Gastric Carcinogenesis and Potential Role of the Transient Receptor Potential Vanilloid 1 (TRPV1) Receptor: An Observational Histopathological Study

Abstract

The potential role of the transient receptor potential Vanilloid 1 (TRPV1) non-selective cation channel in gastric carcinogenesis remains unclear. The main objective of this study was to evaluate TRPV1 expression in gastric cancer (GC) and precursor lesions compared with controls. Patient inclusion was based on a retrospective review of pathology records. Patients were subdivided into five groups: Helicobacter pylori (H. pylori)-associated gastritis with gastric intestinal metaplasia (GIM) (n = 12), chronic atrophic gastritis (CAG) with GIM (n = 13), H. pylori-associated gastritis without GIM (n = 19), GC (n = 6) and controls (n = 5). TRPV1 expression was determined with immunohistochemistry and was significantly higher in patients with H. pylori-associated gastritis compared with controls (p = 0.002). TRPV1 expression was even higher in the presence of GIM compared with patients without GIM and controls (p < 0.001). There was a complete loss of TRPV1 expression in patients with GC. TRPV1 expression seems to contribute to gastric-mucosal inflammation and precursors of GC, which significantly increases in cancer precursor lesions but is completely lost in GC. These findings suggest TRPV1 expression to be a potential marker for precancerous conditions and a target for individualized treatment. Longitudinal studies are necessary to further address the role of TRPV1 in gastric carcinogenesis.

Keywords: H. pylori; TRPV1; gastric cancer; gastritis; intestinal metaplasia; transient receptor potential vanilloid-1.

Figure 1

Microscopic pictures of gastric biopsies after immunohistochemistry. Immunohistochemical staining (TRPV1 expression) is in brown, and hematoxylin counterstain is in blue. (A,B) TRPV1 expression in gastric antral type mucosa controls (10× and 40×). (C,D) TRPV1 expression in H. pylori-associated gastritis in gastric antral type mucosa (10× and 40×). (E,F) Complete loss of TRPV1 expression in gastric adenocarcinoma antral type mucosa (10× and 40×).

Figure 1

Microscopic pictures of gastric biopsies after immunohistochemistry. Immunohistochemical staining (TRPV1 expression) is in brown, and hematoxylin counterstain is in blue. (A,B) TRPV1 expression in gastric antral type mucosa controls (10× and 40×). (C,D) TRPV1 expression in H. pylori-associated gastritis in gastric antral type mucosa (10× and 40×). (E,F) Complete loss of TRPV1 expression in gastric adenocarcinoma antral type mucosa (10× and 40×).

Figure 2

Raincloud plot showing the distribution of TRPV1 expression as quantified in a median IRS: controls, H. pylori-associated gastritis with gastric intestinal metaplasia (H. pylori with GIM), chronic atrophic gastritis with GIM (CAG with GIM) and H. pylori-associated gastritis without GIM (H. pylori without GIM). The plot provides a detailed view of the distribution, central tendency and variability of TRPV1 expression (in IRS) within each group. (A) Raincloud plot of the median IRS all cells combined—showing a significantly higher TRPV1 expression in patients with GIM compared with those without GIM and controls. (B) Raincloud plot showing a significantly higher TRPV1 expression in patients with GIM compared with those without GIM and controls in parietal cells.