Toshitada Takahashi

Clinicopathologic study of large cell anaplastic lymphoma (ki‐1‐positive large cell lymphoma) among the japanese

The clinical, prognostic, phenotypic, and genotypic findings of 30 patients with large cell anaplastic lymphoma (Ki‐1‐positive large cell lymphoma) were analyzed. There were 13 male and 17 female patients (male‐female ratio, 0.8) whose ages ranged from 3 to 81 years of age (mean, 28 years of age; 67% of the patients younger than 30 years of age). The 5‐year survival rate was 52%; this was better than that of other types of high‐grade peripheral T‐cell lymphoma. Histologic examination showed distinctive morphologic features such as tumor cell pleomorphism, sinus infiltration, fibrosis, partial lymph node involvement, sparing of B‐cell regions, and occasional plasma cell infiltrates. Eighty percent of the cases were of T‐cell phenotype, and others expressed neither B‐cell nor T‐cell markers. The tumors were frequently positive for a histocompatibility antigen (HLA‐DR), CD25 (the interleukin‐2 receptor), and epithelial membrane antigen. Rearrangements of the T‐cell receptor beta gene were observed in nine of 13 cases (69%). These findings indicated that many of the tumors had the phenotype and genotype of activated T‐cells. This study also showed that large cell anaplastic lymphoma has a survival figure intermediate between Hodgkins disease and low‐grade peripheral T‐cell lymphoma.

MONOCLONAL ANTIBODY AGAINST PRAD1/CYCLIN D1 STAINS NUCLEI OF TUMOR CELLS WITH TRANSLOCATION OR AMPLIFICATION AT BCL-1 LOCUS

Mouse monoclonal antibodies were produced against the bacterial product encoded by human PRAD1/ cyclin Dl gene, which is known to be involved in tumors with translocation or amplification at BCL‐1 locus of 11ql3. The immunizing antigens used were GST‐PRAD1 and T7 gene 10‐PRAD1 fusion products. Four antibodies were reactive with both PRAD1 fusion products and cell lysates of B‐cell tumor cell lines with t(ll;14)(ql3;q32) and a breast cancer cell line with 11ql3 amplification, on immunoblotting. An immunofluorescence study showed that only one of them stained nuclei of cells with 11q13 abnormalities. Since this antibody proved applicable for conventional paraffin‐embedded tissue sections, immunohistologic staining of various lymphoma tissues was performed. Eight of 11 mantle cell lymphomas showed intermediate to strong positivity and 6 of the positive cases demonstrated characteristic staining patterns that were either predominantly nuclear or both nuclear and cytoplasmic. The nuclear staining pattern was not observed with other types of lymphoma and thus may correlate with PRAD1 mRNA overexpression.

Phenotypic analysis of peripheral T cell lymphoma among the Japanese

From 1980 to 1990, 174 peripheral T cell lymphomas were studied morphologically and immunophenotypically with a panel of monoclonal antibodies which were reactive with T cell differentiation antigens in cryostat sections and/or cell suspensions. Histologically, 57% of the lymphomas were categorized into low‐grade tumors according to the updated Kiel classification, while 41% were high‐grade tumors. By immunologic studies, 50% of the lymphomas were of helper/inducer (CD4) phenotype, 6% were of cytotoxic/suppressor (CD8) phenotype, 3% expressed both CD4 and CD8, 3% lacked both CD4 and CD8, and 36% were phenotypically undetermined because of an admixture of a fairly even number of CD4 and CD8‐positive cells. The phenotypically undetermined cases were more frequently noted in the low‐grade groups than in the high‐grade group, and the latter often showed a loss of pan‐T antigens, although there was no definite correlation between the histologic category and the immunophenotype. CD25, which is strongly manifested in anti‐HTLV‐1 antibody‐positive cases, was negative or only weakly expressed in anti‐HTLV‐1 antibody‐negative cases. Anaplastic large cell lymphomas (LC‐Ana) strongly expressed CD30, which was also detectable in only large blast‐like cells in the low‐grade tumors. Seventy‐one per cent of the lymphomas expressed la antigens. In this series, the clinical data were available on 154 patients. For individual markers, the expression of CD30 and HLA‐DR were associated with a longer actuarial survival (P< 0.01 and P < 0.05 by the generalized Wilcoxon test). The absence of CD25 or the presence of CD3 on tumor cells correlated with a relatively favorable prognosis, but not significantly. The detection of CD4 and CD8 had relatively little prognostic value. In the cases excluding LC‐Ana, a significant difference was also recognized between the groups with and without CD25, CD30 and HLA‐DR (P < 0.05 by the generalized Wilcoxon test). These results suggest that the immunophenotypic analysis of peripheral T cell lymphoma provided its use as an adjunct to a histopathologic diagnosis and was related to prognostic prediction.

Clinicopathologic study of 212 cases of peripheral T-cell lymphoma among the Japanese

Background. Postthymic/peripheral T‐cell malignancy shows significant histopathologic and clinical diversity, even in its prognosis, and the correlations remain to be debated.

Alterations of Integrin Expression in Human Lung Cancer

Integrins are cell‐surface receptors which are involved in cell‐matrix and/or cell‐cell adhesion. They have been suggested to play a role in tumor invasion and metastasis. We examined the expression of various integrin subunits in normal and cancer cells of the lung using 33 human lung cancer cell lines as well as 6 lung cancer samples from which tumor cell lines could be established. This study clearly demonstrated that changes in the expression of certain integrins occur frequently in lung cancer, especially in small cell lung cancer. Loss of the α1 subunit of the β1 integrin family appears to be the most prominent change, although loss of other integrin subunits such as α2 or emergence of some integrin subunits such as αv can also be observed. These results suggest that changes in integrin expression may contribute to the invasive and/or metastatic behavior of lung cancer.

Isolation of a novel cDNA clone showing marked similarity to ME491/CD63 superfamily.

A novel cDNA clone, A15, was isolated by the differential screening of a cDNA library of an immature T cell line, HPB-ALL using radioactive cDNA probes from the mRNA of either HPB-ALL or peripheral blood lymphocytes. It hybridized to a single mRNA species of about 2.0 kilobases which is expressed in HPB-ALL cell line, but not in the PBL or a promyelocytic leukemia cell line, HL-60. The A15 gene codes for a protein of 244 amino acids which contains four potential transmembrane domains and four possible N-linked glycosylation sites. A computer-aided comparison showed a marked similarity to several other membrane proteins: CD9, CD37, CD53, TAPA-1, Sm23, CO-029, and ME491/CD63.

Spontaneous development of autoimmune uveoretinitis in nude mice following reconstitution with embryonic rat thymus

This paper describes the spontaneous occurrence of an autoimmune uveoretinitis in nude (nu/nu) mice reconstituted when 4 weeks old by the grafting of rat embryonic thymus. The uveoretinitis was characterized histologically by progressive loss of the pholoreceptor layer, observed in 4.0, 17.6, 42.9% and 71.4 % of such mice at 3, 5, 7 and 12 months of age. respectively. Mice with uveoretinitis were shown to huve serum IgG antibody reactive by indirect immunofluorcscence with retinal photo receptors, and with interphotoreceptor retinoid‐binding protein (IRBP). but not retinal S‐antigen. by immunoblotting and ELISA. A uveoretinitis could be adoptively transferred to syngeneic ungrafted nude mice by splenic CD4* T cells from diseased animals. This is the first experimental model of a (T cell mediated) autoimmune uveoretinitis which develops spontaneously and which is not dependent upon deliberate sensitization with retinal antigens and adjuvants.

Isolation and characterization of mouse CD7 cDNA.

The human CD7 antigen is a glycoprotein, Mr40 000, expressed on the surface of peripheral blood T-lymphocytes and thymocytes, and is the earliest surface antigen to appear on T-cell lineage cells. In this study, putative mouse CD7 cDNA was identified based on its similarities with human CD7. Five independent clones originating from the same mRNA species were isolated (designated as mCD7) by screening a mouse thymocyte cDNA library with human CD7 cDNA, J61, under moderate stringency. The longest insert of a 995 base pair had an open reading frame of 210 amino acids. Northern blot analysis using the mouse CD7 cDNA probe demonstrated a single 1.2 kilobase mRNA ni the thymus, spleen, bone marrow, and small intestine. The protein deduced from mCD7 cDNA consisted of the leader, extracellular, transmembrane, and cytoplasmic domains of 24, 126, 21, and 39 amino acids, respectively, based on the hydrophobicity plot and the structure of human CD7. The extracellualr domain contained three potential N-glycosilation sites, while the cytoplasmic domain contained one potential protein kinase C phosphorylation site. The amino acid sequence had 45.5% similarity with human CD7, while the similarities for the individual domains ranged from 49.2% to 63.2%. The six highly conserved regions, which may possibly be involved with still unknown CD7-mediated functions, were located in the extracellular and cytoplasmic domains.

Complex intrachromosomal rearrangement in the process of amplification of the L-myc gene in small-cell lung cancer.

The L-myc gene was first isolated from a human small-cell lung cancer (SCLC) cell line on the basis of its amplification and sequence similarity to c-myc and N-myc. A new mechanism of L-myc activation which results from the production of rlf-L-myc fusion protein was recently reported. On the basis of our earlier observation of a rearrangement involving amplified L-myc in an SCLC cell line, ACC-LC-49, we decided to investigate this rearrangement in detail along with the structure of L-myc amplification units in five additional SCLC cell lines. We report here the identification of a novel genomic region, termed jal, which is distinct from rlf and is juxtaposed to and amplified with L-myc during the process of DNA amplification of the region encompassing L-myc. Long-range analysis using pulsed-field gel electrophoresis revealed that the amplified L-myc locus is involved in highly complex intrachromosomal rearrangements with jal and/or rlf. Our results also suggest that the simultaneous presence of rearrangements both in rlf intron 1 and in regions immediately upstream of L-myc may be necessary for the expression of rlf-L-myc chimeric transcripts.

Molecular cloning of the gene coding for the human T cell differentiation antigen CD7

The CD7 molecule is a differentiation antigen found on the surface of T lymphocytes and also on a very minor fraction of acute nonlymphocytic leukemia (ANLL). To study the genomic structure of the CD7 gene, two clones (SY4 and SY22) were isolated by screening a genomic library with a CD7 cDNA probe. Restriction mapping of these two phage clones showed that both overlapped each other, covering a total length of 23 kilobases (kb). Transfection of mouse L cells demonstrated that SY22 contains the gene expressing the CD7 antigen reactive with monoclonal CD7 antibody (Tp40), while SY4 does not. Subcloning of a 10.5 kb fragment from a 14.4 kb insert of SY22 contained the structural gene for the CD7 antigen. Detailed restriction mapping and partial sequence analysis revealed the CD7 gene to consist of four exons. By RNase protection assay, multiple initiation sites — 122 base pairs (bp) to — 38 bp from ATG translation initiation site were demonstrated. The promoter region had high G+C content and contained two SP1 binding sites (CCGCCC) and an AP2 binding site (CCCCAGGC), but lacked CAAT and TATA motifs.