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

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.

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

Targeting drug resistance in neuroblastoma

MCT Research Talks 5th December 2016  rcsi-logo

Cancer Genetics Group

Neuroblastoma is a childhood cancer caused by the abnormal growth and development of neural crest cells (1). The disease commonly affects children age 5 years or younger. Approximately 50% of children have cancer cells that have migrated to distant sites in the body and formed tumour masses at the time of diagnosis. The main challenge in treating neuroblastoma is to combat tumour metastasis and development of resistance to multiple chemotherapeutic drugs. Despite major advances in available therapies, children with drug resistant and/or recurrent neuroblastoma have a dismal outlook with 5 year survival rates of less than 20%.

Research of Prof. Stallings lab is focused on elucidating the molecular events that contribute to the development and progression of neuroblastoma (2).  A major area of research involves the identification and functional analysis of microRNAs that contribute to chemotherapy resistance in neuroblastoma, along with the development of microRNA-mediated therapeutics.

The main research projects were presented at the Departmental meeting on December, 5th.

Microscopic examination of drug resistant neuroblastoma cells KellyCis83. Cells look healthy and can be kept for another 2-3 days to form a more dense population.
Microscopic examination of drug resistant neuroblastoma cells KellyCis83. Cells look healthy and can be kept for another 2-3 days to form a more dense population.

The first talk by Olga Piskareva has explored how current concepts of development of drug resistant, tumour microenvironment and cell-to-cell communication can be applied to reconstruct relapsed or drug resistant neuroblastoma microenvironment using 3D tumour models.

TEM analysis of exosome fractions. Vesicle sizes range from 30 to 200nm in Kellycis83 (A) and Kelly (B) neuroblastoma cells. (C) EVs which appear larger than the 100 nm upper limit for exosomes (D) Close up of the dried exosome preps identify the typical bowl shaped morphology associated with TEM images of exosomes. (3)
TEM analysis of exosome (EV) fractions. Vesicle sizes range from 30 to 200nm in Kellycis83 (A) and Kelly (B) neuroblastoma cells. (C) EVs which appear larger than the 100 nm upper limit for exosomes (D) Close up of the dried exosome preps identify the typical bowl shaped morphology associated with TEM images of exosomes (3).

The second talk was presented by Ciara Fallon. Ciara is our StAR PhD student. She has selected the project ‘Exosome mediated drug resistance in high-risk neuroblastoma’ as her first choice.  At the moment she is doing her lab placement in Cancer Genetics group as a part of the RCSI StAR PhD Programme. Built upon results of the former BioAt PhD Student Ross Conlon (3), Ciara’s project is focused on the validation of exosomal miR-548d-5p as a regulator of cell viability and proliferation in cisplatin sensitive and resistant neuroblastoma cell lines.

Finally, the last, but not least was a talk by John Nolan. His talk entitled “MiRNA-124-3p Reduces Cell Viability in Cisplatin Resistant Neuroblastoma Cell Models” was focused on the results submitted to the Royal College of Surgeons for the Degree of Doctor of Philosophy. His studies cover the development of cross resistance to other drugs, investigation of common altered proteins and signaling pathways in cisplatin resistant neuroblastoma cell lines and validation of miRNA that can target these proteins and stop cell proliferation. Part of the results was published last year in Cancer Letters (4).

The work carried out in Prof. Stallings lab is supported through the research grant to Prof. Ray Stallings and PhD fellowship to John Nolan by National Children’s Research Centre, Crumlin Hospital. ncrc

References:

  1. Davidoff, A. M. Neuroblastoma. 2012 Semin. Pediatr. Surg. 21, 2–14.
  2. Piskareva, O., Stallings, R. Neuroblastoma. In: Epigenetic Cancer Therapy edited by Grey S., Elsevier 2015.
  3. Conlon, R., Analysis of microRNA bearing exosomes in models of drug resistant neuroblastoma. PhD Thesis. Dublin: Royal College of Surgeons in Ireland; 2015.
  4. Piskareva, O., Harvey, H., Nolan, J., Conlon, R., Alcock. L., Buckley, P., Dowling, P., O’Sullivan, F., Bray, I., Stallings, T.L. The development of cisplatin resistance in neuroblastoma is accompanied by epithelial to mesenchymal transition in vitro. 2015 Cancer Letters, 364:142-55.

Reported by Olga Piskareva