributing to local recurrence in esophageal squamous cell carcinoma (ESCC). SATB2, as a transcriptional co-gene, may affect the radioresistance of cancer cells. Consequently, this study aims to elucidate the mechanism by which SATB2 modulates radiotherapy resistance in esophageal cancer.

Methods

We identified highly expressed genes associated with radioresistance in ESCC using the MSigDB database and conducted survival correlation analysis. A radioresistant esophageal squamous cell carcinoma cell line (KYSE150R) was established using the gradient dose method, and RT-qPCR was used to detect the expression of SATB2 in KYSE150 and KYSE150R cells. CCK-8, Transwell, colony formation assay, and cell scratching were performed to determine and evaluate cell proliferation, cell migration, and cell invasion. Furthermore, the expression levels of mRNA and protein were correlated using WB and RT-qPCR. Mitochondrial membrane potential and apoptosis detection kits were used to evaluate the level of apoptosis. Finally, a mouse subcutaneous xenograft tumor model was employed to elucidate the role of SATB2 on the radiotherapy resistance of ESCC in vivo.

Results

Bioinformatics analysis indicated that SATB2 is linked to increased drug resistance in esophageal cancer. The results demonstrated that suppression of SATB2 decelerates cell proliferation and migration, accelerates apoptosis, inhibits the GSK-3β (Ser9) phosphorylation, and reduces β-catenin and target gene C-myc. The addition of the Wnt/β-catenin signaling pathway agonist (CHIR-99021) reversed these effects. Xenograft studies in mice revealed that knockdown of SATB2 reduced ESCC radioresistance.

Conclusion

We concluded that SATB2 may dysregulate the Wnt/β-catenin pathway, thereby facilitating EMT progression and conferring radioresistance.

Utility of SATB2 and MOC-31 Immunostains to Distinguish Between Poorly Differentiated Rectal Adenocarcinoma and Anal Squamous Cell Carcinoma

OBJECTIVES

Colorectal adenocarcinoma and squamous cell carcinoma (SCC) can arise in the anorectum and present a significant diagnostic challenge when poorly differentiated. Accurate diagnosis can significantly influence management, as the treatments for these conditions involve distinct neoadjuvant chemoradiotherapy regimens. MOC-31 and SATB2 have been utilized as specific markers of glandular differentiation and colorectal origin, respectively, but studies have shown that they may be positive in squamous cell carcinoma of other sites. This raises the concern that MOC-31 and SATB2 may be positive in squamous cell carcinoma of the anorectum, and overreliance on these stains may be a potential diagnostic pitfall in differentiating rectal poorly differentiated adenocarcinoma (PDA) from anal nonkeratinizing SCC.

METHODS

We identified biopsies from 10 rectal PDA and 17 anorectal nonkeratinizing SCC cases and stained them for MOC-31 and SATB2.

RESULTS

We found that MOC-31 was highly sensitive, being positive in 10/10 cases of rectal PDA, but not specific, as it was also positive in 11/17 SCC cases. In contrast, SATB2 was both sensitive, with positive staining in 10/10 rectal PDA cases, and specific, with negative staining in 17/17 SCC cases. This includes equivocal staining in 4 of these negative SCC cases. MOC-31 had a sensitivity of 100% and specificity of 35.3%, while SATB2 had a sensitivity of 100% and specificity of 100%.

CONCLUSIONS

Unlike squamous mucosa of the head and neck, and esophagus, SCC of the anus does not frequently stain positively for SATB2. These data suggest that SATB2 is a reliable marker in distinguishing rectal PDA from anorectal nonkeratinizing SCC, whereas MOC-31 is commonly positive in SCC of the anus. It is also important to note that equivocal SATB2 staining may be seen in SCC.

YAP-Activated SATB2 Is a Coactivator of NRF2 That Amplifies Antioxidative Capacity and Promotes Tumor Progression in Renal Cell Carcinoma

Aberrant epigenetic reprogramming contributes to the progression of renal cell carcinoma (RCC). Elucidation of key regulators of epigenetic reprogramming in RCC could help identify therapeutic vulnerabilities to improve treatment. Here, we report upregulation of the nuclear matrix-associated protein, special AT-rich binding protein-2 (SATB2), in RCC samples, which correlated with poor prognosis. SATB2 inhibition suppressed RCC growth and self-renewal capacities. YAP/TEAD4 activated SATB2 expression and depended on SATB2 to enhance cell proliferation. Transcriptome analysis implicated that SATB2 regulates NRF2 downstream targets to suppress oxidative stress without altering NRF2 levels. Integrated chromatin immunoprecipitation sequencing and assay for transposase-accessible chromatin using sequencing analyses demonstrated that SATB2 coordinated with NRF2 to drive enhancer-promoter interactions, amplifying transcriptional activity. SATB2 recruited SWI/SNF complex subunits, including BRD7 or BRG1, to sustain DNA accessibility. Increased SATB2 triggered chromatin remodeling into configurations that rendered RCC more sensitive to SATB2 deficiency. Moreover, SATB2 ablation promoted the sensitivity of RCC to chemotherapy-induced apoptosis. Finally, targeting SATB2 or BRD7 effectively restricted the proliferation of YAP-high tumors in patient-derived xenografts and patient-derived organoids. Together, SATB2 is an oncogenic chromatin organizer in RCC, and targeting SATB2 is an effective strategy to suppress the YAP-high RCC.

SIGNIFICANCE

A YAP-SATB2-NRF2 regulatory axis amplifies antioxidative stress signaling and provides potential therapeutic targets to enhance response to chemotherapy in renal cell carcinoma.

Hsa_circ_0006677 regulates special AT-rich binding protein-2-mediated tumor-suppressive effect via functioning as a miR-1245a sponge in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is still one of the most challenging malignant tumors. Deregulation of circular RNAs (circRNAs) is associated with NSCLC progression. However, the regulatory mechanism of circRNAs in NSCLC still needs to be studied. We selected a differentially expressed hsa_circ_0006677 (circ_0006677) in NSCLC through analyzing the GSE158695 and GSE112214 datasets. Expression of circ_0006677 was evaluated by real-time quantitative polymerase-chain reaction (RT-qPCR). Effects of circ_0006677 overexpression on NSCLC cell proliferation, apoptosis, migration, invasion, and stemness were determined by clonogenic, 5-ethynyl-2’-deoxyuridine (EdU), flow cytometry, transwell, and sphere formation assays. The regulatory mechanism of circ_0006677 was predicted by bioinformatics analysis and verified by dual-luciferase reporter and RIP assays. Animal experiments were carried out to validate the function of circ_0006677 in vivo. We observed the downregulation of circ_0006677 in NSCLC samples and cells. Functionally, circ_0006677 overexpression decreased xenograft tumor growth and restrained NSCLC cell proliferation, invasion, migration, stemness, and induced NSCLC cell apoptosis in vitro. Molecular mechanism experiments exhibited that circ_0006677 functioned as a miR-1245a sponge and mediated SATB2 expression through adsorbing miR-1245a. Either miR-1245a overexpression or SATB2 knockdown weakened circ_0006677 overexpression-mediated repression on proliferation, invasion, migration, and stemness. In conclusion, circ_0006677 regulated SATB2-mediated tumor-suppressive effect via acting as a miR-1245a sponge in NSCLC, providing a new mechanism for understanding the progression of NSCLC.