NAT10-mediated ac 4 C-modified ANKZF1 promotes tumor progression and lymphangiogenesis in clear-cell renal cell carcinoma by attenuating YWHAE-driven cytoplasmic retention of YAP1

Background:Lymphatic metastasis is one of the most common metastatic routes and indicates a poor prognosis in clear-cell renal cell carcinoma(ccRCC).N-acetyltransferase 10(NAT10)is known to catalyze N4-acetylcytidine(ac4C)modification of mRNA and participate in many cellular processes.However,its role in the lymphangiogenic process of ccRCC has not been reported.This study aimed to elucidate the role of NAT10 in ccRCC lymphangiogenesis,providing valuable insights into potential therapeutic targets for intervention.Methods:ac4C modification and NAT10 expression levels in ccRCC were assessed using public databases and clinical samples.Functional investigations involved manipulating NAT10 expression in cellular and mouse models to study its role in ccRCC.Mechanistic insights were gained through a combination of RNA sequencing,mass spectrometry,co-immunoprecipitation,RNA immuno-precipitation,immunofluorescence,and site-specific mutation analyses.Results:We found that ac4C modification and NAT10 expression levels increased in ccRCC.NAT10 promoted tumor progression and lymphangiogene-sis of ccRCC by enhancing the nuclear import of Yes1-associated transcriptional regulator(YAP1).Subsequently,we identified ankyrin repeat and zinc fin-ger peptidyl tRNA hydrolase 1(ANKZF1)as the functional target of NAT10,and its upregulation in ccRCC was caused by NAT10-mediated ac4C modifi-cation.Mechanistic analyses demonstrated that ANKZF1 interacted with tyro-sine 3-monooxygenase/tryptophan 5-monooxygenase activation protein epsilon(YWHAE)to competitively inhibit cytoplasmic retention of YAP1,leading to transcriptional activation of pro-lymphangiogenic factors.Conclusions:These results suggested a pro-cancer role of NAT10-mediated acetylation in ccRCC and identified the NAT10/ANKZF1/YAP1 axis as an under-reported pathway involving tumor progression and lymphangiogenesis in ccRCC.

N6-methyladenosine-modified DBT alleviates lipid accumulation and inhibits tumor progression in clear cell renal cell carcinoma through the ANXA2/YAP axis-regulated Hippo pathway

Background:The mechanism of metabolism reprogramming is an unsolved problem in clear cell renal cell carcinoma(ccRCC).Recently,it was discovered that the Hippo pathway altered tumor metabolism and promoted tumor progression.Thus,this study aimed at identifying key regulators of metabolism reprogramming and the Hippo pathway in ccRCC and pinpointing potential therapeutic targets for ccRCC patients.Methods:Hippo-related gene sets and metabolic gene sets were used to screen potential regulators of the Hippo pathway in ccRCC.Public databases and samples from patients were applied to investigate the association of dihydrolipoamide branched chain transacylase E2(DBT)with ccRCC and Hippo signaling.The role of DBT was confirmed by gain or loss of function assays in vitro and in vivo.Mechanistic results were yielded by luciferase reporter assay,immunoprecipitation,mass spectroscopy,and mutational studies.Results:DBT was confirmed as a Hippo-related marker with significant prognostic predictive value,and its downregulationwas caused bymethyltransferaselike-3(METTL3)-mediated N6-methyladenosine(m6A)modification in ccRCC.Functional studies specified DBT as a tumor suppressor for inhibiting tumor progression and correcting the lipid metabolism disorder in ccRCC.Mechanistic findings revealed that annexin A2(ANXA2)interacted with the lipoyl-binding domain of DBT to activate Hippo signaling which led to decreased nuclear localization of yes1-associated transcriptional regulator(YAP)and transcriptional repression of lipogenic genes.Conclusions:This study demonstrated a tumor-suppressive role for the DBT/ANXA2/YAP axis-regulated Hippo signaling and suggested DBT as a potential target for pharmaceutical intervention in ccRCC.

Oxide formation mechanism of a corrosion-resistant CZ1 zirconium alloy

Tailoring microstructure and microchemistry by altering elemental compositions and thermomechanical treatment parameters enables superior corrosion performance in zirconium alloys for nuclear applications.However,our understanding of the relationship between various defects and the corrosion process remains limited in the newly developed zirconium alloys.Here we report the oxide formation mechanism of a CZ1 zirconium alloy with corrosion resistance surpassing many other zirconium alloy systems,such as Zircaloy-4 and Zr-1Nb-1Sn alloys.Autoclave experiments of CZ1 alloy and Zr1Nb-1Sn model alloy were performed in 360°C water for up to 820 d.We quantitively determined oxide phases by transmission Kikuchi diffraction(TKD)and examined lateral cracks,nano-porosity,and second-phase particles in oxide scales by transmission electron microscopy(TEM).Compared to the Zr-1Nb-1Sn model alloy,CZ1 alloy with lower Nb and Sn concentrations has shown smaller and lower-density lateral cracks but slightly larger oxide grains,reducing the diffusion route for oxidating species.Using analytical scanning and transmission electron microscopy,we demonstrate that due to the lower content of Sn(∼0.9 wt.%),there is less tetragonal ZrO_(2) phase formed in the oxide,and the level of tetragonal to the monoclinic phase transition is reduced.Although the Nb content(0.1 wt.%–0.3 wt.%)is lower than the solid solution limit of Nb in Zr,by introducing minor elements such as Fe,Cr,and Cu,there are still a reasonable number of second-phase particles to relieve the high stress associated with the metal-to-oxide transformation.These mechanisms have substantially changed the density and distribution of lateral cracks in the oxide,thus reducing the corrosion rate of zirconium alloys.