Microarray analysis of responsible genes in increased growth rate in the subline of HL60 (HL60RG) cells.

HL60RG, a subline of human promyelocytic leukemia HL60 cells, has a increased growth rate than their parental cells. To gain information of the mechanisms involved in the increased growth rate of HL60RG, we performed a multiplex fluorescence in situ hybridization (M-FISH), standard cytogenetics analysis (G-banding) and genome scan using 10K SNP mapping array on both cell types. Characteristic genomic alterations in HL60RG cells were identified including uniparental disomy (UPD) of chromosome 1, and hemizygous deletion in 10p and 11p. However, no such defects were observed in HL60 cells. Changes in gene expression in HL60RG cells were determined using expression arrays (Affymetrix GeneChip, HU133A). Candidate genes associated with the rapid growth of HL60RG cells were identified. Two tumor necrosis factor receptors, TNFRSF1B (type II tumor necrosis factor-α receptor) and TNFRSF8 (also known as a tumor marker CD30), which are adjacently located on chromosome 1 showed opposing changes in gene expression in HL60RG cells-over-expression of TNFRSF8 and repression of TNFRSF1B. Differences in the DNA methylation status in the transcriptional regulatory regions of both genes between HL60 and HL60RG was detected by a methylation-specific PCR assay. In conclusion, alterations in chromosome and gene expression in HL60RG may be associated with increased growth rate.

Optimization of the virus concentration method using polyethyleneimine-conjugated magnetic beads and its application to the detection of human hepatitis A, B and C viruses.

To enhance the sensitivity of virus detection by polymerase chain reaction (PCR) and reverse transcription PCR (RT-PCR), a novel virus concentration method using polyethyleneimine (PEI)-conjugated magnetic beads was developed in our previous study. However, several viruses could not be concentrated by this method. In this paper, the conditions of virus concentration were optimized to concentrate a wide range of viruses more efficiently. The PEI beads adsorbed viruses more efficiently than other cationic polymers, and the optimum virus concentration was obtained under weak acidic conditions. Mass spectrometric analysis revealed that several serum proteins, such as complement type 3, complement type 4 and immunoglobulin M (IgM), were co-adsorbed by the PEI beads, suggesting that the beads may adsorb viruses not only by direct adsorption, but also via immune complex formation. This hypothesis was confirmed by the result that poliovirus, which PEI beads could not adsorb directly, could be concentrated by the beads via immune complex formation. On the other hand, hepatitis A (HAV) and hepatitis C (HCV) viruses were adsorbed directly by PEI beads almost completely. Like poliovirus, hepatitis B virus (HBV) was concentrated efficiently by the addition of anti-HBV IgM. In conclusion, virus concentration using PEI beads is a useful method to concentrate a wide range of viruses and can be used to enhance the sensitivity of detection of HAV, HBV and HCV.

Molecular cytogenetic analyses of HIG, a novel human cell line carrying t(1;3)(p36.3;q25.3) established from a patient with chronic myelogenous leukemia in blastic crisis.

Chromosomal abnormalities involving 1p36, 3q21, and/or 3q26 have been reported in a subset of myeloid neoplasms having characteristic dysmegakaryopoiesis, and the overexpression of EVI1 on 3q26 or of MEL1 on 1p36 has been implicated in their pathogenesis. We describe molecular cytogenetic analyses of a novel human cell line, HIG, established from a unique case in which a novel translocation t(1;3)(p36;q26) appeared as the sole additional chromosomal abnormality at the time of blastic transformation of chronic myelogenous leukemia. The patient displayed clinical features resembling those of the 3q21q26 syndrome. The HIG cell line retained der(1)t(1;3)(p36;q26) but lost t(9;22)(q34;q11). To identify the relevant gene that would be deregulated by this translocation, we molecularly cloned the translocation's breakpoints. They were distant from the breakpoint cluster regions of the 3q21q26 syndrome or t(1;3)(p36;q21), and neither the EVI1 nor the MEL1 transcript was detected in the HIG cell line. None of the genes located within 150 kilobase pairs of the breakpoints were aberrantly expressed, suggesting that in this case other gene(s) more distant from the breakpoints are deregulated by possible remote effects. Further analyses of the deregulated genes in the HIG cell line should provide important insight into the mechanisms involved in these types of leukemias.

Role of the p70 S6 kinase cascade in neutrophilic differentiation and proliferation of HL-60 cells-a study of transferrin receptor-positive and -negative cells obtained from dimethyl sulfoxide- or retinoic acid-treated HL-60 cells.

Previously, we suggested that p70 S6 kinase (p70 S6K) plays an important role in the regulation of neutrophilic differentiation of HL-60 cells; this conclusion was based on our analysis of transferrin receptor (Trf-R) positive (Trf-R(+)) and negative (Trf-R(-)) cells that appeared after treatment with dimethyl sulfoxide (Me(2)SO). In this study, we analyzed the upstream of p70 S6K in relation to the differentiation and proliferation of both cell types. The granulocyte colony-stimulating factor (G-CSF)-induced enhancement of phosphatidylinositol 3-kinase (PI3K) activity in Trf-R(+) cells was markedly higher than that in Trf-R(-) cells. Wortmannin, a specific inhibitor of PI3K, partially inhibited G-CSF-induced p70 S6K activity and G-CSF-dependent proliferation, whereas rapamycin, an inhibitor of p70 S6K, completely inhibited these activities. The wortmannin-dependent enhancement of neutrophilic differentiation was similar to that induced by rapamycin. From these results, we conclude that the PI3K/p70 S6K cascade may play an important role in negative regulation of neutrophilic differentiation in HL-60 cells. For the G-CSF-dependent proliferation, however, p70 S6K appears to be a highly important pathway through not only a PI3K-dependent but also possibly an independent cascade.

Secretion of interleukin-6 and vascular endothelial growth factor by spindle cell sarcoma complicating Castleman's disease (so-called 'vascular neoplasia').

So-called 'vascular neoplasia' (VN) is a rare tumour of unknown origin that complicates hyaline vascular type Castleman's disease (CD). This paper reports a case of VN complicating CD of hyaline vascular type, in which neoplastic cells were shown to secrete interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF). In this case, VN first occurred in the retroperitoneum of a 60-year-old male. The lesion showed typical morphology, with three distinct areas: (1) a lymph node-like area with regressively transformed lymph follicles showing hyaline vascular changes and with a hypervascular interfollicular region filled with slit-like vascular channels; (2) an area composed of spindle cell sarcoma; and (3) an area showing angiolipomatous hamartoma. A proportion of the cells in the spindle cell area showed severe pleomorphism. Subcutaneous recurrence after 8 months was composed purely of pleomorphic spindle cells. A karyotypic analysis of the recurrent tumour showed 47, XXY with some instability. Supernatant from primary culture contained high levels of IL-6 and VEGF, suggesting high secretion of these cytokines from neoplastic cells. Immunohistochemically, p53 overexpression was identified only in the pleomorphic spindle cells of the primary lesion and metastatic tumour. No features suggestive of vascular origin were shown on immunohistochemical or electron microscopic analysis of the neoplastic cells. Human herpesvirus type 8 was not detected by immunohistochemistry or PCR analysis. High levels of IL-6 and/or VEGF have been reported to play a role in CD. This is the first case report that clarifies the site of such cytokine production, showing the possibility of CD as a paraneoplastic phenomenon.