Figure S1 from the Small GTPase ARF6 Activates PI3K in Melanoma to Induce a Prometastatic State

Figure S1. Detection of HA-tagged ARF6Q67L in BrafCA;Cdkn2af/f melanoma. a) Anti-HA immunostain of FFPE sections of primary tumors with variable levels of detection of ARF6Q67L -HA. The strongest staining was observed in tumors with the highest level of mRNA detected by qRT-PCR (b). Absent staining of FFPE tumors was observed in tumors with low (6456) and undetectable (6457) levels of mRNA by qRT-PCR of frozen tumors. Scale bars = 20mm, 400x magnification. Control = BrafCA;Cdkn2af/f (Cre-only injection). b) qRT-PCR of Arf6 Q67L-HA from fresh, frozen primary tumor fragments. Bars represent the absolute difference in crossing threshold (Ct) between Arf6Q67L-HA and Gapdh. The Ct threshold that defines detection was established above the background signal for controls in both the BrafCA;Cdkn2af/f and the BrafCA;Cdkn2af/f ;Ptenf/f cohorts (see Figures 1g and S3). With rare exception, positive tumors demonstrated Arf6 Q67L-HA expression levels lower than Gapdh.