Comprehensive Assessment of Host Responses to 5-Fluorouracil-Induced Oral Mucositis through Transcriptomic Analysis.
BACKGROUND
Chemotherapy plays an important role in current cancer therapy; however, several problems remain unsolved on the issue of host-therapeutics interaction. The purpose of this study was to investigate the host responses after 5-flurouracil (5-FU) administration and to find the target genes and their relationship with other cytokines in the 5-FU-induced oral mucositis (OM) mouse model through transcriptomic analysis.


METHODS
Thirty-six 6 to 8 week-old male BALB/c mice were randomly divided into the control group and 5-FU-treated group. In the 5-FU group, mice received 5-FU (100 mg/kg, intraperitoneally) on day 1, day 8, day 15, day 22, and day 29, respectively. We evaluated the oral mucosal change under macroanalysis and histological examination at indicated periods, and then applied transcriptomic analysis of gene expression profile and Immunohistochemical stain to identify the target molecules related to 5-FU-induced OM.


RESULTS
The most prominent histological change in this model was observed in the fifth week. The gene expression of Bone gamma-carboxyglutamate protein, related sequence 1 (Bglap-rs1) (-12.69-fold) and Chitinase 3-like 4 (Chi3l4) (-6.35-fold) were significantly down-regulated in this phase. The quantitative real-time PCR results also revealed the expression levels were 0.62-fold in Bglap-rs1 and 0.13-fold in Chi3l4 compared with the control group. Immunohistochemical stain showed significant expression of cluster of differentiation 11b (p<0.01), interleukin-1β (p<0.001) and tumor necrosis factor-α (p<0.05), and down-regulation of Bglap-rs1 (p<0.01) compared with the control group. By Kyoto Encyclopedia of Genes and Genomes pathway analysis, there were twenty-three pathways significantly participated in this study (p<0.05).


CONCLUSIONS
Through comprehensively transcriptomic analysis and IHC stain, we discovered several valuable pathways, verified the main pro-inflammatory cytokines, and revealed two significantly down-regulated genes in the 5-FU-induced OM model. These findings highlighted the way of seeking effective therapeutic agents for chemotherapy-induced OM in future.
Department of Emergency Medicine, Far Eastern Memorial Hospital, Taipei, 22056, Taiwan; School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, 11031, Taiwan.
Chung-Ta
CT
Chang
Department of Microbiology, China Medical University, Taichung, 40402, Taiwan.
Chien-Yun
CY
Hsiang
Graduate Institute of Chinese Medicine, China Medical University, Taichung, 40402, Taiwan.
Tin-Yun
TY
Ho
School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, 11031, Taiwan; Department of Dentistry, Taipei Medical University Hospital, Taipei, 11031, Taiwan; Department of Dentistry, Lotung Poh-Ai Hospital, Yilan, 26546, Taiwan.
Ching-Zong
CZ
Wu
Department of Periodontics, Chang Gung Memorial Hospital, Linkou, 33305, Taiwan; Graduate Institute of Dental and Craniofacial Science, Chang-Gung University, Taoyuan, 33302, Taiwan.
Hsiang-Hsi
HH
Hong
School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, 11031, Taiwan; Department of General Dentistry, Chang Gung Memorial Hospital, Linkou, 33305, Taiwan.
Yi-Fang
YF
Huang
D000818:Animals; D002688:Chitinases / Q000235:genetics / Q000378:metabolism; D005472:Fluorouracil / Q000633:toxicity; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D013280:Stomatitis / Q000209:etiology / Q000235:genetics / Q000378:metabolism*; D059467:Transcriptome; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
D006023:Glycoproteins; D053583:Interleukin-1beta; D014409:Tumor Necrosis Factor-alpha; C029490:nephrocalcin; D002688:Chitinases; C525260:Ym2 protein, mouse; D005472:Fluorouracil