[Global research hotspots on oncology-bibliometric analysis based on the ESI hot papers].

With the increasing global burden of various cancer, an abundance of papers emerged every year in the research hotspots of oncology, covering a wide range of research types and topics. In order to facilitate interested readers to quickly grasp the frontier and hotspots of cancer research, it would be helpful to sort out and summarize the research topic in a timely manner. According to the classification of disciplines, we screened the Essential Science Indicators (ESI) hot papers released in 2019 for the ones in the oncology field, utilized methods such as bibliometrics, statistical description, hierarchical induction, analysis and interpretation to further reveal the context and characteristics of research in the field of oncology, summarized the latest progresses and future directions in the field, and provided information and hints for the trajectory of future research. A total of 549 papers were included, which were mainly from the field of clinical medicine; the country with the most publications was the United States, while China ranked the fourth in terms of contribution; the research institution with the highest number of published papers was University of Texas system; N Engl J Med published the most papers, with contribution also from highly influential journals in the field of oncology such as Lancet Oncol, J Clin Oncol, JAMA Oncol and Cancer Discov. Oncology remained the most popular research topic in the medical research and spanned a wide spectrum of sub-topics. In this study, we demonstrated and sorted out research frontiers in the field of oncology in 12 different research directions including the basic cancer research, cancer epidemiology, and various tumors types related to different systems and organs.

[An analysis of global research on SARS-CoV-2].

The SARS-CoV-2 has been spread to 26 countries around the world since its outbreak. By February 16, 2020, more than 68 000 people had been diagnosed with COVID-19. Researchers from all over the world have carried out timely studies on this public health emergency and produced a number of scientific publications. This review aims to re-analyze and summarize the current research findings in a timely manner to guide scholars in relevant fields to further SARS-CoV-2 research and assist healthcare professionals in their work and decision-making. The SARS-CoV-2 related terms were selected in both English and Chinese and were searched in several major databases, including Pubmed, Web of Science, CNKI, Wanfang, and VIP databases. The reference list of each search result was screened for relevance, which was further supplemented to the search results. The included studies were categorized by topics with key characteristics extracted, re-analyzed, and summarized. A total of 301 articles were finally included with 136 in Chinese and 165 in English. The number of publications has rapidly increased since mid-January, 2020, and a peak day was 6th February on which 50 articles were published. The top three countries publishing articles were China, the United States and the United Kingdom. The Lancet and its specialty journals have published the most articles, with contribution also from journals such as New England Journal of Medicine ( NEJM), The Journal of the American Medical Association ( JAMA), and Nature. All articles were categorized into epidemiology, clinical diagnosis and treatment, basic research, pregnant women and children, mental health, epidemic prevention & control, and others. The literatures related to SARS-CoV-2 are emerging rapidly. It is necessary to sort out and summarize the research topic in time, which has a good reference value for staff in different positions. At the same time, it is necessary to strengthen the judgment of the quality of literatures.

Is aspirin use associated with a decreased risk of ovarian cancer? A systematic review and meta-analysis of observational studies with dose-response analysis.

OBJECTIVE: Currently available epidemiologic evidences concerning the chemopreventive effect of aspirin on ovarian cancer are inconsistent. Therefore, we aimed to further explore the association by synthesizing evidence from population-based studies. METHODS: We searched PubMed, EMBASE, Web of Science, and Scopus using key words and controlled vocabularies. Title/abstract screening, full-text review, data extraction, and quality assessment were performed independently by reviewers, and a random-effects model was utilized for meta-analysis. Subgroup analysis was conducted based on study locale, and sensitivity analysis was performed by synthesizing studies that adjusted for certain covariates or studies with good quality. Dose-response relation was assessed by a two-stage linear dose-response model. Statistical heterogeneity was evaluated by the I-squared value and a chi-squared test for the Cochrane Q statistic. RESULTS: We identified 8 cohort studies and 15 case-control studies. In overall meta-analysis of risk ratios (RRs) of binary exposure, the synthesized RR was 0.89 (95% CI, 0.83-0.96), and no substantial statistical heterogeneity was observed (I(2)=22.5%, PCochrane=0.168). After stratification by study design, the synthesized RR was 0.85 (95% CI, 0.77-0.94) and 0.95 (95% CI, 0.85-1.05) for case-control and cohort studies, respectively. In sensitivity analysis, the synthesized estimate of long-term use was not statistically significant, whereas the effect measure (RRmeta=0.60, 95% CI, 0.39-0.93) was significant by synthesizing RRs of the highest frequency of use from 2 cohort studies. The dose-response analysis showed an inverse significant association between aspirin use and the risk (RRper 1time/wk=0.94, 95% CI, 0.89-1.00; n=2). Egger's tests showed that publication bias existed for overall meta-analysis, meta-analysis for case-control studies, and studies conducted in the United States. CONCLUSION: In summary, our study suggests that aspirin can reduce the risk of ovarian cancer. In addition, we observed a possible dose-response relation between frequency of use and ovarian cancer risk, but further studies are needed to examine this association.

Can Aspirin Reduce the Risk of Endometrial Cancer?: A Systematic Review and Meta-analysis of Observational Studies.

Current evidences suggest that nonsteroidal anti-inflammatory drugs can reduce the risk of several types of cancer, including breast, prostate, and colorectal cancer. However, evidences regarding the chemopreventive effect of aspirin to endometrial cancer are inconsistent. Therefore, we aimed to further explore the association. We searched PubMed, EMBASE, Web of Science, and Scopus to identify potentially eligible studies. After title/abstract screening and full-text review, we identified 7 cohort studies and 6 case-control studies. Data extraction and quality assessment were performed independently, and a random-effects model was used for data synthesis. Subgroup analysis was conducted based on obesity, hormone replacement therapy use, and cancer subtype; sensitivity analysis was conducted by pooling risk ratios of the highest dosage or longest duration of use. Dose-response relationship was assessed by a 2-stage linear dose-response model. Statistical heterogeneity was assessed by the I value and a χ test for the Cochrane Q statistic. In overall meta-analysis, the pooled risk ratio was 0.93 (95% confidence interval, 0.88-0.99), and no substantial statistical heterogeneity was observed (I = 0.0%, P = 0.550). In subgroup analysis, a negative association was observed for obese women and type I endometrial cancer. Higher dosage or frequency of aspirin use was significantly associated with a reduced risk, and long-term aspirin use was protective only for obese women. In conclusion, our study suggests that the use of aspirin can reduce the risk of endometrial cancer, particularly for obese women. However, the generalizability of our conclusion should be further studied for premenopausal women and type II endometrial cancer.

[Analysis of CHIP-Related Mutation and Risk of Cardio-Cerebrovasculars Events in Patients with Myeloproliferative Neoplasms].

OBJECTIVE: To analyze the mutant spectrum of clonal hematopoiesis of indeterminate potential (CHIP) related mutations and clinical characteristics and to explore the correlation and the possible mechanism between CHIP-related mutations and cardio-cerebrovasculars events (CCEs) in patients with myeloproliferative neoplasms (MPNs). METHODS: The clinical data and next-generation sequencing results of 73 MPN patients in Beijing Anzhen Hospital from August 2019 to July 2022 were retrospectively analyzed. Statistical analyses were conducted by multivariate logistic regression for the effects of CHIP-related mutations and inflammatory cytokines on CCEs for MPNs patients. RESULTS: Fifty-five cases of MPN (75.3%) showed positive in CHIP-related genes. There was no significant difference in variant allele frequency of CHIP-related gene between essential thrombocythemia (ET) and polycythemia vera (PV). CHIP-related gene mutations were mainly single gene mutations, with mutation rate from high to low as JAK2V617F (63.0%, 46/73), ASXL1 (16.4%, 12/73), TET2 (11.0%, 8/73), DNMT3A (9.6%, 7/73), SRSF2 (6.9%, 5/73), SF3B1 (4.1%, 3/73), TP53(1.4%, 1/73) and PPM1D (1.4%, 1/73). The mutation rate of CHIP-related genes in MPN patients >60 years old was significantly higher than that in the patients ≤60 years old ï¼»91.7%(33/36) vs 59.5%(22/37)ï¼½. CCEs occurred in 27 MPNs patients (37.0%, MPNs/CCEs), and 5 had recurrent CCEs, all of which were arterial events. Age (62.8±12.8 years vs 53.9±15.8 years, P =0.015), IL-1ß level (17.7±26.0 vs 4.3±8.6, P =0.012), IL-8 level (360.7±598.6 vs 108.3±317.0, P =0.045), the proportion of the patients with thrombosis history (29.6% vs 2.2%, P =0.020), and the detection rate of CHIP-related mutations (88.9% vs 67.4%, P =0.040) in the group with CCEs were higher than those in the group without CCEs. Multivariate Logistic regression analysis showed that age（OR =0.917， 95%CI ：0.843-0.999, P =0.047）, thrombosis history (OR =34.148， 95%CI ：2.392-487.535, P =0.009), any CHIP-related mutations(OR =16.065， 95%CI ：1.217-212.024， P =0.035), and elevated level of IL-1ß (OR =0.929， 95%CI ：0.870-0.992， P =0.027) were independent risk factors for MPNs/CCEs. CHIP-related gene mutations were not associated with CCEs in MPN patients, but DNMT3A (OR =88.717， 95%CI ：2.690-292.482， P =0.012) and ASXL1 (OR =7.941， 95%CI ：1.045-60.353， P =0.045) were independent risk factors for CCEs in PV. CONCLUSION: There is a higher mutation rate of CHIP-related genes in MPN patients, especially those over 60 years old. Older age, thrombosis history, CHIP-related mutations and IL-1ß elevated levels are independent risk factors for CCEs in MPN. DNMT3A and ASXL1 mutations are independent risk factors for CCEs in PV patients. CHIP-related gene mutations and inflammatory cytokine IL-1 ß elevated levels may be the novel risk factors for CCEs in MPN.

C-reactive protein to albumin ratio predict responses to programmed cell death-1 inhibitors in hepatocellular carcinoma patients.

BACKGROUND: Over the years, programmed cell death-1 (PD-1) inhibitors have been routinely used for hepatocellular carcinoma (HCC) treatment and yielded improved survival outcomes. Nonetheless, significant heterogeneity surrounds the outcomes of most studies. Therefore, it is critical to search for biomarkers that predict the efficacy of PD-1 inhibitors in patients with HCC. AIM: To investigate the role of the C-reactive protein to albumin ratio (CAR) in evaluating the efficacy of PD-1 inhibitors for HCC. METHODS: The clinical data of 160 patients with HCC treated with PD-1 inhibitors from January 2018 to November 2022 at the First Affiliated Hospital of Guangxi Medical University were retrospectively analyzed. RESULTS: The optimal cut-off value for CAR based on progression-free survival (PFS) was determined to be 1.20 using x-tile software. Cox proportional risk model was used to determine the factors affecting prognosis. Eastern Cooperative Oncology Group performance status [hazard ratio (HR) = 1.754, 95% confidence interval (95%CI) = 1.045-2.944, P = 0.033], CAR (HR = 2.118, 95%CI = 1.057-4.243, P = 0.034) and tumor number (HR = 2.932, 95%CI = 1.246-6.897, P = 0.014) were independent prognostic factors for overall survival. CAR (HR = 2.730, 95%CI = 1.502-4.961, P = 0.001), tumor number (HR = 1.584, 95%CI = 1.003-2.500, P = 0.048) and neutrophil to lymphocyte ratio (HR = 1.120, 95%CI = 1.022-1.228, P = 0.015) were independent prognostic factors for PFS. Two nomograms were constructed based on independent prognostic factors. The C-index index and calibration plots confirmed that the nomogram is a reliable risk prediction tool. The ROC curve and decision curve analysis confirmed that the nomogram has a good predictive effect as well as a net clinical benefit. CONCLUSION: Overall, we reveal that the CAR is a potential predictor of short- and long-term prognosis in patients with HCC treated with PD-1 inhibitors. If further verified, CAR-based nomogram may increase the number of markers that predict individualized prognosis.

Investigation of miR-21-5p Key Target Genes and Pathways in Head and Neck Squamous Cell Carcinoma Based on TCGA Database and Bioinformatics Analysis.

Aim: Head and neck squamous cell carcinoma (HNSCC) is the sixth most commonly diagnosed malignancy worldwide. Overexpressed of microRNA-21-5p (miR-21-5p) has been reported to be involved in the development of HNSCC. However, the role of miR-21-5p in HNSCC is still not fully elucidated. The purpose of this study was to explore the underlying molecular mechanisms of miR-21-5p in HNSCC. Methods: RT-qPCR was used to determine the differential expression levels of miR-21-5p in tissue samples of HNSCC patients. Meta-analysis was performed based on miRNA expression data collected from the Gene Expression Omnibus (GEO) database, The Cancer Genome Atlas (TCGA), and published articles to evaluate the expression of miR-21-5p in HNSCC. We investigated the biological function of miR-21-5P by gene ontology enrichment and target prediction analysis. Furthermore, RT-qPCR and IHC were conducted to verify the expression of target genes. Finally, Kaplan-Meier survival analysis was performed to assessed the prognostic value of the putative miR-21-5p target genes. Results: MiR-21-5p was significantly overexpressed in HNSCC compared to healthy tissues (P < .05) and showed potent predictive power with a summary receiver operating characteristic of 0.90. Meanwhile, the expression of miR-21-5p was significantly correlated with tumor stage, T stage and smoking in HNSCC (P < .05). A total of 71 down-regulated genes, both HNSCC-related and miR-21-p5-related, were obtained from the analytical integration. Two predicted genes (ADH7, RDH12) were down-regulated in HNSCC, and significantly negatively correlated with miR-21-5p. IHC and RT-qPCR demonstrated that the expression of ADH7 and RDH12 in HNSCC samples was significantly lower than control. And high expression of ADH7 was associated with better DFS of HNSCC patients. Conclusions: miR-21-5p may target at ADH7, RDH12 and participate in regulation of retinol metabolism, which might affect the prognosis of HNSCC. High expression of ADH7 may indicate better prognosis in HNSCC patients.

Da Vinci robot-assisted pancreato-duodenectomy in a patient with situs inversus totalis: A case report and review of literature.

BACKGROUND: Situs inversus totalis (SIT) is an extremely rare congenital malformation characterized by mirror displacement of the thoracoabdominal organs such as the heart, liver, spleen, and stomach. Herein, we describe a patient with SIT complicated with cholangiocarcinoma who underwent successful pancreaticoduodenectomy with the assistance of a da Vinci robot. CASE SUMMARY: A 58-year-old female presented to the hospital with paroxysmal pain in her left upper abdomen, accompanied by jaundice and staining of the sclera as chief complaints. Imaging examination detected a mass at the distal end of the common bile duct, with inverted thoracic and abdominal organs. Endoscopic retrograde cholangiopancreatography forceps biopsy revealed the presence of a well-differentiated adenocarcinoma. The patient successfully underwent robotic-assisted pancreaticoduodenectomy; the operation lasted 300 min, the intraoperative blood loss was 500 mL, and there were no intraoperative and postoperative complications. CONCLUSION: SIT is not directly related to the formation of cholangiocarcinoma. Detailed preoperative imaging examination is conducive to disease diagnosis and also convenient for determining the feasibility of tumor resection. Robot-assisted pancreaticoduodenectomy for SIT complicated with cholangiocarcinoma provides a safe, feasible, minimally invasive, and complication-free alternative with adequate preoperative planning combined with meticulous intraoperative procedures.

Hypertension is a risk factor for adverse outcomes in patients with coronavirus disease 2019: a cohort study.

BACKGROUND: Comorbidities are commonly seen in patients with coronavirus disease 2019 (COVID-19), but the clinical implication is not yet well-delineated. We aim to characterize the prevalence and clinical implications of comorbidities in patients with COVID-19. METHODS: This is a retrospective multi-centre study involving patients admitted between January 16th and March 10th 2020. The composite endpoint was defined as the presence of at least one of the following, intensive care unit (ICU) admission, or the need for mechanical ventilation, or death. RESULTS: A total of 472 consecutive cases admitted to 51 certified COVID-19 tertiary care hospitals were enrolled (median age was 43 [32-53.5] years and 53.0% were male). There were 101 (21.4%) patients presented with comorbidities, including hypertension (15.0%), diabetes mellitus (7.8%), coronary artery disease (2.6%), chronic obstructive pulmonary disease (1.3%) and cerebrovascular disease (1.9%). The composite endpoint occurred in 65 (13.8%) patients. Multivariate stepwise logistic regression analysis indicated that older age (odds ratio [OR] 1.39, 95% confidence interval (CI) 1.05-1.85, per 10-year increment), antecedent hypertension (OR 2.82, 95% CI 1.09-7.29), neutrophil counts (OR 1.33, 95% CI 1.14-1.56) and lactate dehydrogenase level (OR 1.01, 95% CI 1.00-1.01) were independently associated with the presence of composite endpoint. Hypertensive patients, compared with controls, had a greater chance of experiencing the composite endpoint (p < .001) and each individual endpoint, i.e. ICU admission (p < .001), mechanical ventilation (p < .001) and death (p = .012). In the stepwise regression analysis of anti-hypertensive medications, none of the therapy predicted the composite endpoint. CONCLUSIONS: Hypertension is a common comorbidity in patients with COVID-19 and associated with adverse outcomes. KEY MESSAGES Hypertension was identified as the comorbidity associated with the prognosis of COVID-19 in this retrospective cohort. Patients with hypertension could experience an increased risk of the composite endpoint. Anti-hypertensive therapy did not affect patient outcomes.

Striking dual functionality of a novel Pd@Eu-MOF nanocatalyst in C(sp2)-C(sp2) bond-forming and CO2 fixation reactions.

Pd nanoparticles were immobilized on a highly porous, hydrothermally stable Eu-MOF via solution impregnation and H2 reduction to yield a novel Pd@Eu-MOF nanocatalyst. This composite was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), inductively coupled plasma optical emission spectroscopy (ICP-OES), powder X-ray diffraction (PXRD) and X-ray photoelectron spectroscopy (XPS). Unprecedentedly, the Pd@Eu-MOF nanocatalyst could be applied with excellent results in two strikingly different, mechanistically distinct, reactions i.e., Suzuki-Miyaura cross-coupling and cycloaddition of CO2 to a range of epoxides. Under the best reaction conditions, 98-99% yields have been attained in both catalytic processes. Moreover, in either case the heterogeneous catalyst was easily recovered and efficiently reused for more than four cycles, indicating its high stability and reproducibility. PXRD, TEM and XPS measurements on the recycled catalyst confirmed that it maintained its original structure and morphology; no Pd NP agglomeration was observed.

Tailoring the structure, pH sensitivity and catalytic performance in Suzuki-Miyaura cross-couplings of Ln/Pd MOFs based on the 1,1'-di(p-carboxybenzyl)-2,2'-diimidazole linker.

An array of heterobimetallic Pd/Ln MOFs (1-4) with Sm, Eu, Tb, Dy as preferred metal nodes and 1,1'-di(p-carboxybenzyl)-2,2'-diimidazole (H2L) as a fairly suitable bifunctional organic linker have been synthesized, fully characterized and tested as catalysts in cross-coupling reactions. These robust MOFs, ensuring a uniform distribution of Pd, showed excellent stability in air and high catalytic activity in Suzuki-Miyaura reactions conducted in neat water, neat ethanol as well as water-ethanol mixture. Depending on the solvent, complex 1 could be effectively recycled 4-8 times without significant loss of catalytic activity. Importantly, this complex was found to be pH responsive in a reversible way, enabling convenient recovery from acidic aqueous solutions, indicating good recyclability as well as environment-friendly separation of the metal residues after the reaction.

Induction of apoptosis and autophagic cell death by the vanillin derivative 6-bromine-5-hydroxy-4-methoxybenzaldehyde is accompanied by the cleavage of DNA-PKcs and rapid destruction of c-Myc oncoprotein in HepG2 cells.

Autophagy is a regulated lysosomal pathway involving the bulk degradation of cytoplasmic contents, and is an emerging attractive therapeutic approach for treating cancers. In the present study, we demonstrates that bromovanin (6-bromine-5-hydroxy-4-methoxybenzaldehyde), a vanillin derivative, exhibits a potent antiproliferative effect on a broad spectrum of cancer cell lines, but it induces apoptosis with a large variation in extent on different cancer cell lines. Ultrastructural observation in transmission electron microscopy reveals that autophagy is another type of cell death induced by bromovanin in HepG2 cells. Treatment with bromovanin significantly increases cellular ROS level as well as elicits DNA double-strand breaks as indicated by comet assay and the increased phosphorylated H2AX. Cleavage and inactivation of DNA-PKcs induced by bromovanin is found to occur concurrently with a rapid destruction of c-Myc oncoprotein. These multiple effects of bromovanin, especially the induction of both apoptosis and autophagy, make it very appealing for the development as a novel anticancer drug.

Dose-dependent expression changes of early response genes to ionizing radiation in human lymphoblastoid cells.

The sensitivity of cancer cells as well as normal cells in response to ionizing radiation (IR) is believed to be associated with the early inducible expression of specific genes. Using cDNA microarray technology, here we explored and compared the global transcriptional changes in human lymphoblastoid AHH-1 cells irradiated with 0.05-, 0.2-, 0.5-, 2.0- and 10-Gy doses of gamma-rays 4 h after exposure. A dose as low as 0.05 Gy was efficient in inducing a transcriptional response including the up-regulation of 25 genes, some of which are involved in signal transduction pathways, e.g. BMPR2, GPR124, MAPK8IP2 and AGGF1, and the down-regulation of 18 genes. Expression of some genes was altered only at a specific dose. Most importantly, we discovered a number of radiation-response genes, e.g. DNA repair gene XPC, tumor protein p53 inducible protein 3 gene (TP53I3), immediate early response 5 gene, whose transcriptional levels were increased or depressed by IR in a dose-dependent trend within the dose range 0.05-10 Gy. The dose-dependent induced expression of TP53I3 and XPC was confirmed by Northern blot analyses. Using quantitative real-time PCR, we further confirmed that XPC gene induction was dose dependent as well as time dependent, reaching a peak 4 h post-2 Gy and 10 h post-0.05 Gy. The maximum induced expression level of the XPC gene was higher after 2 Gy (3.2-fold) than 0.05 Gy (1.93-fold). The identification of these radiation-inducible genes, especially those exhibiting a dose-dependent response, not only expands our knowledge of the mechanisms underlying the diverse biological effects induced by IR, but provides candidates for developing novel biomarkers of radiation injury.

HIV-1 Tat depresses DNA-PK(CS) expression and DNA repair, and sensitizes cells to ionizing radiation.

PURPOSE: There is accumulating evidence that cancer patients with human immmunodeficiency virus-1/acquired immunodeficency syndrome (HIV-1/AIDS) have more severe tissue reactions and often develop cutaneous toxic effects when subjected to radiotherapy. Here we explored the effects of the HIV-1 Tat protein on cellular responses to ionizing radiation. METHODS AND MATERIALS: Two Tat-expressing cell lines, TT2 and TE671-Tat, were derived from human rhabdomyosarcoma cells by transfecting with the HIV-1 tat gene. Radiosensitivity was determined using colony-forming ability. Gene expression was assessed by cDNA microarray and immunohybridization. The Comet assay and gamma-H2AX foci were use to detect DNA double-strand breaks (DSBs) and repair. Radiation-induced cell cycle changes were detected by flow cytometry. RESULTS: The radiosensitivity of TT2 and TE671-Tat cells was significantly increased as compared with parental TE671 cells or the control TE671-pCI cells. Tat also increased proliferation activity. The comet assay and gammaH2AX foci detection revealed a decreased capacity to repair radiation-induced DNA DSBs in Tat-expressing cells. Microarray assay demonstrated that the DNA repair gene DNA-PKcs, and cell cycle-related genes Cdc20, Cdc25C, KIF2C and CTS1 were downregulated in Tat-expressing cells. Depression of DNA-PKcs in Tat-expressing cells was further confirmed by RT-PCR and immuno-hybridization analysis. Tat-expressing cells exhibited a prolonged S phase arrest after 4 Gy gamma-irradiation, and a noticeable delay in the initiation and elimination of radiation-induced G(2)/M arrest as compared with parental cells. In addition, the G(2)/M arrest was incomplete in TT2 cells. Moreover, HIV-1 Tat resulted in a constitutive overexpression of cyclin B1 protein. CONCLUSION: HIV-1 Tat protein sensitizes cells to ionizing radiation via depressing DNA repair and dysregulating cell cycle checkpoints. These observations provide new insight into the increased tissue reactions of AIDS cancer patients to radiotherapy.

Vanillin derivative 6-bromine-5-hydroxy-4-methoxybenzaldehyde-elicited apoptosis and G2/M arrest of Jurkat cells proceeds concurrently with DNA-PKcs cleavage and Akt inactivation.

Vanillin, a naturally occurring food component, has been reported to have anti-mutagenic and anti-metastatic potentials, and to inhibit DNA-PKcs activity. However, vanillin itself exhibits very weak antiproliferative activity. We explored the effects of bromovanin (6-bromine-5-hydroxy-4-methoxybenzaldehyde), a novel vanillin derivative, on survival and cell-cycle progression of human Jurkat leukemia cells. Treatment with >10 microM bromovanin significantly elicited apoptosis and G2/M arrest in Jurkat cells in a dose- and time-dependent manner. Bromovanin-induced DNA double-strand breaks (DSB) were demonstrated by means of comet assay as well as detection of phosphorylated H2AX, a sensitive indicator of DNA DSBs. Immuno-hybridization analysis revealed that the cleavage of procaspase-3 and DNA-PKcs occurred concurrently with bromovanin-induced apoptosis. Furthermore, phosphorylated Akt protein (Ser473), which is catalyzed by DNA-PKcs, as well as phosphorylated GSK3beta (a substrate of activated Akt), markedly decreased in bromovanin-treated Jurkat cells, suggesting that bromovanin leads to inactivation of Akt pathway via cleaving DNA-PKcs. These multiple effects, associated with the regimen of cancer therapeutic strategies, make bromovanin very appealing for future development as a novel anticancer drug.

siRNA-mediated silencing of Cockayne Cyndrome group B gene potentiates radiation-induced apoptosis and antiproliferative effect in HeLa cells.

BACKGROUND: Cockayne syndrome (CS) is a rare human genetic disorder characterized by increased UV sensitivity, developmental abnormalities and premature aging. Cells isolated from individuals with CS have a defect in transcription-coupled DNA repair. Despite the repair defect, there is no any increased risk of spontaneous or UV-induced cancer for CS individuals. The strategy of RNA interfering was used here to explore the potential radiosensitizing and anticancer activity of targeting CS group B (CSB) gene. METHODS: The vectors encoding CSB-specific siRNAs were constructed by inserting duplex siRNA encoding oligonucleotides into the plasmid P(silencer TM 3.1). The cell lines expressing the CSB-siRNA were generated from HeLa cells transfected with the above vectors. Colony-forming ability was used to assay cell survival. Cell cycle was analyzed by FACScan flow cytometry. The apoptosis was measured by detecting the accumulation of sub-G(1) population as well as by fluorescence staining assay. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to semi-quantify mRNA expression. Protein level was detected by Western blotting analysis. RESULTS: Two constructs encoding CSB-specific siRNA were generated, both of them resulted in remarkable suppression on CSB expression in HeLa cells, and led to an increased sensitivity to (gamma-ray and UV light. siRNA-mediated silencing of CSB decreased cell proliferation rate, increased spontaneous apoptosis as well as the occurrence of UV- or cisplatin-induced apoptosis by 2 to 3.5 fold. A significant S phase blockage and a remarkable reduction of G(1) population were induced in control HeLa cells at 18 hours after being exposed to 10 J/m(2) of UV light. The S phase blockage was also observed in UV-irradiated CSB-siRNA transfected HeLa cells, but the extent of increased S phase population was lower than that in the UV-irradiated control cells. No or a relative weak reduction on G(1) phase population was observed in UV-irradiated CSB-siRNA transfected HeLa cells. In addition, siRNA-mediated silencing of CSB promoted the elimination of G(2)/M phase cells after UV light radiation. CONCLUSIONS: siRNA-mediated silencing of CSB causes cells to proliferate more slowly, sensitize cells to genotoxicants, and modify UV radiation-induced cell cycle changes. siRNA-mediated inactivation of CSB could be an attractive strategy for ameliorating cancer therapy, which can be fulfilled via the combination of gene therapy and sensitization of radiotherapy or chemotherapy.

Aquatic Therapy Improves Outcomes for Subacute Stroke Patients by Enhancing Muscular Strength of Paretic Lower Limbs Without Increasing Spasticity: A Randomized Controlled Trial.

PURPOSE: The aim of this study was to evaluate the effects of an aquatic exercise program designed to enhance muscular strength in paretic lower limbs in subacute stroke patients. METHOD: Thirty-six subacute stroke patients were randomly divided to a conventional or an aquatic group (n = 18 each). Outcome measures were assessed at baseline and after 8 wks of training. For the paretic lower limbs, maximum isometric voluntary contraction strength of the rectus femoris and biceps femoris caput longus and the tibialis anterior and lateral gastrocnemius was measured. Cocontraction ratios during knee extension and flexion and ankle dorsiflexion and plantarflexion were calculated respectively. In addition, Modified Ashworth Scale, Functional Ambulation Category, and Barthel Index were assessed. RESULTS: Compared with the conventional intervention, the aquatic intervention resulted in significantly higher knee extension (P = 0.002) and ankle plantarflexion torque (P = 0.002), accompanied with a significantly lower knee extension cocontraction ratio in the paretic limb (P = 0.000). Functional Ambulation Category (P = 0.009) and Barthel Index (P = 0.024) were greater in aquatic group than conventional group posttreatment. Modified Ashworth Scale scores did not show any differences between groups. CONCLUSIONS: Aquatic exercise enhanced muscle strength in paretic lower limbs and improved muscle cocontraction without increasing spasticity in subacute stroke patients.

Silencing of DNA-PKcs alters the transcriptional profile of certain signal transduction genes related to proliferation and differentiation in HeLa cells.

DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a member of a sub-family of phosphoinositol 3-kinases, has been reported overexpressed in various human cancers, but its significance is unclear. In the present study, we generated the stable cell line HeLa(siRNAH1) of silenced DNA-PKcs by transfecting HeLa cells with the siRNA construct targeting the catalytic motif of DNA-PKcs. The expression of DNA-PKcs was markedly suppressed in HeLa(siRNAH1) cells, and eventuating in increased cellular sensitivity to ionizing radiation as well as cisplatin. Microarray assay was used to explore the transcriptional profiling of signal transduction-associated genes. The results demonstrated that 15 genes were up-regulated and eight were down-regulated in HeLa(siRNAH1) as compared with the HeLa(control) cells that transfected with non-specific siRNA construct. Seven of the up-regulated genes are associated with the interferon-signaling events, the others function in the BMP signal pathway, or as regulators of cell cycle and differentiation. The down-regulated genes include IL8, IL10RA, DAPK3, and those involved in nuclear factor of activated T cells (NFAT) signal pathway and endocrine responsiveness. Using the NFAT-driving secreted alkaline phosphatase reporter expression system, we further confirmed that NFAT transcriptional activity was markedly minimized after silencing DNA-PKcs. These results demonstrated that inactivation of DNA-PKcs altered the transcriptional level of certain signal transduction-associated genes related to proliferation and differentiation.

Downregulation of c-myc protein by siRNA-mediated silencing of DNA-PKcs in HeLa cells.

DNA-dependent protein kinase (DNA-PK) has been intensively investigated for its roles in the nonhomologous end-joining (NHEJ) pathway of DNA double-strand break repair and maintenance of genomic stability. Its catalytic subunit, DNA-PKcs, a serine/threonine protein kinase, has recently been reported to be overexpressed in various human cancers, but its significance is unclear. In our study, we synthesized 3 small interfering RNA (siRNA) oligonucleotides, which separately target the translation initiation region, catalytic motif and a sequence between the scid-mutation region and the FATC motif of DNA-PKcs; 3 stable cell lines were generated from HeLa cells transfected with these siRNA constructs, respectively. All 3 siRNAs resulted in remarkable depression on DNA-PKcs expression in HeLa cells, and led to an increased sensitivity to 2 or 4 Gy of gamma-ray as well as 5 or 10 J/m(2) of ultraviolet (UV) irradiation. The siRNA targeting the catalytic motif of DNA-PKcs exhibited the greatest efficiency of radiosensitization. We demonstrated that c-myc protein level was suppressed more than 80% by siRNA-mediated silencing of DNA-PKcs. Using an E-box enhancer (c-myc binding element) driving a secreted alkaline phosphatase (SEAP) reporter strategy, we further found that the transcriptional activity of c-myc was extremely suppressed by silencing DNA-PKcs. The highest suppression effect on c-myc expression was observed in the cells transfected with the siRNA targeting the catalytic motif of DNA-PKcs. Moreover, a similar suppression on c-myc expression and activity was also detected in HeLa cells treated with wortmannin, a phosphatidylinositol (PI)-3 kinase inhibitor. However, silencing DNA-PKcs did not change the level of c-myc mRNA. We have further identified the interaction between DNA-PKcs and c-myc protein. Together, our results imply that DNA-PKcs activity is necessary or contributory to the expression of c-myc protein. Targeting DNA-PKcs is an attractive anticancer strategy, which can achieve through at least two mechanistic pathways: (i) sensitizing cancer cells to radiotherapy or chemotherapy of DNA-damaging agents and (ii) downregulation of c-myc protein.