STAM protein suppresses kidney cancer through a dual EGFR and AKT mechanism

A protein called signal transducing adaptor molecule, or STAM, appears to fight clear cell renal cell carcinoma through two separate routes at once, according to a peer-reviewed study published in Cancer Cell International. The research, led by Zugen Chen, Leqi Liang and colleagues with senior author Tuo Deng, builds on earlier work showing that STAM holds back the progression of this aggressive kidney cancer, but the new study is the first to map how the protein does it.

Clear cell renal cell carcinoma is the most common and aggressive subtype of kidney cancer, and it is known for resisting first-line therapy. The team’s previous research had identified an upstream regulatory circuit, the MAGI2AS3/miR-142-3p/STAM axis, that controls STAM levels in the cancer. What remained unclear was precisely how STAM, once present, exerts its tumor-suppressive effect inside the cell.

To answer that question, the researchers used laboratory models of the disease. They induced STAM overexpression in two clear cell renal cell carcinoma cell lines, OSRC-2 and ACHN, and then measured what happened to cell proliferation, migration and invasion. They tracked EGFR endocytosis, autophagy and key signaling pathways using immunofluorescence and western blotting, and they tested tumor growth in a subcutaneous xenograft mouse model.

The results showed that raising STAM levels enhanced the uptake of EGFR, the epidermal growth factor receptor, into the cell through endocytosis, and simultaneously boosted autophagy, the cellular recycling process. Together these changes inhibited the proliferation, migration and invasion of the cancer cells in culture.

The mechanistic picture that emerged has two arms. In the first, STAM inactivates EGFR, which in turn suppresses the MAPK/ERK signaling pathway, a cascade that drives cancer cell growth. In the second, STAM acts on AKT, a central node of the PI3K/AKT survival pathway: the protein reduced the abundance of AKT messenger RNA and also promoted the degradation of AKT protein through both the ubiquitin-proteasome system and the autophagy-lysosome pathway. By depleting AKT on two fronts, STAM inhibits PI3K/AKT signaling and thereby induces autophagy.

The xenograft experiments in mice provided support for this dual mechanism in living tumors. When the researchers activated ERK or inhibited autophagy, the tumor suppression mediated by STAM was reversed, confirming that both arms of the pathway are needed for the full anti-tumor effect.

The authors conclude that STAM functions as a critical tumor suppressor in clear cell renal cell carcinoma through two coordinated mechanisms: inactivation of EGFR to suppress MAPK/ERK signaling, and reduction of AKT mRNA alongside promotion of AKT protein degradation to inhibit PI3K/AKT signaling and induce autophagy. They suggest these findings support STAM as a promising dual-target therapeutic strategy for the disease.

It is important to read these results in context. The evidence comes from cell lines and a mouse xenograft model, not from human patients, so the findings represent preclinical laboratory research rather than demonstrated clinical benefit. The study was published as an open-access article on 27 October 2026, and the publisher notes that this early version is subject to further edits before the final version of record. Even so, the work clarifies why STAM loss may matter in kidney cancer and points to EGFR, AKT and autophagy as linked targets that a future therapy might exploit together.

Subject of Research: Tumor-suppressive mechanisms of STAM in clear cell renal cell carcinoma

Article Title: The dual tumor-suppressive mechanisms of STAM in clear cell renal cell carcinoma: EGFR inactivation and autophagy activation via AKT regulation

Article References: Chen, Z., Liang, L., Peng, L., Liao, M., Lv, W., Ao, S., Peng, Z., Lei, M., Gu, D., Liu, Y., Zeng, G., & Deng, T. (2026). The dual tumor-suppressive mechanisms of STAM in clear cell renal cell carcinoma: EGFR inactivation and autophagy activation via AKT regulation. Cancer Cell International. https://doi.org/10.1186/s12935-026-04491-0

Image Credits: AI Generated

DOI: 10.1186/s12935-026-04491-0

Keywords: STAM, clear cell renal cell carcinoma, kidney cancer, EGFR, AKT, autophagy, MAPK/ERK, PI3K/AKT signaling, tumor suppressor, xenograft model, Cancer Cell International, dual