Establishment and characterization of seven Dunning rat prostatic cancer cell lines and their use in developing methods for predicting metastatic abilities of prostatic cancers.

In vitro cell lines were established from seven biologically distinct in vivo Dunning R3327 rat prostatic tumor sublines. Some of these in vitro cell lines (i.e., G, AT-1, AT-2) retain a low metastatic ability when inoculated back into syngeneic Copenhagen male rats, while others (i.e., AT-3, MAT-LyLu, MAT-Lu) retain a very high metastatic ability. A series of genetic (i.e., DNA content per cell, modal chromosomal number), as well as phenotypic parameters (i.e., morphology, 5 alpha-reductase, androgen receptor, estrogen receptor) were used to validate that the in vitro cell lines retained the major characteristics of the parental in vivo tumor sublines used for their respective establishment. A series of additional characteristics (i.e., morphology, growth rate, saturation density in surface culture, anchorage-dependent and -independent clonogenic potential) were compared between the high vs. the low metastatic in vitro cell lines to determine if a discriminatory parameter could be identified which reproducibly predicted the metastatic abilities of the particular prostatic cancer cell line. While the combination of the in vitro cell lines and their parental in vivo tumor subline will be a valuable tool for developing methods for predicting metastatic ability of prostate cancers, no single parameter yet measured is entirely successful in making this important distinction.