Urokinase-type plasminogen activator and its inhibitor plasminogen activator inhibitor-1

Tumor associated proteolysis is an essential mechanism in invasion and metastasis of cancer. The influence of the serine protease urokinase-like plasminogen activator (u-PA) and its inhibitor plasminogen activator inhibitor-1 (PAI-1) on the clinical prognosis of squamous carcinoma of the head and neck region (HNSCC) was evaluated. U-PA and PAI-1 levels were measured in tumor biopsies of 41 HNSCC patients and 6 biopsies of healthy oral mucosa using ELISA technique. Patients were followed for an average of 24 months. U-PA concentration in tumor tissue was four times higher than in healthy mucosa (4.96 ng/mg protein versus 1.32 ng/mg). PAI-1 levels were 22 times higher (69.55 ng/mg versus 3.18 ng/mg). Univariate Cox regression analysis revealed significant correlation (p=0.022) of PAI-1 with recurrence of the disease and no significance for u-PA. PAI-1 might become a new functional risk factor reflecting clinical prognosis.     

尿激酶型纤溶酶原激活因子及抑制剂表达与人大肠癌细胞转移能力的关系

目的　探讨尿激酶型纤溶酶原激活因子 ( u PA)、尿激酶型纤溶酶原激活因子受体 ( u PAR)和纤溶酶原抑制剂 1( PAI- 1)的表达与人大肠癌细胞系转移能力的关系。方法　用 EL ISA方法测定 3个人大肠癌细胞系培养上清液中 u PA、u PAR和 PAI- 1含量 ;用免疫组化 ABC方法检测 u PA、u PAR和 PAI- 1在细胞中的表达 ;分析其表达与大肠癌细胞转移能力的关系。结果　在培养上清液中具有高转移能力的 HT- 2 9d细胞的 u PA、u PAR及 PAI- 1含量明显高于低转移的 HT- 2 9和不转移的 Wi Dr细胞 ,而 HT- 2 9细胞的 u PA、u PAR及 PAI- 1含量则高于 Wi Dr细胞。免疫组化显示 u PA和 PAI- 1在 HT- 2 9d细胞中的表达高于 HT- 2 9和 Wi Dr细胞。结论　 u PA、u PAR和 PAI-1的表达与大肠癌细胞的转移能力密切相关。     

Significance of urokinase-type plasminogen activator and plasminogen activator inhibitor-1 (PAI-1) expression in human colorectal carcinomas.

Despite the advances in the medical care of colorectal carcinoma patients, the prognosis has improved only marginally over recent decades. Thus, additional prognostic indicators would be of great clinical value to select patients for adjuvant therapy. In the present study, the antigen levels of urokinase-type plasminogen activator (uPA) and its inhibitor PAI-1, and their immunohistochemical staining were compared in paired colorectal tumor (n = 64) and background colon tissue of the same patients with clinical and pathological staging. The antigen levels, measured with an ELISA method, were found to be significantly higher in cancer tissue (mean 1.92 ng/mg protein for uPA and 7.08 for PAI-1) than in corresponding normal mucosa (0.29 ng/mg protein for uPA and 1.11 ng/mg protein for PAI-1). There was a positive correlation between uPA and PAI-1 antigen levels and clinicopathological parameters such as grade (p < 0.001 and p = 0.01, respectively), while for Dukes' stage, only PAI-1 correlated positively (p = 0.018). Nodal status correlated positively with uPA but not with PAI-1 antigen levels. Immunohistochemical localization of both antigens was observed mainly in cancer cells and much less in stromal cells. Staining intensity increased from adenoma to adenocarcinoma. The degree of staining was associated with grade, Dukes' stage and nodal status for uPA (p < 0.001, p = 0.002, p < 0.001, respectively) and only with grade for PAI-1 (p = 0.007).     

尿激酶型纤溶酶原激活物系列与肿瘤转移

尿激酶型纤溶酶原激活物(uPA)属丝氨酸蛋白水解酶,uPA与其受体(uPAR)、抑制剂(uPAI)所形成的作用系统可激活纤溶酶原参与细胞外基质的降解,介导肿瘤的侵袭和转移.现对uPA作用系统中的主要组分及其在肿瘤侵袭转移中作用作一简要介绍.     

胃癌组织中E—CD和UPA的表达及临床病理学评价

目的：探讨胃癌浸润、转移中细胞粘附分子ECD和基质分解酶UPA所发生的功能性改变及其与胃癌生物学行为的关系。方法：采用免疫组化SABC法对42例胃癌标本的ECD、UPA表达情况进行研究，分析了其与临床病理因素的关系及内在联系。结果：ECD在42例胃癌中阴性表达为66．7％（28例），UPA阳性率为64．3％（27例），ECD减低的表达，UPA的高表达与胃癌的高侵袭力、淋巴结转移、组织低分化和病理分期升高有关，且ECD（－）／UPA（＋）组较之ECD（＋）／UPA（－）组有明显的恶性生物学行为。结论：ECD表达减低和UPA的高表达均提示胃癌具恶性生物学行为，ECD／UPA共表达对胃癌生物学行为评估有重要意义。     

E-钙黏附素与尿激酶型纤溶酶激活物在浸润性乳腺癌中的表达及其临床意义

目的通过检测E-钙黏附素(ECD)和尿激酶型纤溶酶原激活物(UPA)基因产物在乳腺癌组织中的表达情况,探讨它们与乳腺癌浸润和转移及其与乳腺癌生物学行为的关系.方法采用免疫组化SABC方法检测ECD与 UPA在86例乳腺浸润癌(其中淋巴结转移62例,无淋巴结转移24例)中的表达,分析其与临床病理的关系及内在联系.结果淋巴结转移组UPA表达比无淋巴结转移组明显高(P<0.01),而ECD表达则减低(P<0.01).UPA的高表达与乳腺癌的高侵袭力、淋巴转移、组织低分化和病理分期升高有关,且ECD(-)/UPA( )组较ECD( )/UPA(-)组有明显的恶性生物学行为.结论 ECD表达减低和UPA高表达均提示其恶性生物学行为,有助于确定术后治疗方案.     

Obesity and colorectal adenomatous polyps

Obesity has been investigated as a risk factor for various malignancies, including colon cancer. A case-control study was conducted on patients in three colonoscopy practices in New York City to determine possible risk factors for colorectal adenomatous polyps, a known precursor lesion for most cases of colorectal cancer. Among 301 case subjects with incidence adenomatous polyps (174 men and 127 women) and 506 control subjects (223 men and 283 women), an increased risk was observed with increasing body mass index in women (odds ratio 2.1, 95% confidence interval 1.1-4.0; for highest versus lowest quartile, linear trend P = .02). A nonsignificant trend was observed for men. The increased risk seen in women is consistent with prior observations regarding reproductive hormonal and dietary risk factors for colorectal cancer.     

Urokinase-type plasminogen activator receptor: a beacon of malignancy?

Discriminating between benign and malignant disease is a pivotal diagnostic issue in the care of women with pelvic masses. Identification of serum biomakers that can rellably make the distinction would aid in the proper referral for patient care and may provide leads in the development of early detection strategies.     

Urokinase-type plasminogen activator expression correlates with tumor angiogenesis and poor outcome in gastric cancer

Urokinase plasminogen activating system (PA system) and vascular endothelial growth factor (VEGF) were recently suggested to contribute synergistically to tumor progression. To evaluate the roles of the PA system and VEGF in gastric cancer, the effects of the PA system and VEGF on tumor angiogenesis and the survival of patients with gastric cancer were investigated. Cancer tissues from 101 gastric cancer patients were assayed immunohistochemically for expression of urokinase-type plasminogen activator (uPA), uPA receptor (uPAR), PA inhibitor-1 (PAI-1) and VEGF protein. The positive rates of uPA, uPAR, PAI-1, VEGF expression were 22.8%, 32.7%, 36.6% and 26.7%, respectively. Positive staining was observed in tumor cells (uPA, uPAR, VEGF), or in both tumor cells and stromal cells (PAI-1). The expressions of uPA, uPAR, PAI-1 and VEGF were significantly correlated with the clinicopathological factors: uPA, depth of tumor invasion, differentiation, lymphatic and vascular invasion; uPAR, tumor size, depth, lymph node involvement, differentiation, vascular invasion; PAI-1, tumor size, depth, lymph node involvement, differentiation, vascular invasion; VEGF, differentiation, vascular invasion. The microvessel density (MVD) assessed immunohistochemically was significantly higher in the patients with expression of uPA, uPAR or VEGF, and stepwise analysis identified uPA as an independent correlated factor with MVD. Furthermore, multivariate analysis demonstrated that depth of tumor invasion, lymph node involvement and uPA expression were independent prognostic factors. uPA is a key factor in the PA system, being associated with a poor outcome of gastric cancer, and contributing not only to invasive activity, but also to angiogenesis. (Cancer Sci 2003; 94: 43–49)     

Immunohistochemical analysis of plasminogen activator expression in human colorectal carcinomas: correlation with CEA distribution and tumor cell kinetics

Fifty cases of colorectal adenocarcinoma were immunohistochemically examined for the relationship between distribution of plasminogen activators (PAs) and the degree of differentiation of cancer cells as reflected by carcinoembryonic antigen (CEA) expression as well as tumor cell kinetics. The A chain of urokinase-type PA (u-PA-A) was mainly observed in the apical portions of highly differentiated cancer cells. Increased expression and change in localization to the cytoplasm were found with progressive dedifferentiation. The numbers of DNA polymerase alpha (pol. alpha) positive cancer cells also increased in line with u-PA-A expression. The B chain of u-PA (u-PA-B), and the A and B chains of tissue-type PA (t-PA-A and -B) did not show similar alteration. The present findings suggest that the distribution of u-PA-A in colorectal carcinoma tissues, the degree of tumor differentiation, and the proliferation kinetics of cancer cells are closely related.     

Urokinase-type plasminogen activator and plasminogen activator inhibitor type 1 and type 2 in stage I malignant melanoma

The urokinase-type plasminogen activator (uPA) and its inhibitors type 1 (PAI-1) and type 2 (PAI-2) are considered to have a key role in the process of invasion and metastasis. We investigated the differences in uPA, PAI-1 and PAI-2 concentrations in primary cutaneous melanoma and normal skin and correlations with well-established melanoma prognostic factors. The study was performed on 43 patients (19 men, 24 women; mean age 57 years) with histologically confirmed primary melanomas <1.5 mm thick. The uPA concentrations were determined in 36 pairs of triton extracts, and the PAI-1 and PAI-2 concentrations in 43 pairs of cytosols prepared from the tumour and adjacent normal tissue samples (matched pairs). The uPA, PAI-1 and PAI-2 concentrations were measured by enzyme-linked immunosorbent assay (ELISA). Significantly higher concentrations of both uPA and PAI-1 were measured in melanomas than in normal surrounding skin (uPA: 1.08 vs 0.48 ng/mg total protein (mgp), p<0.001; PAI-1: 14.07 vs 2.07 ng/mgp, p<0.001). The melanoma uPA, PAI-1 and PAI-2 concentrations correlated significantly (p<0.05) with normal skin (r=0.73, 0.54, 0.38 respectively). The uPA concentrations positively correlated with those of PAI-1 measured in melanomas (r=0.45, p<0.01). PAI-1 values were significantly lower (p<0.001) in the melanomas of Breslow thickness < or =0.75 mm, Clark invasion 0.75 mm, Clark invasion of > or =II and < or =III, with microscopic ulceration and vascular invasion (22.25, 17.67, 27.67, 37.77, respectively). Determination of uPA and PAI-1 can provide significant additional prognostic information for melanoma patients.     

Urokinase-type plasminogen activator induces proliferation in breast cancer cells

Urokinase-type plasminogen activator (uPA) is implicated in various pathophysiological processes, including extracellular matrix turnover, cell migration and invasion. Our study aimed to determine the role of uPA in both proliferation and mitogen-activated protein kinase (MAPK) pathway. Hence, we analyzed the effects induced by exogeneous addition of domain-specific uPA antibodies and uPA-interacting molecules on proliferation of uPA-suppressed MDA-MB-231 breast cancer cells. uPA expression was reduced to 53% by stable transfection with an antisense/vector construct and to 65% by siRNA transfection. Immunocytochemical Ki67 staining and flow cytometry (S-phase) analysis indicated a strong decrease of cellular proliferation activity (35% and 38%, respectively). Exogenous addition of high molecular weight-uPA (HMW-uPA) or incubation with the amino terminal fragment (ATF), which lacks the enzymatic activity of uPA, lead to increased cell proliferation. A strong increase of proliferation was absent when the monoclonal anti-uPAR antibody IIIF10 (blocking uPA binding site), soluble uPAR (scavenger effect) and phosphatidyl-inositol-specific phospholipase C (PI-PLC, degrading uPAR) was added prior to the addition of HMW-uPA. In conclusion, HMW-uPA and ATF induce proliferation of breast cancer cells by binding to uPAR. Thereby, integrins situated adjacent to uPAR carry the signals into the cell, thus stimulating proliferation that is mediated via the MAPK pathway.     

甲状腺癌组织中尿激酶型纤溶酶原激活物和抑制物的表达及其临床意义

目的 :研究纤溶酶原激活物 (uPA)和抑制物 (PAI 1)在甲状腺癌组织中的不同表达 ,总结其在甲状腺癌的发生、发展及侵袭转移过程中的规律和对临床的指导意义。方法 :采用酶联免疫吸附 (ELISA)法检测 4 2例甲状腺癌和 30例良性甲状腺肿瘤组织及正常甲状腺组织中uPA和PAI 1含量 ,从良恶性、临床分期、病理类型等不同方面分别进行对照分析 ,比较其有无差异。结果 :甲状腺瘤组织的uPA含量高于正常甲状腺组织 (P <0 0 5 ) ,PAI 1含量和正常甲状腺组织比较无显著性差异 (P >0 0 5 )。甲状腺癌组织中uPA和PAI 1含量明显高于良性甲状腺肿瘤和癌旁组织 (P <0 0 1) ,且和临床分期呈正相关 (r分别为 0 72 3和 0 795 ,P <0 0 5 )。周围淋巴结转移组的uPA和PAI 1含量明显高于无转移组 (P <0 0 5 )。未分化癌的uPA和PAI 1含量高于乳头状癌和滤泡状癌 (P <0 0 5 ) ,乳头状癌和滤泡状癌uPA值和PAI 1含量比较无显著性差异 (P >0 0 5 ) ,髓样癌的uPA值和PAI 1的含量最低。结论 :检测组织中uPA和PAI 1含量可能对甲状腺癌的侵犯范围、淋巴结转移情况及预后估计等有一定的参考价值     

Urokinase-type plasminogen activator system and breast cancer (Review)

Malignant tumors have a capacity to degrade the extracellular matrix (ECM) by controlled proteolysis. One proteolytic system involved in these processes is the urokinase-type plasminogen activator (uPA) system, which consists of uPA, uPA receptor (uPAR) and uPA inhibitors 1 and 2 (PAI-1 and PAI-2). In the past two decades, study of the uPA system in human breast cancer has yielded valuable insights. Increased levels of uPA, PAI-1 and uPAR have been reported to be associated with poor prognosis in patients with breast cancer. Furthermore, uPA and PAI-1 may be new prognostic markers for axillary node-negative patients. To date, a growing body of evidence has suggested that uPA system promotes tumor metastasis by several different mechanisms, not just by breaking down the ECM. This article is focused on reviewing the current understanding of uPA system members as prognostic markers in breast cancer, and their cellular localization and tissue distribution. Correlations of the uPA system with other informative markers of breast cancer are also discussed.     

Urokinase-type plasminogen activator and its receptor in colorectal cancer: independent prognostic factors of metastasis and cancer-specific survival and potential therapeutic targets

Urokinase-type plasminogen activator (uPA) and its receptor (uPAR), plasminogen (Plg), and plasminogen activator inhibitors-1 and -2 (PAI-1 and PAI-2) have been observed in many cancers and may contribute to progression and metastasis. In our study, we examined the expression of the 5 proteins by immunohistochemistry in 59 consecutive primary colorectal cancers (CRC) and correlated the protein expression with patient outcome. In addition, we determined the effect of down-regulation of uPAR on the invasive/metastatic capability of CRC cells, by measuring antisense-uPAR transfected HCT116 and control cell lines, in terms of uPAR expression, uPA-binding activity, invasiveness through Matrigel in vitro and metastasis after cecal orthotopic implantation in nude mice in vivo. We found that higher expression of uPA or uPAR in primary tumor tissues was positively correlated with distant metastasis of CRC (Mann-Whitney, p < 0.02) and negatively correlated with both patient overall survival (OS) and cancer-specific survival (CSS; Cox model, p < 0.04). The prognostic value of uPA and uPAR for both OS and CSS was independent of other variables (multivariate Cox model, p < 0. 007). Antisense-uPAR transfected HCT116 cells, which expressed significantly lower levels of total cellular and cell surface uPAR proteins and uPA-binding activity compared with either wild-type or cells transfected with vector alone (Bonferroni, p < 0.05/3), consistently showed decreased invasiveness through Matrigel (Bonferroni, p < 0.05/3) and decreased metastasis formation in nude mice (Fisher, p < 0.05). Our data suggest that uPAR and uPA are independent prognostic factors in CRC; anti-uPAR treatment, which affects both uPAR and uPA levels, may have potential for new treatment of the disease.     

Increase of urokinase-type plasminogen activator gene expression in human lung and breast carcinomas

To assess the postulated correlation between plasminogen activators (PAs) and malignancy, we determined the mRNA content for urokinase-type (u-PA) and tissue-type (t-PA) enzymes in a prospective series of 29 primary lung and 27 primary breast carcinomas. Dot blots of total RNAs were hybridized with appropriate cRNA probes under conditions that allow quantitative measurement of the mRNA level for each PA. Most tumors (43 of 56) had a u-PA mRNA content higher than the mean + 1 SD of nonmalignant tissue counterparts. A large, 4- to 20-fold, increase in u-PA mRNA content was demonstrated in 14 of 29 lung carcinomas and in 10 of 27 breast carcinomas. A statistically significant correlation (Fisher's test, P = 0.007) was found between elevated u-PA mRNA content in lung carcinomas and the presence of regional lymph node metastases. These results are consistent with a role for u-PA in tumor invasiveness and metastatic propensity and may have important prognostic and therapeutic implications.     

Adiposity and the risk of colorectal adenomatous polyps: a meta-analysis

Objective  

The findings from epidemiological studies addressing the association between adiposity and the risk of colorectal adenomatous polyps are inconsistent. We performed a meta-analysis of epidemiological studies including cross-sectional, case–control, and cohort studies.     

UROKINASE-TYPE PLASMINOGEN ACTIVATOR,ITS RECEPTOR AND INHIBITOR EXPRESSION IN HEPATOCELLULAR CARCINOMA RELATION TO CANCER INVASIVENESS AND PROGNOSIS

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Tobacco smoking and colorectal hyperplastic and adenomatous polyps.

Colorectal adenomas and possibly some hyperplastic polyps are precursors of colorectal cancer. Tobacco use is associated in epidemiologic studies with these polyps, although links between smoking and colorectal cancer are less consistent. To characterize the role of tobacco in early colorectal carcinogenesis, we compared tobacco use among 4,383 subjects with histologically verified benign (hyperplastic or adenomatous) polyps of the distal colon (descending colon, sigmoid, and rectum) with tobacco use among 33,667 subjects who were endoscopy negative for distal colon tumors, in the screening arm of the Prostate, Lung, Colorectal, and Ovarian Trial, a randomized trial of flexible sigmoidoscopy. Risks, estimated by the odds ratio (OR), associated with current cigarette use were OR = 4.4 [95% confidence interval (95% CI), 3.7-5.2] for hyperplastic polyps only, OR = 1.8 (95% CI, 1.5-2.1) for adenomas only, and OR = 6.2 (95% CI, 4.7-8.3) for subjects with both hyperplastic and adenomatous polyps concurrently. Effects were weaker among ex smokers; the smoking-associated ORs remained consistently higher for hyperplastic polyps. This pattern was also seen in relation to cigarettes smoked per day, smoking duration, and pack-years. Tobacco-associated risks for multiple polyps were also stronger when hyperplastic disease was involved. In conclusion, tobacco use, particularly recent use, increases risk for both adenomatous and hyperplastic polyps, but the risks are substantially greater for hyperplastic lesions.     

Hemochromatosis gene mutations and distal adenomatous colorectal polyps.

Iron has been suggested to be a risk factor for colorectal neoplasia. Some individuals who are heterozygous for mutations in the hemochromatosis gene (HFE) have higher than average serologic measures of iron. We therefore investigated whether heterozygosity for HFE mutations was related to risk of advanced distal adenoma and whether the relationship was affected by dietary iron intake. In the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, 679 persons with advanced distal adenoma and 697 control persons were genotyped for the two major HFE mutations (C282Y and H63D), one HFE polymorphism (IVS2+4), and one polymorphism (G142S) in the transferrin receptor gene (TFRC). HFE haplotypes were also created to examine the effect of haplotype on risk. Food frequency questionnaire data were used to estimate daily iron intake. There was no relationship between any HFE genotype or haplotype and advanced adenoma. Stratification of HFE genotype by TFRC genotype did not change the results. In addition, there was no relationship between dietary iron intake and risk of adenoma or between HFE genotype and risk of adenoma, stratified by iron intake. These results do not support a relationship between HFE heterozygosity and risk of advanced distal adenoma.