NODULAR BASAL-CELL CARCINOMA IN-VIVO VS IN-VITRO - ESTABLISHMENT OF PURE CELL-CULTURES, CYTOMORPHOLOGIC CHARACTERISTICS, ULTRASTRUCTURE, IMMUNOPHENOTYPE, BIOSYNTHETIC ACTIVITIES, AND GENERATION OF ANTISERA

Background and Design: In this study we developed an in vitro model of nodular basal cell carcinoma (BCC). We obtained pure cultures of BCC cells and compared the morphologic characteristics, ultrastructure, im munophenotype, and behavior of cultured tumor cells with those of thei r in vitro counterparts. Tumors were excised from patients undergoing Mohs micrographic surgery. We established 69 primary cell cultures fro m 32 patients with nodular BCC. Results: Three cell types grew in prim ary cultures: fibroblasts, normal-appearing keratinocytes, and cells w ith dual (spindle and epithelioid) morphologic characteristics. Contam inating fibroblasts were removed using 0.125% trypsin-0.02% edetic aci d, and normal-appearing keratinocytes were cornified and eliminated by temporarily increasing the concentration of calcium in the growth med ium. The cells with dual morphologic characteristics remained intact a nd exhibited relentless growth in pure cultures. That these seemingly immortal cell strains represent true nodular BCC was demonstrated. by (1) their biphasic morphologic characteristics and very slow cell grow th rate, (2) their capability for anchorage-independent growth in soft agar, (3) their ultrastructural similarities to freshly excised nodul ar BCC, (4) their ability to generate antibodies selectively labeling nodular BCC tumor nests in vivo, and (5) their immunophenotypic simila rities to BCC in vivo on more than 20 different cell markers. Conclusi ons: This study provides a simple technique for establishing pure cell cultures of nodular BCC and describes extensively the in vitro parame ters of tumor cell growth. The striking differences in behavior of cul tured tumor cells in the presence or absence of normal-appearing kerat inocytes suggest that normal human epidermal keratinocytes can suppres s the growth of BCC cells.