Heterogeneous nuclear rna from lymphocytes of chronic lymphocytic leukaemia: adenylate-rich and double-stranded regions.

Rapidly labelled high molecular weight nuclear RNA from lymphocytes of chronic lymphocytic leukaemia was analysed for ribonuclease-stable adenylate-rich and double-stranded regions. The polyadenylate content corresponds to 0.4-0.5 percent and the content of double-stranded sequences to 2-4 percent of the total nucleotides. Partial association of polyadenylate segments with double-stranded regions was found by comparative analysis of (3H)-adenosine and (3H)-uridine labelled ribonuclease-stable RNA before and after thermal denaturation. Comparison with normal lymphocytes shows lower proportions of polyadenylate-containing RNA binding to poly(U)-Sepharose in leukaemia cells than in normals. Partial degradation of rapidly labelled high molecular weight RNA was found in leukaemia cases with low white cell counts.