Transfer of Sensitivity to Tumor Promoters by Transfection of DNA from Sensitive into Insensitive Mouse JB6 Epidermal Cells

• Published in: Molecular and cellular biology Vol. 3; no. 7; pp. 1182 - 1186
• Main Authors: Colburn, Nancy H., Talmadge, Catherine B., Gindhart, Thomas D.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 01.07.1983
• DOI: 10.1128/mcb.3.7.1182-1186.1983
• ISSN: 1098-5549

Sensitivity to promotion of transformation by tumor promoters in mouse epidermal JB6 cells appears to have a genetic basis since the phenotypes of both promotable and nonpromotable JB6 cells derived from a common parent line are stable. Hybridization of promotable (P + ) and nonpromotable (P − ) cells previously indicated that promotability appears to behave as a dominant trait. These results suggest that it should be possible to find DNA sequences which specify sensitivity to promotion of anchorage independence by 12-o-tetradecanoyl-phorbol-13-acetate (TPA). Cellular DNA isolated from one of two P + lines, JB6 Cl 41 or JB6 Cl 22, was CaPO 4 precipitated and used to transfect the P − cell line JB6 Cl 30. At 7 days posttransfection, the cells were suspended in agar with or without TPA at 1.6 × 10 −8 M and assayed 10 days later for TPA-dependent colony formation. Untreated or Cl 30 DNA-treated P − JB6 Cl 30 cells yielded 40 to 50 colonies per 10 5 cells. In contrast, transfection of Cl 30 cells with "P + DNA" derived from either Cl 41 or Cl 22 yielded 200 to 500 TPA-induced colonies per 10 5 cells, or a five- to eightfold enhancement of promotability. The enhanced promotability obtained after transfection with P + DNA was stable, as judged by the retention of promotability for at least eight passages in cell lines derived from TPA-induced agar colonies. Other transfectants showed irreversible transformation by TPA, as observed in the parental P + lines. When NIH 3T3 cells instead of the putative preneoplastic JB6 Cl 30 cells were used as recipients for transfection of P + DNA, no evidence for acquisition of promotability was obtained. P − JB6 Cl 25, like Cl 30, also permitted expression of transfected P + DNA. These results suggest that sensitivity to phorbol ester promotion of transformation in JB6 cells is determined by DNA sequence(s) present in the P + DNA and requires recipient cells of the appropriate phenotype for expression.