RNA sequencing of siPI4KIIIβ-transfected lung cancer cells

We speculated that Golgi fragmentation in PI4KIIIβ-deficient cells resulted from apoptosis, which initiates caspase-mediated cleavage of the Golgi ribbon at an early stage of the execution phase. Indeed, siPI4KIIIβ-transfected H23 and H2122 lung cancer cell lines demonstrated evidence of apoptosis on the basis of western blotting, flow cytometry, and RNA sequencing, which identified 717 genes up-regulated in shPI4KIIIβ-transfected H23 cells (fold-change > 1.4, P-value < 0.01 by t-test, false discovery rate<10%) that were enriched in, among other Gene Ontology terms, “positive regulation of apoptotic process” (20 genes, P=0.005), “extracellular matrix” (18 genes, P=1.3E-05), and “extracellular matrix organization” (29 genes, P=1.8E-06) (one-sided Fisher’s exact test using Gene Ontology terms). To determine whether apoptosis resulted from impairment of PI4KIIIβ-dependent secretion, we performed conditioned media transfer experiments and found that the proliferative activity of shPI4KIIIβ-transfected cells was rescued by conditioned media from PI4KIIIβ-replete, but not -deficient, cells. Cells from H23 lung cancer cell line were transfected with either shRNAs against human PI4KIIIβ or control shRNAs and subjected to RNA seqeuncing.