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Sphingolipids make up a family of molecules associated with an array of biological functions, including cell death and migration. Sphingolipids are often altered in cancer, though how these alterations lead to tumor formation and progression is largely unknown. Here, we analyzed non-small-cell lung cancer (NSCLC) specimens and cell lines and determined that ceramide synthase 6 (CERS6) is markedly overexpressed compared with controls. Elevated CERS6 expression was due in part to reduction of microRNA-101 (miR-101) and was associated with increased invasion and poor prognosis. CERS6 knockdown in NSCLC cells altered the ceramide profile, resulting in decreased cell migration and invasion in vitro, and decreased the frequency of RAC1-positive lamellipodia formation while CERS6 overexpression promoted it. In murine models, CERS6 knockdown in transplanted NSCLC cells attenuated lung metastasis. Furthermore, combined treatment with L-α-dimyristoylphosphatidylcholine liposome and the glucosylceramide synthase inhibitor D-PDMP induced cell death in association with ceramide accumulation and promoted cancer cell apoptosis and tumor regression in murine models. Together, these results indicate that CERS6-dependent ceramide synthesis and maintenance of ceramide in the cellular membrane are essential for lamellipodia formation and metastasis. Moreover, these results suggest that targeting this homeostasis has potential as a therapeutic strategy for CERS6- overexpressing NSCLC., Introduction Recent evidence has shown altered levels of biologically active sphingolipids and enzymes related to sphingolipid metabolism in cancer, indicating roles for these pathways in cancer pathogenesis and progression (1). [...]

Original citation: J Clin Invest. 2016;126(1):254-265. https://doi.org/10.1172/JCI79775. Citation for this retraction: J Clin Invest. 2019;129(11):5050. https://doi.org/10.1172/JCI133806. At the request of the corresponding author, the JCI is retracting this article. Following [...]