Molecular monitoring by CDKN2A/p16INK4A and RB1 gene methylation in breast cancer

OBJECTIVE

This prospective study aimed to provide a comprehensive analysis of the methylation status of two pivotal genes, CDKN2A/p16INK4A (cyclin-dependent kinase inhibitor 2A) and RB1 (retinoblastoma transcriptional corepressor 1), in breast cancer patients.

METHODS

Samples were obtained from 15 women diagnosed with breast cancer and who underwent a total mastectomy. DNA was extracted from the tumor, non-tumor tissue, and peripheral blood (circulating cell-free DNA). The methylation pattern of cell-free DNA extracted from blood collected on the day of mastectomy was compared with the methylation pattern of cell-free DNA from blood collected 1 year post-surgery. The methylation analysis was carried out by sodium bisulfite conversion and polymerase chain reaction, followed by electrophoresis.

RESULTS

Methylation of CDKN2A/p16INK4A was identified in 13 tumor samples and 12 non-tumor tissue samples. Two patients exhibited CDKN2A/p16INK4A methylation in the cell-free DNA of the first blood collection, while another showed methylation only in the cell-free DNA of the subsequent blood collection. Regarding RB1, 11 tumors and 8 non-tumor tissue samples presented methylation of the gene.

CONCLUSION

This study presents a novel approach for monitoring breast cancer patients through the analysis of cell-free DNA methylation. This analysis can detect changes in methylation patterns before any visible sign of cancer appears in breast tissue and could help predict the recurrence of malignant breast tumors.

Clinical factors associated with severity in patients with inflammatory bowel disease in Brazil based on 2-year national registry data from GEDIIB

The Brazilian Organization for Crohn's Disease and Colitis (GEDIIB) established a national registry of inflammatory bowel disease (IBD). The aim of the study was to identify clinical factors associated with disease severity in IBD patients in Brazil. A population-based risk model aimed at stratifying the severity of IBD based on previous hospitalization, use of biologics, and need for surgery for ulcerative colitis (UC) and Crohn's Disease (CD) and on previous complications for CD. A total of 1179 patients (34.4 ± 14.7y; females 59%) were included: 46.6% with UC, 44.2% with CD, and 0.9% with unclassified IBD (IBD-U). The time from the beginning of the symptoms to diagnosis was 3.85y. In CD, 41.2% of patients presented with ileocolic disease, 32% inflammatory behavior, and 15.5% perianal disease. In UC, 46.3% presented with extensive colitis. Regarding treatment, 68.1%, 67%, and 47.6% received biological therapy, salicylates and immunosuppressors, respectively. Severe disease was associated with the presence of extensive colitis, EIM, male, comorbidities, and familial history of colorectal cancer in patients with UC. The presence of Montreal B2 and B3 behaviors, colonic location, and EIM were associated with CD severity. In conclusion, disease severity was associated with younger age, greater disease extent, and the presence of rheumatic EIM.

hTERT gene methylation in circulating DNA, tumor, and surrounding tissue in breast cancer: a prospective study

BACKGROUND

The human telomerase reverse transcriptase (hTERT) enzyme, encoded by the hTERT gene, synthesizes protective telomeric sequences on chromosomes and plays a fundamental role in cancer formation. Methylation of the hTERT gene has an upregulatory effect, increasing hTERT enzyme synthesis and allowing continuous tumor cell division.

OBJECTIVE

In a group of patients with breast cancer, we aimed to analyze the methylation status of hTERT in the tumor, surrounding tissue, and circulating free deoxyribonucleic acid (cfDNA) of blood collected on the day of mastectomy and then approximately one year later.

DESIGN AND SETTING

A prospective study was conducted at a university hospital in Rio de Janeiro, Brazil.

METHODS

Samples were collected from 15 women with breast cancer on the day of mastectomy and approximately one year postoperatively. cfDNA was analyzed by sodium bisulfite conversion, followed by polymerase chain reaction, electrophoresis, and silver nitrate staining.

RESULTS

Methylation of hTERT was detected in the tumors and surrounding tissues of all 15 patients. Five patients displayed hTERT methylation in the cfDNA from the blood of the first collection. Of the ten patients who returned for the second collection, three showed methylation. Two patients with methylation in the first collection did not display methylation in the second collection. One patient with no methylation in the first collection displayed methylation in the second collection, and one patient had a diminished level of methylation in the second collection.

CONCLUSION

Only one-third of patients displayed methylation in their cfDNA, which may be related to the success of chemotherapy.

Small bowel of patients with asthma and allergic rhinitis: absence of inflammation despite the presence of major cellular components of allergic inflammation

Eosinophils participate in the pathogenesis of inflammatory diseases of the respiratory tract and the gut. We investigated the constitutive presence of eosinophils and mononuclear cells in the macroscopically normal duodenal mucosa of patients with asthma and allergic rhinitis. Macroscopically normal duodenal specimens were obtained at routine endoscopy for upper gastrointestinal symptoms from 16 patients with asthma and 13 patients with allergic rhinitis. Twelve nonatopic patients with irritable bowel syndrome were studied as controls. Specimens were analyzed by immunohistochemistry using a panel of antibodies to human eosinophil cationic protein clone EG1 (EG1) and clone EG2 (EG2), anti-human interleukin (anti-hIL)-5, anti-hIL-4, anti-CD4, and anti-CD68. Significantly increased numbers of eosinophils stained with EG1 and EG2 were found in the duodenum of patients with asthma and allergic rhinitis compared with controls. IL-5+ cells and IL-4+ cells were detected in significantly increased numbers in the duodenal mucosa of patients with asthma and rhinitis compared with controls. Mononuclear cells expressing CD4 (helper T cells) and CD68 (macrophages) also were significantly increased in the duodenal mucosa of asthma and rhinitis compared with controls. Accumulation of eosinophils in conjunction with IL-4+ cells and IL-5+ cells in the noninflamed duodenal mucosa may reflect a predominant T helper cell subset 2 systemic immune response in patients with asthma and allergic rhinitis. The absence of intestinal inflammation despite the marked presence of cells implicated in the allergic inflammation suggests that local mechanisms might determine the state of nonresponsiveness in the gut mucosa of patients with asthma and allergic rhinitis.