Expression of angiopoietin-like 4 (ANGPTL4) in human colorectal cancer: ANGPTL4 promotes venous invasion and distant metastasis

There is strong evidence that the angiopoietin family is involved in the regulation of tumour progression. Recently, it has been reported that angiopoietin-like 4 (ANGPTL4) expression in cancer cells promotes the metastatic process by increasing vascular permeability. The present study was conducted to examine ANGPTL4 expression and its association with clinicopathological factors and prognosis in human colorectal cancers. We examined 144 cases of surgically-resected human colorectal adenocarcinomas by immunohistochemistry, RT-PCR and Western blot analysis. Also, overall survival was investigated. Among 144 cases of adenocarcinoma, 95 cases (66.0%) showed positive staining in the cytoplasm of the carcinoma cells for ANGPTL4. Histologically, well, moderately, poorly differentiated adenocarcinoma or mucinous carcinoma showed 55.2, 79.3, 61.5 or 44.4% expression of ANGPTL4, respectively. The expression of ANGPTL4 was correlated with the depth of tumour invasion (p<0.0005), Vienna classification (category 3-5)(p<0.00005), venous invasion (p<0.0005) and Duke's classification (p<0.005). However, ANGPTL4 expression was not correlated with overall survival. However, all patients (100%) with distant metastasis showed immunopositivity for ANGPTL4. The mRNA and the protein expression of ANGPTL4 were shown in four resected samples and cultured cell lines by RT-PCR or western blot analysis. These findings suggest that ANGPTL4 is one of the factors involved in the progression of human colorectal cancer, especially venous invasion and distant metastasis.     

Proteomics finding heat shock protein 27 as a biomarker for resistance of pancreatic cancer cells to gemcitabine

Pancreatic cancer remains a devastating disease and >96% of patients with pancreatic cancer do not survive for more than 5 years. Gemcitabine (2'-deoxy-2'-difluoro-deoxycytidine: Gemzar) appears to be the only clinically effective drug for pancreatic cancer, but it has little impact on outcome. Proteomic analysis of gemcitabine-sensitive cells (KLM1) and resistant pancreatic cells (KLM1-R) was performed to identify target proteins of the gemcitabine. We found seven proteins, HSP27, peroxiredoxin 2, endoplasmic reticulum protein ERp29 precursor, 6-phosphogluconolactonase, triosphospate isomerase, alpha enolase, and nucleophosmine that could play a role in determining the sensitivity of pancreatic cancer to gemcitabine. We knocked down HSP27 in KLM1-R and the sensitivity to gemcitabine was restored. In addition, increased HSP27 expression in tumor specimens was related to higher resistibility to gemcitabine in patients of pancreatic cancer. HSP27 may play an important role in the resistibility to gemcitabine, and it could also be a possible biomarker for predicting the response of pancreatic cancer patients to treatment with gemcitabine.     

Cleft-type cyclophanes confer neuroprotection against excitatory neurotoxicity in vitro and in vivo through inhibition of NMDA receptors

The cleft-type cyclophanes (ACCn, DNCn and TsDCn) were found to strongly inhibit macroscopic currents at heteromeric NMDA receptors (NR1/NR2) but not AMPA receptors expressed in Xenopus oocytes at voltage-clamp recording. The inhibition by cleft-type cyclophanes was voltage-dependent, because the inhibition was larger at -100 mV than at -20 mV. Mutations at NR1 N650, located in the vestibule of the channel pore, reduced the inhibition by DNCn and TsDCn, suggesting that the residue (N650) interacts with these cleft-type cyclophanes. Cell toxicity of TsDCn on SH-SY5Y cells was slightly weaker than that of memantine. The neuroprotective effects of cleft-type cyclophanes against cell damage caused by NMDA were investigated in cultured rat hippocampal neurons. Addition of 10 microM DNCn or TsDCn into the medium ablated the neurotoxicity induced by NMDA, and a similar effect was also observed with memantine. The neuroprotective effects of cleft-type cyclophanes were then assayed on NMDA-induced seizures in mice. Intracerebroventricular injection of TsDCn (5 mg/mouse) decreased the seizure induced by intraperitoneal injection of NMDA (115 mg/kg) in mice. The results demonstrate that these cleft-type cyclophanes interact directly with the extracellular mouth of the NMDA channel pore and exhibit neuroprotective effects on NMDA-induced excitatory toxicity in primary cultured neurons and mice.     

Antitumor activity of histone deacetylase inhibitors in non-small cell lung cancer cells: development of a molecular predictive model

To ascertain the potential for histone deacetylase (HDAC) inhibitor-based treatment in non-small cell lung cancer (NSCLC), we analyzed the antitumor effects of trichostatin A (TSA) and suberoylanilide hydroxamic acid (vorinostat) in a panel of 16 NSCLC cell lines via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. TSA and vorinostat both displayed strong antitumor activities in 50% of NSCLC cell lines, suggesting the need for the use of predictive markers to select patients receiving this treatment. There was a strong correlation between the responsiveness to TSA and vorinostat (P < 0.0001). To identify a molecular model of sensitivity to HDAC inhibitor treatment in NSCLC, we conducted a gene expression profiling study using cDNA arrays on the same set of cell lines and related the cytotoxic activity of TSA to corresponding gene expression pattern using a modified National Cancer Institute program. In addition, pathway analysis was done with Pathway Architect software. We used nine genes, which were identified by gene-drug sensitivity correlation and pathway analysis, to build a support vector machine algorithm model by which sensitive cell lines were distinguished from resistant cell lines. The prediction performance of the support vector machine model was validated by an additional nine cell lines, resulting in a prediction value of 100% with respect to determining response to TSA and vorinostat. Our results suggested that (a) HDAC inhibitors may be promising anticancer drugs to NSCLC and (b) the nine-gene classifier is useful in predicting drug sensitivity to HDAC inhibitors and may contribute to achieving individualized therapy for NSCLC patients.     

Determination of exposure to cobalt and nickel in the atmosphere in the hard metal industry.

Cobalt and nickel, matrices of hard metal, have been shown to be respiratory sensitizers. Airborne dust at hard metal-grinding worksites in a factor with a work-force of about 180 grinders was analysed for cobalt and nickel. The electron-microscopic X-ray microanalysis of airborne dust particles demonstrated that they had the same metallic components as hard metal products. Andersen sampling revealed that 66% of total dust was respirable (< 7 microns). Consecutive personal sampling for individuals indicated log-normally distributed concentrations of total dust and cobalt. Of the workers surveyed, 12% (16 out of 133) were exposed to cobalt at more than 50 micrograms m-3, while 1.5% (two out of 133) were exposed to nickel concentrations of more than 50 micrograms m-3. A correlation between cobalt exposure concentrations and nickel concentrations for individuals was significant and positive. Further improvement of the working environment is necessary because of the hazard caused by exposure to cobalt and nickel.     

Regulation of cardiac function during a cold pressor test in athletes and untrained subjects

By using (dP/dt)/P of carotid artery pulse, a non-invasive index of cardiac contractility, we examined the regulatory mechanism of cardiac function during a cold pressor test in athletes and untrained subjects. Twenty-four healthy subjects (9 athletes, 8 untrained subjects, and 7 hyperreactors of 4 athletes and 3 untrained subjects with a rise of 15 mmHg or greater in systolic and/or diastolic blood pressure) underwent the cold pressor test according to Hines and Brown (Am Heart J 11:1–9, 1936): immersion of the right hand in 4°C water for 1 min. Although mean blood pressure increased during the cold stress in all the groups, cardiac function differed. In athletes, heart rate and cardiac contractility caused cardiac output to increase while total peripheral resistance (TPR) did not change. In untrained subjects, however, heart rate and cardiac contractility tended to decrease cardiac output and thus TPR increased. In hyperreactors, heart rate and cardiac contractility increased during cold stress, and also TPR increased. After the end of the test, heart rate and cardiac contractility decreased only in untrained group. The findings that during a cold pressor test heart rate and cardiac contractility are enhanced in athletes but depressed in untrained subjects indicate that the state of physical training influences cardiac sympathetic neural reactivity to cold stress, except for hyperreactors.     

Hypoxia promotes fibrogenesis in vivo via HIF-1 stimulation of epithelial-to-mesenchymal transition

Hypoxia has been proposed as an important microenvironmental factor in the development of tissue fibrosis; however, the underlying mechanisms are not well defined. To examine the role of hypoxia-inducible factor-1 (HIF-1), a key mediator of cellular adaptation to hypoxia, in the development of fibrosis in mice, we inactivated Hif-1alpha in primary renal epithelial cells and in proximal tubules of kidneys subjected to unilateral ureteral obstruction (UUO) using Cre-loxP-mediated gene targeting. We found that Hif-1alpha enhanced epithelial-to-mesenchymal transition (EMT) in vitro and induced epithelial cell migration through upregulation of lysyl oxidase genes. Genetic ablation of epithelial Hif-1alpha inhibited the development of tubulointerstitial fibrosis in UUO kidneys, which was associated with decreased interstitial collagen deposition, decreased inflammatory cell infiltration, and a reduction in the number of fibroblast-specific protein-1-expressing (FSP-1-expressing) interstitial cells. Furthermore, we demonstrate that increased renal HIF-1alpha expression is associated with tubulointerstitial injury in patients with chronic kidney disease. Thus, we provide clinical and genetic evidence that activation of HIF-1 signaling in renal epithelial cells is associated with the development of chronic renal disease and may promote fibrogenesis by increasing expression of extracellular matrix-modifying factors and lysyl oxidase genes and by facilitating EMT.     

Serum hepatocyte growth factor and cancer mortality in an apparently healthy Japanese population

Background: In patients with cancer, hepatocyte growth factor (HGF) is elevated and is a predictor of prognosis. We investigated whether serum HGF was a predictive marker for cancer death in a population of community-dwelling Japanese.Methods: We studied 1492 apparently healthy Japanese adults who underwent health examinations in 1999. Those who reported a history of liver disease or malignancy on a baseline questionnaire were excluded, and plasma HGF was measured in the remaining 1470 participants, who were followed periodically for 10 years. Multivariate proportional hazards regression was used to estimate cancer mortality.Results: A total of 169 participants died during follow-up (61 from cancer, 32 from cerebrocardiovascular disease, and 76 from other diseases). Mean HGF at baseline was significantly higher among decedents than among survivors (0.26 ± 0.11 vs 0.23 ± 0.09 ng/ml, respectively; P < 0.01). The Cox proportional hazards model showed that age, systolic blood pressure, HGF (hazard ratio, 1.27; 95% CI, 1.06-1.52; P = 0.009), albumin level, smoking status, and creatinine were independent predictors of all-cause death. Age, HGF (hazard ratio, 1.31; 95% CI, 1.04-1.65; P = 0.02), and total cholesterol were independent predictive markers for cancer death.Conclusions: Serum HGF was a predictor of cancer death in an apparently healthy population of community-dwelling Japanese.     

Cell-kinetic analysis of pancreatic cancers in syrian golden hamsters

Cell-kinetic analysis of pancreatic cancers using bromodeoxyuridine (BrdU) was performed on four transplantable pancreatic ductal adenocarcinomas, which were experimentally induced by givingN-nitrosobis (2-hydroxypropyl) amine (BHP) to Syrian golden hamsters. The volume-doubling time (Td)of the tumor was 0.43, 1.03, 2.30, and 3.50 d for tumor lines J, D, B, and F, respectively. In the pulse-labeling study, the labeling index was 15.8, 23.3, 27.9, and 31.7, respectively. The most rapidly growing tumor line, J, unexpectedly showed the lowest BrdU-labeling index (LI). The further study of tumor using the cumulative-labeling method revealed that the duration of S phase (Ts), the generation time (Tg) and the growth fraction (GF) were 2 h, 14 h, and 90% for tumor J and 12 h, 37 h, and 85% for slowly growing tumor B, respectively. Cells of limited life span (CLLS) of these lines did not differ from each other. These results conclude that the marked difference ofTg between tumor lines J and B resulted in a distinction of their growth rates. The disagreement ofTs/Tg also lead to a reversion of LI between the two lines. Furthermore, LI of BrdU with one-point pulse labeling did not seem to be a sufficient indicator of the growth characteristics, at least, in the present experiment.