Dr Sandra M Bell

Profile

>I obtained my degree in biochemistry from Sussex University and my PhD on colon cancer genetics from Leeds University. Having developed an interest in cancer I then went onto work on positional cloning projects in breast and bladder cancer. I joined the genetics section of the Molecular Medicine Unit in 1996 and worked on a range of projects including the identification of two neurodevelopmental genes MCPH1 and CSMD1. I joined the newly formed section of Ophthalmology and Neuroscience in 2005 establishing my own group investigating the function of the two neurodevelopmental genes MCPH1 and CSMD1 in cancer.

Responsibilities

• Group Leader
• Member of School Ethics Committee

Research interests

Our group works on a range of projects including functional studies on two neurodevelopmental genes MCPH1 and CSMD1 in breast and ovarian cancer. Primary microcephaly (MCPH) (OMIM 251200) is a recessive genetic disorder in which the affected individuals are born with a significantly smaller head size and are mentally retarded. We work on MCPH1 (also called BRIT1), which encodes Microcephalin which contains three BRCA1 carboxyl-terminal (BRCT) motifs. We and co-workers have shown that MCPH1 is involved in DNA repair and regulation of cell cycle checkpoints, particularly the control of entry into mitosis causing premature chromosone condensation.

Figure 1 Mutations in the MCPH1 gene cause microcephaly (A), premature chromosome condensation (B & C) and cancer.

MCPH is thought be a consequence of a mitotic defect during foetal brain development. Abnormalities at mitosis can cause incorrect chromosome organisation and the development of aneuploidy in cancer. Numerous studies have shown that deletions at the MCPH1 (8p22-p23) loci is associated with tumour development and poor prognosis. We therefore propose that, while germ line defects in MCPH1 cause microcephaly, somatic defects may cause cancer (Figure 1).

We have identified reduced Microcephalin expression in both breast and ovarian cancers which is associated with reduced patient survival. We are studying the biological function of Microcephalin to determine how disruption of its activity causes cancer particularly breast and ovarian. Currently we are utilizing high throughput screening techniques using small molecule and whole human genome siRNA libraries to elucidate the function of MCPH1 and identify synthetic lethal genes. I was a founding member of the BioScreening Technology Group (BSTG) established to perform high-throughput, high-content siRNA screens.

Figure 2 Immunohistochemistry staining of paraffin embedded breast cancer samples. Positive nuclear MCPH1 staining (A), loss of MCPH1 expression (B) and comparison of overall survival based on MCPH1 expression in ductal breast cancer patients (C).

CSMD1 (CUB sushi multiple domain protein 1) is a large gene spanning over 2-Mb of chromosome 8p23 (adjacent to MCPH1), which is deleted in many cancer types. A significant amount of evidence points to CSMD1 playing a role in tumour development. We have previously shown that CSMD1 is an independent prognostic factor in breast cancer and we are currently investigating the function of CSMD1 using in vitro and in vivo models.

Current group members

Rachel Hodgson MSc student

Abrar Ashi PhD student

Samuel Burgess PhD student

Joanne Topping, PhD student (Co-supervisor)

Maram AlJuhni PhD student (Co-supervisor)

Ekram Shoaib PhD student (Co-supervisor)

Basma Alenezy PhD student (Co-supervisor)

Previous group members

Danah Al-Qallaf, PhD awarded 2019 (Co-supervisor)

Hannah Gibbs, MSc awarded (Distinction) 2018

Camilla Coulson-Gilmer, PhD awarded 2017

Alexander Hornsey, MSc awarded (Merit) 2017

Thomas Ryan, PhD awarded 2016 (Co-supervisor)

Aeshah Awaji, PhD awarded 2016

Enoir Faraj, MSc student awarded (Distinction) 2015

Kastarzyna Szymanska, awarded 2015 (Co-supervisor)

Shivani Shukla, Research Technician (2014-2015)

Julie Richardson, PhD awarded 2014

Rawiah Alsiary, PhD awarded 2013

Thomas Maisey, Research Technician (2012-2013)

Dr. Victoria Cookson, Post-doctoral researcher (2011-2014)

Mohamed Kamal, PhD awarded 2010

Sudeh Riah, MSc awarded 2006

Raj Achuthan, PhD awarded 2004 (Co-supervisor)

Qualifications

• 1987, BSc (Hons.) Biochemistry, University of Sussex
• 1992, PhD Colon Cancer Genetic, University of Leeds

Professional memberships

• British Association for Cancer Research
• British Society of Cell Biology

Student education

I teach first year MBChB students research skills on the Research Evaluation and Special Studies module and 2nd year MBChB students Genetics in Medicine. I am module lead for the Reasearch project component of the Molecular Medicine MSc. I am also a Personal tutor for 1st & 2nd year MBChB students and Postgraduate Research Tutor for MD/PHD students in Leeds Institute of Medical Research.

I am programme lead for the International PhD Academy: Medical Research based at St James’s University Hospital.

Research groups and institutes

• Leeds Institute of Medical Research at St James's