Naturally occurring mutations in the reverse transcriptase region of hepatitis B virus polymerase from treatment-na?ve Korean patients infected with genotype C2

AIM To report naturally occurring mutations in the reverse transcriptase region(RT) of hepatitis B virus(HBV) polymerase from treatment na?ve Korean chronic patients infected with genotype C2.METHODS Here, full-length HBV reverse transcriptase RT sequences were amplified and sequenced from 131 treatment na?ve Korean patients chronically infected with hepatitis B genotype C2. The patients had two distinct clinical statuses: 59 patients with chronic hepatitis(CH) and 72 patients with hepatocellular carcinoma(HCC). The deduced amino acids(AAs) at42 previously reported potential nucleos(t)ide analog resistance(NAr) mutation positions in the RT region were analyzed. RESULTS Potential NAr mutations involving 24 positions were found in 79 of the 131 patients(60.3%). Notably, AA substitutions at 2 positions(rt184 and rt204) involved in primary drug resistance and at 2 positions(rt80 and rt180) that functioned as secondary/compensatory mutations were detected in 10 patients(1 CH patient and 9 HCC patients) and 7 patients(1 CH and 6 HCC patients), respectively. The overall mutation frequencies in the HCC patients(3.17%, 96/3024 mutations) were significantly higher than the frequencies in the CH patients(2.09%, 52/2478 mutations)(P = 0.003). In addition, a total of 3 NAr positions, rt80, rt139 and rt204 were found to be significantly related to HCC from treatment na?ve Korean patients. CONCLUSION Our data showed that naturally occurring NAr mutations in South Korea might contribute to liver disease progression(particularly HCC generation) in chronic patients with genotype C2 infections.

Telomerase reverse transcriptase promoter mutations in hepatocellular carcinogenesis

Through several studies exploiting next-generation sequencing,we are obtaining a clearer picture of the complex genetic and molecular landscape of hepatocellular carcinoma(HCC).Consistent with the findings of other cancer types,telomerase reverse transcriptase(TERT)promoter mutations have been frequently reported in HCC.C228T and C250T are two major types of hot spot mutations in the TERT promoter region.Besides,in hepatitis B virus(HBV)-related HCC cases,the TERT promoter is recurrently interrupted by integration of HBV DNA.TERT promoter mutations are thought to be an early event in HCC carcinogenesis,and they are significantly associated with disease progression.In this review,we provide an updated overview of the somatic mutations in the TERT promoter region and discuss their possible roles in the development of HCC.

Telomerase-related advances in hepatocellular carcinoma:A bibliometric and visual analysis

BACKGROUND As a critical early event in hepatocellular carcinogenesis,telomerase activation might be a promising and critical biomarker for hepatocellular carcinoma(HCC)patients,and its function in the genesis and treatment of HCC has gained much attention over the past two decades.AIM To perform a bibliometric analysis to systematically assess the current state of research on HCC-related telomerase.METHODS The Web of Science Core Collection and PubMed were systematically searched to retrieve publications pertaining to HCC/telomerase limited to“articles”and“reviews”published in English.A total of 873 relevant publications related to HCC and telomerase were identified.We employed the Bibliometrix package in R to extract and analyze the fundamental information of the publications,such as the trends in the publications,citation counts,most prolific or influential writers,and most popular journals;to screen for keywords occurring at high frequency;and to draw collaboration and cluster analysis charts on the basis of coauthorship and co-occurrences.VOSviewer was utilized to compile and visualize the bibliometric data.RESULTS A surge of 51 publications on HCC/telomerase research occurred in 2016,the most productive year from 1996 to 2023,accompanied by the peak citation count recorded in 2016.Up to December 2023,35226 citations were made to all publications,an average of 46.6 citations to each paper.The United States received the most citations(n=13531),followed by China(n=7427)and Japan(n=5754).In terms of national cooperation,China presented the highest centrality,its strongest bonds being to the United States and Japan.Among the 20 academic institutions with the most publications,ten came from China and the rest of Asia,though the University of Paris Cité,Public Assistance-Hospitals of Paris,and the National Institute of Health and Medical Research(INSERM)were the most prolific.As for individual contributions,Hisatomi H,Kaneko S,and Ide T were the three most prolific authors.Kaneko S ranked first by H-index,G-index,and overall publication count,while Zucman-Rossi J ranked first in citation count.The five most popular journals were the World Journal of Gastroenterology,Hepatology,Journal of Hepatology,Oncotarget,and Oncogene,while Nature Genetics,Hepatology,and Nature Reviews Disease Primers had the most citations.We extracted 2293 keywords from the publications,120 of which appeared more than ten times.The most frequent were HCC,telomerase and human telomerase reverse transcriptase(hTERT).Keywords such as mutational landscape,TERT promoter mutations,landscape,risk,and prognosis were among the most common issues in this field in the last three years and may be topics for research in the coming years.CONCLUSION Our bibliometric analysis provides a comprehensive overview of HCC/telomerase research and insights into promising upcoming research.

Efficacy and safety of tenofovir disoproxil fumarate in pregnancy for the prevention of vertical transmission of HBV infection

AIM:To evaluate the effects of tenofovir disoproxil fumarate(TDF)use during late pregnancy to reduce hepatitis B virus(HBV)transmission in highly viremic mothers.METHODS:This retrospective study included 45 pregnant patients with hepatitis B e antigen(+)chronic hepatitis B and HBV DNA levels>107copies/mL who received TDF 300 mg/d from week 18 to 27 of gestation(n=21).Untreated pregnant patients served as controls(n =24).All infants received 200 IU of hepatitis B immune globulin(HBIG)within 24 h postpartum and 20μg of recombinant HBV vaccine at 4,8,and 24 wk.Perinatal transmission rate was determined by hepatitis B surface antigen and HBV DNA results in infants at week 28.RESULTS:At week 28,none of the infants of TDFtreated mothers had immunoprophylaxis failure,whereas2(8.3%)of the infants of control mothers had immunoprophylaxis failure(P=0.022).There were no differences between the groups in terms of adverse events in mothers or congenital deformities,gestational age,height,or weight in infants.At postpartum week 28,significantly more TDF-treated mothers had levels of HBV DNA<250 copies/mL and normalized alanine aminotransferase compared with controls(62%vs none,P<0.001;82%vs 61%,P=0.012,respectively).CONCLUSION:TDF therapy during the second or third trimester reduced perinatal transmission rates of HBV and no adverse events were observed in mothers or infants.

Effects of Combined siRNA-TR and-TERT on Telomerase Activity and Growth of Bladder Transitional Cell Cancer BIU-87 Cells

The effects of combined RNA interference(RNAi) of human telomerase RNA(hTR) and human telomerase reverse transcriptase(hTERT) genes on telomerase activity in a bladder cancer cell line(BIU-87 cells) were investigated by using gene chip technology in vitro with an attempt to evaluate the role of RNAi in the gene therapy of bladder transitional cell cancer(BTCC).Three TR-specific double-stranded small interfering RNAs(siRNAs) and three TERT-specific double-stranded siRNAs were designed to target different regions of TR and TERT mRNA.The phTR-siRNA,phTERT-siRNA,and the combination of both plasmids phTR+phTERT-siRNA were transfected into BIU-87 cells.The expression of hTR and hTERT mRNA was detected by quantitative fluorescent reverse transcription-polymerase chain reaction,and a telomeric repeat amplification protocol was applied to detect telomerase activity.Growth inhibition of BIU-87 cells was measured by MTT assay.Gene chip analysis was performed to evaluate the effects of the combined RNAi of hTR+hTERT genes on telomerase activity and growth of BIU-87 cells in vitro.The results showed that the expression of hTERT and hTR mRNA was inhibited by pRNAT-hTERT-Ⅲ,pRNAT-hTR-Ⅲ,and pRNAT-hTR-Ⅲ+hTERT-Ⅲ in BIU-87 cells.The inhibition efficiency of pRNAT-hTERT-Ⅲ,pRNAT-hTR-Ⅲ,pRNAT-hTERT-Ⅲ+pRNAT-hTR-Ⅲ was 67% for TERT mRNA,41% for TR mRNA,57% for TR mRNA and 70% for TERT mRNA in BIU-87 cells respectively.The growth of BIU-87 cells was inhibited and telomerase activity was considerably decreased,especially in the cells treated with combined RNAi-hTR and-hTERT.Gene chip analysis revealed that 21 genes were down-regulated(ATM,BAX,BCL2,BCL2L1,BIRC5,CD44,CTNNB1,E2F1,JUN,MCAM,MTA1,MYC,NFKB1,NFKBIA,NME4,PNN,PNN,SERPINE1,THBS1,TNFRSF1A,and UCC1).The results indicated that hTR-siRNA and hTERT-siRNA,especially their combination,siRNA hTR+hTERT,specifically and effectively suppressed the expression of both hTR and hTERT mRNA and telomerase activity.Molecular biological mechanism by which combined siRNA-TR and-TERT inhibited telomerase activity and growth of BIU-87 cells in vitro may involve the down-regulation of the 21 genes.

The expression and significance of hTERT and P53 in thyroid carcinoma

Objective To determine the expression of human telomerase reverse transcriptase (hTERT) and P53 in thyroid carcinoma and its relationship with development and prognosis of the carcinoma. Methods Totally 90 cases of thyroid specimens (60 thyroid carcinomas,10 thyroid adenomas,10 goitres and 10 normal thyroid tissues) were studied by SP immunohistochemical method. Results Positive immunoreactivity of hTERT and P53 was higher in thyroid carcinoma (P<0.05). The positive rates of hTERT and P53 were higher in undifferentiated carcinomas,carcinomas with lymph nodes metastasis or at stage Ⅲ+Ⅳ than in well-differentiated carcinomas,carcinomas without lymph nodes metastasis or at stage Ⅰ+Ⅱ (P<0.05). The expression of hTERT was significantly related with that of P53 (P<0.05). Conclusion Over-expressed hTERT and P53 may be related to the carcinogenesis and progression of thyroid carcinoma and hTERT expression is related to P53 protein. Examination of expression of hTERT and P53 proteins may be helpful to judge the thyroid cancer's behavior and prognosis.

Current status quo on COVID-19 including chest imaging

With each day the number coronavirus disease 2019(COVID-19)cases continue to rise rapidly and our imaging knowledge of this disease is expeditiously evolving.The role of chest computed tomography(CT)in the screening or diagnosis of COVID-19 remains the subject of much debate.Despite several months having passed since identifying the disease,and numerous studies related to it,controversy and concern still exists regarding the widespread use of chest CT in the evaluation and management of COVID-19 suspect patients.Several institutes and organizations around the world have released guidelines,recommendations and statements against the use of CT for diagnosing or screening COVID-19 infection and advocating its use only for those cases with a strong clinical suspicion of complication or an alternate diagnosis.However,these guidelines and recommendations are in disagreement with majority of the widely available literature,which strongly favour CT as a pivotal tool in the early diagnosis,management and even follow-up of COVID-19 infection.This article besides comprehensively reviewing the current status quo on COVID-19 disease in general,also writes upon the current consensus statements/recommendations on the use of diagnostic imaging in COVID-19 as well as highlighting the precautions and various disinfection procedures being employed world-wide at the workplace to prevent the spread of infection.

Advances in BRAF gene mutations in papillary thyroid carcinoma

Thyroid cancer is the most common endocrine system tumor.Ultrasound guided fine needle puncture(FNA)can identify benign and malignant thyroid nodules.However,due to the limitation of cytological detection,some thyroid nodules are difficult to distinguish benign and malignant.BRAF gene mutation is a common human oncogenic mutation and the highest mutation frequency in papillary thyroid carcinoma.The combination of FNA and BRAF gene detection can significantly improve the diagnostic rate of benign and malignant thyroid nodules and make up for the deficiency of single diagnosis of cytology.Moreover,while the incidence of thyroid cancer is growing rapidly worldwide,its mortality remains stable.The problem of overdiagnosis and overtreatment of thyroid cancer is becoming more and more obvious.However,due to the limitations of current studies on BRAF genes,its prognostic value for papillary thyroid carcinoma remains controversial.Therefore,in order to reduce the adverse effects of overdiagnosis and treatment,the relationship between gene and tumor biological behavior needs further study in the future.

Synthesis and anti-HIV activities of phorbol derivatives

In this study,37 derivatives of phorbol esters were synthesized and their anti-HIV-1 activities evaluated,building upon our previous synthesis of 51 phorbol derivatives.12-Para-electron-acceptor-trans-cinnamoyl-13-decanoyl phorbol derivatives stood out,demonstrating remarkable anti-HIV-1 activities and inhibitory effects on syncytia formation.These derivatives exhibited a higher safety index compared with the positive control drug.Among them,12-(trans-4-fluorocinnamoyl)-13-decanoyl phorbol,designated as compound 3c,exhibited the most potent anti-HIV-1 activity(EC_(50)2.9 nmol·L^(−1),CC50/EC_(50)11117.24)and significantly inhibited the formation of syncytium(EC_(50)7.0 nmol·L^(−1),CC50/EC_(50)4891.43).Moreover,compound 3c is hypothesized to act both as an HIV-1 entry inhibitor and as an HIV-1 reverse transcriptase inhibitor.Isothermal titration calorimetry and molecular docking studies indicated that compound 3c may also function as a natural activator of protein kinase C(PKC).Therefore,compound 3c emerges as a potential candidate for developing new anti-HIV drugs.

Structure-based design and optimization lead to the identification of novel dihydrothiopyrano[3,2-d]pyrimidine derivatives as potent HIV-1 inhibitors against drug-resistant variants

With our continuous endeavors in seeking potent anti-HIV-1 agents,we reported here the discovery,biological characterization,and druggability evaluation of a class of nonnucleoside reverse transcriptase inhibitors.To fully explore the chemical space of the NNRTI-binding pocket,novel series of dihydrothiopyrano[3,2-d]pyrimidines were developed by employing the structure-based design strategy.Most of the derivatives were endowed with prominent antiviral activities against HIV-1 wild-type and resistant strains at nanomolar levels.Among them,compound 23h featuring the aminopiperidine moiety was identified as the most potent inhibitor,with EC50values ranging from 3.43 to 21.4 nmol/L.Especially,for the challenging double-mutants F227L+V106A and K103N+Y181C,23h exhibited 2.3-to 14.5-fold more potent activity than the first-line drugs efavirenz and etravirine.Besides,the resistance profiles of 23h achieved remarkable improvement compared to efavirenz and etravirine.The binding target of 23h was further confirmed to be HIV-1 reverse transcriptase.Molecular modeling studies were also performed to elucidate the biological evaluation results and give guidance for the optimization campaign.Furthermore,no apparent inhibition of the major CYP450 enzymes and hERG channel was observed for 23h.Most importantly,23h was characterized by good pharmacokinetic properties and excellent safety in vivo.Collectively,23h holds great promise as a potential candidate for its effective antiviral efficacy and favorable drug-like profiles.

Evolution of blood lipids and risk factors of dyslipidemia among people living with human immunodeficiency virus who had received first-line antiretroviral regimens for 3 years in Shenzhen

Background:Lipid abnormalities are prevalent among people living with human immunodeficiency virus(HIV)(PLWH)and contribute to increasing risk of cardiovascular events.This study aims to investigate the incidence of dyslipidemia and its risk factors in PLWH after receiving different first-line free antiretroviral regimens.Methods:PLWH who sought care at the Third People’s Hospital of Shenzhen from January 2014 to December 2018 were included,and the baseline characteristics and clinical data during the follow-up were collected,including total cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C)and high-density lipoprotein cholesterol(HDL-C).The risk factors of dyslipidemia after antiretroviral therapy were analyzed with the generalized estimating equation model.Results:Among the 7623 PLWH included,the mean levels of TC,HDL-C and LDL-C were 4.23±0.85 mmol/L,1.27±0.29 mmol/L and 2.54±0.65 mmol/L,respectively,and the median TG was 1.17(IQR:0.85-1.68)mmol/L.Compared with that in PLWH receiving tenofovir disoproxil fumarate(TDF)+lamivudine(3TC)+ritonavir-boosted lopinavir(LPV/r),zidovudine(AZT)+3TC+efavirenz(EFV),and AZT+3TC+LPV/r,the incidence of dyslipidemia was lower in PLWH receiving TDF+3TC+EFV.In multivariate analysis,we found that the risks of elevations of TG,TC,and LDL-C were higher with TDF+3TC+LPV/r(TG:odds ratio[OR]=2.82,95%confidence interval[CI]:2.55-3.11,P<0.001;TC:OR=1.24,95%CI:1.14-1.35,P<0.001;LDL:OR=1.06,95%CI:1.00-1.12,P=0.041),AZT+3TC+EFV(TG:OR=1.41,95%CI:1.28-1.55,P<0.001;TC:OR=1.43,95%CI:1.31-1.56,P<0.001;LDL:OR=1.18,95%CI:1.12-1.25,P<0.001),and AZT+3TC+LPV/r(TG:OR=3.08,95%CI:2.65-3.59,P<0.001;TC:OR=2.40,95%CI:1.96-2.94,P<0.001;LDL:OR=1.52,95%CI:1.37-1.69,P<0.001)than with TDF+3TC+EFV,while treatment with TDF+3TC+LPV/r was less likely to restore HDL-C levels compared with TDF+3TC+EFV(OR=0.95,95%CI:0.92-0.97,P<0.001).In addition to antiretroviral regimens,antiretroviral therapy duration,older age,overweight,obesity and other traditional factors were also important risk factors for dyslipidemia.Conclusion:The incidence of dyslipidemia varies with different antiretroviral regimens,with TDF+3TC+EFV having lower risk for dyslipidemia than the other first-line free antiretroviral regimens in China.

Estrogen deficiency reversibly induces telomere shortening in mouse granulosa cells and ovarian aging in vivo

Estrogen is implicated as playing an important role in aging and tumorigenesis of estrogen responsive tissues;however the mechanisms underlying the mitogenic actions of estrogen are not fully understood.Here we report that estrogen deficiency in mice caused by targeted disruption of the aromatase gene results in a signi-ficant inhibition of telomerase maintenance of telomeres in mouse ovaries in a tissue-specific manner.The inhibition entails a significant shortening of telomeres and compromised proliferation in the follicular granulosa cell compartment of ovary.Gene expression analysis showed decreased levels of proto-oncogene c-Myc and the telomerase catalytic subunit,telomerase reverse transcriptase(TERT),in response to estrogen deficiency.Estrogen replacement therapy led to increases in TERT gene expression,telomerase activity,telomere length and ovarian tissue growth,thereby reinstating ovary development to normal in four weeks.Our data demonstrate for the first time that telomere maintenance is the primary mechanism mediating the mitogenic effect of estrogen on ovarian granulosa cell proliferation by upregulating the genes of c-Myc and TERT in vivo.Estrogen deficiency or over-activity may cause ovarian tissue aging or tumorigenesis,respectively,through estrogen regulation of telomere remodeling.

Molecular regulation of telomerase activity in aging

The process of aging is mitigated by the maintenance and repair of chromosome ends(telomeres),resulting in extended lifespan.This review examines the molecular mechanisms underlying the actions and regulation of the enzyme telomerase reverse transcriptase(TERT),which functions as the primary mechanism of telomere maintenance and regulates cellular life expectancy.Underpinning increased cell proliferation,telomerase is also a key factor in facilitating cancer cell immortalization.The review focuses on aspects of hormonal regulations of telomerase,and the intracellular pathways that converge to regulate telomerase activity with an emphasis on molecular interactions at protein and gene levels.In addition,the basic structure and function of two key telomerase enzyme components—the catalytic subunit TERTand the template RNA(TERC)are discussed briefly.

Effect of intestinal ischemia/reperfusion injury on leptin and orexin-A levels

The aim of this paper is to explore the effect of intestinal ischemia/reperfusion(I/R)injury on leptin and orexin-A levels in peripheral blood and central secretory tissues,and to examine the roles of leptin and orexin-A in acute inflammatory responses.An intestinal I/R injury model of rats was made;the rats were grouped according to the time of after 60 min ischemia.Radioimmunoassay was employed to detect the levels of leptin in serum and adipose tissue and orexin-A levels in plasma and hypothalamus.Reverse transcriptase-polymerase chain reaction was used to detect mRNA expressions of adipose leptin and hypothalamus orexin-A.Compared with the levels before the injury,serum leptin in 60 min ischemia/30 min reperfusion(I60pR30p)group decreased and that of I60pR360p group increased.Compared with sham-operation group(sham group)after injury,serum leptin level of I60pR360p group increased,adipose leptin levels of I60pR30p and I60pR90p decreased,and adipose leptin in I60pR360p group increased.After the injury,adipose leptin mRNA expressions of I60pR30p,I60pR240p and I60pR360p increased,whereas that of I60pR150p group decreased as compared with the sham group.There was no significant difference in the protein levels of orexin-A,either between plasma and hypothalamus or between pre-and post-I/R injury.Compared with sham group,hypothalamus orexin-A mRNA expressions of I60pR30p and I60pR90p decreased gradually after the injury,with that of I60pR150p group reaching the lowest,and those of I60pR240p and I60pR360p recovering gradually,although they were still significantly lower than that of sham group.Leptin and orexin-A respond to intestinal I/R injury in a time-dependent manner,with leptin responding more quickly than orexin-A does,and both of them may contribute to the metabolic disorders in acute inflammation.

NRTIs’ effect on the sequence of mitochondrial DNA HV 2 in HIV infected patients

Potent combination antiretroviral therapy(cART)has significantly improved the life expectancy of people living with human immunodeficiency virus(HIV),but it has many side effects such as lipodystrophy(LD),hepatic steatosis,and lactic acidosis.Nucleoside reverse transcriptase inhibitors(NRTIs)could damage the mito-chondria by inhibiting the human DNA polymerase gamma,leading to mtDNA deletion.However,it remains uncertain whether NRTIs could induce the hypervariable region(HV)mutations of the D loop of mitochondria in Chinese HIV/AIDS patients,and whether that effect is different between individuals with and without LD.Hereby,30 Chinese AIDS patients who were receiving antiretroviral drugs were recruited,among which 16 had symptomatic LD and 14 did not.Blood samples were collected prior to and after 96 weeks of treatment.Total DNA was extracted from peripheral blood mononuclear cells(PBMCs).Fragments of 728 bp in length containing HV 2 were amplified by standard polymerase chain reaction(PCR).Direct DNA-sequencing analysis techni-ques were used to detect mitochondrial sequence variants between paired longitudinal samples.Alterations were compared with the revised Cambridge Reference Sequence(rCRS)to determine mutation or polymorphism.Results showed that two years after ART,totally seven cases exhibited sequence variations,five individuals showed 73 A!G revised variation(two with and three without LD),while two cases of LD were found to have other nucleotide alterations.There was no new alteration in individuals without LD.In conclusion,NRTIs could induce mutation of mtDNA HV 2,which might contribute to the development of LD.

Significance of peritoneal lavage cytology based on genetic signatures in gastric cancer

Perit on eal metastasis is the most comm on patter n of recurre nee and the most freque nt cause of death after surgery in patie nts with gastric can cer.Perit on eal free can cer cells dissem in ated from the primary lesi on site have bee n con sidered the main cause of perit on eal metastasis.Perit on eal lavage cytological exam in ati on(PLC)has bee n show n to be an in depe ndent predictor of gastric cancer relapse after curative resection and poor overall survival.However,the conventional cytological examinations have high rates of false-positive and false-negative findings.To improve the sensitivity,molecular-based methods using reverse transcriptase polymerase chain reaction have been developed for detecting cancer cells in peritoneal wash fluids of patients with gastric cancer.We performed a PubMed search for articles describing PLC in gastric can cer.Releva nt articles were reviewed and data on available outcomes elaborated.The cli nical roles and attributes of PLC in gastric can cer were reviewed,and its future applicati on to this disease is discussed.