RESUMO
BACKGROUND: Ganoderma lucidum has been widely used as a herbal medicine for promoting health and longevity in China and other Asian countries. Polysaccharide extracts from Ganoderma lucidum have been reported to exhibit immuno-modulating and anti-tumor activities. In previous studies, F3, the active component of the polysaccharide extract, was found to activate various cytokines such as IL-1, IL-6, IL-12, and TNF-alpha. This gave rise to our investigation on how F3 stimulates immuno-modulating or anti-tumor effects in human leukemia THP-1 cells. RESULTS: Here, we integrated time-course DNA microarray analysis, quantitative PCR assays, and bioinformatics methods to study the F3-induced effects in THP-1 cells. Significantly disturbed pathways induced by F3 were identified with statistical analysis on microarray data. The apoptosis induction through the DR3 and DR4/5 death receptors was found to be one of the most significant pathways and play a key role in THP-1 cells after F3 treatment. Based on time-course gene expression measurements of the identified pathway, we reconstructed a plausible regulatory network of the involved genes using reverse-engineering computational approach. CONCLUSION: Our results showed that F3 may induce death receptor ligands to initiate signaling via receptor oligomerization, recruitment of specialized adaptor proteins and activation of caspase cascades.
Assuntos
Apoptose/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Polissacarídeos/farmacologia , Reishi/química , Apoptose/genética , Apoptose/fisiologia , Western Blotting , Linhagem Celular Tumoral , Citocinas/genética , Citocinas/metabolismo , Medicamentos de Ervas Chinesas/química , Ensaio de Imunoadsorção Enzimática , Perfilação da Expressão Gênica , Humanos , Leucemia Monocítica Aguda/genética , Leucemia Monocítica Aguda/metabolismo , Leucemia Monocítica Aguda/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Reação em Cadeia da Polimerase , Polissacarídeos/química , Receptores de Morte Celular/genética , Receptores de Morte Celular/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transdução de Sinais/fisiologiaRESUMO
Synthetic peptides with the arginine-glycine-aspartate (RGD) motif have been used widely as inhibitors of integrin-ligand interactions to study cell growth, adhesion, migration and differentiation. We designed cyclic-RGD peptide (Tpa-RGDWPC-, cRGD) which could cause cell death in MCF-7 cell line. In order to understand the mechanism involved in cRGD-induced apoptosis, we used microarray, real-time quantitative PCR (Q-PCR) and bioinformatics to study the effects of cRGD on breast cancer cell line MCF-7. By time-series gene expression measurements and our developed software BSIP and GeneNetwork, we reconstructed an apoptosis-related gene network. In the network, caspase-9, located at the upstream, activates downstream effector caspases such as caspase-7, leading to the induction of caspase-4. Combined our previous proteomics data with newly performed docking simulation, it indicated that the cell death induced by cRGD may be triggered through blocking integrin signaling to the extracellular matrix and activation of caspase pathway. This study provides a molecular explanation of cRGD treatment in breast cancer cells and set forth a constructive far-reaching impact on breast cancer therapy.