Yurie Mikami1,2, Shinsuke Fujii1, Kengo Nagata1, Hiroko Wada1, Kana Hasegawa1, Misaki Abe1,3, Reiko U Yoshimoto1,4, Shintaro Kawano2, Seiji Nakamura2, Tamotsu Kiyoshima5. 1. Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan. 2. Section of Maxillofacial Oncology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan. 3. Section of Oral and Maxillofacial Surgery, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan. 4. Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan. 5. Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan. kiyo@dent.kyushu-u.ac.jp.
Abstract
PURPOSE: Keratin 17 (KRT17) has been suggested as a potential diagnostic marker of squamous cell carcinoma including oral squamous cell carcinoma (OSCC). The current study was conducted to clarify the function of KRT17 and its expression mechanism in OSCC. METHODS: Immunohistochemical analyses were carried out to examine the expression of KRT17, GLI family zinc finger (GLI)-1, GLI-2, or cleaved caspase-3 in OSCCs. The expression of KRT17, GLI-1, or GLI-2 was investigated among OSCC cell lines, and the effects of loss-of-function of KRT17 or GLI, using siRNA or inhibitor, on the cell growth of the OSCC cell line HSC-2 particularly with respect to apoptosis were examined. RESULTS: Immunohistochemical analyses of tissue specimens obtained from 78 OSCC patients revealed that KRT17 was not observed in non-tumor regions but was strongly expressed at high frequencies in tumor regions. Knockdown of KRT17 increased the number of cleaved caspase-3-positive cells, leading to the reduction of cell number. Loss-of-function of GLI-1 or GLI-2 also increased the cell numbers of apoptotic cells positive for staining of Annexin-V and propidium iodide (PI) and the terminal deoxynucleotidyl transferase dUTP-biotin nick-end labeling (TUNEL) method, and induced DNA fragmentation. This inhibitory effect on cell growth was partially rescued by exogenous KRT17 expression. In the KRT17-positive regions in OSCCs, GLI-1 or GLI-2 was frequently detected, and the number of cells with cleaved caspase-3 positive was decreased. CONCLUSIONS: KRT17 promotes tumor cell growth, at least partially, through its anti-apoptotic effect as a result of the KRT17 overexpression by GLIs in OSCC.
PURPOSE:Keratin 17 (KRT17) has been suggested as a potential diagnostic marker of squamous cell carcinoma including oral squamous cell carcinoma (OSCC). The current study was conducted to clarify the function of KRT17 and its expression mechanism in OSCC. METHODS: Immunohistochemical analyses were carried out to examine the expression of KRT17, GLI family zinc finger (GLI)-1, GLI-2, or cleaved caspase-3 in OSCCs. The expression of KRT17, GLI-1, or GLI-2 was investigated among OSCC cell lines, and the effects of loss-of-function of KRT17 or GLI, using siRNA or inhibitor, on the cell growth of the OSCC cell line HSC-2 particularly with respect to apoptosis were examined. RESULTS: Immunohistochemical analyses of tissue specimens obtained from 78 OSCC patients revealed that KRT17 was not observed in non-tumor regions but was strongly expressed at high frequencies in tumor regions. Knockdown of KRT17 increased the number of cleaved caspase-3-positive cells, leading to the reduction of cell number. Loss-of-function of GLI-1 or GLI-2 also increased the cell numbers of apoptotic cells positive for staining of Annexin-V and propidium iodide (PI) and the terminal deoxynucleotidyl transferase dUTP-biotin nick-end labeling (TUNEL) method, and induced DNA fragmentation. This inhibitory effect on cell growth was partially rescued by exogenous KRT17 expression. In the KRT17-positive regions in OSCCs, GLI-1 or GLI-2 was frequently detected, and the number of cells with cleaved caspase-3 positive was decreased. CONCLUSIONS:KRT17 promotes tumor cell growth, at least partially, through its anti-apoptotic effect as a result of the KRT17 overexpression by GLIs in OSCC.
Authors: Flavio Protasio Veras; Marjorie Cornejo Pontelli; Camila Meirelles Silva; Juliana E Toller-Kawahisa; Mikhael de Lima; Daniele Carvalho Nascimento; Ayda Henriques Schneider; Diego Caetité; Lucas Alves Tavares; Isadora M Paiva; Roberta Rosales; David Colón; Ronaldo Martins; Italo Araujo Castro; Glaucia M Almeida; Maria Isabel Fernandes Lopes; Maíra Nilson Benatti; Letícia Pastorelli Bonjorno; Marcela Cavichioli Giannini; Rodrigo Luppino-Assad; Sérgio Luna Almeida; Fernando Vilar; Rodrigo Santana; Valdes R Bollela; Maria Auxiliadora-Martins; Marcos Borges; Carlos Henrique Miranda; Antônio Pazin-Filho; Luis Lamberti P da Silva; Larissa Dias Cunha; Dario S Zamboni; Felipe Dal-Pizzol; Luiz O Leiria; Li Siyuan; Sabrina Batah; Alexandre Fabro; Thais Mauad; Marisa Dolhnikoff; Amaro Duarte-Neto; Paulo Saldiva; Thiago Mattar Cunha; José Carlos Alves-Filho; Eurico Arruda; Paulo Louzada-Junior; Renê Donizeti Oliveira; Fernando Queiroz Cunha Journal: J Exp Med Date: 2020-12-07 Impact factor: 14.307