DISTRIBUTION OF BASAL LAMINA TYPE-IV COLLAGEN AND LAMININ IN NORMAL RAT TONGUE MUCOSA AND EXPERIMENTAL ORAL-CARCINOMA - ULTRASTRUCTURAL IMMUNOLOCALIZATION AND IMMUNOGOLD QUANTITATION
Dj. Jiang et al., DISTRIBUTION OF BASAL LAMINA TYPE-IV COLLAGEN AND LAMININ IN NORMAL RAT TONGUE MUCOSA AND EXPERIMENTAL ORAL-CARCINOMA - ULTRASTRUCTURAL IMMUNOLOCALIZATION AND IMMUNOGOLD QUANTITATION, European journal of cancer. Part B, Oral oncology, 30B(4), 1994, pp. 237-243
The relationship of basal lamina, a form of specialised extracellular
matrix which separates epithelial cells and other cell types from adja
cent stroma, to the behaviour of malignant neoplasms of epithelial ori
gin is not well understood. However, it is widely acknowledged that th
e properties of local invasion and metastasis of carcinomas are linked
to extracellular matrix (including basal lamina) changes. In the pres
ent study, the distribution of the major basal lamina components, type
IV collagen and laminin, in normal rat tongue mucosa and experimental
ly induced oral carcinomas was investigated using post-embedding immun
ogold techniques and electron microscopy. The expression of these comp
onents was also quantitatively analysed using morphometry and immunocy
tochemistry. Results indicated that type IV collagen and laminin were
confined to the lamina densa of normal oral epithelial basal lamina, a
nd that both components were also detected in the lamina densa of basa
l lamina associated with carcinomas, and in the extracellular matrix o
f tumours. Furthermore, laminin was detected within stromal fibroblast
s in normal tissues and experimental carcinomas. Quantitative analysis
indicated that expression of laminin was significantly increased in c
arcinomas. In contrast, type IV collagen expression was significantly
decreased. The quantitative changes observed in the two basal lamina c
onstituents may be related to the process of tumour invasion, reflecti
ng altered metabolic activities of tumour and stromal cells. These obs
ervations may be of use in understanding the architectural characteris
tics of oral mucosa basal lamina and in assessing the malignant potent
ial of epithelial dysplasias or ''premalignant'' lesions.