SOX2, a member of the SRY-related HMG-box (SOX) family, is abnormally expressed in many tumors and associated with cancer stem cell-like properties. Previous reports have shown that SOX2 is a biomarker for cancer stem cells in human bladder cancer (BC), and our most recent study has indicated that the inhibition of SOX2 by anticancer compound ChlA-F attenuates human BC cell invasion. We now investigated the mechanisms through which SOX2 promotes the invasive ability of BC cells. Our studies revealed that SOX2 promoted SKP2 transcription and increased SKP2-accelerated Sp1 protein degradation. As Sp1 is a transcriptionally regulated gene, HUR transcription was thereby attenuated, and, in the absence of HUR, FOXO1 mRNA was degraded fast, which promoted BC cell invasion. In addition, SOX2 promoted BC invasion through the upregulation of nucleolin transcription, which resulted in increased MMP2 mRNA stability and expression. Collectively, our findings show that SOX2 promotes BC invasion through both SKP2-Sp1-HUR-FOXO1 and nucleolin-MMP2 dual axes.
Lung adenocarcinoma (LUAD) is the predominant pathological subtype of lung cancer, which is the most prevalent and lethal malignancy worldwide. Cyclins have been reported to regulate the physiology of various types of tumors by controlling cell cycle progression. However, the key roles and regulatory networks associated with the majority of the cyclin family members in LUAD remain unclear. In total, 556 differentially expressed genes were screened from the GSE33532, GSE40791 and GSE19188 mRNA microarray datasets by R software. Subsequently, protein‑protein interaction network containing 499 nodes and 4,311 edges, in addition to a significant module containing 76 nodes and 2,631 edges, were extracted through the MCODE plug‑in of Cytoscape. A total of four cyclin family genes [cyclin (CCNA2, CCNB1, CCNB2 and CCNE2] were then found in this module. Further co‑expression analysis and associated gene prediction revealed forkhead boxM1 (FOXM1), the common transcription factor of CCNB2, CCNB1 and CCNA2. In addition, using GEPIA database, it was found that the high expression of these four genes were simultaneously associated with poorer prognosis in patients with LUAD. Experimentally, it was proved that these four hub genes were highly expressed in LUAD cell lines (Beas‑2B and H1299) and LUAD tissues through qPCR, western blot analysis and immunohistochemical studies. The diagnostic value of these 4 hub genes in LUAD was analyzed by logistic regression, CCNA2 was deleted, following which a nomogram diagnostic model was constructed accordingly. The area under the curve values of CCNB1, CCNB2 and FOXM1 diagnostic models were calculated to be 0.92, 0.91 and 0.96 in the training set (Combined dataset of GSE33532, GSE40791 and GSE19188) and two validation sets (GSE10072 and GSE75037), respectively. To conclude, data from the present study suggested that the FOXM1/cyclin (CCNA2, CCNB1 and/or CCNB2) axis may serve a regulatory role in the development and prognosis of LUAD. Specifically, CCNB1, CCNB2 and FOXM1 have potential as diagnostic markers and/or therapeutic targets for LUAD treatment.
ABSTRACTBladder cancer (BC) is the most expensive cancer to manage on a per-patient basis, costing about $4 billion in total healthcare expenditure per annum in America alone. Therefore, identifying a natural compound for prevention of BC is of tremendous importance for managing this disease. Previous studies have identified isorhapontigenin (ISO) as having an 85% preventive effect against invasive BC formation induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN). The results showed here that ISO treatment inhibited EGF-induced cell transformation of human urothelial cells through induction of tumor suppressor p27 transcription secondary to activation of an E2F1-dependentpathway.ISOtreatmentrenderedcellsresistanttoEGF-induced anchorage-independent growth concurrent with p27 protein induction in both UROtsa and SV-HUC-1 cells. ISO inhibition of EGF-induced cell transformation could be completely reversed by knockdown of p27, indicating that this protein was essential for the noted ISO inhibitory action. Mechanistic studies revealed that ISO treatment resulted in increased expression of E2F1, which in turn bound to its binding site in p27 promoter and initiated p27 transcription. The E2F1 induction was due to the elevation of its translation caused by ISO-induced miR-205 downregulation. Consistently, miR-205 was found to be overexpressed in human BCs, and ectopic expression of miR-205 mitigated ISO inhibitory effects against EGF-induced outcomes. Collectively, the results here demonstrate that ISO exhibits its preventive effect on EGF-induced human urothelial cell transformation by induction of p27 through a miR-205/E2F1 axis. This is distinct from what has been described for the therapeutic effects of ISO on human BC cells.KEYWORDS: ISOp27urothelial cellsbladder cancertransformation Disclosure statementNo potential conflict of interest was reported by the author(s).Ethical standardsEthical approval: All specimens were obtained with appropriate informed consent from the patients and the Medical Ethics Committee of China. And the comprehensive information of tissues were described in Materials and Methods.Author contributionsMH, XH, JX and JS acquisition and analysis of the data, drafting the manuscript; ZT, JW, HC, XW and PS, acquisition of data, critically reviewed the article; HY and JS analysis and interpretation of the data, critically reviewed the article; and CH conception and design, analysis and interpretation of the data, drafting and revising the manuscript. All the authors have read and approved the final manuscript.Data availabilityThe authors declare that all data supporting the findings of this study are available with the article or from the corresponding author upon reasonable request.Supplementary materialSupplemental data for this article can be accessed online at https://doi.org/10.1080/15384101.2022.2074623Additional informationFundingThis work was partially supported by grants from Natural Science Foundation of China (NSFC81773391 to C.H.); Oujiang Research Project (OJQD2022006 to C.H.); Natural Science Foundation of Ningbo (202003N4205 to J.S.); the Research Foundation of Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences (research fund of ningbo institute of life and health industry, university of Chinese academy of sciences 2020YJY0209 to J.S.); the National Natural Science Foundation of China (82003199 to J.S.).
The X-linked inhibitor of apoptosis protein (XIAP) contains three N-terminal BIR domains that mediate anti-apoptosis and one C-terminal RING finger domain whose function(s) are not fully defined. Here we show that the RING domain of XIAP strongly inhibits the expression of p63α, a known tumor suppressor. XIAP knockdown in urothelial cells or RING deletion in knockin mice markedly upregulates p63α expression. This RING-mediated p63α downregulation is critical for the malignant transformation of normal urothelial cells following EGF treatment. We further show that the RING domain promotes Sp1-mediated transcription of miR-4295 which targets the 3'UTR of p63α mRNA and consequently inhibits p63α translation. Our results reveal a previously unknown function of the RING of XIAP in promoting miR-4295 transcription, thereby reducing p63α translation and enhancing urothelial transformation. Our data offer novel insights into the multifunctional effects of the XIAP RING domain on urothelial tumorigenesis and the potential for targeting this frequently overexpressed protein as a therapeutic alternative.
In Fig. 1 H, the image representing the migration of T24T(shp65-2) was incorrect.The bands of GAPDH in Fig. 4 A and RhoGDI α in Fig. 6 G had been wrongly placed.These errors have now been corrected in new figures and do not affect the results or conclusions of this work.
Abstract Our previous studies have demonstrated that X-linked inhibitor of apoptosis protein (XIAP) plays a regulatory role in cancer invasion via mediation of RhoGDIα protein SUMOylation at Ser138 in colorectal cancer HCT116 cells. However, the alteration/association of XIAP in invasion, progression, and lung metastasis of bladder cancer (BC) as well as the molecular mechanisms leading to this XIAP alteration during BC development have not been explored yet. Herein, we found that XIAP was overexpressed in human high grade BCs, high metastatic human BC T24T cells, and in mouse invasive BCs. Mechanistic studies indicated that XIAP overexpression in the highly metastatic T24T cells was due to increased mRNA stability of XIAP in comparison to the parental non-metastatic T24 cells. Results from XIAP mRNA stability regulation revealed that miR-200c was profoundly downregulated in T24T cells and in highly invasive BCs, and that such miR-200c downregulation was mediated by CREB inactivation. Furthermore, miR-200c downregulation reduced its binding to the 3'-UTR region of XIAP mRNA, and resulted in its mRNA stabilization, protein overexpression, and invasive capabilities in T24T cells. Moreover, our results from XIAP-specific shRNA and miR-200c ectopic expression showed that suppression of XIAP profoundly attenuated lung metastasis of T24T cells in nude mice. In conclusion, our findings demonstrate the molecular basis leading to XIAP overexpression and the crucial role of XIAP in BC invasion in vitro and lung metastasis in nude mice. Citation Format: Zhongxian Tian, Honglei Jin, Jingxia Li, Chao Huang, Chuanshu Huang. Downregulation of miR-200c stabilizes XIAP mRNA and contributes to invasion and lung metastasis of bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1062.
BACKGROUND: Since invasive bladder cancer (BC) is one of the most lethal urological malignant tumors worldwide, understanding the molecular mechanisms that trigger the migration, invasion, and metastasis of BC has great significance in reducing the mortality of this disease. Although RelA/p65, a member of the NF-kappa B transcription factor family, has been reported to be upregulated in human BCs, its regulation of BC motility and mechanisms have not been explored yet. METHODS: NF-κBp65 expression was evaluated in N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN)–induced high invasive BCs by immunohistochemistry staining and in human BC cell lines demonstrated by Western Blot. The effects of NF-κBp65 knockdown on BC cell migration and invasion, as well as its regulated RhoGDIα and FBW7, were also evaluated in T24T cells by using loss- and gain-function approaches. Moreover, the interaction of FBW7 with RhoGDIα was determined with immunoprecipitation assay, while critical role of ubiquitination of RhoGDIα by FBW7 was also demonstrated in the studies. RESULTS: p65 protein was remarkably upregulated in the BBN-induced high invasive BCs and in human BC cell lines. We also observed that p65 overexpression promoted BC cell migration by inhibiting RhoGDIα expression. The regulatory effect of p65 on RhoGDIα expression is mediated by its upregulation of FBW7, which specifically interacted with RhoGDIα and promoted RhoGDIα ubiquitination and degradation. Mechanistic studies revealed that p65 stabilizing the E3 ligase FBW7 protein was mediated by its attenuating pten mRNA transcription. CONCLUSIONS: We demonstrate that p65 overexpression inhibits pten mRNA transcription, which stabilizes the protein expression of ubiquitin E3 ligase FBW7, in turn increasing the ubiquitination and degradation of RhoGDIα protein and finally promoting human BC migration. The novel identification of p65/PTEN/FBW7/RhoGDIα axis provides a significant insight into understanding the nature of BC migration, further offering a new theoretical support for cancer therapy.
Abstract The M6A RNA modification plays a crucial role in the progression of tumors. Simultaneously, IGF2BP3 is primarily expressed in the tumor cells of squamous cell carcinoma, rather than in stromal cells, including esophageal squamous cell carcinoma (ESCC), a subtype mainly prevalent in East Asia. However, the mechanism of IGF2BP3 in the progression of esophageal squamous cell carcinoma and its role in the tumor microenvironment (TME) remain unknown and require further exploration. Our research reveals that IGF2BP3 not only plays a significant oncogenic role in tumor cells, including the activation of the Wnt pathway, PI3K-AKT pathway, and MAPK pathway, but also, the high expression of IGF2BP3 is positively correlated with the enrichment of M2 macrophages in ESCC tissues, in the TME, IGF2BP3 promotes the infiltration of M2 macrophages, ultimately facilitating the progression of ESCC. Mechanistically, IGF2BP3 enhances the translation of USP36 mRNA by directly binding to its mRNA, rather than increasing the stability of mRNA. The IGF2BP3-mediated USP36 protein elevation enhances the binding capacity with CTNNB1 protein, reducing its degradation through the ubiquitin-proteasome pathway, and following improved the Wnt/CTNNB1 pathway activating, Ultimate, IGF2BP3 aggravated the malignancy of the tumor. Additionally, the activation of the Wnt pathway promotes TGFB1 transcription and secretion, subsequently activating the polarization of M2 macrophages, infuriating the formation of the tumor immune-suppressive microenvironment, ultimately promoting the progression of esophageal squamous cell carcinoma. Our findings strongly emphasize the oncogenic role of IGF2BP3 in the progression of ESCC both in vitro and in vivo, providing new insights and perspectives for the treatment of esophageal squamous cell carcinoma. Citation Format: Zhongxian Tian, Yongjia Zhou, Yi Ding, Zhengwen Wu, Xiaogang Zhao. IGF2BP3 promotes esophageal squamous cell carcinoma progressions via Wnt/CTNNB1 pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6847.
Abstract Sex-determining region Y-box 2 (SOX2), a well-known stemness biomarker, is highly expressed in a variety of cancers, including human highly invasive bladder cancer (BC). However, the role of SOX2 may vary in different kinds of malignancy. In the present study, we discovered that ChlA-F, a novel conformation derivative of isolate Cheliensisin A (Chel A), remarkably inhibits the invasive ability of human invasive BC cells through downregulation of SOX2 protein expression. We found that ChlA-F treatment dramatically decreases SOX2 protein expression in human high-grade invasive BC cells. Ectopic expression of SOX2 reversed ChlA-F inhibition of cell invasion ability in human bladder cancer cells, suggesting that SOX2 is a major target of ChlA-F during its inhibition of human BC invasion. Mechanistic studies revealed that SOX2 is downregulated by ChlA-F at both the protein degradation and protein translation levels. Further studies revealed that ChlA-F treatment induces HuR protein expression and that the increased HuR interacts with USP8 mRNA, resulting in elevation of USP8 mRNA stability and protein expression. Elevated USP8 subsequently acts as an E3 ligase to promote SOX2 ubiquitination and protein degradation. We also found that ChlA-F treatment substantially increases c-Jun phosphorylation at Ser63 and Ser73, initiating miR-200c transcription. The increased miR-200c directly binds to the 3’-UTR of SOX2 mRNA to suppress SOX2 protein translation. These results present novel mechanistic insight into understanding SOX2 inhibition upon ChlA-F treatment and provide important information for further exploration of ChlA-F as a new therapeutic compound for the treatment of highly invasive/metastatic human BC patients. Citation Format: Xiaohui Hua, Jiheng Xu, Chuanshu Huang, Jingxia Li, Zhongxian Tian, Haishan Huang. The inhibitory effect of compound ChlA-F onhuman bladder cancer cell invasion can be attributed to its blockage of SOX2 protein [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 785.
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