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World J Clin Cases. Apr 6, 2019; 7(7): 819-829
Published online Apr 6, 2019. doi: 10.12998/wjcc.v7.i7.819
Porphyromonas gingivalis and digestive system cancers
Ying Zhou, Guang-Hua Luo
Ying Zhou, Guang-Hua Luo, Comprehensive Laboratory, the Third Affiliated Hospital of Soochow University, Changzhou 213003, Jiangsu Province, China
Author contributions: Zhou Y prepared the manuscript; Luo GH critically revised the intellectual content and gave final approval of manuscript.
Supported by Changzhou High-Level Medical Talents Training Project, No: 2016ZCLJ002.
Conflict-of-interest statement: The authors declare that there is no conflict of interest related to this study.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Guang Hua Luo, MD, PhD, Professor, Comprehensive Laboratory, the Third Affiliated Hospital, Soochow University, No. 185, Juqian Street, Changzhou 213003, Jiangsu Province, China. shineroar@163.com
Telephone: +86-519-68870619 Fax: +86-591-86621235
Received: December 28, 2018
Peer-review started: December 29, 2018
First decision: January 30, 2019
Revised: February 26, 2019
Accepted: March 11, 2019
Article in press: March 11, 2019
Published online: April 6, 2019
Abstract

Porphyromonas gingivalis (P. gingivalis) is an anaerobic gram-negative bacterium that colonizes in the epithelium and has been strongly associated with periodontal disease. Recently, various degrees of associations between P. gingivalis and digestive system cancers, including oral squamous cell carcinoma in the oral cavity, oesophageal squamous carcinoma in the digestive tract, and pancreatic cancer in pancreatic tissues, have been displayed in multiple clinical and experimental studies. Since P. gingivalis has a strong association with periodontal diseases, not only the relationships between P. gingivalis and digestive system tumours but also the effects induced by periodontal diseases on cancers are well-illustrated in this review. In addition, the prevention and possible treatments for these digestive system tumours induced by P. gingivalis infection are also included in this review. At the end, we also highlighted the possible mechanisms of cancers caused by P. gingivalis. One important carcinogenic effect of P. gingivalis is inhibiting the apoptosis of epithelial cells, which also plays an intrinsic role in protecting cancerous cells. Some signalling pathways activated by P. gingivalis are involved in cell apoptosis, tumourigenesis, immune evasion and cell invasion of tumour cells. In addition, metabolism of potentially carcinogenic substances caused by P. gingivalis is also one of the connections between this bacterium and cancers.

Keywords: Porphyromonas gingivalis, Oral squamous cell carcinoma, Oesophageal squamous cell carcinoma, Pancreatic cancer, Periodontal diseases

Core tip:Porphyromonas gingivalis (P. gingivalis) has been discovered in many digestive system cancers, such as oral squamous cell carcinoma, oesophageal squamous cell carcinoma, and pancreatic cancer. For the strong association between P. gingivalis and periodontal diseases, we also interpret how periodontal diseases push effects on digestive system tumours. This review also presents some preventions and possible treatments for these cancers associated with P. gingivalis infection. In addition, the mechanisms by which P. gingivalis affects the occurrence and development of carcinomas are covered, including immune evasion, tumourigenesis, inhibition of apoptosis and invasion of tumour cells.