title: SH003 induces apoptosis of DU145 prostate cancer cells by inhibiting ERK-involved pathway.
abstract: BACKGROUND
  Herbal medicines have been used in cancer treatment, with many exhibiting favorable side effect and toxicity profiles compared with conventional chemotherapeutic agents. SH003 is a novel extract from Astragalus membranaceus, Angelica gigas, and Trichosanthes Kirilowii Maximowicz combined at a 1:1:1 ratio that impairs the growth of breast cancer cells. This study investigates anti-cancer effects of SH003 in prostate cancer cells.
  
  
  METHODS
  SH003 extract in 30% ethanol was used to treat the prostate cancer cell lines DU145, LNCaP, and PC-3. Cell viability was determined by MTT and BrdU incorporation assays. Next, apoptotic cell death was determined by Annexin V and 7-AAD double staining methods. Western blotting was conducted to measure protein expression levels of components of cell death and signaling pathways. Intracellular reactive oxygen species (ROS) levels were measured using H2DCF-DA. Plasmid-mediated ERK2 overexpression in DU145 cells was used to examine the effect of rescuing ERK2 function. Results were analyzed using the Student's t-test and P-values < 0.05 were considered to indicate statistically-significant differences.
  
  
  RESULTS
  Our data demonstrate that SH003 induced apoptosis in DU145 prostate cancer cells by inhibiting ERK signaling. SH003 induced apoptosis of prostate cancer cells in dose-dependent manner, which was independent of androgen dependency. SH003 also increased intracellular ROS levels but this is not associated with its pro-apoptotic effects. SH003 inhibited phosphorylation of Ras/Raf1/MEK/ERK/p90RSK in androgen-independent DU145 cells, but not androgen-dependent LNCaP and PC-3 cells. Moreover, ERK2 overexpression rescued SH003-induced apoptosis in DU145 cells.
  
  
  CONCLUSIONS
  SH003 induces apoptotic cell death of DU145 prostate cancer cells by inhibiting ERK2-mediated signaling.
authors.affiliation: Department of Cancer Preventive Material Development, Graduate School, Kyung Hee University, Seoul, 02447, Korea.
authors.forename: Yu-Jeong
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Jeju International Marine Science center for Research & Education, Korea Institute of Ocean Science & Technology (KIOST), Jeju, 63349, Korea.
authors.forename: Youn Kyung
authors.initials: YK
authors.lastname: Choi
authors.affiliation: Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul, 02447, Korea.
authors.forename: Kang Min
authors.initials: KM
authors.lastname: Lee
authors.affiliation: Department of Biotechnology, Korea National University of Transportation, Jeungpyeong, Chungbuk, 368-701, Korea.
authors.forename: Sung-Gook
authors.initials: SG
authors.lastname: Cho
authors.affiliation: Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul, 02447, Korea.
authors.forename: Soo-Yeon
authors.initials: SY
authors.lastname: Kang
authors.affiliation: Department of Preventive Medicine, College of Korean Medicine, Kyung Hee University, 1 Hoegi, Seoul, 130-701, Korea. epiko@khu.ac.kr.
authors.forename: Seong-Gyu
authors.identifier: http://orcid.org/0000-0001-9260-8889
authors.initials: SG
authors.lastname: Ko
mesh_terms: D029969:Angelica; D017209:Apoptosis / Q000187:drug effects*; D027883:Astragalus Plant; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D008297:Male; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D011471:Prostatic Neoplasms / Q000188:drug therapy*; D029778:Trichosanthes
chemical_list: D010936:Plant Extracts; C000613735:SH003 extract
keywords: Anticancer effect; Apoptosis; DU145 human prostate cancer cells; ERK pathway; Herbal medicine; SH003