SUMMARY Serum amyloid A (SAA) is an acute-phase reactant whose level in the blood is elevated to 1000-fold as part of the body's responses to various injuries, including trauma, infection, inflammation, and neoplasia. As an acute-phase reactant, the liver has been considered to be the primary site of expression. However, limited extrahepatic SAA expression was described in mouse tissues and in cells of human atherosclerotic lesions. Here we describe nonradioactive in situ hybridization experiments revealing that the SAA mRNA is widely expressed in many histologically normal human tissues. Expression was localized predominantly to the epithelial components of a variety of tissues, including breast, stomach, small and large intestine, prostate, lung, pancreas, kidney, tonsil, thyroid, pituitary, placenta, skin epidermis, and brain neurons. Expression was also observed in lymphocytes, plasma cells, and endothelial cells. RT-PCR analysis of selected tissues revealed expression of the SAA1, SAA2, and SAA4 genes but not of SAA3, consistent with expression of these genes in the liver. Immunohistochemical staining revealed SAA protein expression that colocalized with SAA mRNA expression. These data indicate local production of the SAA proteins in histologically normal human extrahepatic tissues.
BRCA1 and BRCA2 carriers are at increased risk for both breast and ovarian cancer, but estimates of lifetime risk vary widely, suggesting their penetrance is modified by other genetic and͞or environmental factors. The BRCA1 and BRCA2 proteins function in DNA repair in conjunction with RAD51. A preliminary report suggested that a single nucleotide polymorphism in the 5 untranslated region of RAD51 (135C͞G) increases breast cancer risk in BRCA1 and BRCA2 carriers. To investigate this effect we studied 257 female Ashkenazi Jewish carriers of one of the common BRCA1 (185delAG, 5382insC) or BRCA2 (6174delT) mutations. Of this group, 164 were affected with breast and͞or ovarian cancer and 93 were unaffected. RAD51 genotyping was performed on all subjects. Among BRCA1 carriers, RAD51-135C frequency was similar in healthy and affected women [6.1% (3 of 49) and 9.9% (12 of 121), respectively], and RAD-135C did not influence age of cancer diagnosis [Hazard ratio (HR) ؍ 1.18 for disease in RAD51-135C heterozygotes, not significant]. However, in BRCA2 carriers, RAD51-135C heterozygote frequency in affected women was 17.4% (8 of 46) compared with 4.9% (2 of 41) in unaffected women (P ؍ 0.07). Survival analysis in BRCA2 carriers showed RAD51-135C increased risk of breast and͞or ovarian cancer with an HR of 4.0 [95% confidence interval 1.6 -9.8, P ؍ 0.003]. This effect was largely due to increased breast cancer risk with an HR of 3.46 (95% confidence interval 1.3-9.2, P ؍ 0.01) for breast cancer in BRCA2 carriers who were RAD51-135C heterozygotes. RAD51 status did not affect ovarian cancer risk. These results show RAD51-135C is a clinically significant modifier of BRCA2 penetrance, specifically in raising breast cancer risk at younger ages. G erm-line mutations in the BRCA1 and BRCA2 genes increase susceptibility for both breast and ovarian cancer. Penetrance of these mutations is incomplete and age-dependent, thus cancer risk in carriers continues to increase with age even though the mean age of cancer diagnosis is younger in BRCA1͞ BRCA2 carriers compared with noncarriers (1). Estimates of penetrance have varied widely, perhaps as a result of different ascertainment schemes and͞or allelic effects. In families ascertained for multiple affected individuals suitable for linkage analysis, lifetime cancer risk (by age 70) was 85% for breast cancer in both BRCA1 and BRCA2 carriers (2, 3), 63% for ovarian cancer in BRCA1 carriers (2), and 27% for ovarian cancer in BRCA2 carriers (3). Significantly lower risk estimates were obtained in studies performed in less selected families or at the population level, with a 36-56% lifetime risk for breast cancer (4-7) and a 16% lifetime risk for ovarian cancer (5). These studies were performed in specific ethnic groups (Ashkenazi Jewish and the Iceland population) that harbor a limited number of specific mutations and could therefore be representative of these alleles, rather than reflect the general penetrance of BRCA1͞BRCA2 mutations. Such differences suggest that penetrance of BRCA1...
The ARMS assay is a rapid, cost-effective, and accurate method for detecting three common mutations in familial Mediterranean fever.
We have screened for CDKN2A germline mutations in 49 Jewish families with two or more cases of melanoma. The Val59Gly mutation, one of the three different alterations identified among these families, was also detected independently in two kindreds from France and one from Spain. The impact of the Val59Gly substitution on the function of the cyclin-dependent kinase inhibitor p16INK4a , a product of the CDKN2A gene, was assessed by protein -protein interaction and cell proliferation assays and related to potential structural alterations predicted by molecular modeling. Seven microsatellite markers in the vicinity of the CDKN2A gene were used to determine whether the mutation in these families is identical by descent, or represents a mutational hotspot in the CDKN2A gene. Our results show that the Val59Gly substitution impairs p16INK4a function, and this dysfunction is consistent with structural predictions. All melanoma-affected individuals tested in the families under study harbor this mutation. Interestingly, the Israeli pedigree includes an affected individual who is homozygous for the Val59Gly mutation. A common haplotype of microsatellite markers has been demonstrated for mutation carriers in all four pedigrees. The Israeli pedigree and one of the French melanoma families are of Moroccan and Tunisian Jewish descent, respectively, and the other families originate from regions of France and Spain close to the Pyrenees. We conclude that the Val59Gly mutation is a major contributor to melanoma risk in the families under study and that it may derive from a single ancestral founder of Mediterranean (possibly Jewish) origin.
Familial Mediterranean fever (FMF) is an inherited disease whose manifestations are acute but reversible attacks of sterile inflammation affecting synovial and serosal spaces. The FMF gene (MEFV) was recently cloned, and it codes for a protein (pyrin/marenostrin) homologous to known nuclear factors. We previously reported the deficient activity of a C5a/interleukin (IL)–8 inhibitor, a physiologic regulator of inflammatory processes, in FMF serosal and synovial fluids. We now describe the concomitant expression ofMEFV and C5a/IL-8–inhibitor activity in primary cultures of human fibroblasts. Fibroblasts grown from synovial and peritoneal tissues displayed C5a/IL-8–inhibitor activity that could be further induced with phorbol myristate acetate (PMA) and IL-1β. Very low levels of chemotactic inhibitor were evident in skin fibroblast cultures or in peritoneal and skin fibroblasts obtained from FMF patients. MEFV was expressed in peritoneal and skin fibroblasts at a lower level than in neutrophils and could be further induced by PMA and IL-1β. In the FMF cultures, the MEFV transcript carried the M694V mutation, consistent with the genetic defect found in patients with this disease. MEFV was also expressed in other cell lines that do not produce C5a/IL-8 inhibitor. These findings suggest that human primary fibroblast cultures express MEFV and produce C5a/IL-8–inhibitor activity. The interrelationship between pyrin, the MEFV product, and the C5a/IL-8 inhibitor requires further investigation.
Familial Mediterranean fever (FMF) is an inherited disease whose manifestations are acute but reversible attacks of sterile inflammation affecting synovial and serosal spaces. The FMF gene (MEFV) was recently cloned, and it codes for a protein (pyrin/marenostrin) homologous to known nuclear factors. We previously reported the deficient activity of a C5a/interleukin (IL)–8 inhibitor, a physiologic regulator of inflammatory processes, in FMF serosal and synovial fluids. We now describe the concomitant expression ofMEFV and C5a/IL-8–inhibitor activity in primary cultures of human fibroblasts. Fibroblasts grown from synovial and peritoneal tissues displayed C5a/IL-8–inhibitor activity that could be further induced with phorbol myristate acetate (PMA) and IL-1β. Very low levels of chemotactic inhibitor were evident in skin fibroblast cultures or in peritoneal and skin fibroblasts obtained from FMF patients. MEFV was expressed in peritoneal and skin fibroblasts at a lower level than in neutrophils and could be further induced by PMA and IL-1β. In the FMF cultures, the MEFV transcript carried the M694V mutation, consistent with the genetic defect found in patients with this disease. MEFV was also expressed in other cell lines that do not produce C5a/IL-8 inhibitor. These findings suggest that human primary fibroblast cultures express MEFV and produce C5a/IL-8–inhibitor activity. The interrelationship between pyrin, the MEFV product, and the C5a/IL-8 inhibitor requires further investigation.
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