RESUMO
Double-stranded RNA-activated protein kinase R (PKR) is highly expressed in colorectal cancer (CRC). However, the role of PKR in CRC remains unclear. The aim of this study was to clarify whether C16 (a PKR inhibitor) exhibits antitumor effects and to identify its target pathway in CRC. We evaluated the effects of C16 on CRC cell lines using the MTS assay. Enrichment analysis was performed to identify the target pathway of C16. The cell cycle was analyzed using flow cytometry. Finally, we used immunohistochemistry to examine human CRC specimens. C16 suppressed the proliferation of CRC cells. Gene Ontology (GO) analysis revealed that the cell cycle-related GO category was substantially enriched in CRC cells treated with C16. C16 treatment resulted in G1 arrest and increased p21 protein and mRNA expression. Moreover, p21 expression was associated with CRC development as observed using immunohistochemical analysis of human CRC tissues. C16 upregulates p21 expression in CRC cells to regulate cell cycle and suppress tumor growth. Thus, PKR inhibitors may serve as a new treatment option for patients with CRC.
Assuntos
Neoplasias Colorretais , Inibidores de Proteínas Quinases , Humanos , Apoptose , Ciclo Celular , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Regulação Neoplásica da Expressão Gênica , Inibidores de Proteínas Quinases/farmacologia , Indóis/farmacologia , Tiazóis/farmacologia , eIF-2 Quinase/antagonistas & inibidores , Inibidor de Quinase Dependente de Ciclina p21/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p21/metabolismoRESUMO
The α-glucosidase gene from Pholiota microspora, designated PnGcs, was amplified and characterized. The open reading frame region of PnGcs, from ATG to the stop codon, is 2937 bp and encodes a protein of 979 amino acids with a signal peptide of 20 amino acids at the N-terminus. The predicted amino acid sequence of PnGcs indicated that it is a glycoside hydrolase family 31 protein. Quantitative reverse transcription PCR was used to investigate PnGcs expression in mycelia cultured in minimal medium containing various carbon sources, as well as in tissue during different stages of development of fruiting bodies. When P. microspora was grown in minimal medium supplemented with different carbon sources, PnGcs expression was highest when induced by maltose. During cultivation on sawdust medium, PnGcs expression increased dramatically at the fruiting body formation stage compared with the mycelial growth stage, which implied that PnGcs is closely associated with fruiting body development.
