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Biology subjects

Hu, C.-M.

Publications and source records attributed to Hu, C.-M..

4 recordsLinked to original sources

Targeting STING-ATM axis overcomes radiotherapy-induced immune suppression and restores anti-tumor immunity in nasopharyngeal carcinoma

BackgroundRadiotherapy (RT) is a standard treatment for nasopharyngeal carcinoma (NPC), however, RT-induced immune suppression and tumor radioresistance limit durable cancer control, with approximately 20% of patients developing recurrence or metastasis after treatment. We investigated the molecular effects of RT on the immune landscape of NPC and identified a key role of the STING-ATM-MPO axis in RT-induced immune suppression, which is associated with regulatory T cell (Treg) expansion and radioresistance. MethodsWe analyzed leukocyte counts from 653 NPC patients before treatment and at multiple time points (week 1-2, week 3-4, and week 5-6) after RT. Single-cell RNA sequencing (scRNA-seq) was performed on peripheral blood mononuclear cell (PBMC) samples from stage I NPC patients (T1N0M0) treated with RT alone. Blood samples were collected before and after 18 Gy RT (in 2 Gy fractions). A randomized six-arm syngeneic mouse tumor model and in vitro cell studies were used to investigate interactions among STING-ATM signaling, immune modulation, and tumor response. ResultsIn NPC patients, RT suppressed cGAS-STING signaling in monocytes and dendritic cells but promoted immunosuppressive programs, including PD-1 signaling, checkpoint expression, regulatory T cell expansion, and upregulation of TGF{beta}1, IL-10, VEGF, PDGF, and MDSC-associated pathways. In a syngeneic mouse model, co-treatment with the STING agonist diABZI reversed these effects and improved tumor control. Bulk RNA sequencing confirmed that RT suppressed cGAS-STING and ATM signaling in both spleens and tumors. Combination treatment restored this signaling, enhanced neutrophil degranulation, and inhibited PD-1 signaling and immune checkpoints. Immunohistochemistry showed that diABZI increased ATM activation, MPO expression, and reduced Treg infiltration in spleens and tumors. ATM activation correlated positively with MPO and inversely with FOXP3 immunoreactivity, suggesting that STING-ATM-MPO activation counteracts Treg-mediated immune suppression. In vitro, diABZI activated STING-ATM signaling in PBMCs, THP-1 cells, and Jurkat T cells, while inhibiting NPC cell growth partly via CYLD upregulation. ConclusionsThese findings link RT-induced suppression to inhibition of cGAS-STING signaling. Activation of STING-ATM-MPO axis counteracts Treg-mediated immune suppression, supporting the therapeutic potential of STING agonists as radiosensitizers in NPC.

cancer biology↗

TRIB2 couples UCP1 degradation to thermogenic adaptation and metabolic health

Genetic variation in TRIB2 has been associated with thermogenesis and fat accumulation, yet the underlying molecular mechanisms remain unclear. Uncoupling protein 1 (UCP1) is a key regulator of adaptive thermogenesis and energy expenditure. Here, we identified a human TRIB2 variant associated with migration patterns along latitude and environmental temperature, which destabilized its mRNA and is consistent with enhanced thermogenic capacity. We demonstrate that loss of Trib2 protects mice from diet-induced obesity, alleviates hepatic steatosis, and improves glucose tolerance and insulin sensitivity. Trib2 knockout mice exhibit elevated UCP1 expression in brown adipose tissue, leading to enhanced thermogenesis and increased heat production. Mechanistically, TRIB2 acts as a scaffold that binds UCP1 through its pseudokinase domain and recruits the E3 ligase MYCBP2, thereby promoting UCP1 ubiquitination and proteasomal degradation. Collectively, our findings reveal a previously unrecognized post-translational mechanism that regulates UCP1 stability and link TRIB2 function to both thermogenic adaptation and metabolic health, thereby highlighting TRIB2 as a potential therapeutic target for obesity and metabolic disorders.

molecular biology↗

Selection and validation of internal control genes for quantitative real-time RT-qPCR normalization of Phlebopus portentosus gene expression under different conditions

Phlebopus portentosus (Berk. and Broome) Boedijin is an attractive edible mushroom and considered as the unique bolete to have achieved artificial cultivation in vitro. Gene expression analysis has become widely used in researches of edible fungi and is important to uncover the functions of genes involved in complex biological processes. Selecting appropriate reference genes is crucial to ensuring reliable results of gene expression analysis by RT-qPCR. In our study, a total of 12 candidate control genes were selected from 25 traditional housekeeping genes based on the expression stability in 9 transcriptomes of 3 developmental stages. These genes were further evaluated using geNorm, NormFinder and RefFinder under different conditions and developmental stages. The results revealed that MSF1-domain-containing protein (MSF1), synaptobrevin (SYB), mitogen-activated protein kinase genes (MAPK), TATA binding protein 1 (TBP1) and SPRY domain protein (SPRY) were the most stable reference genes in all sample treatments, while elongation factor 1-alpha (EF1), Actin and ubiquitin-conjugating enzyme (UBCE) were the most unstably expressed. The gene SYB was selected based on the transcriptome results and was identified as a novel reference gene in P. portentosus. This is the first detailed study for identification reference genes in this fungus and may provide new insights into selecting genes and quantifying gene expression.

microbiology↗

Targeting Reductive Metabolic Shifts by T315I Mutation in BCR-ABL Myeloid Leukemia for Therapy

T315I mutation of Bcr-Abl in chronic myeloid leukemia (CML) leads to therapeutic resistance. It is known that Bcr-Abl transformation causes ROS-induced DNA damages and replication stress, which can be exploited for anti-nucleotide therapy. We developed a small compound, JMF4073, which inhibited pyrimidylate kinases and selectively eliminated Bcr-Abl-transformed, but not untransformed myeloid cells, due to dTTP exhaustion and ROS-induced replication stress. However, T315I-Bcr-Abl-transformed cells were less vulnerable to JMF4073 because of higher dTTP pool and low replication stress. Unlike WT-Bcr-Abl-transformed cells, T315I-Bcr-Abl cells lacked Sirt1- regulated OXPHOS with increased glutamine flux to reductive carboxylation in TCA cycle and glutathione synthesis. Blocking mitochondrial pyruvate carrier (MPC) by UK-5099 reduced NADH and glutathione levels with replication stress induction, thereby converting T315I-Bcr-Abl cells sensitive to JMF4073 with dTTP and dCTP depletion. The combination of JMF4073 with UK-5099 showed in vivo eradication of T315I-Bcr-Abl-CML. These data reveal that T315I mutation causes reductive metabolic shifts in Bcr-Abl-CML, and demonstrate the therapeutic option by co-targeting MPC and pyrimidylate kinases.

cancer biology↗