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Awada A.,Free University of Colombia | Bozovic-Spasojevic I.,Free University of Colombia | Chow L.,UNIMED Medical Institute
Cancer Treatment Reviews | Year: 2012

Overexpression of the human epidermal growth factor receptor 2 (HER2) predicts a poor prognosis in metastatic breast cancer. While the introduction of HER2-targeted therapies, such as the monoclonal antibody trastuzumab and the small-molecule tyrosine kinase inhibitor lapatinib, has significantly improved outcomes in HER2+ breast cancer compared with previously available therapies, use of these targeted therapies is often limited by the development of drug resistance and tolerability issues. These limitations create the need for further development and investigation of new targeted therapies that show potent and selective inhibition of these targets or closely connected molecular pathways. Recently, several agents have demonstrated promising activity in HER2+ metastatic breast cancer, either as monotherapy or in combination therapy, including the tyrosine-kinase inhibitors neratinib (HKI-272) and afatinib (BIBW-2992) and the anti-HER2 monoclonal antibodies pertuzumab and trastuzumab-DM1 (T-DM1). Agents that target other molecular pathways, such as the vascular endothelial growth factor receptor, mammalian target of rapamycin, PI3-kinases, insulin-like growth factor (IGFR), HSP-90, and other kinases also have potential, in combination with anti-HER2 and/or other systemic therapies, to be active in this subtype of breast cancer. Innovative clinical studies are required in well-characterized patient populations to define the true clinical value of these emerging new approaches. © 2012 Elsevier Ltd. Source

Loo W.T.Y.,University of Hong Kong | Jin L.,University of Hong Kong | Cheung M.N.B.,Keenlink Dental Clinic | Wang M.,University of Sichuan | Chow L.W.C.,UNIMED Medical Institute
Journal of Translational Medicine | Year: 2010

Background: DNA methylation of certain genes frequently occurs in neoplastic cells. Although the cause remains unknown, many genes have been identified with such atypical methylation in neoplastic cells. The hypermethylation of E-Cadherin and Cyclooxygenase 2 (COX-2) in chronic inflammation such as chronic periodontitis may demonstrate mild lesion/mutation epigenetic level. This study compares the hypermethylation status of E-Cadherin and COX-2 genes which are often found in breast cancer patients with that in chronic periodontitis.Methods: Total DNA was extracted from the blood samples of 108 systemically healthy non-periodontitis subjects, and the gingival tissues and blood samples of 110 chronic periodontitis patient as well as neoplastic tissues of 106 breast cancer patients. Methylation-specific PCR for E-Cadherin and COX-2 was performed on these samples and the PCR products were analyzed on 2% agarose gel.Results: Hypermethylation of E-Cadherin and COX-2 was observed in 38% and 35% of the breast cancer samples, respectively. In chronic periodontitis patients the detection rate was 25% and 19% respectively, and none was found in the systemically healthy non-periodontitis control subjects. The hypermethylation status was shown to be correlated among the three groups with statistical significance (p < 0.0001). The methylation of CpG islands in E-Cadherin and COX-2 genes in periodontitis patients occurs more frequently in periodontitis patients than in the control subjects, but occurs less frequently than in the breast cancer patients.Conclusions: This set of data shows that the epigenetic change in E-Cadherin and Cyclooxygenase-2 is associated with chronic periodontitis. The epigenetic changes presented in chronic inflammation patients might demonstrate an irreversible destruction in the tissues or organs similar to the effects of cancer. Chronic periodontitis to some extent might be associated with DNA hypermethylation which is related to cancer risk factors. © 2010 Loo et al; licensee BioMed Central Ltd. Source

Wang Z.-Y.,Chinese University of Hong Kong | Loo T.Y.,UNIMED Medical Institute | Shen J.-G.,Chinese University of Hong Kong | Wang N.,Chinese University of Hong Kong | And 5 more authors.
Breast Cancer Research and Treatment | Year: 2012

LDH-A, as the critical enzyme accounting for the transformation from pyruvate into lactate, has been demonstrated to be highly expressed in various cancer cells and its silencing has also been approved relating to increased apoptosis in lymphoma cells. In this study, we intend to investigate the correlation between LDH-A and other clinicopathological factors of breast cancer and whether LDH-A silencing could suppress breast cancer growth, and if so the potential mechanisms. 46 breast cancer specimens were collected to study the relation between LDH-A expression and clinicopathological characteristics including menopause, tumor size, node involvement, differentiation, and pathological subtypes classified by ER, PR, and Her-2. shRNAs were designed and applied to silence LDH-A expression in breast cancer cell lines MCF-7 and MDA-MB-231. The effects of LDH-A reduction on cancer cells were studied by a series of in vitro and in vivo experiments, including cell growth assay, apoptosis evaluation, oxidative stress detection, transmission electron microscopy observation, and tumor formation assay on nude mice. LDH-A expression was found to correlate significantly with tumor size and to be independent for other clinicopathological factors. LDH-A reduction resulted in an inhibited cancer cell proliferation, elevated intracellular oxidative stress, and induction of mitochondrial pathway apoptosis. Meanwhile, the tumorigenic ability of LDH-A deficient cancer cells was significantly limited in both breast cancer xenografts. The Ki67 positive cancer cells were significantly reduced in LDH-A deficiency tumor samples, while the apoptosis ratio was enhanced. Our results suggested that LDH-A inhibition might offer a promising therapeutic strategy for breast cancer. © 2011 Springer Science+Business Media, LLC. Source

Chow L.W.-C.,UNIMED Medical Institute | Chow L.W.-C.,Organisation for Oncology and Translational Research OOTR | Xu B.,Chinese Academy of Sciences | Gupta S.,Tata Memorial Hospital | And 5 more authors.
British Journal of Cancer | Year: 2013

Introduction:Neratinib is a potent irreversible pan-ErbB tyrosine kinase inhibitor that has demonstrated antitumour activity and an acceptable safety profile in patients with human epidermal growth factor receptor (HER)-2-positive breast cancer and other solid tumours.Methods:This was a phase I/II, open-label, two-part study. Part 1 was a dose-escalation study to determine the maximum tolerated dose (MTD) of neratinib plus paclitaxel in patients with solid tumours. Part 2 evaluated the safety, efficacy, and pharmacokinetics of the combination at the MTD in patients with HER2-positive breast cancer.Results:Eight patients were included in the dose-escalation study; no dose-limiting toxicities were observed, and an MTD of oral neratinib 240 mg once daily plus intravenous paclitaxel 80 mg m-2 on days 1, 8, and 15 of each 28-day cycle was determined. A total of 102 patients with HER2-positive breast cancer were enrolled in part 2. The overall median treatment duration was 47.9 weeks (range: 0.1-147.3 weeks). Common treatment-emergent adverse events (all grades/grade ≥3) included diarrhoea (92%/29%; none grade 4), peripheral sensory neuropathy (51%/3%), neutropenia (50%/20%), alopecia (46%/0%), leukopenia (41%/18%), anaemia (37%/8%), and nausea (34%/1%). Three (3%) patients discontinued treatment due to an adverse event (mouth ulceration, left ventricular ejection fraction reduction, and acute renal failure). Among the 99 evaluable patients in part 2 of the study, the overall response rate (ORR) was 73% (95% confidence interval (CI): 62.9-81.2%), including 7 (7%) patients who achieved a complete response; an additional 9 (9%) patients achieved stable disease for at least 24 weeks. ORR was 71% among patients with 0/1 prior chemotherapy regimen for metastatic disease and no prior lapatinib, and 77% among those with 2/3 prior chemotherapy regimens for metastatic disease with prior lapatinib permitted. Kaplan-Meier median progression-free survival was 57.0 weeks (95% CI: 47.7-81.6 weeks). Pharmacokinetic analyses indicated no interaction between neratinib and paclitaxel.Conclusion:The combination of neratinib and paclitaxel was associated with higher toxicity than that of neratinib as a single agent, but was manageable with antidiarrhoeal agents and dose reductions in general. The combination therapy also demonstrated a high rate of response in patients with HER2-positive breast cancer. A phase III trial is ongoing to assess the benefit and risk of this combination in the first-line setting. © 2013 Cancer Research UK. All rights reserved. Source

Chow L.W.C.,Organisation for Oncology and Translational Research | Chow L.W.C.,UNIMED Medical Institute | Chow L.W.C.,University of Hong Kong
Expert Opinion on Investigational Drugs | Year: 2010

Cancer treatment has revolutionized from a "one size fits all" approach to a more individualized approach with the advancement of medicine and molecular biology. Several predictive and prognostic factors have been studied and applied to clinical practice to assist clinicians in cancer management. In breast cancer therapeutics, the appearance of biomarkers such as expressions of hormone receptor and human epidermal growth factor (HER) receptors has modified treatment strategies from chemotherapy to molecular-targeted therapy including endocrine therapy and anti-HER therapy. With better understanding of the molecular level of tumorigenesis, cancer pathogenesis and metastases, several novel biomarkers such as cyclo-oxygennase-2 enzyme and tyrosine kinases have been discovered and new anti-cancer agents have been introduced into the currently available treatments. The change has also modified pre-operative treatment for locally advanced and early breast cancers. The neo-adjuvant treatment indeed provides an excellent platform for translational research which is a widely used research method in clinical research. The study of gene and protein expressions from tissue and blood samples collected before, during and after neo-adjuvant treatment provides a lot of keys to decipher the signaling pathways and discover novel biomarkers which are essential for development of new drugs and prediction of the clinical outcome of therapy. The addition of gene expression profiling to conventional predictive factors will give more prognostic information to clinicians for better management of the disease. © 2010 Informa UK Ltd. Source

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