Enhanced metanephric specification to functional proximal tubule enables toxicity screening and infectious disease modelling in kidney organoids.

While pluripotent stem cell-derived kidney organoids are now being used to model renal disease, the proximal nephron remains immature with limited evidence for key functional solute channels. This may reflect early mispatterning of the nephrogenic mesenchyme and/or insufficient maturation. Here we show that enhanced specification to metanephric nephron progenitors results in elongated and radially aligned proximalised nephrons with distinct S1 - S3 proximal tubule cell types. Such PT-enhanced organoids possess improved albumin and organic cation uptake, appropriate KIM-1 upregulation in response to cisplatin, and improved expression of SARS-CoV-2 entry factors resulting in increased viral replication. The striking proximo-distal orientation of nephrons resulted from localized WNT antagonism originating from the organoid stromal core. PT-enhanced organoids represent an improved model to study inherited and acquired proximal tubular disease as well as drug and viral responses.

Enhanced metanephric specification to functional proximal tubule enables toxicity screening and infectious disease modelling in kidney organoids.

While pluripotent stem cell-derived kidney organoids are now being used to model renal disease, the proximal nephron remains immature with limited evidence for key functional solute channels. This may reflect early mispatterning of the nephrogenic mesenchyme and/or insufficient maturation. Here we show that enhanced specification to metanephric nephron progenitors results in elongated and radially aligned proximalised nephrons with distinct S1 - S3 proximal tubule cell types. Such PT-enhanced organoids possess improved albumin and organic cation uptake, appropriate KIM-1 upregulation in response to cisplatin, and improved expression of SARS-CoV-2 entry factors resulting in increased viral replication. The striking proximo-distal orientation of nephrons resulted from localized WNT antagonism originating from the organoid stromal core. PT-enhanced organoids represent an improved model to study inherited and acquired proximal tubular disease as well as drug and viral responses.

IL-33 promotes gastric tumour growth in concert with activation and recruitment of inflammatory myeloid cells.

Interleukin-33 (IL-33) is an IL-1 family cytokine known to promote T-helper (Th) type 2 immune responses that are often deregulated in gastric cancer (GC). IL-33 is overexpressed in human gastric tumours suggesting a role in driving GC progression although a causal link has not been proven. Here, we investigated the impact of IL-33 genetic deficiency in the well-characterized gp130 F/F mouse model of GC. Expression of IL-33 (and it's cognate receptor, ST2) was increased in human and mouse GC progression. IL-33 deficient gp130 F/F /Il33 -/- mice had reduced gastric tumour growth and reduced recruitment of pro-tumorigenic myeloid cells including key mast cell subsets and type-2 (M2) macrophages. Cell sorting of gastric tumours revealed that IL-33 chiefly localized to gastric (tumour) epithelial cells and was absent from tumour-infiltrating immune cells (except modest IL-33 enrichment within CD11b+ CX3CR1+CD64+MHCII+ macrophages). By contrast, ST2 was absent from gastric epithelial cells and localized exclusively within the (non-macrophage) immune cell fraction together with mast cell markers, Mcpt1 and Mcpt2. Collectively, we show that IL-33 is required for gastric tumour growth and provide evidence of a likely mechanism by which gastric epithelial-derived IL-33 drives mobilization of tumour-promoting inflammatory myeloid cells.

Recessive NOS1AP variants impair actin remodeling and cause glomerulopathy in humans and mice.

Nephrotic syndrome (NS) is a leading cause of chronic kidney disease. We found recessive NOS1AP variants in two families with early-onset NS by exome sequencing. Overexpression of wild-type (WT) NOS1AP, but not cDNA constructs bearing patient variants, increased active CDC42 and promoted filopodia and podosome formation. Pharmacologic inhibition of CDC42 or its effectors, formin proteins, reduced NOS1AP-induced filopodia formation. NOS1AP knockdown reduced podocyte migration rate (PMR), which was rescued by overexpression of WT Nos1ap but not by constructs bearing patient variants. PMR in NOS1AP knockdown podocytes was also rescued by constitutively active CDC42Q61L or the formin DIAPH3 Modeling a NOS1AP patient variant in knock-in human kidney organoids revealed malformed glomeruli with increased apoptosis. Nos1apEx3-/Ex3- mice recapitulated the human phenotype, exhibiting proteinuria, foot process effacement, and glomerulosclerosis. These findings demonstrate that recessive NOS1AP variants impair CDC42/DIAPH-dependent actin remodeling, cause aberrant organoid glomerulogenesis, and lead to a glomerulopathy in humans and mice.

Coordinate expression loss of GKN1 and GKN2 in gastric cancer via impairment of a glucocorticoid-responsive enhancer.

Gastrokines (GKNs) are anti-inflammatory proteins secreted by gastric epithelial (surface mucous and pit) cells, with their aberrant loss of expression causally linked to premalignant inflammation and gastric cancer (GC). Transcriptional mechanisms accounting for GKN expression loss have not been elucidated. Using human clinical cohorts, mouse transgenics, bioinformatics, and transfection/reporter assays, we report a novel mechanism of GKN gene transcriptional regulation and its impairment in GC. GKN1/GKN2 loss is highly coordinated, with both genes showing parallel downregulation during human and mouse GC development, suggesting joint transcriptional control. In BAC transgenic studies, we defined a 152-kb genomic region surrounding the human GKN1/GKN2 genes sufficient to direct their tissue- and lineage-restricted expression. A screen of the 152-kb region for candidate regulatory elements identified a DNase I hypersensitive site (CR2) located 4 kb upstream of the GKN1 gene. CR2 showed overlapping enrichment of enhancer-related histone marks (H3K27Ac), a consensus binding site (GRE) for the glucocorticoid receptor (GR), strong GR occupancy in ChIP-seq data sets and, critically, exhibited dexamethasone-sensitive enhancer activity in reporter assays. Strikingly, GR showed progressive expression loss, paralleling that of GKN1/2, in human and mouse GC, suggesting desensitized glucocorticoid signaling as a mechanism underlying GKN loss. Finally, mouse adrenalectomy studies revealed a critical role for endogenous glucocorticoids in sustaining correct expression (and anti-inflammatory restraint) of GKNs in vivo. Together, these data link the coordinate expression of GKNs to a glucocorticoid-responsive and likely shared transcriptional enhancer mechanism, with its compromised activation contributing to dual GKN loss during GC progression.NEW & NOTEWORTHY Gastrokine 2 (GKN2) is an anti-inflammatory protein produced by the gastric epithelium. GKN2 expression is progressively lost during gastric cancer (GC), which is believed to play a casual role in GC development. Here, we use bacterial artificial chromosome transgenic studies to identify a glucocorticoid-responsive enhancer element that likely governs expression of GKN1/GKN2, which, via parallel expression loss of the anti-inflammatory glucocorticoid receptor, reveals a novel mechanism to explain the loss of GKN2 during GC pathogenesis.

A Toolbox to Characterize Human Induced Pluripotent Stem Cell-Derived Kidney Cell Types and Organoids.

BACKGROUND: The generation of reporter lines for cell identity, lineage, and physiologic state has provided a powerful tool in advancing the dissection of mouse kidney morphogenesis at a molecular level. Although use of this approach is not an option for studying human development in vivo, its application in human induced pluripotent stem cells (iPSCs) is now feasible. METHODS: We used CRISPR/Cas9 gene editing to generate ten fluorescence reporter iPSC lines designed to identify nephron progenitors, podocytes, proximal and distal nephron, and ureteric epithelium. Directed differentiation to kidney organoids was performed according to published protocols. Using immunofluorescence and live confocal microscopy, flow cytometry, and cell sorting techniques, we investigated organoid patterning and reporter expression characteristics. RESULTS: Each iPSC reporter line formed well patterned kidney organoids. All reporter lines showed congruence of endogenous gene and protein expression, enabling isolation and characterization of kidney cell types of interest. We also demonstrated successful application of reporter lines for time-lapse imaging and mouse transplantation experiments. CONCLUSIONS: We generated, validated, and applied a suite of fluorescence iPSC reporter lines for the study of morphogenesis within human kidney organoids. This fluorescent iPSC reporter toolbox enables the visualization and isolation of key populations in forming kidney organoids, facilitating a range of applications, including cellular isolation, time-lapse imaging, protocol optimization, and lineage-tracing approaches. These tools offer promise for enhancing our understanding of this model system and its correspondence with human kidney morphogenesis.

Kidney micro-organoids in suspension culture as a scalable source of human pluripotent stem cell-derived kidney cells.

Kidney organoids have potential uses in disease modelling, drug screening and regenerative medicine. However, novel cost-effective techniques are needed to enable scaled-up production of kidney cell types in vitro We describe here a modified suspension culture method for the generation of kidney micro-organoids from human pluripotent stem cells. Optimisation of differentiation conditions allowed the formation of micro-organoids, each containing six to ten nephrons that were surrounded by endothelial and stromal populations. Single cell transcriptional profiling confirmed the presence and transcriptional equivalence of all anticipated renal cell types consistent with a previous organoid culture method. This suspension culture micro-organoid methodology resulted in a three- to fourfold increase in final cell yield compared with static culture, thereby representing an economical approach to the production of kidney cells for various biological applications.

Overexpression of IL-11 promotes premalignant gastric epithelial hyperplasia in isolation from germline gp130-JAK-STAT driver mutations.

Expression of the cytokine IL-11 is elevated in human Helicobacter pylori infection and progressively increases with worsening gastric pathology. Additionally, IL-11 is required for tumor development in STAT3-dependent murine models of gastric cancer (GC) and, when administered acutely, causes resolving atrophic gastritis. However, it is unclear whether locally elevated IL-11 ligand expression can, in isolation from oncogenic gp130-JAK-STAT pathway mutations, initiate GC pathogenesis. Here we developed a transgenic mouse model of stomach-specific (keratin 19 promoter) IL-11 ligand overexpression. Keratin 19 promoter-IL-11 transgenic ( K19-IL11Tg) mice showed specific IL-11 overexpression in gastric corpus and antrum but not elsewhere in the gastrointestinal tract or in other tissues. K19-IL11Tg mice developed spontaneous premalignant disease of the gastric epithelium, progressing from atrophic gastritis to TFF2-positive metaplasia and severe epithelial hyperplasia, including adenoma-like lesions in a subset of older (1 yr old) animals. Although locally advanced, the hyperplastic lesions remained noninvasive. H. pylori infection in K19-IL11Tg mice accelerated some aspects of the premalignant phenotype. Finally, K19-IL11Tg mice had splenomegaly in association with elevated serum IL-11, with spleens showing an expanded myeloid compartment. Our results provide direct in vivo functional evidence that stomach-specific overexpression of IL-11, in isolation from germline gp130-JAK-STAT3 genetic drivers, is sufficient for premalignant progression. These findings have important functional implications for human GC, in which frequent IL-11 overexpression occurs in the reported absence of somatic mutations in gp130 signaling components. NEW & NOTEWORTHY We provide direct in vivo functional evidence that stomach-specific overexpression of the cytokine IL-11, in isolation from gp130-JAK-STAT3 pathway mutations, can trigger spontaneous atrophic gastritis progressing to locally advanced epithelial hyperplasia (but not dysplasia or carcinoma), which does not require, but may be accelerated by, concomitant Helicobacter pylori infection.

Short bowel syndrome (SBS)-associated alterations within the gut-liver axis evolve early and persist long-term in the piglet model of short bowel syndrome.

BACKGROUND AND AIM: Short bowel syndrome (SBS) is primarily characterized by malabsorption and malnutrition, resulting from loss of intestinal absorptive area following massive small bowel resection (SBR). Bile acids and the gut microbiota are functionally linked within the gut-liver axis; however, SBS-associated disturbances within the gut-liver axis remain largely unexplored. The aim of this study was to characterize the evolution of bile acid alterations within the gut-liver axis at both short-term and long-term time points and to relate these changes to alterations in colonic bacterial composition. METHODS: Four-week-old piglets were assigned to 75% SBR, sham-operation or non-operation control groups. High throughput sequencing was employed to determine bacterial abundance in colonic content and ultra-performance liquid chromatography used to determine the bile acid concentration of gall bladder, portal serum, and fecal samples. RESULTS: Bile acid complexity and relative abundance are altered in the SBS piglet model at two weeks post-SBR, and these changes persisted at six weeks post-SBR. Our examination of the microbial profile revealed an early and persistent loss in bacteria belonging to the Clostridiales order. CONCLUSIONS: This study provides evidence of an early and persistent disturbance of the bile acid profile throughout the entero-hepatic circulation with an increase in the proportion of primary bile acids and a decrease in secondary bile acids following SBR. These changes were associated with a loss of bacteria belonging to the Clostridiales order consistent with a disturbance in the bile-microbial axis following SBR.

Loss of gastrokine-2 drives premalignant gastric inflammation and tumor progression.

Chronic mucosal inflammation is associated with a greater risk of gastric cancer (GC) and, therefore, requires tight control by suppressive counter mechanisms. Gastrokine-2 (GKN2) belongs to a family of secreted proteins expressed within normal gastric mucosal cells. GKN2 expression is frequently lost during GC progression, suggesting an inhibitory role; however, a causal link remains unsubstantiated. Here, we developed Gkn2 knockout and transgenic overexpressing mice to investigate the functional impact of GKN2 loss in GC pathogenesis. In mouse models of GC, decreased GKN2 expression correlated with gastric pathology that paralleled human GC progression. At baseline, Gkn2 knockout mice exhibited defective gastric epithelial differentiation but not malignant progression. Conversely, Gkn2 knockout in the IL-11/STAT3-dependent gp130F/F GC model caused tumorigenesis of the proximal stomach. Additionally, gastric immunopathology was accelerated in Helicobacter pylori-infected Gkn2 knockout mice and was associated with augmented T helper cell type 1 (Th1) but not Th17 immunity. Heightened Th1 responses in Gkn2 knockout mice were linked to deregulated mucosal innate immunity and impaired myeloid-derived suppressor cell activation. Finally, transgenic overexpression of human gastrokines (GKNs) attenuated gastric tumor growth in gp130F/F mice. Together, these results reveal an antiinflammatory role for GKN2, provide in vivo evidence that links GKN2 loss to GC pathogenesis, and suggest GKN restoration as a strategy to restrain GC progression.

A phase II trial to assess the activity of gemcitabine and docetaxel as first line chemotherapy treatment in patients with unresectable leiomyosarcoma.

BACKGROUND: Gemcitabine and docetaxel have been shown to be active in pre-treated relapsed leiomyosarcoma. This study investigated the combination as first line treatment in patients with unresectable locally advanced/metastatic leiomyosarcoma. METHODS: Patients received gemcitabine 900 mg/m(2) days 1 and 8, and docetaxel 100 mg/m(2) day 8, administered 3-weekly for up to 8 cycles, with GCSF support on days 9-15. Patients who had received previous radiotherapy were treated at 75% dose. Patients were evaluated for response by RECIST 1.0 after cycles 2, 4, 6 and 8, and 3-monthly after completing treatment. RESULTS: Forty-four patients were evaluable for response. Eligible patients had histologically proven leiomyosarcoma of the uterus (54.5%) or other sites (45.5%). Thirty-nine patients (84.4%) had metastatic disease, and 5 (15.6%) had locally advanced disease. Six patients (13.6%) had grade 1 disease, and 23 (75%) had grade 2/3 disease. All patients had demonstrated disease progression prior to trial entry. Responses were as follows: partial response 11 (25.0%), stable disease (confirmed) 16 (36.6%), stable disease (unconfirmed) 7 (15.9%), progressive disease 10 (22.7%). Median progression-free survival and overall survival were 7.1 months (95% CI 5.7-8.3) and 17.9 months (95% CI 10.6-25.2), respectively. Progression free rates at 3 and 6 months were 70.5% (95% CI 56.7-84.2%) and 59.1% (95% CI 44.3-73.9%). CONCLUSIONS: This study demonstrates gemcitabine and docetaxel to be active in locally advanced/metastatic leiomyosarcoma in the first line setting. Further investigation comparing with current standard therapies for leiomyosarcoma is warranted.

Changes in the colon microbiota and intestinal cytokine gene expression following minimal intestinal surgery.

AIM: To investigate the impact of minor abdominal surgery on the caecal microbial population and on markers of gut inflammation. METHODS: Four week old piglets were randomly allocated to a no-surgery "control" group (n = 6) or a "transection surgery" group (n = 5). During the transection surgery procedure, a conventional midline incision of the lower abdominal wall was made and the small intestine was transected at a site 225 cm proximal to the ileocaecal valve, a 2 cm segment was removed and the intestine was re-anastomosed. Piglets received a polymeric infant formula diet throughout the study period and were sacrificed at two weeks post-surgery. Clinical outcomes including weight, stool consistency and presence of stool fat globules were monitored. High throughput DNA sequencing of colonic content was used to detect surgery-related disturbances in microbial composition at phylum, family and genus level. Diversity and richness estimates were calculated for the control and minor surgery groups. As disturbances in the gut microbial community are linked to inflammation we compared the gene expression of key inflammatory cytokines (TNF, IL1B, IL18, IL12, IL8, IL6 and IL10) in ileum, terminal ileum and colon mucosal extracts obtained from control and abdominal surgery groups at two weeks post-surgery. RESULTS: Changes in the relative abundance of bacterial species at family and genus level were confined to bacterial members of the Proteobacteria and Bacteroidetes phyla. Family level compositional shifts included a reduction in the relative abundance of Enterobacteriaceae (22.95 ± 5.27 vs 2.07 ± 0.72, P < 0.01), Bacteroidaceae (2.54 ± 0.56 vs 0.86 ± 0.43, P < 0.05) and Rhodospirillaceae (0.40 ± 0.14 vs 0.00 ± 0.00, P < 0.05) following transection surgery. Similarly, at the genus level, changes associated with transection surgery were restricted to members of the Proteobacteria and Bacteroidetes phyla and included decreased relative abundance of Enterobacteriaceae (29.20 ± 6.74 vs 2.88 ± 1.08, P < 0.01), Alistipes (4.82 ± 1.73 vs 0.18 ± 0.13, P < 0.05) and Thalassospira (0.53 ± 0.19 vs 0.00 ± 0.00, P < 0.05). Surgery-associated microbial dysbiosis was accompanied by increased gene expression of markers of inflammation. Within the ileum IL6 expression was decreased (4.46 ± 1.60 vs 0.24 ± 0.06, P < 0.05) following transection surgery. In the terminal ileum, gene expression of TNF was decreased (1.51 ± 0.13 vs 0.80 ± 0.16, P < 0.01) and IL18 (1.21 ± 0.18 vs 2.13 ± 0.24, P < 0.01), IL12 (1.04 ± 0.16 vs 1.82 ± 0.32, P < 0.05) and IL10 (1.04 ± 0.06 vs 1.43 ± 0.09, P < 0.01) gene expression increased following transection surgery. Within the colon, IL12 (0.72 ± 0.13 vs 1.78 ± 0.28, P < 0.01) and IL10 (0.98 ± 0.02 vs 1.95 ± 0.14, P < 0.01) gene expression were increased following transection surgery. CONCLUSION: This study suggests that minor abdominal surgery in infants, results in long-term alteration of the colonic microbial composition and persistent gastrointestinal inflammation.

Altered FXR signalling is associated with bile acid dysmetabolism in short bowel syndrome-associated liver disease.

BACKGROUND & AIMS: Despite the mortality associated with liver disease observed in patients with short bowel syndrome (SBS), mechanisms underlying the development of SBS-associated liver disease (SBS-ALD) are poorly understood. This study examines the impact of bacterially-mediated bile acid (BA) dysmetabolism on farnesoid X receptor (FXR) signalling pathways and clinical outcome in a piglet model of SBS-ALD. METHODS: 4-week old piglets underwent 75% small bowel resection (SBR) or sham operation. Liver histology and hepatic inflammatory gene expression were examined. Abundance of BA biotransforming bacteria was determined and metabolomic studies detailed the alterations in BA composition of stool, portal serum and bile samples. Gene expression of intestinal and hepatic FXR target genes and small heterodimer partner (SHP) transrepression targets were assessed. RESULTS: Histological evidence of SBS-ALD included liver bile duct proliferation, hepatocyte ballooning and fibrosis. Inflammatory gene expression was increased. Microbiota changes included a 10-fold decrease in Clostridium and a two-fold decrease in Bacteroides in SBS-ALD piglets. BA composition was altered and reflected a primary BA dominant composition. Intestinal and hepatic regulation of BA synthesis was characterised by a blunted intestinal FXR activation response and a failure of SHP to repress key hepatic targets. CONCLUSIONS: We propose a pathological scenario in which microbial dysbiosis following SBR results in significant BA dysmetabolism and consequent outcomes including steatorrhoea, persistent diarrhoea and liver damage. Furthermore alterations in BA composition may have contributed to the observed disturbance in FXR-mediated signalling pathways. These findings provide an insight into the complex mechanisms mediating the development of liver disease in patients with SBS.

Phase II study of cediranib in patients with advanced gastrointestinal stromal tumors or soft-tissue sarcoma.

PURPOSE: Cediranib is a potent VEGF signaling inhibitor with activity against all three VEGF receptors and KIT. This phase II study evaluated the antitumor activity of cediranib in patients with metastatic gastrointestinal stromal tumor (GIST) resistant/intolerant to imatinib, or metastatic soft-tissue sarcomas (STS; ClinicalTrials.gov, NCT00385203). EXPERIMENTAL DESIGN: Patients received cediranib 45 mg/day. Primary objective was to determine the antitumor activity of cediranib according to changes in 2[18F]fluoro-2-deoxy-D-glucose positron emission tomography ((18)FDG-PET) tumor uptake in patients with GIST using maximum standardized uptake values (SUVmax). Secondary objectives included objective tumor response and tolerability in patients with GIST/STS. RESULTS: Thirty-four of 36 enrolled patients were treated (GIST n = 24; STS n = 10). At day 29, five patients had confirmed decreases in SUVmax (≥10% from day 8) and two had confirmed partial metabolic responses (≥25% decrease), but arithmetic mean percentage changes in SUVmax, averaged across the cohort, were not significant at day 8 [6.8%; 95% confidence interval (CI), 19.95-33.54) or day 29 (4.6%; 95% CI, 8.05-17.34). Eleven patients with GIST achieved a best objective tumor response of stable disease; eight achieved stable disease ≥16 weeks. In patients with STS, four of six with alveolar soft-part sarcoma (ASPS) achieved confirmed and durable partial responses. The commonest adverse events were diarrhea (85%), fatigue (74%), and hypertension (68%). CONCLUSIONS: In patients progressing on imatinib/sunitinib, cediranib 45 mg/day demonstrated evidence of activity by (18)FDG-PET, but did not reduce average SUVmax. Evidence of antitumor activity was seen in ASPS.

Clinical activity and tolerability of a 14-day infusional Ifosfamide schedule in soft-tissue sarcoma.

Background. Soft-tissue sarcomas (STS) are a heterogeneous group of diseases with lack of effective treatments in most cases. Previous data suggest that continuous infusional ifosfamide regimens might improve cytotoxicity and tolerability compared to standard schedules. Methods. We retrospectively report the outcome of 35 patients affected by STS treated with a 14-day infusional ifosfamide regimen (1000 mg/m(2)/day) in our institution. Predictive factors for toxicity were also explored. Results. Median age was 53 years. There were 16 males and 19 females. Classification by histology was dedifferentiated liposarcoma (DDLPS): 22 (62.8%), synovial sarcoma: 7 (20%), myxoid/round-cell liposarcoma: 3 (8.5%), and others: 3 (8.5%). Overall, 7 patients (20%) achieved partial response (PR) and 10 patients (29%) achieved stable disease (SD). DDLPS showed special sensitivity: 5 patients (22.7%) had PR, 7 patients (31.8%) had SD, and disease control rate was 54.5%. Median progression-free survival and overall survival were 4.2 and 11.2 months, respectively. The most common toxicities were fatigue, nausea, and vomiting (all grades: 85.7%, 83%, and 54.3%, resp.). Neither hypoalbuminaemia nor gender was found to predict toxicity, although encephalopathy predominantly affected females. Conclusion. Ifosfamide administered as a 14-day continuous infusion is a safe regimen in STS with notable activity in DDLPS.

Gut microbial diversity is reduced and is associated with colonic inflammation in a piglet model of short bowel syndrome.

BACKGROUND AND OBJECTIVES: Following small bowel resection (SBR), the luminal environment is altered, which contributes to clinical manifestations of short bowel syndrome (SBS) including malabsorption, mucosal inflammation and bacterial overgrowth. However, the impact of SBR on the colon has not been well-defined. The aims of this study were to characterize the colonic microbiota following SBR and to assess the impact of SBR on mucosal inflammation in the colon. RESULTS: Analysis of the colonic microbiota demonstrated that there was a significant level of dysbiosis both two and six weeks post-SBR, particularly in the phylum Firmicutes, coupled with a decrease in overall bacterial diversity in the colon. This decrease in diversity was associated with an increase in colonic inflammation six weeks post-surgery. METHODS: Female (4-week old) piglets (5-6/group) received a 75% SBR, a transection (sham) or no surgery. Compositional analysis of the colonic microbiota was performed by high-throughput sequencing, two- and six-weeks post-surgery. The gene expression of the pro-inflammatory cytokines interleukin (IL)-1ß, IL-6, IL-8, IL-18 and tumor necrosis factor (TNF)-α in the colonic mucosa was assessed by qRT-PCR and the number of macrophages and percentage inducible nitric oxide synthase (iNOS) staining in the colonic epithelium were quantified by immunohistochemistry. CONCLUSIONS: SBR significantly decreased the diversity of the colonic microbiota and this was associated with an increase in colonic mucosal inflammation. This study supports the hypothesis that SBR has a significant impact on the colon and that this may play an important role in defining clinical outcome.

First-in-human phase I trial of two schedules of OSI-930, a novel multikinase inhibitor, incorporating translational proof-of-mechanism studies.

PURPOSE: OSI-930 is a novel, potent, oral small-molecule receptor tyrosine kinase inhibitor, predominantly against VEGF receptors (VEGFR), c-Kit, and platelet-derived growth factor receptors. A phase I trial was undertaken to determine safety, maximum-tolerated dose (MTD), pharmacokinetics, pharmacodynamics, and antitumor activity of OSI-930 in patients with advanced solid tumors. EXPERIMENTAL DESIGN: OSI-930 was administered once or twice a day using a modified accelerated titration design. Pharmacokinetics and plasma soluble VEGFR2 (sVEGFR2) studies were undertaken. Dynamic contrast-enhanced MRI (DCE-MRI) and 2[18F]fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) MTD expansion cohorts were conducted. RESULTS: Fifty-eight patients received OSI-930 in 2 schedules; once a day schedule: 12 patients at doses up to 1,600 mg without reaching MTD; twice a day schedule: 46 patients at 400 mg (n = 7), 500 mg (n = 31), and 600 mg (n = 8). Dose-limiting toxicities were observed at 600 mg twice a day (n = 3): G3 rash (n = 2) and G4 γ-glutamyltransferase, establishing the MTD at 500 mg twice a day. Common G1-2 toxicities included fatigue, diarrhea, nausea, and rash. Antitumor responses were seen in 2 patients with advanced ovarian cancer [Response Evaluation Criteria in Solid Tumors (RECIST) partial response (PR) (n = 1); GCIG CA125 response (n = 1)]. Eleven of 19 heavily pretreated imatinib-resistant patients with gastrointestinal stromal tumors achieved RECIST stable disease (median duration: 126 days), with FDG-PET scans showing PRs in 4 of 9 patients. OSI-930 exposure increased with dose; substantial decreases in sVEGFR levels were observed with OSI-930 twice a day doses ≥400 mg, while DCE-MRI responses were shown in 4 of 6 patients. CONCLUSIONS: OSI-930 is safe and well tolerated, with pharmacokinetic-pharmacodynamic data supporting proof-of-mechanism with clinically relevant antitumor activity.

Role of palliative chemotherapy in advanced epithelioid sarcoma.

BACKGROUND: Epithelioid sarcoma is a rare soft tissue sarcoma subtype. The response of this disease to chemotherapy is not well described. The aim of this study was to investigate the response rate and progression-free survival in a series of epithelioid sarcoma patients treated with chemotherapy at a single referral center. METHODS: A retrospective search of a prospectively maintained database was made to identify epithelioid sarcoma patients treated with chemotherapy between 1990 and 2009. Radiological response and histological diagnosis were re-reviewed for this study. RESULTS: Twenty-one epithelioid sarcoma patients treated with chemotherapy were identified; follow-up data on palliative chemotherapy was available on 20 of these patients. The median age was 36.5 years (range, 17.4 to 64.8 y) and the male/female ratio was 19:2. Ten patients (50%) were treated with single-agent anthracycline, 9 patients (45%) were treated with a combination therapy (anthracycline and ifosfamide), and 1 patient received trabectedin (5%). Three patients achieved a partial response, 12 had stable disease, and 5 progressed. The median progression-free survival was 29 weeks (95% confidence interval [CI]: 23-35). Seven and 3 patients received second-line and third-line palliative chemotherapy, respectively. The median overall survival from commencing palliative chemotherapy in our series was 51 weeks (95% confidence interval; 29-73). CONCLUSIONS: Systemic chemotherapy provides satisfactory palliation in patients with epithelioid sarcoma. However, this is an aggressive disease, responses to chemotherapy are of short duration and there is a need for more effective novel therapies in the treatment of this condition.

A patient presenting with a perivascular epithelioid cell tumor in the broad ligament: a case report.

INTRODUCTION: Perivascular epithelioid cell tumors are a family of rare mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells. They can originate in any visceral organ or soft tissue and include a range of lesions such as angiomyolipoma, clear cell 'sugar' tumor of the lung, lymphangioleiomyomatosis and clear cell myomelanocytic tumors of the falciparum ligament/ligament teres. Due to their rarity and varied sites and presentation, management of these tumors remains highly challenging. CASE PRESENTATION: A 46-year-old para 2 Caucasian woman initially presented to the general surgeons at our hospital in North West London with abdominal pain. Laparoscopy revealed a right broad ligament hematoma, which was thought to be iatrogenic in origin, from insertion of the Veress needle at the time of surgery, and was managed conservatively. Upon her re-presentation two months later with severe pain, ultrasound scanning revealed the hematoma had increased in size and she underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy. Histology results from necrotic tissue from the hematoma led to a diagnosis of perivascular epithelioid cell tumor. She was then referred to a tertiary oncology center, where she underwent several further operations in an attempt to debulk the tumor for symptomatic relief of her pain, with limited success. She is now taking the immunosuppressive drug sirolimus, which has produced a modest reduction in tumor size. She is now 47 months on from initial presentation. CONCLUSIONS: A literature search has revealed only six other case reports of broad ligament perivascular epithelioid cell tumors, with varied presentations and management. The longest duration of follow-up was 21 months. Only five other cases of perivascular epithelioid cell tumor managed with sirolimus have been reported. We therefore feel that this report highlights some of the difficulties in diagnosing perivascular epithelioid cell tumors, and sheds light on management strategies for a very rare gynecological tumor in addition to sharing our experience in the use of sirolimus in its treatment.

Targeting the Insulin-Like Growth Factor 1 Receptor in Ewing's Sarcoma: Reality and Expectations.

Ewing's sarcoma family of tumours comprises a group of very aggressive diseases that are potentially curable with multimodality treatment. Despite the undoubted success of current treatment, approximately 30% of patients will relapse and ultimately die of disease. The insulin-like growth factor 1 receptor (IGF-1R) has been implicated in the genesis, growth, proliferation, and the development of metastatic disease in Ewing's sarcoma. In addition, IGF1-R has been validated, both in vitro and in vivo, as a potential therapeutic target in Ewing's sarcoma. Phase I studies of IGF-1R monoclonal antibodies reported several radiological and clinical responses in Ewing's sarcoma patients, and initial reports of several Phase II studies suggest that about a fourth of the patients would benefit from IGF-1R monoclonal antibodies as single therapy, with approximately 10% of patients achieving objective responses. Furthermore, these therapies are well tolerated, and thus far severe toxicity has been rare. Other studies assessing IGF-1R monoclonal antibodies in combination with traditional cytotoxics or other targeted therapies are expected. Despite, the initial promising results, not all patients benefit from IGF-1R inhibition, and consequently, there is an urgent need for the identification of predictive markers of response.