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ABSTRACT: The mammalian target of rapamycin/eukaryotic translation inititiation factor 4E binding protein 1 (mTOR/4E-BP1) transduction pathway is activated in a range of malignant cancers, but its role in human gastric cardiac adenocarcinoma (GCA) has not been well defined. The present study used western blotting and reverse transcription polymerase chain reaction (RT-PCR) to assess the expression of mTOR, 4E-BP1 and eukaryotic translation initiation factor 4E (eIF4E) at the protein and mRNA levels in 33 cases of GCA and paired adjacent normal gastric mucosal tissues. The expression of mTOR at the protein level in GCA was significantly lower than that in the corresponding normal gastric mucosa (0.296±0.27 vs. 1.348±0.80, P<0.05), but the ratio of p-mTOR to mTOR was significantly increased in tumor tissues (1.425±1.07 vs. 0.450±0.24, P<0.05). The expression of 4E-BP1 was significantly decreased in GCA compared with normal tissues (p<0.05), while the levels of phosphorylated 4E-BP1 (p-4E-BP1) were markedly increased in tumor tissues (p<0.05). The levels of phosphorylated eIF4E (p‑eIF4E) were significantly higher in the tumors in comparison to the corresponding normal tissues (1.822±0.63 vs. 0.997±0.38, P<0.05), and the levels of p-eIF4E were closely correlated with lymph node metastasis (p<0.05). The mTOR/4E-BP1 signaling pathway is activated in GCA, with mTOR activated mainly through increased mTOR phosphorylation rather than protein overexpression.
Molecular Medicine Reports 11/2012; · 0.42 Impact Factor
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ABSTRACT: To explore the inhibitory effects of rapamycin on proliferation of chronic myelogenous leukemia (CML) cells and its possible mechanism.
The effects of rapamycin at various concentrations on cell proliferation of CML cell line K562 cells were analyzed by MTT. The expressions of mTOR, 4E-BP1 and p70S6K at protein and mRNA level in K562 cells with rapamycin treatment were detected by Western blot and RT-PCR. The protein expressions and phosphorylation of mTOR, 4E-BP1 and p70S6K in primary bone marrow cells from CML patients at chronic phase (CP) were also investigated by Western blot, bone marrow cells from healthy people were used as control. Data were analyzed by the χ(2) test, Fisher's exact test and one-way analysis of variance (ANOVA).
The phosphorylation of mTOR, 4E-BP1 and p70S6K were significantly increased in CML bone marrow cells compared with that of normal control (70.6% vs 30.0%, 76.5% vs 40.0%, 73.5% vs 20.0%, respectively, P < 0.05). The proliferation of K562 cells was significantly inhibited with 20 nmol/L and more rapamycin treatment. The phosphorylation of mTOR was decreased after rapamycin treatment, as well as the expressions of 4E-BP1 and p70S6K at protein and mRNA level (P < 0.05).
mTOR signaling played an important role in CML pathogenesis, and rapamycin could decrease CML cells proliferation by inhibiting the activity of mTOR signaling in vitro.
Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 10/2012; 33(10):843-6.
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ABSTRACT: To construct the human TAP1 expression vector and to evaluate its effects on HLA-I expression in GES-1 cells in vitro.
The human TAP1 expression vector (pcDNA3.1/V5-His-TAP1) was constructed by gene recombination technology. The expression of HLA-I on human gastric epithelial cell line (GES-1 cells) after transfection was detected by RT-PCR, Western blot and flow cytometry (FCM).
Human full-length TAP1 gene was obtained from human peripheral blood mononuclear cells by RT-PCR reaction, then TAP1 gene was inserted into pcDNA3.1/V5-HisB vector to get the TAP1 expression vector (pcDNA3.1/V5-His-TAP1) by recombination technology including digestion with restriction enzymes, ligation and transformation. The vector was sequenced to ensure the sequence fidelity.To further evaluate the function of the TAP1 plasmid we constructed, GES-1 cells were selected as the target cell to be transfected. Firstly RT-PCR and Western blot results showed that the expression of TAP in GES-1 cells was increased after pcDNA3.1/V5-His-TAP1 transfection. Based on the high efficiency of transfection in GES-1 cell, we then detected the expression of HLA-I. The results showed that the expressions of HLA-A, HLA-B and HLA-C at mRNA level were all increased by TAP1 transfection, but no change was found in beta2m mRNA. HLA-I protein level was increased correspondingly with the TAP expression in cells by FCM and Western blot assay.
The TAP1 expression vector was successfully constructed, and it can induce the expression of HLA-I on the GES-1 cells after TAP1 transfection. The results confirm that the TAP1 plays a cruical role in the HLA-I antigen expression and antigen presentation pathway.
Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology 04/2010; 26(4):329-32.
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Zhonghua bing li xue za zhi Chinese journal of pathology 03/2009; 38(2):136-8.
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ABSTRACT: To analyze the changing trends of frequency and localization of gastric cancers arising from the gastric cardia, corpus and antrum during the past 14 years in population of the high incidence area of esophageal and gastric carcinoma in Hebei province, China.
The clinicopathological data of 4334 cases of gastric carcinomas among the local residents of Cixian and Zanhuang counties, initially diagnosed in our department from 1993 to 2006, were retrospectively analyzed. The proportion of gastric carcinomas arising from the gastric cardia, corpus and antrum in different years and in patients with different sex and ages were analyzed and compared, and the changing trends of the frequency of gastric carcinoma arising from different sites of the stomach were statistically analyzed.
Among all the 4334 gastric carcinomas, gastric cardia carcinoma accounted for 68.0%, significantly higher than that of corpus (24.2%) and antrum (7.9%; chi(2) = 124.396, P < 0.0001). An increasing tendency in the proportion of gastric cardia carcinoma from 1993 to 2006 was seen. The percentage of cardiac carcinoma in the high incidence area of esophageal carcinoma (Cixian county) was higher than that in the high incidence area of gastric cancer (Zanhuang county) (71.2% vs. 51.2%; chi(2) = 109.648, P < 0.0001). The increase in the incidence of cardiac carcinoma in Cixian county was mainly due to the increase of cardiac carcinoma from 1993 to 2006, while the contributing factor for the increase in the proportion of cardiac carcinomas was resulted from the decrease of incidence of antrum carcinoma in Zanhuang county during the same period. The occurring site of gastric carcinoma was related with age of patients (chi(2) = 58.380, P < 0.0001). The percentage of carcinoma of the gastric body was highest in < 50 year age group, while that in the gastric cardia was highest in 61 - 70 year age group (71.6%).
The major occurring site of gastric carcinoma is the gastric cardia among the local residents in population of the high incidence areas of esophageal and gastric carcinomas during the past 14 years in Hebei province, China. The increasing trend of cardiac carcinoma and decreasing trend of corpus carcinoma in Cixian county and antrum carcinoma in Zanhuang county will be maintained in the coming years if the epidemiological conditions will not be changed.
Zhonghua zhong liu za zhi [Chinese journal of oncology] 12/2008; 30(11):817-20.
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ABSTRACT: Neurodegenerative disorders are associated with oxidative stress. Low density lipoprotein (LDL) exists in the brain and is especially sensitive to oxidative damage. Oxidative modification of LDL has been implicated in the pathogenesis of neurodegenerative diseases. Therefore, protecting LDL from oxidation may be essential in the brain. The antioxidative effects of endomorphin 1 (EM1) and endomorphin 2 (EM2), endogenous opioid peptides in the brain, on LDL oxidation has been investigated in vitro. The peroxidation was initiated by either copper ions or a water-soluble initiator 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH). Oxidation of the LDL lipid moiety was monitored by measuring conjugated dienes, thiobarbituric acid reactive substances, and the relative electrophoretic mobility. Low density lipoprotein oxidative modifications were assessed by evaluating apoB carbonylation and fragmentation. Endomorphins markedly and in a concentration-dependent manner inhibited Cu2+ and AAPH induced the oxidation of LDL, due to the free radical scavenging effects of endomorphins. In all assay systems, EM1 was more potent than EM2 and l-glutathione, a major intracellular water-soluble antioxidant. We propose that endomorphins provide protection against free radical-induced neurodegenerative disorders.
FEBS Journal 04/2006; 273(6):1275-84. · 3.79 Impact Factor
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ABSTRACT: To explore the changes of rat testicular spermatogenic epithelium stimulated by bacterial lipopolysaccharide (LPS) in vivo.
Twenty Wistar rats were divided into two groups: control group and experimental group. The control group was treated with pyrogen-free saline (1 ml/kg) and the experimental group was injected ip with saline containing LPS (1 mg/kg) once every two days. Two groups were operated after ten days in order to investigate the testicular pathological changes by HE staining and the expression of proliferating cell nuclear antigen( PCNA), alpha-catenin in spermatogenic epithelium by immunohistochemistry assay.
The testes of the experimental group showed inflammatory changes. The positive expression of PCNA in seminiferous epithelium was significantly lower than that of control group. The number of positive cells in every seminiferous, in which only spermatogonia were stained in experimental group were 59 +/- 5 and it showed significant decrease compared with the control (P < 0.01). Furthermore, the percentage of such seminiferous tubules was 0.673 +/- 0.054 and increased apparently (P < 0.01). The expression of alpha-catenin in testicular tissue of the experimental group declined (P < 0.01), and cellular positive granular light density was 0.150 +/- 0.014.
The ability of spermatogonium proliferation and the function of conglutination of cells under inflammatory condition of the testes declined, which may be one of the etiologies of male infertility.
Zhonghua nan ke xue = National journal of andrology 02/2006; 12(2):129-32.
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ABSTRACT: Opioids play a role in the apoptosis machinery. We studied the induction of apoptosis in endomorphin 1 (EM1) and endomorphin 2 (EM2), 2 newly isolated endogenous mu-opioid receptor agonists. These endomorphins were able to reduce the viability of cultured HL-60 cells. The antiproliferative properties of endomorphins appeared to be attributable to their induction of apoptotic cell death as determined by ultrastructural change, internucleosomal DNA fragmentation, and increased proportion of the subdiploid cell population. To elucidate molecular events in the apoptosis, protein expressions of Bcl-2, Bax, Fas, and FasL were measured by western blotting using specific antibodies in HL-60 cells. The level of Bcl-2 indicated down-regulation, but the Bax, Fas, and FasL expression showed up-regulation as compared with the untreated control cells. These data support the idea that endomorphins induce apoptosis in HL-60 cells through the activation of the Bcl-2-Bax and the Fas-FasL pathway. We suggest that endomorphins may play an important role in the regulation of tumor cell death.
Canadian Journal of Physiology and Pharmacology 12/2004; 82(11):1018-25. · 1.95 Impact Factor
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ABSTRACT: ObjectiveTo explore the changes of serum male hormone, androgen binding protein (ABP) expression as well as the proliferation of testicular cells in rats with experimental orchitis induced by bacterial lipoplysaccharide (LPS) in vivo and to elucidate the putative mechanism of LPS on spermatogenesis of testis.MethodsThe serum testosterone (T), luteinizing hormone (LH) levels were detected with magnetic enzyme immunoassay. The expression of proliferating cell nuclear antigen (PCNA) and ABP expression at mRNA level of testis were studied with immuno-histochemical staining and in situ hybrydization respectively.ResultsThe serum T level in rats with experimental orchitis was significantly higher than that in the rats of control (P < 0.05) and ABP mRNA expression in Sertoli cells of testis was significantly increased (P < 0.05) while PCNA expression in seminiferous epithelium in experimental rats significantly was decreased as compared with that of the control (P < 0.05). No significant change in serum LH level was seen between experimental orchitis and control groups (P > 0.05).ConclusionThe serum level of T and ABP expression significantly increased in rats with experimental aspecific orchitis induced by LPS, and at the same time inhibition of cellular proliferation of seminiferous epithelium can be detected, which may be the possible mechanism of male infertility in inflammatory process.
Journal of Reproduction and Contraception.
