9 research outputs found
Correction: Panjideh et al. Improved Therapy of B-Cell Non-Hodgkin Lymphoma by Obinutuzumab-Dianthin Conjugates in Combination with the Endosomal Escape Enhancer SO1861. Toxins 2022, 14, 478
The authors wish to make corrections to their paper [...
Rapid eradication of colon carcinoma by Clostridium perfringens Enterotoxin suicidal gene therapy
Background Bacterial toxins have evolved to an effective therapeutic option
for cancer therapy. The Clostridium perfringens enterotoxin (CPE) is a pore-
forming toxin with selective cytotoxicity. The transmembrane tight junction
proteins claudin-3 and -4 are known high affinity CPE receptors. Their
expression is highly upregulated in human cancers, including breast, ovarian
and colon carcinoma. CPE binding to claudins triggers membrane pore complex
formation, which leads to rapid cell death. Previous studies demonstrated the
anti-tumoral effect of treatment with recombinant CPE-protein. Our approach
aimed at evaluation of a selective and targeted cancer gene therapy of
claudin-3- and/or claudin-4- expressing colon carcinoma in vitro and in vivo
by using translation optimized CPE expressing vector. Methods In this study
the recombinant CPE and a translation optimized CPE expressing vector (optCPE)
was used for targeted gene therapy of claudin-3 and/or -4 overexpressing colon
cancer cell lines. All experiments were performed in the human SW480, SW620,
HCT116, CaCo-2 and HT-29 colon cancer and the isogenic Sk-Mel5 and Sk-Mel5
Cldn-3-YFP melanoma cell lines. Claudin expression analysis was done at
protein and mRNA level, which was confirmed by immunohistochemistry. The CPE
induced cytotoxicity was analyzed by the MTT cytotoxicity assay. In addition
patient derived colon carcinoma xenografts (PDX) were characterized and used
for the intratumoral in vivo gene transfer of the optCPE expressing vector in
PDX bearing nude mice. Results Claudin-3 and -4 overexpressing colon carcinoma
lines showed high sensitivity towards both recCPE application and optCPE gene
transfer. The positive correlation between CPE cytotoxicity and level of
claudin expression was demonstrated. Transfection of optCPE led to targeted,
rapid cytotoxic effects such as membrane disruption and necrosis in claudin
overexpressing cells. The intratumoral optCPE in vivo gene transfer led to
tumor growth inhibition in colon carcinoma PDX bearing mice in association
with massive necrosis due to the intratumoral optCPE expression. Conclusions
This novel approach demonstrates that optCPE gene transfer represents a
promising and efficient therapeutic option for a targeted suicide gene therapy
of claudin-3 and/or claudin-4 overexpressing colon carcinomas, leading to
rapid and effective tumor cell killing in vitro and in vivo
Improved Therapy of B-Cell Non-Hodgkin Lymphoma by Obinutuzumab-Dianthin Conjugates in Combination with the Endosomal Escape Enhancer SO1861
Immunotoxins do not only bind to cancer-specific receptors to mediate the elimination of tumor cells through the innate immune system, but also increase target cytotoxicity by the intrinsic toxin activity. The plant glycoside SO1861 was previously reported to enhance the endolysosomal escape of antibody-toxin conjugates in non-hematopoietic cells, thus increasing their cytotoxicity manifold. Here we tested this technology for the first time in a lymphoma in vivo model. First, the therapeutic CD20 antibody obinutuzumab was chemically conjugated to the ribosome-inactivating protein dianthin. The cytotoxicity of obinutuzumab-dianthin (ObiDi) was evaluated on human B-lymphocyte Burkitt’s lymphoma Raji cells and compared to human T-cell leukemia off-target Jurkat cells. When tested in combination with SO1861, the cytotoxicity for target cells was 131-fold greater than for off-target cells. In vivo imaging in a xenograft model of B-cell lymphoma in mice revealed that ObiDi/SO1861 efficiently prevents tumor growth (51.4% response rate) compared to the monotherapy with ObiDi (25.9%) and non-conjugated obinutuzumab (20.7%). The reduction of tumor volume and overall survival was also improved. Taken together, our results substantially contribute to the development of a combination therapy with SO1861 as a platform technology to enhance the efficacy of therapeutic antibody-toxin conjugates in lymphoma and leukemia
Improved Therapy of B-Cell Non-Hodgkin Lymphoma by Obinutuzumab-Dianthin Conjugates in Combination with the Endosomal Escape Enhancer SO1861
Immunotoxins do not only bind to cancer-specific receptors to mediate the elimination of tumor cells through the innate immune system, but also increase target cytotoxicity by the intrinsic toxin activity. The plant glycoside SO1861 was previously reported to enhance the endolysosomal escape of antibody-toxin conjugates in non-hematopoietic cells, thus increasing their cytotoxicity manifold. Here we tested this technology for the first time in a lymphoma in vivo model. First, the therapeutic CD20 antibody obinutuzumab was chemically conjugated to the ribosome-inactivating protein dianthin. The cytotoxicity of obinutuzumab-dianthin (ObiDi) was evaluated on human B-lymphocyte Burkitt’s lymphoma Raji cells and compared to human T-cell leukemia off-target Jurkat cells. When tested in combination with SO1861, the cytotoxicity for target cells was 131-fold greater than for off-target cells. In vivo imaging in a xenograft model of B-cell lymphoma in mice revealed that ObiDi/SO1861 efficiently prevents tumor growth (51.4% response rate) compared to the monotherapy with ObiDi (25.9%) and non-conjugated obinutuzumab (20.7%). The reduction of tumor volume and overall survival was also improved. Taken together, our results substantially contribute to the development of a combination therapy with SO1861 as a platform technology to enhance the efficacy of therapeutic antibody-toxin conjugates in lymphoma and leukemia
Correction: Panjideh et al. Improved Therapy of B-Cell Non-Hodgkin Lymphoma by Obinutuzumab-Dianthin Conjugates in Combination with the Endosomal Escape Enhancer SO1861. Toxins 2022, 14, 478
The authors wish to make corrections to their paper [...
Glycosylated Triterpenoids as Endosomal Escape Enhancers in Targeted Tumor Therapies
Protein-based targeted toxins play an increasingly important role in targeted tumor therapies. In spite of their high intrinsic toxicity, their efficacy in animal models is low. A major reason for this is the limited entry of the toxin into the cytosol of the target cell, which is required to mediate the fatal effect. Target receptor bound and internalized toxins are mostly either recycled back to the cell surface or lysosomally degraded. This might explain why no antibody-targeted protein toxin has been approved for tumor therapeutic applications by the authorities to date although more than 500 targeted toxins have been developed within the last decades. To overcome the problem of insufficient endosomal escape, a number of strategies that make use of diverse chemicals, cell-penetrating or fusogenic peptides, and light-induced techniques were designed to weaken the membrane integrity of endosomes. This review focuses on glycosylated triterpenoids as endosomal escape enhancers and throws light on their structure, the mechanism of action, and on their efficacy in cell culture and animal models. Obstacles, challenges, opportunities, and future prospects are discussed
Additional file 4: Figure S3. of Rapid eradication of colon carcinoma by Clostridium perfringens Enterotoxin suicidal gene therapy
Influence of optCPE in vivo gene transfer on body weight. Body weight of Co7515* PDX bearing mice was measured during tumor growth inhibition. In all animals no systemic toxicities, such as body weight loss, were observed, which strongly indicates the safety of this gene therapeutic approach. (JPG 283 kb
Additional file 2: Figure S1. of Rapid eradication of colon carcinoma by Clostridium perfringens Enterotoxin suicidal gene therapy
Knockdown of claudin-3 and -4 leads to reduced CPE activity in human colon cancer cells. a Sequences of used short interfering RNA (siRNA) targeting claudin-3 and -4. b Western blot analysis for claudin-3 and claudin-4 gene expression in human colon cancer cell lines SW480 (left panel) and HCT116 (right panel) 72 h after siRNA treatment, showing an efficient down-regulation of both with two independent siRNA compared to control (siCo). c Specific toxin responsiveness of claudin-3 and -4 down-regulated colon cancer cells. 72 h after siRNA transfection tumor cells were treated with recCPE at indicated concentrations for another 72 h. The cytotoxicity was determined by MTT assay and compared to siCo treated cells. A significantly reduced responsiveness (*** P < 0.0001) was demonstrated in both colon cancer cell lines, SW480 (left panel) and HCT116 (right panel). All assays were performed in two independent experiments and are expressed as mean percent of untreated control. Bars: SD. Level of significance was calculated by 2way-ANOVA (Bonferroni posttest). b Cytotoxicity of optCPE gene transfer in siRNA treated colon cancer cells and proof of claudin specificity. The siCldn3 + siCldn4 treated SW480 and HCT116 cells were transfected with optCPE construct 72 h after siRNA treatment. MTT assay was performed 72 h after CPE treatment and a significantly reduced CPE mediated cytotoxicity was observed in down-regulated SW480 (left panel) and also in HCT116 (right panel) cells compared to siCo treated cells. All assays were performed in two independent experiments and expressed as survival in optical density [OD]. Bars: SD. Level of significance was calculated by nonparametric, unpaired students t-test, *** P < 0.0001. Both assays demonstrate high selectivity of CPE on claudin-3 and -4 as down-regulated cells remain unaffected. (JPG 600 kb