title: [Histological features of tumor-bearing tissues formed by human fibroblasts after reprograming by Piwil2].
abstract: OBJECTIVE
  To observe the histological features of tumor-bearing tissues formed by human fibroblasts after reprograming by spermatogonial stem cell self-renewal key regulating gene Piwil2 (Piwil2-iCSC).
  
  
  METHODS
  Piwil2-iCSC tumor spheroids-like colonies were selected for tumor formation assay in four nude mice. Pathological features of Piwil2-iCSC tumors were observed by histology. Stem cell markers and common triploblastic markers were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) assay and immunohistochemistry. Germ cell tumor markers were detected by immunohistochemical examination.
  
  
  RESULTS
  Two weeks after inoculation, subcutaneous tumors were formed in all the four nude mice with a tumor formation rate of 100%. In the Piwil2-iCSC tumor tissues, Piwil2-GFP(+) cells showed high-density nuclear expression and were widely observed in DAPI-stained sections. Numerous mitotic figure of the neoplastic cells were seen (>10 cells/field of vision under high magnification) in HE-stained sections. Enlarged abnormal cell nuclei were observed. RT-PCR assay showed that Piwil2-iCSC tumors still expressed Piwil2 and some self-renewal and pluripotent markers of stem cells and some markers of triploblastic differentiation. Immunohistochemical staining showed that the tumors expressed stem cell markers, triploblastic markers and germ cell tumor markers AFP and HCG.
  
  
  CONCLUSIONS
  Piwil2-iCSC tumors are probably undifferentiated embryonic small cell carcinoma, most likely to be immature teratoma, mixed with yolk sac tumor and choriocarcinoma components. It can be used as a useful model for the research of origin or genesis mechanism of cancer stem cells and the treatment of relevant tumors.
authors.affiliation: Department of Urology, Children's Hospital of Chongqing Medical University; Ministry of Education Key Laboratory of Child Development and Disorders; Chongqing Key Laboratory of Pediatrics, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing 400014, China.
authors.forename: Guangping
authors.initials: G
authors.lastname: Zeng
authors.forename: Xin
authors.initials: X
authors.lastname: Wu
authors.affiliation: Email: dw.he@163.com.
authors.forename: Dawei
authors.initials: D
authors.lastname: He
authors.forename: Yiyao
authors.initials: Y
authors.lastname: Fu
authors.forename: Xing
authors.initials: X
authors.lastname: Liu
authors.forename: Deying
authors.initials: D
authors.lastname: Zhang
authors.forename: Tao
authors.initials: T
authors.lastname: Lin
authors.forename: Guanghui
authors.initials: G
authors.lastname: Wei
mesh_terms: D053687:Adult Stem Cells; D000818:Animals; D060565:Argonaute Proteins / Q000235:genetics*; D000067470:Cellular Reprogramming Techniques; D002822:Choriocarcinoma / Q000473:pathology; D018240:Endodermal Sinus Tumor / Q000473:pathology; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008819:Mice, Nude; D009373:Neoplasms, Germ Cell and Embryonal / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000737:chemistry / Q000473:pathology*; D060888:Real-Time Polymerase Chain Reaction; D018874:Spheroids, Cellular; D013724:Teratoma / Q000473:pathology; D013997:Time Factors
chemical_list: D060565:Argonaute Proteins; C421088:PIWIL1 protein, human