Methylation profiling in promoter sequences of ATM and CDKN2A (p14ARF/p16INK4a ) genes in blood and cfDNA from women with impalpable breast lesions.

The objective of the present study was to evaluate the epigenetic changes occurring in early stages of breast cancer. The present study investigated the methylation profile of the ATM, p14ARF and p16INK4a promoters in total blood and plasma cell-free DNA (cfDNA) from women with impalpable breast lesions compared with in total blood of a control cohort of women without breast lesions. The samples were evaluated using the methylation-specific PCR method. The Fisher's exact test was used to evaluate statistical significance between the methylation and clinical variables. A total of 111 women were evaluated, including 56 women with impalpable breast cancer (39/56 also had paired plasma cfDNA) and 55 women in the control cohort (55 blood DNA). For blood DNA from women with malignant impalpable breast lesions, p16INK4a exhibited the greatest percentage of methylation (48%), followed by ATM (37.5%) and p14ARF (27%) promoters, regardless of age variation. For plasma cfDNA, the methylation rates for ATM, p14ARF and p16INK4a were 26, 26 and 10%, respectively. The methylation rates for the blood DNA of controls were the lowest for ATM (9%), p14ARF (7%) and p16INK4a (7%). The women with impalpable breast lesions (benign and malignant lesions) exhibited the highest methylation rate, regardless of age, compared with the paired plasma cfDNA and controls. This epigenetic change was statistically significant for the promoters of ATM (P=0.009) and p16INK4a (P=0.001) (impalpable breast lesions vs. control). The present study demonstrated that epigenetic changes occurring in the ATM and CDKN2A genes detectable in liquid biopsy were associated with the development of impalpable breast lesions.

Proteomic profile of saliva and plasma from women with impalpable breast lesions.

The present study evaluated the proteomic profile of saliva and plasma from women with impalpable breast lesions using nano-liquid chromatography-quadrupole-time-of-flight (nLC-Q-TOF) technology. Plasma and saliva from patients with fibroadenoma (n=10), infiltrating ductal carcinoma (n=10) and healthy control groups (n=8) were assessed by combinations of inter/intra-group analyses, revealing significant quantitative and qualitative differences. The major differentially-expressed proteins in the saliva of patients compared with the controls were α2-macroglobulin and ceruloplasmin, but the proteins that met the minimum fold-change and P-value cut-offs were leukocyte elastase inhibitor and α-enolase, and deleted in malignant brain tumors 1. Concerning plasma, α-2-macroglobulin and ceruplasmin were upregulated, while other proteins such as haptoglobin, hemopexin and vitamin D-binding protein were downregulated compared with the control. The changes in immune, molecular transport and signaling pathways were the most representative in the proteomic profile of the saliva and plasma. This is the first study to describe the proteome of saliva and plasma from the same women with impalpable breast lesions.

CDKN2A (p14(ARF)/p16(INK4a)) and ATM promoter methylation in patients with impalpable breast lesions.

Early detection of breast cancer increases the chances of cure, but the reliable identification of impalpable lesions is still a challenge. In spite of the advances in breast cancer detection, the molecular basis of impalpable lesions and the corresponding circulating biomarkers are not well understood. Impalpable lesions, classified by radiologists according to the Breast Imaging Reporting and Data System in the categories 3 and 4, can be either benign or malignant (slow growing or aggressive). In this article, we report the DNA methylation pattern in CDKN2A (p14(ARF)/p16(INK4a)) and in ATM gene promoters from 62 impalpable lesions, 39 peripheral blood samples, and 39 saliva samples, assessed by methylation-specific polymerase chain reaction method. ATM showed the greatest percentage of methylation in DNA from lesions (benign and malignant), blood (even with p16(INK4a)), and saliva, followed by p16(INK4a) and p14(ARF). Among the malignant cases, ATM promoter was the most hypermethylated in lesion DNA and in blood and saliva DNAs, and p14(ARF), the least. The highest percentage of p16(INK4a) methylation was found in the blood. Finally, our data are relevant because they were obtained using impalpable breast lesions from patients who were carefully recruited in 2 public hospitals of Rio de Janeiro.

Protein identification from dried nipple aspirate fluid on Guthrie cards using mass spectrometry.

Nipple aspirate fluid (NAF) requires investigation as a potential source of biomarkers for early diagnosis or risk assessment in breast cancer and other breast disorders. The present study demonstrated that proteins were easily extracted from dried NAF spots on Guthrie cards and were suitable for mass spectrometry analysis. NAF was obtained from 80 women, collected on Guthrie cards, between 2007 and 2010. The NAF-proteins were extracted from the card by incubating the card in water. These proteins were then quantified and separated using one-dimensional, 12% SDS-PAGE, gel electrophoresis and on high-resolution gradient gels at different concentrations (4-12, 8-16 and 4-20%). The bands with the most abundant proteins were excised from the gradient gels and the proteins were identified by liquid chromatography quadrupole time of flight. Immunoglobulins, Zn-α2-glicoprotein, apoliprotein D and prolactin inducible protein were among those identified. The NAF-Guthrie card collection method has not been applied previously, however, NAF proteins have been identified using other collecting techniques, confirming the feasibility of the NAF Guthrie card collection method for analyzing the proteins within NAF. The NAF-Guthrie card collecting method has multiple advantages, including being inexpensive, non-invasive, reliable and painless, and the cards can be stored at room temperature. Examining NAF may assist in identifying individuals at a higher risk of breast cancer and in improving patient prognosis.

Measurement of HER2 in saliva of women in risk of breast cancer.

HER2 amplification can be present in ductal carcinoma in situ (DCIS). The aim of the present study was to test the feasibility of measuring soluble HER2 in the saliva of patients at risk of breast cancer towards early diagnosis and prognosis. Women with lesions classified as 4 according to BIRADS and women with spontaneous nipple discharge (NAF) were recruited for this study. Quantification of soluble HER2 in saliva was performed using the enzyme immunoassay ELISA. Median values of HER2 were quantified in saliva of the control groups and in the patient groups. The statistical test nonparametric Mann-Whitney was applied for the evaluation of median differences. Although the medians increased with the severity of the clinical status, no significant difference was found in all possibilities (p > 0.05) when comparing the medians among the patients groups. Interestingly, inter-individual HER2 quantity variations in the saliva were detected in this study in some subjects from each group. Considering possible inter-individual variations, research on saliva-based circulating HER2 has to be reinforced to ensure its correct application in diagnosis, treatment and in follow-up of breast cancer patients. Older and current issues surrounding the controversy about the appropriate methods for HER2 evaluation are discussed.