Primary Gastric Adenocarcinoma Cells Have Distinct Gene-Expression Profiles

By Will Boggs MD

June 23, 2020

NEW YORK (Reuters Health) - Primary gastric adenocarcinoma cells can be divided into five subgroups based on their gene-expression profiles, researchers in China report.

"Our data uncovered a panel of cellular differentiation-related biomarkers, which could be further used to assess tumor differentiation degree and to predict tumor prognosis," Dr. Yan Liu of the Academy of Military Medical Sciences and The Fifth Medical Center of Chinese PLA General Hospital, in Beijing, told Reuters Health by email.

Gastric adenocarcinoma features diverse subtypes and clinical behaviors, and different tumor grading and prognostic classification systems have been proposed.

Dr. Liu and colleagues used single-cell RNA sequencing to construct an unbiased and systemic transcriptomic landscape of distinct gastric adenocarcinoma pathology subtypes.

They identified five cell subgroups with distinct expression profiles. Three of these subgroups exhibited different differentiation grade which corresponded well to histopathological features of the intestinal, diffuse, and mixed types included in the Lauren classification.

Cancer cells of diffuse histology were poorly differentiated, while intestinal types showed various degrees of differentiation.

Low tumor differentiation can predict poor prognosis in gastric adenocarcinoma, suggesting that such tumors may be more aggressive.

The other two subgroups displayed unique transcriptome features. One subtype expressed chief-cell markers consistent with the rare, previously described fundic-gland-type gastric adenocarcinoma (which they labeled chief cell-predominant or GA-FG-CCP).

The other subgroup expressed immune-related signature genes with the infection of Epstein-Barr virus, the researchers report in Gut.

The researchers also analyzed nonmalignant epithelium and identified a potential transition from chief cells into metaplastic cells.

"Single-cell transcriptome profiles may pave the way for dissecting tumor heterogeneity and exploration of rare tumor types, with implications for clinical practice," Dr. Liu said.

SOURCE: Gut, online June 12, 2020.