Evaluating the presence of Mycoplasma hyorhinis, Fusobacterium nucleatum, and Helicobacter pylori in biopsies of patients with gastric cancer

Abstract

Background Gastric cancer is the third leading cause of cancer-related deaths worldwide and has been associated with infections that may promote tumour progression. Accordingly, we analysed the presence of Mollicutes, Mycoplasma hyorhinis, Fusobacterium nucleatum and Helicobacter pylori in gastric cancer tissues and evaluated their correlation with clinicopathological factors. Methods Using a commercial kit, DNA were extracted from 120 gastric samples embedded in paraffin: 80 from patients with gastric cancer and 40 from cancer free patients, dating from 2006 to 2016. Mollicutes and H. pylori were detected by PCR; F. nucleatum and M. hyorhinis were detected by qPCR, together with immunohistochemistry for the latter bacteria. Results Mollicutes were detected in the case and control groups (12% and 2.5%) and correlated with the papillary histologic pattern (P = 0.003), likely due to cell transformation promoted by Mollicutes. M. hyorhinis was detected in the case and control group but was not considered a cancer risk factor. H. pylori was detected at higher loads in the case compared to the control group (8% and 22%, P = 0.008) and correlated with metastasis (P = 0.024), lymphatic invasion (P = 0.033), tumour of diffused type (P = 0.028), and histopathological grading G1/G2 (P = 0.008). F. nucleatum was the most abundant bacteria in the case group, but was also detected in the control group (26% and 2.5%). It increased the cancer risk factor (P = 0.045, OR = 10.562, CI95% = 1.057–105.521), and correlated with old age (P = 0.030) and tumour size (P = 0.053). Bacterial abundance was significantly different between groups (P = 0.001). Conclusion Our findings could improve the control and promote our understanding of opportunistic bacteria and their relevance to malignant phenotypes.

States and hotspots in Helicobacter pylori research from 2002 to 2021: A bibliometric analysis

“…Therefore, in this study, we focused on the analysis of F. nucleatum, a pathogenic bacterium found in the oral microbiota. Indeed, several studies have confirmed that this bacterium has a high prevalence in H. pylori ‐associated gastric cancer, which can increase the expression of gastric cancer‐associated bacteria through DNA alterations 48–50 …”

Downregulated mitochondrial transcription factor A enhances mycoplasma infection to promote the metastasis of hepatocellular carcinoma

“…Annexin A2 is increased in multiple tumors and is associated with tumor grade and clinical outcome 31,32 . Recent studies have uncovered a relationship between ANXA2 and microbial infection 33,34 . For instance, ANXA2 contributes to human papilloma virus infection 35 and participates in HCV replication 35 .…”

“… 31 , 32 Recent studies have uncovered a relationship between ANXA2 and microbial infection. 33 , 34 For instance, ANXA2 contributes to human papilloma virus infection 35 and participates in HCV replication. 35 In addition, ANXA2 facilitates mycoplasma infection through its N‐terminal.…”

Involvement of Fusobacterium nucleatum in malignancies except for colorectal cancer: A literature review

“…F. nucleatum was found to be positive in 19 samples (26.0%) of gastric cancer patients, while 1 sample (2.5%) was found to be positive in cancer-free patients. The prevalence of F. nucleatum was associated with 11-fold increase in the risk of developing gastric cancer, and was related with advanced age ( P =0.030) and large tumor size ( P =0.053) ( 53 ). According to the profiles of gastric epithelium-associated microbiota in patients with gastritis, intestinal metaplasia, and gastric cancer, it was indicated that gastric microenvironment was frequently enriched with Clostridium and Fusobacterium in gastric cancer patients.…”