Actin-like 6A predicts poor prognosis of hepatocellular carcinoma and promotes metastasis and epithelial-mesenchymal transition.
Bottom Line: Opposite results are observed when ACTL6A is knocked down.ACTL6A knockdown has the equal blockage effect as the Notch signaling inhibitor, N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butylester, in HCC cells.Further studies indicate that ACTL6A might manipulate SRY (sex determining region Y)-box 2 (SOX2) expression and then activate Notch1 signaling.
Affiliation: Liver Cancer Laboratory, Department of Surgery, Xiangya Hospital, Central South University, Changsha, China.Show MeSH
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Mentions: To systemically screen the potential signaling manipulated by ACTL6A, a Cignal Finder Cancer 10‐Pathway Reporter Array was used. ACTL6A significantly enhanced the activity of Notch signaling in PLC/PRF5 cells, and ACTL6A knockdown attenuated Notch signaling activity in Hep3B cells (Fig. 4A). Notch signaling is crucial for development and progression of HCC, and Notch receptor is the key role of Notch signaling activation.18, 19 However, which member of the four known Notch receptors (Notch1‐4) is regulated by ACTL6A in HCC was unknown.20, 21, 22 We detected Notch 1‐4 expression in PLC/PRF5, PLC/PRF5‐ACTL6A, Hep3B, and Hep3B‐shACTL6A cells. Ectopic expression of ACTL6A in PLC/PRF5 increased Notch1 expression, whereas knockdown of ACTL6 in Hep3B decreased Notch1 expression. No considerable change was observed for the other three Notch genes (Fig. 4B). Then, we focused on Notch1 signaling members in HCC cells. It showed that a high level of ACTL6A in PLC/PRF5 cells increased Notch intracellular domain (NICD)1, RBP‐Jκ, and Hes1 (Hes family BHLH transcription factor 1) expression. Consistently, knockdown of ACTL6A in Hep3B cells inhibited these gene expressions. Manipulation of ACTL6A expression in cells did not affect Jagged1 expression, which indicated that ACTL6A specifically regulated NICD1, RBP‐Jκ, and Hes1 in Notch1 signaling (Fig. 4C).
Affiliation: Liver Cancer Laboratory, Department of Surgery, Xiangya Hospital, Central South University, Changsha, China.