B

B. cells to undergo epithelial-mesenchymal transition (EMT). EMT is usually associated with enhanced migration and invasion. Our study uncovered a new target, 51 integrin. Targeting 51 integrins might not only prevent metastasis of HNSCC but also delay the development of the primary tumor by reducing tumor cell viability. Cav1 detection might be taken into consideration in the future in the clinic not only to identify patients at high risk of metastasis but also to select patient who might benefit from an anti-integrin therapy. = 0,007). Patients were Estropipate stratified according to the Cav1 gene expression (see suppl. material and methods for Estropipate cut-off value determination), and a Kaplan-Meier analysis of the distant metastasis-free survival (MFS) and of the overall survival (OS) were performed. Cav1 was found to have a prognosis value, since low caveolin expression correlated to adverse prognosis (shorter time to metastasis; 0.001; Figure ?Figure1C)1C) and reduced OS ( 0.005; Figure ?Figure1D1D). Open in a separate window Figure 1 Cav1 expression in human HNSCC tissue specimensA. Quantified analysis of CAV1 transcripts determined in 11 primary tumor samples of patients that developed metastasis (R1) and 57 primary tumor samples of patients that did not developed metastasis (non-R1). The line within the bar represents the mean value and o represent Rabbit Polyclonal to USP6NL individual data point. (*** 0.001). B. Immunohistochemical analysis of Cav1 in R1 and non-R1 FFPE tissus (original magnification: X100). Table show % of non-R1 and R1 tumors with 0%, 1-25%, 25-75% and 75% Cav1-positive cells. C. Kaplan-Meier analysis of the distant metastasis-free survival (MFS) in patients stratified according Cav1 gene expression (CAV1(+) and CAV1 (?)). A cut-off value was determined for Cav1 gene expression (measured by qRT-PCR), corresponding to a 90.1% sensitivity and a 81.4% specificity with respect to the R1 status (90.1% of the R1 lesions display a Cav1 expression level below this cut-off, and 81.4% of the non-R1 tumours express Cav1 levels above this cut-off. More detail in suppl. material and methods). Samples were considered as Cav1-negative is the qRT-PCR Estropipate value was to the cut-off. Shorter time to metastasis *** 0.001). D. Kaplan-Meier analysis of the overall survival (OS) in patients stratified Estropipate according Cav1 gene expression (CAV1(+) and CAV1 (?)) as described in Fig ?Fig1C.1C. Shorter time to death, **= 0.003). Low Cav1 expression increases cell motility and invasion In order to evaluate the impact of the deregulation of Cav1 expression on the propensity of tumour cells to form distant metastasis, we generated a cell line expressing low level Cav1 and performed functional analysis (shRNAcav1-SCC9, Figure ?Figure2A).2A). Migration was analyzed in single and collective cell migration assays. Individual cell migration was examined by live cell imaging in low density cell cultures (Figure ?(Figure2B).2B). Cell tracking measurements revealed that shRNAcav1-cells have a more persistent migration and a significant increase in the speed and velocity of migration than their control counterparts (Figure ?(Figure2B).2B). In other terms SCC9-shRNAcav1 explored larger areas than control cells. Consequences of Cav1 reduction were also determined in a collective 3D cell migration model using SCC9 spheroid. SCC9-shRNActrl poorly migrated out of the spheres on plastic or fibronectin (FN)-coated dishes but strongly on collagen-coated dishes (Figure ?(Figure2C).2C). Independently of the matrix used, shRNAcav1-cells migrated out of aggregates more efficiently and covered an area significantly more important than control cells (Figure ?(Figure2C).2C). Data suggested that although collagen promoted strong evasion of cells, removal of Cav1 not only reinforced the process on collagen but also conferred cells the capacity to efficiently and significantly evade on a new matrix, FN. A strong secretion of FN into the extracellular environment was observed by microscopy in shRNAcav1-cells although no increased expression of FN was detected at the RNA and protein levels (Figure ?(Figure2D2D). Open in a separate window Open.