Future directions in the second-line treatment of non-small cell lung cancer

Principle, application and challenges of development siRNA-based therapeutics against bacterial and viral infections: a comprehensive review

While significant progress has been made in understanding and applying gene silencing mechanisms and the treatment of human diseases, there have been still several obstacles in therapeutic use. For the first time, ONPATTRO, as the first small interfering RNA (siRNA) based drug was invented in 2018 for treatment of hTTR with polyneuropathy. Additionally, four other siRNA based drugs naming Givosiran, Inclisiran, Lumasiran, and Vutrisiran have been approved by the US Food and Drug Administration and the European Medicines Agency for clinical use by hitherto. In this review, we have discussed the key and promising advances in the development of siRNA-based drugs in preclinical and clinical stages, the impact of these molecules in bacterial and viral infection diseases, delivery system issues, the impact of administration methods, limitations of siRNA application and how to overcome them and a glimpse into future developments.

Lipid-based systemic delivery of siRNA

RNAi technology has brought a new category of treatments for various diseases including genetic diseases, viral diseases, and cancer. Despite the great versatility of RNAi that can down regulate almost any protein in the cells, the delicate and precise machinery used for silencing is the same. The major challenge indeed for RNAi-based therapy is the delivery system. In this review, we start with the uniqueness and mechanism of RNAi machinery and the utility of RNAi in therapeutics. Then we discuss the challenges in systemic siRNA delivery by dividing them into two categories-kinetic and physical barriers. At the end, we discuss different strategies to overcome these barriers, especially focusing on the step of endosome escape. Toxicity issues and current successful examples for lipid-based delivery are also included in the review.

Tumor-targeted delivery of siRNA by non-viral vector: safe and effective cancer therapy

RNA interference technology has been developed as a potential therapeutic agent for many indications, including cancer. Silencing a specific oncogene in tumor cells brings about cell death both in vitro and in vivo. However, there is a great need for powerful delivery strategies to enhance the therapeutic effect of small interfering RNA (siRNA). This review summarizes different signaling pathways inhibited by siRNA and the advantages of targeted siRNA as a delivery system.

Recent advances in cancer stem/progenitor cell research: therapeutic implications for overcoming resistance to the most aggressive cancers

Overcoming intrinsic and acquired resistance of cancer stem/progenitor cells to current clinical treatments represents a major challenge in treating and curing the most aggressive and metastatic cancers. This review summarizes recent advances in our understanding of the cellular origin and molecular mechanisms at the basis of cancer initiation and progression as well as the heterogeneity of cancers arising from the malignant transformation of adult stem/progenitor cells. We describe the critical functions provided by several growth factor cascades, including epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFR), stem cell factor (SCF) receptor (KIT), hedgehog and Wnt/beta-catenin signalling pathways that are frequently activated in cancer progenitor cells and are involved in their sustained growth, survival, invasion and drug resistance. Of therapeutic interest, we also discuss recent progress in the development of new drug combinations to treat the highly aggressive and metastatic cancers including refractory/relapsed leukaemias, melanoma and head and neck, brain, lung, breast, ovary, prostate, pancreas and gastrointestinal cancers which remain incurable in the clinics. The emphasis is on new therapeutic strategies consisting of molecular targeting of distinct oncogenic signalling elements activated in the cancer progenitor cells and their local microenvironment during cancer progression. These new targeted therapies should improve the efficacy of current therapeutic treatments against aggressive cancers, and thereby preventing disease relapse and enhancing patient survival.

T-regulatory cells are relatively deficient in squamous carcinomas undergoing regression in mice immunized with a squamous carcinoma vaccine enriched for immunotherapeutic cells

In a prior report (Int J Cancer 2006; 119: 339-348), we described a new vaccination strategy for squamous cell carcinoma (SCC). The vaccine was prepared by transfer of unfractionated DNA-fragments (25 kb) from KLN205 cells, a squamous carcinoma cell line (DBA/2 origin; H-2(d)) into LM cells, a highly immunogenic mouse fibroblast cell line (C3H/He origin; (H-2(k))). As only a small proportion of the transfected cell population was expected to have incorporated DNA segments that included genes specifying antigens associated with the squamous carcinoma cells, we devised a novel strategy to enrich the vaccine for immunotherapeutic cells. Enhanced immunity to squamous carcinoma was induced in tumor-bearing mice treated solely by immunization with the enriched vaccine, which translated into prolonged survival without toxicity. Here, we describe the characteristics of the cell populations infiltrating established squamous carcinomas undergoing regression in mice immunized with vaccines enriched for immunotherapeutic cells. The results indicated that CD8+ T cells were predominant and that T-regulatory cells (FoxP3+, CD4/CD25+, CD4/CD62L(high), CD4/CTLA-4e) were relatively deficient in the regressing tumors. Inflammatory infiltrates were not detected in various organs and tissues of mice immunized with the DNA-based vaccine.

Novel targeted therapies for non-small cell lung cancer

Targeted therapies will advance the treatment of NSCLC as we improve our understanding of the underlying biology of NSCLC and enhance our ability to clinically target the optimal therapy to an individual's cancer. Ongoing translational research including tissue arrays, genomic, and proteomic studies will help to identify clinically useful biomarkers that will allow further classification of NSCLC and may allow accurate prediction of response to specific chemotherapeutic regimens. Advances in targeted therapy in NSCLC are already yielding exciting results, and promises to become an increasingly important adjunct to surgical management of NSCLC.

Gene therapy for lung cancer

Lung cancer patients suffer a 15% overall survival despite advances in chemotherapy, radiation therapy, and surgery due to the usual finding of advanced disease at diagnosis. Attempts to improve survival in advanced disease using various combinations of chemotherapy have demonstrated that no regimen is superior, suggesting a therapeutic plateau and the need for novel, more specific, and less toxic therapeutic strategies. Techniques have been developed that allow transfer of functional genes into mammalian cells, such as those that block activated tumor-promoting oncogenes and/or those that replace inactivated tumor-suppressing or apoptosis-promoting genes. This article will discuss the therapeutic implications of these molecular changes associated with bronchogenic carcinomas, and will then review the status of gene therapies for treatment of lung cancer.