Regulation of transcription patterns, poly(ADP-ribose), and RNA-DNA hybrids by the ATM protein kinase.

The ataxia telangiectasia mutated (ATM) protein kinase is a master regulator of the DNA damage response and also an important sensor of oxidative stress. Analysis of gene expression in ataxia-telangiectasia (A-T) patient brain tissue shows that large-scale transcriptional changes occur in patient cerebellum that correlate with the expression level and guanine-cytosine (GC) content of transcribed genes. In human neuron-like cells in culture, we map locations of poly(ADP-ribose) and RNA-DNA hybrid accumulation genome-wide with ATM inhibition and find that these marks also coincide with high transcription levels, active transcription histone marks, and high GC content. Antioxidant treatment reverses the accumulation of R-loops in transcribed regions, consistent with the central role of reactive oxygen species in promoting these lesions. Based on these results, we postulate that transcription-associated lesions accumulate in ATM-deficient cells and that the single-strand breaks and PARylation at these sites ultimately generate changes in transcription that compromise cerebellum function and lead to neurodegeneration over time in A-T patients.

A nomogram for predicting residual low back pain after percutaneous kyphoplasty in osteoporotic vertebral compression fractures.

To establish a risk prediction model for residual low back pain after percutaneous kyphoplasty (PKP) for osteoporotic vertebral compression fractures. We used retrospective data for model construction and evaluated the model using internal validation and temporal external validation and finally concluded that the model had good predictive performance. INTRODUCTION: The cause of residual low back pain in patients with osteoporotic vertebral compression fractures (OVCFs) after PKP remains highly controversial, and our goal was to investigate the most likely cause and to develop a novel nomogram for the prediction of residual low back pain and to evaluate the predictive performance of the model. METHODS: The clinical data of 281 patients with OVCFs who underwent PKP at our hospital from July 2019 to July 2020 were reviewed. The optimal logistic regression model was determined by lasso regression for multivariate analysis, thus constructing a nomogram. Bootstrap was used to perfomance the internal validation; receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) were used to assess the predictive performance and clinical utility of the model, respectively. Temporal external validation of the model was also performed using retrospective data from 126 patients who underwent PKP at our hospital from January 2021 to October 2021. RESULTS: Lasso regression cross-validation showed that the variables with non-zero coefficients were the number of surgical vertebrae, preoperative bone mineral density (pre-BMD), smoking history, thoracolumbar fascia injury (TLFI), intraoperative facet joint injury (FJI), and postoperative incomplete cementing of the fracture line (ICFL). The above factors were included in the multivariate analysis and showed that the pre-BMD, smoking history, TLFI, FJI, and ICFL were independent risk factors for residual low back pain (P < 0.05). The ROC and calibration curve of the original model and temporal external validation indicated a good predictive power of the model. The DCA curve suggested that the model has good clinical practicability. CONCLUSION: The risk prediction model has good predictive performance and clinical practicability, which can provide a certain basis for clinical decision-making in patients with OVCFs.

Efficacy of omega-3 polyunsaturated fatty acids on hormones, oxidative stress, and inflammatory parameters among polycystic ovary syndrome: a systematic review and meta-analysis.

BACKGROUND: There is a close relationship between hormones, oxidative stress, and inflammatory factors and polycystic ovary syndrome (PCOS). This meta-analysis was conducted to evaluate the changes in hormones, oxidative stress, and inflammatory factors of PCOS patients who were supplemented with omega-3 polyunsaturated fatty acids (n-3 PUFAs). METHODS: The databases of PubMed, Cochrane Library, Embase, and Web of Science were searched from inception to February 2021. We have included all randomized controlled trials (RCTs) that reported the n-3 PUFA treatment in PCOS. Weighted mean differences (WMD) and 95% confidence interval (CI) were calculated, and either the fixed effects model or random effects model was used. RESULTS: 314 studies were initially identified, and 10 RCTs with 610 patients were finally included in the current study. Results suggested that PCOS patients with n-3 PUFAs supplementation may have a reduction in C-reactive protein (CRP; -8.97 mg/dL; 95% CI: -17.66 to -0.28 mg/dL; P=0.04; I2=99%); serum malondialdehyde (MDA; -0.40 mg/dL; 95% CI: -0.56 to -0.25 mg/dL; P<0.00001; I2=42); luteinizing hormone (LH; -1.33 mg/dL; 95% CI: -2.63 to -0.04 mg/dL; P=0.04; I2=0%); serum total testosterone (TT; -0.11 mg/dL; 95% CI: -0.18 to -0.04 mg/dL; P=0.02; I2=73%); and an increase in total antioxidant capacity (TAC; 72.24 mg/dL; 95% CI: 22.32 to 122.16 mg/dL; P=0.005; I2=50%) and serum sex hormone binding globulin (SHBG; 0.68 mg/dL; 95% CI: 0.06 to 1.31 mg/dL; P=0.03; I2=0%).However, no effect on glutathione (GSH; -12.63 mg/dL; 95% CI: -50.34 to 25.07 mg/dL; P=0.51; I2=56%), dehydroepiandrosterone sulfate (DHEAS; -0.01 mg/dL; 95% CI: -1.53 to 1.50 mg/dL; P=0.99; I2=78%), free androgen index (FAI; 0.00 mg/dL; 95% CI: -0.03 to 0.03 mg/dL; P=0.99; I2=0%), or follicle-stimulating hormone (FSH; 0.37 mg/dL; 95% CI: -0.55 to 1.29 mg/dL; P=0.43; I2=61) was found. CONCLUSIONS: This meta-analysis showed that supplementation of n-3 PUFAs in PCOS women can significantly improve CRP, MDA, LH, TT, TAC, and SHBG, but did not affect the concentrations of GSH, DHEAS, FAI, or FSH.

Prognostic impact of eosinophils in peripheral blood and tumor site in patients with esophageal squamous cell carcinoma treated with concurrent chemoradiotherapy.

ABSTRACT: To date, no effective biological markers have been identified for predicting the prognosis of esophageal cancer patients. Recent studies have shown that eosinophils are independent prognostic factors in some cancers. This study aimed to identify the prognostic impact of eosinophils in esophageal squamous cell carcinoma patients treated with concurrent chemoradiotherapy (CCRT).This study enrolled 136 patients who received CCRT for locally advanced unresectable esophageal squamous cell carcinoma (ESCC). We evaluated the survival time and clinical pathological characteristics of eosinophils. The Kaplan-Meier method was used to estimate survival data. The log-rank test was used for univariate analysis and the Cox proportional hazards regression model was used to conduct a multivariate analysis.Kaplan-Meier analysis revealed that high eosinophil infiltration correlated with better overall survival (OS) (P = .008) and better progression-free survival (PFS) (P = .015). The increase in absolute eosinophil count after CCRT also enhanced OS (P = .005) and PFS (P = .007). The PFS and OS in patients with high blood eosinophil count before CCRT (>2%) was better than those with low blood eosinophil count(<2%) (P = .006 and P = .001, respectively). Additionally, the multivariate analysis revealed that disease stage and high eosinophil infiltration, increased peripheral blood absolute eosinophil count after CCRT, and high peripheral blood eosinophil count before CCRT were independent prognostic indicators.High eosinophil count of tumor site, increased peripheral blood absolute eosinophil count after CCRT, and high peripheral blood eosinophil count before CCRT are favorable prognostic factors for patients with ESCC treated with CCRT.

Growth-Regulated Hsp70 Phosphorylation Regulates Stress Responses and Prion Maintenance.

Maintenance of protein homeostasis in eukaryotes under normal growth and stress conditions requires the functions of Hsp70 chaperones and associated cochaperones. Here, we investigate an evolutionarily conserved serine phosphorylation that occurs at the site of communication between the nucleotide-binding and substrate-binding domains of Hsp70. Ser151 phosphorylation in yeast Hsp70 (Ssa1) is promoted by cyclin-dependent kinase (Cdk1) during normal growth. Phosphomimetic substitutions at this site (S151D) dramatically downregulate heat shock responses, a result conserved with HSC70 S153 in human cells. Phosphomimetic forms of Ssa1 also fail to relocalize in response to starvation conditions, do not associate in vivo with Hsp40 cochaperones Ydj1 and Sis1, and do not catalyze refolding of denatured proteins in vitro in cooperation with Ydj1 and Hsp104. Despite these negative effects on HSC70/HSP70 function, the S151D phosphomimetic allele promotes survival of heavy metal exposure and suppresses the Sup35-dependent [PSI+ ] prion phenotype, consistent with proposed roles for Ssa1 and Hsp104 in generating self-nucleating seeds of misfolded proteins. Taken together, these results suggest that Cdk1 can downregulate Hsp70 function through phosphorylation of this site, with potential costs to overall chaperone efficiency but also advantages with respect to reduction of metal-induced and prion-dependent protein aggregate production.

APE1 overexpression promotes the progression of ovarian cancer and serves as a potential therapeutic target.

BACKGROUND: Apurinic/apyrimidinic endonuclease 1 (APE1) is a multifunctional enzyme that is involved in DNA repair and the redox regulation of transcription factors. Blocking these functions leads to cell-growth inhibition, apoptosis and other effects. Previous studies have demonstrated that high expression levels of the APE1 protein are associated with the progression and chemoresistance of cancers. We hypothesized that APE1 silencing in ovarian cancer cells might have anticancer effects mediated by cell-growth inhibition and an increase in drug-sensitivity. OBJECTIVE: In this study, we explored the consequences of APE1 silencing in ovarian cancer cells. METHODS: Immunohistochemistry (IHC) was used to detect the APE1 protein levels in tissue samples from twelve ovarian cancer (OC) patients and eleven non-OC patients. APE1 knockdown was achieved via the stable transfection of SKOV3 and A2780 cells with a construct encoding a short hairpin DNA directed against the APE1 gene. Then, cell proliferation, colony formation, cell cycle and apoptosis assays were performed to reveal the consequences of APE1 silencing in ovarian cancer cells. Additionally, the SKOV3 and A2780 cells were subjected to the treatment with camptothecin (CPT) and ultraviolet rays (UV) to assess the possible link between the APE1 protein and drug-resistance. RESULTS: Our results revealed that the APE1 protein was overexpressed in OC tissues. APE1 knockdown in A2780 and SKOV3 cells reduced cell proliferation, arrested cell cycle progression, repressed colony formation and weakly promoted cell apoptosis through the BAX and BCL-2 apoptotic pathways. Additionally, the down-regulation of APE1 significantly enhanced the sensitivity of ovarian cancer cells to the CPT/UV treatment. CONCLUSION: Our study suggested that the APE1 protein is important for the proliferation and growth of ovarian cancer cells. APE1 silencing might enhance drug-sensitivity, and thus APE1 might serve as a novel anti-OC therapeutic target.

MUS81 is associated with cell proliferation and cisplatin sensitivity in serous ovarian cancer.

The dysfunction of DNA damage repair (DDR) pathway contributes to tumorigenesis and drug-resistance in cancer. MUS81 is a member of the conserved xeroderma pigmentosum group F (XPF) family protein of endonucleases, which is important to the DDR pathway. However, the role of MUS81 in the development of ovarian cancer remains uncertain. To explore the expression of MUS81 and its association to serous ovarian cancer (SOC), 43 biopsies of SOC patients were detected by qRT-PCR, and 29 specimens were further performed by immunohistochemistry analysis. Here, we observed that MUS81 was over-expressed in SOC tissues at both transcript and protein levels, and the expression level of MUS81 protein in ovarian cancer cell lines was also higher than that in human normal ovarian surface epithelial cell line (HOSEpiC). We also found that down-regulation of MUS81 expression in ovarian cancer cells inhibited cell proliferation and colony formation ability, and influenced cell cycle progression. Moreover, inhibition of MUS81 expression induced cellular senescence and enhanced the antitumor effect of cisplatin. Down-regulation of MUS81 expression could suppress the growth and development of SOC. These results indicate that MUS81 might play important roles in the progression of SOC and influence the antitumor effect of cisplatin.

Flexible Transparent Films Based on Nanocomposite Networks of Polyaniline and Carbon Nanotubes for High-Performance Gas Sensing.

A flexible, transparent, chemical gas sensor is assembled from a transparent conducting film of carbon nanotube (CNT) networks that are coated with hierarchically nanostructured polyaniline (PANI) nanorods. The nanocomposite film is synthesized by in-situ, chemical oxidative polymerization of aniline in a functional multiwalled CNT (FMWCNT) suspension and is simultaneously deposited onto a flexible polyethylene terephthalate (PET) substrate. An as-prepared flexible transparent chemical gas sensor exhibits excellent transparency of 85.0% at 550 nm using the PANI/FMWCNT nanocomposite film prepared over a reaction time of 8 h. The sensor also shows good flexibility, without any obvious decrease in performance after 500 bending/extending cycles, demonstrating high-performance, portable gas sensing at room temperature. This superior performance could be attributed to the improved electron transport and collection due to the CNTs, resulting in reliable and efficient sensing, as well as the high surface-to-volume ratio of the hierarchically nanostructured composites. The excellent transparency, improved sensing performance, and superior flexibility of the device, may enable the integration of this simple, low-cost, gas sensor into handheld flexible transparent electronic circuitry and optoelectronic devices.

Elevated homocysteine level and folate deficiency associated with increased overall risk of carcinogenesis: meta-analysis of 83 case-control studies involving 35,758 individuals.

BACKGROUND: Results of the association of folate metabolism and carcinogenesis are conflicting. We performed a meta-analysis to examine the effect of the interaction of serum concentration of homocysteine (Hcy), folate, and vitamin B12 and 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphism on risk of cancer overall. METHOD: Two reviewers independently searched for all published studies of Hcy and cancer in PubMed, EMBASE-MEDLINE and Chinese databases. Pooled results were reported as odds ratios (ORs) and mean differences and presented with 95% confidence intervals (95% CIs) and 2-sided probability values. RESULTS: We identified 83 eligible studies of 15,046 cases and 20,712 controls. High level of Hcy but low level of folate was associated with risk of cancer overall, with little effect by type of cancer or ethnicity. Vitamin B12 level was inversely associated with only urinary-system and gastrointestinal carcinomas and for Asian and Middle Eastern patients. As well, MTHFR C677T, A1298C and G1793A polymorphisms were related to elevated serum level of Hcy, and folate and vitamin B12 deficiency. However, only MTHFR C677T homogeneity/wild-type (TT/CC) polymorphism was positively associated with overall risk of cancer. CONCLUSION: Elevated serum Hcy level and folate deficiency are associated with increased overall risk of cancer.

SIRT7 Exhibits Oncogenic Potential in Human Ovarian Cancer Cells.

BACKGROUND: Sirtuin7 (SIRT7) is a type of nicotinamide adenine dinucleotide oxidized form (NAD+)-dependent deacetylase and the least understood member of the sirtuins family; it is implicated in various processes, such as aging, DNA damage repair and cell signaling transduction. There is some evidence that SIRT7 may function as a tumor trigger for human malignancy. Here, we aimed to explore the biological function of SIRT7 in ovarian carcinoma cells and its potential mechanism. MATERIALS AND METHODS: Expression of SIRT7 in ovarian cancer cell lines was detected by western blotting. Transduced cell lines with SIRT7 knockdown or overexpression were constructed. Cell viability, cologenic, apoptosis-associated and motility assays were performed to elucidate the biological function of SIRT7 in ovarian cancer cells. RESULTS: SIRT7 demonstrated a higher level in ovarian cancer cell lines compared with normal cells. On the one hand, down-regulation of SIRT7 significantly reduced ovarian cancer cell growth, repressed colony formation and increased cancer cell apoptosis; on the other hand, up-regulation promoted the migration of cancer cells. Additionally, repression of SIRT7 also induced change in apoptosis-related molecules and subunits of the NF-κB family. CONCLUSIONS: In the present study, our data indicated that SIRT7 might play a role of oncogene in ovarian malignancy and be a potential therapeutic target.

Human leukocyte antigen-E alleles and expression in patients with serous ovarian cancer.

Human leukocyte antigen-E (HLA-E) is one of the most extensively studied non-classical MHC class I molecules that is almost non-polymorphic. Only two alleles (HLA-E*0101 and HLA-E*0103) are found in worldwide populations, and suggested to be functional differences between these variants. The HLA-E molecule can contribute to the escape of cancer cells from host immune surveillance. However, it is still unknown whether HLA-E gene polymorphisms might play a role in cancer immune escape. To explore the association between HLA-E alleles and the susceptibility to serous ovarian cancer (SOC), 85 primary SOC patients and 100 healthy women were enrolled. Here, we indicated that high frequency of HLA-E*0103 allele existed in SOC patients by the allele-specific quantitative real-time PCR method. The levels of HLA-E protein expression in SOC patients with the HLA-E*0103 allele were higher than those with the HLA-E*0101 allele using immunohistochemistry analysis. The cell surface expression and functional differences between the two alleles were verified by K562 cells transfected with HLA-E*0101 or HLA-E*0103 allelic heavy chains. The HLA-E*0103 allele made the transfer of the HLA-E molecule to the cell surface easier, and HLA-E/peptides complex more stable. These differences ultimately influenced the function of natural killer cells, showing that the cells transfected with HLA-E*0103 allele inhibited natural killer cells to lysis. This study reveals a novel mechanism regarding the susceptibility to SOC, which is correlated with the HLA-E*0103 allele.