Abstract
Chemotherapy-induced senescence promotes immunocyte aggregation in the tumor microenvironment by upregulating the surface expression of activating ligands in cancer cells. However, these senescent tumor cells cannot be completely cleared and can induce tumor recurrence. Previous studiesshowed that soluble natural killer (NK) group 2D (NKG2D) ligands impair the recognition of multiple immune cells. In this study, we established an in vitro senescence model using neuroblastoma cells subjected to low-dose Chemotherapeutic drug doxorubicin or the Aurora A inhibitor MLN8237. The results showed that different neuroblastoma cell lines showed increased secretion of the NKG2D ligand MHC class I polypeptide-related sequence A/B (MICA/B) following proteolysis after treatment, with MICA/B subsequently recruited to exosomes to downregulate NKG2D expression in NK cells. Interestingly, disintegrin and metalloproteinase domain-containing 10 (ADAM10) was upregulated in senescent tumor cells, and combined treatment with the ADAM10 inhibitor GI254023X and chemotherapeutic drugs inhibited MICA/B secretion and enhanced recognition and killing by NK cells. Additionally, we found that expression of the long noncoding RNA MALAT1 was significantly increased in senescent neuroblastoma cells, and that MALAT1 served as a sponge for microRNA (miR)-92a-3p to counteract miR-92a-3p-mediated repression of ADAM10 levels. Furthermore, administration of a MALAT1 inhibitor or an miR-92a-3p mimic reduced the MICA/B shedding and enhanced recognition and killing by NK cells. These results confirmed that low-dose chemotherapy induces senescence in neuroblastoma cells, and that senescent tumor cells promote the shedding of the NKG2D ligand MICA/B through the MALAT1/miR-92a/ADAM10 axis, thereby contributing to the formation of a suppressive immune microenvironment and promoting immune escape.
Highlights
Neuroblastoma is one of the most common extracranial malignant solid tumors during childhood (Gao et al, 2020), and its clinical manifestations are highly heterogeneous among children, with some tumors regressing on their own (Zafar et al, 2021)
It has been widely believed that senescence is a stress response that manifests as a state of irreversible growth arrest; increasing results have shown that senescent tumor cells have the ability to escape immune surveillance (Prieto and Baker, 2019; Toffalori et al, 2019), survive in the body for a long time, re-enter the cell cycle from a state of prolonged arrest, and maintain a vigorous proliferative potential
We examined the release of the Natural killer group 2 member D (NKG2D) ligand MHC class I polypeptide–related sequence A/B (MICA/B) in different neuroblastoma cell lines before and after treatment with a low dose of chemotherapeutic drug
Summary
Neuroblastoma is one of the most common extracranial malignant solid tumors during childhood (Gao et al, 2020), and its clinical manifestations are highly heterogeneous among children, with some tumors regressing on their own (Zafar et al, 2021). Senescent cells continuously secrete a large number of bioactive substances, generally termed senescence-associated secretory phenotype (SASP), which can attract cytotoxic T lymphocytes (CTLs) and natural killer cells (NK) to accumulate to remove senescent tumor cells (Birch and Gil, 2020). This inflammatory response does not completely clear the senescent tumor cells, and some of them evade immune surveillance to enter the cell cycle and become an important cause of tumor recurrence (Saleh et al, 2019). We propose the hypothesis that chemotherapy-induced senescent neuroblastoma cells can inhibit immune cell recognition and killing through SASP, to survive genotoxic stress and relapse
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