C-banding studies in patients with Ph1+ chronic granulocytic leukaemia

Heterochromatin variants in 109 ovarian cancer patients and 192 healthy subjects

Aberrations of the C-band region of chromosome no. 1 (1qh) were studied in 109 patients with ovarian cancer and 192 healthy subjects. The groups were compared for heterochromatin size variations, intrapair size asymmetry, and inversion. No significant correlation was found between the size of 1qh and ovarian cancer. Heterochromatin size asymmetry was estimated visually and determined by objective measurement of 1qh length or area; the methods show strong correlation. The measurements were normalised by comparison with the length or area of 16p or the entire chromosome no. 1. However, since good reliability was found by simply relating the 1qh size difference to the mean 1qh size, this was considered an appropriate and simpler method of normalisation. Asymmetry indices of length and area measurements correlated well, implying that the simpler method of length measurements can be readily used. 1qh asymmetry, measured objectively or estimated visually, was significantly increased in the cancer patient group. The incidence of C-band inversion was significantly increased in the patient group. Moreover, inversion increased significantly with increasing 1qh asymmetry.

Familial occurrence of cancer and heteromorphism of the heterochromatic segment of chromosome 1

During the last decade, evidence has been forthcoming in support of the correlation between heteromorphism of human chromosome 1qh and the incidence of various malignancies in the carriers of such heteromorphism. We present data from a family with hereditary predisposition to cancer. In this family, five members in a sibship of seven developed ovary and/or colon carcinoma at comparatively young ages. A further 4 cases of malignant disease were ascertained, when a pedigree of 36 family members of 3 generations was constructed. Chromosome analysis was carried out in G- and C-banding from peripheral blood cultures of 19 family members. Distinct heteromorphism in the chromosome 1qh region was detected in 15 (79%) of them, including all 3 cancer patients investigated.

Constitutional C-band polymorphism in lymphocytes from patients with chronic myeloid leukemia

The C-band heterochromatin polymorphism of chromosomes 1, 9, and 16 was studied in lymphocytes from 53 patients with Ph1-positive chronic myeloid leukemia (CML) and 183 control persons. The patients had significantly larger heterochromatic blocks on chromosome 16 (p less than 0.01) and fewer partial inversions of chromosome 9 (p less than 0.05) than the control persons, whereas no differences were found for the symmetry/asymmetry pattern. We suggest that the increased constitutive heterochromatin regions may, via sister chromosome exchange, facilitate homo- or hemizygotization of genes which favor neoplasia development and/or progression.

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.

Constitutive heterochromatin studies in patients with solid tumors

Constitutive heterochromatin of chromosomes 1, 9, and 16 was studied in 101 patients with solid tumors and 85 controls. Lymphocyte cultures were used for performing C-banded chromosome preparations. Two homologous chromosomes were regarded as heteromorphic when there was a 25% difference between their C-band size or when they fell into different classes according to the method of Patil and Lubs (1977). A statistically significant difference between patients and controls was found in chromosome 1 heteromorphism. No statistical difference between patients and controls was found in the heteromorphism of chromosomes 9 and 16. The frequencies with which pericentric inversions of the heterochromatin in chromosomes 1 and 9 occurred in cancer patients were 9.9% and 12.9%, respectively. Patients displaying this type of polymorphism usually showed an increased rate of chromosome associations. The most frequent associations were found between heterochromatic regions of chromosomes 1 and 9 and between the chromosome 9 heterochromatin and D acrocentrics. These results support the hypothesis concerning the involvement of constitutive heterochromatin of chromosome 1 in malignant disease.

Constitutional C-band pattern in patients with adenomatosis of the colon and rectum

The pattern of polymorphism in the C-band-positive constitutive heterochromatin of chromosomes #1, #9, and #16 was studied in fibroblasts from 23 unrelated patients with adenomatosis of the colon and rectum and in peripheral lymphocytes from 78 control persons. The parameters of the heterochromatic regions analyzed were relative size, symmetry-asymmetry within homologous chromosome pairs, and frequency of inversions. The polyposis coli patients had a significantly higher frequency (p less than 0.05) of partial and total heterochromatin inversion on chromosome #9 than the control group (37.0% compared with 21.8%). In the other parameters studied, no significant differences were found between patients and controls.

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.

Cytogenetic study of patients with carcinoma of the colon and rectum: particular C-band variants as possible markers for cancer proneness

A possible involvement of chromosomal heterochromatic polymorphisms in propensity to cancer has been considered and discussed by several investigators who studied groups of patients presenting with different forms of malignancy. We report a cytogenetic study on the circulating lymphocytes of patients suffering from colorectal carcinoma, most of whom were of European origin. Significantly increased incidence of polymorphisms of chromosomes #1 and #9 was found, especially partial inversions (PI). Emphasis is given to the problem of selecting adequate controls, which must be as homogeneous as possible.

Heterochromatic variants and their association with neoplasias. I. Chronic and acute leukemia

C-banding studies of the heteromorphism of chromosomes #1, #9, and #16 were performed in 120 leukemic patients: 56 with chronic myelocytic leukemia (CML), 45 with acute lymphoblastic leukemia (ALL), and 19 with acute nonlymphoblastic leukemia (ANLL). No differences were found among patients and controls with regard to sex. Our data showed a significant increase of polymorphism in chromosome #1 in the three neoplastic groups; the heterochromatic variant preferentially involved 1qh-, whereas there were no significant differences in heteromorphism in chromosomes #9 and #16.

Chronic myeloid leukemia with a Philadelphia chromosome involving a t(21;22)

A second example of chronic myeloid leukemia showing translocation of material from the long arm of chromosome #22 to the long arm of chromosome #21, ( 21q +:22q-), is reported. The patient presented with the typical clinico-pathologic features of the disease.

C-band pattern in lymphocytes of patients with soft tissue sarcomas

The pattern of heteromorphisms in the C-band-positive constitutive heterochromatin of human chromosomes No. 1, 9, and 16 was studied in peripheral lymphocytes of 45 patients with soft tissue sarcomas and 78 control individuals. The parameters of the heterochromatic regions analyzed were relative size, symmetry-asymmetry within homologous pairs, and incidence of inversions. No consistent differences were found in these parameters between controls and sarcoma patients.

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

The C-band polymorphism of chromosome #9 in 18 patients with chronic myeloid leukemia (CML) with a Philadelphia chromosome (Ph1) translocation between chromosomes #9 and #22 was examined using C- and Q-banding techniques on the same metaphases and the classification proposed by Patil and Lubs [1]. The C-band polymorphism of chromosome #9 in CML was found not to differ in leukemic cells with the Ph1 and phytohemagglutinin-stimulated lymphocytes without the Ph1 and to have a clonal origin, i.e., to arise from a single cell in which the Ph1 translocation has taken place. A comparison of the C-band polymorphism of chromosome #9, survival after diagnosis of the disease, and abnormal chromosomes in addition to the Ph1 indicates some interesting aspects. Patients with the smallest C-band (level 1) on chromosome #9 not involved in the Ph1 translocation and with a relatively large C-band (level 2) on chromosome #9 with the Ph1 translocation (C9-1,2) tend to have no clonal evolution and short survival after diagnosis of the disease. On the other hand, patients with other types of C-band patterns tend to have evidence of clonal evolution and long survival. This study suggests that the C-banding pattern in Ph1-positive CML might be utilized as a prognostic parameter in the disease and that the C-segment might have biological activity.

Giemsa-11 technique. Applications in the chromosomal characterization of hematologic specimens

Use of the Giemsa-11 procedure for the localization of heterochromatic regions of human chromosomes and for differentiation of primate and rodent chromosomes has been somewhat limited since its discovery in 1972. An adaptation of this technique to the cytogenetic characterization of hematologic specimens has aided in the interpretation of translocations, deletions, and inversions involving human chromosome 9. The chromosomal analyses of 10% of over 100 patients, principally leukemic, were aided through the use of this auxiliary procedure. The diseases of these patients are given and portions of karyotypes are presented to show clarification of abnormalities made possible through the use of the Giemsa-11 technique.

Constitutive heterochromatin (C-banding) studies in patients with testicular malignancies

The heterochromatic index [qh/(p + q) X 100] is a quantitative measure of variations in the heterochromatic regions of C-banded cells which minimizes differential contraction of heterochromatic and euchromatic areas. Heterochromatic indices of the homologues of chromosomes #1, #9, #16, and Y were studied in the genotypes of 48 patients with germinal tumors and in 30 controls. The heterochromatic indices of chromosome #9 in patients showed statistically significant heteromorphism compared with controls. In addition, the heteromorphism was found to increase from the lower malignancy seminoma to the highly malignant teratoma. A similar but statistically nonsignificant pattern was seen in chromosome #16. No statistical difference in the mean of the heterochromatic indices was found in chromosomes #1 and Y. The difference in the mean heterochromatic index in chromosome #9 appeared to be due to an increase in the mean heterochromatic index in chromosome #9 appeared to be due to an increase in the amount of constitutive heterochromatin and not to a decrease.