About 25-50% of women with Cowden disease, a syndrome associated with germ-line mutations of the PTEN gene (at 10q23), develop breast cancer (BC), but PTEN mutations have been found in only 5% of sporadic BCs. However, 29-48% of BCs display loss of heterozygosity in 10q23, and about 40% of BCs show a decrease or absence of PTEN protein levels at the time of diagnosis. Promoter hypermethylation has been identified as an alternative mechanism of tumor-suppressor gene inactivation, but its importance in PTEN silencing in sporadic BC is unknown. We investigated PTEN promoter hypermethylation in 90 sporadic BCs and its correlations with 11 molecular and pathologic parameters, including mRNA levels of PTEN. The study, a methylation-specific PCR assay, was carried out with methylated specific primers designed in a region with scarce homology with the psiPTEN pseudogene. Expression was analyzed by real-time PCR. We found that the PTEN promoter was hypermethylated in 43 BCs (48%). PTEN hypermethylation was associated with ERBB2 overexpression, larger size, and higher histologic grade (P=0.012, 0.03, and 0.009, respectively). We concluded that PTEN promoter hypermethylation is a common event in sporadic BC, correlating with other well-established prognostic factors of this malignancy. Additionally, PTEN mRNA expression was lower in tumors with aberrant methylation.

Our data confirm the variety of benign and malignant pathologies coursing with increased CA-125. Cardiovascular and chronic liver disease were the most frequent diagnoses in patients with increased CA-125; this supports the opinion that CA-125 lacks utility as a marker for malignancy. CA-125 could have a role in the follow-up of cardiovascular, hepatic, and tumoral diseases with serosal involvement.

Background and purpose: Ototoxicity is a known adverse effect of cisplatin (CDDP). Since apoptosis is involved in the development of some pathological conditions associated with the administration of anticancer drugs, we examined, using immunohistochemical and electrophysiological techniques, the apoptotic changes in the cochlea of Sprague-Dawley (SD) rats after an injection of CDDP (5 mgkg -1 body weight). Experimental approach: Luciferase assays were used to determine the different caspase activities and ATP levels in protein extracts of whole cochleae. The expression of several apoptotic-related proteins was measured by means of Western blotting. These analyses were performed 2, 7 and 30 days after the CDDP injection. The auditory brain stem response was obtained before and at the different times after the injection of CDDP, before the animals were killed. Key results: CDDP significantly increased the levels of caspase-3/7 activity and active caspase-3 protein expression and caspase-3 immunofluorescence staining, caspase-9 activity, and Bax protein expression but decreased Bcl-2 protein expression within the rat cochleae. Threshold shifts were significantly elevated 2 days after CDDP treatment. Conclusions and implications: These findings support the hypothesis that cisplatin-related apoptosis evokes an intrinsic pathway of pro-apoptotic signalling within the rat cochleae. Thus, selective inhibition of the sequence of events involved in the intrinsic apoptotic pathway could provide a strategy to minimize cisplatin-induced ototoxicity.

Persistence of plasma DNA with features of tumor DNA may be present after mastectomy in breast cancer patients, and its relation to bad-prognosis histological parameters may suggest undetectable micrometastatic disease.

The INK4a/ARF locus encodes two tumour suppressor proteins, p16INK4a and p14ARF, which act in the two main cell-cycle control pathways, p16-Rb and p14-p53 respectively. The present study examined the mRNA expression of these genes by reverse transcription-polymerase chain reaction (RT-PCR), and the inactivation mechanisms that alter these levels, in 100 primary breast carcinomas. Furthermore, the interdependence of these mechanisms was examined, since it has been reported that p14ARF is altered in most tumours in concordance with p16INK4a. The results show that promoter hypermethylation, tested by methylation-specific PCR (MSP), was the major mechanism of inactivation of these genes and was present in 31 (31%) and 50 (50%) of the tumours that showed decreased p16INK4a and p14ARF expression, respectively. Hemizygous deletion was the second cause of down-regulation. Homozygous deletion was rare and mutation was absent. In most tumours overexpressing p16INK4a or p14ARF, no detectable inactivation mechanisms were observed. Finally, the results indicate that these proteins are often co-altered in primary breast tumours and that p16INK4a and p14ARF had non-independent behaviour, since they were silenced or overexpressed concomitantly with a significant correlation (p < 0.05).