ATM Activation is Key in Vasculogenic Mimicry Formation by Glioma Stem-like Cells

Objective Vasculogenic mimicry(VM)is a novel vasculogenic process integral to glioma stem cells(GSCs)in glioblastoma(GBM).However,the relationship between VM and ataxia-telangiectasia mutated(ATM)serine/threonine kinase activation,which confers chemoradiotherapy resistance,remains unclear.Methods We investigated VM formation and phosphorylated ATM(pATM)levels by CD31/GFAPperiodic acid-Schiff dual staining and immunohistochemical staining in 145 GBM specimens.Glioma stem-like cells(GSLCs)derived from the formatted spheres of U87 and U251 cell lines and their pATM level and VM formation ability were examined using western blot and three-dimensional culture.For the examination of the function of pATM in VM formation by GSLCs,ATM knockdown by shRNAs and deactivated via ATM phosphorylation inhibitor KU55933 were studied.Results VM and high pATM expression occurred in 38.5% and 41.8% of tumors,respectively,and were significantly associated with reduced progression-free and overall survival.Patients with VM-positive GBMs exhibited higher pATM levels(r_(s)=0.425,P=0.01).The multivariate analysis established VM as an independent negative prognostic factor(P=0.002).Furthermore,GSLCs expressed high levels of pATM and formed vascular-like networks in vitro.ATM inactivation or knockdown hindered VM-like network formation concomitant with the downregulation of pVEGFR-2,VE-cadherin,and laminin B2.Conclusion VM may predict a poor GBM prognosis and is associated with pATM expression.We propose that pATM promotes VM through extracellular matrix modulation and VE-Cadherin/pVEGFR-2 activation,thereby highlighting ATM activation as a potential target for enhancing anti-angiogenesis therapies for GBM.

Cosmetic Safety Evaluation Based on In Vitro Three-dimensional Reconstructed Human Epidermis(3D-RHE) Models

Cosmetic safety evaluation employs a series of toxicological tests, on both qualitative and quantitative levels, to assess the potential risks for the daily use of selected cosmetic ingredients and final products. Traditionally, safety evaluation of cosmetics uses animal tests. With the development of in vitro science and the 3R （Reduction, Replacement and Refinement） principle, three-dimensional reconstructed human epidermis （3D-RHE） models have been developed and widely applied in cosmetic safety evaluation. Reconstructed human skin models possess anatomy and metabolism biology similar to real human tissue. This paper reviews the current application of 3D-RHE models in the safety evaluation of skin irritation, eye irritation, phototoxicity and genotoxicity potential of cosmetic ingredients/formulas. The advantages and disadvantages of using skin models are also discussed, and comments and suggestions are given for its future development.

m^(6)A reader YTHDF1 promotes cardiac fibrosis by enhancing AXL translation

Cardiac fibrosis caused by ventricular remodeling and dysfunction such as post-myocardial infarction(MI)can lead to heart failure.RNA N6-methyladenosine(m^(6)A)methylation has been shown to play a pivotal role in the occurrence and development of many illnesses.In investigating the biological function of the m^(6)A reader YTHDF1 in cardiac fibrosis,adeno-associated virus 9 was used to knock down or overexpress the YTHDF1 gene in mouse hearts,and MI surgery in vivo and transforming growth factor-β(TGF-β)-activated cardiac fibroblasts in vitro were performed to establish fibrosis models.Our results demonstrated that silencing YTHDF1 in mouse hearts can significantly restore impaired cardiac function and attenuate myocardial fibrosis,whereas YTHDF1 overexpression could further enhance cardiac dysfunction and aggravate the occurrence of ventricular pathological remodeling and fibrotic development.Mechanistically,zinc finger BED-type containing 6 mediated the transcriptional function of the YTHDF1 gene promoter.YTHDF1 augmented AXL translation and activated the TGF-β-Smad2/3 signaling pathway,thereby aggravating the occurrence and development of cardiac dysfunction and myocardial fibrosis.Consistently,our data indicated that YTHDF1 was involved in activation,proliferation,and migration to participate in cardiac fibrosis in vitro.Our results revealed that YTHDF1 could serve as a potential therapeutic target for myocardial fibrosis.

ARF-mediated SUMOylation of Apak antagonizes ubiquitylation and promotes its nucleolar accumulation to inhibit 47S pre-rRNA synthesis

Ribosomes are among the most fundamental molecular machines in all cells,as they are required for protein synthesis.Most structural rRNA components are generated in the nucleolus and assembled into pre-ribosomal particles.Here we show Apak,a previously identified p53 inhibitor,as a novel ribosomal stress response protein.In unstressed cells,Apak is bound to the deSUMOylase SENP1 in the nucleoplasm and targeted for proteasomal degradation by MDM2 ubiquitin ligase.Upon ribosomal stress,SENP1 dissociates fromApak and the tumor suppressor protein ARF couplesUbc9 with Apak to promote Apak SUMOylation on zinc fingers.This results in Apak protein stabilization and translocation to the nucleolus,where Apak inhibits the pre-rRNA synthesis.These findings provide a molecular mechanism whereby ARF coordinates Apak to regulate ribosome biogenesis upon cellular stress.

A method for distinguishing benign and malignant pulmonary nodules based on 3D dual path network aided by K-means clustering analysis

In the USA,there were about 1806590 new cancer cases in 2020,and 606520 cancer deaths are expected to have occurred in 2021.Lung cancer has become the leading cause of death from cancer in both men and women(Siegel et al.,2020).Clinical studies show that the five-year survival rate of lung cancer patients after early diagnosis and treatment intervention can reach 80%,compared with that of patients having advanced lung cancer.Thus,the early diagnosis of lung cancer is a key factorto reduce mortality.