A 150-kDa glycoprotein isolated from Solanum nigrum L. has cytotoxic and apoptotic effects by inhibiting the effects of protein kinase C alpha, nuclear factor-kappa B and inducible nitric oxide in HCT-116 cells.
This study was carried out to investigate the anticancer effects of a 150-kDa glycoprotein isolated from Solanum nigrum L. (SNL glycoprotein) on spontaneously and experimentally induced tumor promotion in HCT-116 cells. For spontaneously induced tumor promotion, we evaluated the cytotoxic and apoptotic effects in HCT-116 cells using 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide (MTT), DNA fragmentation, and H33342 and ethidium bromide staining assays. SNL glycoprotein had remarkable, dose-dependent cytotoxic and apoptosis-inducing effects at low concentrations. For experimentally induced tumor promotion, we investigated whether the SNL glycoprotein was able to regulate the activity of protein kinase C alpha (PKCalpha), the DNA binding activation of nuclear factor-kappa B (NF-kappaB), the activity of NF-kappaB protein, and the production of nitric oxide (NO) in HCT-116 cells stimulated with 12-O-tetradecanoylphorbol 13-acetate (TPA) using electrophoretic mobility shift assays (EMSA), Western blot analysis, and NO assays. As expected, SNL glycoprotein dose-dependently inhibited PKCalpha translocation, NF-kappaB DNA binding activity, NF-kappaB protein activity and NO production in HCT-116 cells stimulated with TPA (61.68 ng/ml, 100 nM). Collectively, these results suggest that SNL glycoprotein can induce apoptosis through the modulation of signal mediators. Therefore, we speculate that it could be used as a chemotherapy agent even at low concentrations in HCT-116 cells.
Lee
Sei-Jung
SJ
No. 521, Molecular Biochemistry Laboratory and Biodefensive Substances Group, Institute of Biotechnology, Chonnam National University, 300 Yongbong-Dong, Kwangju, 500-757, South Korea.
Oh
Phil-Sun
PS
Ko
Jeong-Hyeon
JH
Lim
Kwang
K
Lim
Kye-Taek
KT
D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053938:DNA Fragmentation / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D006023:Glycoproteins / Q000302:isolation & purification / Q000494:pharmacology*; D045325:HCT116 Cells; D006801:Humans; D008970:Molecular Weight; D016328:NF-kappa B / Q000037:antagonists & inhibitors*; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D010940:Plant Proteins / Q000494:pharmacology*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D051571:Protein Kinase C-alpha; D032324:Solanum nigrum; D013755:Tetradecanoylphorbol Acetate / Q000037:antagonists & inhibitors; D051996:Transcription Factor RelA
D000970:Antineoplastic Agents; D006023:Glycoproteins; D016328:NF-kappa B; D010940:Plant Proteins; D051996:Transcription Factor RelA; C508662:glycoprotein 150-kDa, Solanum nigrum; D009569:Nitric Oxide; C496628:PRKCA protein, human; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha; D013755:Tetradecanoylphorbol Acetate