Targeted delivery of exosomal miR-484 reprograms tumor vasculature for chemotherapy sensitization.

The vascular dysfunction of ovarian cancer (OC) contributes to the chemotherapeutic resistance. In this study, we aimed to explore whether exosome-mediated angiogenesis blocking could improve the chemotherapy sensitivity via vascular normalization. Exosomes were armed with RGD on the surface by fusing Lamp2b. Candidate miRNAs related to tumor angiogenesis was detected by qRT-PCR. RGD-modified exosomes were loaded with miRNAs via electroporation. The therapeutic effects of the exosomes on angiogenesis, vascular normalization, and chemotherapy sensitivity were systemically analyzed in the xenograft model. RGD-modified exosomes were relatively enriched in the tumor mass, both the tumor cell and the endothelial cells. Among the miRNA candidates, miR-484 was found down-regulated in both the cancer cells and the angiogenic endothelial cells. In vivo xenograft model experiment revealed that injection of RGD-modified exosomes loaded with miR-484 induced vessel normalization and in turn sensitized the cancer cells to chemotherapy induced apoptosis. Mechanistically, miR-484 simultaneously inhibited the expression of VEGF-A from the cancer cells and the corresponding receptors in the endothelial cells. Targeted delivery of miR-484 via RGD-modified exosomes improves the vascular normalization, sensitizes the cancer to chemotherapy, and prolongs the survival time of tumor-bearing mice after chemotherapy, opening an avenue for the clinical management of chemotherapy resistance.

Preparation of multifunctional nanobubbles and their application in bimodal imaging and targeted combination therapy of early pancreatic cancer.

Pancreatic cancer will gradually become the second leading cause of cancer death due to its poor suitability for surgical treatment, frequent recurrence and metastasis, and insensitivity to radiotherapy and chemotherapy. Strategies for precise early detection and effective targeted treatment of pancreatic cancer are urgently needed. Because of its unique advantages, molecular targeted contrast-enhanced ultrasound imaging (CEUI) has generated new opportunities to overcome this challenge. The aim of this study was to explore multifunctional nanobubbles named IR780-NBs-DTX as novel ultrasound contrast agents (UCAs) for dual-mode targeted imaging and photothermal ablation combined with chemotherapy for pancreatic cancer. An optimized "film hydration method" was used to prepare IR780-NBs-DTX in this research. The characteristics and ability of the new UCAs were detected via in vitro, in vivo and ex vivo experiments. The initial dose of 0.15 mg IR-780 iodide/1.0 mg DTX was considered to be the best formula for IR780-NBs-DTX, and the concentration of 6 ×106 bubbles/mL was best for CEUI. The excellent characteristics of IR780-NBs-DTX, including a uniform nanoscale particle size (349.8± 159.1 nm, n= 3), good performance in dual-mode imaging, high stability and reliable biocompatibility, were also proven. In the in vitro cell experiments, IR780-NBs-DTX targeted more pancreatic cancer cells than the control treatments, and the targeting rate was approximately 95.6± 1.7%. Under irradiation with an 808 nm laser, most cells died. Furthermore, the in vivo study demonstrated that IR780-NBs-DTX could precisely detect pancreatic cancer through near infrared fluorescence (NIRF) imaging and CEUI, and the tumor almost disappeared at 18 days after combined treatment. In ex vivo experiments, immunohistochemistry (IHC) and immunofluorescence (IF) showed that the expression of HSP70 increased and that of PCNA decreased, and many apoptotic tumor cells were observed by TUNEL staining in the IR780-NBs-DTX group. The newly prepared IR780-NBs-DTX are novel nanosized UCAs with high efficiency for dual-mode molecular targeted imaging and combined therapy, and they may have future potential applications in the precise detection and effective targeted therapy of small and metastatic lesions in the early stage of pancreatic cancer.

NF-YA transcriptionally activates the expression of SOX2 in cervical cancer stem cells.

Roles for SOX2 have been extensively studied in several types of cancer, including colorectal cancer, glioblastoma and breast cancer, with particular emphasis placed on the roles of SOX2 in cancer stem cell. Our previous study identified SOX2 as a marker in cervical cancer stem cells driven by a full promoter element of SOX2 EGFP reporter. Here, dual-luciferase reporter and mutagenesis analyses were employed, identifying key cis-elements in the SOX2 promoter, including binding sites for SOX2, OCT4 and NF-YA factors in SOX2 promoter. Mutagenesis analysis provided additional evidence to show that one high affinity-binding domain CCAAT box was precisely recognized and bound by the transcription factor NF-YA. Furthermore, overexpression of NF-YA in primitive cervical cancer cells SiHa and C33A significantly activated the transcription and the protein expression of SOX2. Collectively, our data identified NF-YA box CCAAT as a key cis-element in the SOX2 promoter, suggesting that NF-YA is a potent cellular regulator in the maintenance of SOX2-positive cervical cancer stem cell by specific transcriptional activation of SOX2.