Type IV collagen, type IV collagenase activity and ability of cell proliferation in human thyroid tumours.
BACKGROUND
The processes of malignant tumour invasion and metastasis are known to include the destruction of cell stroma and vascular basement membrane. It has been suggested that type IV collagenase degrades type IV collagen, a main component of the basement membrane.


METHODS
In our study, type IV collagenase activity in human thyroid tumours was measured by the Liotta method. The degree of destruction of diseased regions of thyroid tumours was immunohistochemically determined by anti-type IV collagen antibody staining. Cell proliferation in the tumours was estimated using anti-proliferating cell nuclear antigen (PCNA) and epidermal growth factor receptor (EGFR).


RESULTS
T4 thyroid carcinomas with higher type IV collagenase activity and very weak type IV discontinuous immunostaining for type IV collagen of follicular basement membranes, exhibited many PCNA or EGFR positive cells. In benign tumours, normofollicular- or macrofollicular-type tumours with low type IV collagenase activity showed few PCNA and EGFR positive cells and intact type IV collagen of basement membranes, as seen in normal thyroids. Conversely, an atypical adenoma with higher type IV collagenase activity showed many PCNA and EGFR positive cells and weak type IV discontinuous immunostaining for type IV collagen, as in thyroid carcinomas.


CONCLUSIONS
These findings suggest that staining for type IV collagen and type IV collagenase activity reflect the ability of cell proliferation, and help predict the aggressiveness of invasion and metastasis in human thyroid tumours.
Kusunoki
Takeshi
T
Department of Otolaryngology, Kinki University School of Medicine, Osaka, Japan.
Nishida
Shozo
S
Kimoto-Kinoshita
Saori
S
Murata
Kiyotaka
K
Satou
Takao
T
Tomura
Takanori
T
D002455:Cell Division; D024141:Collagen Type IV / Q000378:metabolism*; D017364:Collagenases / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism; D006801:Humans; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D013961:Thyroid Gland / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology
D024141:Collagen Type IV; D018809:Proliferating Cell Nuclear Antigen; D066246:ErbB Receptors; D017364:Collagenases