RESUMO
Mammalian, or mechanistic, target of rapamycin complex 2 (mTORC2) regulates a variety of vital cellular processes, and its aberrant functioning is often associated with various diseases. Rictor is a peculiar and distinguishing mTORC2 component playing a pivotal role in controlling its assembly and activity. Among extant organisms, Rictor is conserved from unicellular eukaryotes to metazoans. We replaced two distinct, but conserved, glycine residues in both the Dictyostelium piaA gene and its human ortholog, RICTOR The two conserved residues are spaced â¼50 amino acids apart, and both are embedded within a conserved region falling in between the Ras-GEFN2 and Rictor-_V domains. The effects of point mutations on the mTORC2 activity and integrity were assessed by biochemical and functional assays. In both cases, these equivalent point mutations in the mammalian RICTOR and DictyosteliumpiaA gene impaired mTORC2 activity and integrity. Our data indicate that the two glycine residues are essential for the maintenance of mTORC2 activity and integrity in organisms that appear to be distantly related, suggesting that they have a evolutionarily conserved role in the assembly and proper mTORC2 functioning.
Assuntos
Dictyostelium/metabolismo , Glicina/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Proteína Companheira de mTOR Insensível à Rapamicina/metabolismo , Sequência de Aminoácidos , Animais , Dictyostelium/genética , Glicina/genética , Humanos , Mamíferos , Alvo Mecanístico do Complexo 2 de Rapamicina/genética , Proteína Companheira de mTOR Insensível à Rapamicina/genética , Relação Estrutura-AtividadeRESUMO
Pancreatic cancer is one of the most lethal cancers with high metastatic potential and strong chemoresistance. The capability of a tumor to grow and propagate is dependent on a small subset of cells within a tumor, termed cancer stem cells. Cancer stem cells exhibit great tumorigenicity and are closely correlated with drug resistance and tumor recurrence. The aim of our study was to illustrate electrochemotherapy as an effective treatment for pancreatic cancer along with the expression change in stemness genes (Nanog, Sox2 and Oct3/4) in pancreatic cancer cells post electrochemotherapy with bleomycin, cisplatin and oxaliplatin. Our results showed the enhanced expression of Nanog and decreased expression level of Oct3/4 after electrochemotherpy. We thus propose that these stemness markerS may have important roles in the initiation and/or recurrence of pancreatic cancer, and consequently may serve as important molecular diagnostics and/or therapeutic targets for the development of novel treatment strategies in pancreatic cancer patients. In conclusion, targeting these stemness factors could potentially improve electrochemotherapy as a treatment and preventing recurrence.
