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.

Background: Although circulating tumour DNA has been detected in patients with different types of cancer, little is known of free RNA in cancer patients. Aims: We investigated the presence of RNA from epithelial tumours in plasma from patients with colorectal carcinomas, and its correlation with tumour characteristics and circulating tumour cells. Methods: β-actin mRNA was analysed to assess the viability of plasma RNA in samples from 53 patients with colonic cancer and 25 controls. Subsequently, nested primers were used to detect the presence of cytokeratin 19 (CK19) and carcinoembryonic antigen (CEA) RNA in the same samples. Nine clinicopathological parameters were studied to correlate the molecular and clinical parameters. Additionally, we investigated for micrometastases in blood in 18 of these patients and in 10 of the controls samples. Results: All samples had detectable quantities of β-actin RNA. In the controls, one case (4%) was positive for CEA and five (20%) for CK19 RNA; of the 53 patients, 17 cases (32%) were positive for CEA and 39 (73.6%) for CK19 RNA. This was statistically significant (p=0.000001). Advanced stages (p=0.03) and soluble CEA status (p=0.03) were associated with the presence of CEA, CK19, or both RNAs in plasma. Lymph node metastases (p=0.06) and vascular invasion (p=0.07) were almost significant. On the basis of these results, we examined the possible presence of micrometastases in blood in several of these patients. The presence of plasma tumour RNA was found to be associated with circulating tumour cells in blood (p=0.04). Conclusions: Epithelial tumour RNA is detectable in plasma from colon cancer patients. This molecular event is associated with advanced stages and circulating tumour cells. Our results could offer new approaches in the diagnosis and monitoring of colon cancer.

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.