Search

Background: The role of tumor-associated macrophages (TAMs) in glioblastoma (GBM) disease progression has received increasing attention. Recent advances have shown that TAMs can be re-programmed to exert a pro-inflammatory, anti-tumor effect to control GBMs. However, imaging methods capable of differentiating tumor progression from immunotherapy treatment effects have been lacking, making timely assessment of treatment response difficult. We showed that tracking monocytes using iron oxide nanoparticle (USPIO) with MRI can be a sensitive imaging method to detect therapy response directed at the innate immune system. Methods: We implanted syngeneic mouse glioma stem cells into C57/BL6 mice and treated the animals with either niacin (a stimulator of innate immunity) or vehicle. Animals were imaged using an anatomical MRI sequence, R2* mapping, and quantitative susceptibility mapping (QSM) before and after USPIO injection. Results: Compared to vehicles, niacin-treated animals showed significantly higher susceptibility and R2*, representing USPIO and monocyte infiltration into the tumor. We observed a significant reduction in tumor size in the niacin-treated group 7 days later. We validated our MRI results with flow cytometry and immunofluoresence, which showed that niacin decreased pro-inflammatory Ly6C high monocytes in the blood but increased CD16/32 pro-inflammatory macrophages within the tumor, consistent with migration of these pro-inflammatory innate immune cells from the blood to the tumor. Conclusion: MRI with USPIO injection can detect therapeutic responses of innate immune stimulating agents before changes in tumor size have occurred, providing a potential complementary imaging technique to monitor cancer immunotherapies. Manuscript highlight: We show that iron oxide nanoparticles (USPIOs) can be used to label innate immune cells and detect the trafficking of pro-inflammatory monocytes into the glioblastoma. This preceded changes in tumor size, making it a more sensitive imaging technique. [ABSTRACT FROM AUTHOR]

The financial viability of many not‐for‐profit organisations is linked to community fundraising by volunteers. This study explored predictors of volunteer retention and fundraising performance in relay for life (RFL), an international volunteer community‐based cancer fundraising event. A self‐report survey completed by 1298 RFL volunteers (24% response) assessed: satisfaction with volunteering; organisational commitment; psychological sense of connection; motives; social norms; capacity to volunteer as in perceived behavioural control and barriers to volunteering; satisfaction with community; behavioural intention. Primary outcomes were return participation in RFL and funds raised. Returning volunteers reported higher perceived behavioural control and satisfaction with community. Indirect effects through age‐moderated intention‐to‐return were higher satisfaction with volunteering; organisational commitment; psychological sense of connection; capacity to volunteer. Funds raised were higher in teams with volunteers who were older, strongly committed to the organisation and motivate to fight cancer; with low interest in social/entertainment. Strategies to nurture the volunteer‐organisation relationship and enhance volunteer capabilities may be most crucial for event success and long‐term viability. [ABSTRACT FROM AUTHOR]