Mucinous cystic neoplasms of the mesentery: a case report and review of the literature

<p>Abstract</p> <p>Background</p> <p>Mucinous cystic neoplasms arise in the ovary and various extra-ovarian sites. While their pathogenesis remains conjectural, their similarities suggest a common pathway of development. There have been rare reports involving the mesentery as a primary tumour site.</p> <p>Case presentation</p> <p>A cystic mass of uncertain origin was demonstrated radiologically in a 22 year old female with chronic abdominal pain. At laparotomy, the mass was fixed within the colonic mesentery. Histology demonstrated a benign mucinous cystadenoma.</p> <p>Methods and results</p> <p>We review the literature on mucinous cystic neoplasms of the mesentery and report on the pathogenesis, biologic behavior, diagnosis and treatment of similar extra-ovarian tumors. We propose an updated classification of mesenteric cysts and cystic tumors.</p> <p>Conclusion</p> <p>Mucinous cystic neoplasms of the mesentery present almost exclusively in women and must be considered in the differential diagnosis of mesenteric tumors. Only full histological examination of a mucinous cystic neoplasm can exclude a borderline or malignant component. An updated classification of mesenteric cysts and cystic tumors is proposed.</p

MT-LOOP-dependent localization of membrane type I matrix metalloproteinase (MT1-MMP) to the cell adhesion complexes promotes cancer cell invasion.

Localization of membrane type I matrix metalloproteinase (MT1-MMP) to the leading edge is thought to be a crucial step during cancer cell invasion. However, its mechanisms and functional impact on cellular invasion have not been clearly defined. In this report, we have identified the MT-LOOP, a loop region in the catalytic domain of MT1-MMP ((163)PYAYIREG(170)), as an essential region for MT1-MMP to promote cellular invasion. Deletion of the MT-LOOP effectively inhibited functions of MT1-MMP on the cell surface, including proMMP-2 activation, degradation of gelatin and collagen films, and cellular invasion into a collagen matrix. This is not due to loss of the catalytic function of MT1-MMP but due to inefficient localization of the enzyme to β1-integrin-rich cell adhesion complexes at the plasma membrane. We also found that an antibody that specifically recognizes the MT-LOOP region of MT1-MMP (LOOPAb) inhibited MT1-MMP functions, fully mimicking the phenotype of the MT-LOOP deletion mutant. We therefore propose that the MT-LOOP region is an interface for molecular interactions that mediate enzyme localization to cell adhesion complexes and regulate MT1-MMP functions. Our findings have revealed a novel mechanism regulating MT1-MMP during cellular invasion and have identified the MT-LOOP as a potential exosite target region to develop selective MT1-MMP inhibitors

Discoidin domain receptor 2 mediates collagen-induced activation of membrane-type 1 matrix metalloproteinase in human fibroblasts

Membrane-Type 1 Matrix Metalloproteinase (MT1-MMP) is a membrane-bound MMP that is highly expressed in cells with invading capacity including fibroblasts and invasive cancer cell. A potential physiological stimulus for MT1-MMP expression is fibrillar collagen, and it has been shown that it upregulates both MT1-MMP gene and functions in various cell types. However, the mechanisms of collagen-mediated MT1-MMP activation is not clearly understood. In this study we identified discoidin domain receptor 2 (DDR2) as a crucial receptor that mediates this process in human fibroblasts. Knocking down DDR2, but not β1 integrin subunit, a common subunit for all collagen-binding integrins, inhibited collagen-induced activation of proMMP-2 and upregulation of MT1-MMP at the gene and protein level. Interestingly DDR2 knockdown or pharmacological inhibition of DDR2 also inhibited MT1-MMP-dependent cellular degradation of collagen film, suggesting that cell surface collagen degradation by MT1-MMP involves DDR2-mediated collagen signalling. This DDR2-mediated mechanism is only present in non-transformed mesenchymal cells, as collagen-induced MT1-MMP activation in HT1080 fibrosarcoma cells and MT1-MMP function in MDA-MB231 breast cancer cells were not affected by DDR kinase inhibition. DDR2 activation was found to be noticeably more effective when cells were stimulated by collagen without non-helical telopeptides region compared to intact collagen fibrils. Those data suggest that DDR2 is a microenvironmental sensor that regulates fibroblasts migration in collagen-rich environment

MT-LOOP-dependent localization of membrane type I matrix metalloproteinase (MT1-MMP) to the cell adhesion complexes promotes cancer cell invasion.

Localization of membrane type I matrix metalloproteinase (MT1-MMP) to the leading edge is thought to be a crucial step during cancer cell invasion. However, its mechanisms and functional impact on cellular invasion have not been clearly defined. In this report, we have identified the MT-LOOP, a loop region in the catalytic domain of MT1-MMP ((163)PYAYIREG(170)), as an essential region for MT1-MMP to promote cellular invasion. Deletion of the MT-LOOP effectively inhibited functions of MT1-MMP on the cell surface, including proMMP-2 activation, degradation of gelatin and collagen films, and cellular invasion into a collagen matrix. This is not due to loss of the catalytic function of MT1-MMP but due to inefficient localization of the enzyme to β1-integrin-rich cell adhesion complexes at the plasma membrane. We also found that an antibody that specifically recognizes the MT-LOOP region of MT1-MMP (LOOPAb) inhibited MT1-MMP functions, fully mimicking the phenotype of the MT-LOOP deletion mutant. We therefore propose that the MT-LOOP region is an interface for molecular interactions that mediate enzyme localization to cell adhesion complexes and regulate MT1-MMP functions. Our findings have revealed a novel mechanism regulating MT1-MMP during cellular invasion and have identified the MT-LOOP as a potential exosite target region to develop selective MT1-MMP inhibitors

ADAM10 controls collagen signaling and cell migration on collagen by shedding the ectodomain of discoidin domain receptor 1 (DDR1)

Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase that binds and transmits signals from various collagens in epithelial cells. However, how DDR1-dependent signaling is regulated has not been understood. Here we report that collagen binding induces ADAM10-dependent ectodomain shedding of DDR1. DDR1 shedding is not a result of an activation of its signaling pathway since DDR1 mutants defective in signaling were shed in an efficient manner. DDR1 and ADAM10 were found to be in a complex on the cell surface, but shedding did not occur unless collagen bound to DDR1. Using a shedding resistant DDR1 mutant, we found that ADAM10-dependent DDR1 shedding regulates the half-life of collagen-induced phosphorylation of the receptor. Our data also revealed that ADAM10 plays an important role in regulating DDR1 mediated cell adhesion to achieve efficient cell migration on collagen matrices

Discoidin domain receptor 2 mediates collagen-induced activation of membrane-type 1 matrix metalloproteinase in human fibroblasts

Membrane-Type 1 Matrix Metalloproteinase (MT1-MMP) is a membrane-bound MMP that is highly expressed in cells with invading capacity including fibroblasts and invasive cancer cell. A potential physiological stimulus for MT1-MMP expression is fibrillar collagen, and it has been shown that it upregulates both MT1-MMP gene and functions in various cell types. However, the mechanisms of collagen-mediated MT1-MMP activation is not clearly understood. In this study we identified discoidin domain receptor 2 (DDR2) as a crucial receptor that mediates this process in human fibroblasts. Knocking down DDR2, but not β1 integrin subunit, a common subunit for all collagen-binding integrins, inhibited collagen-induced activation of proMMP-2 and upregulation of MT1-MMP at the gene and protein level. Interestingly DDR2 knockdown or pharmacological inhibition of DDR2 also inhibited MT1-MMP-dependent cellular degradation of collagen film, suggesting that cell surface collagen degradation by MT1-MMP involves DDR2-mediated collagen signalling. This DDR2-mediated mechanism is only present in non-transformed mesenchymal cells, as collagen-induced MT1-MMP activation in HT1080 fibrosarcoma cells and MT1-MMP function in MDA-MB231 breast cancer cells were not affected by DDR kinase inhibition. DDR2 activation was found to be noticeably more effective when cells were stimulated by collagen without non-helical telopeptides region compared to intact collagen fibrils. Those data suggest that DDR2 is a microenvironmental sensor that regulates fibroblasts migration in collagen-rich environment

ADAM10 controls collagen signaling and cell migration on collagen by shedding the ectodomain of discoidin domain receptor 1 (DDR1)

Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase that binds and transmits signals from various collagens in epithelial cells. However, how DDR1-dependent signaling is regulated has not been understood. Here we report that collagen binding induces ADAM10-dependent ectodomain shedding of DDR1. DDR1 shedding is not a result of an activation of its signaling pathway since DDR1 mutants defective in signaling were shed in an efficient manner. DDR1 and ADAM10 were found to be in a complex on the cell surface, but shedding did not occur unless collagen bound to DDR1. Using a shedding resistant DDR1 mutant, we found that ADAM10-dependent DDR1 shedding regulates the half-life of collagen-induced phosphorylation of the receptor. Our data also revealed that ADAM10 plays an important role in regulating DDR1 mediated cell adhesion to achieve efficient cell migration on collagen matrices