The interaction between m⁶A-methylated RNA and chromatin modification remains largely unknown. We found that targeted inhibition of bromodomain-containing protein 4 (BRD4) by siRNA or its inhibitor (JQ1) significantly decreases mRNA m⁶A levels and suppresses the malignancy of breast cancer (BC) cells via increased expression of demethylase AlkB homolog 5 (ALKBH5). Mechanistically, inhibition of BRD4 increases the mRNA stability of ALKBH5 via enhanced binding between its 3' untranslated regions (3'UTRs) with RNA-binding protein RALY. Further, BRD4 serves as a scaffold for ubiquitin enzymes tripartite motif containing-21 (TRIM21) and ALKBH5, resulting in the ubiquitination and degradation of ALKBH5 protein. JQ1-increased ALKBH5 then demethylates mRNA of extra spindle pole bodies like 1 (ESPL1) and reduces binding between ESPL1 mRNA and m⁶A reader insulin like growth factor 2 mRNA binding protein 3 (IGF2BP3), leading to decay of ESPL1 mRNA. Animal and clinical studies confirm a critical role of BRD4/ALKBH5/ESPL1 pathway in BC progression. Further, our study sheds light on the crosstalks between histone modification and RNA methylation.

Chemical modifications of nitrogenous bases or ribosemoieties are common in RNA molecules and these RNA modifications regu-late tumor progression by modulating gene expression in malignancies.Therefore,delving into the role of RNA modifications in tumor pro-gression is essential for understanding tumor progression mechanisms and developing intervention strategies.Mitochondria are crucial for maintaining the energy state of malignant tumor cells.Recent studies have indicated that RNA modifications and tumor mitochondria are closely connected,implying that mitochondrial function within tumors can be disrupted due to RNA modifications.This article focuses on the role and underlying mechanisms of RNA modifications in tumor mitochondria,offering crucial insights for a deeper understanding of the reg-ulatory mechanisms of tumor metabolism and the development of new innovative therapeutic strategies.

Objective:To reassess the prognostic value of minimal residual disease (MRD) and IKZF1 gene deletions in adults with B-cell acute lymphoblastic leukemia (B-ALL) who received pediatric-specific chemotherapy regimens during the Nanfang Hospital PDT-ALL-2016 trial.Methods:We retrospectively analyzed the prognosis of 149 adult patients with B-ALL who were admitted to Nanfang Hospital from January 2016 to September 2020. Prognostic factors were identified using Cox regression models.Results:The complete remission rate was 93.2% in 149 patients, with a 5-year overall survival (OS) rate of (54.3±5.0) % and a cumulative incidence of relapse (CIR) of (47.5±5.2) %. The Cox regression analysis revealed that MRD positivity at day 45 (MRD 3) after induction therapy was independently associated with relapse risk ( HR=2.535, 95% CI 1.122-5.728, P=0.025). Deletion of IKZF1 gene was independently associated with mortality risk ( HR=1.869, 95% CI 1.034-3.379, P=0.039). Based on MRD 3 and IKZF1 gene status, we categorized adult patients with B-ALL into the low-risk (MRD 3-negative and IKZF1 gene deletion-negative) and high-risk (MRD 3-positive and/or IKZF1 gene wild type) groups. The 5-year OS and CIR rates were (45.5±6.0) % vs (69.4±8.6) % ( P<0.001) and (61.6±8.3) % vs (25.5±6.5) % ( P<0.001), respectively, in the high-risk and low-risk groups, respectively. The multivariate analysis showed that the high-risk group was an independent risk factor for OS ( HR=3.937, 95% CI 1.975-7.850, P<0.001) and CIR ( HR=4.037, 95% CI 2.095-7.778, P<0.001) . Conclusion:The combined use of MRD and IKZF1 gene in prognostic stratification can improve clinical outcome prediction in adult patients with B-ALL, helping to guide their treatment.

N ⁶-methyladenosine (m⁶A) modification is critical for mRNA splicing, nuclear export, stability and translation. Fat mass and obesity-associated protein (FTO), the first identified m⁶A demethylase, is critical for cancer progression. Herein, we developed small-molecule inhibitors of FTO by virtual screening, structural optimization, and bioassay. As a result, two FTO inhibitors namely 18077 and 18097 were identified, which can selectively inhibit demethylase activity of FTO. Specifically, 18097 bound to the active site of FTO and then inhibited cell cycle process and migration of cancer cells. In addition, 18097 reprogrammed the epi-transcriptome of breast cancer cells, particularly for genes related to P53 pathway. 18097 increased the abundance of m⁶A modification of suppressor of cytokine signaling 1 (SOCS1) mRNA, which recruited IGF2BP1 to increase mRNA stability of SOCS1 and subsequently activated the P53 signaling pathway. Further, 18097 suppressed cellular lipogenesis via downregulation of peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT/enhancer-binding protein alpha (C/EBPα), and C/EBPβ. Animal studies confirmed that 18097 can significantly suppress in vivo growth and lung colonization of breast cancer cells. Collectively, we identified that FTO can work as a potential drug target and the small-molecule inhibitor 18097 can serve as a potential agent against breast cancer.

Objective:To explore the regulatory effect of cellular FLICE-like inhibitory protein (cFLIP) on myocardial ischemia-reperfusion injury based on the RIPK1/RIPK3/MLKL-mediated necroptosis pathway.Methods:The cardiomyocyte hypoxia/reoxygenation (H/R) model was constructed by hypoxia for 4 h/reoxygenation for 12 h, and the rat ischemia reperfusion (I/R) model was constructed by ligating the left anterior descending artery for 30 min and reperfusion for 3 h. CCK-8 method was used to detect the viability of cardiomyocytes in each group. DAPI/PI double staining was used to observe changes in necrosis rate of myocardial cell. STRING database was used to predict the protein interaction network of cFLIP. TTC staining was used to detect the area of myocardial infarction in each group of rats, and the protein expression of cFLIPL, cFLIPS, p-RIPK1, p-RIPK3 and p-MLKL were detected by Western blot.Results:In cardiomyocyte H/R injury and myocardial tissue I/R injury, the protein expressions of cFLIPL and cFLIPS were significantly down-regulated, while the levels of p-RIPK1, p-RIPK3 and p-MLKL were increased significantly. Up-regulating the protein expression of cFLIPL and cFLIPS could significantly reduce the damage of cardiomyocytes and the rate of cell necrosis induced by H/R, and decrease the area of myocardial infarction caused by I/R. STRING database results showed that cFLIP had direct protein interactions with RIPK1 and RIPK3. Overexpression of cFLIP in cardiomyocyte and myocardial tissue significantly inhibited H/R or I/R induced the phosphorylation levels of RIPK1, RIPK3 and MLKL.Conclusions:Overexpression of cFLIP can significantly inhibit the RIPK1/RIPK3/MLKL-mediated necroptosis, thereby reducing myocardial cell damage and decreasing the area of myocardial infarction.

Objective To study the effect of Sildenafil in the treatment of hypoxemia after operation of cyanotic congenital heart disease.Methods A total of 34 cases with hypoxemia after operation of cyanotic congenital heart disease were collected between January 2009 to January 2015.They took Sildenafil with the dosage of 0.3-0.5 mg/kg every 6 hour.The change of heart rate (HR),systolic blood pressure (SBP),central venous pressure (CVP),pulmonary artery pressure (PAP),arterial partial pressure of oxygen [pa (O2)],arterial partial pressure of carbon dioxide [Pa (CO2)],oxygenation index [pa (O2)/FiO2],peak airway pressure (Ppeak),positive inotropic drug score (PIDS) and the lower bound of liver were observed at 4 time points,including before taking the medicine,after taking the medicine for 1 hour,after taking the medicine 1 day and after the ventilator was removed.Based on the data,the therapeutic effects of Sildenafil were studied.Results All 34 cases were cured.At the time point of 1 hour after taking Sildenafil,PAP,CVP and Ppeak decreased significantly,but pa (O2) and pa (O2)/FiO2 increased significantly (P ＜ 0.05).At the time point of 1 day after taking Sildinafil,SBP increased steadily,but PAP and CVP continued to get lower,and PIDS decreased significantly,while the liver lower bound was significantly reduced (P ＜ 0.05).At the time point of removing the ventilator,pa (O2) reached to (144.12 ± 26.25) mmHg,and hypoxemia was corrected,but PAP was reduced to (37.47 ± 3.77) mmHg,PIDS decreased to (17.56-± 1.94) scores,and heart failure was corrected.Compared with the previous 3 time points,there were statistically significant differences (P ＜ 0.05).Conclusion Sildenafil can highly selectively decrease pulmonary vascular resistance and obviously promote the correction of hypoxemia after operation of cyanotic congenital heart disease.