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.

Study on the Detection of Telomerase Activity by Combining DNA Sequence Analysis with TRAP

Telomeric repeat amplification protocol (TRAP) is now a conventional assay for detecting telomerase activity. However, this method presents problems owing to tedious quantitation, radioisotopic handling. In order to alleviate these inconveniences, a novel telomerase DNA sequencing assay together with TRAP to detect human telomerase activity was developed. It was used to detect telomerase activity in Hela, HLF, MCF, K562, SMMC 7721 cells, Leukocytes and RNase pretreated or heat treated cells as control. Telomerase activity assayed by this method was positive when the number of K562 cells examined was 102,103, and 104. The telomerase activity depended on the number of K562 cells used in the assay. Telomerase activity of Rnase pretreated cells or heat treated cells, and human normal peripheral blood leukocyte(Leu) were negative. The result of this method was available within a few hours and was handled without radioisotope. Further studies should be taken to detect telomerase activity in quantitation.

Microbiota in patients with cefuroxime resistance and anal fistula revealed by 16S ribosomal DNA

BACKGROUND Anal fistula is increasingly prevalent due to modern lifestyle factors,and surgery remains the primary treatment.However,the rising incidence of antibiotic resistance,particularly to cefuroxime,complicates perioperative management.The role of gut microbiota in influencing this resistance is not well understood.AIM To investigate the relationship between gut microbiota composition and cefuroxime resistance in anal fistula patients and to assess probiotic intervention impact.METHODS This study included 30 anal fistula patients categorized into cefuroxime-sensitive(Cefur-S)and cefuroxime-resistant(Cefur-NS)groups.Gut microbiota samples were collected during colonoscopy,and 16S ribosomal DNA sequencing was performed to analyze microbial diversity.Patients in the Cefur-NS group received a 7-day course of Clostridium butyricum tablets.Post-intervention,microbial composition and cefuroxime resistance were reassessed.RESULTS Alpha and beta diversity analyses showed no significant differences in microbial diversity between the Cefur-S and Cefur-NS groups.However,effect size analysis identified Roseburia and Butyricicoccus as dominant genera in the Cefur-S group,with higher butyrate production potentially protecting against cefuroxime resistance.Post-intervention,the Cefur-NS group showed a significant reduction in cefuroxime resistance,improved stool consistency,and reduced bowel movement frequency.CONCLUSION This study suggests that specific gut microbiota,particularly Butyricicoccus and Roseburia,may mitigate cefuroxime resistance in anal fistula patients by increasing butyrate production.Probiotic intervention targeting gut microbiota composition presents a promising strategy for reducing antibiotic resistance and improving clinical outcomes.

Complete resection of recurrent anal canal cancer using endoscopic submucosal dissection and transanal resection: A case report

BACKGROUND Early anal canal cancer is frequently treated with endoscopic submucosal dis-section(ESD)to preserve anal function.However,if the lesion is in the anal canal,then significant difficulties such as bleeding and challenges associated with scope manipulation can arise.CASE SUMMARY A 70-year-old woman undergoing follow-up after transverse colon cancer surgery was diagnosed with anal canal cancer extending to the dentate line.The patient underwent a combination of ESD and transanal resection(TAR).The specimen was excised in pieces,which resulted in difficulty performing the pathological evaluation of the margins,especially on the anal side where TAR was performed and severe crushing was observed.Careful follow-up was performed,and local recurrence was observed 3 years postoperatively.Because the patient had super-ficial cancer without lymph node metastasis,local resection was performed again.The second treatment attempt was improved as follows:(1)TAR and ESD were performed appropriately based on the situation by the same physician;(2)A needle scalpel was used during TAR to prevent tissue crushing;and(3)The lesion borders were marked using ESD techniques before treatment.Complete resection was performed without complications.CONCLUSION Anal canal lesions can be safely and reliably removed when ESD and TAR are used appropriately.

Inhibition of Telomerase with hTERT Antisense Increases Susceptibility of Leukemic Cells to CDDP-induced Apoptosis

Objective: To investigated the e?ect of inhibition of telomerase with hTERT antisense on leukemic cells (HL-60 and K562) to CDDP-induced apoptosis. Methods: Antisense phosphorothioate oligodeoxynucleotide (AS PS-ODN) was synthesized and puri?ed. Telomerase activity was detected by Telomerase PCR ELASA kit and cell apoptosis was observed by morphological method and determined by ?owcytometry. Results: AS PS-ODN could signi?cantly inhibit telomerase activity by down regulat- ing the hTERT expression, and increase the susceptibility of leukemic cells to CDDP-induced apoptosis. Conclusion: Inhibition of telomerase with hTERT antisense can increases the susceptibility of leukemic cells to CDDP-induced apoptosis.

Trichostatin A Induces Apoptosis by Inhibiting Telomerase Activity and Expression of Telomerase Reverse Transcriptase in HL-60 Cells

Aim To investigate the effects of trichostatin A （TSA） on telomerase activity and the expression of human telomerase reverse transcriptase （hTERT） during apoptosis in vitro and the mechanisms in HL-60 cells. Methods The proliferative activity of HL-60 cells was assessed by MTT assay. Cell apoptosis was analyzed by flow cytometry. Telomerase activity was examined by TRAP-ELISA. The expression of telomerase subunits was analyzed by RT-PCR. Results A time- and dose-dependent inhibition was detected in HL-60 cells treated with TSA. After treatment with 600 nmol· L^-1 TSA for 48 h, the apoptosis rate in HL-60 cells was 42. 6% and telomerase activity decreased 1.95 ± 0.25, 1.73 ± 0. 12, and 1.52 ± 0. 09 for 12, 24, and 48 h, respectively. The expression of hTERTmRNA decreased. No significant changes were observed in the expression of hTRmRNA and hTPI mRNA. Condusion TSA inhibits telomerase activity and induces apoptosis in HL-60 cells. The underlying mechanism may be related to the down-regulation of hTERT transcription.

Telomerase Activity in Human Renal Cell Carcinoma with Reference to Clinicopathologic Features

Objective: To study the telomerase activity in human renal cell carcinoma and to evaluate the correlation with the clinicobiologic features of the neogrowth.Methods: The telomerase activity was studied by means of a modified telomeric repeat amplification protocol (TRAP) in 32 renal cell carcinoma tissues, 32 normal renal tissues and 32 paracancer tissues and its correlation with the clinicopathologic features of the tumor was evaluated.Results: Telomerase activity was strongly positive in 17, positive in 12 and negative in 3 cases of renal cell carcinoma tissues, the total positive rate being 91%. Telomerase activity was weakly positive (6%) in only 2 out of 32 samples of normal renal cortex tissues and positive in 6 paracancer tissues (19%), the difference was conspicuous (P<0.01).Conclusion: The positive rate of telomerase activity was significantly higher in renal cell carcinoma tissues and might serve as a prognostic marker for estimating the biologic characteristics of renal cell carcinoma.

Expression of Telomerase Activity in Gastric Cancer Cells

Objective To study the relationship between telomerase activity and biological behavior in human gastric cancer cells and appraise the clinical significance of detecting telomerase activity.Methods The telomerase activity in 47 gastric cancer tissue samples , their matched normal tissues, 7 gastric ulcer and 2 gastric cancer cell lines was detected using a PCR-based non-radioisotopic telomeric repeat amplification protocol (TRAP) assay. Results None of the 47 samples from normal gastric tissues expressed telomerase activity. The 41 of 47 cases of gastric cancer presented telomerase activity with an 87.2 % positive rate (P < 0.001). 2/2 gastric cancer cell lines and 0/7 gastric ulcer line were also positive for telomerase activity. The activity of telomerase was associated with the pathological differentiation of gastric cancer. Conclusion Telomerase activity may be related to the biological behavior of gastric cancer and can help in assessing the malignant potential of gastric cancer. Telomerase activity will be a good diagnostic marker for the detection of gastric cancer.

Effects of Artificially Designed shRNA of chTR on Telomerase Activity

[Objective] The study was to investigate the inhibitory effects of shRNA of chTR on telomerase activity in MDCC-MSB1 cells. [Method] The artificially designed and synthesized short hairpin RNA(shRNA) of chicken telomerase RNA(chTR) was used to construct the expression vector that was subsequently transfected to MDCC-MSB1 cells, then the telomerase activity of these cells measured by improved TRAP method. [Result] Compared to the CK group, the telomerase activities in the treatment cells showed no obvious decrease in 24 h after transfection, while decreased remarkably 48 h later, among which in the cells transfected by interference vector pSi-chTR-sh1 presented the most obvious inhibitory effects. [Conclusion] This vector could effectively inhibit the telomerase activities in MDCC-MSB1 cells.

Telomerase activity in gastric cancer and its clinical implications

AIM To study the telomerase expression in gastric carcinoma and its clinical implications. METHODS Telomerase activity was examined in gastric cancer and corresponding normal tissues using a modified TRAP (telomeric repeat amplification protocol) assay (TRAP eze) in tissue samples from 94 gastric carcinomas and 58 normal tissues, 12 gastric adenomas and 9 gastric ulcer lesions. RESULTS Telomerase activity was present in 81 of the 94 (86 2%) gastric cancer tissues, whereas no telomerase activity was detected in any normal tissues. The incidence of telomerase activity in gastric cancer tissues was unrelated to the tumor diameter, histological grade, tumor invasion in depth, lymph node metastasis and TNM stage. CONCLUSION Telomerase plays an important role in carcinogenesis and progression of gastric cancer, and it is suggested to be a useful tumor marker.

Effect of VEGF,P53 and telomerase on angiogenesis of gastric carcinoma tissue

Objective:To investigate the effect of vascular endothelial growth factor(VEGF),P53 and telomerase on angiogenesis in gastric carcinoma tissue.Methods:A total of 95 surgical resection samples of gastric cancer tissue after pathological diagnosis are collected to observe the VEGF,P53 and telomerase expression using immunohistochemical methods.Relationship between their expression and its influence on angiogenesis in gastric carcinoma tissue were analyzed.Results:Microvascular density(MVD)and the expression of VEGF,P53 and telomerase were positively correlated.Expression of VEGF and P53 protein were related to tumor type and lymph metastasis,and also a correlation was observed between P53 and VEGF.The telomerase expression had no correlation with VEGF,and P53.Conclusions:VEGF angiogenesis has a angiogenesis promoting effect on gastric cancer tissue development and plays an important role in tumor generation and metastasis.Mutant P53 promotes the tumor angiogenesis generation by adjusting VEGF.Telomerase has a certain role in promoting activity of angiogenesis through different way rather than P53.

Inhibitory Effects of Selenium on Telomerase Activity and hTERT Expression in Cadmium-transformed 16HBE Cells

To investigate the effects of sodium selenite on telomerase activity and expression of hTERT mRNA in cadmium-transformed 16HBE cells. Methods Telomerase activity and expression of genes were measured after cultured cadmium-transformed 16HBE cells were exposed to sodium selenite at different doses （0.625, 1.25, 2.50, 5.00 pmol/L） for 24 hours. Results Selenium decreased telomerase activity in cadmium-transformed 16HBE cells. There existed an obvious dose-effect relationship between the selenium concentration and these changes. The expression of hTERT and c-myc mRNA also decreased but the expression of madl mRNA increased after exposure to selenium for 24 hours. No difference was found in expression of hTRF1 and hTRF2 mRNA after incubated with sodium selenite for 24 hours, compared with control group. Conclusion Selenium inhibits telomerase activity by decreasing hTERT and c-myc mRNA expression and increasing madl mRNA expression in cadmium-transformed 16HBE cells and selenium concentration is significantly correlated with these changes.

Telomerase and hTERT: Can they serve as markers for gastric cancer diagnosis?

AIM: To investigate telomerase activity and human telomerase reverse transcriptase (hTERT) expression in normal human gastric mucosal epithelial cells (nhGMECs) and fibroblasts (nhGMFs).

Telomeres,telomerase and colorectal cancer

Colorectal cancer(CRC)is the third most common cancer worldwide and,despite improved treatments,is still an important cause of cancer-related deaths.CRC encompasses a complex of diseases arising from a multistep process of genetic and epigenetic events.Besides heterogeneity in the molecular and biological features of CRC,chromosomal instability is a hallmark of cancer and cancer cells may also circumvent replicative senescence and acquire the ability to sustain unlimited proliferation.Telomere/telomerase interplay is an important mechanism involved in both genomic stability and cellular replicative potential,and its dysfunction plays a key role in the oncogenetic process.The erosion of telomeres,mainly because of cell proliferation,may be accelerated by specific alterations in the genes involved in CRC,such as APC and MSH2.Although there is general agreement that the shortening of telomeres plays a role in the early steps of CRC carcinogenesis by promoting chromosomal instability,the prognostic role of telomere length in CRC is still under debate.The activation of telomerase reverse transcriptase(TERT),the catalytic component of the telomerase complex,allows cancer cells to grow indefinitely by maintaining the length of the telomeres,thus favouring tumour formation/progression.Several studies indicate that TERT increases with disease progression,and most studies suggest that telomerase is a useful prognostic factor.Plasma TERT mRNA may also be a promising marker for the minimally invasive monitoring of disease progression and response to therapy.

Testicular expression of survivin and human telomerase reverse transcriptase(hTERT)associated with spermatogenic function in infertile patients

Aim： To characterize the coexpression of survivin, an inhibitor of apoptosis （IAF）, and human telomerase reverse transcriptase （hTERT） in human testes with varying spermatogenic function. Methods： Transcript levels of survivin mRNA and hTERT mRNA were determined in normal testes （n = 11） and testes with defective spermatogenesis （n = 28） using real-time reverse-transcription polymerase chain reaction （RT-PCR）. The histological work-up was performed according to a modified Johnsen score. Results： Expressions of both survivin and hTERT were highest at median levels of 96.8 and 709 in normal spermatogenesis and dropped to 53.3 and 534 in testes with postmeiotic spermatogenic arrest （n = 10）. In severe spermatogenic failure （n = 18）, survivin expression was lacking in most specimens （n = 16）, whereas at least low levels of testicular hTERT expression were largely detectable with a normalized expression of 73 in premeiotic spermatogenic arrest （n = 7） and 45 in patients with Sertoli cell-only syndrome （SCOS） （n = 3）. Both survivin and hTERT expressions increased with a progressing Johnsen score （P for trend = 0.001）. Conclusion： Although both survivin and hTERT are correlated with spermatogenic function, they show different expression patterns in testes of infertile patients. These findings substantiate results from studies in the rodent testis suggesting a predominant expression of survivin in meiotically dividing germ cells. （Asian J Andro12006 Jan; 8： 95-100）

Telomere,telomerase and digestive cancer

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Common telomerase reverse transcriptase promoter mutations in hepatocellular carcinomas from different geographical locations

AIM: To determine the mutation status of human telomerase reverse transcriptase gene(TERT) promoter region in hepatocellular carcinoma(HCC) from different geographical regions.METHODS: We analyzed the genomic DNA sequences of 59 HCC samples comprising 15 cell lines and 44 primary tumors,collected from patients living in Asia,Europe and Africa.We amplified a 474 bp DNA fragment of the promoter region of TERT gene including the 1295228 and 1295250 sequence of chromosome 5 by using PCR.Amplicons were then sequenced by Sanger technique and the sequence data were analyzed with by using DNADynamo software in comparison with wild type TERT gene sequence as a reference.RESULTS: The TERT mutations were found highly frequent in HCC.Eight of the fifteen tested cell lines displayed C228 T mutation,and one had C250 T mutation with a mutation frequency up to 60%.All of the mutations were heterozygous and mutually exclusive.Ten out of forty-four tumors displayed C228 T mutation,and additional five tumors had C250 T mutation providing evidence for mutation frequency of 34% in primary tumors.Considering the geographic origins of HCC tumors tested,TERT promoter mutation frequencies were higher in African(53%),when compared to non-African(24%) tumors(P = 0.056).There was also a weak inverse correlation between TERT promoter mutations and murine double minute 2 single nucleotide polymorphism 309 TG polymorphism(P = 0.058).Mutation frequency was nearly two times higher in established HCC celllines(60%) compared to the primary tumors(34%).CONCLUSION: TERT promoter is one of most frequent mutational targets in liver cancer,and hepatocellular carcinogenesis is highly associated with the loss of telomere-dependent cellular senescence control.

Effects of Cadmium on Telomerase Activity,Expressions of TERT,C-myc and P53,and Apoptosis of Rat Hepatocytes

This study investigated the effect of cadmium on the telomerase activity,the expression of TERT,c-myc and p53 and the apoptosis of rat hepatocytes.The rats were administrated 5,10 and 20 μmol/kg cadmium chloride intraperitoneally and sacrificed 48 h after the initial treatment.The telomerase activity of the rat hepatocytes was measured by the telomeric repeat amplification protocol (TRAP),and apoptosis was detected by flow cytometry.The mRNA expressions of TERT,c-myc and p53 were measured by reverse transcription-polymerase chain reaction (RT-PCR).C-myc and P53 proteins were determined by immunochemistry.The results showed that cadmium chloride increased the hepatocellular telomerase activity in a dose-dependant manner and induced the apoptosis of hepatocytes significantly.The value of relative coefficient between the telomerase activity and the apoptosis rate was 0.9398.RT-PCR revealed that specific bands corresponding to the TERT mRNA,c-myc mRNA,and p53 mRNA were displayed at 185,342 and 538 bp respectively.Cadmium chloride could substantially increase the mRNA expressions of TERT,c-myc and p53 in rat hepatocytes,as compared with control.Moreover,cadmium chloride at the doses of 5,10 and 20 μmol/kg could increase the content of P53 protein in rat hepatocytes obviously,but only that at the doses of 10 and 20 μmol/kg substantially promoted the c-myc protein level in rat hepatocytes.Our study herein suggested that cadmium may contribute to the carcinogenesis by activating telomerase,and overexpressing the mRNAs of TERT,c-myc and p53,and causing apoptosis of normal cells.

Inhibition of telomerase with human telomerase reverse transcriptase antisense increases the sensitivity of tumor necrosis factor-α-induced apoptosis in prostate cancer cells

Aim： To investigate the effect of inhibition of telomerase with human telomerase reverse transcriptase （hTERT） antisense on tumor necrosis factor-α （TNF-α-induced apoptosis in prostate cancer cells （PC3）. Methods： Antisense phosphorothioate oligodeoxynucleotide （AS PS-ODN） was synthesized and purified. Telomerase activity was measured using the telomeric repeat amplification protocol （TRAP） and polymerase chain reaction enzyme-linked immunoassay （PCR-ELISA）. hTERT mRNA was measured by reverse transcription PCR （RT-PCR） assay and gel-image system, hTERT protein was detected by immunochemistry and flow cytometry. Cell viability was detected by 3-（4, 5-dimethylthiazol-2-yl）-2,5-Diphenyltetrazolium （MTT） assay. Cell apoptosis was observed by morphological method and determined by flow cytometry. Results： The telomerase activity decreased with time after hTERT AS PS-ODN treatment. The levels of hTERT mRNA decreased with time after hTERT AS PS-ODN treatment, which appeared before the decline of the telomerase activity. The percentage of positive cells of hTERT protein declined with time after hTERT AS PS-ODN treatment, which appeared after the decline of hTERT mRNA. There was no difference in telomerase activity, hTERT mRNA and protein levels between hTERT sense phosphorothioate oligodeoxynucleotide （S PS-ODN） and the control group. The cell viability decreased with time after hTERT AS PS-ODN combined with TNF-α treatment. The percentage of apoptosis increased with time after hTERT AS PS-ODN combined with TNF-α treatment. There was no difference in cell viability and the percentage of apoptosis between hTERT S PS-ODN and the control group. Conclusion： hTERT AS PS-ODN can significantly inhibit telomerase activity by downregulating the hTERT mRNA and protein expression, and inhibition of telomerase with hTERT antisense can enhance TNF-α- induced apoptosis of PC3 cells.