Elevated Cathepsin Research Articles

Clinical Significance of Cathepsin D Concentration in Tumor Cytosol of Primary Breast Cancer

Cathepsin D is the proteolytic enzyme most frequently implicated as a prognostic factor in primary breast cancer. In the present study we evaluated by means of an immunoradiometric assay the tumor content of this protease in primary breast cancer, its relationship with tumor-related clinical and pathological parameters, and its prognostic significance in a large series of breast cancer patients. The study comprised 1033 women with histologically established invasive breast cancer. Cathepsin D was measured in cytosol samples by means of an immunoradiometric assay to determine the total amount of cathepsin D (52 kDa, 48 kDa and 34 kDa). Evaluation of relapse-free survival and cause-specific survival was performed in the group of 1003 patients without evidence of metastasis at the time of initial diagnosis. The median follow-up of the patients who were free of recurrence was 54 months. Cathepsin D levels showed a wide range among the studied tumors (n = 1033; median (range) 41 (0.9-2504) pmol/mg protein). Statistical analysis showed that the median cathepsin D levels were considerably higher in large tumors (T2-4) than in smaller ones (T1) (p = 0.017), as well as in node-positive than in node-negative tumors (p = 0.004). Cathepsin D levels were also higher in ductal tumors than in the other histological types (p = 0.001), as well as in moderately or poorly differentiated tumors (p < 0.001). Likewise, the median value of the protease was significantly higher in ER or PgR-positive tumors than in hormone receptor-negative ones (p = 0.011 and p = 0.004, respectively), as well as in aneuploid tumors than in diploid tumors (p = 0.029). Multivariate analysis demonstrated that elevated cathepsin D levels (> 59 pmol/mg protein) were notably associated with a shorter cause-specific survival in the whole group of patients with breast cancer, as well as in the subgroup of node-positive patients (p < 0.05). This study suggests that elevated intratumoral cathepsin D levels may identify a subset of node-positive breast cancer patients showing a high probability of earlier death.

Clinical significance of cathepsin D concentration in tumor cytosol of primary breast cancer.

Cathepsin D is the proteolytic enzyme most frequently implicated as a prognostic factor in primary breast cancer. In the present study we evaluated by means of an immunoradiometric assay the tumor content of this protease in primary breast cancer, its relationship with tumor-related clinical and pathological parameters, and its prognostic significance in a large series of breast cancer patients. The study comprised 1033 women with histologically established invasive breast cancer. Cathepsin D was measured in cytosol samples by means of an immunoradiometric assay to determine the total amount of cathepsin D (52 kDa, 48 kDa and 34 kDa). Evaluation of relapse-free survival and cause-specific survival was performed in the group of 1003 patients without evidence of metastasis at the time of initial diagnosis. The median follow-up of the patients who were free of recurrence was 54 months. Cathepsin D levels showed a wide range among the studied tumors (n=1033; median (range) 41 (0.9-2504) pmol/mg protein). Statistical analysis showed that the median cathepsin D levels were considerably higher in large tumors (T2-4) than in smaller ones (T1) (p=0.017), as well as in node-positive than in node-negative tumors (p=0.004). Cathepsin D levels were also higher in ductal tumors than in the other histological types (p=0.001), as well as in moderately or poorly differentiated tumors (p<0.001). Likewise, the median value of the protease was significantly higher in ER or PgR-positive tumors than in hormone receptor-negative ones (p=0.011 and p=0.004, respectively), as well as in aneuploid tumors than in diploid tumors (p=0.029). Multivariate analysis demonstrated that elevated cathepsin D levels (>59 pmol/mg protein) were notably associated with a shorter cause-specific survival in the whole group of patients with breast cancer, as well as in the subgroup of node-positive patients (p<0.05). This study suggests that elevated intratumoral cathepsin D levels may identify a subset of node-positive breast cancer patients showing a high probability of earlier death. (Int J Biol Markers 2005; 20: 103-11).

Increased cystatin C serum concentrations in patients with hepatic diseases of various severities

Background: Indicators for long-term monitor of the progress of hepatic diseases are of great clinical importance. Since elevated cathepsin was observed in liver diseases, the aim of this study is to investigate the involvement of cystatin C, a very potent inhibitor of cathepsin and a recently introduced marker for renal function, and to see the applicability of serum cystatin C being a convenient marker for the progression of liver diseases. Methods: One hundred eighty consecutive patients with chronic liver disease of various severities and 45 healthy controls were recruited to determine their serum cystatin C concentrations by N Latex Cystatin C kit, as well as certain relevant clinical values, including alanine transaminase (ALT), aspartate transaminase (AST) and AFP. Results: Average serum cystatin C concentration of patients with hepatic diseases was significantly higher than that of control (0.0902±0.0025 mg/dl vs. 0.067±0.007 mg/dl; p<0.001), and a linear regression analysis has revealed a direct relation between cystatin C and the severity of liver diseases ( Y=1.172+5.492 X, R 2=0.088, p<0.001). Conclusion: This study suggested that cystatin C may be an applicable monitoring marker for monitoring liver functions and progression of liver fibrosis.

Neutrophil-derived MMP-9 mediates synergistic mobilization of hematopoietic stem and progenitor cells by the combination of G-CSF and the chemokines GROβ/CXCL2 and GROβT /CXCL2Δ4

AbstractMobilized peripheral blood stem cells (PBSCs) are widely used for transplantation, but mechanisms mediating their release from marrow are poorly understood. We previously demonstrated that the chemokines GROβ/CXCL2 and GROβT/CXCL2Δ4 rapidly mobilize PBSC equivalent to granulocyte colony-stimulating factor (G-CSF) and are synergistic with G-CSF. We now show that mobilization by GROβ/GROβT and G-CSF, alone or in combination, requires polymorphonuclear neutrophil (PMN)–derived proteases. Mobilization induced by GROβ/GROβT is associated with elevated levels of plasma and marrow matrix metalloproteinase 9 (MMP-9) and mobilization and MMP-9 are absent in neutrophil-depleted mice. G-CSF mobilization correlates with elevated neutrophil elastase (NE), cathepsin G (CG), and MMP-9 levels within marrow and is partially blocked by either anti–MMP-9 or the NE inhibitor MeOSuc-Ala-Ala-Pro-Val-CMK. Mobilization and protease accumulation are absent in neutrophil-depleted mice. Synergistic PBSC mobilization observed when G-CSF and GROβ/GROβT are combined correlates with a synergistic rise in the level of plasma MMP-9, reduction in marrow NE, CG, and MMP-9 levels, and a coincident increase in peripheral blood PMNs but decrease in marrow PMNs compared to G-CSF. Synergistic mobilization is completely blocked by anti–MMP-9 but not MeOSuc-Ala-Ala-Pro-Val-CMK and absent in MMP-9–deficient or PMN-depleted mice. Our results indicate that PMNs are a common target for G-CSF and GROβ/GROβT-mediated PBSC mobilization and, importantly, that synergistic mobilization by G-CSF plus GROβ/GROβT is mediated by PMN-derived plasma MMP-9.

Transcription of human cathepsin L mRNA species hCATL B from a novel alternative promoter in the first intron of its gene

Cathepsin L is a lysosomal cysteine protease over-expressed in malignancy. It is very potent in degrading collagen, elastin, laminin and other components of the basement membrane and therefore, has been implicated in tumor invasion and metastasis. Two mRNA species, hCATL A and hCATL B, which contain an identical open reading frame and different 5′UTRs, were demonstrated to be encoded by the same gene located on chromosome 9q21–22. We have previously cloned and characterized the promoter responsible for the transcription of hCATL A (hCATL A promoter). However, it was not clear whether hCATL B is a splice variant of hCATL A or transcribed from a different promoter. In the present study, we demonstrate for the first time that hCATL B is transcribed from an alternate promoter (hCATL B promoter) located in the first intron of hCATL. This TATA-less promoter initiates transcription from two cytosine nucleotides present 191 and 367 bases upstream to the translation start codon. Deletion analysis revealed that the core promoter region lies upstream to these transcription initiation sites. This region contains several putative transcription factor-binding sites like AP-1, AP-4, GATA-1, Lmo2, NF-kB, MZF-1, NF-AT, etc. In U-87 MG cells, hCATL B promoter exhibits at least six times less activity than our previously characterized hCATL A promoter. However, this promoter is significantly more active in malignantly transformed cells as compared to its activity in untransformed cells. Thus, our results conclusively demonstrate that hCATL B mRNA is transcribed from an alternate promoter. Increased transcriptional activity from this promoter contributes to the elevated cathepsin L expression in transformed cells.

Alterations in cathepsin H activity and protein patterns in human colorectal carcinomas.

Our analyses of cathepsin H activity levels and protein forms in human colorectal cancers compared to matched control mucosa support the concept that altered proteinase expression patterns may reflect both cancer stage and site. Cathepsin H-specific activity was significantly increased in colorectal cancers compared to control mucosa (P = 0.003;n = 77). Highest specific activities and cancer/normal ratios (C/N) for activity were measured in Dukes' B and C stage carcinomas, cancers involved in local spread and invasion to lymph nodes. In contrast, cathepsin B and L activities analysed in the same paired extracts had been shown to be most frequently elevated in earlier stage carcinomas (Dukes' A and B), confirming that cathepsin H demonstrates a distinct pattern of expression during colorectal cancer progression. Although cathepsin H activities were most commonly elevated in Dukes' C cancers at all colon sites, both specific activity and C/N ratios were significantly higher for cancers of the left colon compared to other colon locations. A subset of 43 paired extracts analysed on Western blots also revealed consistent changes in cathepsin H protein forms in cancers. Normal mucosa typically showed a strong protein doublet at 31 and 29 kDa while cancers demonstrated decreased expression or total loss of the 31 kDa protein (90% of cases), equal or increased expression of the 29-kDa protein (67% of cases) and the new appearance or up-regulation of a cathepsin H band at 22 kDa (78% of cases). C/N ratios for cathepsin H enzyme activity correlated significantly with C/N ratios for the 29 kDa mature single-chain protein form (P< 0.001), with increased activity most commonly associated with elevated expression of 29-kDa cathepsin H but also with up-regulation of the 22-kDa band, suggesting a shift to more fully processed, mature active cathepsin H protein forms in cancers. Changes in cathepsin H expression were also detected by immunohistochemistry as elevated cathepsin H staining in tumour epithelial cells. © 2000 Cancer Research Campaign

Cathepsins B, H, L and cysteine protease inhibitors in malignant prostate cell lines, primary cultured prostatic cells and prostatic tissue

Elevated activities of cysteine proteinases, the cathepsins B, H, L (CB, CH, CL) and diminished cysteine protease inhibitors (CPI) have been demonstrated in a variety of tumours and have been suggested to contribute to invasion and metastasis. The situation for prostate cancer is still unknown. In this study, using fluorimetric assays, the catalytic activities of CB, CH, CL were measured in prostatic tissue samples after radical prostatectomy, adenomectomy, transurethral resection of the prostate, in cell cultures grown from cancerous and non-cancerous parts of human prostate after prostatectomy and in the cell lines LNCaP, DU 145 and PC 3. CPIs were determined using heat activation before testing their inhibitory activity against purified CB. Comparing matched pairs of normal and cancerous tissue samples from the prostate, significantly decreased levels of CB, CL in malignant parts of the prostate were found. In contrast, primary cell cultures from cancerous samples showed elevated levels of CB, CH, CL and increased ratios of cathepsins to CPI compared with cell cultures from normal prostate. Established cell lines showed a similar distribution pattern of each cathepsin, DU 145 containing the highest levels, followed by LNCaP and PC 3. Our results suggest that elevated cathepsin levels and consequently increased ratios of cathepsins to CPI in primary cell cultures from cancerous versus non-cancerous parts of the prostate may be indicative of a cellular proteolytic imbalance in prostatic cancer cells. In this respect, primary cell culture experiments should be preferred to determinations in tissue samples.

Developmental Regulation of Invariant Chain Proteolysis Controls MHC Class II Trafficking in Mouse Dendritic Cells

Dendritic cells (DCs) developmentally regulate their capacity for antigen presentation by controlling the transport and surface expression of MHC class II molecules. These events reflect a developmental regulation of invariant (Ii) chain cleavage, most likely by the cysteine protease cathepsin S. In immature DCs, inefficient Ii chain cleavage due to low cathepsin S activity leads to the transport of class II-Ii chain complexes to lysosomes, while in mature DCs, elevated cathepsin S activity results in efficient delivery of class II αβ dimers to the plasma membrane. Cathepsin S is not controlled transcriptionally but by a novel mechanism involving alterations in the expression and localization of an endogenous cathepsin S inhibitor cystatin C. Thus, the ratio of cystatin C to cathepsin S in developing DCs helps to determine the fate of newly synthesized MHC class II molecules.

Elevations in Cathepsin B Protein Content and Enzyme Activity Occur Independently of Glycosylation during Colorectal Tumor Progression

Western blots, enzyme assays, protein glycosylation studies, and immunohistochemical staining were used to characterize cathepsin B expression at successive stages of colorectal tumor progression. In normal colon mucosa and premalignant adenomas, cathepsin B expression was predominantly due to mature two-chain protein detected on Western blots as the nonglycosylated 27-kDa form, with overexpression of this protein occurring in only 4 of 18 adenomas. Overexpression increased significantly in Dukes A and B carcinomas (26 of 37 cases), with cathepsin B protein generally detectable in carcinomas as a combination of both 27-kDa nonglycosylated and 28-kDa glycosylated mature two-chain forms. Glycosylated cathepsin B protein in carcinoma extracts was sensitive to PNGase F but resistant to Endo H, indicating a pattern consistent with complex rather than high mannose type glycosylation. When sorted by advancing tumor stage, peak expression of cathepsin B protein occurred in carcinomas involved in local invasion compared with adenomas or metastatic cancers. At all stages, cathepsin B activity correlated significantly with the levels of heavy chain mature cathepsin B protein (r = 0.6682, p < 0.0001) irrespective of glycosylation. Immunohistochemical staining of cathepsin B protein revealed fine diffuse cytoplasmic staining in both adenomas and carcinomas compared with coarse granular cytoplasmic staining (typical of lysosomes) seen in matched normal mucosa. Our results demonstrate several sequential, apparently independent changes in cathepsin B expression during colorectal tumor progression including early changes in subcellular localization, up-regulation of cathepsin B protein and activity in invasive cancers, and altered protein glycosylation detected in malignant tumors at all stages.

Cathepsin B-like activity as a serum tumour marker in ovarian carcinoma.

Serum cathepsin B-like activity was determined in 75 patients with ovarian carcinomas and in control groups. Ovarian cancers were of FIGO stages I-IV. Control groups consisted of 15 healthy women, 20 patients with myomas of the uterus, and 17 with benign ovarian cysts. Preoperative results showed elevated cathepsin B-like activity in 100% of the patients with ovarian cancers in relation to healthy subjects and patients with myomas, and in 78% in relation to benign ovarian cysts. Cathepsin B activity increased progressively with the FIGO stage of the disease, but the differences among particular stages were not statistically significant. In serous tumours cathepsin activity was significantly higher only in comparison to endometrioid ones (p < 0.001). Antipapain capacity of cystatins in the sera was also determined. No significant correlation between cathepsin B-like, and antipapain activity of cystatins was found. Serum cathepsin B-like activity may be helpful in the preoperative differential diagnosis between ovarian carcinomas and benign ovarian or uterine tumours.

Sequence analysis and distribution of two new human cathepsin L splice variants

Despite elevated cathepsin L mRNA levels in kidney tumors, cathepsin L protein/activity was scarcely detectable in these tumors. As a possible reason, we detected two new splice variants of human cathepsin L mRNAs not identical to those previously reported. Besides the normal ‘full-length’ mRNA (hCATL-A) there is one form lacking 27 nucleotides (hCATL-A I) and another form lacking 90 nucleotides (hCATL-A II) in exon I. The splice variants do not influence the amino acid sequence of the translational product. hCATL-A and hCATL-A I probably form a secondary structure at the 5′ non-coding sequence not present in hCATL-A II.

Cathepsin G and elastase in synovial fluid and peripheral blood in reactive and rheumatoid arthritis.

The purpose of the study was to evaluate the involvement of serine proteinases cathepsin G and elastase on pathomechanisms in synovial fluid (SF) of patients with reactive (ReA) and rheumatoid, (RA) arthritis. Cathepsin G, elastase, and their endogenous inhibitors alpha1-antichymotrypsin (alpha1-ACT) and alpha1-proteinase inhibitor (alpha1-PI) were identified immunohistochemically from SF and peripheral blood (PB) of patients with ReA and RA. Cathepsin G and elastase activities in SF and PB were measured spectrophotometrically. Dot-immunostaining was used to identify cathepsin G, elastase, but also alpha1-ACT and alpha1-PI from SF and PB. Cathepsin G and elastase-like activities (IU/I) were slightly elevated in ReA SF compared to the corresponding peripheral blood values (11.4 +/- 9.2 vs 4.8 +/- 1.7, NS, and 5.1 +/- 2.8 vs 2.3 +/- 2.2, NS), which was similar to what was seen in RA (16.4 +/- 6.2 vs 0.53 +/- 0.4, p < 0.05, and 6.51 +/- 1.8 vs 1.22 +/- 0.58, p < 0.05). Although some samples did not contain cathepsin G and/or elastase-like activities, all samples contained immunoreactive enzyme, but also alpha1-ACT and alpha1-PI. In ReA SF, in contrast to monocytes, all polymorphonuclear (PMN) cells contained cathepsin G and elastase. Cathepsin G and elastase activities correlated with each other (r = 0.78, p < 0.05) suggesting PMN / primary granules as their likely source. There was a closer association between the cathepsin G or elastase and SF leukocyte count in ReA than in RA. In ReA and RA SF elevated cathepsin G and elastase activities are detected compared to activity levels in PB suggesting local production mainly from PMNs. The co-existence of highly cellular SF and cathepsin G and elastase activity in the documented presence of endogenous inhibitors in ReA SF together with the, known, usually self-remitting clinical course of ReA, suggest a brisk and even exaggerated local PMN serine proteinase release; sparing of joints does not seem to be due to lack or inhibition of PMN responses but rather to a successful down-regulation or cessation of the responses initially elicited.

Elevated Cathepsin D Expression in Kainate-Evoked Rat Brain Neurodegeneration

Expression patterns of cathepsin D (lysosomal aspartic protease) and glial fibrillary acidic protein (GFAP, a marker of reactive astroglia) were determined by Northern blot analysis and immunohistochemistry in the rat brain during neurodegeneration accompanying kainate-evoked seizures. The level of cathepsin D mRNA in the hippocampus, limbic cortex, and temporoparieto-occipital neocortex was shown to increase, starting at 6 h after kainate treatment, and reaching peak values at 3-7 days after the neurotoxin administration. A similar time course of elevated accumulation was noted for GFAP mRNA in these structures. Immunohistochemical analysis performed 3 days after kainate treatment showed that the increased cathepsin D levels were confined mainly to the degenerating neurons in the susceptible brain areas, while the elevated GFAP immunoreactivity was observed in reactive astrocytes. Although cathepsin D and GFAP expression levels were elevated by kainate administration, their expression patterns revealed significant differences with regard to both intensity and site of induction.

Cathepsin D activity is increased in alveolar macrophages and bronchoalveolar lavage fluid of smokers.

Cathepsin D activity was determined in alveolar macrophages (AM) and cell-free bronchoalveolar lavage fluid (BALF) from volunteers who were current cigarette smokers and compared with that found in lifetime nonsmokers. Enzyme activity was determined with a highly sensitive and specific substrate [D-Phe-Ser(0-CH2-C6H5)-Phe-Phe-Ala-Ala-pAB]. Specific activity was more than three times higher in AM from smokers than in cells from nonsmokers (37,880 +/- 2,090 versus 10,300 +/- 1,200; p less than 0.001) and approximately seven times higher in BALF from smokers than from nonsmokers (3,620 +/- 490 versus 515 +/- 165; p less than 0.001). This study demonstrated that cigarette smoke is a potent inducer of cathepsin D activity in AM in vivo. Because cathepsin D is capable of degrading a variety of proteins, the finding of high concentrations of the enzyme in AM and BALF from smokers, along with previous observations of elevated cathepsin B activity, suggests that lysosomal enzymes may cause or contribute to structural lung damage associated with cigarette smoking.

Effects of indomethacin and leupeptin on muscle cathepsin B activity and protein degradation during sepsis

The roles of prostaglandins and lysosomal proteases in accelerated skeletal muscle proteolysis during sepsis are not yet fully understood. In this study rats received intraperitoneal injections of the prostaglandin synthesis inhibitor indomethacin (IND, 5.0 mg/kg), the lysosomal cathepsin B inhibitor leupeptin (LEU, 2.5 mg/kg), or normal saline 2 hr before cecal ligation and puncture (a model of intraabdominal sepsis) or sham-operation. The injections were repeated every 6 hr for a total of four doses. Sixteen hours after operation, intact extensor digitorum longus (EDL) muscles were harvested and cathepsin B activity was measured in one muscle. The contralateral muscle was incubated in oxygenated Krebs-Henseleit bicarbonate buffer containing glucose (10 m M) and cycloheximide (0.5 m M), and protein degradation rate was determined as the release of tyrosine into the incubation medium. Both muscle cathepsin B activity and protein degradation rate were higher in septic than in sham-operated rats. Treatment with IND or LEU significantly reduced the elevated cathepsin B activity in septic muscles, but failed to significantly alter muscle proteolysis. In nonseptic muscle, both cathepsin B activity and protein degradation rate were unaffected by the different types of treatment. The results suggest that although prostaglandins may influence muscle lysosomal protease activity, neither prostaglandins nor the lysosomal protease cathepsin B appear to be major regulators of accelerated muscle protein breakdown during sepsis.

Mitogenic effects of certain cathepsins and calciferin on the intact liver in vivo

1. 1. Calciferin, a new parathyroid hormone stimulating the release of cathepsins D and L (but not B) from isolated lysosomes, or the release of cathepsin D from erythrocytes or ghosts in vitro, elevated free cathepsin D in the blood, and at the same time stimulated DNA synthesis in the intact liver when it was injected into mice. 2. 2. Both calciferin and free cathepsin D in the blood (rats) were elevated concomitantly soon after 70% hepatectomy, reaching a peak around 5 hr. The cathepsin D-elevation was almost proportional to fractional hepatectomies. 3. 3. Cathepsin L (but not B), when injected intraperitoneally into mice, stimulated DNA synthesis and mitosis in the intact liver much like cathepsin D, the effect of which was reported earlier. 4. 4. In contrast to the mitogenic effects of calciferin or cathepsins (D and L) in vivo, only cathepsin L (but not cathepsin D or calciferin) in low concentrations appeared to stimulate DNA synthesis in the cultured liver cells, and also stimulated adenylate cyclase of isolated liver plasma membranes in vitro. Dibutyryl-cyclic AMP in concentrations lower than 10 −5 M also stimulated DNA synthesis in cultured liver cells.

Regulation of Cartilage Acid Hydrolases by Growth Hormone*

The in vivo regulation of three acid hydrolases, namely cathepsin D, cathepsin B, and acid phosphatase, by GH was investigated. The costal cartilage cathepsin D and acid phosphatase activities of hypophysectomized rats were reduced relative to those found in normal controls. Treatment of hypophysectomized animals with GH enhanced rat growth rate and increased these two enzyme activities toward normal levels. Results of pepstatin experiments suggested that the elevated cartilage cathepsin D activity corresponded to an increase in enzyme concentration. A degree of specificity in this regulation was apparent because cartilage cathepsin B, unlike cathepsin D and acid phosphatase, was refractory to hypophysectomy and GH treatment. In contradistinction to cartilage, none of these hepatic enzymes responded to GH, and only cathepsin B activity was diminished by hypophysectomy. Centrifugational and detergent studies indicated that changes in enzyme activities induced by GH treatment were not due to the differential release of acid hydrolases from subcellular compartments. Overall, our results suggest that costal cartilage cathepsin D and acid phosphatase activities are GH dependent and may be related to cartilage growth. These observations may provide insight into the mechanism of GH action and, derivatively, skeletal growth.

Stomach ulcer and lysosomal cathepsin.

Gastric ulcers were induced in rats by i.m. injections of vitamin A, and i.p. injection of histamine, or injections of both vitamin A and histamine. The incidence of ulcer formation was highest in the vitamin A-histamine group. However, ulcer formation also occurred after the administration of vitamin A alone as a lysosomal labilizer. Furthermore, the vitamin A-histamine group showed a remarkably elevated cathepsin activity in the tissue of gastric wall. In the experiments of ulcer formation by vitamin A injections, the specific activity and the enzyme release of cathepsin were elevated already in the early stage after vitamin A administration. Consequently, cathepsin activity in stomach juice was remarkably elevated in the stage of the ulcer formation. In the clinic, the cathepsin activity in the mucous membrane of human gastric wall was remarkably high in the antrum and the angulus of the stomach, in which ulcer formation tends to occur most frequently. In view of these results, cathepsin in the stomach seems to play an important role in the formation of gastric ulcers.

Elevated serum cathepsin B1-like activity in women with neoplastic disease

Activities of selected hydrolytic enzymes were assessed in blind-coded sera of 121 women with invasive cancer of various organs. Acetylglucosaminidase, β-glucuronidase, and alkaline phosphatases were not markedly elevated above controls. In contrast, cathepsin B1-like (CB1) activity in sera before therapy averaged 45-fold greater than that of 56 normal controls ( P < 0.001) and 95% of the values exceeded 0–20 units, the levels characteristic of 95% of healthy controls. CB1 also increased progressively during transition from preinvasive to invasive squamous cervical carcinoma ( P < 0.001). Patients with recurrent or Stages III–IV disease had higher CB1 levels than those with Stages I–II tumors ( P < 0.02). In women with gynecologic cancer who showed objective remissions to surgery or chemotherapy, mean pretreatment levels of CB1 fell from 226 and 330 units, respectively, to normal within 12–38 days of surgery or ca. 4 months of chemotherapy. CB1 remained elevated when tumors were refractory to treatment. Subjects with inflammatory, degenerative, or other non-neoplastic disease showed no CB1 elevation, but CB1 was enhanced in women with endometriosis or endometrial hyperplasia. A generalized increase in serum acid and alkaline hydrolases, including CB1, was found in advanced pregnancy. Although the nature of the increments in CB1-like activity in cancer remains to be determined, such analyses may help supplement present methods of physical diagnosis.

Hepatic cell integrity in hypodynamic states.

Changes in liver integrity were studied in isolated perfused cat livers during simulated shock conditions (i.e., combined hypoxia, acidosis, and ischemia) or under the influence of each hypodynamic state separately. The combined hypodynamic stimuli depressed carbon clearance 51% and significantly elevated lactic acid dehydrogenase (LDH) and cathepsin D activities in the perfusate. The perfused liver was more seriously affected by hypoxia than by acidosis or ischemia alone. Reticuloendothelial clearance was depressed 20% and 25% in acidosis and hypoxia, respectively. Hypoxia also induced a 3-fold increase in cathepsin D and a 13-fold increase in LDH activities in the perfusate. After 150 min of hypoxia or ischemia, free cathepsin D in liver tissue increased significantly. The impairment of liver cell integrity (i.e., of Kupffer and parenchymal cells) occurred between 60 and 90 min during simulated shock conditions, indicating that the liver is stable for 60 min when it is exposed to hypoperfusion. The perfused liver is sensitive to local stimuli that predominate in circulatory shock, particularly hypoxia. These stimuli promote the release of lysosomal and cytoplasmic enzymes as well as depress phagocytosis by the reticuloendothelial system, phenomena that exacerbate the shock state.