Cudrania tricuspidata Stem Extract Induces Apoptosis via the Extrinsic Pathway in SiHa Cervical Cancer Cells

PLoS One. 2016 Mar 9;11(3):e0150235. doi: 10.1371/journal.pone.0150235. eCollection 2016.

Abstract

The focus of this study is the anti-cancer effects of Cudrania tricuspidata stem (CTS) extract on cervical cancer cells. The effect of CTS on cell viability was investigated in HPV-positive cervical cancer cells and HaCaT human normal keratinocytes. CTS showed significant dose-dependent cytotoxic effects in cervical cancer cells. However, there was no cytotoxic effect of CTS on HaCaT keratinocytes at concentrations of 0.125-0.5 mg/mL. Based on this cytotoxic effect, we demonstrated that CTS induced apoptosis by down-regulating the E6 and E7 viral oncogenes. Apoptosis was detected by DAPI staining, annexin V-FITC/PI staining, cell cycle analysis, western blotting, RT-PCR, and JC-1 staining in SiHa cervical cancer cells. The mRNA expression levels of extrinsic pathway molecules such as Fas, death receptor 5 (DR5), and TNF-related apoptosis-inducing ligand (TRAIL) were increased by CTS. Furthermore, CTS treatment activated caspase-3/caspase-8 and cleavage of poly (ADP-ribose) polymerase (PARP). However, the mitochondrial membrane potential and expression levels of intrinsic pathway molecules such as Bcl-2, Bcl-xL, Bax, and cytochrome C were not modulated by CTS. Taken together, these results indicate that CTS induced apoptosis by activating the extrinsic pathway, but not the intrinsic pathway, in SiHa cervical cancer cells. These results suggest that CTS can be used as a modulating agent in cervical cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects*
  • Cell Cycle / drug effects
  • Cell Line, Tumor
  • Cell Shape / drug effects
  • Chromatography, High Pressure Liquid
  • Down-Regulation / drug effects
  • Female
  • Humans
  • Keratinocytes / cytology
  • Keratinocytes / drug effects
  • Moraceae / chemistry*
  • Oncogene Proteins, Viral / genetics
  • Oncogene Proteins, Viral / metabolism
  • Phenols / analysis
  • Plant Extracts / pharmacology*
  • Plant Stems / chemistry*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Small Interfering / metabolism
  • Receptors, Death Domain / metabolism
  • Signal Transduction / drug effects*
  • Uterine Cervical Neoplasms / pathology*
  • Volatile Organic Compounds / analysis

Substances

  • Oncogene Proteins, Viral
  • Phenols
  • Plant Extracts
  • RNA, Messenger
  • RNA, Small Interfering
  • Receptors, Death Domain
  • Volatile Organic Compounds

Grants and funding

This research was supported by the basic program (2015R1A2A2A09001137) of the National Research Foundation of Korea (NRF), http://www.nrf.re.kr/nrf_eng_cms. D.Y. Yoon was supported partially by the Priority Research Centers Program (2012-0006686). The authors are grateful to Pharma Teksol and Chungcheongbukdo Bio CS for their intellectual and financial support of this project. There was no additional external funding received for this study.