Biological Effects of CRISPR/Cas9-mediated Knockout of RAB27A in SCLC

Small cell lung cancer (SCLC) is characterized by rapid growth and early metastasis. Identifying new molecular targets are important in the pathogenesis of SCLC in order to develop new treatment strategies. RAB27A is the critical protein for intracellular exosome trafficking and is a driver of tumour progression. However, demonstrating the potential impact of suppressing RAB27A in SCLC as therapeutic approach is an important deficiency. RAB27A gene knockout SCLC cell lines were generated using a CRISPR/cas9 system. qRT-PCR, Western blotting and Sanger sequencing were performed to confirm RAB27A knockout in SCLC cells. TEM and EXOCET assays were used to detect the alteration of exosomes. Proliferation and colony formation were detected by MTT and microscopy. Subsequently, we intrapulmonally injected N417 and H524 SCLC cells(control and RAB27A knockout for each cell) into SCID mice. The effects of RAB27A knockout on mouse tumor model were analysed using 18F-FDG PET/CT scans.Knocking out RAB27A significantly decreased the expression of CD9, CD63, Tsg101, exosome secretion and exosomal protein in SCLC(p