Objective To construct the eukaryotic expression vector of human telomerase RNA component ( hTR) and study its biological function tentatively .Methods hTR Gene was obtained by PCR from cDNA template , which was reverse transcribed from 293T mRNA and cloned into pCDNA3.0 vector.The recombinant plasmid and empty vector were trans-fected into 293T cells, and hTR expression was identified by qRT-PCR.HepG2 cells that stably transfected with pCDNA3.0-hTR were constructed and identified by qRT-PCR.These cells were used to assess the interaction of hTR with human telomerase revese transcriptase ( hTERT ) and dyskerin .Telomerase activity was also detected in HepG 2 cells transfected with pCDNA3.0-hTR.Results pCDNA3.0-hTR eukaryotic expression vector was successfully constructed by double digestion identification .The inserted fragment was confirmed by sequencing .The expression of hTR in human 293T cells and HepG2 pCDNA3.0-hTR stable cell line was identified.In addition, qRT-PCR and Western blotting results showed that hTR could interact with hTERT and dyskerin , while hTR overexpression could not regulate the telomerase activity in HepG2 cells.Conclusion The eukaryotic expression vector of pCDNA 3.0-hTR is successfully constructed and expressed.This study will contribute to the further study of cancer therapy targeting hTR .

Hepatitis B virus (HBV) infection is a major global public health issue. Clinical cure (also known as functional cure) of chronic hepatitis B (CHB) is the ideal therapeutic goal recommended by the latest guidelines for the prevention and treatment of CHB in China and globally. Optimized treatment regimens with direct-acting antiviral agents ［e.g., nucleos(t)ide analogues］ or immunomodulators (e.g., pegylated interferon-α) sequentially or in combination tend to have low cure rates. Rapid development has been achieved in the research and development of drugs for the treatment of CHB. This article reviews the clinical study of new antiviral drugs for CHB, including the selection of subjects, study design, dosage, dose escalation, adverse events, and efficacy evaluation. It is necessary to introduce the knowledge of quantitative pharmacology to analyze the association of drug exposure in body with efficacy and adverse reactions, and exploratory indicators should be incorporated for comprehensive analysis. This review provides related experience and new ideas for the clinical research and development of new anti-HBV drugs.

Objective:To evaluate the drug-drug interactions and the tolerability of combined medication between yimitasvir phosphate capsules with sofosbuvir tablets, omeprazole magnesium enteric-coated tablets, and rosuvastatin calcium tablets in healthy volunteers.Methods:A randomized, open, and continuous administration design was used in trial 1 (yimitasvir phosphate capsules with sofosbuvir tablets). 28 subjects were randomly divided into two groups. A non-randomized, open design was used in trial 2 (yimitasvir phosphate capsules with omeprazole magnesium enteric-coated tablets), and included 42 subjects divided into three groups. The open design method was used in trial 3 (yimitasvir phosphate capsules with rosuvastatin calcium tablets), and included 14 subjects. The plasma concentrations of yimitasvir phosphate, sofosbuvir and their main metabolites GS-331007, omeprazole and rosuvastatin were validated by a liquid chromatography/tandem mass spectrometry (LC-MS/MS). The pharmacokinetic parameters were calculated by Phoenix winNonlin software.Results:(1) in trial 1, after single and co-administration, the 90% CI of sofosbuvir C max and AUC 0-tau geometric mean ratio (GMR) were 152.0% (118.0% ~ 197.0%) and 230.0% (184.0% ~ 287.0%), with an increase of 52.0% and 130.0% compared to single dose of sofosbuvir, respectively. The 90% CI of GS-331007 C max GMR was 74.0% (67.5% ~ 81.2%) and reduced by 26% compared to single dose of sofosbuvir. (2) in trial 2, the 90% CI of C max GMR after yimitasvir single or co-administration at the same time, with a 4-hours interval, or with a 12- hours interval were 68.9% (44.5% ~ 106.7%) , 64.0% (43.8% ~ 93.6%) and 56.4%(38.9% ~ 81.9%), and the 90% CI of AUC 0-t GMR were 68.6% (46.5% ~ 101.2%), 68.3% (47.6% ~ 98.0%) and 60.5% (41.8% ~ 87.5%), respectively. Compared with single dose of yimitasvir, the C max and AUC 0-t were decreased by 31.1% and 31.4%, 36.0% and 31.7%, 43.6% and 39.5%, respectively. (3) In trial 3, after single and co-administration, the 90% CI of rosuvastatin C max and AUC 0-72 GMR were 172.4% (153.6% ~ 193.5%) and 158.0% (144.3% ~ 172.9%), respectively, with an increase of 74.9% and 60.5% compared to single dose of rosuvastatin. There were no serious adverse events and adverse events leading to withdrawal from the trial. Conclusion:Yimitasvir phosphate capsules have drug-drug interactions with sofosbuvir tablets, omeprazole magnesium enteric-coated tablets, and rosuvastatin calcium tablets.