Cell lines of human oral squamous-cell carcinomas retaining their differentiated phenotype

Two cell lines from head-and-neck squamous-cell carcinomas (SCC) have been established and characterized. Cell line R105 was derived from a xenografted SCC of the floor of the mouth and cell line T87/rc from a SCC of the epiglottis. Identification of individual cytokeratins 4, 5, 7, 8, 10, 13, 14, 18 and 19 led to the conclusion that both cell types had squamous characteristics and that keratinization occurred in xenografts. Ultrastructurally, junctional complexes were observed in both cell lines. Characteristic marker chromosomes were found and although both cell lines were derived from male patients, the Y chromosome was missing from all examined cells. The basic biological parameters of both cell lines were modal chromosome numbers of 59 (R105) and 60 (T87/rc), a doubling time of 60 (R105) and 45 hr (T87/rc) and a DNA index of 1.54 (R105) and 1.31 (T87/rc). The tumorigenicity of the 2 cell lines was proved by the ability to form colonies on a plastic substratum, as well as in a soft agar assay. Furthermore, the cells could produce multi-cellular tumour spheroids, and formed tumour nodules after subcutaneous inoculation into nude mice. The R105 tumour cells appeared to be better differentiated than the T87/rc as observed by histology and immuno(histo)chemistry. Both cell lines appear to retain SCC differentiation after being xenografted into nude mice, cultured for more than 40 passages in vitro and thereafter again xenografted into nude mice.