P2Y2R-mediated inflammasome activation is involved in tumor progression in breast cancer cells and in radiotherapy-resistant breast cancer

Abstract

In the tumor microenvironment, extracellular nucleotides are released and accumulate, and can activate the P2Y2 receptor (P2Y2R), which regulates various responses in tumor cells, resulting in tumor progression and metastasis. Moreover, the inflammasome has recently been reported to be associated with tumor progression. However, the role of P2Y2R in inflammasome activation in breast cancer cells is not yet well defined. Therefore, in this study, we investigated the role of P2Y2R in inflammasome-mediated tumor progression in breast cancer using breast cancer cells and radiotherapy-resistant (RT-R) breast cancer cells. We established RT-R-breast cancer cells (RT-R-MDA-MB-231, RT-R-MCF-7, and RT-R-T47D cells) by repeated irradiation (2 Gy each, 25 times) in a previous study. In this study, we found that the RT-R breast cancer cells exhibited an increased release of adenosine triphosphate (ATP) and P2Y2R activity. In particular, the RT-R-MDA-MB-231 cells derived from highly metastatic MDA-MB-231 cells, exhibited a markedly increased ATP release, which was potentiated by tumor necrosis factor (TNF)-α. The MDA-MB-231 cells exhibited inflammasome activation, as measured by caspase-1 activity and interleukin (IL)-1β secretion following treatment with TNF-α and ATP; these effects were enhanced in the RT-R-MDA-MB-231 cells. However, the increased caspase-1 activities and IL-1β secretion levels induced in response to treatment with TNF-α or ATP were significantly reduced by P2Y2R knockdown or the presence of apyrase in both the MDA-MB-231 and RT-R-MDA-MB-231 cells, suggesting the involvement of ATP-activated P2Y2R in inflammasome activation. In addition, TNF-α and ATP increased the invasive and colony-forming ability of the MDA-MB-231 and RT-R-MDA-MB-231 cells, and these effects were caspase-1-dependent. Moreover, matrix metalloproteinase (MMP)-9 activity was modulated by caspase-1, in a P2Y2R-dependent manner in the MDA-MB-231 and RT-R-MDA-MB-231 cells. Finally, nude mice injected with the RT-R-MDA-MB-231-EV cells (transfected with the empty vector) exhibited increased tumor growth, and higher levels of MMP-9 in their tumors and IL-1β levels in their serum compared with the mice injected with the RT-R-MDA-MB-231- P2Y2R shRNA cells (transfected with P2Y2R shRNA). On the whole, the findings of this study suggest that extracellular ATP promotes tumor progression in RT-R-breast cancer cells and breast cancer cells by modulating invasion and associated molecules through the P2Y2R-inflammasome activation pathway.

Signaling Through Purinergic Receptor P2Y2 Enhances Macrophage IL-1β Production

“…However, P2Y 2 R has also been shown to be involved in pro-inflammatory responses [35,36]. Recently, it has been described that P2Y 2 R is required to induce IL-1β production in irradiated tumor cells by a pannexin-1-dependent mechanism [37], although the downstream P2Y 2 R signaling is unknown, it would suggest a physiological context in which macrophages would show a pro-inflammatory response as indicated in this manuscript. P2Y 2 R, as many G protein-coupled receptors, signals through PI3K, PLC activation and a subsequent intracellular calcium release [14], although the exact mechanism remains unclear [38,39].…”

P2Y2R has a significant correlation with Notch‑4 in patients with breast cancer

“…P2Y 2 R expression is also significantly increased in tumor tissue and has a significant correlation only with Notch-4 of the cancer stem cell markers evaluated. In our previous study, we suggested that P2Y 2 R has an important role in tumor progression and metastasis in highly metastatic breast cancer cells, such as MDA-MB-231 and RT-R breast cancer cells (16)(17)(18)(19). In addition, Ko et al (19).…”

miR-103 promotes the metastasis and EMT of hepatocellular carcinoma by directly inhibiting LATS2

“…Patients with HCC generally have a poor prognosis due to the highly invasive nature of the disease ( 2 ). A large number of studies have reported that the inactivation of tumor suppressor genes and the activation of oncogenes is responsible for the metastasis of HCC ( 3 - 5 ). However, the mechanisms underlying recurrence and metastasis in HCC have not yet been fully determined.…”