Microcalcifications in breast cancer: Exploring their molecular formation and biological significance

MCT Research Talks – 23th January 2017

Survival rates for breast cancer have risen significantly over the past few decades, in large part due to a considerable increase in the number of tumours detected via mammography at an early, more easily-treated stage. The presence of microcalcifications on a mammogram constitutes an important diagnostic clue to radiographers, with approximately 30% of invasive breast tumours and up to 90% of cases of ductal carcinoma in situ (DCIS) being detected by the presence of calcifications. Some studies have also suggested that the presence of calcifications may act as a prognostic factor, as patients presenting with breast tumours with associated calcifications have a worse prognosis than those without.
Despite their importance in breast cancer diagnosis, the exact mechanism by which microcalcifications are formed remains largely unexplored. Our group previously established the first in vitro model of mammary cell microcalcification (1) which we have recently extended to the human the breast cancer cell line MDA-MB-231. When cultured with a cocktail of osteogenic-reagents for a prolonged period, these cells produce deposits of calcium phosphate.

Figure 1. Alizarin Red S stained MDA-MB-231 cell monolayer, grown in DMEM (Control) or DMEM supplemented with osteogenic cocktail and dexamethasone (OC+Dex). Red staining indicates presence of calcified deposits.

Using a combination of histological staining, quantitative measurement of calcium content, alkaline phosphatase activity and analysis of gene expression, we can monitor the changes in cell phenotype leading to onset of mineralisation. The nature of our model allows for easy manipulation of cell culturing conditions and by adding various inhibitory compounds or cytokines to our culture media, we can identify the key pathways and targets necessary for calcification production. In doing so, we hope to build up a comprehensive understanding of the cellular and molecular basis underlying the formation of these important diagnostic clues.

Recommended reading:

Cox RF, Hernandez-Santana A, Ramdass S, McMahon G, Harmey JH, Morgan MP.  Microcalcifications in breast cancer: novel insights into the molecular mechanism and functional consequence of mammary mineralisation. Br J Cancer. 106(3):525-37 PMID: 22233923 (Jan 2012)

Shane O’Grady, Maria Morgan

Irish Association of Pharmacologists Announcement

Dear IAP Members

I wanted to update you on developments over the past number of weeks.

I can report that we have made progress with an application for the IAP to join the European Association for Clinical Pharmacology & Therapeutics (EACPT -https://www.eacpt.eu/who-we-are-2/), who responded very positively and who have said that they will put our application to their executive committee at their next meeting in April. We look forward in hope to the last blank space in Western Europe being filled in blue very soon (see: https://www.eacpt.eu/members/national-society-affiliated-to-eacpt/).

We have also applied for membership of the Federation of European Pharmacological Societies (EPHAR -http://www.ephar.org/home.html), who have also responded very positively to our initial enquiries.

We are currently working on the IAP website and expect to be able to update you on developments shortly.

In the meantime, we would very much appreciate your promoting the newly constituted IAP to those who you think would be interested in becoming members. We anticipate that the benefits will soon include membership of European federations and the opportunities for contact with European colleagues.

Thomas

Prof. Thomas Walther
President
Irish Association of Pharmacologists

The role of the anorectic neuropeptide CART in breast cancer

MCT Research Talks – 16th January 2017

Breast cancer currently affects 1 in 8 women in Ireland, with over 3000 reported cases each year. The most common subtype of breast cancer, known as Estrogen Receptor positive (ER+) breast cancer, accounts for roughly 70% of all breast cancers diagnosed. The most common drug used to treat this disease (Tamoxifen) works by preventing estrogen from driving the growth of the cancer cells, however, roughly 1 in 3 women will be resistant to tamoxifen treatment, highlighting the need for further research into this field. A number of years ago, though mining of publically available datasets, we identified a gene known as CART to be a marker of poor prognosis in ER+ breast cancer. CART (The Cocaine- and Amphetamine-Regulated Transcript) is a neuropeptide involved in processes such as feeding and drug reward. We have identified that high expression of CART in breast cancer patients correlates with poor overall survival, and also a poor response to tamoxifen. We also demonstrated that CART could influence the activity of ERα in a ligand-independent manner [1]. Our current research focuses on combining proteomic (mass-spectrometry) and transcriptomic (RNA-seq) approaches in order to fully understand the role CART plays in ER+ breast cancer. We aim to modulate the expression of these identified targets in order to investigate whether any of these targets could slow the growth of breast cancer cells in vitro. Combining these approaches, we hope to identify novel therapeutic opportunities for patients with ER+ breast cancer.

Recommended reading:

[1] DJ Brennan, DP O’Connor et al., The Cocaine- and Amphetamine-Regulated Transcript mediates ligand-independent activation of ERα, and is an independent prognostic factor in node-negative breast cancer. Oncogene 2012, 31, 3483–3494; doi:10.1038/onc.2011.519

Brian Mooney, Darran O’Connor

Recent MCT Papers In High Impact Journals With Commentaries

CNV and Schizophrenia Working Groups of the Psychiatric Genomics Consortium; Psychosis Endophenotypes International Consortium. [including Waddington J]. Contribution of copy number variants to schizophrenia from a genome-wide study of 41,321 subjects. Nat Genet. 2017 Jan;49(1):27-35. PMID: 27869829

John Waddington writes about his group’s participation in a global research endeavour that has produced a series of articles in Nature, Nature Genetics and Nature Neuroscience on the pathobiology of schizophrenia The Psychiatric Genomics Consortium (PGC) unites investigators around the world to conduct meta- and mega-analyses of genome-wide genomic data on psychiatric disorders, to achieve goals that cannot be reached by individual or indeed most national programmes. Its website (www.med.unc.edu/pgc) provides information about the organization, implementation and results of the PGC. This consortium began in early 2007 and has rapidly become a collaborative confederation of investigators from 38 countries. There are samples from more than 900,000 individuals currently in analysis, and this number is growing rapidly. The PGC is the largest consortium and the largest biological experiment in the history of psychiatry.
From 2007-11, the PGC focused on several disorders, from schizophrenia through to autism, attention-deficit hyperactivity disorder, bipolar disorder and major depressive disorder. These now extend to large studies of eating disorders, substance use disorders, obsessive-compulsive disorder/Tourette’s Syndrome and post-traumatic stress disorder. Initially, the PGC focused on common single nucleotide polymorphisms (SNPs) but has expanded to include copy number variation (CNVs) and uncommon/rare genetic variation. The PGC has received funding from many sources. It has relied heavily on the goodwill of its members and their donated effort, with the establishment andgenotyping of its primary studies funded by a wide range of national, international and commercial entities.

We have been involved in the Schizophrenia Working Group of the PGC for many years, from its progenitor organisation the International Schizophrenia Consortium, primarily through substantial funding from the Wellcome Trust for five centres across the island of Ireland (one led by us) to contribute DNA from well characterised patient populations to a national dataset curated at Trinity College Dublin. This dataset has then been shared with the PGC. The resultant studies have evolved from the first investigation of CNVs in schizophrenia (3,391 cases, 3,181 controls; Nature 2008; 455: 237-41), through to the largest GWAS study on schizophrenia undertaken to date (36,989 cases, 113,075 controls; Nature 2014; 511: 421-7), to this most recent publication (21,094 cases, 20,227 controls; Nature Genetics 2017; 49: 27-35), the largest study of CNVs in schizophrenia yet undertaken. This has been, and continues to be, an exemplary, rewarding journey of global collaboration to illuminate the pathobiology of the intractable human condition that is psychotic illness.

 


Chion A, O’Sullivan JM, Drakeford C, Bergsson G, Dalton N, Aguila S, Ward S, Fallon PG, Brophy TM, Preston RJ, Brady L, Sheils, O, Laffan M, McKinnon TA, O’Donnell JS. N-linked glycans within the A2 domain of von Willebrand factor modulate macrophage-mediated clearance. Blood. 2016 Oct 13;128(15):1959-1968. PMID: 27554083.

Jamie Marie O’Sullivan writes about this study:

Von Willebrand factor (VWF) is a large multimeric plasma sialoglycoprotein that plays two critical roles in normal haemostasis. First it mediates platelet adhesion to exposed subendothelial collagen at sites of vascular injury. Second, VWF acts as a carrier molecule for procoagulant factor VIII, thereby protecting it from premature proteolytic degradation and clearance. Deficiency of either VWF (von Willebrand disease, VWD) or FVIII (Haemophilia A) is associated with a significant bleeding phenotype. Conversely, elevated plasma levels of the VWF-FVIII complex constitute a dose dependent risk factor for both venous and arterial thrombosis. Consequently, understanding the factors that determine how plasma VWF levels are regulated is not only of basic scientific interest, but also direct clinical importance.

Despite the fact that type 1 von Willebrand disease constitutes the most common inherited bleeding disorder worldwide, the mechanisms underlying the reduced plasma VWF levels in these patients is not well established. However, emerging evidence suggests that reduced circulatory half-life may be important in a significant number of patients. However the biological mechanisms underlying VWF clearance from the plasma remains elusive. Work is on-going within the group of Professor James O’Donnell to investigate the importance of specific VWF domains in modulating half-life in vivo.

In the October issue of Blood the group published novel findings demonstrating a critical role for VWF glycosylation in determining its circulatory half-life. By examining the clearance of various truncated fragments of VWF, we observed that the A domains of VWF contain a receptor-recognition site important in mediating VWF binding to macrophages in vitro, and in regulating VWF clearance by macrophages in vivo. Furthermore site-directed mutagenesis demonstrated a key role for N-linked glycan structures at position N1515 and N1574 within the A domains in protecting VWF against macrophage-mediated clearance. More specifically, the protective effect of these large complex N-linked glycan structures may be due to steric hindrance, with shielding of cryptic binding sites for macrophage clearance receptor low density lipoprotein receptor-related protein 1 (LRP1).

Defining the mechanisms underpinning VWF clearance is not only of direct translational relevance, but may also have important implications for the development of novel therapeutic agents with significant commercial appeal. For example, the estimated cost of clotting factor concentrates to the global market is predicted to exceed €10 billion per annum by 2020. It is therefore perhaps unsurprising that major pharmaceutical companies (including Baxter®, Bayer®, Novo Nordisk® and Octapharma®) are actively pursuing development of longer-acting coagulation factor products (including VWF and FVIII) as a priority. Our novel findings further scientific understanding in relation to the molecular mechanisms involved in regulating coagulation glycoprotein clearance from plasma.


McGettrick AF, Corcoran SE, Barry PJ, McFarland J, Crès C, Curtis AM, Franklin E, Corr SC, Mok KH, Cummins EP, Taylor CT, O’Neill LA, Nolan DP. Trypanosoma brucei metabolite indolepyruvate decreases HIF-1α and glycolysis in macrophages as a mechanism of innate immune evasion. Proc Natl Acad Sci U S A. 2016 Nov 29;113(48):E7778-E7787. PMID: 27856732.

Dr. Anne McGettrick and Sarah Corcoran at Trinity College Dublin lead a team of researchers including Dr. Annie Curtis (now at MCT) on a study that uncovered how the African parasites trypanosomes evade the immune system in their hosts, The biochemists have unearthed a metabolic by-product of trypanosome activity known as indolepyruvate modulates the inflammatory response of the host and evades immune detection. This discovery may offer excellent possibilities for developing anti-trypanosome drugs and therapies because inhibiting the production of indolepyruvate may be key in fighting the parasite. Full details can be found here https://www.tcd.ie/news_events/articles/solving-a-putrid-camel-pee-riddle-may-aid-millions-affected-by-sleeping-sickness/7385

The cerebrovascular nature of neurological disorders

MCT Research Talks – 9th January 2017

Guest speaker: Dr. Matthew Cambell

At MCT, we are very excited to announce our visiting guest speaker Dr Matthew Campbell from the Smurfit Institute of Genetics in Trinity College Dublin. Dr Campbell is a prestigious and young emerging principal investigator in Ireland who has made significant contributions in the fields of Neuroscience, Inflammation and the Vasculature System, core research areas that are also conducted within the MCT department.

Dr. Matthew Cambell

Dr Campbell aims to elucidate and address questions associated with dysfunctional vasculature within neural tissues. Recently published in Nature Medicine, Dr Campbell made a significant discovery uncovering the role of the NLRP3 inflammasome in the development of one of the most common forms of central retinal blindness, AMD. His lab is now pursuing a range of novel therapeutic solutions for the treatment of AMD and recently reported on the translational potential of human IL-18 as an immunotherapy.

Dr Campbell interests also focus on the blood-brain barrier, where he recently reported for the first time on the auto-regulated diffusion of amyloid-β in Alzheimer’s disease. More recently, he has identified molecular mechanisms underlying the development of chronic traumatic encephalopathy (CTE) to concussive injuries in athletes and military personnel. He spearheads a project involving the use of RNA interference (RNAi) to modulate levels of distinct tight junction proteins at the blood-brain barrier. This led to a novel form of patented technology that was termed “Neural Barrier Modulation” which could have broad applications for a range of neurological conditions.

Dr Campbell is the recipient of Ireland’s most prestigious prize for young researchers, the “President of Ireland Young Researcher Award (PIYRA)“, in addition to the international Genentech/ARVO fellowship. He will be speaking today on ‘the cerebrovascular nature of neurological disorders’ at 12 pm in Tutorial Room 2/3. Lunch will be provided for all after the talk.

All welcome!!

Written by Dr Claire McCoy, Lecturer in Biochemistry, MCT, RCSI.

Immunometabolism, Is it under the eye of the clock

Annie Curtis reports

Our Immune-clock laboratory has a real interest in metabolism and how alterations in metabolic pathways termed “metabolic reprogramming” can shape the type of immune response. This area called “Immunometabolism” has exploded in the last 5 years, and the implications are massive. It appears that macrophages use one metabolic pathway to become highly proinflammatory and another metabolic pathway to resolve inflammation and promote wound healing.  So why is our laboratory so interested in this? Well, if you think about daily changes in our environment, the two biggest are the sleep/wake cycle and the other is feeding/fasting. It is now clear that clocks in metabolic tissues like the liver/pancreas/adipose tissue prepare the body to deal with this daily rhythm in feeding/fasting. Based on this, our interest is to figure out if the clock within macrophages is somehow altering its metabolism over the course of the day and is that leading to changes in macrophage function, particularly the inflammatory response.

Jamie Early, my PhD student

Jamie Early, my PhD who “lives” in Prof. Luke O’Neills laboratory at TCD and I were invited to submit this first ever review on circadian immunometabolism, and you can find it here.

Additional reading

  1. Early JO, Curtis AM Immunometabolism: Is it under the eye of the clock?Semin Immunol. 2016 Oct;28(5):478-490

Follow me on Twitter @curtisannie

Here’s to a successful 2017!!

Many thanks to all members of MCT; without you, our success would not be possible. Wishing you and your family all the warmth this Holiday Season has to offer. Have a wonderful Christmas and a New Year filled with peace, joy and success.

MCT staff in 2016

Tracy Robson

Its about Time! The role of body clocks in health and disease

Annie Curtis reports

How metabolic and immune parameters vary across the 24 hours (1).

Body clocks tend to garner quite a bit of attention from the media. Folks are obsessed with sleep, either they cant get enough or they are getting too much, and all of us can relate to the symptoms of jet lag and morning versus evening types. Therefore it’s a great topic to discuss with wider audiences. I really enjoy chatting with people about the implications of our internal timing system and that research now shows that living in synchrony with your body clock can improve overall health. For the SFI Science week I was asked to provide an interview to the Daily Star called “The Science of Sleep Explained”. I was also asked to go on the “Alive and Kicking” show on Newstalk Radio with Ciara Kelly, you can listen to the interview: What type of sleeper are you? Are you an owl or a lark?

Additional reading:

  1. Early JO, Curtis AM Immunometabolism: Is it under the eye of the clock?Semin Immunol. 2016 Oct;28(5):478-490

Annie Curtis on Twitter @curtisannie

Using genotype data to infer population structure and history

MCT Research Talk – 12th December

The Human Genetic Variation Research Group 

The Monday 12th December MCT Seminar Series will feature presentations from Amy Cole and Edmund Gilbert, of the Human Genetic Variation Research Group at RCSI. Led by Prof. Gianpiero Cavalleri, this research group studies large genetic datasets to investigate population structure, natural selection and the genetic basis of human disease.

Andean native in a small village on the outskirts of Cuzco

Amy Cole’s research focuses on identifying adaptive genetic variants in high altitude populations.  There are more than 140 million people living at high altitude who are exposed to two primary environmental extremes; hypobaric hypoxia and cold. At altitudes >2500 m individuals have between 11-14% effective oxygen availability, instead of the 21% available at sea level. Previous studies have identified genetic signals of selection across the genome, which have facilitated an adaptive phenotype for survival in this hypoxic environment.  Studying these indigenous high altitude populations will enable us to shed light on genes and molecular mechanisms involved in the response to hypoxia. This insight can help shed light on a number of illnesses associated with hypoxic states in low altitude populations, such as pneumonia, chronic obstructive pulmonary disease, asthma and cancer.

Research group en route to Cerro de Pasco

Today Amy presented research on a whole genome sequencing project on native high altitude Quechua individuals, recruited from the city of Cerro de Pasco, Peru, during a field trip in 2015.  Amy recently completed a three-month lab placement at MD Anderson Cancer Center with Professor Chad Huff’s research group. Here Amy performed a number of computational analyses to identify regions of the genome that are under selection in this cohort.

Edmund Gilbert’s research involves investigating the genetic structure and diversity found within the Irish. As an island population on the west of Europe, the Irish population is, from the genetic perspective, relatively homogenous compared to populations of the European mainland. As a results of this elevated homogeneity, the Irish population is well suited to studies of genetic disease. Such studies have recently shifted focus towards rare variants, which are more geographically stratified than more common variants. Therefore understanding the population structure within Ireland is key for the optimal design of genetic disease causing rare variant identification within the Irish.

Today Edmund will be presenting research investigating the extent of fine-scale population structure found within Ireland. He has been using SNP-array genotype data from the genetic ancestry DNA cohort called the “Irish DNA Atlas”. The Atlas is a cohort of individuals with Irish ancestry from three generations ago who have all eight of their great-grandparents born within 50 km. Edmund will be presenting analysis based on the suite of software known as fineStructure; investigating both fine-scale structure as well as the genetic ancestry of this structure.

Amy Cole, Edmund Gilbert, Gianpiero Cavalleri

MCT student, Lisa Dwane, talks about her research and recent achievements

cropped-RCSI-logo-1.jpgFollowing completion of my Pharmacology degree in UCD, I began a PhD in breast cancer research under the supervision of Dr. Darran O’Connor, a career I have always been very determined to follow. My research is focused on endocrine-driven breast cancer and understanding the molecular mechanisms that drive this subtype of cancer. Currently, half of breast cancer patients that receive anti-endocrine therapies will relapse, so there is an urgent need for the identification of novel therapeutic targets. Our research is focused on the deubiquitinating enzyme USP11, which we believe plays a key role in driving endocrine-driven breast cancer. When we silence USP11 in vitro, we see a reduction in estrogen receptor activity and cell viability. During the final year of my PhD, I hope to elucidate the mechanism by which USP11 plays this role, and determine the prognostic relevance of USP11 in breast cancer. This could potentially lead to a better understanding of endocrine-driven breast cancer and with further validation, USP11 may represent a novel therapeutic target.

Lisa Dwane presents her research at the Irish Cancer Society’s Researcher of the Year Award. december, 1st, 2016. TCD
Lisa Dwane presents her research at the Irish Cancer Society’s Researcher of the Year Award. December, 1st, 2016. TCD

As a pharmacologist, I was thrilled to win best oral presentation at the Irish Association of Pharmacologists Annual Meeting! The standard of talks throughout the day were excellent, with a wide range of topics explored. I was also a finalist for the Irish Cancer Society’s Researcher of the Year Award, which took place 1st December at Trinity College Dublin. The purpose of the evening was to communicate our research to a lay audience, which proved more difficult than expected! Although I didn’t take home the award it was a very enjoyable evening, and the experience was invaluable. As scientists it is important for us to share and communicate our research with the general public and this was a skill I gained from the night!

Winners and finalists for the Irish Cancer Society’s Researcher of the Year Award
Winners and finalists for the Irish Cancer Society’s Researcher of the Year Award