Heparan sulfate glycosaminoglycans are receptors sufficient to mediate the initial binding of adenovirus types 2 and 5.

Cell infection by adenovirus serotypes 2 and 5 (Ad2/5) initiates with the attachment of Ad fiber to the coxsackievirus and Ad receptor (CAR) followed by alpha(v) integrin-mediated entry. We recently demonstrated that heparan sulfate glycosaminoglycans (HS GAGs) expressed on cell surfaces are involved in the binding and infection of Ad2/5 (M. C. Dechecchi, A. Tamanini, A. Bonizzato, and G. Cabrini, Virology 268:382-390, 2000). The role of HS GAGs was investigated using extracellular soluble domain 1 of CAR (sCAR-D1) and heparin as soluble receptor analogues of CAR and HS GAGs in A549 and recombinant CHO cell lines with differential levels of expression of the two receptors and cultured to various densities. Complete inhibition of binding and infection was obtained by preincubating Ad2/5 with both heparin (10 microg/ml) and sCAR-D1 (200 microg/ml) in A549 cells. Partial inhibition was observed when heparin and sCAR-D1 were preincubated separately with Ad. The level of heparin-sensitive [(3)H]Ad2/5 binding doubled in sparse A549 cells (50 to 70,000 cells/cm(2)) with respect to that of cells grown to confluence (200 to 300,000 cells/cm(2)), in parallel with increased expression of HS GAGs. [(3)H]Ad2 bound to sparse CAR-negative CHO cells expressing HS GAGs (CHO K1). No [(3)H]Ad2 binding was observed in CHO K1 cells upon competitive inhibition with heparin and in HS GAG-defective CHO A745, D677, and E606 clones. HS-sensitive Ad2 infection was obtained in CAR-negative sparse CHO K1 cells but not in CHO A745 cells, which were permissive to infection only upon transfection with CAR. These results demonstrate that HS GAGs are sufficient to mediate the initial binding of Ad2/5.

Co-existence of cutaneous T-cell lymphoma and B hairy cell leukemia.

A primary cutaneous form of peripheral T-cell lymphoma (PTCL) and a low grade B-cell non-Hodgkin's lymphoma that was classified as a variant of hairy cell leukemia (HCL) were simultaneously diagnosed in a 79-year-old woman by both phenotypic and genotypic analyses. The coexistence of a T- and B-cell lymphoma in the same patient is rare, and, to our knowledge, this particular association has not been previously described. The patient was referred to our Department for evaluation of multiple cutaneous itchy, reddish plaques; laboratory analyses disclosed a lymphocytosis, that presented 6 years earlier. A bone marrow aspirate showed a 50% B-cell interstitial infiltrate, while a skin biopsy surprisingly revealed a PTCL. Clonality of both neoplastic processes was assessed by Southern blot analysis. The indolent clinical course of the cutaneous disease, and the low and stable number of circulating neoplastic T cells supported the diagnosis of a mycosis fungoides (MF)-like PTCL. Possible oncogenic events and/or putative underlying viral infections which could have played a role in the occurrence of B- and T-cell non-Hodgkin's lymphomas in the same patient are discussed.

Anomalous transcripts and allelic deletions of the FHIT gene in human esophageal cancer.

The fragile histidine triad (FHIT) gene is localized on chromosome 3p14 and spans the common fragile site FRA3B. Even though its role in carcinogenesis is still unclear, this gene is frequently inactivated by carcinogen-induced intragenic deletions in many types of cancers, and FHIT abnormal transcripts are found in many primary tumors and tumor-derived cell lines. We evaluated FHIT gene involvement in 39 esophageal carcinomas (18 adenocarcinomas [AC¿, 21 squamous cell carcinomas [SCC]) by both reverse transcriptase-polymerase chain reaction (RT-PCR) amplification and loss of heterozygosity analysis (LOH). Thirty cases (77%) displayed either aberrant FHIT transcripts (12 cases) and/or LOH (24 cases); among these, only 6 samples displayed both aberrant transcripts and LOH, thus suggesting that the two events are probably independent. Moreover, LOH was significantly higher in SCC (80%) than in AC (44%), and because most of our patients are heavy smokers and/or alcohol consumers, these results suggest that the FHIT gene might be a common target for carcinogens also in the esophagus.

Identification of a 3 kb Alu-mediated BRCA1 gene rearrangement in two breast/ovarian cancer families.

Most of the hereditary breast cancers are attributed to constitutive alterations of either BRCA1 or BRCA2 genes; nonetheless, germline mutations of these genes in 'high risk' families are found less frequently than expected from linkage data. Recent findings suggest that major genomic rearrangements of the BRCA1 gene might account for at least some of the apparently mutation negative cases. We studied 60 affected probands belonging to families with a strong history of breast and/or ovarian cancer who scored negative for BRCA1 gene mutations by PTT and SSCP analysis. DNA was analysed by the Southern blotting procedure using three different restriction enzymes, and two probes obtained by RT-PCR of the 5' and 3' BRCA1 coding sequence. A 3 kb deletion encompassing exon 17 and causing a frameshift mutation was identified in two independently ascertained families. RT-PCR and long-range DNA PCR were employed to characterize the rearrangement that was finally shown to be the result of a recombination between two very similar Alu repeats. This type of mutation is not identified by the conventional methods of mutation detection which are based on PCR amplification of single exons. Therefore, further search for gene rearrangements is needed to better define the proportion of 'high risk' families that might be explained by gross genomic alterations of the BRCA1 gene.

Identification of seven new BRCA1 germline mutations in Italian breast and breast/ovarian cancer families.

We analyzed 16 Italian breast and breast/ovarian cancer families for BRCA1 germline mutations using a combination of the protein truncation test (PTT) and the single-strand conformation polymorphism techniques. Genomic DNA from the affected proband of each family was analyzed by applying the PTT to exon 11 of the BRCA1 gene. This initial screening led to the identification of truncated protein products in three families that were shown to carry three different frameshift mutations. In the families that scored negative in the PTT, single-strand conformation polymorphism analysis of the entire coding sequence of the gene revealed four additional mutations consisting of one nonsense, one in-frame deletion, one frameshift, and one missense mutation (in a family with a case of male breast cancer). The four frameshift mutations resulted in a decreased expression of the mutant allele, whereas no loss of transcript was associated with the other three mutations. All mutant alleles were shown to cosegregate with the cancer phenotype within the families, and none have previously been reported.