Sarcolectin and interferon in the regulation of cell growth

Abstract

Sarcolectin is an endolectin present in a great variety of conjunctival tissues (muscles, cartilage, sarcomas), but also in brain or placental extracts of vertebrates, including primates. When purified to electrophoretical homogeneity as a 65-kd protein, it agglutinates cells and has an affinity for simple sugars. In addition, it is able to inhibit the synthesis of interferon (IFN)-dependent secondary proteins and to restore cells to their status ad primum. The biological effect of Poly(I).Poly(C)-induced feedback interferon is inhibited by the addition of sarcolectins, which also abolishes cellular refractoriness to repeated IFN induction. Similarly, sequential association of, first, Poly(I).Poly(C); 4-5 h later, sarcolectin restores the full capacity of both to promote cell growth, unrestrained by IFN. Indeed, the secondary proteins which are in the process of being synthesized are inhibited. In a great variety of animal cells, sarcolectin can also initiate growth after it has been blocked by IFN. This is not an all-or-none effect, but a balance may be struck by IFN and sarcolectin, depending on their respective concentrations and specific activity. We propose that the coordination of these cellular functions of Poly(I).Poly(C), IFN, and sarcolectin takes place in the form of a triangular growth-regulatory cycle and postulate that they thus maintain a balance during differentiated normal tissue development.

Determination of the Levels of Expression of Sarcolectin and Calcyclin and of the Percentages of Apoptotic But Not Proliferating Cells to Enable Distinction Between Recurrent and Nonrecurrent Cholesteatomas

“…In this context, we are interested in the role that sarcolectin might exert in various invasion phenomena 20 . Sarcolectin is a sialic acid‐binding protein that interacts specifically with the lymphokine macrophage migration inhibitory factor 21 and is a natural interferon antagonist 22 . Interferon might play some significant roles in cholesteatoma development, namely, by modulating (along with tumor necrosis factor‐α) the level of expression of tenascin 23 (i.e., an adhesion molecule).…”

The levels of expression of galectin-1, galectin-3, and the Thomsen-Friedenreich antigen and their binding sites decrease as clinical aggressiveness increases in head and neck cancers

“…Having indicated by this study the usefulness of monitoring endogenous lectin expression, other lectin-related characteristics should be taken into consideration to contribute independent prognostic values to the TNM classification system. One example may be sarcolectin, which is a sialic acid-binding and lymphokine-binding protein 35 that acts as a human interferon ␣/␤ antagonist and a growth regulator, 36 for which we recently demonstrated a prognostic value in oral cavity and lung tumors. 32,37 In conclusion, the characterization of the expression of galectin-3 and the T antigen along with their respective binding sites and, to a lesser extent, of galectin-1 and galectin-1-binding sites appears to contribute additional prognostic value to conventional clinical staging of patients with HNSCC.…”

Migration Inhibitory Factor-Binding Sarcolectin from Human Placenta is Indistinguishable from a Subfraction of Human Serum Albumin

“…Sarcolectin that is localized on the surface of fibroblasts and sarcoma cells is suggested to be involved in homeostatic control mechanisms during differentiated tissue development (Chany, 1987;Chany-Fournier et a/., 1990;Jiang et a/., 1987Jiang et a/., ,1988. Its binding to cell surfaces and to its major target protein of human placenta, namely MIF, shows only a limited extent of sugar selectivity, as seen with a panel of negatively charged carbohydrates.…”