Toshio Kakihara

Expression of Deoxycytidine Kinase (dCK) Gene in Leukemic Cells in Childhood: Decreased Expression of dCK Gene in Relapsed Leukemia

Competitive RT-PCR was used to determine the quantitative variation in the expression of deoxycytidine kinase (dCK) gene in childhood leukemic cells. The degree of dCK gene expression varied over a 50-fold range. In two cases in which both primary and relapsed leukemic cells were analysed, decreased expression of dCK gene was found in relapsed leukemic cells. The sequence variation analysis using bisbenzimide/polyethylene glycol electrophoresis demonstrated no sequence alteration of dCK cDNA in all cases. These results indicate that the expression of dCK gene varies in patients and suggests decreased expression of the dCK gene as one of the mechanisms responsible for clinical resistance to ara-C.

Clear cell sarcoma arising in the transverse colon.

A case of clear cell sarcoma (CCS) arising in the transverse colon is presented. The tumor consisted of sheets or small nests of epithelioid malignant cells possessing pleomorphic nuclei with one or more prominent nucleoli and ample clear or slightly eosinophilic cytoplasm. Some of the tumor cells contained various amounts of melanin pigments that were confirmed by histochemical and ultrastructural examinations. Immunohistochemical examination showed a positive immunoreactivity for HMB45 and S‐100 protein. A metastatic nodule, which was found 9 months after surgery, showed similar histological findings to those of the primary one but lacked melanin pigments. Reverse transcriptase– polymerase chain reaction using total ribonucleic acid obtained from metastatic nodule demonstrated the presence of EWS‐ATF‐1 fusion gene. Based on these findings, the present case tumor is a CCS of the colon.

Both acute phase and constitutive serum amyloid A are present in atherosclerotic lesions

The polymorphic protein, serum amyloid A (SAA), consists of acute phase Isotypes and a constitutive Isotype. Both are associated mostly with high density lipoproteins (HDL) In the circulation. In the present study, both SAA isotypes were detected by Immunohistochemistry and Immunoblotting using monocional antlbodies In atherosclerotic lesions. As the distribution of SAA was identical with that of apolipoprotein B and SAA is known to be associated also with low density lipoproteins (LDL), SAA may also be delivered to the artery wall by LDL.

High incidence of angiotensin I converting enzyme genotype II in Kawasaki disease patients with coronary aneurysm.

Abstract A 287 base pair insertion/deletion polymorphism in intron 16 of the angiotensin I converting enzyme (ACE) gene was examined by polymerase chain reaction in 36 Kawasaki disease patients (16 without coronary aneurysm, 20 with coronary aneurysm). A polymorphism in the ACE gene was characterized by three genotypes: two D alleles (genotype DD), two I alleles (genotype II), and heterozygous allele (genotype DI). Genotype II was found in 65% of the patients with aneurysm and 12.5% of those without aneurysm (P < 0.01, odds ratio 13.0, 95% confidence intervals). Conclusion Patients with Kawasaki disease and coronary aneurysm more often than expected had the genotype II suggesting that reactions induced by the type of ACE polymorphism predispose to coronary aneurysm formation.

Expression of multidrug resistance-related genes does not contribute to risk factors in newly diagnosed childhood acute lymphoblastic leukemia

Abstract Background: The present study was designed to evaluate the association of multidrug resistance gene (MDR1), multidrug resistance‐associated protein (MRP) gene and lung resistance protein (LRP) gene expression (mRNA levels) with risk factors such as phenotype, age and leukocyte count in newly diagnosed childhood acute lymphoblastic leukemia, because biological mechanisms contributing to risk factors were not known.

Low Expression of the Deoxycytidine Kinase (dCK) Gene in a 1-β-D- Arabinofuranosylcytosine-Resistant Human Leukemic Cell Line KY-Ra

Molecular change of the deoxycytidine kinase (dCK) gene in a 1-beta-D-arabinofuranosylcytosine-resistant human leukemic cell line (KY-Ra) was investigated. KY-Ra showed the same restriction pattern of genomic DNA and the same nucleotide sequences of the dCK gene as the parental cell line. However, the amount of deoxycytidine kinase mRNA was markedly decreased in KY-Ra compared to the parental cell line. This is the first report showing that the down regulation of dCK gene expression may be affected by a different mechanism than mutation.

SERUM LEVEL AND GENE POLYMORPHISM OF ANGIOTENSIN I CONVERTING ENZYME IN JAPANESE CHILDREN

The aim of the present study was to determine the distribution of the insertion/deletion polymorphism of angiotensin I converting enzyme (ACE) gene in Japanese children. In addition, the relationship between this polymorphism and serum ACE levels in the same population were analyzed. Insertion/deletion polymorphism located in intron 16 of the ACE gene was examined by polymerase chain reaction in Japanese children aged 10–15 years. Allele frequencies were 0.64 for the insertion allele and 0.36 for the deletion allele in 122 subjects. No association was found between genotypes in this polymorphism and the level of systolic or diastolic blood pressure. A significant relationship between this polymorphism and serum ACE activity was observed. These results suggest that interindividual variability of serum ACE level is strongly influenced by the ACE genotype as early as in childhood.

Primary tuberculous osteomyelitis of the mandible

We present a case of a 3-year-old boy with primary tuberculous osteomyelitis of the mandible. He complained of a left submandibular mass. Radiographic examination revealed osteolytic lesions in the left mandibular angle, the left scapula and the left ulna. A biopsy from the mandible showed non-caseating epithelial granuloma. The mandibular mass spontaneously regressed in a month without definitive diagnosis. Swelling of the bilateral mandibular body was found 2 years later. He was diagnosed as having tuberculous osteomyelitis by culture study and treated with isoniazid and rifampicin without recurrence. Here we stress the importance of considering tuberculous osteomyelitis in the differential diagnosis of jaw lesions to prevent serious systemic spread.

Impaired tubular excretory function as a late renal side effect of chemotherapy in children.

Purpose Renal drug excretion is variously influenced by nephrotoxic drugs. This study was designed to evaluate renal function as a late renal side effects in children receiving combination chemotherapy for malignancy. Patients and Methods Follow-up studies of 30 newly diagnosed patients were performed a median of 12 months after completion of chemotherapy. The glomerular filtration rate (GFR) was measured using sodium thiosulfate. The following were also assessed: urinary high-molecular-weight fraction (urinary albumin/urinary creatinine ratio); para-aminohippurate (PAH) clearance; urinary low-molecular-weight fraction (urinary &bgr;2-microglobulin/urinary creatinine ratio); and routine serum and urinary parameters. Results Serum and urinary electrolytes were normal in most patients. GFR was low in four patients (13%). Urinary high-molecular-weight fraction was elevated in two patients. Urinary low-molecular-weight fraction was elevated in one patient. PAH clearance was below the referenced normal value in 73% of the patients. Conclusions This report demonstrates decreased PAH clearance as a late renal side effect of chemotherapy and suggests disturbed function of the organic anion transport system. The unexpected high serum concentration of drugs excreted through the organic anion transport system may induce severe side effects. Elucidation of the mechanism and clinical relevance of decreased PAH clearance is warranted.

Characterization of newly established human myeloid leukemia cell line (KF-19) and its drug resistant sublines.

A new human myeloid leukemia cell line, designated KF-19, and its drug resistant sublines have been established. The KF-19 cell line was established from the pericardial effusion of a patient with acute myeloid leukemia clinically resistant to chemotherapy and KF-19 cells were characterized by expression of myeloid markers and differentiation into neutrophil- and macrophage-like cells upon optimal stimulations. KF-19AraC, KF-19ADR and KF-19VCR were established as sublines resistant to cytosine arabinoside (AraC), adriamycin (ADR) and vincristine (VCR), respectively. Efflux of the corresponding drugs was documented in each cell line. Expression of the MDR1 gene and the P-glycoprotein was found only in KF-19ADR, which showed a cross resistance to anthracyclines and vinca alkaloids; this resistance was reversed by verapamil or cyclosporin A. KF-19VCR lacking MDR1 gene and P-glycoprotein expression showed only resistance to vinca alkaloids, which was partially reversed by verapamil and cyclosporin A. Unexpectedly, KF-19ADR and KF-19VCR displayed cross resistance to AraC, despite lack of alterations of deoxycytidine kinase (dCK) and deaminase (dA) activities. KF-19AraC showed an efflux of AraC as well as a decreased level of dCK, but not of dA. In addition, KF-19AraC showed cross resistance to VCR in the efflux assay. The cell lines reported herein will provide new aspects on the mechanisms of drug resistance in leukemic cells.