The clinical and cytogenetic significance of C-banding on chromosome #9 in patients with Ph1-positive chronic myeloid leukemia

Cytogenetic findings in 111 ovarian cancer patients: therapy-related chromosome aberrations and heterochromatic variants

The chromosomes of 111 ovarian cancer patients were studied in G- and C-banded slides from peripheral blood lymphocyte (PBL) cultures for chromosome damage caused by chemotherapy and radiotherapy and for asymmetry of the constitutive heterochromatin of chromosomes 1, 9, and 16. We also monitored the survival of these patients to determine whether any secondary neoplasia induced by the therapy and report the findings of our investigations. Melphalan (MEL) was the only drug used in single-drug chemotherapy. The incidence of chromosome abnormalities in melphalan-treated cells (25%) was higher than in the control group (17%). The incidence of structural changes was also higher (10.5%) in the MEL-treated group than in controls (6%). After treatments with combinations of drugs, the incidence of structural changes remained at the same level (11%). In the patients receiving combined treatment with MEL and radiation, the rate of structural changes increased dramatically (24%). The overall rate of chromosome aberrations in this group was also higher (50%). Combination of two or more drugs and radiation produced only 14% structural chromosome changes. The overall rate of chromosome aberrations was also low (20%) in this group. Of 111 patients studied, only 33 were alive 6 years after initiation of the study. Of the surviving patients, eight had rearranged chromosomes in the first analysis. After 5 years, new blood samples were collected from these patients and chromosome analyses showed abnormal karyotypes in all eight patients. All chromosome abnormalities in the second analysis were completely unrelated to those in the first analysis, however. Whether the chromosome changes in the second analysis were due to therapy or to other unknown factors could not be determined. Data on C-banding and the distribution of inversions indicated that 91% of the patients had C-band heteromorphisms of chromosomes 1, 91% had heteromorphisms of chromosome 9, and 69% had heteromorphisms of chromosome 16. Furthermore, inversions were observed in chromosome 1 (41% of patients), chromosome 9 (28% of patients), and chromosome 16 (5% of patients).

Constitutive heterochromatin polymorphisms in children with acute lymphoblastic leukemia

The C-band heterochromatin polymorphisms of chromosomes 1, 9, and 16 were studied on peripheral lymphocytes of 67 children with acute lymphoblastic leukemia (ALL) and 50 control individuals. A statistically significant difference between patients and controls was found for large heterochromatin regions (level 3) of chromosomes 1 and 9 (P < 0.001) and for small heterochromatin regions (level 1) of chromosome 16 (P < 0.001). The patients also showed a significant increase in chromosomes 1 and 9 heteromorphism with respect to controls (P < 0.001).

Heterochromatic variants and their association with neoplasias: V. Non-Hodgkin's lymphomas

A study of heterochromatic regions in chromosomes #1, #9, and #16 was performed on lymphocytes of peripheral blood from 55 normal individuals and 50 patients with non-Hodgkin's lymphoma (NHL). Heteromorphism was present in 90% of the NHL patients, compared with 44% in normal individuals (p less than 0.001). An increase of inv(1), 1qh-, and 9qh-variants was observed in malignant lymphoma patients with respect to controls.

Heteromorphism of C-band positive chromosomal regions in CML patients

The heteromorphism of constitutive heterochromatin in chromosomes #1, #9, and #16 was investigated in 44 chronic myelocytic leukemia patients and 44 controls using bone marrow and peripheral blood lymphocyte cultures. A significant increase in the length of C-band region in all the three chromosome pairs as well as a statistically significant difference in the homologs of chromosome #1 was observed in chronic myelocytic leukemia patients when compared with the controls. The frequency of inversions was also greater in the patients than in the controls. A random translocation of 22q was found on either homolog of chromosome #9.

C-band heteromorphism in breast cancer patients

The pattern of heteromorphism in the C-band-positive constitutive heterochromatin of human chromosomes #1, #9, and #16 was studied in peripheral lymphocytes of 54 breast cancer patients and 78 control individuals. The parameters of the heterochromatic regions analyzed were relative size, symmetry-asymmetry within homologous pairs, and prevalence of inversions. Significant differences between the two groups were found in C-band size of chromosomes #1, #9, and #16 and in incidence of inversions on chromosomes #1 and #9. Significant differences were noted between premenopausal and postmenopausal cancer patients in regard to inversions on chromosome #9 and between familial and sporadic patients in regard to C-band size on chromosome #16.

Variability of chromosomes 1, 9, and 16 in children with malignant diseases

Heterochromatic segments of chromosomes #1, #9, and #16 were analyzed in 38 children with malignant disease and 42 healthy persons. The analysis was carried out on C-banded metaphases obtained by peripheral blood culture. Using a quantitative method of analysis, an association was established between C-segment length of chromosome #9 and malignant disease in children. A disturbed quantitative relation of C-heterochromatin of chromosomes #1, #9, and #16 was also found in the group of children with malignant disease.