TY - JOUR
T1 - Phototherapy-induced antitumor immunity
T2 - Long-term tumor suppression effects via photoinactivation of respiratory chain oxidase-triggered superoxide anion burst
AU - Lu, Cuixia
AU - Zhou, Feifan
AU - Wu, Shengnan
AU - Liu, Lei
AU - Xing, Da
N1 - Publisher Copyright:
© Mary Ann Liebert, Inc. 2016.
PY - 2016/2/10
Y1 - 2016/2/10
N2 - Aims: Our previous studies have demonstrated that as a mitochondria-targeting cancer phototherapy, high-fluence, low-power laser irradiation (HF-LPLI) results in oxidative damage that induces tumor cell apoptosis. In this study, we focused on the immunological effects of HF-LPLI phototherapy and explored its antitumor immune regulatory mechanism. Results: We found not only that HF-LPLI treatment induced tumor cell apoptosis but also that HF-LPLI-treated apoptotic tumor cells activated macrophages. Due to mitochondrial superoxide anion burst after HF-LPLI treatment, tumor cells displayed a high level of phosphatidylserine oxidation, which mediated the recognition and uptake by macrophages with the subsequent secretion of cytokines and generation of cytotoxic T lymphocytes. In addition, in vivo results showed that HF-LPLI treatment caused leukocyte infiltration into the tumor and efficaciously inhibited tumor growth in an EMT6 tumor model. These phenomena were absent in the respiration-deficient EMT6 tumor model, implying that the HF-LPLI-elicited immunological effects were dependent on the mitochondrial superoxide anion burst. Innovation: In this study, for the first time, we show that HF-LPLI mediates tumor-killing effects via targeting photoinactivation of respiratory chain oxidase to trigger a superoxide anion burst, leading to a high level of oxidatively modified moieties, which contributes to the phenotypic changes in macrophages and mediates the antitumor immune response. Conclusion: Our results suggest that HF-LPLI may be an effective cancer treatment modality that both eradicates the treated primary tumors and induces an antitumor immune response via photoinactivation of respiratory chain oxidase to trigger superoxide anion burst.
AB - Aims: Our previous studies have demonstrated that as a mitochondria-targeting cancer phototherapy, high-fluence, low-power laser irradiation (HF-LPLI) results in oxidative damage that induces tumor cell apoptosis. In this study, we focused on the immunological effects of HF-LPLI phototherapy and explored its antitumor immune regulatory mechanism. Results: We found not only that HF-LPLI treatment induced tumor cell apoptosis but also that HF-LPLI-treated apoptotic tumor cells activated macrophages. Due to mitochondrial superoxide anion burst after HF-LPLI treatment, tumor cells displayed a high level of phosphatidylserine oxidation, which mediated the recognition and uptake by macrophages with the subsequent secretion of cytokines and generation of cytotoxic T lymphocytes. In addition, in vivo results showed that HF-LPLI treatment caused leukocyte infiltration into the tumor and efficaciously inhibited tumor growth in an EMT6 tumor model. These phenomena were absent in the respiration-deficient EMT6 tumor model, implying that the HF-LPLI-elicited immunological effects were dependent on the mitochondrial superoxide anion burst. Innovation: In this study, for the first time, we show that HF-LPLI mediates tumor-killing effects via targeting photoinactivation of respiratory chain oxidase to trigger a superoxide anion burst, leading to a high level of oxidatively modified moieties, which contributes to the phenotypic changes in macrophages and mediates the antitumor immune response. Conclusion: Our results suggest that HF-LPLI may be an effective cancer treatment modality that both eradicates the treated primary tumors and induces an antitumor immune response via photoinactivation of respiratory chain oxidase to trigger superoxide anion burst.
UR - http://www.scopus.com/inward/record.url?scp=84956963157&partnerID=8YFLogxK
U2 - 10.1089/ars.2015.6334
DO - 10.1089/ars.2015.6334
M3 - Article
C2 - 26413929
AN - SCOPUS:84956963157
SN - 1523-0864
VL - 24
SP - 249
EP - 262
JO - Antioxidants and Redox Signaling
JF - Antioxidants and Redox Signaling
IS - 5
ER -