MTT assay based inhibition analysis of A2780 cells proliferation using Mollugo nudicaulis Lam. extract with CXCR4 and HER2 expression

It is of interest to document the inhibition of A2780 cell proliferation using Mollugo nudicaulis Lam.(M.nudicaulis) extract by MTT assay and by monitoring the CXCR4 and HER2 expression through RT-PCR analysis. Results shown that the n-hexane extract of M.nudicaulis have anticancer activity IC₅₀ values of 32.46±0.92 µg/mL on A2780 cell lines. It is further found that the CXCR4 and HER2 mRNA and protein expression were significantly reduced in M.nudicaulis treated A2780 cell lines. Thus, the n-hexane extract of M.nudicaulis is a natural source of bioactive compounds as potential anticancer agents.     

X-ray microanalysis of colloidal-gold-labelled lysosomes in rat liver sinusoidal cells after incubation for acid phosphatase activity

The lysosomal apparatus of the Kupffer and endothelial cells of the sinusoidal lining of the rat liver was found to take up colloidal-gold particles with a mean diameter of 5 nm, prepared according to a modified method. After incubation of the glutaraldehyde-perfusion-fixed tissue in a lead-containing medium for the demonstration of acid phosphatase activity, a reaction product was observed in the gold-loaded lysosomes. By X-ray microanalysis of such lysosomes, the presence of osmium, gold and lead was detected qualitatively in the unstained sections from the tissue, which after the incubation had been post-fixed with an OsO4-solution to which K4Fe(CN)6 had been added to enhance the contrast. The quantitative computer-assisted processing of the X-ray microanalytical data from such lysosomes enabled to determine the gold-to-lead ratio and the individual gold and lead peak intensities derived from both the M chi and L chi values in the spectra. On the basis of these results and those obtained similarly in control lysosomes containing either only gold or only lead phosphate precipitate, it was found that only the L chi values were reliable, whereas the M chi values from the same lysosomal spectra were unrealistic, due to deconvolution problems in the computer programs applied. Based upon the L chi values it was found that among the population of lysosomes in single Kupffer cells, studied after a 60-min interval between the injection of the gold colloid and fixation, three types of lysosomal contents could be quantitated by X-ray microanalysis, viz. one type with only gold, one with only lead, one with gold and lead, in various ratios. This quantitative approach might make it possible to detect variations in lysosomal composition associated with ageing.     

Gap junction ultrastructure in rat liver parenchymal cells after in vivo ischemia

The ultrastructure of gap junctions between rat liver parenchymal cells has been studied after in vivo ischemia, with and without subsequent blood reflow. Freeze fracture replicas were analysed by electron microscopic observation, optical diffraction and morphometric analysis. In control specimens gap junction connexons were widely dispersed and arranged in nearly random fashion over nearly the whole junctional area, with only minute spots of hexagonal connexon arrangement. An ischemic period of 30 min, from which the vast majority of cells are capable of recovery after restoration of the blood supply, usually entails only a slight enlargement of the areas of hexagonally arranged connexons. After 120 min of ischemia without reflow, which results in necrosis of most parenchymal cells, all gap junctions showed a completely hexagonal arrangement of connexons. The numerical density of connexons after 30 and 120 min of ischemia without reflow was significantly higher than in controls, whereas after 30 min of ischemia followed by 2 h of reflow the numerical density had returned to control levels. A fully hexagonal arrangement of gap junction connexons, as occurs after longer periods of ischemia, seems to be related to irreversible cell damage and presumably to metabolic uncoupling of cells. This was preceded by an increase in the numerical density of connexons, which is probably a reversible phenomenon.     

Copy number alterations and allelic ratio in relation to recurrence of rectal cancer

Background

In rectal cancer, total mesorectal excision surgery combined with preoperative (chemo)radiotherapy reduces local recurrence rates but does not improve overall patient survival, a result that may be due to the harmful side effects and/or co-morbidity of preoperative treatment. New biomarkers are needed to facilitate identification of rectal cancer patients at high risk for local recurrent disease. This would allow for preoperative (chemo)radiotherapy to be restricted to high-risk patients, thereby reducing overtreatment and allowing personalized treatment protocols. We analyzed genome-wide DNA copy number (CN) and allelic alterations in 112 tumors from preoperatively untreated rectal cancer patients. Sixty-six patients with local and/or distant recurrent disease were compared to matched controls without recurrence. Results were validated in a second cohort of tumors from 95 matched rectal cancer patients. Additionally, we performed a meta-analysis that included 42 studies reporting on CN alterations in colorectal cancer and compared results to our own data.

Results

The genomic profiles in our study were comparable to other rectal cancer studies. Results of the meta-analysis supported the hypothesis that colon cancer and rectal cancer may be distinct disease entities. In our discovery patient study cohort, allelic retention of chromosome 7 was significantly associated with local recurrent disease. Data from the validation cohort were supportive, albeit not statistically significant, of this finding.

Conclusions

We showed that retention of heterozygosity on chromosome 7 may be associated with local recurrence in rectal cancer. Further research is warranted to elucidate the mechanisms and effect of retention of chromosome 7 on the development of local recurrent disease in rectal cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1550-0) contains supplementary material, which is available to authorized users.     

FGF signalling through RAS/MAPK and PI3K pathways regulates cell movement and gene expression in the chicken primitive streak without affecting E-cadherin expression

Background  

FGF signalling regulates numerous aspects of early embryo development. During gastrulation in amniotes, epiblast cells undergo an epithelial to mesenchymal transition (EMT) in the primitive streak to form the mesoderm and endoderm. In mice lacking FGFR1, epiblast cells in the primitive streak fail to downregulate E-cadherin and undergo EMT, and cell migration is inhibited. This study investigated how FGF signalling regulates cell movement and gene expression in the primitive streak of chicken embryos.     

Liquid chromatography-tandem mass spectrometric assay for the PARP-1 inhibitor olaparib in combination with the nitrogen mustard melphalan in human plasma

A bioanalytical assay for the new poly(ADP-ribose) polymerase-1 inhibitor olaparib in combination with melphalan was developed and validated. For the quantitative assay, human plasma samples were pre-treated on ice using protein precipitation with 2% (v/v) acetic acid in acetonitrile containing erlotinib and melphalan-d? as internal standards. The extract was diluted with water and injected into the chromatographic system. This system consisted of a sub-2 μm particle, trifunctional bonded octadecyl silica column with an isocratic elution using 0.01% (v/v) of formic acid in a mixture of water and methanol. The eluate was transferred into the electrospray interface with positive ionization and the analyte was detected in the selected reaction monitoring mode of a triple quadrupole mass spectrometer. The assay was validated in a 10-5000 ng/ml calibration range for both drugs. The lowest level of this range corresponded to the lower limit of quantification. Within day precisions were 3.0-9.3%, between day precisions 6.0-9.8% and accuracies were between 101 and 110% for the whole calibration range. After validation the assay was used to assess the pharmacokinetics of olaparib in a patient with metastatic breast carcinoma. In addition, systemic exposure of melphalan was monitored in patients subjected to isolated hepatic perfusion with this drug. Both applications show that the new assay can be applied for human pharmacokinetic studies for both drugs.     

Gastric cancers of Western European and African patients show different patterns of genomic instability

Background

Infection with H. pylori is important in the etiology of gastric cancer. Gastric cancer is infrequent in Africa, despite high frequencies of H. pylori infection, referred to as the African enigma. Variation in environmental and host factors influencing gastric cancer risk between different populations have been reported but little is known about the biological differences between gastric cancers from different geographic locations. We aim to study genomic instability patterns of gastric cancers obtained from patients from United Kingdom (UK) and South Africa (SA), in an attempt to support the African enigma hypothesis at the biological level.

Methods

DNA was isolated from 67 gastric adenocarcinomas, 33 UK patients, 9 Caucasian SA patients and 25 native SA patients. Microsatellite instability and chromosomal instability were analyzed by PCR and microarray comparative genomic hybridization, respectively. Data was analyzed by supervised univariate and multivariate analyses as well as unsupervised hierarchical cluster analysis.

Results

Tumors from Caucasian and native SA patients showed significantly more microsatellite instable tumors (p < 0.05). For the microsatellite stable tumors, geographical origin of the patients correlated with cluster membership, derived from unsupervised hierarchical cluster analysis (p = 0.001). Several chromosomal alterations showed significantly different frequencies in tumors from UK patients and native SA patients, but not between UK and Caucasian SA patients and between native and Caucasian SA patients.

Conclusions

Gastric cancers from SA and UK patients show differences in genetic instability patterns, indicating possible different biological mechanisms in patients from different geographical origin. This is of future clinical relevance for stratification of gastric cancer therapy.

     

Intimal lining layer macrophages but not synovial sublining macrophages display an IL-10 polarized-like phenotype in chronic synovitis

Introduction

Synovial tissue macrophages play a key role in chronic inflammatory arthritis, but the contribution of different macrophage subsets in this process remains largely unknown. The main in vitro polarized macrophage subsets are classically (M1) and alternatively (M2) activated macrophages, the latter comprising interleukin (IL)-4 and IL-10 polarized cells. Here, we aimed to evaluate the polarization status of synovial macrophages in spondyloarthritis (SpA) and rheumatoid arthritis (RA).

Methods

Expression of polarization markers on synovial macrophages, peripheral blood monocytes, and in vitro polarized monocyte-derived macrophages from SpA versus RA patients was assessed by immunohistochemistry and flow cytometry, respectively. The polarization status of the intimal lining layer and the synovial sublining macrophages was assessed by double immunofluorescence staining.

Results

The expression of the IL-10 polarization marker cluster of differentiation 163 (CD163) was increased in SpA compared with RA intimal lining layer, but no differences were found in other M1 and M2 markers between the diseases. Furthermore, no significant phenotypic differences in monocytes and in vitro polarized monocyte-derived macrophages were seen between SpA, RA, and healthy controls, indicating that the differential CD163 expression does not reflect a preferential M2 polarization in SpA. More detailed analysis of intimal lining layer macrophages revealed a strong co-expression of the IL-10 polarization markers CD163 and cluster of differentiation 32 (CD32) but not any of the other markers in both SpA and RA. In contrast, synovial sublining macrophages had a more heterogeneous phenotype, with a majority of cells co-expressing M1 and M2 markers.

Conclusions

The intimal lining layer but not synovial sublining macrophages display an IL-10 polarized-like phenotype, with increased CD163 expression in SpA versus RA synovitis. These differences in the distribution of the polarized macrophage subset may contribute to the outcome of chronic synovitis.     

Effects of age,replicative lifespan and growth rate of human nucleus pulposus cells on selecting age range for cell-based biological therapies for degenerative disc diseases

Autologous disc cell implantation, growth factors and gene therapy appear to be promising therapies for disc regeneration. Unfortunately, the replicative lifespan and growth kinetics of human nucleus pulposus (NP) cells related to host age are unclear. We investigated the potential relations among age, replicative lifespan and growth rate of NP cells, and determined the age range that is suitable for cell-based biological therapies for degenerative disc diseases. We used NP tissues classified by decade into five age groups: 30s, 40s, 50s, 60s and 70s. The mean cumulative population doubling level (PDL) and population doubling rate (PDR) of NP cells were assessed by decade. We also investigated correlations between cumulative PDL and age, and between PDR and age. The mean cumulative PDL and PDR decreased significantly in patients in their 60s. The mean cumulative PDL and PDR in the younger groups (30s, 40s and 50s) were significantly higher than those in the older groups (60s and 70s). There also were significant negative correlations between cumulative PDL and age, and between PDR and age. We found that the replicative lifespan and growth rate of human NP cells decreased with age. The replicative potential of NP cells decreased significantly in patients 60 years old and older. Young individuals less than 60 years old may be suitable candidates for NP cell-based biological therapies for treating degenerative disc diseases.     

Quantitative and selective assay of 5-methylindirubine, an inhibitor of cyclin-dependent kinases, in murine plasma using coupled liquid chromatography and electrospray tandem mass spectrometry

A sensitive and rapid LC-MS/MS assay for the quantitative determination of 5-methylindirubine (5-MI) in murine plasma is described. A 50-microL-murine plasma aliquot was spiked with an internal standard, indirubine-3-monoxime (IMO), and extracted with 1.25 mL diethyl ether. Dried extracts were reconstituted in methanol-water (8:2, v/v) and 10 microL-volumes were injected onto the HPLC system. Separation was achieved on a Gemini C18 column (150 mm x 2.1 mm ID, particle size 5 microm) using an alkaline eluent (10 mM ammonium hydroxide-methanol (5:95, v/v)). Detection was performed by negative ion electrospray followed by tandem mass spectrometry. The assay quantifies 5-MI in a range from 1 to 500 ng/mL using 50 microL of murine EDTA plasma samples. Validation results demonstrate that 5-MI concentrations can be accurately and precisely quantified in murine plasma. This assay is used to support pre-clinical pharmacologic studies with 5-MI.