Integrin α11 is overexpressed by tumour stroma of head and neck squamous cell carcinoma and correlates positively with alpha smooth muscle actin expression
The presence of myofibroblasts in the stroma of tongue and oral cancer has been associated with poor prognosis by several studies 8. Integrin‐mediated interactions between extracellular matrix and the cytoskeleton seem to promote myofibroblast differentiation 12. Collagen‐binding integrins α1β1 13 and α2β1 14 were the first shown to influence myofibroblast differentiation under some conditions in vitro. Another collagen receptor, α11β1, has been also shown to regulate myofibroblast differentiation 15. Integrin α11 is expressed in many tissues in the embryo but disappears with maturation in adult tissues 16. However, it has been proved that its expression is upregulated in malignant conditions such as non‐small‐cell lung carcinoma, where it has been suggested to be connected to cancer cell growth 17. We also showed previously overexpression of integrin α11 in CAFs isolated from oral squamous cell carcinomas, but its expression in patient samples with either oral or head and neck carcinomas was not investigated at that time 19.
The aim of this study was to investigate the expression pattern of integrin α11 in HNSCC and its correlation with the well‐known myofibroblast marker α‐SMA.
We provide here data showing that integrin α11 is overexpressed in stroma of primary HNSCC and that it colocalizes with α‐SMA. Expression of α‐SMA at tumour front but not tumour centre had prognostic value for patient survival, indicating that tumour front is essential for evaluating stromal molecules as prognostic biomarkers in HNSCC.