Immunotherapy has only limited efficacy against pancreatic ductal adenocarcinoma (PDAC) due to the presence of an immunosuppressive tumor-associated stroma. Here, we demonstrate an effective modulation of that stroma by irreversible electroporation (IRE), a local ablation technique that has received regulatory approval in the United States. IRE induces immunogenic cell death, activates dendritic cells, and alleviates stroma-induced immunosuppression without depleting tumor-restraining collagen. The combination of IRE and anti-programmed cell death protein 1 (anti-PD1) immune checkpoint blockade promotes selective tumor infiltration by CD8+ T cells and significantly prolongs survival in a murine orthotopic PDAC model with a long-term memory immune response. Our results suggest that IRE is a promising approach to potentiate the efficacy of immune checkpoint blockade in PDAC.

Exosomes have attracted tremendous attention due to their important role in physiology, pathology, and oncology, as well as promising potential in biomedical applications. Although great efforts have been dedicated to investigating their biological properties and applications as natural cancer drug-delivery systems, the systemic biodistribution of exosomes remains underexplored. In addition, exosome-based drug delivery is inevitably hindered by the robust liver clearance, leading to suboptimal tumor retention and therapeutic efficiency. In this study, we report one of the first examples using in vivo positron emission tomography (PET) for noninvasive monitoring of copper-64 ( 64 Cu)-radiolabeled polyethylene glycol (PEG)-modified exosomes, achieving excellent imaging quality and quantitative measurement of blood residence and tumor retention. PEGylation not only endowed exosomes with a superior pharmacokinetic profile and great accumulation in the tumor versus traditionally reported native exosomes but also reduced premature hepatic sequestration and clearance of exosomes, findings that promise enhanced therapeutic delivery efficacy and safety in future studies. More importantly, this study provides important guidelines about surface engineering, radiochemistry, and molecular imaging in obtaining accurate and quantitative biodistribution information on exosomes, which may benefit future exploration in the realm of exosomes.

Prostate cancer (PCa) remains the most prevalent malignancy among males in the western world. Though hormonal therapies through chemical or surgical castration have been proposed many years ago, heretofore, such mainstay for the treatment on advanced PCa has not fundamentally changed. These therapeutic responses are temporary and most cases will eventually undergo PCa recurrence and metastasis, or even progress to castration-resistant prostate cancer (CRPC) due to persistent development of drug resistance. Prostate cancer stem cells (PCSCs) are a small population of cells, which possess unlimited self-renewal capacities, and can regenerate tumorigenic progenies, and play an essential role in PCa therapy resistance, metastasis and recurrence. Nowadays advanced progresses have been made in understanding of PCSC properties, roles of androgen receptor signaling and ATP-binding cassette sub-family G member 2 (ABCG2), as well as roles of genomic non-coding microRNAs and key signaling pathways, which have led to the development of novel therapies which are active against chemoresistant PCa and CRPC. Based on these progresses, this review is dedicated to address mechanisms underlying PCa chemoresistance, unveil crosstalks among pivotal signaling pathways, explore novel biotherapeutic agents, and elaborate functional properties and specific roles of chemoresistant PCSCs, which may act as a promising target for novel therapies against chemoresistant PCa.

Despite recent advances in our understanding of the biological behavior of prostate cancer (PCa), PCa is becoming the most common malignancy in men worldwide. The phosphatidylinositol 3-kinase (PI3K)/AKT pathway has been implicated in prostate carcinogenesis. Inflammatory cytokines (CCR9, IL-6, and TLR3) regulate PI3K/AKT signaling during apoptosis of PCa cells, and PI3K/AKT signaling participates with androgen-, 1alpha,25(OH)2-vitamin D3-, and prostaglandin-associated mechanisms and is regulated by ErbB, EGFR, and the HER family during cell growth. During metastasis of PCa cells, the PI3K/AKT/NF-kappaB/BMP-2-Smad axis, PTEN/PI3K/AKT pathway, and PI3K/AKT/mTOR signaling regulates tumor cell metastasis and invasion. The present review focuses on the PI3K/AKT signal pathway and discusses the role of the PI3K/AKT signal pathway in PCa tumorigenesis.

Podocyte dysfunction is important in the onset and development of diabetic nephropathy (DN). Histone deacetylases (HDACs) have been recently proved to play critical roles in the pathogenesis of DN. As one subtype of the class IIa HDACs, HDAC9 is capable to repress/de-repress their target genes in tumor, inflammation, atherosclerosis and metabolic diseases. In the present study, we investigate whether HDAC9 is involved in the pathophysiologic process of DN, especially the podocyte injury. Firstly, we explored the expression patterns and localization of HDAC9 and found that HDAC9 expression was significantly up-regulated in high glucose (HG)-treated mouse podocytes, as well as kidney tissues from diabetic db/db mice and patients with DN. Secondly, knockdown of HDAC9 in mouse podocytes significantly suppressed HG-induced reactive oxygen species (ROS) generation, cell apoptosis and inflammation through JAK2/STAT3 pathway and reduced the podocytes injury by decreasing the expression levels of Nephrin and Podocin. Moreover, in diabetic db/db mice, silencing of HDAC9 attenuated the glomerulosclerosis, inflammatory cytokine release, podocyte apoptosis and renal injury. Collectively, these data indicate that HDAC9 may be involved in the process of DN, especially podocyte injury. Our study suggest that inhibition of HDAC9 may have a therapeutic potential in DN treatment.

The regulation of microRNA-192 (miR-192) is impaired in many cancers. Here, we investigated the role of miR-192 in the proliferation, cell cycle progression, and apoptosis of bladder cancer cells. Human bladder cancer cells were transfected with human miR-192 precursor or non-specific control miRNA. The effect of miR-192 on cell proliferation was assessed by a MTT assay. The effects of miR-192 on cell cycle regulation and apoptosis were evaluated by flow cytometry. Western blot was used to analyze the protein levels of cyclin D1, p21, p27, Bcl-2, Bax, and Mcl-1. We found that overexpression of miR-192 significantly decreased the proliferation of bladder cancer cells by 22 and 54 % at 48 and 72 h, respectively. MiR-192-overexpressing cells exhibited a significant increase in G0/G1 phase and a significant decrease in S phase compared to the control miRNA-transfected cells. Moreover, overexpression of miR-192 significantly induced apoptotic death in bladder cancer cells, increased the levels of p21, p27, and Bax, and decreased the levels of cyclin D1, Bcl-2, and Mcl-1. Taken together, these data suggest that miR-192 may be a suppressor for bladder cancer cells by cell cycle regulation.

Kaposi’s sarcoma (KS) remains the most common tumor arising in patients with HIV/AIDS, and involvement of the oral cavity represents one of the most common clinical manifestations of this tumor. HIV infection incurs an increased risk for periodontal diseases and oral carriage of a variety of bacteria. Whether interactions involving pathogenic bacteria and oncogenic viruses in the local environment facilitate replication or maintenance of these viruses in the oral cavity remains unknown. In the current study, our data indicate that pretreatment of primary human oral fibroblasts with two prototypical pathogen-associated molecular patterns (PAMPs) produced by oral pathogenic bacteria–lipoteichoic acid (LTA) and lipopolysaccharide (LPS), increase KSHV entry and subsequent viral latent gene expression during de novo infection. Further experiments demonstrate that the underlying mechanisms induced by LTA and/or LPS include upregulation of cellular receptor, increasing production of reactive oxygen species (ROS), and activating intracellular signaling pathways such as MAPK and NF-κB, and all of which are closely associated with KSHV entry or gene expression within oral cells. Based on these findings, we hope to provide the framework of developing novel targeted approaches for treatment and prevention of oral KSHV infection and KS development in high-risk HIV-positive patients.

Eighty percent of lung cancers originate as subtle premalignant changes in the airway mucosal epithelial layer of bronchi and alveoli, which evolve and penetrate deeper into the parenchyma. Liquid-ventilation, with perfluorocarbons (PFC) was first demonstrated in rodents in 1966 then subsequently applied as lipid-encapsulated PFC emulsions to improve pulmonary function in neonatal infants suffering with respiratory distress syndrome in 1996. Subsequently, PFC nanoparticles (NP) were extensively studied as intravenous (IV) vascular-constrained nanotechnologies for diagnostic imaging and targeted drug delivery applications.Methods: This proof-of-concept study compared intratumoral localization of fluorescent paramagnetic (M) PFC NP in the Vx2 rabbit model using proton (1H) and fluorine (19F) magnetic resonance (MR) imaging (3T) following intratracheal (IT) or IV administration. MRI results were corroborated by fluorescence microscopy.Results: Dynamic 1H-MR and 19F-MR images (3T) obtained over 72 h demonstrated marked and progressive accumulation of M-PFC NP within primary lung Vx2 tumors during the first 12 h post IT administration. Marked 1H and 19F MR signal persisted for over 72 h. In contradistinction, IV M-PFC NP produced a modest transient signal during the initial 2 h post-injection that was consistent circumferential blood pool tumor enhancement. Fluorescence microscopy of excised tumors corroborated the MR results and revealed enormous intratumor NP deposition on day 3 after IT but not IV treatment. Rhodamine-phospholipid incorporated into the PFC nanoparticle surfactant was distributed widely within the tumor on day 3, which is consistent with a hemifusion-based contact drug delivery mechanism previously reported. Fluorescence microscopy also revealed similar high concentrations of M-PFC NP given IT for metastatic Vx2 lung tumors. Biodistribution studies in mice revealed that M-PFC NP given IV distributed into the reticuloendothelial organs, whereas, the same dosage given IT was basically not detected beyond the lung itself. PFC NP given IT did not impact rabbit behavior or impair respiratory function. PFC NP effects on cells in culture were negligible and when given IV or IT no changes in rabbit hematology nor serum clinical chemistry parameters were measured.Conclusion: IT delivery of PFC NP offered unique opportunity to locally deliver PFC NP in high concentrations into lung cancers with minimal extratumor systemic exposure.