RET Pathway Regulation in Cancer Cells

Example 1

Cells were treated with the indicated compounds for 7 hours before lysis with Buffer RLT (QIAGEN, Hilden, Germany) containing 1% β-mercaptoethanol. Total RNA was isolated using the Rneasy Plus Mini kit (QIAGEN, Hilden, Germany) according to the manufacturer's instructions. First-strand cDNA was synthesized using the SuperScript VILO Master Mix (Thermo Fisher Scientific, Waltham, MA) according to the manufacturer's instructions. Real-time qPCR was run on ViiA 7 Real Time PCR System (Thermo Fisher Scientific). For qRT-PCR, the expression of the reference gene glucuronidase beta (GUSB) was used to normalize expression of the target genes DUSP6, SPRY4, and glycogen synthase kinase 3 beta (GSK3B). Replicate qRT-PCR reactions were analyzed for each sample, and QuantStudio Real-Time PCR software (Life Technologies, Carlsbad, CA) normalized the average expression of DUSP6, SPRY4, or GSK3B to the average expression of the reference gene GUSB in each sample. FIGS. 1A-1C show relative transcript expression of RET pathway targets DUSP6 and SPRY4 and AKT-pathway target GSK3B 7 hours after treatment of L2C/ad cells (FIG. 1A), MZ-CRC-1 cells (FIG. 1B), or TT MTC cells (FIG. 1C) with Compound 1 or cabozantinib. FIG. 2 shows relative transcript expression of DUSP6, SPRY4 and GSK3B from KIF5B-RET NSCLC PDX. Tumors collected at the indicated times (hours) after administration of last dose. Data are the mean+SD. *P<0.05, **P<0.01, ***P<0.001, 2-sided Student's t-test. SD, standard deviation.