Blocking the immune-suppressing molecule CD276 slowed gastric cancer growth in laboratory models and, when combined with an anti-PD-1 antibody, produced the strongest tumor suppression observed in the work, alongside increased infiltration of cancer-killing T cells inside tumors. That is the central finding of a study published in Cell & Bioscience, which positions CD276, a molecule broadly overexpressed across solid tumors, as a candidate target for overcoming resistance to immune checkpoint therapy in stomach cancer.
The research team, whose investigators include Jie Li, Binghe Zhao, Lu Liu and Xinxin Wang, integrated several layers of analysis: transcriptomic data from human tumor cohorts, functional experiments in gastric cancer cell lines, mechanistic dissection of signaling pathways, and immune co-culture systems that allowed them to observe how tumor cells and T cells influence one another. The goal was to clarify how CD276 drives malignancy and immune evasion, and whether inhibiting it could enhance anti-PD-1 efficacy.
The first step was confirming that CD276 is upregulated in gastric cancer. Using data from The Cancer Genome Atlas, the researchers found significant CD276 upregulation in gastric cancer tissue. But overexpression alone does not prove the molecule drives malignancy, so the team moved from correlation to manipulation.
In AGS and MKN-28 gastric cancer cells, the researchers silenced CD276 and observed broad effects. Proliferation slowed, colony formation declined, and migration diminished. RNA sequencing and Western blot analysis revealed reduced phosphorylation of p38 and MEK, two nodes in the MAPK signaling pathway. That pathway carries growth and survival signals in many cancers, and its dampening after CD276 knockdown suggests the molecule helps gastric cancer cells maintain the proliferative drive that fuels tumor progression. The result points to a cell-intrinsic role for CD276 in promoting malignancy.
The second half of the study examined CD276’s role in immune evasion. In co-culture experiments pairing gastric cancer cells with T cells derived from peripheral blood mononuclear cells, inhibiting CD276 changed the immune balance in the cancer cells’ disfavor. The proportion of GzmB-positive CD8+ T cells, the cytotoxic population that directly kills tumor cells, increased. At the same time, the population of PD-1-positive, Tim-3-positive T cells, a phenotype associated with exhaustion, decreased. When the researchers added PD-1 blockade to CD276 inhibition, these effects were potentiated, suggesting the two interventions act on complementary arms of immune suppression.
In animal models, the combination held up. Anti-CD276 plus anti-PD-1 therapy exerted the strongest tumor suppression of the conditions tested in the in vivo experiments. Analysis of treated tumors showed increased infiltration of CD45-positive immune cells, a marker of total leukocyte presence, and specifically increased CD3-positive, CD8-positive T cells, the cytotoxic lymphocytes that mediate antitumor immunity. The combination, in other words, did not only suppress tumors directly; it remodeled the tumor microenvironment in a way that invited more immune attack.
Public database analyses added a population-level dimension. High CD276 expression in tumors correlated with infiltration of regulatory T cells and M2 macrophages, two cell types that suppress immune responses. Low CD276 expression, by contrast, correlated with the presence of naïve and effector T cells and monocytic dendritic cells, and with favorable predicted responses to PD-1 and CTLA-4 blockade. Notably, the analyses also found CD276 upregulation in immunotherapy-resistant cases, linking the molecule to clinical resistance rather than merely to immune suppression in the abstract.
Taken together, the results sketch a dual mechanism. CD276 promotes gastric cancer through cell-intrinsic MAPK signaling that supports proliferation, colony formation and migration, while simultaneously being associated with a suppressive microenvironment rich in regulatory T cells and M2 macrophages and depleted of effective cytotoxic T cells. Removing CD276 attacks both arms at once, and pairing its removal with PD-1 blockade compounds the effect, because the checkpoint inhibitor unleashes the T cells that CD276 inhibition has already shifted away from exhaustion. The authors conclude that targeting CD276 exerts dual anti-tumor effects and synergizes with PD-1 blockade, positioning the strategy as a candidate approach to overcome immune checkpoint resistance in gastric cancer.
The study carries the usual caveats of preclinical research. The functional experiments relied on two gastric cancer cell lines, AGS and MKN-28, and the in vivo findings come from animal models rather than human patients. The database analyses linking CD276 expression to immune cell infiltration and predicted immunotherapy response are correlational and cannot by themselves establish causation. The published version is also an accepted-manuscript release shared ahead of final editorial production, a format that provides faster access to peer-reviewed research but remains subject to further edits before the Version of Record appears. Even so, the convergence of evidence across human transcriptomic data, cell-line experiments, immune co-cultures and animal models gives the CD276 hypothesis breadth, and it offers a rationale for testing anti-CD276 agents in combination with checkpoint inhibitors in gastric cancer.
Subject of Research: Preclinical investigation of CD276 as a driver of gastric cancer progression and a target for enhancing anti-PD-1 immunotherapy
Article Title: Targeting CD276 inhibits gastric cancer progression and synergizes with anti-PD-1 therapy to enhance T-cell immunity
Article References: Li, J., Zhao, B., Liu, L., Wu, D., Zheng, D., Li, J., Wang, H., Xue, F., Dai, B., Yamamoto, M., Nomura, S., Tsukamoto, T., Liu, T., Wu, Z., & Wang, X. (2026). Targeting CD276 inhibits gastric cancer progression and synergizes with anti-PD-1 therapy to enhance T-cell immunity. Cell & Bioscience. https://doi.org/10.1186/s13578-026-01653-5
Image Credits: AI Generated
DOI: 10.1186/s13578-026-01653-5
Keywords: CD276, B7-H3, gastric cancer, anti-PD-1, immune checkpoint resistance, MAPK pathway, T-cell exhaustion, tumor microenvironment, regulatory T cells, M2 macrophages, immunotherapy, preclinical study
News Source: Nathaniel Bowman. (October 30, 2026). CD276 Blockade Slows Gastric Cancer and Boosts Anti-PD-1 Immunotherapy in Preclinical Study. Scienmag.
