Differences in human C-band pattern between two European populations

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.

Characterization of restriction enzyme banding polymorphisms in human chromosomes

C and Re-banding chromosome heteromorphisms were analysed in blood cultures from 43 normal individuals. Restriction enzymes used were AluI, DdeI, HaeIII, and MboI. Chromosome pairs exhibiting heteromorphisms were: 1, 3, 4, 6, 9, 10, 12-16, and 18-22. Each individual showed a specific combination of C- and Re-banding heteromorphisms not shared by any other individual in the series. Some polymorphisms could be detected by all the banding methods used. Others could be detected by some of the banding methods, and in some cases by only one of the banding methods used. The efficiency of each banding method to detect chromosomal polymorphisms depended on the type of polymorphism and the chromosomal pair analysed. Our results indicate that Re-banding polymorphisms occur due to changes in base composition of different fractions of heterochromatin or due to the presence or absence of different heterochromatic subsets. C- and Re-banding are complementary methods that expand the identification of chromosomal markers and which can be used to identify the parental origin of individual chromosomes.

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.

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.

Polymorphism of heterochromatin areas on chromosomes 1, 9, 16 and Y in long-lived subjects and persons of different ages in two regions of the Soviet Union

Variants of chromosome polymorphism were analyzed in long-lived individuals and in subjects aged 40-79 years (170 persons) in two regions of the Soviet Union. The results of this analysis allow the suggestion that there is an association between the individual variants of chromosome polymorphism as regards C heterochromatin and the longevity phenomenon. Large size C segments on the human Y chromosome and the long Y chromosome were found both in the Ukrainian and Abkhasian long-lived males. In the long-lived females the chromosome polymorphism variants were associated with a region of their residence. The long-lived females of Abkhasia had a decreased relative size of C segments on chromosome 1 and an increased absolute and relative size of C segments on chromosome 9, while in their Ukrainian counterparts there was an increased relative size of C segments on chromosome 1 and a decreased one on chromosome 16.

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.

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.