Three cases of neurilemmomatosis are reported. A 22-year-old man without any relatives with similar symptoms visited our clinic, complaining of multiple skin tumors since the age of 15 and bilateral acoustic nerve symptoms since 19. Physical examination revealed no pigmented or depigmented spots. Histopathological examination of the eight tumors excised from the skin, acoustic nerve and spinal cord showed that these were all neurilemmomas. A 36-year-old man with a 15 year history of multiple skin tumors and one year history of acoustic nerve symptoms was seen at our clinic, revealing no pigmentary disorders. The tumors excised from the skin and bilateral acoustic nerves were all neurilemmomas histopathologically. A 5-year-old boy, who was the only child of the second case and had had several skin tumors since his birth, visited us after postoperative death of his father. He revealed no pigmentary abnormalities. The histology of the skin tumor was neurilemmoma. The absence of neurofibromas and pigmented spots in these patients with neurilemmomatosis suggests that this disorder might be close to, but distinct from neurofibromatosis. Although familial cases of neurilemmomatosis like our case 2 and 3 reported so far are very few, they support a possibility that neurilemmomatosis might be a genetically determined neurocutaneous syndrome, a kind of phacomatosis.

Acute unclassified/undifferentiated leukemia (AUL) is classified into following 3 subgroups; 1) cases with coexpression of myeloid and lymphoid antigens on a single blast, 2) cases with coexistence of heterogenous subpopulations, 3) cases showing lineage-switch during the clinical course. Most cases in the groups 2 and 3 were not different from those in group 1 because of the presence of one or more common antigen (s) on the blasts. Accordingly, AUL can be considered as a candidate of leukemia arising form multipotential stem cells and the phenotype and genotype are represent a potential for myeloid and lymphoid differentiation. We should recognize that dual genotypes of IgH and TCR genes in B-precursor cell leukemia differ from such multipotentiality of leukemic cells, because the genotype occurs in re-arrangement process for IgH gene diversity after malignant transformation.

We performed cytogenetic studies and breakpoint cluster region (bcr) rearrangement analysis in two cases of juvenile chronic myeloid leukemia (JCML) which is special type of chronic myeloid leukemia (CML). Case 1 (8-month-old male) and case 2 (3-month-old female) showed clinical and hematologic manifestations similar to CML. Each of case 1 and 2 had normal karyotype and no bcr rearrangement. These findings suggest that JCML is a different heterogeneous disorder from that of adult CML.

The 14;19 translocation [t(14;19) (q32;q13)] is a recurring chromosomal translocation observed in leukemic cells of chronic lymphocytic leukemia showing prolymphocytic transformation. We have cloned the breakpoint junction of the translocation and identified a new gene, bcl-3, on the chromosome band 19q13 adjacent to the breakpoint. The translocation occurred at the switch region of the alpha constant locus of the immunoglobulin heavy chain gene and the upper stream of the bcl-3 gene, resulting in a head-to-head recombination between the two genes on the 14q+ chromosome. The bcl-3 gene was highly expressed in the leukemic cells carrying the 14;19 translocation. The bcl-3 gene product contained repeat structures found in proteins involved in cell cycle control and cell lineage determination. These results suggest that the bcl-3 is a proto-oncogene that may contribute to the development of leukemias carrying the 14;19 translocation.

Most of human follicular lymphomas (approximately 90% in U.S.A. or approximately 30% in Japan) possess the t(14; 18) chromosome translocation that directly involves the IgH locus on chromosome 14 and the bcl-2 gene on chromosome 18. The t(14; 18) chromosome translocation occurs nearly exclusively at two hot spots, a major breakpoint clustering region (mbr) within the 2nd exon noncoding region and the minor breakpoint clustering region (mcr) within the 3' flanking region of the bcl-2 gene. Here we show that the rearrangement of the bcl-2 gene occurs in a significant fraction (approximately 10%) of B-CLL. All of the rearranged bcl-2 genes were juxtaposed with Ig lambda or Ig kappa genes, implying that the bcl-2 gene is preferentially linked to the IgL genes in CLL.

In t(14;18) lymphomas, bcl-2 gene is activated by the juxtaposition of immunoglobulin (Ig) gene. The fused bcl-2-Ig gene generates chimeric mRNAs which consist of bcl-2 at 5' side and Ig at 3' side. Chimeric mRNA does not disrupt the bcl-2 coding frame of 239 amino acid polypeptide. Activated bcl-2 gene introduced in normal B lymphoblastoid cells (LCL) demonstrated an increased cloning efficiency in soft agar but failed to confer tumorigenicity to LCLs as a single agent. bcl-2 gene rearrangement in Japaneses B cell lymphoma was studied and found that 10 out of 32 cases of follicular lymphoma (31%) and 5 out of 56 cases of diffuse lymphoma (9%) were rearranged, suggesting less frequency of B cell lymphoma, particularly follicular lymphoma in Japan is partly due to less bcl-2 involvement than American cases. Three cases out of 15 cases with bcl-2 rearrangement demonstrated a unique pattern of rearrangement. Two cases of the three were analysed and found that both cases were translocated at the later step than DH-JH joining of Ig rearrangement. Thus, bcl-2 translocation in Japanese B cell lymphomas might occur at the later stage of B cell development, when compared with that in American cases. Less involvement of bcl-2 in Japanese B cell lymphoma may be explained by low susceptibility to bcl-2 rearrangement at the step of DH-JH recombination.

A leukemia line KOPN30bi was established from a patient of acute lymphoblastic leukemia with Philadelphia chromosome. The clonal rearrangement of the immunoglobulin heavy chain gene was identical between KOPN30bi and the predominant clone in the fresh sample (S1) from which KOPN30bi was established, indicating that they are of the same clonal origin. The study of the T cell receptor (TCR) genes including TCR beta, gamma, delta loci showed none of these loci was identical between KOPN30bi and S1. The result of the TCR delta region analysis which was rearranged on one of the alleles in KOPN30bi and was deleted on both alleles in S1, however, indicated KOPN30bi was not a derivative of S1. Polymerase chain reaction, using oligonucleotide probe corresponding to the N region sequence of V gamma-J gamma juncture of KOPN30bi, indicated that only one % of the blast cells in S1 corresponded to KOPN30bi. These studies indicated that the predominant clone in the fresh sample, although it occupied more than 99% of the blasts, did not represent the characteristics of the target cell for leukemogenesis, and furthermore that the leukemogenic molecular mechanisms such as P190 type BCR/ABL translocation are not enough to freeze the differentiation of the target cell.

We studied gene rearrangement and expression of immunoglobulin heavy (IgH) chain, T cell receptor (TCR) beta, gamma and delta chains in neoplastic T cells from patients with leukemia and lymphoma. Rearrangements of TCR beta and gamma chain genes were observed in most of T cell neoplasms. TCR delta chain gene rearrangements or deletions were detected in all 77 T cell neoplasms; 6 of 9 CD3- T cell neoplasms showed rearrangement, whereas biallelic deletion of TCR delta chain gene was the most common pattern in CD3+ T cell neoplasm (65 of 68 patients). One patient with CD3- T cell leukemia had TCR delta chain gene rearrangement with a germline configuration of TCR beta, gamma and IgH chain genes. TCR gamma and delta chain gene transcripts were detected in most of the CD3- T cell neoplasms, whereas mature TCR alpha and beta chain mRNA were demonstrated in the majority of the CD3+ T cell neoplasms. In 6 patients with CD7+ CD3- CD4- CD8- MPO- leukemia, only 2 patients had rearrangements and weak expressions of IgH, TCR gamma and delta chain genes. We also present two cases of double negative (CD3+ CD4- CD8-) leukemia; one is TCR gamma delta bearing LGL, the other is TCR alpha beta bearing ATL. These results suggest that most of T cell neoplasms preserve a pattern of genotypic and phenotypic expression reflecting their developmental pathways and differentiation levels of TCR bearing normal T cells.

We have carried out the molecular and cell-biological analysis on Ph1-positive leukemias in this study. Five out of nine Ph1-positive ALL cases showed molecular rearrangement within the classical bcr sequence (or M-bcr), similar as those in 47 CML cases. We examined 4 cases of Ph1-positive ALL presenting no rearrangement of M-bcr and found that, in 2 of 4 cases, one showed the breakpoint in a 5 kb segment of the bcr gene first intron (bcr-2) and the other in bcr-1, 16 kb upstream of bcr-2. Ph1-positive ALL frequently showed biphenotypical or biclonal phenotypes of myeloid and lymphoid lineages. Furthermore, we demonstrated the ability of two Ph1-positive ALL cell lines to differentiate into monocytic lineage in vitro, thus suggesting the possibility that these Ph1-positive ALL cells might reside on the stage of multipotent stem cell along the hematopoietic cell differentiation. Two out of 31 CML cases showed the mutations of the ras genes by the polymerase chain reaction; one case in the crisis phase and the other in the chronic phase. However, no mutations of the fms genes was detected. Two cases in the crisis phase of 24 CML patients (11 cases in the chronic phase and 13 cases in the crisis phase) contained rearrangements of the p53 gene by Southern analysis. Furthermore, the transcriptional alteration was found in 2 CML-BC and 2 CML-BC derived cell lines' samples, suggesting a important role of the p53 gene in the transformation of CML into the crisis phase.

The undifferentiated carcinoma cell line (HMG) was established from a nude mouse tumor which had been produced by transplantation of a intraperitoneal tumor of 27-year-old woman. The HMG cell line has the following biological properties. 1. The HMG cells are round to oval in shape and grow as floating cell aggregates like a rouleau or a cluster of grapes. 2. 100 passages have been carried out over a year, and the population doubling time is about 17 hrs. 3. In the original tumor, keratin and vimentin were expressed simultaneously, in HMG cells, however, only localization of vimentin was confirmed. 4. By chromosomal analysis, over 90% of the cells revealed 46, XX, with no karyological abnormalities, at passage 82. 5. When heterotransplanted into the subcutis of a nude mouse, HMG cells produced a undifferentiated carcinoma resembling the original tumor.

Overexpression of many growth factors/receptors and decreased expression of TGF beta type I play an important role in progression of human gastric carcinomas. Abnormal regulation of transcription of these genes should be involved in cancer progression. Advanced gastric carcinomas showing metastasis sometimes reveal amplification of oncogenes. Development and progression of scirrhous gastric carcinoma are brought about by the accumulation of growth factors such as TGF beta, IGF, PDGF and FGF and by the amplification of SAM gene. Loss of heterozygosity (LOH) on chromosomes 1q, 5q and 17p frequently takes place in well differentiated type gastric carcinomas, while no LOH on chromosomes 1q and 5q occurs in poorly differentiated type. LOH on chromosomes 5q and 17p is detected even in early gastric carcinomas, although LOH on 1q and 7p is found only in advanced gastric carcinomas. Thus, the accumulation of multi-autocrine growth factors and multiple genetic alterations evidently participates in biological malignancy of gastric carcinomas.

Information on the presence of specific chromosomal structural abnormalities in certain tumors has been increasing. Although the tumor specific chromosomal abnormalities were deemed important, it was not until the chromosomal location of several oncogenes was determined that the real molecular significance became apparent. It now appears that many of the genes associated with animal tumors are located near specific translocations in human cancers. The specificity of chromosomal changes have not only been used diagnostically and prognostically, but also they present key information for the molecular analysis in determining the nature of the genes of human neoplasia. In recent years, great advances have been made in our understanding of the molecular structure of the specific chromosomal translocations in certain hematologic disorders. The present report will briefly describe chromosomal rearrangements and how oncogenes or cancer related genes involved can be affected.

A case of syncytial variant of nodular sclerosing Hodgkin's disease in a 34-year-old woman is reported. Histologically, numerous Reed-Sternberg (RS) cells and their variants were seen in sheets. They were positive for CD30, CD15, CD25, and HLA-DR antigens. In addition, they expressed CD45 antigen and T-cell antigens (CD2, CD4). Molecular genetic analysis showed that this case had a germ line configuration for T-cell receptor (TCR) beta chain, TCR gamma chain, and immunoglobulin heavy chain genes. The percentage of the neoplastic cells in the specimen identified by CD30 positive cells was about 20% which was far above sensitivity of the molecular genetic analysis. Such analysis is reliable as to judgement of the results. Thus, these findings suggest that the RS cells and their variants in the present case are not derived from mature T cell in spite of their T-cell antigens expression.