Prognostic impact of urokinase-type plasminogen activator (PA), PA inhibitor type-1, and tissue-type PA antigen levels in node-negative breast cancer: a prospective study on multicenter basis.

Urokinase-type plasminogen activator (u-PA) is a key protease in cancer invasion and metastasis. Recent studies demonstrated that u-PA, plasminogen activator inhibitor type-1 (PAI-1), and tissue-type plasminogen activator (t-PA) are prognostic factors in breast cancer. However, there have been no prospective studies of node-negative breast cancer on a multicenter basis. On the other hand, some patients, even those with node-negative breast cancer, developed recurrence, and only tumor size is available as a predicting factor in this group. Therefore, it is necessary to find other prognostic factors in node-negative breast cancer to determine suitable adjuvant therapies. Tissue samples in this prospective study were obtained from 130 patients with node-negative invasive breast cancer who underwent radical operation at four hospitals. The median follow-up was 52.6 months. u-PA, PAI-1, and t-PA antigen levels were assayed by ELISA kits using the cytosolic fractions of tumors. Patients with high u-PA, high PAI-1, or low t-PA had significantly higher relapse rates than did those with low u-PA, low PAI-1, or high t-PA, respectively, by the Kaplan-Meier method (P = 0.006, 0.032, and 0.028, respectively). Analyses of the combinations of both u-PA and PAI-1 or both u-PA and t-PA showed that the differences in relapse rate between the high- and low-risk groups were statistically very significant. In the univariate analysis, u-PA, PAI-1, t-PA, progesterone receptor, and tumor size (T3 versus T1) were significantly correlated with relapse. However, the multivariate analysis revealed that only u-PA (P = 0.023) was an independent prognostic factor. This study showed that u-PA was a new significant independent prognostic factor in node-negative breast cancer.

Stimulation of human platelet Ca(2+)-ATPase and Ca2+ restoration by calpain.

To clarify the possible role of calpain (calcium activated neutral protease; EC 3.4.22.17) in Ca2+ homeostasis of human platelets, we investigated the effects of cell permeable calpain inhibitors, calpeptin and E-64d (EST), on the restoration of cytoplasmic Ca2+ ([Ca2+]i) in both Fura-2 and aspirin (ASA) loaded platelets. Although neither calpeptin (30 microM) nor EST (250 microM) altered the increase of [Ca2+]i in thrombin (1 U/ml) stimulated platelets, both calpain inhibitors delayed the decrease of [Ca2+]i back towards the basal level. These observations suggested that calpain might be involved in Ca2+ restoration. Then, the activity of Ca(2+)-ATPase was examined in thrombin (2 U/ml) stimulated platelets. Thrombin produced a rapid rise in Ca(2+)-ATPase activity by 2-fold at 8 s of incubation, which then returned to below the basal activity within 2 min. Calpeptin inhibited transient Ca(2+)-ATPase activation induced by thrombin in a dose related manner. Ca(2+)-ATPase of isolated platelet membranes was digested by purified human platelet calpain-I and Ca(2+)-ATPase activity was investigated. With a short incubation (8-15 s), Ca(2+)-ATPase activity was increased about 2-fold and then it decreased below the basal level at longer incubations or at a higher calpain/membrane ratio. The initial rate of Ca2+ uptake was also increased by about 2-fold with a short incubation (8-15 s). For molecular characterization of the Ca(2+)-ATPase, the formation of the enzyme-phosphate complex (EP) was investigated. The membrane bound intact 105 kD Ca(2+)-ATPase was converted by calpain to a fragment of approximately 50 kD.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of dual-head coincidence gamma camera FDG imaging with FDG PET in detection of breast cancer and axillary lymph node metastasis.

UNLABELLED: Dual-head coincidence gamma camera 18F-fluorodeoxyglucose (FDG) imaging was compared with FDG PET in the detection of breast cancer and axillary lymph node metastasis. METHODS: Both coincidence gamma camera FDG imaging and FDG PET were performed in a cylindrical phantom containing spheres of different sizes and activity ratios (5:1, 10:1 and 15:1) and in 30 women (age range 32-78 y) with suspected breast cancer. Biopsies or mastectomies were performed in all patients. Images were visually assessed, and the count ratio between tumor and normal tissue (T/N ratio) was calculated. RESULTS: In the phantom studies, coincidence gamma camera imaging visualized the smallest sphere (1.0 cm) at a ratio of 15:1 but not at ratios of 5:1 and 10:1. Coincidence gamma camera imaging visualized the other spheres (> or =1.3 cm) at all ratios. PET visualized all spheres at all ratios. In the clinical studies, 22 of 26 breast carcinomas detected by PET were also detected by coincidence gamma camera imaging.. Coincidence gamma camera imaging detected all of the carcinomas > or =2 cm in diameter (n = 10) and 12 of 16 carcinomas <2 cm. In breast carcinomas detected by both PET and coincidence gamma camera imaging, the T/N ratio in non-attenuation-corrected PET (7.12 +/- 7.13) was significantly higher than in coincidence gamma camera imaging (2.90 +/- 1.47, P < 0.005). Four of 8 axillary lymph node metastases detected by PET were detected by coincidence gamma camera imaging. Of 9 axillary lymph node metastases <1.0 cm in diameter, 7 and 3 were detected by PET and coincidence gamma camera imaging, respectively. CONCLUSION: Coincidence gamma camera imaging is useful in detecting breast carcinoma > or =2 cm in diameter but is not reliable for breast carcinoma <2 cm in diameter. Coincidence gamma camera imaging may be useless or even dangerous in the detection of axillary lymph node metastasis.

A prospective study on the prognostic significance of urokinase-type plasminogen activator levels in breast cancer tissue.

Urokinase-type plasminogen activator (u-PA), which cleaves plasminogen to yield plasmin, is a serine protease of fibrinolysis and is presumed to play a key role in extracellular proteolysis and facilitate the migration of cancer cells. This study was conducted prospectively to evaluate the prognostic significance of u-PA antigen level in breast cancer tissues. u-PA concentrations in the cytosol of 226 breast cancer tissues were determined prospectively by enzyme-linked immunosorbent assay using cytosol fractions prepared for steroid hormone assay. The median follow-up period of the patients was 60 months. Various prognostic factors were evaluated by univariate analysis or multivariate analysis using the Cox proportional-hazards method. Patients with primary breast cancer containing high levels of u-PA had a significantly shorter disease-free survival than patients with low levels of u-PA antigens. In multivariate analysis, a high level of u-PA was an independent risk factor for disease-free survival, being independent of age, axillary node status, and estrogen receptor status. Among the major prognostic factors, a high u-PA antigen level, lymph node involvement, and a positive estrogen receptor status were the most important for predicting relapse-free survival (P = 0.044, P < 0.0001, P = 0.0039). This first prospective study confirmed the prognostic significance of the u-PA antigen level in association with other major prognostic factors. The results of our present study suggest that u-PA in breast cancer tissue might be involved in breast cancer invasion and metastasis.

Purification and characterization of endogenous protein activator of human platelet proteasome.

An endogenous activator of 20S proteasome was purified from human platelets and its effect on three peptidase activities of proteasome was studied. This activator had a molecular weight of 170 kDa, and was composed of 32 kDa polypeptides as determined by SDS-PAGE. It was highly labile upon heat treatment (56 degrees C, 20 s) and proteinase (pronase CB) digestion. Suc-LLVY-MCA degrading activity of the platelet proteasome showed positive cooperativity between two or more catalytic sites because the coefficient was 1.54 when analyzed by use of the Hill plot. The endogenous activator increased Vmax and caused a loss of cooperativity. The plot of reaction velocity as a function of activator concentration yielded a saturation curve, implying the binding of the activator to proteasome. Boc-LTR-MCA degrading activity followed Michaelis-Menten kinetics. The activator enhanced the activity by increasing Vmax and decreasing Km. In contrast, CBz-LLE-2NA degrading activity could not be analyzed according to any kinetic scheme reported so far. The activator stimulated this activity at lower substrate concentrations (below 200 microM), while it inhibited the activity at higher substrate concentrations (400-800 microM). It is concluded from these findings that the endogenous protein activator may regulate the intracellular proteasome activity by functioning as a positive allosteric effector.

The long-term effect of eicosapentaenoic acid on serum levels of lipoprotein (a) and lipids in patients with vascular disease.

The effects of eicosapentaenoic acid (EPA) on serum lipoprotein (a) (Lp(a)) and other lipid levels in patients with vascular disease were examined. The serum levels of Lp(a), total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) and very-low-density lipoprotein (VLDL) were measured in 24 patients with vascular disease. An elevated serum Lp(a) level (39 +/- 22 mg/dl) was noted in 9 patients, elevated total cholesterol level (263 +/- 31 mg/dl) in 12 patients, elevated triglyceride level (240 +/- 98 mg/dl) in 10 patients and elevated LDL level (651 +/- 88 mg/dl) in 6 patients before administration of EPA. EPA (1,800 mg/day) was given to these patients for long periods ranging from 6 to 24 months. The serum levels of Lp(a), TC, TG and LDL were lowered significantly (p < 0.05) after EPA administration for 12 and 18 months, for 6, 12, 18 and 24 months, for 18 months and for 12 and 18 months, respectively. These findings indicated that long-term administration of EPA may lower Lp(a) and serum lipids, which is beneficial for patients with various arterial diseases in terms of preventing progression of the disease.

Purification and characterization of Ca2+-activated neutral protease inhibitor from human platelets.

An endogenous inhibitor of Ca2+-activated neutral protease (CANP) was purified to homogeneity from the soluble fraction of human platelets by the combination of heat treatment, ammonium sulfate fractionation, ion exchange chromatography and gel filtration. The purified inhibitor was found to be a tetramer composed of identical subunits and each subunit has a molecular weight of 63 K. The purified protein exerted specific inhibition against the low Ca2+-requiring form of CANP (mu-CANP) purified from human platelets in the presence of micromolar concentration of Ca2+. The kinetic study revealed that the inhibition is non-competitive with Ki value of 3.2 X 10(-8) M.

The effects of calpeptin (a calpain specific inhibitor) on agonist induced microparticle formation from the platelet plasma membrane.

Platelets activated by various agonists produce formation of vesicles shed from the plasma membrane (microparticles). However, the mechanism of microparticle (MP) formation has not been clarified yet. The aim of the present study was to determine the possibility of involvement of calpain (a Ca(2+)-dependent thiol protease) in MP formation. Washed platelets preincubated with calpeptin, a cell permeable calpain specific inhibitor, or with a vehicle were activated by thrombin plus collagen or by calcium ionophore A23187. Flow cytometry was used to detect the amount of microparticle formation by using murine monoclonal antibodies against GP IIb-IIIa or GP IIb and fluorescein 5-isothiocyanate labeled goat anti-mouse IgG. MP formation stimulated either by thrombin plus collagen or by A23187 was inhibited by calpeptin in a dose dependent manner. The microparticle formation from platelets activated by A23187 reached a plateau in approximately 5 min after activation, whereas that from platelets activated by thrombin plus collagen reached a plateau at 30 min following the stimulation. These time sequences corresponded well with those of degradation of actin-binding protein (ABP), a well known substrate of calpain, of platelets activated by these two stimulations. However, the inhibition of MP formation by calpeptin was more marked in the early stage (within 10 min) than in the late stage (after 30 min) of platelet activation. At 30 min after platelet activation by either two stimulations, a significant amount of microparticle formation was observed in the presence of 30 microM calpeptin, which inhibited hydrolysis of ABP almost completely. Our data suggest the involvement of calpain in the early stage (especially within 10 min) of microparticle formation.

Suppression by antithrombotic agents of pseudointimal hyperplasia of polytetrafluoroethylene graft implanted into venous system.

The lumen of the polytetrafluoroethylene graft (PTFE) implanted into a rabbit inferior vena cava (IVC) was markedly narrowed by 4 weeks after grafting. This was due to initial thrombosis on the luminal surface of the graft, which was followed by pseudointimal hyperplasia (PIH). To elucidate the role of the initial thrombosis in subsequent PIH, the effect of ticlopidine (T) and/or warfarin (W) on PIH was studied in an animal model. A PTFE tube graft was implanted into a rabbit IVC. Twenty eight rabbits were randomly assigned to the following experimental groups. Eight rabbits without antithrombotic agents were observed for 2 weeks (A, n = 4) and 4 weeks (B, n = 4) after grafting. T (100 mg/kg/day) and W (0.33 mg/kg/day) were orally administered for 4 weeks to group C (n = 4) and group D (n = 4), respectively. A combination of a half dose of T and W ((T + W)/2) was given for 2 weeks (E, n = 4) and 4 weeks (F, n = 4) after grafting. Four rabbits in group G received the combination of T and W for the first 2 weeks and were observed for an additional 2 weeks without medication. All the grafts were patent at time of harvest. The dry weight of the intraluminal deposit (DW) was determined as an indicator of PIH (A:35 +/- 1 mg/graft, B:40 +/- 8, C:22 +/- 3, D:22 +/- 3, E:14 +/- 2, F:15 +/- 3, G:23 +/- 2). Administration of T or W was equally effective in reducing DW and (T+W)/2 was more effective than a single agent.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood compatibility of venous prosthesis made of textile or non-textile material.

To study blood compatibility of venous prosthesis made of textile or non-textile material, the inferior vena cava of 37 rabbits was partly replaced by 3 mm internal diameter synthetic tube graft made of textile material (T: woven tetron) or non-textile material (P: polytetrafluoroethylene). At designated time intervals after the replacement (5 hours to 4 weeks), graft patency was examined and the dry weight of intraluminal deposits was measured. The harvested grafts were then subjected to light and scanning electron microscopy. All the T-grafts were occluded as early as 5 hours after grafting but when ticlopidine was administered prior to the grafting, all the grafts were patent. All the P-grafts were patent up to 4 weeks after grafting, though the amount of intraluminal deposits was increased in a time related manner, narrowing the lumen of the grafts. The luminal surface of the P-grafts harvested at 5 hours after grafting was covered by piles of fibrin networks entrapping erythrocytes without an association of platelet aggregates, which resembles the finding in the T-grafts harvested from the ticlopidine treated rabbits. In the P-grafts, both the proximal and distal luminal surfaces near the anastomosis were fully covered with endothelial cells by 2 weeks and the entire luminal surface was covered with these cells by 4 weeks. From these results, the following conclusions were obtained; (1) P-graft was superior to T-graft for venous prosthesis, which is mainly due to the inertness of P against platelet activation. (2) Though the luminal surface of the P-grafts was completely covered with endothelial cells by 4 weeks after grafting, the lumen was markedly narrowed by intimal hyperplasia.

Bedside monitoring of warfarin therapy by a whole blood capillary coagulation monitor.

A recently developed portable capillary coagulation monitor device allows rapid determination of prothrombin time (PT) in sec. and in International Normalized Ratio (INR) from a drop of whole blood. Considering a possible application of this device for monitoring of warfarin therapy at bedside or at outpatient clinic, a comparative study was performed in patients receiving warfarin between the whole blood capillary PT(WBC-PT) and conventional laboratory tests such as plasma PT (LAB-PT) and Thrombotest (TTO). There was an excellent positive correlation (r = 0.95, n = 49) between LAB-PT(sec) and WBC-PT(sec). As the correlation coefficient between WBC-PT(sec) and the reciprocal of LAB-PT(%) was excellent (r = 0.95, n = 49), it is feasible to convert WBC-PT(sec) to LAB-PT(%) by the following formula; y = 313.48x +8.29 (x:reciprocal value of LAB-PT(%), y:WBC-PT). As the correlation between WBC-PT(sec) and TTO(sec) was also excellent (r = 0.85, n = 63), TTO(%) may be likewise estimated by the following formula; y = 66.49x + 11.36 (x:reciprocal value of TTO(%), y:WBC-PT). From these observations it is concluded that the determination of WBC-PT is simple and accurate and that the monitoring of warfarin therapy is easily performed by the present method.

Activation of coagulation and fibrinolysis during surgery, analyzed by molecular markers.

Activation of hemostasis during surgery was investigated in 30 elective cases, who underwent either gastric (group G) or hepatic (group H) resection by a serial determination of various molecular markers such as fibrinopeptide A (FPA), fibrinopeptide B beta 15-42 (B beta 15-42) D-dimer, thrombin-antithrombin III complex (TAT) and plasmin-alpha 2 plasmin inhibitor complex (PIC). In both groups, the values of FPA and TAT were significantly elevated intraoperatively, indicating an occurrence of hypercoagulable state. The degree of the elevation was more marked in group H, probably due to greater tissue damage during hepatic resection. Also in both groups, the values B beta 15-42 and PIC were significantly increased during surgery, while the amount of D-dimer was within normal range in most cases, indicating the occurrence of the primary fibrinolysis. These findings are compatible with our previous observations on the postoperative changes in hemostasis. There were statistically significant but variable correlations between the values of fibrinopeptides and the enzyme-inhibitor complexes. The absolute values of the molecular markers of fibrinolysis were always higher than those of coagulation, suggesting that a considerable amount of plasmin, rather than thrombin, is released by surgical tissue damages.

Potential etiologic role of PAF in two major septic complications; disseminated intravascular coagulation and multiple organ failure.

A possible role of platelet-activating factor (PAF) in the occurrence of the two septic complications, i.e., disseminated intravascular coagulation (DIC) and multiple organ failure (MOF) was investigated, employing a rabbit model and a novel PAF antagonist E5880. By an instillation of fecal suspension into the common bile duct of the rabbit, manifestations of DIC and MOF were observed with high reproducibility by 9 hours after the septic insult. E5880 was intravenously administered to 12 rabbits for 1 hour after the septic insult at dose of 1 mg/kg (n = 6) or 3mg/kg (n = 6). All the rabbits were subjected to observation of vital signs and serial determination of laboratory tests for 9 hours and then lung, liver and kidney were removed for histological examination. Blood endotoxin level increased significantly by 9 hours after the septic insult. Although administration of E5880 did not affect the endotoxemia, the antagonist attenuated in a dose related manner laboratory manifestation of DIC such as thrombocytopenia and prolonged prothrombin time as well as that of MOF such as increase in serum bilirubin and creatinine level. The beneficial effect of E5880 on MOF was also confirmed by the histological evaluation. These observations indicated that PAF is deeply involved in the occurrence of DIC and MOF due to sepsis and E5880 may be one of the modalities to treat or prevent these two major septic complications.

Screening for primary hyperparathyroidism (PHPT) in clinic patients: differential diagnosis between PHPT and malignancy-associated hypercalcemia by routine blood tests.

Screening for primary hyperparathyroidism (PHPT) by measurement of the serum calcium concentration detects one patient per 500-1000 individuals in Western countries, and one patient per 2500-5000 subjects in Japan. Among clinic patients, however, the presence of many false-positive cases due to malignancy-associated hypercalcemia (MAH) reduces the benefit of such screening. We evaluated a new method of screening for PHPT based on the results of routine blood tests using the hospital information system (HIS) at our hospital. This new method could distinguish PHPT from MAH. This study included 25179 blood samples in which the serum calcium (Ca), albumin (Alb), chloride (Cl) and inorganic phosphate (IP) concentrations had been measured between March, 1994 and February, 1995 at Osaka University Medical Hospital. The HIS was programmed to pick blood samples that satisfied Formula 1 [Ca(mEq/ml) > 0.3 x Alb(g/dl) + 4.1] and Formula 2 ([Cl(mEq/ml)-84] x [10 x Alb-15]/[IP(mg/dl)/3.1] > 400). Of data from 25179 blood samples collected, those from 54 patients satisfied both Formulae 1 and 2. The patients from which these samples were derived from were subject to further analysis: medical records were studied and the intact-parathyroid hormone concentration was measured if necessary. Of these 54 cases, 19 patients (35.2%) were subsequently diagnosed with PHPT, including two, who were newly diagnosed with PHPT by this screening procedure. Although 35 (64.8%) of 54 patients were false-positive, many of them were treated with blood purification therapies in the Department of Pediatrics or the Intensive Care Unit (ICU). On the other hand, there were four false-positive cases (7.4%) caused by MAH. False-negative case in this study was only one patient (5%), whose diagnosis was normocalcemic PHPT. When omitting samples from pediatric patients and those in ICU, this screening procedure for PHPT has the advantage of being able to differentiate this diagnosis from MAH.

Measurement of the expression of oncofetal fibronectin mRNA in thyroid carcinomas by competitive reverse transcription-polymerase chain reaction.

Abundant expression of oncofetal fibronectin mRNA has been observed in thyroid papillary and anaplastic carcinomas. In this study, we measured relative expression levels of oncofetal fibronectin mRNA in thyroid cancer tissues by competitive reverse transcription polymerase chain reaction (RT-PCR) using thyroglobulin mRNA as an internal control. By this method, all papillary and anaplastic carcinomas and 3 of 6 follicular carcinomas were distinguished from benign tissues, such as normal thyroid tissues, follicular adenomas, and adenomatous goiters. Furthermore, 2 anaplastic carcinomas were clearly distinguished from differentiated carcinomas. These results suggest the possibility of establishing a more accurate preoperative or postoperative diagnosis of papillary and anaplastic carcinomas by measuring the relative expression level of oncofetal fibronectin to thyroglobulin in thyroid tumors.

The expression of urokinase type plasminogen activator is a novel prognostic factor in dukes B and C colorectal cancer.

Urokinase type plasminogen activator (u-PA) secreted by cancer cells is considered to play a key role in promoting invasion and metastasis of cancer cells. This study was designed to evaluate the expression and prognostic value of u-PA in Dukes B and C colorectal cancer. u-PA expression was investigated in 57 Dukes B or C colorectal cancers using a monoclonal antibody against u-PA. u-PA expression was mainly observed on the cytoplasm of cancer cells, and was associated with relapse, especially hematogenous metastasis (p=0.025, the chi2 test). Patients with high u-PA expression had a lower rate of DFS (9/22 events) compared to those with low u-PA expression (6/35 events) (p=0.061, log-rank test). This study demonstrated that u-PA expression might be a novel prognostic factor in Dukes B and C colorectal cancer.

A new method of purification and sensitive bioassay of platelet-activating factor (PAF) in human whole blood.

There is no satisfactory assay procedure of PAF in human whole blood in terms of sensitivity, reproducibility and simplicity. This is due to coexisting lipids from plasma and cellular membranes which inhibit measurement of PAF in various assay procedures, including bioassay. In the present study, an attempt was made to eliminate these interfering lipid inhibitors from blood samples. Lipids in human whole blood were extracted according to the method of Bligh & Dyer and the organic layer was dried under a stream of nitrogen. Then, the dried organic layer was dissolved in diethyl-ether and the solution was kept at -20 degrees C which was then centrifuged. The resulting supernatant was then applied to an anion-exchange column and the PAF fraction was obtained by step-wise gradient elution. The fraction was further purified by normal phase HPLC. Then PAF in the final sample was determined by sensitive bioassay using rabbit platelets containing fibrinogen and epinephrine. The recovery rate of PAF throughout this procedure was constant and satisfactory (37.4 +/- 9.7%), which was confirmed using [3H]-PAF. The lower limit of the present assay was estimated to be 5pg in 1 ml of blood and it was sensitive enough to detect PAF in blood samples from healthy volunteers and patients with sepsis or liver cirrhosis. Furthermore, attempts were made to compare the sensitivity and the recovery of our method with these of a commercially available radioimmunoassay (RIA) kit for PAF. However, it was not possible to detect any amount of authentic PAF added to whole blood.

Mechanism of growth inhibition by calpain inhibitor in MCF-7 cells.

BACKGROUND: A calpain inhibitor, calpeptin, inhibited the cell growth of ER (estrogen receptor) positive breast cancer cells, such as MCF-7, T-47D, and ZR-75-1 in the presence of E2. The mechanism of this inhibition has not been clarified yet. MATERIALS AND METHODS: MCF-7 cells were employed to investigate the mechanism of the inhibition. We studied the effect of calpeptin on the secretion of insulin-like growth factor-I (IGF-I) and transforming growth factor (TGF-alpha). RESULTS: The secretion of IGF-I or TGF-alpha was not changed by calpeptin either in the presence or absence of E2. Moreover, the binding of IGF-I or TGF-alpha to MCF-7 cells augmented by the addition of E2 was not affected by calpeptin. CONCLUSIONS: These results indicated that the inhibition of cell growth in MCF-7 by calpeptin was not due to the modulation of autocrine growth factors and their receptors.

Thrombomodulin is a new biological and prognostic marker for breast cancer: an immunohistochemical study.

BACKGROUND: Thrombomodulin (TM) is a natural anticoagulant which inhibits thrombin. Recent studies have reported that TM is correlated with vascular diseases and a few cancers. The aim of this study was to evaluate the role and the prognostic value of TM in breast cancer. PATIENTS AND METHODS: TM expression in samples from 60 invasive breast cancer patients was examined immunohistochemically with a polyclonal antibody against TM. RESULTS: TM staining was observed mainly on both the cytoplasm and cell surface in cancer cells and on endothelial cells around or in cancer tissue. TM expression in cancer cells was not correlated with the clinicopathological features. However, low TM expression was significantly correlated with a high relapse rate (p = 0.047 by the chi 2 test and 0.05 by the Kaplan-Meier method). CONCLUSIONS: TM might play an active role in cancer invasion and metastasis, and serve as a new prognostic factor in invasive breast cancer.

Urokinase type plasminogen activator receptor is a novel prognostic factor in breast cancer.

BACKGROUND: There have been many reports that the u-PA system plays an important role in cancer invasion and metastasis. The binding of u-PA to its specific cell-surface receptor, u-PAR, is necessary for the activation of u-PA system. The aim of this study is to evaluate the role and the prognostic value of u-PAR in cancer invasion and metastasis. PATIENTS AND METHODS: u-PAR expression in 104 breast cancers was investigated immunohistochemically using a monoclonal antibody against u-PAR. RESULTS: u-PAR expression was mainly observed both on cancer cells and stromal cells. Patients with high u-PAR expression in cancer cells or stromal cells had a high relapse rate compared with patients with low u-PAR expression by the Kaplan-Meier method (p = 0.035 and 0.011, respectively). In uni- and multivariate analysis, u-PAR expression in stromal cells was significantly correlated with relapse (p = 0.017 and 0.043, respectively). CONCLUSIONS: This study has shown that not only cancer cells but also stromal cells have an important roles in breast cancer invasion and metastasis, and that u-PAR expression in cancer cells and stromal cells might be a novel prognostic factor in breast cancer.