p150 overexpression in gastric carcinoma: the association with p53, apoptosis and cell proliferation

To clarify the significance of p150 expression, 102 gastric carcinomas were immunohistochemically investigated and 14 fresh samples of the cancer were analyzed with the immunoblot method. Tumor cell apoptosis was assessed by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-digoxigenin nick end labeling (TUNEL). Both Ki-67 antigen and p53 expression were analyzed immunohistochemically. Eighty-six out of 102 (85%) gastric cancers stained positively for p150. All 14 tumors analyzed by Western blotting overexpressed p150. Statistical analysis revealed a close association between p150 overexpression and the clinicopathologic parameters of gastric cancer. All well-differentiated cancers showed high p150 expression (p < 0.005). Furthermore, high p150 expression was more frequently seen in tumors at early invasive stages (p < 0.005), in tumors without metastases (both local and distant, p < 0.005) and in early TNM stages (p < 0.005) in general. As we have found for cervix and esophagus carcinoma, when tumors progress to high malignancy and metastasis, p150 begins to regress and then breaks down. A good correlation of p150 expression, but not p53 expression, with tumor cell apoptosis could be demonstrated (p < 0.01). The Ki-67 labeling index, i.e., the index for a proliferative marker, showed no correlation with either p150 or p53 expression. The results suggest that p150 may be a new early tumor marker for gastric carcinoma similar to that for esophagus and cervix carcinoma.     

Overexpression of inducible nitric oxide synthase in gastric mucosa of rats with portal hypertension: correlation with gastric mucosal damage

BACKGROUND: An increased biosynthesis of nitric oxide (NO) has been implicated in the hyperdynamic circulation and development of collaterals of portal hypertension (PHT) because of its potent vasodilatory effects. NO is synthesized from L-arginine by three different isozymes of nitric oxide synthase (nNOS, iNOS and eNOS). Thus, the expression of inducible NOS (iNOS) might account for NO overproduction in PHT. However, in previous investigations, the role of iNOS in the pathogenesis of PHT gastropathy remained controversial. Our current study was in both molecular and protein levels to determine whether the expression of iNOS is responsible for PHT gastropathy. MATERIALS AND METHODS: PHT was induced experimentally by partial ligation of the portal vein. Fourteen days after partial ligation of the portal vein, the rats were randomly assigned to receive either vehicle or L-NAME (NOS inhibitor) at doses of 5 mg/kg/day, 10 mg/kg/day, or 25 mg/kg/day by gastric lavage twice a day for 1 week. Sham operated rats served as controls. Northern hybridization and in situ hybridization are used to compare the expression of gastric mucosa iNOS mRNA in the PHT rats and the controls. NO was measured by the Griess method after reduction of nitrate to nitrite with nitrate reductase. Immunohistochemical staining was carried out to detect the iNOS protein. In addition, the severity of gross gastric mucosal lesions was evaluated macroscopically by a gross ulcer index. RESULTS: The iNOS expression at both mRNA and protein was prominently increased in PHT rats, accompanied with the enhanced NO production. The gastric mucosa iNOS mRNA and serum NO levels were significantly decreased after L-NAME administration (P < 0.05). However, the markedly reduced gastric mucosal damage in PHT rats was observed only at high does of L-NAME (25 mg/kg/day) administration. CONCLUSION: PHT triggers overexpression of iNOS mRNA and proteins in rat gastric mucosa, but that this alone does not account for PHT gastropathy.     

Wild type p73 overexpression and high-grade malignancy in breast cancer

The overexpression of wild type p73 is the most frequent alteration of p73 in malignancies. We investigated, in 70 breast carcinomas, p73 mRNA expression and its relationship to p53 mutations, determined by an immunohistochemical method, and loss heterozygosity (LOH) status of the 1p36 region, together with its possible implication in the pathogenesis of breast carcinomas. LOH, amplifying DNA by PCR using 5 markers, of 1p36 region (one intragenic to p73 gene) was found in 17% of cases but no significant correlation was observed with p73 overexpression. p53 positive immunostaining was present in 33% of breast carcinomas, and these exhibited a statistically significant relation with p73 overexpressed tumors. Overexpression of p73 mRNA was observed in 19 tumors (27%). The analysis of cases with p73 overexpression and cases with normal mRNA expression, in terms of age and pathologic characteristics of the tumors showed a significant association of p73 overexpression and tumors with lymph node metastases, vascular invasion and higher pathologic stage. These results suggest that p73 overexpression is a molecular alteration that could be implicated in the tumorigenesis of breast carcinomas and, eventually, in a poor clinical behavior.     

蛋白酶体β5亚单位过表达对氧化环境下人晶状体上皮细胞的影响

【目的】探讨蛋白酶体筇亚单位（PSMB5）基因过表达对氧化条件下晶状体上皮细胞的影响。【方法】构建重组质粒pcDNA3．1-PSMB5并将其转染人人晶状体上皮细胞株SRAO1／04中，形成稳定表达，同时设pcDNA3．1空载体为对照组。RT—PCR法及Western blot法分别检测PSMB5基因及蛋白的表达情况。H2O2分别作用PSMB5转染细胞及空载体转染细胞，MTT法检测细胞增殖能力的变化。【结果】转染后用G418筛选3周后，获得PSMB5转染及空载体转染的G418抗性的细胞克隆。转染PSMB5基因的细胞PSMB5 mRNA表达强度明显增高．而空载体转染细胞与未转染细胞无显著差异：转染PSMB5基因的细胞的PSMB5蛋白表达也显著高于空载体转染细胞。低浓度H2O2作用后，转染PSMB5基因的细胞增殖能力高于空载体转染细胞。【结论】低浓度氧化环境下蛋白酶体历亚单位PSMB5过表达能对人晶状体上皮细胞具有保护作用。     

Correlation between c-erbB-4 receptor expression and response to gemcitabine-cisplatin chemotherapy in non-small-cell lung cancer.

Background:While the overexpression of c-erbB gene family inseveral malignancies is associated with poorer prognosis, the associationbetween the expression of the cellular markers and the response tochemotherapy is not yet clear. In this study we investigated the expressionof c-erbB-4 receptor in NSCLC and correlated it with the response togemcitabine–cisplatin combination chemotherapy. Patients and methods:Forty-three NSCLC patients withhistologically or cytologically proven disease were treated withgemcitabine–cisplatin combination chemotherapy. Immunohistochemicalstains for c-erbB-4 receptor were performed in 20 cases on paraffin sectionsusing the avidin-biotin-peroxidase method. Results:Two patients achieved complete response (5%), and16 achieved partial response (37%) yielding an overall objectiveresponse rate of 42%. Minimal response was observed in seven patients(16%) and disease stabilization in 7%. Immunohistochemical stainwas positive for the presence of c-erbB-4 receptor in 25% of patients,and negative in 75%. No response was documented in c-erbB-4 positivepatients (0 of 5) while an objective response (complete, partial orminimal) was seen in 11 of 15 (73%) c-erbB-4 negative patients.Negative stain for c-erbB-4 significantly favored response togemcitabine–cisplatin combination (P < 0.01). Conclusion:C-erbB-4 expression status showed no correlation withsurvival and cannot be accepted at this time as a guiding factor fortherapeutic management. These interesting results deserve further evaluationin a large-scale prospective trial before treatment recommendations on thebasis of c-erbB-4 presence can be finally made.     

The effect of moesin overexpression on ageing of human dermal microvascular endothelial cells

Abstract:  Senescence of microvascular endothelial cells is known to play an important role in the pathophysiology of vascular diseases related to ageing, but the accurate mechanism or related genes are not known. Moesin, a cytoskeletal protein and the most potent candidate as an ageing-related protein, showed obvious changes in expression when compared before and after ageing. In this study, a lentivirus was used to overexpress moesin in endothelial cells. The expression of cell cycle mediators such as p16, cyclin D1 and cdk4, which can be the markers of ageing, was compared by RNA and was shown to be suppressed in moesin overexpressed endothelial cells. In conclusion, it can be said that the expression of moesin delays senescence of human dermal microvascular endothelial cells and this fundamental discovery can be used as a basis for understanding the mechanism of ageing and age-related diseases.     

鼠脑出血后海马内皮素-1变化与脑出血继发性损伤

目的:研究脑出血后脑内内皮素(ET-1)表达与脑出血灶周围组织水肿之间的关系。方法:采用脑内注射胶原酶建立大鼠脑出血模型,SD大鼠30只单纯随机分为注射胶原酶4,24,48,72h组及假手术组,通过免疫组化、彩色病理图像分析系统及干湿法观察脑出血后海马ET-1表达和脑出血灶周围脑组织水含量。结果:给大鼠尾壳核注射胶原酶0.5IU,4h后即可见直径约2.5mm的血肿,脑水含量即明显升高,24h达高峰;与此同时脑出血后4h海马CA1犤(37.6±7.3)个/切片犦、CA3区犤(41.3±3.7)个/切片犦的阳性细胞数较假手术组犤(18.3±4.0),(27.1±4.3)个/切片犦明显增加,24h犤(75.8±6.6),(88.4±9.6)个/切片犦最为显著,阳性细胞数及平均截面积除72h组外,明显高于对照组,均有统计学的显著性意义(t=2.306～5×106,P<0.01或P<0.05),72h后阳性细胞数已逐渐接近正常。结论:大鼠脑出血后脑内ET-1过度表达可能是血肿周围存在水肿和继发性缺血的重要因素之一。     

异烟肼耐药耻垢分枝杆菌的建立及药物敏感性的测定

耐药结核病的涌现,使发展新型抗耐药结核药物变得尤为迫切。本研究选择生长快且无致病性的耻垢分枝杆菌为研究对象,探索快速评价药物抗异烟肼耐药结核分枝杆菌的能力。inhA是异烟肼的作用靶点,由于inhA的突变或者过表达可以引起结核分枝杆菌对异烟肼耐药性的产生。通过将inhA克隆入pMV261中,构建过表达inhA的耻垢分枝杆菌。结果显示,过量表达inhA的耻垢分枝杆菌对异烟肼的敏感性下降了100倍以上。建立了利用刃天青为指示剂的抗异烟肼耐药株的快速药效评价方法,可快速对药物的活性进行定性或定量评价,为进行新型抗结核药物的高通量筛选和药效评价奠定基础。     

环氧化酶2过表达对铝盐致大鼠海马神经元损伤的影响

目的:研究环氧化酶2(COX-2)过表达与铝盐致大鼠海马神经元损伤间的关系.方法:原代海马神经元培养7d,予以铝盐负荷(终浓度200 μmol/L )建立大鼠海马神经元损伤模型,以神经元转染COX-2过表达腺病毒(MOI=100),Western Blot检测COX-2的蛋白表达水平,酶化学法检测海马神经元超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、乳酸脱氢酶(LDH)漏出率及MTT值,倒置荧光显微镜观察海马神经元病理形态变化.结果:COX-2过表达腺病毒转染的神经元COX-2蛋白表达增加(P＜0.01),SOD活性、MDA含量、LDH漏出率、MTT值,以及大鼠海马神经元细胞的形态和结构未见明显异常变化.而COX-2过表达腺病毒转染在铝盐负荷基础上的海马神经元细胞MTT值和SOD活性明显下降,LDH漏出率和MDA含量明显上升(P＜0.01或P＜0.05),表现为严重的细胞损伤.结论:单纯的一定程度COX-2过表达不会造成神经元明显损伤,但可增加神经元对铝盐损伤的敏感性.     

Overexpressions of Cyclin B1, cdc2, p16 and p53 in human breast cancer: the clinicopathologic correlations and prognostic implications

Purpose

The molecular mechanisms that are responsible for the initiation and progression of breast cancers are largely unknown. This study was to analyze the cyclin B1, cdc2, p53 and p16 tumor suppressor genes in human breast cancer.

Materials and Methods

To investigate the role of cyclin B1, cdc2, p53 and p16 in the pathogenesis and progression of breast carcinomas, 98 cases of breast cancers were examined by immunohistochemical method. The correlations of cyclin B1, cdc2, p53 and p16 expression with various clinico-pathologic findings were analysed.

Results

In the normal breast tissues, cyclin B1, cdc2 and p16 were weakly expressed, while p53 was not expressed. On the other hand, cyclin B1, cdc2, p53 and p16 were overexpressed in breast cancer, showing correlation between the expression of cyclin B1 and cdc2 and breast cancers (p=0.00). The overexpressions of cdc2 and p16 were correlated with an infiltrative tumor border pattern and this was statistically significant (p<0.05). In addition, the overexpression of cdc2 was correlated with histologic high grade carcinomas (p=0.00).

Conclusion

Cyclin B1 and cdc2 appeared to be involved in the genesis or progression of breast cancers. In addition, the overexpressions of p16 and p53 may play important roles in more aggressive tumor and the overexpression of cdc2 is associated with progression of tumor to a higher grade of breast carcinomas. The deranged overexpressions of cyclin B1, cdc2, p16 and p53 may play an important role in human breast carcinogenesis.