The future of immune checkpoint combinations with tumor-targeted small molecule drugs

DNA-based immunotherapy for cancer: In vivo approaches for recalcitrant targets

Immunotherapy has revolutionized cancer treatment and complements traditional therapies, including surgery, chemotherapy, radiation therapy, and targeted therapies. Immunotherapy redirects the patient's immune system against tumors via several immune-mediated approaches. Over the past few years, therapeutic immunization, which enable the patient's T cells to better recognize and kill tumors, have been increasingly tested in the clinic, with several approaches demonstrating treatment improvements. There has been a renewed interest in cancer vaccines due to advances in tumor antigen identification, immune response optimization, novel adjuvants, next-generation vaccine delivery platforms, and antigen designs. The COVID-19 pandemic accelerated progress in nucleic acid-based vaccine manufacturing, which spurred broader interest in mRNA or plasmid platforms. Enhanced DNA vaccine designs, including optimized leader sequences and RNA and codon optimizations, improved formulations, and delivery via adaptive electroporation using stereotactic intramuscular/intradermal methods have improved T cell responses to plasmid-delivered tumor antigens. Additionally, advancements for direct in vivo delivery of DNA-encoded monospecific/bispecific antibodies offer novel tumor-targeting strategies. This review summarizes the recent clinical data for therapeutic cancer vaccines utilizing the DNA platform, including vaccines targeting common tumor-associated and viral antigens and neoantigen vaccines using nucleic acid technologies. We also summarize preclinical data using DNA-launched monoclonal/bispecific antibodies, underscoring their potential as a novel cancer therapy tool.

Applications of Flow Cytometry in Drug Discovery and Translational Research

Flow cytometry is a mainstay technique in cell biology research, where it is used for phenotypic analysis of mixed cell populations. Quantitative approaches have unlocked a deeper value of flow cytometry in drug discovery research. As the number of drug modalities and druggable mechanisms increases, there is an increasing drive to identify meaningful biomarkers, evaluate the relationship between pharmacokinetics and pharmacodynamics (PK/PD), and translate these insights into the evaluation of patients enrolled in early clinical trials. In this review, we discuss emerging roles for flow cytometry in the translational setting that supports the transition and evaluation of novel compounds in the clinic.

Aberrant promoter hypermethylation of miR-335 and miR-145 is involved in breast cancer PD-L1 overexpression

PD-L1 is one of the most important immune checkpoint molecules in breast cancer that plays an important role in suppressing the immune system when confronted with tumor cells and is regulated by various microRNAs. Among them, microRNA-335-3p and microRNA-145-5p, regulated by DNA methylation, have tumor suppressor activities. We studied the role of miR-335 and -145 on PD-L1 suppression in breast cancer. The expression of miR-355 and miR-145 was significantly downregulated in BC tissues and cell lines compared to their controls, and their downregulation was negatively correlated with PD-L1 overexpression. In-silico and luciferase reporter systems confirmed that miR-335 and -145 target PD-L1. In BC tissues and cell lines, cancer-specific methylation was found in CpG-rich areas upstream of miR-335 and-145, and up-regulation of PD-L1 expression was connected with hypermethylation (r = 0.4089, P = 0.0147, and r = 0.3373, P = 0.0475, respectively). The higher levels of miR-355 and -145 in BC cells induced apoptosis, arrested the cell cycle, and reduced proliferation significantly. In summary, we found that miR-335 and -145 are novel tumor suppressors inactivated in BC, and these miRs may serve as potential therapeutic targets for breast cancer treatment.