1
|
Shalom B, Salaymeh Y, Risling M, Katzav S. Unraveling the Oncogenic Potential of VAV1 in Human Cancer: Lessons from Mouse Models. Cells 2023; 12:cells12091276. [PMID: 37174676 PMCID: PMC10177506 DOI: 10.3390/cells12091276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/23/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
VAV1 is a hematopoietic signal transducer that possesses a GDP/GTP nucleotide exchange factor (GEF) that is tightly regulated by tyrosine phosphorylation, along with adapter protein domains, such as SH2 and SH3. Research on VAV1 has advanced over the years since its discovery as an in vitro activated oncogene in an NIH3T3 screen for oncogenes. Although the oncogenic form of VAV1 first identified in the screen has not been detected in human clinical tumors, its wild-type and mutant forms have been implicated in mammalian malignancies of various tissue origins, as well as those of the hematopoietic system. This review article addresses the activity of human VAV1 as an overexpressed or mutated gene and also describes the differences in the distribution of VAV1 mutations in the hematopoietic system and in other tissues. The knowledge accumulated thus far from GEMMs expressing VAV1 is described, with the conclusion that GEMMs of both wild-type VAV1 and mutant VAV1 do not form tumors, yet these will be generated when additional molecular insults, such as loss of p53 or KRAS mutation, occur.
Collapse
Affiliation(s)
- Batel Shalom
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University, Jerusalem 91120, Israel
| | - Yaser Salaymeh
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University, Jerusalem 91120, Israel
| | - Matan Risling
- Department of Military Medicine and "Tzameret", Faculty of Medicine, Hebrew University, Jerusalem 91120, Israel
- Medical Corps, Israel Defense Forces, Tel-Hashomer 02149, Israel
| | - Shulamit Katzav
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University, Jerusalem 91120, Israel
| |
Collapse
|
2
|
Vav1 accelerates Ras-driven lung cancer and modulates its tumor microenvironment. Cell Signal 2022; 97:110395. [PMID: 35752351 DOI: 10.1016/j.cellsig.2022.110395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/13/2022] [Accepted: 06/20/2022] [Indexed: 11/23/2022]
Abstract
The potential impact of Vav1 on human cancer was only recently acknowledged, as it is detected as a mutant or an overexpressed gene in various cancers, including lung cancer. Vav1, which is normally and exclusively expressed in the hematopoietic system functions as a specific GDP/GTP nucleotide exchange factor (GEF), strictly regulated by tyrosine phosphorylation. To investigate whether Vav1 plays a causative or facilitating role in-vivo in lung cancer development and to examine whether it co-operates with other oncogenes, such as mutant K-Ras, we generated novel mouse strains that express: Vav1 or K-RasG12D in type II pneumocytes, as well as a transgenic mouse line that expresses both Vav1 and K-RasG12D in these cells. Coexpression of Vav1 and K-RasG12D in the lungs dramatically increased malignant lung cancer lesions, and did so significantly faster than K-RasG12D alone, strongly suggesting that these two oncogenes synergize to enhance lung tumor development. Vav1 expression alone had no apparent effects on lung tumorigenesis. The increase in lung cancer in K-RasG12D/Vav1 mice was accompanied by an increase in B-cell, T-cells, and monocyte infiltration in the tumor microenvironment. Concomitantly, ERK phosphorylation was highly elevated in the lungs of K-RasG12 D/Vav1 mice. Also, several cytokines such as IL-4 and IL-13 which play a significant role in the immune system, were elevated in lungs of Vav1 and K-RasG12 D/Vav1 mice. Our findings emphasize the contribution of Vav1 to lung tumor development through its signaling properties.
Collapse
|
3
|
Vav1 Promotes B-Cell Lymphoma Development. Cells 2022; 11:cells11060949. [PMID: 35326399 PMCID: PMC8946024 DOI: 10.3390/cells11060949] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 03/06/2022] [Accepted: 03/08/2022] [Indexed: 02/07/2023] Open
Abstract
Vav1 is normally and exclusively expressed in the hematopoietic system where it functions as a specific GDP/GTP nucleotide exchange factor (GEF), firmly regulated by tyrosine phosphorylation. Mutations and overexpression of Vav1 in hematopoietic malignancies, and in human cancers of various histologic origins, are well documented. To reveal whether overexpression of Vav1 in different tissues suffices for promoting the development of malignant lesions, we expressed Vav1 in transgenic mice by using the ubiquitous ROSA26 promoter (Rosa Vav1). We detected Vav1 expression in epithelial tissues of various organs including pancreas, liver, and lung. While carcinomas did not develop in these organs, surprisingly, we noticed the development of B-cell lymphomas. Rac1-GTP levels did not change in tissues from Rosa Vav1 mice expressing the transgenic Vav1, while ERK phosphorylation increased in the lymphomas, suggesting that signaling pathways are evoked. One of the growth factors analyzed by us as a suspect candidate to mediate paracrine stimulation in the lymphocytes was CSF-1, which was highly expressed in the epithelial compartment of Rosa Vav1 mice. The expression of its specific receptor, CSF-1R, was found to be highly expressed in the B-cell lymphomas. Taken together, our results suggest a potential cross-talk between epithelial cells expressing Vav1, that secrete CSF-1, and the lymphocytes that express CSF-1R, thus leading to the generation of B-cell lymphomas. Our findings provide a novel mechanism by which Vav1 contributes to tumor propagation.
Collapse
|
4
|
Vav1: A Dr. Jekyll and Mr. Hyde protein--good for the hematopoietic system, bad for cancer. Oncotarget 2016; 6:28731-42. [PMID: 26353933 PMCID: PMC4745688 DOI: 10.18632/oncotarget.5086] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 08/07/2015] [Indexed: 01/10/2023] Open
Abstract
Many deregulated signal transducer proteins are involved in various cancers at numerous stages of tumor development. One of these, Vav1, is normally expressed exclusively in the hematopoietic system, where it functions as a specific GDP/GTP nucleotide exchange factor (GEF), strictly regulated by tyrosine phosphorylation. Vav was first identified in an NIH3T3 screen for oncogenes. Although the oncogenic form of Vav1 identified in the screen has not been detected in clinical human tumors, its wild-type form has recently been implicated in mammalian malignancies, including neuroblastoma, melanoma, pancreatic, lung and breast cancers, and B-cell chronic lymphocytic leukemia. In addition, it was recently identified as a mutated gene in human cancers of various origins. However, the activity and contribution to cancer of these Vav1 mutants is still unclear. This review addresses the physiological function of wild-type Vav1 and its activity as an oncogene in human cancer. It also discusses the novel mutations identified in Vav1 in various cancers and their potential contribution to cancer development as oncogenes or tumor suppressor genes.
Collapse
|
5
|
Sebban S, Farago M, Rabinovich S, Lazer G, Idelchuck Y, Ilan L, Pikarsky E, Katzav S. Vav1 promotes lung cancer growth by instigating tumor-microenvironment cross-talk via growth factor secretion. Oncotarget 2015; 5:9214-26. [PMID: 25313137 PMCID: PMC4253429 DOI: 10.18632/oncotarget.2400] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Vav1 is a signal transducer that functions as a scaffold protein and a regulator of cytoskeleton organization in the hematopoietic system, where it is exclusively expressed. Recently, Vav1 was shown to be involved in diverse human cancers, including lung cancer. We demonstrate that lung cancer cells that abnormally express Vav1 secrete growth factors in a Vav1-dependent manner. Transcriptome analysis demonstrated that Vav1 depletion results in a marked reduction in the expression of colony-stimulating-factor-1 (CSF1), a hematopoietic growth factor. The association between Vav1 expression and CSF1 was further supported by signal transduction experiments, supporting involvement of Vav1 in regulating lung cancer secretome. Blocking of ERK phosphorylation, led to a decrease in CSF1 transcription, thus suggesting a role for ERK, a downstream effector of Vav1, in CSF1 expression. CSF1-silenced cells exhibited reduced focus formation, proliferation abilities, and growth in NOD/SCID mice. CSF1-silenced H358 cells resulted in significantly smaller tumors, showing increased fibrosis and a decrease in tumor infiltrating macrophages. Finally, immunohistochemical analysis of primary human lung tumors revealed a positive correlation between Vav1 and CSF1 expression, which was associated with tumor grade. Additional results presented herein suggest a potential cross-talk between cancer cells and the microenvironment controlled by CSF1/Vav1 signaling pathways.
Collapse
Affiliation(s)
- Shulamit Sebban
- Departement of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hadassah Medical School - Hebrew University, Jerusalem, Israel
| | - Marganit Farago
- Departement of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hadassah Medical School - Hebrew University, Jerusalem, Israel
| | - Shiran Rabinovich
- Departement of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hadassah Medical School - Hebrew University, Jerusalem, Israel
| | - Galit Lazer
- Departement of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hadassah Medical School - Hebrew University, Jerusalem, Israel
| | - Yulia Idelchuck
- Departement of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hadassah Medical School - Hebrew University, Jerusalem, Israel
| | - Lena Ilan
- Departement of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hadassah Medical School - Hebrew University, Jerusalem, Israel
| | - Eli Pikarsky
- Department of Immunology and Cancer Research and Department of Pathology, Institute for Medical Research Israel-Canada, Hadassah Medical School - Hebrew University, Jerusalem, Israel
| | - Shulamit Katzav
- Departement of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hadassah Medical School - Hebrew University, Jerusalem, Israel
| |
Collapse
|
6
|
Ilan L, Katzav S. Human Vav1 expression in hematopoietic and cancer cell lines is regulated by c-Myb and by CpG methylation. PLoS One 2012; 7:e29939. [PMID: 22253833 PMCID: PMC3256210 DOI: 10.1371/journal.pone.0029939] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 12/07/2011] [Indexed: 01/09/2023] Open
Abstract
Vav1 is a signal transducer protein that functions as a guanine nucleotide exchange factor for the Rho/Rac GTPases in the hematopoietic system where it is exclusively expressed. Recently, Vav1 was shown to be involved in several human malignancies including neuroblastoma, lung cancer, and pancreatic ductal adenocarcinoma (PDA). Although some factors that affect vav1 expression are known, neither the physiological nor pathological regulation of vav1 expression is completely understood. We demonstrate herein that mutations in putative transcription factor binding sites at the vav1 promoter affect its transcription in cells of different histological origin. Among these sites is a consensus site for c-Myb, a hematopoietic-specific transcription factor that is also found in Vav1-expressing lung cancer cell lines. Depletion of c-Myb using siRNA led to a dramatic reduction in vav1 expression in these cells. Consistent with this, co-transfection of c-Myb activated transcription of a vav1 promoter-luciferase reporter gene construct in lung cancer cells devoid of Vav1 expression. Together, these results indicate that c-Myb is involved in vav1 expression in lung cancer cells. We also explored the methylation status of the vav1 promoter. Bisulfite sequencing revealed that the vav1 promoter was completely unmethylated in human lymphocytes, but methylated to various degrees in tissues that do not normally express vav1. The vav1 promoter does not contain CpG islands in proximity to the transcription start site; however, we demonstrated that methylation of a CpG dinucleotide at a consensus Sp1 binding site in the vav1 promoter interferes with protein binding in vitro. Our data identify two regulatory mechanisms for vav1 expression: binding of c-Myb and CpG methylation of 5′ regulatory sequences. Mutation of other putative transcription factor binding sites suggests that additional factors regulate vav1 expression as well.
Collapse
Affiliation(s)
- Lena Ilan
- Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hadassah Medical School, Hebrew University, Jerusalem, Israel
| | - Shulamit Katzav
- Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hadassah Medical School, Hebrew University, Jerusalem, Israel
- * E-mail:
| |
Collapse
|
7
|
Lazer G, Idelchuk Y, Schapira V, Pikarsky E, Katzav S. The haematopoietic specific signal transducer Vav1 is aberrantly expressed in lung cancer and plays a role in tumourigenesis. J Pathol 2009; 219:25-34. [DOI: 10.1002/path.2579] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
8
|
Chrencik JE, Brooun A, Zhang H, Mathews II, Hura GL, Foster SA, Perry JJP, Streiff M, Ramage P, Widmer H, Bokoch GM, Tainer JA, Weckbecker G, Kuhn P. Structural basis of guanine nucleotide exchange mediated by the T-cell essential Vav1. J Mol Biol 2008; 380:828-43. [PMID: 18589439 DOI: 10.1016/j.jmb.2008.05.024] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2008] [Revised: 05/08/2008] [Accepted: 05/11/2008] [Indexed: 12/27/2022]
Abstract
The guanine nucleotide exchange factor (GEF) Vav1 plays an important role in T-cell activation and tumorigenesis. In the GEF superfamily, Vav1 has the ability to interact with multiple families of Rho GTPases. The structure of the Vav1 DH-PH-CRD/Rac1 complex to 2.6 A resolution reveals a unique intramolecular network of contacts between the Vav1 cysteine-rich domain (CRD) and the C-terminal helix of the Vav1 Dbl homology (DH) domain. These unique interactions stabilize the Vav1 DH domain for its intimate association with the Switch II region of Rac1 that is critical for the displacement of the guanine nucleotide. Small angle x-ray scattering (SAXS) studies support this domain arrangement for the complex in solution. Further, mutational analyses confirms that the atypical CRD is critical for maintaining both optimal guanine nucleotide exchange activity and broader specificity of Vav family GEFs. Taken together, the data outline the detailed nature of Vav1's ability to contact a range of Rho GTPases using a novel protein-protein interaction network.
Collapse
Affiliation(s)
- Jill E Chrencik
- Department of Cellular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Katzav S. Flesh and blood: The story of Vav1, a gene that signals in hematopoietic cells but can be transforming in human malignancies. Cancer Lett 2007; 255:241-54. [PMID: 17590270 DOI: 10.1016/j.canlet.2007.04.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Revised: 04/30/2007] [Accepted: 04/30/2007] [Indexed: 01/08/2023]
Abstract
Cancer results from the interaction of multiple aberrations including activation of dominant oncogenes and upregulation of signal transduction pathways. Identification of the genes involved in malignant transformation is a pre-requisite for understanding cancer and improving its diagnosis and treatment. Quite a few of the genes that have been implicated in cancer are mutant or aberrantly expressed versions of genes that are important mediators of the normal growth that occurs during development. An important example of this is Vav1, a cytoplasmic signal transducer protein initially identified as an oncogene. Physiological expression of Vav1 is restricted to the hematopoietic system, where its best-known function is as a GDP/GTP nucleotide exchange factor for Rho/Rac GTPases, an activity strictly controlled by tyrosine phosphorylation. Vav1 was shown to regulate cytoskeletal rearrangement during activation of hematopoietic cells. Vav1 can also mediate other cellular functions including activation of the JNK, ERK, Ras, NF-kB, and NFAT pathways, in addition to association with numerous adapter proteins such as Shc, NCK, SLP-76, GRB2, and Crk. Although the oncogenic form of Vav1 has not been detected in clinical human tumors, its wild-type form has recently been implicated in mammalian malignancies such as neuroblastoma, melanoma, pancreatic tumors and B-cell chronic lymphocytic leukemia. This review addresses the physiological function of wild-type Vav1, its mode of activation as an oncogene, and its emerging role as a transforming protein in human cancer.
Collapse
Affiliation(s)
- Shulamit Katzav
- The Hubert H. Humphrey center for Experimental Medicine & Cancer Research, The Hebrew University-Hadassah Medical School, P.O. Box 12272, Jerusalem 91120, Israel.
| |
Collapse
|