3-Methyladenine suppresses cell migration and invasion of HT1080 fibrosarcoma cells through inhibiting phosphoinositide 3-kinases independently of autophagy inhibition

  • Authors:
    • Shingo Ito
    • Nobuko Koshikawa
    • Shigenobu Mochizuki
    • Keizo Takenaga
  • View Affiliations

  • Published online on: August 1, 2007     https://doi.org/10.3892/ijo.31.2.261
  • Pages: 261-268
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Abstract

3-Methyladenine (3-MA) inhibits class III phosphoinositide 3-kinase (PI3K) and is widely used as an inhibitor of autophagy. 3-MA has also been shown to stimulate cell death of tumor cells under nutrient-starved conditions by inhibiting autophagy. To explore the possibility of this type of autophagy inhibitors as anticancer drugs, we examined the effects of 3-MA on the phenotypes of highly metastatic human fibrosarcoma HT1080 cells. We report here that although 3-MA did not markedly affect cell survival of the cells under either normal or amino acid-starved conditions, it strongly inhibited the invasiveness of the cells. 3-MA rapidly suppressed actin rich membrane ruffle and/or lamellipodia formation under normal conditions, leading to inhibition of cell migration and invasion of the cells without substantial inhibitions of small GTPase Rac activity and the production of matrix metalloproteinases MMP-2 and MMP-9. 3-MA abolished class I and class II PI3Ks in in vitro lipid kinase assays, and suppressed cell motility of the cells more strongly than the other PI3K inhibitors wortmannin and LY294002. Downregulation of Beclin 1, a protein required for autophagic body formation, by transfection of Beclin 1 siRNA did not inhibit membrane ruffle formation and cell migration. These results suggest that 3-MA suppresses the invasion of HT1080 cells, independently of autophagy inhibition, through inhibition of type I and II PI3Ks and possibly other molecules.

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August 2007
Volume 31 Issue 2

Print ISSN: 1019-6439
Online ISSN:1791-2423

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Spandidos Publications style
Ito S, Koshikawa N, Mochizuki S and Takenaga K: 3-Methyladenine suppresses cell migration and invasion of HT1080 fibrosarcoma cells through inhibiting phosphoinositide 3-kinases independently of autophagy inhibition. Int J Oncol 31: 261-268, 2007
APA
Ito, S., Koshikawa, N., Mochizuki, S., & Takenaga, K. (2007). 3-Methyladenine suppresses cell migration and invasion of HT1080 fibrosarcoma cells through inhibiting phosphoinositide 3-kinases independently of autophagy inhibition. International Journal of Oncology, 31, 261-268. https://doi.org/10.3892/ijo.31.2.261
MLA
Ito, S., Koshikawa, N., Mochizuki, S., Takenaga, K."3-Methyladenine suppresses cell migration and invasion of HT1080 fibrosarcoma cells through inhibiting phosphoinositide 3-kinases independently of autophagy inhibition". International Journal of Oncology 31.2 (2007): 261-268.
Chicago
Ito, S., Koshikawa, N., Mochizuki, S., Takenaga, K."3-Methyladenine suppresses cell migration and invasion of HT1080 fibrosarcoma cells through inhibiting phosphoinositide 3-kinases independently of autophagy inhibition". International Journal of Oncology 31, no. 2 (2007): 261-268. https://doi.org/10.3892/ijo.31.2.261