Of immune checkpoint maladies and remedies: The throwing of jabs in the oncogenic ring of PDAC

Driver Mutations in Pancreatic Cancer and Opportunities for Targeted Therapy

Pancreatic cancer is the sixth leading cause of cancer-related mortality globally. As the most common form of pancreatic cancer, pancreatic ductal adenocarcinoma (PDAC) represents up to 95% of all pancreatic cancer cases, accounting for more than 300,000 deaths annually. Due to the lack of early diagnoses and the high refractory response to the currently available treatments, PDAC has a very poor prognosis, with a 5-year overall survival rate of less than 10%. Targeted therapy and immunotherapy are highly effective and have been used for the treatment of many types of cancer; however, they offer limited benefits in pancreatic cancer patients due to tumor-intrinsic and extrinsic factors that culminate in drug resistance. The identification of key factors responsible for PDAC growth and resistance to different treatments is highly valuable in developing new effective therapeutic strategies. In this review, we discuss some molecules which promote PDAC initiation and progression, and their potential as targets for PDAC treatment. We also evaluate the challenges associated with patient outcomes in clinical trials and implications for future research.

Is the new angel better than the old devil? Challenges and opportunities in CD47- SIRPα-based cancer therapy

The efficacy of immunotherapies is limited due to the impenetrable nature of the tumor microenvironment (TME). The TME of many tumors is immune-privileged, thus allowing them to evade host immunosurveillance. One mechanism through which this occurs is via the overexpression of CD47, a 'don't eat me' protein that can interact with SIRPα on myeloid cells to suppress their phagocytic action. In recent times, many studies are focusing on CD47-SIRPα-dependent immunotherapies to incite a 'seek and eat' interaction between phagocytes and tumors. Thus, in this review, we highlight the basic molecular properties and mechanisms of CD47-SIRPα cascade. In addition, we discuss the major challenges and potential remedies associated with CD47-SIRPα-based immunotherapies.

Cancer Immunotherapy and Delivery System: An Update

With an understanding of immunity in the tumor microenvironment, immunotherapy turns out to be a powerful tool in the clinic to treat many cancers. The strategies applied in cancer immunotherapy mainly include blockade of immune checkpoints, adoptive transfer of engineered cells, such as T cells, natural killer cells, and macrophages, cytokine therapy, cancer vaccines, and oncolytic virotherapy. Many factors, such as product price, off-target side effects, immunosuppressive tumor microenvironment, and cancer cell heterogeneity, affect the treatment efficacy of immunotherapies against cancers. In addition, some treatments, such as chimeric antigen receptor (CAR) T cell therapy, are more effective in treating patients with lymphoma, leukemia, and multiple myeloma rather than solid tumors. To improve the efficacy of targeted immunotherapy and reduce off-target effects, delivery systems for immunotherapies have been developed in past decades using tools such as nanoparticles, hydrogel matrix, and implantable scaffolds. This review first summarizes the currently common immunotherapies and their limitations. It then synopsizes the relative delivery systems that can be applied to improve treatment efficacy and minimize side effects. The challenges, frontiers, and prospects for applying these delivery systems in cancer immunotherapy are also discussed. Finally, the application of these approaches in clinical trials is reviewed.

Current and Future Therapies for Pancreatic Ductal Adenocarcinoma

Simple Summary

Pancreatic cancer is the fourth leading cause of cancer-related mortality worldwide. The poor survival associated with this disease is due to delayed diagnosis, a lack of reliable biomarkers, and tumour resistance to treatment. Currently, surgery is the only curative treatment option, but few patients are eligible for this procedure. Developing resistance to current chemotherapies such as gemcitabine has led to a reduction in effective therapy options for patients and an urgent requirement for the development of novel therapeutic avenues. Potential success has been noted in therapeutic approaches such as synthetic lethality and immunotherapy. An array of clinical trials are currently recruiting, primarily in the area of monoclonal antibodies in combination with other therapies such as chemotherapy and immune checkpoint inhibitors. This review article aims to highlight the potential these therapies have to improve patient prognosis and survival.

Abstract

Pancreatic cancer is one of the leading causes of cancer-related death worldwide. This is due to delayed diagnosis and resistance to traditional chemotherapy. Delayed diagnosis is often due to the broad range of non-specific symptoms that are associated with the disease. Resistance to current chemotherapies, such as gemcitabine, develops due to genetic mutations that are either intrinsic or acquired. This has resulted in poor patient prognosis and, therefore, justifies the requirement for new targeted therapies. A synthetic lethality approach, that targets specific loss-of-function mutations in cancer cells, has shown great potential in pancreatic ductal adenocarcinoma (PDAC). Immunotherapies have also yielded promising results in the development of new treatment options, with several currently undergoing clinical trials. The utilisation of monoclonal antibodies, immune checkpoint inhibitors, adoptive cell transfer, and vaccines have shown success in several neoplasms such as breast cancer and B-cell malignancies and, therefore, could hold the same potential in PDAC treatment. These therapeutic strategies could have the potential to be at the forefront of pancreatic cancer therapy in the future. This review focuses on currently approved therapies for PDAC, the challenges associated with them, and future directions of therapy including synthetically lethal approaches, immunotherapy, and current clinical trials.

MMP-7 marks severe pancreatic cancer and alters tumor cell signaling by proteolytic release of ectodomains

Pancreatic cancer incurs the worst survival rate of the major cancers. High levels of the protease matrix metalloproteinase-7 (MMP-7) in circulation correlate with poor prognosis and limited survival of patients. MMP-7 is required for a key path of pancreatic tumorigenesis in mice and is present throughout tumor progression. Enhancements to chemotherapies are needed for increasing the number of pancreatic tumors that can be removed and for preventing relapses after surgery. With these ends in mind, selective inhibition of MMP-7 may be worth investigation. An anti-MMP-7 monoclonal antibody was recently shown to increase the susceptibility of several pancreatic cancer cell lines to chemotherapeutics, increase their apoptosis, and decrease their migration. MMP-7 activities are most apparent at the surfaces of innate immune, epithelial, and tumor cells. Proteolytic shedding of multiple protein ectodomains by MMP-7 from such cell surfaces influence apoptosis, proliferation, migration, and invasion. These activities warrant targeting of MMP-7 selectively in pancreatic cancer and other tumors of mucosal epithelia. Competitive and non-competitive modes of MMP-7 inhibition are discussed.

Application of Mass Spectrometry in Pancreatic Cancer Translational Research

Pancreatic cancer (PC) is one of the most common malignant tumors in the digestive tract worldwide, with increased morbidity and mortality. In recent years, with the development of surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy, and the change of the medical thinking model, remarkable progress has been made in researching comprehensive diagnosis and treatment of PC. However, the present situation of diagnostic and treatment of PC is still unsatisfactory. There is an urgent need for academia to fully integrate the basic research and clinical data from PC to form a research model conducive to clinical translation and promote the proper treatment of PC. This paper summarized the translation progress of mass spectrometry (MS) in the pathogenesis, diagnosis, prognosis, and PC treatment to promote the basic research results of PC into clinical diagnosis and treatment.