title: Paper-Based MicroRNA Expression Profiling from Plasma and Circulating Tumor Cells.
abstract: Molecular characterization of circulating tumor cells (CTCs) holds great promise for monitoring metastatic progression and characterizing metastatic disease. However, leukocyte and red blood cell contamination of routinely isolated CTCs makes CTC-specific molecular characterization extremely challenging.
  
  
  
  Here we report the use of a paper-based medium for efficient extraction of microRNAs (miRNAs) from limited amounts of biological samples such as rare CTCs harvested from cancer patient blood. Specifically, we devised a workflow involving the use of Flinders Technology Associates (FTA)®Elute Card with a digital PCR-inspired "partitioning" method to extract and purify miRNAs from plasma and CTCs.
  
  
  
  We demonstrated the sensitivity of this method to detect miRNA expression from as few as 3 cancer cells spiked into human blood. Using this method, background miRNA expression was excluded from contaminating blood cells, and CTC-specific miRNA expression profiles were derived from breast and colorectal cancer patients. Plasma separated out during purification of CTCs could likewise be processed using the same paper-based method for miRNA detection, thereby maximizing the amount of patient-specific information that can be derived from a single blood draw.
  
  
  
  Overall, this paper-based extraction method enables an efficient, cost-effective workflow for maximized recovery of small RNAs from limited biological samples for downstream molecular analyses.
authors.affiliation: Department of Laboratory Medicine, NUH, Singapore, Singapore; patv29@nus.edu.sg evelyn_koay@nuhs.edu.sg.|Department of Pathology, Yong Loo Lin School of Medicine, NUS, Singapore, Singapore.
authors.forename: Sai Mun
authors.initials: SM
authors.lastname: Leong
authors.affiliation: Department of Laboratory Medicine, NUH, Singapore, Singapore.
authors.forename: Karen Mei-Ling
authors.initials: KM
authors.lastname: Tan
authors.affiliation: Department of Pathology, Yong Loo Lin School of Medicine, NUS, Singapore, Singapore.
authors.forename: Hui Wen
authors.initials: HW
authors.lastname: Chua
authors.affiliation: Department of Laboratory Medicine, NUH, Singapore, Singapore.
authors.forename: Mo-Chao
authors.initials: MC
authors.lastname: Huang
authors.affiliation: CellSievo Pte Ltd., Singapore, Singapore.
authors.forename: Wai Chye
authors.initials: WC
authors.lastname: Cheong
authors.affiliation: CellSievo Pte Ltd., Singapore, Singapore.
authors.forename: Mo-Huang
authors.initials: MH
authors.lastname: Li
authors.affiliation: Tucker Medical, Novena Specialist Center, Singapore, Singapore.
authors.forename: Steven
authors.initials: S
authors.lastname: Tucker
authors.affiliation: Department of Laboratory Medicine, NUH, Singapore, Singapore; patv29@nus.edu.sg evelyn_koay@nuhs.edu.sg.|Department of Pathology, Yong Loo Lin School of Medicine, NUS, Singapore, Singapore.
authors.forename: Evelyn Siew-Chuan
authors.initials: ES
authors.lastname: Koay
mesh_terms: D020869:Gene Expression Profiling / Q000379:methods*; D006801:Humans; D035683:MicroRNAs / Q000032:analysis / Q000097:blood* / Q000235:genetics* / Q000302:isolation & purification; D009360:Neoplastic Cells, Circulating / Q000378:metabolism* / Q000473:pathology; D010209:Paper; D014407:Tumor Cells, Cultured
chemical_list: D035683:MicroRNAs