- Email: [email protected]
S2041 Oncogenic Met Receptor Promotes Tumorigenesis and Metastases in Normal Intestinal Epithelial Cells
AGA Abstracts
study is to determine whether HuR binding to survivin mRNA plays a role in the overexpression of survivin in esophageal cancer cells. Methods: Studies were conducted in normal human esophageal cells and in TE-7 human esophageal adenocarcinoma cells. Levels of protein expression were measured by Western blot. RNA binding was examined by biotinylated RNA pull-down and RNP-IP assays. Survivin mRNA stability was examined by measuring its half-life. HuR function was tested by its silencing and overexpression. Results: HuR is overexpressed in both whole cell lysates and cytoplasmic fractions of TE-7 esophageal cancer cells in comparison to normal esophageal cells. HuR directly bound to the survivin 3' UTR as measured by RNA-pull down assays and further confirmed by RNP-IP assays. mRNA stability assays demonstrate that survivin mRNA is more stable in TE-7 cells when compared to normal cells. HuR silencing resulted in decreased levels of survivin protein in TE-7 cells. Conclusions: These findings demonstrate that HuR is overexpressed in esophageal cancer cells and directly binds survivin mRNA. This interaction enhances stabilization of survivin mRNA and may be an important mechanism of survivin overexpression in esophageal cancer cells.
confirm and explore the functional consequences of the genes affected by TFF3. (Support: NCI RO1-CA109189; The Chemotherapy Foundation; Gastric Cancer/Peptic Ulcer Research Foundation) S2040 Acetylcholine-Induced Colon Cancer Cell Migration Is Mediated By Epidermal Growth Factor Receptor (EGFR)-Dependent Activation of Both ERK and PI3K Signaling Angelica Belo, Kunrong Cheng, Jasleen Shant, Jean-Pierre Raufman Emerging evidence, including up-regulated expression, supports a key role for muscarinic receptor (MR) activation in colon cancer. In mice, genetic ablation of M3R attenuates colon tumor formation (Cancer Res 68:3573,2008). Cholinergic agonists stimulate colon cancer cell proliferation by transactivation of EGFR (Cancer Res 63:6744,2003), but their actions on cell migration, a requirement for cancer metastasis, is unknown. Our aims were (1) To investigate the actions of acetylcholine (ACh) on colon cancer cell migration and (2) To elucidate mechanisms underlying these actions. Cell migration was measured using a validated monolayer wounding assay; movement of the leading edge was determined by photomicrography (Zeiss Axiovert 200). Serum-free media was used as control. Human H508 colon cancer cells, that express EGFR and M3R, were grown to confluence and preincubated with mitomycin C (10 μg/ml) to inhibit cell proliferation, a potential confounding variable. During 24-h incubation, ACh (100 μM) stimulated a 3-fold increase in cell migration; indistinguishable from EGF (10 μg/ml). Maximal migration was observed with 100 μM ACh; 11.8±0.6 vs 4.1±0.4 with vehicle alone at 8 h (mean±SEM distance migrated in arbitrary units; p<0.001, ANOVA). Atropine (1 μM) blocked the effect of ACh. Moreover, in SNUC4 colon cancer cells that lack MR expression, EGF caused a 3-fold increase in migration but ACh had no effect. ACh-induced H508 cell migration was blocked by inhibitors of EGFR activation (PD168393 and AG1478; p<0.01), and of ERK (PD98059 and U0126; p<0.01) and PI3K (LY294002 and wortmannin; p<0.001) signaling. Likewise, ACh-induced cell migration was blocked by inhibitors of key PI3K targets: Akt (API-2; p<0.001) and GSK-3 (Inhibitor IX; p<0.05). Consistent with matrix metalloproteinase-7 (MMP-7)-mediated transactivation of EGFR (Biochem Pharm 73:1001,2007), ACh-induced migration was inhibited by an MMP inhibitor (GM6001; p<0.01) and by anti-EGFR (p<0.05), anti-MMP-7 (p<0.01), and anti-HB-EGF antibodies (p<0.05). Collectively, these findings indicate that ACh-induced migration is regulated by MMP-7-mediated release of HB-EGF causing activation of EGFR and downstream signaling by both ERK and PI3K/Akt. Finally, inhibiting key proteins, Rho A and ROCK, that interact with the cytoskeleton blocked ACh-induced H508 cell migration (3.8±0.6 control, 11.9±1.1 ACh, 3.1±0.4 ACh+exoenzyme C3, 4.7±1.3 ACh+Y27632; p<0.01 for ACh vs. ACh plus these Rho A and ROCK inhibitors, respectively). In conclusion, ACh stimulates colon cancer cell migration by a mechanism involving MMP7-mediated transactivation of EGFR and consequent activation of both ERK and PI3K/ Akt signaling.
S2038 Establishing Models for Determining the Role of Increased Wnt5a Expression in Intestinal Tumor Growth Elvira Bakker, Werner Helvensteyn, Wendy van Veelen, Ernst J. Kuipers, Ron Smits Background: The vast majority of colorectal cancer patients die from metastatic disease. Therefore, it is important to understand the underlying mechanisms of CRC progression. More and more evidence is being reported about the importance of the interaction between tumor cells and surrounding stromal tissue for tumor invasion and metastasis. In this respect, tumor-associated macrophages are of special interest as they have been suggested to stimulate angiogenesis and invasiveness. One of the factors shown to be expressed at increased levels by macrophages in intestinal tumors is Wnt5a, belonging to the so-called non-canonical class of Wnt signaling molecules. In Vitro data suggest that Wnt5a is involved in tumor cell growth and migration, angiogenesis and epithelial to mesenchymal transitions, key steps in cancer progression. At present, it is however unclear to which extent and through which mechanisms, Wnt5a contributes to the malignant behavior of colorectal tumors In Vivo. Therefore, we have set out to generate a mouse model in which expression of Wnt5a can be controlled in a tissue-specific and temporal fashion. Methods: Several transgenic mouse lines have been generated carrying the Wnt5a gene driven by a Doxycycline(Dox)-responsive promoter. To test the functionality of each TetO-Wnt5a transgenic line, the founder lines were crossed with animals expressing the rtTA2 transcription factor in all their tissues. By providing Dox in the drinking water, this transcription factor will activate expression of transgenic Wnt5a. In initial experiments we have used isolated tail fibroblasts to assess tight control of gene expression. Results: Using isolated tail fibroblasts, we identified one transgenic line showing a tight Dox-induced expression of Wnt5a. Expression was undetectable without Dox-induction, whereas a robust induction was observed when Dox was added to the fibroblast cultures. Subsequently, we have shown that Wnt5a expression was efficiently induced in double transgenic mice provided with Dox in their drinking water. Preliminary experiments suggest that induced expression of Wnt5a has severe effects on mouse embryonal development, whereas it appears to be well-tolerated in adult animals. Conclusions: We have successfully generated a transgenic model in which Wnt5a expression can be induced in a controlled fashion. In the future, this model will be combined with transgenic models allowing macrophage- or intestinal-specific induction of Wnt5a that will subsequently be crossed with Apc mutant models developing spontaneous intestinal tumors. These experiments will help us to better understand the role of Wnt5a in intestinal tumor growth.
S2041 Oncogenic Met Receptor Promotes Tumorigenesis and Metastases in Normal Intestinal Epithelial Cells Jimmy Bernier, Walid Chababi, Véronique Pomerleau, Caroline Saucier Compelling lines of evidence imply that deregulation of the Met receptor tyrosine kinase contributes to the etiology and progression of colorectal cancer. Notably, a recent study has shown that co-expression of the Met receptor and of its ligand, the hepatocyte growth factor in primary colon cancer predicts tumor stage and clinical outcome. However, the functional significance for the Met receptor in early neoplasic transformation of the intestinal epithelium and its contribution to the transition of colorectal cancers from a non-invasive to a metastatic malignant phenotype remain poorly defined. In this study, we have investigated whether oncogenic engagement of the Met receptor is alone sufficient to induce cancer behaviors in the non-transformed intestinal epithelial crypt cell model, the IEC-6 cells. Our results demonstrate that the expression of an oncogenic form of the Met receptor in IEC-6 cells is sufficient to induce epithelial to mesenchymal transition, proliferation, loss of growth contact inhibitory signals and anchorage-independent growth. Of significance, we show that oncogenic activation of the Met receptor confers to normal intestinal epithelial cells the capacity to induce angiogenic responses, tumor formation and experimental lung metastases in nude mice. Overall, these results support the concept that deregulation of the Met receptor signaling pathways contributes to the initiation and malignant progression of colorectal cancer by affecting a wide variety of cancer biological processes. Thus, this validates that the Met receptor and its downstream signaling pathways represent attractive targets for the development of new therapeutic approaches for the treatment of colorectal cancer.
S2039 The Effect of Altering Trefoil Factor-3 (TFF3) Expression On Gene Expression and Function in Human Gastrointestinal Cancer Cells Hisayuki Matsunaga, Xiuliang Bao, Lawrence Werther, Soichiro Miura, Steven H. Itzkowitz BACKGROUND: Trefoil Factor-3 (TFF3) is normally expressed by intestinal epithelial cells and promotes wound healing by enhancing epithelial cell migration while preventing apoptosis. We previously demonstrated that in human stomach, TFF3 is expressed in a cancer-associated fashion and correlates with poor prognosis (Clin Cancer Res 8:1092, 2002). We also showed that TFF3 expression in rat colorectal cancer (CRC) cells correlated with cancer cell invasion and poor survival (Clin Exp Metast 22:157, 2005), and that TFF3 was expressed by all human CRC liver metastases (Clin Exp Metast, in press, 2008). AIMS: To determine: 1) the effect of TFF3 expression on oncogenic gene expression in human gastric cancer cells; and 2) the functional effect of reducing TFF3 expression in human CRC cells. METHODS: TFF3 expression was induced in TFF3-negative AGS gastric cancer cells using an inducible pTet-On expression system. Genes that were up- or down-regulated were analyzed by cDNA microarray (GeneChipR Human Genome U133 plus 2.0 array, Affymetrix). siRNA was used to inhibit TFF3 expression in human CRC cells (LS-B, LS-C). Cell proliferation and etoposide-induced apoptosis were analyzed. RESULTS: In AGS cells, compared to empty vector controls, TFF3 induction resulted in at least a 2-fold up-regulation of 137 genes and down-regulation of 187 genes. 23 up-regulated genes are oncogenesis-associated, promoting cell migration/motility (CAMK4, CD44, CFL-1, ACTN4, CD151, HSPB1), proliferation (PCIF1), anti-apoptosis (CUL-7, CAPN14, TAOK2, MDK), invasion and metastasis (CD44, ACTN4, CD151) and a loss of cell adhesion (SAMD1, ZYX). 32 down-regulated genes are oncogenesis-associated, including genes involved in tumor suppression (PTPRD, ENO1, G3BP1, G3BP2, BCOR, KLF6, CCNK), apoptosis (KSR1, RHBDF1, DAPK3, STK17A, BRCC3, GULP1, GTSE1, VDAC1, SCYE1), proliferation (RHBDF1, WHSC1, CDC25C, TOB2, BRCC3), motility (FAM84A), and actin polymerization (PLXNB2, ENC1), cell adhesion (CLDN4, claudin-4). In gastric cancer, CLDN4 reduction has been associated with diffuse type and higher malignant grade. In LS-B and LS-C CRC cells, siRNA inhibited TFF3 expression by 77.7% and 70.6%, respectively. This was associated with 15.2% and 15.1% inhibition of proliferation, and 11% and 10.4% reversal of the anti-apoptotic effect of TFF3. CONCLUSIONS: These findings provide novel insights into the potential tumor-promoting mechanisms of action of TFF3 in human gastric and colon cancer cells. Further work will
AGA Abstracts
S2042 Focal Adhesion Dynamics in Invasive Pancreatic Tumor Cells Are Regulated By SRC Activation of the Large GTPase Dynamin 2 Yu Wang, Hong Cao, Mark A. McNiven Pancreatic tumor cells have a strong tendency to invade into surrounding parenchyma and metastasize to distal organs. During this invasive process, focal adhesions (FAs) play an essential role in the coordination of cell adhesion, lamellipodia extension and subsequently, cell migration. Indeed, many FA proteins are significantly upregulated in pancreatic cancers. Currently, however, the mechanisms that regulate the turnover of these structures are poorly understood. One of these proteins is the large GTPase Dynamin2 (Dyn2), which has an established role in endocytosis and appears to regulate FA turnover by an undefined mechanism. The GOAL of this study was to define the contribution of Dyn2 to FA turnover that enhances pancreatic tumor cell adhesion and invasion. Importantly, we find that activation of Src kinase, either through expression of a constitutively active Src mutant (SrcY530F), or EGF stimulation, markedly increases recruitment of Dyn2 to FAs. Conversely, expression of a Src SH2 domain mutant (R178L) that prevents the localization of Src to FAs, or treatment
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study is to determine whether HuR binding to survivin mRNA plays a role in the overexpression of survivin in esophageal cancer cells. Methods: Studies were conducted in normal human esophageal cells and in TE-7 human esophageal adenocarcinoma cells. Levels of protein expression were measured by Western blot. RNA binding was examined by biotinylated RNA pull-down and RNP-IP assays. Survivin mRNA stability was examined by measuring its half-life. HuR function was tested by its silencing and overexpression. Results: HuR is overexpressed in both whole cell lysates and cytoplasmic fractions of TE-7 esophageal cancer cells in comparison to normal esophageal cells. HuR directly bound to the survivin 3' UTR as measured by RNA-pull down assays and further confirmed by RNP-IP assays. mRNA stability assays demonstrate that survivin mRNA is more stable in TE-7 cells when compared to normal cells. HuR silencing resulted in decreased levels of survivin protein in TE-7 cells. Conclusions: These findings demonstrate that HuR is overexpressed in esophageal cancer cells and directly binds survivin mRNA. This interaction enhances stabilization of survivin mRNA and may be an important mechanism of survivin overexpression in esophageal cancer cells.
confirm and explore the functional consequences of the genes affected by TFF3. (Support: NCI RO1-CA109189; The Chemotherapy Foundation; Gastric Cancer/Peptic Ulcer Research Foundation) S2040 Acetylcholine-Induced Colon Cancer Cell Migration Is Mediated By Epidermal Growth Factor Receptor (EGFR)-Dependent Activation of Both ERK and PI3K Signaling Angelica Belo, Kunrong Cheng, Jasleen Shant, Jean-Pierre Raufman Emerging evidence, including up-regulated expression, supports a key role for muscarinic receptor (MR) activation in colon cancer. In mice, genetic ablation of M3R attenuates colon tumor formation (Cancer Res 68:3573,2008). Cholinergic agonists stimulate colon cancer cell proliferation by transactivation of EGFR (Cancer Res 63:6744,2003), but their actions on cell migration, a requirement for cancer metastasis, is unknown. Our aims were (1) To investigate the actions of acetylcholine (ACh) on colon cancer cell migration and (2) To elucidate mechanisms underlying these actions. Cell migration was measured using a validated monolayer wounding assay; movement of the leading edge was determined by photomicrography (Zeiss Axiovert 200). Serum-free media was used as control. Human H508 colon cancer cells, that express EGFR and M3R, were grown to confluence and preincubated with mitomycin C (10 μg/ml) to inhibit cell proliferation, a potential confounding variable. During 24-h incubation, ACh (100 μM) stimulated a 3-fold increase in cell migration; indistinguishable from EGF (10 μg/ml). Maximal migration was observed with 100 μM ACh; 11.8±0.6 vs 4.1±0.4 with vehicle alone at 8 h (mean±SEM distance migrated in arbitrary units; p<0.001, ANOVA). Atropine (1 μM) blocked the effect of ACh. Moreover, in SNUC4 colon cancer cells that lack MR expression, EGF caused a 3-fold increase in migration but ACh had no effect. ACh-induced H508 cell migration was blocked by inhibitors of EGFR activation (PD168393 and AG1478; p<0.01), and of ERK (PD98059 and U0126; p<0.01) and PI3K (LY294002 and wortmannin; p<0.001) signaling. Likewise, ACh-induced cell migration was blocked by inhibitors of key PI3K targets: Akt (API-2; p<0.001) and GSK-3 (Inhibitor IX; p<0.05). Consistent with matrix metalloproteinase-7 (MMP-7)-mediated transactivation of EGFR (Biochem Pharm 73:1001,2007), ACh-induced migration was inhibited by an MMP inhibitor (GM6001; p<0.01) and by anti-EGFR (p<0.05), anti-MMP-7 (p<0.01), and anti-HB-EGF antibodies (p<0.05). Collectively, these findings indicate that ACh-induced migration is regulated by MMP-7-mediated release of HB-EGF causing activation of EGFR and downstream signaling by both ERK and PI3K/Akt. Finally, inhibiting key proteins, Rho A and ROCK, that interact with the cytoskeleton blocked ACh-induced H508 cell migration (3.8±0.6 control, 11.9±1.1 ACh, 3.1±0.4 ACh+exoenzyme C3, 4.7±1.3 ACh+Y27632; p<0.01 for ACh vs. ACh plus these Rho A and ROCK inhibitors, respectively). In conclusion, ACh stimulates colon cancer cell migration by a mechanism involving MMP7-mediated transactivation of EGFR and consequent activation of both ERK and PI3K/ Akt signaling.
S2038 Establishing Models for Determining the Role of Increased Wnt5a Expression in Intestinal Tumor Growth Elvira Bakker, Werner Helvensteyn, Wendy van Veelen, Ernst J. Kuipers, Ron Smits Background: The vast majority of colorectal cancer patients die from metastatic disease. Therefore, it is important to understand the underlying mechanisms of CRC progression. More and more evidence is being reported about the importance of the interaction between tumor cells and surrounding stromal tissue for tumor invasion and metastasis. In this respect, tumor-associated macrophages are of special interest as they have been suggested to stimulate angiogenesis and invasiveness. One of the factors shown to be expressed at increased levels by macrophages in intestinal tumors is Wnt5a, belonging to the so-called non-canonical class of Wnt signaling molecules. In Vitro data suggest that Wnt5a is involved in tumor cell growth and migration, angiogenesis and epithelial to mesenchymal transitions, key steps in cancer progression. At present, it is however unclear to which extent and through which mechanisms, Wnt5a contributes to the malignant behavior of colorectal tumors In Vivo. Therefore, we have set out to generate a mouse model in which expression of Wnt5a can be controlled in a tissue-specific and temporal fashion. Methods: Several transgenic mouse lines have been generated carrying the Wnt5a gene driven by a Doxycycline(Dox)-responsive promoter. To test the functionality of each TetO-Wnt5a transgenic line, the founder lines were crossed with animals expressing the rtTA2 transcription factor in all their tissues. By providing Dox in the drinking water, this transcription factor will activate expression of transgenic Wnt5a. In initial experiments we have used isolated tail fibroblasts to assess tight control of gene expression. Results: Using isolated tail fibroblasts, we identified one transgenic line showing a tight Dox-induced expression of Wnt5a. Expression was undetectable without Dox-induction, whereas a robust induction was observed when Dox was added to the fibroblast cultures. Subsequently, we have shown that Wnt5a expression was efficiently induced in double transgenic mice provided with Dox in their drinking water. Preliminary experiments suggest that induced expression of Wnt5a has severe effects on mouse embryonal development, whereas it appears to be well-tolerated in adult animals. Conclusions: We have successfully generated a transgenic model in which Wnt5a expression can be induced in a controlled fashion. In the future, this model will be combined with transgenic models allowing macrophage- or intestinal-specific induction of Wnt5a that will subsequently be crossed with Apc mutant models developing spontaneous intestinal tumors. These experiments will help us to better understand the role of Wnt5a in intestinal tumor growth.
S2041 Oncogenic Met Receptor Promotes Tumorigenesis and Metastases in Normal Intestinal Epithelial Cells Jimmy Bernier, Walid Chababi, Véronique Pomerleau, Caroline Saucier Compelling lines of evidence imply that deregulation of the Met receptor tyrosine kinase contributes to the etiology and progression of colorectal cancer. Notably, a recent study has shown that co-expression of the Met receptor and of its ligand, the hepatocyte growth factor in primary colon cancer predicts tumor stage and clinical outcome. However, the functional significance for the Met receptor in early neoplasic transformation of the intestinal epithelium and its contribution to the transition of colorectal cancers from a non-invasive to a metastatic malignant phenotype remain poorly defined. In this study, we have investigated whether oncogenic engagement of the Met receptor is alone sufficient to induce cancer behaviors in the non-transformed intestinal epithelial crypt cell model, the IEC-6 cells. Our results demonstrate that the expression of an oncogenic form of the Met receptor in IEC-6 cells is sufficient to induce epithelial to mesenchymal transition, proliferation, loss of growth contact inhibitory signals and anchorage-independent growth. Of significance, we show that oncogenic activation of the Met receptor confers to normal intestinal epithelial cells the capacity to induce angiogenic responses, tumor formation and experimental lung metastases in nude mice. Overall, these results support the concept that deregulation of the Met receptor signaling pathways contributes to the initiation and malignant progression of colorectal cancer by affecting a wide variety of cancer biological processes. Thus, this validates that the Met receptor and its downstream signaling pathways represent attractive targets for the development of new therapeutic approaches for the treatment of colorectal cancer.
S2039 The Effect of Altering Trefoil Factor-3 (TFF3) Expression On Gene Expression and Function in Human Gastrointestinal Cancer Cells Hisayuki Matsunaga, Xiuliang Bao, Lawrence Werther, Soichiro Miura, Steven H. Itzkowitz BACKGROUND: Trefoil Factor-3 (TFF3) is normally expressed by intestinal epithelial cells and promotes wound healing by enhancing epithelial cell migration while preventing apoptosis. We previously demonstrated that in human stomach, TFF3 is expressed in a cancer-associated fashion and correlates with poor prognosis (Clin Cancer Res 8:1092, 2002). We also showed that TFF3 expression in rat colorectal cancer (CRC) cells correlated with cancer cell invasion and poor survival (Clin Exp Metast 22:157, 2005), and that TFF3 was expressed by all human CRC liver metastases (Clin Exp Metast, in press, 2008). AIMS: To determine: 1) the effect of TFF3 expression on oncogenic gene expression in human gastric cancer cells; and 2) the functional effect of reducing TFF3 expression in human CRC cells. METHODS: TFF3 expression was induced in TFF3-negative AGS gastric cancer cells using an inducible pTet-On expression system. Genes that were up- or down-regulated were analyzed by cDNA microarray (GeneChipR Human Genome U133 plus 2.0 array, Affymetrix). siRNA was used to inhibit TFF3 expression in human CRC cells (LS-B, LS-C). Cell proliferation and etoposide-induced apoptosis were analyzed. RESULTS: In AGS cells, compared to empty vector controls, TFF3 induction resulted in at least a 2-fold up-regulation of 137 genes and down-regulation of 187 genes. 23 up-regulated genes are oncogenesis-associated, promoting cell migration/motility (CAMK4, CD44, CFL-1, ACTN4, CD151, HSPB1), proliferation (PCIF1), anti-apoptosis (CUL-7, CAPN14, TAOK2, MDK), invasion and metastasis (CD44, ACTN4, CD151) and a loss of cell adhesion (SAMD1, ZYX). 32 down-regulated genes are oncogenesis-associated, including genes involved in tumor suppression (PTPRD, ENO1, G3BP1, G3BP2, BCOR, KLF6, CCNK), apoptosis (KSR1, RHBDF1, DAPK3, STK17A, BRCC3, GULP1, GTSE1, VDAC1, SCYE1), proliferation (RHBDF1, WHSC1, CDC25C, TOB2, BRCC3), motility (FAM84A), and actin polymerization (PLXNB2, ENC1), cell adhesion (CLDN4, claudin-4). In gastric cancer, CLDN4 reduction has been associated with diffuse type and higher malignant grade. In LS-B and LS-C CRC cells, siRNA inhibited TFF3 expression by 77.7% and 70.6%, respectively. This was associated with 15.2% and 15.1% inhibition of proliferation, and 11% and 10.4% reversal of the anti-apoptotic effect of TFF3. CONCLUSIONS: These findings provide novel insights into the potential tumor-promoting mechanisms of action of TFF3 in human gastric and colon cancer cells. Further work will
AGA Abstracts
S2042 Focal Adhesion Dynamics in Invasive Pancreatic Tumor Cells Are Regulated By SRC Activation of the Large GTPase Dynamin 2 Yu Wang, Hong Cao, Mark A. McNiven Pancreatic tumor cells have a strong tendency to invade into surrounding parenchyma and metastasize to distal organs. During this invasive process, focal adhesions (FAs) play an essential role in the coordination of cell adhesion, lamellipodia extension and subsequently, cell migration. Indeed, many FA proteins are significantly upregulated in pancreatic cancers. Currently, however, the mechanisms that regulate the turnover of these structures are poorly understood. One of these proteins is the large GTPase Dynamin2 (Dyn2), which has an established role in endocytosis and appears to regulate FA turnover by an undefined mechanism. The GOAL of this study was to define the contribution of Dyn2 to FA turnover that enhances pancreatic tumor cell adhesion and invasion. Importantly, we find that activation of Src kinase, either through expression of a constitutively active Src mutant (SrcY530F), or EGF stimulation, markedly increases recruitment of Dyn2 to FAs. Conversely, expression of a Src SH2 domain mutant (R178L) that prevents the localization of Src to FAs, or treatment
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