Background CAR T-cell therapy has been recently unveiled as one of the most promising cancer therapies in hematological malignancies. However, solid tumors mount a profound line of defense to escape immunosurveillance by CAR T-cells. Among them, cytokines with an inhibitory impact on the immune system such as IL-10 and TGFβ are of great importance: TGFβ is a pleiotropic cytokine, which potently suppresses the immune system and is secreted by a couple of TME resident and tumor cells. Methods In this study, we hypothesized that knocking out the TGFβ receptor II gene, could improve CAR T-cell functions in vitro and in vivo. Hereby, we used the CRISPR/Cas9 system, to knockout the TGFβRII gene in T-cells and could monitor the efficient gene knock out by genome analysis techniques. Next, Mesothelin or Claudin 6 specific CAR constructs were overexpressed via IVT-RNA electroporation or retroviral transduction and the poly-functionality of these TGFβRII KO CAR T-cells in terms of proliferation, cytokine secretion and cytotoxicity were assessed and compared with parental CAR T-cells. Results Our experiments demonstrated that TGFβRII KO CAR T-cells fully retained their capabilities in killing tumor antigen positive target cells and more intriguingly, could resist the anti-proliferative effect of exogenous TGFβ in vitro outperforming wild type CAR T-cells. Noteworthy, no antigen or growth factor-independent proliferation of these TGFβRII KO CAR T-cells has been recorded. TGFβRII KO CAR T-cells also resisted the suppressive effect of induced regulatory T-cells in vitro to a larger extent. Repetitive antigen stimulation demonstrated that these TGFβRII KO CAR T-cells will experience less activation induced exhaustion in comparison to the WT counterpart. Conclusion The TGFβRII KO approach may become an indispensable tool in immunotherapy of solid tumors, as it may surmount one of the key negative regulatory signaling pathways in T-cells.

186 Re-1-hydroxyethylidene-1,1-diphosphonate (HEDP) is an attractive radiopharmaceutical for the treatment of bone pain arising from skeletal metastatic lesions. Currently, 186 Re-HEDP is most commonly used in European countries. The aim of this study was to investigate the palliative efficacy and adverse effects of 186 Re-HEDP in patients with different types of cancers and skeletal bone pain. Methods: Nineteen (8 male, 11 female) patients with various cancers (breast, prostate, renal cell carcinoma, colon, and neuroendocrine tumors) and painful bone metastases were included in the study. A dose of 1,480-3,330 MBq (40-90 mCi) of 186 Re-HEDP was administered intravenously. The patients' level of pain relief was assessed by the Visual Analog Scale for 8 wk after treatment and by a weekly blood cell count to evaluate for hematologic toxicity. Results: The overall response rate was 89.5%, and the mean pain score assessed by the Visual Analog Scale was reduced from 9.1 to 5.3 after 1 wk (P 5 0.003). No adverse effects were reported by patients during intravenous administration or for up to 24 h after administration. A flare reaction was seen in 63.2% of patients, mainly during days 1-3, and lasted for 2-4 d. There was no significant correlation between the response to therapy and the flare reactions (P . 0.05). The nadir of platelet reduction occurred at the fourth or fifth week and led to platelet infusion in only 4 patients with a low baseline platelet count and diffuse skeletal metastases. Bone marrow suppression occurred in patients receiving higher doses, but no clinical problems were seen except in 2 patients who required packed cell transfusion similar to their prior transfusions. Conclusion: 186 Re-HEDP is an effective radiopharmaceutical for the palliative treatment of metastatic bone pain and has minimal adverse effects.Key Words: rhenium 186(tin) etidronate; pain palliation; bone metastasis Nucl Med Technol 2013; 41:192-196 DOI: 10.2967/jnmt.113.124297 The skeleton is the most common site of metastatic disease, and tumors arising from the breast, prostate, lung, thyroid, and kidney commonly spread to bone. The frequency of bone metastases has been estimated at 65%-75% in patients with breast and prostate cancer (1,2) and about 30%-40% in those with lung cancer (3). Bone pain, as the main symptom of skeletal metastases and the most common type of cancer-related pain, obviously has a negative impact on quality of life (4). Currently, the factors contributing to cancer pain are not completely understood (5,6), and metastatic bone pain might be poorly localized for external radiation therapy (7). Various modalities have been introduced for the treatment of bone metastases, including analgesics, hormone therapy, cytotoxic drugs, biphosphonates, and surgery; however, they are not effective in all patients with painful refractory skeletal metastases. An alternative approach is systemic administration of radiopharmaceuticals, which is a valuable and effective method for relieving bone pain in patients with ...

Background: CAR T-cell therapy has been recently unveiled as one of the most promising cancer therapies in hematological malignancies. However, solid tumors mount a profound line of defense to escape immunosurveillance by CAR T-cells. Among them, cytokines with an inhibitory impact on the immune system such as IL-10 and TGFβ are of great importance: TGFβ is a pleiotropic cytokine, which potently suppresses the immune system and is secreted by a couple of TME resident and tumor cells. Methods: In this study, we hypothesized that knocking out the TGFβ receptor II gene, could improve CAR T-cell functions in vitro and in vivo. Hereby, we used the CRISPR/Cas9 system, to knockout the TGFβRII gene in T-cells and could monitor the efficient gene knock out by genome analysis techniques. Next, Mesothelin or Claudin 6 specific CAR constructs were overexpressed via IVT-RNA electroporation or retroviral transduction and the poly-functionality of these TGFβRII KO CAR T-cells in terms of proliferation, cytokine secretion and cytotoxicity were assessed and compared with parental CAR T-cells.Results: Our experiments demonstrated that TGFβRII KO CAR T-cells fully retained their capabilities in killing tumor antigen positive target cells and more intriguingly, could resist the anti-proliferative effect of exogenous TGFβ in vitro outperforming wild type CAR T-cells. Noteworthy, no antigen or growth factor-independent proliferation of these TGFβRII KO CAR T-cells has been recorded. TGFβRII KO CAR T-cells also resisted the suppressive effect of induced regulatory T-cells in vitro to a larger extent. Repetitive antigen stimulation demonstrated that these TGFβRII KO CAR T-cells will experience less activation induced exhaustion in comparison to the WT counterpart. Conclusion: The TGFβRII KO approach may become an indispensable tool in immunotherapy of solid tumors, as it may surmount one of the key negative regulatory signaling pathways in T-cells.

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Background: Complementary experiments on nanomedicines as proper candidates for the control and treatment of cancer are widely being conducted nowadays. In the previous study, the effect of BCc1 nanomedicine, which is synthetized based on nanochelating technology, on overall survival (OS) and quality of life of gastric cancer patients was evaluated after 18 months of consumption. The OS of the same patients is reported in this study after 40 months. Methods: A double-blind, randomized, placebo-controlled, parallel, multicenter design was used in this study. 123 metastatic and non-metastatic gastric cancer patients of both genders (between 25 and 85 years old) participated in this experiment to evaluate their OS after consuming BCc1 for 40 months and to identify the adverse events of this nanomedicine. Results: The median OS of metastatic patients was 257 days in the BCc1 group [95% confidence interval (CI): 144. 142-369.858], while it was 161 days in the placebo [95% CI: 118.462-203.538]; hazard ratio (HR): 0.802 [95% CI: 0.483-1.333] (P-Value = 0.395). Similarly, the median OS of non-metastatic patients was 718 days in the BCc1 group [95% CI; 577.706-860.213], while it was 520 days in the placebo [95% CI: 460.280- 580.690]; HR: 0.807 [95% CI: 0.343,1.902] (P-Value = 0.624). There was no evidence of adverse events after 40 months.Conclusion: The OS improvement of metastatic and non-metastatic gastric cancer patients in the previous (18 months of follow-up) and current (40 months of follow-up) studies showed that BCc1 can be used along with base treatments to improve cancer patients’ OS. Trial registration: IRCTID, IRCT2017101935423N1.Registered on 19 October 2017, http://www.irct.ir/ IRCT2017101935423N1.