Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.23.5 (cathepsin D)
 4,130 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Breast growth and development is influenced by oestrogens and the growth of many breast cancers is driven by oestrogens, an effect which is utilised in the endocrine treatment of breast cancer. Oestrogens act by binding to the oestrogen receptor, a specific protein which in turn binds to specific regulatory regions of DNA, thereby altering gene expression. The effects of oestrogens may be mediated by growth factors and other substances under oestrogen regulation. Oestrogen receptor status in breast tumours can be determined by cytosolic radioligand binding assays, enzyme linked immunoassay, immunohistochemistry and measurement of messenger RNA levels. Tumour oestrogen receptor content is an established but not absolute predictor of both response to endocrine therapy and prognosis in breast cancer. Paradoxically, a small proportion of apparently oestrogen receptor negative tumours do respond to endocrine therapy, perhaps reflecting expression of low and unmeasurable levels of receptor or tumour heterogeneity with respect to receptor expression. A larger proportion of oestrogen receptor positive tumours unexpectedly fail to respond to endocrine therapy; in these cases it is possible that oestrogen receptor has become dissociated from the transcriptional and translational events which it normally regulates. Determination of levels of expression of substances regulated by oestrogens can provide information regarding the functional integrity of the oestrogen response pathway and such substances include the progesterone receptor, plasminogen activator, cathepsin D and a variety of messenger RNA sequences.
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PMID:Oestrogen receptor and oestrogen regulated proteins in human breast cancer: a review. 268 40

Proteases are involved in the invasion and metastasis of tumours by destruction of the basal membrane and connective tissue. As levels in malignant tissue have both prognostic and therapeutic implications, we examined 318 frozen samples from malignant tumours and comparable non-malignant tissue looking for urokinase plasminogen activator (uPA), tissue plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) levels with ELISA, as well as cathepsin D with RIA. Oestrogen receptor (ER) levels, progesterone receptor (PrgR) levels and epidermal growth factor receptors (EGFR) were measured by biochemical methods at the same time. Significantly raised levels of uPA, PAI-1 and cathepsin D were found in malignant tissue, with PAI-1 particularly high in carcinoma of the cervix. Significantly raised tPA levels were found in breast cancer tissue with a more favourable clinical prognosis, with a positive correlation between tPA and ER. No correlation could be shown between uPA, PAI-1 and cathepsin D with other prognostic factors for breast cancer. It could be that routine, uncomplicated estimation of tumour-associated proteases such as uPA, tPA, PAI-1 and cathepsin D will provide an independent prognostic marker for therapeutic decisions with regard to gynaecological tumours and breast cancer.
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PMID:Proteases associated with gynecological tumors. 2156 82