title: MicroRNAs are differentially deregulated in mammary malignant phyllodes tumour.
abstract: OBJECTIVE
  MicroRNAs (miRs) have been shown to play important roles in tumour progression. Their expression pattern can be useful for cancer classification. However, little is known about miRs in mammary phyllodes tumours (PT).
  
  
  RESULTS
  In this study, polymerase chain reaction (PCR)-based miR profiling was performed in a small PT cohort to identify deregulated miRs in malignant PT. The purported roles and targets of these miRs were further validated. Unsupervised clustering of miR expression profiling segregated PT into different grades, implicating the miR profile in PT classification. Among the deregulated miRs, miR-21, miR-335 and miR-155 were validated to be higher in malignant than in lower-grade PT in the independent cohort by quantitative PCR (qPCR) (P ≤ 0.032). Their expression correlated with some of the malignant histological features, including high stromal cellularity, nuclear pleomorphism and mitosis. Subsequent analysis of their downstream proteins, namely PTEN for miR-21/miR-155 and Rb for miR-335, also showed an independent significant negative association between miR and protein expression.
  
  
  CONCLUSIONS
  Differential expression of miRs in PT could be useful in diagnosis and grading of PT. Their deregulated expression, together with the altered downstream targets, implicated their active involvement in PT malignant transformation.
authors.affiliation: Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Julia Y S
authors.initials: JY
authors.lastname: Tsang
authors.affiliation: Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Yun-Bi
authors.initials: YB
authors.lastname: Ni
authors.affiliation: Department of Biomedical Sciences, City University of Hong Kong, Hong Kong.
authors.forename: Enders Ko
authors.initials: EK
authors.lastname: Ng
authors.affiliation: Department of Surgery, The University of Hong Kong, Hong Kong.
authors.forename: Vivian Y
authors.initials: VY
authors.lastname: Shin
authors.affiliation: Department of Pathology, Alice Ho Miu Ling Nethersole Hospital, Hong Kong.
authors.forename: Ko-Fung
authors.initials: KF
authors.lastname: Mak
authors.affiliation: Department of Pathology, University of the Philippines, Manila, Philippines.
authors.forename: Edna May L
authors.initials: EM
authors.lastname: Go
authors.affiliation: Department of Pathology, University of the Philippines, Manila, Philippines.
authors.forename: John
authors.initials: J
authors.lastname: Tawasil
authors.affiliation: Departments of Pathology, Kwong Wah Hospital, Hong Kong.
authors.forename: Siu-Ki
authors.initials: SK
authors.lastname: Chan
authors.affiliation: Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Chun-Wai
authors.initials: CW
authors.lastname: Ko
authors.affiliation: Department of Surgery, The University of Hong Kong, Hong Kong.
authors.forename: Ava
authors.initials: A
authors.lastname: Kwong
authors.affiliation: Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Gary M
authors.initials: GM
authors.lastname: Tse
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D016161:Genes, Retinoblastoma; D019942:Genes, p16; D006801:Humans; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D051059:PTEN Phosphohydrolase / Q000235:genetics; D003557:Phyllodes Tumor / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D012334:RNA, Neoplasm / Q000235:genetics* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C524942:MIRN155 microRNA, human; C524940:MIRN21 microRNA, human; C556347:MIRN335 microRNA, human; D035683:MicroRNAs; D012334:RNA, Neoplasm; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human
keywords: PTEN; Phyllodes tumuor of breast; Retinoblastoma; microRNA