The usefulness of in vivo gene expression investigations from peripheral white blood cells: a preliminary study

Alterations of once/tumour suppressor genes are involved in the formation o f human hematological malignancies. Previously, in animal models, we demons trated the applicability of in vivo gene expression investigations to monit or the effects of certain carcinogenic chemicals. In our present study we d etermined the expression of once/suppressor genes from isolated peripheral white blood cells of patients with chronic myeloid leukaemia (CLL) and non- Hodgkin lymphoma (NHL). Gene expressions were determined by isolation of to tal RNA and slot blot hybridization with chemiluminescently labeled gene pr obes (Ha-ras, c-myc and p53) Expression levels were compared before and aft er treatment with a combined cytostatic protocol, containing cyclophosphami de, doxorubicin, vincristine and prednisolone (CHOP). Both the CLL and NHL group of patients exhibited significantly higher expression of the investig ated genes than healthy controls. One month after the cytostatic treatment, we found considerably fewer individuals with overexpressed oncogenes than before the treatment. Our study proved that once/tumour suppressor gene exp ressions could be used as biomarkers of certain hematological malignancies, and to monitor the therapeutical effect of cytostatic drugs. (C) 1999 Lipp incott Williams & Wilkins.