Designing a humanized immunotoxin based on DELTA-stichotoxin-Hmg2a toxin: an in silico study.

Breast cancer remains the most frequently diagnosed cancer and the principal cause of mortality by malignancy in women. HER2 positive subtype includes 15-20% of breast cancer cases. This receptor could be an appropriate mark for targeting breast cancer cells. Immunotherapy methods compared to current cancer treatment methods have the lowest side effects. DELTA-stichotoxin-Hmg2a is isolated from the sea anemone and kills cells through pore formation. In the current study, we designed and evaluated an immunotoxin composed of pertuzumab and DELTA-stichotoxin-Hmg2a-derived scFv by bioinformatics tools. The designed immunotoxin was constructed using the amino acid sequences. Then, secondary structure and physico-chemical features were studied, and the tertiary structure of the immunotoxin was built according to the homology modeling methods. The validation and allergenicity of the model were assessed. The immunotoxin and receptor were docked and molecular dynamics simulation indicated the construct stability. The analysis results indicated that the construct is a stable protein that could have a natural-like structure and would not be an allergen, so this immunotoxin could effectively target HER2 receptors. Therefore, our designed immunotoxin could be an appropriate immunotoxin against HER2-positive breast cancer and could be a challenging topic for future in vitro and in vivo studies.

Mir-122 upregulation and let-7f downregulation combination: The effects on hepatic differentiation of hiPSCs on the PCL-Gel-HA nanofibrous scaffold.

Cell therapy and tissue engineering as promising candidates for the liver transplantation dilemma are of special interest. Induced pluripotent stem cells (iPSCs) are one of the best sources in this field, but their differentiation methods to hepatocytes have remained challenging. We transduced human iPSCs (hiPSCs) with miR-122 and off-let-7f (hiPSCsmiR-122 + off-let-7f ) to evaluate how they can differentiate hiPSCs to hepatocyte-like cells (HLCs) without any extrinsic growth factor. Additionally, we studied the effect of Poly ɛ-caprolactone-gelatin-hyaluronic acid (PCL-Gel-HA) nanofibrous scaffold as an extracellular matrix (ECM) simulator on differentiation improvement. Definitive endoderm markers (FOXA2 and SOX17), as well as hepatic markers (AFP, Albumin, CK18, HNF4α) expression, were significantly higher in hiPSCsmiR-122 + off-let-7f derived HLCs (hiPSCs-HLCs) compared to the control group (miR-scramble transduced hiPSCs: hiPSCsscramble ). hiPSCs-HLCs indicated hepatocyte morphological characteristics and positive immunostaining for AFP, Albumin and HNF4α. Albumin and urea secretion were significantly higher in hiPSCs-HLCs than hiPSCsscramble . Comparing these markers in the PCL-Gel-HA group with the tissue culture plate (TCP) group revealed that PCL-Gel-HA could improve differentiation towards HLCs significantly. Regarding our results, these microRNAs can be used to differentiate hiPSCs to the functional hepatocytes for disease modelling, drug screening and cell-based therapy in future studies.