The role of aldehyde dehydrogenase 1 (ALDH1) as an ovarian cancer stem cell marker and its clinical significance have rarely been explored. We used an Aldefluor assay to isolate ALDH1-bright (ALDH1(br)) cells from epithelial ovarian cancer cell lines and characterized the properties of the stem cells. ALDH1(br) cells were enriched in ES-2 (1.3%), TOV-21G (1.0%), and CP70 (1.2%) cells. Both ALDH1(br) and ALDH1(low) cells repopulated stem cell heterogeneity, formed spheroids, and grew into tumors in immunocompromised mice, although these processes were more efficient in ALDH1(br) cells. In the ES-2 and CP70 cells, ALDH1(br) cells conferred more chemoresistance, and were more enriched in CD44 (by 1.74-fold and 5.18-fold, respectively) than in CD133 (by 1.39-fold and 1.17-fold, respectively), compared with ALDH1(low) cells. Immunohistochemical staining for ALDH1 on a tissue microarray containing 84 epithelial ovarian cancer samples revealed that patients with higher ALDH1 expression (>50%) had poor overall survival, compared with those with lower ALDH1 (P = 0.004) and yielded an odds ratio of death of 2.43 (95% CI = 1.12 to 5.28) by multivariate analysis. The results did not support ALDH1 alone as an ovarian cancer stem cell marker, but demonstrated that ALDH1 is associated with CD44 expression, chemoresistance, and poor clinical outcome. The use of a combination of ALDH1 with other stem cell markers may help define ovarian cancer stem cells more stringently.

BACKGROUND: DNA methylation may be used a potential biomarker for detecting cervical cancer. The authors of this report used quantitative methylation analysis of 4 genes in a full spectrum of cervical lesions to test its potential clinical application. METHODS: This hospital-based, retrospective, case-control study was conducted in 185 patients and included patients who had a normal uterine cervix (n ¼ 53), cervical intraepithelial neoplasm type 1 (CIN1) (n ¼ 37), CIN2 (n ¼ 22), CIN3 (n ¼ 24), carcinoma in situ (CIS) (n ¼ 22), squamous cell carcinoma (SCC, n ¼ 20), and adenocarcinoma (AC) (n ¼ 7). Methylation levels of the genes sex-determining region Y, box 1 (SOX1); paired box gene 1 (PAX1); LIM homeobox transcription factor 1a (LMX1A), and NK6 transcription factor-related locus 1 (NKX6-1) were determined by using real-time methylation-specific polymerase chain reaction (PCR) amplification. Cutoff values of the percentage of methylation reference (PMR) for different diagnoses were determined to test the sensitivity and specificity and to generate receiver operating characteristic (ROC) curves. Two-sided Mann-Whitney U tests were used to test differences in PMR between groups. RESULTS: The PMRs of the 4 genes were significantly higher in CIN3 and worse (CIN3þ) lesions than the PMRs in specimens of normal cervix and CIN1 or CIN2 (P < .001). ROC curve analysis demonstrated that the sensitivity, specificity, and accuracy for detecting CIN3þ lesions were 0.88, 0.82, and 0.95, respectively, for SOX1; 0.78, 0.91, and 0.89, respectively, for PAX1; 0.77, 0.88, and 0.90, respectively, for LMX1A; and 0.93, 0.97, and 0.97, respectively, for NKX6-1. CONCLUSIONS: The current results indicated that quantitative PCR-based testing for DNA methylation of 4 genes holds great promise for cervical cancer screening and warrants further population-based studies using standardized DNA methylation testing. Cancer 2010;116:4266-74.

This study demonstrates the potential use of methylated BHLHE22/CDO1/CELF4 panel for endometrial cancer screening of cervical scrapings. Clin Cancer Res; 23(1); 263-72. ©2016 AACR.

BackgroundDespite of the trend that the application of DNA methylation as a biomarker for cancer detection is promising, clinically applicable genes are few. Therefore, we looked for novel hypermethylated genes for cervical cancer screening.Methods and FindingsAt the discovery phase, we analyzed the methylation profiles of human cervical carcinomas and normal cervixes by methylated DNA immunoprecipitation coupled to promoter tiling arrays (MeDIP-on-chip). Methylation-specific PCR (MSP), quantitative MSP and bisulfite sequencing were used to verify the methylation status in cancer tissues and cervical scrapings from patients with different severities. Immunohistochemical staining of a cervical tissue microarray was used to confirm protein expression. We narrowed to three candidate genes: DBC1, PDE8B, and ZNF582; their methylation frequencies in tumors were 93%, 29%, and 100%, respectively. At the pre-validation phase, the methylation frequency of DBC1 and ZNF582 in cervical scraping correlated significantly with disease severity in an independent cohort (n = 330, both P<0.001). For the detection of cervical intraepithelial neoplasia 3 (CIN3) and worse, the area under the receiver operating characteristic curve (AUC) of ZNF582 was 0.82 (95% confidence interval  = 0.76–0.87).ConclusionsOur study shows ZNF582 is frequently methylated in CIN3 and worse lesions, and it is demonstrated as a potential biomarker for the molecular screening of cervical cancer.