TY - JOUR
T1 - c‐Ha‐rasEJ transfection of rat aortic smooth muscle cells induces epidermal growth factor responsiveness and characteristics of a malignant phenotype
AU - Sadhu, D. N.
AU - Lundberg, M. S.
AU - Burghardt, R. C.
AU - Ramos, K. S.
N1 - Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 1994/12
Y1 - 1994/12
N2 - Although the role of several protooncogenes, including sis, myc, and myb in the regulation of growth and differentiation of vascular cells has been examined in some detail, limited information is available on the contribution of ras genes to these processes. In the present studies the influence of oncogenic ras transfection on the phenotypic expression of rat aortic smooth muscle cells (SMCs) was examined. Cultured rat aortic SMCs during early passage (P4) were transfected by lipofection with c‐Ha‐rasEJ in a pSV2 neo vector or with pSV2 neo vector alone. Stable transfectants were selected in G418 over a 6‐week period. Oncogene‐transfected cells (ras‐LF‐1) exhibited differences in morphology and growth pattern relative to vector controls (neo‐LF‐1), or naive SMCs, including the development of prominent processes and the appearance of focal cellular arrangements giving rise to latticelike structures. Southern analysis revealed multiple integration of oncogenic ras in ras LF‐1 cells. Transfection of c‐Ha‐rasEJ was associated with a twofold increase in p21 levels relative to pSV2 vector controls demonstrating that exogenous ras was expressed in these cells. Overexpression of ras p21 afforded SMCs a lower serum requirement for growth compared to vector controls, anchor‐age independent growth on soft agar, and acquisition of epidermal growth factor (EGF) responsiveness. Stimulation of serum‐deprived SMCs with 5% fetal bovine serum (FBS) increased steady‐state levels of c‐Ha‐ras mRNA in both ras‐LF‐1 and neo‐LF‐1 but ras induction was more pronounced in ras‐transfected cells. α‐smooth muscle (SM) actin gene expression was markedly reduced in ras‐transfected cells relative to vector controls. These results show that transfection of c‐Ha‐rasEJ into aortic SMCs induces an altered phenotypic state characterized by alterations in growth factor‐related signal transduction and tumorigenic potential. © 1994 Wiley‐Liss, Inc.
AB - Although the role of several protooncogenes, including sis, myc, and myb in the regulation of growth and differentiation of vascular cells has been examined in some detail, limited information is available on the contribution of ras genes to these processes. In the present studies the influence of oncogenic ras transfection on the phenotypic expression of rat aortic smooth muscle cells (SMCs) was examined. Cultured rat aortic SMCs during early passage (P4) were transfected by lipofection with c‐Ha‐rasEJ in a pSV2 neo vector or with pSV2 neo vector alone. Stable transfectants were selected in G418 over a 6‐week period. Oncogene‐transfected cells (ras‐LF‐1) exhibited differences in morphology and growth pattern relative to vector controls (neo‐LF‐1), or naive SMCs, including the development of prominent processes and the appearance of focal cellular arrangements giving rise to latticelike structures. Southern analysis revealed multiple integration of oncogenic ras in ras LF‐1 cells. Transfection of c‐Ha‐rasEJ was associated with a twofold increase in p21 levels relative to pSV2 vector controls demonstrating that exogenous ras was expressed in these cells. Overexpression of ras p21 afforded SMCs a lower serum requirement for growth compared to vector controls, anchor‐age independent growth on soft agar, and acquisition of epidermal growth factor (EGF) responsiveness. Stimulation of serum‐deprived SMCs with 5% fetal bovine serum (FBS) increased steady‐state levels of c‐Ha‐ras mRNA in both ras‐LF‐1 and neo‐LF‐1 but ras induction was more pronounced in ras‐transfected cells. α‐smooth muscle (SM) actin gene expression was markedly reduced in ras‐transfected cells relative to vector controls. These results show that transfection of c‐Ha‐rasEJ into aortic SMCs induces an altered phenotypic state characterized by alterations in growth factor‐related signal transduction and tumorigenic potential. © 1994 Wiley‐Liss, Inc.
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U2 - 10.1002/jcp.1041610312
DO - 10.1002/jcp.1041610312
M3 - Article
C2 - 7962130
AN - SCOPUS:0028170709
SN - 0021-9541
VL - 161
SP - 490
EP - 500
JO - Journal of Cellular Physiology
JF - Journal of Cellular Physiology
IS - 3
ER -