RESUMO
The integrated stress response (ISR) is a key cellular signaling pathway activated by environmental alterations that represses protein synthesis to restore homeostasis. To prevent sustained damage, the ISR is counteracted by the upregulation of growth arrest and DNA damage-inducible 34 (GADD34), a stress-induced regulatory subunit of protein phosphatase 1 that mediates translation reactivation and stress recovery. Here, we uncover a novel ISR regulatory mechanism that post-transcriptionally controls the stability of PPP1R15A mRNA encoding GADD34. We establish that the 3' untranslated region of PPP1R15A mRNA contains an active AU-rich element (ARE) recognized by proteins of the ZFP36 family, promoting its rapid decay under normal conditions and stabilization for efficient expression of GADD34 in response to stress. We identify the tight temporal control of PPP1R15A mRNA turnover as a component of the transient ISR memory, which sets the threshold for cellular responsiveness and mediates adaptation to repeated stress conditions.
Assuntos
Regiões 3' não Traduzidas , Proteína Fosfatase 1 , Animais , Humanos , Camundongos , Regiões 3' não Traduzidas/genética , Adaptação Fisiológica/genética , Elementos Ricos em Adenilato e Uridilato/genética , Células HEK293 , Proteína Fosfatase 1/metabolismo , Proteína Fosfatase 1/genética , Estabilidade de RNA/genética , RNA Mensageiro/metabolismo , RNA Mensageiro/genética , Estresse Fisiológico/genética , Tristetraprolina/metabolismo , Tristetraprolina/genéticaRESUMO
BACKGROUND: Granulocyte colony-stimulating factor (G-CSF) expressed in engineered Escherichia coli (E. coli) as a recombinant protein is utilized as an adjunct to chemotherapy for improving neutropenia. Recombinant proteins overexpression may lead to the creation of inclusion bodies whose recovery is a tedious and costly process. To overcome the problem of inclusion bodies, secretory production might be used. To achieve a mature secretory protein product, suitable signal peptide (SP) selection is a vital step. OBJECTIVE: In the present study, we aimed at in silico evaluation of proper SPs for secretory production of recombinant G-CSF in E. coli. METHODS: Signal peptide website and UniProt were used to collect the SPs and G-CSF sequences. Then, SignalP were utilized in order to predict the SPs and location of their cleavage site. Physicochemical features and solubility were investigated by ProtParam and Protein-sol tools. Fusion proteins sub-cellular localization was predicted by ProtCompB. RESULTS: LPP, ELBP, TSH, HST3, ELBH, AIDA and PET were excluded according to SignalP. The highest aliphatic index belonged to OMPC, TORT and THIB and PPA. Also, the highest GRAVY belonged to OMPC, ELAP, TORT, BLAT, THIB, and PSPE. Furthermore, G-CSF fused with all SPs were predicted as soluble fusion proteins except three SPs. Finally, we found OMPT, OMPF, PHOE, LAMB, SAT, and OMPP can translocate G-CSF into extracellular space. CONCLUSION: Six SPs were suitable for translocating G-CSF into the extracellular media. Although growing data indicate that the bioinformatics approaches can improve the precision and accuracy of studies, further experimental investigations and recent patents explaining several inventions associated to the clinical aspects of SPs for secretory production of recombinant GCSF in E. coli are required for final validation.
Assuntos
Biologia Computacional , Escherichia coli/genética , Fator Estimulador de Colônias de Granulócitos , Sinais Direcionadores de Proteínas/genética , Proteínas Recombinantes de Fusão , Simulação por Computador , Fator Estimulador de Colônias de Granulócitos/genética , Fator Estimulador de Colônias de Granulócitos/metabolismo , Patentes como Assunto , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismoRESUMO
Breast cancer is a major clinical challenge that affects a wide range of the female population and heavily burdens the health system. In the past few decades, attempts have been made to understand the etiology of breast cancer, possible environmental risk factors, and the genetic predispositions, pathogenesis, and molecular aberrations involved in the process. Studies have shown that breast cancer is a heterogeneous entity; each subtype has its specific set of aberrations in different cell signaling pathways, such as Notch, Wnt/ß-catenin, transforming growth factor-ß, and mitogen-activated protein kinase pathways. One novel group of molecules that have been shown to be inducted in the regulation of multiple cell signaling pathways is the long noncoding RNAs (lncRNAs). These molecules have important implications in the regulation of multiple signaling pathways by interacting with various genes, affecting the transcription process, and finally, playing roles in posttranslational control of these genes. There is growing evidence that lncRNAs are involved in the process of breast cancer formation by effecting the aforementioned signaling pathways, and that this involvement can have significant diagnostic and prognostic values in clinical contexts. The present review aims to elicit the significance of lncRNAs in the regulation of cell signaling pathways, and the resulting changes in cell survival, proliferation, and invasion, which are the hallmarks of breast cancer.
Assuntos
Neoplasias da Mama/genética , Proliferação de Células/genética , RNA Longo não Codificante/genética , Neoplasias da Mama/patologia , Movimento Celular/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , PrognósticoRESUMO
Breast cancer is one of the most lethal malignancies in women in the world. Various factors are involved in the development and promotion of the malignancy; most of them involve changes in the expression of certain genes, such as microRNAs (miRNAs). MiRNAs can regulate signaling pathways negatively or positively, thereby affecting tumorigenesis and various aspects of cancer progression, particularly breast cancer. Besides, accumulating data demonstrated that miRNAs are a novel tool for prognosis and diagnosis of breast cancer patients. Herein, we will review the roles of these RNA molecules in several important signaling pathways, such as transforming growth factor, Wnt, Notch, nuclear factor-κ B, phosphoinositide-3-kinase/Akt, and extracellular-signal-regulated kinase/mitogen activated protein kinase signaling pathways in breast cancer.
Assuntos
Neoplasias da Mama/genética , Carcinogênese/genética , MicroRNAs/genética , Neoplasias da Mama/patologia , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/genética , NF-kappa B/genética , Fosfatidilinositol 3-Quinase/genética , Receptores Notch/genética , Transdução de Sinais/genética , Proteínas Wnt/genéticaRESUMO
OBJECTIVE: Gastric cancer is the third-leading cause of cancer-related mortality and the fifth most common cancer globally. Polyunsaturated fatty acids (PUFAs) are considered as functional ingredients that improve the efficacy of chemotherapeutic drugs. The aim of this study is to investigate the effect of PUFAs administration on matrix metalloproteinases (MMPs). METHODS: This study was designed as a randomized, double-blind trial. Thirty-four newly diagnosed patients with gastric cancer were randomly divided into two groups: control group (n = 17) and case group (n =17). Both groups received the same dose (75 mg/m2) of cisplatin. Control group received cisplatin plus placebo and the case group received cisplatin plus PUFAs [3600 mg/day, for three courses (each course included 3 weeks)]. The mRNA and protein expression of MMPs determined by real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC), respectively. RESULTS: The relative gene expression of MMP-1 and MMP-9 was significantly lower in case group than control. The protein expression of MMP-1 and MMP-9 was significantly lower in case group than control. CONCLUSION: According to the results of this study, PUFAs reduced the expression of MMPs in gastric cancer cells. It seems that PUFAs may have an inhibitory effect on invasion and metastasis of gastric cancer cells.