RNA m1A methylation regulates glycolysis of cancer cells through modulating ATP5D.

Studies on biological functions of RNA modifications such as N6-methyladenosine (m6A) in mRNA have sprung up in recent years, while the roles of N1-methyladenosine (m1A) in cancer progression remain largely unknown. We find m1A demethylase ALKBH3 can regulate the glycolysis of cancer cells via a demethylation activity dependent manner. Specifically, sequencing and functional studies confirm that ATP5D, one of the most important subunit of adenosine 5'-triphosphate synthase, is involved in m1A demethylase ALKBH3-regulated glycolysis of cancer cells. The m1A modified A71 at the exon 1 of ATP5D negatively regulates its translation elongation via increasing the binding with YTHDF1/eRF1 complex, which facilitates the release of message RNA (mRNA) from ribosome complex. m1A also regulates mRNA stability of E2F1, which directly binds with ATP5D promoter to initiate its transcription. Targeted specific demethylation of ATP5D m1A by dm1ACRISPR system can significantly increase the expression of ATP5D and glycolysis of cancer cells. In vivo data confirm the roles of m1A/ATP5D in tumor growth and cancer progression. Our study reveals a crosstalk of mRNA m1A modification and cell metabolism, which expands the understanding of such interplays that are essential for cancer therapeutic application.

Targeted mRNA demethylation using an engineered dCas13b-ALKBH5 fusion protein.

Studies on biological functions of N6-methyladenosine (m6A) modification in mRNA have drawn significant attention in recent years. Here we describe the construction and characterization of a CRISPR-Cas13b-based tool for targeted demethylation of specific mRNA. A fusion protein, named dm6ACRISPR, was created by linking a catalytically inactive Type VI-B Cas13 enzyme from Prevotella sp. P5-125 (dPspCas13b) to m6A demethylase AlkB homolog 5 (ALKBH5). dm6ACRISPR specifically demethylates m6A of targeted mRNA such as cytochrome b5 form A (CYB5A) to increase its mRNA stability. It can also demethylate ß-catenin-encoding CTNNB1 mRNA that contains multiple m6A sites to trigger its translation. In addition, the dm6ACRISPR system incurs efficient demethylation of targeted epitranscriptome transcripts with limited off-target effects. Targeted demethylation of transcripts coding for oncoproteins such as epidermal growth factor receptor (EGFR) and MYC can suppress proliferation of cancer cells. Together, we provide a programmable and in vivo manipulation tool to study mRNA modification of specific genes and their related biological functions.

Low initial trough concentration of rituximab is associated with unsatisfactory response of first-line R-CHOP treatment in patients with follicular lymphoma with grade 1/2.

For follicular lymphoma (FL) with grade 1/2, the complete response (CR) rate of the first-line R-CHOP treatment was significantly low. In this study, we assessed the rationality of the administration of rituximab for FL patients with grade 1/2 based on concentration-response relationship analyses. Thus, we conducted a prospective pharmacokinetic (PK) study in 68 FL patients with grades 1-3 treated with R-CHOP at 21-day intervals. Plasma rituximab concentrations were quantified using ELISA and the population PK modeling was established with Phoenix® NLMETM. The first cycle trough concentration (C1-trough) of rituximab was a significant independent risk factor for achieving CR in matched-pair logistic regression analysis, rather than the concentrations in later cycles; the recommendatory minimum optimal C1-trough was 13.60 µg/mL. Patients with grade 1/2 had significantly lower C1-trough compared with grade 3 (12.21 µg/mL vs. 23.45 µg/mL, P < 0.001), only 30% patients with grade 1/2 could reach 13.60 µg/mL, compared with 91.67% in patients with grade 3, which was in accord with its unsatisfactory CR rates (43.33% vs. 76.32%). The stage indicating the tumor burden (the target) was a crucial influence factor for C1-trough, accounting for 40.70% of its variability, 70% patients with grade 1/2 were stage IV in this study, since the systemic therapy only started at the disseminated disease stage. The initial dose of 1800 mg was recommended by Monte Carlo simulation for patients with grade 1/2. In summary, low C1-trough accounted for low-grade FL's unsatisfactory CR rate, designing the first dosage of rituximab should be a very important component of individualized therapy for FL.

Transfer RNA demethylase ALKBH3 promotes cancer progression via induction of tRNA-derived small RNAs.

Transfer RNA is heavily modified and plays a central role in protein synthesis and cellular functions. Here we demonstrate that ALKBH3 is a 1-methyladenosine (m1A) and 3-methylcytidine (m3C) demethylase of tRNA. ALKBH3 can promote cancer cell proliferation, migration and invasion. In vivo study confirms the regulation effects of ALKBH3 on growth of tumor xenograft. The m1A demethylated tRNA is more sensitive to angiogenin (ANG) cleavage, followed by generating tRNA-derived small RNAs (tDRs) around the anticodon regions. tDRs are conserved among species, which strengthen the ribosome assembly and prevent apoptosis triggered by cytochrome c (Cyt c). Our discovery opens a potential and novel paradigm of tRNA demethylase, which regulates biological functions via generation of tDRs.

Use of a Remote Oncology Pharmacy Service Platform for Patients With Cancer During the COVID-19 Pandemic: Implementation and User Acceptance Evaluation.

BACKGROUND: The COVID-19 outbreak has increased challenges associated with health management, especially cancer management. In an effort to provide continuous pharmaceutical care to cancer patients, Sun Yat-sen University Cancer Center (SYSUCC) implemented a remote pharmacy service platform based on its already existing web-based hospital app known as Cloud SYSUCC. OBJECTIVE: The aim of this study was to investigate the characteristics, acceptance, and initial impact of the Cloud SYSUCC app during a COVID-19 outbreak in a tertiary cancer hospital in China. METHODS: The total number of online prescriptions and detailed information on the service were obtained during the first 6 months after the remote service platform was successfully set up. The patients' gender, age, residence, primary diagnosis, drug classification, weekly number of prescriptions, and prescribed drugs were analyzed. In addition, a follow-up telephonic survey was conducted to evaluate patients' satisfaction in using the remote prescription service. RESULTS: A total of 1718 prescriptions, including 2022 drugs for 1212 patients, were delivered to 24 provinces and municipalities directly under the Central Government of China between February 12, 2020, and August 11, 2020. The majority of patients were female (841/1212, 69.39%), and 90.18% (1093/1212) of them were aged 31-70 years old. The top 3 primary diagnoses for which remote medical prescriptions were made included breast cancer (599/1212, 49.42%), liver cancer (249/1212, 20.54%), and thyroid cancer (125/1212, 10.31%). Of the 1718 prescriptions delivered, 1435 (83.5%) were sent to Guangdong Province and 283 (16.5%) were sent to other provinces in China. Of the 2022 drugs delivered, 1012 (50.05%) were hormonal drugs. The general trend in the use of the remote prescription service declined since the 10th week. A follow-up telephonic survey found that 88% (88/100) of the patients were very satisfied, and 12% (12/100) of the patients were somewhat satisfied with the remote pharmacy service platform. CONCLUSIONS: The remote pharmacy platform Cloud SYSUCC is efficient and convenient for providing continuous pharmaceutical care to patients with cancer during the COVID-19 crisis. The widespread use of this platform can help to reduce person-to-person transmission as well as infection risk for these patients. Further efforts are needed to improve the quality and acceptance of the Cloud SYSUCC platform, as well as to regulate and standardize the management of this novel service.

Level of N6-Methyladenosine in Peripheral Blood RNA: A Novel Predictive Biomarker for Gastric Cancer.

BACKGROUND: Dysregulation of N6-methyladenosine (m6A) is associated with various human diseases including cancer. This study aimed to evaluate the level of m6A as a biomarker for gastric cancer (GC) diagnosis. METHODS: Peripheral blood samples were collected from 100 GC patients, 30 benign gastric disease (BGD) patients, and 75 healthy controls (HCs). Levels of m6A in total RNA and expression of m6A-related proteins were analyzed. RESULTS: The m6A levels in peripheral blood RNA were significantly increased in the GC group compared with those in the BGD or HC groups; moreover, levels increased with the progression and metastasis of GC and decreased in GC patients after surgery. The area under the curve (AUC) for m6A in the GC group was 0.929 (95% CI, 0.88-0.96), which is markedly greater than the AUCs for carcinoembryonic antigen (CEA; 0.694) and carbohydrate antigen 199 (CA199; 0.603). The combination of CEA and CA199 with m6A improved the AUC to 0.955 (95% CI, 0.91-0.98). The expressions of m6A demethylases ALKBH5 and FTO were significantly downregulated in the GC group compared with the HC group. Coculture with GC cells increased the m6A of RNA in promyelocytic (HL-60) and monocytic (THP-1) leukemia cells and nontumorigenic human peripheral blood B lymphocyte cells (PENG-EBV). Furthermore, a xenograft model enhanced the m6A in peripheral blood RNA of mice. Accordingly, expressions of ALKBH5 and FTO were decreased both in vitro and in vivo. CONCLUSIONS: Level of m6A in peripheral blood RNA is a promising noninvasive diagnostic biomarker for GC patients.

N6-methyladenosine induced miR-143-3p promotes the brain metastasis of lung cancer via regulation of VASH1.

BACKGROUND: Brain metastasis (BM) is one of the principal causes of mortality for lung cancer patients. While the molecular events that govern BM of lung cancer remain frustrating cloudy. METHODS: The miRNA expression profiles are checked in the paired human BM and primary lung cancer tissues. The effect of miR-143-3p on BM of lung cancer cells and its related mechanisms are investigated. RESULTS: miR-143-3p is upregulated in the paired BM tissues as compared with that in primary cancer tissues. It can increase the invasion capability of in vitro blood brain barrier (BBB) model and angiogenesis of lung cancer by targeting the three binding sites of 3'UTR of vasohibin-1 (VASH1) to inhibit its expression. Mechanistically, VASH1 can increase the ubiquitylation of VEGFA to trigger the proteasome mediated degradation, further, it can endow the tubulin depolymerization through detyrosination to increase the cell motility. m6A methyltransferase Mettl3 can increase the splicing of precursor miR-143-3p to facilitate its biogenesis. Moreover, miR-143-3p/VASH1 axis acts as adverse prognosis factors for in vivo progression and overall survival (OS) rate of lung cancer. CONCLUSIONS: Our work implicates a causal role of the miR-143-3p/VASH1 axis in BM of lung cancers and suggests their critical roles in lung cancer pathogenesis.

m6A-induced lncRNA RP11 triggers the dissemination of colorectal cancer cells via upregulation of Zeb1.

BACKGROUND: Long noncoding RNAs (lncRNAs) have emerged as critical players in cancer progression, but their functions in colorectal cancer (CRC) metastasis have not been systematically clarified. METHODS: lncRNA expression profiles in matched normal and CRC tissue were checked using microarray analysis. The biological roles of a novel lncRNA, namely RP11-138 J23.1 (RP11), in development of CRC were checked both in vitro and in vivo. Its association with clinical progression of CRC was further analyzed. RESULTS: RP11 was highly expressed in CRC tissues, and its expression increased with CRC stage in patients. RP11 positively regulated the migration, invasion and epithelial mesenchymal transition (EMT) of CRC cells in vitro and enhanced liver metastasis in vivo. Post-translational upregulation of Zeb1, an EMT-related transcription factor, was essential for RP11-induced cell dissemination. Mechanistically, the RP11/hnRNPA2B1/mRNA complex accelerated the mRNA degradation of two E3 ligases, Siah1 and Fbxo45, and subsequently prevented the proteasomal degradation of Zeb1. m6A methylation was involved in the upregulation of RP11 by increasing its nuclear accumulation. Clinical analysis showed that m6A can regulate the expression of RP11, further, RP11 regulated Siah1-Fbxo45/Zeb1 was involved in the development of CRC. CONCLUSIONS: m6A-induced lncRNA RP11 can trigger the dissemination of CRC cells via post-translational upregulation of Zeb1. Considering the high and specific levels of RP11 in CRC tissues, our present study paves the way for further investigations of RP11 as a predictive biomarker or therapeutic target for CRC.

ABCC2 rs2273697 is associated with valproic acid concentrations in patients with epilepsy on valproic acid monotherapy.

Valproic acid (VPA), a widely used antiepileptic drug, is characterized by intensive inter-individual variability in concentration. Both efflux and influx transporters are reported to play important roles in the disposition of VPA, however, no comprehensive investigation into the association of the single nucleotide polymorphism (SNP) in ABC/SLC families with VPA concentration are reported. In the present study, we investigated the association of 12 SNPs in ABCC2, ABCC4, ABCG2, MCT1, MCT2, and OATP2B1 in 187 Chinese patients with epilepsy on VPA monotherapy with the trough concentrations of VPA. The data showed that VPA concentration in patients with ABCC2 rs2273697 AA genotype was significantly higher than that in those with GA+GG genotypes (p=0.000). The findings of the present study suggest that ABCC2 polymorphisms influence VPA concentrations in patients with epilepsy on VPA monotherapy, which may affect the treatment outcomes.

Epigenetic down regulation of G protein-coupled estrogen receptor (GPER) functions as a tumor suppressor in colorectal cancer.

BACKGROUND: Estrogenic signals are suggested to have protection roles in the development of colorectal cancer (CRC). The G protein-coupled estrogen receptor (GPER) has been reported to mediate non-genomic effects of estrogen in hormone related cancers except CRC. Its expression and functions in CRC were investigated. METHODS: The expression of GPER and its associations with clinicopathological features were examined. The mechanisms were further investigated using cells, mouse xenograft models, and clinical human samples. RESULTS: GPER was significantly (p < 0.01) down regulated in CRC tissues compared with their matched adjacent normal tissues in our two cohorts and three independent investigations from Oncomine database. Patients whose tumors expressing less (n = 36) GPER showed significant (p < 0.01) poorer survival rate as compared with those with greater levels of GPER (n = 54). Promoter methylation and histone H3 deacetylation were involved in the down regulation of GPER in CRC cell lines and clinical tissues. Activation of GPER by its specific agonist G-1 inhibited proliferation, induced cell cycle arrest, mitochondrial-related apoptosis and endoplasmic reticulum (ER) stress of CRC cells. The upregulation of reactive oxygen species (ROS) induced sustained ERK1/2 activation participated in G-1 induced cell growth arrest. Further, G-1 can inhibit the phosphorylation, nuclear localization, and transcriptional activities of NF-κB via both canonical IKKα/ IκBα pathways and phosphorylation of GSK-3ß. Xenograft model based on HCT-116 cells confirmed that G-1 can suppress the in vivo progression of CRC. CONCLUSIONS: Epigenetic down regulation of GPER acts as a tumor suppressor in colorectal cancer and its specific activation might be a potential approach for CRC treatment.

Genetic markers in CYP2C19 and CYP2B6 for prediction of cyclophosphamide's 4-hydroxylation, efficacy and side effects in Chinese patients with systemic lupus erythematosus.

AIMS: The aim of the study was to investigate the combined impact of genetic polymorphisms in key pharmacokinetic genes on plasma concentrations and clinical outcomes of cyclophosphamide (CPA) in Chinese patients with systemic lupus erythematosus (SLE). METHODS: One hundred and eighty nine Chinese SLE patients treated with CPA induction therapy (200 mg, every other day) were recruited and adverse reactions were recorded. After 4 weeks induction therapy, 128 lupus nephritis (LN) patients continued to CPA maintenance therapy (200-600 mg week(-1)) for 6 months, and their clinical outcomes were recorded. Blood samples were collected for CYP2C19, CYP2B6, GST and PXR polymorphism analysis, as well as CPA and its active metabolite (4-hydroxycyclophosphamide (4-OH-CPA)) plasma concentration determination. RESULTS: Multiple linear regression analysis revealed that CYP2B6 -750 T > C (P < 0.001), -2320 T > C (P < 0.001), 15582C > T (P = 0.017), CYP2C19*2 (P < 0.001) and PXR 66034 T > C (P = 0.028) accounted for 47% of the variation in 4-OH-CPA plasma concentration. Among these variants, CYP2B6 -750 T > C and CYP2C19*2 were selected as the combination genetic marker because these two SNPs contributed the most to the inter-individual variability in 4-OH-CPA concentration, accounting for 23.6% and 21.5% of the variation, respectively. Extensive metabolizers (EMs) (CYP2B6 -750TT, CYP2C19*1*1) had significantly higher median 4-OH-CPA plasma concentrations (34.8, 11.0 and 6.6 ng ml(-1) for EMs, intermediate metabolizers (IMs) and poor metabolizers (PMs), P < 0.0001), higher risks of leukocytopenia (OR = 7.538, 95% CI 2.951, 19.256, P < 0.0001) and gastrointestinal toxicity (OR = 7.579, 95% CI 2.934, 19.578, P < 0.0001), as well as shorter median time to achieve complete remission (13.2, 18.3 and 23.3 weeks for EMs, IMs and PMs, respectively, P = 0.026) in LN patients than PMs (CYP2B6 -750CC, CYP2C19*2*2) and IMs. CONCLUSIONS: Our findings have indicated that genetic markers of drug metabolizing enzymes could predict the 4-hydroxylation, adverse reactions and clinical efficacy of CPA. This is a necessary first step towards building clinical tools that will help assess clinical benefit and risk before undergoing CPA treatment in Chinese SLE patients.

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) in paired maternal and neonatal samples from South China: Placental transfer and potential risks.

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) are attracting more and more attention for the neurodevelopment toxicity effects. We evaluated the concentrations of 15 individual OH-PBDEs and 3 bromophenol (BRP) congeners in 30 mother-newborn paired placenta, breast milk, fetal cord blood, and neonatal urine samples collected from South China. The geometric mean (GM) concentrations of ∑OH-PBDEs were 37.6, 61.3, and 76.8pgg(-1) ww in placenta, breast milk, and cord blood, respectively. The GM concentrations of ∑BRPs were 47.6, 119, and 30.2pgg(-1) ww in placenta, breast milk, and cord blood, respectively. The GM concentrations of ∑OH-PBDEs and ∑BRPs in neonatal urine were 72.0 and 79.8pgml(-1), respectively. Of the 15 OH-PBDE congeners analyzed, the three most frequently detected congeners were 2'-OH-BDE-68 (72.1%), 6-OH-BDE-47 (67.6%), and 2'-OH-BDE-28 (65.8%). The estimated daily intake (EDI) of OH-PBDEs for the breast-fed infants was 9.31±4.00ngkg(-1) bw day. The accumulation of OH-PBDEs in newborns was much lower than the estimated lowest observed-effect concentration (LOEC) of neurotoxicity. The present study provided the first systematic fundamental data that exposure to OH-PBDEs for newborn and their mothers in South China.

Signaling related with biphasic effects of bisphenol A (BPA) on Sertoli cell proliferation: a comparative proteomic analysis.

BACKGROUND: Biphasic effects on cell proliferation of bisphenol A (BPA) can occur at lesser or greater exposures. Sertoli cells play a pivotal role in supporting proliferation and differentiation of germ cells. The mechanisms responsible for inverse effects of great and low concentrations of BPA on Sertoli cell proliferation need further study. METHODS: We utilized proteomic study to identify the protein expression changes of Sertoli TM4 cells treated with 10(-8)M and 10(-5)M BPA. The further mechanisms related to mitochondria, energy metabolism and oxidative stress were investigated by qRT-PCR and Western-blotting analysis. RESULTS: Proteomic studies identified 36 proteins and two major clusters of proteins including energy metabolism and oxidative stress expressed with opposite changes in Sertoli cells treated with 10(-8)M and 10(-5)M BPA, respectively, for 24h. Exposure to 10(-5)M BPA resulted in greater oxidative stress and then inhibited cell proliferation, while ROS scavenger NAC effectively blocked these effects. Exposure to 10(-8)M BPA caused higher intercellular ATP, greater activities of mitochondria, and resulted in significant proliferation of TM4 cells, while oligomycin A, an inhibitor of ATP synthase, abolished these growth advantages. CONCLUSIONS: Our study demonstrated that micromolar BPA inhibits proliferation of Sertoli cells by elevating oxidative stress while nanomolar BPA stimulates proliferation by promoting energy metabolism. GENERAL SIGNIFICANCE: Micromolar BPA inhibits cell proliferation by elevating oxidative stress while nanomolar BPA stimulates cell proliferation by promoting energy metabolism.

Association of LEPR and ANKK1 Gene Polymorphisms with Weight Gain in Epilepsy Patients Receiving Valproic Acid.

BACKGROUND: Weight gain is the most frequent adverse effect of valproic acid (VPA) treatment, resulting in poor compliance and many endocrine disturbances. Similarities in the weight change of monozygotic twins receiving VPA strongly suggests that genetic factors are involved in this effect. However, few studies have been conducted to identify the relevant genetic polymorphisms. Additionally, the causal relationship between the VPA concentration and weight gain has been controversial. Thus, we investigated the effects of single nucleotide polymorphisms (SNPs) in several appetite stimulation and energy homeostasis genes and the steady state plasma concentrations (Css) of VPA on the occurrence of weight gain in patients. METHODS: A total of 212 epilepsy patients receiving VPA were enrolled. Nineteen SNPs in 11 genes were detected using the Sequenom MassArray iPlex platform, and VPA Css was determined by high-performance liquid chromatography (HPLC). RESULTS: After 6 months of treatment, 20.28% of patients were found to gain a significant amount of weight (weight gained ≥7%). Three SNPs in the leptin receptor (LEPR), ankyrin repeat kinase domain containing 1 (ANKK1), and α catalytic subunit of adenosine monophosphate-activated protein kinase (AMPK) showed significant associations with VPA-induced weight gain (p < 0.001, p = 0.017 and p = 0.020, respectively). After Bonferroni correction for multiple tests, the genotypic association of LEPR rs1137101, the allelic association of LEPR rs1137101, and ANKK1 rs1800497 with weight gain remained significant. However, the VPA Css in patents who gained weight were not significantly different from those who did not gain weight (p = 0.121). CONCLUSIONS: LEPR and ANKK1 genetic polymorphisms may have value in predicting VPA-induced weight gain.

Bisphenol A modulates colorectal cancer protein profile and promotes the metastasis via induction of epithelial to mesenchymal transitions.

More and more evidences indicate that endocrine disruptor chemicals such as bisphenol A (BPA) can act as carcinogens and enhance susceptibility to tumorigenesis. Although the gut is in direct contact with orally ingested BPA, effects of BPA on occurrence and development of colorectal cancer remain an unexplored endpoint. Colorectal cancer SW480 cells treated with nanomolar (10(-8) M) or greater (10(-5) M) concentrations of BPA were compared with responses of a control group. Proteomic study revealed that more than 56 proteins were modulated following exposure to BPA, which are relevant to structure, motility and proliferation of cells, production of ATP, oxidative stress, and protein metabolism. Further studies revealed that BPA increased migration and invasion and triggered transformations from epithelial to mesenchymal transitions (EMTs) of colorectal cancer cells, which was characterized by acquiring mesenchymal spindle-like morphology and increasing the expression of N-cadherin with a concomitant decrease of E-cadherin. Accordingly, BPA treatment increased the expression of transcription factor Snail. Furthermore, signal AKT/GSK-3ß-mediated stabilization of Snail is involved during BPA-induced EMT of colon cancer cells. Our study first demonstrated that the xenoestrogen BPA at nanomolar and greater concentrations modulates the protein profiles and promotes the metastasis of colorectal cancer cells via induction of EMT.

[Effects of carbamazepine on plasma concentrations of valproic acid and its toxic metabolite in epileptic patients].

To investigate the effects of carbamazepine (CBZ) on the plasma concentrations of valproic acid (VPA) and its toxic metabolite 2-propyl-4-pentenoic acid (4-ene VPA) in epileptic patients, the plasma concentrations of VPA and 4-ene VPA were determined, and the effect of CBZ on pharmacokinetics of VPA was evaluated. All patients had been divided into two groups (VPA group, n = 87; and VPA+CBZ group, n = 19). As compared to VPA group, the combination of CBZ significantly (P < 0.01) decreased the trough concentration of VPA [VPA group, (69.5 +/- 28.8) microg x mL(-1); VPA+CBZ group, (46.3 +/- 25.6) microg x mL(-1)] and does-adjusted VPA trough concentration [VPA group, (4.89 +/- 2.21) microg x mL(-1) x mg(-1) x kg(-1); VPA+CBZ group, (3.14 +/- 1.74) microg x mL(-1) x mg(-1) x kg(-1)]. However, the addition of CBZ did not influence the concentration of 4-ene VPA. The present study revealed that coadministration of CBZ can reduce VPA plasma concentration and may impact VPA clinical effect, therefore therapeutic drug mornitoring of VPA should be used when combined use of CBZ and VPA.

Infusion-Related Reactions Induced by Cadonilimab (PD-1/CTLA-4 Bispecific Antibody): Seven Case Reports.

Introduction: Cadonilimab (AK104) is an innovative human programmed cell death-1 (PD-1)/cytotoxic T lymphocyte antigen-4 (CTLA-4) bispecific antibody. Compared with the combination therapy of PD-1 and CTLA-4 blockers, less cellular toxicity of cadonilimab was significantly manifested. As one of the characteristic adverse effects of cadonilimab, infusion-related reactions (IRRs) represent fever, chills, rash, decreased blood pressure, and other symptoms. Case Presentation: Here, we documented seven cases of IRRs after the administration of cadonilimab. The symptoms of IRRs were relieved after the discontinuation of cadonilimab and the administration of diphenhydramine, dexamethasone, and cimetidine. Notably, 3 patients were able to tolerate the subsequent cadonilimab therapy under the pretreatment. Conclusion: In this study, we discovered that cadonilimab-related IRRs might be lessened or prevented by administering medication and the proper pretreatment and lowering the infusion rate.

METTL3 promotes cellular senescence of colorectal cancer via modulation of CDKN2B transcription and mRNA stability.

Cellular senescence plays a critical role in cancer development, but the underlying mechanisms remain poorly understood. Our recent study uncovered that replicative senescent colorectal cancer (CRC) cells exhibit increased levels of mRNA N6-methyladenosine (m6A) and methyltransferase METTL3. Knockdown of METTL3 can restore the senescence-associated secretory phenotype (SASP) of CRC cells. Our findings, which were confirmed by m6A-sequencing and functional studies, demonstrate that the cyclin-dependent kinase inhibitor 2B (CDKN2B, encoding p15INK4B) is a mediator of METTL3-regulated CRC senescence. Specifically, m6A modification at position A413 in the coding sequence (CDS) of CDKN2B positively regulates its mRNA stability by recruiting IGF2BP3 and preventing binding with the CCR4-NOT complex. Moreover, increased METTL3 methylates and stabilizes the mRNA of E2F1, which binds to the -208 to -198 regions of the CDKN2B promoter to facilitate transcription. Inhibition of METTL3 or specifically targeting CDKN2B methylation can suppress CRC senescence. Finally, the METTL3/CDKN2B axis-induced senescence can facilitate M2 macrophage polarization and is correlated with aging and CRC progression. The involvement of METTL3/CDKN2B in cell senescence provides a new potential therapeutic target for CRC treatment and expands our understanding of mRNA methylation's role in cellular senescence.

N6-methyladenosine facilitates mitochondrial fusion of colorectal cancer cells via induction of GSH synthesis and stabilization of OPA1 mRNA.

Mitochondria undergo fission and fusion that are critical for cell survival and cancer development, while the regulatory factors for mitochondrial dynamics remain elusive. Herein we found that RNA m6A accelerated mitochondria fusion of colorectal cancer (CRC) cells. Metabolomics analysis and function studies indicated that m6A triggered the generation of glutathione (GSH) via the upregulation of RRM2B-a p53-inducible ribonucleotide reductase subunit with anti-reactive oxygen species potential. This in turn resulted in the mitochondria fusion of CRC cells. Mechanistically, m6A methylation of A1240 at 3'UTR of RRM2B increased its mRNA stability via binding with IGF2BP2. Similarly, m6A methylation of A2212 at the coding sequence (CDS) of OPA1-an essential GTPase protein for mitochondrial inner membrane fusion-also increased mRNA stability and triggered mitochondria fusion. Targeting m6A through the methyltransferase inhibitor STM2457 or the dm6ACRISPR system significantly suppressed mitochondria fusion. In vivo and clinical data confirmed the positive roles of the m6A/mitochondrial dynamics in tumor growth and CRC progression. Collectively, m6A promoted mitochondria fusion via induction of GSH synthesis and OPA1 expression, which facilitated cancer cell growth and CRC development.