Identifying post-translationally modified proteins in breast cancer cells for investigating the mechanisms of action of a potential anti-cancer drug

Phosphorylation is one of the most commonly occurring post-translational modifications (PTMs) of proteins. Phosphorylation plays key roles in activation or deactivation of protein function, degradation, folding, intracellular signaling, cell growth and cell proliferation. It is estimated that, protein can be phosphorylated anywhere from 10-15% of proteins in human genome. Due to their importance in multiple aspects of cell function, identification of protein phosphorylation sites will yield better understanding of regulatory pathways and cellular responses. Moreover, perturbations in the phosphorylation process can cause uncontrolled cell growth and cell development. Thus elucidating the changes in protein phosphorylation status for a given cellular condition will help to identify key signaling pathways and proteins significant in disease progression. However, identifying global phosphorylation events and generating a meaningful interpretation of these events is difficult. Phosphorylated proteins are usually low in abundance and require high-resolution methods, such as mass spectrometry to accurately identify these events. In this study, a breast cancer cell culture model was used to explore the efficacy of an optimized enrichment step in delineating between untreated (control) breast cancer cells and breast cancer cells treated with a natural products’ mixture (NI-07) containing eight different plant extracts. After enrichment of the phosphorylated proteins fraction, results were uploaded to mass spectrometry analysis to identify the proteins present. From this dataset, few selected protein of interest was chosen to illustrate the utility of high-resolution phospho-proteomics for identifying areas for further research (particularly with treatment strategies). Furthermore, understanding the targets of phosphorylation could become exploitable in drug development strategies for cancer treatment. This study will lay the foundation for understanding the mechanism of action for candidate drug with potential anti-cancer properties, helping elucidate their biological targets

Embargo status: Restricted until 09/2022. To request the author grant access, click on the PDF link to the left.