Abstract:
Effective cancer therapy depends not only on destroying the primary tumor but also on conditioning the host immune system to recognize and eliminate residual tumor cells and prevent metastasis. In this study, a tumor integrin αvβ6-targeting peptide (the HK peptide)-functionalized graphene oxide (GO) was coated with a photosensitizer (HPPH). The resulting GO conjugate, GO(HPPH)-PEG-HK, was investigated whether it could destroy primary tumors and boost host antitumor immunity. We found that GO(HPPH)-PEG-HK exhibited significantly higher tumor uptake than GO(HPPH)-PEG and HPPH. Photodynamic therapy (PDT) using GO(HPPH)-PEG suppressed tumor growth in both subcutaneous and lung metastatic mouse models. Necrotic tumor cells caused by GO(HPPH)-PEG-HK PDT activated dendritic cells and significantly prevented tumor growth and lung metastasis by increasing the infiltration of cytotoxic CD8+ T lymphocytes within tumors as evidenced by in vivo optical and single-photon emission computed tomography (SPECT)/CT imaging. These results demonstrate that tumor-targeted PDT using GO(HPPH)-PEG-HK could effectively ablate primary tumors and destroy residual tumor cells, thereby preventing distant metastasis by activating host antitumor immunity and suppressing tumor relapse by stimulation of immunological memory.
Abstract:
Increased recruitment of tumor-associated macrophages (TAM) to tumors following chemotherapy promotes tumor resistance and recurrence and correlates with poor prognosis. TAM depletion suppresses tumor growth, but is not highly effective due to the effects of tumorigenic mediators from other stromal sources. Here, we report that adoptive macrophage transfer led to a dramatically enhanced photodynamic therapy (PDT) effect of 2-(1-hexyloxyethyl)-2-devinyl pyropheophor-bide-alpha (HPPH)-coated polyethylene glycosylated nanographene oxide [GO(HPPH)-PEG] by increasing its tumor accumulation. Moreover, tumor treatment with commonly used chemotherapeutic drugs induced an increase in macrophage infiltration into tumors, which also enhanced tumor uptake and the PDT effects of GO(HPPH)-PEG, resulting in tumor eradication. Macrophage recruitment to tumors after chemotherapy was visualized noninvasively by near-infrared fluorescence and single-photon emission CT imaging using F4/80-specific imaging probes. Our results demonstrate that chemotherapy combined with GO(HPPH)-PEG PDT is a promising strategy for the treatment of tumors, especially those resistant to chemotherapy. Furthermore, TAM-targeted molecular imaging could potentially be used to predict the efficacy of combination therapy and select patients who would most benefit from this treatment approach.
Abstract:
Effective cancer therapy depends not only on destroying the primary tumor but also on conditioning the host immune system to recognize and eliminate residual tumor cells and prevent metastasis. In this study, a tumor integrin αvβ6-targeting peptide (the HK peptide)-functionalized graphene oxide (GO) was coated with a photosensitizer (HPPH). The resulting GO conjugate, GO(HPPH)-PEG-HK, was investigated whether it could destroy primary tumors and boost host antitumor immunity. We found that GO(HPPH)-PEG-HK exhibited significantly higher tumor uptake than GO(HPPH)-PEG and HPPH. Photodynamic therapy (PDT) using GO(HPPH)-PEG suppressed tumor growth in both subcutaneous and lung metastatic mouse models. Necrotic tumor cells caused by GO(HPPH)-PEG-HK PDT activated dendritic cells and significantly prevented tumor growth and lung metastasis by increasing the infiltration of cytotoxic CD8+ T lymphocytes within tumors as evidenced by in vivo optical and single-photon emission computed tomography (SPECT)/CT imaging. These results demonstrate that tumor-targeted PDT using GO(HPPH)-PEG-HK could effectively ablate primary tumors and destroy residual tumor cells, thereby preventing distant metastasis by activating host antitumor immunity and suppressing tumor relapse by stimulation of immunological memory.
Overexpression of human epidermal growth factor receptor 2 (HER2) plays important roles in tumorigenesis and tumor progression in breast cancer. Nuclear imaging of HER2 expression in tumors might detect all HER2-positive tumors throughout the body and guide HER2-targeted therapies for patients. We therefore aimed to develop a HER2-targeted peptide probe for breast cancer imaging. A novel SPECT imaging probe, 99mTc-HYNIC-H6F, was prepared and then evaluated in breast cancer animal models.
Epidermal growth factor receptor mutant III (EGFRvIII) is exclusively expressed in tumors, such as glioblastoma, breast cancer and hepatocellular carcinoma, but never in normal organs. Increasing evidence suggests that EGFRvIII has clinical significance in glioblastoma prognosis due to its enhanced tumorigenicity and chemo/radio resistance, thus the development of an imaging approach to early detect EGFRvIII expression with high specificity is urgently needed. To illustrate this point, we developed a novel anti-EGFRvIII monoclonal antibody 4G1 through mouse immunization, cell fusion and hybridoma screening and then confirmed its specificity and affinity by a serial of assays. Following biodistribution and small animal single-photon emission computed tomography (SPECT/CT) imaging of 125I-4G1 in EGFRvIII positive/negative tumor-bearing mice were performed and evaluated to verify the tumor accumulation of this radiotracer. The biodistribution indicated that 125I-4G1 showed prominent tumor accumulation at 24 h post-injection, which reached maximums of 11.20 ± 0.75% ID/g and 13.98 ± 0.57% ID/g in F98npEGFRvIII and U87vIII xenografts, respectively. In contrast, 125I-4G1 had lower tumor accumulation in F98npEGFR and U87MG xenografts. Small animal SPECT/CT imaging revealed that 125I-4G1 had a higher tumor uptake in EGFRvIII-positive tumors than that in EGFRvIII-negative tumors. This study demonstrates that radiolabeled 4G1 can serve as a valid probe for the imaging of EGFRvIII expression, and would be valuable into the clinical translation for the diagnosis, prognosis, guiding therapy, and therapeutic efficacy evaluation of tumors.
Oncotarget. ,8(4):6364-6375.
DOI: 10.18632/oncotarget.14088.
Publication Date:Jan 24,2017
Abstract:
The aims of this study were to evaluate and compare efficacies of Tc-99m-3PRGD2 integrin receptor imaging under variety of conditions for the diagnosis of breast lesions, in addition to comparison with mammography.Tc-99m-3PRGD2-based molecular imaging is a sensitive method for the differential diagnosis of breast lesions. Particularly, Tc-99m-3PRGD2-SPECT/CT has better diagnostic value in dense mammary gland as compared with mammography. Combining two methods can significantly improve the diagnostic efficiency.
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Cancer Invest. ,35(2):108-115.
DOI:10.1080/07357907.2016.1270957
Publication Date(Web):Jan 31 ,2017
Abstract:
Targeted theranostic nano-system integrating functions of both diagnosis and therapy shows great potential for improving diagnosis and therapeutic efficacy. Herein, multifunctional nanoparticle based on activatable hyaluronic acid (HA) conjugating two near-infrared (NIR) dyes of Cy5.5 and IR825 was successfully designed and fabricated, and simultaneously used as a carrier for encapsulating perfluorooctylbromide (PFOB). In this system, PFOB showed good capability to absorb the X-rays, Cy5.5 on the outer surface acted as a fluorescent dye activatable by hyaluronidases (Hyals) in the tumor, and IR825 in the core as a photothermal agent. The obtained nanoparticles (NPs) of PFOB@IR825-HA-Cy5.5 can be utilized for triple X-ray computed tomography (CT), fluorescence and photoacoustic imaging. When PFOB@IR825-HA-Cy5.5 NPs were intravenously injected into the mice bearing HT-29 tumor, efficient tumor accumulation was clearly observed, as revealed by the triple modal imaging. An in vivo tumor treatment experiment was conducted by combination of PFOB@IR825-HA-Cy5.5 and near-infrared laser irradiation, achieving effective tumor ablation in mice. Therefore, PFOB@IR825-HA-Cy5.5 NPs is a safe, efficient, imageable photothermal nanoprobe, showing great potential for cancer theranostics.
Biomaterials. ,2017 ,132:72-84
DOI:10.1016/j.biomaterials.2017.04.006
Publication Date(Web):Apr 8 ,2017
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