The pleiotrophin-ALK axis is required for tumorigenicity of glioblastoma stem cells.

Increasing evidence suggests that brain tumors arise from the transformation of neural stem/precursor/progenitor cells. Much current research on human brain tumors is focused on the stem-like properties of glioblastoma. Here we show that anaplastic lymphoma kinase (ALK) and its ligand pleiotrophin are required for the self-renewal and tumorigenicity of glioblastoma stem cells (GSCs). Furthermore, we demonstrate that pleiotrophin is transactivated directly by SOX2, a transcription factor essential for the maintenance of both neural stem cells and GSCs. We speculate that the pleiotrophin-ALK axis may be a promising target for the therapy of glioblastoma.

The critical role of cyclin D2 in cell cycle progression and tumorigenicity of glioblastoma stem cells.

Cancer stem cells are believed to be responsible for tumor initiation and development. Much current research on human brain tumors is focused on the stem-like properties of glioblastoma stem cells (GSCs). However, little is known about the molecular mechanisms of cell cycle regulation that discriminate between GSCs and differentiated glioblastoma cells. Here we show that cyclin D2 is the cyclin that is predominantly expressed in GSCs and suppression of its expression by RNA interference causes G1 arrest in vitro and growth retardation of GSCs xenografted into immunocompromised mice in vivo. We also demonstrate that the expression of cyclin D2 is suppressed upon serum-induced differentiation similar to what was observed for the cancer stem cell marker CD133. Taken together, our results demonstrate that cyclin D2 has a critical role in cell cycle progression and the tumorigenicity of GSCs.

Mutations of the epigenetics-modifying gene (DNMT3a, TET2, IDH1/2) at diagnosis may induce FLT3-ITD at relapse in de novo acute myeloid leukemia.

Gene mutations were found in acute myeloid leukemia (AML) and their importance has been noted. To clarify the importance and stability of mutations, we examined gene mutations in paired samples at diagnosis and relapse of 34 adult AML patients. Five acquired gene mutations were detected at relapse. Of the 45 gene mutations at diagnosis, 11 of them were lost at relapse. The acquired mutations at relapse were all class I mutations as Fms-like tyrosine kinase 3 (FLT3) and rat sarcoma viral oncogene homolog (RAS) mutations. The disappeared mutations at relapse were 3 of 11 internal tandem duplications of FLT3 (FLT3-ITD) (27.3%), 3 of 3 FLT3 tyrosine kinase domain (FLT3-TKD) (100%), 3 of 13 Nucleophosmin 1 (23.1%) and 2 of 5 CCAAT/enhancer-binding protein-α (40%) mutations. However, epigenetics-modifying gene (DNMT3a, TET2 and IDH1/2) mutations had no change between diagnosis and relapse samples, and may become minimal residual disease marker. The frequency of FLT3-ITD at relapse in patients with DNMT3a mutation at diagnosis is significantly higher than those in patients without them (P=0.001). Moreover, the high frequency of FLT3-ITD at relapse is also seen in AML cases that initially present with any epigenetics-modifying gene mutations (P<0.001). Our results indicate that epigenetics-modifying gene mutations may cause genetic instability and induce FLT3-ITD, leading to resistance to therapy and relapse.

Drug targeting efficacy to underlying muscle following topical application. I. Evaluation based on a physiological pharmacokinetic model.

A physiological pharmacokinetic model describing the absorption and disposition of topically applied drugs was proposed, and the effect of various pharmacokinetic and physiological parameters on the drug delivery into the targeted muscle was simulated. The proposed model consists of vehicle, and stratum corneum, viable epidermis and muscle below the application and reference sites, and plasma, each joined with transfer clearance and plasma flow. Indomethacin concentrations in tissues and plasma after topical application to rats could be explained by the model. Most indomethacin delivered into the underlying muscle was via direct penetration. The model simulation showed that the increase in plasma clearance and clearance between viable skin and muscle, and the decrease in application area and plasma flow rate into viable skin and muscle would promote the targeting efficacy of topically applied drugs to the underlying muscle.

Analysis of skin permeation-enhancing mechanism of iontophoresis using hydrodynamic pore theory.

The effects of constant DC iontophoresis (0-1.5 mA/0.966 cm(2)) on the permeation of three hydrophilic compounds, antipyrine (ANP, M.W. 188.23), sucrose (SR, M.W. 342.30) and 1-kestose (KT, M.W. 506.73), through excised hairless rat skin were evaluated using hydrodynamic pore theory. The electro-osmotic flow caused by iontophoresis was measured using deuterium oxide (D(2)O). The penetration-enhancing mechanism of iontophoresis was found to increase solvent flow through electro-osmosis and pore enlargement and/or new pore production in the skin barrier, together with enhancement of electrochemical potential difference across the skin. These effects were closely related to the strength of the current applied. The electro-osmotic flow of D(2)O (J(D(2)O)) greatly enhanced the skin permeation clearance of all hydrophilic penetrants (CL(drug)). Pore production was classified into reversible and irreversible processes, which resulted from lower (0-0.5 mA/0.966 cm(2)) and higher (0.5-1. 5 mA/0.966 cm(2)) currents, respectively. Thus, the enhancing effects of iontophoresis on skin permeation of nonionic hydrophilic compounds can be explained by increase in pore size and higher solvent flow.

Relationship of intra-abdominal adiposity and peripheral fat distribution to lipid metabolism in an island population in western Japan: gender differences and effect of menopause.

Intra-abdominal adiposity is associated with unfavorable serum lipid profiles (high total cholesterol or triacylglycerol, and low high-density lipoprotein cholesterol) in obese people. However, the relation in mainly nonobese Japanese population is not well known. We examined the relationship between intra-abdominal adiposity measured by ultrasonography and body fat distribution with serum lipids in Japanese people living in an island in western Japan. Mainly nonobese healthy individuals (98 men, 72 premenopausal and 182 postmenopausal women) aged between 33 and 69 years were examined. Accumulation of intra-abdominal fat (Pmax) and abdominal subcutaneous fat (Smin) was measured by ultrasonography. We also measured triceps and subscapular skinfold thicknesses, and the concentrations of total cholesterol, triacylglycerol and high-density lipoprotein (HDL) cholesterol. In men and postmenopausal women, Pmax correlated significantly with the majority of serum lipids after adjusting for age, body mass index and smoking habit. In premenopausal women, Pmax correlated significantly with only total cholesterol, but marginally with triacylglycerol and HDL/total cholesterol ratio after adjustment. Our findings suggest that intra-abdominal adiposity is related to unfavorable lipid profile in both genders among mainly nonobese Japanese population.

A study of the impact of occupational and domestic factors on insomnia among industrial workers of a manufacturing company in Japan.

Insomnia is one of the most common health problems and has recently been re-termed 'Disorders of initiating and Maintaining Sleep', or DIMS. The main purpose of the present study was to investigate the relationship between daily psychosocial stressors, to which workers are exposed in occupational and/or private life, and insomnia among male industrial workers in a medium-sized company located in Nagasaki City, Japan. All of the workers in the company (n = 368, male = 319) were asked to answer six sleep related questions and 24 questions about working and private conditions. Two hundred and seventy-one (85.0%) of them completed the questionnaire (average age was 40.9 years old). Twenty seven point seven per cent of the subjects complained of insomnia in the last month prior to the survey and the prevalence was in general accord with previous surveys. On the other hand, the proportion of hypnotic use (1.1%), especially in insomniac group (2.7%) was lower than previous reports. The results of multiple logistic regression analysis demonstrated that four psychosocial factors were significantly associated with insomnia: i.e. VDT work overload (odds ratio [OR] 5.058; 95% confidence intervals [95% CI] 2.381-10.745), limited space of bedroom (OR 2.612; 95% CI 1.283-5.683), over-involvement in job (OR 2.78; 95% CI 1.188-6.540), frequent alcohol beverages consumption (OR 2.595; CI 1.77-5.719).

An application of the hydrodynamic pore theory to percutaneous absorption of drugs.

Skin permeability of drugs was evaluated based on the hydrodynamic pore theory. Four polar solutes were used, with differing molecular sizes--ethylene glycol, 1,3-butylene glycol, antipyrine and sucrose--and isosorbide dinitrate was also selected as a lipophilic drug. The skin permeations of solvent (D2O) and one of these drugs were measured simultaneously under various osmotic pressures to calculate the reflection coefficient. The clearance of isosorbide dinitrate was independent of the solvent flux, whereas a linear relationship was obtained between the solvent flux and the clearance of each hydrophilic drug except for sucrose. The reflection coefficient of the hydrophilic drugs increased with increasing molecular radius. These results suggest that the convective flow contributes significantly to the total skin permeability of hydrophilic drugs and that the extent of contribution decreases with increasing molecular size of the drugs. The pore radius of the skin barrier could be estimated from the reflection coefficient of the hydrophilic drugs and the resulting value was compared with that for the other absorption sites, jejunum, rectum, and nose. The apparent water influx was also compared to assess the volume occupied by the pores. The pore radius and apparent influx of skin were lower than those for the other absorption sites, which is apparently one reason for low skin permeability of drugs, especially hydrophilic drugs.

Structural analysis of repetitive DNA sequences in the goat growth hormone gene region.

Two clones that contain goat growth hormone (gGH) genes were isolated from goat genomic library using goat growth hormone cDNA as a probe. One clone CgGH contained gGH1 gene, and another clone, EgGH, contained gGH2 and gGH3 genes. The clone EgGH contained 491 bp inserted sequence, just upstream of the gGH3 gene, which was not present in the clone CgGH. From the sequencing data of the flanking regions of these gGH genes, short interspersed repetitive sequences (SINES) were found. Four SINES's existed in the CgGH clone and eight SINES's existed in the EgGH clone. The number of the repetitive DNA sequences in the goat genome was estimated about 10(2) copies from the analysis of the reassociation rate. As the number of gGH genes (gGH1, gGH2, and gGH3) per genome was different among individual goats, DNA fragments containing gGH1 gene, and that containing gGH2 and gGH3 genes, were estimated to be allelic on the goat chromosome.

Cloning and sequencing of cDNA that encodes goat growth hormone.

The cDNA that encodes goat growth hormone (gGH) was isolated from a goat pituitary cDNA library. The cDNA, about 880 base pairs long, had a coding sequence, 5'- and 3'-untranslated regions and a poly(A) chain. The cDNA could encode a polypeptide of 217 amino acids. The amino acid sequence homology between gGH and the sequences of bovine GH, rat GH and human GH was 99, 83 and 66%, respectively. By Northern blot hybridization, we found that the possible gGH gene is transcribed in the goat pituitary.