Suppression of CD44 expression decreases migration and invasion of human glioma cells

We have reported high expression of CD44H in human glioma cells. To investigate the role of CD44H in the invasion of human glioma, we established a CD44-anti-sense-gene-expression glioma cell line named U-251A1. The expression of CD44H in the G-418-selected U-251A1 cells was reduced to 20% of that in the parental U-251SP cells, as determined by flow-cytometry analysis. We first examined the migratory responses of U-251A1 cells in vitro by time-lapse video-microscopic sparse cell-migration assay on hyaluronic acid or on chondroitin 6 sulfate. U-251A1 cells did not show significant differences in motility on any substrate, while U-251SP and other CD44H-positive glioma cells showed dose-dependent increase of migration specifically on hyaluronic acid. To examine the physiologic function of CD44H in gliomas in vivo, U-251A1 and its control cells, U-251S1, which retain CD44-sense-expression vector, were injected stereotactically into the brains of nude mice. U-251A1 cells were localised in the region of the injection site, with relatively well demarcated borders between tumour and brain tissue, while the control cells demonstrated a cell-infiltration pattern. Our data suggest that CD44H may be required for infiltration of glioma cells through its interaction with hyaluronic acid, a major component of the brain extracellular matrix. © 1996 Wiley-Liss, Inc.     

Expression of the multidrug-resistance-associated protein (MRP) gene in human colorectal,gastric and non-small-cell lung carcinomas

MRP has been identified as another multidrug-resistance (MDR) gene and may be involved in an alternative MDR mechanism in some solid tumors. We investigated the expression of MRP mRNA in multidrug-resistant KB sublines (KB-8-5, KB-C2, C-A40 and C-A120), human non-small-cell lung carcinomas (NSCLC), gastric and colorectal carcinomas, and compared it with that in drug-sensitive human KB cells, MRP gene expression was elevated in 8 of 9 (89%) squamous-cell carcinomas of the lung. Furthermore, MRP expression in 4 squamous-cell carcinomas (L13, 18, 19 and 20) was more than 3.6 times higher than in KB-3-I cells, and the average MRP mRNA expression level of all squamous-cell carcinomas was significantly higher than that of adenocarcinoma of the lung and of colorectal and gastric carcinomas. These results suggested that the MRP is responsible, at least in part, for drug resistance in some squamous-cell carcinomas of the lung. © 1996 Wiley-Liss, Inc.     

Glucose-regulated stresses induce resistance to camptothecin in human cancer cells

The glucose-regulated stress response in mammalian cells is characterized by the increased synthesis of glucose-regulated proteins (GRPs). In this study, we found that GRP-inducing conditions in culture led to induction of resistance to the topoisomerase I-targeted drug camptothecin in human colon cancer HT-29 and ovarian cancer A2780 cells. The induction of camptothecin resistance was accompanied by decreased levels of camptothecin-induced cleavable complexes, as measured by a topoisomerase I band depletion assay. However, topoisomerase I protein levels were the same in both stressed and non-stressed cells. Furthermore, when isolated nuclei from stressed and non-stressed cells were treated with camptothecin, similar levels of cleavable complexes were obtained, suggesting that the activity of topoisomerase I did not change in stressed cells. In contrast, intracellular accumulation of camptothecin decreased in stressed cells. Our results indicate that stress-induced camptothecin resistance could be explained by reduced camptothecin accumulation, leading to decreased numbers of cleavable complexes, without quantitative or qualitative changes in topoisomerase I levels. In addition, cell cycle analysis revealed that the GRP-inducing treatments resulted in an accumulation of G₁/G₀-phase cells. As camptothecin shows an S-phase-specific cytotoxicity, the G₁/G₀-phase accumulation is another mechanism for camptothecin resistance. Since a glucose-regulated response is produced by hypoxia and nutrient deprivation that occur naturally in solid tumors, the resistance observed here can occur in some solid tumors and can be an obstacle to chemotherapy. © 1996 Wiley-Liss, Inc.     

11q23 Aberration is an additional chromosomal change in de novo acute leukemia after treatment with etoposide and mitoxantrone

We report on 2 patients with acute leukemia who had an 11q23 chromosomal aberration as an additional change after treatment with etoposide and mitoxantrone, agents that affect topoisomerase II (Topo II). One patient with Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (L2) received chemotherapy, including 1,000 mg of etoposide and 75 mg of mitoxantrone. She relapsed 10 months later. Analysis at time of relapse showed a chromosomal aberration of del(11)(q23) as an additional cytogenetic change. The other patient was diagnosed with acute monoblastic leukemia (M5a) and received two autologous peripheral blood stem-cell transplantations. Her cumulative doses of etoposide and mitoxantrone were 6,000 mg and 42 mg, respectively. She also relapsed, and analysis at that time revealed del(11)(q23) as an additional chromosomal aberration. The mixed lineage leukemia/(myeloid-lymphoid leukemia (MLL) gene was not rearranged in either case, making these cases distinct from previously described therapy-related leukemias caused by Topo II Inhibitors. Based on these two cases, it may be that Topo II inhibitors can cause clonal evolution affecting chromosome band 11q23. © 1996 Wiley-Liss, Inc.     

Decreased Triglyceride and Increased Serum Lipoprotein Lipase Levels Are Correlated to Increased High-Density Lipoprotein-Cholesterol Levels after Laparoscopic Sleeve Gastrectomy

IntroductionLaparoscopic sleeve gastrectomy (LSG) significantly increases high-density lipoprotein cholesterol (HDL-C) and lipoprotein lipase (LPL) in pre-heparin serum (pre-heparin LPL levels). LPL is a regulator of serum triglyceride (TG) and HDL-C production; this may be the mechanism for HDL-C increase after LSG. This study aimed to elucidate the mechanism of increase in HDL-C levels by examining the relationship between changes in serum HDL-C levels and LPL after LSG.MethodsWe retrospectively reviewed 104 obese patients, who underwent LSG and were followed up for 12 months. We analyzed the relationship between changes in serum HDL-C levels and various clinical parameters after LSG.ResultsA significant decrease was observed in the patients'' BMI and serum TG levels after LSG. Conversely, HDL-C levels and pre-heparin LPL levels were significantly increased after LSG. Simple linear regression showed that changes in HDL-C levels were significantly correlated with total weight loss percentage, change in TG levels, abdominal fat areas, and pre-heparin LPL levels. Additionally, the multiple regression model revealed that a decrease in TG levels and an increase in pre-heparin LPL levels were correlated with increased HDL-C levels after LSG.Discussion/ConclusionThese results show that a decrease in TG levels and an increase in LPL are mechanisms for increased HDL-C levels after LSG.     

Comparative allelotype of early and advanced stage non-small cell lung carcinomas

To identify chromosomal loci of tumor suppressor genes involved in the genesis and progression of non-small cell lung carcinoma (NSCLC), comparative allelotype analysis was performed in 23 stage I primary lung tumors and in 22 metastatic lung tumors to the brain. In total, 84 loci on all 22 autosomal chromosomes were examined for loss of heterozygosity (LOH) by restriction fragment length polymorphism (RFLP) analysis with 40 polymorphic DNA probes and polymerase chain reaction (PCR)-LOH analysis of 44 polymorphic loci. LOH on chromosome arms 3p, 13q, and 17p was detected frequently (>60%) in both stage I primary lung tumors and brain metastases, whereas the incidence of LOH on chromosome arms 2q, 5q, 9p, 12q, 18q, and 22q was more than 60% only in brain metastases. In particular, the incidence of LOH on chromosome arms 2q, 9p, 18q, and 22q in brain metastases was significantly higher than that in stage I primary lung tumors (P < 0.05). These results indicate that tumor suppressor genes on chromosome arms 3p, 13q, and 17p are involved in the genesis of NSCLC, whereas those on several chromosome arms, especially on 2q, 9p, 18q and 22q, play an important role in the progression of NSCLC. Genes Chromosom Cancer 17:71–77 (1996). © 1996 Wiley-Liss, Inc.     

Cystine and Theanine as Stress-Reducing Amino Acids—Perioperative Use for Early Recovery after Surgical Stress

Perioperative nutritional therapy requires the consideration of metabolic changes, and it is desirable to reduce stress aiming at early metabolic normalization. Glutathione (GSH) is a tripeptide composed of glutamic acid, cysteine, and glycine. It is one of the strongest antioxidants in the body and important for adjusting immune function. Cystine and theanine (γ-glutamylethylamide) provide substrates of GSH, cysteine and glutamic acid, promoting the synthesis of GSH. It has been reported that the ingestion of cystine (700 mg) and theanine (280 mg) exhibits inhibitory effects against excess inflammation after strong exercise loads in athletes, based on which its application for invasive surgery has been tried. In patients undergoing gastrectomy, ingestion of cystine (700 mg) and theanine (280 mg) for 10 days from 5 days before surgery inhibited a postoperative increase in resting energy expenditure, promoted recovery from changes in interleukin-6, C-reactive protein, lymphocyte ratio, and granulocyte ratio and inhibited an increase in body temperature. In a mouse small intestine manipulation model, preoperative 5-day administration of cystine/theanine inhibited a postoperative decrease in GSH in the small intestine and promoted recovery from a decrease in behavior quantity. Based on the above, cystine/theanine reduces surgical stress, being useful for perioperative management as stress-reducing amino acids.