Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The proteolytic activity in homogenates and extracts of subcellular fractions prepared from subcutaneous Lewis lung carcinoma was determined using proteins and synthetic peptides as substrates. The presence of cathepsin D, plasminogen activator, cathepsin B-, cathepsin G- and elastase-like enzymes was observed. No difference was revealed between the proteolytic activity in homogenates of Lewis lung carcinoma, at the growth stage examined, and in homogenates of normal lung. High specific activities were found in the lysosomal extract, whereas decreasing activities were found in the nuclear extract, the homogenate and the postlysosomal mitochondrial supernatant; no active or trypsin-activatable collagenase activity was detected. The presence in the tumor tissue of these enzymatic activities is in agreement with their proposed role in the process of metastasis. The lack of differences between homogenates of tumor and normal lung tissue suggests that the use of whole cells is required to selectively study tumor proteinases specifically involved in tumor malignancy.
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PMID:Methodologic problems encountered in the assay of proteinases in Lewis lung carcinoma, a mouse metastasizing tumor. 629 35

The activities of an acid proteinase, of an alkaline proteinase, of a lysine aminopeptidase and of a proteinase B inhibitor were measured in benign and malignant tumors of the human uterus. In carcinomas of the corpus uteri the activity of the acid proteinase (cathepsin D) was increased compared to normal endometrium. This could probably be the result of cell destruction within the tumor. In leiomyomas of the uterus the activities of the alkaline proteinase, of the lysine aminopeptidase, and of the proteinase inhibitor were decreased compared to the normal myometrium. These results suggest that a decrease in the rate of degradation of myofibrillar proteins relative to the rate of protein synthesis may be responsible for the growth of myomas.
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PMID:Activities of proteinases and of a proteinase B inhibitor in tumors of the human uterus. 637 84

Protein degradation was measured as tyrosine release rate from proteins of extensor digitorum longus (EDL) muscles and as urinary excretion of 3-methylhistidine in freely fed adult nongrowing C57BL/6J mice with sarcomas, to study protein degradation in cancer-induced wasting of skeletal muscles. Whole muscle protein breakdown rate was unchanged, whereas protein synthesis was depressed, leading to an increased net degradation of skeletal muscles with loss of soluble, myofibrillar, and collagen proteins. Starvation for 24 hours elevated whole muscle protein breakdown in mice with and without sarcomas. Subsequent refeeding for 24 hours normalized the degradation. Adaptation to anorexia in pair-fed controls was achieved by a decrease in muscle protein turnover evaluated by urinary excretion of 3-methylhistidine over 5 days. The measurement of "catabolic decrease" of muscle protein breakdown protected the muscle mass in mice without tumors, but it was ineffective in tumor-bearing animals. The unchanged rate of breakdown of proteins in whole EDL muscles from tumor-bearing mice was accompanied by increased maximum cathepsin D activity and by elevated autolytic activity at acid pH in some muscles. Therefore, cathepsin D activity and net protease activities did not reflect whole muscle protein degradation in tumor-induced malnutrition. The results demonstrate that wasting of skeletal muscles in experimental cancer was not dependent on increased degradation but was dependent on depressed protein synthesis.
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PMID:Lack of evidence for elevated breakdown rate of skeletal muscles in weight-losing, tumor-bearing mice. 657 91

Cancer patients have increased insulin resistance in skeletal muscles and probably also in the liver. The insulin production in response to a glucose challenge is decreased. This is associated with decreased glucose uptake in peripheral tissues and increased gluconeogenesis from amino acids, lactate, and glycerol. The correlation between the insulin response to a glucose challenge and the activities of glycolytic and oxidative rate-limiting enzymes in muscle tissue suggests a common denominator for these metabolic alterations. The most prominent feature in alteration of lipid metabolism is a reduction of body fat, probably dependent on increased lipolysis. The released fatty acids are oxidized outside the tumor mass. Species characteristics may be important for the degree of hyperlipidemia. Wasting of the skeletal muscle mass is caused by decreased protein synthesis and probably increased degradation. Anorexia can induce but not entirely explain this altered protein metabolism. Decreased physical activity may be another important factor for the depressed protein synthesis. Total parenteral nutrition (TPN) improves the muscle protein synthesis. The mechanism behind increased fractional degradation of muscle proteins in vitro is not clear, but it may be coupled to increased cathepsin D activity.
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PMID:Metabolism in peripheral tissues in cancer patients. 680 27

In view of the postulated role of cathepsin D in cachexia, investigations have been pursued on the host tissue response of cathepsin D activity in DBA/2 mice inoculated with 5 X 10(5) L1210 tumor cells. The results confirmed previous investigators' findings of the increase in cathepsin D activity (specific activity) in liver and muscle of tumor bearers. In addition, it was found that this increase was a general response of the host since heart, kidney, lung, and spleen cathepsin D specific activity were also enhanced in tumor bearers. These increases ranged from an average of 10% for spleen to 100% for gastrocnemius muscle. This effect was age related in heart and kidney. As a working hypothesis, we propose the concept that tumor bearers release protease-enhancing factor(s) which trigger increase or enhancement of cathepsin D activity in host tissues by yet unknown mechanisms. Pepstatin (60 mg/kg), a known inhibitor of cathepsin D in vitro, was shown to provide long-lasting inhibition (3 to 6 days) of cathepsin D in vivo in non-tumor bearers particularly in spleen, liver, kidney, lung, and heart. Evidence is provided from assays of cell fractions that this inhibition takes place at or in the lysosome. The duration of the effectiveness of pepstatin was altered in tumor bearers in that cathepsin D activity of heart, lung, and spleen had returned to near normal values in 48 hr following pepstatin injection. However, in muscle, liver, and kidney, significant inhibition (90%) still persisted in tumor bearers as it did in non-tumor bearers. Pepstatin or related antiproteases may prove useful as "anticachexia" agents by decreasing proteolysis in muscle and other tissues.
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PMID:Host cathepsin D response to tumor in the normal and pepstatin-treated mouse. 685 May 78

Rabbit antiserum against human liver cathepsin D was raised. The antiserum did not cross-react with cathepsins D from tissues of other species (bovine liver, bovine spleen, chicken liver). The study of cathepsins D isolated from human pathologically altered tissues showed that cathepsins from kidney malignant tumor and from myeloleucosis-induced spleen tumor were immunologically identical to the enzyme from normal liver. Cathepsins from liposarcoma and uterine myoma were characterized by partial identity with the enzyme from normal liver. Cathepsins D isolated from various human livers exhibited individual quantitative differences in antigenic properties, a fact to be taken into account in development of an immunochemical method for identification of cathepsin D. The low immunogenicity of human cathepsin D for rabbits and inadequate suitability of these animals for raising appropriate antisera was also considered.
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PMID:[Immunochemical studies of human cathepsin D]. 692 40

In solid s.c. tumors of a variant of the murine B16 melanoma with high metastatic potential (B16F10), there was a 2- to 7-fold elevation of lysosomal cathepsin B activity when compared to the B16F1 variant with low metastatic potential. The highest activities (based on either protein or DNA) of cathepsin B were found in tumors of less than 1 g. When B16F1 and B16F10 melanoma variants were grown in tissue culture, the metastatic differential in cathepsin B activity was lost as the cells were subcultured. However, this differential in cathepsin B activity could be restored by reestablishing the cultured cells as s.c. tumors. The activities of four other lysosomal enzymes (cathepsin D, beta-N-acetylglucosaminidase, beta-glucuronidase, and acid phosphatase) showed little evidence of a positive correlation with the metastatic potential of the B16 melanoma variants. Eighty to 90% of cathepsin B activity has been localized to a fraction containing viable tumor cells which was isolated by centrifugal elutriation. In contrast, only 50% of cathepsin D activity was in the viable tumor cell fraction, and from 30 to 70% of beta-N-acetylglucosaminidase, beta-glucuronidase, and acid phosphatase. Elevated levels of cathepsin B in the high metastatic B16F10 variant are consistent with the idea that cathepsin B may play a direct or a regulatory role in tumor metastasis.
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PMID:Cathepsin B activity in B16 melanoma cells: a possible marker for metastatic potential. 705 93

The purpose of this study was to determine whether or not alternations in tumor growth induced by changes in thyroid status were mediated through changes in key enzymes, whose activity is known to be influenced by thyroid hormones. The activities of three lysosomal enzymes (cathepsin B1, cathepsin D, and acid phosphatase) and thymidylate synthetase were measured in implanted mammary tumors as well as in the livers of host animals that were either euthyroid, hypothyroid, or hyperthyroid. Hypothyroidism produced no significant change in enzyme activity in the tumors. Hyperthyroidism, on the other hand, did cause a significant increase in the activity of all lysosomal enzymes in the tumors, but did not affect thymidylate synthetase levels. In the livers of the host animals, hypothyroidism produced a significant decrease in cathepsin B1 and a significant increase in acid phosphatase but did not change cathepsin D or thymidylate synthetase levels. Hyperthyroidism produced a significant increase in all enzymes measured in the livers of the host animals. The significant decrease in tumor weight with hypothyroidism did not correlate with the insignificant changes in the enzymes tested. Similarly, there was no correlation between the significant increase in the enzymes levels found with hyperthyroidism and the insignificant change in tumor weight.
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PMID:Effect of altered thyroid status on lysosomal enzymes and thymidylate synthetase activity in tumors and livers of host animals. 707 81

National screening programs resulting in an increased detection rate of prostatic adenocarcinoma have prompted the search for new methods of predicting disease outcome that can be applied to the initial narrow bore needle biopsy specimens. Cathepsin D, a lysosomal aspartyl protease and autocrine mitogen, has been studied in a wide variety of human neoplasms as an invasion and metastasis marker. Prostatic carcinoma needle biopsy tumor cell cathepsin D content was measured in 61 men using a semiquantitative image analysis assisted immunohistochemical procedure. Results were compared with preoperative serum prostatic specific antigen levels, tumor grade, DNA ploidy status, pathologic stage after radical prostatectomy and disease recurrence during a median 2.6 year follow-up. Biopsy cathepsin D levels significantly correlated with tumor grade (P = .022) and DNA ploidy status (P = .028) by logistic regression analysis. Post-prostatectomy pathologic stage and disease recurrence did not correlate with tumor cathepsin D levels. Final prostatectomy grade and DNA ploidy status independently predicted metastasis and post-operative disease recurrence (P < .001). Although this study did not find independent prognostic status for cathepsin D in prostate cancer, the correlation with tumor grade and DNA ploidy status is noteworthy and the inter-relationship of outcome variables may prove of interest and warrant further evaluation of this potential predictor or CO-predictor of disease outcome.
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PMID:Quantitative immunohistochemical determination of cathepsin D levels in prostatic carcinoma biopsies. Correlation with tumor grade, stage, PSA level, and DNA ploidy status. 754 34

The purpose of this study was to characterize the clinical and histological features of intraoral squamous cell carcinoma in men who were seropositive for the human immunodeficiency virus and to evaluate viral cofactors (human papillomavirus, herpes simplex virus, Epstein-Barr virus), proliferative index (proliferating cell nuclear antigen), a factor associated with invasion (cathepsin D), and mutated tumor suppressor gene and proto-oncogene products (mutated p53, c-erbB-2). Four men who were seropositive for the human immunodeficiency virus and had acquired immunodeficiency syndrome presented with painful oral lesions of variable duration. Oral cancer risk factors included heavy tobacco use (four of four), heavy alcohol use (three of four), and previous radiotherapy (one of four). The lesions consisted of ulcers (two of four), a fungating mass (one of four), and papillary erythroplakia (one of four). Incisional biopsy specimens were obtained. High-stringency in situ hybridization was performed with DNA probes to the human papillomavirus (types 6/11; 16/18; 31/33/35) and Epstein-Barr virus: Immunocytochemical studies for the herpes simplex virus, proliferating cell nuclear antigen, cathepsin D, mutated p53, and c-erbB-2 were performed. Two lesions were moderately differentiated squamous cell carcinoma, one lesion was a basaloid squamous cell carcinoma, and one was carcinoma in situ. Stage of disease at diagnosis was II (one of four), III (two of four), and IV (one of four). Three cases were positive for the human papillomavirus, one case was positive for Epstein-Barr virus, and three cases were positive for the herpes simplex virus. C-erbB-2 was focally positive in one case, and mutated p53 was positive in a separate case.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Intraoral squamous cell carcinoma in human immunodeficiency virus infection. A clinicopathologic study. 755 63


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