Background Tumor local and distant relapse recurrence after radiotherapy (RT) is one of the critical factors leading to poor prognosis. The effective antitumor effects of RT are dependent upon the participation of innate and adaptive components of the immune system. C5a/C5aR1 signaling can regulate antitumor immune effect in the tumor microenvironment (TME). Thus, exploring the changes and mechanism in the TME induced by RT-mediated complement activation may provide a novel perspective for reversing radioresistance. Methods First, fractionated radiation of 8 Gy ×3 fractions were targeted at Lewis lung carcinoma (LLC) tumor-bearing female mice to measure the infiltration of CD8 + T cell and analyze the RNA sequencing (RNA-seq) in RT-recruited CD8 + T cells. Second, tumor growth was measured in LLC tumor-bearing mice treated with RT either with or without C5aR1 inhibitor to clarify the antitumor effect of RT combined with C5aR1 inhibitor. Third, we detected the expression of C5a/C5aR1 and their signaling pathways on radiated tumor tissues. Furthermore, we investigated the expression of C5a in tumor cells at different time points after different doses of RT. Results In our system, RT induced the increased infiltration of CD8 + T cells and local activation of complement C5a/C5aR. Concurrent administration of RT and blocking of C5aR improved radiosensitivity and tumor-specific immune response, which was reflected by high C5aR expression in CD8 + T cells. The AKT/NF-κB pathway was found to be an important signaling pathway in C5a/C5aR axis mediation by RT. Conclusions RT promotes the release of C5a from tumor cells and leads to up-regulation of C5aR1 expression via the AKT/NF-κB pathway. Inhibition of the combination of complement C5a and C5aR could improve RT sensitivity. Our work provides evidence that the combination of RT and C5aR blockade opens a new window of opportunity to promote anti-tumor therapeutic effects in lung cancer.
The anaplastic lymphoma kinase (ALK) rearrangements, mostly EML4‐ALK fusion, occur in 3‐7% of lung cancer patients and define a patient population that could respond to receptor tyrosine kinase inhibitor Crizotinib and Ceritinib. Currently, ALK testing is mostly conducted by either fluorescence in situ hybridization (FISH) or polymerase chain reaction (PCR) methods, either of which has its own limitations. The detection of the ALK protein in lung cancer patient tissues by IHC was found to be difficult mostly due to the low abundance of its fusion product. To overcome this limitation, we have developed an ALK mouse monoclonal antibody (clone 1A4) that is more sensitive than a current rabbit ALK antibody D5F3. Our initial analyses revealed that 1A4 can correctly identify all 5 EML4‐ALK positive samples that were previously confirmed by QPCR tests, while did not yield significant background on all 30 EML4‐ALK negative lung cancer samples. By using a different IHC detection system, we further tested 1A4 on 17 ALK‐positive and 10 ALK‐negative lung cancer biopsy specimens that have been validated by either FISH or PCR from another hospital. The IHC result of the antibody 100% agreed with the previous molecular diagnosis. The high concordance of the IHC results by the novel ALK antibody with other DNA/RNA based detection methods suggested that 1A4 could be used routinely for screening ALK‐rearrangement genetic events among patients.This research is partly supported by Chinese 863 research grant number 2014AA020909.
All non-small cell lung cancer (NSCLC) patients are recommended to be screened for anaplastic lymphoma kinase (ALK)-rearrangement despite its low occurrence (< 7%). This is due to recent advances in treatment for patients with ALK-positive NSCLC with receptor tyrosine kinase inhibitors Crizotinib and Ceritini. Current rearranged-ALK testing includes fluorescence in situ hybridization (FISH), reverse transcription polymerase chain reaction (RT-PCR), and immunohistochemistry (IHC). Despite the high sensitivities and specificities, the limitations of the first two assays include time-consuming, infeasible, and specialized techniques that make them unsuitable for the routine screening for which IHC has been proposed. However, the biggest obstacle to detecting rearranged-ALK in lung cancer patients by IHC is the lack of highly sensitive ALK antibodies that detect the extremely low abundance of ALK in patients. To overcome this limitation, we have developed an ALK mouse monoclonal antibody (clone OTI1A4) with higher sensitivity in comparison to a rabbit ALK antibody (clone D5F3). Moreover, OTI1A4 identified ALK-positive NSCLC samples (16/16 cases) and showed negative staining for ALK-negative samples (11/11 cases) previously validated by FISH (10/16 ALK-positive cases) or qPCR (10/16 ALK-positive cases). This indicated the potential advantage of using clone OTI1A4 over FISH or qPCR to detect ALK rearrangements. Lastly, there was 100% concordance between OTI1A4 and D5F3 in detecting ALK-rearranged NSCLC samples previously confirmed by FISH (76 ALK-positive and 438 ALK-negative samples). These results support the possibility that ALK clone OTI1A4 could be used for routine screening of patients with ALK-positive NSCLC by IHC. Citation Format: Hsiangmin Lu, Rachel Gonzalez, Yi Shen, Mu-lan Jin, Yipan Wu, Yungang Zhang, Kehu Yuan, Boyang Chu, Lili Qi, Huibo Liu, Chenlin Wang, Guangli Wang, Youmin Shu, Julie McDowell, Donghui Ma, Wei-wu He, Jian Chen, Ray Lin. A new, highly sensitive ALK antibody improves the screening of rearranged-ALK by IHC. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 415.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.