Michael Duffy | University College of Dublin (original) (raw)

Papers by Michael Duffy

British Journal of Cancer, Apr 1, 1980

The concentration of bound sialic acid in the sera of 56 normal subjects and 65 subjects with bre... more The concentration of bound sialic acid in the sera of 56 normal subjects and 65 subjects with breast cancer was measured, in order to determine (1) whether serum sialic acid concentrations are raised in breast cancer and (2) whether the concentration of sialic acid in serum reflects tumour stage. The amount of sialic acid in serum was compared to serum carcinoembryonic antigen (CEA) values. Urinary hydroxyproline and serum alkaline phosphatase concentrations were used as indicators of bone and liver involvement. Erythrocyte sedimentation rate (ESR) was also measured.

Cancer Management and Research, 2018

The purpose of this study was to evaluate the combined measurement of serum CEA, TPA, and CA 15-3... more The purpose of this study was to evaluate the combined measurement of serum CEA, TPA, and CA 15-3, using an individual reference limit (IRL), for predicting distant metastases in asymptomatic women following a diagnosis of primary breast cancer. Methods: A total of 231 patients were followed up for a mean of 5.5±1.6 years. An IRL for defining critical changes (CCs) in marker levels was used as a warning signal of pending distant metastases. Results: Sensitivity, specificity, and accuracy of the combined CEA-TPA-CA 15-3 marker panel for predicting patient outcome were 95.2%, 97.8%, and 97.9%, respectively. In all, 19 (8.3%) patients relapsed with a mean lead time to radiological evidence of metastases of 11.7±13.8 months. Conclusion: We concluded that the combined measurement of CA 15-3, CEA, and TPA using an IRL for determining the CC in markers levels is an accurate strategy for predicting outcome during postoperative monitoring of asymptomatic breast cancer patients. Whether the early prediction of metastasis and subsequent administration of therapy impacts on patient outcome should now be the objective of a prospective clinical trial. The marker panel described here could serve as the basis for such a trial.

International Journal of Cancer, 2000

TIMP-2 is an endogenous inhibitor of MMPs. Most data from model systems suggest that high levels ... more TIMP-2 is an endogenous inhibitor of MMPs. Most data from model systems suggest that high levels of this inhibitor prevent metastasis. In human breast cancers, however, we show that high levels of TIMP-2 correlate with both shortened disease-free interval and overall survival. In primary breast cancers, TIMP-2 levels showed no significant relationship with either tumor size or axillary node status but correlated inversely with estrogen receptor levels. TIMP-2 levels also correlated significantly with those for TIMP-1. We conclude that high levels of endogenous TIMP-2, like other protease inhibitors such as PAI-1 and TIMP-1, correlate with progression of human breast cancer.

Cancer Biology & Therapy, 2013

Annals of Oncology, 2011

Background: Triple-negative breast cancers lack expression of estrogen and progesterone receptors... more Background: Triple-negative breast cancers lack expression of estrogen and progesterone receptors and overexpression of human epidermal growth factor receptor 2 (HER2). Unlike other subgroups of patients with breast cancer, targeted therapy is currently unavailable for these patients. The aim of this study was to investigate v-src sarcoma viral oncogene homolog (Src) as a potential target for the treatment of triple-negative breast cancer. Methods: Expression of Src was measured in 87 triple-negative and 93 non-triple-negative breast cancers. Dasatinib (an inhibitor of Src) was tested in a panel of breast cancer cell lines. Results: Cytoplasmic expression of Src was detected in 83 (95%) triple-negative samples versus 78 (84%) non-triplenegative samples (P = 0.012), while membrane Src was detected in 78% triple-negative compared with 38% of nontriple-negative specimens (P < 0.0001). Dasatinib inhibited growth in three of five triple-negative cell lines (IC 50 < 1 lM). Dasatinib combined with cisplatin was synergistic in the three dasatinib-sensitive cell lines (combination index < 0.9). Dasatinib, in combination with 5#-deoxy-5#-fluoruridine, displayed synergy or additivity. Moderate synergy was observed with docetaxel (Taxotere) in two cell lines but the combination was antagonistic in HCC-1143 cells. Conclusions: We conclude that dasatinib with cisplatin is a rational drug combination for testing in triple-negative breast cancer.

Clinical Chemistry, 2022

Background OncoMasTR is a recently developed multigene prognostic test for early-stage breast can... more Background OncoMasTR is a recently developed multigene prognostic test for early-stage breast cancer. The test has been developed in a kit-based format for decentralized deployment in molecular pathology laboratories. The analytical performance characteristics of the OncoMasTR test are described in this study. Methods Expression levels of 6 genes were measured by 1-step reverse transcription-quantitative PCR on RNA samples prepared from formalin-fixed, paraffin-embedded (FFPE) breast tumor specimens. Assay precision, reproducibility, input range, and interference were determined using FFPE-derived RNA samples representative of low and high prognostic risk scores. A pooled RNA sample derived from 6 FFPE breast tumor specimens was used to establish the linear range, limit of detection, and amplification efficiency of the individual gene expression assays. Results The overall precision of the OncoMasTR test was high with an SD of 0.16, which represents less than 2% of the 10-unit risk ...

International Journal of Gynecologic Cancer, 2016

ObjectiveTo present an update of the European Group on Tumor Markers guidelines for serum markers... more ObjectiveTo present an update of the European Group on Tumor Markers guidelines for serum markers in epithelial ovarian cancer.MethodsSystematic literature survey from 2008 to 2013. The articles were evaluated by level of evidence and strength of recommendation.ResultsBecause of its low sensitivity (50–62% for early stage epithelial ovarian cancer) and limited specificity (94–98.5%), cancer antigen (CA) 125 (CA125) is not recommended as a screening test in asymptomatic women. The Risk of Malignancy Index, which includes CA125, transvaginal ultrasound, and menopausal status, is recommended for the differential diagnosis of a pelvic mass. Because human epididymis protein 4 has been reported to have superior specificity to CA125, especially in premenopausal women, it may be considered either alone or as part of the risk of ovarian malignancy algorithm, in the differential diagnosis of pelvic masses, especially in such women. CA125 should be used to monitor response to first-line chemot...

Background: Previously we showed that oncogene Ha-Ras stimulates the metastatic activity of both ... more Background: Previously we showed that oncogene Ha-Ras stimulates the metastatic activity of both spontaneously transformed and v-src-transformed Syrian hamster fibroblasts in vivo. We revealed that Ha-Ras/RalGDS/Ral-associated signalling pathway was the most important for metastasis among the variety of Ha-Ras associated signaling cascades.

Clinical chemistry, Jan 10, 2017

Cancer Research, 2006

Estrogens have many cellular functions, including their interactions with estrogen receptors α an... more Estrogens have many cellular functions, including their interactions with estrogen receptors α and β (ERα and ERβ). Earlier, we determined that the estrogen-ER complex stimulates the transcriptional activity of the matrix metalloproteinase 26 (MMP-26) gene promoter. We then determined that ERβ is susceptible to MMP-26 proteolysis whereas ERα is resistant to the protease. MMP-26 targets the NH2-terminal region of ERβ coding for the divergent NH2-terminal A/B domain that is responsible for the ligand-independent transactivation function. As a result, MMP-26 proteolysis generates the COOH-terminal fragments of ERβ. Immunohistochemical analysis of tissue microarrays derived from 121 cancer patients corroborated these data and revealed an inverse correlation between the ERα-dependent expression of MMP-26 and the levels of the intact ERβ in breast carcinomas. MMP-26 is not expressed in normal mammary epithelium. The levels of MMP-26 are strongly up-regulated in ductal carcinoma in situ (D...

British Journal of Ophthalmology, 1998

Aim-To determine the potential role of basic fibroblast growth factor (bFGF) and platelet derived... more Aim-To determine the potential role of basic fibroblast growth factor (bFGF) and platelet derived growth factor (PDGF) in the pathogenesis of proliferative vitreoretinopathy (PVR). Methods-An enzyme linked immunosorbent assay technique was used to determine the quantities of bFGF and PDGF in 38 vitreous samples taken from patients undergoing trans pars plana vitrectomy (PPV) for a variety of vitreoretinal disorders. Results-bFGF levels ranged from undetectable to 318.7 pg/ml. The mean concentration was 27.57 pg/ml. PDGF levels ranged from undetectable to 160 pg/ml, the mean concentration being 40.06 pg/ml. Eight of 13 patients with clinical evidence of retinal detachment (RD) and PVR had significantly elevated bFGF concentrations, whereas only one of 11 patients with RD and no PVR had detectable bFGF; seven of eight patients with RD and PVR had elevated PDGF concentrations in the vitreous, whereas all 10 patients with RD and no PVR had no detectable vitreous PDGF. Eight patients with vitreous haemorrhage had raised PDGF concentrations, and the levels were particularly high (>120 pg/ml) in those two patients with active neovascularisation. Two out of nine patients with vitreous haemorrhage had raised bFGF levels. Conclusions-bFGF and PDGF concentrations are elevated in PVR even in the absence of vitreous haemorrhage, and not in patients with RD uncomplicated by PVR. This observation suggests that both cytokines may be involved in the pathogenesis of PVR.

Investigational New Drugs

TP53 (p53) and MYC are amongst the most frequently altered genes in cancer. Both are thus attract... more TP53 (p53) and MYC are amongst the most frequently altered genes in cancer. Both are thus attractive targets for new anticancer therapies. Historically, however, both genes have proved challenging to target and currently there is no approved therapy against either. The aim of this study was to investigate the effect of the mutant p53 reactivating drug, COTI-2 on MYC. Total MYC, pSer62 MYC and pThr58 MYC were detected using Western blotting. Proteasome-mediated degradation was determined using the proteasome, inhibitor MG-132, while MYC half-life was measured using pulse chase experiments in the presence of cycloheximide. Cell proliferation was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Treatment of 5 mutant p53 breast cancer cell lines with COTI-2 resulted in dose-dependent MYC degradation. Addition of the proteasome inhibitor, MG132, rescued the degradation, suggesting that this proteolytic system was at least partly responsible fo...

Cancers

Mutant p53 is one of the most attractive targets for new anti-cancer drugs. Although traditionall... more Mutant p53 is one of the most attractive targets for new anti-cancer drugs. Although traditionally regarded as difficult to drug, several new strategies have recently become available for targeting the mutant protein. One of the most promising of these involves the use of low molecular weight compounds that promote refolding and reactivation of mutant p53 to its wild-type form. Several such reactivating drugs are currently undergoing evaluation in clinical trials, including eprenetapopt (APR-246), COTI-2, arsenic trioxide and PC14586. Of these, the most clinically advanced for targeting mutant p53 is eprenetapopt which has completed phase I, II and III clinical trials, the latter in patients with mutant TP53 myelodysplastic syndrome. Although no data on clinical efficacy are currently available for eprenetapopt, preliminary results suggest that the drug is relatively well tolerated. Other strategies for targeting mutant p53 that have progressed to clinical trials involve the use of ...

Medical Oncology

TP53 (p53) is mutated in 80–90% of cases of triple-negative breast cancer (TNBC). Statins, which ... more TP53 (p53) is mutated in 80–90% of cases of triple-negative breast cancer (TNBC). Statins, which are widely used to treat elevated cholesterol, have recently been shown to degrade mutant p53 protein and exhibit anti-cancer activity. The aim of this work was to evaluate the potential of statins in the treatment of TNBC. The anti-proliferative effects of 2 widely used statins were investigated on a panel of 15 cell lines representing the different molecular subtypes of breast cancer. Significantly lower IC50 values were found in triple-negative (TN) than in non-TN cell lines (atorvastatin, p < 0.01; simvastatin p < 0.05) indicating greater sensitivity. Furthermore, cell lines containing mutant p53 were more responsive to both statins than cell lines expressing wild-type p53, suggesting that the mutational status of p53 is a potential predictive biomarker for statin response. In addition to inhibiting proliferation, simvastatin was also found to promote cell cycle arrest and indu...

Cancers, 2019

In pre-clinical studies, triple-negative breast cancer (TNBC) cells have demonstrated sensitivity... more In pre-clinical studies, triple-negative breast cancer (TNBC) cells have demonstrated sensitivity to the multi-targeted kinase inhibitor dasatinib; however, clinical trials with single-agent dasatinib showed limited efficacy in unselected populations of breast cancer, including TNBC. To study potential mechanisms of resistance to dasatinib in TNBC, we established a cell line model of acquired dasatinib resistance (231-DasB). Following an approximately three-month exposure to incrementally increasing concentrations of dasatinib (200 nM to 500 nM) dasatinib, 231-DasB cells were resistant to the agent with a dasatinib IC50 value greater than 5 μM compared to 0.04 ± 0.001 µM in the parental MDA-MB-231 cells. 231-DasB cells also showed resistance (2.2-fold) to the Src kinase inhibitor PD180970. Treatment of 231-DasB cells with dasatinib did not inhibit phosphorylation of Src kinase. The 231-DasB cells also had significantly increased levels of p-Met compared to the parental MDA-MB-231 ce...

Translational Oncology, 2018

TP53 is the most frequently mutated gene in human cancer and thus an attractive target for novel ... more TP53 is the most frequently mutated gene in human cancer and thus an attractive target for novel cancer therapy. Several compounds that can reactive mutant p53 protein have been identified. APR-246 is currently being tested in a phase II clinical trial in high-grade serous ovarian cancer. We have used RNA-seq analysis to study the effects of APR-246 on gene expression in human breast cancer cell lines. Although the effect of APR-246 on gene expression was largely cell line dependent, six genes were upregulated across all three cell lines studied, i.e., TRIM16, SLC7A11, TXNRD1, SRXN1, LOC344887, and SLC7A11-AS1. We did not detect upregulation of canonical p53 target genes such as CDKN1A (p21), 14-3-3σ, BBC3 (PUMA), and PMAIP1 (NOXA) by RNA-seq, but these genes were induced according to analysis by qPCR. Gene ontology analysis showed that APR-246 induced changes in pathways such as response to oxidative stress, gene expression, cell proliferation, response to nitrosative stress, and the glutathione biosynthesis process. Our results are consistent with the dual action of APR-246, i.e., reactivation of mutant p53 and modulation of redox activity. SLC7A11, TRIM16, TXNRD1, and SRXN1 are potential new pharmacodynamic biomarkers for assessing the response to APR-246 in both preclinical and clinical studies.

Breast Cancer Research, 2000

The matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases. Their primary... more The matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases. Their primary function is degradation of proteins in the extracellular matrix. Currently, at least 19 members of this family are known to exist. Based on substrate specificity and domain organization, the MMPs can be loosely divided into four main groups: the interstitial collagenases, gelatinases, stromelysins and membrane-type MMPs. Recent data from model systems suggest that MMPs are involved in breast cancer initiation, invasion and metastasis. Consistent with their role in breast cancer progression, high levels of at least two MMPs (MMP-2 and stromelysin-3) have been found to correlate with poor prognosis in patients with breast cancer. Because MMPs are apparently involved in breast cancer initiation and dissemination, inhibition of these proteinases may be of value both in preventing breast cancer and in blocking metastasis of established tumours

Translational Cancer Research, 2016