0bjective To observe the cell membrane penetration of protein transduction domain (PTD)-HBeAg fusion protein in vitro.Methods The sequence of trans-activator of transcription (Tat)-PTD was synthesized and the whole HBcAg gene was amplified by polymerase chain reaction (PCR).Overlap extension PCR was employed to fuse Tat-PTD and whole HBcAg gene.Then the fusion gene was cloned into prokaryotic expression vector pMAL-c2X.The correct vector was transformed into E.coli Rosetta-gamiTM 2(DE3),and the protein was induced by isopropyl β-D-1-thiogalactopyranoside(IPTG).Western blot was used tO identify the protein. Furthermore,the fusion protein PTD-HBcAg was purified by affinity chromatography.HBcAg protein expressed using the same methods was employed as eontr0l.The purified protein was added tO HuH-7 cell culture,then the transduction of PTD-HBcAg and HBcAg in cells were detected by indirect immunofluorescence assay (IFA).Results The fusion protein was effectively expressed in E. Coli and purified by affinity chromatography.Both purified PTD-HBcAg and HBcAg could be recognized by HBeAg monoclonal antibody in Western blot analysis.IFA visualization showed that PTD-HBeAg could be introduced into HUH-7 ceils while HBcAg only could not be detected in cells.Conclusions PTD-HBcAg fusion protein can be expressed effectively and purified in prokaryotic expression system.PTD could mediate HBcAg penetrating eell membrane into the cells.

Objective:To explore the feasibility of circulating tumor cell (CTC) dual-antibody enrichment and dual-antibody detection for epithelial-mesenchymal phenotypes in patients with hepatocellular carcinoma (HCC), and investigate the clinical diagnostic value of CTC typing in evaluating postoperative recurrence and prognosis of HCC.Methods:Of 89 HCC patients who underwent surgical treatment in Zhejiang Jinhua Guangfu Tumor Hospital from March 2020 to January 2024 were enrolled into this study, including 73 males and 16 females, aged (64.4±9.5) years old. The peripheral blood samples of patients were collected before operation. Epithelial CTC, mesenchymal CTC and hybrid epithelial-mesenchymal CTC in blood samples of patients with HCC were enriched and detected by EpCAM/CSV double capture antibodies and PanCK/CSV double detection antibodies. Kaplan-Meier analysis was employed to assess recurrence-free survival (RFS) and overall survival (OS) rates. Univariate and multivariate Cox regression were used to analyze the effects of different types of CTC on postoperative RFS and OS.Results:The detection rates of total CTC, epithelial CTC, mesenchymal CTC and hybrid epithelial-mesenchymal CTC were 92.1% (82/89), 64.0% (57/89), 62.9% (56/89) and 55.1% (49/89), respectively. Multivariate Cox regression analysis showed that HCC patients with more mesenchymal CTC ( HR=2.408, 95% CI: 1.580-3.668) and hybrid epithelial-mesenchymal CTC ( HR=1.840, 95% CI: 1.004-3.371) in peripheral blood had higher postoperative recurrence risk (both P<0.05). Univariate Cox regression showed patients with more total CTC ( HR=1.426, 95% CI: 1.040-1.954, P=0.028) was associated with survival. Conclusion:The technique of epithelial-mesenchymal phenotypes analysis of circulating tumor cells based on dual-antibody capture and dual-antibody detection is feasible. The number of mesenchymal CTC and hybrid epithelial-mesenchymal CTC before operation is the influencing factor of postoperative recurrence in patients with hepatocellular carcinoma.