CHEK2 Identified as a Potential Target to Improve Immunotherapy in Solid Tumors

“Taken together, CHEK2 expression has the potential to predict resistance or non-response to immunotherapy.”

BUFFALO, NY - June 20, 2025 – A new review was published in Volume 16 of Oncotarget on June 10, 2025, titled “Beyond DNA damage response: Immunomodulatory attributes of CHEK2 in solid tumors.”

In this paper, led by first author Helen Qian and corresponding author Crismita Dmello from Northwestern University Feinberg School of Medicine, researchers compiled growing evidence that the CHEK2 gene, long known for its role in repairing DNA damage, may also influence how tumors respond to immunotherapy. Their analysis suggests that problems in CHEK2 function might make cancer cells more vulnerable to immune system attacks, highlighting a new opportunity to improve treatment outcomes in solid tumors.

Immune checkpoint inhibitors (ICIs) have transformed cancer treatment; however, they are effective in only a subset of patients. This review suggests that tumors with reduced CHEK2 activity may accumulate more mutations that produce signals the immune system can recognize. These signals, known as neoantigens, help immune cells identify and destroy cancer cells more effectively. The review connects this process not only to CHEK2’s established role in the DNA damage response but also to a newly proposed function in shaping the immune environment of tumors.

CHEK2 normally helps maintain genomic stability by enabling precise DNA repair. When this function is lost, cells rely on more error-prone repair methods, leading to additional mutations. These mutations can increase tumor mutational burden, which has been linked to better outcomes with immunotherapy. Beyond DNA repair, the review highlights a second mechanism: activation of the cGAS-STING pathway. This pathway detects fragments of damaged DNA and triggers inflammation that attracts immune cells to the tumor.

The authors highlight studies where CHEK2-deficient tumors responded better to PD-1 inhibitors, a common type of immune checkpoint inhibitor. In both lab models and early-stage clinical settings, CHEK2 loss was associated with increased infiltration of CD8+ T cells—immune cells essential for attacking cancer cells. In cancers such as glioblastoma and renal cell carcinoma, which are typically resistant to immunotherapy, reduced CHEK2 expression was linked with more favorable immune activity and higher expression of interferon-related genes.

The compiled evidence points to CHEK2 as a potential biomarker for identifying patients likely to respond to immunotherapy. In addition, combining CHEK2 inhibitors with existing immunotherapies may enhance anti-tumor effects, particularly in cancers with limited treatment options. The review notes that some clinical trials using the CHEK1/2 inhibitor prexasertib alongside immune checkpoint therapies have already shown promising early results.

“The initial results from this Phase I clinical trial support the immunomodulatory role of CHEK2 expression and even suggest CHEK2 potentiates immunosuppression.”

Although more research is needed to confirm these mechanisms and improve treatment approaches, this review underscores the expanding role of DNA repair genes like CHEK2—not only in maintaining genome integrity but also in helping the immune system fight cancer.

Continue reading: DOI: https://doi.org/10.18632/oncotarget.28740

Correspondence to: Crismita Dmello - crismita.dmello@northwestern.edu 

Keywords: cancer, CHEK2, immune checkpoint inhibitors, immunomodulation

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