Longitudinal Bottom-Up Proteomics of Serum, Serum Extracellular Vesicles, and Cerebrospinal Fluid Reveals Candidate Biomarkers for Early Detection of Glioblastoma in a Murine Model

Glioblastoma Multiforme (GBM) is a brain tumor with a poor prognosis and low survival rates. GBM is diagnosed at an advanced stage, so little information is available on the early stage of the disease and few improvements have been made for earlier diagnosis. Longitudinal murine models are a promising platform for biomarker discovery as they allow access to the early stages of the disease. Nevertheless, their use in proteomics has been limited owing to the low sample amount that can be collected at each longitudinal time point. Here we used optimized microproteomics workflows to investigate longitudinal changes in the protein profile of serum, serum small extracellular vesicles (sEVs), and cerebrospinal fluid (CSF) in a GBM murine model. Baseline, pre-symptomatic, and symptomatic tumor stages were determined using non-invasive motor tests. Forty-four proteins displayed significant differences in signal intensities during GBM progression. Dysregulated proteins are involved in cell motility, cell growth, and angiogenesis. Most of the dysregulated proteins already exhibited a difference from baseline at the pre-symptomatic stage of the disease, suggesting that early effects of GBM might be detectable before symptom onset.

Ethyl acrylate (EA) exposure and thyroid carcinogenicity in rats and mice with relevance to human health

Ethyl acrylate (EA) was classified by IARC as a Group-2B Carcinogen based, in part, on data suggesting increased incidence of thyroid neoplasia in rats and mice exposed chronically to EA vapors. We examined chronic exposure of rats and mice to EA vapors, evaluated the data on the incidence of thyroid follicular neoplasia, and determined the relevance of thyroid tumors to human health risk. The data revealed a small statistically significant increase in thyroid tumors in EA-exposed male rats and mice. The tumor incidences were within the range of historical controls and were not consistently dose-dependent. Most thyroid tumors in exposed animals were benign. Chronic exposure of EA to rats and mice (drinking water or gavage) and dogs (capsules) had no evidence of thyroid neoplasia. Results from chronic studies, in vivo and in vitro data, and ToxCastTM/Tox 21 HTPS did not support genotoxic/mutagenic potential for EA. This suggests that the associations between EA exposure and thyroid neoplasia represent chance or random observations rather than a compound-mediated effect. Due to species-specific physiological differences, the hypothalamic-pituitary-thyroid axis of rodents is more sensitive to endocrine disruptive chemicals than that of humans which further suggests that findings in rodents have questionable relevance to human health.

C3 Drives Inflammatory Skin Carcinogenesis Independently of C5

Nonmelanoma skin cancer such as cutaneous squamous cell carcinoma (cSCC) is the most common form of cancer and can occur as a consequence of DNA damage to the epithelium by UVR or chemical carcinogens. There is growing evidence that the complement system is involved in cancer immune surveillance; however, its role in cSCC remains unclear. Here, we show that complement genes are expressed in tissue from patients with cSCC, and C3 activation fragments are present in cSCC biopsies, indicating complement activation. Using a range of complement-deficient mice in a two-stage mouse model of chemically-induced cSCC, where a subclinical dose of 7,12-dimethylbenz[a]anthracene causes oncogenic mutations in epithelial cells and 12-O-tetradecanoylphorbol-13-acetate promotes the outgrowth of these cells, we found that C3-deficient mice displayed a significantly reduced tumor burden, whereas an opposite phenotype was observed in mice lacking C5aR1, C5aR2, and C3a receptor. In addition, in mice unable to form the membrane attack complex, the tumor progression was unaltered. C3 deficiency did not affect the cancer response to 7,12-dimethylbenz[a]anthracene treatment alone but reduced the epidermal hyperplasia during 12-O-tetradecanoylphorbol-13-acetate-induced inflammation. Collectively, these data indicate that C3 drives tumorigenesis during chronic skin inflammation, independently of the downstream generation of C5a or membrane attack complex.

Multimerization through Pegylation Improves Pharmacokinetic Properties of scFv Fragments of GD2-Specific Antibodies

Antigen-binding fragments of antibodies specific to the tumor-associated ganglioside GD2 are well poised to play a substantial role in modern GD2-targeted cancer therapies, however, rapid elimination from the body and reduced affinity compared to full-length antibodies limit their therapeutic potential. In this study, scFv fragments of GD2-specific antibodies 14.18 were produced in a mammalian expression system that specifically bind to ganglioside GD2, followed by site-directed pegylation to generate mono-, di-, and tetra-scFv fragments. Fractionated pegylated dimers and tetramers of scFv fragments showed significant increase of the binding to GD2 which was not accompanied by cross-reactivity with other gangliosides. Pegylated multimeric di-scFvs and tetra-scFvs exhibited cytotoxic effects in GD2-positive tumor cells, while their circulation time in blood significantly increased compared with monomeric antibody fragments. We also demonstrated a more efficient tumor uptake of the multimers in a syngeneic GD2-positive mouse cancer model. The findings of this study provide the rationale for improving therapeutic characteristics of GD2-specific antibody fragments by multimerization and propose a strategy to generate such molecules. On the basis of multimeric antibody fragments, bispecific antibodies and conjugates with cytotoxic drugs or radioactive isotopes may be developed that will possess improved pharmacokinetic and pharmacodynamic properties.

Impact of protamine I on colon cancer proliferation, invasion, migration, diagnosis and prognosis

This paper investigates protamine I (PRM1) expression and its effects on proliferation, invasion and migration of colon cancer cells as well as its function in clinical diagnosis and prognosis. Gene chips were used to screen differentially expressed genes. PRM1 expression was detected by Western blotting and quantitative real time-polymerase chain reaction (qRT-PCR). Hematoxylin and eosin (HE) staining and immunohistochemistry were utilized to compare the expression of PRM1 from multiple differentiation levels of colon cancer tissues. Cell viability, cell apoptosis and cell cycle were tested using the MTT assay and flow cytometry. Cell invasion and migration capability were tested using the Transwell assay and wound healing. In vivo effects of PRM1 on colon cancer were explored using a xenograft model. PRM1 expression in serum was detected by enzyme-linked immunosorbent assay (ELISA). The expression level of PRM1 was significantly higher in colon cancer tissues and the staining degree of PRM1 in poorly-differentiated was stronger. pcDNA3.1-PRM1 decreased cell apoptosis while it increased the proliferation, cell invasion and migration. The si-PRM1 group displayed an opposite tendency. The serum PRM1 level was significantly higher and could serve as a diagnostic biomarker for colon cancer.

Nucleic acid hybridization on an electrically reconfigurable network of gold-coated magnetic nanoparticles enables microRNA detection in blood

There is intense interest in quantifying the levels of microRNA because of its importance as a blood-borne biomarker. The challenge has been to develop methods that can monitor microRNA expression both over broad concentration ranges and in ultralow amounts directly in a patient's blood. Here, we show that, through electric-field-induced reconfiguration of a network of gold-coated magnetic nanoparticles modified by probe DNA (DNA-Au@MNPs), it is possible to create a highly sensitive sensor for direct analysis of nucleic acids in samples as complex as whole blood. The sensor is the first to be able to detect concentrations of microRNA from 10 aM to 1 nM in unprocessed blood samples. It can distinguish small variations in microRNA concentrations in blood samples of mice with growing tumours. The ultrasensitive and direct detection of microRNA using an electrically reconfigurable DNA-Au@MNPs network makes the reported device a promising tool for cancer diagnostics.

NMR-based metabolic profiling of urine, serum, fecal, and pancreatic tissue samples from the Ptf1a-Cre; LSL-KrasG12D transgenic mouse model of pancreatic cancer

Pancreatic cancer is the third leading cause of cancer deaths in the United States with more than 53,000 expected to be diagnosed with the disease in 2018. The median survival time after diagnosis is four to six months. The poor survival statistics are due in part to the fact that pancreatic cancer is typically asymptomatic until it reaches advanced stages of the disease. Although surgical resection provides the best chance of survival, pancreatic cancer is rarely detected when surgery is still possible due, in part, to lack of effective biomarkers for early detection. The goal of the research reported here was to determine if it was possible to identify metabolic biomarkers for detection of pre-cancerous pancreatic intraepithelial neoplasia (PanIN) that precede pancreatic adenocarcinoma. The transgenic Ptf1a-Cre; LSL-KrasG12D mouse strain was used as a model of pancreatic cancer progression. Nuclear magnetic resonance (NMR) spectroscopy was employed to compare metabolic profiles of urine, sera, fecal extracts, and pancreatic tissue extracts collected from control and study mice aged 5, 11, and 15 months, including 47 mice with tumors. We were able to identify the following potential biomarkers: decreased 3-indoxylsulfate, benzoate and citrate in urine, decreased glucose, choline, and lactate in blood, and decreased phenylalanine and benzoate and increased acetoin in fecal extracts. Potential biomarkers were validated by p-values, PLS-DA VIP scores, and accuracies based on area under ROC curve analyses. Essentially, all of the metabolic profiling changes could be explained as being associated with the consequences of bicarbonate wasting caused by a complete substitution of the normal pancreatic acinar tissue by tissue entirely composed of PanIN. Given the nature of the mouse model used here, our results indicate that it may be possible to use NMR-based metabolic profiling to identify biomarkers for detection of precancerous PanIN that immediately precede pancreatic cancer.

Effects of CAR-regimen autohemochemotherapy on redox-dependent processes in erythrocytes of tumor-bearing organism in experimental ovarian cancer

THE PURPOSE

The purpose of the study was to investigate the effect of the scheme autohemochemotherapy ATS on redox-dependent processes in red blood cells of tumor-bearing organism at an experimental ovarian cancer.

METHODS

We studied the dynamics of redox-dependent processes in red blood cells of rats with experimental ascitic ovarian tumor during CAP-regimen autohemochemotherapy (cyclophosphamide, doxorubicin and cisplatin). We assessed the indicators of oxidative modification of proteins in erythrocytes - carbonyl derivatives at l = 346 nm, 370 nm, 430 nm and 530 nm, the parameters of lipid peroxidation - malondialdehyde, ketodienes, diene conjugates, Schiff bases; the enzymatic part of antioxidant system - the activity of catalase, glutathione transferase and superoxide dismutase biochemically.

RESULTS

The red blood cells of tumor-bearing animals were found having increased the products of lipid peroxidation and oxidative modification of proteins while reducing the activity of antioxidant enzymes, suggesting a state of oxidative and carbonyl stress.

CONCLUSION

We showed that extracorporeal incubation of cytotoxic drugs used in the CAP scheme with autoblood prior to infusion - the method of autohemochemotherapy - either in monochemotherapy, or in CAP-regimen, decreases the levels of lipid peroxidation, oxidative modification of proteins and increases activity of first line antioxidant defense enzymes - catalase and superoxide dismutase in circulating red blood cells. Such dynamics of redox-dependent processes suggests a stabilizing effect of autohemochemotherapy on circulating erythrocytes in a tumor-bearing organism.

In vivo cancer targeting and fluorescence-CT dual-mode imaging with nanoprobes based on silver sulfide quantum dots and iodinated oil

In this article, a fluorescence-CT dual-mode nanoprobe is successfully synthesized by making use of distearoylphosphatidylethanolamine-poly(ethylene glycol)-folate (DSPE-PEG2000-FA) and other amphiphilic molecules to coat silver sulfide (Ag2S) quantum dots (QDs) and iodinated oil simultaneously. In vitro experiments show that the fluorescence wavelength of the nanoprobe is 1170 nm in the near infrared-II region. Its size is 139.6 nm, it has good dispersibility, and it has low cellular toxicity at concentrations up to 25 μg mL(-1) Ag. In vivo experiments revealed that the probe has a rather long circulation time (blood half-life of 5.7 hours), and the tissue histopathological tests show that it is not obviously harmful to major organs' normal function. Biochemical analysis (glutamic pyruvic transaminase and glutamic oxaloacetic transaminase levels) and blood analysis (white blood cell, red blood cell, hemoglobin and blood platelet counts) reveal that it has little influence on blood within 15 days of administration. When injected into HeLa xenograft nude mice by the tail vein, the probe elicited intensely enhanced fluorescence and X-ray computed tomography (CT) signals in the tumors after 24 hours, and the structure, size and position of tumor tissue were shown clearly. In a word, the probe has good tumor targeting capabilities, and it has significant value in fluorescence-CT dual-mode imaging in vivo.

Investigating the role of Pluronic-g-Cationic polyelectrolyte as functional stabilizer for nanocrystals: Impact on Paclitaxel oral bioavailability and tumor growth

Paclitaxel (PTX) is a potent anticancer drug which suffers limitations of extremely low oral bioavailability due to low solubility, rapid metabolism and efflux by P-gp transporters. The main objective of this study was to overcome the limitation of PTX by designing delivery systems that can enhance the absorption using multiple pathways. A novel Pluronic-grafted chitosan (Pl-g-CH) copolymer was developed and employed as a functional stabilizer for nanocrystals (NCs) and hypothesized that it would improve PTX absorption by several mechanisms and pathways. Pl-g-CH was synthesized and characterized using (1)H NMR and then used as a stabilizer during nanocrystal development. To establish our proof of concept the optimized formulation having a particle size 192.7 ± 9.2 nm and zeta potential (+) 38.8 ± 3.12 mV was studied extensively on in vitro Caco-2 model. It was observed that nanocrystals rendered higher PTX accumulation inside the cell than Taxol™. P-gp inhibitory potential of Pl-g-CH was proved by flow cytometry and fluorescence microscopy where the much enhanced fluorescence intensity of Rhodamine 123 (Rho-123, P-gp substrate) was observed in the presence of Pl-g-CH. In addition, a significant decrease in Trans Epithelial Electrical Resistance (TEER) of Caco-2 cell monolayers was observed with nanocrystals as well as with Taxol™ (in the presence of free Pl-g-CH compared to only Taxol™). This supports the role of the stabilizer in reversible opening of tight junctions between cells which can allow paracellular transport of drug. The in vivo results were in complete corroboration with in vitro results. Nanocrystals resulted in much enhanced absorption with 12.6-fold improvement in relative bioavailability to that of Taxol™. Concomitantly efficacy data in B16 F10 murine melanoma model also showed a significant reduction in tumor growth with nanocrystals compared to Taxol™ and control. Based on the results it can be suggested that nanocrystals with functional stabilizers can be a promising approach for the oral delivery of anticancer drugs which are P-gp substrates

STATEMENT OF SIGNIFICANCE

Nanocrystals are currently one of the most explored novel drug delivery systems especially for oral delivery of drugs because of ease in synthesis and high drug loading. But their use is still limited for oral delivery of anticancer drugs which are P-gp substrates. This particular study aims at widening the scope of nanocrystals by using a functional stabilizer which participates in enhancing the oral absorption of anticancer drugs and controlling the tumor growth.

[Blood DNA Radiosensitivity May Be Predictive Marker for Efficacy of Radiation Therapy in Glioma Tumorbearing Individuals]

Animal and clinical studies were conducted to evaluate the association between the blood DNA radiosensitivity, assessed by determining the original S-index ex vivo, and the response of gliomas to irradiation in vivo. Possible modifications of the latter after administration of iron-containing water (ICW) in rats were also explored. The study was performed on the rats with subcutaneously implanted experimental glioma-35. The tumors were locally X-irradiated with a single 15 Gy dose as a radiation therapy (RT). ICW (60-63 mg · Fe 2+/l) was administered as a drinking water for 3 days before treatment. The animals underwent blood sampling for analysis of the DNA concentration and leukocyte count. The DNA index was estimated 24 h after RT. The S-index was evaluated within 4 h before RT. The mean initial S-index in the blood samples of glioma-bearing rats was 0.73 ± 0.05. Addition of ICW ex vivo resulted in a significantly increased S-index in a half of the samples. In general, the irradiated rats, which had been given pretreatment with ICW and demonstrated an ex vivo increase of the S-index to > 1.0, showed the most marked inhibition of tumor progression and the smallest tumor volume 25 days after irradiation. They also exhibited the lowest rate of growth and the longest survival. Determination of the biochemical S-index and evaluation of its changes ex vivo caused by ICW may be predictive of the response of experimental glioma to irradiation with radiomodification. The S-index may serve as a predictive indicator in clinic of the efficient evaluation of RT in patients with glioma.

Sandwiched Electrochemiluminescent Peptide Biosensor for the Detection of Prognostic Indicator in Early-Stage Cancer Based on Hollow, Magnetic, and Self-Enhanced Nanosheets

Currently, peptide-based protein-recognition has been recognized as an effective and promising approach for protein assays. However, sandwiched peptide-based biosensor with high sensitivity and low background has not been proposed before. Herein, a sandwiched electrochemiluminescence (ECL) peptide-based biosensor is constructed for Cyclin A(2) (CA2), a prognostic indicator in early stage of multiple cancers, based on nanosheets with hollow, magnetic, and ECL self-enhanced properties. First, hollow and magnetic manganese oxide nanocrystals (H-Mn(3)O(4)) are synthesized using triblock copolymeric micelles with core-shell-corona architecture as templates. Then, polyethyleneimine (PEI) and the composite of platinum nanoparticles and tris (4,4'-dicarboxylicacid-2,2'-bipyridyl) ruthenium (II) (PtNPs-Ru) are immobilized on H-Mn(3)O(4) to form H-Mn(3)O(4) -PEI-PtNPs-Ru nanocomposite, in which PEI as coreactant can effectively enhance the luminous efficiency and PtNPs as nanochannels can greatly accelerate the electron transfer. Finally, due to the coordination between Eu(3+) and carboxyl, the obtained H-Mn(3)O(4) -PEI-PtNPs-Ru aggregates locally to form sheet-like nanostructures ((H-Mn(3)O(4) -PEI-PtNPs-Ru)(n) -Eu(3+)), by which the luminous efficiency is further increased. Based on the nanosheets and two designed peptides, a sandwiched ECL biosensor, using palladium nanocages synthesized through galvanic replacement reaction as substrate, is proposed for CA2 with a linear range from 0.001 to 100 ng mL(-1) and a detection limit of 0.3 pg mL(-1).

Role of sesamol-loaded floating beads in gastric cancers: a pharmacokinetic and biochemical evidence

CONTEXT

Sesamol, a potential antioxidant with marked anticancer potential suffers from issues of extensive tissue distribution and local gastric irritation on oral administration.

OBJECTIVE

To develop multiunit gastro-retentive floating beads (S-FBs) for localised and prolonged release of sesamol to treat gastric cancers.

MATERIALS AND METHODS

S-FBs prepared using calcium carbonate, sodium alginate and hydroxypropylmethyl cellulose (HPMC) in different proportions, were characterised and evaluated in vivo in N-methyl-N-nitro-N-nitroguanidine-induced gastric cancer in rats. Single oral dose plasma pharmacokinetic study was also performed for free sesamol and S-FBs.

RESULTS AND DISCUSSION

Restraining sesamol in floating beads, significantly lowered the release (diffusion controlled) rate, increased t50% (31 times) and reduced its in vivo clearance (>1.5 times). Preclinical evaluation showed S-FBs (10 mg/kg) to be significantly better than free sesamol and better/equivalent to methotrexate (2 mg/kg).

CONCLUSION

Most of the natural phytochemical or antioxidants show pretreatment effectiveness. We, however, developed and established S-FBs for sustained curative effect.

Effect of alkyl length of peptide-polymer amphiphile on cargo encapsulation stability and pharmacokinetics of 3-helix micelles

3-Helix micelles have demonstrated excellent in vitro and in vivo stability. Previous studies showed that the unique design of the peptide-polymer conjugate based on protein tertiary structure as the headgroup is the main design factor to achieve high kinetic stability. In this contribution, using amphiphiles with different alkyl tails, namely, C16 and C18, we quantified the effect of alkyl length on the stability of 3-helix micelles to delineate the contribution of the micellar core and shell on the micelle stability. Both amphiphiles form well-defined micelles, <20 nm in size, and show good stability, which can be attributed to the headgroup design. C18-micelles exhibit slightly higher kinetic stability in the presence of serum proteins at 37 °C, where the rate constant of subunit exchange is 0.20 h(-1) for C18-micelles vs 0.22 h(-1) for C16-micelles. The diffusion constant for drug release from C18-micelles is approximately half of that for C16-micelles. The differences between the two micelles are significantly more pronounced in terms of in vivo stability and extent of tumor accumulation. C18-micelles exhibit significantly longer blood circulation time of 29.5 h, whereas C16-micelles have a circulation time of 16.1 h. The extent of tumor accumulation at 48 h after injection is ∼43% higher for C18-micelles. The present studies underscore the importance of core composition on the biological behavior of 3-helix micelles. The quantification of the effect of this key design parameter on the stability of 3-helix micelles provides important guidelines for carrier selection and use in complex environment.

Serum biomarkers for personalization of nanotherapeutics-based therapy in different tumor and organ microenvironments

Enhanced permeation and retention (EPR) effect, the mechanism by which nanotherapeutics accumulate in tumors, varies in patients based on differences in the tumor and organ microenvironment. Surrogate biomarkers for the EPR effect will aid in selecting patients who will accumulate higher amounts of nanotherapeutics and show better therapeutic efficacy. Our data suggest that the differences in the vascular permeability and pegylated liposomal doxorubicin (PLD) accumulation are tumor type as well as organ-specific and significantly correlated with the relative ratio of MMP-9 to TIMP-1 in the circulation, supporting development of these molecules as biomarkers for the personalization of nanoparticle-based therapy.

[Dynamics of rat blood serum biochemical parameters under malignant growth in condition of the antioxidant substance "greenization green R" introduction]

Under malignant growth, the alterations of blood serum biochemical parameters including activity of studied enzymes were observed. The drug "Grinization GRIN R" was shown to stabilize the tumor growth of Guerin's carcinoma as well as biochemical parameters in the range close to normal values. The changes of protein metabolism parameters appeared to be significant. Also the considerable changes of AST and ALT activities were demonstrated. In the case, there was significant difference between the groups studied (p < 0.05). Administration of rats with drug "Grinization (Grin R" in different doses led to decreasing of average tumor volume in dynamics. Increasing and normalization of total protein level in rats with Guerin's carcinoma was established under "Grinization GRIN" administration in doses 115 mg/kg and 270 mg/kg. The meaning of albumin concentration approached to physiological normal value under "Grinization GRIN" administration in dose 270 mg/kg. Meanwhile AST and ALT activities were approaching to normal values in rats with Guerin's carcinoma under "Grinization GRIN" administration in dose 270 mg/kg. Such effects were observed mainly at the 18th and 23th days after tumor inoculation in comparison with tumor control (Guerin's carcinoma) values.

The ketogenic diet and hyperbaric oxygen therapy prolong survival in mice with systemic metastatic cancer

Introduction

Abnormal cancer metabolism creates a glycolytic-dependency which can be exploited by lowering glucose availability to the tumor. The ketogenic diet (KD) is a low carbohydrate, high fat diet which decreases blood glucose and elevates blood ketones and has been shown to slow cancer progression in animals and humans. Abnormal tumor vasculature creates hypoxic pockets which promote cancer progression and further increase the glycolytic-dependency of cancers. Hyperbaric oxygen therapy (HBO₂T) saturates tumors with oxygen, reversing the cancer promoting effects of tumor hypoxia. Since these non-toxic therapies exploit overlapping metabolic deficiencies of cancer, we tested their combined effects on cancer progression in a natural model of metastatic disease.

Methods

We used the firefly luciferase-tagged VM-M3 mouse model of metastatic cancer to compare tumor progression and survival in mice fed standard or KD ad libitum with or without HBO₂T (2.5 ATM absolute, 90 min, 3x/week). Tumor growth was monitored by in vivo bioluminescent imaging.

Results

KD alone significantly decreased blood glucose, slowed tumor growth, and increased mean survival time by 56.7% in mice with systemic metastatic cancer. While HBO₂T alone did not influence cancer progression, combining the KD with HBO₂T elicited a significant decrease in blood glucose, tumor growth rate, and 77.9% increase in mean survival time compared to controls.

Conclusions

KD and HBO₂T produce significant anti-cancer effects when combined in a natural model of systemic metastatic cancer. Our evidence suggests that these therapies should be further investigated as potential non-toxic treatments or adjuvant therapies to standard care for patients with systemic metastatic disease.

[Biochemical features of cancer cachexia under conditions of different provision with vitamin A]

On the model of tumor growth of Guerin's carcinoma and experimental modeling of vitamin A provision the biochemical characteristics of tumor cachexia in animals with malignant tumors and different vitamin A provision status were studied. It is determined that tumor growth in the body, deprived of vitamin A, is characterized by negative nitrogen balance, decrease of glucose, free fatty acids and ketone bodies level in the blood serum, which indicates the increase of cancer cachexia.

Pharmacokinetic advantage of intraperitoneal injection of docetaxel in the treatment for peritoneal dissemination of cancer in mice

Intraperitoneal administration of docetaxel has been used to treat peritoneal dissemination of cancer, but its safety has not yet been confirmed. We have compared the pharmacokinetic behaviour of docetaxel after intravenous and intraperitoneal administration in CD-1-nu/nu mice bearing MKN-45P, a gastric cancer variant line producing peritoneal dissemination. Docetaxel (8mg kg−1) was intravenously or intraperitoneally injected into the mice and at designated times the drug concentration was measured in plasma, ascites fluid, and abdominal tissues (liver, kidney, intestine and spleen, solid cancer, and suspended free cancer). The pharmacokinetic behaviour of docetaxel was similar in control mice and cancer-bearing mice after administration via either route, except that the transfer of docetaxel from the abdominal cavity to systemic blood (plasma) was slower in cancer-bearing mice than in control mice. As expected, the intraperitoneal drug concentration was much higher (approximately 100-fold) and was maintained for a longer time in the intraperitoneal injection group than in the intravenous injection group. The drug concentrations in peritoneal solid cancer tissue and suspended free cancer cells were also significantly higher for a longer time in the intraperitoneal injection group than in the intravenous injection group. The values of the plasma area under concentration-time curves (AUC) were similar for both administration routes. The ratio of AUC ascite/AUC plasma after intraperitoneal administration was higher than after intravenous administration. The drug concentration in abdominal organs after intraperitoneal injection was lower during the first 2 h, then became similar to those after intravenous injection. These results indicated that the intraperitoneal administration of docetaxel for peritoneal dissemination was likely to be an effective treatment method, without causing any increase in systemic toxicity.

Comparative pharmacokinetics of RAD001 (everolimus) in normal and tumor-bearing rodents

PURPOSE

Comparative pharmacokinetic (PK) analysis of the mTOR inhibitor RAD001 (everolimus) in rats and mice.

METHODS

Blood cell partitioning, plasma protein binding and PK parameters of RAD001 in blood and tissues (including brain) of both mice and rats were determined. PK modeling predicted plasma/blood and tumor levels from a variety of regimens and these were compared with the known human PK profile. DCE-MRI was used to compare tumor vascularity between mice and rats. Estimation of IC50 values in vitro and ED50 values in vivo were used to provide an indication of anti-tumor activity.

RESULTS

The PK properties of RAD001 differed between mice and rats, including erythrocyte partitioning, plasma protein binding, plasma/blood t(1/2), oral bioavailability, volume of distribution, tissue/tumor penetration and elimination. Modeling of tumor and blood/plasma PK suggested that in mice, multiple daily administrations result in a 2-fold increase in tumor levels of RAD001 at steady state, whereas in rats, a 7.9-fold increase would occur. Weekly high-dose regimens were predicted not to facilitate tumor accumulation in either species. Total tumor levels of RAD001 were four- to eight-fold greater in rats than in mice. Rat tumors had a >2-fold greater plasma content and permeability compared to mouse tumors, which could contribute to differences in tumor drug uptake. Maximal antitumor effects (T/C of 0.04-0.35) were observed in both species after daily administration with similar C(max) and AUC values of unbound (free) RAD001. These free levels of RAD001 are exceeded in serum from cancer patients receiving clinically beneficial daily regimens. In rodents, brain penetration of RAD001 was poor, but was dose-dependent and showed over-proportional uptake in rats with a longer t(1/2) compared to the systemic circulation.

CONCLUSIONS

The PK of RAD001 differed between mice and rats, with rats having a PK profile closer to that of humans. High intermittent doses of RAD001 may be more appropriate for treatment of brain tumors.

The antiproliferative cytostatic effects of a self-activating viridin prodrug

Although viridins like wortmannin (Wm) have long been examined as anticancer agents, their ability to self-activate has only recently been recognized. Here, we describe the cytostatic effects of a self-activating viridin (SAV), which is an inactive, polymeric prodrug. SAV self-activates to generate a bioactive, fluorescent viridin NBD-Wm with a half-time of 9.2 hours. With cultured A549 cells, 10 micromol/L SAV caused growth arrest without inducing apoptosis or cell death, a cytostatic action markedly different from other chemotherapeutic agents (vinblastine, camptothecin, and paclitaxel). In vivo, a SAV dosing of 1 mg/kg once in 48 hours (i.p.) resulted in growth arrest of an A549 tumor xenograft, with growth resuming when dosing ceased. With a peak serum concentration of SAV of 2.36 micromol/L (at 2 hours post i.p. injection), the concentration of bioactive NBD-Wm was 41 nmol/L based on the partial inhibition of neutrophil respiratory burst. Therefore, SAV was present as an inactive prodrug in serum (peak = 2.36 micromol/L), which generated low concentrations of active viridin (41 nmol/L). SAV is a prodrug, the slow release and cytostatic activities of which suggest that it might be useful as a component of metronomic-based chemotherapeutic strategies.

[Changes and significance of peripheral blood count in tumor rejection induced by a low dose of melphalan in C57BL/6 mice]

AIM

To investigate the relationship between changes of peripheral blood counts and tumor rejection induced by a low dose of melphalan in C57BL/6 mice.

METHODS

Mouse lymphoma EL4 cells were inoculated subcutaneously into wild type C57BL/6 mice. Twelve days later, 7.5 mg/kg melphalan were administered intraperitoneally and the same volume of Normal Saline as control. Tumor sizes were observed and recorded subsequently. Blood samples were obtained from orbital venous sinus on different days before and after melphalan treatment, and then complete blood counts were performed and the relationship between the alterations of blood counts and tumor shrinkage after melphalan treatment was analyzed.

RESULTS

Tumor sizes decreased and tumors disappeared after 7.5 mg/kg melphalan treatment; while tumors grow continuously in control mice. The number of WBC was increased a little (10.6 + or - 2.3) x 10(9)/L 6 h after melphalan treatment, but there was no significant difference with mice before melphalan injection (9.8 + or - 0.32) x 10(9)/L (P>0.05); The number of WBC decreased significantly at 4(th) day after melphalan treatment (P<0.01); Later it increased a little, but at 28(th); day after melphalan it still obviously lower than that of the normal (P<0.01). Hemoglobin (Hb) concentration decreased from (132 + or - 7) g/L before melphalan treatment to (110 + or - 14) g/L at 6 h after melphalan treatment (P<0.05). Later, the amount of Hb was decreasing and at 7th day it got to its lowest point (96 + or - 5) g/L. It increased gradually back to normal in 2 weeks after melphalan treatment. The platelet count increased to (1502 + or - 142) x 10(9)/L 6 h after melphalan treatment, significantly higher that that (914 + or - 322) x 10(9)/L before melphalan injection (P<0.01). It maintained at a high level for one week and it recovered back to normal level at 28(th) day after melphalan treatment.

CONCLUSION

Tumor shrinkage after melphalan treatment was not related to the decreased number of WBC or RBC, but correlated with the increased number of platelet in 10 days after melphalan treatment.

Capsaicin alleviates the imbalance in xenobiotic metabolizing enzymes and tumor markers during experimental lung tumorigenesis

Lung cancer is currently a leading cause of death all over the world. Environmental risk factors, particularly genotoxic chemicals such as polycyclic aromatic hydrocarbons (PAH), are likely to account for a much higher mortality. Xenobiotic metabolizing enzymes are potentially chief determinants in both the susceptibility to the mutagenic effects of chemical carcinogens and in the response of tumors to chemotherapy. The well-known carcinogen benzo(a)pyrene (B(a)P) of PAH family was given orally (50 mg/kg body weight) to induce lung cancer in Swiss albino mice. B(a)P induction altered the levels of cytochromes (P450, b5), activities of phase I biotransformation enzymes (NADPH-cytochrome P450 reductase, NADH-cytochrome b5 reductase and epoxide hydrolase), phase II enzymes (glutathione-S-transferase, UDP-glucuronyl transferase and DT-diaphorase), and the levels of serum tumor markers. Treatment with capsaicin (CAP) (10 mg/kg body weight) to the lung carcinoma mice restored back the activities of phase I and II biotransformation enzymes and the levels of tumor markers to near normalcy. The above findings were substantiated by immunoblotting and immunohistochemical analysis of cytochrome P450 1A1 (CYP1A1) in the lung tissues. Our present study unravels that CAP can effectively detoxify the carcinogens which discloses its anti-carcinogenic effect during experimental lung cancer.

[Peculiarities of fractional composition of serum glycoproteins in Guerin's carcinoma development under condition of different vitamin A provision]

The most substantial change in the ratio between glycoprotein fractions distributing in the blood serum of rat under conditions of different vitamin A provision (0.50-0.70 micromol/L) are observed; they are characteristic of gamma-globulin, haptoglobin and alpha 1-acid glycoprotein; the intensity of colouring of their bars decreases on serum electrophoregrammes. At the same time, the decline of intensity of bar coloration of ceruloplasmin fraction takes place under the conditions of middle vitamin A deficiency (0.35-0.50 micromol/L) while that of transferrin takes place at marginal A-deficient state (< 0.35 micromol/L). In latent and logarithmic periods of Guerin's carcinoma growth, regardless of conditions of different vitamin A provision, the intensity of bars colouring, on electrophoregrammes, which correspond to immunoglobulin, haptoglobin, ceruloplasmin alpha2-Macroglobulin, alpha 1-acid glycoprotein and alpha1-antytrypsyn, increases. In a stationary period of tumour growth a decrease of coloration intensity of gamma- and alpha2-globulin fractions is observed.

[Prognostic significance of lysosomal cysteine proteases in the estimation of the effectiveness of the antitumorigenic therapy]

The influence of the untitumor drugs, cyclophosphamide (CPA) and nitrosomethylurea (NMM) on the activity of lysosomal cysteine proteases cathepsin B and L in the tumor tissue was studied. Regression or reduction in the rate of growth of LS and RLS (drug sensitive and resistant sarcomas, respectively) during injection of CPA or NMM was accompanied by the increase in the activity of cysteine proteases cathepsin B and L in the tumor tissue. The increase of cathepsin B and L activity in the tumor tissue was correlated with the therapeutic effect of the used drugs. Data obtained suggest that cathepsin B and L activity in the tumor tissue have a prognostic significance for the effectiveness of antitumor therapy.

Redefining the target again: chemotherapeutics as vascular disrupting agents?

In this issue of Cancer Cell, Shaked et al. (2008) provide novel mechanistic evidence that some chemotherapeutics induce circulating endothelial progenitor (CEP) mobilization with subsequent homing to tumor vasculature. Addition of an anti-VEGFR2 antibody increased antitumor activity only in combination with CEP-mobilizing chemotherapeutics. Here we discuss the implications of this work.

Comparative studies of the effects of Tabebuia avellanedae bark extract and beta-lapachone on the hematopoietic response of tumour-bearing mice

The effects of Tabebuia avellanedae (TACE), traditionally prescribed in the treatment of cancer, and the naphtoquinone beta-lapachone (beta-lap) on the growth and differentiation of granulocyte and macrophage progenitor cells (CFU-GM) were studied in Ehrlich ascites tumour-bearing mice. Myelosuppression concomitant with increases in spleen CFU-GM and in serum colony-stimulating activity (CSA) were observed in these animals. Treatment with TACE (30-500 mg/kg) and beta-lap (1-5mg/kg) reversed these effects in a dose-dependent manner. The optimal biologically active doses of 120 mg/kg TACE and 1mg/kg beta-lap prolonged life span of tumour-bearing mice, both producing the same rate of extension in the duration of survival. Toxic manifestations were produced by the higher doses of beta-lap in normal and tumour-bearing mice. In spite of similarities between treatments, TACE concentrations used to treat the animals presented no traces of beta-lap, as measured by TLC and HPLC analyses. Our findings suggest that the antitumour effect of TACE and beta-lap, acting synergistically with other factors, such as specific cytokines, may result from enhanced macrophage activation against tumour cells. In addition, it is clear from our results that hematopoietic disorders produced by tumours are an important pathological condition that must be considered in drug development.

Dichlorotetra-mu-Isobutyratodirhenium(III): enhancement of cisplatin action and RBC-stabilizing properties

BACKGROUND

Previous investigations showed antitumor properties of dirhenium carboxylate introduced to tumor-bearing animals at high doses. The development of liposomal forms of rhenium substances and the activity of dichlorotetra-mu-isobutyratodirhenium (III) (Re1) in stabilizing red blood cells (RBC) shown in experiments in vitro and in vivo enabled the use of this substance in the present study. The aim of the work was to investigate the antitumor properties of Re1 in liposomal form alone and together with cisplatin, and to analyze whether Re1 can support RBC in the model of tumor growth.

MATERIALS AND METHODS

Introduction of a single dose of cisplatin and liposomal forms of Re1 according to a scheme of antioxidant therapy was tested in a rat model of specific Guerink (T-8) carcinoma. The dynamics of tumor growth, weights of isolated tumors, RBC morphology and hemoglobin levels were measured.

RESULTS

The cluster rhenium compound, Re1, with carboxylic ligands had its own anticancer properties and enhanced cisplatin action on tumor growth. Introduction of the rhenium substance led to an increase in quantities of normal RBC forms in blood of tumor-bearing animals. Possible mechanisms of enhancement of cisplatin efficiency by Re1 according to its structural peculiarities are discussed.

CONCLUSION

A novel antitumor system including the use of a cluster rhenium compound and cisplatin is presented. Enhancement of cisplatin action and antitumor properties of rhenium compound initially took place due to the properties of quadruple metal-to-metal bond between two atoms of rhenium.

Establishment of the enzyme-linked immunosorbent assay system to detect the amino terminal secretory form of rat Erc/Mesothelin

By representational difference analysis, we previously identified the rat Erc (Expressed in renal carcinoma) gene that was more abundantly expressed in the renal carcinoma tissues of Eker rats than in the rat normal kidney. In this study, we raised antibodies against the amino-terminal portion of the rat Erc, and demonstrated the existence of a approximately 30-kDa secretory form in the supernatant of cultured cells derived from rat renal carcinoma. The enzyme-linked immunosorbent assay (ELISA) system using these antibodies detected high concentrations of this form in the sera of Eker rats bearing renal carcinomas, and in the sera of rats transplanted with mesothelioma cells. Mesothelin, a human homolog of the rat Erc, was recently reported to be a serum marker of malignant mesothelioma. The prognosis of mesothelioma is poor and there is no effective treatment at present. There are several rat model systems of mesothelioma that may be promising tools in the development of an antimesothelioma treatment. We hope our ELISA to detect the soluble form of rat Erc/Mesothelin is useful in the rat model system to exploit the antimesothelioma therapy to be used in human cases.

The platelet aggregation-inducing factor aggrus/podoplanin promotes pulmonary metastasis

Tumor cell-induced platelet aggregation has been reported to facilitate hematogenous metastasis. Aggrus/podoplanin is a platelet aggregation-inducing factor that is up-regulated in a number of human cancers and has been implicated in tumor progression. We studied herein the role of Aggrus in tumor growth, metastasis , and survival in vivo. Aggrus expression in Chinese hamster ovary cells promoted pulmonary metastasis in both an experimental and a spontaneous mouse model. No differences in the size of metastatic foci or in primary tumor growth were found in either set of mice. Aggrus expressing cells , which were covered with platelets, arrested in the lung microvasculature 30 minutes after injection. In addition, lung metastasis resulting from Aggrus expression decreased the survival of the mice. By generating several Aggrus point mutants, we revealed that point mutation at the platelet aggregation-stimulating domain of Aggrus(Thr34 and Thr52) obliterated both platelet aggregation and metastasis. Furthermore, administration of aspirin to mice reduced the number of metastatic foci. These results indicate that Aggrus contributes to the establishment of metastasis by promoting platelet aggregation without affecting subsequent growth. Thus, Aggrus could serve as an ideal therapeutic target for drug development to block metastasis.

[Monitoring changes of serum protein markers in metastatic colorectal carcinoma model]

OBJECTIVE

To investigate the changes of several protein markers in a metastatic colorectal carcinoma model by serum proteomic analysis.

METHODS

The pEGFP-N1 plasmid with enhanced expression of green fluorescence protein (EGFP) was transfected into human colon carcinoma cell line SW480 to obtain a stable SW480-EGFP cell line, the SW480-EGFP cells were then injected subcutaneously into nude mice. The harvested tumor cells were implanted orthotopically into the colon of the nude mice. Real-time tumor growth and metastasis formation were visualized by whole-body fluorescent imaging system. Serum samples at different metastatic stages were collected and differential proteomic profiles were investigated by two-dimensional gel electrophoresis (2DE) and matrix-assisted laser absorption/ionization time of flight mass spectrometry (MALDI-TOF MS).

RESULTS

The SW480- EGFP cells enabled to express EGFP stably. The rates of subcutaneous and orthotropic tumor formation were 100%. The metastasis rates to local lymph nodes, liver and lung were 100%, 40% and 30%, respectively. Furthermore, 5 differentially expressed proteins were analyzed by serum proteome technologies, including haptoglobin alpha chain, apolipoprotein E, apolipoprotein A-IV, Ig kappa chain V region chain L and transferrin.

CONCLUSIONS

Visualized metastatic model of colorectal carcinoma was successfully established. Several differentially expressed serum proteins collected at different stages after the occurrence of metastasis were identified. These differentially expressed proteins may be candidate serum biomarkers for diagnosis and therapeutic evaluation of colorectal carcinoma metastasis.

Antitumor activity ofHypericum hookerianum against DLA induced tumor in mice and its possible mechanism of action

A large number of plants belonging to the genus Hypericum and their phytoconstituents are known to possess potent anticancer nature. Earlier studies from our laboratories indicated a strong cytotoxic nature of the methanol extract of Hypericum hookerianum stem (MEHH). In the present study, the in vivo antitumor activity of MEHH against the Dalton's lymphoma ascitic (DLA) model was determined at 100 and 200 mg/kg body weight given orally for 10 days. The results indicate that administration of the extract not only increased the survival of animals with ascites tumor, decreased the body weight induced by the tumor burden and reduced the packed cell volume and viable tissue cell count, but also altered many hematological parameters changed during tumor progression indicating the potent antitumor nature of the extract. Hematological and biochemical analysis were carried out to prove the anticancer and antioxidant nature of the extract.

A novel immunotherapeutic modality with direct hemoperfusion targeting transforming growth factor-beta prolongs the survival of tumor-bearing rats

Immune responses are frequently depressed in patients with cancer. One of the reasons for a poor immune response is the presence of increased levels of immunosuppressive substances associated with tumor growth. Transforming growth factor-beta (TGF-beta), a representative immunosuppressive cytokine, plays various roles in the progression of cancer. To remove immunosuppressive substances from tumor-bearing hosts, we developed an immunosuppressive substance adsorption (ISA) column for direct hemoperfusion (DHP) treatment. It is filled with extra-fine fibers that can adsorb TGF-beta. In this study, we investigated the effects of this DHP treatment on serum levels and activities of TGF-beta, cellular immune responses, and anti-tumor effects in KDH-8 (TGF-beta-producing hepatocellular carcinoma cell line)-bearing rats. We further studied the ability of ISA fibers to adsorb tumor-associated immunosuppressive cytokines [TGF-beta, interleukin (IL)-6 and vascular endothelial growth factor (VEGF)] in samples of body fluids obtained from patients with metastatic cancer. DHP treatment decreased serum levels and activities of TGF-beta in tumor-bearing rats and restored T lymphocyte response to mitogen. Tumor growth in rats treated by DHP was significantly slower than that in untreated rats. The survival time of treated rats was significantly longer than that of untreated rats. The concentrations of TGF-beta, IL-6, and VEGF in the samples of human body fluids were decreased markedly by in vitro treatment with ISA fibers. These results suggest that DHP treatment with an ISA column, which removes TGF-beta and other immunosuppressive substances from the sera of tumor-bearing hosts, is potentially a new immunotherapeutic strategy for cancer.

Organ-specific metastatic tumor cell adhesion and extravasation of colon carcinoma cells with different metastatic potential

Adhesive and invasive characteristics appear to be crucial for organ-specific metastasis formation. Using intravital microscopy we investigated the relation between the metastatic potential of colon carcinoma cells and their adhesive and invasive behavior during early steps of metastasis within microvasculatures of rat liver, lung, intestine, skin, muscle, spleen, and kidney in vivo. Colon carcinoma cells with low (HT-29P), intermediate (KM-12C), and high (HT-29LMM, KM-12L4) metastatic potential were injected into nude or Sprague-Dawley rats. Initial interactions with host organ microvasculatures were semiquantitatively analyzed throughout 20 to 30 minutes. Circulating cells passed microvessels in all observed organs without size restriction. All cell lines showed high adhesion rates, independent from their metastatic potential, within liver and lung but very rarely in other organs. Diameters of involved microvessels were larger than diameters of adherent tumor cells. Cell extravasation of highly metastatic HT-29LMM and KM-12L4 cells into liver parenchyma was significantly higher compared to low metastatic cells (P<0.05). Our results indicate that colon carcinoma cells can arrest in target organs without size restriction. Cell adhesion of circulating tumor cells occurred in metastatic target organs only, likely attributable to specific interactions. Migration into target organs correlated with their metastatic potential.

Method for improved accuracy in endogenous urea recovery marker calibrations for microdialysis in tumors

INTRODUCTION

Urea has been proposed as an endogenous recovery marker for microdialysis for absolute concentration calculations of analytes in microdialysis samples. Previously we demonstrated a linear relationship between urea concentrations in a rat mammary carcinoma and that in plasma, validating its use as a recovery marker for that particular tumor. In this paper, we have extended the validation to two other tumor lines, thereby providing confidence that the calibration is constant across tumor types. To improve the accuracy in the determination of the plasma/tumor urea relationship from no net flux calibrations, we extended the range of the calibration by adding exogenous urea to tumor bearing animals. This method enabled more accurate calculations of absolute recovery from plasma and dialysate urea concentrations. We confirm that by using this method the calibration is valid across three different tumor lines. The existence of a common calibration between tumors provides rationale for using plasma urea as a recovery marker for clinical trials. The existence of a common calibration between tumor types bypasses the need to perform time consuming calibrations for each patient. This makes the procedure much more practical for clinical studies.

METHODS

The no net flux technique was used to determine the plasma vs. tumor urea relationship for the R3230Ac mammary carcinoma, 9 L glioma, and a fibrosarcoma (FSa), grown in Fischer 344 rats. Plasma urea was stably increased beyond the normally occurring concentration for some of the data points by subcutaneous bolus administration to extend the range of data for the no net flux calibration.

RESULTS

Urea recovery was unaffected by plasma urea concentration and was consistent with other reported values. The relationship between plasma and tumor urea was fit by a line, and linear regressions of the data with the extended plasma urea range had better R2 values than we reported previously. Statistical comparison of the regressions suggests that within reasonable uncertainty limits, they are the same for the different tumor types.

DISCUSSION

Increasing the plasma urea concentration range for no net flux calibrations of urea as an endogenous recovery marker in tumors resulted in more accurate determination of the plasma/tumor urea relationship. A single linear regression may describe the relationship between plasma and tumor urea concentration across tumor lines for a given set of microdialysis parameters.

Role of STAT3 and NFκB signaling in the serum factor-induced apoptosis in AK-5 cells

AK-5, a rat histiocytoma, is rejected in about 70% of the syngeneic animals when injected subcutaneously. The sera from the tumor rejecting animals possess a potent factor, referred to as serum factor (SF) that induces apoptosis in AK-5 tumor cells. In the present study, we show that treatment with SF or JAK/STAT inhibitors AG490 and Piceatannol induces apoptosis to a similar extent in BC-8 (a single cell clone of AK-5) cells. Our results demonstrate downregulation of a transcription factor, STAT3, as a critical regulator of SF-induced apoptosis in BC-8 cells. SF treatment enhanced the activity of NFkappaB, another transcription factor that regulates both pro- and antiapoptotic genes. The enhanced NFkappaB activity resulted in the elevation of TRAIL and its receptor DR4, both known to induce apoptosis. Activation of death receptors in turn enhances caspase-8 activity and stimulates the downstream pathways regulating BC-8 cell apoptosis. SF induced apoptosis in BC-8 cells mediated through downregulation of STAT3 and elevated NFkappaB activity is abrogated by treatment with MAPK inhibitors-PD98059 and SB203580. Our studies therefore indicate that modulation of MAPK activity plays a central role in SF-induced death signaling pathways in BC-8 cells.

A liquid chromatographic–tandem mass spectrometric method for the determination of two selective thymidylate synthase inhibitors, BGC945 and BGC638, in mouse plasma

A LC-tandem mass spectrometry method to quantify the quinazoline-based thymidylate synthase inhibitors BGC945 and BGC638 in mouse plasma was developed. BGC945 and BGC638 were extracted from mouse plasma using protein precipitation with acetonitrile. Chromatography was performed on a Fluophase RP 5 microm, 100 mmx2.0mm i.d. column using a gradient of ammonium acetate and acetonitrile as a mobile phase with a flow rate of 0.2 mLmin(-1). The injection volume for each sample was 20 microL with a total run time of 7.5 min. This method was validated in the range 25-4000 nM (r2=0.99). The analytical assay performance showed that the method was accurate (mean intra- and inter-day assay R.E. were below 12% and 11%, respectively), reproducible (mean intra- and inter-day R.S.D. were less than 13% and 5% for all quality control levels, respectively) and sensitive (lower limit of quantification was 25 nM) in the range studied. This validated method has been used to define the first pharmacokinetic report of BGC945 and BGC638 in mice.

A high-performance liquid chromatographic assay for determination of cisplatin in plasma, cancer cell, and tumor samples

A method for determination of cis-diaminedichloroplatinum (II) (cisplatin) in ultrafiltered plasma, cell, and tumour samples is described. Cisplatin separation was carried out on a reversed-phase column using methanol-acetonitrile-water as the mobile phase. The flow rate was maintained constant at 1.6 mL/min and analysis was performed at 23 degrees C. Detection was carried out by absorbance at 254 nm. The method was linear in the range of 0.2-10 microg/mL, and the coefficients of variation were <10%. Using this technique, we measured the intracellular accumulation of cisplatin in cancer cells and in tumours of mice receiving treatment with cisplatin and evaluated the pharmacokinetics of cisplatin in nu/nu mice after intraperitoneal (i.p.) administration. The method proved to be adequate for measuring cisplatin both in vitro and in vivo and could be suitable for studies of cisplatin pharmacokinetics in animal models.

Elevated blood lactate is not a primary cause of anorexia in tumor-bearing rats

Tumor-bearing (TB) rats exhibit elevated concentrations of lactate in blood contiguous with the development of anorexia. Continuous intravenous infusion of lactate into non-TB rats reduced food intake at plasma concentrations lower than those observed in anorectic TB rats. Levels of neuropeptide Y (NPY) were elevated in the ventromedial (VMH) and dorsomedial hypothalamic regions of lactate-infused rats. The addition of the enhancer of pyruvate dehydrogenase activity, dichloroacetate (DCA), to the drinking water of TB rats (0.1-0.4%) normalized blood lactate concentration but had no significant effect on anorexia. However, the elevated concentration of NPY in the VMH of anorectic TB rats was also normalized by the DCA treatment. No alterations in regional hypothalamic levels of corticotropin-releasing factor were observed within any treatment conditions. These results suggest that, although hyperlactatemia may be involved in maintaining elevated NPY concentrations in anorectic TB rats, it does not appear to be a significant factor in the etiology of experimental cancer anorexia.

In vivo protein biotinylation for identification of organ-specific antigens accessible from the vasculature

We describe a new methodology, based on terminal perfusion of rodents with a reactive ester derivative of biotin that enables the covalent modification of proteins readily accessible from the bloodstream. Biotinylated proteins from total organ extracts can be purified on streptavidin resin in the presence of strong detergents, digested on the resin and subjected to liquid chromatography-tandem mass spectrometry for identification. In the present study, in vivo biotinylation procedure led to the identification of hundreds of proteins in different mouse organs, including some showing a restricted pattern of expression in certain body tissues. Furthermore, biotinylation of mice with F9 subcutaneous tumors or orthotopic kidney tumors revealed both quantitative and qualitative differences in the recovery of biotinylated proteins, as compared to normal tissues. This technology is applicable to proteomic investigations of the differential expression of accessible proteins in physiological and pathological processes in animal models, and to human surgical specimens using ex vivo perfusion procedures.

Alterations in hemorheological properties of erythrocytes in nude mice with erythroleukemia and the treatment effects of etoposide

The purpose of this study was to examine the changes of hemorheological properties of erythrocytes in the nude mice with erythroleukemia and the treatment effects of etoposide (VP16). Thirty mice were randomly divided into three groups: the control group (C group), injected with 1 ml saline solution, the MEL group (M group) injected with 1 ml MEL (murine erythroleukemia cell line) and the MEL + VP16 group (V group) injected with 1 ml MEL and from the 8th day after injection, 20 microl VP16 (1 microg/microl) was injected intraperitoneally every five days. One week after MEL injection, erythroblastic cells increased in the bone marrow and proerythroblasts were found in the peripheral blood, suggesting that erythroleukemia was induced. Abnormalities were also found in spleens and livers later. At around twenty days after injection, the mice in M group died and about four weeks after injection, the mice in V group also died. Compared with C group, the hemorheological indexes [the deformation index DI, orientation index (DI(or)), and the small deformation index (DI(d))], electrophoretic mobility, membrane fluidity as well as osmotic fragility of red blood cells (RBC) in M and V groups changed significantly. But after VP16 administration, the changes of above parameters in V group were less significant than those of M group. The results above suggested that intraperitoneal injection of MEL cells could cause erythroleukemia in nude mice, VP16 could alleviate the erythroleukemia symptom and improve the hemorheological properties, and could prolong V group nude mice survival.

High throughput quantitative analysis of serum proteins using glycopeptide capture and liquid chromatography mass spectrometry

It is expected that the composition of the serum proteome can provide valuable information about the state of the human body in health and disease and that this information can be extracted via quantitative proteomic measurements. Suitable proteomic techniques need to be sensitive, reproducible, and robust to detect potential biomarkers below the level of highly expressed proteins, generate data sets that are comparable between experiments and laboratories, and have high throughput to support statistical studies. Here we report a method for high throughput quantitative analysis of serum proteins. It consists of the selective isolation of peptides that are N-linked glycosylated in the intact protein, the analysis of these now deglycosylated peptides by liquid chromatography electrospray ionization mass spectrometry, and the comparative analysis of the resulting patterns. By focusing selectively on a few formerly N-linked glycopeptides per serum protein, the complexity of the analyte sample is significantly reduced and the sensitivity and throughput of serum proteome analysis are increased compared with the analysis of total tryptic peptides from unfractionated samples. We provide data that document the performance of the method and show that sera from untreated normal mice and genetically identical mice with carcinogen-induced skin cancer can be unambiguously discriminated using unsupervised clustering of the resulting peptide patterns. We further identify, by tandem mass spectrometry, some of the peptides that were consistently elevated in cancer mice compared with their control littermates.

Dose-Dependent Effects of Dietary - and -Tocopherols on Genetic Instability in Mouse Mutatect Tumors

Vitamin E in foodstuffs is a mixture of tocopherols. In mouse Mutatect tumors, a model designed to detect DNA mutations, the hypoxanthine phosphoribosyltransferase (Hprt) gene mutation frequency is associated with the number of tumor-infiltrating neutrophils and both are markedly decreased in mice fed high levels of alpha-tocopherol. Dietary alpha-tocopherol is also associated with a decrease in neutrophil-associated loss of an interleukin 8 (IL-8)-expressing transgene in this tumor model. We examined Hprt gene mutation frequency (expressed as the number of 6-thioguanine-resistant colonies per 10(5) clonable tumor cells), IL-8 transgene loss, and myeloperoxidase activity (an indirect measure of neutrophil number) in tumors from Mutatect mice fed diets supplemented with various concentrations of D-alpha-tocopherol acetate and/or D-gamma-tocopherol acetate or neither tocopherol for 4 weeks. Hprt gene mutation frequency and myeloperoxidase activity were statistically significantly lower in tumor cells from mice fed alpha-tocopherol at 50 or 100 mg/kg body weight per day than in tumor cells from mice fed 0 mg/kg body weight per day alpha-tocopherol (P<.001 for each comparison). IL-8 transgene loss occurred in 28 of 28 tumors (100%; 95% confidence interval [CI] = 86% to 100%) from mice fed alpha-tocopherol at 50 mg or less/kg body weight per day and seven of 18 tumors (39%; 95% CI = 24% to 54%) from mice fed 100 mg/kg body weight per day (P<.001, Fisher's exact test, referent groups [pooled] 0, 25, and 50 mg/kg). gamma-Tocopherol had no detectable effect on any of the three endpoints. Thus, dietary alpha-tocopherol decreases two forms of genetic instability in a dose-dependent manner in this experimental tumor model.

[Extracellular DNA fragments and DNAse activity in blood serum of rats with transplantated Guerin's carcinoma after multiple exposures to low doses of X-irradiation]

The fraction composition of extracellular free DNA (cfDNA) and activity of serum DNAses in blood of rats with the tumor transplantated against a background of the low-dose X-irradiation were investigated. Heterogeneous fragments of cfDNA and high level of DNAse activity were revealed in the serum of irradiated rats. The definite sizes of high-molecular homogenous fraction of cfDNA, which is observed in the serum of irradiated and unirradiated rats with tumor, and its presence from the first stages of tumor growth independent of serum DNAses activity show, that the emergence of this fraction is not accidental. Previous fractionated irradiation makes influence on the investigation data only on the primary stages of tumor growth.

[Effect of low-intensity laser radiation on the functional potential of neutrophilic granulocytes in blood of tumor-bearing animals]

Peripheral blood was sampled for cytochemical assay of cationic proteins from three groups of animals--intact ones, those with tumor C45 and bearers of the same tumor treated with helium-laser radiation and chemotherapy. Radiotherapy involved such manifestations of enhanced nonspecific antitumor resistance and, in particular, mobilization of the cellular component, as increased number of neutrophils containing cationic protein granules and relatively high levels of such proteins in them. Cytochemical assay of cationic proteins in neutrophil granules may serve as a criterion of nonspecific antitumor resistance assessment.

[Comparative characteristic of serpin--alpha-1 proteinase inhibitor in human and mice serum]

Serpin alpha-1-proteinase inhibitor have been studied in human subjects and in mice of different lines as acute phase reactant and during tumor development. In humans, there was no difference of serpin activity between men and women. Increased activity was noted in men with acute trauma (acute phase reaction). Comparatively to male, in female mice of different lines decreased activity of serum alpha-1-proteinase inhibitor, was shown. There was no increase of alpha-1-proteinase inhibitor activity during inflammation induced by zymosan administration in mice. alpha-1-proteinase inhibitor belongs to acute phase reactants in humans but not in mice; for mice alpha-2-macroglobulin is a more typical acute phase reactant as compared to alpha-1-proteinase inhibitor. Murine tumor development (hepatoma HA-1, lymphosarcoma LS, Lewis lung adenocarcinoma) was followed by a decreased activity of serum alpha-1-proteinase inhibitor both in successfully treated and untreated groups. According to data of literature, similar dated were obtained in humans with tumors. It was suggested that changes of expressiln of alpha-1-proteinase inhibitor by tumors and its secretion were involved in decreased activity of alpha-1-proteinase inhibitor.

Circumvention of multidrug resistance and reduction of cardiotoxicity of doxorubicin in vivo by coupling it with low density lipoprotein

Doxorubicin (Dox) was coupled into human low density lipoprotein (LDL) to form a complex LDL-Dox. In in vitro studies, the accumulation of LDL-Dox in human resistant hepatoma (R-HepG2) cells was found to be higher than that of free Dox in the cells, resulting in an increase of the cytotoxic effect on the cells. Moreover, in in vivo studies, under the same dosage of drugs (1 mg/kg), the anti-proliferative effect on the tumor cells of LDL-Dox in nude mice bearing R-HepG2 cells was higher than that of free Dox as evidenced by the larger reduction in tumor volumes and tumor weights in LDL-Dox treated group. Histological studies showed that LDL-Dox treatment did not cause any heart damage when compared with the control group. In contrast, Dox treatment caused disruption and vacuolization of myocardial filament. Plasma lactate dehydrogenase activity and plasma creatine kinase activity in nude mice bearing R-HepG2 cells were found to be elevated in the Dox-treated group but remained unchanged in LDL-Dox-treated group. The present studies indicate that when Dox is coupled with LDL, the multidrug resistance can be circumvented and the cardiotoxicity can be reduced.