Changes in expression of surface and core antigens of hepatitis B virus in different mutant clones of hepatoma PLC-PRF-5 cells.

Mutant clones of human hepatocarcinoma PLC-PRF-5 cells carrying a hepatitis B virus (HBV) genome have been obtained using selection for resistance to the toxic action of a variety of preparations to induce cell differentiation. The clones differed in various features such as expression of alpha-fetoprotein (AFP) and albumin as well as in growth rates, ability to grow in semisolid media and to be cloned in agar. Expression of the surface antigen (HBsAg) was significantly increased in mutant cells exhibiting differentiation features in contrast to the parental cells.

Cytogenetic analysis of human hepatocarcinoma cell line PLC-PRF-5 and its mutant clones with different degrees of cell differentiation.

A detailed analysis was made of the karyotype of human hepatocarcinoma cell line PLC-PRF-5 containing an integrated hepatitis B viral genome and 10 mutant clones derived from the line. These clones are drug resistant and display features of cell differentiation. Cytogenetic manifestations of gene amplification common to many cells resistant to drugs were not observed in these clones, but certain tendencies of karyotype evolution involving material from chromosomes 7 and 11, as well as chromosomes 5 and 15, were recorded for a group of cytostatic-resistant clones.

The activity of nucleolar organizer regions of human bone marrow cells studied with silver staining. II. Acute leukemia.

The activity of nucleolar organizer regions (NOR) in chromosomes and interphase nuclei of bone marrow cells from 11 adult patients with acute lymphoblastic leukemia (ALL), 35 patients with acute nonlymphoblastic leukemia (ANLL), and eight healthy donors has been studied with silver nitrate staining. PHA-stimulated lymphocytes of the same individuals were used as standards of the maximum silver-staining patterns for each person. In 90% of patients with acute leukemia the average number of Ag+NOR in metaphases was lower when compared with that of PHA-stimulated lymphocytes.