Suppression of src-induced transformed phenotype by expression of tropomyosin-1.
Suppression of high M(r) tropomyosins (TMs) is a common feature of transformed cells. Previous work from this laboratory has demonstrated that the isoform 1 of TM, TM1, acts as an anti-oncogene in ras-transformed murine fibroblasts. In this study, we have investigated whether TM1 is a ras-specific suppressor, or a general suppressor protein of the cellular transformation. V-src transformed fibroblasts, which express decreased TM1, were transduced with a full-length cDNA to overexpress TM1. Both the control and the transduced cells expressed v-src kinase at comparable levels. TM1 expressing (src-T1) cells grew at a lower rate in monolayer, exhibited well spread, flat morphology than the control cells. Enhanced expression of TM1 resulted in improved microfilamental architecture. More significantly, src-T1 cells completely failed to grow under anchorage independent conditions. These data demonstrate that TM1 is as an anti-oncogene of functionally diverse oncogenes, and it is a class II tumor suppressor protein.
Prasad
G L
GL
Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.
Masuelli
L
L
Raj
M H
MH
Harindranath
N
N
D016475:3T3 Cells; D000818:Animals; D002455:Cell Division; D002471:Cell Transformation, Neoplastic; D029721:Drosophila Proteins; D051379:Mice; D015688:Oncogene Protein pp60(v-src) / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D014335:Tropomyosin / Q000096:biosynthesis* / Q000235:genetics
D029721:Drosophila Proteins; C097163:Tm2 protein, Drosophila; C490774:Tpm1 protein, mouse; D014335:Tropomyosin; D015688:Oncogene Protein pp60(v-src)