Comparison of polypeptide profiles in normal and transformed kidney cell lines derived from control, dimethylnitrosamine-treated, and renal tumor-bearing rats, with particular reference to contractile proteins
Hard, G.C.; Clarke, F.M.; Toh, B.H.
Cancer Research 40(10): 3728-3734
1980
ISSN/ISBN: 0008-5472 PMID: 6893677 Document Number: 155171
The polypeptide profiles of 3 malignantly transformed kidney cell lines of mesenchymal type, established in culture from rats treated 2 h, 24 h and 4 days previously with a single carcinogenic dose of dimethylnitrosamine were compared with the profiles of 3 cell lines derived from advanced renal mesenchymal tumors which were induced by the same carcinogenic regimen and with cultures of normal mesenchymal cells isolated from the kidneys of untreated rats. Polyacrylamide gel electrophoresis and quantitative gel densitometry demonstrated that the polypeptide profiles of the transformed kidney cells closely resembled those of the tumor cells. This strongly suggests that the mesenchymal cells, which are derived from rat kidneys very shortly after the carcinogenic insult and which express transformation in vitro, represent the same target cell populations as those transforming in vivo to produce macroscopic renal mesenchymal tumors some 6 mo. later. Individual samples of fibroblast-like mesenchymal cells grown from the kidneys of normal rats were characterized by polypeptide profiles of a consistent pattern, regardless of whether they were assayed at subcultures 1, 2 or 3. However, there were distinct points of difference between these and the common profiles of th tumor and transformed cell lines. The most prominent differences involved those bands corresponding to fibronectin, myosin (H chain), actin and calmodulin. Actin and myosin contents of tumor and transformed cells were significantly decreased when compared with normal rat kidney cells, although the actin/myosin ratios did not vary. Fibronectin was decreased in the neoplastic state, whereas calmodulin showed a pronounced increase in comparison with the normal rat kidney cell counterparts.