Regulation of metaplasia and dysplasia in the stomach by the stromal microenvironment

Research on the microenvironment associated with gastric carcinogenesis has focused on cancers of the stomach and often underestimates premalignant stages such as metaplasia and dysplasia. Since epithelial interactions with T cells, macrophages, and type 2 innate lymphoid cells (ILC2s) are indispensable for the formation of precancerous lesions in the stomach, understanding the cellular interactions that promote gastric precancer warrants further investigation. Although various types of immune cells have been shown to play important roles in gastric carcinogenesis, it remains unclear how stromal cells such as fibroblasts influence epithelial transformation in the stomach, especially during precancerous stages. Fibroblasts exist as distinct populations across tissues and perform different functions depending on the expression patterns of cell surface markers and secreted factors. In this review, we provide an overview of known microenvironmental components in the stroma with an emphasis on fibroblast subpopulations and their roles during carcinogenesis in tissues including breast, pancreas, and stomach. Additionally, we offer insights into potential targets of tumor-promoting fibroblasts and identify open areas of research related to fibroblast plasticity and the modulation of gastric carcinogenesis. This review summarizes how metaplasia (normal cells changing into different types) turns into dysplasia (abnormal cell growth) in the stomach due to injury and the role of stroma during the process. Led by Dr. James R. Goldenring, the team has discovered that the stomach develops metaplasia to heal damaged tissue and suggested several biomarkers to define the change. They recently found that certain types of metaplasia repopulate the stomach lining after damage and can progress into the next stage under the influence of the microenvironment. The current study provides insights into how the stromal components in the stomach contribute to carcinogenesis, focusing on fibroblast subpopulations. This could be important for future gastric cancer treatments. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author.