Biomedical subjects
Publications and source records attributed to G Sozzi.
We report the cytogenetic analysis of five cases of follicular thyroid adenoma. In two of them, we observed an identical t(2;3)(q12-13;p24-25) as a unique chromosome change. A third case showed a hyperdiploid karyotype with trisomies of chromosomes 7 and 12. Two cases had a normal diploid karyotype. These changes could define subgroups of follicular adenomas endowed with different malignant potential.
A family of growth arrest specific (Gas) genes was operationally defined on the basis of the strategy utilized to isolate them e.g. differential expression in quiescent and growing cells. Our interest in the Gas-3 gene was prompted by our previously reported localization of the gene on the mouse chromosome 11.44 +/- 1.9 cM proximal to the Trp53 locus and by the finding, by others, that it codes for a myelin protein and that a point mutation in its fourth putative transmembrane region is associated with the trembler mutation. We have isolated the human homologous of the mouse Gas-3 gene and utilized the cloned sequences as a probe to localize the gene on human chromosomes both by analysis of human-rodent somatic cell hybrids and in situ hybridization of human metaphases. We have now localized the human Gas-3 gene on chromosome 17p12-13. Its possible role in both the development of neoplasia in neurofibromatosis patients and in the myelin degenerative disease as the Charcot-Marie-Tooth is discussed.
Human melanoma provides a model to study malignant transformation and tumor progression. Expression of ras oncogenes in cultured normal human diploid melanocytes has induced a subset of phenotypic traits that are characteristic of malignant melanoma cells, including altered morphology, anchorage independence, induction of class II MHC antigens, up-regulation of the ganglioside GD3, and chromosomal abnormalities. However, other characteristics of melanoma, such as loss of expression of adenosine deaminase-binding protein and tumorigenicity, were not observed. We report here that melanocytes infected with a retrovirus containing the viral Ha-ras oncogene underwent complete transformation, acquiring all phenotypic characteristics of malignant melanomas observed in vivo. Transformation occurred in a sequential manner and was associated with spontaneous chromosomal instability. Cytogenetic analysis of transformed melanocytes indicated that the earliest structural chromosomal abnormalities were isochromosomes 6p and 9q followed by complete loss of chromosome 1p, all common karyotypic abnormalities described in human melanomas. The findings suggest that these chromosome regions which are deleted or relatively deficient may contain genes that are critical for the initiation and progression of the melanoma phenotype.
A cytogenetic analysis was performed on direct preparations and short-term cell cultures of lung tumor and normal bronchial epithelium of 19 patients carrying either a first or a second primary lung cancer. In 9 tumors (6 squamous cell carcinomas, 1 adenocarcinoma, 1 mucoepidermoid carcinoma, and 1 small cell lung carcinoma) successfully analyzed, pseudodiploid and hyperdiploid karyotypes were observed with a heterogeneous pattern of chromosome abnormalities but with a consistent involvement (5 cases) of the short or the long arm of chromosome 3. The normal bronchial epithelial cells had a normal karyotype in 11 patients, whereas in 6 patients clonal and nonclonal chromosomal abnormalities were observed. Involvement of chromosome 7 was present in 4 cases. In addition, overexpression of the growth factor receptors, epidermal growth factor receptor and HER-2/neu, was found in 9 of 18 tumors and in 6 of 13 bronchial epithelium samples. These findings suggest that early genetic lesions could be present in the normal bronchial epithelial cells that are the target of further complex and multiple genetic changes occurring during the pathogenesis of lung cancer.
The chromosomal localization of hTMnm, a gene coding for a cytoskeletal tropomyosin non-muscle isoform involved in the activation of the TRK proto-oncogene in various human tumors, was determined by Southern blot analysis of a panel of human-rodent somatic cell hybrids. Using as a probe an Alu-free intronic fragment related to the tropomyosin sequence fused to the TRK tyrosine kinase domain, the hTMnm gene was assigned to the long arm of chromosome 1. Subsequently, in situ hybridization of the same probe to human metaphase chromosomes localized the hTMnm gene to 1q31. Since we have recently assigned the TRK locus to chromosome 1q32-q41, the generation of the hybrid transforming sequence tropomyosin-TRK may be due to an intrachromosomal rearrangement of the long arm of chromosome 1.
In this report we confirm the localization of the human RET proto-oncogene to chromosome 10q11.2, both by Southern blot analysis of a panel of human-rodent somatic cell hybrids and by in situ hybridization on human metaphase chromosomes. Previously, we had assigned to the same chromosome region the gene termed H4. In about 25% of papillary thyroid carcinomas, this gene was shown to rearrange with RET to give rise to the transforming sequence PTC. The analysis of different cell hybrids containing subfragments of chromosome 10, in conjunction with pulse field gel electrophoresis, established that H4 is mapped distally to RET at a distance not less than 280 kb. These findings suggest that intrachromosomal rearrangements are responsible for PTC activation in papillary thyroid carcinomas.
Short-term cultures of three cases of peripheral neuroepitheliomas were studied using G-banding technique. A t(11;22)(q24;q12) was recognized in all three tumors. The results strengthen the hypothesis of a common histogenesis for neuroepithelioma, Ewing's sarcoma, and the Askin tumor.
A cytogenetic analysis of a lung metastasis of an adamantinoma of the tibia, a rare tumor of the long bones, revealed a karyotype 52, XY, t(7;13)(q32;q14), +7, +12, +13, +19, +der(7) t(7;13), +der(13) t(7;13). The t(7;13) was found to be constitutional in the patient and was also present in peripheral blood lymphocytes of his unaffected father. However, both subjects displayed normal levels of esterase D enzyme activity.
Chromosome analysis in short-term lines of three primary and seven metastatic malignant melanomas showed aneuploid karyotypes with recurrent abnormalities of chromosomes 1 (five cell lines), 6 (nine cell lines), and 7 (six cell lines). The breakpoints observed on the rearranged chromosomes frequently coincided with loci of known oncogenes and fragile sites. Two of the cell lines were analyzed after xenograft into nude mice and showed the presence of the same chromosomal changes observed in the parental cell lines, indicating the stability of the karyotype. A tendency toward an increased chromosomal fragility in peripheral blood lymphocytes was observed in five melanoma patients compared to ten normal individuals. However, there was no increased level of expression of specific fragile sites corresponding to the breakpoints observed in melanoma cells.
A cytogenetic study was performed in 27 patients suspected of t-MDS or t-ANLL. In 12 patients the diagnosis of t-MDS or t-ANLL was confirmed by morphological, cytochemical and immunophenotypical analysis. The cases were classified as RA (one), RAEB (four), CMML (two), ANLL (five). They had received chemotherapy and/or RT for Hodgkin's disease (eight cases), solid tumours (three cases) and multiple myeloma (one case). Clonal chromosome abnormalities were found in bone marrow or peripheral blood cells in all the 12 cases. Five patients had a clonal abnormality of chromosome no. 5 (monosomy, deletions, translocation and inversion of 5q). The critical region on chromosome no. 5 comprised bands q12-q34. Monosomy and deletion of chromosome 7q was observed in the other two patients. In the six remaining patients various karyotypic patterns were observed including a t(4;11) (q21;q23) in one case, monosomies (four cases) and trisomies (one case) of different chromosomes. In the other 15 cases, the presence of a normal karyotype together with the morphological and immunophenotypical characterisation was consistent with a diagnosis of non-neoplastic specimens.
Experimental studies have suggested that the pineal hormone melatonin, in addition to its documented antineoplastic action, plays a role in the physiological regulation of blood cell proliferation. Based on these data, we evaluated the clinical effects of melatonin therapy in patients with myelodysplastic syndrome (MDS) secondary to cancer chemotherapy for primary neoplasms. The study was carried out on six patients, and melatonin was given orally at a dose of 20 mg/daily, following a schedule prepared to reproduce the circadian rhythm of the pineal hormone. A transient improvement in platelet and neutrophil count was achieved in two of five patients with thrombocytopenia and in two of four patients with neutropenia before therapy, respectively, while no effect was seen on hemoglobin concentration. Mean survival time was 12.5 months, and a long survival, greater than 30 months, was achieved in two of six patients. These preliminary results seem to suggest that melatonin may have a role in the treatment of MDS induced by previous cancer chemotherapy.
A 42-year-old Italian man affected with a multisystemic disease is presented. The main features were: polyneuropathy, organomegaly (liver, spleen and lymph nodes enlargement), endocrinopathy (loss of libido, low plasmatic levels of testosterone), monoclonal protein (k-light chains only in 100-fold-concentrated urine sample, without other signs of plasmocytic proliferation), skin changes. Clinical skin alterations were striking: diffuse thickening, hyperpigmentation, hyperhidrosis , hypertrichosis, while histo- and immunopathological examination of skin biopsies showed proliferation of dermal collagen fibers and deposition of melanin in the epidermis. These findings were suggestive for the diagnosis of Crow-Fukase (POEMS) syndrome, associated with peculiar angiofollicular lymph node hyperplasia (Castleman's disease). The patient was followed up for 15 months with steroids, systemic chemotherapy, plasma-exchange and immunomodulating drugs. A massive anasarca complicated the picture leading him to death. Actually the pathomechanisms of this rare disease have not been fully elucidated. The relations between this syndrome and some malignant lymphoproliferative diseases (i.e. osteosclerotic myeloma) are controversial; at least a part of its features could be either reactive or tissue-specific-antibody mediated. A genetic influence should be suggested from the Japanese reports.
The chromosomal localization of TRK, a gene coding for a putative receptor molecule with an associated tyrosine kinase activity that we have found activated in 25% of patients with papillary thyroid carcinoma, was determined by Southern blot analysis of a panel of human-rodent somatic cells using a cDNA clone containing the entire human TRK proto-oncogene (Martin-Zanca et al., 1986). The TRK gene was assigned to chromosome 1. One hybrid that had retained only the short arm of the human chromosome 1 was negative. Subsequently, in situ hybridization of the same probe to human metaphase chromosomes localized the TRK gene to 1q32-q41.
The authors describe a case of chronic neutrophilic leukemia (CNL) showing trisomy of chromosome 8. This anomaly, particularly common in cases of myelodysplastic syndrome (MDS), has never been previously found to be associated with this rare type of leukemia. Thus CNL may occasionally be cytogenetically indistinguishable from cases of MDS.
In this report we assigned to chromosome 10q the human oncogene PTC frequently associated with the papillary type of thyroid carcinoma. Using an informative panel of human-mouse somatic cell hybrids and 'in situ' hybridization to human metaphase chromosomes, we localized the PTC gene at bands q11-q12 of chromosome 10. These bands belong to one of the two regions on chromosome 10 linked to the cancer syndrome multiple endocrine neoplasia type 2A (MEN2A). Therefore, it is suggested that genes clustered in certain regions of chromosome 10 could be involved in the developmental regulation of the thyroid gland.
Blast cells from five cases of secondary unclassifiable leukemia following therapy for Hodgkin's disease were studied by cytochemical, immunological and cytogenetic analyses. Cytochemical and immunological reactivity were in accordance with poorly differentiated, myeloid blasts. The four cases in which karyotype analysis was performed showed specific chromosomal abnormalities. No evidence of multiple lineage involvement was found. Problems in classifying these cases of secondary ANLL were due to the high grade of undifferentiation of the blast cells. Their low cytochemical reactivity with markers of myeloid differentiation was similar to what may be observed in patients with acute undifferentiated leukemia or with chronic myeloid leukemia in blast crisis.
Twenty-one clones from an early culture of a histocompatibility leukocyte antigen (HLA) class II negative human metastatic melanoma (Me 9229) were screened for susceptibility to phenotypic modulation induced by recombinant interferon-gamma (rIFN-gamma) by using SPV-L3, a monoclonal antibody to HLA-DQ antigens, in indirect immunofluorescence followed by fluorescence-activated cell sorter analysis. After treatment with 500 U/ml of rIFN-gamma for 3 days one of the clones (9229/18) expressed high levels of DQ antigens, in terms of percentage of positive cells, whereas many other clones were much less susceptible or remained DQ negative. Scatchard analysis of the data of specific binding of 125-I-labeled rIFN-gamma revealed that one clone susceptible (9229/18) and one clone resistant (9229/5) to HLA-DQ modulation expressed similar numbers of interferon-gamma binding sites per cell; dose-response experiments showed that all clones could be induced to express HLA-DR and -DP antigens after exposure to rIFN-gamma. However, the DQ-negative profile of clone 9229/5 was not modified even after incubation with up to 1 X 10(4) U/ml of rIFN-gamma or by extending the culture time in the presence of this lymphokine up to 120 hr. Furthermore, Northern blot analysis indicated a direct correlation between changes in the levels of HLA-DR and -DQ-specific mRNA after rIFN-gamma treatment, and the lack or expression of HLA class II antigens at the cell surface of the two different clones. Karyotype studies did not reveal differences between clones 9229/5 and 9229/18 and Southern blot analysis indicated that both clones had similar EcoRI and HindIII restriction patterns for DR and DQ gene sequences. Finally, strong DQ-specific mRNA signal and antigen expression at the cell surface could be induced even on clone 9229/5 by treating the cells with supernatants from mixed lymphocyte cultures, recently shown to contain a class II-inducing factor different from interferon-gamma. Taken together these results indicate that DQ antigens can be modulated even in clones resistant to rIFN-gamma induction and suggest that the differential susceptibility observed in response to this lymphokine could play a role in the genesis of the phenomenon of intratumor heterogeneity.
Although amitriptyline is not usually regarded as toxic to the peripheral nervous system (PNS) and is even prescribed by some for neuropathic pain, there are sporadic reports of peripheral neuropathy following overdose or prolonged use of the drug. The scarcity of data leads us to report a case we have followed for 3 years clinically and electromyographically. A 54 year old man on oral amitriptyline 150 mg uninterruptedly for 2 years consulted us for lower limb paresthesias and was found on clinical examination to have reduced ankle jerks and mild distal global hypoesthesia. EMG yielded a pattern of sensorimotor neuropathy compatible with axonal disease in all four limbs. The history was unremarkable and the laboratory data were within normal limits. After discontinuation of amitriptyline therapy both the clinical and EMG pattern gradually normalized. We draw attention to the possible risk, infrequent though it is, of PNS neurotoxicity of a widely used drug reputedly harmless from this point of view.