RESUMEN

OBJECTIVE: Cervical cancer screening by primary human papilloma virus detection and cytology is fraught with low specificity and variable sensitivity, respectively. Cytology-histology correlation remains modest. Biomarkers associated with early genetic events in cervical squamous carcinogenesis and detectable in cytology material are likely to be relevant. Human telomerase RNA component (hTERC) gene overexpression and aneuploidy are promising candidates in view of their reported early and consistent association with cervical squamous oncogenesis. METHODS: We analysed hTERC gene expression and chromosome 7 ploidy by fluorescent in-situ hybridisation (FISH) in 50 women with cytological precursor squamous intraepithelial lesions and available histology outcomes. Results were expressed as percentages of cells showing ≥3 signals, mean signals/nucleus, and maximum amplitude across various cytology and histology categories. Proportions of positive cases were calculated from threshold values derived from 6 controls. Distribution of above indices with respect to ≥cervical intraepithelial neoplasia 2 (CIN2) was explored. RESULTS: For both genetic aberrations, there was significant positive correlation (for all indices) between the proportion of positive cases and worsening cytological and histological outcomes (P < .05), with significant intergroup differences (P < .05). High-grade lesions (≥CIN2) had significantly higher results compared to

Asunto(s)

Cromosomas Humanos Par 7/genética , Expresión Génica/genética , ARN/genética , Telomerasa/genética , Displasia del Cuello del Útero/genética , Displasia del Cuello del Útero/patología , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/patología , Adulto , Anciano , Alphapapillomavirus/patogenicidad , Cuello del Útero/patología , Cuello del Útero/virología , Citodiagnóstico/métodos , ADN Viral/genética , Detección Precoz del Cáncer/métodos , Femenino , Humanos , Persona de Mediana Edad , Infecciones por Papillomavirus/diagnóstico , Infecciones por Papillomavirus/genética , Infecciones por Papillomavirus/patología , Ploidias , Neoplasias del Cuello Uterino/diagnóstico , Adulto Joven , Displasia del Cuello del Útero/diagnóstico

RESUMEN

Telomeres protect chromosomal ends and they are maintained by the specialised enzyme, telomerase. Endometriosis is a common gynaecological disease and high telomerase activity and higher hTERT levels associated with longer endometrial telomere lengths are characteristics of eutopic secretory endometrial aberrations of women with endometriosis. Our ex-vivo study examined the levels of hTERC and DKC1 RNA and dyskerin protein levels in the endometrium from healthy women and those with endometriosis (n = 117). The in silico study examined endometriosis-specific telomere- and telomerase-associated gene (TTAG) transcriptional aberrations of secretory phase eutopic endometrium utilising publicly available microarray datasets. Eutopic secretory endometrial hTERC levels were significantly increased in women with endometriosis compared to healthy endometrium, yet dyskerin mRNA and protein levels were unperturbed. Our in silico study identified 10 TTAGs (CDKN2A, PML, ZNHIT2, UBE3A, MCCC2, HSPC159, FGFR2, PIK3C2A, RALGAPA1, and HNRNPA2B1) to be altered in mid-secretory endometrium of women with endometriosis. High levels of hTERC and the identified other TTAGs might be part of the established alteration in the eutopic endometrial telomerase biology in women with endometriosis in the secretory phase of the endometrium and our data informs future research to unravel the fundamental involvement of telomerase in the pathogenesis of endometriosis.

RESUMEN

Telomerase has emerged as an important primary target in anticancer therapy. It is a distinctive reverse transcriptase enzyme, which extends the length of telomere at the 3' chromosomal end, and uses telomerase reverse transcriptase (TERT) and telomerase RNA template-containing domains. Telomerase has a vital role and is a contributing factor in human health, mainly affecting cell aging and cell proliferation. Due to its unique feature, it ensures unrestricted cell proliferation in malignancy and plays a major role in cancer disease. The development of telomerase inhibitors with increased specificity and better pharmacokinetics is being considered to design and develop newer potent anticancer agents. Use of natural and synthetic compounds for the inhibition of telomerase activity can lead to an opening of new vistas in cancer treatment. This review details about the telomerase biochemistry, use of natural and synthetic compounds; vaccines and oncolytic virus in therapy that suppress the telomerase activity. We have discussed structure-activity relationships of various natural and synthetic telomerase inhibitors to help medicinal chemists and chemical biology researchers with a ready reference and updated status of their clinical trials. Suppression of human TERT (hTERT) activity through inhibition of hTERT promoter is an important approach for telomerase inhibition.

Asunto(s)

Neoplasias , Telomerasa , Proliferación Celular , Inhibidores Enzimáticos/farmacología , Humanos , Neoplasias/tratamiento farmacológico , Telomerasa/genética , Telomerasa/metabolismo , Telómero/metabolismo

RESUMEN

Telomerase activity has been regarded as a critical step in cellular immortalization and carcinogenesis and because of this, regulation of telomerase represents an attractive target for anti-tumor specific therapeutics. Recently, one avenue of cancer research focuses on antisense strategy to target the oncogenes or cancer driver genes, in a sequence specific fashion to down-regulate the expression of the target gene. The protein catalytic subunit, human telomerase reverse transcriptase (hTERT) and the template RNA component (hTERC) are essential for telomerase function, thus theoretically, inhibition of telomerase activity can be achieved by interfering with either the gene expression of hTERT or the hTERC of the telomerase enzymatic complex. The present study showed that phosphorothioate antisense oligonucleotide (sASO)-nuclear localization signal (NLS) peptide conjugates targeting hTERC could inhibit telomerase activity very efficiently at 5 µM concentration but less efficiently at 1 µM concentration. On the other hand, siRNA targeting hTERT mRNA could strongly suppress hTERT expression at 200 nM concentration. It was also revealed that siRNA targeting hTERT could induce telomere attrition and then irreversible arrest of proliferation of cancer cells.

Asunto(s)

Puntos de Control del Ciclo Celular/efectos de los fármacos , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Señales de Localización Nuclear/química , Oligonucleótidos Antisentido , Fosfatos/química , Telomerasa/antagonistas & inhibidores , Telómero/química , Proliferación Celular/efectos de los fármacos , Activación Enzimática , Células HeLa , Humanos , Péptidos/química , ARN Mensajero/genética , ARN Interferente Pequeño/genética , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Telomerasa/química , Células Tumorales Cultivadas

RESUMEN

BACKGROUND: GLOBOCAN 2018 latest data show cervical cancer ranks fourth in morbidity and mortality among women. Many genes in cervical lesions differ in sensitivity and specificity. However, the diagnostic molecules for early cervical cancer are not very clear. This paper screens biomarkers for early molecular diagnosis of Mongolian patients with cervical cancer. METHODS: Immunohistochemical SP method was used to detect the expression of p16INK4a and Notch1 protein in paraffin sections of 226 Mongolian patients with HPV16-positive cervical lesions after pathological examination, and 100 of them were randomly selected by fluorescence in situ hybridization to detect hTERC gene. The HPV16-binding human cervical cancer SiHa cell line was used to silence the expression of HPV16 E6/E7 gene by RNA interference, and the expression of p16INK4a , Notch1, and hTERC genes and protein expression levels were detected by RT-PCR and Western blot. RESULTS: The positive expression rates of p16INK4a , Notch1, and hTERC genes in HPV16-positive cervical cancer, CIN-III, CIN-II, CIN-I, uterine leiomyoma, and chronic cervicitis were significantly different (P < .05); the positive expression rates of the three genes were also significantly different in the same type of cervical lesions (P < .05); RNA interference can effectively inhibit HPV16 E6/E7, p16INK4a and Notch1 gene expression, but has no effect on hTERC gene expression. CONCLUSION: The p16INK4a gene can be used as a biomarker for early screening of cervical cancer, and the hTERC gene can be used to confirm the clinical diagnosis of cervical cancer.

Asunto(s)

Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Infecciones por Papillomavirus/patología , ARN/genética , Receptor Notch1/genética , Telomerasa/genética , Neoplasias del Cuello Uterino/virología , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Papillomavirus Humano 16/patogenicidad , Humanos , Proteínas Oncogénicas Virales/genética , Proteínas E7 de Papillomavirus/genética , Infecciones por Papillomavirus/genética , Infecciones por Papillomavirus/virología , Receptor Notch1/metabolismo , Proteínas Represoras/genética , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/patología

RESUMEN

Disturbances in telomere maintenance are common in cancer. We recently showed that Single-strand-selective monofunctional uracil-DNA glycosylase 1 (SMUG1) promotes telomere homeostasis by regulating the stability of the telomeric RNA component (hTERC). SMUG1-mediated recognition of base modifications may function in a regulated process serving to fine-tune the levels of hTERC.

RESUMEN

Liver kinase B1 (LKB1) is a critical tumor suppressor that is frequently mutated in human cancers. LKB1 has serine/threonine protein kinase activity, which regulates gene expression by phosphorylation of Yes-Associated protein (YAP). The phosphorylation-dependent YAP shuttling is critically important intracellular mechanism in the Hippo pathway. In our previous study, we found that the amplification of hTERC was significant higher in the bronchial brushing cells of patients with lung cancer, however, the underlying molecular mechanism is not clear. In this study, we showed that LKB1 overexpression could phosphorylate YAP and promoted its nuclear rejection. Silencing LKB1 could dephosphorylate YAP and promoted its entry into the nucleus. Here, we found that LKB1 inhibited the mRNA expression and the amplification of hTERC. YAP further up-regulated hTERC at mRNA and gene amplification levels. Therefore, we suggest that LKB1 may inhibit the expression and amplification of hTERC through the axis of LKB1-pYAP(YAP)-hTERC.

RESUMEN

Telomeres at the termini of human chromosomes are shortened with each round of cell division due to the "end replication problem" as well as oxidative stress. During carcinogenesis, cells acquire or retain mechanisms to maintain telomeres to avoid initiation of cellular senescence or apoptosis and halting cell division by critically short telomeres. The unique reverse transcriptase enzyme complex, telomerase, catalyzes the maintenance of telomeres but most human somatic cells do not have sufficient telomerase activity to prevent telomere shortening. Tissues with high and prolonged replicative potential demonstrate adequate cellular telomerase activity to prevent telomere erosion, and high telomerase activity appears to be a critical feature of most (80-90%) epithelial cancers, including endometrial cancer. Endometrial cancers regress in response to progesterone which is frequently used to treat advanced endometrial cancer. Endometrial telomerase is inhibited by progestogens and deciphering telomere and telomerase biology in endometrial cancer is therefore important, as targeting telomerase (a downstream target of progestogens) in endometrial cancer may provide novel and more effective therapeutic avenues. This review aims to examine the available evidence for the role and importance of telomere and telomerase biology in endometrial cancer.

RESUMEN

Engaging a telomere maintenance mechanism during DNA replication is essential for almost all advanced cancers. The conversion from normal and premalignant somatic cells to advanced malignant cells often results (85%-90%) from the reactivation of the functional ribonucleoprotein holoenzyme complex, referred to as telomerase. Modulation of the human telomerase reverse transcriptase (hTERT) appears to be rate limiting to produce functional telomerase and engage a telomere maintenance mechanism. The remaining 10% to 15% of cancers overcome progressively shortened telomeres by activating an alternative lengthening of telomeres (ALT) maintenance mechanism, through a DNA recombination pathway. Exploration into the specific mechanisms of telomere maintenance in cancer have led to the development of drugs such as Imetelstat (GRN163L), BIBR1532, 6-thio-dG, VE-822, and NVP-BEZ235 being investigated as therapeutic approaches for treating telomerase and ALT tumors. The successful use of 6-thio-dG (a nucleoside preferentially recognized by telomerase) that targets and uncaps telomeres in telomerase positive but not normal telomerase silent cells has recently shown impressive effects on multiple types of cancer. For example, 6-thio-dG overcomes therapy-resistant cancers in a fast-acting mechanism potentially providing an alternative or additional route of treatment for patients with cancer. In this perspective, we provide a synopsis of the current landscape of telomeres and telomerase processing in cancer development and how this new knowledge may improve outcomes for patients with cancer.

Asunto(s)

Antineoplásicos/uso terapéutico , Neoplasias/tratamiento farmacológico , Telómero/efectos de los fármacos , Humanos , Neoplasias/metabolismo , Telomerasa/metabolismo , Homeostasis del Telómero/efectos de los fármacos

RESUMEN

Approximately 20-40% of high-grade Cervical Intraepithelial Neoplasia (CIN) regresses spontaneously, but the natural prognosis of an individual lesion is unpredictable. Gain of the chromosomal 3q region, which contains the human telomerase RNA gene on 3q26, is found in CIN lesions and cervical carcinoma and shows correlation with disease grade. The aim of this study is to assess whether 3q26 gain as a single genetic marker can predict the natural prognosis of high-grade CIN, by performing a review of the literature and pilot study. A literature review was conducted. Additionally, we performed a pilot study in 19 patients with histologically confirmed high-grade CIN lesions who were followed for a mean of 115 days, after which loop excision was performed. Fluorescent in situ hybridization analysis was performed on the initial diagnostic biopsies to determine gain of 3q26. Eight studies were included in the literature overview, with a total of 407 patients. Of these, only 22 patients had high-grade lesions. All studies found an association between 3q26 gain and disease prognosis. Positive predictive values (PPV) ranged from 50 to 93%, negative predictive values (NPV) ranged from 75 to 100%. Only five out of 155 patients (3.2%) without 3q26 gain showed disease persistence or progression. In our pilot study on 3q26 gain in high-grade CIN, the PPV of 3q26 gain for disease persistence was 67%, the NPV 100%. All four patients without 3q26 gain showed disease regression. In conclusion, the absence of 3q26 gain in diagnostic biopsies may be applied to identify high-grade CIN lesions with a high probability of disease regression.

Asunto(s)

Biomarcadores de Tumor/genética , Cromosomas Humanos Par 3/genética , Regresión Neoplásica Espontánea/genética , Displasia del Cuello del Útero/genética , Neoplasias del Cuello Uterino/genética , Adulto , Progresión de la Enfermedad , Femenino , Marcadores Genéticos , Humanos , Persona de Mediana Edad , Proyectos Piloto , Pronóstico , Neoplasias del Cuello Uterino/patología , Displasia del Cuello del Útero/patología

RESUMEN

BACKGROUND: Esophageal squamous cell precursor lesions remain one of the most controversial topics in pathology and clinical management. AIMS: To analyze the dysregulation of human telomerase RNA component (hTERC) in esophageal squamous cell precursor lesions and the clinicopathological correlations with the characteristics of esophageal squamous cell precursor lesions. METHODS: Florescence in situ hybridization was performed to detect hTERC amplification in different gradings of esophageal squamous cell precursor lesions. With retrospective follow-up data, clinicopathological correlations between hTERC and esophageal squamous cell precursor lesions were subjected to logistic regression analysis. RESULTS: hTERC amplification gradually increased with upgrading of dysplasia, reaching the highest level in high-grade intraepithelial neoplasia, and there was a significant difference between the low-grade intraepithelial neoplasia group and the high-grade intraepithelial neoplasia group (P = 0.00). Logistic regression analysis showed that hTERC amplification was correlated with both dysplasia grading and ulcer characteristics of esophageal squamous cell precursor lesions (P < 0.05). CONCLUSIONS: hTERC amplification with increasing grading of esophageal squamous cell precursor lesions and the presence of ulcer characteristics might provide an important molecular and pathological marker for the diagnosis and clinical prognosis of esophageal squamous cell precursor lesions, especially for those ambiguous cases with more divergence in classification.

Asunto(s)

Biomarcadores de Tumor/genética , Neoplasias Esofágicas/genética , Carcinoma de Células Escamosas de Esófago/genética , Amplificación de Genes , Lesiones Precancerosas/genética , ARN/genética , Telomerasa/genética , Adulto , Anciano , Anciano de 80 o más Años , Biopsia , Neoplasias Esofágicas/enzimología , Neoplasias Esofágicas/patología , Carcinoma de Células Escamosas de Esófago/enzimología , Carcinoma de Células Escamosas de Esófago/patología , Femenino , Predisposición Genética a la Enfermedad , Humanos , Hibridación Fluorescente in Situ , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Fenotipo , Lesiones Precancerosas/enzimología , Lesiones Precancerosas/patología , Estudios Retrospectivos , Factores de Riesgo

RESUMEN

OBJECTIVE: This study aimed to demonstrate the predictive value of miR-21-5p, miR-34a, and human telomerase RNA component (hTERC) in cervical cancer (CC) development and evaluated their potential possibility for future clinical applications. METHODS: Specimens were collected from the normal cervix, cervical intraepithelial neoplasia (CIN) I, CIN II/III, cervical squamous cell carcinoma. Cytological evaluations and histopathologic examinations were conducted in all subjects, along with the assessment of human papillomavirus (HPV) DNA. The expression levels of the miR-21-5p and miR-34a were detected by RT-PCR. hTERC amplification was detected by dual-color interphase fluorescence in situ hybridization (FISH). Then miRNA, hTERC expressions were compared with the cytological and histologic examination. RESULTS: Compared to that in the benign samples, the expression of miR-21-5p and miR-34a in abnormal samples was significantly upregulated and downregulated, gradually corresponding to the severity of cervical lesions (P < 0.05). There was a trend toward an increasing amplification of hTERC with the increasing severity of cervical lesions. miR-21-5p and miR-34a expression, and hTERC amplification were more specific than HPV positivity in differentiating low-grade cervical disorders from high-grade ones (P < 0.05). CONCLUSIONS: MiR-21-5p upregulation, miR-34a downregulation, and hTERC amplification were associated with the aggressive progression of CC, which suggests that miR-21-5p, miR-34a and hTERC might serve as surrogate markers for CC progression and potential molecular targets for blockage of the development of CC.

Asunto(s)

MicroARNs/genética , ARN/genética , Telomerasa/genética , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/patología , Adulto , ADN Viral/genética , Progresión de la Enfermedad , Femenino , Amplificación de Genes/genética , Humanos , Persona de Mediana Edad , Procesos Neoplásicos , Infecciones por Papillomavirus/virología , Displasia del Cuello del Útero/genética , Displasia del Cuello del Útero/patología , Displasia del Cuello del Útero/virología , Neoplasias del Cuello Uterino/virología

RESUMEN

Telomerase, the enzyme that elongates telomeres in most eukaryotes, is a ribonucleoprotein complex composed of a reverse transcriptase catalytic subunit (TERT in human, Est2 in the budding yeast S. cerevisiae), regulatory factors and a noncoding RNA called hTERC (in human) or TLC1 (in budding yeast). Telomerase trafficking is a major process in the biogenesis and regulation of telomerase action at telomeres. Due to its higher signal-to-noise ratio, imaging of the telomerase RNA moiety is frequently used to determine telomerase intracellular localization. Here we describe how to image telomerase RNA in human and yeast cells using fluorescence in situ hybridization.

Asunto(s)

Hibridación Fluorescente in Situ , Imagen Molecular , ARN/genética , Saccharomycetales/genética , Telomerasa/genética , Línea Celular , Humanos , Hibridación Fluorescente in Situ/métodos , Imagen Molecular/métodos , Saccharomycetales/metabolismo

RESUMEN

Congenital limb anomalies are outcome of improper bone formation during embryonic development when cells divide, differentiate with high rate. So, telomerase activity is essential to maintain telomere length for such highly dividing cells. Here, we report four cases of congenital limb anomalies with detailed structures of limbs along with other clinical manifestations of age less than two years. We compared telomere length, expression of telomerase and telomere-associated genes of Peripheral Blood Mononuclear Cells (PBMC) in patient and four age-matched normal individual. Patient-1 was diagnosed with congenital limb hypogenesis ectrodactyly sequence, an autosomal dominant disorder, showing absence of digits and fibula in upper and lower limb respectively. Both mother and grandmother of Patient-1 showed similar hypogenesis of limbs. Patient-2 showed bilateral clenched hand with arthrogryposis, microcephaly and holoprosencephaly. Both Patient-3 and Patient-4 has no radius in upper limb. Additionally, Paient-3 showed right sided orbital Space Occupying Lesion (SOL) and Paranasal Sinuses (PNS) whereas Patient-4 showed fused kidney with fanconi anaemia. Furthermore, all the patients showed shorter telomere length, inactive telomerase and de-regulated expression of telomere-associated proteins in PBMC compared with age-matched control group. So, we can conclude that congenital limb anomalies may be linked with telomeropathy and a study with large number of samples is required to firmly establish such association.

RESUMEN

Oral squamous cell carcinoma (OSCC) is the most common oral cancer, and major efforts is being made to identify molecular markers capable to differentiate oral potentially malignant lesions (OPMLs) with indolent course from lesions with aggressive behavior. We undertook a study to evaluate if gain of the human telomerase RNA component (hTERC) gene in OPMLs could indicate lesions at high risk of developing OSCC. The study was performed on 30 OPMLs with long-term follow-up using a dual-color interphase fluorescence in situ hybridization (FISH) for hTERC status. Progression to malignancy was observed in 9 of 10 cases harboring hTERC gain and in 1 of 20 cases retaining a normal copy number of hTERC (P < .0001). Combining morphological grading and FISH analysis, all the cases with high-grade squamous intraepithelial lesion or carcinoma in situ harboring hTERC amplification progressed to OSCC, whereas none of the low-grade squamous intraepithelial lesions without hTERC gain progressed. Intermediate situations occurred. The data suggest that precise morphological evaluation together with FISH assessment for hTERC gain might pave the way to stratify OPMLs into high-risk and low-risk categories and could be helpful in selecting the most appropriate treatment.

Asunto(s)

Biomarcadores de Tumor/genética , Carcinoma in Situ/genética , Carcinoma de Células Escamosas/genética , Amplificación de Genes , Neoplasias de Cabeza y Cuello/genética , Hibridación Fluorescente in Situ , Neoplasias de la Boca/genética , Lesiones Precancerosas/genética , ARN/genética , Telomerasa/genética , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma in Situ/enzimología , Carcinoma in Situ/mortalidad , Carcinoma in Situ/patología , Carcinoma de Células Escamosas/enzimología , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/patología , Progresión de la Enfermedad , Femenino , Neoplasias de Cabeza y Cuello/enzimología , Neoplasias de Cabeza y Cuello/mortalidad , Neoplasias de Cabeza y Cuello/patología , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/enzimología , Neoplasias de la Boca/mortalidad , Neoplasias de la Boca/patología , Clasificación del Tumor , Lesiones Precancerosas/enzimología , Lesiones Precancerosas/mortalidad , Lesiones Precancerosas/patología , Valor Predictivo de las Pruebas , Medición de Riesgo , Factores de Riesgo , Carcinoma de Células Escamosas de Cabeza y Cuello , Factores de Tiempo

RESUMEN

AIMS: Telomerase is reactivated in most cancers and there is accumulating evidence that this is a driver event in malignant melanoma (MM). Thus, our aim was to evaluate if in-situ hybridization (ISH)-based quantification of telomerase RNA (hTR) could be used to distinguish MM from naevi, and if there was a correlation with the Breslow thickness. RESULTS AND METHODS: We created a tissue microarray (TMA) from formalin-fixed and paraffin-embedded tissue samples from 17 MM and 23 naevi, performed ISH targeting hTR, and quantified the signals. We found a more than eightfold greater number of hTR signals per nucleus in the MM samples compared to the naevi, and a positive correlation (P = 0.0381) between the number of hTR signals per nucleus and the Breslow thickness. CONCLUSION: Quantification of hTR ISH signals clearly distinguish MM from naevi (P < 0.0001) and the number of signals per nucleus correlates with the Breslow thickness, suggesting that hTR might be a valuable biomarker in MM. Furthermore, as ISH-based detection requires the presence of both hTR and telomerase reverse transcriptase (hTERT), it might be an indicator of active telomerase and thus have future relevance as a predictive biomarker for anti-telomerase treatment.

Asunto(s)

Biomarcadores de Tumor/metabolismo , Melanoma/enzimología , Nevo/enzimología , ARN/metabolismo , Neoplasias Cutáneas/enzimología , Telomerasa/metabolismo , Humanos , Inmunohistoquímica , Hibridación in Situ/métodos , Melanoma/diagnóstico , Nevo/diagnóstico , Neoplasias Cutáneas/diagnóstico

RESUMEN

Telomeres play an important role in the maintenance of genomic stability/integrity and are synthesized by the RNA-dependent polymerase telomerase. Progressive telomere shortening contributes to both in vitro and in vivo aging, and telomere length dynamics and telomerase expression profile in human tissues during extrauterine life have been well characterized. However, little is known about these changes in the early stage of gestation. In the present study, we determined telomere length and the expression of telomerase core units (telomerase reverse transcriptase, hTERT, and telomerase RNA component, hTERC) in human fetus tissues from 6 to 11 weeks of gestational age. A sharp decline in telomere length occurred between 6 and 7 weeks of gestational age, and a relatively stable or slightly shortened telomere length was thereafter maintained until birth. The inverse correlation between TERT or TERC expression and gestational age was steadily observed in these fetus tissues. Taken together, there is a rapid reduction followed by a slow erosion of telomere length in human fetus from gestational age 6-11 weeks, while hTERT and hTERC expression decreases steadily during this period. The present findings not only contribute to better understandings of telomere/telomerase biology in human embryonic development, but also are implicated in telomere/telomerase-related diseases or problems.

Asunto(s)

Desarrollo Fetal/genética , Acortamiento del Telómero , Telómero/genética , Feto/enzimología , Feto/fisiología , Edad Gestacional , Humanos , Telomerasa/metabolismo

RESUMEN

Objective To investigate the expression of human telomerase RNA component (hTERC)gene in cervical scraping samples, and the relationship between hTERC gene and cervical lesions. Methods The fluorescent in situ hybridization (FISH) was used to detect the expression of hTERC oncogene in cervical scraping samples in 100 cases, including 76 cases with cervical intraepithelial neoplasia, meanwhile, high risk human papillomavirus (HR-HPV) were detected by Hybrid Capture 2 (HC2) . The other 24 cases were negative for intraepithelial lesion (NILM). Results The positive expression rates of the hTERC gene in NILM,ASCUS, ASC-H, LSIL, HSIL and cervical cancer were 0, 32.25 %, 75.00 %, 35.71 %, 81.81 % and 100.00 % respectively. hTERC gene positive expression in normal group was less significantly than that in abnormal groups (P <0.05). There was a significantly difference between HSIL and ASCUS, LSIL (x2 = 6.1736, x2 =5.0004, P <0.05). The positive expression rates of the HR-HPV in ASCUS, ASC-H, LSIL and HSIL or higher lesions were 54.80 %, 75.00 %, 60.70 %, 90.90 % and 100.00 % respectively. HR-HPV positive expression in HSIL or higher lesions were more significantly than that in ASCUS group (x2=4.1767, P<0.05). Conclusion The overexpression of hTERC gene may play an important role in cervical carcinogenesis, therefore it can be used as a better tumor marker for prospective in early cervical cancer progresses.

RESUMEN

Objective: To explore the relationship of human telomerase mRNA component gene (hTERC) expression with the degree of cervical lesions and the infection of different genotypes of human papilloma virus(HPV). Methods: The thinprep cytologic test (TCT) specimens from 34 pathologically confirmed cervical intraepithelial neoplasia (CIN, including 8 CIN I, 9. CIN II, 17 CIN III), 36 invasive squamous cervical carcinoma (ISCC), and 20 chronic cervicitis patients were included in the present study. HPV subtype infection was detected by channelization hybridization gene chip and hTERC expression was tested by fluorescence in situ hybridization(FISH). The relationship between hTERC expression, the degree of cervical lesions and the infection with HPV was analyzed. Results: The positive rates of hTERC in chronic cervicitis, CIN I, CIN II, CIN III, and ISCC specimens were 0.00% (0/20), 50. 00% (4/8), 77.78% (7/9), 82.35% (14/17), and 97.22% (35/36), respectively. The positive rates of hTERC increased with the increase of cervical lesion degree, and there were significant differences between the three subgroups(P<0.05). The HPV infection rates were 10.00% (2/20), 37.50% (3/8), 66.67% (6/9), 88.24% (15/17), and 91.67% (33/36), respectively. The positive rates of hTERC in HPV16 type-positive, other high-risk type positive and negative/low-risk type positive groups were 90.38% (47/52), 66.67% (4/6), and 28.13% (9/32), respectively, with significant difference found between each two groups (P<0.01). Conclusion: The progress of cervical lesions and HPV infection are closely related to the positive rates of hTERC. HPV16 infection is the main cause for the high-level cervical lesions, and HPV58, 33, 52 have some advantages in CIN or ISCC.

RESUMEN

OBJECTIVE To explore the predictive value of human telomerase RNA gene component(hTERC) gene amplification and high-risk human papilomavirus(HR-HPV) testing in cervical intraepithelial neoplasia(CIN) as a marker for early diagnosis of cervix carcinoma.METHODS Fluorescence in situ hybridization(FISH) was used to detect the amplification of hTERC of cervical epithelial cells in 72 cases.By using hybrid capture 2(HC-2),two types of the HR-HPV DNA(HPV16/18) of each case were detected.Then,the results were compared with the pathologic diagnosis.The dual-color probe we used was GLP TERC/CSP 3.HeLa cells and lymphocytes from normal marrow were the positive control,while the cervical specimens from healthy outpatients were the negative control.RESULTS hTERC Gene amplification of specimens was tested in 72 cases,the positive amplification rate of hTERC gene in the cervicitis/CINⅠgroup and normal,compared to the cervical carcinomas(100%) and CIN Ⅱ/Ⅲ(68.75%),which showed a significant difference.The rates in CINⅡ and CINⅢ were 60.00% and 83.33%,respectively,which showed a significant difference compared with normal and CINⅠ/inflammation groups.hTERC gene amplification was positive in both HeLa cells and lymphocytes from normal marrow and HC-2 testing was positive in 32 cases of patients containing 11 cases of CINⅡ/Ⅲ,3 cases of cervical cancer,18 cases of cervicitis/CIN1 diagnosed.The positive predictive value(PPV) and specificity(Sp) of hTERC for the high-grade CIN was significantly higher than the PPV and Sp of HC-2 HR-HPV testing.CONCLUSIONS hTERC Gene involves in the progression and occurrence of cervical intraepithelial neoplasia and cervical squamous carcinoma.As a marker for early diagnosis of cervical intraepithelial neoplasia and cervical squamous carcinoma,the FISH method for hTERC gene is more reliable to differentiate the malignant diseases from the benign ones in cervixes than HC-2 HR-HPV DNA testing.The combined detection of HR-HPV and hTERC gene will provide more effective and suitable management to enhance the early diagnosis rate of cervical intraepithelial neoplasia and cervical squamous carcinoma.