Patricia Gregory

Cell surface involvement in cancer metastasis: an NMR study

NMR spectroscopy is one of the few techniques which has the sensitivity to detect subtle changes to the surface chemistry of cells. It has previously been demonstrated that high resolution 1H NMR methods can distinguish tumour cells with the capacity to metastasise and this information appears to arise from a type of proteolipid in or attached to the plasma membrane. Here we report that the 1H NMR signal, which we have used to identify metastatic cells in rat tumours, is significantly reduced in intensity after cultured cells are treated with trypsin/EDTA. The long T 2 relaxation value (⪢ 350 ms) observed in metastatic cells is absent after enzyme treatment. 2D scalar correlated NMR (COSY) spectra of these treated cells show that a cross peak normally associated with malignancy and metastatic disease is markedly reduced. These findings indicate that the plasma membrane lipid particle which generates the high resolution spectrum is directly affected by trypsin/EDTA. Alterations to the cell surface properties were also demonstrated in vivo since reduced numbers of metastases were observed in animals injected with enzyme‐treated cells. The correlation between the absence of a long T 2 relaxation value and the diminished numbers of metastases in animals suggests that the plasma membrane particle is involved in the metastatic process.

Xenografted Small Cell Undifferentiated Cancer of Prostate: Possible Common Origin With Prostatic Adenocarcinoma

The first xenograft line of small cell undifferentiated carcinoma of the prostate (UCRU-PR-2) has been established and characterized. The donor tumor and the xenograft share the common morphological and ultrastructural features of small cell undifferentiated carcinoma (including neurosecretory granules) but also elaborate epithelial membrane antigen and carcinoembryonic antigen, in addition to neurone-specific enolase. The line expresses a diploid DNA complement. Androgen and estrogen receptors are not expressed, although prostatic acid phosphatase is present in sera from tumor-bearing mice in low levels. From these studies, we postulate a possible common stem cell origin for adenocarcinoma and small cell undifferentiated carcinoma of the prostate; further studies of a cell line derived from this tumor may clarify the issue.