The efficacy of sunitinib treatment of renal cancer is associated with the protein PHAX in vitro
Abstract
Anti-angiogenic agents, such as the multi-tyrosine kinase inhibitor sunitinib, are key first line therapies for metastatic clear cell renal cell carcinoma (ccRCC), but their mechanism of action is not fully understood. Here, we take steps towards validating a computational prediction based on differential transcriptome network analysis that phosphorylated adapter RNA export protein (PHAX) is associated with sunitinib drug treatment. The regulatory impact factor differential network algorithm run on patient tissue samples suggests PHAX is likely an important regulator through changes in genome-wide network connectivity. Immunofluorescence staining of patient tumours showed strong localisation of PHAX to the microvasculature consistent with the anti-angiogenic effect of sunitinib. In normal kidney tissue, PHAX protein abundance was low but increased with tumour grade (G1 vs. G3/4; p < 0.01), consistent with a possible role in cancer progression. In organ culture, ccRCC cells had higher levels of PHAX protein expression than normal kidney cells, and sunitinib increased PHAX protein expression in a dose dependent manner (untreated vs. 100 µM; p < 0.05). PHAX knockdown in a ccRCC organ culture model impacted the ability of sunitinib to cause cancer cell death (p < 0.0001 untreated vs. treated), suggesting a role for PHAX in mediating the efficacy of sunitinib.
Citation
Al-Lamki , R S , Hudson , N J , Bradley , J R , Warren , A Y , Eisen , T , Welsh , S J , Riddick , A C P , O'Mahony , F C , Turnbull , A , Powles , T , SCOTRRCC Collaborative , Reverter , A , Harrison , D J & Stewart , G D 2020 , ' The efficacy of sunitinib treatment of renal cancer is associated with the protein PHAX in vitro ' , Biology , vol. 9 , no. 4 , 74 . https://doi.org/10.3390/biology9040074
Publication
Biology
Status
Peer reviewed
ISSN
2079-7737Type
Journal article
Description
This work was supported by: Chief Scientist Office, Scotland (grant number ETM37 to G.D.S. and D.J.H.), Cancer Research UK (Experimental Cancer Medicine Centre; CRUK Grant C505/A7328) (to D.J.H.), Cancer Research UK (Experimental Cancer Medicine Centre (to T.P.), Medical Research Council (to D.J.H.), Renal Cancer Research Fund (to G.D.S. and D.J.H.), Kidney Cancer Scotland (to G.D.S.), NIHR Cambridge Biomedical Research Centre, and an educational grant from Pfizer (to T.P.).Collections
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