Recombinant immunotoxin targeting GPC3 is cytotoxic to H446 small cell lung cancer cells

Comparison of two immunotoxins against DLL3 receptor; as an inhibitor for small cell lung cancer

Despite the efforts of researchers to develop new treatments for small cell lung cancer (SCLC), achieving effective treatment has not yet happened. Targeted therapy utilizing delta-like ligand 3 (DLL3), which is highly expressed in SCLC patients, holds promise as a potential solution. Immunotoxins, consisting of bacterial toxins from the ADP-ribosyl transferase toxin family have shown effectiveness in targeting cancer cells. In this study, we investigated the binding ability, cytotoxicity, apoptosis induction rate, and permeability of two immunotoxins based on the rovalpituzumab antibody. The binding ability of immunotoxins to the receptor was performed by the Cell-ELISA method. Following this, the cell viability of cancer and normal cells immunotoxins was evaluated using the MTT assay. The ability to induce apoptosis and the penetration of immunotoxins was assessed by flow cytometry and Western blotting method. The binding ability of the immunotoxin Rova-Typh to the DLL3 receptor was higher compared to the immunotoxin Rova-GrB. The cell viability of A549 cancer cells treated with immunotoxins showed IC50 concentrations of 338 and 734 nM for immunotoxins Rova-GrB and Rova-Typh, respectively. The induction of apoptosis by immunotoxin Rova-Typh was greater compared to immunotoxin Rova-GrB. The designed immunotoxins in prokaryotic hosts exhibit good anticancer performance in A549 lung cancer cells. Additionally, the bacterial toxin-based immunotoxin has a greater ability to induce apoptosis compared to human enzymes and can be considered as a therapeutic option for SCLC cancer.

CAR-T cell therapy: Challenge and opportunity for effective treatment of small cell lung cancer

Small cell lung cancer (SCLC) is a devastating malignancy characterized by rapid metastasis, drug resistance, and frequent recurrence. Owing to the paucity of existing therapeutic options, the prognosis of SCLC remains poor. Recently, the combination of immune checkpoint inhibitors and chemotherapy has resulted in modest improvements in treatment responses. In this review, we characterize the biological signature of SCLC and outline the obstacles to current treatment, including impaired antigen presentation and T cell infiltration. These obstacles may potentially be overcome by chimeric antigen receptor (CAR)-T cell therapy. For the first time, we summarize the available data and discuss the future prospects of CAR-T cell therapy for the treatment of SCLC. Given the high heterogeneity and immunosuppressive tumor microenvironment of SCLC, structural modifications of CAR-T cells and combination therapy may be required to elicit a successful antitumor response. Further research, including clinical trials, is needed to determine the suitability of CAR-T cell therapy as a treatment for SCLC.

Emerging trends in immunotoxin targeting cancer stem cells

Cancer stem cells (CSCs) are self-renewing multipotent cells that play a vital role in the development of cancer drug resistance conditions. Various therapies like conventional, targeted, and radiotherapies have been broadly used in targeting and killing these CSCs. Among these, targeted therapy selectively targets CSCs and leads to overcoming disease recurrence conditions in cancer patients. Immunotoxins (ITs) are protein-based therapeutics with selective targeting capabilities. These chimeric molecules are composed of two functional moieties, i.e., a targeting moiety for cell surface binding and a toxin moiety that induces the programmed cell death upon internalization. Several ITs have been constructed recently, and their preclinical and clinical efficacies have been evaluated. In this review, we comprehensively discussed the recent preclinical and clinical advances as well as significant challenges in ITs targeting CSCs, which might reduce the burden of drug resistance conditions in cancer patients from bench to bedside.

Pseudomonas aeruginosa in Cancer Therapy: Current Knowledge, Challenges and Future Perspectives

Drug resistance, undesirable toxicity and lack of selectivity are the major challenges of conventional cancer therapies, which cause poor clinical outcomes and high mortality in many cancer patients. Development of alternative cancer therapeutics are highly required for the patients who are resistant to the conventional cancer therapies, including radiotherapy and chemotherapy. The success of a new cancer therapy depends on its high specificity to cancer cells and low toxicity to normal cells. Utilization of bacteria has emerged as a promising strategy for cancer treatment. Attenuated or genetically modified bacteria were used to inhibit tumor growth, modulate host immunity, or deliver anti-tumor agents. The bacteria-derived immunotoxins were capable of destructing tumors with high specificity. These bacteria-based strategies for cancer treatment have shown potent anti-tumor effects both in vivo and in vitro, and some of them have proceeded to clinical trials. Pseudomonas aeruginosa, a Gram-negative bacterial pathogen, is one of the common bacteria used in development of bacteria-based cancer therapy, particularly known for the Pseudomonas exotoxin A-based immunotoxins, which have shown remarkable anti-tumor efficacy and specificity. This review concisely summarizes the current knowledge regarding the utilization of P. aeruginosa in cancer treatment, and discusses the challenges and future perspectives of the P. aeruginosa-based therapeutic strategies.