Laminin receptor expression and function in small-cell lung carcinoma (original) (raw)
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Role of laminin in the attachment and metastasis of murine tumor cells
Cancer Research, 1982
We have studied the attachment of two murine metastatic cell lines and of a transformed, nonmetastatic sarcoma cell line to type IV (basement membrane) collagen. The metastatic cells attached preferentially to type IV collagen, whereas the non metastatic cells attached best to type I collagen. Laminin in creased both the rate and the number of metastatic cells attaching to type IV collagen, while fibronectin had no effect. Antibodies to laminin prevented the attachment of metastatic cells to type IV collagen, while antibodies to fibronectin pre vented the attachment of the nonmetastatic cells. The number of pulmonary métastases which formed after i.v. injection of cells into C57BL mice was used to measure the metastatic propensity of these cell lines. A subpopulation of the metastatic cells selected for by their ability to attach to type IV collagen in the presence of laminin produced more métastases than did unattached cells or cells attached with fibronectin. In addition, incubation of metastatic cells with antibody to laminin prior to injection into mice markedly reduced the number of lung mé tastases. These data suggest that laminin promotes the attach ment of metastatic tumor cells to basement membrane during the metastatic process.
Laminin receptors on SCLC cells
British Journal of Cancer, 1991
Several studies have suggested a correlation between the metastatic potential and the expression of adhesion molecules and/or their receptors on tumour cell surface membranes. In this study we investigated the expression of functional laminin receptors on small cell lung cancer (SCLC) cells. To this aim we set up an adherence assay to determine the in vitro binding capability of tumour cell lines to laminin. All of the three SCLC lines tested and cells from a short-term SCLC line adhered to laminin in cell culture plates, and the affinity of cell-matrix adhesion proved to be higher than the cell-cell adhesion. This effect was always laminin dose-dependent. On a laminin affinity chromatography column three major proteins could be eluted with EDTA from soluble extracts of SCLC lines. Their molecular weights of 120, 90 and 30 kDa suggested a possible relationship with the integrin family. This putative integrin laminin receptor expressed on SCLC does not react with fibronectin, vitronectin or collagen.
Role of laminin receptor in tumor cell migration
Cancer Research, 1987
Polyclonal antisera were made against biochemically purified laminili receptor protein as well as against synthetic peptides deduced from a complementary DNA clone corresponding to the COOH-terminal end of the laminin receptor (U. M. Wewer et al., Proc. Nati. Acad. Sci. USA, 83: 7137-7141, 1986). These antisera were used to study the potential role of laminin receptor in laminin-mediated attachment and haptotactic migration of human A20S8 melanoma cells. The anti-laminin receptor antisera reacted with the surface of suspended, nonpermeabilized mela noma and carcinoma cells. The anti-laminin receptor antisera blocked the surface interaction of A2058 cells with endogenous laminin, resulting in the inhibition of laminin-mediated cell attachment. The A20S8 mela noma cells migrated toward a gradient of solid phase laminin or fibronectin (haptotaxis). Anti-laminin antiserum abolished haptotaxis on lam inin but not on fibronectin. Synthetic peptide GRGDS corresponding to the fibronectin cell-binding domain inhibited haptotaxis on fibronectin but not on laminin. Both types of anti-laminin receptor antisera inhibited haptotaxis on laminin but not on fibronectin. Using immunohistochemis-Iry, invading human carcinoma cells in vivo exhibited a marked cytoplasmic ¡mmunoreactivityfor the receptor antigen. Together these find ings indicate a specific role for the laminin receptor in laminin-mediated migration and that the ligand binding of the laminin receptor is encom passed in the COOH-terminal end of the protein.
Differential expression of a laminin-Like substance by high- and low-Metastatic tumor cells
American Journal Of Pathology
High-metastatic murine fibrosarcoma cells readily attached to Type IV (basement membrane) collagen, whereas low-metastatic cells isolated from the same tumor did not. The addition of laminin--a glycoprotein that facilitates the adherence of epithelial cells to their basement membranes--enhanced the attachment of the low-metastatic cells, but not the high-metastatic cells. Using anti-laminin antibodies and a laminin-binding lectin as probes, the authors were able to identify by immunofluorescence a moiety associated with the high-metastatic cells, but not the low-metastatic cells, which cross-reacted with murine laminin purified from the EHS sarcoma. When extracts from the high-metastatic cells were separated by affinity chromatography, with the laminin-binding lectin as the affinity substrate, a substance was isolated that had an apparent molecular weight of 56,000 daltons. The affinity-purified material reacted strongly with anti-laminin antibodies by enzyme-linked immunosorbent as...
Expression of 32/67-kDa laminin receptor in laminin adhesion-selected human colon cancer cell lines
British Journal of Cancer, 1998
Laminin promotes the malignant phenotype, and the expression of certain laminin receptors is increased in malignancy. Previously, we demonstrated that a laminin-adhesive subolone of a human colon cancer cell line showed increased tumorigenicity in nude mice and increased affinity of the P, integrin for laminin relative to the laminin-non-adhesive subolone. The total amount of either 1 integrin protein or mRNA did not increase. As levels of the 32/67-kDa laminin receptor (67LR) correlate with malignancy, we examined 67LR expression in the laminin adhesion-selected human colon cancer cells. The laminin-adhesive subolone, which was more tumorigenic in both heterotopic and orthotopic locations than in a laminin-non-adhesive subolone, showed cell-surface membrane staining of 67LR, whereas the laminin-non-adhesive subolone showed cytoplasmic staining of 67LR. No difference in either the amount of 67LR mRNA or the amount of protein was observed in the parental cells than in the laminin-adhesive and non-adhesive subolones. When assayed on a laminin affinity column, more 67LR molecules bound to the column with cell extracts from the laminin-adhesive subolone than was observed with the nonadhesive subclone. These findings suggest that the increased tumorigenicity of laminin adhesion-selected tumour cells might be due to an alteration in the distribution and/or adhesiveness of multiple receptors including 67LR and P1 integrin.
Lung Cancer, 1993
We investigated the interaction between human lung cancer cells, laminin, and several differentiating agents. When grown on laminin coated substrate eight out of 11 small cell lung cancer (SCLC) cell lines exhibited attachment to laminin and three had extensive outgrowth of long neurite-like processes. Of seven non-small cell lung cancer cell lines, selected for their in vitro anchorage-independent growth, attachment was observed in only three cell lines, and process formation was far less extensive than in SCLC cell lines. Among several differentiating agents, only dcAMP, which alone induced attachment and some process formation, increased laminin-mediated attachment and process formation of two SCLC cell lines, NCI-N417 a variant cell line, and NCI-H345, a classic cell line. The expression of several neuroendocrine and neuronal markers was investigated in these two SCLC cell lines. The expression of the light subunit of neurofilaments increased in NCI-N417 within 3 to 4 days of seeding, while NCI-H345 exhibited approximately 5 fold increase in expression of the GRP gene and a 3 fold increase expression of the P-actin gene. The expression of a number of other neuroendocrine and neuronal markers did not change following growth on laminin. The doubling times remained unchanged independent of the presence of and attachment to laminin while topoisomerase II gene expression levels in NCI-N417 cells decreased approximately 5 fold when cells were growing on laminin.
International Journal of Cancer, 2009
Laminin-332 (LN-332), which is essential for epithelial cell adhesion and migration, is up-regulated in most invasive carcinomas. Association between LN-332 and carcinoma cell integrins and stroma collagen is thought to be important for tumor growth and metastasis. Here, we show that function blocking LN-332 antibodies interfering with cellular adhesion and migration in vitro evoke apoptotic pathways. The antibodies also target epithelial tumors in vivo. Antibodies against the cell binding domain of the a3 chain of LN-332 inhibited tumor growth by up to 68%, and antibodies against the matrix binding domains of the b3 and c2 chains significantly decreased lung metastases. The LN-332 antibodies appear to induce tumor cell anoikis and subsequent programmed cell death and reduce migration by interfering with tumor cell matrix interactions. ' 2009 UICC Laminins are trimeric basement membrane (BM) glycoproteins with roles in cell adhesion, proliferation, migration and differentiation. In mammals, 5 genetically distinct a, 3b and 3g chains can form at least 14 different combinations of these chains. 1,2 Laminin-332 (LN-332, previously termed laminin-5) that has chain composition a3:b3:g2 (Supplementary ) is essential for anchorage of epithelial cells and specifically found in epithelial BMs. 3-5 LN-332 defects lead to detachment of epithelia and the fatal skin blistering disease junctional epidermolysis bullosa. 6-8 LN-332 also has a role in proliferation and locomotion of epithelial cells, such as in keratinocytes of healing wounds. 9,10 The globular domain (Gdomain) of the a3 chain binds to the cell surface through integrin receptors a6b4 and a3b1 11 and evokes anti-apoptotic signals through focal adhesion kinase, 12,13 while the short arms of the b3 and g2 chains bind to Type VII collagen in the stroma. 14 LN-332 is up-regulated in various epithelial cancers, including colon, gastric, mammary duct and squamous cell carcinomas, as well as melanomas, 15-18 but not in mesenchymal cancers. 15,16 High expression of the g2 chain of LN-332 has been found to correlate with poor prognosis of cervical squamous cell carcinomas. 19 LN-332 is also a major scattering factor stimulating invasive and metastatic capacity of several tumor cell lines in vitro. 20,21 In the cancer tissue, the protein is primarily expressed at the invasive front, as well as in micro-metastases. Down-regulation of LN-332 has been reported in epithelial prostate cancer 22 and also in breast cancers. LN-332 expression has been associated with tumorigenesis. Thus, when HT1080 tumor cells constitutively expressing laminin b3 and g2 chains but not a3 were transfected with laminin a3 cDNA, the cells grew significantly larger tumors in nude mice than untransformed cells. 24 Moreover, LN-332 negative (as well as a4 integrin negative) keratinocytes did not become tumorigenic upon transfection with Ras-IjBa in contrast to normal keratinocytes. Since most cancers are of epithelial origin and positive for LN-332 expression, the question arises if this protein can have a general role for the adhesion and migration process of invading carcinoma cells, and if interference with those functions might influence tumor growth and spread. To address these questions, we have studied the role of LN-332 for carcinoma cell adhesion and migration in vitro and shown that interference with the binding of this protein to the cells inhibits these functions and induces apoptosis. Furthermore, we show that antibodies against the cell and matrix binding domains of LN-332 target to several types of carcinomas growing in vivo and effectively inhibit tumor growth and metastasis in mice. We hypothesize that the LN-332 antibodies induce tumor cell anoikis and decrease metastasis by dissociating the cells from the extracellular matrix.
The Journal of Pathology, 2003
In human tissues, the laminin (Ln) α1 chain shows a restricted and developmentally regulated distribution in basement membranes (BMs) of a subset of epithelial tissues, including those of renal proximal convoluted tubules. The present study investigated the distribution of the Ln α1 chain in renal cell carcinomas (RCCs) and oncocytomas as well as in xenografted tumours induced in nude mice with four characterized RCC cell lines. These cell lines were also used in cell adhesion studies with purified laminins. By immunohistochemistry it was found that the Ln α1 chain is widely present in the BMs of RCCs, all of the specimens presenting immunoreactivity. High-grade RCCs tended to contain more BM-confined and stromal immunoreactivity than low-grade tumours, none of the grade 3 (G3) carcinomas being negative and all of the metastatic specimens showing partial or overall BM immunoreactivity. Double immunolabelling experiments showed that in RCC BMs but not in vessel walls, the Ln α1 chain was co-distributed with Ln α5, β1, and β2 chains, implying the presence of Ln-1/Ln-3 and Ln-10/Ln-11. In papillary RCCs, the Ln α1 chain co-localized with Ln-5. The oncocytomas lacked immunoreactivity for the Ln α1 chain. Xenografted tumours induced in nude mice showed BM-like deposition of the Ln α1 chain. In cell adhesion studies, mouse and human Ln-1 were equally effective in promoting cell adhesion of all RCC cell lines. For each cell line, Ln-10 and Ln-10/11 were equally effective adhesive substrates, all cell lines adhering more avidly to these laminins than to mouse or human Ln-1. As judged by inhibition assays employing specific integrin antibodies, adhesion of normal human renal proximal tubular epithelial (RPTE) cells and RCC cells from a G1 tumour to human Ln-1 was mediated mainly by α 6 β 1 integrin, while only the G1 RCC cells adhered to mouse Ln-1 by using α 6 β 1 integrin. For adhesion to Ln-10, RPTE cells and RCC cells from a G1 tumour used an unidentified β 1 integrin. Cells from G3 tumours mainly used an α 3 β 1 integrin complex for adhesion to mouse Ln-1 and to human Ln-1 and Ln-10. For all cells, adhesion to the Ln-10/11 mixture was mediated by an unidentified integrin complex or by other adhesion molecules. These results show that laminin trimers containing the α1 chain are, in contrast to oncocytomas, abundant in the BMs of RCCs. This is in keeping with their suggested origin from renal proximal tubular epithelium known for its capacity to produce the Ln α1 chain. The results also show that RCC cells utilize complex, mainly integrin α 3 β 1 -and integrin α 6 β 1 -mediated, mechanisms for adhesion to laminins. The adhesion to Ln-1 changes from integrin α 6 β 1 to integrin α 3 β 1 upon increasing malignancy and, especially for Ln-10 and Ln-10/11, other adhesion molecules of non-integrin type may contribute to the adhesion.
The 67kDa laminin receptor increases tumor aggressiveness by remodeling laminin-1
The association between expression of the 67 kDa laminin receptor (67LR) and tumor aggressiveness has been convincingly demonstrated although the exact function of this molecule in the metastatic process has remained unclear. In this study, we tested whether the laminin-1, upon interaction with 67LR, promotes tumor cell aggressiveness; the investigation was based on: (i) the previous demonstration that soluble 67LR, as well as a 20-amino-acid peptide corresponding to the 67LR laminin binding site, changes the conformation of laminin upon interaction with this adhesion molecule and (ii) the known relevance of microenvironment remodeling by the tumor, leading to structural modification of extracellular matrix components in tumor progression. MDAMB231 breast carcinoma cells plated on peptide G-treated laminin-1 exhibited a polygonal array of actin filament bundles compared with cells seeded on native laminin-1 which presented the actin bundles organized as multiple cables parallel to margins. Furthermore, in cells seeded on peptide G-treated laminin-1, 67LR was distinct from the a6 integrin subunit in filopodia protrusions in addition to colocalizing with this integrin in focal adhesion plaques as it occurs when cells are plated on native laminin-1. In addition to differences in tumor cell adhesion and migration found in cells exposed to peptide G-treated vs native laminin-1, breast carcinoma cells seeded on modified laminin-1 showed a 6-fold increase in invasion capability compared with cells seeded on unmodified laminin-1. Alterations in actin organization as well as adhesion, migration and especially invasion observed in MDAMB231 cells in the presence of peptide G-treated laminin-1 were even found in MDAMB231 cells that, after selection for 67LR high expression, were seeded on native laminin-1. As the 67LR shedding is proportional to its expression level, these findings indicate a role for 67LR in changing laminin structure.