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Alterations in BRCA1 and BRCA2 genes account for a large proportion of hereditary breast and ovarian cancers. Mutations and variants of unknown pathological significance have been identified in both genes; however, most of them have been studied only at the genomic level, and their effect on mRNA expression remains unknown. We identified two BRCA1 and six BRCA2 splice site variants, and one BRCA2 alteration at exon 14. Our aim was to ascertain the effect on RNA processing of the variants still unclassified. We found that BRCA1 c.IVS11 + 1G>A, BRCA2 c.7252_7272delinsTG, BRCA2 c.IVS2 + 1G>A, BRCA2 c.IVS13-2A>G, BRCA2 c.IVS21 + 4A>G, and BRCA2 c.9345G>A lead to aberrant transcripts in lymphocytes. Five of these six splice site variants caused a complete inactivation of the mutant allele because they produced frameshift similar to previously described deleterious exonic variants. Therefore, we consider them to be true deleterious mutations, possibly associated with an increased lifetime risk of breast or ovarian cancer. BRCA1 c.IVS17 + 6C>G, BRCA2 c.IVS12-9del4, and BRCA2 IVS1-9del3 represent rare variants, not disrupting normal mRNA processing. The last two BRCA2 genetic variants had not been reported in the Breast Cancer Information Core BIC database.

1. 1. We have measured protein kinase C (PKC) activity in cytosolic fractions of leech central nervous system. 2. 2. Phosphatidylserine and oleylacetylglycerol enhanced the activity of the enzyme in a dose-dependent manner even in the absence of calcium. 3. 3. Most of the substrates of the calcium-dependent protein kinase are substrates of the PKC. 4. 4. H-7 and polymyxin B inhibited both PKC and Ca 2+ -dependent protein kinase.

BRCA1, the predisposing gene for familial breast and ovarian cancer localized on chromosome 17q21.3 has been recently cloned. The gene comprises 22 coding exons which span 100 kB of genomic sequence. The protein predicted is 1863 aminoacids long. 31 mutations have been identified in constitutional DNA of affected member from various family of which 22 were distinct. Not one of 22 transcribed exons seems to be a preferential target site for mutations. Overall germline BRCA1 mutations account for 1–2% of all breast cancers and about 3% of ovarian cancers. The lifetime risk of breast and ovarian cancer in BRCA1 mutation carriers is high: the risk of breast cancer is about 50% by age 50 and 70% by age 70. The average risk of ovarian cancer is 40% by age 70. BRCA1 has never been found mutated in sporadic carcinomas, however, loss of heterozigosity in the region of BRCA1 has been observed in 40% of breast and about 60% of ovarian cancers. The lifetime risk to develop the familial form of the disease may be calculated by identifying mutations in BRCA1 or BRCA2 genes. From the screening of 1100 medical records of patients subjected to mastectomy in S. Chiara Hospital in Pisa during the period 1990–1994, the patients with a referred familial recurrence of breast or ovarian cancer were selected for interview. 81 patients belonging to 75 families fitted the BRCA1 eligibility criteria. 37 patients belonging to different families were analyzed for BRCA1 germline mutation. All 37 families are Caucasian and principally reside in Tuscany. Mutation screening was done by ASO (allelic specific oligo hybridization) for three common mutations and by direct sequencing of each of the coding exons. The analysis is under way and approximately 50% ofthe coding region has been screened up to now. We have so far identified 7 mutations of which 5 are different. Three are frameshift and 2 missense. Only one of the mutations found has been reported previously (5382insC). The insertion of an A has been reported in three different families, the aplotype analysis has been performed to ascertain if a common ancestor exist for those three families. No evident correlation between phenotype and genotype has been detected. CG and GC are fellows of the Italian Association for Cancer Research. This work was supported by AIRC and CNR PF ACRO grants.