EFFECT OF HISTAMINE AND THE H-2 ANTAGONIST CIMETIDINE ON THE GROWTH AND MIGRATION OF HUMAN NEOPLASTIC GLIA

Histamine is known to act, at least in part, as a growth factor, as pr oduction of this neurotransmitter has been found to accelerate the rat e of tissue proliferation in wound repair, embryogenesis and malignant growth. Histamine favours in vivo tumour cell proliferation via H-2 r eceptors. Cimetidine is an H-2 blocker and has been shown to inhibit t umour cell growth. In the present study, the growth modulating effects of histamine and cimetidine were assessed on five cell lines derived from human brain tumours of different histological types and grades of malignancy. Each cell line was treated with either cimetidine or hist amine for 24 h before kinetic analyses, with PCNA, or motility assays, using Transwell migration chambers incorporating a microporous membra ne, were carried out. Cimetidine significantly inhibited cell prolifer ation in three out of the five cell lines, which may indicate the depe ndence of proliferation of these cell lines on stimulation of the H-2 receptor. With regard to migration, it was observed that in the majori ty of cell lines, cimetidine induced migration whilst histamine inhibi ted it. It was concluded that the link between effects of histamine on proliferation and its effects on migration must be clarified using a larger sample of cell lines.