School of Physical and Chemical Sciences Seminar Series

This is the eighth in a series of joint school seminars showcasing SPCS research ....

Speaker

Ian Shaw and Phil Butler

Institute

School of Physical and Chemical Sciences Te Kura Matū

Time & Place

Wed, 31 Jul 2019 12:00:00 NZST in West room 701

All are welcome

Abstract

Ian Shaw: Hormone Mimicry, Health & Wellbeing

We are exposed to myriad chemicals every day, they all impact our biochemistry and cause some aberrations (usually too small to measure).  Some of these chemical exposures interfere with hormone receptors and have effects akin to hormones because their chemical structures mimic the natural hormone (i.e. endocrine disrupting chemicals; EDCs).  A sub-class of the EDCs interfere with sex hormone receptors (estrogen mimics, testosterone mimics) and cause effects that are occurring in animals and humans across the world.  This will be the subject of Ian’s talk.

To begin, Ian will outline how hormones work, then focus on the female hormone (17β-estradiol) and its mimics, their sources, and human exposures.  He’ll explore hormone/receptor interactions and show how estrogen mimics fit and activate estrogen receptors using in silico molecular modelling. The cellular effects of estrogen receptor occupancy by estrogen mimics will be introduced and then set in the context of estrogen mimics as cancer risk factors – this will be illustrated by Ian’s student’s work on cultured breast cancer cells which express Estrogen Receptor (ER)-α and colon cancer cells which express ER-β and the proliferative effects of estrogen mimics.  This all points to estrogen mimics as cancer risk factors.  On the positive side, they might also have some positive effects by underpinning food functionality…

Ian will extend his thinking to androgen receptors and their role in prostate cancer, and how some testosterone-mimicking drugs used during prostate cancer (e.g. dexamethasone to treat skin disorders) might lead to cancer cell proliferation.

Finally, Ian will show how his research group is beginning to use molecular dynamics to better understand the sequence of events from estrogen mimic interaction with ERs to conformational change which leads to cellular response.  Our understanding of the intimate relationship between a ligand and its receptor might open new cancer drug targets.

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Phil Butler:  MARS pre-clinical imaging – the diagnostic benefits of small pixels and good energy data

MARS scanners use energy-resolving photon-counting CZT Medipix3RX detectors that measure the energy of photons on a five-point scale and with a spatial resolution of 110 microns. The energy information gives good material discrimination and quantification. The 3D reconstruction gives a voxel size of 70 microns. I present images of pre-clinical specimens, including excised atheroma, bone and joint samples, and nanoparticle contrast agents along with images from living humans.

All Welcome