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Knockdown of RhoQ, a member of Rho GTPase, accelerates TGF-β-induced EMT in human lung adenocarcinoma. Biochem Biophys Rep 2022; 32:101346. [PMID: 36120491 PMCID: PMC9474329 DOI: 10.1016/j.bbrep.2022.101346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/30/2022] [Accepted: 09/08/2022] [Indexed: 11/22/2022] Open
Abstract
Lung cancer is the leading cause of cancer-related deaths worldwide, and the most common subtype of lung cancer is adenocarcinoma. RhoQ is a Rho family GTPase with primary sequence and structural similarities to Cdc42 and RhoJ. RhoQ is involved in neurite outgrowth via membrane trafficking and is essential for insulin-stimulated glucose uptake in mature adipocytes. However, the function of RhoQ in lung adenocarcinoma (LUAD) remains unclear. In this study, RhoQ siRNAs were introduced into A549 and PC-9 cells. Expression level of EMT-related genes and invasion ability were investigated using Western blot and transwell assay. To examine the relationship between RhoQ expression and prognosis of LUAD, Kaplan–Meier plotter was used. We discovered that suppressing RhoQ expression promoted TGF-β-mediated EMT and invasion in LUAD cell lines. Furthermore, RhoQ knockdown increased Smad3 phosphorylation and Snail expression, indicating that RhoQ was involved in TGF/Smad signaling during the EMT process. Moreover, Kaplan–Meier plotter analysis revealed that low RhoQ levels were associated with poor overall survival in patients with LUAD. In conclusion, these findings shed light on RhoQ's role as a negative regulator of TGF-β-mediated EMT in LUAD. Knockdown of RhoQ expression promoted TGF-β-mediated EMT and invasion in human lung adenocarcinoma cells. RhoQ knockdown increased Smad3 phosphorylation and Snail expression during the EMT process. Low RhoQ levels were associated with poor overall survival in patients with lung adenocarcinoma.
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Huang D, Zeng Y, Deng HY, Fu BD, Ke Y, Luo JY, Yu JC, Yu ST. SYTL5 Promotes Papillary Thyroid Carcinoma Progression by Enhancing Activation of the NF-κB Signaling Pathway. Endocrinology 2022; 164:6828016. [PMID: 36378561 DOI: 10.1210/endocr/bqac187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 11/03/2022] [Accepted: 11/08/2022] [Indexed: 11/17/2022]
Abstract
The function and mechanism of SYTL5 in papillary thyroid carcinoma (PTC) are still unclear. In this research, we found that SYTL5 was significantly overexpressed in PTC tissues compared with normal thyroid tissues. SYTL5 downregulation significantly weakened the proliferative, migratory, and invasive abilities of PTC cells. In addition, upregulated SYTL5 could promote cancer progression by activating the NF-κB signaling pathway. RAC1b expression is positively associated with SYTL5, and overexpressed RAC1b abrogated the antitumor effect after SYTL5 inhibition. In conclusion, our findings identify the oncogenic role of SYTL5 in PTC by activation of the NF-κB signaling pathway, thus facilitating PTC development and progression.
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Affiliation(s)
- Da Huang
- Department of Thyroid surgery, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China
| | - Ying Zeng
- Second College of Clinical Medicine, Nanchang University, Nanchang, Jiangxi 330038, China
| | - Han-Yue Deng
- Second College of Clinical Medicine, Nanchang University, Nanchang, Jiangxi 330038, China
| | - Bi-Dong Fu
- Second College of Clinical Medicine, Nanchang University, Nanchang, Jiangxi 330038, China
| | - Yun Ke
- Second College of Clinical Medicine, Nanchang University, Nanchang, Jiangxi 330038, China
| | - Jing-Yi Luo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong 510060, China
| | - Ji-Chun Yu
- Department of Thyroid surgery, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China
| | - Shi-Tong Yu
- Department of General Surgery & Guangdong Provincial Key Laboratory of Precision Medicine for Gastrointestinal Tumor, Nanfang Hospital, The First School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong 510150, China
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Ungefroren H, Braun R, Lapshyna O, Konukiewitz B, Wellner UF, Lehnert H, Marquardt JU. Suppressive Role of ACVR1/ALK2 in Basal and TGFβ1-Induced Cell Migration in Pancreatic Ductal Adenocarcinoma Cells and Identification of a Self-Perpetuating Autoregulatory Loop Involving the Small GTPase RAC1b. Biomedicines 2022; 10:biomedicines10102640. [PMID: 36289908 PMCID: PMC9599656 DOI: 10.3390/biomedicines10102640] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/10/2022] [Accepted: 10/17/2022] [Indexed: 11/16/2022] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) cells are known for their high invasive/metastatic potential, which is regulated in part by the transforming growth factor β1 (TGFβ1). The involvement of at least two type I receptors, ALK5 and ALK2, that transmit downstream signals of the TGFβ via different Smad proteins, SMAD2/3 and SMAD1/5, respectively, poses the issue of their relative contribution in regulating cell motility. Real-time cell migration assays revealed that the selective inhibition of ALK2 by RNAi or dominant-negative interference with a kinase-dead mutant (ALK2-K233R) strongly enhanced the cells’ migratory activity in the absence or presence of TGFβ1 stimulation. Ectopic ALK2-K233R expression was associated with an increase in the protein levels of RAC1 and its alternatively spliced isoform, RAC1b, both of which are implicated in driving cell migration and invasion. Conversely, the RNAi-mediated knockdown or CRISPR/Cas9-mediated knockout of RAC1b resulted in the upregulation of the expression of ALK2, but not that of the related BMP type I receptors, ALK3 or ALK6, and elevated the phosphorylation of SMAD1/5. PDAC is a heterogeneous disease encompassing tumors with different histomorphological subtypes, ranging from epithelial/classical to extremely mesenchymal. Upon treatment of various established and primary PDAC cell lines representing these subtypes with the ALK2 inhibitor, LDN-193189, well-differentiated, epithelial cell lines responded with a much stronger increase in the basal and TGFβ1-dependent migratory activity than poorly differentiated, mesenchymal ones. These data show that (i) ALK2 inhibits migration by suppressing RAC1/RAC1b proteins, (ii) ALK2 and RAC1b act together in a self-perpetuating the autoregulatory negative feedback loop to mutually control their expression, and (iii) the ALK2 antimigratory function appears to be particularly crucial in protecting epithelial subtype cells from becoming invasive, both spontaneously and in a TGFβ-rich tumor microenvironment.
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Affiliation(s)
- Hendrik Ungefroren
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Kiel, D-24105 Kiel, Germany
- Correspondence:
| | - Rüdiger Braun
- Clinic for Surgery, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany
| | - Olha Lapshyna
- Clinic for Surgery, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany
| | - Björn Konukiewitz
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Kiel, D-24105 Kiel, Germany
| | - Ulrich F. Wellner
- Clinic for Surgery, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany
| | | | - Jens-Uwe Marquardt
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany
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A Regulatory Axis between Epithelial Splicing Regulatory Proteins and Estrogen Receptor α Modulates the Alternative Transcriptome of Luminal Breast Cancer. Int J Mol Sci 2022; 23:ijms23147835. [PMID: 35887187 PMCID: PMC9319905 DOI: 10.3390/ijms23147835] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/13/2022] [Accepted: 07/14/2022] [Indexed: 11/17/2022] Open
Abstract
Epithelial splicing regulatory proteins 1 and 2 (ESRP1/2) control the splicing pattern during epithelial to mesenchymal transition (EMT) in a physiological context and in cancer, including breast cancer (BC). Here, we report that ESRP1, but not ESRP2, is overexpressed in luminal BCs of patients with poor prognosis and correlates with estrogen receptor α (ERα) levels. Analysis of ERα genome-binding profiles in cell lines and primary breast tumors showed its binding in the proximity of ESRP1 and ESRP2 genes, whose expression is strongly decreased by ERα silencing in hormone-deprived conditions. The combined knock-down of ESRP1/2 in MCF-7 cells followed by RNA-Seq, revealed the dysregulation of 754 genes, with a widespread alteration of alternative splicing events (ASEs) of genes involved in cell signaling, metabolism, cell growth, and EMT. Functional network analysis of ASEs correlated with ESRP1/2 expression in ERα+ BCs showed RAC1 as the hub node in the protein-protein interactions altered by ESRP1/2 silencing. The comparison of ERα- and ESRP-modulated ASEs revealed 63 commonly regulated events, including 27 detected in primary BCs and endocrine-resistant cell lines. Our data support a functional implication of the ERα-ESRP1/2 axis in the onset and progression of BC by controlling the splicing patterns of related genes.
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Bailly C, Beignet J, Loirand G, Sauzeau V. Rac1 as a therapeutic anticancer target: Promises and limitations. Biochem Pharmacol 2022; 203:115180. [PMID: 35853497 DOI: 10.1016/j.bcp.2022.115180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/13/2022] [Accepted: 07/13/2022] [Indexed: 11/16/2022]
Abstract
Small molecule inhibitors of GTPases are increasingly considered for the treatment of multiple human pathologies. The GTPase Rac1 (Ras-related C3 botulinum toxin substrate 1) plays major roles in vital cellular processes, notably in the control cell motility and dynamic, the regulation of oxidative stress, and in inflammatory and immune surveillance. As such, Rac1 is viewed as a potential target to combat cancers but also diverse inflammatory, metabolic, neurodegenerative, respiratory, cardiovascular, viral, and parasitic diseases. Potent and selective Rac1 inhibitors have been identified and designed, such as compounds GYS32661 and MBQ-167 both in preclinical development for the treatment of advanced solid tumors. The pleiotropic roles and ubiquitous expression of the protein can be viewed as limitations for anticancer approaches. However, the frequent overexpression and/or hyperactivation of the Rac1 in difficult-to-treat chemoresistant cancers, make Rac1 an attractive target in oncology. The key roles of Rac1 in multiple cellular pathways, together with its major implications in carcinogenesis, tumor proliferation and metastasis, support the development of small molecule inhibitors. The challenge is high and the difficulty shall not be underestimated, but the target is innovative and promising in combination with chemo- and/or immuno-therapy. Opportunities and challenges associated with the targeting of Rac1 are discussed.
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Affiliation(s)
- Christian Bailly
- OncoWitan, Scientific Consulting Office, Lille (Wasquehal), 59290, France.
| | - Julien Beignet
- SATT Ouest Valorisation, 30 boulevard Vincent Gâche, CS 70211, 44202 Nantes cedex, France
| | - Gervaise Loirand
- Université de Nantes, CHU Nantes, CNRS, INSERM, Institut du thorax, Nantes, France
| | - Vincent Sauzeau
- Université de Nantes, CHU Nantes, CNRS, INSERM, Institut du thorax, Nantes, France
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Rac1 as a Target to Treat Dysfunctions and Cancer of the Bladder. Biomedicines 2022; 10:biomedicines10061357. [PMID: 35740379 PMCID: PMC9219850 DOI: 10.3390/biomedicines10061357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/06/2022] [Accepted: 06/07/2022] [Indexed: 12/28/2022] Open
Abstract
Bladder pathologies, very common in the aged population, have a considerable negative impact on quality of life. Novel targets are needed to design drugs and combinations to treat diseases such as overactive bladder and bladder cancers. A promising new target is the ubiquitous Rho GTPase Rac1, frequently dysregulated and overexpressed in bladder pathologies. We have analyzed the roles of Rac1 in different bladder pathologies, including bacterial infections, diabetes-induced bladder dysfunctions and bladder cancers. The contribution of the Rac1 protein to tumorigenesis, tumor progression, epithelial-mesenchymal transition of bladder cancer cells and their metastasis has been analyzed. Small molecules selectively targeting Rac1 have been discovered or designed, and two of them—NSC23766 and EHT 1864—have revealed activities against bladder cancer. Their mode of interaction with Rac1, at the GTP binding site or the guanine nucleotide exchange factors (GEF) interaction site, is discussed. Our analysis underlines the possibility of targeting Rac1 with small molecules with the objective to combat bladder dysfunctions and to reduce lower urinary tract symptoms. Finally, the interest of a Rac1 inhibitor to treat advanced chemoresistance prostate cancer, while reducing the risk of associated bladder dysfunction, is discussed. There is hope for a better management of bladder pathologies via Rac1-targeted approaches.
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Ungefroren H, Thürling I, Färber B, Kowalke T, Fischer T, De Assis LVM, Braun R, Castven D, Oster H, Konukiewitz B, Wellner UF, Lehnert H, Marquardt JU. The Quasimesenchymal Pancreatic Ductal Epithelial Cell Line PANC-1-A Useful Model to Study Clonal Heterogeneity and EMT Subtype Shifting. Cancers (Basel) 2022; 14:cancers14092057. [PMID: 35565186 PMCID: PMC9101310 DOI: 10.3390/cancers14092057] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 04/13/2022] [Accepted: 04/18/2022] [Indexed: 12/18/2022] Open
Abstract
Simple Summary Malignant tumors often escape therapy due to clonal propagation of a subfraction of drug-resistant cancer cells. The underlying phenomenon of intratumoral heterogeneity is driven by epithelial–mesenchymal plasticity (EMP) involving the developmental programs, epithelial–mesenchymal transition (EMT), in which epithelial cells are converted to invasive mesenchymal cells, and the reverse process, mesenchymal–epithelial transition (MET), which allows for metastatic outgrowth at distant sites. For therapeutic targeting of EMP, a better understanding of this process is required; however, cellular models with which to study EMP in pancreatic ductal adenocarcinoma (PDAC) are scarce. Using single-cell clonal analysis, we have found the PDAC cell line, PANC-1, to consist of cells with different E/M phenotypes and functional attributes. Parental PANC-1 cultures could be induced in vitro to shift towards either a more mesenchymal or a more epithelial phenotype, and this bidirectional shift was controlled by the small GTPases RAC1 and RAC1b, together identifying PANC-1 cells as a useful model with which to study EMP. Abstract Intratumoral heterogeneity (ITH) is an intrinsic feature of malignant tumors that eventually allows a subfraction of resistant cancer cells to clonally evolve and cause therapy failure or relapse. ITH, cellular plasticity and tumor progression are driven by epithelial–mesenchymal transition (EMT) and the reverse process, MET. During these developmental programs, epithelial (E) cells are successively converted to invasive mesenchymal (M) cells, or back to E cells, by passing through a series of intermediate E/M states, a phenomenon termed E–M plasticity (EMP). The induction of MET has clinical potential as it can block the initial EMT stages that favor tumor cell dissemination, while its inhibition can curb metastatic outgrowth at distant sites. In pancreatic ductal adenocarcinoma (PDAC), cellular models with which to study EMP or MET induction are scarce. Here, we have generated single cell-derived clonal cultures of the quasimesenchymal PDAC-derived cell line, PANC-1, and found that these differ strongly with respect to cell morphology and EMT marker expression, allowing for their tentative classification as E, E/M or M. Interestingly, the different EMT phenotypes were found to segregate with differences in tumorigenic potential in vitro, as measured by colony forming and invasive activities, and in circadian clock function. Moreover, the individual clones the phenotypes of which remained stable upon prolonged culture also responded differently to treatment with transforming growth factor (TGF)β1 in regard to regulation of growth and individual TGFβ target genes, and to culture conditions that favour ductal-to-endocrine transdifferentiation as a more direct measure for cellular plasticity. Of note, stimulation with TGFβ1 induced a shift in parental PANC-1 cultures towards a more extreme M and invasive phenotype, while exposing the cells to a combination of the proinflammatory cytokines IFNγ, IL1β and TNFα (IIT) elicited a shift towards a more E and less invasive phenotype resembling a MET-like process. Finally, we show that the actions of TGFβ1 and IIT both converge on regulating the ratio of the small GTPase RAC1 and its splice isoform, RAC1b. Our data provide strong evidence for dynamic EMT–MET transitions and qualify this cell line as a useful model with which to study EMP.
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Affiliation(s)
- Hendrik Ungefroren
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, D-23538 Lübeck, Germany; (I.T.); (T.K.); (T.F.); (D.C.); (J.-U.M.)
- Clinic for Surgery, University Hospital Schleswig-Holstein, Campus Lübeck, University of Lübeck, D-23538 Lübeck, Germany; (B.F.); (R.B.); (U.F.W.)
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Kiel, D-24105 Kiel, Germany;
- Correspondence:
| | - Isabel Thürling
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, D-23538 Lübeck, Germany; (I.T.); (T.K.); (T.F.); (D.C.); (J.-U.M.)
| | - Benedikt Färber
- Clinic for Surgery, University Hospital Schleswig-Holstein, Campus Lübeck, University of Lübeck, D-23538 Lübeck, Germany; (B.F.); (R.B.); (U.F.W.)
| | - Tanja Kowalke
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, D-23538 Lübeck, Germany; (I.T.); (T.K.); (T.F.); (D.C.); (J.-U.M.)
| | - Tanja Fischer
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, D-23538 Lübeck, Germany; (I.T.); (T.K.); (T.F.); (D.C.); (J.-U.M.)
| | - Leonardo Vinícius Monteiro De Assis
- Institute for Neurobiology, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, D-23538 Lübeck, Germany; (L.V.M.D.A.); (H.O.)
| | - Rüdiger Braun
- Clinic for Surgery, University Hospital Schleswig-Holstein, Campus Lübeck, University of Lübeck, D-23538 Lübeck, Germany; (B.F.); (R.B.); (U.F.W.)
| | - Darko Castven
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, D-23538 Lübeck, Germany; (I.T.); (T.K.); (T.F.); (D.C.); (J.-U.M.)
| | - Henrik Oster
- Institute for Neurobiology, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, D-23538 Lübeck, Germany; (L.V.M.D.A.); (H.O.)
| | - Björn Konukiewitz
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Kiel, D-24105 Kiel, Germany;
| | - Ulrich Friedrich Wellner
- Clinic for Surgery, University Hospital Schleswig-Holstein, Campus Lübeck, University of Lübeck, D-23538 Lübeck, Germany; (B.F.); (R.B.); (U.F.W.)
| | | | - Jens-Uwe Marquardt
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, D-23538 Lübeck, Germany; (I.T.); (T.K.); (T.F.); (D.C.); (J.-U.M.)
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Sauzeau V, Beignet J, Vergoten G, Bailly C. Overexpressed or hyperactivated Rac1 as a target to treat hepatocellular carcinoma. Pharmacol Res 2022; 179:106220. [PMID: 35405309 DOI: 10.1016/j.phrs.2022.106220] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/31/2022] [Accepted: 04/05/2022] [Indexed: 12/12/2022]
Abstract
Despite novel targeted and immunotherapies, the prognosis remains bleak for patients with hepatocellular carcinoma (HCC), especially for advanced and/or metastatic forms. The rapid emergence of drug resistance is a major obstacle in the success of chemo-, targeted-, immuno-therapies of HCC. Novel targets are needed. The prominent roles of the small GTPase Rac1 in the development and progression of HCC are discussed here, together with its multiple protein partners, and the targeting of Rac1 with RNA-based regulators and small molecules. We discuss the oncogenic functions of Rac1 in HCC, including the contribution of Rac1 mutants and isoform Rac1b. Rac1 is a ubiquitous target, but the protein is frequently overexpressed and hyperactivated in HCC. It contributes to the aggressivity of the disease, with key roles in cancer cell proliferation, tumor metastasis and resistance to treatment. Small molecule targeting Rac1, indirectly or directly, have shown anticancer effects in HCC experimental models. Rac1-binding agents such as EHT 1864 and analogues offer novel opportunities to combat HCC. We discuss the different modalities to repress Rac1 overactivation in HCC with small molecules and the combination with reference drugs to promote cancer cell death and to repress cell invasion. We highlight the necessity to combine Rac1-targeted approach with appropriate biomarkers to select Rac1 activated tumors. Our analysis underlines the prominent oncogenic functions of Rac1 in HCC and discuss the modalities to target this small GTPase. Rac1 shall be considered as a valid target to limit the acquired and intrinsic resistance of HCC tumors and their metastatic potential.
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Affiliation(s)
- Vincent Sauzeau
- Université de Nantes, CHU Nantes, CNRS, INSERM, Institut du Thorax, Nantes, France.
| | - Julien Beignet
- SATT Ouest Valorisation, 30 boulevard Vincent Gâche, CS 70211, 44202 Nantes Cedex, France
| | - Gérard Vergoten
- University of Lille, Inserm, INFINITE - U1286, Institut de Chimie Pharmaceutique Albert Lespagnol (ICPAL), Faculté de Pharmacie, 3 rue du Professeur Laguesse, BP-83, 59006, Lille, France
| | - Christian Bailly
- OncoWitan, Scientific Consulting Office, Lille, Wasquehal 59290, France.
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Schmidtlein PM, Volz C, Hackel A, Thürling I, Castven D, Braun R, Wellner UF, Konukiewitz B, Riemekasten G, Lehnert H, Marquardt JU, Ungefroren H. Activation of a Ductal-to-Endocrine Transdifferentiation Transcriptional Program in the Pancreatic Cancer Cell Line PANC-1 Is Controlled by RAC1 and RAC1b through Antagonistic Regulation of Stemness Factors. Cancers (Basel) 2021; 13:cancers13215541. [PMID: 34771704 PMCID: PMC8583136 DOI: 10.3390/cancers13215541] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 10/29/2021] [Accepted: 11/02/2021] [Indexed: 01/29/2023] Open
Abstract
Simple Summary For patients with metastatic pancreatic ductal adenocarcinoma (PDAC) there is currently no cure; hence, novel effective therapies are desperately needed. Among PDAC patients, the tumor cell phenotypes are heterogeneous as a result of epithelial–mesenchymal transition, a process that endows them with the ability to metastasize, resist therapy, and generate cancer stem cells. The heightened plasticity of quasimesenchymal and potentially metastatic tumor cells may, however, also be exploited for their transdifferentiation into benign, highly differentiated or post-mitotic cells. Since PDAC patients often have a need for replacement of insulin-producing cells, conversion of tumor cells with a ductal/exocrine origin to endocrine β cell-like cells is an attractive therapeutic option. Successful transdifferentiation into insulin-producing cells has been reported for the quasimesenchymal cell line PANC-1; however, the mechanistic basis of this transformation process is unknown. Here, we show that the small GTPases, RAC1 and RAC1b control this process by antagonistic regulation of stemness genes. Abstract Epithelial–mesenchymal transition (EMT) is a driving force for tumor growth, metastatic spread, therapy resistance, and the generation of cancer stem cells (CSCs). However, the regained stem cell character may also be exploited for therapeutic conversion of aggressive tumor cells to benign, highly differentiated cells. The PDAC-derived quasimesenchymal-type cell lines PANC-1 and MIA PaCa-2 have been successfully transdifferentiated to endocrine precursors or insulin-producing cells; however, the underlying mechanism of this increased plasticity remains elusive. Given its crucial role in normal pancreatic endocrine development and tumor progression, both of which involve EMT, we analyzed here the role of the small GTPase RAC1. Ectopic expression in PANC-1 cells of dominant negative or constitutively active mutants of RAC1 activation blocked or enhanced, respectively, the cytokine-induced activation of a ductal-to-endocrine transdifferentiation transcriptional program (deTDtP) as revealed by induction of the NEUROG3, INS, SLC2A2, and MAFA genes. Conversely, ectopic expression of RAC1b, a RAC1 splice isoform and functional antagonist of RAC1-driven EMT, decreased the deTDtP, while genetic knockout of RAC1b dramatically increased it. We further show that inhibition of RAC1 activation attenuated pluripotency marker expression and self-renewal ability, while depletion of RAC1b dramatically enhanced stemness features and clonogenic potential. Finally, rescue experiments involving pharmacological or RNA interference-mediated inhibition of RAC1 or RAC1b, respectively, confirmed that both RAC1 isoforms control the deTDtP in an opposite manner. We conclude that RAC1 and RAC1b antagonistically control growth factor-induced activation of an endocrine transcriptional program and the generation of CSCs in quasimesenchymal PDAC cells. Our results have clinical implications for PDAC patients, who in addition to eradication of tumor cells have a need for replacement of insulin-producing cells.
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Affiliation(s)
- Paula Marie Schmidtlein
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany; (P.M.S.); (C.V.); (I.T.); (D.C.); (J.-U.M.)
| | - Clara Volz
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany; (P.M.S.); (C.V.); (I.T.); (D.C.); (J.-U.M.)
| | - Alexander Hackel
- Department of Rheumatology and Clinical Immunology, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany; (A.H.); (G.R.)
| | - Isabel Thürling
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany; (P.M.S.); (C.V.); (I.T.); (D.C.); (J.-U.M.)
| | - Darko Castven
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany; (P.M.S.); (C.V.); (I.T.); (D.C.); (J.-U.M.)
| | - Rüdiger Braun
- Clinic for Surgery, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany; (R.B.); (U.F.W.)
| | - Ulrich Friedrich Wellner
- Clinic for Surgery, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany; (R.B.); (U.F.W.)
| | - Björn Konukiewitz
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Kiel, D-24105 Kiel, Germany;
| | - Gabriela Riemekasten
- Department of Rheumatology and Clinical Immunology, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany; (A.H.); (G.R.)
| | | | - Jens-Uwe Marquardt
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany; (P.M.S.); (C.V.); (I.T.); (D.C.); (J.-U.M.)
| | - Hendrik Ungefroren
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany; (P.M.S.); (C.V.); (I.T.); (D.C.); (J.-U.M.)
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Kiel, D-24105 Kiel, Germany;
- Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, D-23538 Lübeck, Germany
- Correspondence:
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A Comparative Endocrine Trans-Differentiation Approach to Pancreatic Ductal Adenocarcinoma Cells with Different EMT Phenotypes Identifies Quasi-Mesenchymal Tumor Cells as Those with Highest Plasticity. Cancers (Basel) 2021; 13:cancers13184663. [PMID: 34572891 PMCID: PMC8466512 DOI: 10.3390/cancers13184663] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 09/01/2021] [Accepted: 09/14/2021] [Indexed: 12/11/2022] Open
Abstract
Simple Summary Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancer types with the quasi-mesenchymal (QM) subtype of PDAC having the worst prognosis. De-differentiation of the ductal tumor cells to a mesenchymal phenotype occurs as a result of epithelial–mesenchymal transition (EMT), a process associated with the acquisition of stem cell traits. While QM tumor cells are highly metastatic and drug-resistant, their increased plasticity opens a window of opportunity for trans-differentiation into non-malignant pancreatic cells. In this study we compared established PDAC-derived cell lines of either epithelial (E) or QM phenotype for their potential to be differentiated to pancreatic endocrine cells. We found that QM cells responded more strongly than E cells with transcriptional activation of a pancreatic progenitor or pancreatic β cell-specific program. Our results bear strong implications for a novel type of targeted therapy, namely EMT-based trans-differentiation of highly metastatic PDAC cells in vivo to non-malignant endocrine cells. Abstract Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and therapy-resistant cancer types which is largely due to tumor heterogeneity, cancer cell de-differentiation, and early metastatic spread. The major molecular subtypes of PDAC are designated classical/epithelial (E) and quasi-mesenchymal (QM) subtypes, with the latter having the worst prognosis. Epithelial–mesenchymal transition (EMT) and the reverse process, mesenchymal-epithelial transition (MET), are involved in regulating invasion/metastasis and stem cell generation in cancer cells but also early pancreatic endocrine differentiation or de-differentiation of adult pancreatic islet cells in vitro, suggesting that pancreatic ductal exocrine and endocrine cells share common EMT programs. Using a panel of PDAC-derived cell lines classified by epithelial/mesenchymal expression as either E or QM, we compared their trans-differentiation (TD) potential to endocrine progenitor or β cell-like cells since studies with human pancreatic cancer cells for possible future TD therapy in PDAC patients are not available so far. We observed that QM cell lines responded strongly to TD culture using as inducers 5′-aza-2′-deoxycytidine or growth factors/cytokines, while their E counterparts were refractory or showed only a weak response. Moreover, the gain of plasticity was associated with a decrease in proliferative and migratory activities and was directly related to epigenetic changes acquired during selection of a metastatic phenotype as revealed by TD experiments using the paired isogenic COLO 357-L3.6pl model. Our data indicate that a QM phenotype in PDAC coincides with increased plasticity and heightened trans-differentiation potential to activate a pancreatic β cell-specific transcriptional program. We strongly assume that this specific biological feature has potential to be exploited clinically in TD-based therapy to convert metastatic PDAC cells into less malignant or even benign cells.
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The RNA-Binding Protein ESRP1 Modulates the Expression of RAC1b in Colorectal Cancer Cells. Cancers (Basel) 2021; 13:cancers13164092. [PMID: 34439247 PMCID: PMC8392041 DOI: 10.3390/cancers13164092] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/03/2021] [Accepted: 08/09/2021] [Indexed: 12/14/2022] Open
Abstract
Simple Summary Colorectal cancer (CRC) ranks third for incidence and second for number of deaths among cancer types worldwide. Poor patient survival due to inadequate response to currently available treatment regimens points to the urgent requirement for personalized therapy in CRC patients. Our aim was to provide mechanistic insights into the pro-tumorigenic role of the RNA-binding protein ESRP1, which is highly expressed in a subset of CRC patients. We show that, in CRC cells, ESRP1 binds to and has the same trend in expression as RAC1b, a well-known tumor promoter. Thus, RAC1b may be a potential therapeutic target in ESRP1-overexpressing CRC. Abstract RNA binding proteins are well recognized as critical regulators of tumorigenic processes through their capacity to modulate RNA biogenesis, including alternative splicing, RNA stability and mRNA translation. The RNA binding protein Epithelial Splicing Regulatory Protein 1 (ESRP1) can act as a tumor suppressor or promoter in a cell type- and disease context-dependent manner. We have previously shown that elevated expression of ESRP1 in colorectal cancer cells can drive tumor progression. To gain further insights into the pro-tumorigenic mechanism of action of ESRP1, we performed cDNA microarray analysis on two colorectal cells lines modulated for ESRP1 expression. Intriguingly, RAC1b was highly expressed, both at mRNA and protein levels, in ESRP1-overexpressing cells, while the opposite trend was observed in ESRP1-silenced CRC cells. Moreover, RAC1 and RAC1b mRNA co-immunoprecipitate with ESRP1 protein. Silencing of RAC1b expression significantly reduced the number of soft agar colonies formed by ESRP1-overexpressing cells, suggesting that ESRP1 acted, at least partially, through RAC1b in its tumor-promoting activities in CRC cells. Thus, our data provide molecular cues on targetable candidates in CRC cases with high ESRP1 expression.
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Repurposing Niclosamide for Targeting Pancreatic Cancer by Inhibiting Hh/Gli Non-Canonical Axis of Gsk3β. Cancers (Basel) 2021; 13:cancers13133105. [PMID: 34206370 PMCID: PMC8269055 DOI: 10.3390/cancers13133105] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 06/15/2021] [Accepted: 06/17/2021] [Indexed: 12/14/2022] Open
Abstract
Simple Summary The current obstacles for discovering new drugs for cancer therapy have necessitated the development of the alternative strategy of drug repurposing, the identification of new uses for approved or investigational drugs for new therapeutic purposes. Niclosamide (Nic) is a Food and Drug Administration (FDA)-approved anti-helminthic drug, reported to have anti-cancer effects, and is being assessed in various clinical trials. In the current study, we assessed the therapeutic efficacy of Nic on pancreatic cancer (PC) in vitro. Our results revealed mitochondrial stress and mTORC1-dependent autophagy as the predominant players of Nic-induced PC cell death. This study provided a novel mechanistic insight for anti-cancer efficacy of Nic by increasing p-Gsk3β that modulates molecular signaling(s), including inhibition of hedgehog (Hh) signaling-mediated cellular proliferation and increased apoptosis through mTORC1-dependent autophagy may prove helpful for the development of novel PC therapies. Abstract Niclosamide (Nic), an FDA-approved anthelmintic drug, is reported to have anti-cancer efficacy and is being assessed in clinical trials for various solid tumors. Based on its ability to target multiple signaling pathways, in the present study, we evaluated the therapeutic efficacy of Nic on pancreatic cancer (PC) in vitro. We observed an anti-cancerous effect of this drug as shown by the G0/G1 phase cell cycle arrest, inhibition of PC cell viability, colony formation, and migration. Our results revealed the involvement of mitochondrial stress and mTORC1-dependent autophagy as the predominant players of Nic-induced PC cell death. Significant reduction of Nic-induced reactive oxygen species (ROS) and cell death in the presence of a selective autophagy inhibitor spautin-1 demonstrated autophagy as a major contributor to Nic-mediated cell death. Mechanistically, Nic inhibited the interaction between BCL2 and Beclin-1 that supported the crosstalk of autophagy and apoptosis. Further, Nic treatment resulted in Gsk3β inactivation by phosphorylating its Ser-9 residue leading to upregulation of Sufu and Gli3, thereby negatively impacting hedgehog signaling and cell survival. Nic induced autophagic cell death, and p-Gsk3b mediated Sufu/Gli3 cascade was further confirmed by Gsk3β activator, LY-294002, by rescuing inactivation of Hh signaling upon Nic treatment. These results suggested the involvement of a non-canonical mechanism of Hh signaling, where p-Gsk3β acts as a negative regulator of Hh/Gli1 cascade and a positive regulator of autophagy-mediated cell death. Overall, this study established the therapeutic efficacy of Nic for PC by targeting p-Gsk3β mediated non-canonical Hh signaling and promoting mTORC1-dependent autophagy and cell death.
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Nozaki M, Nishizuka M. Repression of RhoJ expression promotes TGF-β-mediated EMT in human non-small-cell lung cancer A549cells. Biochem Biophys Res Commun 2021; 566:94-100. [PMID: 34119829 DOI: 10.1016/j.bbrc.2021.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 06/02/2021] [Indexed: 12/13/2022]
Abstract
Non-small-cell lung cancer (NSCLC) accounts for most cancer-related deaths because of its strong metastatic ability. It is important to understand NSCLC's molecular mechanisms of metastasis. RhoJ, a protein that belongs to the Rho family of small GTPases, regulates endothelial motility, angiogenesis, and adipogenesis. Recently, bioinformatics analysis showed that NSCLC patients with lower RhoJ expression had a worse survival outcome than those with high RhoJ expression. However, little is known about RhoJ's role in NSCLC. In the present study, we demonstrated that RhoJ knockdown accelerated TGF-βmediated epithelial-to-mesenchymal transition (EMT), an important cancer metastasis process, in A549 and PC-9 cells. Furthermore, using Matrigel-coated transwell chambers, we showed that RhoJ knockdown enhanced the invasion capacity of A549 cells that had undergone EMT. Also, reduced RhoJ expression increased Smad3 phosphorylation and Snail expression during the EMT process. Our results provide the first evidence of a potential novel role for RhoJ in the inhibition of EMT via modulation of the TGF-β-Smad signaling pathway, and shed new light on the mechanisms underlying EMT in NSCLC.
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Affiliation(s)
- Misa Nozaki
- Graduate School of Sustainable Community Studies, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Makoto Nishizuka
- Graduate School of Sustainable Community Studies, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan; Department of Applied Biology and Food Sciences, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan.
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Autocrine TGFβ1 Opposes Exogenous TGFβ1-Induced Cell Migration and Growth Arrest through Sustainment of a Feed-Forward Loop Involving MEK-ERK Signaling. Cancers (Basel) 2021; 13:cancers13061357. [PMID: 33802809 PMCID: PMC8002526 DOI: 10.3390/cancers13061357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 03/11/2021] [Accepted: 03/14/2021] [Indexed: 11/30/2022] Open
Abstract
Simple Summary Transforming growth factor (TGF) β signaling is intimately involved in nearly all aspects of tumor development and is known for its role as both a tumor suppressor in benign tissues and a tumor promoter in advanced cancers. This dual role is also reflected by cancer cell-produced TGFβ that eventually acts on the same cell(s) in an autocrine fashion. Recently, we observed that endogenous TGFB1 can inhibit rather than stimulate cell motility in cell lines with high autocrine TGFβ production. The unexpected anti-migratory role prompted us to evaluate how autocrine TGFβ1 impacts the cells’ migratory and proliferative responses to exogenous (recombinant human) TGFβ. Surprisingly, endogenous TGFB1 opposed the migratory and growth-inhibitory responses induced by exogenous TGFβ1 by driving a self-perpetuating feedforward loop involving MEK-ERK signaling. Our observation has implications for the use of TGFβ signaling inhibitors in cancer therapy. Abstract Autocrine transforming growth factor β (aTGFβ) has been implicated in the regulation of cell invasion and growth of several malignant cancers such as pancreatic ductal adenocarcinoma (PDAC) or triple-negative breast cancer (TNBC). Recently, we observed that endogenous TGFB1 can inhibit rather than stimulate cell motility in cell lines with high aTGFβ production and mutant KRAS, i.e., Panc1 (PDAC) and MDA-MB-231 (TNBC). The unexpected anti-migratory role prompted us to evaluate if aTGFβ1 may be able to antagonize the action of exogenous (recombinant human) TGFβ (rhTGFβ), a well-known promoter of cell motility and growth arrest in these cells. Surprisingly, RNA interference-mediated knockdown of the endogenous TGFB1 sensitized genes involved in EMT and cell motility (i.e., SNAI1) to up-regulation by rhTGFβ1, which was associated with a more pronounced migratory response following rhTGFβ1 treatment. Ectopic expression of TGFB1 decreased both basal and rhTGFβ1-induced migratory activities in MDA-MB-231 cells but had the opposite effect in Panc1 cells. Moreover, silencing TGFB1 reduced basal proliferation and enhanced growth inhibition by rhTGFβ1 and induction of cyclin-dependent kinase inhibitor, p21WAF1. Finally, we show that aTGFβ1 promotes MEK-ERK signaling and vice versa to form a self-perpetuating feedforward loop that is sensitive to SB431542, an inhibitor of the TGFβ type I receptor, ALK5. Together, these data suggest that in transformed cells an ALK5-MEK-ERK-aTGFβ1 pathway opposes the promigratory and growth-arresting function of rhTGFβ1. This observation has profound translational implications for TGFβ signaling in cancer.
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15
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Melchionna R, Trono P, Tocci A, Nisticò P. Actin Cytoskeleton and Regulation of TGFβ Signaling: Exploring Their Links. Biomolecules 2021; 11:biom11020336. [PMID: 33672325 PMCID: PMC7926735 DOI: 10.3390/biom11020336] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/15/2021] [Accepted: 02/20/2021] [Indexed: 12/14/2022] Open
Abstract
Human tissues, to maintain their architecture and function, respond to injuries by activating intricate biochemical and physical mechanisms that regulates intercellular communication crucial in maintaining tissue homeostasis. Coordination of the communication occurs through the activity of different actin cytoskeletal regulators, physically connected to extracellular matrix through integrins, generating a platform of biochemical and biomechanical signaling that is deregulated in cancer. Among the major pathways, a controller of cellular functions is the cytokine transforming growth factor β (TGFβ), which remains a complex and central signaling network still to be interpreted and explained in cancer progression. Here, we discuss the link between actin dynamics and TGFβ signaling with the aim of exploring their aberrant interaction in cancer.
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Affiliation(s)
- Roberta Melchionna
- Tumor Immunology and Immunotherapy Unit, IRCCS Regina Elena National Cancer Institute, via Chianesi 53, 00144 Rome, Italy; (R.M.); (P.T.); (A.T.)
| | - Paola Trono
- Tumor Immunology and Immunotherapy Unit, IRCCS Regina Elena National Cancer Institute, via Chianesi 53, 00144 Rome, Italy; (R.M.); (P.T.); (A.T.)
- Institute of Biochemistry and Cell Biology, National Research Council, via Ramarini 32, 00015 Monterotondo Scalo, Rome, Italy
| | - Annalisa Tocci
- Tumor Immunology and Immunotherapy Unit, IRCCS Regina Elena National Cancer Institute, via Chianesi 53, 00144 Rome, Italy; (R.M.); (P.T.); (A.T.)
| | - Paola Nisticò
- Tumor Immunology and Immunotherapy Unit, IRCCS Regina Elena National Cancer Institute, via Chianesi 53, 00144 Rome, Italy; (R.M.); (P.T.); (A.T.)
- Correspondence: ; Tel.: +39-0652662539
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16
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Eiden C, Ungefroren H. The Ratio of RAC1B to RAC1 Expression in Breast Cancer Cell Lines as a Determinant of Epithelial/Mesenchymal Differentiation and Migratory Potential. Cells 2021; 10:cells10020351. [PMID: 33567745 PMCID: PMC7915250 DOI: 10.3390/cells10020351] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/27/2021] [Accepted: 02/03/2021] [Indexed: 12/13/2022] Open
Abstract
Breast cancer (BC) is a heterogenous disease encompassing tumors with different histomorphological phenotypes and transcriptionally defined subtypes. However, the non-mutational/epigenetic alterations that are associated with or causally involved in phenotype diversity or conversion remain to be elucidated. Data from the pancreatic cancer model have shown that the small GTPase RAC1 and its alternatively spliced isoform, RAC1B, antagonistically control epithelial–mesenchymal transition and cell motility induced by transforming growth factor β. Using a battery of established BC cell lines with either a well-differentiated epithelial or poorly differentiated mesenchymal phenotype, we observed subtype-specific protein expression of RAC1B and RAC1. While epithelial BC lines were RAC1Bhigh and RAC1low, mesenchymal lines exhibited the reverse expression pattern. High RAC1B and/or low RAC1 abundance also correlated closely with a poor invasion potential, and vice versa, as revealed by measuring random cell migration (chemokinesis), the preferred mode of cellular movement in cells that have undergone mesenchymal transdifferentiation. We propose that a high RAC1B:RAC1 ratio in BC cells is predictive of an epithelial phenotype, while low RAC1B along with high RAC1 is a distinguishing feature of the mesenchymal state. The combined quantitative assessment of RAC1B and RAC1 in tumor biopsies of BC patients may represent a novel diagnostic tool for probing molecular subtype and eventually predict malignant potential of breast tumors.
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Affiliation(s)
- Caroline Eiden
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany;
| | - Hendrik Ungefroren
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany;
- Clinic for General Surgery, Visceral, Thoracic, Transplantation and Pediatric Surgery, University Hospital Schleswig-Holstein, Campus Kiel, D-24105 Kiel, Germany
- Correspondence: ; Tel.: +49-451-3101-7866
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RAC1B Regulation of TGFB1 Reveals an Unexpected Role of Autocrine TGFβ1 in the Suppression of Cell Motility. Cancers (Basel) 2020; 12:cancers12123570. [PMID: 33260366 PMCID: PMC7760153 DOI: 10.3390/cancers12123570] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/25/2020] [Accepted: 11/27/2020] [Indexed: 12/22/2022] Open
Abstract
Autocrine transforming growth factor (TGF)β has been implicated in epithelial-mesenchymal transition (EMT) and invasion of several cancers including pancreatic ductal adenocarcinoma (PDAC) as well as triple-negative breast cancer (TNBC). However, the precise mechanism and the upstream inducers or downstream effectors of endogenous TGFB1 remain poorly characterized. In both cancer types, the small GTPase RAC1B inhibits cell motility induced by recombinant human TGFβ1 via downregulation of the TGFβ type I receptor, ALK5, but whether RAC1B also impacts autocrine TGFβ signaling has not yet been studied. Intriguingly, RNA interference-mediated knockdown (RNAi-KD) or CRISPR/Cas-mediated knockout of RAC1B in TGFβ1-secreting PDAC-derived Panc1 cells resulted in a dramatic decrease in secreted bioactive TGFβ1 in the culture supernatants and TGFB1 mRNA expression, while the reverse was true for TNBC-derived MDA-MB-231 cells ectopically expressing RAC1B. Surprisingly, the antibody-mediated neutralization of secreted bioactive TGFβ or RNAi-KD of the endogenous TGFB1 gene, was associated with increased rather than decreased migratory activities of Panc1 and MDA-MB-231 cells, upregulation of the promigratory genes SNAI1, SNAI2 and RAC1, and downregulation of the invasion suppressor genes CDH1 (encoding E-cadherin) and SMAD3. Intriguingly, ectopic re-expression of SMAD3 was able to rescue Panc1 and MDA-MB-231 cells from the TGFB1 KD-induced rise in migratory activity. Together, these data suggest that RAC1B favors synthesis and secretion of autocrine TGFβ1 which in a SMAD3-dependent manner blocks EMT-associated gene expression and cell motility.
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18
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Ungefroren H, Wellner UF, Keck T, Lehnert H, Marquardt JU. The Small GTPase RAC1B: A Potent Negative Regulator of-and Useful Tool to Study-TGFβ Signaling. Cancers (Basel) 2020; 12:E3475. [PMID: 33266416 PMCID: PMC7700615 DOI: 10.3390/cancers12113475] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 02/06/2023] Open
Abstract
RAC1 and its alternatively spliced isoform, RAC1B, are members of the Rho family of GTPases. Both isoforms are involved in the regulation of actin cytoskeleton remodeling, cell motility, cell proliferation, and epithelial-mesenchymal transition (EMT). Compared to RAC1, RAC1B exhibits a number of distinctive features with respect to tissue distribution, downstream signaling and a role in disease conditions like inflammation and cancer. The subcellular locations and interaction partners of RAC1 and RAC1B vary depending on their activation state, which makes RAC1 and RAC1B ideal candidates to establish cross-talk with cancer-associated signaling pathways-for instance, interactions with signaling by transforming growth factor β (TGFβ), a known tumor promoter. Although RAC1 has been found to promote TGFβ-driven tumor progression, recent observations in pancreatic carcinoma cells surprisingly revealed that RAC1B confers anti-oncogenic properties, i.e., through inhibiting TGFβ-induced EMT. Since then, an unexpected array of mechanisms through which RAC1B cross-talks with TGFβ signaling has been demonstrated. However, rather than being uniformly inhibitory, RAC1B interacts with TGFβ signaling in a way that results in the selective blockade of tumor-promoting pathways, while concomitantly allowing tumor-suppressive pathways to proceed. In this review article, we are going to discuss the specific interactions between RAC1B and TGFβ signaling, which occur at multiple levels and include various components such as ligands, receptors, cytosolic mediators, transcription factors, and extracellular inhibitors of TGFβ ligands.
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Affiliation(s)
- Hendrik Ungefroren
- First Department of Medicine, Campus Lübeck, University Hospital Schleswig-Holstein, D-23538 Lübeck, Germany;
- Clinic for General Surgery, Visceral, Thoracic, Transplantation and Pediatric Surgery, Campus Kiel, University Hospital Schleswig-Holstein, D-24105 Kiel, Germany
| | - Ulrich F. Wellner
- Clinic for Surgery, Campus Lübeck, University Hospital Schleswig-Holstein, D-23538 Lübeck, Germany; (U.F.W.); (T.K.)
| | - Tobias Keck
- Clinic for Surgery, Campus Lübeck, University Hospital Schleswig-Holstein, D-23538 Lübeck, Germany; (U.F.W.); (T.K.)
| | | | - Jens-Uwe Marquardt
- First Department of Medicine, Campus Lübeck, University Hospital Schleswig-Holstein, D-23538 Lübeck, Germany;
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Pan S, Hu Y, Hu M, Jian H, Chen M, Gan L, Zheng P, He Y, Wang J. Platelet-derived PDGF promotes the invasion and metastasis of cholangiocarcinoma by upregulating MMP2/MMP9 expression and inducing EMT via the p38/MAPK signalling pathway. Am J Transl Res 2020; 12:3577-3595. [PMID: 32774720 PMCID: PMC7407735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Accepted: 05/30/2020] [Indexed: 06/11/2023]
Abstract
Cholangiocarcinoma (CCA) is an aggressive tumour with a poor prognosis due to its late clinical presentation and the lack of effective non-surgical therapies. Previous studies have reported that platelets are implicated in tumour invasion and metastasis, while their role and the underlying mechanism in CCA remain unclear. Here, we show that platelets are hyperactivated in patients with CCA and that platelet-derived growth factor (PDGF) promotes the migration of CCA tumour cells both in vitro and in vivo. Further investigations revealed that PDGF can upregulate the expression of MMP2/MMP9 and induce epithelial-mesenchymal transition (EMT) by activating the p38/MAPK signalling pathway in CCA cells. In addition, the expression of MMP2/MMP9 was associated with lymph node metastasis and poor prognosis in CCA patients after surgical resection. In conclusion, our findings demonstrate that platelets play an important role in facilitating the invasion and metastasis of CCA cells by secreting PDGF, which may provide a novel target for CCA treatment.
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Affiliation(s)
- Shuguang Pan
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical UniversityChongqing 400038, China
| | - Ying Hu
- Oncology Department, Southwest Hospital, Third Military Medical UniversityChongqing 400038, China
| | - Mengjia Hu
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical UniversityChongqing 400038, China
| | - Hongmei Jian
- Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical UniversityChongqing 400038, China
| | - Mo Chen
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical UniversityChongqing 400038, China
| | - Lang Gan
- Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical UniversityChongqing 400038, China
| | - Ping Zheng
- Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical UniversityChongqing 400038, China
| | - Yu He
- Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical UniversityChongqing 400038, China
| | - Junping Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical UniversityChongqing 400038, China
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RAC1B Induces SMAD7 via USP26 to Suppress TGFβ1-Dependent Cell Migration in Mesenchymal-Subtype Carcinoma Cells. Cancers (Basel) 2020; 12:cancers12061545. [PMID: 32545415 PMCID: PMC7352540 DOI: 10.3390/cancers12061545] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/04/2020] [Accepted: 06/08/2020] [Indexed: 12/27/2022] Open
Abstract
The small GTPase RAC1B has been shown to act as a powerful inhibitor of the transforming growth factor (TGF)β type I receptor ALK5 and TGFβ1/ALK5-induced epithelial–mesenchymal transition and cell motility. However, the precise mechanism has remained elusive. RNAi-mediated knockdown of RAC1B in the pancreatic ductal adenocarcinoma (PDAC)-derived cell line Panc1 failed to alter transcriptional activity from a transfected ALK5 promoter–reporter construct. In contrast, pharmacological inhibition of the proteasome decreased the abundance of ALK5 protein in cell lines of the mesenchymal subtype (Panc1, IMIM-PC-1, and breast cancer MDA-MB-231), but not in a PDAC cell line of the epithelial subtype (Colo357). Here, we focused on the inhibitory Smad protein, SMAD7, as a potential candidate for RAC1B-mediated inhibition of cell migration. In Panc1 cells devoid of RAC1B, SMAD7 protein was dramatically reduced and these cells were refractory to TGFβ1-induced upregulation of SMAD7 protein but not mRNA expression. Intriguingly, RNAi-mediated knockdown or ectopic overexpression of SMAD7 in Panc1 cells up- or downregulated, respectively, ALK5 protein expression and mimicked the suppressive effect of RAC1B on TGFβ/SMAD3-dependent transcriptional activity, target gene expression and cell migration. Transfection of SMAD7 was further able to partially rescue cells from the RAC1B knockdown-mediated increase in migratory properties. Conversely, knockdown of SMAD7 was able to partially rescue Panc1 and MDA-MB-231 cells from the antimigratory effect of ectopically expressed RAC1B. Finally, we demonstrate that RAC1B upregulation of SMAD7 protein requires intermittent transcriptional induction of the deubiquitinating enzyme USP26. Our data suggest that RAC1B induces SMAD7 by promoting its deubiquitination and establishes this Smad as one of RAC1B’s downstream effectors in negative regulation of ALK5 and TGFβ1-induced cell migration in mesenchymal-type carcinoma cells.
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A Comprehensive Molecular Characterization of the Pancreatic Neuroendocrine Tumor Cell Lines BON-1 and QGP-1. Cancers (Basel) 2020; 12:cancers12030691. [PMID: 32183367 PMCID: PMC7140066 DOI: 10.3390/cancers12030691] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/04/2020] [Accepted: 03/12/2020] [Indexed: 02/08/2023] Open
Abstract
Experimental models of neuroendocrine tumor disease are scarce, with only a few existing neuroendocrine tumor cell lines of pancreatic origin (panNET). Their molecular characterization has so far focused on the neuroendocrine phenotype and cancer-related mutations, while a transcription-based assessment of their developmental origin and malignant potential is lacking. In this study, we performed immunoblotting and qPCR analysis of neuroendocrine, epithelial, developmental endocrine-related genes as well as next-generation sequencing (NGS) analysis of microRNAs (miRs) on three panNET cell lines, BON-1, QGP-1, and NT-3. All three lines displayed a neuroendocrine and epithelial phenotype; however, while insulinoma-derived NT-3 cells preferentially expressed markers of mature functional pancreatic β-cells (i.e., INS, MAFA), both BON-1 and QGP-1 displayed high expression of genes associated with immature or non-functional β/δ-cells genes (i.e., NEUROG3), or pancreatic endocrine progenitors (i.e., FOXA2). NGS-based identification of miRs in BON-1 and QGP-1 cells revealed the presence of all six members of the miR-17–92 cluster, which have been implicated in β-cell function and differentiation, but also have roles in cancer being both oncogenic or tumor suppressive. Notably, both BON-1 and QGP-1 cells expressed several miRs known to be negatively associated with epithelial–mesenchymal transition, invasion or metastasis. Moreover, both cell lines failed to exhibit migratory activity in vitro. Taken together, NT-3 cells resemble mature functional β-cells, while both BON-1 and QGP-1 are more similar to immature/non-functional pancreatic β/δ-cells or pancreatic endocrine progenitors. Based on the recent identification of three transcriptional subtypes in panNETs, NT-3 cells resemble the “islet/insulinoma tumors” (IT) subtype, while BON-1 and QGP-1 cells were tentatively classified as “metastasis-like/primary” (MLP). Our results provide a comprehensive characterization of three panNET cell lines and demonstrate their relevance as neuroendocrine tumor models.
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Negative Control of Cell Migration by Rac1b in Highly Metastatic Pancreatic Cancer Cells Is Mediated by Sequential Induction of Nonactivated Smad3 and Biglycan. Cancers (Basel) 2019; 11:cancers11121959. [PMID: 31817656 PMCID: PMC6966648 DOI: 10.3390/cancers11121959] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 12/02/2019] [Accepted: 12/04/2019] [Indexed: 02/07/2023] Open
Abstract
Expression of the small GTPase, Ras-related C3 botulinum toxin substrate 1B (RAC1B), a RAC1-related member of the Rho GTPase family, in tumor tissues of pancreatic ductal adenocarcinoma (PDAC) has been shown previously to correlate positively with patient survival, but the underlying mechanism(s) and the target genes involved have remained elusive. Screening of a panel of established PDAC-derived cell lines by immunoblotting indicated that both RAC1B and Mothers against decapentaplegic homolog 3 (SMAD3) were more abundantly expressed in poorly metastatic and well-differentiated lines as opposed to highly metastatic, poorly differentiated ones. Both siRNA-mediated RAC1B knockdown in the transforming growth factor (TGF)-β-sensitive PDAC-derived cell lines, Panc1 and PaCa3, or CRISPR/Cas-mediated knockout of exon 3b of RAC1 in Panc1 cells resulted in a dramatic decrease in the expression of SMAD3. Unexpectedly, the knockdown of SMAD3 reproduced the promigratory activity of a RAC1B knockdown in Panc1 and PaCa3, but not in TGF-β-resistant BxPC3 and Capan1 cells, while forced expression of SMAD3 alone was able to mimic the antimigratory effect of ectopic RAC1B overexpression in Panc1 cells. Moreover, overexpression of SMAD3 was able to rescue Panc1 cells from the RAC1B knockdown-induced increase in cell migration, while knockdown of SMAD3 prevented the RAC1B overexpression-induced decrease in cell migration. Using pharmacological and dominant-negative inhibition of SMAD3 C-terminal phosphorylation, we further show that the migration-inhibiting effect of SMAD3 is independent of its activation by TGF-β. Finally, we provide evidence that the antimigratory program of RAC1B-SMAD3 in Panc1 cells is executed through upregulation of the migration and TGF-β inhibitor, biglycan (BGN). Together, our data suggest that a RAC1B-SMAD3-BGN axis negatively controls cell migration and that SMAD3 can induce antimigratory genes, i.e., BGN independent of its role as a signal transducer for TGF-β. Therefore, targeting this novel pathway for activation is a potential therapeutic strategy in highly metastatic PDAC to interfere with invasion and metastasis.
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