Oral cancer: Role of the basement membrane in invasion

Abstract

Invasive growth of cancer cells is a complex process involving specific interactions between tumour cells and the orderly, integrated complexes of the extracellular matrix. Basement membranes have been proposed as one constituent of extracellular matrix which carries responsibility for regulating invasion and metastasis. Using a chemically induced rat tongue carcinoma model, it has been shown that components of the basement membrane and its overall structure are altered during tumour invasion, and methods have been developed to quantitate some of these differences. Since the basement membrane can be specifically characterized by its fibrous protein network of Type IV collagen and laminin, which is embedded in a heparan sulphate-rich proteoglycan matrix, these components have been targeted. In particular, the current paper presents results in the context of current concepts of early changes in neoplastic invasion of underlying connective tissues. In consequence, further elaboration of the underlying mechanisms of epithelial migration in oral cancer may allow an exploration of the use of alterations in expression of basement membrane components as prognostic indicators.

Progressive Extracellular Matrix Disorganization in Chemically Induced Murine Oral Squamous Cell Carcinoma

“…Interaction between tumor cells and extracellular matrix (ECM) components is essential for tumor growth [7,8] and for the onset of cell spreading and subsequent metastatic activity [9].…”

Expressão da laminina na membrana basal em carcinoma escamocelular oral

“…This finding suggests that adjacent cells to the basal membrane and tumor cells were still able to secrete laminin, confirming similar description in the literature. 7,8,12,25 Maatta et al (2001) 1 published the results of specific marking of various laminin isoforms, and found that human carcinomas are generally capable of synthesizing sizeable amounts of different laminin chains. It was also noted that carcinomas contained nearly all of the existing laminin chains in their basal membranes, suggesting the macromolecule deposition on the basal membrane is not totally lost during tumor invasion.…”

“…After establishing this bond, the tumor begins to secrete enzymes 9,10 that cause membrane rupture by destroying type IV collagen and laminin; tumor cells are then able to penetrate the connective tissue and start the invasion process. 11,12 These changes in basal membrane distribution have been demonstrated by immunohistochemical techniques using anti-collagen IV and anti-laminin antibodies, 3 the latter of which was used in this study.…”

A Study Of Morphometrical Differences Between Normal Mucosa, Dysplasia , Squamous Cell Carcinoma & Pseudoepitheliomatous Hyperplasia Of The Oral Mucosa

“…Loss of basement membrane has been associated with many types of carcinomas, and with tumour cells in lymph node and organ metastases. While invasive tumours may retain their ability to synthesize basement membrane constituents, assembly is often defective, and other loss may be due to decreased synthesis or increased turnover of basement membrane components stimulated by tumour cell-derived proteases 7 . Cases with insitu carcinoma shows, microinvasion, thinning, fragmentation, and disruption of the basement membrane in the foci of microinvasion but not elsewhere.…”