In vitro down regulation of ICAM-1 and E-cadherin and in vivo reduction oflung metastases of TS/A adenocarcinoma by a lysozyme derivative

The aim of the present investigation was to examine the effects of the lyso zyme derivative mPEG-lyso then egg-white lysozyme coupled with polyoxyethyl englycol), on TS/A adenocarcinoma cell line in vivo and in vitro, mPEG-lyso reduces the number of ICAM-1(+) and E-cadherin(+) cells of TS/A adenocarci noma cell line in vitro, and causes a marked decrease of spontaneous lung m etastases in vivo. In both cases, mPEG-lyso reduces the number of tumour ce lls in sythesis and pre-mitotic phases. In connection with the reduction of cells expressing adhesion molecules, mPEG-lyso reduces the number of infil trating leukocytes in the primary tumour in vivo and reduces the binding ca pacity of splenocytes to tumour cells in vitro. These data stress, for the first time, that the in vivo control of mPEG-lyso on lung metastasis format ion of solid metastasising tumours may be due to a combination of effects o n tumour cells in addition to those on host's immune system.