We have studied somatic cell hybrids between either mouse peritoneal macrophages or spleen cells and HT-1080-6TG human fibrosarcoma cells for the expression of mouse lactic dehydrogenase A (LDH-A).
These results indicate that a major fraction of latent TGF-beta 1 that is produced by the cells is deposited to and remains associated with the pericellular matrices of cultured fibroblasts and fibrosarcoma cells, and that matrix-associated TGF-beta 1 is very susceptible to release by various proteolytic enzymes.
An immunocytochemical method was used to test the reactivity of the anti-P-glycoprotein antibodies, C219, MRK 16, JSB-1 and 265/F4 against multidrug resistant (MDR) variants derived from the human small cell lung carcinoma line, NCI-H69, the mouse fibrosarcoma line, RIF-1 and the mouse mammary tumour cell line, EMT6.
An immunocytochemical method was used to test the reactivity of the anti-P-glycoprotein antibodies, C219, MRK 16, JSB-1 and 265/F4 against multidrug resistant (MDR) variants derived from the human small cell lung carcinoma line, NCI-H69, the mouse fibrosarcoma line, RIF-1 and the mouse mammary tumour cell line, EMT6.
To determine whether the PKC and PKA pathways functionally interact during modulation of PAI gene expression, we assessed changes in gene transcription rates, mRNA, and antigen levels of PAI-1 and PAI-2 in HT-1080 fibrosarcoma cells treated with the PKC activator phorbol 12-myristate 13-acetate (PMA), alone or in combination with cAMP agonists and analogs.
Using two-domain-specific anti-tenascin monoclonal antibodies, we have studied the expression and distribution of tenascin in four cultured normal human fibroblasts, two simian-virus-40-(SV40)-transformed and three tumor-derived (melanoma, rhabdomyosarcoma and fibrosarcoma) cell lines.
Matrix metalloproteinase 9 (92-kDa gelatinase/type IV collagenase) from HT 1080 human fibrosarcoma cells. Purification and activation of the precursor and enzymic properties.
Matrix metalloproteinase 9 (92-kDa gelatinase/type IV collagenase) from HT 1080 human fibrosarcoma cells. Purification and activation of the precursor and enzymic properties.
In contrast, a mutein of TNF-alpha, designated as F4236, having the cell-adhesive sequence (Tyr-Ile-Gly-Ser-Arg) at the N-terminus of the TNF molecule did not enhance metastasis, but rather exhibited similar antitumor activity to wild-type TNF-alpha in fibrosarcoma-bearing mice.
The motility stimulation of the fibrosarcoma cells with AMF is associated with the phosphorylation of the AMF receptor, a 78-kDa cell surface glycoprotein (gp78), suggesting protein kinase participation in migratory signal transduction.
The motility stimulation of the fibrosarcoma cells with AMF is associated with the phosphorylation of the AMF receptor, a 78-kDa cell surface glycoprotein (gp78), suggesting protein kinase participation in migratory signal transduction.
Gene transcription rates and mRNA levels of plasminogen activator inhibitor type 2 (PAI-2) are markedly induced by the tumor promoting agent phorbol 12-myristate 13-acetate (PMA) in human HT1080 fibrosarcoma cells.
Gene transcription rates and mRNA levels of plasminogen activator inhibitor type 2 (PAI-2) are markedly induced by the tumor promoting agent phorbol 12-myristate 13-acetate (PMA) in human HT1080 fibrosarcoma cells.
A moderate heat stress, sufficient to induce heat shock protein 70 mRNA approximately 100-fold, resulted in a two- to three-fold increase in functionally active PAI-1 in the conditioned medium of human HT-1080 fibrosarcoma and Hep G2 hepatoma cells.
Gelatinase assay of enzyme secreted by cultured human fibrosarcoma cells (HT-1080) revealed only low levels of 92-kDa type IV collagenase activity, whereas considerable activity of the 72-kDa enzyme was present.
We have found that HT1080 x human fibroblast hybrids have reduced ability to invade a reconstituted basement membrane (Matrigel) in vitro compared to HT1080 cells, and abundantly secrete only the 68-72 kDa gelatinase/type IV collagenase.