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Intrinsic and acquired resistance to HER-targeting drugs occurs in a significant proportion of HER2-overexpressing breast cancers. Thus, there remains a need to identify predictive biomarkers that could improve patient selection and circumvent these types of drug resistance. Here, we report the identification of neuromedin U (NmU) as an extracellular biomarker in cells resistant to HER-targeted drugs. NmU overexpression occurred in cells with acquired or innate resistance to lapatinib, trastuzumab, neratinib, and afatinib, all of which displayed a similar trend upon short-term exposure, suggesting NmU induction may be an early response. An analysis of 3,489 cases of breast cancer showed NmU to be associated with poor patient outcome, particularly those with HER2-overexpressing tumors independent of established prognostic indicators. Ectopic overexpression of NmU in drug-sensitive cells conferred resistance to all HER-targeting drugs, whereas RNAi-mediated attenuation sensitized cells exhibiting acquired or innate drug resistance. Mechanistic investigations suggested that NmU acted through HSP27 as partner protein to stabilize HER2 protein levels. We also obtained evidence of functional NmU receptors on HER2-overexpressing cells, with the addition of exogenous NmU eliciting an elevation in HER2 and EGFR expression along with drug resistance. Finally, we found that NmU seemed to function in cell motility, invasion, and anoikis resistance. In vivo studies revealed that NmU attenuation impaired tumor growth and metastasis. Taken together, our results defined NmU as a candidate drug response biomarker for HER2-overexpressing cancers and as a candidate therapeutic target to limit metastatic progression and improve the efficacy of HER-targeted drugs. Cancer Res; 74(14); 3821–33. ©2014 AACR.

Clinically faithful pre-clinical models are essential for screening therapies and studying resistance mechanisms. Historically models have failed to predict response in the clinical setting. Current models seldom incorporate surgical resection, and commonly use young animals whose immune contexture differs from older patients. Here, we have established an orthotopic model, employing the syngeneic, mesenchymal-NFpp10a-cell line, in both young and aged mice. We have characterised the model's response to standard of care resection and temozolomide (TMZ) treatment. We have further studied response to anti-PD1 therapy (adjuvant and neoadjuvant). NFpp10a-Luc2 expressing cells were orthotopically implanted into C57BL/6 mice (aged { > 18months} and young {6-8weeks}) and weekly bioluminescence imaging (BLI) performed to monitor tumour growth. Several therapeutic interventions were assessed to study tumour growth and survival: (1)surgical resection, (2)TMZ, (3)anti-PD1 (4)neoadjuvant anti-PD1. RNAseq, murine microenvironment cell population (mMCP) counter and gene ontology analyses characterised treatment related changed in the TME. We demonstrated survival advantage in aged mice undergoing resection (Resection:33.5 days vs Non-Resection:18 days;p=0.0166). Subsequently, we observed that TMZ and anti-PD1 monotherapy had no impact on NFpp10a-Luc2 growth (TMZ-overall:p=0.9001, and anti-PD1-overall:p = 0.7933) or survival (TMZ-overall:p = 0.3035, anti-PD1-overall:p= 0.6328). Neoadjuvant anti-PD1 treated mice demonstrated no survival advantage compared to IgG control (33-days vs 35-days:p = 0.9429). or BLI signal (p = 0.1703). NFpp10a-Luc2 forms immune-cold TME relative to commonly employed models. mMCP counter analysis demonstrates neoadjuvant anti-PD1 induced influx of CD8+-T cells, B cells, and monocytes into the TME compared to IgG control, and was associated with significantly upregulated CXCR3 chemokine receptor binding pathway on gene ontology analysis (p = 0.0045). Overall, we have, for the first time established and characterised response of the NFpp10a-Luc2-C57BL/6 model to resection, TMZ and anti-PD1 therapies. NFpp10a-Luc2 tumours demonstrate similar therapeutic resistance and TME profile compared to human mesenchymal GBM. The model may therefore be employed in future pre-clinical studies to guide clinical trials in mesenchymal GBM.

While magnetic resonance imaging (MRI) is the predominant imaging modality for glioblastoma (GBM), pre-clinical MRI scanner availability is limited. As pre-clinical CT is more widely available and cost-effective, this study aimed to 1) establish preclinical-GBM CT and CT-radiomic workflows, 2) identify whether CE-CT could detect murine orthotopic GBM tumours on two CT instruments [TRIUMPHX-O-CT; IVISSPECTRUM-CT], 3) assess whether CT-radiomic features could distinguish tumour from normal tissue, and support earlier detection of tumours, 4) verify translation of pre-clinical CT-radiomic pipelines to, and assess pre-clinical CT-features in, clinical CE-CT scans.U87R-Luc2(n=25) and NFpp10a-Luc2(n=10) orthotopic GBM models were established and tumours monitored via bioluminescence imaging (BLI). Concurrently, mice underwent CE-CT (IV-iodine/300mg/mL/50kV-scan). Extracted radiomic features (PyRadiomics) underwent dimensionality reduction (Spearman correlation; >0.85). Remaining features were analysed (Recursive feature elimination (RFE)/RepeatedCV/randomforest) in normal and tumour tissue and across timepoints (TRIUMPHX-O-CT-Wk3vsWk6,Wk6vsWk9/12; IVISSPECTRUM-CT-Wk6vsWk9/12).CE-CT and radiomic pipelines were successfully established for orthotopic GBM models, using both CT-systems. On visual assessment of images, BLI was significantly more sensitive, with tumours detectable at Wk1 (BLI) vs Wk9 (CE-CT). However, RFE analysis identified CT-radiomic features (first_order&glcm) which differentiated tumour from normal tissue (TRIUMPHX-O-CT). A subsequent feature set (first_order,glcm,gldm&glzm) were identified (TRIUMPHX-O-CT/IVISSPECTRUM-CT), detecting tumours earlier (Wk3&Wk6) than possible by visual assessment of CTs. Preclinical radiomic methods were successfully applied to exploratory clinical CE-CT scans(n=10). Here, several preclinical CT-features (e.g. Zone_Entropy) showed increased intensity in tumour regions. Overall experimental BLI is the most sensitive method for pre-clinical intracranial tumour detection. However, analysis of clinically relevant CT-radiomic features may facilitate tumour identification and earlier tumour detection (Wk3/Wk6-TRIUMPHX-O-CT/Wk6-IVISSPECTRUM-CT) than possible by visual assessment of CT (Wk9). Clinically relevant CT-derived radiomic features may therefore support intracranial rodent tumour assessment. Importantly, preclinical radiomic methods successfully translate to clinical CT-radiomic analysis. Parallel trends in tumour-specific feature intensities across pre-clinical and clinical scans suggest species conservation of features.

Despite magnetic resonance imaging (MRI) being the gold-standard imaging modality in the glioblastoma (GBM) setting, the availability of rodent MRI scanners is relatively limited. CT is a clinically relevant alternative which is more widely available in the pre-clinic. To study the utility of contrast-enhanced (CE)-CT in GBM xenograft modelling, we optimized CT protocols on two instruments (IVIS-SPECTRUM-CT;TRIUMPH-PET/CT) with/without delivery of contrast. As radiomics analysis may facilitate earlier detection of tumors by CT alone, allowing for deeper analyses of tumor characteristics, we established a radiomic pipeline for extraction and selection of tumor specific CT-derived radiomic features (inc. first order statistics/texture features). U87R-Luc2 GBM cells were implanted orthotopically into NOD/SCID mice (n=25) and tumor growth monitored via weekly BLI. Concurrently mice underwent four rounds of CE-CT (IV iomeprol/iopamidol; 50kV-scan). N=45 CE-CT images were semi-automatically delineated and radiomic features were extracted (Pyradiomics 2.2.0) at each imaging timepoint. Differences between normal and tumor tissue were analyzed using recursive selection. Using either CT instrument/contrast, tumors > 0.4cm3 were not detectable until week-9 post-implantation. Radiomic analysis identified three features (waveletHHH_firstorder_Median, original_glcm_Correlation and waveletLHL_firstorder_Median) at week-3 and -6 which may be early indicators of tumor presence. These features are now being assessed in CE-CT scans collected pre- and post-temozolomide treatment in a syngeneic model of mesenchymal GBM. Nevertheless, BLI is significantly more sensitive than CE-CT (either visually or using radiomic-enhanced CT feature extraction) with luciferase-positive tumors detectable at week-1. In conclusion, U87R-Luc2 tumors > 0.4cm3 are only detectable by Week-8 using CE-CT and either CT instrument studied. Nevertheless, radiomic analysis has defined features which may allow for earlier tumor detection at Week-3, thus expanding the utility of CT in the preclinical setting. Overall, this work supports the discovery of putative prognostic pre-clinical CT-derived radiomic signatures which may ultimately be assessed as early disease markers in patient datasets.

Resistance to chemotherapy often results from dysfunctional apoptosis, however multiple proteins with overlapping functions regulate this pathway. We sought to determine whether an extensively validated, deterministic apoptosis systems model, &lsquo, DR_MOMP&rsquo, could be used as a stratification tool for the apoptosis sensitiser and BCL-2 antagonist, ABT-199 in patient-derived xenograft (PDX) models of colorectal cancer (CRC). Through quantitative profiling of BCL-2 family proteins, we identified two PDX models which were predicted by DR_MOMP to be sufficiently sensitive to 5-fluorouracil (5-FU)-based chemotherapy (CRC0344), or less responsive to chemotherapy but sensitised by ABT-199 (CRC0076). Treatment with ABT-199 significantly improved responses of CRC0076 PDXs to 5-FU-based chemotherapy, but showed no sensitisation in CRC0344 PDXs, as predicted from systems modelling. 18F-Fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) scans were performed to investigate possible early biomarkers of response. In CRC0076, a significant post-treatment decrease in mean standard uptake value was indeed evident only in the combination treatment group. Radiomic CT feature analysis of pre-treatment images in CRC0076 and CRC0344 PDXs identified features which could phenotypically discriminate between models, but were not predictive of treatment responses. Collectively our data indicate that systems modelling may identify metastatic (m)CRC patients benefitting from ABT-199, and that 18F-FDG-PET could independently support such predictions.

Glioblastoma (GBM), a highly invasive and vascular malignancy is shown to rapidly develop resistance and evolve to a more invasive phenotype following bevacizumab (Bev) therapy. Rho Guanine Nucleotide Exchange Factor proteins (RhoGEFs) are mediators of key components in Bev resistance pathways, GBM and Bev-induced invasion. To identify GEFs with enhanced mRNA expression in the leading edge of GBM tumours, a cohort of GEFs was assessed using a clinical dataset. The GEF &beta, Pix/COOL-1 was identified, and the functional effect of gene depletion assessed using 3D-boyden chamber, proliferation, and colony formation assays in GBM cells. Anti-angiogenic effects were assessed in endothelial cells using tube formation and wound healing assays. In vivo effects of &beta, Pix/COOL-1-siRNA delivered via RGD-Nanoparticle in combination with Bev was studied in an invasive model of GBM. We found that siRNA-mediated knockdown of &beta, Pix/COOL-1 in vitro decreased cell invasion, proliferation and increased apoptosis in GBM cell lines. Moreover &beta, Pix/COOL-1 mediated endothelial cell migration in vitro. Mice treated with &beta, Pix/COOL-1 siRNA-loaded RGD-Nanoparticle and Bev demonstrated a trend towards improved median survival compared with Bev monotherapy. Our hypothesis generating study suggests that the RhoGEF &beta, Pix/COOL-1 may represent a target of vulnerability in GBM, in particular to improve Bev efficacy.

Angiogenesis is a key tumor microenvironment (TME) event underpinning tumor growth and metastasis. Nevertheless, the relatively poor performance of anti-angiogenic therapies in clinical trials compared to pre-clinical studies implies that classical subcutaneous xenograft models have limited predictive potential in this setting. To address this issue, we established orthotopic surgical resection models of breast cancer, which replicate the phenotype of clinical post-resection micro-metastasis. To demonstrate the power and precision of these models, we recapitulated the BETH adjuvant trial (NCT00625898) where the addition of bevacizumab (BVZ) to chemotherapy plus trastuzumab (Trast) failed to provide additional benefit. SCID mice were orthotopically implanted with bioluminescent Her2+ MDA-MB-231 or HCC1954 cells and tumors resected c.5 weeks later. Following resection, mice were treated with 10 mg/kg Trast +5 mg/kg paclitaxel (PAC) IP once weekly for 6 cycles +/− weekly BVZ (5 mg/kg IP). Metastasis was monitored by imaging. Using these models our data confirms that the addition of the anti-angiogenic antibody BVZ to adjuvant Trast + chemotherapy provides no additional benefit compared with Trast + chemotherapy alone. Previous studies using non-resection subcutaneously engrafted xenografts failed to predict this outcome. Our results provide compelling evidence for the utility of cell line xenograft resection models to predict clinical outcome for TME targeting agents.

GBM is a devastating disease with peak incidence in the seventh decade. Pre-clinical models are essential for studying resistance mechanisms and screening novel therapies. However, historically these models have failed to predict response in humans. Current models seldom incorporate surgical resection, and commonly use young animals whose immune contexture differs from older patients. Here, we have established an orthotopic model employing the syngeneic mesenchymal-NFpp10a-cell line which incorporates surgical resection in aged mice. We further characterise response to ICI and temozolomide monotherapy. NFpp10a and GL261-cell lines were exposed in vitro to irradiation (0Gy/2Gy/5Gy) and response assessed using colony formation assays. NFpp10a formed significantly more colonies at 5Gy compared to GL261 at both day 10 (NFpp10a 5.167 vs GL261 1.4; p=0.0017) and day 14 (NFpp10a 3.5 vs GL261 0; p< 0.0001). Hence, NFpp10a displays increased radioresistance. Next, NFpp10a-luciferin expressing cells were orthotopically implanted into young (6-8weeks;n=16) and aged (18months;n=16) C57BL/6-mice. Weekly bioluminescence imaging (BLI) was performed to monitor growth. Mice undergoing resection showed a median 18.47-fold drop in BLI signal. We demonstrated resection survival advantage in aged mice (Resection:33.5 days vs Non-Resection:18 days, p= 0.0166) and showed young age to be a positive prognostic factor (Young:62 days vs Aged:22 days, p=0.0002). Subsequently, we orthotopically implanted NFpp10a-Luc2 cells into C57BL/6 mice and treated with temozolomide (n=24) or PBS control (n=23), and anti-PD1 (n=24) or IgG (n=23). We observed that temozolomide and anti-PD1 monotherapy had no impact on NFpp10-Luc2 growth (temozolomide-overall:p=0.9001, anti-PD1-overall:p=0.7933) or survival (temozolomide-overall:p=0.3035, anti-PD1-overall:p=0.6328). Overall, we have established an NFpp10-Luc2 mesenchymal-GBM model in aged mice which incorporates surgical resection and accurately displays significant resistance to temozolomide and anti-PD1 monotherapy. We are currently employing this model to study the efficacy of neoadjuvant anti-PD1 therapy. Mechanistic analyses with multiplex-immunohistochemistry, scRNA and whole exome sequencing are planned to interrogate treatment effects on the tumor microenvironment.

Heart failure with preserved ejection fraction (HFpEF) is emerging as a metabolic disease. HFpEF initiation and progression is associated with the pro-inflammatory state found in conditions such as hypertension, obesity and diabetes. Although the role of dietary fat in the genesis of metabolic disorders and tissue inflammation has been characterised, dietary fat induced cardiac pathology and inflammation in the context of pressure-overload is less well defined. In this study, we reveal the cardioprotective effects of saturated fat intake on cardiac phenotype and cardiac inflammation in an established rat model of hypertension. Ten week old male normotensive Wistar (WKY), control rats (n=10), and matched SHR (n=20), were split into low-10%kcal and high-45%kcal fat chow. After 16 wks of diet intake, bodyweight profiles were similar among all groups (p=NS). Unconscious tail-cuff plethysmography confirmed elevated arterial pressure (>140mmHg) in both SHR dietary groups, (SBP in 45%kcal; 154.4 ± 21.7 mmHg, p+ macrophage infiltration was increased (10%kcal; 122.5 cells/mm 2 , & 45%kcal; 151.1 cells/mm 2 , p

Sunitinib is a tyrosine kinase inhibitor approved for the treatment of multiple solid tumors. However, cardiotoxicity is of increasing concern, with a need to develop rational mechanism driven approaches for the early detection of cardiac dysfunction. We sought to interrogate changes in cardiac energy substrate usage during sunitinib treatment, hypothesising that these changes could represent a strategy for the early detection of cardiotoxicity. Balb/CJ mice or Sprague-Dawley rats were treated orally for 4 weeks with 40 or 20 mg/kg/day sunitinib. Cardiac positron emission tomography (PET) was implemented to investigate alterations in myocardial glucose and oxidative metabolism. Following treatment, blood pressure increased, and left ventricular ejection fraction decreased. Cardiac [18F]-fluorodeoxyglucose (FDG)-PET revealed increased glucose uptake after 48 hours. [11C]Acetate-PET showed decreased myocardial perfusion following treatment. Electron microscopy revealed significant lipid accumulation in the myocardium. Proteomic analyses indicated that oxidative metabolism, fatty acid β-oxidation and mitochondrial dysfunction were among the top myocardial signalling pathways perturbed. Sunitinib treatment results in an increased reliance on glycolysis, increased myocardial lipid deposition and perturbed mitochondrial function, indicative of a fundamental energy crisis resulting in compromised myocardial energy metabolism and function. Our findings suggest that a cardiac PET strategy may represent a rational approach to non-invasively monitor metabolic pathway remodeling following sunitinib treatment.

Background: Glioblastoma (GBM), being a highly vascularised and locally invasive tumour, is an attractive target for anti-angiogenic and anti-invasive therapies. The GBM/endothelial cell response to gossypol/temozolomide (TMZ) treatment was investigated with a particular aim to assess treatment effects on cancer hallmarks. Methods: Cell viability, endothelial tube formation and GBM tumour cell invasion were variously assessed following combined treatment in vitro. The U87MG-luc2 subcutaneous xenograft model was used to investigate therapeutic response in vivo. Viable tumour response to treatment was interrogated using immunohistochemistry. Combined treatment protocols were also tested in primary GBM patient-derived cultures. Results: An endothelial/GBM cell viability inhibitory effect, as well as an anti-angiogenic and anti-invasive response, to combined treatment have been demonstrated in vitro. A significantly greater anti-proliferative (P=0.020, P=0.030), anti-angiogenic (P=0.040, P

Background: One of the key events in the progression of cancer metastasis is the migration of tumor cells through the vascular endothelium. Tumors induce abnormal endothelial permeability to promote cancer cell invasion. Recently, inhibition of tumor-induced vascular permeability has been shown to attenuate metastasis in vivo (Tichet M et al. Nat Commun. 2015;6:6993). Low molecular weight heparins (LMWHs) inhibit metastasis in vivo (Klerk et al. J Clin Oncol. 2005;23(10):2130-5) but may cause bleeding complications when used at effective doses. Consequently, LMWHs are unlikely to be used for prevention of metastatic progression unless bleeding side-effects can be diminished. To address this issue, we have recently demonstrated that a LMWH/statin combination (tinzaparin and simvastatin) attenuates abnormal vascular permeability and reduces epithelial cell transmigration at concentrations unlikely to cause bleeding side-effects in vivo. (Kevane et al. Res Pract Thromb Haemost. 2017;1(1)). Here, we aim to interrogate the anti-metastatic effect of the LMWH/statin combination (tinzaparin and simvastatin) in an orthotopic surgical resection model of triple negative breast cancer implementing a LMWH/stain dose that does not increase bleeding risk. Methods: NOD/SCID mice were surgically implanted with 5x105 MDA-MB-231-LUC2 triple negative breast cancer cells in the right inguinal mammary fat pad. Tumors were allowed to grow until they reached 250mm3. Subsequently, primary tumors were surgically resected. 5 days post-resection, mice were randomized into 4 groups (group 1: 0.5% methylcellulose (vehicle), group 2: 150IU/kg TNZ, group 3: 3mg/kg SVS and group 4: TNZ (150IU/kg) and SVS (3mg/kg)) and treated daily for 4 weeks. Post-resection metastatic progression was monitored by weekly bioluminescence imaging (BLI) [IVIS Spectrum]. Animals that displayed metastatic progression or significant regrowth of primary tumour were euthanized. At time of death, apical lymph nodes and lungs were removed and fixed in 10% formalin for quantification of metastatic burden Results: Prior to study commencement it was determined that a combination of 150IU/kg TNZ and 3mg/kg SVS did not significantly increase bleeding time in a cohort of tumour naïve animals. Following primary tumor resection, BLI assessment of metastatic progression revealed that 150IU/kg TNZ, 3mg/kg SVS and combination therapy of 150IU/kg TNZ and 3mg/kg SVS significantly (P= 0.0373, P=0.0086 and P=0.0409 respectively N=11) increased the time to metastasis compared to the vehicle treated animals. Conclusion: For the first time we demonstrate that tinzaparin and simvastatin may be combined to significantly delay time to metastasis while diminishing the associated bleeding risk of LMWHs in a clinically relevant mouse model of aggressive triple negative breast cancer. Citation Format: Ian S. Miller, Liam P. Shiels, Grace Buckley, Kate Connor, Annette T. Byrne, Fionnuala Ní Ainle. Interrogating the in vivo anti-metastatic action of tinzaparin and simvastatin in an orthotopic surgical resection mouse model of triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2012.

Background: Prior data (Barron et al. Cancer Res. 2014 74:4065-77) suggests that pre-diagnostic exposure to aspirin can have significant effects on breast tumor biology and patient outcome. It has been proposed that aspirin inhibition of COX-2 may suppress lymphangiogenesis and metastasis (Karnezis et al Cancer Cell. 2014. 21:181-95). Here, we sought to recapitulate pre-diagnostic aspirin exposure in rodent models of Her2+ breast cancer and elucidate mechanisms of action. We also determined the effect of aspirin on tumor stroma, using a co-culture system of human tumor and mesenchymal stem cells (MSC). Methods: NOD/SCID mice were orthotopically implanted with Her2+ MDA-MB-231 or HCC1954 cells. 48hr later, animals began a daily low dose [30mg/kg or 120mg/kg] of aspirin, until tumors reached 250mm3. They were then resected. 3 weeks later, HCC1954 implanted animals were treated with trastuzumab (15mg/kg) and paclitaxel (5mg/kg) for 6 weeks. Primary tissues were analysed by immunohistochemistry to assess VEGF-C, -D, COX-2, LYVE1 and CD31. RNAseq was performed on tumours to identify aspirin perturbed molecular pathways. To determine the stromal response to aspirin, patient derived MSCs were cultured either alone or with HCC1954 cells and exposed to aspirin (2.5 or 7.5mM). Secreted VEGF-C was quantified. A tubule formation assay was performed to determine the impact of aspirin on angiogenesis. Pro-angiogenic protein expression was investigated using a human angiogenesis array platform. Results: A significant delay in tumor growth was observed in both tumor models following aspirin treatment (p Conclusion: We have successfully recapitulated pre-treatment aspirin response in surgical resection models of Her2+ breast cancer, with IHC analysis confirming the impact of treatment on angiogenic and lymphangiogenic factors. RNAseq analysis implicates aspirin mediated alterations in cellular metabolism. Our data further reveals increased response to aspirin in stromal cell populations. Citation Format: Ian S. Miller, Sonja Khan, Liam P. Shiels, Sudipto Das, Bruce Moran, Finbarr P. Leacy, Paul M. Loadman, Robert S. Kerbel, Darran O' Connor, Kathleen Bennett, Róisín M. Dwyer, Annette T. Byrne. Mechanistic interrogation of pre-treatment low dose aspirin effects in HER 2 positive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1254. doi:10.1158/1538-7445.AM2017-1254

Malignant pleural mesothelioma (MPM) is an aggressive inflammatory cancer associated with exposure to asbestos. Untreated, MPM has a median survival time of 6 months,and most patients die within two years of diagnosis. There is an urgent need to identify new therapies for treating MPM patients.

Intrinsic and acquired resistance to HER-targeting drugs occurs in a significant proportion of HER2-overexpressing breast cancers. Thus, there remains a need to identify predictive biomarkers that could improve patient selection and circumvent these types of drug resistance. Here, we report the identification of neuromedin U (NmU) as an extracellular biomarker in cells resistant to HER-targeted drugs. NmU overexpression occurred in cells with acquired or innate resistance to lapatinib, trastuzumab, neratinib, and afatinib, all of which displayed a similar trend upon short-term exposure, suggesting NmU induction may be an early response. An analysis of 3,489 cases of breast cancer showed NmU to be associated with poor patient outcome, particularly those with HER2-overexpressing tumors independent of established prognostic indicators. Ectopic overexpression of NmU in drug-sensitive cells conferred resistance to all HER-targeting drugs, whereas RNAi-mediated attenuation sensitized cells exhibiting acquired or innate drug resistance. Mechanistic investigations suggested that NmU acted through HSP27 as partner protein to stabilize HER2 protein levels. We also obtained evidence of functional NmU receptors on HER2-overexpressing cells, with the addition of exogenous NmU eliciting an elevation in HER2 and EGFR expression along with drug resistance. Finally, we found that NmU seemed to function in cell motility, invasion, and anoikis resistance. In vivo studies revealed that NmU attenuation impaired tumor growth and metastasis. Taken together, our results defined NmU as a candidate drug response biomarker for HER2-overexpressing cancers and as a candidate therapeutic target to limit metastatic progression and improve the efficacy of HER-targeted drugs. Cancer Res; 74(14); 3821–33. ©2014 AACR.

Background: Sunitinib is a multi-targeted agent approved for treatment of a number of cancers. However, since approval, data has continually emerged relating to toxicity profiles including hypertension, hand-foot syndrome and fatigue. Underlying mechanisms are unresolved. It has been hypothesised that the multi-parameter toxicity profile is related to ‘on-target’ kinase inhibition in ‘off-target’ tissues. Methods: To interrogate off-target effects, the Zeptosens Reverse Phase protein Array (RPA) platform was used to assess tissues obtained from mice treated with sunitinib (40 mg/kg) for 4 weeks. Additional tissue was collected for histological analyses and pathophysiologic changes assessed. Results: RPA data analyses on all organs collected (heart, kidney, liver, brain, intestine and skin) revealed the presence of differentially expressed proteins associated with damage and/or stress. Of note, Cyclin D1, MEK and phosphorylated-p21(CIP/WAF1) expression increased by 1.8-fold (p < 0.05), 2.2-fold (p < 0.1) and 1.7-fold (p < 0.1) respectively in the kidneys of sunitinib treated mice. These proteins are associated with kidney damage after chemotherapy, and induction of genes associated with renal immune response, inflammation and apoptosis. Mild proteinuria was observed in sunitinib treated animals, however no gross change in renal glomerular ultrastructure was visible via electron microscopy. Phosphorylated-FGFR1, cleaved Caspase-7, and phosphorylated-cMYC expression decreased by 0.45-fold (p < 0.05), 0.4-fold (p < 0.1) and 0.8-fold (p < 0.1) respectively in the skin of sunitinib treated mice. Down-regulation of these proteins has been associated with a perturbation of cutaneous wound healing (p-FGFR1/cleaved Caspase-7). Mice treated with high dose sunitinib (80 mg/kg) showed overt signs of skin toxicity. Histopathologic studies of the thyroid gland revealed decreased thyroid epithelial cell height (p < 0.05). Nevertheless, serum levels of triiodothyronine and thyroxine remained unchanged. An orthogonal validation study (Western blotting) is ongoing based on gene ontology, pathway analysis and observed fold changes in critical signalling pathway proteins involved in cellular stress. Conclusions: Implementation of a combined histopathologic/ RPA approach may provide a sensitive method to mechanistically elucidate the off-target toxicity sequelae associated with TKIs approved in the oncology setting. Work was supported by an EU funded Industry Academia Pathways and Partnerships Marie Curie Award (AngioTox) Grant Number 251528. RPAs were performed at Bayer Technology Services, Leverkusen, Germany. Citation Format: Alice C. O’Farrell, Adam Lafferty, Ian Miller, Rhys Evans, Maurice Cary, David Murray, Marina Alamanou, Girish Mallya Udupi, Liam Shiels, William M. Gallagher, Annette T. Byrne. Proteomic analysis of off-target toxicities following treatment with the tyrosine kinase inhibitor sunitinib. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3010.