Cetuximab sensitivity of head and neck squamous cell carcinoma xenografts is associated with treatment-induced reduction of EGFR, pEGFR, and pSrc
2013 (English)Manuscript (preprint) (Other academic)
BACKGROUND: The aim of this study was to validate in vitro drug sensitivity testing of head and neck squamous cell carcinoma (HNSCC)cell lines in an in vivo xenograft model, and to identify treatment-induced changes in the EGFR signaling pathway that could be used as markersfor cetuximab treatment response.
METHODS: The in vitro cetuximab sensitivity of two HNSCC cell lines, UT-SCC-14 and UTSCC-45, was assessed using a crystal violet assay. In order to determine the corresponding in vivo sensitivity, UT-SCC-14 and UT-SCC-45 xenografts were generated in female BALB/c (nu/nu) nude mice. Mice were given three injections of intraperitoneal cetuximab or PBS and the tumor volume was recorded continuously. The expression of epidermal growth factor receptor (EGFR), phosphorylated EGFR (pEGFR), phosphorylated Src (pSrc), and Ki67 was investigated by immunohistochemistry.
RESULTS: The treatment sensitive UT-SCC-14 cells were found to have an intrinsic cetuximab sensitivity (ICmabS) of 0.15 whereas the ICmabS of the insensitive cell line UT-SCC-45 was 0.78. The corresponding size ratio between untreated and cetuximab treated xenografts was 0.22 and 0.83 for UT-SCC-14 and UT-SCC-45, respectively. UT-SCC-14 cells had a higher baseline expression of pEGFR as compared to UT-SCC-45. Furthermore, in UT-SCC-14 xenografts there was a decrease in EGFR, pEGFR and pSrc upon cetuximab treatment. In contrast, a slight cetuximab-induced increase in EGFR, pEGFR and pSrc was observed in treatment-resistant UT-SCC-45 xenografts.
CONCLUSIONS: The in vitro treatment sensitivity was reproduced in the in vivo model and cetuximab sensitivity was found to associate with a treatment-induced reduction in pEGFR and pSrc.
Place, publisher, year, edition, pages
Medical and Health Sciences Clinical Medicine
IdentifiersURN: urn:nbn:se:liu:diva-113742OAI: oai:DiVA.org:liu-113742DiVA: diva2:784448