Micronuclei as biomarkers for evaluating the risk of malignant transformation in the uterine cervix

Abstract

ABSTRACT. We evaluated micronucleus and apoptosis occurrence among women with normal smears and women with different kinds of cervical abnormalities, i.e., inflammatory processes and low-and high-grade squamous intraepithelial lesions (N = 12, N = 10 and N = 27, respectively). The sample included 59 women who were seen at a public medical service for cervical cancer prevention in Feira de Santana, Bahia, Brazil. The diagnosis was established by means of cytological, colposcopic, and histopathological examination. Cytogenetic analysis was performed on 2000 cells from each woman and included assessment of micronuclei and nuclear degenerative Micronucleus analysis in uterine cervix abnormalities abnormalities indicative of apoptosis (karyorrhexis, pyknosis and condensed chromatin). Micronucleus frequency was significantly higher in the women with high-grade squamous intraepithelial lesions than in the women without cervical abnormalities or inflammatory processes (P < 0.001) or in the women with low-grade squamous intraepithelial lesions (P < 0.005). The frequency of apoptosis was similar in women without cervical abnormalities and women showing high-grade squamous intraepithelial lesions (P > 0.50), and significantly lower in women without cervical abnormalities and in women showing high-grade squamous intraepithelial lesions than in women showing inflammatory processes or low-grade squamous intraepithelial lesions (P < 0.0001). These results indicate that, in addition to Papanicolaou cervical cytological analysis, it would be useful to use micronucleus analysis to screen women who are at risk of developing cervical cancer. The assessment of nuclear degenerative abnormalities indicative of apoptosis increased the sensitivity of this test.

Comment on the Paper by Safi Oz et al. Entitled ‘Evaluation of Micronuclei, Nuclear Anomalies and the Nuclear/Cytoplasmic Ratio of Exfoliated Cervical Epithelial Cells in Genital Candidiasis'

“…Minimal values were reported by Aires et al [17] (0.15‰) (3-fold higher than the value found by Safi Oz et al) and the maximal value by Chakrabarti and Dutta [18] (4.9‰ in postmenopausal women, 98-fold higher than the value found by Safi Oz et al). It is noteworthy that the last authors found 1.9‰ cells with MN in premenopausal women.…”

Cytokinesis-Block Micronucleus Assay Adapted for Analyzing Genomic Instability of Human Mesenchymal Stem Cells

“…Analysis of MN in interphasic cells of cell smears has been used to detect chromosomal alterations that arise due to the aneugenic and clastogenic effects caused by a variety of compounds. It is being used in the analysis of exfoliated cells to detect precancerous and cancerous lesions, determining high-risk groups for tumors in the oral cavity, urinary tract (bladder), cervix, and esophagus [37,38]. The frequency of micronucleated cells increases in tissues exposed to carcinogens before any clinical symptom emerges.…”

Association between cervical lesion grade and micronucleus frequency in the Papanicolaou test

“…As a result, false negatives account for 10–50% of Pap test results (Dehner, 1993). Complementary methods aimed at increasing the sensitivity of screening for cervical cancer have been described, including high-risk HPV testing (Abreu et al , 2012) and micronucleus (MN) identification (Aires et al , 2011; Gayathri et al , 2012). Although HPV testing is considered the gold standard for diagnosing this viral infection and has the potential to improve the effectiveness of screening programs, its implementation must still be kept low-cost in order to be used in low-income populations (Abreu et al , 2012).…”