Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.23.5 (cathepsin D)
4,130 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have studied the intracellular transport of the pulmonary surfactant SP-C precursor in vitro and in vivo. In order to monitor the route of the SP-C precursor, we constructed various C-terminally truncated forms of SP-C, which were tagged with a sequence derived from the C-terminus of the human c-myc gene (aa 409-419). Expression of these constructs under the control of the SV40 enhancer and the huMT-II promoter in stably transformed Chinese hamster ovary (CHO) cells revealed that the complete precursor molecule is localized mostly in vesicular structures, probably of lysosomal origin. The truncated precursor lacking the last 22 amino acids at the C-terminus (SP-C/Ctag), however, was restricted to the endoplasmic reticulum as shown by immunofluorescence, using antibodies directed against the tag-sequence, the lysosomal enzyme cathepsin D, the enzyme disulfide isomerase, and the Golgi zone. The intracellular localization was substantiated by subcellular fractionation analysis, suggesting that the last 22 amino acids are necessary for intracellular targeting. Furthermore, Triton X-114 extractions from CHO cells revealed a modification of the SP-C precursor. In vitro translation and pulse-chase experiments in the absence or presence of microsomes showed that the modification occurs post-translationally and in a time-dependent manner. Membrane association studies using an SP-C precursor lacking the mature peptide indicated that the modification is of hydrophobic nature but not a thioester-linked fatty acid.
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PMID:The C-terminal domain of the pulmonary surfactant protein C precursor contains signals for intracellular targeting. 159 Oct 9

In breast cancer, axillary lymph node invasiveness is the major prognostic factor in predicting relapse and metastasis. Nevertheless, since 30% of node-negative tumors also relapse, it is necessary to develop other independent prognostic factors. Oncogene amplification and the level of cathepsin D (cath-D), an acidic lysosomal protease produced and secreted in excess by breast cancer cells, have been proposed as additional prognostic factors. We have compared the cytosolic cath-D level and the amplification of three oncogenes: c-myc, neu-erb-B-2 and int-2 in 140 primary breast carcinomas and 64 axillary lymph nodes collected in 1987 and 1988 at the Cancer Center of Montpellier (Centre Paul Lamarque). None of the patients had previously received hormonal or chemotherapy. The cath-D concentration was measured with an immunoradiometric assay using monoclonal antibodies. DNA purified from the same samples was analyzed by a standard Southern blotting technique to estimate oncogene amplification. No correlation was found between the level of cath-D in the tumor and node invasiveness. Using a cut-off level of 60 pmol/mg protein, the status of cath-D was not correlated with neu-erb-B-2 and int-2 amplification and only correlated with c-myc amplification (P = 0.011). Both c-myc and cath-D are associated with cell proliferation, induced by estrogens in ER+ breast cancer, and constitutively produced in ER- breast cancer. The level of cath-D was significantly higher in the invaded lymph nodes (P = 0.04) than in the histologically non-invaded ones. Nevertheless, some non-invaded lymph nodes contained a high level of cath-D, as confirmed by immunoperoxidase staining. In conclusion, in breast cancer, a high cytosolic cath-D concentration is more frequent in tumors with c-myc amplification but is dissociated from neu-erb-B-2 or int-2 amplification, suggesting that the determination of these three markers will have an additional prognostic value.
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PMID:Cathepsin D assay in primary breast cancer and lymph nodes: relationship with c-myc, c-erb-B-2 and int-2 oncogene amplification and node invasiveness. 214 10

Fibroblastoid synovial lining cells isolated from rheumatoid and other chronic inflammatory synovial tissue exhibit distinctive and sustained alterations in serial culture not commonly found in similarly cultured cells from osteoarthritic synovium. These are demonstrable using a multi-gene dot blot assay by labelling reverse transcribed fibroblast cDNA which is hybridized to plasmids containing relevant target gene inserts. Cultured synovial fibroblastoid cells from patients with chronic inflammatory synovitis expressed significantly higher levels of stromelysin, vimentin and TIMP-1 mRNA and lower levels of c-myc compared to cells isolated from osteoarthritis synovium although with considerable variation. Early fetal synovial lining cells were similar to cells from osteoarthritis synovium but vimentin expression was higher. Marked differences in patterns of gene expression between cell lines persisted through 10 serial passages over 6-8 months. In whole synovia, the average level of mRNA for stromelysin, vimentin, IL-4, IL-6, TIMP-1, cathepsin D, gelatinase, TGF alpha, c-fms and DR beta were preferentially expressed in inflammatory tissue while c-myc expression was higher in osteoarthritis synovium. Inflammatory synovium also expressed TNF alpha, IL-1 alpha, IL-1 beta, IL-2, c-sis, tissue plasminogen activator, CSF-1, and GM-CSF. This pattern resembles, in part, that found in cultured inflammatory fibroblasts but, in addition, gene products apparently reflecting the presence of activated monocytes and lymphocytes were detected. These results provide evidence that profiles of certain gene activation in cells from patients with inflammatory synovitis differ from those with non-inflammatory disease and suggest that the fibroblastoid cells are responsible for a considerable proportion of the altered phenotypic expression pattern in whole tissue. Furthermore, this modulated pattern of gene activation appears to be an intrinsic pro-inflammatory characteristic of the fibroblastoid cells initiated in response to chronic inflammation and persists for a prolonged period in the absence of other inflammatory cells.
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PMID:Sustained and distinctive patterns of gene activation in synovial fibroblasts and whole synovial tissue obtained from inflammatory synovitis. 809 Nov 28

Endometrial cancers have been considered to be less prevalent in Japan than in Western countries. However, with the increase in life expectancy, the Westernization of the Japanese diet, and changes in the hormonal environment, the prevalence of the disease has gradually increased even in our country. Similar increases in cancers of the breasts, lungs, colons, and ovaries have been noted in recent years. Much is still unknown regarding the pathogenesis and natural history of endometrial cancer. Although endometrial hyperplasia is considered to be a precancerous lesion of endometrial carcinoma, the relationship between those diseases has not been elucidated to the same degree as that between cervical cancer and cervical dysplasia, or carcinoma in situ. Research findings in genetic oncology have revealed that tumorigenesis involves a multi-step process. It is probable that activation of multiple genes, inactivation of anti-oncogenes, and disappearance of normal inhibitor genes occur in the process of the development of endometrial cancer. The purpose of this study is to elucidate the relationship between oncogenes and the development of endometrial cancer. In addition, the significance of endometrial hyperplasia as a clinical entity is also be evaluated. The roles played by oncogenes in endometrial cancers and endometrial hyperplasias were examined using the most recent molecular biological and immunohistochemical methods. Also, the differences in cellular proliferation and tissue invasiveness were discussed. Results obtained were as follows. Evaluation of cell proliferation (PCNA, FCM) revealed that there was no difference in proliferative activity between atypical hyperplasia and well differentiated adenocarcinoma. Evaluation of oncogene abnormalities (c-myc,c-erbB-2,K-ras,p53) revealed that the development of endometrial cancer was a multistep process involving several oncogenes, as it has been noted in the development of other cancers. Evaluation of extracellular matrix and related factors (cathepsin D, laminin, type IV collagen, tenascin, CD44) showed that tissue invasiveness differed between atypical hyperplasia and well differentiated adenocarcinoma.
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PMID:[Evaluation of the degree of biological behavior in endometrial hyperplasia and endometrial carcinoma: an investigation of proliferative activity, oncogene, and extracellular matrix]. 810 84

Breast cancer is a complex but increasingly well-understood disease. Clearly, multiple alterations from normal mammary cells are required to achieve a transformed phenotype. Furthermore, there may be several possible alterations within broad categories that will produce the transformations leading to the malignant state. The specific set of alterations within a given cancer may thus provide necessary information about how it is unique and how it may best be treated. Several of the newer biologic markers of breast cancer may provide very specific treatment information. erbB-2 may predict for improved response to doxorubicin, rather than CMF. hsp 27 may predict for failure of doxorubicin. pS2 or EGFR may provide supplemental information predicting response to hormonal therapy. Each of these variables has strong evidence to support its use in this manner, but that evidence has been obtained on limited numbers of patients treated in a limited number of ways. The most established markers, with multiple studies indicating their prognostic benefit, are erbB-2, cathepsin D, and proliferation markers. Of the several proliferation markers there may be no one choice that is best. However, very clearly, any marker must be carefully assessed for appropriate cut-off values, and cut-off values established by one cohort of patients should be verified against another cohort of patients. The oncoproteins associated with cell cycle regulation (cyclin D, p53, Rb, and c-myc) have shown strong promise of providing important prognostic information. The limited studies to date indicate that these markers are independent of one another. Cell cycle regulation may be an area in which any defect may serve to deregulate the cell, and therefore several defects in one cell would be unlikely. The specific nature of the defect in a given cancer may be very important. With the advent of immunohistochemical methods to measure most of the markers, more information may become available. Finally, the burgeoning area of tumor-stromal interactions is replete with potentially important markers of cancer prognosis. The growth factors, which are marginally a part of this area owing to the probable importance of paracrine effects on cancer cell growth, have progressively developed a body of literature supporting their prognostic potential. However, they have rarely been studied in conjunction with the other aspects of tumor-stromal cooperation. The markers of metastatic potential, nm23 and angiogenesis, have been shown in small cohorts to have considerable prognostic import.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Overview of the biologic markers of breast cancer. 815 Jul 84

Estrogen receptor positive ovarian cancer is often refractile to antiestrogen therapy. Here we describe the SKOV3 human ovarian carcinoma cell line as an in vitro model for estrogen and antiestrogen resistant ovarian cancer. While SKOV3 cells expressed estrogen receptor (ER) mRNA and protein at a similar level as the estrogen responsive T47D breast carcinoma cell line, their growth was not responsive to estradiol (E2) and was not inhibited by the antiestrogens OH-tamoxifen and ICI 164,384. The ER in SKOV3 cells was normal with respect to apparent Kd for binding with E2, E2 regulation of a transiently transfected ERE driven reporter gene, and E2 stimulation of expression of the early growth response genes c-myc and c-fos. However, the SKOV3 cells exhibited no expression of the progesterone receptor gene (PR) even after addition of E2, and the protein products of the estrogen responsive genes HER-2/neu and cathepsin D were expressed at constitutive levels that were not regulated by E2. Therefore, estrogen resistance in these cells may be a result of constitutive expression and loss of E2 regulation of selected growth regulatory gene products rather than a defect in estrogen activation of ER as a transcriptional regulator.
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PMID:SKOV3 ovarian carcinoma cells have functional estrogen receptor but are growth-resistant to estrogen and antiestrogens. 854 Dec 24

Doxorubicin shows a wide spectrum of activities in solid tumors, especially against breast carcinoma. The aim of this study was to examine if doxorubicin, when given at lower concentrations than applied in clinic, may induce changes in treated cells. With this purpose we developed human breast adenocarcinoma SK-BR-3 cell line resistant to doxorubicin. The sensitivity of these cells to doxorubicin and to some other cytostatics used in cancer treatment was determined by colorimetric MTT assay. Some parameters which may be of importance as prognostic factors in treatment of breast cancer were analyzed as well. The expression of genes involved in mitotic signal pathway (EGF, TGF alpha, EGF-R, erbB-2, erbB-3, c-myc and c-H-ras) was determined immunocytochemically. The concentrations of cathepsins were determined using quantitative immunoreactive assays (cathepsins B and L) or immunoradiometric assay (cathepsin D). The results revealed that even low doses of doxorubicin can induce numerous changes in treated cells: they become resistant to doxorubicin, and cross-resistant to several other cytostatics. The expression of the above mentioned genes involved in mitotic signal transduction, as well as cathepsins D and L, was similar in both parental and doxorubicin treated cells.
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PMID:Characterization of human breast adenocarcinoma SK-BR-3 cells resistant to doxorubicin. 937 56

IIB-BR-G is an undifferentiated, highly heterogeneous, hormone receptor negative human breast cancer cell line previously established in our laboratory from a patient's primary tumor. An in vitro growing cell line (IIB-BR-G) and a xenotransplanted tumor growing in nude mice (IIB-BR-G(NUDE)) were derived. To further characterize these systems, immunocytochemical analysis was performed for differentiation antigens (PEM 200 kDa, CEA, NCA 90 kDa), blood-group related antigens (Le(x), sTn), oncogenes and tumor suppressor gene products (Her-2/neu protein, p53), metastasis-related cathepsin D and CD63/5.01 Ag, and the chemokine monocyte chemotactic protein 1 (MCP-1). Expression of markers was heterogeneous in these different systems. Previously reported karyotypic analysis has shown extensive chromosomal alterations including double min. Searching for oncogene amplification, we detected augmented copy number of c-myc and c-fos, the last one with two rearranged fragments. No amplification was found for c-erbB-2 in the cell line or in IIB-BR-G(NUDE), although this oncogene was amplified in the patient's primary tumor DNA. The differences observed between the patient's tumor, the cell line and the IIB-BR-G(NUDE) tumors are probably due to clonal expansion of cell variants not present in the original tumor. Electron microscopy of IIB-BR-G growing cells revealed epithelial characteristics with abundant dense granules, presumably secretory, distributed all over the cytoplasm and great nuclear pleomorphism. In vitro, IIB-BR-G cells showed a significant number of invading cells by Matrigel assay. After nearly 40 sequential subcutaneous passages of the original xenograft through nude mice, 80% of recipients developed spontaneous metastases, primarily to the lung and lymph nodes. Since this experimental model allowed to analyze changes produced in cancer cells from the primary tumor during adaptation to in vitro and in vivo growth, our results provide novel insights on the behaviour of hormone independent metastatic breast cancer.
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PMID:The human breast cancer cell line IIB-BR-G has amplified c-myc and c-fos oncogenes in vitro and is spontaneously metastatic in vivo. 962 Apr 46

The mammary gland seems to be the only organ that is not fully developed at birth. Estrogens stimulate breast tissue via estrogen receptors (ERs). In the mammary gland, ER-mediated mechanisms have been shown to regulate: various growth factors, such as TGF-alpha and TGF-beta; enzymes, such as cathepsin D and plasminogen-activator; proto-oncogenes, such as c-fos, c-myc and HER-2/neu; cyclines and other regulatory substances that provide signaling systems for cell division and differentiation; other steroid receptors and epidermal growth factor receptors. Estrogen target genes contain estrogen-responsive elements. In these genes, transcription will be activated through interaction with the estrogen/ER protein complex. Subsequent activation of proto-oncogenes provides an explanation for the stimulating effect of estrogens on the glandular breast. Progesterone may be the key in influencing the risk of breast cancer with the peak of mitotic activity in the breast during the luteal phase of the menstrual cycle. On the other hand, in human breast cancer cell lines, both proliferation and inhibition have been observed with various progestational agents. Relevant biological and clinical issues are pregnancy and exposure to exogenous hormones. The intense hormonal stimulation of pregnancy (both estrogen and progesterone) has no adverse impact on the course of breast cancer. Pregnancy, with its mammogenetic differentiation, results in the protection of this organ from carcinogenesis. Characterization of specific lobular morphology serves as an indicator of the level of differentiation achieved by the organ, and thus provides means to assess the risk of the gland undergoing neoplastic transformation when exposed to given agents. Sufficient evidence exists to indicate the possibility of a slightly increased risk of breast cancer after approximately one decade of postmenopausal estrogen use. A review of the epidemiologic studies of postmenopausal hormone replacement and the risk of breast cancer fails to provide definitive evidence. Recent information derives from observations of cellular proliferation, plasma and tissue estradiol and progesterone receptor levels, and the percentage of apoptotic epithelial cells in human breast tissue. Several studies suggest that short-term, continuous combined HRT does not increase breast cancer recurrence or mortality. The participation of sexual hormones in the mammogenetic process during pregnancy might serve as an intermediate end point in assessing the effectiveness of hormones as chemopreventive agents. Investigations based on history, and breast morphology, should enable us to select estrogens and progestogens for HRT, and adopt optimal therapeutic regimens.
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PMID:Potential benefits of estrogens and progestogens on breast cancer. 992 May 36

The enzyme poly(A) polymerase (PAP) catalyses the polyadenylation of mRNA and its activity levels vary within the cell cycle. The levels of activity of this enzyme were measured in the cytosol of breast tumours from 62 untreated patients and compared to clinical prognostic parameters as well as other biological markers. The enzyme levels measured ranged from 3 to 46 units/mg protein. A statistically significant association was observed between high PAP activity values and the TNM stage of the disease as well as node invasiveness. Furthermore, there was a positive correlation between PAP activity values and c-erbB-2 overexpression but not with its amplification. No significant correlation was observed with c-myc amplification or overexpression and cathepsin D levels. A direct relationship between steroid receptor content and PAP activity levels, which was more prominent in the case of the progesterone receptor, was observed. However, also on the basis of previous data PAP activity may prove to be indicative of aggressive disease. Furthermore, measurements of PAP activity may contribute to the definition of the biological profile of tumour cells.
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PMID:Poly(A)polymerase activity levels in breast tumour cytosols. 1008 76


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