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 of human hematological malignancies. Previously, in animal models, we demonstrated the applicability of in vivo gene expression investigations to monitor the effects of certain carcinogenic chemicals. In our present study we determined 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 total RNA and slot blot hybridization with chemiluminescently labeled gene probes (Ha-ras, c-myc and p53) Expression levels were compared before and after treatment with a combined cytostatic protocol, containing cyclophosphamide, doxorubicin, vincristine and prednisolone (CHOP). Both the CLL and NHL group of patients exhibited significantly higher expression of the investigated 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 expressions could be used as biomarkers of certain hematological malignancies, and to monitor the therapeutical effect of cytostatic drugs. (C) 1999 Lippincott Williams & Wilkins.