Epigallocatechin-3-gallate potentiates curcumin's ability to suppress uterine leiomyosarcoma cell growth and induce apoptosis

Akiko Kondo, Takashi Takeda, Bin Li, Kenji Tsuiji, Mari Kitamura, Tze Fang Wong, Nobuo Yaegashi

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)

Abstract

Background: Uterine leiomyosarcoma (LMS) has an unfavorable response to standard chemotherapeutic regimens. Two natural occurring compounds, curcumin and epigallocatechin gallate (EGCG), are reported to have anti-cancer activity. We previously reported that curcumin reduced uterine LMS cell proliferation by targeting the AKT-mTOR pathway. However, challenges remain in overcoming curcumin's low bioavailability. Methods: The human LMS cell line SKN was used. The effect of EGCG, curcumin or their combination on cell growth was detected by MTS assay. Their effect on AKT, mTOR, and S6 was detected by Western blotting. The induction of apoptosis was determined by Western blotting using cleaved-PARP specific antibody, caspase-3 activity and TUNEL assay. Intracellular curcumin level was determined by a spectrophotometric method. Antibody against EGCG cell surface receptor, 67-kDa laminin receptor (67LR), was used to investigate the role of the receptor in curcumin's increased potency by EGCG. Results: In this study, we showed that the combination of EGCG and curcumin significantly reduced SKN cell proliferation more than either drug alone. The combination inhibited AKT, mTOR, and S6 phosphorylation, and induced apoptosis at a much lower curcumin concentration than previously reported. EGCG enhanced the incorporation of curcumin. 67LR antibody partially rescued cell proliferation suppression by the combination treatment, but was not involved in the EGCG-enhanced intracellular incorporation of curcumin. Conclusions: EGCG significantly lowered the concentration of curcumin required to inhibit the AKT-mTOR pathway, reduce cell proliferation and induce apoptosis in uterine LMS cells by enhancing intracellular incorporation of curcumin, but the process was independent of 67LR.

Original languageEnglish
Pages (from-to)380-388
Number of pages9
JournalInternational Journal of Clinical Oncology
Volume18
Issue number3
DOIs
Publication statusPublished - 2013 Jun

Keywords

  • 67-kDa laminin receptor
  • AKT
  • Curcumin
  • EGCG
  • Uterine leiomyosarcoma
  • mTOR

ASJC Scopus subject areas

  • Surgery
  • Hematology
  • Oncology

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