ABSTRACT
This study fabricates a nanoparticle delivery system of gold nanoparticles-dextran nanoparticles loaded with hypoxia-activated paclitaxel dimeric prodrug nanoparticles (PTX2-NP) and photosensitizer chlorin e6/paclitaxel-nanoparticle/gold@N-(2-hydroxypropyl) (Ce6/PTX2-NP/G@NHs) and analyzed the possible molecular mechanism for enhancing the radiosensitivity of non-small cell lung cancer (NSCLC). Ce6/PTX2-NP/G@NHs were prepared by a coupling reaction and dextran inclusion, followed by characterization using spectroscopy techniques. The cellular uptake and cytotoxicity of Ce6/PTX2-NP/G@NHs were analyzed. Radiosensitizing effects of the nanoparticles were evaluated by determining the malignant phenotypes and reactive oxygen species production of A549 cells and PI3K/AKT pathway-related proteins under 685 nm laser irradiation. A549 tumor-bearing nude mice were modeled to further confirm the radiosensitizing effect. Ce6/PTX2-NP/G@NHs were effectively internalized by A549 cells, producing cytotoxicity under laser irradiation. Ce6/PTX2-NP/G@NHs reduced cell viability, clonogenic potential, migration, and invasion along with reactive oxygen species (ROS) production while promoting apoptosis in A549 cells under laser irradiation. By inhibiting the PI3K/AKT pathway, Ce6/PTX2-NP/G@NHs increased the sensitivity of A549 cells to radiotherapy where apoptotic body (ApoBD)-mediated neighboring effects also played a key role. Ce6/PTX2-NP/G@NHs accumulated in tumor sites of nude mice and enhanced the radiosensitivity of NSCLC. Ce6/PTX2-NP/G@NHs showed no obvious toxicity or side effects in vivo. Collectively, the new Ce6/PTX2-NP/G@NHs nanoparticle delivery system can enhance the radiosensitivity of NSCLC via the promotion of ApoBD-mediated neighboring effects and inactivation of the PI3K/AKT pathway.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Extracellular Vesicles , Lung Neoplasms , Metal Nanoparticles , Photochemotherapy , Radiation-Sensitizing Agents , Animals , Mice , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/radiotherapy , Photochemotherapy/methods , Mice, Nude , Cell Line, Tumor , Reactive Oxygen Species/metabolism , Dextrans , Gold , Phosphatidylinositol 3-Kinases , Proto-Oncogene Proteins c-akt , Lung Neoplasms/drug therapy , Lung Neoplasms/radiotherapy , Metal Nanoparticles/therapeutic use , Radiation-Sensitizing Agents/pharmacology , Paclitaxel/pharmacology , Radiation Tolerance , Extracellular Vesicles/metabolismABSTRACT
[This corrects the article DOI: 10.3389/fonc.2020.01523.].
ABSTRACT
Meningioma is the most frequent primary tumor of the central nervous system. Important advances have been achieved in the treatment of meningioma in recent decades. Although most meningiomas are benign and have a good prognosis after surgery, clinicians often face challenges when the morphology of the tumor is complicated or the tumor is close to vital brain structures. At present, the longstanding treatment strategies of meningioma are mainly surgery and radiotherapy. The effectiveness of systemic therapy, such as chemotherapy or targeted therapy, has not been confirmed by big data series, and some clinical trials are still in progress. In this review, we summarize current treatment strategies and future research directions for meningiomas.
ABSTRACT
Temozolomide (TMZ), a DNA alkylating agent, represents the most important chemotherapeutic option for the treatment of glioblastoma in the clinic. Despite its frequent use, the therapeutic efficacy of TMZ remains very limited due to its frequent resistance in glioblastoma. Previous evidence suggested that curcumin (CUM), an ingredient of the Indian spice turmeric, is able to sensitize glioblastoma to TMZ treatment. However, the underlying molecular mechanism remains elusive. In the present study, we performed in vitro and in vivo experiments to evaluate the interaction of CUM and TMZ on the inhibition of glioblastoma and to investigate its potential mechanisms of action using U87MG cell lines and xenograft mouse models. We demonstrated that CUM enhanced the therapeutic response to TMZ in U87MG glioblastoma by enhancing apoptosis. We then proceeded to investigate the potential apoptotic signaling pathways that are involved. We observed a synergistic effect of the combination of CUM and TMZ in generating reactive oxygen species (ROS) production, suggesting that ROS may contribute to the impact of CUM on sensitizing TMZ treatment. We also showed that CUM and TMZ treatment alone significantly suppressed phosphorylated AKT and mTOR, whereas their combination achieved a more pronounced inhibitory effect. These data indicated that blockage of AKT/mTOR signaling appeared to contribute to the elevated apoptosis caused by the combination treatment with CUM and TMZ. In conclusion, this study provided molecular insights into the effects of CUM on the therapeutic response of glioblastoma to TMZ and opened new avenues for optimizing the therapeutic effects of TMZ-based therapies.
