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1.
Andrology ; 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38591173

RESUMO

BACKGROUND: The etiology of chronic prostatitis remains unclear; consequently, this disease is associated with recurrence and ineffective clinical therapy. Therefore, there is an urgent need to investigate the underlying pathogenesis of chronic prostatitis in order to develop more efficacious treatments. OBJECTIVE: The previous study found that knocking out of PEBP4 leads to chronic prostatitis in the male mice. This research aimed to identify the role of PEBP4 in prostatitis, determine the molecular pathogenic mechanisms associated with chronic prostatitis, and provide guidelines for the development of new treatment strategies for chronic prostatitis. MATERIALS AND METHODS: A PEBP4 exon knockout strain (PEBP4-/-) was established in C57BL/6 mice via the Cre-loxP system. Hematoxylin-eosin (H&E) staining was used to investigate histological changes. RNA-sequencing was used to investigate the gene expression signature of the prostate and the levels of inflammatory cytokines were determined by real-time polymerase chain reaction (RT-PCR). The expression of PEBP4 protein in prostate tissue was determined by immunohistochemistry in specimens from patients with BPH and BPH combined with chronic prostatitis. Finally, we used a CRISPR-Cas9 plasmid to knockout PEBP4 in RWPE-1 cells; western blotting was subsequently used to measure the level of activation in the NF-κB signaling pathway after activating with TNF-α. RESULTS: Hemorrhage and inflammatory cell infiltration were incidentally observed in the seminal vesicles and prostate glands of PEBP4-/- mice after being fed with a normal diet for 1 year. In addition, we found significantly lower (p < 0.001) expression levels of PEBP4 protein in prostate tissues from patients with benign prostate hyperplasia (BPH) and chronic and non-bacterial prostatitis (CNP) when compared to those with BPH only. The reduced expression of PEBP4 led to a higher risk of prostatitis recurrence in patients after 2 years of follow-up. Increased levels of NF-κB and IκB phosphorylation were observed in PEBP4-knockout RWPE-1 cells and prostate glands from PEBP4-/- mice. CONCLUSION: The knockout of PEBP4 in experimental mice led to chronic prostatitis and the reduced expression of PEBP4 in patients with higher risk of chronic and non-bacterial prostatitis suggested that PEBP4 might act as a protective factor against chronic prostatitis. The knockout of PEBP4 in RWPE-1 cells led to the increased activation of NF-κB and IκB, thus indicating that inhibition of PEBP4 faciliated the NF-κB signaling cascade. Our findings provide a new etiology and therapeutic target for chronic prostatitis.

2.
Cell Mol Life Sci ; 81(1): 133, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38472560

RESUMO

Acute lung injury (ALI) is a common clinical syndrome, which often results in pulmonary edema and respiratory distress. It has been recently reported that phosphatidylethanolamine binding protein 4 (PEBP4), a basic cytoplasmic protein, has anti-inflammatory and hepatoprotective effects, but its relationship with ALI remains undefined so far. In this study, we generated PEBP4 knockout (KO) mice to investigate the potential function of PEBP4, as well as to evaluate the capacity of alveolar fluid clearance (AFC) and the activity of phosphatidylinositide 3-kinases (PI3K)/serine-theronine protein kinase B (PKB, also known as AKT) signaling pathway in lipopolysaccharide (LPS)-induced ALI mice models. We found that PEBP4 deficiency exacerbated lung pathological damage and edema, and increased the wet/dry weight ratio and total protein concentration of bronchoalveolar lavage fluid (BALF) in LPS-treated mice. Meanwhile, PEBP4 KO promoted an LPS-induced rise in the pulmonary myeloperoxidase (MPO) activity, serum interleuin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α levels, and pulmonary cyclooxygenase-2 (COX-2) expression. Mechanically, PEBP4 deletion further reduced the protein expression of Na+ transport markers, including epithelial sodium channel (ENaC)-α, ENaC-γ, Na,K-ATPase α1, and Na,K-ATPase ß1, and strengthened the inhibition of PI3K/AKT signaling in LPS-challenged mice. Furthermore, we demonstrated that selective activation of PI3K/AKT with 740YP or SC79 partially reversed all of the above effects caused by PEBP4 KO in LPS-treated mice. Altogether, our results indicated the PEBP4 deletion has a deterioration effect on LPS-induced ALI by impairing the capacity of AFC, which may be achieved through modulating the PI3K/AKT pathway.


Assuntos
Lesão Pulmonar Aguda , Lipopolissacarídeos , Animais , Camundongos , Lesão Pulmonar Aguda/induzido quimicamente , Lipopolissacarídeos/farmacologia , Pulmão/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , ATPase Trocadora de Sódio-Potássio/metabolismo , ATPase Trocadora de Sódio-Potássio/farmacologia , ATPase Trocadora de Sódio-Potássio/uso terapêutico , Fator de Necrose Tumoral alfa/metabolismo
3.
Front Pharmacol ; 13: 964829, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36120358

RESUMO

Liver fibrosis is a pathological process which can progress to hepatocirrhosis, even hepatocellular carcinoma. Phosphatidylethanolamine-binding protein 4 (PEBP4) is a secreted protein involved in regulating many molecular pathways, whereas its roles in diseases including hepatic fibrosis remain undefined. The nuclear factor-κappa B (NF-κB) signaling pathway has been found to be involved in the development of liver fibrosis. In this study, we generated a hepatocyte-conditional knockout (CKO) mouse model of PEBP4, and explored the potential functions of PEBP4 on liver fibrosis and the NF-κB signaling pathway in a mouse model of carbon tetrachloride (CCl4)-induced liver fibrosis. We demonstrated that PEBP4 CKO aggravated CCl4-triggered liver fibrosis, as evidenced by altered histopathology, an increase in the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and hydroxyproline (HYP) levels, and more collagen deposition, as well as by enhanced expression of fibrotic markers including α-smooth muscle actin (α-SMA), collagen I and collagen III. Mechanistically, PEBP4 deficiency activated the NF-κB signaling pathway, as indicated by increased phosphorylation of NF-κB p65 and inhibitor protein κB inhibitor-α (IκB-α), and nuclear NF-κB p65 expression in the fibrotic liver. Notably, the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) partially blocked the activation of the NF-κB pathway, and reversed the pro-fibrotic effect of PEBP4 deletion in CCl4-treated mice. Together, these results suggest that PEBP4 deficiency results in aggravation of liver fibrosis and activation of the NF-κB signaling pathway, supporting a novel concept that PEBP4 is a crucial player in hepatic fibrosis, but also might be a negative regulator of the NF-κB signaling in liver fibrosis.

4.
Int J Mol Sci ; 23(15)2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35955931

RESUMO

Phosphatidylethanolamine binding protein 4 (PEBP4) is an understudied multifunctional small protein. Previous studies have shown that the expression of PEBP4 is increased in many cancer specimens, which correlates to cancer progression. The present study explored the mechanism by which PEBP4 regulates the growth and progression of hepatocellular carcinoma cells. Thus, we showed that knockdown of PEBP4 in MHCC97H cells, where its expression was relatively high, diminished activities of serine/threonine protein kinase B (PKB, also known as Akt), mammalian target of rapamycin complex 1(mTORC1), and mTORC2, events that were not restored by insulin-like growth factor 1 (IGF-1). Conversely, overexpression of PEBP4 in MHCC97L cells with the low endogenous level yielded opposite effects. Furthermore, physical association of PEBP4 with Akt, mTORC1, and mTORC2 was observed. Interestingly, introduction of AktS473D mutant, bypassing phosphorylation by mTORC2, rescued mTORC1 activity, but without effects on mTORC2 signaling. In contrast, the effect of PEBP4 overexpression on the activity of mTORC1 but not that of mTORC2 was suppressed by MK2206, a specific inhibitor of Akt. In conjunction, PEBP4 knockdown-engendered reduction of cell proliferation, migration and invasion was partially rescued by Akt S473D while increases in these parameters induced by overexpression of PEBP4 were completely abolished by MK2206, although the expression of epithelial mesenchymal transition (EMT) markers appeared to be fully regulated by the active mutant of Akt. Finally, knockdown of PEBP4 diminished the growth of tumor and metastasis, whereas they were enhanced by overexpression of PEBP4. Altogether, our study suggests that increased expression of PEBP4 exacerbates malignant behaviors of hepatocellular cancer cells through cooperative participation of mTORC1 and mTORC2.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Proteína de Ligação a Fosfatidiletanolamina/metabolismo , Carcinoma Hepatocelular/genética , Humanos , Neoplasias Hepáticas/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo
5.
Front Immunol ; 13: 901566, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35874667

RESUMO

Acute liver injury (ALI) is a disease that seriously threatens human health and life, and a dysregulated inflammation response is one of the main mechanisms of ALI induced by various factors. Phosphatidylethanolamine binding protein 4 (PEBP4) is a secreted protein with multiple biological functions. At present, studies on PEBP4 exist mainly in the field of tumors and rarely in inflammation. This study aimed to explore the potential roles and mechanisms of PEBP4 on lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced ALI. PEBP4 was downregulated after treatment with LPS/D-GalN in wild-type mice. PEBP4 hepatocyte-conditional knockout (CKO) aggravated liver damage and repressed liver functions, including hepatocellular edema, red blood cell infiltration, and increased aspartate aminotransferase (AST)/alanine aminotrans-ferase (ALT) activities. The inflammatory response was promoted through increased neutrophil infiltration, myeloperoxidase (MPO) activities, and cytokine secretions (interleukin-1ß, IL-1ß; tumor necrosis factor alpha, TNF-α; and cyclooxygenase-2, COX-2) in PEBP4 CKO mice. PEBP4 CKO also induced an apoptotic effect, including increasing the degree of apoptotic hepatocytes, the expressions and activities of caspases, and pro-apoptotic factor Bax while decreasing anti-apoptotic factor Bcl-2. Furthermore, the data demonstrated the levels of Toll-like receptor 4 (TLR4), phosphorylation-inhibitor of nuclear factor kappaB Alpha (p-IκB-α), and nuclear factor kappaB (NF-κB) p65 were upregulated, while the expressions of cytoplasmic IκB-α and NF-κB p65 were downregulated after PEBP4 CKO. More importantly, both the NF-κB inhibitor (Ammonium pyrrolidinedithiocarbamate, PDTC) and a small-molecule inhibitor of TLR4 (TAK-242) could inhibit TLR4/NF-κB signaling activation and reverse the effects of PEBP4 CKO. In summary, the data suggested that hepatocyte-conditional knockout of PEBP4 aggravated LPS/D-GalN-induced ALI, and the effect is partly mediated by activation of the TLR4/NF-κB signaling pathway.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , NF-kappa B , Proteína de Ligação a Fosfatidiletanolamina , Animais , Doença Hepática Induzida por Substâncias e Drogas/genética , Galactosamina/toxicidade , Hepatócitos/metabolismo , Humanos , Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Fígado/patologia , Camundongos , Camundongos Knockout , Inibidor de NF-kappaB alfa/metabolismo , NF-kappa B/metabolismo , Proteína de Ligação a Fosfatidiletanolamina/genética , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
6.
Onco Targets Ther ; 12: 7685-7690, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31571919

RESUMO

Phosphatidylethanolamine-binding protein 4 (PEBP4) has been found to be highly expressed in many tumors and to be closely related to the proliferation, differentiation, and metastasis of tumors. PEBP4 has also been found to be involved in many cancer-activated signaling pathways and to cause therapeutic resistance. In this study, we first reviewed the morphological structure and expression of PEBP4, then discussed the roles of PEBP4 in individualized treatment of some cancers, and finally explored the possibilities of cultivating PEBP4 as a therapeutic target.We also identified the main signaling pathways in which PEBP4 affects different cancers. It is here concluded that over-expression of PEBP4 can enhance the proliferation and metastasis of the cancer cells and the resistance to radiotherapy/chemotherapy in cancers.

7.
J Autoimmun ; 105: 102309, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31402200

RESUMO

IgA nephropathy (IgAN) is the most common glomerulonephritis worldwide and a major cause of chronic kidney disease and failure. IgAN is driven by an autoimmune reaction against galactose-deficient IgA1 that results in the generation of autoantibodies and large IgG-IgA immune complexes. Immune complexes accumulate in the glomerular mesangium causing chronic inflammation and renal scarring. A significant proportion of IgAN patients develop end-stage kidney disease and require dialysis or transplantation. Currently, there are no approved specific therapies that can ameliorate the systemic autoimmune reaction in IgAN and no biomarkers that can predict renal inflammation and scarring. In this study, we used shotgun LC-MS/MS proteomics to compare small volumes of urine from healthy subjects and IgAN patients. We identified multiple urine proteins with unknown renal or IgAN function. Our attention was captured by the increase of phosphatidylethanolamine binding protein-4 (PEBP4) in IgAN urine. The function of PEBP4 in IgAN or renal disease is unknown. Increased levels of urine and serum PEBP4 were subsequently validated in different cohorts of IgAN patients and PEBP4 was linked to declining kidney function in IgAN. Strong PEBP4 staining was sporadically seen in IgAN kidney biopsies, colocalising with IgA in glomeruli and in the lumen of kidney tubules. In a small number of IgAN biopsies, PEBP4 colocalised with IgA and CD19 while the increased excretion of PEBP4 in IgAN urine was accompanied by increased excretion of classic B-cell factors BAFF, BCMA and TACI as well as IgA and IgG. PEBP4 is a new IgAN-related protein with unknown function and a likely renal disease marker in urine and serum.


Assuntos
Linfócitos B/imunologia , Glomerulonefrite por IGA/imunologia , Imunoglobulina A/imunologia , Rim/imunologia , Proteína de Ligação a Fosfatidiletanolamina/imunologia , Adulto , Complexo Antígeno-Anticorpo/imunologia , Autoanticorpos/imunologia , Linfócitos B/metabolismo , Biomarcadores/metabolismo , Biópsia , Estudos de Casos e Controles , Feminino , Galactose/imunologia , Galactose/metabolismo , Mesângio Glomerular/imunologia , Mesângio Glomerular/metabolismo , Glomerulonefrite por IGA/metabolismo , Humanos , Rim/metabolismo , Falência Renal Crônica/imunologia , Falência Renal Crônica/metabolismo , Masculino
8.
J Cell Biochem ; 120(4): 5386-5395, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30367510

RESUMO

Phosphatidylethanolamine-binding protein 4 (PEBP4), a member of the PEBP family, has been reported to play a pivotal role in tumor progression. However, its role in epithelial-to-mesenchymal transition (EMT) in non-small cell lung cancer (NSCLC) cells remains unclear. Here, we investigated the effects and underlying mechanism of PEBP4 in NSCLC EMT. Three human NSCLC cell lines (A549, H1299, and H460) were transfected with pcDNA3.1-PEBP4 or PEBP4-targeting small interfering RNA. Then, cell proliferation was analyzed by the MTT assay, and cell migration and invasion were analyzed by the transwell chamber assay. Protein and messenger RNA expression of the related genes and proteins were assessed by Western blot analysis and quantitative real-time polymerase chain reaction, respectively. Results showed that PEBP4 was highly expressed in the human lung cancer tissues and three human NSCLC cell lines. Pretreatment with pcDNA3.1-PEBP4 promoted the proliferation, invasion, and migration of NSCLC cells and increased EMT in vitro and lung tumor metastasis in vivo. Whereas knockdown of PEBP4 suppressed NSCLC cell migration, PEBP4, and invasion with prevented EMT. Furthermore, PEBP4 overexpression significantly promoted the transcriptional activity of sonic hedgehog (Shh) signaling in NSCLC cells. Further analysis showed that using cyclopamine to inhibit Shh signaling significantly ameliorated the effect on cell proliferation, invasion, and migration, as well as EMT triggered by PEBP4 overexpression. Together, these results suggest that PEBP4 may promote tumorigenesis in NSCLC by regulating cell proliferation and EMT via activation of the Shh signaling pathway.


Assuntos
Carcinogênese/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Transição Epitelial-Mesenquimal/genética , Proteína de Ligação a Fosfatidiletanolamina/genética , Células A549 , Animais , Carcinoma Pulmonar de Células não Pequenas/patologia , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica/genética , Proteínas Hedgehog/antagonistas & inibidores , Proteínas Hedgehog/genética , Xenoenxertos , Humanos , Camundongos , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Metástase Neoplásica , RNA Interferente Pequeno/genética , Transdução de Sinais/genética , Alcaloides de Veratrum/farmacologia
9.
Biomed Pharmacother ; 90: 659-664, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28415045

RESUMO

Phosphatidylethanolamine-binding protein 4 (PEBP4), a member of the PEBP family, plays a pivotal role in tumor progression. However, the roles of PEBP4 in breast cancer remain unclear. Therefore, in the present study, we investigated the effects of PEBP4 on breast cancer cell proliferation, migration and invasion, and the underlying mechanism was also explored. Our results showed that the expression of PEBP4 was significantly up-regulated in breast cancer cell lines. Knockdown of PEBP4 inhibited breast cancer cell proliferation in vitro and tumor growth in vivo. Furthermore, knockdown of PEBP4 suppressed breast cancer cell migration and invasion with prevented EMT. Mechanistically, knockdown of PEBP4 inhibited breast cancer cell proliferation and migration through the inactivation of PI3K/Akt signaling pathway. In conclusion, the present study demonstrated for the first time that knockdown of PEBP4 inhibited the proliferation, invasion and tumorigenesis in breast cancer cells. Thus, PEBP4 may serve as a potential therapeutic target for the treatment of breast cancer.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Movimento Celular/genética , Proliferação de Células/genética , Invasividade Neoplásica/genética , Proteína de Ligação a Fosfatidiletanolamina/genética , Carcinogênese/genética , Carcinogênese/patologia , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal/genética , Feminino , Técnicas de Silenciamento de Genes/métodos , Humanos , Células MCF-7 , Invasividade Neoplásica/patologia , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais/genética
10.
Oncotarget ; 8(11): 18177-18184, 2017 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-28193908

RESUMO

Phosphatidylethanolamine-binding protein 4 (PEBP4) has previously been reported to be upregulated in various cancers. However, the physiological functions of PEBP4 in gastric cancer are still unknown. Aiming to clarify the properties and role of PEBP4 in the development and invasion of gastric cancer, we performed several biological assays and a knockdown assay. The expression level of PEBP4 was shown to be significantly upregulated in gastric cancer tissue samples, and knockdown of the expression of PEBP4 induced significant inhibitory effects on cell proliferation, migration and invasiveness. In addition, it was demonstrated that PEBP4 was associated with the development and invasion of gastric cancer cells through activation of the PI3K/Akt signaling pathway. Our findings supported the hypothesis that PEBP4 might be a novel potential drug target for the treatment of gastric cancer.


Assuntos
Proteína de Ligação a Fosfatidiletanolamina/metabolismo , Transdução de Sinais/fisiologia , Neoplasias Gástricas/patologia , Adulto , Idoso , Western Blotting , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Feminino , Técnicas de Silenciamento de Genes , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas c-akt/metabolismo , Neoplasias Gástricas/metabolismo
11.
Biomed Pharmacother ; 81: 1-6, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27261570

RESUMO

Hypoxia induced epithelial-to-mesenchymal transition (EMT) to facilitate the tumor biology. Phosphatidylethanolamine-binding protein 4 (PEBP4) is a member of the PEBP family and has been reported to be upregulated in various cancer types. The definite function of PEBP4 in regulating the EMT of prostate cancer, however, is still unclear. Here, we examined the functional role of PEBP4 and the underlying molecular mechanisms in hypoxia-induced EMT in prostate cancer cells. Our results showed that PEBP4 mRNA and protein expression was markedly increased in the human prostate cancer tissues and cell lines. Knockdown of PEBP4 significantly inhibited hypoxia-induced migration/invasion and EMT program. Furthermore, knockdown of PEBP4 prevented hypoxia-induced the expression of p-Akt and p-mTOR in prostate cancer cells. Taken together, this study reported here provided evidence that knockdown of PEBP4 inhibited hypoxia-induced EMT in prostate cancer cells. Our study uncovered a novel role for PEBP4 in prostate cancer progression, which might support the potential for PEBP4 targeting in prostate cancer therapy.


Assuntos
Transição Epitelial-Mesenquimal , Inativação Gênica , Proteína de Ligação a Fosfatidiletanolamina/metabolismo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Hipóxia Celular , Linhagem Celular Tumoral , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Masculino , Invasividade Neoplásica , Proteína de Ligação a Fosfatidiletanolamina/genética , Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias da Próstata/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo
12.
Biochim Biophys Acta ; 1863(7 Pt A): 1682-9, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27033522

RESUMO

Phosphatidylethanolamine binding proteins (PEBP) represent a superfamily of proteins that are conserved from bacteria to humans. In mammals, four members have been identified, PEBP1-4. To determine the functional differences among PEBP1-4 and the underlying mechanism for their actions, we performed a sequence alignment and found that PEBP4 contains a signal peptide and potential glycosylation sites, whereas PEBP1-3 are intracellular proteins. To test if PEBP4 is secreted, we made constructs with Myc epitope at the amino (N) terminus or carboxyl (C) terminus to mask the signal sequence or keep it free, respectively. Our data revealed that both mouse and human PEBP4 were secreted when the epitope was tagged at their C-terminus. To our surprise, secretion was dependent upon the C-terminal conserved domain in addition to the N-terminal signal sequence. When the epitope was placed to the N-terminus, the recombinant protein failed to secrete and instead, was retained in the cytoplasm. Mass spectrometry detected asparagine (N)-glycosylation on the secreted PEBP4. Although overexpression of N-terminal tagged PEBP4 resulted in an inhibition of ERK activation by EGF, that with a C-terminal epitope tag did not have such an effect. Likewise, transfection of PEBP4 shRNA did not appear to affect ERK activation, suggesting that PEBP4 does not participate in the regulation of this pathway. In contrast, PEBP4 siRNA suppressed phosphorylation of Act at S473. Therefore, our results suggest that PEBP4 is a multifunctional protein and can be secreted. It will be important to investigate the mechanism by which PEBP4 is secreted and regulates cellular events.


Assuntos
Proteína de Ligação a Fosfatidiletanolamina/metabolismo , Sequência de Aminoácidos , Ativação Enzimática , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glicosilação , Células HEK293 , Humanos , Dados de Sequência Molecular , Proteína de Ligação a Fosfatidiletanolamina/química , Proteína de Ligação a Fosfatidiletanolamina/genética , Fosforilação , Processamento de Proteína Pós-Traducional , Sinais Direcionadores de Proteínas , Proteômica/métodos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , Alinhamento de Sequência , Análise de Sequência de Proteína , Espectrometria de Massas em Tandem , Transfecção
13.
Tumour Biol ; 37(2): 1699-705, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26311050

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is one of the most common malignancies in the world. Numerous studies have linked the activation of AKT to the progression of PDAC. Phosphatidylethanolamine-binding protein 4 (PEBP4) has been reported to be upregulated in various cancer types. However, its expression pattern and biological functions in PDAC are unknown. In this study, it was found that the messenger RNA (mRNA) and protein level of PEBP4 was elevated in PDAC samples. Forced expression of PEBP4 in PDAC cell lines promoted cell growth and migration, while downregulation of PEBP4 in PDAC cells by RNA interference (RNAi) inhibited the growth, migration, and metastasis of the cancer cells. PEBP4 interacted with AKT and promoted the phosphorylation of serine 473 in AKT. Collectively, this study suggested that PEBP4 might promote the progression of PDAC through activating AKT signaling and PEBP4 might be a promising therapeutic target for PDAC treatment.


Assuntos
Carcinoma Ductal Pancreático/patologia , Movimento Celular , Neoplasias Pancreáticas/patologia , Proteína de Ligação a Fosfatidiletanolamina/metabolismo , Animais , Western Blotting , Carcinoma Ductal Pancreático/metabolismo , Proliferação de Células/fisiologia , Xenoenxertos , Humanos , Imuno-Histoquímica , Imunoprecipitação , Camundongos , Neoplasias Pancreáticas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Transfecção
14.
J Thorac Dis ; 7(10): 1806-16, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26623104

RESUMO

BACKGROUND: While phosphatidylethanolamine-binding protein 4 (PEBP4) is a key factor in the malignant proliferation and metastasis of tumor cells, the exact regulatory network governing its roles remains unclear. This study was designed to investigate the effect of PEBP4 on PI3K/Akt/mTOR pathway and explore its molecular network that governs the proliferation and metastasis of tumor cells. METHODS: After the recombinant plasmid pcDNA3.1-PEBP4 was constructed, the recombinant plasmid pcDNA3.1-PEBP4 and PEBP4-targeting siRNA were transfected into lung cancer HCC827 cell line. The expressions of PI3K/Akt/mTOR pathway components in HCC827 cells in each group were determined using Western blotting. In the HCC827 cells, the effect of PI3K pathway inhibitor LY294002 on the expressions of PI3K/Akt/mTOR pathway components under the effect of PEBP4 was determined using Western blotting, and the effects of LY294002 on the cell viability, proliferation, and migration capabilities under the overexpression of PEBP4 were determined using MTT method, flow cytometry, and Transwell migration assay. Furthermore, the effect of mTOR inhibitor rapamycin (RAPA) on the expressions of PI3K/Akt/mTOR pathway components under the effect of PEBP4 was determined using Western blotting, and the effects of RAPA on the cell viability, proliferation, and migration capabilities under the overexpression of PEBP4 were determined using MTT method, flow cytometry, and Transwell migration assay. RESULTS: As shown by Western blotting, the protein expressions of p-Akt and phosphorylated mTOR (p-mTOR) were significantly higher in the pcDNA3.1-PEBP4-transfected group than in the normal control group and PEBP4 siRNA group (P<0.05); furthermore, the protein expressions of p-Akt and p-mTOR significantly decreased in the PEBP4 targeting siRNA-transfected group (P<0.05). Treatment with LY294002 significantly inhibited the protein expressions of p-Akt and p-mTOR in HCC827 cells (P<0.05). In contrast, treatment with RAPA only significantly inhibited the protein expression of p-mTOR (P<0.05). As shown by MTT, flow cytometry, and Transwell migration assay, both LY294002 and RAPA could significantly lower the viability of HCC827 cells and inhibit their proliferation and invasion (P<0.05); meanwhile, they could reverse the effect of PEBP4 in promoting the proliferation and migration of HCC827 cells (P<0.05). CONCLUSIONS: The overexpression of PEBP4 increases the phosphorylation levels of Akt and mTOR in lung cancer cells. The PI3K/Akt/mTOR signaling axis may be a key molecular pathway via which PEBP4 promotes the proliferation and invasion of non-small cell lung cancer (NSCLC) cells; also, it may serve as a potential therapeutic target.

15.
J Proteomics ; 89: 227-37, 2013 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-23665002

RESUMO

Lung cancer (LC) and chronic obstructive pulmonary disease (COPD) commonly coexist in smokers, and the presence of COPD increases the risk of developing LC. The aim of this study was to identify distinct proteomic profiles able to discriminate these two pathological entities. Protein content was assessed in the bronchoalveolar lavage (BAL) of 60 patients classified in four groups: COPD, COPD and LC, LC without COPD, and control with neither COPD nor LC. Proteins were separated into spots by bidimensional polyacrylamide gel electrophoresis (2D-PAGE) and examined by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/TOF). A total of 40 proteins were differentially expressed in the LC and/or COPD groups as compared with the control group. Distinct protein profiles were identified and validated for each pathological entity (LC and COPD). The main networks involved were related to inflammatory signalling, free radical scavenging and oxidative stress response, and glycolysis and gluconeogenesis pathways. The most relevant signalling link between LC and COPD was through the NF-κB pathway. In conclusion, the protein profiles identified contribute to elucidate the underlying pathogenic pathways of both diseases, and provide new tools of potential use as biomarkers for the early diagnosis of LC. BIOLOGICAL SIGNIFICANCE: Sequence coverage. The protein sequence coverage (95%) was estimated for specific proteins by the percentage of matching amino acids from the identified peptides having confidence greater than or equal to 95% divided by the total number of amino acids in the sequence. Ingenuity Pathways Analysis. Mapping of our proteins onto biological pathways and disease networks demonstrated that 22 proteins were linked to inflammatory signalling (p-value: 1.35 10(-08)-1.42 10(-02)), 15 proteins were associated with free radical scavenging and oxidative stress response (p-value: 4.93 10(-11)-1.27 10(-02)), and 9 proteins were related with glycolysis and gluconeogenesis pathways (p-value: 7.39 10(-09)-1.58 10(-02)).


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas de Neoplasias/metabolismo , Proteômica , Doença Pulmonar Obstrutiva Crônica/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Eletroforese em Gel Bidimensional , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/patologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
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