title: Correlation of HIWI and HILI Expression with Cancer Stem Cell Markers in Colorectal Cancer.
abstract: OBJECTIVE
  Cancer stem cells (CSCs) constitute a sub-population of tumor cells that possess stem cell properties, such as self-renewal and the ability of differentiation. The presence of CSCs is associated with metastatic potential, treatment resistance and poor patient prognosis. Recently, aberrant expression of P-element induced wimpy testis proteins-PIWI (HIWI and HILI) has been identified in various types of tumors. The aim of the study was to evaluate the clinical significance of the HIWI and HILI expression and its relationship with cancer stem cells markers in 72 patients with colorectal carcinoma (CRC).
  
  
  METHODS
  The expression level of HIWI and HILI and cancer stem cells markers in paired cancerous and non-cancerous tissues was measured by real-time reverse transcription-polymerase chain reaction (RT-PCR) assay. Immunohistochemistry was performed to confirm the observed changes on mRNA level and detect tissue localization of PIWI proteins.
  
  
  RESULTS
  Significantly higher mRNA levels of HIWI and decreased HILI mRNA were measured in colorectal cancer tissues compared to corresponding non-cancerous samples. The changes in HIWI mRNA level in cancer tissues were correlated with OCT4 expression. Positive correlations between HILI level and SOX2 were also observed in cancerous tissues.
  
  
  CONCLUSIONS
  Our results indicate a reciprocal regulation between HIWI, HILI and some CSCs markers in colorectal cancer.
authors.affiliation: Regional Specialist Hospital in Wroclaw, Research and Development Centre, Wroclaw, Poland litwin@wssk.wroc.pl.
authors.forename: Monika
authors.initials: M
authors.lastname: Litwin
authors.affiliation: Regional Specialist Hospital in Wroclaw, Research and Development Centre, Wroclaw, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Dubis
authors.affiliation: Regional Specialist Hospital in Wroclaw, Research and Development Centre, Wroclaw, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Arczyńska
authors.affiliation: Department of Histology and Embryology, Wroclaw Medical University, Wroclaw, Poland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Piotrowska
authors.affiliation: Department of Obstetrics and Gynaecology, Regional Specialist Hospital in Wroclaw, Research and Development Centre, Wroclaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Frydlewicz
authors.affiliation: Regional Specialist Hospital in Wroclaw, Research and Development Centre, Wroclaw, Poland Illimites Foundation, Wroclaw, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Karczewski
authors.affiliation: Department of Histology and Embryology, Wroclaw Medical University, Wroclaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Dzięgiel
authors.affiliation: Regional Specialist Hospital in Wroclaw, Research and Development Centre, Wroclaw, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Witkiewicz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D060565:Argonaute Proteins / Q000096:biosynthesis* / Q000235:genetics; D014408:Biomarkers, Tumor; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology; D050814:Octamer Transcription Factor-3 / Q000096:biosynthesis; D011379:Prognosis; D012333:RNA, Messenger / Q000096:biosynthesis; D055748:SOXB1 Transcription Factors / Q000096:biosynthesis; D013737:Testis / Q000378:metabolism / Q000473:pathology
chemical_list: D060565:Argonaute Proteins; D014408:Biomarkers, Tumor; D050814:Octamer Transcription Factor-3; C421088:PIWIL1 protein, human; C486868:PIWIL2 protein, human; C494173:POU5F1 protein, human; D012333:RNA, Messenger; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors
keywords: HILI; HIWI; cancer stem cells; colorectal cancer; gene expression