title: Presence of Porphyromonas gingivalis in esophagus and its association with the clinicopathological characteristics and survival in patients with esophageal cancer.
abstract: BACKGROUND
  Mounting evidence suggests a causal relationship between specific bacterial infections and the development of certain malignancies. However, the possible role of the keystone periodontal pathogen, Porphyromonas gingivalis, in esophageal squamous cell carcinoma (ESCC) remains unknown. Therefore, we examined the presence of P. gingivalis in esophageal mucosa, and the relationship between P. gingivalis infection and the diagnosis and prognosis of ESCC.
  
  
  METHODS
  The presence of P. gingivalis in the esophageal tissues from ESCC patients and normal controls was examined by immunohistochemistry using antibodies targeting whole bacteria and its unique secreted protease, the gingipain Kgp. qRT-PCR was used as a confirmatory approach to detect P. gingivalis 16S rDNA. Clinicopathologic characteristics were collected to analyze the relationship between P. gingivalis infection and development of ESCC.
  
  
  RESULTS
  P. gingivalis was detected immunohistochemically in 61 % of cancerous tissues, 12 % of adjacent tissues and was undetected in normal esophageal mucosa. A similar distribution of lysine-specific gingipain, a catalytic endoprotease uniquely secreted by P. gingivalis, and P. gingivalis 16S rDNA was also observed. Moreover, statistic correlations showed P. gingivalis infection was positively associated with multiple clinicopathologic characteristics, including differentiation status, metastasis, and overall survival rate.
  
  
  CONCLUSIONS
  These findings demonstrate for the first time that P. gingivalis infects the epithelium of the esophagus of ESCC patients, establish an association between infection with P. gingivalis and the progression of ESCC, and suggest P. gingivalis infection could be a biomarker for this disease. More importantly, these data, if confirmed, indicate that eradication of a common oral pathogen could potentially contribute to a reduction in the overall ESCC burden.
authors.affiliation: Henan Key Laboratory of Cancer Epigenetics, Cancer Institute, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, 471003 China.
authors.forename: Shegan
authors.initials: S
authors.lastname: Gao
authors.affiliation: Henan Key Laboratory of Cancer Epigenetics, Cancer Institute, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, 471003 China.
authors.forename: Shuoguo
authors.initials: S
authors.lastname: Li
authors.affiliation: Henan Key Laboratory of Cancer Epigenetics, Cancer Institute, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, 471003 China.
authors.forename: Zhikun
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Henan Key Laboratory of Cancer Epigenetics, Cancer Institute, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, 471003 China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Liang
authors.affiliation: Henan Key Laboratory of Cancer Epigenetics, Cancer Institute, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, 471003 China.
authors.forename: Tanyou
authors.initials: T
authors.lastname: Shan
authors.affiliation: Henan Key Laboratory of Cancer Epigenetics, Cancer Institute, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, 471003 China.
authors.forename: Mengxi
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Henan Key Laboratory of Cancer Epigenetics, Cancer Institute, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, 471003 China.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Henan Key Laboratory of Cancer Epigenetics, Cancer Institute, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, 471003 China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Henan Key Laboratory of Cancer Epigenetics, Cancer Institute, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, 471003 China.
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
authors.affiliation: Department of Oncology, Anyang People's Hospital, Anyang, 471500 China.
authors.forename: Fuyou
authors.initials: F
authors.lastname: Zhou
authors.affiliation: Henan Key Laboratory of Cancer Epigenetics, Cancer Institute, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, 471003 China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Yuan
authors.affiliation: Henan Key Laboratory of Cancer Epigenetics, Cancer Institute, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, 471003 China.
authors.forename: Ruinuo
authors.initials: R
authors.lastname: Jia
authors.affiliation: Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland ; Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Room 263D, 501 South Preston Street, Louisville, KY 40202 USA.
authors.forename: Jan
authors.initials: J
authors.lastname: Potempa
authors.affiliation: Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Room 263D, 501 South Preston Street, Louisville, KY 40202 USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Scott
authors.affiliation: Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Room 263D, 501 South Preston Street, Louisville, KY 40202 USA.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Lamont
authors.affiliation: Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Room 263D, 501 South Preston Street, Louisville, KY 40202 USA.
authors.forename: Huizhi
authors.initials: H
authors.lastname: Wang
authors.affiliation: Henan Key Laboratory of Cancer Epigenetics, Cancer Institute, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, 471003 China ; Department of Oncology, Henan University of Science and Technology, 24 Jinghua Road, Jianxi Qu, Luoyang, 471500 Henan China.
authors.forename: Xiaoshan
authors.initials: X
authors.lastname: Feng
keywords: 16S rDNA; Differentiation; ESCC; Lys-gingipain; Metastasis; Oral pathogen; Overall survival rate; Porphyromonas gingivalis; Prognoses