Expression of c-erbB-2 oncogene protein, epidermal growth factor receptor, and TGF-β1 in human pancreatic ductal adenocarcinoma

Objective: To detect the relations of c-erbB-2 onco-gene protein, epidermal growth factor receptor (EG-FR) and transforming growth factor-β1 (TGF-β1)to the progression or metastasis of pancreatic carci-noma.Methods: Using streptavidinbiotin complex (SABC)method, c-erbB-2 oncongene protein, we examinedimmunohistochemically EGFR and TGF-β1 expres-sions in wax-tissue sections from 10 individuals withnormal pancreas (NP), 13 patients with chronic pan-creatitis (CP) and 36 patients with pancreatic ductaladenocarcinoma (PC).Results: The positive expression rates of c-cerbB-2oncogene protein, EGFR and TGF-β1 in the NP, CPand PC groups were 0, 0, 10%; 7.7%, 7.7%,7.7%; and 41.7%, 50.0%, 44.4%, respectively.The positive expression rates of the three specific pro-teins increased more significantly in the PC groupthan in the NP and CP groups (P【0.05). The indi-vidual expression of c-erbB-2, EGFR and TGF-β1was not related to the age and sex of the patients aswell as the site, size and histopathological grade oftumors (P】0.05), but to the clinical stage of tumors(P【0.01). The coexpression rate of the three pro-teins was 27.8 % (10/36). This coexpression in thePC group was correlated with the histopathologicalgrades and clinical stages of tumors (P【0.01).Conclusion: Detection of c-erbB-2 oncogene protein,EGFR, and TGF-β1 expressions in pancreatic tissueis helpful to judge the malignancy, progression, andmetastasis of PC.

Transretinoic acid inhibits rats gastric epithelial dysplasia induced by N-methyi-N-nitro-N-nitrosoguanidine:influences on cell apoptosis and expression of its regulatory genes

INTRODUCTIONGastric epithelial dysplasia (GED) hypothetically is a straight-forward concept: dysplastic epithelium replacing the normal gastric epithelium of the stomach [1].In the stomach ,like any other segment of the gut ,it is defined as an unequivocal non-invasive epithelial change[2,3].The observation of gastric dysplasia as a cancerous lesion was recognized over a century ago ,but it is only after the advent of gastroscopy that its clinical significance has been stressed[4-7].

Overexpression of Bcl-2 partly inhibits apoptosis of human cervical cancer SiHa cells induced by arsenic trioxide

OBJECTIVE: To study the biological effect of arsenic trioxide (As2O3) on human cervical cancer SiHa cells and SiHa cells overexpressing bcl-2 gene. METHODS: SiHa cells with overexpression of Bcl-2 (SiHa-Bcl2 cells) were established by transfecting SiHa cells with Bcl-2 expression vector. The sensitivities of SiHa and SiHa-Bcl2 cells to As2O3 were determined using MTT (Thiazolyl blue) reduction and colony forming ability assay, morphological analysis, flow cytometric analysis, DNA agarose gel electrophoresis, in situ cell death detection (TUNEL), Northern blot, RT-PCR and Western blot. RESULTS: As2O3 inhibited the growth of SiHa cells and induced G2/M arrest and apoptosis of the cells. RT-PCR and Western blot analysis revealed that As2O3 induced SiHa cell apoptosis possibly via inhibiting the expression of HPV16 E7 and decreasing the expression of c-myc. However, we found that SiHa-Bcl2 cells partly resisted As2O3 induced apoptosis, which might be related to the prevention of the down-regulation of HPV16 E7 and c-myc gene expression. Nevertheless, As2O3 at a high concentration could still induce apoptosis of SiHa-Bcl2 cells mainly via decreasing Bcl-2 expression and slightly inhibiting viral gene expression. CONCLUSION: As2O3 is an inducer of the apoptosis of human cervical carcinoma cells and the cells overexpressing Bcl-2 can partly resist As2O3 induced apoptosis, but the exact mechanism is unclear.

Effect of compound Guizhu capsule on phosphate and tension homology deleted on chromsome ten and murine double mimute 2 gene expression in lung cancer of mice

OBJECTIVE: To observe the inhibitory effect of the Chinese herbal compound Guizhu capsule(CGZC)on lung cancer and explore the possible mechanism underlying its actions by evaluating its effects on the expression of phosphate and tension homology deleted on chromsome ten(PTEN) and murine double mimute 2(MDM2) in lung cancer model mice.METHODS: A mouse model of transplanted lung cancer was established by subcutaneous inoculation of cancer cells into the axillae of mice. Twenty-four hours later, the mice were weighed and randomly divided into the model control group, cisplatin group(DDP group), and high, moderate and low dosage CGZC groups, with ten mice in each group. The control mice received an equal volume of distilled water. DDP was intraperitoneally injected at 1 mg/kg in the DDP group, once a day for 3days. CGZC diluted with distilled water was admin-istered at 20 g/kg(10 times the clinical adult dosage) in the high-dose group, 10 g/kg(5 times the clinical adult dosage) in the moderate-dose group and 5 g/kg(2.5 times the clinical adult dosage) in the low-dose group once a day for 10 days. On the11 th day, the mice were weighed and killed. The tumor tissues were weighed and the tumor inhibition rate was calculated. PTEN and MDM2 protein expression were detected by immunohistochemical analysis of tumor tissues.RESULTS: The CGZC high-and moderate-dose groups showed a significant inhibitory effect on tumor growth(P < 0.05); there was no significant difference between the high dose group and the DDP group(P > 0.05). The CGZC high-dose group also showed enhanced expression of PTEN protein(P <0.01) and decreased expression of MDM2 protein(P < 0.01) in lung cancer cells of the mice. There was no significant difference between the high dose group and the DDP group.CONCLUSION: CGZC has a significant inhibitory effect on transplanted lung cancer in mice. The mechanism may involve reducing expression of PTEN and decreasing the expression of MDM2 in the lung cancer tissues of the mice.

Noni(Morinda citrifolia L.) fruit juice delays immunosenescence in the lymphocytes in lymph nodes of old F344 rats

Objective： Aging is associated with the development of diseases because of immunosuppression and altered functioning of the neuroendocrine system. The medicinal properties of Morinda citrifolia L. have been widely exploited for the treatment of age-associated diseases. This study aims to investigate the in vitro and in vivo effects of noni（M. citrifolia） fruit juice（NFJ） on neuro-immunomodulation in the lymph node lymphocytes of F344 rats.Methods： Lymphocytes isolated from axillary and inguinal lymph nodes of young（3–4 months） and old（18–21 months） rats were treated in vitro with different concentrations（0.0001%, 0.01%, and 1%） of NFJ for a period of 24 h. In the in vivo study, old（16–17 months） male F344 rats were treated with 5 mL/kg body weight of 5%, 10% and 20% of NFJ, twice a day, by oral gavage, and lymph node lymphocytes were isolated after 60 d. Concanavalin A（Con A）-induced lymphocyte proliferation, interleukin-2（IL-2）and interferon-γ（IFN-γ） production and expression of intracellular markers, such as phosphoextracellular signal-regulated kinase（p-ERK1/2）, phospho-γ AMP response element-binding protein,phospho-protein kinase B（p-Akt）, phospho-tyrosine hydroxylase（p-TH）, phospho-nuclear factor of κ light polypeptide gene enhancer in B-cells inhibitor-α（p-IκB-α） and phospho-nuclear factor-κB（p-NF-κB p65 and p50） were examined in the lymphocytes of lymph nodes.Results： NFJ increased Con A-induced lymphocyte proliferation, IL-2 and IFN-γ production, and p-ERK1/2 expression both in vitro and in vivo. In in vivo NFJ-treated old rats, lymph node lymphocytes showed increased expression of p-TH and Akt, nitric oxide production and decreased expression of p-NF-κB p65 and p50.Conclusion： These results suggest that the immunostimulatory properties of NFJ are facilitated through intracellular signaling pathways involving ERK1/2, Akt and NF-κB.

Diazoxide preconditioning plus subsequent hypothermia increased resistance of rat cultured hippocampal neurons against hypoxia-reoxygenation injury

Background Cerebral ischemia-reperfusion/hypoxia-reoxygenation insult triggers lots of pathophysiological and biochemical events that separately affect the evolution of cerebral damage. Accordingly, all known effective neuroprotective measures should be taken to get the optimal efficacy of therapy. This study was undertaken to investigate whether diazoxide （DZ） preconditioning combined with the following hypothermia could contribute to synergistic neuroprotection compared with either hypothermia or DZ preconditioning alone. Methods Cultured for 9-10 days in vitro, the hippocampal neurons of SD rats were preconditioned with DZ 0 pmol/L or DZ 250 pmol/L for 1 hour per day and this treatment lasted for 3 days. Subsequently, neurons were subjected to deprivation of oxygen for 4 hours at 37°0, 34°C, 30℃ and 22℃, respectively. This experiment consisted of 8 groups （4 temperature groups and 4 combination groups） and each group contained 12-well or 2-dish cells. Survival rate, expression of Bcl-2, fluorescence magnitude of intracellular calcium, and concentration of malondialdehyde （MDA） were determined at 24 hours after reoxygenation. Results The survival rate and expression of Bcl-2 were both increased in individually hypothermic conditions compared with those at 370G （P〈0.05）, whereas intracellular calcium and MDA did the opposite exhibition simultaneously （P〈0.05）. 22℃ contributed to a higher survival rate and greater expression of Bcl-2 in comparison with other hypothermia （P〈0.05）. Preceding administration of 250 pmol/L DZ took the similar effects on the neurons like hypothermia. Moreover, compared with individual hypothermia or DZ preconditioning, the neuronal survival rate and expression of Bcl-2 in the combination group were increased significantly （P〈0.05）, whereas the calcium fluorescence density and concentration of MDA were reduced further （P〈0.05）. 250 Iamol/L DZ preconditioning combined with 22℃ provided a maximal neuroprotection. Conclusions Compared with either individual hypothermia or DZ preconditioning, the combination of both treatments conferred synergistic protection for cultured hippocampal neurons in vitro against hypoxia- reoxygenation insult.