Objective:To design protein binders of human epidermal growth factor receptor-2(HER2,also known as ErbB2)using de novo protein design and to preliminarily evaluate their biological effects on tumor cells.Methods:Based on de novo protein design strategy,RosettaDesign and ProteinMPNN algorithms were used to design the binding proteins targeting ErbB2.Concurrently,AlphaFold was applied to assess structural accuracy of the protein binders and their interactions with ErbB2.Subsequently,yeast surface display technology combined with dual-fluorescence high-throughput flow cytometry were performed to screen for protein binders which were capable of specifically binding to ErbB2 specifically.Selected binding proteins were expressed and purified in Eschrichia coli system.Bio-layer interferometry(BLI)was used to validate the binding specificity of the purified protein binders to ErbB2.Finally,Western blotting and CCK-8 assay were used to evaluate the effects of the candidate binding protein on the downstream signaling of ErbB2 and cell proliferation capacity in ovarian cancer(SK-OV-3)and pancreatic cancer(BxPC-3)cell lines,respectively.Results:In this study,the protein binders targeting ErbB2 were successfully designed,a corresponding binding protein library was established,and a protein binder that specifically binds to ErbB2 was screened out from the library.After BLI verification,this protein binder could effectively bind to ErbB2.Further investigation revealed that in ErbB2-high-expressing SK-OV-3 and BxPC-3 cells,this protein binder could effectively inhibit cell proliferation and reduce the phosphorylation level of AKT,a signaling molecule downstream of ErbB2.Conclusion:Based on the strategy of de novo protein design,this study successfully constructed a protein binder that can effectively bind to ErbB2.The binder can effectively inhibit the activation of the downstream signaling pathway mediated by ErbB2 and the proliferation of tumor cells.This indicates the potential application value of de novo designed protein binders targeting ErbB2 in cancer therapy,providing a novel research approach for the field of targeted tumor therapy.

Objective:To design protein binders of human epidermal growth factor receptor-2(HER2,also known as ErbB2)using de novo protein design and to preliminarily evaluate their biological effects on tumor cells.Methods:Based on de novo protein design strategy,RosettaDesign and ProteinMPNN algorithms were used to design the binding proteins targeting ErbB2.Concurrently,AlphaFold was applied to assess structural accuracy of the protein binders and their interactions with ErbB2.Subsequently,yeast surface display technology combined with dual-fluorescence high-throughput flow cytometry were performed to screen for protein binders which were capable of specifically binding to ErbB2 specifically.Selected binding proteins were expressed and purified in Eschrichia coli system.Bio-layer interferometry(BLI)was used to validate the binding specificity of the purified protein binders to ErbB2.Finally,Western blotting and CCK-8 assay were used to evaluate the effects of the candidate binding protein on the downstream signaling of ErbB2 and cell proliferation capacity in ovarian cancer(SK-OV-3)and pancreatic cancer(BxPC-3)cell lines,respectively.Results:In this study,the protein binders targeting ErbB2 were successfully designed,a corresponding binding protein library was established,and a protein binder that specifically binds to ErbB2 was screened out from the library.After BLI verification,this protein binder could effectively bind to ErbB2.Further investigation revealed that in ErbB2-high-expressing SK-OV-3 and BxPC-3 cells,this protein binder could effectively inhibit cell proliferation and reduce the phosphorylation level of AKT,a signaling molecule downstream of ErbB2.Conclusion:Based on the strategy of de novo protein design,this study successfully constructed a protein binder that can effectively bind to ErbB2.The binder can effectively inhibit the activation of the downstream signaling pathway mediated by ErbB2 and the proliferation of tumor cells.This indicates the potential application value of de novo designed protein binders targeting ErbB2 in cancer therapy,providing a novel research approach for the field of targeted tumor therapy.

Objective To investigate the causes , surgical methods and complications of reoperation of thyroid carcinoma and management .Methods Clinical data of patients with thyroid carcinoma in Department of General Surgery of Tang Du Hospital during Jan .2007 to Apr.2012 were retrospectively analyzed .The causes and complications were studied.Results Postoperative complications happened to 5 cases(13.51%), among whom 2 cases had temporary recurrent laryngeal nerve palsy and they recovered after 2 to 6 months , 2 cases had temporary hypocalcemic convulsions and the symptom resolved after one-week treatment with intravenous calcium gluconate , and 1 case had bucking and recovered after one week of treatment .Conclusion For patients with thy-roid disease,detailed preoperative examination , intraoperative frozen pathological examination , intraoperative explo-ration and the right operation method are the key factors to prevent thyroid carcinoma reoperation .Careful dissection and gradually sever of upper pole of thyroid lobe reduce complications of thyroid carcinoma reoperation .