Development and validation of an AI-enabled digital breast cancer assay to predict early-stage breast cancer recurrence within 6 years.

BACKGROUND: Breast cancer (BC) grading plays a critical role in patient management despite the considerable inter- and intra-observer variability, highlighting the need for decision support tools to improve reproducibility and prognostic accuracy for use in clinical practice. The objective was to evaluate the ability of a digital artificial intelligence (AI) assay (PDxBr) to enrich BC grading and improve risk categorization for predicting recurrence. METHODS: In our population-based longitudinal clinical development and validation study, we enrolled 2075 patients from Mount Sinai Hospital with infiltrating ductal carcinoma of the breast. With 3:1 balanced training and validation cohorts, patients were retrospectively followed for a median of 6 years. The main outcome was to validate an automated BC phenotyping system combined with clinical features to produce a binomial risk score predicting BC recurrence at diagnosis. RESULTS: The PDxBr training model (n = 1559 patients) had a C-index of 0.78 (95% CI, 0.76-0.81) versus clinical 0.71 (95% CI, 0.67-0.74) and image feature models 0.72 (95% CI, 0.70-0.74). A risk score of 58 (scale 0-100) stratified patients as low or high risk, hazard ratio (HR) 5.5 (95% CI 4.19-7.2, p < 0.001), with a sensitivity 0.71, specificity 0.77, NPV 0.95, and PPV 0.32 for predicting BC recurrence within 6 years. In the validation cohort (n = 516), the C-index was 0.75 (95% CI, 0.72-0.79) versus clinical 0.71 (95% CI 0.66-0.75) versus image feature models 0.67 (95% CI, 0.63-071). The validation cohort had an HR of 4.4 (95% CI 2.7-7.1, p < 0.001), sensitivity of 0.60, specificity 0.77, NPV 0.94, and PPV 0.24 for predicting BC recurrence within 6 years. PDxBr also improved Oncotype Recurrence Score (RS) performance: RS 31 cutoff, C-index of 0.36 (95% CI 0.26-0.45), sensitivity 37%, specificity 48%, HR 0.48, p = 0.04 versus Oncotype RS plus AI-grade C-index 0.72 (95% CI 0.67-0.79), sensitivity 78%, specificity 49%, HR 4.6, p < 0.001 versus Oncotype RS plus PDxBr, C-index 0.76 (95% CI 0.70-0.82), sensitivity 67%, specificity 80%, HR 6.1, p < 0.001. CONCLUSIONS: PDxBr is a digital BC test combining automated AI-BC prognostic grade with clinical-pathologic features to predict the risk of early-stage BC recurrence. With future validation studies, we anticipate the PDxBr model will enrich current gene expression assays and enhance treatment decision-making.

L-arginine improves endothelial function, independently of arginine uptake, in aortas from chronic renal failure female rats.

Endothelial cell dysfunction (ECD) is a common feature of chronic renal failure (CRF). Defective nitric oxide (NO) generation due to decreased endothelial nitric oxide synthase (eNOS) activity is a crucial parameter characterizing ECD. Decreased activity of cationic amino acid transporter-1 (CAT-1), the selective arginine transporter of eNOS, has been shown to inhibit eNOS in uremia. Recently, we failed to demonstrate a decrease in glomerular arginine transport in uremic female rats (Schwartz IF, Grupper A, Soetendorp H, Hillel O, Laron I, Chernichovski T, Ingbir M, Shtabski A, Weinstein T, Chernin G, Shashar M, Hershkoviz R, Schwartz D. Am J Physiol Renal Physiol 303: F396-F404, 2012). The current experiments were designed to determine whether sexual dimorphism which characterizes glomerular arginine transport system in uremia involves the systemic vasculature as well and to assess the effect of L-arginine in such conditions. Contractile and vasodilatory responses, ultrastructural changes, and measures of the L-arginine-NO system were performed in thoracic aortas of female rats subjected to 5/6 nephrectomy. The contractile response to KCl was significantly reduced, and acetylcholine-induced vasodilation was significantly impaired in aortas from CRF dames compared with healthy rats. Both of these findings were prevented by the administration of arginine in the drinking water. The decrease in both cGMP generation, a measure of eNOS activity, and aortic eNOS and phosphorylated eNOS abundance observed in CRF rats was completely abolished by l-arginine, while arginine transport and CAT-1 protein were unchanged in all experimental groups. Arginine decreased both serum levels of advanced glycation end products and the asymmetrical dimethylarginine/arginine ratio and restored the endothelial ultrastructure in CRF rats. In conclusion. arginine administration has a profound beneficial effect on ECD, independently of cellular arginine uptake, in CRF female rats.

Analytical Validation of the PreciseDx Digital Prognostic Breast Cancer Test in Early-Stage Breast Cancer.

BACKGROUND: PreciseDx Breast (PDxBr) is a digital test that predicts early-stage breast cancer recurrence within 6-years of diagnosis. MATERIALS AND METHODS: Using hematoxylin and eosin-stained whole slide images of invasive breast cancer (IBC) and artificial intelligence-enabled morphology feature array, microanatomic features are generated. Morphometric attributes in combination with patient's age, tumor size, stage, and lymph node status predict disease free survival using a proprietary algorithm. Here, analytical validation of the automated annotation process and extracted histologic digital features of the PDxBr test, including impact of methodologic variability on the composite risk score is presented. Studies of precision, repeatability, reproducibility and interference were performed on morphology feature array-derived features. The final risk score was assessed over 20-days with 2-operators, 2-runs/day, and 2-replicates across 8-patients, allowing for calculation of within-run repeatability, between-run and within-laboratory reproducibility. RESULTS: Analytical validation of features derived from whole slide images demonstrated a high degree of precision for tumor segmentation (0.98, 0.98), lymphocyte detection (0.91, 0.93), and mitotic figures (0.85, 0.84). Correlation of variation of the assay risk score for both reproducibility and repeatability were less than 2%, and interference from variation in hematoxylin and eosin staining or tumor thickness was not observed demonstrating assay robustness across standard histopathology preparations. CONCLUSION: In summary, the analytical validation of the digital IBC risk assessment test demonstrated a strong performance across all features in the model and complimented the clinical validation of the assay previously shown to accurately predict recurrence within 6-years in early-stage invasive breast cancer patients.

Embryonic porcine liver as a source for transplantation: advantage of intact liver implants over isolated hepatoblasts in overcoming homeostatic inhibition by the quiescent host liver.

Cell therapy as an alternative to orthotopic liver transplantation represents a major challenge, since negligible proliferation of isolated hepatocytes occurs after transplantation because of the stringent homeostatic control displayed by the host liver. Thus, different modalities of liver injury as part of the pretransplant conditioning are a prerequisite for this approach. The major objective of the present study was to test whether xenotransplantation of pig fetal liver fragments, in which potential cell-cell and cell-stroma interactions are spared, might afford more robust growth and proliferation compared with isolated pig fetal hepatoblasts. After transplantation into SCID mice, fetal liver tissue fragments exhibited marked growth and proliferation, in the setting of a quiescent host liver, compared with isolated fetal hepatoblasts harvested at the same gestational age (embryonic day 28). The proliferative advantage of fetal pig liver fragments was clearly demonstrated by immunohistochemical and morphometric assays and was observed not only after implantation into the liver but also into extrahepatic sites, such as the spleen and the subrenal capsule. The presence of all types of nonparenchymal liver cells that is crucial for normal liver development and regeneration was demonstrated in the implants. Preservation of the three-dimensional structure in pig fetal liver fragments enables autonomous proliferation of transplanted hepatic cells in the setting of a quiescent host liver, without any requirement for liver injury in the pretransplant conditioning. The marked proliferation and functional maturation exhibited by the pig fetal liver fragments suggests that it could afford a preferable source for transplantation.

Laser-induced hyperthermia for treatment of granulation tissue growth in rats.

OBJECTIVE: We aimed to develop a new technique for treatment of granulation tissue (GT) growth using local hyperthermia. METHODS: A temperature-controlled diode laser system was developed for induction of mild hyperthermia in real time. GT was generated by harvesting the skin over the gluteal fascia in rats. Histopathological analysis was used to estimate the effect of hyperthermia on the tissue. RESULTS: In untreated rats, GT was detected within 3 days and reached maximal thickness after 12 days. Hyperthermia at 43 degrees C and above significantly decreased GT thickness (n = 8 per group). Hyperthermia at 48 degrees C for 3 minutes was the most efficient parameter for treatment of GT (51% reduction), with minimal (5%) muscle necrosis. CONCLUSIONS: Hyperthermia can significantly inhibit GT growth, with minimal damage to surrounding structures. Our findings suggest a possible role for hyperthermia as a therapeutic model against GT. Further research and long-term studies are needed to explore the utility of laser-induced hyperthermia for inhibition of GT growth.

Indeterminate nodules by the Bethesda system for reporting thyroid cytopathology in Israel: Frequency, and risk of malignancy after reclassification of follicular thyroid neoplasm with papillary-like features.

OBJECTIVE: We aimed to determine the frequency and risk of malignancy (ROM) for indeterminate thyroid nodules, categories III (B3) and IV (B4) of the Bethesda System for Reporting Thyroid Cytopathology (BSRTC), at a large institution in Israel. Additionally, we investigated the impact of redefining follicular neoplasm with papillary-like nuclear features (NIFTP) as non-malignant on malignancy rates. METHODS: In this retrospective study of all thyroid fine needle aspirations (FNAs) performed at Tel Aviv-Sourasky Medical Center between January 2013 and December 2015, we assessed ROM for B3 and B4 nodules. Potential risk factors thought to affect a-priori ROM were assessed. Suspected NIFTP lesions were re-examined, and if proven, reclassified as benign. RESULTS: 3701 nodules were sampled in 2919 FNAs performed on 2674 patients. B3 reports comprised 7.7% of all nodules (n = 284); B4 represented 3.6% (n = 132). In multivariate logistic regression, male gender, being of former Soviet Union origin, and smoking increased ROM for B3 nodules by a factor of 7.97 (P = 0.002; CI: 2.2-23.4), 9.15 (P = 0.021; CI:1.4-60.0), and 11.0 (P = 0.001; CI 2.8-44.8), respectively. Reclassifying NIFTP decreased ROM from 14% to 12.5% for B3, and from 26.7% to 25% for B4 nodules. NIFTP comprised 9.5% of previously diagnosed resected malignant tumors. CONCLUSIONS: The relative frequencies of B3 and B4 nodules and their associated malignancy rates were consistent with previous series. Risk factors identified for malignancy may help characterize patients most likely to benefit from surgery. Reclassifying NIFTP had a substantial impact on the ROM in the resected tumors previously diagnosed as malignant.

A novel assessment of the quality of immunohistostaining overcomes the limitations of current methods.

Quality assurance has become an integral part of surgical pathology. Despite the development of interdisciplinary quality systems, however, the means for objective analysis in surgical pathology are limited. Immunohistostaining is a multi-factorial procedure that depends on the quality of reagents and antibodies employed in the process and on technical methodology. In the present study, we aim to establish a straightforward procedure for objective quality evaluation of the components involved in immunohistostaining. The quality of two of these components, the primary antibody and the automated staining device, was assessed by employing each component from two different sources, one serving as the test substance and the second as the reference. Assessment was performed by at least two pathologists in a blinded fashion using pre-established quality criteria and scores. The quality analysis of two automated devices revealed a significant difference between the reference and tested devices (3.5+/-1.7 and 4.2+/-1.5, respectively, P>0.05), while the analysis of two selected antibodies did not reveal any statistical difference. The described method provided objective quality assessment of selected components affecting immunohistostaining by elaborating numeric values that enabled statistical analysis. This approach is applicable to any given component in various surgical pathology procedures.

A Novel Urine-Based Assay for Bladder Cancer Diagnosis: Multi-Institutional Validation Study.

BACKGROUND: CellDetect is a unique histochemical stain enabling color and morphological discrimination between malignant and benign cells based on differences in metabolic signature. OBJECTIVE: The objective of the present study was to validate the performance of this assay in a controlled, blinded, multicenter study. DESIGN, SETTING, AND PARTICIPANTS: The study, conducted in nine hospitals, included patients with documented history of bladder cancer, monitored for urothelial carcinoma (UCC) or scheduled for bladder cancer surgery. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Cystoscopy and/or biopsy were used as a reference standard to determine sensitivity and specificity. Smears were stained by CellDetect and interpreted by two cytologists blinded to the patient's final diagnosis. The findings were compared with those of standard urine cytology and BTA stat. RESULTS AND LIMITATIONS: Two hundred and seventeen voided urine specimens were included. Ninety-six (44%) were positive by histology and 121 (56%) were negative by either cystoscopy or histology. The overall sensitivity of CellDetect was 84%. Notably, the sensitivity for detecting low-grade nonmuscle-invasive bladder cancer tumors was greater than this of BTA stat (78% vs 54%) and more than two-fold higher compared with standard cytology (33%, p ≤ 0.05). The specificity was 84% in patients undergoing routine surveillance by cystoscopy. At a median follow-up of 9 mo, 21% of the patients with positive CellDetect and negative reference standard developed UCC, which was significantly higher compared with the 5% of the true negative cases. Limitations include the lack of instrumental urine samples and the lack of patients with nongenitourinary cancers in the study population. CONCLUSIONS: This study validates the performance of CellDetect as a urine-based assay to identify UCC in patients with history of bladder cancer. The high sensitivity was maintained across all cancer grades and stages without compromising the assay specificity. Further studies are required to test whether this novel stain can be incorporated in routine bladder cancer surveillance as a noninvasive alternative to cystoscopy. PATIENT SUMMARY: Surveillance of bladder cancer requires frequent invasive procedures. In the present study, we validate the ability of a novel biomarker to accurately identify early-stage tumors in urine specimens for the noninvasive monitoring of patients with history of bladder cancer.

Combined acetyl-11-keto-ß-boswellic acid and radiation treatment inhibited glioblastoma tumor cells.

Glioblastoma multiforme (GBM) is the most common and most aggressive subtype of malignant gliomas. The current standard of care for newly diagnosed GBM patients involves maximal surgical debulking, followed by radiation therapy and temozolomide chemotherapy. Despite the advances in GBM therapy, its outcome remains poor with a median survival of less than two years. This poor outcome is partly due to the ability of GBM tumors to acquire adaptive resistance to therapy and in particular to radiation. One of the mechanisms contributing to GBM tumor progression and resistance is an aberrant activation of NF-ĸB, a family of inducible transcription factors that play a pivotal role in regulation of many immune, inflammatory and carcinogenic responses. Acetyl-11-keto-ß-boswellic acid (AKBA) is a pentacyclic terpenoid extracted from the gum Ayurvedic therapeutic plant Boswellia serrata. AKBA is anti-inflammatory agent that exhibits potent cytotoxic activities against various types of tumors including GBM. One of the mechanisms underlying AKBA anti-tumor activity is its ability to modulate the NF-ĸB signaling pathway. The present study investigated in vitro and in vivo the effect of combining AKBA with ionizing radiation in the treatment of GBM and assessed AKBA anti-tumor activity and radio-enhancing potential. The effect of AKBA and/or radiation on the survival of cultured glioblastoma cancer cells was evaluated by XTT assay. The mode of interaction of treatments tested was calculated using CalcuSyn software. Inducing of apoptosis following AKBA treatment was evaluated using flow cytometry. The effect of combined treatment on the expression of PARP protein was analysed by Western blot assay. Ectopic (subcutaneous) GBM model in nude mice was used for the evaluation of the effect of combined treatment on tumor growth. Immunohistochemical analysis of formalin-fixed paraffin-embedded tumor sections was used to assess treatment-related changes in Ki-67, CD31, p53, Bcl-2 and NF-ĸB-inhibitor IĸB-α. AKBA treatment was found to inhibit the survival of all four tested cell lines in a dose dependent manner. The combined treatment resulted in a more significant inhibitory effect compared to the effect of treatment with radiation alone. A synergistic effect was detected in some of the tested cell lines. Flow cytometric analysis with Annexin V-FITC/PI double staining of AKBA treated cells indicated induction of apoptosis. AKBA apoptotic activity was also confirmed by PARP cleavage detected by Western blot analysis. The combined treatment suppressed tumor growth in vivo compared to no treatment and each treatment alone. Immunohistochemical analysis showed anti-angiogenic and anti-proliferative activity of AKBA in vivo. It also demonstrated a decrease in p53 nuclear staining and in Bcl-2 staining and an increase in IĸB-α staining following AKBA treatment both alone and in combination with radiotherapy. In this study, we demonstrated that AKBA exerts potent anti-proliferative and apoptotic activity, and significantly inhibits both the survival of glioblastoma cells in vitro and the growth of tumors generated by these cells. Combination of AKBA with radiotherapy was found to inhibit factors which involved in cell death regulation, tumor progression and radioresistence, therefore it may serve as a novel approach for GBM patients.

Multicentre validation of a microRNA-based assay for diagnosing indeterminate thyroid nodules utilising fine needle aspirate smears.

AIMS: The distinction between benign and malignant thyroid nodules has important therapeutic implications. Our objective was to develop an assay that could classify indeterminate thyroid nodules as benign or suspicious, using routinely prepared fine needle aspirate (FNA) cytology smears. METHODS: A training set of 375 FNA smears was used to develop the microRNA-based assay, which was validated using a blinded, multicentre, retrospective cohort of 201 smears. Final diagnosis of the validation samples was determined based on corresponding surgical specimens, reviewed by the contributing institute pathologist and two independent pathologists. Validation samples were from adult patients (≥18 years) with nodule size >0.5 cm, and a final diagnosis confirmed by at least one of the two blinded, independent pathologists. The developed assay, RosettaGX Reveal, differentiates benign from malignant thyroid nodules, using quantitative RT-PCR. RESULTS: Test performance on the 189 samples that passed quality control: negative predictive value: 91% (95% CI 84% to 96%); sensitivity: 85% (CI 74% to 93%); specificity: 72% (CI 63% to 79%). Performance for cases in which all three reviewing pathologists were in agreement regarding the final diagnosis (n=150): negative predictive value: 99% (CI 94% to 100%); sensitivity: 98% (CI 87% to 100%); specificity: 78% (CI 69% to 85%). CONCLUSIONS: A novel assay utilising microRNA expression in cytology smears was developed. The assay distinguishes benign from malignant thyroid nodules using a single FNA stained smear, and does not require fresh tissue or special collection and shipment conditions. This assay offers a valuable tool for the preoperative classification of thyroid samples with indeterminate cytology.

Analytical validity of a microRNA-based assay for diagnosing indeterminate thyroid FNA smears from routinely prepared cytology slides.

BACKGROUND: The majority of thyroid nodules are diagnosed using fine-needle aspiration (FNA) biopsies. The authors recently described the clinical validation of a molecular microRNA-based assay, RosettaGX Reveal, which can diagnose thyroid nodules as benign or suspicious using a single stained FNA smear. This paper describes the analytical validation of the assay. METHODS: More than 800 FNA slides were tested, including slides stained with Romanowsky-type and Papanicolaou stains. The assay was examined for the following features: intranodule concordance, effect of stain type, minimal acceptable RNA amounts, performance on low numbers of thyroid cells, effect of time since sampling, and analytical sensitivity, specificity, and reproducibility. RESULTS: The assay can be run on FNA slides for which as little as 1% of the cells are thyroid epithelial cells or from which only 5 ng of RNA have been extracted. Samples composed entirely of blood failed quality control and were not classified. Stain type did not affect performance. All slides were stored at room temperature. However, the length of time between FNA sampling and processing did not affect assay performance. There was a high level of concordance between laboratories (96%), and the concordance for slides created from the same FNA pass was 93%. CONCLUSIONS: The microRNA-based assay was robust to various physical processing conditions and to differing sample characteristics. Given the assay's performance, robustness, and use of routinely prepared FNA slides, it has the potential to provide valuable aid for physicians in the diagnosis of thyroid nodules. Cancer Cytopathol 2016;124:711-21. © 2016 Rosetta Genomics. Cancer Cytopathology published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

[Avascular necrosis of the jaw bone after bisphosphonate therapy].

Bisphosphonates have an antiosteolytic effect by the inhibition of osteoclastic action. Although the exact mode of action is not completely understood, major progress on both the cellular and molecular levels has been made in recent years. Bisphosphonates alleviate pain and reduce complications, such as pathologic fractures, or hypercalcemia. Dental and periodontal research has shown great interest in clinical applications of bisphosphonates' antiosteolytic and antiosteoclastic traits, since they can be applied to counteract bone loss in chronic periodontitis. Investigations have associated avascular necrosis events in the jawbones with bisphosphonate therapy. Maxillary and mandibular osteonecrotic foci accompanied by pain, inconvenience and purulent exudates were incidentally found in patients who were taking pamidronate (Aredia), zolendronate (Zometa) and even alendronate (Fosalan). Our institutional database search over the past year yielded ten patients who were admitted to the Oral and Maxillofacial Surgery Unit at the Tel Aviv Sourasky Medical Center, due to an osteonecrotic bone lesion coupled with a prior history of bisphosphonate therapy. All these patients also had a recent dental extraction. They were all treated according to the osteomyelitis protocol, and their response to therapy varied from several weeks to many months, with some cases requiring repeat surgical intervention (curettage or sequestrectomy). This article strives to alert on the possible linkage between drug therapy using bisphosphonates and the serious event of avascular jawbone necrosis. The important role of the oral surgeon in following up on this group of patients should not be underestimated.

Targeting ErbB-1 and ErbB-4 in irradiated head and neck cancer: results of in vitro and in vivo studies.

BACKGROUND: ErbB oncogenes have a major role in cancer. The role of ErbB-4 in cancer cell biology and the effect of anti-ErbB-1 and anti-ErbB-4 monoclonal antibodies were evaluated in this study. METHODS: ErbB-4 expression and binding was evaluated by Western blot, enzyme-linked immunosorbent assay (ELISA), fluorescent microscopy, and flow cytometry. Cell survival was measured by XTT assay. Tumor progression was followed up in nude mice model. RESULTS: High ErbB-1 levels in head and neck cancer cell lines were determined, whereas ErbB-4 expression varied. Specific antibody binding to the cells was demonstrated. High ErbB-4 expressing squamous cell carcinoma 1 (SCC-1) cells proliferated faster and generated faster growing tumors in mice. Cetuximab and mAb-3 reduced cell survival proportional to ErbB-1 and ErbB-4 expression. Combination of antibodies with irradiation was most effective in reducing cell survival and tumor growth. CONCLUSION: ErbB-4 plays a role in head and neck cancer cell biology. Anti-ErbB-4 targeted therapy can serve as a new strategy against head and neck cancer when combined with established treatments.

Angioimmunoblastic T-cell lymphoma presenting as giant kidneys: a case report.

INTRODUCTION: Angioimmunoblastic T-cell lymphoma is a rare form of tumor of the lymph nodes or lymphoid tissue. In this report we describe an unusual presentation of angioimmunoblastic T-cell lymphoma consisting of giant kidneys with no nephrotic syndrome. CASE PRESENTATION: A 46-year-old Arabic man from Gaza was hospitalized in our ward due to abdominal pain and a weight loss of 20 kg during the preceding two months. The results of the physical examination and laboratory tests raised the possibility of neoplastic disease. A computerized tomographic scan of the abdomen showed huge kidneys, and a kidney biopsy showed infiltration by lymphocytes and eosinophils. The genetic examination revealed T-cell lymphoma. Diagnosis was made by a lymph node biopsy, which shows typical findings of angioimmunoblastic T-cell lymphoma. CONCLUSIONS: Angioimmunoblastic T-cell lymphoma can present with huge kidneys without nephrotic syndrome.

Anti-ERBb4 targeted therapy combined with radiation therapy in prostate cancer. Results of in vitro and in vivo studies.

PURPOSE: To evaluate the efficiency of anti ErbB4 targeted therapy combined with irradiation (XRT) over each modality alone in prostate cancer. RESULTS: Clones with high ErbB4 expression grew faster than those with low ErbB4 expression. XRT inhibited the growth of both expressive and non-expressive ErbB4 cells, while mAb inhibited only high ErbB4-expressing cells. The combination of XRT and mAb resulted in a 30% reduction of the survival of high ErbB4 expressing cells over XRT alone (p = 0.013). In tumor bearing mice the tumor size in the combined arm was 1 mm at 4 weeks compared to 2-3 mm and 4-5 mm in the radiation and mAb arms (p' value of 0.02 and 0.087 respectively). METHODS: Clones with low and high expression of ErbB4 isolated by a limited dilution technique from an androgen-independent Cl-1 cell line were used. The cells from these clones were exposed to XRT (single dose of 2-6 Gy) and to anti-ErbB4 monoclonal antibody (mAb). The XTT test was used to measure cell survival. In addition, tumor-bearing nude mice were treated either by XRT, mAb or by a combined treatment. Tumor sizes were recorded at given time points. CONCLUSION: Anti ErbB4 combined with XRT is possibly more effective than each modality alone in prostate cancer.

Rosiglitazone improves aortic arginine transport, through inhibition of PKCalpha, in uremic rats.

Peroxisome proliferator-activated receptor (PPAR) agonists were shown to inhibit atherosclerosis through augmentation of endothelial nitric oxide synthase (eNOS) activity. In addition, rosiglitazone exerts a beneficial effect in chronic renal failure (CRF). Since l-arginine transport by CAT-1 (the specific arginine transporter for eNOS) is inhibited in uremia, we aimed to explore the effect of rosiglitazone on arginine transport in CRF. Arginine uptake by aortic rings was studied in control animals, rats, 6 wk following 5/6 nephrectomy (CRF) and rats with CRF treated with rosiglitazone. The decrease of arginine transport in CRF was prevented by rosiglitazone. Immunobloting revealed that CAT-1 protein was decreased in CRF but remained unchanged following rosiglitazone administration. Protein content of the membrane fraction of PKCalpha and phosphorylated CAT-1 increased significantly in CRF, effects that were prevented by rosiglitazone. PKCalpha phosphorylation was unchanged but significantly attenuated by rosiglitazone in CRF. Ex vivo administration of phorbol-12-myristate-13-acetate to rosiglitazone-treated CRF rats significantly attenuated the effect of rosiglitazone on arginine uptake. The decrease in cGMP response to carbamyl-choline (eNOS agonist) was significantly attenuated by rosiglitazone in CRF. Western blotting and immunohistochemistry analysis revealed that protein nitration was intensified in the endothelium of CRF rats and this was attenuated by rosiglitazone. In conclusion, rosiglitazone prevents the decrease in arginine uptake in CRF through both depletion and inactivation of PKCalpha. These findings are associated with restoration of eNO generation and attenuation of protein nitration and therefore may serve as a novel mechanism to explain the beneficial effects of rosiglitazone on endothelial function in uremia.

A profound decrease in maternal arginine uptake provokes endothelial nitration in the pregnant rat.

While a specific role for nitric oxide (NO) in inducing the hemodynamic alterations of pregnancy is somewhat controversial, it is widely accepted that excess NO is generated during pregnancy. L-Arginine is the sole precursor for NO biosynthesis. Among several transporters that mediate L-arginine uptake, cationic amino acid transporter-1 (CAT-1) acts as the specific arginine transporter for endothelial NO synthase. The present study was designed to test the hypothesis that, during pregnancy, when arginine consumption by the fetus is significantly increased, compensatory changes in maternal arginine uptake affect the endothelium. Uptake of radiolabeled arginine (L-[3H]arginine) by freshly harvested maternal aortic rings from pregnant rats decreased by 65 and 30% in mid- and late pregnancy, respectively, compared with those obtained from virgin animals. This decrease was associated with a significant increase in endothelial protein nitration (the footprint of peroxynitrite generation), as shown by both Western blotting and immunohistochemistry utilizing anti-nitrotyrosine antibodies, reflecting endothelial damage. Northern blot analysis revealed that steady-state aortic CAT-1 mRNA levels did not change throughout pregnancy, whereas CAT-1 protein abundance was significantly increased, peaking at mid-pregnancy. Protein content of protein kinase C (PKC)-alpha, which was previously shown to decrease CAT-1 activity, increased significantly in the pregnant animals and was associated with a significant increase in CAT-1 phosphorylation. Intraperitoneal injection of alpha-tocopherol, a PKC-alpha inhibitor, prevented the decrease in arginine transport and attenuated protein nitration. In conclusion, aortic arginine uptake is reduced during pregnancy, through posttranslational modulation of CAT-1 protein, presumably via upregulation of PKC-alpha. The aforementioned findings are associated with an increase in protein nitration and, therefore, in selected individuals, may lead to the development of certain forms of endothelial dysfunction, like preeclampsia.

ErbB-4 may control behavior of prostate cancer cells and serve as a target for molecular therapy.

PURPOSE: To assess ErbB-4 expression in advanced human prostate cancer (PC) cell lines, the role of ErbB-4 in motility, migration, and proliferative/tumorigenic potential of PC cells, and efficacy of anti-ErbB-4 monoclonal antibody (Mab) treatment on PC cells in vitro and tumor growth in vivo. MATERIALS AND METHODS: Established advanced human PC cell lines (PC-3, Cl-1, and Du-145) were evaluated for ErbB-4 expression. Several Cl-1 cell line clones expressing various levels of ErbB-4 were isolated, their motility, migration capacity, and in vitro proliferation as well as survival following Mab treatment were evaluated. Tumorigenicity and proliferation capacity of these clones in vivo and efficacy of Mab treatment on tumor growth were estimated by measurements of subcutaneous tumors developed in nude mice. RESULTS: PC cell lines studied express ErbB-4. Both PC-3 and Du-145 cell lines express high ErbB-4 levels; only 50% of Cl-1 cells express ErbB-4 with large heterogeneity. Cl-1 sub-clones highly expressing ErbB-4 showed increased cell motility, migration, and proliferation rate in vitro and enhanced growth in vivo, compared to clones with low ErbB-4 expression. Mab treatment inhibited the growth of cells expressing high but not low ErbB-4 levels in vitro and decreased the growth of subcutaneous tumors in nude mice generated by ErbB-4 highly expressing cells. CONCLUSIONS: High expression of ErbB-4 in prostate cancer Cl-1 cell clones correlated with high proliferative and migration capacity and high tumorigenic potential. The inhibitory effect of Mab on cell proliferation and on subcutaneous tumor growth suggests ErbB-4's potential as a target for molecular anticancer therapy.

Aggressive resection of retroperitoneal sarcoma is superior to simple excision: an animal study using a novel model for retroperitoneal sarcoma.

BACKGROUND AND OBJECTIVES: Retroperitoneal sarcomas constitute a difficult management problem. The need for, and extent of, aggressive surgery continues to be debated. The aim of our study was to compare the impact of radical en bloc resection of retroperitoneal sarcoma with complete resection of the tumor alone in a rat model. METHODS: Under laparoscopic guidance, a fibrosarcoma cell line suspension was injected into the left paranephric space of a rat, resulting in the development of a macroscopic retroperitoneal tumor. Ten days after inoculation, 50 rats were randomized into three groups: (1) local resection, (2) radical resection, and (3) follow-up only. Groups 1 and 2 were further randomized for sacrifice 1 month after surgery or were followed up for 2 months. RESULTS: Local recurrence: 46% of group 1, while none in group 2 developed local recurrence during the same follow-up period (P = 0.02). Survival: 33% of group 1 were alive after 2 months, as compared with 54.5% of group 2. (P = 0.04). All rats in the control group died within <25 days. CONCLUSIONS: Our results suggest that aggressive en bloc resection of retroperitoneal sarcomas with adjacent viscera, even when macroscopically uninvolved with disease, has an advantage over complete local resection alone.