Isolation and characterization of a highly malignant variant of the SW480 human colon cancer cell line.
We found that the human colon cancer cell line SW480 consists of two distinct subpopulations which we have designated E-type (epithelial) and R-type (round). Pure cultures of each type were obtained by subcloning, and both have maintained their characteristic phenotypes for at least 1 year (40 passages). E-type cells are the major (> 98%) type in the parental SW480 cell line. They form flat epithelial-like colonies. In contrast, R-type cells, which constitute a minor fraction (< 2%) of the parental cell line, have a rounded shape and grow in clusters of piled-up cells. Compared to E-type cells or the parental SW480 cells, isolated R-type cells display decreased doubling time, loss of contact inhibition, less adhesiveness to culture plates, higher anchorage-independent growth in soft agar, and a much more aneuploid karyotype. When injected s.c. into nude mice, R-type cells produce much larger tumors within the same period of time than E-type cells, and the tumors are less differentiated than those produced by the E-type cells. Cell fusion experiments between R-type and E-type cells revealed that the R-type phenotype is dominant, and the results suggest that this is due to one or a few genetic changes. Taken together, these findings suggest that the R-type cells represent a more malignant variant of the E-type cells. They may be useful, therefore, for studying mechanisms involved in tumor progression.
Tomita
N
N
Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, New York, New York 10032.
Jiang
W
W
Hibshoosh
H
H
Warburton
D
D
Kahn
S M
SM
Weinstein
I B
IB
D000818:Animals; D002455:Cell Division; D002459:Cell Fusion; D002869:Chromosome Aberrations; D002999:Clone Cells; D003110:Colonic Neoplasms / Q000235:genetics / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D014407:Tumor Cells, Cultured