Heterochromatic variants and their association with neoplasias. II. Preleukemic states

Searching for electrical properties, phenomena and mechanisms in the construction and function of chromosomes

OUR STUDIES REVEAL PREVIOUSLY UNIDENTIFIED ELECTRICAL PROPERTIES OF CHROMOSOMES: (1) chromosomes are amazingly similar in construction and function to electrical transformers; (2) chromosomes possess in their construction and function, components similar to those of electric generators, conductors, condensers, switches, and other components of electrical circuits; (3) chromosomes demonstrate in nano-scale level electromagnetic interactions, resonance, fusion and other phenomena similar to those described by equations in classical physics. These electrical properties and phenomena provide a possible explanation for unclear and poorly understood mechanisms in clinical genetics including: (a) electrically based mechanisms responsible for breaks, translocations, fusions, and other chromosomal abnormalities associated with cancer, intellectual disability, infertility, pregnancy loss, Down syndrome, and other genetic disorders; (b) electrically based mechanisms involved in crossing over, non-disjunction and other events during meiosis and mitosis; (c) mechanisms demonstrating heterochromatin to be electrically active and genetically important.

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.

Hodgkin's disease developing after spontaneous remission of chronic lymphocytic leukemia

We present a 71-year-old patient with chronic lymphocytic leukemia diagnosed 27 years ago. Initially, the disease was staged as Rai II and the patient suffered from secondary immunoglobulin deficiency. Nevertheless, no treatment was necessary at that time. Because of disease progression a single course of chemotherapy was given in 1984. During the following year there was a constant decline of the WBC, accompanied by normalization of the immunoglobulins; both have remained stable ever since that time. However, there was still residual bone marrow infiltration, indicating persisting CLL. In 1993 cervical lymphadenopathy occurred with acute onset. A diagnostic lymphadenectomy revealed Hodgkin's disease of the nodular-sclerosing subtype. The patient was staged as II-III according to the Ann Arbor Classification and underwent radiation therapy. Cytogenetic examination of the bone marrow revealed a normal karyotype with an inversion of chromosome 9. This case demonstrates the rate coincidence of two lymphoproliferative disorders in the same patient. The clinical course and the immunologic findings of this patient are presented, together with a review of the literature.

Chromosome 9 anomalies as the primary clonal alteration in a case of squamous cell carcinoma of the epiglottis

We present the cytogenetic characterization of a short-term culture of a primary squamous cell carcinoma of the epiglottis from a 67-year-old male patient who was admitted to this hospital for treatment. This patient had a history of chronic exposure to tobacco and alcohol, environmental carcinogens known to be related to the etiology of the disease. The tumor karyotype showed three distinct clones: 1) cells with chromosome 9 anomalies; 2) cells with chromosome 9 and other clonal structural anomalies involving chromosomes 1, 11, 14, and 17; and 3) cells whose chromosomes were partially or totally pulverized. The anomalies on chromosome 9 were homozygous inversion (p12q13), deletions at regions q22, q34.1, and p13, and i(9q) formation. Structural clonal anomalies on other chromosomes included translocations, deletions, and isochromosome formation. The presence of a chromosome 9 anomaly alone or in conjunction with other anomalies suggests that this aberration may be a nonrandom primary event in the progression of squamous cell carcinoma of the head and neck.

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 variability in children with acute lymphoblastic leukemia

An analysis of the C-segment variability of chromosomes 1, 9, and 16 was carried out in 38 children with ALL, and 90 control subjects. When studying location variants, no differences were found between group of patients and the normal controls. A larger quantity of structural heterochromatin was, however, observed on chromosomes 1, 9, and 16, and a higher frequency of homologous chromosomes heteromorphism in children with ALL when compared with the control group.

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.

Variability of Euchromatic and Heterochromatic Regions of Y Chromosome in Two Types of Cancer Patients

Heteromorphism of Y chromosome was studied in head and neck cancer patients and leukemia patients. The results were compared with similar data obtained for healthy men. It was observed that, compared to the controls, mean lengths of Y chromosome were nonsignificantly higher for leukemia patients and lower for head and neck cancer patients. The euchromatic region of Y chromosome (Y-eu) remained comparable in the controls and the leukemia patients, whereas it was smaller in patients with head and neck malignancies. The heterochromatic region (Y-het) was more or less analogous in controls and head and neck cancer patients, however, it was significantly larger in patients with leukemia (P < 0.02).

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: 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.

Heterochromatic variants and their association with neoplasias: III. Multiple myeloma

The incidence of heterochromatic variants was assessed in 26 patients with multiple myeloma (MM) and 55 control individuals. An enhanced frequency of heteromorphism was present in 92% of the MM population compared with 44% of the control group (p less than 0.001). Significant differences with regard to controls were observed in chromosome pairs #1, #9, and #16 due to 1qh-, inv(1),inv(9) and 16qh- variants. We suggest that MM would present an intermediate heterochromatic behavior between hematologic diseases and solid tumors.

Cytogenetic instability in a family with gastric cancer recurrence

An index case with a congenital malformation syndrome enabled detection of a family that had a previous history of spontaneous abortuses and recurrence of neoplasia through three generations. Cytogenetic analysis performed on lymphocytes from 11 subjects in the second and third generation showed karyotypic alterations in both tumor bearers and apparently normal subjects. Chromosome variations consisted of: spontaneous chromosome fragility; chromosome translocations; polymorphisms in the heterochromatic regions in chromosomes Y, #1, #16, #22. The inheritance pattern of all chromosome rearrangements and heteromorphisms observed was established starting with the second generation, and the contribution of specific individuals was identified. Although the relationship between chromosomal instability and predisposition to gastric cancer does not appear to be coincidental, no specific chromosome alteration in normal somatic cells was shared by all members of the family who developed or are at risk of developing tumors.

Length polymorphisms of the human Y chromosome in patients with chronic myelogenous leukemia

The extent of length heteromorphisms of the human Y chromosomes was measured in 50 patients with chronic myelogenous leukemia and was compared with 50 normal controls. No significant difference (p greater than 0.05) in the size of the Y chromosome was noted between these two groups. These findings differ from an earlier investigation, where a longer heterochromatic segment of Y chromosome was noted in malignant tumors and it was stressed that constitutive heterochromatin plays a role in susceptibility of cancer. Present investigation, however, suggests that this is not the case in patients with chronic myelogenous leukemia.

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.

Prognostic importance of hypodiploid hemopoietic precursors in myelodysplastic syndromes

It has been suggested that a poor prognosis and the development of leukemia in patients with myelodysplasia may be related to chromosomal abnormalities. We measured the DNA content of bone marrow cells with flow cytometry in 19 hematologically normal subjects and in 70 patients who had recently been diagnosed as having myelodysplasia. Thirty-four of the patients were found to have aneuploidy. This was not related to the percentage of blast cells in the bone marrow, and there was no demarcation in terms of DNA content between patients with a high percentage of blast cells and those with a low percentage of such cells. Patients with hypodiploid marrow cells had a significantly shorter survival time than other patients (P = 0.001). Patients with hyperdiploid marrow and those whose marrow had a normal DNA content had similar survival times. Hypodiploidy appears to be a better indicator of poor survival than the marrow blast-cell count. Patients with sideroblastic anemia invariably had cells with a normal or high DNA content; none of these patients died during the study. Our data suggest that there is a relation between the loss of chromosomal material and progression toward a leukemic phenotype. It is tempting to speculate that this process may involve a loss of negative regulatory genes ("anti-oncogenes").