Altered cytochrome 2E1 and 3A P450-dependent drug metabolism in advanced ovarian cancer correlates to tumour-associated inflammation.

BACKGROUND AND PURPOSE: Previous work has focussed on changes in drug metabolism caused by altered activity of CYP3A in the presence of inflammation and, in particular, inflammation associated with malignancy. However, drug metabolism involves a number of other P450s, and therefore, we assessed the effect of cancer-related inflammation on multiple CYP enzymes using a validated drug cocktail. EXPERIMENTAL APPROACH: Patients with advanced stage ovarian cancer and healthy volunteers were recruited. Participants received caffeine, chlorzoxazone, dextromethorphan, and omeprazole as in vivo probes for CYP1A2, CYP2E1, CYP2D6, CYP3A, and CYP2C19. Blood was collected for serum C-reactive protein and cytokine analysis. KEY RESULTS: CYP2E1 activity was markedly up-regulated in cancer (6-hydroxychlorzoxazone/chlorzoxazone ratio of 1.30 vs. 2.75), while CYP3A phenotypic activity was repressed in cancer (omeprazole sulfone/omeprazole ratio of 0.23 vs. 0.49). Increased activity of CYP2E1 was associated with raised serum levels of IL-6, IL-8, and TNF-α. Repression of CYP3A correlated with raised levels of serum C-reactive protein, IL-6, IL-8, and TNF-α. CONCLUSIONS AND IMPLICATIONS: CYP enzyme activity is differentially affected by the presence of tumour-associated inflammation, affecting particularly CYP2E1- and CYP3A-mediated drug metabolism, and may have profound implications for drug development and prescribing in oncological settings.

Enhancement of non-invasive trans-membrane drug delivery using ultrasound and microbubbles during physiologically relevant flow.

Sonoporation has been associated with drug delivery across cell membranes and into target cells, yet several limitations have prohibited further advancement of this technology. Higher delivery rates were associated with increased cellular death, thus implying a safety-efficacy trade-off. Meanwhile, there has been no reported study of safe in vitro sonoporation in a physiologically relevant flow environment. The objective of our study was not only to evaluate sonoporation under physiologically relevant flow conditions, such as fluid velocity, shear stress and temperature, but also to design ultrasound parameters that exploit the presence of flow to maximize sonoporation efficacy while minimizing or avoiding cellular damage. Human umbilical vein endothelial cells (EA.hy926) were seeded in flow chambers as a monolayer to mimic the endothelium. A peristaltic pump maintained a constant fluid velocity of 12.5 cm/s. A focused 0.5 MHz transducer was used to sonicate the cells, while an inserted focused 7.5 MHz passive cavitation detector monitored microbubble-seeded cavitation emissions. Under these conditions, propidium iodide, which is normally impermeable to the cell membrane, was traced to determine whether it could enter cells after sonication. Meanwhile, calcein-AM was used as a cell viability marker. A range of focused ultrasound parameters was explored, with several unique bioeffects observed: cell detachment, preservation of cell viability with no membrane penetration, cell death and preservation of cell viability with sonoporation. The parameters were then modified further to produce safe sonoporation with minimal cell death. To increase the number of favourable cavitation events, we lowered the ultrasound exposure pressure to 40 kPapk-neg and increased the number of cavitation nuclei by 50 times to produce a trans-membrane delivery rate of 62.6% ± 4.3% with a cell viability of 95% ± 4.2%. Furthermore, acoustic cavitation analysis showed that the low pressure sonication produced stable and non-inertial cavitation throughout the pulse sequence. To our knowledge, this is the first study to demonstrate a high drug delivery rate coupled with high cell viability in a physiologically relevant in vitro flow system.

Alterations of choline phospholipid metabolism in endometrial cancer are caused by choline kinase alpha overexpression and a hyperactivated deacylation pathway.

Metabolic rearrangements subsequent to malignant transformation are not well characterized in endometrial cancer. Identification of altered metabolites could facilitate imaging-guided diagnosis, treatment surveillance, and help to identify new therapeutic options. Here, we used high-resolution magic angle spinning magnetic resonance mass spectroscopy on endometrial cancer surgical specimens and normal endometrial tissue to investigate the key modulators that might explain metabolic changes, incorporating additional investigations using qRT-PCR, Western blotting, tissue microarrays (TMA), and uptake assays of [(3)H]-labeled choline. Lipid metabolism was severely dysregulated in endometrial cancer with various amino acids, inositols, nucleobases, and glutathione also altered. Among the most important lipid-related alterations were increased phosphocholine levels (increased 70% in endometrial cancer). Mechanistic investigations revealed that changes were not due to altered choline transporter expression, but rather due to increased expression of choline kinase α (CHKA) and an activated deacylation pathway, as indicated by upregulated expression of the catabolic enzymes LYPLA1, LYPLA2, and GPCPD1. We confirmed the significance of CHKA overexpression on a TMA, including a large series of endometrial hyperplasia, atypical hyperplasia, and adenocarcinoma tissues, supporting a role for CHKA in malignant transformation. Finally, we documented several-fold increases in the uptake of [(3)H]choline in endometrial cancer cell lines compared with normal endometrial stromal cells. Our results validate deregulated choline biochemistry as an important source of noninvasive imaging biomarkers for endometrial cancer.

A fast modified protocol for random-access ultra-high density whole-genome scan: a tool for personalized genomic medicine, positional mapping, and cytogenetic analysis.

BACKGROUND: High density single nucleotide polymorphism (SNP) genotyping array is widely applied on genome-wide association study of common diseases. In these studies, a fixed batch-size of 48 or 96 samples allows high-throughput analysis. To enhance the clinical application of microarray analysis on personalized medicine, we describe a modified PCR purification protocol without batch-size limitation for whole-genome scan using ultra-high density SNP microarray. METHODS: Enzyme-digested PCR products were purified with the use of magnetic beads. Separation of the magnetic particles applies magnetic stand devices instead of vacuum pumps. With no batch-size limitation, we genotyped 17 genomic samples and 3 whole genome amplified samples in order to examine the performance of the modified protocol. RESULTS: Our method is simple and fast, provides sufficient amount and high quality PCR products for subsequent fragmentation and labeling procedures prior to GeneChip hybridization. We show that the purified DNA can be genotyped with good QC call rate of >93% in average similar to standard protocol. With the use of the short protocol, we successfully identified the breakpoint localization of a ring chromosome in a female and located the disease gene in a consanguineous family affected by limb-girdle muscular dystrophy. CONCLUSION: By modifying a single step in the original protocol, we are able to speed up the overall genotyping analysis and change the batch-wise analysis to random-access analysis for ultra-high density whole-genome scan for personalized medicine, positional mapping, and cytogenetic analysis.