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During attempts to transform a normal human fibroblast strain (GM730) by X-irradiation, we obtained a partially transformed cell strain (GM730pt) which demonstrates several aspects of the transformed phenotype including morphological changes, increased saturation density, growth in soft agar, and focus formation in long-term cultures. When GM730pt cells were transfected with the feline c-myc gene, morphology of the cells changed dramatically following seven days of expression. Transfection of other plasmid DNAs or oncogenes such as pUC8, pSV2neo, src, sis, and H-ras had little or no effects on the phenotype of GM730pt cells. On the other hand, a gel purified, small fragment of c-myc DNA had a complete cell alteration activity. Furthermore, Bal 31 deletion and M13 sequencing experiments showed that the alteration seen in GM730pt cells is delimited to a 24 nucleotide stretch (active myc element) from the second intron of the feline c-myc gene that contains a T-rich sequence.

Four cases of acute infantile leukemia with translocation (4;11) (q21;q23) are reported. Although leukemia with this chromosomal abnormality has been classified as L2 acute lymphoblastic leukemia by the FAB classification, two of our cases appeared to be of myelomonocyte origin as demonstrated by cytochemical, immunologic, and electron microscopic studies and differentiation induction by 12-tetradecanoyl-phorbol-13-acetate and methylformamide. This chromosomal change is associated with poor prognosis.

The Wilms'-tumor gene WT1 may have a different function from a tumor-suppressor gene in some leukemias. Using the 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat leukemia system, we examined whether WT1 expression was involved during leukemogenesis, since this model enabled us to analyze cells altered by DMBA at various stages of leukemogenesis. By the semi-quantitative reverse-transcriptase polymerase chain reaction(RT-PCR) method, WT1 expression was detected in 15 (71%) of 21 DMBA-induced erythroblastic leukemias. Among 15 WT1-expressing leukemias, GATA-1, which is an erythroid-specific transcription factor and might regulate WT1 expression, was also expressed in 13 cases (p < 0.05). On the other hand, WT1 expression was not detected in any normal or early pre-leukemic rats and was detected in 1 of 8 rats in late pre-leukemic stages. These results showed that cells with a high expression level of WT1 tended to develop into leukemia and that WT1 contributed to leukemogenesis in the late stage, suggesting that the expression of WT1 plays an important role in cell proliferation and in maintaining the viability of some leukemia cells. Int. J. Cancer 72:696–699, 1997. © 1997 Wiley-Liss, Inc.

We studied the inhibitory effect of seven anticancer drags and α-, recombinant β-, and recombinant γ-interferons on the in vitro growth of two established human renal cell carcinomas and 16 renal cell carcinomas obtained from patients using monolayer culture and the double-layer soft agar system.

Allelic loss of chromosome 17p with a mutated p53 gene on the remaining allele has been observed in various kinds of human cancers. To examine the significance of allelic loss of chromosome 17p in human urothelial cancer with special attention to the clinicopathological features, 49 tumors with various stages and grades from 43 cases (35 bladder cancers and 8 renal pelvic or ureteral cancers) were examined for loss of heterozygosity using 5 polymorphic probes on chromosome 17p. Thirty-seven cases were informative, and allelic loss of chromosome 17p was observed in 15 (41%) of them. In bladder cancers, the loss of 17p was observed with significantly higher frequency (p < 0.01) in cases with invasive (≥pT2) tumors (7/10, 70%) than in cases with superficial (pTa or pTl) tumors (4/21, 19%). In renal pelvic or ureteral cancers, none of 2 superficial tumors and all of 4 invasive tumors showed the allelic loss. As to tumor grade, the allelic loss was observed in 1/9 (11%) for grade 1 cases, 6/18 (33%) for grade 2 cases, and 8/10 (80%) grade 3 cases (grade 1 versus 3, p < 0.01; grade 2 versus 3, p < 0.05). On the other hand, examination of clinical features, such as primary tumor site, tumor multiplicity or previous history of urothelial cancer did not significantly influence the frequency of the allelic loss.

In situ hybridization of 3H-labelled ribosomal RNA to the chromosomes of rat bone marrow cells revealed that clusters of ribosomal cistrons (rDNA) are located in the secondary constrictions of chromosomes No. 3 and 12 and near the centromere of chromosome No. 11, both associated with the late DNA-replicating regions. They were not found in Nos. 1, 2, 13, 19, 20, and the Y chromosome.

This study was conducted to clarify the quantitative and qualitative changes in the cells of the islets of Langerhans in the autotransplanted pancreas in dogs and to correlate these changes with alterations of glucose tolerance. The left lobe of a canine pancreas was transplanted into the left iliac fossa. The splenic vessels were anastomosed to the left iliac vessels. The pancreatic duct was left open to the peritoneal cavity. Open biopsies of the autotransplanted pancreas were performed 3, 7, 11, and 14 weeks after transplantation. The islets in the transplanted pancreas were examined ultrastruc-turally; B-cells, A-cells, and D-cells were identified immunohistochemically and their percentages were determined. Intravenous glucose tolerance tests were performed 3, 5, 7, 11, and 14 weeks after operation, and several indexes (Kvalues and integrated response and increased values for baseline serum and immunoreactive insulin) were calculated. Fibrosis of the transplanted pancreas progressed after transplantation. The percentage of B-cells fell significantly (p <0.01), whereas that of A-and D-cells did not have significant changes. The ultrastructural study revealed an increase in collagen bundles, degranulation of B-cells, and marked preservation of A-cell granules 3 weeks after transplantation. B-Cells with dark cytoplasm were found 7 weeks after operation. In contrast, clusters of immature B-cells were seen in some sections of the pancreas 14 weeks after autotransplantation. The integrated response in baseline serum was increased significantly (p <0.01), and the Kvalue was decreased significantly (p <0.01) 11 weeks after autotransplantation when compared with the initial posttransplant period. On the other hand, 14 weeks after autotransplantation, neither the integrated response in baseline serum nor the Kvalue showed significant difference from the initial posttransplant period. It may be that the trend toward slight recovery of glucose metabolism 14 weeks after autotransplantation was associated with the clusters of immature B-cells observed ultrastructurally, although the number of B-cells was relatively decreased. Further studies must be done to clarify this phenomenon.

The paper presents an autopsy case of mixed connective tissue disease (MCTD) with pulmonary hypertension (PH) and a review of literature. A 33-year-old woman with Raynaud's phenomenon and dyspnea of one year duration was diagnosed as having MCTD on the basis of a higher titer (1:163,840) of serum antibodies to the ribonucleoprotein (RNP). Cardiac catheterization showed complicating PH, confirmed an autopsy by the findings of concentric intimal cellular proliferation and typical plexiform lesions in the small arteries and arterioles of the lung, suggesting primary PH. Fatal PH with MCTD has been reported only 6 cases in literature including our case. All were young females, with histopathological findings consistent with plexogenic pulmonary arteriopathy in 5 cases and with recurrent pulmonary thromboembolism in the other. The aetiology of PH is still unknown, but it may be due to vasoconstriction evoked by the hyper-reactivity of the vessels.

We raised monoclonal antibody (MAb) against a synthetic oligopeptide corresponding to a portion of the predictedv-ablprotein sequence (379–390). This MAb reacted with all of theabl-geneproducts (pl45c-abl, pl50c-abland 210bcr-ablfused protein) and was not specific for any one of them. Immunocytochemically, we investigated the expression and localization of theabl-geneproducts in various leukemic cell lines. Positive immunoreactions were observed in Ph1positive leukemic cell lines (K562 and KU-812) and erythro-leukemic cell lines (HEL and K3D) and were located on the cell membrane. Electron microscopically, a different distribution pattern was observed among the cell lines: linear and almost even in Ph1positive leukemic cell lines, whereas spotted or budding-like in erythroleukemic cell lines. Ph1translocation produces p210nbcr-ablfused protein with not only altered autophosphorylation activities but also altered subcellular distribution patterns.

Cytogenetic studies on 64 rat leukemias induced with 7,8,12- and 6,8,12-trimethylbenz(a)anthracene were performed. Highly distinctive changes were found repeatedly in one special pair of chromosomes. 10 leukemias (15.6%) showed the presence of stemline(s) with trisomy of the largest telocentric chromosome (C-1 trisomy). Another chromosome abnormality, elongation of one of the pairs of the same chromosome (long C-1), was found in 5 leukemias (7.8%) as the predominant stemline and in 7 other cases as a small cell population. This chromosome abnormality, despite slight differences in their elongation rate, was defined as a new specific chromosome abnormality. Other chromosome abnormalities not related with C-1 chromosome were found in 8 cases (12.5%). The remaining 41 leukemias (64.1%) had the predominant stemline with normal karyotype. From this study it appears that three structurally different hydrocarbon carcinogens, 7,12-dimethylbenz(a)anthracene and 7,8,12- and 6,8,12-trimethylbenz(a)anthracene act on blood-forming cells by a common specific mechanism.

The incidence of chromosome aberrations in rat bone marrow, examined 6 hr after the administration of 7,12-dimethylbenz(a)anthracene, was significantly enhanced by induction of anemia 0-48 hr before the carcinogen treatment and was suppressed by induction of polycythemia. The suppressive influence of polycythemia was reversed by sheep erythropoietin injected shortly before or after the carcinogen injection; this suppressive effect was proportional to the dose of erythropoietin used. These data suggest that erythropoietin is essential to make bone-marrow cells susceptible to chromosome aberrations with 7,12-dimethylbenz(a)anthracene. The incidence of carcinogen-induced leukemia was also increased by anemia and suppressed by polycythemia induction.

THE role of chromatid exchange in the origin of chromosome aberrations has been a subject of research since the chromatid exchange hypothesis of chromosome aberrations was proposed1. Which of the breakage–treunion hypothesis2and the exchange hypothesis better explains the origin of chromosome aberrations is still disputed3,4. The part played by DNA repair in aberration and exchange formation has been identified5,6, and there is much evidence for non-random distribution of chromosome aberrations, especially in the heterochromatic regions7,8. We have shown previously by autoradiography, that sister chromatid exchanges (SCEs) induced by 7,12-dimethylbenz(a)anthracene (DMBA) are frequently associated with aberrations8. Newly introduced 5-bromodeoxyuridine(BUdR)–33258 Hoechst methods for SCEs9,10have made it possible to reanalyse these problems in more detail and with considerable accuracy. The results presented here indicate that two different hydrocarbon carcinogens, DMBA and 7,8,12-trimethylbenz(a)-anthracene (TMBA), induce aberrations localised in the same chromosomal regions of the rat bone marrow cells and that the targets for chromosome aberrations and for SCE are identical; in other words, both phenomena are related.

A preliminary survey for tumorbearing fish among sole caught in waters of Wakasa Bay area, Japan was carried out. Five sole, one Limanda herzensteiniand 4 Hippoglossoides dubius, with skin tumors were obtained. Histological observations of the lesions in both species revealed marked proliferation of epithelial elements accompanied with increase in fibrous structure of connective tissue. In addition marked increase of melanin-containing cells was observed in tissue sections of growth of L. herzensteiniwith darker appearance. The gross and microscopic findings of H. dubiusresembled descriptions of the epithelial papillomas reported by other authors to occur among flathead sole populations near Friday Harbor, Washington.

THE 33258 Hoechst fluorescence1and 33258 Hoechst–Giemsa2methods for differential staining of bromodeoxy-uridine (BrdU)-incorporated chromatids are attractive because of their rapidity and high sensitivity in revealing small sister chromatid exchanges which escape detection by autoradiography. Since carcinogen-induced chromatid breaks are associated with sister chromatid exchanges3and breakage formation parallels carcinogenesis in typical cases4,5, these methods are essential for understanding the role of chromosome aberrations in carcinogenesis. We show here that other photosensitive dyes such as thionin can replace 33258 Hoechst in the latter method and that the mechanisms of the differential Giemsa method involves photolysis of the BrdU-substituted DNA combined with these photosensitive dyes.

A high percentage of consistent chromosome abnormality, trisomy of the longest telocentric chromosome, was found in leukemias induced in rats of the Long-Evans strain by pulse doses of 7,12-dimethylbenz[a]anthracene. Cells with this abnormality were large, immature, and mononuclear and tended toward erythroblastic maturation.