lmmunohistochemical characterization of transplantable rat squamous cell carcinoma (FF-6) in skin and thymus

Abstract

FF-6 is a transplantable squamous cell carcinoma which originally arose in the facial skin of a DA rat. It was established after maintaining the tumor in the subcutaneous tissue or peritoneal cavity of DA rats conventionally for over 30 generations. When the soybean-sized original FF-6 tumor was transplanted subcutaneously, it became an oval, hard, whitish, solitary and thumb-head-sized nodule within one month. After intraperitoneal transplantation of FF-6, it formed many nodules ranging from miliary to thumb-head size, which adhered andlor metastasized to many abdominal organs. When FF-6, cut into small pieces, was injected into the lower lip, the tumor grew bigger in situ, and metastasized to regional lymph nodes. Histologically, FF-6 was characterized as a well-differentiated squamous cell carcinoma, showing positive staining with anti-keratin, anti-laminin, anti-collagen type IV, antifibronectin and UB- 14 antibodies. This transplantable tumor may be useful for analyzing the mechanisms of proliferation and metastasis of squamous cell carcinoma in vivo, and the host defence mechanism in rats, as well as being a suitable model of human squamous cell carcinoma.