Differential roles of protein kinase C and pertussis toxin-sensitive G-binding proteins in modulation of melanoma cell proliferation and motility by thrombospondin 1.

Thrombospondin 1 (TSP1) is an angiogenesis inhibitor that decreases tumor growth. We now report that TSP1 directly inhibits the proliferation of human melanoma cells. TSP1, peptides, and a recombinant fragment from the type I repeats, but not peptides that bind CD36 or CD47, inhibit the proliferation of A2058 melanoma cells.

Transfection of thrombospondin 1 complementary DNA into a human breast carcinoma cell line reduces primary tumor growth, metastatic potential, and angiogenesis.

Previous studies demonstrated that metastatic MDA-MB-435 breast carcinoma cells synthesized and secreted less of the extracellular matrix protein thrombospondin 1 (TSP1) than nonmetastatic breast carcinoma cell lines, a trend also observed for melanoma and lung carcinoma cell lines. To directly examine the effect of tumor cell TSP1 expression on tumor growth and metastasis. MDA-MB-435 cells were transfected with full length THBS-1 cDNA linked to a constitutive cytomegalovirus promoter, or with the cytomegalovirus vector alone.

Apolipoprotein E (ApoE), a novel heparin-binding protein inhibits the development of Kaposi's sarcoma-like lesions in BALB/c nu/nu mice.

Recombinant apolipoprotein E-3 (ApoE-3), expressed in Escherichia coli, was purified and used in an in vitro and an in vivo model system for acquired immunodeficiency syndrome-associated Kaposi's sarcoma (AIDS-KS). This protein blocked cell proliferation and chemotaxis of AIDS-KS cells in response to activated lymphocyte conditioned medium (AL-CM) and oncostatin M (OSM). ApoE-3 also inhibited the formation of neoangiogenic lesions induced in BALB/c nu/nu mice by AIDS-KS cells.

Expression of the extracellular matrix molecule thrombospondin inversely correlates with malignant progression in melanoma, lung and breast carcinoma cell lines.

Thrombospondin (TSP) is a member of a family of extracellular matrix glycoproteins that may participate in multiple aspects of the metastatic cascade. We report an inverse correlation of steady-state Thbs-1 mRNA and protein expression with malignant progression among murine melanoma and human lung and breast carcinoma cell lines. Murine K-1735 melanoma cell lines of low metastatic potential, including K-1735 lines transfected with the murine nm23-1 cDNA, expressed higher TSP levels than related highly metastatic lines.

Specific simple sugars promote chemotaxis and chemokinesis of corneal endothelial cells.

Bovine corneal endothelial cells showed a strong migratory response to specific simple sugars (D-glucose and sucrose, but not L-glucose, sorbitol, lactose, or D-galactose) at concentrations above 10 mM. Checkerboard analysis of the migratory responses in modified Boyden chambers indicated both chemotactic and chemokinetic effects. Serum starvation of the cultures increased the chemotaxis towards D-glucose and 2-deoxy-D-glucose, but not towards sucrose.