This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Palumbo, A. P. Articles by Calabretta, B. Search for Related Content PubMed PubMed Citation Articles by Palumbo, A. P. Articles by Calabretta, B.

Altered Expression of Growth-regulated Protooncogenes in Human Malignant Plasma Cells¹

Department of Medicine and Experimental Oncology, Division of Hematology, School of Medicine, University of Torino, Torino 10126, Italy [A. P. P., A. P., U. D., M. M., M. B.], and Department of Pathology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140 [B. C.]

The expression of three growth-regulated protooncogenes, c-myc, c-myb, and p53, and the S-phase-specific histone H3 gene, was compared in bone marrow cells from multiple myeloma patients and normal controls by measuring the amount of specific RNA by Northern blot analysis. Four samples contained at least 72% of myeloma cells, one sample 43%, and one 11%. Expression of the protooncogenes was similar in normal and myeloma bone marrow cells, whereas that of histone H3 gene was significantly reduced (between 10 and 15 times) in samples containing at least 43% of malignant plasma cells and not detectable in those containing more than 72% of neoplastic cells.

Protooncogene levels of expression were compared to those of the H3 gene to distinguish the increased expression of a growth-regulated gene due to a true deregulation from overexpression reflecting solely an increase in the fraction of cycling cells. The ratios of expression of protooncogenes to histone H3 were markedly increased in multiple myeloma cells; the highest ratios were found in the patients with the highest number of malignant plasma cells. These results suggest that the expression of three growth-regulated oncogenes (c-myc, c-myb, p53) is altered in myelomatous plasma cells.

¹ This work was supported by a grant from the Italian National Research Council, Special Project "Oncology," N. 87.01192.44, Associazione Italiana Ricerca Cancro, Angela Bossolasco Foundation (A. P. P.), and National Cancer Institute Grant CA 46782 (B. C.).

² Scholar of the Leukemia Society of America. To whom requests for reprints should be addressed.

Received 7/ 8/88. Revised 4/10/89. Accepted 5/30/89.