Aberrant Promoter Methylation and Expression of UTF1 during Cervical Carcinogenesis

Abstract

Promoter methylation profiles are proposed as potential prognosis and/or diagnosis biomarkers in cervical cancer. Up to now, little is known about the promoter methylation profile and expression pattern of stem cell (SC) markers during tumor development. In this study, we were interested to identify SC genes methylation profiles during cervical carcinogenesis. A genome-wide promoter methylation screening revealed a strong hypermethylation of Undifferentiated cell Transcription Factor 1 (UTF1) promoter in cervical cancer in comparison with normal ectocervix. By direct bisulfite pyrosequencing of DNA isolated from liquid-based cytological samples, we showed that UTF1 promoter methylation increases with lesion severity, the highest level of methylation being found in carcinoma. This hypermethylation was associated with increased UTF1 mRNA and protein expression. By using quantitative RT-PCR and Western Blot, we showed that both UTF1 mRNA and protein are present in epithelial cancer cell lines, even in the absence of its two main described regulators Oct4A and Sox2. Moreover, by immunofluorescence, we confirmed the nuclear localisation of UTF1 in cell lines. Surprisingly, direct bisulfite pyrosequencing revealed that the inhibition of DNA methyltransferase by 5-aza-2′-deoxycytidine was associated with decreased UTF1 gene methylation and expression in two cervical cancer cell lines of the four tested. These findings strongly suggest that UTF1 promoter methylation profile might be a useful biomarker for cervical cancer diagnosis and raise the questions of its role during epithelial carcinogenesis and of the mechanisms regulating its expression.

DNA Promoter Methylation-dependent Transcription of the Double C2-like Domain β (DOC2B) Gene Regulates Tumor Growth in Human Cervical Cancer

“…Therefore, new screening modalities with high sensitivity and specificity need to be evaluated and pursued. Toward this, DNA methylation markers can be highly useful in screening early stages of cervical cancer (2,38,39). Hypermethylation of the DOC2B promoter and its low expression during the pre-malignant condition shows its potential as a marker for early screening of cervical cancer.…”

Expression profile of undifferentiated cell transcription factor 1 in normal and cancerous human epithelia

“…; Guenin et al . ). Figure shows representative images of UTF1 staining in each tissue type, with their corresponding negative controls (capital and lower case letters respectively).…”

“…; Guenin et al . ). Interestingly, we found that UTF1 expression was not associated with that of Sox2 and Oct4A in any of the epithelial cell lines.…”

“…To provide a global score for each case, the results obtained using the two scales were multiplied, yielding a single scale of 0, +1, +2, +3, +4, +6 and +9 (Guenin et al . ). For scoring only the nuclear staining was taken into consideration.…”

“…In addition, we have previously shown that UTF1 overexpression was associated with cervical carcinogenesis (Guenin et al . ). Nevertheless, no further data are available about its expression profile in other human normal epithelia and their corresponding tumours.…”