Cathepsin B Expression Research Articles

Cathepsin B protein levels in endometrial cancer: Potential value as a tumour biomarker

Objective Lysosomal cysteine protease Cathepsin-B has been implicated in the progression of various human tumours. We examined Cathepsin-B protein levels in endometrial carcinoma patients–mainly post-menopausal–and investigated their possible association with clinical and pathological parameters in order to assess Cathepsin-B's significance as a potential tumour biomarker. Methods The indirect immunoperoxidase method was used for Cathepsin-B immunohistochemical staining of 64 paraffin-embedded endometrial tumour tissues, having follow-up period of 18–240 months. Steroid hormone receptors were measured as well. Tissue samples were staged following the FIGO criteria. Results Positive Cathepsin-B immunostaining was observed in 27 patients (42.2%) and was significantly associated with the FIGO stage of the disease ( p = 0.006), as well as cervical and stromal invasion ( p = 0.001 and p = 0.037, respectively) and progesterone receptor status ( p = 0.027). Positive Cathepsin-B expression was also inversely related to Disease-free Survival ( p = 0.034) and Overall Survival ( p = 0.035) in univariate analysis, as well as in multivariate analysis ( p = 0.022 and p = 0.035, respectively). Conclusion Increased Cathepsin-B expression was found to be predictive of more aggressive tumour behaviour over time and can be regarded as an unfavourable and independent tumour marker for endometrial cancer patients with a long follow-up.

Cathepsin B is a target of Hedgehog signaling in pancreatic cancer

This study investigated the influence of cathepsin B (CATB), a downstream target of Hedgehog (Hh) signaling, in pancreatic cancer. Cyclopamine (Hh signal inhibitor) suppressed expression of Shh, as well as Hh-induced transcription factor Gli1, and induced apoptosis in Shh-positive pancreatic cancer cell line (PANC-1). Microarray analysis revealed CATB as a gene downregulated by Hh. Cyclopamine reduced CATB protein and mRNA levels. Cyclopamine or CATB inhibitor reduced PANC-1 cell invasiveness ( P < 0.05). CATB expression in human pancreatic cancer tissues tended to correlate with Shh expression ( P = 0.053). Conclusively, Hh targets CATB and Hh signaling through CATB might influence pancreatic cancer cell invasiveness.

Cathepsin B is involved in the apoptosis intrinsic pathway induced by Bacillus Calmette-Guérin in transitional cancer cell lines

Bacillus Calmette-Guérin (BCG) is the most effective treatment for superficial and in situ transitional bladder cancer. Although the complete mechanisms for its effect are not fully understood yet, both immunological and direct effects on tumor cells have been proposed. It has been proposed that apoptotic tumor cells could be better inducers of immunity than necrotic ones. Thus, apoptosis of bladder cancer cells could contribute to a global response to BCG. Lysosomal hydrolase cathepsin B (CB) is involved in the apoptotic process and has a key role in breast cancer cell programmed death through the activation of a pro-apoptotic protein BID. Truncated BID participates in the mitochondrial apoptotic pathway that involves the activation of pro-caspase 9. The possibility that CB can be involved in apoptosis of TCC line has not been explored yet. Therefore, we analyzed the participation of CB in BCG-induced apoptosis of human and murine TCC lines. Apoptosis was evaluated by a morphologic assay and CB activity by a substrate-specific colorimetric method. Expression of CB, BID and pro-caspase 9 was determined by Western blotting. BCG induced apoptosis of murine (MBT2, MB49) and human (T24) TCC lines. An increase in both CB activity and protein was also observed. The apoptosis of T24 and MB49 cell lines was mediated by activation of pro-caspase 9 and BID, both proteins are involved in mitochondrial apoptosis. Apoptosis and activation of pro-caspase 9 and BID were inhibited by CA-074Me (CA), a cell permeable CB inhibitor. Thus, CB is involved in BCG-induced apoptosis of TCC lines, using at least in part the mitochondrial pathway.

Differential Expression of Cathepsins and Cystatin C in Ovine Uteroplacental Tissues

Cathepsins (CTSs) are peptidases that have biological roles in degrading extracellular matrix, catabolism of intracellular proteins, and processing of pro-hormones. Cystatin C (CST3) is a secreted inhibitor of lysosomal cysteine proteases cathepsin B (CTSB) and CTSL. Our working hypothesis is that cathepsins and cystatins play important roles in implantation and placentation in sheep. Expression of CTSB, CTSD, CTSH, CTSK, CTSL, CTSS, CTSZ, and CST3 mRNAs was detected in ovine uteroplacental tissues with distinct temporal and/or spatial expression patterns between Days 40 and 120 of pregnancy. Of particular note, CTSB, CTSD, and CTSZ mRNAs were predominantly detected in the chorion of the placenta and were more abundant in the placentomes than the intercaruncular endometria. CTSL and CST3 mRNAs were abundant in the endometrial epithelia and chorion, whereas CTSK, CTSS and CTSH mRNAs were most abundant in the stratum compactum stroma of the intercaruncular endometrium. Consistent with localisation of mRNAs, immunoreactive CTSL and CST3 proteins were mainly observed in the intercaruncular endometrial glands and intercotyledonary placenta during later pregnancy. These results support the working hypothesis that CTS and CST3 in uteroplacental tissues are involved in endometrial remodelling and placentation in sheep.

Tumor Cell–Derived and Macrophage-Derived Cathepsin B Promotes Progression and Lung Metastasis of Mammary Cancer

Proteolysis in close vicinity of tumor cells is a hallmark of cancer invasion and metastasis. We show here that mouse mammary tumor virus-polyoma middle T antigen (PyMT) transgenic mice deficient for the cysteine protease cathepsin B (CTSB) exhibited a significantly delayed onset and reduced growth rate of mammary cancers compared with wild-type PyMT mice. Lung metastasis volumes were significantly reduced in PyMT;ctsb(+/-), an effect that was not further enhanced in PyMT;ctsb(-/-) mice. Furthermore, lung colonization studies of PyMT cells with different CTSB genotypes injected into congenic wild-type mice and in vitro Matrigel invasion assays confirmed a specific role for tumor-derived CTSB in invasion and metastasis. Interestingly, cell surface labeling of cysteine cathepsins by the active site probe DCG-04 detected up-regulation of cathepsin X on PyMT;ctsb(-/-) cells. Treatment of cells with a neutralizing anti-cathepsin X antibody significantly reduced Matrigel invasion of PyMT;ctsb(-/-) cells but did not affect invasion of PyMT;ctsb(+/+) or PyMT;ctsb(+/-) cells, indicating a compensatory function of cathepsin X in CTSB-deficient tumor cells. Finally, an adoptive transfer model, in which ctsb(+/+), ctsb(+/-), and ctsb(-/-) recipient mice were challenged with PyMT;ctsb(+/+) cells, was used to address the role of stroma-derived CTSB in lung metastasis formation. Notably, ctsb(-/-) mice showed reduced number and volume of lung colonies, and infiltrating macrophages showed a strongly up-regulated expression of CTSB within metastatic cell populations. These results indicate that both cancer cell-derived and stroma cell-derived (i.e., macrophages) CTSB plays an important role in tumor progression and metastasis.

Ecstasy‐induced Apoptosis and Lysosomal Protease Alterations in Differentiated PC12 Cells

Ecstasy (MDMA), has been shown to cause oxidative stress-induced apoptosis. MDMA induces apoptosis via the caspase. However, the role of cystatin C (CC), cathepsin B (CB) and cathepsin D (CD) has not been investigated. The objective of this study is to characterize alterations in CB, CD and CC following MDMA exposure. Cell viability with differentiated PC12 cells exposed to MDMA. Immunocytochemistry, western blotting analysis and TUNEL staining were performed to confirm apoptosis and the presence of CC, CB and CD. MDMA reduced cell viability in a dose and time dependent manner. Positive TUNEL staining confirmed apoptosis and immunocytochemical analysis demonstrated the presence of CC-immuno-like reactivity (IR), CB-IR, and CD-IR in PC12 cells treated with MDMA. Additionally, enzyme analysis indicated alterations in CC, CB and CD activity and expression, respectively, verses the untreated control. Following 3.5mM MDMA exposure at 24 and 48 h, CB activity decreased significantly (64.79%, p<0.001) and (53.13% p<0.001)respectively compared to untreated control. Papain was used to access CC activity. Papain activity decreased significantly at 24 and 48 h (18.33%, p<0.001) and 34.35%, p<0.001) respectively with 3.5mM MDMA, compared to untreated control. Alterations in these proteases may suggest involvement of CC, CB and CD in an MDMA-induced apoptotic pathway. Research supported by NIH/NIGMS/MBRS S06GM08111 and RCMI/NIH RR03020

ALTERATIONS IN P53 AND CATHEPSIN D FOLLOWING HYDROGEN PEROXIDE EXPOSURE IN PC12 CELLS

BACKGROUND Oxidative stress induced-apoptosis increases the expression of certain transcriptional factors and protein expression in the cell. Specifically, P53, which is a DNA transcriptional factor, plays an important role in the regulation of apoptosis (programmed cell death) and increases in expression following oxidative stress. Cathepsin D (CD), and Cathepsin B (CB), which are lysosomal proteases, are also associated with apoptosis as seen in the expression change during oxidative stress induced-apoptosis. Interestingly, P53 is a transcriptional factor for CD and is believed that CB regulates p53. PURPOSE In this study our objective is to look at the regulation of CD by p53 and CB. METHODS In each experiment PC12 cells were treated with 100ìM H2O2 for 30min, 4hrs, 12hrs, and 24hrs. Pifithrin, (p53 inhibitor) and Papstatin A (Cathepsin D inhibitor) were also used to determine the role of P53 and CD following H2O2. Cell viability was measured by MTS. Apoptosis was determined using TUNEL staining. CD, CB, and p53 expression was quantified using western blot analysis. RESULTS H2O2 caused a decrease in cell viability in a concentration dependent manner. Western Blot analysis showed the temporal expression of phospho-P53 and CD following exposure to 100ìM of H2O2. Interestingly, an increase in cell viability and a reduction in CD expression was observed following exposure to H2O2 along with P53 inhibition. CONCLUSION These results suggest P53 and CD may be involved in a common pathway of cell death following H2O2 exposure. Research supported by NIH/NIGMS/MBRS S06GM08111 and RCMI/NIH RR03020

Cathepsin B mediates TRAIL-induced apoptosis in oral cancer cells

The death ligand TRAIL (tumor necrosis factor-related apoptosis inducing ligand) triggers apoptosis in a variety of cancer cells, which implies the potential for therapeutic applications. The purpose of this study was to investigate the role of the lysosomal protease cathepsin B (CB) in mediating TRAIL-induced cell death in oral squamous cell carcinoma (OSCC) cells. OSCC cell lines from primary tumor and lymph node metastasis were examined for expression of apoptosis markers by Western blots, enzyme activity assays, nuclear fragmentation assays, and FACS analysis. Gene-specific ribozymes or chemical inhibitors were used to inhibit CB or caspases in target cells. TRAIL-induced activation of caspase-3, cleavage of Bid and poly-ADP-ribose polymerase, release of cytochrome c, and DNA fragmentation were blocked either by a pan-caspase inhibitor (zVAD-fmk) or a CB inhibitor (CA074Me), consistent with the involvement of TRAIL as well as CB in cell death. The primary tumor cells were more susceptible to apoptosis than their corresponding lymph node metastatic cells. Stable transfection of a ribozyme which inhibited CB expression also decreased the apoptotic process. We conclude that TRAIL-induced apoptotic cell death in OSCC cells is mediated through CB or through caspase activation. Our data point to a new tumor-suppressive role for CB in OSCC which is opposed to the invasion- and metastasis-promoting functions of lysosomal proteases.

Optical Imaging of Spontaneous Breast Tumors Using Protease Sensing ‘Smart’ Optical Probes

The objective of this study was to determine if spontaneous breast cancer lesions can be detected by fluorescence reflectance imaging (FRI) and fluorescence mediated tomography (FMT) using protease-sensing optical probes. Transgenic (FVB/N-TgN (WapHRAS)69Lin Y)) mice, which spontaneously develop breast cancer, were injected intravenously with a cathepsin-sensing fluorescent imaging probe. FRI and FMT were performed 24 hours after probe injection and region of interest (ROI) analysis was performed. Magnetic resonance images were acquired for anatomic coregistration with the FMT data. Moreover, correlative immunohistochemistry and fluorescence microscopy were performed. All tumor nodules were clearly delineated by FRI showing an average signal intensity of 380 +/- 106 AU. Similarly, tumors were clearly detected by FMT imaging. Immunohistochemistry confirmed cathepsin-B expression of primary tumors and fluorescence microscopy revealed a strong Cy 5.5 deposition in the tissue. FRI and FMT using "smart" protease sensing probes permits detection of experimental spontaneous breast cancers. Because the expression levels of various proteases correlate with patient outcome, this technique may not only help to detect, but also to differentiate breast cancers noninvasively.

Prognostic impact of cysteine proteases cathepsin B and cathepsin L in pancreatic adenocarcinoma.

The cysteine proteases cathepsin B (CTSB) and L (CTSL) have been implicated in tumor spread and metastatic formation. In pancreatic adenocarcinoma, the role of these proteases is not very well defined. To find out which cell types produce CTSB and CTSL and to evaluate the prognostic impact of these proteases, 70 specimens from curatively resected patients with pancreatic adenocarcinoma were examined by in situ hybridization and immunohisto-chemistry. Seventy patients with ductal adenocarcinoma of the pancreas were studied after R0 resection with a follow-up of at least 3 years. CTSB and CTSL expression was performed immunohisto-chemically using polyclonal anti-CTSB and CTSL antibodies. To detect cell types involved in producing CTSB and CTSL as well as the intracellular localization of specific mRNA sequences, nonisotopic in situ hybridization was performed. The correlations among CTSB and CTSL expression, clinicopathologic parameters, and clinical outcome were analyzed. The immunoreactivity was 96% for CTSB and 90% for CTSL. Positive mRNA signals were obtained in the cytoplasm tumor cells, macrophages, and fibroblasts in 77% for CTSB and 81% for CTSL, respectively. Statistical analysis showed a significant correlation between CTSB/CTSL expression and tumor grading (P < 0.05) and between CTSB and lymphatic invasion (P = 0.05). Kaplan-Meier analyses revealed statistical significance for CTSB/CTSL expression with the survival after curative resection (P < 0.05). Both proteases are strong prognostic markers in multivariate analysis (P = 0.0001) beside UICC stage, nodal status, tumor size, and grading (P < 0.05). Furthermore, CTSB expression is an independent prognostic marker for cancer recurrence within 6 months after curative surgery in multivariate analysis (P = 0.0001). CTSB and CTSL are strong and independent prognostic markers in resectable pancreatic adenocarcinoma rather than UICC stage, TNM classification, or tumor grading. Furthermore, CTSB is a predictor for early recurrence after curative resection. These data underline the significance of tumor-associated proteolysis for cancer invasion and metastasis and may lead to defining subgroups of patients with early recurrence and poor outcome.

High expression of cathepsin B in transitional bladder carcinoma correlates with tumor invasion.

Cathepsin B (CB) is a lysosomal cysteine proteinase synthesized as a zymogen of 39-47 kilodaltons (kD), which is subsequently converted into an active single- chain form of 33 kD (CB33) and, by additional processing, into the active 2-chain form containing a heavy chain of 27-29 kD (CB(27-29)) and a light chain of 4-6 kD. Increased or altered CB expression has been documented in a variety of tumor cells, but to the authors' knowledge only one study published to date has reported clinicopathologic significance for CB in transitional cell carcinoma (TCC) of the bladder. In this work, CB expression was determined by Western blot analysis in TCC bladder tissue from 30 patients. Nontumor bladder tissue was also analyzed for CB expression. The study results demonstrate higher expression of CB in TCC invasive tumors than in superficial bladder carcinoma. Furthermore, whereas normal bladder only expressed the 29-kD CB protein, tumor and peritumoral tissue demonstrated the 27- to 29-kD CB form. Immunohistochemical staining did not evidence changes in CB localization between tumor and nontumor tissue. According to the results of the current study, bladder tumor progression appears to be associated with quantitative changes in CB protein expression, as well as with qualitative changes related to the type of CB expressed.

Cathepsin B expression and its relationship with microvessel density and biological behaviour of colorectal carcinoma

Objective: To investigate cathepsin B(CB) expression in colorectal carcinoma and its relationship with microvessel density (MVD) and biological behavior. Methods: CB and MVD were detected by immunohistochemistry in 47 cases of colorectal carcinoma. Results: The expression of CB in mucinous colorectal carcinoma was significantly higher than that in no-mucinous colorectal carcinoma. There was significant difference (P<0.05). The MVD in group with positive CB was stronger than that in group with negative CB. There was also significant difference (P<0.05). Conclusion: The results suggest that CB expression has correlation with MVD, invasion and metastasis in colorectal carcinoma, especially in mucinous colorectal carcinoma.

Angiogenesis and cathepsin expression are prognostic factors in pancreatic adenocarcinoma after curative resection.

Curative resection of pancreatic adenocarcinoma is the only clinical parameter related to a favorable prognosis while other clinicopathological parameters fail. To evaluate whether angiogenesis, vascular endothelial growth factor (VEGF) or certain tumor proteases, e.g., cathepsin B (CTSB) and L (CTSL), are factors of prognostic relevance, we investigated their expression in patients with long- and short-term survival after curative resection (RO) because of pancreatic adenocarcinoma. Twenty-nine tissue samples from patients with adenocarcinoma of the pancreas were examined. The patients were selected in a long-term survival group with a survival > or = 24 mo (n = 18) and a shortterm survival group of patients, who died within 8 mo after surgery because of their malignancy (n = 11). The microvessel quantification was performed immunohistochemically using a monoclonal anti-CD34 antibody. VEGF, CTSB, and CTSL expressions was studied using polyclonal antibodies (PAbs). The median microvessel density (MVD) was 75 (range 39-182). MVD correlated significantly with the survival time after surgery (p = 0.0132) but not with clinicopathological parameters. In cancer cells, VEGF was positive in 82.8% and showed significant correlation with the MVD (p = 0.0002) and survival time (p = 0.0395). Positive immunoreactivity could be obtained for 96.5% for CTSB and 84.2% for CTSL. Expression of both proteases correlated significantly with the survival time after surgery (CTSB p = 0.0002, CTSL p = 0.0001). Furthermore, CTSB expression correlated with invasion of the perineural space. Thus, a short postoperative survival correlated with a high MVD, and highly expressed VEGF, CTSB, and CTSL. No significant correlation between MVD, VEGF, as well as CTSL and clinicopathological parameters was found. For routinely assessed markers (e.g., TNM-stage, UICC-stage, and so on) no significant correlation with survival time was found in this small group of patients. These findings indicate that the MVD, VEGF, CTSB, and CTSL are prognostic factors after curative resection, whereas other parameters (TNM, UICC, and so on) failed to show prognostic relevance in our group of patients. Furthermore, the correlation between MVD and VEGF underlines the importance of this growth factor for angiogenesis and tumor growth. The correlation between CTSB and perineural invasion demonstrates the involvement of cathepsins in local tumor invasion.

Prognostic impact of Cathepsin B and matrix metalloproteinase-9 in pulmonary adenocarcinomas by immunohistochemical study

The expression of Cathepsin B (CB) and matrix metalloproteinase-9 (MMP-9) in extirpated tissues of adenocarcinomas in non-small cell lung cancer from 90 cases was investigated immunohistologically, and the correlations between the extent of the expression and the clinicopathological features were assessed for investigaiting the process of tumor metastasis. It is important to reveal the mechanisms of destruction of the basal membrane and infiltration of tumor cells at the primary lesion. Sections were obtained from 10%-formalin-fixed and paraffin-embedded tissues. They were reacted with an anti-human CB polyclonal antibody or an anti-human MMP-9 polyclonal antibody. Of 90 patients, 58 (64.4%) and 39 (48.3) cases were found to be positive for CB and MMP-9 expression, respectively. A significantly higher extent of the CB expression was observed in the tissues of patients who showed postoperative recurrence of the tumor ( P=0.013). Especially, a similar observation was obtained among early cases of T1N0 ( P=0.023). In contrast, no such tendency was demonstrated in the expression profile of MMP-9. Furthermore, the enzyme expressions were compared among different types of metastases. Patients with higher extents of CB expression tended to show significantly higher rates of hematogenous and intrapulmonary metastases ( P=0.023 and P=0.010, respectively). However, there was no significant correlation between MMP-9 expression and the prognostic factor of the patients. Therefore, we suggested that evaluation of CB expression in the tumor tissue might be useful as a postoperative prognostic factor of pulmonary adenocarcinoma. Especially, early cancer of T1N0 cases showing higher expression of CB may need postoperative adjuvant chemotherapy.

Cathepsin B activity and protein levels in thyroid carcinoma, Graves' disease, and multinodular goiters.

Cathepsin B (CB) is involved in the hydrolysis of thyroglobulin (Tg) and thought to be regulated by thyroid stimulating hormone (TSH) in the normal thyroid. Our analyses of 91 thyroid tissues from 71 patients with Graves' disease (GD), multinodular goiter (MNG), papillary carcinoma (PC), or follicular carcinoma (FC), demonstrated a 2-fold increase in expression of CB in GD and an average increase of 1.5-fold in MNG (varying from 10-fold below normal to 6-fold above normal in MNG nodules), as might be predicted by the altered functional status of thyroid follicular cells in those diseases. However, CB activity was not downregulated in conjunction with the known "blocking effect" of malignancy on many thyroid functions, but rather increased on average 9-fold in papillary carcinomas (n = 33), and also showed a marked increase in 2 follicular carcinomas. Activity measurements were confirmed by CB protein detection on Western blot with moderately increased CB protein levels demonstrated in GD, variable expression in nodules of MNG, and markedly increased protein expression in carcinomas. In all diseased states, increased protein was detected primarily as overexpression of the 27 kd heavy chain of 2-chain mature CB and less frequently as overexpression of 31 kd single-chain mature CB. However, an additional 35 kd protein form was noted in 3 of 9 PCs, 1 of 2 FCs, and 1 of 4 GD cases but in none of 10 MNG cases. In conjunction with elevated CB activity plus additional protein bands on Western blots, altered patterns of CB immunohistochemical staining were observed, irrespective of the type of thyroid disease, suggesting certain common changes in CB expression, posttranslational processing, and vesicular trafficking. In summary, GD and MNG thyroid tissues demonstrated altered CB expression in keeping with predicted functional changes in thyroid follicular cells, while increased CB expression in carcinomas indicated a more pathological role for CB in thyroid cancers, possibly related to the processes of invasion or metastasis.

High levels of cathepsin B predict poor outcome in patients with breast cancer.

Cathepsin B (CB) is a thiol-stimulated protease implicated in cancer invasion and metastasis. Other proteases involved in cancer spread such as urokinase-type plasminogen activator (uPA) and cathepsin D have previously been shown to be prognostic markers in breast cancer. CB was assayed by ELISA in 193 patients with primary breast cancer. CB levels were significantly higher in both primary and metastatic breast tumors than in fibroadenomas (p = 0.0001). In the primary carcinomas, CB levels showed no significant correlation with either nodal status, tumor size or estrogen receptor (ER) status. Patients with primary breast cancers containing high levels of CB had a significantly shorter disease-free interval (p = 0.01, chi-square = 6.61) and overall survival (p = 0.014, chi-square = 6.08) than patients with low levels of the protease. However, in multivariate analysis, using nodal status, tumor size, ER status and urokinase plasminogen activator (uPA), CB was not an independent prognostic marker. In contrast, nodal status, ER status and uPA were prognostic in multivariate analysis. In conclusion, CB, like certain other proteases implicated in cancer metastasis, correlates with poor outcome in patients with breast cancer. These results thus support the evidence from model systems linking CB to cancer spread. Inhibition of CB expression or activity might therefore be exploited for anti-metastatic therapies.

Extracellular matrix modulates mesangial cell apoptosis and mRNA expression of cathepsin-B and tissue transglutaminase.

Mesangial matrix is a dynamic structure which modulates mesangial cell function. Since accumulation of matrix precedes the development of focal glomerulosclerosis, we studied the effect of different matrices on mesangial cell (MC) apoptosis. Suspended mesangial cells became apoptotic in a time dependent manner. Collagen type III did not modulate MC apoptosis when compared to cells grown on plastic. MCs grown on Matrigel, collagen type I and IV showed an increased number of apoptotic cells when compared to MCs grown on plastic. DNA end-labeling further confirmed these observations. MCs grown on Matrigel showed enhanced (P < 0.05) mRNA expression for tissue transglutaminase (TTG) and cathepsin-B. Mesangial cells grown on Matrigel also showed enhanced expression of superoxide dismutase (SOD). We conclude that mesangial cells require attachment to the matrix for their survival and alteration of the quality of matrix modulates mesangial cell apoptosis.

Morphine induces splenocyte apoptosis and enhanced mRNA expression of cathepsin-B.

Morphine has been demonstrated to modulate immune function. We studied whether morphine modulates apoptosis of splenocytes. Splenocytes were isolated from control and morphine treated rats. Splenocytes isolated from morphine treated rats showed increased percentage (P < 0.001) of apoptosis when compared to splenocytes isolated from untreated rats (control, 4.7 +/- 1.0% apoptotic splenocytes/field vs. morphine, 47.8 +/- 3.4% apoptotic splenocytes/field). These results were further confirmed by gel electrophoresis as well as by end-labeling DNA of splenocytes isolated from control and morphine treated rats. Splenocytes from morphine treated rats showed a classical ladder pattern with integer multiples of 180 base pairs. Splenocytes from morphine treated rats also showed increased mRNA expression of cathepsin-B, a gene associated with active cell death. These results suggest that morphine may also be modulating immune function by enhancing apoptosis of splenocytes.

Relationship between morphological diversity and AgNORs or cathepsin B expression in colorectal cancers.

The biological characteristics associated with the morphological diversity of colorectal cancers were investigated to elucidate the causes of this diversity. We examined the proliferative and infiltrating activity of tumor cells, indicated by the mean number of Ag nucleolar organizer region associated proteins (NORs) per nucleus (MNA) and the immunohistochemical response to cathepsin B(CB), in various morphological types of early and advanced colorectal cancers. We examined 73 colorectal cancers obtained by endoscopic and surgical resection. MNA values for sessile and flat-elevated cancers were greater than the values for pedunculate, subpedunculate, and flat-or-depressed early cancers (sessile, P < 0.05). In advanced cancers invading the muscularis propria, protruding cancers showed significantly higher MNA values than small ulcerative cancers (P < 0.01). CB expression increased significantly with the progression of colorectal cancers (P < 0.01), but was not related to morphological diversity in early and advanced cancers. In both sessile and flat cancers, CB expression was higher in moderately differentiated than in well differentiated adenocarcinomas. These results indicate that, in colorectal cancers, protruding early cancers without stalks and protruding advanced cancers have higher proliferative activity than pedunculate or flat early cancers and small ulcerative advanced cancers, respectively, and that CB expression is not associated with morphological diversity, but with depth of invasion and histological differentiation.

Fasciola hepatica:Irradiation-Induced Alterations in Carbohydrate and Cathepsin-B Protease Expression in Newly Excysted Juvenile Liver Fluke

Creaney, J., Wilson, L., Dosen, M., Sandeman, R. M., Spithill, T. W., and Parsons, J. C. 1996.Fasciola hepatica:Irradiation-induced alterations in carbohydrate and cathepsin-B protease expression in newly excysted juvenile liver fluke.Experimental Parasitology83,202–215. Irradiation has been successful in the attenuation of infective stage parasites for use as vaccines against a number of parasites includingFasciolaspp. The mechanisms of action of irradiation-attenuated vaccines, however, are not clearly understood. In this study, we examined the effect of 3, 10, and 40 krad of γ-irradiation on the expression of carbohydrates and cathepsin-B by newly excysted juvenileFasciola hepatica(NEJ). Following irradiation of metacercariae, the expression of concanavalin A (ConA)-specific sugars was decreased on the surface of NEJ and the expression of wheat germ agglutinin (WGA)-specific sugars was increased in the gut and reduced on the surface of NEJ. Cathepsin proteases are a major component of liver fluke excretory/secretory material (ES) and can cleave host immunoglobulin (Ig). Cathepsin-B protease was localized in nonirradiated NEJ to the gut lumen and to secretory granules within the gut epithelia. Irradiation of fluke with 3, 10, and 40 krad of γ-rays significantly reduced the tissue expression of cathepsin-B at 8 hr postirradiation in an apparently dose-dependent manner. After a further 24 hr culture tissue expression of cathepsin-B was significantly reduced in 10- and 40-krad-irradiated NEJ. Protease activity of ES samples collected over a 24-hr period from irradiated and nonirradiated NEJ culturedin vitrowere tested using a rabbit Ig cleavage assay. The proteolytic activity of ES from 10- and 40-krad-irradiated NEJ was reduced during the initial 6 hr in culture and between 12 and 24 hr when compared to ES from nonirradiated controls. Biosynthetic labeling experiments using [35S]methionine and [35S]cysteine indicated that ES material was actively synthesised during 48 hrin vitroculture. Therefore, from this study, we conclude that γ-irradiation of NEJ alters expression of cathepsin-B protease and WGA- and ConA-specific sugars which may be detrimental to parasite invasion and contribute to the protective immune responses generated in the host by irradiation-attenuated metacercariae ofFasciolaspp.