Stromal laminin chain distribution in normal, hyperplastic and malignant oral mucosa: relation to myofibroblast occurrence and vessel formation.
BACKGROUND
The contribution of stromal laminin chain expression to malignant potential, tumour stroma reorganization and vessel formation in oral squamous cell carcinoma (OSCC) is not fully understood. Therefore, the expression of the laminin chains alpha2, alpha3, alpha4, alpha5 and gamma2 in the stromal compartment/vascular structures in OSCC was analysed.


METHODS
Frozen tissue of OSCC (9x G1, 24x G2, 8x G3) and normal (2x)/hyperplastic (11x) oral mucosa was subjected to laminin chain and alpha-smooth muscle actin (ASMA) immunohistochemistry. Results were correlated to tumour grade. The relation of laminin chain positive vessels to total vessel number was assessed by immunofluorescence double labelling with CD31.


RESULTS
Stromal laminin alpha2 chain significantly decreases and alpha3, alpha4, alpha5 and gamma2 chains and also ASMA significantly increase with rising grade. The amount of stromal alpha3, alpha4 and gamma2 chains significantly increased with rising ASMA positivity. There is a significant decrease in alpha3 chain positive vessels with neoplastic transformation.


CONCLUSIONS
Mediated by myofibroblasts, OSCC development is associated with a stromal up-regulation of laminin isoforms possibly contributing to a migration promoting microenvironment. A vascular basement membrane reorganization concerning alpha3 and gamma2 chain laminins during tumour angioneogenesis is suggested.
Franz
Marcus
M
Department of Internal Medicine I, University Hospital of Jena, Jena, Germany.
Wolheim
Anke
A
Richter
Petra
P
Umbreit
Claudia
C
Dahse
Regine
R
Driemel
Oliver
O
Hyckel
Peter
P
Virtanen
Ismo
I
Kosmehl
Hartwig
H
Berndt
Alexander
A
D000199:Actins / Q000032:analysis; D001485:Basement Membrane / Q000473:pathology; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D003238:Connective Tissue / Q000098:blood supply / Q000473:pathology; D042783:Endothelial Cells / Q000473:pathology; D004730:Endothelium, Vascular / Q000473:pathology; D005347:Fibroblasts / Q000473:pathology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D006965:Hyperplasia; D007797:Laminin / Q000032:analysis*; D009061:Mouth Mucosa / Q000098:blood supply / Q000473:pathology*; D009062:Mouth Neoplasms / Q000098:blood supply / Q000473:pathology*; D009389:Neovascularization, Pathologic / Q000473:pathology*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000032:analysis; D015854:Up-Regulation
D000199:Actins; C501369:LAMA4 protein, human; C400567:LAMC2 protein, human; D007797:Laminin; D019408:Platelet Endothelial Cell Adhesion Molecule-1; C102645:laminin alpha 2; C097043:laminin alpha5; C095567:laminin alpha 3