Paradoxical role of autophagy in the dysplastic and tumor-forming stages of hepatocarcinoma development in rats

Many reports have shown that autophagy has a role as both a promoter and inhibitor in tumor development. However, the mechanism of this paradox is unknown. Tumor development is a multistep process. Therefore, we investigated whether the role of autophagy in hepatocarcinoma formation depended on the stage of tumor development. Based on our results, autophagy inhibition by chloroquine had a tumor-promotive effect in the rat model with N-diethylnitrosamine-induced hepatocarcinogenesis in its dysplastic stage (Ds) and a tumor-suppressive effect in its tumor-forming stage (Ts). In the Ds, autophagy inhibition enhanced cell proliferation, DNA damage and inflammatory cytokines expression in liver. These changes were dependent on the upregulation of reactive oxygen species (ROS) that was resulted from autophagy inhibition, and ultimately accelerated the process of hepatocarcinogenesis. However, in the Ts, autophagy inhibition restrained tumor formation by decreasing tumor cell survival and proliferation. In this stage, autophagy inhibition led to excessive ROS accumulation in the tumor, which promoted cell apoptosis, and prominently suppressed tumor cell metabolism. Taken together, our data suggested that autophagy suppressed hepatocarcinogenesis in the Ds by protecting normal cell stability and promoted hepatocarcinogenesis in the Ts by supporting tumor cells growth. Autophagy always had a role as a protector throughout the process of hepatocarcinoma development.

Bisphosphonate treatment and risk of esophageal cancer: a meta-analysis of observational studies

The use of bisphosphonates and the risk of esophageal cancer have recently received increasing concern and related studies have yielded controversial results. The present meta-analysis of observational studies shows that no clear association between bisphosphonate treatment and risk of esophageal cancer was observed.

INTRODUCTION

Epidemiological evidence suggests that bisphosphonate treatment can increase the risk of esophageal cancer. However, data on this issue are unstable and controversial. We conducted a meta-analysis to provide a quantitative assessment of the association between use of bisphosphonates and risk of esophageal cancer.

METHODS

We searched the Medline and Embase databases up to May 2012 to identify studies related to bisphosphonates and esophageal cancer. Summary effect estimates with 95 % confidence intervals (CI) were derived using a fixed or random effects model, depending on the heterogeneity of the included studies.

RESULTS

Seven epidemiologic studies that consisted of four cohort studies and three case-control studies were included in this meta-analysis. In our primary analysis, bisphosphonate treatment was not associated with risk of esophageal cancer in both cohort studies [pooled relative risk (RR) 1.23, 95 % CI 0.79-1.92] and case-control studies [pooled odds ratio (OR) 1.24, 95 % CI 0.98-1.57]. Evidence for the presence of significant heterogeneity was found in cohort studies (p = 0.009, I (2) = 74 %) but not in case-control studies (p = 0.338, I (2) = 7.8 %). In our secondary analysis, no significant increased risk of esophageal cancer was found in alendronate users (pooled RR 1.08, 95 % CI 0.67-1.75 in cohort studies; pooled OR 1.16, 95 % CI 0.82-1.63 in case-control studies).

CONCLUSIONS

Based on current evidences, bisphosphonate treatment was not significantly associated with excess risk of esophageal cancer.

Lactobacillus isolates from healthy volunteers exert immunomodulatory effects on activated peripheral blood mononuclear cells

As probiotics in the gut, Lactobacilli are believed to play important roles in the development and maintenance of both the mucosal and systemic immune system of the host. This study was aimed to investigate the immuno-modulatory function of candiate lactobacilli on T cells. Lactobacilli were isolated from healthy human feces and the microbiological characteristics were identified by API 50 CHL and randomly amplified polymorphic DNA (RAPD) assays. Anti-CD3 antibody activated peripheral blood mononuclear cells (PBMCs) were treated by viable, heat-killed lactobacilli and genomic DNA of lactobacilli, and cytokine profiles were tested by ELISA. Isolated lactobacilli C44 and C48 were identified as L. acidophilus and L. paracacei, which have properties of acid and bile tolerance and inhibitor effects on pathogens. Viable and heat-killed C44 and C48 induced low levels of proinflammatory cytokines (TNF-α, IL-6 and IL-8) and high levels of IFN-γ and IL-12p70 in PBMCs. In anti-CD3 antibody activated PBMCs, viable and heat-killed C44 increased Th2 cytokine levels (IL-5, IL-6 and IL-10), and simultaneously enhanced Th1 responses by inducing IFN-γ and IL-12p70 production. Different from that of lactabacillus strains, their genomic DNA induced low levels of IL-12p70, IFN-γ and proinflammatory cytokines in PBMCs with or without anti-CD3 antibody activation. These results provided in vitro evidence that the genomic DNA of strains of C44 and C48, especially C44, induced weaker inflammation, and may be potentially applied for treating allergic diseases.

Vessel Boundary Detection for its 3D Reconstruction by Using a Deformable Model (GVF Snake)

Vessel boundary detection and 3D modeling is a difficult but necessary task in analyzing the mechanics of inflammation and the structure of the microvasculature. We present in this paper a method of analyzing this structure by the means of the deformable model (using GVF Snake) for vessel boundary detection and three-dimensional reconstruction. For this purpose, we used a virtual vessel model and produced synthetic images. From these images, we obtained contours of vessels by the GVF Snake and then reconstructed a three-dimensional structure by using the coordinates of the Snakes.

Cross talk between PKC and CREB in the induction of COX-2 by PGF2α in human amnion fibroblasts

Compelling evidence indicates a crucial role of prostaglandin F2α (PGF2α) in parturition. Both the maternal and fetal sides of the fetal membranes synthesize PGF2α, which exerts effects via the prostaglandin F2α receptor (FP) that is coupled to the activation of protein kinase C (PKC). Cyclooxygenase-2 (COX-2) catalyzes the rate-limiting step of the inducible synthesis of prostaglandin. Although activation of PKC is known to induce COX-2 expression, it is not clear whether PGF2α can induce COX-2 via FP receptor-coupled PKC activation. COX-2 promoter carries a cAMP-response element (CRE) and phosphorylation of CRE binding protein 1 (CREB1) is associated with COX-2 expression in human amnion fibroblasts. We demonstrated that human amnion fibroblasts produced PGF2α and expressed FP receptor. PGF2α increased COX-2 expression and CREB1 phosphorylation, which could be blocked by either the FP receptor antagonist AL8810 or PKC inhibitor Ro31-7549. The PKC activator, phorbol-12-myristate-13-acetate (PMA), could mimic the induction of COX-2 and CREB1 phosphorylation. The induction of COX-2 by PGF2α and PMA could be attenuated by the small interfering RNA-mediated knockdown of CREB1 expression or overexpressing dominant-negative CREB1. A chromatin immunoprecipitation assay showed that the binding of CREB1 to the COX-2 promoter was increased by PGF2α and PMA in amnion fibroblasts. In conclusion, we provide evidence that PGF2α induces COX-2 expression via the FP receptor and phosphorylates CREB1 by PKC, thus increasing CREB1 binding to the COX-2 promoter and the expression of COX-2 in human amnion fibroblasts. This feed-forward loop may be crucial for the production of prostaglandins in the fetal membranes prior to the onset of labor.

Exotic quantum spin models in spin-orbit-coupled Mott insulators

We study cold atoms in an optical lattice with synthetic spin-orbit coupling in the Mott-insulator regime. We calculate the parameters of the corresponding tight-binding model using Peierls substitution and "localized Wannier states method" and derive the low-energy spin Hamiltonian for bosons and fermions. The spin Hamiltonian is a combination of Heisenberg model, quantum compass model and Dzyaloshinskii-Moriya interactions and it has a rich classical phase diagram with collinear, spiral and vortex phases. We discuss the state of the art of experiments to realize and detect magnetic orderings in strongly correlated optical lattices.

A new molecular diagnostic approach to assess Y chromosome microdeletions in infertile men

OBJECTIVE

A key cause of spermatogenetic failure in infertile males is microdeletions in the azoospermia factor (AZF) regions of the Y chromosome. This study screened for microdeletions in the AZF regions using suspension array technology and compared the results with those from polymerase chain reaction (PCR).

METHODS

Patients with spermatogenetic failure (n=507) and healthy control sperm donors (n=100) were recruited. DNA samples were analysed using both multiplex PCR with gel electrophoresis and suspension array technology.

RESULTS

The suspension array method identified 45 infertile males with Y chromosome microdeletions, while none was found in the controls. Amongst the AZF subregions, two cases had deletions in AZFa, three in AZFb, 35 in AZFc, three in AZFbc and two in AZFabc. The results from 507 patients were identical when analysed with either suspension array or multiplex PCR, however suspension array technology offered improved sensitivity, may be more accurate and could give time and cost savings.

CONCLUSIONS

Suspension array technology offers a rapid and high-throughput method for Y chromosome microdeletion screening in infertile men.

OS057. Pathophysiological role of elevated tissue transglutaminase in autoantibody-induced features of preeclampsia in pregnant mice

INTRODUCTION

Preeclampsia (PE) is highly associated with the presence of autoantibodies that activate the major angiotensin receptor, AT1R. These autoantibodies (termed AT1-AA) cause most features of PE when introduced into pregnant mice and are believed to contribute to disease pathogenesis. Tissue transglutaminase (tTG) is a prominent member of a family of enzymes that crosslink proteins by catalyzing the formation of an isopeptide bond between the amide group of glutamine and the free amino group of lysine and is believed to play a role in AT1R activation.

OBJECTIVES

To test the hypothesis that tTG plays a role in autoantibody-mediated AT1R activation and thereby contributes to the pathophyhsiology of PE.

METHODS

Western blotting was used to quantify tTG in placentas of normotensive pregnant women and those with PE. Immunohistochemistry was used to determine cellular localization of tTG, AT1R and glutamyl-lysine isopeptides in placenta tissue. Co-immunoprecipitation experiments were used to explore the possible association of tTG and AT1R. Finally, in an effort to determine the role of tTG in AT1-AA-induced features of PE in vivo, we treated autoantibody-injected pregnant mice with cystamine, a potent tTG inhibitor.

RESULTS

Western blot analysis showed elevated tTG in placentas of women with PE. Immunohistochemical analysis revealed that increased levels of tTG, glutamyl-lysineisopeptides, AT1R co-localized in the microvillous membrane of PE placentas. Immunoprecipitation of tTG from human trophoblast cell (HTR) lysates resulted in the co-immunoprecipitation of AT1R, thereby providing evidence for an interaction between tTG and AT1R in HTR cells. Finally, we found that cystamine treatment significantly attenuated key features associated with PE including hypertension and proteinuria in the PE-IgG-injected pregnant mice.

CONCLUSION

Taken together, we identified a previously unrecognized role of elevated tTG in PE likely by activating or stabilizing AT1Rs. These studies provide novel mechanisms of autoantibody-induced AT1R activation by elevated placental tTG, highlight the role of tTG in the pathogenesis of PE and suggest novel therapeutic strategies for the disease.

Effect of soy isoflavones on blood pressure: a meta-analysis of randomized controlled trials

BACKGROUND AND AIM

The effect of soy isoflavones on blood pressure is controversial. The objective of this study was to evaluate the effect of dietary soy isoflavones on blood pressure.

METHODS AND RESULTS

Trials were searched in PubMed, the Cochrane Library, Embase and references cited in related reviews and studies. A total of eleven trials were reviewed. Meta-analysis results showed a mean decrease of 2.5 mm Hg (95% CIs, - 5.35 to 0.34 mm Hg; P = 0.08) for systolic blood pressure and 1.5 mm Hg (95% CIs, - 3.09 to 0.17 mm Hg; P = 0.08) for diastolic blood pressure in the soy isoflavones-treated group compared to placebo. Meta-regression and subgroup analyses indicated that blood pressure status was a significant predictor of heterogeneity for the effect of soy isoflavones on blood pressure. Subgroup analysis of hypertensive subjects revealed that a greater blood pressure reduction was identified in the soy isoflavone-treated group compared to placebo (5 trials; SBP: - 5.94, 95% CIs [- 10.55, - 1.34] mm Hg, P = 0.01; DBP: - 3.35, 95% CIs [- 6.52, - 0.19] mm Hg, P = 0.04). In contrast, treatment with soy isoflavones did not lead to a significant reduction in blood pressure in normotensive subjects (6 trials; SBP: 0.29, 95% CIs [- 2.39, 2.97] mm Hg, P = 0.83; DBP: - 0.43, 95% CIs [- 1.66, 0.81] mm Hg, P = 0.50).

CONCLUSION

Soy isoflavones had an effect of lowering blood pressure in hypertensive subjects, but not in normotensive subjects. Larger trials need to be carried out to confirm the present findings.

Serum carotenoids and pulmonary function in older community-dwelling women

BACKGROUND AND OBJECTIVES

Deterioration in pulmonary function is associated with greater disability and mortality in older adults. Dietary antioxidants are implicated in lung health, but the relationship between major dietary antioxidants, such as serum carotenoids, and pulmonary function have not been well characterized. Serum carotenoids are considered the most reliable indicator of fruit and vegetable intake.

SUBJECTS AND METHODS

We examined the relationship between serum α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin, and lycopene with pulmonary function (forced expiratory volume in one second [FEV1] and forced vital capacity [FVC]) in a population-based sample of 631 moderately to severely disabled community-dwelling older women (Women's Health and Aging Study I) in Baltimore, Maryland, USA.

RESULTS

Higher serum α-carotene and β-carotene concentrations were positively associated with both FEV1 and FVC, respectively (all P < 0.05), in separate multivariate linear regression models adjusting for age, race, education, cognition, anemia, inflammation, and chronic diseases. Total serum carotenoids were associated with FEV1 (P = 0.08) and FVC (P = 0.06), respectively, in similar models. No association was found between β-cryptoxanthin, lutein/zeaxanthin, and lycopene, and FEV1 or FVC.

CONCLUSIONS

Higher serum α-carotene and β-carotene concentrations, which reflect greater intake of orange and dark green leafy fruits and vegetables, were associated with better pulmonary function among older community-dwelling women.function may lead to food avoidance and to a higher incidence of digestive complaints.

Relationship of household food insecurity to anaemia in children aged 6-59 months among families in rural Indonesia

BACKGROUND

Anaemia is a significant global public health problem in developing countries with adverse health effects on young children. Household food insecurity, which reflects a household's access, availability and utilisation of food, has not been well characterised in relation to anaemia in children.

OBJECTIVE

To examine the relationship of household food insecurity with anaemia (Hb <11 g/dl) in children.

METHODS

In a cross-sectional study of 4940 rural households participating in the Indonesian Nutrition Surveillance System, household food insecurity was measured using a modified 9-item food security questionnaire and related to anaemia in children aged 6-59 months.

RESULTS

The proportion of households with an anaemic child was 56·6%. In households with and without anaemic children, the mean (SD) food insecurity score was 1·82 (1·72) vs 1·55 (1·54) (p<0·0001), respectively. In a multivariate logistic regression model, food insecurity score was related to anaemia in children (odds ratio 0·77, 95% confidence interval 0·63-0·95, p=0·01) when the highest quintile of food insecurity score was compared with the lowest quintile, adjusting for potential confounders.

CONCLUSION

A higher household food insecurity score is associated with greater prevalence of anaemia in children in rural families in Indonesia.

Development of Magnetically Suspended Vaneless Centrifugal Blood Pump for Cardiopulmonary Bypass

An ideal blood pump would provide sufficient flow rate against vessel pressure without hemolysis or thrombus formation. In preceding studies, it is known that non-contact operation by magnetic bearing system gives high mechanical reliability, low hemolysis and low thrombus formation. Therefore, in the present study a magnetically suspended vaneless centrifugal blood pump (MSVC-BP) has been developed for the use of cardiopulmonary bypass, in which the magnetic suspension centers the centrifugal rotor avoiding any contact. To predict the flow pattern in the pump head and to calculate shear stress on the rotor, numerical analysis has been performed using the TASCflow®. In vitro tests of hydrodynamic performance of the present pump have been carried out in mock circular system with glycerin solution, attaining a maximum flow rate of 12 L/min at 2200 rpm. In vivo tests of hemodynamic performance of the pump have also led to reasonable results for clinical usage.

The Sp1 transcription factor is crucial for the expression of 11beta-hydroxysteroid dehydrogenase type 2 in human placental trophoblasts

CONTEXT

Overexposure of the fetus to glucocorticoids early in gestation is detrimental to fetal development. Glucocorticoid concentrations in the fetal circulation are kept low by 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2, encoded by HSD11B2) in the placental syncytiotrophoblasts. However, cytotrophoblasts, the progenitors of syncytiotrophoblasts, express low levels of 11β-HSD2. Here we studied the molecular mechanisms underlying 11β-HSD2 induction upon syncytialization.

METHODS

Freshly isolated human term placental cytotrophoblasts and in vitro differentiated syncytiotrophoblasts were examined to determine the methylation status of HSD11B2 promoter. The transcription factor responsible for 11β-HSD2 induction was identified by observing its expression upon syncytialization, the effect of its attenuation, and its binding to the HSD11B2 promoter.

RESULTS

11β-HSD2 expression was markedly increased upon syncytialization in vitro. No methylation differences of HSD11B2 promoter were found between cytotrophoblasts and syncytiotrophoblasts. Expression of the transcription factor Sp1 was markedly induced during syncytialization and further increased by activation of the cAMP pathway, which correlated with 11β-HSD2 expression. Importantly, small interfering RNA-mediated knockdown of Sp1 expression or inhibition of Sp1 activity with mithramycin A markedly attenuated not only basal but also cAMP pathway-stimulated expression of 11β-HSD2 in the syncytiotrophoblasts. Stimulation of the cAMP pathway also increased the binding of Sp1 and RNA polymerase II to HSD11B promoter in syncytiotrophoblasts. Concomitantly, acetylation at histone H3K9 was increased whereas methylation at histone H3K9 was decreased.

CONCLUSIONS

11β-HSD2 induction upon syncytialization is at least in part due to the increased expression of Sp1 upon activation of the cAMP pathway rather than the differential methylation of the HSD11B2 promoter.

Cross talk between cAMP and p38 MAPK pathways in the induction of leptin by hCG in human placental syncytiotrophoblasts

Leptin produced by the placental syncytiotrophoblasts participates in a number of processes in pregnancy including implantation, proliferation of the cytotrophoblasts, and nutrient transfer across the placenta. Despite the functional significance of leptin in pregnancy, the regulation of leptin synthesis is poorly understood in human placental syncytiotrophoblasts. In this study, we investigated the role of endogenous human chorionic gonadotropin (hCG) in the regulation of leptin production as well as the underlying mechanism involving the cross talk between cAMP and p38 mitogen-activated protein kinase (MAPK) pathways. We found that neutralization of endogenous hCG with its antibody dose dependently decreased leptin mRNA level and secretion, whereas exogenous hCG increased leptin mRNA level and secretion. Activation of the cAMP pathway with dibutyryl cAMP (db cAMP) or forskolin recapitulated the stimulatory effect of hCG on leptin expression. Inhibition of protein kinase A with H89 not only reduced the basal leptin expression but also attenuated the induced leptin expression by hCG. Treatment of the syncytiotrophoblasts with db cAMP and hCG phosphorylated p38 MAPK. Inhibition of p38 MAPK with SB203580 not only reduced the basal leptin production but also attenuated the leptin-induced production by both hCG and db cAMP. These data suggest that endogenous hCG plays a significant role in maintaining leptin production in human placental syncytiotrophoblasts, and this effect involves a cross talk between cAMP and p38 MAPK pathways.

C10ORF97 is a novel tumor-suppressor gene of non-small-cell lung cancer and a functional variant of this gene increases the risk of non-small-cell lung cancer

In an earlier study we showed that C10ORF97 (chromosome-10, open reading frame-97) was expressed in almost all of the tissues and cell lines tested, and that it inhibited the growth of seven tumor cell lines, including two lung carcinoma cell lines (A549 and PG). Here, we show that C10ORF97 is downregulated in non-small-cell lung cancer (NSCLC) tissue compared with normal lung tissue. Overexpression of C10ORF97 significantly suppressed human lung carcinoma A549 cell growth (proliferation and anchorage-independent growth in soft agar) and motility (migration and adhesion). This tumor-suppressive function of C10ORF97 was also verified in vivo. We further found that C10ORF97 caused G(1) arrest of A549 cells and modulated the expression level of several cell-cycle regulators (such as CDK2, cyclin-E and p27). These effects of C10ORF97 were mediated by physical association between C10ORF97 and Jun-activating domain-binding protein-1 (JAB1), and blocking of JAB1-mediated translocation of p27 from the nucleus to the cytoplasm. Together, these results indicated that C10ORF97 functions as a novel tumor suppressor by modulating several key G(1)/S-regulatory proteins by interacting with JAB1. These findings led us to hypothesize that a single-nucleotide polymorphism (SNP) in the C10ORF97 gene that affects its expression might be associated with susceptibility to NSCLC. SNP216 C>T (rs2297882) in the C10ORF97 Kozak sequence was identified, and allele T of SNP216 suppressed C10ORF97 expression in vitro and in vivo. Furthermore, the TT genotype of SNP216 was associated with an increased risk of NSCLC (adjusted odds ratio=1.73 (95% confidence interval: 1.33-2.25), P=4.6 × 10(-5)). These data indicated that C10ORF97 is a tumor suppressor of NSCLC progression and C10ORF97-SNP216 may serve as a predictor of NSCLC.

Association of intergenic polymorphism of organic anion transporter 1 and 3 genes with hypertension and blood pressure response to hydrochlorothiazide

BACKGROUND

Organic anion transporter (OAT) 1 and OAT3, encoded by a tightly linked gene pair, play a key role in renal secretion of diuretics. However, no study has yet examined the influence of OAT1 and OAT3 polymorphisms on high blood pressure (BP) and the response to thiazide diuretics. We hypothesized that intergenic polymorphisms between OAT1 and OAT3 might be associated with adult hypertension and the antihypertensive effects of hydrochlorothiazide (HCTZ).

METHODS

The association of an intergenic polymorphism (rs10792367) with hypertension risk was investigated in two independent case-control studies (n = 1,592 and 602), and then a combined analysis was performed for improving power (1,106 cases and 1,088 controls) with adjustment for geographic location. Two clinical trials (n = 542 and 274) were conducted in untreated hypertensive patients for the association of rs10792367 with antihypertensive responses to 4 and 8 weeks of HCTZ treatment.

RESULTS

No significant association was found between rs10792367 and hypertension after adjustment for conventional risk factors in either the two populations, respectively, or the combined two population. After adjustment for pretreatment BP and other confounders, HCTZ-induced reduction in systolic BP was 4.8 mm Hg (P = 0.006, first trial) and 6.1 mm Hg (P = 0.003, in second trial) lower, respectively, in C allele carriers than in GG carriers in the two clinical trials.

CONCLUSIONS

Intergenic polymorphism rs10792367 between OAT1 and OAT3 is not associated with hypertension, but appears to be involved in between-individual variations in antihypertensive responses to HCTZ.

Abstract P1-03-06: Population Based In Vivo Biomarker Discovery Using Engineered Human Tumors

Background:

Tumors from patients exhibit significant inter-tumor variation, where each tumor harbors a unique set of genetic alterations that impact prognosis and response to treatment. Unfortunately, this variation contributes to low response rates in the clinic and creates significant challenges for treating patients with appropriate drugs. Cancer cell line based xenografts have traditionally been the preclinical model of choice to assess the efficacy of clinical compounds; however, such in vitro models exhibit inherent artifacts, and are unable to adequately capture natural variation seen in human tumor populations. It has therefore become a priority in oncology and personalized medicine to match patients to drugs that will result in a favorable treatment outcome. In this report, we describe a population based approach for response prediction featuring naturally occurring variation in tumors derived from genetically defined human-in-mouse models of cancer. Materials and Methods:

A population of De novo human breast tumors were generated by genetically engineering normal primary human breast epithelial cells with HER2 and SV40 early region (HER2/SV40er) or KRAS and SV40 early region (KRAS/SV40er) in an in vivo Human-In-Mouse (HIM) tissue transgenic model (Wu et al, Proc Natl Acad Sci U S A 2009, 106: 7022-2027). Each tumor of the population has been comprehensively characterized histopathologically, and at the RNA and DNA level. Furthermore, the population has been adapted to conduct quantitative efficacy studies of anti-cancer agents and combinations. Results:

The HER2/SV40er and the KRAS/SV40er HIM tumors develop as invasive human breast adenocarcinoma that are histologically similar to those observed in patients. Microarray and CGH profiling demonstrated significant inter-tumor variation among the established tumors, as has been reported for patient tumors. Moreover, the KRAS/SV40er tumors clustered with basal type breast cancers from patients, a poor prognosis human breast cancer subtype. Both HER2/SV40er and KRAS/SV40er tumors exhibited variable responses to treatments with the potent selective triple VEGFR inhibitor, tivozanib. Further characterization of those tumors, both pre-and post-treatment, identified potential biomarkers for tumor response to tivozanib. Discussion:

The genetically defined human-in-mouse tumors exhibited natural variations similar to that occurs in human cancer. This population-based HIM system enables us to identify and validate biomarkers of therapeutic response in an in vivo human tumor model. Figure available in online version.