The synthesis and secretion of insulin-like growth factor binding proteins (IGFBPs) were studied in MDA-MB-23 1 (estrogen-receptor-negative), MCF-7/6 (estrogen-receptor-positive, invasive) and in MCF-7/AZ (estrogen-receptor-positive, non-invasive) human breast carcinoma cell lines. Cells were grown or maintained in a chemically defined medium. Under these conditions, we found different patterns of IGFBPs in the three cell types. MDA-MB-231 cells secrete most of the IGFBPs they produce whereas MCF-7/6 and MCF-7/AZ cells maintain a high intracellular level. In MDA-MB-231 cells, the major IGFBP is IGFBP-4 which is the minor form in MCF-7/6 and MCF-7/AZ cells. IGFBP-2 and IGFBP-5 are predominant in MCF-7/6 cells while MCF-7/AZ cells produce far less IGFBPs and do not contain detectable amounts of 29-32-kDa forms (IGFBP-5). In MCF-7/6 cells, estradiol-17/? specifically decreases both the intracellular content and secretion of IGFBP-2 and IGFBP-5. Estrogen regulation of IGFBPs cell content and secretion was found to be tamoxifen-resistant, and only slightly antagonized by ICI 182,780, a pure antiestrogen. The function of these regulations relative to the invasive phenotype and proliferation has now to be determined.

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We used enzymatic activity and immunochemical quantifications to analyse the expression and secretion of cathepsin D by human breast cancer cell lines of different invasive potentials (MCF-7/6, MCF-7/AZ, MDA-MB-231). This study does not directly prove that cathepsin D or procathepsin D is involved in human breast cancer cell invasion and metastasis but it shows that the proportion of procathepsin D (activity and antigen) secreted by the human breast cancer cell lines tested correlates with their invasive potential. In the estrogen receptor-positive MCF-7 subclones, this proportion is increased by estradiol only in the invasive MCF-7/6 variant. The cell content in procathepsin D is increased by estrogens to a greater extent in MCF-7/6 cells as compared to non-invasive MCF-7/AZ cells. Tamoxifen appears to be an estrogen agonist concerning cathepsin D regulation, whereas ICI 182,780 is a true antagonist. Our results suggest that synthesis and secretion of cathepsin D are regulated at two distinct levels and differentially affected by estrogens. Synthesis only seems to be affected in non-invasive MCF-7/AZ cells, whereas in invasive MCF-7/6 cells, both synthesis and the efficiency of secretion are increased by estrogens. Our results also confirm that the key site of regulation leading to lysosomal enzyme oversecretion is the Golgi apparatus insulin-like growth factor-II/mannose 6-phosphate receptor.

Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disease that is inherited in an autosomal recessive manner and is caused by mutations in the MEFV gene. As the name indicates, FMF occurs within families and is more common in individuals of Mediterranean descent than in persons of any other ethnicity. To date, 314 mutations have been reported. We studied a Moroccan family with a total of five members, including a mother who was presenting with symptoms of FMF, while her four children remained asymptomatic. The five patients were screened by DNA sequencing of exon 2 and exon 10 of the MEFV gene. Then, complete exome sequencing analysis of the MEFV gene was done for the patients in whom a novel mutation was detected. This analysis identified a novel single base Cytosine (C) insertion mutation in the coding region of the MEFV gene, named c.441dupC (p. Glu148Argfs*5 or E148RfsX5), which resulted in a mutated Pyrin/Marenostrin protein. This is the first report of a new mutation in exon 2 of the MEFV gene in a Moroccan family. This novel insertion mutation may provide important information for further studies of FMF pathogenesis.