Viral transformation of cells from persons at high risk of cancer

Fanconi anemia neuroinflammatory syndrome: brain lesions and neurologic injury in Fanconi anemia

ABSTRACT

Fanconi anemia (FA) is a complex inherited bone marrow failure syndrome characterized by chromosomal instability and defective DNA repair, causing sensitivity to DNA interstrand crosslinking agents. Our understanding of the full adult phenotype of the disease continues to evolve, because most patients with FA died of marrow failure in the first decade of life before more recent advances in allogeneic hematopoietic cell transplantation. Herein, we report a previously undescribed, clinically concerning, progressive neurologic syndrome in patients with FA. Nine nonimmunosuppressed pediatric patients and young adults with FA presented with acute and chronic neurological signs and symptoms associated with distinct neuroradiological findings. Symptoms included, but were not limited to, limb weakness, papilledema, gait abnormalities, headaches, dysphagia, visual changes, and seizures. Brain imaging demonstrated a characteristic radiographic appearance of numerous cerebral and cerebellar lesions with associated calcifications and often a dominant ring-enhancing lesion. Tissue from the dominant brain lesions in 4 patients showed nonspecific atypical glial proliferation, and a small number of polyomavirus-infected microglial cells were identified by immunohistochemistry in 2 patients. Numerous interventions were pursued across this cohort, in general with no improvement. Overall, these patients demonstrated significant progressive neurologic decline. This cohort highlights the importance of recognizing FA neuroinflammatory syndrome, which is distinct from malignancy, and warrants careful ongoing evaluation by clinicians.

XYY Caryotype and Medulloblastoma

The case is described of a child who presented a slight psychomotor retardation and malformative signs, together with an XYY caryotype, and who died at the age of 7 years from a medulloblastoma, as could be later confirmed by autoptic examination.

The relations between chromosomal and neoplastic pathology are described.

Interferon system in cells from human tumors and from persons predisposed to cancer

In the present study, the interferon system was evaluated in fibroblasts from persons predisposed to leukemia or other cancers, in fibroblasts from persons with neoplastic disease, and in human tumor cells. Of 31 normal fibroblast strains from patients with tumors or diseases associated with a high incidence of malignancy, only one cell strain had a poor response to either of the two interferon inducers used, polyinosinic-polycytidylic acid and Chikungunya virus. On the other hand, cell cultures of five human tumors were much less sensitive to the antiviral effect of these interferon inducers and of human interferon and produced less interferon in response to Chikungunya virus than any of the nontumor tissues studied.

Cell-cell contact interactions conditionally determine suppression and selection of the neoplastic phenotype

Separation of chemical and physical carcinogenesis into the stages of initiation (mutation) and promotion (selection) established that incipient neoplastic cells could persist in the organism indefinitely without expression. Spontaneous mutations associated with cancer also lie dormant in untreated normal tissue. Without selection, there is no tumor development. Experiments in cell culture showed that confluent normal fibroblasts suppress growth of contacting transformed fibroblasts, and that normal keratinocytes similarly suppress tumor formation by adjacent papilloma cells. With cells that are generally more susceptible to transformation, however, prolonged contact inhibition progressively selects mutants that favor neoplastic growth. Selection of individual mutant cells allows them to become a significant fraction of the population and creates an enlarged target for additional genetic hits. Crucially, this enrichment step, not the initial mutation step, is the numerically limiting factor in tumor development. Unexpectedly, variants that are resistant to spontaneous transformation are selected in vitro by growing cells for many low density passages at maximal exponential rate. Confluent cultures of resistant variants suppress the growth and normalize the morphology of contacting transformed cells. Varying the conditions for selection shows that tumorigenic transformation is preceded by intermediate steps of progressively higher saturation density that are increasingly permissive for the expression of the more neoplastic cells in the population. There is also evidence of increasing permissiveness with age of normal tissues in vivo for solitary cancer cells transplanted in their midst. Spontaneous transformation in culture can be used to identify dietary components that are required for promotion and may therefore be applicable in prevention of human cancer.

Reflections on the pathogenesis of Down syndrome

Present efforts to identify, isolate, and characterize in molecular terms the "consensus" segment of 21q sufficient to cause most of the major and some of the most characteristic minor manifestations of Down syndrome will soon provide answers to many questions. However, we think that a reductionist approach to explain the Down syndrome phenotype in a "linear" manner from the DNA sequence of the segment will be doomed to failure from the outset because of the open, complex, nonlinear, hierarchical nature of morphogenetic systems. Neo-Darwinism is under strong attack; most genetic changes accumulated over time may very well be of neutral effect, and detailed studies in several related groups of vertebrate species has shown that molecular and organismal evolution are largely independent of one another. It has been pointed out recently that biology lacks a theory of ontogenetic and phylogenetic development, and that a purely "genocentric" view of biology at the expense of the complexly hierarchical intrinsic epigenetic attributes of developmental systems is "out of focus with respect to ... biological organization and morphogenesis," and may be "a residue of nineteenth century romantic idealism." Down syndrome impresses us as a paradigm of increased developmental variability due to a deceleration of the rate of development (neoteny) with many anomalies of incomplete morphogenesis (vestigia), atavisms, increased morphometric variability with many decreased means, increased variances, and increased fluctuating asymmetry. These abnormalities, together with highly increased risk of prenatal death and postnatal morbidity, impaired growth, and abnormal CNS and gonadal structure and function characteristic of most aneuploidy syndromes, suggest to us that the pathogenesis of Down syndrome is best viewed in terms of the mechanisms of speciation. Transgenic experiment involving sequential or overlapping pieces of "the consensus segment" on distal 21q22.1-22.3 may help decide to what extent the Down syndrome phenotype can be resolved into the additive effect of several pleiotropic oligogenes with epistatic interaction or the indirect secondary "mass" effect of a specific segment of 21q with epistatic interaction involving multiple loci on 21q and other chromosomes.

Constitutional chromosome aberrations as pathogenetic events in hematologic malignancies

A predisposition to tumor development is associated with some constitutional chromosomal abnormalities. Investigations of families with an apparent hereditary cancer and constitutional chromosome rearrangements have led to the molecular identification of tumor suppressor genes. Under the somatic mutation theory for the development of cancer, two mutational events are required. The first step may be a constitutional event and the second an acquired genetic mutation. Cytogenetic studies were performed on 5633 bone marrow specimens from patients with hematologic malignancies from a single institution. Fifty cases of constitutional chromosome aberrations were detected. Data collected from the literature and from our series are reviewed and compared with the incidence of specific constitutional chromosome aberrations in the newborn population. Possible mechanisms that may predispose individuals with constitutional chromosome aberrations to the development of a hematologic malignancy are reviewed.

Induction of transformation of human respiratory epithelium in vitro. Preliminary investigation

Malignancy is the result of multistep transformational changes of normal somatic cells. In the case of respiratory epithelial malignancies this process lasts for several years. Many methods have been explored to mimic this process in an extracorporal model. In the present investigation we combined several of these methods. Organ cultures were prepared from tracheal specimens and were then consecutively treated with human papilloma virus, benzo(a)pyrene, methylnitronitrosoguanine and tetradecanoyl phorbol acetate. Identical numbers of organ cultures from the same specimen were maintained without exposure to carcinogens. After 6 weeks these cultures were further cultivated either in mixed cultures (MC) with autologous isotopic fibroblasts or under the kidney capsule of the nude mouse (SRC). These two methods were combined after a few months: MC cells were transplanted under the SRC or SRC transplants were explanted in cell culture. This long-term selection procedure revealed striking differences between control and treated organ cultures. Three-dimensional structures containing epithelial cells were isolated from both organ cultures but survived more than 3 months only from treated cultures. Only MC from treated organ cultures produced nodules under SRC. The incidence and morphology of the nodules in the SRC were directly related to carcinogen treatment, with more nodules with pronounced epithelial cell atypia obtained from treated organ cultures. MC and SRC showed the importance of a time factor for selecting cells with changed growth behavior--increased time increased the incidence of such cells.

Increased spindle resistance to antimicrotubule agents in cells prone to chromosomal nondisjunction

The cytological behavior of the spindle apparatus was studied in cells prone to nondisjunction (ND), i.e., PHA-stimulated lymphocytes derived from children suffering from different types of neoplasia. These cells, which exhibited a high frequency of nonspecific aneuploidy, revealed an increased resistance of the spindle fibers to colchicine, podophyllotoxin, and cold, which was several times that of lymphocytes derived from healthy children. The results are in accord with previous findings showing a high resistance of spindle microtubules to the antimicrotubular agents colchicine, podophyllotoxin, vinblastine, and cold in PHA-stimulated lymphocytes derived from individuals prone to meiotic ND. It is therefore assumed that high resistance of the spindle apparatus to antimicrotubule agents characterizes cells at high risk for aneuploidy, and possibly, the overstabilized spindle fibers are responsible for failure of chromosomal disjunction.

Chemical and viral transformation of cultured skin fibroblasts from patients with familial polyposis coli

Treatment of skin fibroblasts from an FPC patient with 4NQO or MNNG followed by sequential passaging caused morphological changes of the cells, which showed characteristics of transformed cells such as a high frequency of colony formation in agarose, increased growth ability, and chromosomal abnormalities. This and other fibroblast lines from 5 of 12 FPC patients had an increased susceptibility to 4NQO cytotoxicity, which was caused by enhanced 4NQO-reductase activity rather than by reduced DNA repair. However, the susceptibility to cytotoxicity of MNNG and repair of MNNG-damaged DNA were normal in FPC cells. The tumor promoters TPA and DHTB enhanced the frequency of chemical transformation of the FPC fibroblasts, and protease inhibitors suppressed the promoter-enhanced transformation. The skin fibroblasts from many FPC patients exhibited increased susceptibility to transformation by murine sarcoma viruses. Analysis of the viral DNA and RNA after infection revealed that the increased susceptibility is determined at an early stage of transformation. Two out of 5 MNNG-transformed clones of FPC fibroblasts, isolated from agarose, had increased expression of c-Ki-ras or c-Ha-ras, and 4 of 4 MSV-transformed clones showed high expression of viral Ki-ras. These clones grew further after isolation from agarose, but were mortal and did not form tumors in nude mice. The present results suggest that additional changes in morphologically transformed FPC fibroblasts are required for malignant transformation.

Abnormal properties of skin fibroblasts from patients with breast cancer

The growth properties of fibroblasts from the thoracic skin of patients with mammary cancers were compared to those of fibroblastic cultures from patients with benign lesions or having undergone surgery for non-neoplastic diseases. As expected, an inverse correlation was found between the doubling potential of fibroblasts in vitro and the donor's age for cells from patients with benign lesions; however no correlation, was found with cultures from cancer patients. Moreover, the latter group responded in an abnormal way to three biological parameters: anchorage dependence, colony formation on monolayers of normal human epithelial cells and saturation densities in overcrowded culture conditions. Skin fibroblasts from one patient with a benign lesion, whose mother had developed a breast cancer, displayed all the abnormal growth properties. Periodic controls of this patient resulted in the early detection of a carcinoma 3 years after the first operation for a benign microcystic lesion. Finally, we found that multiple subcultivations in overcrowded culture conditions cause the selection of a fibroblastic cell subset with greater growth potential which, in the cell strain tested, could invade foreign tissue in vitro.

Susceptibility of skin fibroblasts from patients with retinoblastoma to transformation by murine sarcoma virus

Cultured skin fibroblasts from patients with retinoblastoma (RB) of different etiology have been studied for their susceptibility to transformation by murine sarcoma virus. The cells from patients with a deletion in chromosome 13 (13q-) and those from sporadic unilateral cases due to somatic mutation were as sensitive as normal cells. However, the cells from familial cases showed an extremely high sensitivity to transformation. Moreover, in familial cases the susceptibility was significantly higher in bilaterally affected patients than in unilateral cases. These findings suggest that the heritable RB gene is different from 13q- and its degree of expression is also manifest at the cellular level.

Klinefelter's syndrome and acute non-lymphocytic leukemia

In five out of 51 adult, male patients with acute non-lymphocytic leukemia, Klinefelter's syndrome was demonstrated karyotypically. The incidence of this syndrome in our material is very much increased in comparison with the frequency at birth. In this article the medical histories of the patients are given and the possible connection between the constitutional chromosome abnormality and acute non-lymphocytic leukemia is discussed. Immunological or hormonal abnormalities or an increased virus susceptibility might be predisposing factors.

On the nature of susceptibility to cancer. The presidential address

The most prominent factor determining susceptibility to cancer is age. However, there is little evidence that the aging process per se increases susceptibility to cancer. Rather, age provides the time necessary for the accumulation of cellular events required for the development of neoplasia. The variations in the patterns of cancer incidence rates seen with age can be explained by alterations in conditions of exposure to carcinogenic stimuli. There is no evidence that the pool of susceptible individuals in a population is limited. Cancer occurs as a random event in a population with greater or lesser frequency according to the presence of risk factors. In populations with an increased frequency of cancer such as those with genetic abnormalities, immune deficiency syndromes, or altered hormonal states, the risk of developing cancer is never generalized to all tissues but is characteristic of particular tissues at risk. Any circumstance of internal or external origin that disturbs homeostasis of particular tissues at risk. Any circumstance of internal or external origin that disturbs homeostasis over a prolonged period of time increases the susceptibility to cancer for the tissue concerned. Susceptibility to cancer does not mean that cancer is inevitable. Only a small number of those susceptible to cancer by virtue of a special risk factor develop the disease. Furthermore, most patients who develop cancer have no determinable risk factors. Although all evidence points to a multifactorial, multistage process, the rate of somatic mutation appears to be the key determinant factor in susceptibility to cancer. This concept is supported by research studies showing that the onset of atherosclerosis is initiated by somatic mutations, and the finding that the same chemical mutagens can advance the development of both diseases.

Relationship of SV40 T-antigen expression in vitro to disorders of bone marrow function

Skin fibroblasts from patients with a variety of hematologic disorders were infected with SV40 virus in vitro in attempts to discover the reason for increased susceptibility of Fanconi anemia cells to this transforming virus. The proportion of skin fibroblasts expressing SV40 T-antigen by immunofluorescent methods was elevated in 12 patients with Fanconi anemia and in seven of nine obligate heterozygous relatives. Elevated expression was also observed in three patients with other hematological disorders at high risk of acute non-lymphocytic leukemia, but was not apparent in seven sporadic aplastic anemia patients or four of their relatives. T-antigen expression was elevated in about one-half of patients with thrombocytopenia-absent radius syndrome and related conditions, with familial aplastic anemia, and in their normal relatives. In the conditions under study, elevated T-antigen expression seemed clearly correlated with predisposition to leukemia, which may be genetically determined, but it was not associated with cytogenetic or anemic manifestations.

Chromosome fragility and susceptibility of Bloom's syndrome fibroblasts to SV40 transformation

A comparison of the frequencies of chromosomal aberrations and the rates of SV40 transformation was made using fibroblasts obtained from 2 patients with Bloom's syndrome (BS) and from a normal individual. BS cells were found to be more susceptible to chromosome damage, in confirmation of earlier reports, but surprisingly, BS cells were distinctly less prone to transformation.

Human skin fibroblasts from individuals genetically predisposed to cancer are sensitive to an SV40-induced T antigen display and transformation

In the present study we have used a viral probe to determine the genetic susceptibility of fibroblastic cell strains derived from individuals with hereditary adenomatosis of the colon and rectum (ACR), an autosomal dominant trait. This report shows an increased sensitivity of apparently karyologically-normal diploid skin fibroblasts from ACR individuals to an SV40-induced T antigen display and transformation. None of the SV40-transformed cells grew as tumors in athymic mice and they all appeared to have a finite life span. The results suggest that the induction of T antigen positive cells by SV40 may be used as a marker of cancer risk in this cell system.

SV40 T-antigen expression in acute non-lymphocytic leukaemia

Susceptibility to SV40 virus infection has been suggested as an in vitro marker of predisposition to leukaemia and possibly other cancers in man. To evaluate this relationship, sporadic as well as familial cases of acute non-lymphocytic leukaemia were tested. Among skin fibroblast lines from 22 patients without family history of leukaemia, eight had values above the 95% confidence limit for the normal control population. In four leukaemia-prone families, elevated T-antigen expression was found in all four patients tested and in three-quarters of 36 blood relatives. In addition, elevated values were found in two of three cases of acute myelogenous leukaemia associated with constitutional cytogenetic anomalies, and in all three cases with preleukaemic haematologic disorders. Since SV40 T-antigen expression was elevated in most persons prone to acute non-lymphocytic leukaemia, as well as over one-third of sporadic cases, heritable risk factors may be involved in both groups.

G2 chromosomal radiosensitivity in Fanconi's anemia

Both the peripheral lymphocytes from 4 patients affected with the inherited disease Fanconi's anemia (FA), and tissue-culture fibroblasts from skin biopsies from 3 patients similarly affected were found to be about twice as sensitive to the induction of chromatid-type chromosomal aberrations by X-rays administratered in the G2 phase of the cell cycle as cells from normal controls. Using tritiated thymidine labelling of peripheral lymphocytes and of cultured fibroblasts, it was determined that 3 affected patients and 3 normal controls all had similar percent labeled mitoses (PLM) curves, so the increased induced aberration yields seen in the FA cells do not appear to be simply a consequences of a longer than normal G2 phase of the cell cycle.

DNA repair defects and chromosome instability disorders

Xeroderma pigmentosum (XP), Fanconi anaemia (FA), ataxia telangiectasia (AT) and Bloom disease (BS) are four rare autosomal recessive disorders in which there is defective DNA repair and/or chromosome instability and proneness to malignancy. Between 80 and 90% of patients with XP have a defect, demonstrable at cell level, of excision of DNA lesions induced by ultraviolet rays, while the remainder have a cellular error of post-replication repair. XP cells are also deficient in repairing DNA damage caused by a variety of chemical mutagens. There are at least five different complementation groups of the first, or classical, type of XP (A to D, etc.) Apparently group C patients, as well as those with defective post-replication repair, do not show the progressive neurological illness found in a proportion of the other patients. AT is heterogeneous clinically and genetically. Clinically it presents with a progressive neurological illness, progressive telangiectases and a developmental disorder of the thymus. AT is characterized by sensitivity to X-rays and AT cells are unable to repair gamma-ray-induced damage to bases in the DNA. It appears that in many cases of the disorder a chromosomally marked cellular clone is found. In BS the main defect, which results in growth retardation, sun-induced lesions of the face and susceptibility to infection, appears to be a slow DNA chain maturation during DNA synthesis. An increase of sister chromatid exchanges is characteristically seen in the chromosomes of cultured BS cells. In FA, in which there is progressive pancytopenia with eventual bone marrow exhaustion and a tendency to haemorrhage and infection, the cellular defect seems to consist of faulty removal of repair of cross-links in the DNA. In this condition, as in BS and AT, various structural chromosome changes are detected in cultured cells. Patients with XP develop skin cancers in early life and often maligant melanomas. In the other three disorders, in which an immune deficiency is often present, leukaemia and related proliferative disorders are a frequent cause of death while other malignancies also occur. There is some evidence that points to an increased risk of malignancy in heterozygotes who carry the FA and AT genes.

Genetic mechanisms in cancer predisposition: report of a cancer family

A family is described in which four children developed cancer affecting different organs:lymphoma, meningeal sarcoma, osteogenic sarcoma, and adenocarcinoma of the cecum. Since there was only one other case of cancer in previous generations of this family, an hypothesis is put forth to explain this unusual aggregation on the basis of recombination of common genes. It is postulated that each parent carried a different combination of genes which, though not associated with increased cancer predisposition in the combinations in which they were present in the parents, due to independent assortment resulted in a combination producing cancer susceptibility in half of the offspring. Such genetic loci could include factors similar to an oncogene which is normally held in control by genes at another locus; thus the dominant oncogene without the dominant controlling genes would make for cancer susceptibility, while the controlling genes without the oncogene would be associated with cancer resistance since two mutations would then be required for malignant development. To explain the occurrence of lymphoma in one of the children in this family, a third set of genes is included in this model--genes affecting immunocompetence, in which the normal allele is dominant. This three locus model has the advantage of being able to explain not only the occasional cancer family, but also the distribution of cancer susceptibility and resistance in the general population.

New aspects of preleukemic disorders

Preleukemic disorders are a controversial group of panmyelopathic disturbances that often precede the emergence of acute myeloblastic or myelomonocytic leukemia. In most instances, these preleukemic disorders are characterized by slowly developing myeloblastosis of the bone marrow. They include preleukemia, primary acquired panmyelopathy with myeloblastosis or smouldering acute leukemia, erythroleukemia, and subacute myelomonocytic leukemia. Sometimes, transitions between these various preleukemic disorders may be observed in a single individual. Abnormalities in cellular differentiation are expressed in cytochemical aberrations and in elaboration of colony forming units by marrow cells of patients with preleukemic disorders. Cytogenic and cellular kinetic abnormalities link preleukemic disorders closely to acute myeloblastic or myelomonocytic leukemia, although in many patients with preleukemic disorders, conversion to acute leukemia is not observed or perhaps not recognized. Understanding pathogenetic and pathophysiological aspects of preleukemic disorders may shed light on aspects of cellular proliferation and cellular differentiation in the acute leukemias.

Inherited aplastic anaemia with increased endoreduplications: a new syndrome of Fanconi's anaemia variant?

Two sisters with aplastic anaemia without other congenital anomalies are described. Peripheral blood cytogenetic studies revealed an increase in endoreduplications in the absence of other unstable chromosome anomalies. Increased expression of T-antigen following SV40 virus infection in vitro was demonstrated in both sisters, as well as other normal family members. We feel that these patients represent a variant of Fanconi's anaemia. The importance of performing chromosome studies in idiopathic aplastic anaemia is emphasized.

Genetics of SV40 T-antigen expression: studies of twins, heritable syndromes and cancer families

Susceptibility of human skin fibroblasts to SV40 virus infection has been suggested as a marker of cancer risk. To evaluate the role of heritable factors in the regulation of SV40 T-antigen, fibroblasts from 9 pairs of identical twins and 129 members of cancer-prone families, including 16 with cancer, were tested in a 3-day immunofluorescence assay. In the twin study, the variance of T-antigen values was significantly less in identical than in fraternal or non-twin sibs, suggesting a heritable component in the regulation of SV40 infection. In the families, T-antigen values of parents and children were compared to models of Mendelian inheritance. At least three modes of inheritance--autosomal dominant, recessive, and X-linker--were observed. The distribution of offspring values compared to those of their parents suggested that interaction of multiple genetic factors influences the T-antigen value in individual patients. With the exception of Fanconi's anemia, the values for patients with cancer or predisposing syndromes were not uniformly elevated. The utility of this assay as a marker of cancer risk appears limited because of the complexity of factors that influence T-antigen expression in individual cases.

Double primary cancers in 2 young sibs, leukemia in another, and dextrocardia in a fourth

Two brothers developed multiple primary neoplasms in childhood; one had glioblastoma and non-Hodgkin's lymphoma at age 11 years, and the other brain tumor and acute leukemia at six years. A third brother died with myelogenous leukemia at thre years, and a fourth with cyanotic congenital heart disease at 11 weeks. Each child also had at least one hamartomatous lesion of the skin. The clinical features suggested von Recklinghausen's neurofibromatosis or other inherited cancer syndrome, but laboratory studies identified no markers of susceptibility to familial neoplasia.

Mutation and cancer in man

The risk of cancer can be increased by both genetic predisposition and environmental exposure. A common mechanism, mutation, may be involved in both. The rate of mutation in germ cells is the principal determinant of the incidence of genetically predisposed individuals, whereas the rate in somatic cells is the principal determinant in those not so predisposed. Many environmental carcinogens produce their effects via increased somatic mutation rates. The individuals of a population may be classified according to the operation of genetic predisposition, exposure to environmental carcinogens (mutagens), both, or neither. This last group reflects "background" somatic mutation rates.

SV40 T-antigen expression in skin fibroblasts from clinically normal individuals and from ten cases of Fanconi anemia

Previous studies of the expression of SV40 genetic information by skin fibroblasts included limited numbers of cell donors and failed to adequately consider possible effects of age, sex, and ethnic origin on assay results. A population of 76 healthy subjects were selected for study following determination of personal and family disease history and karyological analysis. Skin fibroblasts from these individuals were tested for expression of SV40 T-antigen by indirect immunofluorescent assay. The data were normally distributed and showed no significant differences between the age, sex, or ethnic groups tested. The occurrence of rare karyological anomalies in this control population had no effect on T-antigen expression. Fibroblasts from 10 Fanconi anemia patients demonstrated significantly elevated expression of T antigen compared to the well-defined control population, based on simple statistical criteria. T-antigen expression was elevated in two young patients prior to the onset of anemia and did not appear to correlate with the incidence or severity of other specific symptoms. Thus, elevated T-antigen expression in Fanconi anemia fibroblasts reflects an actual defect at the cellular level, rather than clinical, age, sex or ethnic factors not previously considered.

Klinefelter's syndrome and bladder cancer

A patient with Klinefelter's syndrome is described who also had transitional cell carcinoma of the bladder. His mother and maternal grandfather died of neoplasms. It is suggested that neoplasm and aneuploidy in the same family could have been caused by an inherited chromosomal instability rather than coincidence.

Cytogenetic analysis of X-ray-induced chromosome aberrations in spontaneously leukaemic AKR mice

The increased frequency of numerical and structural chromosomal aberrations in spontaneously leukaemic AKR mice, compared with the values of healthy control CBA/H-T6T6 mice, induced by X-irradiation, migh be connected with the predisposition to malignant growth, probably indirectly helping the virus activation, or acting together with the immune deficiency, by creating a weaker system that is more sensitive to carcinogenic agents.

Susceptibility of cells from patients with primary immunodeficiency diseases to transformation by simian virus 40

Skin fibroblasts were cultured from 15 patients with primary immunodeficiency diseases associated with a high cancer risk, including sex-linked agammaglobulinemia, IgA deficiency, variable immunodeficiency, ataxia-telangiectasia (cerebellar malfunction and abnormalities of blood vessels and immune response), Wiskott-Aldrich syndrome (low platelet count, eczema, and abnormal immune mechanism), and severe combined system (cellular and humoral) immunodeficiency. Fourteen of 15 cell strains were found to have low or regular susceptibility to transformation with the tumor virus, simian virus 40. The data are consistent with the view that the frequent occurrence of malignancy in patients with primary immunodeficiency is due to abnormalities of the immunologic surveillance mechanism.