Regulation of Myc transcription by an enhancer cluster dedicated to pluripotency and early embryonic expression.

MYC plays various roles in pluripotent stem cells, including the promotion of somatic cell reprogramming to pluripotency, the regulation of cell competition and the control of embryonic diapause. However, how Myc expression is regulated in this context remains unknown. The Myc gene lies within a ~ 3-megabase gene desert with multiple cis-regulatory elements. Here we use genomic rearrangements, transgenesis and targeted mutation to analyse Myc regulation in early mouse embryos and pluripotent stem cells. We identify a topologically-associated region that homes enhancers dedicated to Myc transcriptional regulation in stem cells of the pre-implantation and early post-implantation embryo. Within this region, we identify elements exclusively dedicated to Myc regulation in pluripotent cells, with distinct enhancers that sequentially activate during naive and formative pluripotency. Deletion of pluripotency-specific enhancers dampens embryonic stem cell competitive ability. These results identify a topologically defined enhancer cluster dedicated to early embryonic expression and uncover a modular mechanism for the regulation of Myc expression in different states of pluripotency.

P53 and BCL-2 family proteins PUMA and NOXA define competitive fitness in pluripotent cell competition.

Cell Competition is a process by which neighboring cells compare their fitness. As a result, viable but suboptimal cells are selectively eliminated in the presence of fitter cells. In the early mammalian embryo, epiblast pluripotent cells undergo extensive Cell Competition, which prevents suboptimal cells from contributing to the newly forming organism. While competitive ability is regulated by MYC in the epiblast, the mechanisms that contribute to competitive fitness in this context are largely unknown. Here, we report that P53 and its pro-apoptotic targets PUMA and NOXA regulate apoptosis susceptibility and competitive fitness in pluripotent cells. PUMA is widely expressed specifically in pluripotent cells in vitro and in vivo. We found that P53 regulates MYC levels in pluripotent cells, which connects these two Cell Competition pathways, however, MYC and PUMA/NOXA levels are independently regulated by P53. We propose a model that integrates a bifurcated P53 pathway regulating both MYC and PUMA/NOXA levels and determines competitive fitness.

The prevalence of osteoporosis in China, a community based cohort study of osteoporosis.

Background: Osteoporosis has already been a growing health concern worldwide. The influence of living area, lifestyle, socioeconomic, and medical conditions on the occurrence of osteoporosis in the middle-aged and elderly people in China has not been fully addressed. Methods: The study was a multicenter cross-sectional study on the middle-aged and elderly permanent residents, which gathered information of 22,081 residents from June 2015 to August 2021 in seven representative regions of China. The bone mineral density of lumbar vertebrae and hip were determined using the dual-energy X-ray absorptiometry densitometer instruments. Serum levels of bone metabolism markers were also measured. Information about education, smoking, and chronic diseases were also collected through face-to-face interviews. Age-standardized prevalence and 95% confidence intervals (CIs) of osteopenia and osteoporosis by various criteria were estimated by subgroups and overall based on the data of China 2010 census. The relationships between the osteoporosis or osteopenia and sociodemographic variables or other factors were examined using univariate linear models and multivariable multinomial logit analyses. Results: After screening, 19,848 participants (90%) were enrolled for the final analysis. The age-standardized prevalence of osteoporosis was estimated to be 33.49%(95%CI, 32.80-34.18%) in the middle-aged and elderly Chinese permanent residents, for men and women was 20.73% (95% CI, 19.58-21.87%) and 38.05% (95% CI, 37.22-38.89%), respectively. The serum concentrations of bone metabolic markers, and calcium and phosphorus metabolism were influenced by age, body mass index (BMI), gender, education level, regions, and bone mass status. Women, aged 60 or above, BMI lower than 18.5 kg/m2, low education level including middle school, primary school and no formal education as well as current regular smoking, a history of fracture were all significantly associated with a higher risk of osteoporosis and osteopenia in the middle-aged and elderly people. Conclusions: This study revealed dramatic regional differences in osteoporosis prevalence in China, and female, aged 60 or older, low BMI, low education level, current regular smoking, and a history of fracture were associated with a high risk of osteoporosis. More prevention and treatment resources should be invested into particular population exposed to these risk factors.

Retracted: The Effects of Ludartin on Cell Proliferation, Cell Migration, Cell Cycle Arrest and Apoptosis Are Associated with Upregulation of p21WAF1 in Saos-2 Osteosarcoma Cells In Vitro.

The authors repeated experiments and found that the results shown in figure 2 were not reproducible. Reference: Shuang-li Zhang, Bao-lin Li, Wei Li, Ming Lu, Lin-ying Ni, Hui-li Ma, Qing-gang Meng. The Effects of Ludartin on Cell Proliferation, Cell Migration, Cell Cycle Arrest and Apoptosis Are Associated with Upregulation of p21WAF1 in Saos-2 Osteosarcoma Cells In Vitro. Med Sci Monit 2018; 24: LBR4926-4933. 10.12659/MSM.909193.

Novel Cucurbitane Triterpenes from the Tubers of Hemsleya amabilis with Their Cytotoxic Acitivity.

Chemical research of the medicinal plant Hemsleya amabilis (Cucurbitaceae) yielded five new cucurbitane-type triterpenes hemslelis A⁻E (1⁻5) by silica gel column, ODS column, and semi-HPLC techniques. Their structures were determined by spectroscopic analysis and examined alongside existing data from prior studies. Compounds 1⁻5 were evaluated for their cytotoxic activities against three human tumor cell lines, Hela, HCT-8, and HepG-2, with the IC50 ranging from 5.9 to 33.9 µM compared to Cisplatin.

The Effects of Ludartin on Cell Proliferation, Cell Migration, Cell Cycle Arrest and Apoptosis Are Associated with Upregulation of p21WAF1 in Saos-2 Osteosarcoma Cells In Vitro.

BACKGROUND The aim of this study was investigate the effects of the sesquiterpene lactone, ludartin, on cell proliferation, cell migration, apoptosis, and the cell cycle in osteosarcoma cell lines, compared with a normal osteoblast cell line. MATERIAL AND METHODS Osteosarcoma cell lines, MG-63 Saos-2 U-2OS, T1-73 143B, and HOS, and normal hFOB 1.19 osteoblasts, were cultured and treated with increasing doses of ludartin, The MTT colorimetric assay was used to measure cell metabolic activity and viability. Apoptosis was studied by fluorescence-activated cell sorting (FACS) using 4',6-diamidino-2-phenylindole (DAPI) nuclear staining and Annexin-V/propidium iodide (PI) staining. Cell cycle was studied using flow cytometry. Cell migration and invasion were studied using wound healing and Boyden chamber assays. Protein expression was measured by Western blotting. RESULTS Ludartin inhibited cell viability, cell migration, cell proliferation, and increased cell apoptosis, in all osteosarcoma cell lines, with an IC50 dose ranging from 15-30 µM. The greatest effects were on the Saso-2 osteosarcoma cells, with an IC50 of 15 µM. However, ludartin showed minor cytotoxic effects of the normal hFOB 1.19 osteoblasts (IC50 >100 µM). Ludartin exerted its anti-proliferative effects on Saos-2 cells via induction of apoptosis and cell cycle arrest at the G2/M checkpoint, associated with reduced expression of Cdc25c (Ser216), Cdc25c, pCdc2 (Tyr15), and Cdc2 and increased expression of p21WAF1. Ludartin inhibited cell migration and invasion of the Saos-2 cells. CONCLUSIONS The dose-dependent effects of ludartin on cell proliferation, migration, apoptosis, cell cycle arrest at the G2/M checkpoint involved p21WAFI in Saos-2 osteosarcoma cells.

Biosensor of alkaline phosphatase based on non-fluorescent FRET of Eu3+-doped oxide nanoparticles and phosphorylated peptide labeled with cyanine dye.

Dephosphorylation of biomolecules under the catalysis of alkaline phosphatase (ALP) is a critical physiological process. Abnormal levels of ALP activity have been associated with a number of diseases; thus, a simple and sensitive assay of ALP activity is highly demanded. Herein, to simulate biological conditions, we labeled a hydrosoluble phosphorylated heptapeptide Gly-Pro-Gly-Asn-p-Tyr-Gly-Ala (pGA) with aminated heptamethine cyanine dye (Cy) to give a low fluorescent labeled peptide Cy-pGA. The synthesized Cy-pGA and Eu3+-doped oxide Y0.6Eu0.4VO4 nanoparticles (NPs) were employed respectively as acceptor and donor to in situ form a non-fluorescent Fluorescence Resonance Energy Transfer (FRET) Cy-pGA-NP system, with the help of the strong interaction between Eu3+ ions in the NPs and phosphate group in Cy-pGA. The breaking of the FRET system of Cy-pGA-NP was triggered by the removal of phosphate group in Cy-pGA catalyzed by ALP and resulting in the release of fluorescent Y0.6Eu0.4VO4 NPs. Thus, the formed Cy-pGA-NP as a sensitive sensor can very well respond to the activity of ALP by measuring the time-resolved fluorescent intensity at near-infrared 617 nm (λ ex = 320 nm, delay time 400 µs). This sensor can not only accurately measure the activity of ALP (1-5 mU/mL) in the designed solutions, but it can also be applied to detect the activity of ALP in biological samples, such as cell lysate and human serum, without the interference of autofluorescent background of biosamples and screen ALP inhibitor by a simple mix-and-measure manner. Graphical abstract A biosensor of alkaline phosphatase (ALP) based on non-fluorescent FRET of Eu3+-doped oxide Y0.6Eu0.4VO4 nanoparticles and the phosphorylated heptapeptide labeled with cyanine dye (Cy-pGA).

Predicting factors associated with frailty in aged patients with bone-arthrosis pain in the clinic.

OBJECTIVES: To identify frail and pre-frail patients in a group of patients older than 60 years. METHODS: The phenotype model of Fried's method was used to identify frailty and pre-frailty in total of 78 participants. Cognitive ability and psychosocial function tests were also given to 59 of the 78 patients. RESULTS: Prevalence of frailty and pre-frailty was 14.1% (11/78) and 46.2% (36/78), respectively. Of the 5 phenotype variables, weak grip strength was the most commonly seen variable with 53.8% of all participants and 100% in the frail group. Low energy expenditure, however, was not self-reported by any participant in the current study (0%). Prevalence of frailty in the present study is associated with chronological age. The current study indicates that 4 phenotypic variables (unintentional weight loss, self-reported exhaustion, gait speed and grip strength) contribute to the development to frailty, and that cognitive impairment and psychosocial frailty also predict frailty or pre-frailty in the patients older than 60 years old irrespective of chronic pain or osteoarthritis. The findings of the current study suggest frailty and pre-frailty are common in senior Chinese patients with chronic diseases. CONCLUSION: Recognition and identification of frailty in a rehabilitation clinic or hospital might help physicians to provide appropriate counseling to patients and families about adverse outcomes of certain treatments such as surgery, and could optimize management of coexisting chronic diseases that might contribute to or be affected by frailty.

Synthesis and in vitro antiproliferative evaluation of novel nonsymmetrical disulfides bearing 1,3,4-oxadiazole moiety.

A series of novel nonsymmetrical disulfides bearing 1,3,4-oxadiazole moiety were designed, synthesized and evaluated for their in vitro antiproliferative activities against SMMC-7721, Hela and A549 human cancer cell lines by CCK-8 assay. The preliminary bioassay results demonstrated that all tested compounds 7a-7o exhibited antiproliferation with different degrees, and some compounds showed better effects than positive control 5-fluorouracil against various cancer cell lines. Among these compounds, compound 7j showed significant antiproliferative activity against SMMC-7721 cells with IC50 value of 3.40µM. Compound 7a displayed highly effective biological activity against Hela cells with IC50 value of 4.26µM. Compound 7g exhibited the best inhibitory effect against A549 cells with IC50 value of 6.26µM.

Synthesis and antiproliferative evaluation of novel 1,2,4-triazole derivatives incorporating benzisoselenazolone scaffold.

A series of novel 1,2,4-triazole derivatives incorporating benzisoselenazolone scaffold were designed, synthesized and evaluated for their in vitro antiproliferative activities against human cancer cell lines SMMC-7721, Hela, A549, and normal cell lines L929 by CCK-8 assay. The preliminary bioassay results demonstrated that most of the tested compounds 3a-3n exhibited antiproliferation with different degrees, and some compounds showed better effects than positive controls ethaselen and 5-fluorouracil (5-FU) against various cancer cell lines. Among these compounds, compounds 3b and 3c displayed highly effective biological activities against SMMC-7721cells with IC50 values of 6.02 and 6.01 µM, respectively. Compound 3n showed significant antiproliferative activities against Hela cells with IC50 value of 3.94 µM. Compound 3n exhibited the best inhibitory effect against A549 cells with IC50 value 9.14 µM. Furthermore, most of the tested compounds showed weak cytotoxic effect against the normal cell lines L929. The pharmacological results suggest that the substituent groups are vital for improving the potency and selectivity of this class of compounds.

Endostar combined with irinotecan/calcium folinate/5-fluorouracil (FOLFIRI) for treating advanced colorectal cancer: A clinical study.

PURPOSE: The current study aimed to evaluate the short-term efficacy and safety of endostar plus irinotecan/calcium folinate/5-fluorouracil (FOLFIRI) in treatment of advanced colorectal cancer (CRC). METHODS: Forty patients with advanced CRC were enrolled in this study and randomly assigned to two groups. The control group (n = 18) and tested group (n = 22) were received FOLFIRI alone and FOLFIRI plus endostar, respectively. The end points were overall response rate, progression-free survival (PFS) and toxicity. RESULTS: A total of 38 patients (17 in control group and 21 in tested group) completed two cycles of treatment and were deemed assessable for response. Patients treated with FOLFIRI plus endostar experienced a obviously higher overall response rate (42.9%) compared with patients who received FOLFIRI alone (29.4%) and a statistically significant improvement in median PFS (14.5 vs. 11.0  months). The toxicity of FOLFIRI/endostar was comparative to that of FOLFIRI with regard to gastrointestinal reactions, haematologic toxicity, peripheral neuropathy and cholinergic syndrome. Cardiovascular adverse reactions including electrocardiogram abnormality and hypertension, which might be ascribed to endostar treatment, were reversible and manageable. CONCLUSION: The addition of endostar to FOLFIRI resulted in a higher overall response rate and longer PFS and did not increase unacceptable adverse responses in patients with advanced CRC. Future randomised controlled clinical trials with a larger group of patients are warranted to further investigate the value of FOLFIRI plus endostar in CRC treatment.

Associations between the dietary intake of antioxidant nutrients and the risk of hip fracture in elderly Chinese: a case-control study.

The role of oxidative stress in skeletal health is unclear. The present study investigated whether a high dietary intake of antioxidant nutrients (vitamins C and E, ß-carotene, animal-derived vitamin A, retinol equivalents, Zn and Se) is associated with a reduced risk of hip fracture in elderly Chinese. This 1:1 matched case-control study involved 726 elderly Chinese with hip fracture and 726 control subjects, recruited between June 2009 and May 2013. Face-to-face interviews were conducted to determine habitual dietary intakes of the above-mentioned seven nutrients based on a seventy-nine-item FFQ and information on various covariates, and an antioxidant score was calculated. After adjustment for potential covariates, dose-dependent inverse associations were observed between the dietary intake of vitamin C, vitamin E, ß-carotene, and Se and antioxidant score and the risk of hip fracture (P for trend ≤ 0·005). The OR of hip fracture for the highest (v. lowest) quartile of intake were 0·39 (95 % CI 0·28, 0·56) for vitamin C, 0·23 (95 % CI 0·16, 0·33) for vitamin E, 0·51 (95 % CI 0·36, 0·73) for ß-carotene, 0·43 (95 % CI 0·26, 0·70) for Se and 0·24 (95 % CI 0·17, 0·36) for the antioxidant score. A moderate-to-high dietary intake of retinol equivalents in quartiles 2-4 (v. 1) was found to be associated with a lower risk of hip fracture (OR range: 0·51-0·63, P< 0·05). No significant association was observed between dietary Zn or animal-derived vitamin A intake and hip fracture risk (P for trend >0·20). In conclusion, a higher dietary intake of vitamins C and E, ß-carotene, and Se and a moderate-to-high dietary intake of retinol equivalents are associated with a lower risk of hip fracture in elderly Chinese.

Establishment of an ELISA to detect Kaposi's sarcoma-associated herpesvirus using recombinant ORF73.

Kaposi's sarcoma-associated herpesvirus (KSHV) is causally related to Kaposi's sarcoma (KS), primary effusion lymphoma (PEL) and a proportion of cases of multicentric Castleman's disease (MCD). The ORF73 protein was cloned into pQE80L-orf73 and expressed in E.coli and purified. The expressed recombinant ORF73 was identified by sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE). A protein of about 27 kDa was expressed as expected. Western Blotting showed that the purified recombinant ORF73 reacted with KSHV positive serum. The immunogenicity of the recombinant ORF73 was further analysed by ELISA and the optimal conditions were determined. The ORF73 ELISA was used to compare the KSHV seroprevalence between Hubei and Xinjiang Han people. The Han people in Xinjiang have significantly higher KSHV seroprevalence than their counterparts in Hubei (6.7% vs 2.9%, P = 0.005).