Domain generalization across tumor types, laboratories, and species - Insights from the 2022 edition of the Mitosis Domain Generalization Challenge.

Recognition of mitotic figures in histologic tumor specimens is highly relevant to patient outcome assessment. This task is challenging for algorithms and human experts alike, with deterioration of algorithmic performance under shifts in image representations. Considerable covariate shifts occur when assessment is performed on different tumor types, images are acquired using different digitization devices, or specimens are produced in different laboratories. This observation motivated the inception of the 2022 challenge on MItosis Domain Generalization (MIDOG 2022). The challenge provided annotated histologic tumor images from six different domains and evaluated the algorithmic approaches for mitotic figure detection provided by nine challenge participants on ten independent domains. Ground truth for mitotic figure detection was established in two ways: a three-expert majority vote and an independent, immunohistochemistry-assisted set of labels. This work represents an overview of the challenge tasks, the algorithmic strategies employed by the participants, and potential factors contributing to their success. With an F1 score of 0.764 for the top-performing team, we summarize that domain generalization across various tumor domains is possible with today's deep learning-based recognition pipelines. However, we also found that domain characteristics not present in the training set (feline as new species, spindle cell shape as new morphology and a new scanner) led to small but significant decreases in performance. When assessed against the immunohistochemistry-assisted reference standard, all methods resulted in reduced recall scores, with only minor changes in the order of participants in the ranking.

Enhancing mitosis quantification and detection in meningiomas with computational digital pathology.

Mitosis is a critical criterion for meningioma grading. However, pathologists' assessment of mitoses is subject to significant inter-observer variation due to challenges in locating mitosis hotspots and accurately detecting mitotic figures. To address this issue, we leverage digital pathology and propose a computational strategy to enhance pathologists' mitosis assessment. The strategy has two components: (1) A depth-first search algorithm that quantifies the mathematically maximum mitotic count in 10 consecutive high-power fields, which can enhance the preciseness, especially in cases with borderline mitotic count. (2) Implementing a collaborative sphere to group a set of pathologists to detect mitoses under each high-power field, which can mitigate subjective random errors in mitosis detection originating from individual detection errors. By depth-first search algorithm (1) , we analyzed 19 meningioma slides and discovered that the proposed algorithm upgraded two borderline cases verified at consensus conferences. This improvement is attributed to the algorithm's ability to quantify the mitotic count more comprehensively compared to other conventional methods of counting mitoses. In implementing a collaborative sphere (2) , we evaluated the correctness of mitosis detection from grouped pathologists and/or pathology residents, where each member of the group annotated a set of 48 high-power field images for mitotic figures independently. We report that groups with sizes of three can achieve an average precision of 0.897 and sensitivity of 0.699 in mitosis detection, which is higher than an average pathologist in this study (precision: 0.750, sensitivity: 0.667). The proposed computational strategy can be integrated with artificial intelligence workflow, which envisions the future of achieving a rapid and robust mitosis assessment by interactive assisting algorithms that can ultimately benefit patient management.

A combination of Beers and STOPP criteria better detects potentially inappropriate medications use among older hospitalized patients with chronic diseases and polypharmacy: a multicenter cross-sectional study.

BACKGROUND: Research on potentially inappropriate medications (PIM) and medication-related problems (MRP) among the Chinese population with chronic diseases and polypharmacy is insufficient. OBJECTIVES: This study aimed to investigate the prevalence of PIM and MRP among older Chinese hospitalized patients with chronic diseases and polypharmacy and analyze the associated factors. METHODS: A retrospective cross-sectional study was conducted in five tertiary hospitals in Beijing. Patients aged ≥ 65 years with at least one chronic disease and taking at least five or more medications were included. Data were extracted from the hospitals' electronic medical record systems. PIM was evaluated according to the 2015 Beers criteria and the 2014 Screening Tool of Older Persons' Prescriptions (STOPP) criteria. MRPs were assessed and classified according to the Helper-Strand classification system. The prevalence of PIM and MRP and related factors were analyzed. RESULTS: A total of 852 cases were included. The prevalence of PIM was 85.3% and 59.7% based on the Beers criteria and the STOPP criteria. A total of 456 MRPs occurred in 247 patients. The most prevalent MRP categories were dosages that were too low and unnecessary medication therapies. Hyperpolypharmacy (taking ≥ 10 drugs) (odds ratio OR 3.736, 95% confidence interval CI 1.541-9.058, P = 0.004) and suffering from coronary heart disease (OR 2.620, 95%CI 1.090-6.297, P = 0.031) were the influencing factors of inappropriate prescribing (the presence of either PIM or MRP in a patient). CONCLUSION: PIM and MRP were prevalent in older patients with chronic disease and polypharmacy in Chinese hospitals. More interventions are urgently needed to reduce PIM use and improve the quality of drug therapies.

The Establishment of China Bronchiectasis Registry and Research Collaboration (BE-China): Protocol of a prospective multicenter observational study.

BACKGROUND: Bronchiectasis is a highly heterogeneous chronic airway disease with marked geographic and ethnic variations. Most influential cohort studies to date have been performed in Europe and USA, which serve as the examples for developing a cohort study in China where there is a high burden of bronchiectasis. The Establishment of China Bronchiectasis Registry and Research Collaboration (BE-China) is designed to: (1) describe the clinical characteristics and natural history of bronchiectasis in China and identify the differences of bronchiectasis between the western countries and China; (2) identify the risk factors associated with disease progression in Chinese population; (3) elucidate the phenotype and endotype of bronchiectasis by integrating the genome, microbiome, proteome, and transcriptome with detailed clinical data; (4) facilitate large randomized controlled trials in China. METHODS: The BE-China is an ongoing prospective, longitudinal, multi-center, observational cohort study aiming to recruit a minimum of 10,000 patients, which was initiated in January 2020 in China. Comprehensive data, including medical history, aetiological testing, lung function, microbiological profiles, radiological scores, comorbidities, mental status, and quality of life (QoL), will be collected at baseline. Patients will be followed up annually for up to 10 years to record longitudinal data on outcomes, treatment patterns and QoL. Biospecimens, if possible, will be collected and stored at - 80 °C for further research. Up to October 2021, the BE-China has enrolled 3758 patients, and collected 666 blood samples and 196 sputum samples from 91 medical centers. The study protocol has been approved by the Shanghai Pulmonary Hospital ethics committee, and all collaborating centers have received approvals from their local ethics committee. All patients will be required to provide written informed consent to their participation. CONCLUSIONS: Findings of the BE-China will be crucial to reveal the clinical characteristics and natural history of bronchiectasis and facilitate evidence-based clinical practice in China. Trial registration Registration Number in ClinicalTrials.gov: NCT03643653.

USP7 sustains an active epigenetic program via stabilizing MLL2 and WDR5 in diffuse large B-cell lymphoma.

Activated B-cell-like (ABC)-diffuse large B-cell lymphoma (ABC-DLBCL) is a common subtype of non-Hodgkin's lymphoma with poor prognosis. The survival of ABC-DLBCL relies on constitutive activation of BCR signaling, but the underlying molecular mechanism is not fully addressed. By mining The Cancer Genome Atlas database, we found that the expression of ubiquitin-specific protease 7 (USP7) is significantly elevated in three cancer types including DLBCL. Interestingly, unlike germinal center B-cell-like (GCB)-DLBCL, ABC-DLBCL shows upregulated expression of USP7. Inhibiting the enzymatic activity of USP7 (P22077) has a drastic effect on ABC-DLBCL, but not GCB-DLBCL cells. Compared to GCB-DLBCL, ABC-DLBCL cells show transcriptional upregulation of multiple components of BCR-signaling. USP7 inhibition significantly reduces the expression of upregulated components of BCR signaling. Mechanistically, USP7 inhibition greatly reduces the methylation of histone 3 on lysine 4 (H3K4me2), which is an epigenetic marker for active enhancers. USP7 inhibition greatly reduces the protein level of WDR5 and MLL2, key components of lysine-specific methyltransferase complex (complex of proteins associated with Set1 [COMPASS]). In ABC-DLBCL cells, USP7 stabilizes WDR5 and MLL2. In patients, the expression of USP7 is significantly associated with components of BCR signaling (LYN, SYK, BTK, PLCG2, PRKCB, MALT1, BCL10, and CARD11) and targets of BCR signaling (MYC and IRF4). In summary, we demonstrated an essential role of USP7 in ABC-DLBCL by organizing an oncogenic epigenetic program via stabilization of WDR5 and MLL2. Targeting USP7 might be a novel and efficient approach to treat patients with ABC-DLBCL and it might be better than targeting individual components such as BTK in BCR signaling.

Peripheral blood circular RNA hsa_circ_0058493 as a potential novel biomarker for silicosis and idiopathic pulmonary fibrosis.

Existing studies reported that some circular RNAs (circRNAs) play vital roles in the development of pulmonary fibrosis. However, few studies explored the biomarker potential of circRNAs for pulmonary fibrosis based on population data. Therefore, we aimed to identify peripheral blood circRNAs as potential biomarkers for diagnosing silicosis and idiopathic pulmonary fibrosis (IPF). In brief, an RNA-seq screening based on 4 silicosis cases and 4 controls was initially performed. Differentially expressed circRNAs were combined with the human serum circRNA dataset to identify overlapping serum-detectable circRNAs, followed by validation using the GEO dataset (3 IPF cases and 3 controls) and subsequent qRT-PCR, including 84 additional individuals. Following the above steps, 243 differentially expressed circRNAs were identified during the screening stage, with fold changes ≥ 1.5 and P < 0.05. Of note, the human serum circRNA dataset encompassed 28 of 243 circRNAs. GEO (GSE102660) validation revealed two highly expressed circRNAs (P < 0.05) in the IPF case group. Furthermore, at the enlarged sample validation stage, hsa_circ_0058493 was highly expressed in both silicosis and IPF cases (silicosis: P = 1.16 × 10-6; IPF: P = 7.46 × 10-5). Additionally, hsa_circ_0058493 expression was significantly increased in MRC-5 cells upon TGF-ß1 treatment, while hsa_circ_0058493 knockdown inhibited the expression of fibrotic molecules by affecting the epithelial-mesenchymal transition process. These shreds of evidence indicated that hsa_circ_0058493 might serve as a novel biomarker for diagnosing silicosis and IPF.

Comparison of the prevalence and nature of potentially inappropriate medication use in geriatric outpatients between tertiary and community healthcare settings: a multicenter cross-sectional study.

Background Geriatric outpatients with polypharmacy have a high risk of potentially inappropriate medication (PIM) use. Aim To identify differences in both prevalence and patterns of PIMs and drug-related problems (DRPs) in older outpatients who visited the tertiary hospitals (THs) and community health centers (CHCs) and analyze associated factors. Method A prospective cross-sectional study was conducted in five THs and five CHCs from September 2018 to November 2019 in Beijing, China. Data were collected from outpatients aged ≥ 65 years with chronic diseases and polypharmacy. PIMs were evaluated using the 2015 and 2019 Beers Criteria and the Screening Tool of Older Persons' Prescriptions (STOPP) criteria. DRPs were classified using the Helper-Strand DRP Classification. The prevalence and types of PIMs and DRPs were compared, and relevant factors were analyzed. Results The prevalence of PIMs based on the 2015 Beers Criteria was higher in patients from the THs, while PIMs based on the 2019 Beers Criteria did not show a significant difference. PIM prevalence based on STOPP Criteria and DRPs was higher in patients from CHCs. Visiting CHCs was an independent factor of PIMs based on the 2015 Beers Criteria (OR 0.774, 95% CI 0.604-0.992) and the STOPP Criteria (OR 2.427, 95% CI 1.883-3.128), and DRPs (OR 3.612, 95% CI 2.682-4.865). Conclusion Differences in PIM and DRP might be due to the patients and settings. Specific measures to improve the appropriateness of medications in both settings should be used.

Endobronchial Therapy With Gentamicin and Dexamethasone After Airway Clearance by Bronchoscopy in Exacerbation of Non-Cystic Fibrosis Bronchiectasis: A Real-World Observational Study.

Background: The exacerbation of non-cystic fibrosis bronchiectasis (NCFB) may lead to poor prognosis. The objective of this study was to retrospectively analyze the clinical efficacy and safety of endobronchial therapy with gentamicin and dexamethasone after airway clearance by bronchoscopy in the exacerbation of NCFB. Methods: We retrospectively reviewed 2,156 patients with NCFB between January 2015 and June 2016 and 367 consecutive patients with exacerbation of bronchiectasis who had complete data and underwent airway clearance (AC) by bronchoscopy. The final cohort included 181 cases of intratracheal instillation with gentamicin and dexamethasone after AC (a group with airway drugs named the drug group) and 186 cases of AC only (a group without airway drugs named the control group). The last follow-up was on June 30, 2017. Results: The total cough score and the total symptom score in the drug group were improved compared to those in the control group during 3 months after discharge (p < 0.001). Re-examination of chest HRCT within 4-6 months after discharge revealed that the improvements of peribronchial thickening, the extent of mucous plugging, and the Bhalla score were all significantly improved in the drug group. Moreover, the re-exacerbations in the drug group were significantly decreased within 1 year after discharge. Univariate analysis showed a highly significant prolongation of the time to first re-exacerbation in bronchiectasis due to treatment with airway drugs compared with that of the control group. Multivariate Cox regression analysis showed that the risk of first re-exacerbation in the drug group decreased by 29.7% compared with that of the control group. Conclusion: Endobronchial therapy with gentamicin and dexamethasone after AC by bronchoscopy is a safe and effective method for treating NCFB.

Cordycepin Alleviates Anterior Cruciate Ligament Transection (ACLT)-Induced Knee Osteoarthritis Through Regulating TGF-ß Activity and Autophagy.

INTRODUCTION: Osteoarthritis is the most prevalent articular disease in the elderly. We aimed to explore the role of cordycepin (COR) in the progression and development of osteoarthritis and its correlation with TGF-ß activity and autophagy. METHODS: Sprague Dawley rats were induced by anterior cruciate ligament transection (ACLT) to establish knee osteoarthritis model. To investigate the role of COR in knee osteoarthritis, rats were injected with 5, 10, and 20 mg/kg of COR before joint surgery. After surgery, paw withdrawal mechanical threshold (PWMT) was performed. HE staining and Alcian blue staining were carried out to detect cartilage damage. ELISA was used to detect the level of TGFß in the serum. Protein expression was analyzed by Western blotting. RESULTS: In this study, we found that the PWMT of rats with osteoarthritis induced by ACLT was decreased significantly, accompanied by obvious histological and cartilage damage. After different doses of COR treatment, the PWMT of osteoarthritis rats induced by ACLT was increased in a dose-dependent manner. In addition, compared with the control group, COR treatment also reversed the effect of ACLT on cartilage injury in rats. Furthermore, the level of TGF-ß in serum of ACLT rats was increased significantly, which may be related to the overexpression of TGF-ß R1. However, the increase of serum TGF-ß level in ACLT rats was reversed by COR treatment in a dose-dependent manner. It is worth noting that TGF-ß overexpression reduced the proportion of autophagy-related protein LC3-II/I, thus inhibiting autophagy. In order to further confirm the effect of TGF-ß on autophagy, TGF-ß was overexpressed or the autophagy inhibitor 3-MA was applied. The results showed that TGF-ß overexpression and 3-MA treatment reversed the effect of COR on autophagy. CONCLUSION: In summary, our findings declared that COR alleviated ACLT-induced osteoarthritis pain and cartilage damage by inhibiting TGF-ß activity and inducing autophagy in rat model with knee osteoarthritis.

Multi-omics analysis reveals the functional transcription and potential translation of enhancers.

Enhancer can transcribe RNAs, however, most of them were neglected in traditional RNA-seq analysis workflow. Here, we developed a Pipeline for Enhancer Transcription (PET, http://fun-science.club/PET) for quantifying enhancer RNAs (eRNAs) from RNA-seq. By applying this pipeline on lung cancer samples and cell lines, we showed that the transcribed enhancers are enriched with histone marks and transcription factor motifs (JUNB, Hand1-Tcf3 and GATA4). By training a machine learning model, we demonstrate that enhancers can predict prognosis better than their nearby genes. Integrating the Hi-C, ChIP-seq and RNA-seq data, we observe that transcribed enhancers associate with cancer hallmarks or oncogenes, among which LcsMYC-1 (Lung cancer-specific MYC eRNA-1) potentially supports MYC expression. Surprisingly, a significant proportion of transcribed enhancers contain small protein-coding open reading frames (sORFs) and can be translated into microproteins. Our study provides a computational method for eRNA quantification and deepens our understandings of the DNA, RNA and protein nature of enhancers.

Puerarin 6″-O-xyloside suppresses growth, self-renewal and invasion of lung cancer stem-like cells derived from A549 cells via regulating Akt/c-Myc signalling.

Cancer stem cells have been identified as the major cause of cancer initiation and progression. To investigate the effects of puerarin 6″-O-xyloside (PXY), derived from Pueraria lobata (Willd.) Ohwi, on lung cancer stem cells, we enriched and identified a subpopulation of lung cancer stem-like cells (LCSLCs) derived from lung adenocarcinoma A549 cells with traits including high self-renewal and invasive capability in vitro, elevated tumourigenicity in vivo, and high expression of stem cell markers CD44, CD133 and aldehyde dehydrogenase 1 (ALDH1). We found that PXY could impair cell viability, suppress self-renewal and invasive capability, and decrease CD133, CD44 and ALDH1 mRNA expression in LCSLCs in a dose-dependent manner. Furthermore, we showed that PXY suppressed the self-renewal and invasive capability of LCSLCs at least in part through suppressing the activation of Akt/c-Myc signalling. In conclusion, PXY can block the traits of LCSLCs, indicating that PXY may be a candidate compound for lung adenocarcinoma therapy via eliminating LCSLCs.

Population pharmacokinetics of high-dose methotrexate in Chinese pediatric patients with medulloblastoma.

Methotrexate (MTX) pharmacokinetics has substantial inter-individual variability and toxicity. In children with medulloblastoma treated with high-dose methotrexate (HD-MTX), the pharmacokinetic properties of methotrexate have not been established. A total of 660 serum samples from 105 pediatric patients with medulloblastoma were included in a population pharmacokinetic (PPK) analysis of methotrexate by using the nonlinear mixed-effects modeling method. The basic one-compartment population pharmacokinetic model was established by NONMEM software and the first-order conditional estimation (FOCE) method, and the final covariate model was obtained by the stepwise regression method. Weight (WT), creatinine clearance (CrCL), and whether the treatment was combined with dexamethasone (DEX) were covariates that had significant effects on the clearance rate (CL) of the model. The pharmacokinetic equation of CL in the final covariate model was as follows: CLi = 9.23× (1 + 0.0005× (θCrCL -105.78)) × (1 + 0.0017× (θWT -16)) × eηcl,i (L/h), IF (θDEX ) CLi = 1.19× CLi (L/h). The estimation accuracy of all pharmacokinetic parameters were acceptable (relative standard error < 14.74%). The goodness-of-fit diagram and bootstrap tests indicated that the final PPK model was stable with acceptable predictive ability. The PPK model may be useful for determining personalized medication levels in pediatric medulloblastoma patients undergoing HD-MTX therapy.

Analysis of curative effect of adjuvant therapy with bronchoalveolar lavage on COPD patients complicated with pneumonia.

Clinical effect of adjuvant therapy with bronchoalveolar lavage on chronic obstructive pulmonary disease (COPD) patients complicated with pneumonia and its influence on the expression levels of inflammatory factors were studied. One hundred and twenty mild-moderate COPD patients complicated with pneumonia treated in the Department of Respiratory Medicine, The Sixth People's Hospital of Nantong from February 2016 to February 2017 were selected and randomly divided into three groups: One-time lavage group (n=40), two-time lavage group (n=40) and control group (n=40). Fasting peripheral blood was collected from all the patients in the morning. The lung function and blood gas analyses, and the detection of peripheral white blood cells (WBC), procalcitonin (PCT) and C-reactive protein (CRP) were performed. Moreover, the messenger RNA (mRNA) levels of interleukin-6 (IL-6), IL-8, tumor necrosis factor-α (TNF-α) and leukotriene B4 (LTB4) in lavage fluid were detected via reverse transcription-quantitative polymerase chain reaction. The lung functions of patients in the two-time lavage group were significantly improved compared with that in the one-time lavage group (p<0.01). pH and PaO2 in two-time lavage group were higher than those in the one-time lavage group (p<0.01). Peripheral WBC, PCT and CRP levels in the two-time lavage group were lower than those in the one-time lavage group (p<0.05). The mRNA levels of IL-6, IL-8, TNF-α and LTB4 in lavage fluid in two-time lavage group were lower than those in one-time lavage group (p<0.01). IL-6, IL-8, TNF-α and LTB4 expression levels in lavage fluid in two-time lavage group were lower than those in one-time lavage group (p<0.01). In conclusion, the adjuvant therapy with bronchoalveolar lavage improves the therapeutic effect on COPD patients complicated with pneumonia, which can significantly reduce the expression levels of inflammatory factors, and facilitate the control of pulmonary infection and recovery of lung function.

Differential Effects of Mycobacterium bovis BCG on Macrophages and Dendritic Cells from Murine Spleen.

Macrophages (MΦ) and dendritic cells (DCs) are both pivotal antigen presenting cells capable of inducing specific cellular responses to inhaled mycobacteria, and thus, they may be important in the initiation of early immune responses to mycobacterial infection. In this study, we evaluated and compared the roles of murine splenic DCs and MΦs in immunity against Mycobacterium bovis Bacillus Calmette-Guérin (M.bovis BCG). The number of internalized rBCG-GFP observed was obviously greater in murine splenic MΦs compared with DCs, and the intracellular reactive oxygen species (ROS), inducible nitric oxide synthase (iNOS) and nitric oxide (NO) levels in MΦs were all higher than in DCs. DCs have a stronger capacity for presenting Ag85A peptide to specific T hybridoma and when the murine splenic MΦs were infected with BCG and rBCG::Ag85A, low level of antigen presenting activity was detected. These data suggest that murine splenic MΦs participate in mycobacteria uptake, killing and inducing inflammatory response, whereas the murine splenic DCs are primarily involved in specific antigen presentation and T cell activation.

Gambogic acid-induced degradation of mutant p53 is mediated by proteasome and related to CHIP.

As an oncoprotein, mutant p53 is a potential tumor-specific target for cancer therapy. Most mutated forms of the protein are largely accumulated in cancer cells due to their increased stability. In the present study, we demonstrate that mutant p53 protein stability is regulated by gambogic acid (GA). Following GA exposure, protein levels of mutant p53 decreased while the mRNA levels were not affected in MDA-MB-435 cells, which indicate that GA down-regulates mutant p53 at post-transcription level. Co-treatment with GA and cycloheximide, a protein synthesis inhibitor, induced a decrease of half-life of mutant p53 protein. These findings indicated that the reduction of mutant p53 by GA was due to the destabilization and degradation of the protein. Furthermore, inhibition of proteasome activity by MG132 blocked GA-induced down-regulation of mutant p53, causing mutant p53 accumulation in detergent-insoluble cellular fractions. Further studies revealed that mutant p53 was ubiquitinated and it was chaperones related ubiquitin ligase carboxy terminus of Hsp70-interacting protein (CHIP) rather than MDM2 involved in the degradation of mutant p53. In addition, GA prevented Hsp90/mutant p53 complex formation and enhanced interaction of mutant p53 with Hsp70. Depletion of CHIP stabilized mutant p53 in GA treated cells. In conclusion, mutant p53 may be down-regulated by GA through chaperones-assisted ubiquitin/proteasome degradation pathway in cancer cells.

Hybrid cells differentiate to hepatic lineage cells and repair oxidative damage.

Hybrid cells derived from stem cells play an important role in organogenesis, tissue regeneration and cancer formation. However, the fate of hybrid cells and their range of function are poorly understood. Fusing stem cells and somatic cells induces somatic cell reprogramming, and the resulting hybrid cells are embryonic stem cell-like cells. Therefore, we hypothesize that fusion-induced hybrid cells may behave like ES cells in certain microenvironments. In this study, human hepatic cells were induced to apoptosis with H(2)O(2), and then co-cultured with hybrid cells that had been derived from mouse ES cells and human hepatic cells using a transwell. After co-culturing, the degree of apoptosis was evaluated using Annexin-V/PI double-staining analysis, flow cytometry and Western-blot. We observed that H(2)O(2)-induced cell apoptosis was inhibited by co-culture. In addition, the activity of injury-related enzymes (GSH-Px, LDH and SOD) and the level of albumin release in the co-culture system trended toward the level of normal undamaged hepatic cells. The stably increased levels of secretion of ALB in the co-culture system also confirmed that co-culture with hybrid cells helped in recovery from injury. The fate of the hybrid cells was studied by analyzing their gene expression and protein expression profiles. The results of RT-PCR indicated that during co-culturing, like ES cells, hybrid cells differentiated into hepatic lineage cells. Hybrid cells transcripted genes from both parental cell genomes. Via immunocytochemical analysis, hepatic directional differentiation of the hybrid cells was also confirmed. After injecting the hybrid cells into the mouse liver, the GFP-labeled transplanted cells were distributed in the hepatic lobules and engrafted into the liver structure. This research expands the knowledge of fusion-related events and the possible function of hybrid cells. Moreover, it could indicate a new route of differentiation from pluripotent cells to tissue-specific cells via conditional co-culture.

Involvement of p53 in oroxylin A-induced apoptosis in cancer cells.

Oroxylin A, a naturally occurring monoflavonoid extracted from Scutellariae radix, exhibits anticancer activity and induces apoptosis in human hepatocellular carcinoma HepG2 cells according to our previous data. In this study, we investigate whether p53 is involved in oroxylin A-triggered viability inhibition and apoptosis induction in cancer cells. In a panel of different cancer cell lines, more potent inhibitory effects of oroxylin A were observed in wtp53 cells than those in mtp53 or p53-null cells. Moreover, p53-siRNA-transfected HepG2 cells showed lower levels of apoptosis induced by oroxylin A than control-siRNA-transfected cells. Likewise, after oroxylin A treatment, p53-null K-562 cells displayed promoted apoptosis rate when transfected with wtp53 plasmid. Western blot and real-time RT-PCR assay revealed that oroxylin A markedly upregulated p53 protein expression in HepG2 and p53-overexpressing K-562 cells, but had no influence on p53 mRNA synthesis. Furthermore, after co-treatment with cycloheximide, oroxylin A still exerted a little effect on p53 expression. The negative regulator of p53, MDM2 protein was detected, and downregulated expression was observed. In the presence of MG132, an inhibitor of proteasome-mediated proteolysis, no change in p53 expression was obtained. Additionally, the antioxidant N-acetyl-L-cysteine could obviously abrogate p53 stabilization triggered by oroxylin A. Therefore, it is summarized that oroxylin A stabilized p53 expression and induced apoptosis at the posttranslational level via downregulating MDM2 expression and interfering MDM2-modulated proteasome-related p53 degradation. This indicated that oroxylin A could be served as a potential, novel agent candidate for cancer therapy.

Gambogic acid reduced bcl-2 expression via p53 in human breast MCF-7 cancer cells.

PURPOSE: In this study, we investigated the correlation between p53 and bcl-2 in gambogic acid (GA)-induced apoptosis. METHOD: MTT assay was employed to evaluate MCF-7 cell viability after GA treatment. Cell morphological changes were observed follow-up under the inverted microscope after GA withdrawal. To observe the cell apoptosis, DAPI staining was used. Meanwhile, p53 small interfering RNA (si-RNA) was adopted to knock p53 down. All expressions of p53 and bcl-2 were evaluated by Western blot analysis. RESULTS: MTT assay showed that GA inhibited MCF-7 cell growth effectively in a time-dependent manner. With 0.5 h GA treatment, p53 was significantly increased, whereas bcl-2 was reduced potently with 6 h GA treatment. After GA withdrawal, p53 expressions were maintained in high levels. Furthermore, bcl-2 decreasing was attenuated after co-treatment with PFT alpha, a p53 transcription blocker. Same result was observed after p53 knock-down by p53 si-RNA. CONCLUSIONS: Gambogic acid induced human breast cancer cells MCF-7 apoptosis by reducing bcl-2 expression via p53.

Macranthoside B, a hederagenin saponin extracted from Lonicera macranthoides and its anti-tumor activities in vitro and in vivo.

Macranthoside B (MB) is a hederagenin saponin extracted from the flower bud of Lonicera macranthoides. In this study, we defined the anticancer effect of MB both in vitro and in vivo using cell proliferation assays and xenograft tumor growth assays. Our data indicate that MB inhibits the proliferation of various kinds of cancer cells with IC(50) values in the range of 10-20 microM. Moreover, the volume and weight of xenograft tumors in nude mice treated with 5mg/kgMB were decreased remarkably compared to those of the vehicle control group. Furthermore, DAPI staining and flow cytometry analysis with Annexin V/PI double staining revealed that more apoptotic cells were observed following MB treatment. In addition, degradation of PARP (poly-ADP-ribose polymerase), and activation of the caspase cascade for intrinsic pathways were observed. We also found that the expression of Bcl-2 protein decreased and the protein level of Bax increased which leading to an increase of the Bax/Bcl-2 ratio. Our results showed that MB exhibited strong anti-tumor effect and mitochondrion-mediated apoptosis induction involved in it.

Gambogic acid down-regulates MDM2 oncogene and induces p21(Waf1/CIP1) expression independent of p53.

Gambogic acid (GA), the natural compound extracted from gamboges, has recently been established as a potent anti-tumor agent. Although it was proved that GA enhances p53 protein level through inhibition of MDM2 in p53 wild-type cancer cells, the mechanisms of MDM2 inhibition especially with the absence of p53 are not fully understood. Herein we further studied the MDM2 regulation by GA and propose novel explanations of its unrecognized mechanism. Regardless of p53 status, GA reduced MDM2 expression in a concentration- and time-dependent manner. Moreover, the inhibitory effects were exhibited at both transcriptional and posttranslational levels. We found that P1 and P2 promoter of MDM2 were both responsive to GA, resulting in decreased Mdm2 RNA level. At the posttranslational level, GA promoted the autoubiquitination of MDM2, followed by proteasome-mediated degradation. Additionally, GA increased p21(Waf1/CIP1) expression in p53 null cancer cells, which was associated with GA-mediated impairing of the interaction between MDM2 and p21(Waf1/CIP1). Furthermore, the apoptosis, cytotoxicity and G2/M cell cycle arrest induced by GA were detected in both p53 wild-type and p53 null cancer cells. In vivo anti-tumor activity of GA was also confirmed in H1299 xenografts. It is concluded that GA down-regulates the MDM2 oncogene and exerts the anti-tumor activity independent of p53, and therefore provide more evidences for its therapeutic application.