Shape-Morphing of an Artificial Protein Cage with Unusual Geometry Induced by a Single Amino Acid Change

Artificial protein cages are constructed from multiple protein subunits. The interaction between the subunits, notably the angle formed between them, controls the geometry of the resulting cage. Here, using the artificial protein cage, “TRAP-cage”, we show that a simple alteration in the position of a single amino acid responsible for Au(I)-mediated subunit–subunit interactions in the constituent ring-shaped building blocks results in a more acute dihedral angle between them. In turn, this causes a dramatic shift in the structure from a 24-ring cage with an octahedral symmetry to a 20-ring cage with a C2 symmetry. This symmetry change is accompanied by a decrease in the number of Au(I)-mediated bonds between cysteines and a concomitant change in biophysical properties of the cage

Preoperative PET-CT is useful for predicting recurrent extrahepatic metastasis of hepatocellular carcinoma after resection

Purpose In recent years, it has been reported that use of 18F-FDG PET-CT can reveal the degree of hepatocellular carcinoma malignancy. We evaluate the ability of a preoperative 18F-FDG PET-CT to predict the recurrence of extrahepatic metastasis of HCC after surgery. Methods We retrospectively examined 67 patients who received 18F-FDG PET-CT prior to curative hepatic resection for HCC between April 2010 and March 2016. Multivariate Cox regression analysis was performed to identify the factors associated with recurrence of extrahepatic metastasis of HCC after surgery. We also evaluated the sensitivity, specifity, positive predictive value, negative predictive value and accuracy of diagnosis of 18F-FDG PET-CT for recurrent extrahepatic metastasis of HCC after surgery. Results The multivariate analysis identified a tumor-to-normal liver standardized uptake value ratio (TNR) ≥ 1.53 (hazard ratio [HR], 0.037; P = 0.003), multiple tumor nodules (HR, 0.121; P = 0.007), and presence of microvascular invasion (HR, 0.094; P = 0.003) as independent predictors of distant metastasis recurrence. A TNR ≥ 1.53 showed a sensitivity of 91.7 %, specificity of 76.4 %, positive predictive value of 45.8 %, negative predictive value of 97.7 %, and accuracy of 79.1 % for diagnosing distant metastasis recurrence of HCC. In a binomial logistic regression analysis of tumor factors associated with a TNR ≥ 1.53, poor tumor differentiation and large tumor size were significant factors. Conclusion 18F-FDG PET-CT and microvascular invasion may be useful for predicting the recurrence of extrahepatic metastasis of HCC after surgery.アクセプト後にアブストラクトに変更あ