v 6 Integrin Promotes the Invasion of Morphoeic Basal Cell Carcinoma through Stromal Modulation (original) (raw)
Related papers
2008
Basal cell carcinoma (BCC) is the most prevalent cancer in the Western world and its incidence is increasing. The pathogenesis of BCC involves deregulated Sonic hedgehog signaling, leading to activation of the Gli transcription factors. Most BCCs have a nodular growth pattern, and are indolent, slowgrowing, and considered ''low-risk'' lesions. In contrast, the ''high-risk'' morphoeic variant, which causes significant morbidity, has an infiltrative growth pattern, and is so-called because of its densely fibrous stroma. As AvB6 is capable of promoting both carcinoma invasion and fibrosis, we examined the expression of this integrin in BCCs and found that the morphoeic type showed significantly higher AvB6 expression than the nodular type (P = 0.0009). In order to examine the function of AvB6, we transfected the transcription factors Gli1 or Gli2 into NTERT, human keratinocytes to generate a BCC model. These cells expressed AvB6 and were invasive, although inhibition of AvB6 had no direct effect on cell invasion. However, the cells showed AvB6-dependent activation of transforming growth factor-B1, which induced transdifferentiation of human fibroblasts into myofibroblasts. Paracrine secretion of hepatocyte growth factor/scatter factor by these myofibroblasts promoted c-Met-dependent tumor invasion in both Transwell and three-dimensional organotypic assays. These experimental in vitro findings were confirmed using human clinical samples in which we showed that the stroma of morphoeic BCC is myofibroblast-rich compared with nodular BCC (P = 0.0036), that myofibroblasts express hepatocyte growth factor/scatter factor, and that morphoeic BCCs are strongly c-Met-positive. These data suggest that AvB6-dependent transforming growth factor-B1 activation induces both the infiltrative growth pattern and fibrotic stroma so characteristic of morphoeic BCC. [Cancer Res 2008;68(9):3295-303]
AvB6 Integrin Promotes the Invasion of Morphoeic Basal Cell Carcinoma through Stromal Modulation
2000
Basal cell carcinoma (BCC) is the most prevalent cancer in the Western world and its incidence is increasing. The pathogen- esis of BCC involves deregulated Sonic hedgehog signaling, leading to activation of the Gli transcription factors. Most BCCs have a nodular growth pattern, and are indolent, slow- growing, and considered ''low-risk'' lesions. In contrast, the ''high-risk'' morphoeic variant, which causes
British Journal of Plastic Surgery, 2004
Specimens of basal cell carcinomas collected from 28 patients were classified into three groups: superficial, nodular, and infiltrative, according to their microarchitecture. The specimens were then subjected to histological characterization by means of a biotinylated hyaluronan-binding probe (HABP). By using Ki-67 and PCNA the proliferative activity of the BCC tumours was evaluated with immunohistological techniques. In superficial BCC the tumour islands displayed moderate hyaluronan (HA) staining. Feeble proliferation, denoted by modest mitotic activity and weak Ki-67 and PCNA immunoreactivity, occurred within the tumour islands. The surrounding connective tissue resembled normal skin, and no differentiated tumour stroma was observed. In nodular BCC, the HA staining of the tumour strands was weak to moderate, denoting increased proliferative activity. The differentiated surrounding tumour stroma stained strongly for HA. Tumour islands of infiltrative BCC stained weakly to moderately to HA and evidenced intense proliferation. The intensely HA-stained tumour stroma ended abruptly and the adjacent areas were almost devoid of HA. This study showed that the proliferative activity of BCC cells is associated with increased expression of HA in the tumour stroma. Modification of tumour-associated connective tissue indicates a close relationship between the tumour cells and the adjacent matrix. In particular, in infiltrative BCC, such alterations include degeneration and possible modification and remodelling of the surrounding extracellular matrix. These processes involving areas of probable importance for tumour progression, should be considered when deciding the extent of intended surgical resection.
A role of PDGFR in basal cell carcinoma proliferation
Proceedings of the National Academy of Sciences, 2001
Activation of the hedgehog pathway, through the loss of patched (PTC) or the activation of smoothened (SMO), occurs frequently in basal cell carcinoma (BCC), the most common human cancer. However, the molecular basis of this neoplastic effect is not understood. The downstream molecule Gli1 is known to mediate the biological effect of the pathway and is itself up-regulated in all BCCs. Gli1 can drive the production of BCCs in the mouse when overexpressed in the epidermis. Here we show that Gli1 can activate platelet-derived growth factor receptor ␣ (PDGFR␣) in C3H10T 1 ⁄2 cells. Functional up-regulation of PDGFR␣ by Gli1 is accompanied by activation of the ras-ERK pathway, a pathway associated with cell proliferation. The relevance of this mechanism in vivo is supported by a high level expression of PDGFR␣ in BCCs of mice and humans. In the murine BCC cell line ASZ001, in which both copies of the PTC gene are inactivated, DNA synthesis and cell proliferation can be slowed by re-expression of PTC, which downregulates PDGFR␣ expression, or by downstream inhibition of PDGFR␣ with neutralizing antibodies. Therefore, we conclude that increased expression of PDGFR␣ may be an important mechanism by which mutations in the hedgehog pathway cause BCCs.
Basal Cell Carcinoma in Gorlin’s Patients: a Matter of Fibroblasts-Led Protumoral Microenvironment?
PLOS ONE, 2015
Basal cell carcinoma (BCC) is the commonest tumor in human. About 70% sporadic BCCs bear somatic mutations in the PATCHED1 tumor suppressor gene which encodes the receptor for the Sonic Hedgehog morphogen (SHH). PATCHED1 germinal mutations are associated with the dominant Nevoid Basal Cell Carcinoma Syndrome (NBCCS), a major hallmark of which is a high susceptibility to BCCs. Although the vast majority of sporadic BCCs arises exclusively in sun exposed skin areas, 40 to 50% BCCs from NBCCS patients develop in non photo-exposed skin. Since overwhelming evidences indicate that microenvironment may both be modified by-and influence the-epithelial tumor, we hypothesized that NBCCS fibroblasts could contribute to BCCs in NBCCS patients, notably those developing in non photoexposed skin areas. The functional impact of NBCCS fibroblasts was then assessed in organotypic skin cultures with control keratinocytes. Onset of epidermal differentiation was delayed in the presence of primary NBCCS fibroblasts. Unexpectedly, keratinocyte proliferation was severely reduced and showed high levels of nuclear P53 in both organotypic skin cultures and in fibroblast-led conditioning experiments. However, in spite of increased levels of senescence associated β-galactosidase activity in keratinocytes cultured in the presence of medium conditioned by NBCCS fibroblasts, we failed to observe activation of P16 and P21 and then of bona fide features of senescence. Constitutive extinction of P53 in WT keratinocytes resulted in an invasive phenotype in the presence of NBCCS fibroblasts. Finally, we found that expression of SHH was limited to fibroblasts but was dependent on the presence of keratinocytes. Inhibition of SHH binding resulted in improved epidermal morphogenesis. Altogether, these data suggest that the repertoire of diffusible factors (including SHH) expressed by primary NBCCS fibroblasts generate a stress affecting keratinocytes behavior and epidermal homeostasis. Our findings suggest that defects in dermo/epidermal interactions could contribute to BCC susceptibility in NBCCS patients.
The Journal of cell biology, 1998
Integrin activation is a multifaceted phenomenon leading to increased affinity and avidity for matrix ligands. To investigate whether cytokines produced during stromal infiltration of carcinoma cells activate nonfunctional epithelial integrins, a cellular system of human thyroid clones derived from normal glands (HTU-5) and papillary carcinomas (HTU-34) was employed. In HTU-5 cells, alphavbeta3 integrin was diffused all over the membrane, disconnected from the cytoskeleton, and unable to mediate adhesion. Conversely, in HTU-34 cells, alphavbeta3 was clustered at focal contacts (FCs) and mediated firm attachment and spreading. alphavbeta3 recruitment at FCs and ligand-binding activity, essentially identical to those of HTU-34, occurred in HTU-5 cells upon treatment with hepatocyte growth factor/scatter factor (HGF/SF). The HTU-34 clone secreted HGF/SF and its receptor was constitutively tyrosine phosphorylated suggesting an autocrine loop responsible for alphavbeta3 activated state. ...
Indian Journal of Medical and Paediatric Oncology
Background: Concurrent with the conversion of nondiseased epithelial tissue to precancerous epithelium and finally to carcinoma, the stroma also changes from normal-to-primed to tumor-associated reactive stroma. Cancerous cells secrete cytokines that promote differentiation of fibroblasts into cancer-associated fibroblasts/myofibroblasts. Myofibroblasts are tumor promoting and correlate with poor survival in many cancers. Vimentin expression is noted in epithelial cells of histologically more malignant oral squamous cell carcinoma (OSCC). Aim and Objectives: The aim of this study is to understand the role of tumor microenvironment by analyzing the expression of α-smooth muscle actin (α-SMA) in stromal myofibroblasts and to find a possible association between intensity and pattern of myofibroblast expression and progression of oral lesions from mild, moderate, and severe dysplasia to verrucous and invasive carcinomas. Materials and Methods: The study was divided into two groups. Sixty cases of premalignant lesions and 60 cases of OSCC were taken as the study groups. Smooth muscle cells surrounding the blood vessels were taken as positive control (internal control). Immunohistochemistry (IHC) for α-SMA was performed for the identification of myofibroblasts. The cases were then assessed for intensity and pattern of myofibroblastic proliferation. IHC for vimentin-positive epithelial cells was also done. Results: Fisher's exact test and Chi-square test were used. There was an increased α-SMA expression in malignant cases. Few cases of dysplasia showed focal staining pattern, whereas network pattern predominated in invasive carcinomas. Vimentin expression was seen in histologically more malignant OSCC cases and higher number of myofibroblasts was observed in such cases. Conclusion: Myofibroblasts increase as the disease progresses. Network arrangement of myofibroblasts represents higher invasive characteristics and a weaker prognosis.
Cancer …, 2008
The A v B 6 integrin is up-regulated on epithelial malignancies and has been implicated in various aspects of cancer progression. Immunohistochemical analysis of A v B 6 expression in 10 human tumor types showed increased expression relative to normal tissues. Squamous carcinomas of the cervix, skin, esophagus, and head and neck exhibited the highest frequency of expression, with positive immunostaining in 92% (n = 46), 84% (n = 49), 68% (n = 56), and 64% (n = 100) of cases, respectively. We studied the role of A v B 6 in Detroit 562 human pharyngeal carcinoma cells in vitro and in vivo. Prominent A v B 6 expression was detected on tumor xenografts at the tumor-stroma interface resembling the expression on human head and neck carcinomas. Nonetheless, coculturing cells in vitro with matrix proteins did not up-regulate A v B 6 expression. Detroit 562 cells showed A v B 6-dependent adhesion and activation of transforming growth factor-B (TGF-B) that was inhibited >90% with an A v B 6 blocking antibody, 6.3G9. Although both recombinant soluble TGF-B receptor type-II (rsTGF-BRII-Fc) and 6.3G9 inhibited TGF-B-mediated Smad2/ 3 phosphorylation in vitro, there was no effect on proliferation. Conversely, in vivo, 6.3G9 and rsTGF-BRII-Fc inhibited xenograft tumor growth by 50% (n = 10, P < 0.05) and >90% (n = 10, P < 0.001), respectively, suggesting a role for the microenvironment in this response. However, stromal collagen and smooth muscle actin content in xenograft sections were unchanged with treatments. Although further studies are required to consolidate in vitro and in vivo results and define the mechanisms of tumor inhibition by A v B 6 antibodies, our findings support a role for A v B 6 in human cancer and underscore the therapeutic potential of function blocking A v B 6 antibodies.