RESUMO
BACKGROUND/AIM: We have tested whether the anticancer peptide, PNC-27, that kills cancer cells but not normal cells by binding to cancer cell membrane HDM-2 forming pores, kills CD44+ colon cancer stem cells. MATERIALS AND METHODS: Flow cytometry determined the CD44 and HDM-2 expression on six-colon cancer cell lines and one normal cell line (CCD-18Co). MTT, LDH release, annexin V binding and caspase 3 assays were used to assess PNC-27-induced cell death. Bioluminescence imaging measured PNC-27 effects on in vivo tumor growth. RESULTS: High percentages of cells in all six tumor lines expressed CD44. PNC-27 co-localized with membrane HDM-2 only in the cancer cells and caused total cell death (tumor cell necrosis, high LDH release, negative annexin V and caspase 3). In vivo, PNC-27 caused necrosis of tumor nodules but not of normal tissue. CONCLUSION: PNC-27 selectively kills colon cancer stem cells by binding of this peptide to membrane H/MDM-2.
Assuntos
Antineoplásicos/farmacologia , Biomarcadores Tumorais , Neoplasias do Colo/etiologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Animais , Antineoplásicos/uso terapêutico , Biomarcadores , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Modelos Animais de Doenças , Humanos , Receptores de Hialuronatos/metabolismo , Camundongos , Terapia de Alvo Molecular , Necrose/patologia , Ligação Proteica , Proteína Supressora de Tumor p53/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
5,7-dihydroxy-3',4',6-trimethoxyflavone, commonly known as eupatilin, is a traditional Asian medicinal plant, which is mainly used for the treatment of gastritis, as well as its use as an anti-inflammatory agent. Eupatilin is a bioactive compound; however, its effects on osteosarcoma (OS) have remained to be elucidated. Therefore, the present study aimed to investigate the effects of eupatilin on this malignant bone tumor, using the U-2 OS cell line. The experimental results revealed that eupatilin inhibited U-2 OS cell growth in a concentration-dependent manner and induced G2/M phase cell cycle arrest and apoptosis. Additionally, western blot analysis indicated that eupatilin was able to trigger the mitochondrial apoptotic pathway, demonstrated by the enhanced Bax/B cell lymphoma-2 ratio, decrease in mitochondrial membrane potential, release of cytochrome c, caspase-3 and -9 activation and poly(ADP-ribose)polymerase cleavage detected in the U-2 OS cells. These results indicated that eupatilin was able to inhibit U-2 OS cancer cell proliferation by the induction of apoptosis via the mitochondrial intrinsic pathway. Eupatilin may therefore represent a novel anticancer drug for use in the treatment of osteosarcoma.