Epidermal growth factor receptor (EGFR) signaling pathways promote human keratinocyte survival and proliferation. In contrast, transforming growth factor-beta (TGF-beta) signaling pathways are strongly anti-proliferative. Receptor type protein tyrosine phosphatase-kappa (RPTP-kappa) specifically dephosphorylates EGFR, thereby blocking EGFR-dependent signaling, and inhibiting proliferation. We r...

Transforming growth factor beta 1 (TGF-beta 1) is a potent inhibitor of cellular proliferation in a variety of cell types, including skin keratinocytes. TGF-beta 1 suppression of c-myc transcription has been implicated in the mechanism of TGF-beta 1 inhibition of keratinocytes, and evidence suggests that the protein product of the retinoblastoma gene (pRB) is a necessary component in this pathw...

The effects of exogenously added transforming growth factor (TGF alpha and TGF beta on the growth of BALB/MK cells were examined. TGF alpha supplanted the epidermal growth factor (EGF) requirement in these cells. In contrast, TGF beta reversibly inhibited the growth of BALB/MK cells by abrogating the stimulatory actions of EGF or TGF alpha. The inhibitory effects of TGF beta appeared to be medi...

PURPOSE Transforming growth factor beta1 (TGF-beta) stimulates the differentiation of myofibroblasts as indicated by the nascent expression of alpha-smooth muscle (alpha-SM) actin protein and its organization into stress fibers. Downstream messengers of TGF-beta in the conversion from the fibroblast to the myofibroblast phenotype were investigated. Whether TGF-beta increases the transcription o...

The aim of this study was to determine the differential effects of latent and activated transforming growth factor (TGF)-beta(1) in growth control of normal and proliferating hepatocytes in vivo. Rats were injected with adenoviruses expressing control transgenes (Ctrl), latent TGF-beta(1) [TGF-beta(L)], or activated TGF-beta(1) [TGF-beta(A)]. Additional animals underwent two-thirds partial hepa...

Transforming growth factor-beta 1 (TGF-beta 1) selectively modulates hematopoietic cell proliferation. The proliferation of FDC-P1 clone MAC-11, a factor-dependent murine myeloid progenitor cell line, was inhibited differentially by TGF-beta 1: strongly in macrophage colony-stimulating factor (M-CSF), mildly in interleukin-3, and not at all in granulocyte-macrophage-CSF (GM-CSF). Flow cytometry...

Transforming growth factor (TGF)-beta may play an important role in airway remodeling, and the fibrogenic effect of TGF-beta may be mediated through connective tissue growth factor (CTGF) release. We investigated the role of MAPKs and phosphatidylinositol 3-kinase (PI3K) and the effects of inflammatory cytokines on TGF-beta-induced CTGF expression in human airway smooth muscle cells (ASMC). We ...

Platelet-derived type beta transforming growth factor (TGF beta) is a potent inhibitor of DNA synthesis in primary monolayer cultures of adult rat hepatocytes. TGF beta induced a 50% inhibition of epidermal growth factor (EGF)-mediated DNA synthesis at approximately 5 X 10(12) M. This inhibition did not appear to be due to a delay in the peak of DNA synthesis or a toxic action, nor could it be ...

Conditioned media collected under serum-free conditions over 24 to 48 h from 18 human colon adenocarcinoma cell lines were analyzed for transforming growth factor, types alpha and beta (TGF-alpha and -beta), and platelet-derived growth factor in assays for anchorage-independent growth and radioreceptor competition. Detectable levels of TGF-alpha, TGF-beta, and platelet-derived growth factor wer...

Transforming growth factor-beta (TGF-beta) is a pleiotropic growth factor with actions that are dependent on circumstances, including dose, target cell type, and context. TGF-beta can elicit both growth-promoting and growth-suppressive activities. In normal tissues, TGF-beta generally acts to restrict growth and maintain differentiation. However, during tumorigenesis, changes in TGF-beta expres...