Intestinal-type gastric cancer, one of the two major histological subtypes described in the Laurén classification, is characterized by gland-forming tumor cells and is frequently associated with chronic atrophic gastritis and intestinal metaplasia. It is the more common subtype in high-incidence regions and is often diagnosed at advanced stages, when the tumor has already invaded the stomach wall or metastasized. Understanding the molecular circuitry that drives this subtype’s progression is therefore a pressing clinical need, and the new study adds a previously underexplored gene to the growing map of gastric cancer biology.

RFWD3, short for Ring Finger and WD Repeat Domain 3, is best known for its role in genome maintenance. The protein it encodes functions as an E3 ubiquitin ligase, a class of enzymes that attach small ubiquitin tags to target proteins, thereby marking them for degradation or altering their activity. In prior research, RFWD3 has been implicated in the cellular response to DNA damage, where it helps regulate the stability of proteins such as p53 and RPA, key actors in DNA repair and checkpoint control. Because cancer cells often exploit DNA damage response pathways to survive the genomic chaos they generate, genes like RFWD3 have attracted attention as potential vulnerabilities.

To investigate RFWD3’s role in this cancer subtype, the team analyzed paired tumor and adjacent normal tissue samples from 86 patients with intestinal-type gastric cancer. Using immunohistochemistry to visualize protein localization and quantitative reverse transcription PCR to measure mRNA levels, the researchers found that RFWD3 expression was markedly higher in tumor tissues than in matched normal gastric mucosa at both the protein and transcript levels. The overexpression was not uniform across all cases, but the overall trend was statistically significant, suggesting that RFWD3 upregulation is a recurring feature of this subtype rather than an idiosyncratic artifact.

Importantly, the researchers also correlated RFWD3 expression with clinicopathological characteristics. They observed that higher RFWD3 levels were associated with deeper tumor invasion, more advanced TNM stage, and the presence of lymph node metastasis. These associations hint that RFWD3 is not merely a passive byproduct of tumor growth but may actively participate in the processes that allow gastric cancer cells to colonize surrounding tissue and spread to distant sites. The authors caution, however, that their cohort was relatively small and that survival analysis was not performed, so RFWD3’s prognostic value remains to be confirmed in larger, longitudinal studies.

To probe RFWD3’s functional role, the team turned to loss-of-function experiments in gastric cancer cell lines. Using small interfering RNA to knock down RFWD3 expression, they measured the consequences for cell proliferation using CCK-8 and colony formation assays. The results were striking: cells depleted of RFWD3 proliferated more slowly and formed fewer colonies than control cells, indicating that RFWD3 supports the replicative capacity of gastric cancer cells. The effect was consistent across the cell lines examined, reinforcing the conclusion that RFWD3’s influence is not limited to a single genetic background.

The researchers next examined whether RFWD3 affects the migratory and invasive behavior of gastric cancer cells, properties that are central to metastasis. In wound healing assays, cells lacking RFWD3 closed scratch wounds more slowly than controls, suggesting impaired migration. In Transwell invasion assays, which measure the ability of cells to penetrate a matrix-coated membrane, RFWD3 knockdown significantly reduced the number of invading cells. Together, these experiments indicate that RFWD3 promotes the motile and invasive phenotype that allows gastric cancer cells to breach tissue barriers and disseminate.

Apoptosis, the programmed cell death pathway that cancer cells frequently evade, was also influenced by RFWD3 status. Flow cytometric analysis revealed that RFWD3 knockdown increased the proportion of cells in early and late apoptosis compared with controls. The researchers further found that silencing RFWD3 led to changes in the expression of apoptosis-related proteins, including an increase in the pro-apoptotic marker Bax and a decrease in the anti-apoptotic protein Bcl-2, shifting the balance toward cell death. These molecular changes suggest that RFWD3 helps gastric cancer cells resist the apoptotic signals that would otherwise eliminate them.

At the mechanistic level, the study points toward RFWD3’s established role in DNA damage response signaling as a plausible explanation for its oncogenic behavior. By modulating the ubiquitination and stability of checkpoint proteins, RFWD3 may help cancer cells tolerate the DNA damage they accumulate during rapid division and treatment stress. Disrupting this function, as the knockdown experiments demonstrate, appears to sensitize cells to apoptotic cues and restrain their ability to proliferate and invade. The authors suggest that this mechanism could be exploited therapeutically, although they emphasize that much work remains to translate the finding into clinical practice.

The study’s limitations are acknowledged by the authors themselves. The sample size was modest, survival outcomes were not analyzed, and the mechanistic experiments relied on cell line models rather than animal studies or patient-derived organoids. Moreover, the precise molecular targets of RFWD3’s ubiquitin ligase activity in gastric cancer cells have not been fully identified, leaving open the question of which specific proteins mediate its effects on proliferation, invasion, and apoptosis. Despite these caveats, the convergence of expression data, clinicopathological correlations, and functional knockdown experiments provides a coherent body of evidence that RFWD3 participates in the biology of intestinal-type gastric cancer. As researchers continue to dissect the molecular determinants of this disease, RFWD3 joins the expanding list of candidate targets that may one day inform both risk stratification and drug development for a cancer that still claims hundreds of thousands of lives each year.

Subject of Research: Expression characteristics of RFWD3 in intestinal type gastric cancer and its regulatory effects on tumor cell proliferation, invasion, and apoptosis

Article Title: Expression characteristics of RFWD3 in intestinal type gastric cancer and its regulatory effects on tumor cell proliferation, invasion, and apoptosis

Article References: wu, X., gao, Y., cui, Z., zhao, J., meng, C., & li, N. (2026). Expression characteristics of RFWD3 in intestinal type gastric cancer and its regulatory effects on tumor cell proliferation, invasion, and apoptosis. BMC Cancer. https://doi.org/10.1186/s12885-026-17129-1

Image Credits: AI Generated

DOI: 10.1186/s12885-026-17129-1

Keywords: Expression, characteristics, RFWD3, intestinal, type, gastric, cancer, regulatory, effects, tumor, cell, proliferation