Influence of Proteolytic Treatment on the Lectin-Binding Capacity of Tumor Cells

Author(s): Rimpler, M.

Abstract: The study demonstrates that proteolytic enzymes can alter the glycoprotein composition of the surface at different tumor cell lines. This membrane modulation measured! by lectin binding, is being considered as a prerequisite for the main target, namely the individualized therapeutic use of proteases for adjuvant cancer treatment.The treatment of a human bladder carcinoma cell line and the murine melanoma cell line B16 as well as its variant Fl with bromelain and ficin resulted in a reduced binding of Concanavalin A (ConA). No difference to the controls could be seen when the B16 variant F10 was further examined, whereas a human pancreas carcinoma cell line showed an elevated ConA binding.The experiments with wheat germ agglutinin (WGA) and the lectins from elder bark (SNA) and from Maackia amurensis (MAA) with specifity for N-acetylneuraminic acid also showed a strongly reduced binding after protease treatment. Finally a panel, of different proteases showed similar binding effects with the exception of actinidin that revealed no detectable changes in lectin binding. Plasmin and elastase, assayed in physiological concentrations, also showed no remarkable effect. Not unexpected but still surprising, further purification of pure bromelain resulted in a loss of surface. modulating capacity. Concerning the protease concentrations a dose dependence could not be noted in the range from 0.17-2.04 U per ml.Alltogether the findings support the advanced use of enzymes as an approach for the successful adjuvant cancer treatment. This is due to the fact that the metastatic potential is modulated by enzymes as the recognition signals are being altered enzymatically.

Keyword(s): Proteasen

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