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Colin Clarke,
Stephen F Madden,
Padraig Doolan,
Sinead T Aherne,
Helena Joyce,
Lorraine O' Driscoll,
William M Gallagher,
Bryan T Hennessy,
Michael Moriarty, John Crown,
Susan Kennedy,
Martin Clynes
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ABSTRACT: Weighted gene coexpression network analysis (WGCNA) is a powerful "guilt-by-association" based method to extract coexpressed groups of genes from large heterogeneous mRNA expression datasets. We have utilised WGCNA to identify 11 corregulated gene clusters across 2342 breast cancer samples from 13 microarray-based gene expression studies. A number of these transcriptional modules were found to be correlated to clinicopathological variables (e.g. tumour grade), survival endpoints for breast cancer as a whole (disease free survival (DFS), distant disease free survival (DDFS) and overall survival (OS)) and also its molecular subtypes (luminal A, luminal B, HER2+ and basal-like). Examples of findings arising from this work include the identification of a cluster of proliferation-related genes, that when upregulated correlated to increased tumour grade and were associated with poor survival in general. The prognostic potential of novel genes e.g. ubiquitin-conjugating enzyme E2S (UBE2S) within this group were confirmed in an independent dataset. In addition, gene clusters were also associated with survival for breast cancer molecular subtypes including a cluster of genes that was found to correlate with prognosis exclusively for basal-like breast cancer. The upregulation of several single genes within this coexpression cluster e.g. the potassium channel, subfamily K, member 5 (KCNK5) were associated with poor outcome for the basal-like molecular subtype. We have developed an online database to allow user friendly access to the coexpression patterns and the survival analysis outputs uncovered in this study (Availability: http://glados.ucd.ie/Coexpression/).
Carcinogenesis 06/2013; · 5.70 Impact Factor
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ABSTRACT: PARP inhibitors, both as monotherapy and in combination with cytotoxic drugs, are currently undergoing clinical trials in several different cancer types. In this investigation, we compared the antiproliferative activity of two PARP/putative PARP inhibitors, i.e., olaparib and iniparib, in a panel of 14 breast cancer cell lines (seven tripe-negative and seven non-triple-negative). In almost all cell lines investigated, olaparib was a more potent inhibitor of cell growth than iniparib. Inhibition by both drugs was cell line-dependent and independent of the molecular subtype status of the cells, i.e., whether cells were triple-negative or non-triple negative. Although the primary target of PARP inhibitors is PARP1, no significant association was found between baseline levels of PARP1 activity and inhibition with either agent. Similarly, no significant correlation was evident between sensitivity and levels of CDK1, BRCA1 or miR-182. Combined addition of olaparib and either the CDK1 inhibitor, RO-3306 or a pan HER inhibitor (neratinib, afatinib) resulted in superior growth inhibition to that obtained with olaparib alone. We conclude that olaparib, in contrast to iniparib, is a strong inhibitor of breast cancer cell growth and may have efficacy in breast cancer irrespective of its molecular subtype, i.e., whether HER2-positive, estrogen receptor (ER)-positive or triple-negative. Olaparib, in combination with a selective CDK1 inhibitor or a pan HER inhibitor, is a potential new approach for treating breast cancer.
Cancer biology & therapy 06/2013; 14(6):537-45. · 2.64 Impact Factor
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ABSTRACT: BACKGROUND: Companion biomarkers are biomarkers that are used in combination with specific therapies and that prospectively help predict likely response or severe toxicity. In this article we review the role of companion biomarkers in guiding treatment in patients with cancer.Content:In addition to the established companion biomarkers such as estrogen receptors and HER2 (human epidermal growth factor receptor 2) in breast cancer, several new companion biomarkers have become available in recent years. These include v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations for the selection of patients with advanced colorectal cancer who are unlikely to benefit from anti-epidermal growth factor receptor antibodies (cetuximab or panitumumab), epidermal growth factor receptor (EGFR) mutations for selecting patients with advanced non-small cell lung cancer (NSCLC) for treatment with tyrosine kinase inhibitors (gefitinib or erlotinib), v-raf murine sarcoma viral oncogene homolog B1 (BRAF) mutations for selecting patients with advanced melanoma for treatment with anti-BRAF agents (vemurafenib and dabrafenib), and anaplastic lymphoma receptor tyrosine kinase (ALK) translocations for identifying patients with NSCLC likely to benefit from crizotinib.Summary:The availability of companion biomarkers should improve drug efficacy, decrease toxicity, and lead to a more individualized approach to cancer treatment.
Clinical Chemistry 05/2013; · 7.91 Impact Factor
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ABSTRACT: BACKGROUND: Triple-negative breast cancer (TNBC) accounts for 15-20% of breast cancers but is responsible for a disproportionate number of deaths. We investigated the relevance, in TNBC, of nano-sized exosomes expelled from cells. Specifically, we compared effects of exosomes derived from the claudin-low TNBC cell line Hs578T and its more invasive Hs578Ts(i)8 variant, as well as exosomes from TNBC patient sera compared to normal sera. METHODS: Exosomes were isolated from conditioned media (CM) of Hs578T and Hs578Ts(i)8 cells and from sera by filtration and ultracentrifugation. Successful isolation was confirmed by transmission electron microscopy and immunoblotting. Subsequent analysis, of secondary/recipient cells in response to exosomes, included proliferation; motility/migration; invasion; anoikis assays and endothelial tubule formation assays. RESULTS: Hs578Ts(i)8-exosomes versus Hs578T-exosomes significantly increased the proliferation, migration and invasion capacity of all three recipient cell lines evaluated i.e. SKBR3, MDA-MB-231 and HCC1954. Exosomes from Hs578Ts(i)8 cells also conferred increased invasiveness to parent Hs578T cells. Hs578Ts(i)8-exosomes increased sensitivity of SKBR3, MDA-MB-231 and HCC1954 to anoikis when compared to the effects of Hs578T-exosomes reflecting the fact that Hs578Ts(i)8 cells are themselves innately more sensitive to anoikis. In relation to vasculogenesis and subsequent angiogenesis, Hs578Ts(i)8-exosomes versus Hs578T-exosomes stimulated significantly more endothelial tubules formation. Finally, our pilot translational study showed that exosomes from TNBC patients' sera significantly increased recipient cells' invasion when compared to those derived from age- and gender-matched healthy control sera. CONCLUSION: This study supports the hypothesis that TNBC exosomes may be involved in cancer cell-to-cell communication, conferring phenotypic traits to secondary cells that reflect those of their cells of origin.
European journal of cancer (Oxford, England: 1990) 02/2013; · 4.12 Impact Factor
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Brigid C Browne,
Alex J Eustace,
Susan Kennedy,
Neil A O'Brien,
Kasper Pedersen,
Martina S J McDermott,
Annemarie Larkin,
Jo Ballot,
Thamir Mahgoub,
Francesco Sclafani,
Stephen Madden,
John Kennedy,
Michael J Duffy, John Crown,
Norma O'Donovan
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ABSTRACT: Insulin-like growth factor-1 receptor (IGF1R) signalling is implicated in resistance to trastuzumab. However, the benefit of co-targeting HER2 and IGF1R has not been extensively studied, and the relationship between activated IGF1R and clinical response to trastuzumab has not been reported. This study aimed to evaluate the combination of trastuzumab with IGF1R tyrosine kinase inhibitors (TKIs) in a panel of HER2-positive breast cancer cell lines, and to examine the relationship between IGF1R expression and activation and response to trastuzumab in HER2-positive breast cancer patients. The anti-proliferative effects of trastuzumab combined with IGF1R TKIs BMS-536924 or NVP-AEW541 were measured in nine HER2-positive cell lines. IGF1R and phosphorylated IGF1R/insulin receptor (pIGF1R/IR) were measured by immunohistochemistry in 160 tumour samples from trastuzumab-treated patients (ICORG 06-22). The HER2-positive cell lines displayed varying sensitivity to IGF1R TKIs alone (IC(50)s: 0.7 to >10 μM). However, when combined with trastuzumab, a significantly enhanced effect was observed in five cell lines treated with BMS-536924, and three with NVP-AEW541. While IGF1R levels correlated with reduced response to NVP-AEW541 alone, neither IGF1R nor pIGF1R were predictive of response to BMS-536924 or NVP-AEW541 in combination with trastuzumab. Low HER2 levels correlated with response to BMS-536924 in combination with trastuzumab. Akt levels correlated with improved response to trastuzumab and NVP-AEW541 (P = 0.039). Cytoplasmic IGF1R staining was observed in all tumours, membrane IGF1R was detected in 13.8 %, and pIGF1R/IR was detected in 48.8 %. Although membrane IGF1R staining was associated with larger tumour size (P = 0.041), and lower tumour grade (P = 0.024), no association between IGF1R or pIGF1R/IR and patient survival was observed. In conclusion, while neither IGF1R expression nor activation was predictive of response to trastuzumab, these pre-clinical data provide evidence that co-targeting HER2 and IGF1R may be beneficial in some HER2-amplified breast cancers.
Breast Cancer Research and Treatment 11/2012; · 4.43 Impact Factor
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ABSTRACT: The aim of this study was to investigate the effect of lapatinib, a selective inhibitor of EGFR/HER2 tyrosine kinases, on pancreatic cancer cell lines both alone and in combination with chemotherapy. Two cell lines, BxPc-3 and HPAC, displayed the greatest sensitivity to lapatinib (IC(50) < 2 μM). Lapatinib also demonstrated some activity in three K-Ras mutated pancreatic cancer cell lines which displayed resistance to erlotinib. Drug effect/combination index (CI) isobologram analysis was used to study the interactions of lapatinib with gemcitabine, cisplatin and 5'deoxy-5'fluorouridine. Concentration-dependent anti-proliferative effects of lapatinib in combination with chemotherapy were observed. To evaluate the potential effect of lapatinib in pancreatic cancer tumours, and to identify a subset of patient most likely to benefit from lapatinib, expression of EGFR and HER2 were investigated in 72 pancreatic cancer tumour specimens by immunohistochemistry. HER2 membrane expression was observed in only 1 % of cases, whereas 44 % of pancreatic tumours expressed EGFR. Based on our in vitro results, lapatinib may provide clinical benefit in EGFR positive pancreatic ductal adenocarcinoma.
Investigational New Drugs 10/2012; · 3.36 Impact Factor
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ABSTRACT: Lapatinib, a tyrosine kinase inhibitor of HER2 and EGFR and is approved, in combination with capecitabine, for the treatment of trastuzumab-refractory metastatic breast cancer. In order to establish a possible gene expression response to lapatinib, a panel of breast cancer cell lines with varying sensitivity to lapatinib were analysed using a combination of microarray and qPCR profiling.
Co-inertia analysis (CIA), a data integration technique, was used to identify transcription factors associated with the lapatinib response on a previously published dataset of 96 microarrays. RNA was extracted from BT474, SKBR3, EFM192A, HCC1954, MDAMB453 and MDAMB231 breast cancer cell lines displaying a range of lapatinib sensitivities and HER2 expression treated with 1 μM of lapatinib for 12 hours and quantified using Taqman RT-PCR. A fold change ≥ ± 2 was considered significant.
A list of 421 differentially-expressed genes and 8 transcription factors (TFs) whose potential regulatory impact was inferred in silico, were identified as associated with lapatinib response. From this group, a panel of 27 genes (including the 8 TFs) were selected for qPCR validation. 5 genes were determined to be significantly differentially expressed following the 12 hr treatment of 1 μM lapatinib across all six cell lines. Furthermore, the expression of 4 of these genes (RB1CC1, FOXO3A, NR3C1 and ERBB3) was directly correlated with the degree of sensitivity of the cell line to lapatinib and their expression was observed to "switch" from up-regulated to down-regulated when the cell lines were arranged in a lapatinib-sensitive to insensitive order. These included the novel lapatinib response-associated genes RB1CC1 and NR3C1. Additionally, Cyclin D1 (CCND1), a common regulator of the other four proteins, was also demonstrated to observe a proportional response to lapatinib exposure.
A panel of 5 genes were determined to be differentially expressed in response to lapatinib at the 12 hour time point examined. The expression of these 5 genes correlated directly with lapatinib sensitivity. We propose that the gene expression profile may represent both an early measure of the likelihood of sensitivity and the level of response to lapatinib and may therefore have application in early response detection.
Molecular Cancer 06/2012; 11:41. · 3.99 Impact Factor
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ABSTRACT: Numerous transgenic models have been generated to study breast cancer. However, despite many advantages, traditional transgenic models for breast cancer are also burdened with difficulties in early detection and longitudinal observation of transgene-induced tumours, which in most cases are randomly located and occur at various time points. Methods such as palpation followed by mechanical measurement of the tumours are of limited value in transgenic models. There is a crucial need for making these previously generated models suitable for modern methods of tumour visualisation and monitoring, e.g. by bioluminescence-based techniques. This approach was successfully used in the current study.
A new mouse strain (MMTV-Luc2 mice) expressing Luc2 luciferase primarily in mammary tissue in females, with low-level background expression in internal organs, was generated and bred to homozygosity. After these mice were intercrossed with MMTV-PyVT mice, all double transgenic females developed mammary tumours by the age of 10 weeks, the localisation and progression of which could be effectively monitored using the luminescence-based in vivo imaging. Luminescence-based readout allowed for early visualisation of the locally overgrown mammary tissue and for longitudinal evaluation of local progression of the tumours. When sampled ex vivo at the age of 10 weeks, all tumours derived from MMTV-Luc2PyVT females displayed robust bioluminescent signal.
We have created a novel transgenic strain for visualisation and longitudinal monitoring of mammary tumour development in transgenic mice as an addition and/or a new and more advanced alternative to manual methods. Generation of this mouse strain is vital for making many of the existing mammary tumour transgenic models applicable for in vivo imaging techniques.
BMC Cancer 05/2012; 12:209. · 3.01 Impact Factor
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Journal of Clinical Oncology 05/2012; 30(26):e257-9. · 18.37 Impact Factor
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ABSTRACT: Breast cancers that are negative for estrogen receptor (ER), progesterone receptors (PR) and HER2, using standard clinical assays, have been dubbed triple-negative (TN). Unlike other molecular subtypes of invasive breast cancer, validated targeted therapies are currently unavailable for patients with TN breast cancer. Preclinical studies however, have identified several potential targets such as epidermal growth factor receptor (EGFR), SRC, MET and poly ADP ribose polymerase 1/2 (PARP1/2). Because of tumor heterogeneity, it is unlikely that any single targeted therapy will be efficacious in all patients with TN breast cancer. The rational way forward for treating these patients is likely to be biomarker-driven, combination targeted therapies or combination of targeted therapy with cytotoxic chemotherapy.
International Journal of Cancer 05/2012; 131(11):2471-7. · 5.44 Impact Factor
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Patrick O'Leary,
Bryan T. Hennessy,
Ana-Maria Gonzalez-Angulo,
Darran P. O'Connor,
Donal J. Brennan,
Yue Fan, John Crown,
Gordon B. Mills,
Fredrik Ponten,
Mathias Uhlen,
Karin Jirstrom,
William M. Gallagher,
Radoslaw Zagozdzon
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ABSTRACT: Introduction: Peroxiredoxin-1 (PRDX1) is a multifunctional protein, acting as a hydrogen peroxide (H2O2) scavenger, molecular chaperone and immune mediator. Differential expression of PRDX1 has been described in many tumor types, including lung and ovarian carcinoma. Despite the wealth of knowledge about PRDX1 functionality, its role in human breast cancer has not been fully elucidated. Preclinical studies suggest that PRDX1 may be protective against oncogene-induced mammary carcinogenesis, indicating that it may be an important biomarker. In this study, we describe PRDX1 as a robust prognostic biomarker in estrogen receptor α (ER)-positive breast cancer and propose a molecular mechanism which explains this observation.
Materials and Methods: The anti-PRDX1 antibody was validated in breast cancer cell lines using Western blotting, immunohistochemistry and reverse phase protein array (RPPA) technology following exogenous overexpression or shRNA-mediated knockdown of PRDX1. PRDX1 protein expression was evaluated using two independent breast cancer cohorts: a 512 patient tissue microarray (TMA) and a 712 patient RPPA cohort. Increase in cellular content of H2O2 was accomplished via treatment of cell lines with exogenous (H2O2) or activation of oncogenic pathways (611CTF-HER2 overexpression). Western blotting and RPPA were used to assess changes in ERα and oncogenic signaling proteins in cell lines and a third breast cancer cohort, consisting of 410 patients.
Results: High expression of PRDX1 protein was associated with a favorable outcome in ER-positive, but not ER-negative breast cancer cases across both cohorts (evaluable data for 975 patients total; log-rank p-value: TMA=0.022; RPPA=0.002). Exogenous treatment with (H2O2) or induction of oncogenic signaling suppressed ERα protein and stimulated phosphorylation/activation of Akt kinase in ER-positive cell lines. Knockdown of PRDX1 further sensitized the cells to the (H2O2)-mediated effect whilst overexpression protects against it. These observations were further validated in an additional cohort of ER-positive tumor samples, where PRDX1 protein levels correlated with ERα (positive) and pAkt-473 protein expression (negative).
Conclusions: Our findings provide robust evidence of the importance of PRDX1 as a biomarker of favorable prognosis in ER-positive breast cancer. We suggest that PRDX1 acts as a shielding mechanism for ERα protein by counteracting (H2O2)-mediated suppression of this molecule in ER-positive tumors, and suppressing phosphorylation of Akt kinase under these oxidative stress conditions. This strongly implies that (H2O2) and PRDX1 are important role players in the crosstalk between oncogenic (e.g. HER2- or PI3K-induced) and ER-driven signaling pathways in breast cancer. Understanding the mechanisms underlying the regulation of oxidative stress response in ER-positive breast cancer can allow for better tailoring the management of this disease.
Proceedings of the AACR Special Conference on Molecularly Targeted Therapies: Mechanisms of Resistance, San Diego, CA; 05/2012
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Lynnette Fernández-Cuesta,
Catherine Oakman,
Priscila Falagan-Lotsch,
Ke-Seay Smoth,
Emmanuel Quinaux,
Marc Buyse,
M Stella Dolci,
Evandro De Azambuja,
Pierre Hainaut,
Patrizia Dell'orto,
Denis Larsimont,
Prudence A Francis, John Crown,
Martine Piccart-Gebhart,
Giuseppe Viale,
Angelo Di Leo,
Magali Olivier
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ABSTRACT: Pre-clinical data suggest p53-dependent anthracycline-induced apoptosis and p53-independent taxane activity. However, dedicated clinical research has not defined a predictive role for TP53 gene mutations. The aim of the current study was to retrospectively explore the prognosis and predictive values of TP53 somatic mutations in the BIG 02-98 randomized phase III trial in which women with node-positive breast cancer were treated with adjuvant doxorubicin-based chemotherapy with or without docetaxel.
The prognostic and predictive values of TP53 were analyzed in tumor samples by gene sequencing within exons 5 to 8. Patients were classified according to p53 protein status predicted from TP53 gene sequence, as wild-type (no TP53 variation or TP53 variations which are predicted not to modify p53 protein sequence) or mutant (p53 nonsynonymous mutations). Mutations were subcategorized according to missense or truncating mutations. Survival analyses were performed using the Kaplan-Meier method and log-rank test. Cox-regression analysis was used to identify independent predictors of outcome.
TP53 gene status was determined for 18% (520 of 2887) of the women enrolled in BIG 02-98. TP53 gene variations were found in 17% (90 of 520). Nonsynonymous p53 mutations, found in 16.3% (85 of 520), were associated with older age, ductal morphology, higher grade and hormone-receptor negativity. Of the nonsynonymous mutations, 12.3% (64 of 520) were missense and 3.6% were truncating (19 of 520). Only truncating mutations showed significant independent prognostic value, with an increased recurrence risk compared to patients with non-modified p53 protein (hazard ratio = 3.21, 95% confidence interval = 1.740 to 5.935, P = 0.0002). p53 status had no significant predictive value for response to docetaxel.
p53 truncating mutations were uncommon but associated with poor prognosis. No significant predictive role for p53 status was detected.
ClinicalTrials.gov NCT00174655.
Breast cancer research: BCR 05/2012; 14(3):R70. · 5.24 Impact Factor
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ABSTRACT: In this article, we report the findings of a comprehensive structure-activity relationship study of N-(6-ferrocenyl-2-naphthoyl) dipeptide ethyl esters, in which novel analogues were designed, synthesized, and evaluated in vitro for antiproliferative effect. Two new compounds, 2 and 16, showed potent nanomolar activity in the H1299 NSCLC cell line, with exceptional IC(50) values of 0.13 and 0.14 μM, respectively. These compounds were also found to have significant activity in the Sk-Mel-28 malignant melanoma cell line (IC(50) values of 1.10 and 1.06 μM, respectively). Studies were also conducted to elucidate the mode of action of these novel organometallic anticancer compounds. Cell cycle analysis in the H1299 cell line suggests these compounds induce apoptosis, while guanine oxidation studies confirm that 2 is capable of generating oxidative damage via a ROS-mediated mechanism.
Journal of Medicinal Chemistry 05/2012; 55(11):5455-66. · 4.80 Impact Factor
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David Cameron,
Michelle Casey,
Michael Press,
Deborah Lindquist,
Tadeusz Pienkowski,
C. Gilles Romieu,
Stephen Chan,
Agnieszka Jagiello-Gruszfeld,
Bella Kaufman, John Crown, [......],
Vera Gorbounova,
Johannes Isaac Raats,
Dimosthenis Skarlos,
Beth Newstat,
Debasish Roychowdhury,
Paolo Paoletti,
Cristina Oliva,
Stephen Rubin,
Steven Stein,
Charles E. Geyer
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ABSTRACT: Purpose Lapatinib is a small molecule, dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR) and human epidermal
growth factor receptor type 2 (HER2). Initial results of a phase III trial demonstrated that lapatinib plus capecitabine is
superior to capecitabine alone in women with HER2-positive advanced breast cancer that progressed following prior therapy
including trastuzumab. Updated efficacy and initial biomarker results from this trial are reported. Methods Women with HER2-positive, locally advanced or metastatic breast cancer previously treated with anthracycline-, taxane-, and
trastuzumab-containing regimens were randomized to lapatinib 1,250mg/day continuously plus capecitabine 2,000mg/m2 days1–14 of a 21-day cycle or capecitabine 2,500mg/m2 on the same schedule. The primary endpoint was time to progression (TTP) as determined by an independent review panel. Relationship
between progression-free survival (PFS) and tumor HER2 expression and serum levels of HER2 extracellular domain (ECD) were
assessed. Results 399 women were randomized. The addition of lapatinib prolonged TTP with a hazard ratio (HR) of 0.57 (95% CI, 0.43–0.77; P<0.001) and provided a trend toward improved overall survival (HR: 0.78, 95% CI: 0.55–1.12, P=0.177), and fewer cases with CNS involvement at first progression (4 vs. 13, P=0.045). Baseline serum HER2 ECD did not predict for benefit from lapatinib. Conclusion The addition of lapatinib to capecitabine provides superior efficacy for women with HER2-positive, advanced breast cancer
progressing after treatment with anthracycline-, taxane-, and trastuzumab-based therapy. Biomarker studies could not identify
a subgroup of patients who failed to benefit from the addition of lapatinib to capecitabine.
Breast Cancer Research and Treatment 04/2012; 112(3):533-543. · 4.43 Impact Factor
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ABSTRACT: Overexpression of HER-2 in breast cancer is frequently associated with expression of EGFR, and EGFR expression influences
response to HER-2 inhibition. The aim of this study was to examine the effects of combining dual inhibition of EGFR and HER-2,
using trastuzumab, gefitinib and lapatinib, in HER-2 overexpressing breast cancer cells. Combination proliferation assays
were performed in two HER-2 positive breast cancer cell lines, SKBR-3 and BT-474. Trastuzumab combined with lapatinib was
also tested in BT-474 xenografts. In proliferation assays, dual targeting with trastuzumab and gefitinib or lapatinib showed
synergy or additivity in both SKBR-3 and BT-474 cells. Trastuzumab (10 nM) or gefitinib (5 µM) alone did not induce significant
apoptosis, whereas lapatinib (0.75 µM) induced significant apoptosis in SKBR-3 cells. Trastuzumab combined with lapatinib
further enhanced apoptosis induction. Trastuzumab (10 nM) and gefitinib (5 µM) induced apoptosis comparable to lapatinib alone
(0.75 µM), suggesting that inhibition of both EGFR and HER-2 may be required to induce apoptosis in these cells. Pre-treatment
with trastuzumab and gefitinib or lapatinib enhanced response to chemotherapy in vitro. The combination of trastuzumab and lapatinib also effectively blocked tumour growth in vivo. Dual targeting of EGFR and HER-2, by combining trastuzumab with EGFR/HER-2 tyrosine kinase inhibitors, may improve response
in HER-2 overexpressing breast cancer cells that also express EGFR.
KeywordsBreast tumour–ErbB2–Epidermal growth factor receptor–Gefitinib–Herceptin–Lapatinib
Investigational New Drugs 04/2012; 29(5):752-759. · 3.36 Impact Factor
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ABSTRACT: Early detection of cancer is vital to improved overall survival rates. At present, evidence is accumulating for the clinical
value of detecting occult tumor cells in peripheral blood, plasma, and serum specimens from cancer patients. Both molecular
and cellular approaches, which differ in sensitivity and specificity, have been used for such means. Circulating tumor cells
and extracellular nucleic acids have been detected within blood, plasma, and sera of cancer patients. As the presence of malignant
tumors are clinically determined and/or confirmed upon biopsy procurement—which in itself may have detrimental effects in
terms of stimulating cancer progression/metastases—minimally invasive methods would be highly advantageous to the diagnosis
and prognosis of breast cancer and the subsequent tailoring of targeted treatments for individuals, if reliable panels of
biomarkers suitable for such an approach exist. Herein, we review the current advances made in the detection of such circulating
tumor cells and nucleic acids, with particular emphasis on extracellular nucleic acids, specifically extracellular mRNAs and
discuss their clinical relevance.
KeywordsBreast cancer-Extracellular nucleic acids-Circulating tumor cells-Exosomes-Cancer stem cells
Breast Cancer Research and Treatment 04/2012; 123(3):613-625. · 4.43 Impact Factor
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Sara A Hurvitz,
David J Betting,
Howard M Stern,
Emmanuel Quinaux,
Jeremy Stinson,
Somasekar Seshagiri,
Ying Zhao,
Marc Buyse,
John Mackey,
Adrian Driga, [......], John Crown,
Carla Falkson,
Adam Brufsky,
Tadeusz Pienkowski,
Wolfgang Eiermann,
Miguel Martin,
Valerie Bee,
Omkar Marathe,
Dennis J Slamon,
John M Timmerman
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ABSTRACT: The mechanisms by which trastuzumab imparts clinical benefit remain incompletely understood. Antibody-dependent cellular cytotoxicity via interactions with Fcγ receptors (FcγR) on leukocytes may contribute to its antitumor effects. Single-nucleotide polymorphisms (SNP) in FCGR3A and FCGR2A genes lead to amino acid substitutions at positions 158 and 131, respectively, and affect binding of antibodies to FcγR such that 158V/V and 131H/H bind with highest affinity. This study aimed to determine whether high-affinity SNPs are associated with disease-free survival (DFS) among patients with HER2-positive nonmetastatic breast cancer.
Genomic DNA was isolated from 1,286 patients enrolled in a trial of adjuvant trastuzumab-based chemotherapy. Genotyping was conducted using Sanger sequencing and Sequenom mass spectrometry.
Patient samples (N = 1,189) were successfully genotyped for FCGR3A and 1,218 for FCGR2A. Compared with the overall results of the BCIRG006 study, in the subset of patients genotyped in this analysis, a less robust improvement in DFS was observed for the trastuzumab arms than control arm (HR, 0.842; P = 0.1925). When stratified for prognostic features, the HR in favor of trastuzumab was consistent with that of the overall study (HR, 0.74; P = 0.036). No correlation between DFS and FCGR3A/2A genotypes was seen for trastuzumab-treated patients (158V/V vs. V/F vs. F/F, P = 0.98; 131H/H vs. H/R vs. R/R, P = 0.76; 158V/V and/or 131H/H vs. others, P = 0.67).
This analysis evaluating the association between FCGR3A/2A genotypes and trastuzumab efficacy in HER2-positive breast cancer did not show a correlation between FCGR3A-V/F and FCGR2A-H/R SNPs and DFS in patients treated with trastuzumab.
Clinical Cancer Research 04/2012; 18(12):3478-86. · 7.74 Impact Factor
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Claire Corcoran,
Sweta Rani,
Keith O'Brien,
Amanda O'Neill,
Maria Prencipe,
Rizwan Sheikh,
Glenn Webb,
Ray McDermott,
William Watson, John Crown,
Lorraine O'Driscoll
[show abstract]
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ABSTRACT: Hormone-refractory prostate cancer remains hindered by inevitable progression of resistance to first-line treatment with docetaxel. Recent studies suggest that phenotypic changes associated with cancer may be transferred from cell-to-cell via microvesicles/exosomes. Here we aimed to investigate phenotypic changes associated with docetaxel-resistance in order to help determine the complexity of this problem and to assess the relevance of secreted exosomes in prostate cancer.
Docetaxel-resistant variants of DU145 and 22Rv1 were established and characterised in terms of cross-resistance, morphology, proliferation, motility, invasion, anoikis, colony formation, exosomes secretion their and functional relevance. Preliminary analysis of exosomes from relevant serum specimens was also performed. Acquired docetaxel-resistance conferred cross-resistance to doxorubicin and induced alterations in motility, invasion, proliferation and anchorage-independent growth. Exosomes expelled from DU145 and 22Rv1 docetaxel-resistant variants (DU145RD and 22Rv1RD) conferred docetaxel-resistance to DU145, 22Rv1 and LNCap cells, which may be partly due to exosomal MDR-1/P-gp transfer. Exosomes from prostate cancer patients' sera induced increased cell proliferation and invasion, compared to exosomes from age-matched controls. Furthermore, exosomes from sera of patients undergoing a course of docetaxel treatment compared to matched exosomes from the same patients prior to commencing docetaxel treatment, when applied to both DU145 and 22Rv1 cells, showed a correlation between cellular response to docetaxel and patients' response to treatment with docetaxel.
Our studies indicate the complex and multifaceted nature of docetaxel-resistance in prostate cancer. Furthermore, our in vitro observations and preliminary clinical studies indicate that exosomes may play an important role in prostate cancer, in cell-cell communication, and thus may offer potential as vehicles containing predictive biomarkers and new therapeutic targets.
PLoS ONE 01/2012; 7(12):e50999. · 4.09 Impact Factor
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Dennis Slamon,
Wolfgang Eiermann,
Nicholas Robert,
Tadeusz Pienkowski,
Miguel Martin,
Michael Press,
John Mackey,
John Glaspy,
Arlene Chan,
Marek Pawlicki, [......],
Guido Sauter,
Gunter von Minckwitz,
Frances Visco,
Valerie Bee,
Marc Buyse,
Belguendouz Bendahmane,
Isabelle Tabah-Fisch,
Mary-Ann Lindsay,
Alessandro Riva, John Crown
[show abstract]
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ABSTRACT: Trastuzumab improves survival in the adjuvant treatment of HER-positive breast cancer, although combined therapy with anthracycline-based regimens has been associated with cardiac toxicity. We wanted to evaluate the efficacy and safety of a new nonanthracycline regimen with trastuzumab.
We randomly assigned 3222 women with HER2-positive early-stage breast cancer to receive doxorubicin and cyclophosphamide followed by docetaxel every 3 weeks (AC-T), the same regimen plus 52 weeks of trastuzumab (AC-T plus trastuzumab), or docetaxel and carboplatin plus 52 weeks of trastuzumab (TCH). The primary study end point was disease-free survival. Secondary end points were overall survival and safety.
At a median follow-up of 65 months, 656 events triggered this protocol-specified analysis. The estimated disease-free survival rates at 5 years were 75% among patients receiving AC-T, 84% among those receiving AC-T plus trastuzumab, and 81% among those receiving TCH. Estimated rates of overall survival were 87%, 92%, and 91%, respectively. No significant differences in efficacy (disease-free or overall survival) were found between the two trastuzumab regimens, whereas both were superior to AC-T. The rates of congestive heart failure and cardiac dysfunction were significantly higher in the group receiving AC-T plus trastuzumab than in the TCH group (P<0.001). Eight cases of acute leukemia were reported: seven in the groups receiving the anthracycline-based regimens and one in the TCH group subsequent to receiving an anthracycline outside the study.
The addition of 1 year of adjuvant trastuzumab significantly improved disease-free and overall survival among women with HER2-positive breast cancer. The risk-benefit ratio favored the nonanthracycline TCH regimen over AC-T plus trastuzumab, given its similar efficacy, fewer acute toxic effects, and lower risks of cardiotoxicity and leukemia. (Funded by Sanofi-Aventis and Genentech; BCIRG-006 ClinicalTrials.gov number, NCT00021255.).
New England Journal of Medicine 10/2011; 365(14):1273-83. · 53.30 Impact Factor
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Paul Dowling,
Colin Clarke,
Kim Hennessy,
Beatriz Torralbo-Lopez,
Jo Ballot, John Crown,
Ingrid Kiernan,
Kenneth J O'Byrne,
M John Kennedy,
Vincent Lynch,
Martin Clynes
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ABSTRACT: Early detection, clinical management and disease recurrence monitoring are critical areas in cancer treatment in which specific biomarker panels are likely to be very important in each of these key areas. We have previously demonstrated that levels of alpha-2-heremans-schmid-glycoprotein (AHSG), complement component C3 (C3), clusterin (CLI), haptoglobin (HP) and serum amyloid A (SAA) are significantly altered in serum from patients with squamous cell carcinoma of the lung. Here, we report the abundance levels for these proteins in serum samples from patients with advanced breast cancer, colorectal cancer (CRC) and lung cancer compared to healthy controls (age and gender matched) using commercially available enzyme-linked immunosorbent assay kits. Logistic regression (LR) models were fitted to the resulting data, and the classification ability of the proteins was evaluated using receiver-operating characteristic curve and leave-one-out cross-validation (LOOCV). The most accurate individual candidate biomarkers were C3 for breast cancer [area under the curve (AUC) = 0.89, LOOCV = 73%], CLI for CRC (AUC = 0.98, LOOCV = 90%), HP for small cell lung carcinoma (AUC = 0.97, LOOCV = 88%), C3 for lung adenocarcinoma (AUC = 0.94, LOOCV = 89%) and HP for squamous cell carcinoma of the lung (AUC = 0.94, LOOCV = 87%). The best dual combination of biomarkers using LR analysis were found to be AHSG + C3 (AUC = 0.91, LOOCV = 83%) for breast cancer, CLI + HP (AUC = 0.98, LOOCV = 92%) for CRC, C3 + SAA (AUC = 0.97, LOOCV = 91%) for small cell lung carcinoma and HP + SAA for both adenocarcinoma (AUC = 0.98, LOOCV = 96%) and squamous cell carcinoma of the lung (AUC = 0.98, LOOCV = 84%). The high AUC values reported here indicated that these candidate biomarkers have the potential to discriminate accurately between control and cancer groups both individually and in combination with other proteins.
International Journal of Cancer 09/2011; 131(4):911-23. · 5.44 Impact Factor
