Influence of laminin substratum on cell proliferation and CALC I gene expression in medullary thyroid carcinoma C cell lines (original) (raw)

Co-expression of laminin and a 67 kDa laminin-binding protein in teratocarcinoma embryoid bodies

The International journal of developmental biology, 1994

The synthesis of laminin chains is usually correlated to specific functions of laminin during embryo development. In this study we show that the CE44 teratocarcinoma embryoid bodies synthesize B1 and B2 chains of laminin as well as a 67 kDa laminin-binding protein while simultaneously differentiating into parietal endoderm. The intracystic presence of laminin and the 67 kDa cell surface laminin-receptor in teratocarcinoma differentiated cells suggest that the B chains of laminin play an important role in induction and/or mediation of cell differentiation and confirm the importance of laminin A chain in cell polarization and the supramolecular rearrangement of definitive basement membrane.

Laminin-Induced Signaling in Tumor Cells: The Role of the Mr 67,000 Laminin Receptor

Cancer Research, 2004

The expression of the M r 67,000 laminin receptor, a nonintegrin laminin receptor, was found to be up-regulated in neoplastic cells and to directly correlate with invasion and metastatic potential. In the present study, we investigated the role of laminin receptor in mediating laminin effects and the involvement of the mitogen-activated protein kinases (MAPK) cascades and dual-specificity phosphatases in laminin signaling in human melanoma cells. Using stable transfection of A375SM melanoma cells, we established lines expressing reduced or elevated laminin receptor. The antisense-transfected cells demonstrated reduced attachment to laminin and reduced invasion through Matrigel-coated filters. In addition, both matrix metalloproteinase-2 (MMP-2) mRNA expression and activity were significantly reduced in the antisense-transfected cells. Antisensetransfected cells showed a reduction in mRNA level of the ␣6B integrin subunit isoform, whereas no change in the mRNA level of the ␣6A isoform was observed. We found that exogenous laminin reduced the phosphorylated (active) form of extracellular signal-regulated kinase, c-Jun NH 2terminal protein kinase, and p38 in all of the cells, irrespective of the expression of the laminin receptor. Furthermore, the phosphorylation of extracellular signal-regulated kinase, c-Jun NH 2 -terminal protein kinase, and p38 was significantly higher in the cell lines expressing reduced laminin receptor, regardless of the exposure to exogenous laminin. This increase of MAPK phosphorylation was accompanied by a significant reduction in MKP-1 phosphatase mRNA level and a significant increase in PAC-1 phosphatase mRNA level. In conclusion, our results confirm the involvement of the laminin receptor in different mechanisms related to tumor dissemination and provide first evidence of the involvement of MAPK and dual-specificity phosphatases in its signal transduction pathway.

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...

An immunohistochemical study of laminin in basal cell carcinoma

Journal of Cutaneous Pathology, 2010

Background: Laminins are components of the extracellular matrix that mediate cell adhesion, growth, migration, proliferation and differentiation. Basement membrane (BM) laminins, in particular, may play a role in enhancing carcinoma cell motility. Aim: To evaluate the distribution pattern of laminin in basal cell carcinoma (BCC), as regards the basement membrane, cellular cytoplasm, peritumoral lacunae and surface epithelium and to correlate laminin distribution with different variants of BCC. Patients and Methods: Skin biopsy specimens were obtained from 21 BCC patients for routine histopathological and immunohistochemical study. Laminin was evaluated qualitatively and semiquantitatively using monoclonal mouse antihuman antibody (Dako-Laminin, 4C7. Code No: MO638, which reacts with the terminal globular domain of the α5 chain) Results: The majority of BCC cases showed patchy cytoplasmic distribution of laminin. The BM expression of laminin, in most cases, was well defined, fine and linear with irregular areas of thickening. Staining intensity was moderate in differentiated and mixed variants, weak in superficial spreading and absent in morpheic types. Conclusion: Cytoplasmic and basement membrane laminin is important in the pathogenesis and invasion of BCC. Most laminin was in basement membrane zone (BMZ), and the more differentiated the tumor, the more cytoplasmic and BM staining it expressed.

An Immunohistochemical study of laminin in cutaneous and mucosal squamous cell carcinomas

Background: Laminins are components of the extracellular matrix that mediate cell adhesion, growth, migration, proliferation and differentiation. Basement membrane (BM) laminins, in particular, may play a role in enhancing carcinoma cell motility. Aim: To evaluate the distribution pattern of laminin in basal cell carcinoma (BCC), as regards the basement membrane, cellular cytoplasm, peritumoral lacunae and surface epithelium and to correlate laminin distribution with different variants of BCC. Patients and Methods: Skin biopsy specimens were obtained from 21 BCC patients for routine histopathological and immunohistochemical study. Laminin was evaluated qualitatively and semiquantitatively using monoclonal mouse antihuman antibody (Dako-Laminin, 4C7. Code No: MO638, which reacts with the terminal globular domain of the α5 chain) Results: The majority of BCC cases showed patchy cytoplasmic distribution of laminin. The BM expression of laminin, in most cases, was well defined, fine and linear with irregular areas of thickening. Staining intensity was moderate in differentiated and mixed variants, weak in superficial spreading and absent in morpheic types. Conclusion: Cytoplasmic and basement membrane laminin is important in the pathogenesis and invasion of BCC. Most laminin was in basement membrane zone (BMZ), and the more differentiated the tumor, the more cytoplasmic and BM staining it expressed.

The follicular thyroid cell line PCCL3 responds differently to laminin and to polylaminin, a polymer of laminin assembled in acidic pH

Molecular and Cellular Endocrinology, 2013

The extracellular-matrix protein laminin forms polymers both in vivo and in vitro. Acidification of pH leads to the formation of an artificial polymer with biomimetic properties, named polylaminin (polyLM). Follicle cells in the thyroid are in close contact with laminin, but their response to this important extracellular signal is still poorly understood. PCCL3 thyroid follicular cells cultured on glass, on regular laminin (LM) or on laminin previously polymerized in acidic pH (polyLM) showed different cell morphologies and propensities to proliferate, as well as differences in the organization of their actin cytoskeleton. On polyLM, cells displayed a typical epithelial morphology and radially organized actin fibers; whereas on LM, they spread irregularly on the substrate, lost cell contacts, and developed thick actin fibers extending through the entire cytoplasm. Iodide uptake decreased similarly in response to both laminin substrates, in comparison to glass. On both the LM and polyLM substrates, the expression of the sodium iodide symporter (NIS) decreased slightly but not significantly. NIS showed dotted immunostaining at the plasma membrane in the cells cultured on glass; on polyLM, NIS was observed mainly in the perinuclear region, and more diffusely throughout the cytoplasm on the LM substrate. Additionally, polyLM specifically favored the maintenance of cell polarity in culture. These findings indicate that PCCL3 cells can discriminate between LM and polyLM and that they respond to the latter by better preserving the phenotype observed in the thyroid tissue.