HMGB1 is negatively correlated with the development of endometrial carcinoma and prevents cancer cell invasion and metastasis by inhibiting the process of epithelial-to-mesenchymal transition.

High-mobility group box protein 1 (HMGB1), a nuclear protein that plays a significant role in DNA architecture and transcription, was correlated with the progression of some types of cancer. However, the role of HMGB1 in endometrial cancer cell invasion and metastasis remains unexplored. HMGB1 expression was initially assessed by immunohistochemistry and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in normal endometrial tissue and endometrial carcinoma tissue. High expressions of HMGB1 protein were detected in normal endometrial tissues; however, in endometrial cancer tissues, the expressions of HMGB1 were found to be very weak. Furthermore, HMGB1 expressions were negatively correlated with advanced stage and lymph node metastasis in endometrial cancer. Then by RT-qPCR, Western blot and immunocytochemistry, HMGB1 was also detected in primary cultured endometrial cells and four kinds of endometrial cancer cell lines (Ishikawa, HEC-1A, HEC-1B and KLE). We found that the expression of HMGB1 was much higher in normal endometrial cells than in endometrial cancer cells, and reduced expression levels of HMGB1 were observed especially in the highly metastatic cell lines. Using lentivirus transfection, HMGB1 small hairpin RNA was constructed, and this infected the lowly invasive endometrial cancer cell lines, Ishikawa and HEC-1B. HMGB1 knockdown significantly enhanced the proliferation, invasion and metastasis of endometrial cancer cells and induced the process of epithelial-to-mesenchymal transition. These results can contribute to the development of a new potential therapeutic target for endometrial cancer.

Suicidal Ideation and Psychological Strain Among Patients Diagnosed With Stomach Cancer: The Mediation of Psychopathological Factors.

Patients with stomach cancer are at high risk to experience suicidal ideation. Strain theory of suicide assumes that suicide is preceded by psychological strain. Despite wide international acceptance of the theory, its use with a sample of patients with stomach cancer has not previously been reported. The aims were to examine the relationship between psychological strain and suicidal ideation among patients with stomach cancer and to determine whether psychopathological factors act as mediators. A cross-sectional study was undertaken involving subjects with no history of mental disorder, and questionnaires were administered by face-to-face interview. Patients who experienced more psychological strain, especially coping strain, are more likely to experience suicidal ideation. The mediation effects of hopelessness and psychological distress are significant. Psychological strain, hopelessness, and psychological distress may be the vital factors among patients with stomach cancer in the suicide-risk assessment interview and for care planning and psychological intervention.

Epidemiology and clinical characteristics of patients with glaucoma: An analysis of hospital data between 2003 and 2012.

PURPOSE: To assess demographic and clinical characteristics of glaucoma patients in an Ophthalmologic Hospital of Jinan, China from 2003 to 2012. MATERIALS AND METHODS: Medical charts of patients with primary open-angle glaucoma (POAG), primary angle closure glaucoma (PACG), and secondary glaucoma (SG) were reviewed. The main outcome measures of patients with glaucoma included basic demographic data (age at presentation, gender, and residence), clinical characteristics (admission date, intraocular pressure, and naked vision), and previous history (injury, cardiovascular disease, diabetes mellitus, hypertension, smoking, and alcohol consumption). RESULTS: Data from 1458 glaucoma patients were reviewed, of which PACG and SG patients accounted for 45.40% and 47.19%, respectively. The average age of all patients with glaucoma increased from 56.05 years in 2003 to 57.83 years in 2012, and the proportion of patients from rural areas rose from 46.43% to 59.13% during 10-year period. Female gender, cardiovascular disease, and hypertension were associated with PACG. POAG was related to smoking and alcohol consumption. There was positive correlation between SG and history of injury and diabetes mellitus. CONCLUSION: PACG and SG are the major types of glaucoma. Gender, injury, diabetes mellitus, cardiovascular disease, hypertension, smoking, and alcohol consumption were associated with different types of glaucoma.

Acetylpuerarin increases cell viability and reduces apoptosis in rat hippocampal neurons following oxygen­glucose deprivation/reperfusion.

The effects of acetylpuerarin treatment following oxygen-glucose deprivation/reperfusion (OGD/R) were examined in rat hippocampal neurons in vitro and compared with the effects of acetylpuerarin in normoxic cells to confirm acetylpuerarin's potential neuroprotective effects, including apoptosis inhibition. Wistar rat embryo hippocampal cells (day 18, E18) cultured for 8 days were subjected to 3 h OGD treatment, followed by reperfusion for 12, 24 or 36 h. For each time interval, a group of cells was left untreated (OGD/R-only groups) and treated with 0.1, 0.4 and 1.6 µM acetylpuerarin (OGD/R+acetylpuerarin). Neuron viability, apoptosis and caspase-8 and -3 activities were assessed by the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), 4',6-diamidino-2-phenylindole (DAPI) and terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling (TUNEL) and spectrophotometric assays, respectively. Fas-ligand (Fas-L), Fas-associated death domain (FADD) and tumor necrosis factor-α (TNF-α) were determined by western blot analysis. Compared with control cells, OCD/R+acetylpuerarin cells treated with 0.1, 0.4 and 1.6 µM doses showed a concentration-dependent increase in hippocampal cell survival and viability by 69.93 ± 2.28%, 81.49 ± 2.13% and 85.28 ± 2.38% at 12 h, 68.59 ± 3.02%, 77.85 ± 2.84% and 85.64 ± 4.39% at 24 h and 69.70 ± 1.70%, 77.21 ± 3.21% and 83.90 ± 2.12% at 36 h (P<0.05). Furthermore, OCD/R+acetylpuerarin cells exhibited a dose-dependent decrease in caspase-8 and -3 activation, TUNEL and DAPI-positive neurons and Fas-L, FADD and TNF-α expression. In conclusion, acetylpuerarin protects against OGD/R-induced neuronal apoptosis predominantly in the first 24 h following ischemia, which may be useful in mediating neuronal apoptosis in ischemic stroke patients.

Telomere dysfunction induced by chemotherapeutic agents and radiation in normal human cells.

The number of long-term survivors of patients with various malignancies (>5 years) is increasing mainly owing to advances in cancer therapeutics, but long-term side effects of the cancer treatment in this population have emerged as an important health and socio-economical issue. Telomeres and telomerase are known to be essential for regulation of cellular life-span and maintenance of genomic stability, and earlier studies have demonstrated that cancer patients who receive chemotherapy have shorter telomeres in their blood cells, indicating accelerated telomere erosion and a potential contribution of telomere loss to late side-effects. Little is currently known about the effect of chemotherapeutic agents and radiation on telomere dynamics including potential effects on telomere length, structure, function, telomerase activity, and telomere shelterin proteins in normal human cells. In the present study, we had addressed this issue experimentally. The treatment of normal human T lymphocytes and fibroblasts with chemotherapeutic agents doxorubicin (DOX) or etoposide (VP16) led to significant shortening of telomeres, down-regulation of telomerase activity, and diminished expression of telomerase reverse transcriptase (hTERT) and the telomere binding proteins TPP1 and POT1. More importantly, telomere dysfunction was observed in cells treated with DOX or VP16. Furthermore, all the above alterations were similarly found in the cells receiving γ-irradiation. Taken together, both chemotherapy and radiotherapy significantly impair telomere maintenance and function in normal human cells. Conceivably telomere dysfunction causes shortened life-span and genomic instability of normal human cells, and thereby contributes to tissue/organ damage and secondary malignancies in long-term survivors of cancer.

Activation of telomerase by seminal plasma in malignant and normal cervical epithelial cells.

Seminal fluids are involved in the development of cervical cancer but the underlying mechanism is unclear. Because cellular transformation requires telomerase activation by expression of the telomerase reverse transcriptase (hTERT) gene, we examined the role of seminal fluids in telomerase activation. Significantly elevated hTERT mRNA and telomerase activity were observed in cervical cell lines (HeLa, SiHa and Caski) treated with seminal plasma. Normal cervical epithelial cells expressed minimal levels of hTERT mRNA and telomerase activity, and seminal plasma substantially enhanced both expression and activity. The hTERT promoter activity was similarly increased in seminal plasma-treated HeLa cells and this effect was closely correlated with increased Sp1 expression and binding to the hTERT promoter. Cyclooxygenase-2 (COX-2) was simultaneously increased in HeLa cells exposed to seminal plasma, and blockade of COX-2 induction abolished seminal plasma stimulation of the hTERT promoter activity, hTERT expression and telomerase activity. Prostaglandin E2 (PGE2) mimics the effect of seminal plasma, stimulating Sp1 expression, enhancing Sp1 occupancy on the hTERT promoter and promoter activity. Moreover, tumour growth was robustly enhanced when HeLa cells together with seminal plasma were injected into nude-mice. Taken together, seminal plasma stimulates COX-2-PGE2-Sp1-dependent hTERT transcription, which provides insights into the putative mechanism underlying telomerase activation in cervical epithelial and cancer cells.

Premature senescence of T cells in long-term survivors of renal transplantation.

Prevention of graft rejection in renal transplant recipients depends on chronic treatment with immunosuppressive agents. However, impaired immune functions and immunosurveillance may cause infection, cancer and many other problems, which subsequently compromise quality of life and survival of patients. In the present study, we assessed potential premature immune-senescence in long-term survivors of kidney transplant patients receiving immunosuppressive agents. Peripheral blood lymphocytes derived from patients had significantly shorter telomeres than those from age- and sex-matched healthy individuals. Consistent with this, lower expression of telomerase reverse transcriptase (hTERT) and telomerase activity was observed in patients' lymphocytes. The level of p16(ink4A) expression was elevated in patients' cells. Moreover, the CD8(+)/CD28(-) fraction of late-stage differentiated T cells was significantly increased in the patients. In vitro studies further showed that cyclosporine A, a widely used immunosuppressive drug in transplant patients, attenuated induction of hTERT and telomerase activation in T cells treated with the mitogenic agent concanavalin A. Taken together, immunosuppressant-mediated premature senescence of T lymphocytes occurs in renal transplant recipients.

Activation of telomerase by human cytomegalovirus.

BACKGROUND: The mechanism by which human cytomegalovirus (HCMV) stimulates oncogenesis is unclear. Because cellular immortalization and transformation require telomerase activation by expression of the telomerase reverse transcriptase (hTERT) gene, we examined the role of HCMV in telomerase activation. METHODS: Normal human diploid fibroblasts (HDFs) and human malignant glioma (MG) cell lines were infected with HCMV or transfected with expression vectors encoding HCMV immediate early (IE) antigen 72 or 86. hTERT expression and promoter activity and telomerase activity were evaluated using reverse transcription-polymerase chain reaction, a luciferase reporter assay, and a telomeric repeat amplification protocol, respectively. hTERT promoter occupancy by the transcription factor Sp1, IE antigens, and histone deacetylases (HDACs) was assessed by chromatin immunoprecipitation. hTERT and IE protein expression in human primary glioblastoma multiforme (GBM) was determined immunohistochemically. All statistical tests were two-sided. RESULTS: In telomerase and hTERT-negative HDFs, HCMV infection induced constitutive hTERT expression and telomerase activation. The hTERT promoter activity in HDFs and MG cell lines was statistically significantly enhanced by HCMV in a dose-dependent manner (mean luciferase activity [arbitrary units] in control HDFs and in HDFs infected with HCMV at multiplicities of infection [MOIs] of 0.1 = 6 and 521, respectively, difference = 515, 95% CI = 178 to 850; mean activity at MOI of 1 and 10 = 8828 and 59,923, respectively; P < .001 comparing control with HCMV-infected cells at all MOIs). Ectopic expression of HCMV IE-72 protein also stimulated hTERT promoter activity in HDFs. HCMV-mediated transactivation of the hTERT gene was dependent on the presence of Sp1-binding sites in the hTERT promoter and was accompanied by increases in Sp1 binding, acetylation of histone H3, and a reduction in HDAC binding at the core promoter. In specimens of GBM, HCMV IE and hTERT proteins were colocalized in malignant cells and their levels paralleled each other. CONCLUSIONS: HCMV activates telomerase in both HDFs and malignant cells. These findings begin to reveal a novel mechanism by which HCMV infection may be linked to or modulate oncogenesis through telomerase activation.

The opposing effect of hypoxia-inducible factor-2alpha on expression of telomerase reverse transcriptase.

Hypoxia-inducible factor-1alpha (HIF-1alpha) has been implicated in the transcriptional regulation of the telomerase reverse transcriptase (hTERT) gene expression and telomerase activity, essential elements for cellular immortalization and transformation. However, controversial results were obtained in different studies. Moreover, it is totally unclear whether HIF-2alpha, the paralog of HIF-1alpha, plays a role in regulating hTERT expression. In the present study, we found that hypoxic treatment enhanced hTERT mRNA expression and telomerase activity in three renal cell carcinoma (RCC) cell lines with different genetic backgrounds. Both HIF-1alpha and HIF-2alpha were capable of significantly increasing the hTERT promoter activity in these cells. Moreover, depleting HIF-2alpha led to a down-regulation of hTERT mRNA level in RCC A498 cells expressing constitutive HIF-2alpha. It was found that HIF-2alpha bound to the hTERT proximal promoter and enhanced the recruitment of the histone acetyltransferase p300 and histone H3 acetylation locally in A498 cells treated with hypoxia. Increased levels of hTERT mRNA were observed in two of three hypoxia-treated malignant glioma cell lines. However, HIF-1alpha stimulated whereas HIF-2alpha inhibited the hTERT promoter activity in these glioma cell lines. Ectopic expression of HIF-2alpha resulted in diminished hTERT expression in glioma cells. Collectively, HIF-1alpha activates hTERT and telomerase expression in both RCC and glioma cells, and HIF-2alpha enhances hTERT expression in RCC cells, whereas it represses the hTERT transcription in glioma cells. These findings reveal a complex relationship between HIF-1alpha/2alpha and hTERT/telomerase expression in malignant cells, which may have both biological and clinical implications.

Differential expression of full-length telomerase reverse transcriptase mRNA and telomerase activity between normal and malignant renal tissues.

Activation of telomerase, a key event during immortalization and malignant transformation, requires expression of the telomerase reverse transcriptase (hTERT). Consistently, lack of telomerase activity and hTERT expression occurs in most normal human somatic cells. However, it has been observed that both normal and cancerous renal tissues express hTERT whereas only the latter exhibits telomerase activity. The mechanism underlying the dissociation between hTERT expression and telomerase activity is unclear. In the present study, we examined telomerase activity and alternative splicing of hTERT transcripts in renal cell carcinoma (RCC) specimens and adjacent normal tissues from 33 patients with RCC. Telomerase activity was detectable in 27 of 33 (82%) RCC samples but none in their normal counterparts. Thirty-two of 33 tumors expressed overall hTERT mRNA and 27 of them contained full-length hTERT transcripts, all with telomerase activity. Although 42% (14 of 33) of normal renal samples expressed hTERT mRNA, none of them had full-length hTERT transcripts, coinciding with lack of telomerase activity. The presence of full-length hTERT mRNA and telomerase activity was significantly associated with c-MYC induction. In tumors, absence of full-length hTERT mRNA or telomerase activity defines a subgroup of nonmetastatic, early-stage RCCs. Taken together, telomerase repression in normal renal tissues is attributed to the absence of full-length hTERT transcripts, whereas telomerase activation is achieved via induction of or switch to expression of full-length hTERT mRNA during the oncogenic process of kidneys, and associated with aggressive RCCs.