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Triple Negative Breast Cancer (TNBC) continues to present a challenge in the clinic, as there is still no approved targeted therapy. TNBC is the worst sub-type of breast cancer in terms of prognosis and exhibits a deficiency in estrogen, progesterone, and human epidermal growth factor 2 (HER2) receptors. One possible option for the treatment of TNBC is chemotherapy. The issue with many chemotherapy drugs is that their effectiveness is diminished due to poor water solubility, and the method of administration directly or with a co-solvent intravenously can lead to an increase in toxicity. The issues of drug solubility can be avoided by using liposomes as a drug delivery carrier. Liposomes are engineered, biological nanoconstructs that possess the ability to encapsulate both hydrophobic and hydrophilic drugs and have been clinically approved to treat cancer. Specific targeting of cancer cell receptors through the use of ligands conjugated to the surface of drug-loaded liposomes could lessen damage to normal, healthy tissue. This study focuses on polyethylene glycol (PEG)-coated, folate conjugated, benzoporphyrin derivative (BPD)-loaded liposomes for treatment via photodynamic therapy (PDT). The folate receptor is over expressed on TNBC cells so these liposomes are targeted for greater uptake into cancer cells. PDT involves remotely irradiating light at 690 nm to trigger BPD, a hydrophobic photosensitive drug, to form reactive oxygen species that cause tumor cell death. BPD also displays a fluorescence signal when excited by light making it possible to image the fluorescence prior to PDT and for theranostics. In this study, free BPD, non-targeted and folate-targeted PEGylated BPD-loaded liposomes were introduced to a metastatic breast cancer cell line (MDA-MB-231) in vitro. The liposomes were reproducibly synthesized and characterized for size, polydispersity index (PDI), zeta potential, stability, and BPD release kinetics. Folate competition tests, fluorescence confocal imaging, and MTT assay were used to observe and quantify targeting effectiveness. The toxicity of BPD before and after PDT in monolayer and 3D in vitro cultures with TNBC cells was observed. This study may contribute to a novel nanoparticle-mediated approach to target TNBC using PDT.

Mesenchymal tumor subpopulations secrete pro-tumorigenic cytokines and promote treatment resistance1-4. This phenomenon has been implicated in chemorefractory small cell lung cancer and resistance to targeted therapies5-8, but remains incompletely defined. Here, we identify a subclass of endogenous retroviruses (ERVs) that engages innate immune signaling in these cells. Stimulated 3 prime antisense retroviral coding sequences (SPARCS) are oriented inversely in 3' untranslated regions of specific genes enriched for regulation by STAT1 and EZH2. Derepression of these loci results in double-stranded RNA generation following IFN-γ exposure due to bi-directional transcription from the STAT1-activated gene promoter and the 5' long terminal repeat of the antisense ERV. Engagement of MAVS and STING activates downstream TBK1, IRF3, and STAT1 signaling, sustaining a positive feedback loop. SPARCS induction in human tumors is tightly associated with major histocompatibility complex class 1 expression, mesenchymal markers, and downregulation of chromatin modifying enzymes, including EZH2. Analysis of cell lines with high inducible SPARCS expression reveals strong association with an AXL/MET-positive mesenchymal cell state. While SPARCS-high tumors are immune infiltrated, they also exhibit multiple features of an immune-suppressed microenviroment. Together, these data unveil a subclass of ERVs whose derepression triggers pathologic innate immune signaling in cancer, with important implications for cancer immunotherapy.

Cancer continues to be one of the most difficult global healthcare problems. Although there is a large library of drugs that can be used in cancer treatment, the problem is selectively killing all the cancer cells while reducing collateral toxicity to healthy cells. There are several biological barriers to effective drug delivery in cancer such as renal, hepatic, or immune clearance. Nanoparticles loaded with drugs can be designed to overcome these biological barriers to improve efficacy while reducing morbidity. Nanomedicine has ushered in a new era for drug delivery by improving the therapeutic indices of the active pharmaceutical ingredients engineered within nanoparticles. First generation nanomedicines have received widespread clinical approval over the past two decades, from Doxil® (liposomal doxorubicin) in 1995 to Onivyde® (liposomal irinotecan) in 2015. This review highlights the biological barriers to effective drug delivery in cancer, emphasizing the need for nanoparticles for improving therapeutic outcomes. A summary of different nanoparticles used for drug delivery applications in cancer are presented. The review summarizes recent successes in cancer nanomedicine in the clinic. The clinical trials of Onivyde leading to its approval in 2015 by the Food and Drug Adminstration are highlighted as a case study in the recent clinical success of nanomedicine against cancer. Next generation nanomedicines need to be better targeted to specifically destroy cancerous tissue, but face several obstacles in their clinical development, including identification of appropriate biomarkers to target, scale-up of synthesis, and reproducible characterization. These hurdles need to be overcome through multidisciplinary collaborations across academia, pharmaceutical industry, and regulatory agencies in order to achieve the goal of eradicating cancer. This review discusses the current use of clinically approved nanomedicines, the investigation of nanomedicines in clinical trials, and the challenges that may hinder development of the nanomedicines for cancer treatment.

Cancer immunotherapy is a rapidly evolving and paradigm shifting treatment modality that adds a strong tool to the collective cancer treatment arsenal. It can be effective even for late stage diagnoses and has already received clinical approval. Tumors are known to not only avoid immune surveillance but also exploit the immune system to continue local tumor growth and metastasis. Because of this, most immunotherapies, particularly those directed against solid cancers, have thus far only benefited a small minority of patients. Early clinical substantiation lends weight to the claim that cancer immunotherapies, which are adaptive and enduring treatment methods, generate much more sustained and robust anticancer effects when they are effectively formulated in nanoparticles or scaffolds than when they are administered as free drugs. Engineering cancer immunotherapies using nanomaterials is, therefore, a very promising area worthy of further consideration and investigation. This review focuses on the recent advances in cancer immunoengineering using nanoparticles for enhancing the therapeutic efficacy of a diverse range of immunotherapies. The delivery of immunostimulatory agents to antitumor immune cells, such as dendritic or antigen presenting cells, may be a far more efficient tactic to eradicate tumors than delivery of conventional chemotherapeutic and cytotoxic drugs to cancer cells. In addition to its immense therapeutic potential, immunoengineering using nanoparticles also provides a valuable tool for unearthing and understanding the basics of tumor biology. Recent research using nanoparticles for cancer immunotherapy has demonstrated the advantage of physicochemical manipulation in improving the delivery of immunostimulatory agents. In vivo studies have tested a range of particle sizes, mostly less than 300 nm, and particles with both positive and negative zeta potentials for various applications. Material composition and surface modifications have been shown to contribute significantly in selective targeting, efficient delivery and active stimulation of immune system targets. Thus, these investigations, including a wide array of nanoparticles for cancer immunotherapy, substantiate the employment of nanocarriers for efficacious cancer immunotherapies.

Glioblastoma Multiforme (GBM) is a common primary brain cancer with a poor prognosis and a median survival of less than 14 months. Current modes of treatment are associated with deleterious side effects that reduce the life span of the patients. Nanomedicine enables site-specific delivery of active pharmaceutical ingredients and facilitates entrapment inside the tumor. Polo-like kinase 1 (PLK-1) inhibitors have shown promising results in tumor cells. GSK461364A (GSK) is one such targeted inhibitor with reported toxicity issues in phase 1 clinical trials. We have demonstrated in our study that the action of GSK is time dependent across all concentrations. There is a distinct 15&minus, 20% decrease in cell viability via apoptosis in U87-MG cells dosed with GSK at low concentrations (within the nanomolar and lower micromolar range) compared to higher concentrations of the drug. Additionally, we have confirmed that PLGA-PEG nanoparticles (NPs) containing GSK have shown significant reduction in cell viability of tumor cells compared to their free equivalents. Thus, this polymeric nanoconstruct encapsulating GSK can be effective even at low concentrations and could improve the effectiveness of the drug while reducing side effects at the lower effective dose. This is the first study to report a PLK-1 inhibitor (GSK) encapsulated in a nanocarrier for cancer applications.