The relationship between bcl-2 oncogene expression and clinicopathological criteria in various stages of cervical neoplasia in Egyptian women

PURPOSE

To assess the degree of bcl-2 expression in the various stages of cervical neoplasia in a sample population of Egyptian women and relate the findings to clinicopathological criteria of invasive cervical cancer.

METHODS

Bcl-2 protein expression was assessed by immuno-histochemistry in 40 patients with cervical neoplasia (intraepithelial and invasive) in comparison to 20 patients with benign changes. Patients with invasive disease were followed up 2 years later and the outcome was correlated to the bcl-2 status at the time of diagnosis.

RESULTS

Bcl-2 expression increased from 20% in normal cervical tissue to 42.9% in cervical intraepithelial neoplasia grade II then dropped to 33% in invasive disease. Bcl-2 was not expressed (0%) in patients with advanced disease stage and grade nor in patients with lympho-vascular space invasion.

CONCLUSION

Bcl-2 expression is reduced along the spectrum from benign towards invasive disease of the cervix. The maximum expression found in CIN II may suggest increased potential of progression to CIN III.

Dissociation of the E-Cadherin-Catenin-Complex (CCC) Is an Early and Progressive Event in Lobular Neoplasia

Recent data suggests that some lobular carcinoma in situ (LCIS) lesions may behave as precursors to invasive lobular carcinoma (ILC). Loss of E-cadherin (E-CD) mediated cell adhesion is characteristic of both LCIS and ILC and is reflected in the dis-cohesive appearance of the individual cells. Subsequent dissociation of the intracellular E-cadherin-catenin-complex (CCC) facilitates tumor progression, invasion and migration. Whether disruption of the CCC plays a role in the progression of select LCIS lesions to ILC remains unclear. The aim of this study was to evaluate the relation between loss of E-CD and dissociation of the CCC in pure LCIS and LCIS with concurrent ILC (LCIS w/ILC). Methods Thirty patients undergoing mastectomy for LCIS alone or LCIS w/ ILC were prospectively enrolled to an IRB-approved protocol. FFPE blocks were retrieved and sections prepared for IHC. 18 cases had LCIS w/ ILC, 12 cases had pure-LCIS. IHC was performed for ER, PR, E-CD, N-cadherin (N-CD), and α-, β- and phospho-β-catenin. ER/PR positivity was scored as any nuclear staining, and E-CD and N-CD by any membranous staining. a- and β-catenin expression was scored by site (membranous/cytoplasmic/nuclear) of staining compared to normal. Dissociation of the CCC was defined by loss of membranous α- and β-catenin expression.Results Median age at surgery was 51yrs (range 40-79); patients with pure LCIS were younger than those with LCIS w/ ILC (median 48yrs vs 57yrs, p=.0002). Among 18 cases of LCIS w/ ILC, the median tumor size was 2cm (range 1.4-5.7), 9 patients had N1 disease and 1 had M1 disease. All pure LCIS, LCIS w/ ILC and ILC lesions were ER/PR positive and E-CD negative. N-CD expression was also absent in all pure LCIS, LCIS w/ ILC and ILC lesions. Normal α-catenin membranous expression was confirmed in all normal epithelial cells but decreased with the transition from in-situ to invasive disease: pure-LCIS lesions 83%; LCIS w/ ILC 28%; ILC 0%. Loss of membranous α-catenin expression was accompanied by cytoplasmic α-catenin expression in all lesions. A similar trend of decreasing membranous staining from in-situ to invasive disease was observed for β-catenin, however in contrast to α-catenin, cytoplasmic β-catenin expression decreased from 67% in pure LCIS to 11% in LCIS w/ ILC and 6% in ILC. Active β-catenin (nuclear staining) was not seen in pure LCIS lesions and was only present in one case of LCIS w/ ILC. Inactive (phospho) β-catenin expression was present in all lesions.Conclusion Loss of E-CD expression is an early event in lobular neoplasia however subsequent dissociation of the intracellular CCC a a ppears to be a progressive process with complete dissociation occurring only in invasive lesions. This finding suggests that complete disruption of the CCC may be required to facilitate maintenance of the invasive phenotype; however, the absence of N-CD expression and predominance of inactive β-catenin in both in situ and invasive lesions suggests that alternate mechanisms are also required to mediate the pro-invasive effects of CCC dissociation. Further studies into the mechanisms of CCC dissociation and downstream events in lobular carcinoma are needed to define the role of this process in the transition from in-situ to invasive disease.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6149.

Quantitative Analysis of HER2 Receptors Expression In Vivo by Near-Infrared Optical Imaging

Purpose: HER2 overexpression has been associated with a poor prognosis and resistance to therapy in breast cancer patients. However, up to now, quantitative estimates of this important characteristic have been limited to ex vivo ELISA essays of tissue biopsies and/or PET-based analysis. We aim at developing a novel approach in optical imaging, involving specific probes that do not interfere with the binding of the therapeutic agents, thus, excluding competition between therapy and imaging. Affibody-based molecular probes seem to be ideal for in vivo analysis of HER2 receptors using near-infrared optical imaging. To achieve quantification of HER2 receptors and overcome experimental uncertainties, we analyze post-injection temporal variations of the fluorescence intensity in the tumor area.Experimental design: Quantitative in vivo near-infrared imaging uses HER2-specific albumin-binding domain-fused-(ZHER2:342)2 Affibody molecules, labeled with AlexaFluor750 dye, as targeting agents. Subcutaneous tumor xenografts, expressing different levels of HER2 (BT474, MDA-MB361, MCF7, U251), are imaged at different times post-injection. Mathematical modeling allowed assessment of correlation between measured characteristics and HER2 expression levels from ex-vivo assays of the same tumors.Results: Affibody-Alexa Fluor conjugates may be used as a specific near-infrared probe for the non-invasive imaging of HER2-positive tumors, while analysis of the imaging parameters, directly estimated from the sequence of optical images, provides quantitative insight on the HER2 overexpression, as suggested by observed correlation between tumor cell amplification/overexpression of HER2, and these parameters.Conclusions: Method might potentially be employed in clinic for noninvasive monitoring of the HER2 expression variation in response to therapeutic intervention.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5002.

Negative Estrogen Receptor and HER2 Assays at Core Biopsy of Invasive Cancers Should Be Confirmed in the Surgical Specimens

Background: Management of patients with invasive breast carcinoma is determined by the expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) in the tumor cells. It is therefore critical to accurately assess ER, PR, and HER2 (ERPRH2) and avoid false-negative results that could lead to withholding of potentially beneficial therapy. Most laboratories, including ours, evaluate ERPRH2 status of invasive carcinoma on core biopsy (CB) material. We also routinely retest the cancer in the surgical specimen (SS) for any marker negative on CB. Our study evaluates discrepancies in ER and HER2 results in CB and SS to determine if repeat testing is necessary.Methods: Retrospective review of the pathology database found 186 invasive carcinomas from 181 patients in which ERPRH2 had been performed on the CB, and negative stains repeated on the SS. For the purpose of this study, immunoperoxidase stains (IHC) were repeated simultaneously on the CB and SS for the marker with discordant result, using the same antibody. Two study pathologists reviewed all IHC. HER2 FISH was performed on the SS for all cases with a discordant HER2 IHC result.Results: The concordance rate between CB and SS results was 97.3% (181/186) and discordant results were found in 5/186 (2.7%) cases (Table 1). Three cases were discordant in ER (including 2 cases that were PR(-) on CB and SS) and two cases were discordant for HER2. Discrepancy was due to intratumoral heterogeneity in 2 cases. The CB sampled the HER2(-) area of the tumor in one case, but staining of a larger section unveiled the positive focus; the positive result was confirmed by amplification of HER2 detected by FISH. The second case was an invasive lobular carcinoma (IL) with mixed classical and histiocytoid morphology; only the classical IL was ER(+), but the CB had sampled the histiocytoid IL. In two other cases the discrepancy resulted from technical error. Both cases had been prospectively interpreted as ER(-) on CB and ER(+) on SS, but repeat IHC for ER showed positive staining in both the CB and SS. The fifth case was HER2 (0/1+) on CB but equivocal (1-2+) in the SS, where a larger portion of tumor was evaluated; the equivocal result led to reflex HER2 FISH with detection of low level HER2 amplification. Relying solely on the CB would have resulted in the misclassification of 2 tumors as triple negative; repeat stains on the SS showed that one was HER2(+) and the other ER(+).Conclusions: Concordance in the ER and HER2 results between CB and SS was high (97.3%), but 2.7% of cases showed discordant findings. Factors associated with discordance included intratumoral heterogeneity tumor, technical error, and equivocal findings. A triple negative profile on CB converted to either ER(+) or HER2(+) after staining on SS in 2 cases (40% of discordant cases and 1.1% of all cases), impacting patient management. Our findings suggest that any ER and/or HER2 negative result obtained at CB should be confirmed on the SS to ensure appropriate patient management.Findings of discordant casesCaseER (%)HER2HER2 FISH CBSSCBSSSS1OOO3+4.42O951+1+N/P3O1001+1+N/P45501+1+N/P590N/P0-1+1-2+2.6N/P- not performed

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6008.

Near-infrared spectra absorbance of blood from sickle cell patients and normal individuals

Limited data are available regarding the physicochemical dynamics of tissue hypoxia in sickle cell disease. Studies using near-infrared spectroscopy (NIRS) have reported that patients with sickle cell disease (SCD) have lower cerebral oxygen saturation values (rSO2) than normal individuals. The reason SCD patients have subnormal rSO2 values is not known. It may be related to the degree of anaemia, sickle haemoglobin, disease complications and the possibility of SCD different NIRS absorbance spectra than normal. This study compared NIRS absorbance spectra of blood with adult haemoglobin AA, sickle haemoglobin SS, and AS. Venous blood was collected from SCD (SS and AS) and non-SCD patients (AA). Whole blood, cell free haemoglobin samples were scanned through the wavelength range of 600-1000 nm. The results showed no different NIRS spectra absorbance between the haemoglobin's AA, SS. It thus appears that lower brain oxygen saturation in sickle cell anaemia patients is related to impaired oxygen carrying capacity or delivery by sickle haemoglobin.

Population structure and geographical subdivision of the Leishmania major vector Phlebotomus papatasi as revealed by microsatellite variation

Multi-locus microsatellite typing (MLMT) has been employed to infer the population structure of Phlebotomus papatasi (Scopoli) (Diptera: Psychodidae) sandflies and assign individuals to populations. Phlebotomus papatasi sandflies were collected from 35 sites in 15 countries. A total of 188 P. papatasi individuals were typed using five microsatellite loci, resulting in 113 different genotypes. Unique microsatellite signatures were observed for some of the populations analysed. Comparable results were obtained when the data were analysed with Bayesian model and distance-based methods. Bayesian statistic-based analyses split the dataset into two distinct genetic clusters, A and B, with further substructuring within each. Population A consisted of five subpopulations representing large numbers of alleles that were correlated with the geographical origins of the sandflies. Cluster B comprised individuals collected in the Middle East and the northern Mediterranean area. The subpopulations B1 and B2 did not, however, show any further correlation to geographical origin. The genetic differentiation between subpopulations was supported by F statistics showing statistically significant (Bonferroni-corrected P < 0.005) values of 0.221 between B2 and B1 and 0.816 between A5 and A4. Identification of the genetic structure of P. papatasi populations is important for understanding the patterns of dispersal of this species and to developing strategies for sandfly control.

Anti-atherogenic effect of statins: role of nitric oxide, peroxynitrite and haem oxygenase-1

BACKGROUND AND PURPOSE

The pleiotropic effects of HMG-CoA inhibitors (statins), which include anti-inflammation, antioxidation and immunomodulation, are not yet fully understood. The present study was designed to elucidate the role of nitric oxide (NO), peroxynitrite (ONOO(-)) and haem oxygenase-1 (HO-1) in the anti-atherogenic effect of statins.

EXPERIMENTAL APPROACH

Normal and atherosclerotic New Zealand rabbits were treated with atorvastatin or simvastatin in the presence or absence of inhibitors and promoters of endothelial nitric oxide synthase (eNOS) and HO-1. NO and ONOO(-) released from isolated aortae by calcium ionophore were measured with nanosensors placed 6 +/- 2 nm from aortic endothelium. Expression of eNOS and HO-1 protein, HO activity, plasma malondialdehyde (MDA) and vessel wall thickness were also measured.

KEY RESULTS

Hypercholesterolaemia decreased eNOS expression by 31 +/- 3%, decreased NO (230 +/- 16 vs. 433 +/- 17 nmol x L(-1) control) and increased cytotoxic ONOO(-) (299 +/- 15 vs. 187 +/- 11 nmol x L(-1) control). The concentration ratio of [NO]/[ONOO(-)] decreased from 2.3 +/- 0.1 (normal) to 0.7 +/- 0.1 indicating an increase of nitroxidative stress in atherosclerotic endothelium. Expression of HO-1 protein increased by 20 +/- 8% in atherosclerosis and further increased (about 30%) after treatment with statins. Statins partially restored the [NO]/[ONOO(-)] balance (1.5 +/- 0.1 for atorvastatin and 1.4 +/- 0.1 simvastatin), decreased MDA and wall thickening. Promoters of eNOS and HO-1 (L-arginine and haemin) ameliorated the [NO]/[ONOO(-)] ratio while their inhibitors (L-NAME or tin-protoporphyrin) showed no improvement in these ratio.

CONCLUSIONS AND IMPLICATIONS

Atherosclerosis induced an endothelial [NO]/[ONOO(-)] balance indicative of endothelial dysfunction. Statins showed anti-atherosclerotic effects mediated by HO-1/eNOS, restoring the [NO]/[ONOO(-)] imbalance and reducing lipid peroxidation.

Clinical experiences and biochemical findings with tacrine (THA)

A clinical comparison of tacrine (THA) and placebo was performed in 15 Alzheimer patients using a double blind crossover technique over 4 plus 4 weeks with one drug-free week in between. Treatment results, as evaluated by clinical rating scales and neuropsychological tests, were mostly negative. Side effects were few, except for elevation liver enzymes which occurred in one third of the patients. CSF levels of the monoamine metabolites HVA and 5-HIAA increased on tacrine as evidence for activation of dopamine and serotonin pathways through cholinergic receptors. Pharmacokinetic investigations showed that the oral bioavailability of tacrine was low and greatly varying between subjects. Patients with high bioavailability of the drug tended to improve more, and also to have more liver enzyme elevations, than those with low bioavailability. A gel preparation for rectal administration was manufactured for comparison of plasma levels attained during one week's treatment with levels attained with oral capsules. Preliminary results indicate that the dose of tacrine can be reduced to 50 per cent when administered rectally, probably as by this route the rapid first-pass metabolism of the drug in the liver is diminished. A clinical trial of tacrine via the rectal route would be justified as this could decrease the number of patients with liver side effects and increase the number of patients improving on the treatment.

Use of piecewise stationary segmentation as a pre-treatment for synchronization measures

The analysis of the synchronization between biological signals can be helpful for the characterization of biological functions. Biological signals are however often strongly non stationary. This is in contradiction to the assumption of commonly used synchronization measures which assume that the signal is stationary. We propose to use a piecewise stationary pre-segmentation (PSP) of the signals of interest, before the computation of synchronization measures. We show on synthetic as well as real biological signals (EEG and uterine EMG) that the proposed piecewise stationary pre-segmentation approach increases the accuracy of the measures by making a good tradeoff between the stationary assumption and length of the analyzed segments, when compared to the classical windowing method.

Molecular targeting of HER2 for diagnosis and therapy of breast cancer

Abstract #6004

Background: Expression of HER2 receptors in breast cancer is correlated with poor prognosis and may be different in distant metastases as compared to the primary tumor. We are developing methods to assess global expression of HER2 in vivo and to deliver therapeutic agents specifically to HER2-positve cells.&#x2028; Materials and Methods: As the targeting agent we use an Affibody molecule (http://www.affibody.com). These very stable and highly soluble proteins are relatively small (8.3 kDa) and bind to HER2 receptors with high affinity (22 pM). For imaging with PET, SPECT, or optical methods, an appropriate group containing the imaging beacon can be attached by a selective chemical reaction to a unique C-terminal cysteine residue of Affibody. For therapeutic purposes, they can be conjugated to multifunctional nanoparticles containing both imaging and therapeutic agents. We have conjugated affibody molecules with thermo-sensitive liposomes or gold nanoparticles (subsequently activated with neutrons) and characterized their biodistribution using optical imaging and SPECT, respectively. We used PET imaging with 18F-ZHER2-Affibody to monitor the down-regulation of HER2 following four doses (50 mg/kg) of 17-dimethylaminoethylamino-17-demethoxy-geldanamycin, 17-DMAG, an inhibitor of Hsp90 known to decrease HER2 expression. Animals were scanned before and after treatment. Immediately after the last scan, the mice were euthanized and tumors were frozen for ex-vivo analysis of receptor expression. For optical imaging, we used AlexaFluor dyes conjugated with affibody molecules containing an albumin binding domain that extended their circulation time. We have attached nanoparticles (liposomes and gold) to Affibody molecules using the same type of maleimide chemistry.&#x2028; Results: Our results showed that Affibody molecules do not affect the targeted cells and that their binding does not interfere with either the binding or the effectiveness of trastuzumab. 18F-ZHER2-Affibody was eliminated quickly from blood and normal tissues, providing high tumor/blood and tumor/muscle ratios by 1h post injection. The signal obtained from PET and optical imaging correlated well with the number of receptors expressed in the studied tumors as assessed by western blot, ELISA, and IHC. Following 17-DMAG treatment, the level of HER2 expression, estimated by PET imaging, in BT474 and Mcf-7/clone18 tumors decreased 70% and 30%. This change was confirmed by the biodistribution studies, ELISA and western blot.&#x2028; Discussion: This strategy, involving assessment of target presence and distribution in an individual patient followed by optimized, target-specific drug delivery, may significantly improve efficacy of breast cancer treatment while reducing side effects.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6004.

Nonlinearity testing in the case of non Gaussian surrogates, applied to improving analysis of synchronicity in uterine contraction

Surrogates are commonly used to test a particular hypothesis on time series. The parameter commonly used in the literature to test these hypotheses is the z score. The z score assumes that the distribution of the statistics obtained on the surrogates is Gaussian. In this paper, we propose the use of a more general parameter than the z score that will also work in the case of non-Gaussian distribution of the statistics. We also derive a statistical test, based on the fitting of the distribution of the surrogate measure profile, in order to test the initial hypothesis. We validate the proposed approach on both synthetic signals and real uterine EMG signals by using the nonlinear correlation coefficient as initial statistic. We further show that this corrected nonlinear correlation coefficient can discriminate between pregnancy contractions and labor in a monkey, but the uncorrected nonlinear correlation coefficient cannot. This makes the corrected nonlinear correlation coefficient a promising candidate in a future application for preterm labor prediction in humans.

Value of chest radiography in predicting treatment response in children aged 3-59 months with severe pneumonia

SETTING

International multicentric study at nine tertiary care centres.

OBJECTIVE

The World Health Organization (WHO) currently does not recommend chest radiographs (CXRs) for routine management of pneumonia. We evaluated the use of CXR for the prediction of treatment failure in children with severe pneumonia.

DESIGN

We used WHO vaccine trials radiographic assessment, clinical and nasopharyngeal microbiological data from 1121 3-59-month-old children recruited using the WHO definition of severe pneumonia in the Amoxicillin Penicillin Pneumonia International Study (APPIS). Using Poisson regression, we estimated the relative risk of developing clinical treatment failure and predictive preventive benefit of the CXR and examined the concordance of the CXR findings with the nasopharyngeal microbiological data.

RESULTS

A CXR with 'significant pathology' (defined by the WHO algorithm as end-point consolidation, pleural fluid and other infiltrates) was associated with a high risk of treatment failure, especially in children who received penicillin as compared to oral amoxicillin. Significant pathology was also associated with nasopharyngeal isolation of penicillin-resistant Streptococcus pneumoniae. Children with a normal CXR had a reduced risk of clinical treatment failure.

CONCLUSIONS

CXR with significant pathology independently and additively predicts clinical treatment failure. If CXR and the WHO tool are available, they can be used in the management of severe pneumonia.

Inhibition activities ofcolchicum luteumbaker on lipoxygenase and other enzymes

In vitro enzymes inhibition activities of the crude methanolic extract and various fractions of Colchicum luteum Baker (Liliaceae) including chloroform, ethyl acetate, n-butanol and aqueous were carried out against actylcholinesterase, butyrylcholinesterase, lipoxygenase and urease enzymes. A significant enzyme inhibition activity (89%) is shown by the crude methanolic extract and its fractions against lipoxygenase, while low to significant activity (32-75%) was evident against butyrylcholinesterase. The crude methanolic extract and its various fractions demonstrated low activity (29-61%) against acetylcholinesterase and no activity against urease.

Cyclophosphamide induces mRNA, protein and enzyme activity of cytochrome P450 in rat

The effects of cyclophosphamide (CPA) on CYP enzymes in vivo and its auto induction in rat were investigated in Wistar/Fu male rats at a single dose (40 or 200 mg kg(-1)) or as repeated dose of 200 mg kg(-1) CPA. After a single dose of CPA, mRNAs of CYPs 2B1, 2B2, 3A2, 2C11 were significantly induced up to 220-, 6.7-, 5.0- and 5.8-fold at the low dose CPA, and 4800-, 52-, 22- and 2.5-fold at the high dose. CYP2B1/2 and CYP3A proteins were increased by 4- and 2-fold (low dose) and by 28- and 1.7-fold (high dose). CYP2C11 protein levels were not altered. Microsomal activities of CYP2B, CYP3A and 2C11 were increased by 2-, 1.8- and 1.3-fold at low dose CPA, and 3.2-, 1.7- and 1.6-fold at high dose. A significant (p<0.05) decrease in CPA concentration and a significant (p<0.05) increase in 4-OH-CPA levels were observed with repeated administration of CPA. Acute induction effect on CYP2B1, 2B2, 2C11 and 3A2 and a substantial up regulation of CYP2B1 mRNA were observed after a single dose of CPA, auto induction was observed by repeated administration.

Imaging techniques for Kaposi's sarcoma

Kaposi[']s sarcoma (KS) is a multicentric tumour that most frequently involves the skin but can involve other tissues as well. Clinicians treating patients with KS or conducting clinical trials in this disease can benefit from imaging studies to document the extent of disease, to document changes with therapy, and to assess the extent of visceral and lymphatic involvement. A number of conventional techniques can be of use in meeting these needs, such as conventional light photography to assess skin or mucosal lesions, computed tomography of the chest to assess pulmonary disease, and magnetic resonance imaging. In addition, a number of techniques are being developed with the goals of providing improved differentiation of KS from other diseases or providing information about the degree of angiogenesis in the lesions and other physiological factors. We present here an overview of both established and experimental modalities of imaging in KS.

Low-molecular weight heparin in patients with recurrent early miscarriages of unknown aetiology

The aim of this randomised prospective study was to assess the efficacy of early thromboprophylaxis with low-molecular weight heparin (LMWH) in women with a history of recurrent first trimester spontaneous abortion or miscarriages without identifiable causes vs no treatment. The study comprised of 340 women with unexplained spontaneous recurrent miscarriages. Patients in group A were prescribed LMWH (Enoxaparin sodium 0.2 ml, 20 mg, once daily subcutaneously) from the time of confirmation of fetal viability by ultrasonography until 34 weeks' gestation, and folic acid tablets 0.5 mg daily until 13 weeks' gestation. Patients in group B were given folic acid tablets 0.5 mg daily until 13 weeks' gestation. Termination of pregnancy was the primary outcome. There was a significant difference in the incidence of both early (4.1% vs 8.8%) and late miscarriages (1.1% vs 2.3%) in group A than in group B, respectively. There were no differences between both groups as regards the occurrence of pre-eclampsia, placental abruption, caesarean delivery, intra-partum bleeding or ecchymosis at operative wounds. There were no differences in most of the neonatal values between both groups. However, the mean birth weight was significantly higher in group A. LMWH seems to be a safe drug and effective in significantly reducing the incidence of recurrent miscarriages of unknown aetiology when given in the first trimester and continued throughout pregnancy.

The epidermal growth factor receptor mediates allergic airway remodelling in the rat

The chronicity of bronchial asthma is attributed to persistent airway inflammation and to a variety of structural changes, or remodelling, that includes smooth muscle and goblet cell hyperplasia. To investigate the mechanisms of airway remodelling, the current authors used an established allergen (ovalbumin; OVA)-driven rodent model (the Brown Norway rat). Brown Norway rats were sensitised to OVA and challenged three times at 5-day intervals to evoke airway remodelling. The effects of an epidermal growth factor (EGF) receptor inhibitor, AG1478, and a cysteinyl leukotriene-1 receptor antagonist, montelukast, on epithelial and airway smooth muscle (ASM) cell proliferation in vivo in response to repeated OVA challenge were tested. Three challenges with leukotriene (LT)D(4) were given, to examine their effects on remodelling with and without AG1478 pretreatment. OVA challenges caused ASM hyperplasia, with an increase in mass, epithelial cell proliferation and goblet cell proliferation. AG1478 prevented the changes, as did montelukast. Multiple OVA challenges increased heparin-binding EGF-like growth factor but not EGF expression by airway epithelium. LTD(4) reproduced the changes in remodelling induced by OVA and this was blocked by AG1478. Allergen-induced airway epithelial and airway smooth muscle remodelling is mediated by cysteinyl leukotrienes via the cysteinyl leukotriene-1 receptor with downstream effects on the epidermal growth factor receptor axis.