Y27632 Promotes Proliferation via EGFR Signaling in a Newly Isolated and Characterized Human Primary Sebocyte Cell Line

The study addressed the lack of Asian human sebocyte cell lines for in vitro research by deriving a new line from human breast skin tissue, confirmed by the expression of sebaceous gland-specific markers. The cell line could be passaged indefinitely with Y27632 and inactivated fibroblasts, maintaining a normal karyotype. It showed spontaneous stratification, with monolayer regions expressing proliferation markers and stratified regions showing differentiation. Lipid accumulation was induced by linoleic acid, with insulin and 5α-DHT enhancing lipid synthesis in the presence of linoleic acid and calcium chloride. Y27632 promoted proliferation through EGFR-CRAF-MEK-ERK and AKT pathways, not involving ROCK1/2, challenging previous assumptions about its mechanism. This finding could impact the understanding of stem cell biology, as Y27632 is commonly used to promote human ES cell growth.