ABSTRACT
Endoxifen, the primary active metabolite of tamoxifen, is currently being investigated as a novel endocrine therapy for the treatment of breast cancer. Tamoxifen is a selective estrogen receptor modulator that elicits potent anti-breast cancer effects. However, long-term use of tamoxifen also induces bone loss in premenopausal women and is associated with an increased risk of endometrial cancer in postmenopausal women. For these reasons, we have used a rat model system to comprehensively characterize the impact of endoxifen on the skeleton and uterus. Our results demonstrate that endoxifen elicits beneficial effects on bone in ovary-intact rats and protects against bone loss following ovariectomy. Endoxifen is also shown to reduce bone turnover in both ovary-intact and ovariectomized rats at the cellular and biochemical levels. With regard to the uterus, endoxifen decreased uterine weight but maintained luminal epithelial cell height in ovariectomized animals. Within luminal epithelial cells, endoxifen resulted in differential effects on the expression levels of estrogen receptors α and ß as well as multiple other genes previously implicated in regulating epithelial cell proliferation and hypertrophy. These studies analyze the impact of extended endoxifen exposure on both bone and uterus using a Food and Drug Administration-recommended animal model. Although endoxifen is a more potent breast cancer agent than tamoxifen, the results of the present study demonstrate that endoxifen does not induce bone loss in ovary-intact rats and that it elicits partial agonistic effects on the uterus and skeleton in ovariectomized animals.
Subject(s)
Bone Remodeling/drug effects , Bone and Bones/drug effects , Breast Neoplasms/drug therapy , Cell Proliferation/drug effects , Selective Estrogen Receptor Modulators/pharmacology , Tamoxifen/analogs & derivatives , Uterus/drug effects , Animals , Endometrium/drug effects , Endometrium/metabolism , Endometrium/pathology , Estrogen Receptor alpha/drug effects , Estrogen Receptor alpha/metabolism , Estrogen Receptor beta/drug effects , Estrogen Receptor beta/metabolism , Female , Organ Size , Osteoporosis/chemically induced , Ovariectomy , Rats , Selective Estrogen Receptor Modulators/adverse effects , Tamoxifen/adverse effects , Tamoxifen/pharmacology , Uterus/metabolism , Uterus/pathologyABSTRACT
Hereditary tyrosinemia type 1 (HT1) is an autosomal recessive disease caused by deficiency in fumarylacetoacetate hydrolase, the last enzyme in the tyrosine catabolic pathway. In this study, we investigated whether fumarylacetoacetate hydrolase deficient (FAH-/-) pigs, a novel large-animal model of HT1, develop fibrosis and cirrhosis characteristic of the human disease. FAH-/- pigs were treated with the protective drug 2-(2-nitro-4-trifluoromethylbenzoyl)-1, 3 cyclohexandione (NTBC) at a dose of 1 mg/kg per day initially after birth. After 30 days, they were assigned to one of three groups based on dosing of NTBC. Group 1 received ≥0.2 mg/kg per day, group 2 cycled on/off NTBC (0.05 mg/kg per day × 1 week/0 mg/kg per day × 3 weeks), and group 3 received no NTBC thereafter. Pigs were monitored for features of liver disease. Animals in group 1 continued to have weight gain and biochemical analyses comparable to wild-type pigs. Animals in group 2 had significant cessation of weight gain, abnormal biochemical test results, and various grades of fibrosis and cirrhosis. No evidence of hepatocellular carcinoma was detected. Group 3 animals declined rapidly, with acute liver failure. In conclusion, the FAH-/- pig is a large-animal model of HT1 with clinical characteristics that resemble the human phenotype. Under conditions of low-dose NTBC, FAH-/- pigs developed liver fibrosis and portal hypertension, and thus may serve as a large-animal model of chronic liver disease.
Subject(s)
Tyrosinemias/pathology , Animals , Chronic Disease , Disease Models, Animal , Elasticity Imaging Techniques , Female , Heptanoates/metabolism , Humans , Hydrolases/deficiency , Hydrolases/metabolism , Kidney/metabolism , Kidney/pathology , Liver/pathology , Liver/physiopathology , Liver Cirrhosis/pathology , Magnetic Resonance Spectroscopy , Male , Metabolic Networks and Pathways , Phenotype , Portal Pressure , Sus scrofa , Tyrosine/metabolism , Weight GainABSTRACT
We tested the hypothesis that ex vivo hepatocyte gene therapy can correct the metabolic disorder in fumarylacetoacetate hydrolase-deficient (Fah(-/-)) pigs, a large animal model of hereditary tyrosinemia type 1 (HT1). Recipient Fah(-/-) pigs underwent partial liver resection and hepatocyte isolation by collagenase digestion. Hepatocytes were transduced with one or both of the lentiviral vectors expressing the therapeutic Fah and the reporter sodium-iodide symporter (Nis) genes under control of the thyroxine-binding globulin promoter. Pigs received autologous transplants of hepatocytes by portal vein infusion. After transplantation, the protective drug 2-(2-nitro-4-trifluoromethylbenzyol)-1,3 cyclohexanedione (NTBC) was withheld from recipient pigs to provide a selective advantage for expansion of corrected FAH(+) cells. Proliferation of transplanted cells, assessed by both immunohistochemistry and noninvasive positron emission tomography imaging of NIS-labeled cells, demonstrated near-complete liver repopulation by gene-corrected cells. Tyrosine and succinylacetone levels improved to within normal range, demonstrating complete correction of tyrosine metabolism. In addition, repopulation of the Fah(-/-) liver with transplanted cells inhibited the onset of severe fibrosis, a characteristic of nontransplanted Fah(-/-) pigs. This study demonstrates correction of disease in a pig model of metabolic liver disease by ex vivo gene therapy. To date, ex vivo gene therapy has only been successful in small animal models. We conclude that further exploration of ex vivo hepatocyte genetic correction is warranted for clinical use.
Subject(s)
Genetic Therapy/methods , Liver/metabolism , Tyrosinemias/metabolism , Tyrosinemias/therapy , Animals , Cyclohexanones/pharmacology , Disease Models, Animal , Hepatocytes/drug effects , Hepatocytes/metabolism , Hydrolases/genetics , Hydrolases/metabolism , Immunohistochemistry , Nitrobenzoates/pharmacology , Swine , Transplantation, Homologous , Tyrosinemias/enzymology , Tyrosinemias/geneticsABSTRACT
BACKGROUND: Decellularized heart valves are emerging as a potential alternative to current bioprostheses for valve replacement. Whereas techniques of decellularization have been thoroughly examined, terminal sterilization techniques have not received the same scrutiny. METHODS: This study evaluated low-dose gamma irradiation as a sterilization method for decellularized heart valves. Incubation of valves and transmission electron microscopy evaluation after different doses of gamma irradiation were used to determine the optimal dose of gamma irradiation. Quantitative evaluation of mechanical properties was done by tensile mechanical testing of isolated cusps. Sterilized decellularized heart valves were tested in a sheep model (n = 3 [1 at 1,500 Gy and 2 at 3,000 Gy]) of pulmonary valve replacement. RESULTS: Valves sterilized with gamma radiation between 1,000 Gy and 3,000 Gy were found to be optimal with in vitro testing. However, in vivo testing showed deteriorating valve function within 2 months. On explant, the valve with 1,500 Gy gamma irradiation showed signs of endocarditis with neutrophils on hematoxylin and eosin staining, and positive gram stain resembling streptococcus infection. The 3,000 Gy valves had no evidence of infection, but the hematoxylin and eosin staining showed evidence of wound remodeling with macrophages and fibroblasts. Tensile strength testing showed decreased strength (0 Gy: 2.53 ± 0.98 MPa, 1,500 Gy: 2.03 ± 1.23 MPa, and 3,000 Gy: 1.26 ± 0.90 MPa) with increasing levels of irradiation. CONCLUSIONS: Low-dose gamma irradiation does not maintain the mechanical integrity of valves, and the balance between sterilization and damage may not be able to be achieved with gamma irradiation. Other methods of terminal sterilization must be pursued and evaluated.
Subject(s)
Bioprosthesis , Gamma Rays , Heart Valve Prosthesis , Heart Valves/injuries , Heart Valves/radiation effects , Sterilization/methods , Animals , Heart Valves/cytology , In Vitro Techniques , Radiation Dosage , Sheep , SwineABSTRACT
BACKGROUND AND AIMS: Direct injection of chemotherapy into the portal vein for treatment of liver metastases may increase hepatic tissue levels while decreasing systemic levels and toxicities. We aimed to evaluate EUS-guided portal injection chemotherapy (EPIC) by using drug-eluting microbeads or nanoparticles and compare it with systemic injection. METHODS: We conducted a comparative feasibility trial in the acute porcine model (24 anesthetized pigs). Pigs were treated with irinotecan, doxorubicin, or albumin-bound paclitaxel nanoparticles (n = 8/group). Within each group, pigs were treated with EPIC or a systemic intravenous injection of drug and saline solution into the portal vein (n = 4/treatment). Irinotecan or doxorubicin were loaded onto microbeads for EPIC treatment only. We examined drug levels in tissue (1 hour) and plasma (15 minutes). RESULTS: EUS-guided access and injection was successful in all animals. EPIC with irinotecan-loaded microbeads showed nearly double the hepatic concentration compared with systemic injection (6242 vs 3692 ng/g) and almost half the systemic levels. EPIC with doxorubicin-loaded microbeads showed a 5-fold increase in hepatic levels (35,450 vs 6930 ng/g) and a 30-fold decrease in cardiac levels (153 vs 4805 ng/g) compared with systemic administration (P < .05 for both). EPIC with albumin-bound paclitaxel nanoparticles increased hepatic concentrations by 60% and decreased systemic levels by 24% to 32%. CONCLUSIONS: EPIC holds promise as a new treatment for hepatic metastases.
Subject(s)
Antineoplastic Agents/administration & dosage , Endosonography/methods , Liver Neoplasms/drug therapy , Neoplasms, Experimental , Acute Disease , Animals , Feasibility Studies , Injections, Intravenous , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/secondary , Male , Microspheres , Portal Vein , SwineABSTRACT
OBJECTIVE: To develop an animal model for radiofrequency endometrial ablation (EA) and evaluate histopathologic outcomes of EA in New Zealand White (NZW) rabbits. STUDY DESIGN: A pilot study was conducted. A radiofrequency EA device was developed and a variety of EA settings were tested on euthanized NZW rabbits. An algorithm was developed to determine target EA parameters. Bilateral radiofrequency EA was performed via laparotomy using 5.2 mm, 6.1 mm, or 7.1 mm diameter x 100 mm bipolar probes on 10 live NZW rabbits. All rabbits were screened for endometrial cancer (EC). Rabbits were euthanized 3 weeks following EA, and histopathologic analysis of postablation hysterectomy specimens was performed. RESULTS: Bilateral radiofrequency EA was successful in rabbits that were candidates for the procedure, and uterine assessment was feasible in all rabbits. One case of EC was detected. Uterine anatomy was variable among rabbits. The optimal EA setting was 4.5 W/cm2 x 20 seconds, which provided consistent thermal destruction to the endometrium and inner myometrium as verified by histology. CONCLUSION: Use of a radiofrequency EA algorithm tailored to individual NZW rabbits produces consistent thermal destruction of the endometrium and inner myometrium. This animal model can be used to study the long-term consequences of EA and the association with EC.
Subject(s)
Disease Models, Animal , Endometrial Ablation Techniques/methods , Endometrial Neoplasms/surgery , Animals , Endometrial Neoplasms/pathology , Endometrium/pathology , Endometrium/surgery , Female , Pilot Projects , RabbitsABSTRACT
Obesity is on the rise in westernized countries, and visceral obesity in particular is associated with enhanced risk of developing metabolic disease and accelerated aging. Various dietary restriction regimens have been shown to extend healthy lifespan in a variety of species. However, identification of alternative approaches that could be more acceptable to humans is actively being pursued. We have shown previously that mice deficient in pregnancy-associated plasma protein-A (PAPP-A) have an extended healthy lifespan on a regular chow diet. In this study, we determined the lifespan of PAPP-A knock-out (KO) and wild-type (WT) littermates fed a high fat diet (HFD) starting at 12 months of age. PAPP-A KO and WT mice had equivalent weight gain as measured over 25 weeks on HFD. However, PAPP-A KO mice on HFD had a significant increase in lifespan (P=0.018). Body composition and tissue pathology were assessed in a separate cohort of mice after 30 weeks on HFD. Percent body fat was equivalent in the two groups. However, there was a decrease in visceral fat depot weights and an increase in serum adiponectin levels in PAPP-A KO compared to WT mice. Major pathological differences were seen in kidney, heart and testes, with PAPP-A KO mice having little, if any, evidence of inflammation, mineralization, or degeneration in these tissues compared to WT mice. Thus, PAPP-A is a novel drug target with the potential to promote healthy longevity without a need for dietary restriction.
Subject(s)
Diet, High-Fat/adverse effects , Pregnancy-Associated Plasma Protein-A/deficiency , Adipose Tissue/pathology , Aging/pathology , Animals , Body Composition/physiology , Disease Models, Animal , Heart Diseases/etiology , Heart Diseases/pathology , Intra-Abdominal Fat/pathology , Kidney Diseases/etiology , Kidney Diseases/pathology , Longevity/physiology , Male , Mice, Knockout , Organ Size/physiology , Pregnancy-Associated Plasma Protein-A/genetics , Pregnancy-Associated Plasma Protein-A/physiology , Survival Analysis , Testicular Diseases/etiology , Testicular Diseases/pathology , Weight Gain/physiologyABSTRACT
BACKGROUND: GI perforations occur rarely during endoscopy but have life-threatening implications. OBJECTIVE: To evaluate endoscopic band ligation (EBL) for closure of acute GI perforations by using a porcine model. DESIGN: Investigator-initiated interventional pilot study by using an in vivo porcine model. SETTING: Tertiary-care institution. SUBJECTS: Ten domestic pigs. INTERVENTION: Each animal underwent a single endoscopic procedure, with creation of a single GI lumen perforation. Perforations of 10 to 20 mm were created in the esophagus, stomach, duodenum, and colon. EBL was used for closure. Fourteen days later, the pigs were killed, microbial cultures were obtained, and histologic review was done. MAIN OUTCOME MEASUREMENTS: Immediate and delayed endoscopic closure of the perforation site, evidence of clinical peritonitis during the 14-day follow-up. RESULTS: Ten pigs completed the protocol and survived without clinical peritonitis during the 14-day follow-up. Endoscopic closure of a 15-mm esophageal perforation failed, thus, no attempt was made to close a 20-mm esophageal perforation. Closure of all other perforations was successful. At necropsy, fibrinous peritonitis was suspected in one animal with a 10-mm duodenal perforation. Chronic inflammation and fibroplasia at the perforation sites were the most common histologic findings. LIMITATIONS: The applicability of widespread use in humans remains unknown despite successful case reports in the medical literature. CONCLUSION: EBL can be used successfully to close 10 to 20 mm perforations within normal stomach, duodenum, and colon and can prevent clinically relevant intra-abdominal infections. However, for esophageal perforations, closure may be limited to small (≤10 mm), iatrogenic perforations.
Subject(s)
Endoscopy, Gastrointestinal/methods , Esophageal Perforation/surgery , Intestinal Perforation/surgery , Animals , Colonic Diseases/surgery , Disease Models, Animal , Duodenal Diseases/surgery , Esophageal Perforation/physiopathology , Intestinal Perforation/physiopathology , Ligation/methods , Minimally Invasive Surgical Procedures/methods , Pilot Projects , Sensitivity and Specificity , Sus scrofa , Video RecordingABSTRACT
Hereditary tyrosinemia type I (HT1) is caused by deficiency in fumarylacetoacetate hydrolase (FAH), an enzyme that catalyzes the last step of tyrosine metabolism. The most severe form of the disease presents acutely during infancy, and is characterized by severe liver involvement, most commonly resulting in death if untreated. Generation of FAH(+/-) pigs was previously accomplished by adeno-associated virus-mediated gene knockout in fibroblasts and somatic cell nuclear transfer. Subsequently, these animals were outbred and crossed to produce the first FAH(-/-) pigs. FAH-deficiency produced a lethal defect in utero that was corrected by administration of 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3 cyclohexanedione (NTBC) throughout pregnancy. Animals on NTBC were phenotypically normal at birth; however, the animals were euthanized approximately four weeks after withdrawal of NTBC due to clinical decline and physical examination findings of severe liver injury and encephalopathy consistent with acute liver failure. Biochemical and histological analyses, characterized by diffuse and severe hepatocellular damage, confirmed the diagnosis of severe liver injury. FAH(-/-) pigs provide the first genetically engineered large animal model of a metabolic liver disorder. Future applications of FAH(-/-) pigs include discovery research as a large animal model of HT1 and spontaneous acute liver failure, and preclinical testing of the efficacy of liver cell therapies, including transplantation of hepatocytes, liver stem cells, and pluripotent stem cell-derived hepatocytes.
Subject(s)
Hydrolases/deficiency , Liver Diseases/enzymology , Tyrosinemias/enzymology , Animals , Disease Models, Animal , Female , Gene Knockout Techniques , Genotype , Liver Diseases/metabolism , Male , Pregnancy , SwineABSTRACT
The role of GLI1 in pancreatic tumor initiation promoting the progression of preneoplastic lesions into tumors is well established. However, its function at later stages of pancreatic carcinogenesis remains poorly understood. To address this issue, we crossed the gli1 knock-out (GKO) animal with cre-dependent pancreatic activation of oncogenic kras concomitant with loss of the tumor suppressor tp53 (KPC). Interestingly, in this model, GLI1 played a tumor-protective function, where survival of GKO/KPC mice was reduced compared with KPC littermates. Both cohorts developed pancreatic cancer without significant histopathological differences in survival studies. However, analysis of mice using ultrasound-based imaging at earlier time points showed increased tumor burden in GKO/KPC mice. These animals have larger tumors, decreased body weight, increased lactate dehydrogenase production, and severe leukopenia. In vivo and in vitro expression studies identified FAS and FAS ligand (FASL) as potential mediators of this phenomenon. The FAS/FASL axis, an apoptotic inducer, plays a role in the progression of pancreatic cancer, where its expression is usually lost or significantly reduced in advanced stages of the disease. Chromatin immunoprecipitation and reporter assays identified FAS and FASL as direct targets of GLI1, whereas GKO/KPC mice showed lower levels of this ligand compared with KPC animals. Finally, decreased levels of apoptosis were detected in tumor tissue in the absence of GLI1 by TUNEL staining. Together, these findings define a novel pathway regulated by GLI1 controlling pancreatic tumor progression and provide a new theoretical framework to help with the design and analysis of trials targeting GLI1-related pathways.
Subject(s)
Kruppel-Like Transcription Factors/antagonists & inhibitors , Pancreatic Neoplasms/pathology , Animals , Disease Progression , Humans , Mice , Mice, Knockout , Zinc Finger Protein GLI1ABSTRACT
We investigated pregnancy-associated plasma protein-A (PAPP-A) in diabetic nephropathy. Normal human kidney showed specific staining for PAPP-A in glomeruli, and this staining was markedly increased in diabetic kidney. To assess the possible contribution of PAPP-A in the development of diabetic nephropathy, we induced diabetes with streptozotocin in 14-month-old WT and Papp-A knockout (KO) mice. Renal histopathology was evaluated after 4 months of stable hyperglycemia. Kidneys from diabetic WT mice showed multiple abnormalities including thickening of Bowman's capsule (100% of mice), increased glomerular size (80% of mice), tubule dilation (80% of mice), and mononuclear cell infiltration (90% of mice). Kidneys of age-matched non-diabetic WT mice had similar evidence of tubule dilation and mononuclear cell infiltration to those of diabetic WT mice, indicating that these changes were predominantly age-related. However, thickened Bowman's capsule and increased glomerular size appeared specific for the experimental diabetes. Kidneys from diabetic Papp-A KO mice had significantly reduced or no evidence of changes in Bowman's capsule thickening and glomerular size. There was also a shift to larger mesangial area and increased macrophage staining in diabetic WT mice compared with Papp-A KO mice. In summary, elevated PAPP-A expression in glomeruli is associated with diabetic nephropathy in humans and absence of PAPP-A is associated with resistance to the development of indicators of diabetic nephropathy in mice. These data suggest PAPP-A as a potential therapeutic target for diabetic nephropathy.
Subject(s)
Diabetic Nephropathies/pathology , Kidney/pathology , Pregnancy-Associated Plasma Protein-A/deficiency , Aging/pathology , Animals , Bowman Capsule/pathology , Diabetes Mellitus, Experimental/pathology , Diabetic Nephropathies/etiology , Diabetic Nephropathies/physiopathology , Female , Glomerular Mesangium/pathology , Humans , Kidney Glomerulus/metabolism , Kidney Glomerulus/pathology , Mice , Mice, Knockout , PregnancyABSTRACT
PURPOSE: MUC1 is a tumor-associated antigen that is aberrantly expressed in cancer and inflammatory bowel disease (IBD). Even though immune cells express low MUC1 levels, their modulations of MUC1 are important in tumor progression. Consistent with previous clinical data that show increased myeloid-derived suppressor cells (MDSCs) in IBD, we now show that downregulation of MUC1 on hematopoietic cells increases MDSCs in IBD, similar to our data in tumor-bearing mice. We hypothesize that MDSC expansion in IBD is critical for tumor progression. EXPERIMENTAL DESIGN: To mechanistically confirm the linkage between Muc1 downregulation and MDSC expansion, we generated chimeric mice that did not express Muc1 in the hematopoietic compartment (KOâWT). These mice were used in two models of colitis and colitis-associated cancer (CAC) and their responses were compared with wild-type (WT) chimeras (WTâWT). RESULTS: KOâWT mice show increased levels of MDSCs during colitis and increased protumorigenic signaling in the colon during CAC, resulting in larger colon tumors. RNA and protein analysis show increased upregulation of metalloproteinases, collagenases, defensins, complements, growth factors, cytokines, and chemokines in KOâWT mice as compared with WTâWT mice. Antibody-mediated depletion of MDSCs in mice during colitis reduced colon tumor formation during CAC. CONCLUSION: Development of CAC is a serious complication of colitis and our data highlight MDSCs as a targetable link between inflammation and cancer. In addition, the lack of MUC1 expression on MDSCs can be a novel marker for MDSCs, given that MDSCs are still not well characterized in human cancers.
Subject(s)
Colitis, Ulcerative/complications , Colonic Neoplasms/etiology , Crohn Disease/pathology , Mucin-1/physiology , Myeloid Cells/pathology , Animals , Azoxymethane/toxicity , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Blotting, Western , Bone Marrow Transplantation , Carcinogens/toxicity , Colitis, Ulcerative/chemically induced , Colitis, Ulcerative/metabolism , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , Crohn Disease/genetics , Crohn Disease/metabolism , Female , Flow Cytometry , Gene Expression Profiling , Humans , Immunoenzyme Techniques , Mice , Mice, Knockout , Myeloid Cells/metabolism , Oligonucleotide Array Sequence Analysis , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
Although the biological role of KRAS is clearly established in carcinogenesis, the molecular mechanisms underlying this phenomenon are not completely understood. In this study, we provide evidence of a novel signaling network regulated by the transcription factor GLI1 mediating KRAS-induced carcinogenesis. Using pancreatic cancer (a disease with high prevalence of KRAS mutations) as a model, we show that loss of GLI1 blocks the progression of KRAS-induced pancreatic preneoplastic lesions in mice with pancreas-specific Cre-activated oncogenic mutant kras. Mice lacking GLI1 develop only low-grade lesions at low frequency, and in most cases, the pancreata are histologically normal. Further characterization of the phenotype showed a decrease in the activation of STAT3 in pancreatic preneoplastic lesions; STAT3 is a transcription factor required for the development of premalignant lesions and their progression into pancreatic cancer. Analysis of the mechanisms revealed a key role for GLI1 in maintaining the levels of activated STAT3 through the modulation of IL-6 signaling. GLI1 binds to the IL-6 mouse promoter and regulates the activity and expression of this cytokine. This newly identified GLI1/IL-6 axis is active in fibroblasts, a known source of IL-6 in the tumor microenvironment. Sonic hedgehog induces GLI1 binding to the IL-6 promoter and increases IL-6 expression in fibroblasts in a paracrine manner. Finally, we demonstrate that mutant KRAS initiates this cascade by inducing the expression of Sonic hedgehog in cancer cells. Collectively, these results define a novel role for GLI1 in carcinogenesis acting as a downstream effector of oncogenic KRAS in the tumor microenvironment.
Subject(s)
Cell Transformation, Neoplastic/metabolism , Gene Expression Regulation, Neoplastic , Kruppel-Like Transcription Factors/metabolism , Pancreatic Neoplasms/metabolism , Proto-Oncogene Proteins p21(ras)/biosynthesis , Tumor Microenvironment , Animals , Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/pathology , Fibroblasts/metabolism , Fibroblasts/pathology , Hedgehog Proteins/genetics , Hedgehog Proteins/metabolism , Interleukin-6/biosynthesis , Interleukin-6/genetics , Kruppel-Like Transcription Factors/genetics , Mice , Mice, Knockout , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Proto-Oncogene Proteins p21(ras)/genetics , STAT3 Transcription Factor/genetics , STAT3 Transcription Factor/metabolism , Zinc Finger Protein GLI1ABSTRACT
Myocardial reperfusion following ischemia may paradoxically cause additional injury, including microvascular damage and edema. These structural alterations augment tissue echogenicity, which is measurable by ultrasonic integrated backscatter (IB). We sought to characterize alterations in myocardial IB in an ischemic and reperfused region of the rat heart. Myocardial IB of the regions of interest in 12 adult male Sprague-Dawley rats was studied at baseline, during ischemia, and chronologically after coronary reopening, using an ultrasound frequency of 8 MHz. IB did not significantly change between baseline and ischemia. However, within 1 min of reperfusion, IB significantly increased and continued to increase until 10 min of reperfusion, when a plateau was reached. Areas of high echogenicity were comparable to infarcted areas on gross pathologic slices and had edema with extravasation of red blood cells. Myocardial reperfusion following ischemia significantly augments tissue echogenicity. A continuing increase of IB suggests a rapid progression of reperfusion injury.
Subject(s)
Myocardial Ischemia/diagnostic imaging , Myocardial Reperfusion , Animals , Disease Models, Animal , Male , Rats , Rats, Sprague-Dawley , Reproducibility of Results , UltrasonographyABSTRACT
The pregnancy-associated plasma protein-A knockout (PAPP-A KO) mouse is a model of reduced local insulin-like growth factor (IGF)-I activity with normal circulating IGF-I levels. In this study, PAPP-A KO mice had significantly increased mean (27%), median (27%), and maximum (35%) life span compared with wild-type (WT) littermates. End-of-life pathology indicated that the incidence of neoplastic disease was not significantly different in the two groups of mice; however, it occurred in older aged PAPP-A KO compared with WT mice. Furthermore, PAPP-A KO mice were less likely to show degenerative changes of age. Scheduled pathologies at 78, 104, and 130 weeks of age indicated that WT mice, in general, had more degenerative changes and tumors earlier than PAPP-A KO mice. This was particularly true for abnormalities in heart, testes, brain, kidney, spleen, and thymus. In summary, the major contributors to the extended life span of PAPP-A KO mice are delayed occurrence of fatal neoplasias and decreased incidence of age-related degenerative changes.
Subject(s)
Age Distribution , Aging/metabolism , Disease/etiology , Longevity , Neoplasms/epidemiology , Pregnancy-Associated Plasma Protein-A/deficiency , Animals , Female , Incidence , Insulin-Like Growth Factor I/metabolism , Kaplan-Meier Estimate , Male , Mice , Mice, Inbred Strains , Mice, KnockoutABSTRACT
PURPOSE: The purpose of this study was to assess whether alemtuzamab, a large antibody of 150 kDa, would be able to penetrate through the full-thickness retina of Dutch-belted rabbits. METHODS: Four Dutch-belted rabbits had intravitreal injections of alemtuzumab (1.5 mg in 0.05 mL). One rabbit each was killed at Day 1, Day 8, Day 15, and Day 29. The eyes were examined under frozen section and graded by immunostaining techniques for the degree of penetration of alemtuzumab into the retina. The degree of retinal staining was graded from 0 (no stain) to 4+ (marked stain). RESULTS: All study eyes showed antibody staining of the full-thickness retina as follows: 4+ at Day 1, 4+ at Day 8, 3+ at Day 15, and 2+ at Day 29. CONCLUSION: A 1.5-mg intravitreal dose of alemtuzumab was able to penetrate full-thickness retina throughout the full 29-day course of the study. Retinal toxicity studies are required before clinical use.
Subject(s)
Antibodies, Monoclonal/pharmacokinetics , Antineoplastic Agents/pharmacokinetics , Retina/metabolism , Alemtuzumab , Animals , Antibodies, Monoclonal, Humanized , Antibodies, Neoplasm , Biological Transport , Immunoenzyme Techniques , Injections , Male , Rabbits , Vitreous BodySubject(s)
Granuloma, Pyogenic/veterinary , Histoplasma/isolation & purification , Histoplasmosis/veterinary , Monkey Diseases/pathology , Papio , Amputation, Surgical/veterinary , Animals , Dermatitis/pathology , Dermatitis/veterinary , Diagnosis, Differential , Female , Granuloma, Pyogenic/pathology , Granuloma, Pyogenic/surgery , Histoplasmosis/pathology , Histoplasmosis/surgery , Monkey Diseases/surgeryABSTRACT
Lymphocyte differentiation from naive CD4(+) T cells into mature Th1, Th2, Th17, or T regulatory cell (Treg) phenotypes has been considered end stage in character. In this study, we demonstrate that dendritic cells (DCs) activated with a novel immune modulator B7-DC XAb (DC(XAb)) can reprogram Tregs into T effector cells. Down-regulation of FoxP3 expression after either in vitro or in vivo Treg-DC(XAb) interaction is Ag-specific, IL-6-dependent, and results in the functional reprogramming of the mature T cell phenotype. The reprogrammed Tregs cease to express IL-10 and TGFbeta, fail to suppress T cell responses, and gain the ability to produce IFN-gamma, IL-17, and TNF-alpha. The ability of IL-6(+) DC(XAb) and the inability of IL-6(-/-) DC(XAb) vaccines to protect animals from lethal melanoma suggest that exogenously modulated DC can reprogram host Tregs. In support of this hypothesis and as a test for Ag specificity, transfer of DC(XAb) into RIP-OVA mice causes a break in immune tolerance, inducing diabetes. Conversely, adoptive transfer of reprogrammed Tregs but not similarly treated CD25(-) T cells into naive RIP-OVA mice is also sufficient to cause autoimmune diabetes. Yet, treatment of normal mice with B7-DC XAb fails to elicit generalized autoimmunity. The finding that mature Tregs can be reprogrammed into competent effector cells provides new insights into the plasticity of T cell lineage, underscores the importance of DC-T cell interaction in balancing immunity with tolerance, points to Tregs as a reservoir of autoimmune effectors, and defines a new approach for breaking tolerance to self Ags as a strategy for cancer immunotherapy.
Subject(s)
Antibodies/pharmacology , Autoimmunity/drug effects , B7-1 Antigen/immunology , Forkhead Transcription Factors , Interleukin-17/biosynthesis , T-Lymphocytes, Regulatory/cytology , Animals , Cell Communication/immunology , Cytokines/biosynthesis , Dendritic Cells/immunology , Immune Tolerance , Mice , Multiple Myeloma/therapy , Programmed Cell Death 1 Ligand 2 Protein , T-Cell Antigen Receptor Specificity , T-Lymphocytes, Regulatory/immunology , VaccinesABSTRACT
Mice in a colony used for pancreatic cancer research and maintained in a barrier animal facility presented with vulvar masses. A census and examination of all colony animals was conducted on 17 February 2006; line, gender, and mass location were recorded; a slide caliper was used to measure the width, length, and height of each mass; and the volume of each mass was calculated. Progeny female mice from crossbreeding of the B6.FVB-Tg(Ipf1-cre)1Tuv and B6;129-Kras2tm4Tyj (KRAS(G12D/+)) strains presented with external vulvar and periauricular papillomas. The papillomas were present in 41.2% of all female crossbred mice and ranged in size from 8 to 36 mm3. Age of mice and tumor size were not correlated. Compared with the B6.FVB-Tg(Ipf1-cre)1Tuv line, the crossbred female mice were more likely to have a vulvar mass, with an odds ratio of 29.3, 95% confidence interval (1.5, 563.9) and a positive predictive value of 42.9%. Diagnostic evaluation, including electron microscopy, light microscopy, serology, and bacteriology, did not reveal a viral or other infectious etiology. Therefore, we speculate that interaction between the genetic background of the mice and the introduced Kras oncogene may be responsible for these papillomas.