Journal: Cancers
Article Title: Wnt5a Regulates Focal Adhesion Formation to Promote Migration in Ewing Sarcoma
doi: 10.3390/cancers17223712
Figure Lengend Snippet: ( A ) Western blot for pFAK (Tyr 397) and pSrc (Tyr 416) in seven Ewing sarcoma cell lines treated with vehicle control (DMSO) versus WNT974, with a decrease in both pFAK and pSrc in the majority of cell lines treated with WNT974. ( B ) Immunofluorescence example for pFAK (Tyr 397) in A4573 cells. Note that pFAK (green) is found in the protrusions of the DMSO-treated A4573 cells but is found in the centralized clumps of actin (pink) in the WNT974-treated cells. With WNT974 treatment, there is a statistically significant decrease in pFAK puncta and the amount of pFAK throughout the cells. Green-fluorescent insert demonstrates pFAK with dots representative of Volocity analysis. ( C ) Boyden chamber assay using two different doses of FAK inhibitor GSK2256098 in A4573 and TC71 cells. Note that migration is significantly impaired in both cell lines upon treatment with the FAK inhibitor, even at nanomolar doses. ( D ) Treatment with Src inhibitor, saracatinib (1 μM), also results in a statistically significant decrease in cell migration, also suggesting that Src is important for Ewing sarcoma cell migration. In addition to catalytic proteins, focal adhesions contain adaptor proteins that mediate interactions between the cytoskeleton and the extracellular matrix . ALCAM is an adaptor protein that contains immunoglobulin-rich domains with the amino-terminal V-type immunoglobulin domain required for cell-to-cell adhesive interactions. ALCAM can form homotypic or heterotypic interactions, and its expression is highest at areas of cell-to-cell contact where it can interact with other cell adhesion molecules [ , ]. ALCAM is expressed in over 70% of pediatric sarcomas, so we started by assessing changes in protein expression with WNT974 treatment . ALCAM protein levels were unchanged with WNT974 treatment, so we next evaluated ALCAM distribution in the cell (Supplementary E). As shown in A, the vehicle control-treated cells maintain a small number, typically 2–3, of well-formed long protrusions in which ALCAM can be found throughout, in addition to its presence in the perinuclear region of the cytoplasm. In contrast, in cells treated with WNT974, there is bright centralized clumping of ALCAM and a notable loss of long protrusions in most of the cells. The highest concentration of ALCAM in these cells appears to overlap the nucleus, in contrast to the perinuclear cytoplasmic distribution in the vehicle control-treated cells. In addition, many of the WNT974-treated cells demonstrate a more circumferential ruffled appearance to the plasma membrane. In addition, there is a decrease in the number of long protrusions from the cells with WNT974 treatment ( A). ALCAM is a member of a family of cell adhesion molecules. Another family member that has been implicated in sarcoma biology is MCAM [ , , ]. The involvement of ALCAM in Wnt5a-mediated cytoskeletal rearrangements is specific, because no such changes were appreciated with MCAM immunofluorescence ( A). * p = 0.05, ** p = 0.01, **** p = 0.0001.
Article Snippet: Blocked slides were incubated with primary antibodies including ALCAM (Novus, #NBP2-37358, 1:1000), vinculin (Abcam, #ab129002, 1:1000), and phosphorylated Fak (Tyr397) (Abcam, #ab81298, 1:200) overnight at 4 °C, washed in PBS, incubated with Alexa Fluor 488-conjugated, donkey anti-mouse secondary antibody (1:1000; Life Technologies), Alexa Fluor 555-conjugated goat anti-rabbit secondary, or Alexa Fluor 647-conjugated goat anti-mouse, plus Dapi 1:1000 for 1 h, and then visualized with a Nikon Spinning Disc confocal microscope, including 2 μM Z-stacks.
Techniques: Western Blot, Control, Immunofluorescence, Boyden Chamber Assay, Migration, Adhesive, Expressing, Concentration Assay, Clinical Proteomics, Membrane