title: ALDH1-high ovarian cancer stem-like cells can be isolated from serous and clear cell adenocarcinoma cells, and ALDH1 high expression is associated with poor prognosis.
abstract: Cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) are defined as a small population of cancer cells that have high tumorigenicity. Furthermore, CSCs/CICs are resistant to several cancer therapies, and CSCs/CICs are therefore thought to be responsible for cancer recurrence after treatment and distant metastasis. In epithelial ovarian cancer (EOC) cases, disease recurrence after chemotherapy is frequently observed, suggesting ovarian CSCs/CICs are involved. There are four major histological subtypes in EOC, and serous adenocarcinoma and clear cell adenocarcinoma are high-grade malignancies. We therefore analyzed ovarian CSCs/CICs from ovarian carcinoma cell lines (serous adenocarcinoma and clear cell adenocarcinoma) and primary ovarian cancer cells in this study. We isolated ovarian CSCs/CICs as an aldehyde dehydrogenase 1 high (ALDH1(high)) population from 6 EOC cell lines (3 serous adenocarcinomas and 3 clear cell adenocarcinomas) by the ALDEFLUOR assay. ALDH1(high) cells showed greater sphere-forming ability, higher tumorigenicity and greater invasive capability, indicating that ovarian CSCs/CICs are enriched in ALDH1(high) cells. ALDH1(high) cells could also be isolated from 8 of 11 primary ovarian carcinoma samples. Immunohistochemical staining revealed that higher ALDH1 expression levels in ovary cancer cases are related to poorer prognosis in both serous adenocarcinoma cases and clear cell adenocarcinoma cases. Taken together, the results indicate that ALDH1 is a marker for ovarian CSCs/CICs and that the expression level of ALDH1 might be a novel biomarker for prediction of poor prognosis.
authors.affiliation: Department of Pathology, Sapporo Medical University School of Medicine, Chuo-Ku, Sapporo, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Kuroda
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Hirohashi
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Torigoe
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Yasuda
authors.forename: Akari
authors.initials: A
authors.lastname: Takahashi
authors.forename: Hiroko
authors.initials: H
authors.lastname: Asanuma
authors.forename: Rena
authors.initials: R
authors.lastname: Morita
authors.forename: Tasuku
authors.initials: T
authors.lastname: Mariya
authors.forename: Takuya
authors.initials: T
authors.lastname: Asano
authors.forename: Masahito
authors.initials: M
authors.lastname: Mizuuchi
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Saito
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Sato
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000175:diagnosis / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D000328:Adult; D000368:Aged; D000080924:Aldehyde Dehydrogenase 1 Family; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D018284:Cystadenocarcinoma, Serous / Q000175:diagnosis / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D005260:Female; D015870:Gene Expression; D006801:Humans; D007527:Isoenzymes / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D009367:Neoplasm Staging; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology; D009928:Organ Specificity; D010051:Ovarian Neoplasms / Q000175:diagnosis / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D061251:Primary Cell Culture; D011379:Prognosis; D050697:Retinal Dehydrogenase / Q000235:genetics* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D007527:Isoenzymes; D000080924:Aldehyde Dehydrogenase 1 Family; C510223:ALDH1A1 protein, human; D050697:Retinal Dehydrogenase