Cancer immunotherapy has emerged as a promising cancer treatment. However, the presence of immune-refractory tumor cells limits its clinical success by blocking amplification of anti-tumor immunity. Previously, we found that immune selection by immunotherapy drives the evolution of tumors toward multi-modal resistant and stem-like phenotypes via transcription induction of AKT co-activator TCL1A by NANOG. Here, we report a crucial role of HSP90A at the crossroads between NANOG-TCL1A axis and multi-aggressive properties of immune-edited tumor cells by identifying HSP90AA1 as a NANOG transcriptional target. Furthermore, we demonstrate that HSP90A potentiates AKT activation through TCL1A-stabilization, thereby contributing to the multi-aggressive properties in NANOG^high tumor cells. Importantly, HSP90 inhibition sensitized immune-refractory tumor to adoptive T cell transfer as well as PD-1 blockade, and re-invigorated the immune cycle of tumor-reactive T cells. Our findings implicate that the HSP90A-TCL1A-AKT pathway ignited by NANOG is a central molecular axis and a potential target for immune-refractory tumor.

Cancer immunotherapy, in the form of vaccination, adoptive cellular transfer, or immune checkpoint inhibitors, has emerged as a promising practice within the field of oncology. However, despite the developing field's potential to revolutionize cancer treatment, the presence of immunotherapeutic-resistant tumor cells in many patients present a challenge and limitation to these immunotherapies. These cells not only indicate immunotherapeutic resistance, but also show multi-modal resistance to conventional therapies, abnormal metabolism, stemness, and metastasis. How can immunotherapeutic-resistant tumor cells render multi-malignant phenotypes? We reasoned that the immune-refractory phenotype could be associated with multi-malignant phenotypes and that these phenotypes are linked together by a factor that acts as the master regulator. In this review, we discussed the role of the embryonic transcription factor NANOG as a crucial master regulator we named "common factor" in multi-malignant phenotypes and presented strategies to overcome multi-malignancy in immunotherapeutic-resistant cancer by restraining the NANOG-mediated multi-malignant signaling axis. Strategies that blunt the NANOG axis could improve the clinical management of therapy-refractory cancer.

Cancer immunoediting drives the adaptation of tumor cells to host immune surveillance. Previously, we have demonstrated that immunoediting driven by cytotoxic T lymphocytes (CTLs) enriches NANOG⁺ tumor cells with immune-refractory properties. Here, we found that CTL-mediated immune pressure triggered cross-resistance of tumor cells to the complement system, a part of the innate immune system. In this process, NANOG upregulated the membrane-bound complement regulatory protein (mCRP) CD59 through promoter occupancy, thereby contributing to the resistance of tumor cells against complement-dependent cytotoxicity (CDC). Notably, targeting of NANOG sensitized the immune-refractory tumor cells to trastuzumab-mediated CDC. Collectively, our results revealed a possible mechanism through which selection imposed by T-cell based immunotherapy triggered complement-resistant phenotypes in the tumor microenvironment (TME), by establishing a firm molecular link between NANOG and CD59 in immune-edited tumor cells. We believe these results hold important implications for the clinical application of CDC-mediated therapeutic antibody.

Lee HJ, et al. Immune Netw. 2026 Feb;26(1):e11. https://doi.org/10.4110/in.2026.26.e11

4-O-Methyl-ascochlorin (MAC), a derivative of the prenyl–phenol antibiotic ascochlorin extracted from the fungus Ascochyta viciae, shows anticarcinogenic effects on various cancer cells. 5-Fluorouracil (5-FU) is used to treat colorectal cancer (CRC); however, its efficacy must be enhanced. In this study, we investigated the molecular mechanisms by which MAC acts synergistically with 5-FU to inhibit cell proliferation and induce apoptosis in CRC cells. MAC enhanced the cytotoxic effects of 5-FU by suppressing the Akt/mTOR/p70S6K and Wnt/β-catenin signaling pathways. It also reduced the viability of 5-FU-resistant (5-FU-R) cells. Furthermore, expression of anti-apoptosis-related proteins and cancer stem-like cell (CSC) markers by 5-FU-R cells decreased in response to MAC. Similar to MAC, the knockdown of CTNNB1 induced apoptosis and reduced expression of mRNA encoding CRC markers in 5-FU-R cells. In summary, these results suggest that MAC and other β-catenin modulators may be useful in overcoming the 5-FU resistance of CRC cells.

Immune checkpoint blockade (ICB) has revolutionized the therapeutic landscape across various cancer types. However, the emergence of resistance to ICB therapy limits its clinical application. Therefore, it is necessary to better understand immune-resistance mechanisms that could be targeted by actionable drugs and important to identify predictive markers for selecting patients. In this study, by analyzing transcriptomic data from patients treated with PD-1 blockade and tumor models refractory to anti–PD-1 therapy, we identified WEE1 as a resistance factor conferring cancer stem cell–like properties as well as immune-refractory phenotypes to tumor cells. WEE1 is transcriptionally upregulated by stemness factor NANOG and predominantly localized in the cytoplasm, not the nucleus, following AKT-dependent S642 phosphorylation in immune-refractory tumor cells. Mechanistically, cytoplasmic WEE1 drove AKT hyperactivation via the HSP90A/TCL1A/AKT auto-amplification loop and upregulated the expression of refractory factors such as CYCLIN A for hyperproliferation and MCL-1 for resistance to T-cell killing. Of note, CXCL10 was downregulated, resulting in insufficient T-cell infiltration. The NANOG/WEE1/AKT axis was also conserved in various human cancers. Importantly, targeting WEE1 with a clinically relevant inhibitor sensitized NANOG+ immune-refractory tumors to ICB, reinvigorating antitumor immunity by disrupting the HSP90A/TCL1A/AKT loop. Thus, our findings demonstrate the oncogenic role of cytoplasmic WEE1 in immune-refractoriness and conferring cancer stem cell–like properties of tumor cells through AKT hyperactivation and provide a rationale for combining a WEE1 inhibitor to control anti–PD-1 therapy–refractory tumors.