Research Position in Cancer Biology

**Research Position in Cancer Biology**:
The Chelico lab at the University of Saskatchewan, Department of Biochemistry, Microbiology, and Immunology, is seeking a motivated researcher to study the biochemical mechanism of how APOBEC3 enzymes contribute to breast cancer.

**Scientific Background**:Cancers are caused by genomic instability at the level of the chromosome or nucleotide. Genomic instability originates from external carcinogens, inherited mutations, endogenous chemical damage of DNA, or as discovered in 2013, endogenous enzymatic activity of APOBEC3 (A3) single-stranded (ss)DNA cytosine deaminases.

The seven A3 enzymes in humans (A3A, A3B, A3C, A3D, A3F, A3G, A3H) deaminate ssDNA cytosines to uracils at specific sequence contexts and are normally expressed as an antiviral defense in germ cells, lymphocytes, and infected epithelial cells. A3 enzymes induce functional inactivation of viral DNA sequences through their promutagenic potential. A3 catalyzed uracils lead to C to T transition mutations in viral DNA due to uracil remaining in the template during replication. It is not known why but in some tissues A3 expression is upregulated (13-60 fold) and cytosine deamination happens in human genomic DNA when it is transiently ssDNA, such as during replication or repair. Depending on the cellular context, the uracil can escape faithful repair and be a template during DNA replication or promote transversion mutations if the uracil is excised and repaired via low fidelity DNA repair pathways. Multiple cancer genomes contain mutations in sequence contexts that match the in vitro deamination specificities of A3A, A3B, and A3H haplotype I.

**Primary Purpose**:While there are genomic and clinical studies correlating A3-induced mutations with cancer, many of the mechanistic steps in how the A3 activity that induces uracils results in the broad type mutations in cancer genomes and how their protein interaction network affects their activity remains to be determined. There are two research projects available in these areas to provide the mechanistic details that are currently lacking in the field.
- Work independently and troubleshoot protocols
- Learn new methods and integrate them into the lab’s workflow
- Train junior lab members and assist in supervising students
- Order reagents and manage laboratory inventory
- Coordinate with the Principle Investigator and organizing day-to-day lab operations
- Handle multiple priorities and manage time effectively

**Skills**:Key skills include:

- Mammalian cell culture
- Co-immunoprecipitation (co-IP)
- Immunoblotting (Western blot)
- Colony formation and drug sensitivity assays
- Immunofluorescence microscopy
- Mouse xenograft studies

It is especially valuable if these techniques were applied in the context of:

- DNA repair pathways
- Ubiquitination and protein-protein interactions
- Somatic mutagenesis and genome instability

Experience working in a collaborative lab environment and participating in manuscript preparation is considered an asset.

**How to Apply**:Applicants should submit their C.V. along with a one-page cover letter titled “I want to work on APOBECs and cancer”. The cover letter should detail:

- An example of how you have experienced and dealt with competing priorities and multitasking
- A summary of a project idea based on what interests you in these recent lab publications: PMID: 38548018, PMID: 37324648, PMID: 36444883

**Department**: Biochemistry, Microbiology, and Immunology
**Status**: Term 1 year with the possibility of extension
**Employment Group**: Research Positions - Non-union
**Full Time Equivalent (FTE)**: 1.0
**Salary**: The starting salary will be commensurate with education and experience.
**Posted Date**: 7/18/2025
**Closing Date**: 8/21/2025
**Number of Openings**:1
**Work Location**:On Campus