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

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.

Chromosomes in the genesis and progression of ependymomas

Cytogenetic analysis was performed on cultures of primary ependymal tumors with different degrees of malignancy (I-IV) obtained from four patients, none of whom had received therapy before karyotypic evaluation. The most common abnormalities were monosomy 17 and 22 in four cases and losses of sex chromosomes in three cases. Structural rearrangements of chromosome 2 were a finding for all cases and involved loss of material at 2q32-34. Other structural chromosome abnormalities detected involved chromosomes 4, 6, 10, 11, 12, and X. We also reviewed data on 22 cases previously reported.

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).

Variations in centromeric heterochromatin among patients with pre-malignant and malignant oral diseases

Polymorphism of heterochromatic regions of chromosomes 1, 9 and 16 was studied in 60 oral cancer patients, in 40 patients with oral submucous fibrosis (OSMF) and in 60 normal healthy subjects. The size heteromorphism was significantly greater (p less than 0.001) in chromosome I of the patients. Localization variants were also significantly more frequent among the patients (p less than 0.05 for OSMF and less than 0.001 for oral cancer patients). The C-band heteromorphism patterns remained comparable in OSMF and in oral cancer patients, with chromosome I being the most frequently involved. On correlating the tobacco/areca-nut chewing habit with the presence of C-band heteromorphism, we observed that C-band heteromorphism was present in 89% of the habit-free oral cancer patients and 80% of the OSMF patients with relatively shorter exposure to this habit, i.e. less than 5 years. This signifies that genetic factors are important in the causation of oral precancerous and cancerous conditions and that polymorphism of the heterochromatic regions does appear to play a role in these conditions.

Constitutive heterochromatin C-band polymorphism in prostatic cancer

The size of the heterochromatin C-bands on chromosomes has been reported to be associated with some, but by no means all, human malignancies. No studies along these lines have been performed in prostatic cancer. We therefore investigated the size, incidence of inversions, and symmetry versus asymmetry of C-band heteromorphisms on chromosomes 1, 9, and 16 in peripheral blood lymphocytes from 52 prostatic cancer patients and 183 healthy individuals. There were no differences in C-band heteromorphism on chromosomes 1, 9, and 16 between the patients and the controls. Neither were there any differences when patients with early-stage disease were compared with patients with more advanced cancer. Younger (aged less than 70 years) cancer patients had significantly higher frequencies of larger C-bands on chromosomes 1 (p less than 0.01) and 16 (p less than 0.001) than did patients aged more than 70 years at diagnosis. This could indicate a possible relationship between the amount of constitutive heterochromatin on chromosomes 1 and 16 and susceptibility to early development of prostatic cancer but could also result from the age differences between the two patient groups.

Heteromorphism of chromosome 1, 9 and 16 homologues in high- and medium-longevity level regions

Regional and age-related peculiarities of chromosomal polymorphism are established as a result of studies in C-band heteromorphism of chromosomes 1, 9 and 16 in the long-lived subjects, their relatives and population groups of the Abkhazian and Ukrainian regions. Heteromorphism frequencies of chromosomes 1 and 9 homologues are high in the Abkhazian as compared with the Ukrainian regions. Age-related differences as to the degree of expression of chromosome 9 C-band heteromorphism found are as follows: in the Abkhazian region the frequency of variants with a high degree of heteromorphism increases with age, while in the Ukrainian region, with a low degree of heteromorphism, it decreases.

Densitometric measurements of C bands of chromosomes 1, 9, 16, and Y in leukemic and preleukemic disorders

Fifty-six patients with blood disorders (23 with chronic myeloid leukemia, 14 with acute myeloblastic leukemia, seven with acute lymphoblastic leukemia, one with chronic lymphocytic leukemia, and 11 with preleukemia states) were studied. A quantitative and objective method of C band length analysis with well-matched controls was used. The C bands of chromosome pairs 1, 9, and 16 presented a normal distribution that was similar in patients and controls, whereas the Y chromosome presented an abnormal distribution. Smaller C bands in 1qh and higher indexes of intrapair heteromorphism in pairs 1 and 9 were detected in the CML group; the group of acute leukemias (myeloblastic and lymphoblastic) presented a smaller index only in pair 1qh. No other differences in length, heteromorphism, inversion frequency, or sex were detected.

Heterochromatic variants and their association with neoplasias: IV. Colon adenomas and carcinomas

C-band polymorphisms in peripheral blood lymphocytes of 62 patients (33 with colon adenomas and 29 with colon carcinomas) were studied. A significant difference in the frequency of heterochromatic variants in chromosomes #1 in both colon adenoma (56%) and carcinoma (67%) with respect to controls (18%) was observed (p less than 0.001). The heterochromatic variants preferentially involved in both pathologies were inv(1), 1qh-, and inv(9), compared with controls. No differences were found between colon adenomas and carcinomas. We suggest that 1qh- and inv(1) variants are important heterochromatic changes in neoplasia.

C-band polymorphisms in lymphocytes of patients with ovarian or breast adenocarcinoma

To establish the significance of the variability of human chromosome constitutive heterochromatin areas (C-band variants) in a risk of malignancy, C-banding pattern study has been performed in 33 female patients with ovarian or breast adenocarcinoma. The control group included 180 healthy women. The following characteristics of C-bands on chromosomes #1, #9, and #16 were studied: (a) size, (b) size heteromorphisms and (c) inversions, using quantitative and semiquantitative methods of analysis. Our data show no significant difference in the presence of C-band size and location variants in chromosomes #1, #9, and #16 between the patients with adenocarcinoma of the ovary or breast and healthy women. From that we conclude that there is no causal association between the presence of C-band variants on chromosomes #1, #9, and #16 and an elevated risk of ovarian and breast adenocarcinoma.

Constitutional interstitial deletion of 11p11 and pericentric inversion of chromosome 9 in a patient with Wiedemann-Beckwith syndrome and hepatoblastoma

A constitutional interstitial deletion on the short arm of chromosome #11 and an inversion of the heterochromatin of chromosome #9 were detected in a 1.5-year-old boy with Wiedemann-Beckwith syndrome (WBS) and hepatoblastoma. Of 37 malignant and nine benign neoplasms reported in approximately 250 cases with complete and incomplete forms of WBS, this is the fourth patient with hepatoblastoma. To date, 28 cases of WBS have been cytogenetically investigated with banding techniques. Constitutional anomalies have been found in only nine cases: Various anomalies resulting in a common triplication of the 11p15 region in six cases, reciprocal translocations t(11;22) and t(X;1) and an inversion of chromosome #2 in the three remaining cases. Triplication 11p15 was only present in one of four cases with a tumor. The breakpoints of the unique del(11)(p11.1p11.2) present in our case are proximal to those of del(11p13-11p14) and dup(11p15) observed thus far in both the aniridia-Wilms' tumor association and in WBS. Inversion of chromosome #9--one of the heterochromatin variants associated with elevated chromosomal instability, increased congenital abnormalities, and cancer proneness--may have been causally connected with a genetic imbalance resulting in the de novo deletion of 11p11. Therefore, we suggest that in these high-risk groups, C-banding studies should be performed together with high resolution chromosome analysis in order to also reveal the incidence and significance of C-band variants in individuals with such cancer prone syndromes.

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.

Chromosome 1 heterochromatin variants and cancer: a reassessment

Evidence for a relationship between chromosome #1 heterochromatin polymorphisms and cancer has been reviewed. Eighty-four of 135 (62%) patients with epithelial malignancies were heteromorphic for C-band size compared with 38 of 107 (36%) controls (significant at the 0.1% level). However, only 33 of 67 (49%) patients with nonepithelial malignancies were heteromorphic (not significantly different from controls). Similarly, the incidence of partial inversions of the C-band region in one or both homologs was significantly greater than controls [28 of 107 (26%)] for patients with epithelial [66 of 135 (49%)] but not nonepithelial [25 of 67 (37%)] malignancies. However, when the presence of either or both size heteromorphism and inversions were assessed, the incidence was significantly higher in patients with nonepithelial [46 of 67 (69%), including 11 of 11 patients with leukemia or myeloproliferative disorders] as well as epithelial [112 of 135 (83%)] malignancies compared with controls [52 of 107 (49%)]. Forty-seven of the patients did not differ significantly from controls with respect to the incidence of chromosome #1 heteromorphism as revealed by the Giemsa-11 technique. However, 26 patients assessed for their chromosome #1 lateral asymmetry pattern differed significantly from controls, having a higher incidence of compound asymmetry with a large proximal and small distal block and a lower incidence of simple asymmetry.

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.

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.

C-banding studies in lymphocytes from patients with tumors of the nervous system

C-banding studies were performed on cultured peripheral blood lymphocytes from 100 patients with tumors of the nervous system and 30 controls. The classification of Patil and Lubs and the heterochromatic index (HI) of Neeley were used to evaluate the heteromorphism. No overall significant differences were found in the frequency of C-band variants when the findings in both tumoral populations and controls were compared, but we did find an excess of 9qh inversions in some groups of tumor patients. An increase in the amount of heterochromatin in patients with pituitary adenomas and high malignancy grade astrocytomas was noted.