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Biomedical subjects

G Sozzi

Publications and source records attributed to G Sozzi.

At least 19 recordsLinked to original sources
PubMed2006

Effect of inducible FHIT and p53 expression in the Calu-1 lung cancer cell line.

Loss of FHIT expression and p53 mutations are critical events in the early stages of lung carcinogenesis. The restoration of Fhit function in FHIT-negative cancer cells has been reported to cause tumour suppression by inhibition of cell proliferation and/or activation of apoptotic pathways. However, the studies designed to elucidate the biological role of Fhit and its potential interaction with p53 have produced conflicting results. We investigated here the effects of the simultaneous restoration of FHIT and p53 in Calu-1 cells by using a hormone-inducible gene expression system. We demonstrate that the restoration of FHIT expression reinforces the anti-proliferative effect associated with the simultaneous replacement of p53. Indeed, a more pronounced inhibition of cell proliferation associated with an earlier and higher induction of p21(waf1) mRNA and protein expression was observed in Fhit/p53-expressing cells compared with cells expressing p53 alone. This effect was not due to Fhit-mediated up-regulation of p53 expression; in fact p53 protein was expressed at the same level in both FHIT-positive and FHIT-negative cell clones. Consistent with this result, Fhit did not affect the expression of MDM2, a protein known to interact directly with p53 and target p53 for proteolytic degradation, thus down-regulating its activity.

Acid Anhydride Hydrolases↗
PubMed2006

Increased sensitivity to cisplatin in non-small cell lung cancer cell lines after FHIT gene transfer.

To evaluate the relevance of fragile histidine triad (FHIT) status in relation to drug treatment, we analyzed the sensitivity of the Fhit-negative non-small cell lung cancer (NSCLC) cell line NCI-H460 to different drugs, after treatment with an adenoviral vector expressing the FHIT transgene. Expression of Fhit resulted in reduced sensitivity to etoposide, doxorubicin, and topotecan. This feature was associated with Fhit-induced downregulation of DNA topoisomerases I and II. In contrast, expression of Fhit did not modulate sensitivity to Taxol, but produced a slight increase in sensitivity to cisplatin, as shown by colony-forming assays. Analysis of apoptosis revealed that, after cisplatin exposure, the number of apoptotic cells was two-fold higher in Fhit-expressing H460 cells. Moreover, it appeared that wildtype p53 was required for sensitization to cisplatin because the effect was marginal in A549 and Calu-1 cells, where the p53 pathway is altered and simultaneous restoration of p53 and Fhit in Calu-1 cells increased cisplatin sensitivity. Fhit could also partially restore sensitivity to cisplatin in Bcl-2- and Bcl-x(L)-overexpressing H460 cells that are normally resistant to this drug. Our results support the possible relevance of FHIT in cisplatin-based chemotherapy as well as in the reversal of drug resistance in NSCLC.

Acid Anhydride Hydrolases↗
PubMed2002

Detection of bladder cancer by multitarget multicolour FISH: comparative analysis on archival cytology and paraffin-embedded tissue.

Detection of bladder cancer by multitarget multicolour FISH: comparative analysis on archival cytology and paraffin-embedded tissue We have evaluated the possibility of using the same specimen for both cytological diagnosis and multitarget multicolour FISH (MtMcFISH) analysis in order to determine whether the routinely processed specimens used for diagnosis were also suitable for this ancillary procedure. For this purpose 18 positive samples (11 voided urine and seven bladder washings) were selected, together with a representative section of the corresponding immediately previous or subsequent histological specimens. Two negative cytology slides were added as negative controls. FISH analysis revealed a normal pattern for each probe in the two negative controls and an abnormal pattern in the 18 positive cases. In the latter the same FISH alterations were found in the cytology samples and in the corresponding histological sections, and superimposable cytological/histological features were observed in two cases where two different histology samples were analyzed. The results clearly show that MtMcFISH may be successfully applied to destained routinely processed cytology slides.

Carcinoma, Transitional Cell↗
PubMed2001

SYT-SSX fusion genes and prognosis in synovial sarcoma.

A case series of 64 synovial sarcomas was characterized for the SYT-SSX fusion transcripts and statistically analysed in order to correlate molecular data with prognosis and morphology. SYT-SSX1 fusion transcript appeared to be an independent, though not reaching statistical significance (P = 0.183), prognostic factor clearly associated with a reduced metastasis-free survival. Regarding the association between transcript type and histologic subtype we found, a borderline P value (P = 0.067) between the SYT-SSX1 transcript and the biphasic subtype which, subsequently expanding the analysis to 70 cases, turned out to be significant. However, we could not confirm the prediction value of the biphasic subtype for the presence of the SYT-SSX1 transcript since in our hands 6 out 33 (18%) biphasic tumours carried the SYT-SSX2 transcript.

Adolescent↗
PubMed2001

c-KIT and c-KIT ligand (SCF) in synovial sarcoma (SS): an mRNA expression analysis in 23 cases.

In a previous immunophenotypic molecular-based analysis it was shown that bcl2 over-expression characterizes the SS gene profile in addition to the non-random translocations. Here we show that the over-expression of an additional potentially antiapoptotic gene, the c-KIT gene, is associated with this tumour. Interestingly, whereas bcl2 over-expression appears to be restricted to the spindle cell tumoral component, c-kit mainly involves the epithelial component of biphasic SS. Twenty-three primary and metastatic samples from 21 patients were analysed by immunophenotyping (23/23), immunoprecipitations and Western blotting (3/23), and RT-PCR (23/23). Ten cases were biphasic and 13 monophasic in sub-type. Twelve, 10 and 1 case carried the SYT-SSX1, SYT-SSX2 and SYT-SSX4 fusion transcript, respectively. Co-presence of both c-Kit and SCF mRNA was observed in almost all cases (20/23), suggesting the occurrence of an autocrine loop. Immunophenotyping, confirmed by biochemical analyses, showed a modulation of c-Kit expression which was faint in the spindle and strong in the epithelial component, respectively. The study was complemented by c-Met/HGF receptor/ligand expression and c-Met protein analysis with results superimposable to those already reported. Since in each tumour, epithelial and spindle cell components harbour the same type of translocation t(X;18) the present findings suggest a shifting of the anti-apoptotic role from BCL2 to c-KIT gene during the transition from the uncommitted spindle to the differentiated epithelial cells.

Adolescent↗
PubMed2001

Analysis of circulating tumor DNA in plasma at diagnosis and during follow-up of lung cancer patients.

We evaluated whether the amount of circulating DNA in plasma could discriminate between lung cancer patients and healthy individuals and whether it is related to disease progression, and we analyzed the kinetics of plasma DNA in disease-free, surgically resected patients. Plasma DNA quantification and analysis of microsatellite alterations were performed in a consecutive series of 84 patients with non-small cell lung cancer, who were studied during follow-up, and 43 healthy controls. In patients, the mean values of plasma DNA concentration were higher than in controls even considering stage Ia patients. Sensitivity and specificity estimates were calculated as the area under the receiver operating characteristic curve (AUC-ROC) curve and showed a value of 0.844. Variations in DNA level and in microsatellite changes correlated with the clinical status of 38 patients monitored during follow-up. The data suggest that quantification and molecular characterization of plasma DNA in lung cancer patients are valuable noninvasive diagnostic tools for discriminating patients from unaffected individuals and for detecting early recurrence during follow-up.

Adult↗
PubMed2001

Identification of a novel spliced variant of the SYT gene expressed in normal tissues and in synovial sarcoma.

Synovial sarcoma (SS) is cytogenetically characterized by the translocation t(X;18)(p11.2-q11.2) generating a fusion between the SYT gene on chromosome 18 and one member of the SSX family gene (SSX1; SSX2; SSX4) on chromosome X. Here, we report for the first time that 2 forms of SYT mRNA are present in both normal tissues and SSs. By amplifying the full-length SYT cDNA of two SSs, we detected 2 bands, here designated N-SYT and I-SYT. The latter, previously undescribed, contains an in-frame insertion of 93 bp. Its sequencing revealed a 100% homology with the mouse SYT gene. These two SYT forms were present, although in different amounts, in all human normal tissues examined, including kidney, stomach, lung, colon, liver and synovia. Coexistence of N-SYT and I-SYT (both fused with SSX) was detected in a series of 59 SSs (35 monophasic and 24 biphasic) and in a SS cell line. A preliminary analysis of the differential expression levels of N-SYT and I-SYT in SSs revealed that the latter was consistently overexpressed, suggesting a role in SS pathogenesis.

Alternative Splicing↗
PubMed2001

Effect of adenoviral transduction of the fragile histidine triad gene into esophageal cancer cells.

Reintroduction of a tumor suppressor gene product in cancer cells is a promising strategy for cancer gene therapy. The fragile histidine triad (FHIT) gene has been identified in a region at chromosome 3p14.2, which is deleted in many tumors, including esophageal cancer. Previous studies have shown frequent biallelic alterations of the FHIT gene in numerous tumors, and have demonstrated a tumor suppressor function of Fhit. We have studied the biological effects of adenoviral-FHIT transduction in esophageal cancer cell lines. Results showed suppression of cell growth in vitro in three of seven esophageal cancer cell lines, all seven of which showed abundant expression of the transgene. Adenoviral-FHIT expression, but not control adenoviral infections, induced caspase-dependent apoptosis in two esophageal cancer cell lines, TE14 and TE4, which express no or very little Fhit, respectively. Treatment of TE14 cells with adenoviral-FHIT vectors resulted in abrogation of tumorigenicity in nude mice. A third esophageal cancer cell line, TE12, without detectable endogenous Fhit, showed accumulation of cells at S to G2-M and a small apoptotic cell fraction after adenoviral-FHIT transduction. Thus, adenoviral-FHIT expression can inhibit the growth of esophageal cancer cells, at least in part through caspase-dependent apoptosis, suggesting that adenoviral-FHIT infection should be explored as a therapeutic strategy.

Acid Anhydride Hydrolases↗
PubMed2001

Refinement within single yeast artificial chromosome clones of a minimal region commonly deleted on the short arm of chromosome 7 in Wilms tumours.

Cytogenetic and molecular data indicate an involvement of genes mapped to the proximal portion of the short arm of chromosome 7 (7p) in Wilms tumours (WTs). We have analysed 38 WTs using a panel of eight microsatellite markers mapped to proximal 7p. Loss of heterozygosity (LOH) in tumour, compared with matched constitutional DNA, was identified in eight cases. To define better the minimal region commonly deleted in these tumours, they were analysed with nine additional markers, mapped within the region of interest. One tumour (case 30) showed LOH for only one marker (D7S510), while maintaining heterozygosity for the two immediately flanking loci (D7S555 and D7S668). This result was confirmed by fluorescence in situ hybridisation analysis, which showed that in the majority (65%) of nuclei from tumour 30 hybridising with a bacterial artificial chromosome clone containing the D7S510 locus, only one signal was visible. Noticeably, both markers defining the limits of the observed deleted region are simultaneously present within two distinct overlapping yeast artificial chromosome (YAC) clones mapped to chromosome bands 7p13-p14. This suggests that the maximum length of the missing DNA fragment was approximately 1.3 Mb, corresponding to the length of the smaller of the two YAC clones. In all other cases that showed LOH, the deletion encompassed the 7p13-p14 region. For this reason, we speculate that the identified interval contains a gene whose inactivation is important for the development of at least a fraction of WTs.

Child↗
PubMed2000

Low grade fibromyxoid sarcoma. a further low-grade soft tissue malignancy characterized by a ring chromosome.

Supernumerary rings in the context of a simple karyotype characterize several low-grade malignant tumors of soft tissue and bone. Low-grade fibromyxoid sarcoma is an uncommon low-grade sarcoma, the cytogenetics of which has not yet been reported. Here we describe the first molecular-cytogenetic characterization of a pulmonary metastasis of low-grade fibromyxoid sarcoma. The histology of the primary and recurrent tumors was consistent with the diagnosis of low-grade fibromyxoid sarcoma of the usual type, whereas the pulmonary metastasis was of the "giant rosettes" variant. Cytogenetic analysis revealed a ring chromosome. Because gain of material of chromosomes 7 and 16 was detected by CGH, the ring chromosome is assumed to be composed of material from these respective chromosomes.

Adult↗
PubMed2000

A novel zinc finger gene is fused to EWS in small round cell tumor.

Ewing sarcoma family of tumors share recurrent translocations that fuse EWS from 22q12 to five different members of transcription factors namely FLI-1, ERG, ETV1, E1AF and FEV. Different classes of DNA binding proteins, ATF1, WT1 and CHOP are fused to EWS generating distinct tumor phenotypes: clear cell sarcoma, desmoplastic small round cell tumor, and myxoid liposarcoma, respectively. We have cloned a novel gene located at 22q12 fused to EWS by a submicroscopic inversion of 22q in a small round cell sarcoma showing a translocation (t(1;22)(p36.1;q12). The gene, designated ZSG (Zinc finger Sarcoma Gene), is a putative Cys2-His2 zinc finger protein which contains a POZ transcriptional repressor-like domain at the N-terminus. The rearrangement involves intron 8 of EWS and exon 1 of ZSG creating a chimeric sequence containing the transactivation domain of EWS fused to zinc finger domain of ZSG. This product lacks the transcriptional repressor domain at the N-terminus of ZSG. A rearrangement of the second ZSG allele was also found in tumor cells. This is the first example of an intra-chromosomal rearrangement of chromosome 22, undetectable by cytogenetics, activating EWS in soft tissue sarcoma.

Adolescent↗
PubMed2000

Low frequency of alterations of the alpha (PPP2R1A) and beta (PPP2R1B) isoforms of the subunit A of the serine-threonine phosphatase 2A in human neoplasms.

The phosphatase 2A (PP2A) is one of the major cellular serine-threonine phosphatases. It was recently shown that the gene encoding for the beta isoform of its subunit A, PPP2R1B, is altered in human lung and colorectal carcinomas, suggesting a role in human tumorigenesis. Here, we report the detection of mutations in breast, lung carcinomas and melanomas in the genes of both alpha (PPP2R1A) and beta isoforms. Mutations affecting PPP2R1B were found in four breast carcinomas, while mutations in PPP2R1A were found in carcinomas of the breast and of the lung and in one melanoma. Most of the mutations affecting PPP2R1B were exons deletions, suggesting abnormal splicing. These splicing abnormalities were detected in tumor samples in the absence of the normal splicing product, and were not found in several normal controls. In one case, a homozygous deletion present in tumor DNA, and not in the matched normal control was demonstrated. Mutations affecting the PPP2R1A gene were nucleotide substitutions changing highly conserved amino acids and one frame-shift. Although the frequency of alterations is low, the inclusion of both isoforms of subunit A in the genes mutated in human cancer and the addition of breast cancer to the list of neoplasms in which PPP2R1B is altered, strengthen the potential role of PP2A in human tumorogenesis.

Amino Acid Substitution↗
PubMed2000

Analysis of SYT-SSX fusion transcripts and bcl-2 expression and phosphorylation status in synovial sarcoma.

Synovial sarcomas (SS) are characterized by a chromosomal translocation t(X;18)(p11.2;q11.2) which usually fuses the SYT gene from chromosome 18 to SSX1 or SSX2 genes on chromosome X. Also, a variant SYT-SSX4 fusion gene has recently been shown in a single SS case. In addition to these cytogenetic changes, bcl-2 expression, as assessed by immunohistochemistry, has been reported to be an almost general constitutive alteration of SS. In the present work, we analyze a series of 36 SS surgical samples (from 34 patients) by RT-PCR for the presence of the SYT-SSX1 or the SYT-SSX2 fusion transcript. The analysis was extended to SYT-SSX4 on SYT-SSX1-negative and SYT-SSX2-negative cases only. Our results showed a significant correlation between the SYT-SSX2 fusion and the monophasic SS histologic subtype. SYT-SSX1 fusion transcripts were present in both monophasic and biphasic tumors. The SYT-SSX4 fusion type was detected in a single monophasic SS. In the same series of SS cases, we also confirmed and extended the previously reported constitutive expression of bcl-2 protein, by using both immunohistochemical and western blot analysis. Moreover, we demonstrated that the BCL-2 gene is not rearranged or amplified at genomic level, indicating that the high levels of bcl-2 expression observed in SS might result from transcriptional activation of the gene and/or protein stabilization. Finally, we show that bcl-2 is not phosphorylated in tumors from patients who had been preoperatively treated with radio/chemotherapy, in tumors from untreated patients, or in an SS cell line (CME-1) after in vitro treatment with cytotoxic concentrations of DNA-damaging agents or taxanes. These data indicate that SS cells are unable to activate an apoptosis pathway involving bcl-2 phosphorylation/inactivation and may provide a possible explanation for the limited effectiveness of conventional pharmacological treatments of this tumor type.

Adolescent↗
PubMed2000

The expression of MDM2/CDK4 gene product in the differential diagnosis of well differentiated liposarcoma and large deep-seated lipoma.

Ordinary lipomas are cytogenetically characterized by a variety of balanced rearrangements involving chromosome segment 12q13-15, whereas well differentiated liposarcomas (WDL) show supernumerary ring and giant marker chromosomes, known to contain amplified 12q sequences. The tight correlation between the presence of ring chromosomes and both amplification and overexpression of MDM2 and CDK4 genes suggests the exploration of the possibility that immunocytochemistry (ICC) might assist in the differential diagnosis of lipoma-like well differentiated liposarcomas (LL-WDL) and large deep-seated lipomas (LDSL). For this purpose, 21 cases of the former and 19 cases of the latter tumours were analysed by ICC and, according to the availability of material, by molecular and cytogenetic approaches. All lipomas displayed a null MDM2/CDK4 phenotype, whereas all LL-WDL showed MDM2/CDK4 or CDK4 phenotypes. Southern blot analysis performed on 16 suitable cases, complemented by fluorescence in situ hybridization and classical cytogenetic analysis in 11 cases, was consistent with, and further supported the immunophenotyping data. In conclusion, MDM2/CDK4 product-based immunophenotyping appears to represent a valuable method for the categorization of arguable LDSL.

Adult↗
PubMed2000

Morphologic-cytogenetic analysis of dedifferentiated liposarcomas with an extensive misleading leiomyosarcomatous component.

This report describes two cases of recurrent retroperitoneal dedifferentiated liposarcoma characterized by an extensive leiomyomatous component that prevented the correct diagnosis before the last recurrence. Strong immunoreactivity with smooth muscle and desmin antibodies and ultrastructural features consistent with leiomyosarcoma were observed in the spindle-cell and/or myxoid-like components in all four recurrences in case 1, and in the spindle-cell component of the primary tumor and the first recurrence in case 2. In case 1, the correct diagnosis was suggested by the cytogenetic evidence of ring markers, a hallmark of well-differentiated/dedifferentiated liposarcoma. In case 2, tumor type was yielded mainly by the morphology of the second recurrence, which consisted entirely of a well-differentiated liposarcoma, a sclerosing inflammatory variant, as confirmed by the karyotype. Reevaluation of the first two surgical specimens of each case revealed small areas consistent with well-differentiated liposarcoma that had been previously overlooked. Despite the smooth-muscle antigen profile, both cases retained an mdm2+/p53+/cdk4+ immunophenotype consistent with the genotype.

Aged↗