title: Touch imprint cytology with massively parallel sequencing (TIC-seq): a simple and rapid method to snapshot genetic alterations in tumors.
abstract: Identifying genetic alterations in tumors is critical for molecular targeting of therapy. In the clinical setting, formalin-fixed paraffin-embedded (FFPE) tissue is usually employed for genetic analysis. However, DNA extracted from FFPE tissue is often not suitable for analysis because of its low levels and poor quality. Additionally, FFPE sample preparation is time-consuming. To provide early treatment for cancer patients, a more rapid and robust method is required for precision medicine. We present a simple method for genetic analysis, called touch imprint cytology combined with massively paralleled sequencing (touch imprint cytology [TIC]-seq), to detect somatic mutations in tumors. We prepared FFPE tissues and TIC specimens from tumors in nine lung cancer patients and one patient with breast cancer. We found that the quality and quantity of TIC DNA was higher than that of FFPE DNA, which requires microdissection to enrich DNA from target tissues. Targeted sequencing using a next-generation sequencer obtained sufficient sequence data using TIC DNA. Most (92%) somatic mutations in lung primary tumors were found to be consistent between TIC and FFPE DNA. We also applied TIC DNA to primary and metastatic tumor tissues to analyze tumor heterogeneity in a breast cancer patient, and showed that common and distinct mutations among primary and metastatic sites could be classified into two distinct histological subtypes. TIC-seq is an alternative and feasible method to analyze genomic alterations in tumors by simply touching the cut surface of specimens to slides.
authors: Genome Analysis Center, Yamanashi Prefectural Central Hospital, 1-1-1 Fujimi, Kofu, Yamanashi, 400-8506, Japan.|Pathology Division, Laboratory Department, Yamanashi Prefectural Central Hospital, 1-1-1 Fujimi, Kofu, Yamanashi, 400-8506, Japan.
authors: Kenji
authors: K
authors: Amemiya
authors: Genome Analysis Center, Yamanashi Prefectural Central Hospital, 1-1-1 Fujimi, Kofu, Yamanashi, 400-8506, Japan.
authors: Yosuke
authors: 0000-0002-8002-834X
authors: Y
authors: Hirotsu
authors: Lung Cancer and Respiratory Disease Center, Yamanashi Prefectural Central Hospital, 1-1-1 Fujimi, Kofu, Yamanashi, 400-8506, Japan.
authors: Taichiro
authors: T
authors: Goto
authors: Department of Breast Surgery, Yamanashi Prefectural Central Hospital, 1-1-1 Fujimi, Kofu, Yamanashi, 400-8506, Japan.
authors: Hiroshi
authors: H
authors: Nakagomi
authors: Genome Analysis Center, Yamanashi Prefectural Central Hospital, 1-1-1 Fujimi, Kofu, Yamanashi, 400-8506, Japan.
authors: Hitoshi
authors: H
authors: Mochizuki
authors: Pathology Division, Laboratory Department, Yamanashi Prefectural Central Hospital, 1-1-1 Fujimi, Kofu, Yamanashi, 400-8506, Japan.
authors: Toshio
authors: T
authors: Oyama
authors: Genome Analysis Center, Yamanashi Prefectural Central Hospital, 1-1-1 Fujimi, Kofu, Yamanashi, 400-8506, Japan.|The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors: Masao
authors: M
authors: Omata
mesh_terms: D000483:Alleles; D003581:Cytodiagnosis / Q000379:methods; D018450:Disease Progression; D014644:Genetic Variation; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000235:genetics; D009154:Mutation; D009369:Neoplasms / Q000175:diagnosis* / Q000235:genetics*
keywords: 
  FFPE
  ; Cytology; heterogeneity; mutation; next-generation sequencing; tumor