Target Nanoparticles against Pancreatic Cancer: Fewer Side Effects in Therapy

CRISPR-Cas9 for selective targeting of somatic mutations in pancreatic cancers

Somatic mutations are desirable targets for selective elimination of cancer, yet most are found within noncoding regions. We have adapted the CRISPR-Cas9 gene editing tool as a novel, cancer-specific killing strategy by targeting the subset of somatic mutations that create protospacer adjacent motifs (PAMs), which have evolutionally allowed bacterial cells to distinguish between self and non-self DNA for Cas9-induced double strand breaks. Whole genome sequencing (WGS) of paired tumor minus normal (T-N) samples from three pancreatic cancer patients (Panc480, Panc504, and Panc1002) showed an average of 417 somatic PAMs per tumor produced from single base substitutions. Further analyses of 591 paired T-N samples from The International Cancer Genome Consortium found medians of ∼455 somatic PAMs per tumor in pancreatic, ∼2800 in lung, and ∼3200 in esophageal cancer cohorts. Finally, we demonstrated 69-99% selective cell death of three targeted pancreatic cancer cell lines using 4-9 sgRNAs designed using the somatic PAM discovery approach. We also showed no off-target activity from these tumor-specific sgRNAs in either the patient's normal cells or an irrelevant cancer using WGS. This study demonstrates the potential of CRISPR-Cas9 as a novel and selective anti-cancer strategy, and supports the genetic targeting of adult cancers.

The future opportunities and remaining challenges in the application of nanoparticle-mediated hyperthermia combined with chemo-radiotherapy in cancer

A pivotal cause of death in the modern world, cancer is an insidious pathology that should be diagnosed at an early stage for successful treatment. Development of therapeutic interventions with minimal invasiveness and high efficacy that can discriminate between tumor and normal cells is of particular interest to the clinical science, as they can enhance patient survival. Nanoparticles are an invaluable asset that can be adopted for development of such diagnostic and therapeutic modalities, since they come in very small sizes with modifiable surface, are highly safe and stable, and can be synthesized in a controlled fashion. To date, different nanoparticles have been incorporated into numerous modalities such as tumor-targeted therapy, thermal therapy, chemotherapy, and radiotherapy. This review article seeks to deliver a brief account of recent advances in research and application of nanoparticles in hyperthermia-based cancer therapies. The most recent investigations are summarized to highlight the latest advances in the development of combined thermo-chemo-radiotherapy, along with the challenges associated with the application of nanoparticles in cancer therapy. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Nanoparticle-based immunotherapy of pancreatic cancer

Pancreatic cancer (PC) has a complex and unique tumor microenvironment (TME). Due to the physical barrier formed by the desmoplastic stroma, the delivery of drugs to the tumor tissue is limited. The TME also contributes to resistance to various immunotherapies such as cancer vaccines, chimeric antigen receptor T cell therapy and immune checkpoint inhibitors. Overcoming and/or modulating the TME is therefore one of the greatest challenges in developing new therapeutic strategies for PC. Nanoparticles have been successfully used as drug carriers and delivery systems in cancer therapy. Recent experimental and engineering developments in nanotechnology have resulted in increased drug delivery and improved immunotherapy for PC. In this review we discuss and analyze the current nanoparticle-based immunotherapy approaches that are at the verge of clinical application. Particularly, we focus on nanoparticle-based delivery systems that improve the effectiveness of PC immunotherapy. We also highlight current clinical research that will help to develop new therapeutic strategies for PC and especially targeted immunotherapies based on immune checkpoint inhibitors.

Rosiglitazone protects INS-1E cells from human islet amyloid polypeptide toxicity

Human islet amyloid polypeptide (hIAPP or amylin) is a hormone co-secreted with insulin by pancreatic β-cells, and is the main component of islet amyloid. Islet amyloid is found in the pancreas of patients with type 2 diabetes and may be involved in β-cell dysfunction and death, observed in this disease. Thus, counteracting islet amyloid toxicity represents a therapeutic approach to preserve β-cell mass and function. In this sense, thiazolidinediones (TZDs), as rosiglitazone, have shown protective effects against other harmful insults to β-cells. For this reason, we investigated whether rosiglitazone could protect β-cells from hIAPP-induced cell death and the underlying mechanisms mediating such effect. Here, we show that rosiglitazone improved the viability of hIAPP-exposed INS-1E cells. This benefit is not dependent on the insulin-degrading enzyme (IDE) since rosiglitazone did not modulate IDE protein content and activity. However, rosiglitazone inhibited hIAPP fibrillation and decreased hIAPP-induced expression of C/EBP homologous protein (CHOP) (CTL 100.0 ± 8.4; hIAPP 182.7 ± 19.1; hIAPP + RGZ 102.8 ± 9.5), activating transcription factor-4 (ATF4) (CTL 100.0 ± 3.1; hIAPP 234.9 ± 19.3; hIAPP + RGZ 129.6 ± 3.0) and phospho-eukaryotic initiation factor 2-alpha (p-eIF2α) (CTL 100.0 ± 31.1; hIAPP 234.1 ± 36.2; hIAPP + RGZ 150.4 ± 18.0). These findings suggest that TZDs treatment may be a promising approach to preserve β-cell mass and function by inhibiting islet amyloid formation and decreasing endoplasmic reticulum stress hIAPP-induced.

Genetically modified immunomodulatory cell-based biomaterials in tissue regeneration and engineering

To date, the wide application of cell-based biomaterials in tissue engineering and regeneration is remarkably hampered by immune rejection. Reducing the immunogenicity of cell-based biomaterials has become the latest direction in biomaterial research. Recently, genetically modified cell-based biomaterials with immunomodulatory genes have become a feasible solution to the immunogenicity problem. In this review, recent advances and future challenges of genetically modified immunomodulatory cell-based biomaterials are elaborated, including fabrication approaches, mechanisms of common immunomodulatory genes, application and, more importantly, current preclinical and clinical advances. The fabrication approaches can be categorized into commonly used (e.g., virus transfection) and newly developed approaches. The immunomodulatory mechanisms of representative genes involve complicated cell signaling pathways and metabolic activities. Wide application in curing multiple end-term diseases and replacing lifelong immunosuppressive therapy in multiple cell and organ transplantation models is demonstrated. Most significantly, practices of genetically modified organ transplantation have been conducted on brain-dead human decedent and even on living patients after a series of experiments on nonhuman primates. Nevertheless, uncertain biosecurity, nonspecific effects and overlooked personalization of current genetically modified immunomodulatory cell-based biomaterials are shortcomings that remain to be overcome.

Recent Advances in Stimuli-Sensitive Amphiphilic Polymer-Paclitaxel Prodrugs

Paclitaxel (PTX) is a broad-spectrum chemotherapy drug employed in the treatment of a variety of tumors. However, the clinical applications of PTX are limited by its poor water solubility. Adjuvants are widely used to overcome this issue. However, these adjuvants often have side effects and poor biodistribution. The smart drug delivery system is a promising strategy for the improvement of solubility, permeability, and stability of drugs, and can promote sustained controlled release, increasing therapeutic efficacy and reducing side effects. Polymeric prodrugs show great advantages for drug delivery due to their high drug loading and stability. There has been some groundbreaking work in the development of PTX-based stimulus-sensitive polymeric prodrug micelles, which is summarized in this study. We consider these in terms of the four main types of stimulus (pH, reduction, enzyme, and reactive oxygen species (ROS)). The design, synthesis, and biomedical applications of stimulus-responsive polymeric prodrugs of PTX are reviewed, and the current research results and future directions of the field are summarized.

A Review on the Efficacy and Safety of Nab-Paclitaxel with Gemcitabine in Combination with Other Therapeutic Agents as New Treatment Strategies in Pancreatic Cancer

Pancreatic cancer has one of the highest mortality rates among cancers, and a combination of nab-paclitaxel with gemcitabine remains the cornerstone of first-line therapy. However, major advances are required to achieve improvements in patient outcomes. For this reason, several research groups have proposed supplementing treatment with other therapeutic agents. Ongoing studies are being conducted to find the optimal treatment in a first-line setting. In this work, we used a search strategy to compare studies on the efficacy and safety of nab-paclitaxel with gemcitabine in combination with other therapeutic agents based on the criteria of the Preferred Reporting Items for Systematic Reviews. We found seven studies in different clinical phases that met the inclusion criteria. The seven therapeutic agents were ibrutinib, necuparanib, tarextumab, apatorsen, cisplatin, enzalutamide, and momelotinib. Although these therapeutic agents have different mechanisms of action, and molecular biology studies are still needed, the present review was aimed to answer the following question: which formulations of the nab-paclitaxel/gemcitabine regimen in combination with other therapeutic agents are safest for patients with previously untreated metastatic pancreas ductal adenocarcinoma? The triple regimen is emerging as the first-line option for patients with pancreatic cancer, albeit with some limitations. Thus, further studies of this regimen are recommended.