Histone methyltransferase DOT1L coordinates AR and MYC stability in prostate cancer

The histone methyltransferase DOT1L methylates lysine 79 (K79) on histone H3 and is involved in Mixed Lineage Leukemia (MLL) fusion leukemogenesis; however, its role in prostate cancer (PCa) is undefined. Here we show that DOT1L is overexpressed in PCa and is associated with poor outcome. Genetic and chemical inhibition of DOT1L selectively impaired the viability of androgen receptor (AR)-positive PCa cells and organoids, including castration-resistant and enzalutamide-resistant cells. The sensitivity of AR-positive cells is due to a distal K79 methylation-marked enhancer in the MYC gene bound by AR and DOT1L not present in AR-negative cells. DOT1L inhibition leads to reduced MYC expression and upregulation of MYC-regulated E3 ubiquitin ligases HECTD4 and MYCBP2, which promote AR and MYC degradation. This leads to further repression of MYC in a negative feed forward manner. Thus DOT1L selectively regulates the tumorigenicity of AR-positive prostate cancer cells and is a promising therapeutic target for PCa.

Histone methyltransferase, DOTL1 is implicated in the pathogenesis of MLL-rearranged leukemia, however, not much is known of its role in prostate cancer (PCa). Here, the authors report that DOTL1 inhibition suppresses both androgen receptor and MYC pathways in a negative feed forward manner to reduce growth of AR-positive PCa.

[The surgical treatment of male perineum Paget's disease]

Objective: To evaluatethe clinical efficacy and complications of skin graft and flap plastic technique covered the defect in perineal Paget's disease postoperatively. Methods: The study comprised 6 patients diagnosed with perineal Paget's disease at Beijing Chao-Yang Hospital from June 2017 to July 2019, with all available clinical data reviewed. The defects after resection of lesions were reconstructed with skin graft, advancement skin flap during the operation, respectively. The operation time, the skin graft or flap survival situation, intraoperative and postoperative complications were recorded. Results: Of all 6 patients, Ray stage A1consisted of 1 case, A2 5 cases. The age was (68±9) years, the hospitalization time was (14.8±8.1) days, the BMI was (25.6±3.7) kg/m(2), the operation time was (132.0±80.7) min, and the average blood loss was (18.3±11.7) ml. Five cases was with Paget's disease, and 1 case with skin adenocarcinoma with Paget's disease were diagnosed by pathology. The defects of 4 cases and 2 cases after removal of the tumor were reconstructed with scrotal advancement skin flap and skin graft, respectively. The skin graft and flap survived well during afollow-up of (15.3±8.1) months.There has been no local recurrence. The foreskin edema and wound infection were noted in 4 cases and 1 case, respectively. There was no other related complications. Conclusion: Perineal Paget's disease can be managed by resection and immediate reconstruction with skin graft or flap according to the size and location of the defect, and the clinical efficacy is distinct.

miR-146a alleviates the apoptosis of hippocampal neurons induced by microglia activation via targeting TRAF6

OBJECTIVE

To identify the role of miR-146a and tumor necrosis factor receptor-associated factor 6 (TRAF6) for improving the apoptosis of hippocampal neurons induced by microglia activation.

METHODS

Mouse microglial cell line (BV2 cell) was employed and treated with lipopolysaccharide. Mouse hippocampal nerve cell line (HT22 cell) was then grown in BV2 conditioned medium, and miR-146a overexpression and silencing cell lines were constructed. CCK8 and clone formation test were utilized to evaluate the proliferation ability of the transfected cells, and the level of inflammatory factors was measured by ELISA. Apoptosis was determined extensively by flow cytometry. The apoptosis-related protein and TRAF6 protein expressions were verified by Western blot. TRAF6 was identified to be the target gene of miR-146a based on double Luciferase Report. Finally, both TRAF6 and miR-146a were used to treat HT22 cells and the above indexes were detected repeatedly.

RESULTS

Interleukin (IL)-1β, tumor necrosis factor-α, and IL-6 expressions in BV2 cells increased significantly. miR-146a overexpression distinctly increased the cell proliferation ability and B-cell lymphoma-2 expression ((Bcl-2, p < 0.05); meanwhile, the apoptosis rate of cells, apoptosis-related proteins (Bcl-2 associated X and cleaved caspase-3), and TRAF6 gene and protein expressions were significantly decreased (p < 0.05). However, these above results were reversed for miR-146a silence. There is a targeting relationship between miR-146a and TRAF6. Silencing TRAF6 gene can promote HT22 cells' proliferation and inhibit apoptosis. The effect of miR-146a on HT22 cells was reversed by adding TRAF6 mimics to miR-146a overexpression cells.

CONCLUSION

miR-146a can inhibit the apoptosis of hippocampal neurons caused by microglia activation via targeting TRAF6 and down-regulating its expression.

Quantitative evaluation of carotid atherosclerotic vulnerable plaques using in vivo T1 mapping cardiovascular magnetic resonaonce: validation by histology

BACKGROUND

It has been proved that multi-contrast cardiovascular magnetic resonance (CMR) vessel wall imaging could be used to characterize carotid vulnerable plaque components according to the signal intensity on different contrast images. The signal intensity of plaque components is mainly dependent on the values of T1 and T2 relaxation. T1 mapping recently showed a potential in identifying plaque components but it is not well validated by histology. This study aimed to validate the usefulness of in vivo T1 mapping in assessing carotid vulnerable plaque components by histology.

METHODS

Thirty-four subjects (mean age, 64.0 ± 8.9 years; 26 males) with carotid plaques referred to carotid endarterectomy were prospectively enrolled and underwent 3 T CMR imaging from May 2017 to October 2017. The T1 values of intraplaque hemorrhage (IPH), necrotic core (NC) and loose matrix (LM) which were identified on multi-contrast vessel wall images or histology were measured on in-vivo T1 mapping. The IPHs were divided into two types based on the proportion of the area of fresh hemorrhage on histology. The T1 values of different plaque components were compared using Mann-Whitney U test and the agreement between T1 mapping and histology in identifying and quantifying IPH was analyzed with Cohen's Kappa and intraclass correlation coefficient (ICC).

RESULTS

Of 34 subjects, 19 had histological specimens matched with CMR imaging. The mean T1 values of IPH (651 ± 253 ms), NC (1161 ± 182 ms) and LM (1447 ± 310 ms) identified by histology were significantly different. The T1 values of Type 1 IPH were significantly shorter than that of Type 2 IPH (456 ± 193 ms vs. 775 ± 205 ms, p < 0.001). Moderate to excellent agreement was found in identification (kappa = 0.51, p < 0.001), classification (kappa = 0.40, p = 0.028) and segmentation (ICC = 0.816, 95% CI 0.679-0.894) of IPHs between T1 mapping and histology.

CONCLUSIONS

The T1 values of carotid plaque components, particularly for intraplaque hemorrhage, are differentiable, and the stage of intraplaque hemorrhage can be classified according to T1 values, suggesting the potential capability of assessment of vulnerable plaque components by T1 mapping.

A systematic survey of randomised trials that stopped early for reasons of futility

Background

Randomised trial protocols may incorporate interim analyses, with the potential to stop the study for futility if early data show insufficient promise of a treatment benefit. Previously, we have shown that this approach will theoretically lead to mis-estimation of the treatment effect. We now wished to ascertain the importance of this phenomenon in practice.

Methods

We reviewed the methods and results in a set of trials that had stopped for futility, identified through an extensive literature search. We recorded clinical areas, interventions, study design, outcomes, trial setting, sponsorship, planned and actual treatment effects, sample sizes; power; and if there was a data safety monitoring board, or a published protocol. We identified: if interim analyses were pre-specified, and how many analyses actually occurred; what pre-specified criteria might define futility; if a futility analysis formed the basis for stopping; who made the decision to stop; and the conditional power of each study, i.e. the probability of statistically significant results if the study were to continue to its complete sample size.

Results

We identified 52 eligible trials, covering many clinical areas. Most trials had multiple centres, tested drugs, and 40% were industry sponsored. There were 75% where at least one interim analysis was planned a priori; a majority had only one interim analysis, typically with about half the target total sample size. A majority of trials did not pre-define a stopping rule, and a variety of reasons were given for stopping. Few studies calculated and reported low conditional power to justify the early stop. When conditional power could be calculated, it was typically low, especially under the current trend hypothesis. However, under the original design hypothesis, a few studies had relatively high conditional power. Data collection often continued after the interim analysis.

Conclusions

Although other factors will typically be involved, we conclude that, from the perspective of conditional power, stopping early for futility was probably reasonable in most cases, but documentation of the basis for stopping was often missing or vague. Interpretation of truncated trials would be enhanced by improved reporting of stopping protocols, and of their actual execution.

TRIM24 aggravates the progression of ovarian cancer through negatively regulating FOXM1 level

OBJECTIVE

This study aims to uncover the biological functions of the feedback loop tripartite motif-containing 24 (TRIM24)/Forkhead Box M1 (FOXM1) in the pathological progression of ovarian cancer (OC) and the underlying mechanism.

PATIENTS AND METHODS

The expression levels of TRIM24 and FOXM1 in OC tissues and cells were determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The potential correlation between TRIM24 level and clinical indexes of OC patients was analyzed. The Kaplan-Meier curves were depicted for evaluating the prognostic potentials of TRIM24 and FOXM1 in OC patients. The regulatory effects of TRIM24 and FOXM1 on proliferative, migratory, and invasive capacities of SKOV3 and OVCAR3 cells were assessed through functional experiments. The rescue experiments were performed to clarify the feedback loop TRIM24/FOXM1 in influencing the progression of OC.

RESULTS

TRIM24 was upregulated in OC tissues and cells. The high level of TRIM24 was linked to higher rates of lymphatic and distant metastasis and worse survival in OC patients. The silence of TRIM24 attenuated proliferative, migratory, and invasive capacities of SKOV3 and OVCAR3 cells. FOXM1 level was negatively regulated by TRIM24, which was downregulated in OC. The low level of FOXM1 predicted worse survival in OC patients. Besides, the rescue experiments demonstrated that the feedback loop TRIM24/FOXM1 aggravated the malignant progression of OC.

CONCLUSIONS

TRIM24 is upregulated in OC tissues, and closely linked to the occurrence of lymphatic and distant metastasis. Through negatively regulating FOXM1 level, TRIM24 aggravates the progression of OC.

Prospects of Application of Microbial Biofilm to Estimate PMI of Corpses in Water

Abstract

In forensic pathology, the estimation of postmortem interval （PMI） has always been a difficult issue, and there is still lack of effective methods to estimate PMI of corpses in water. Microbial biofilm refers to the microbial population attached to non-biological or biological surfaces by microorganisms during microbial growth, that has a three-dimensional structure, surrounded by extracellular polymers and matrix networks created by itself. A series of community succession phenomena of microorganisms occur during the occurrence and development of microbial population. The microbial community and its succession process of this kind of biofilm attached to the surface of a corpse in water may become a new basis for estimation of the PMI of corpses in water. This review elucidates on the concept, classification, research methods, and influencing factors of biofilm and analyzes its application prospects in PMI estimation of corpses in water, which would provide new ideas for the researches in this field.