Chunxian Wei

Background & AimsPien Tze Huang (PZH) is a well-established traditional medicine with beneficial effects against inflammation and cancer. We aimed to explore the chemopreventive effect of PZH in colorectal cancer (CRC) through modulating gut microbiota.MethodsCRC mouse models were established by azoxymethane plus dextran sulfate sodium treatment or in Apcmin/+ mice treated with or without PZH (270 mg/kg and 540 mg/kg). Gut barrier function was determined by means of intestinal permeability assays and transmission electron microscopy. Fecal microbiota and metabolites were analyzed by means of metagenomic sequencing and liquid chromatography mass spectrometry, respectively. Germ-free mice or antibiotic-treated mice were used as models of microbiota depletion.ResultsPZH inhibited colorectal tumorigenesis in azoxymethane plus dextran sulfate sodium–treated mice and in Apcmin/+ mice in a dose-dependent manner. PZH treatment altered the gut microbiota profile, with an increased abundance of probiotics Pseudobutyrivibrio xylanivorans and Eubacterium limosum, while pathogenic bacteria Aeromonas veronii, Campylobacter jejuni, Collinsella aerofaciens, and Peptoniphilus harei were depleted. In addition, PZH increased beneficial metabolites taurine and hypotaurine, bile acids, and unsaturated fatty acids, and significantly restored gut barrier function. Transcriptomic profiling revealed that PZH inhibited PI3K–Akt, interleukin-17, tumor necrosis factor, and cytokine–chemokine signaling. Notably, the chemopreventive effect of PZH involved both microbiota-dependent and -independent mechanisms. Fecal microbiota transplantation from PZH-treated mice to germ-free mice partly recapitulated the chemopreventive effects of PZH. PZH components ginsenoside-F2 and ginsenoside-Re demonstrated inhibitory effects on CRC cells and primary organoids, and PZH also inhibited tumorigenesis in azoxymethane plus dextran sulfate sodium–treated germ-free mice.ConclusionsPZH manipulated gut microbiota and metabolites toward a more favorable profile, improved gut barrier function, and suppressed oncogenic and pro-inflammatory pathways, thereby suppressing colorectal carcinogenesis. Pien Tze Huang (PZH) is a well-established traditional medicine with beneficial effects against inflammation and cancer. We aimed to explore the chemopreventive effect of PZH in colorectal cancer (CRC) through modulating gut microbiota. CRC mouse models were established by azoxymethane plus dextran sulfate sodium treatment or in Apcmin/+ mice treated with or without PZH (270 mg/kg and 540 mg/kg). Gut barrier function was determined by means of intestinal permeability assays and transmission electron microscopy. Fecal microbiota and metabolites were analyzed by means of metagenomic sequencing and liquid chromatography mass spectrometry, respectively. Germ-free mice or antibiotic-treated mice were used as models of microbiota depletion. PZH inhibited colorectal tumorigenesis in azoxymethane plus dextran sulfate sodium–treated mice and in Apcmin/+ mice in a dose-dependent manner. PZH treatment altered the gut microbiota profile, with an increased abundance of probiotics Pseudobutyrivibrio xylanivorans and Eubacterium limosum, while pathogenic bacteria Aeromonas veronii, Campylobacter jejuni, Collinsella aerofaciens, and Peptoniphilus harei were depleted. In addition, PZH increased beneficial metabolites taurine and hypotaurine, bile acids, and unsaturated fatty acids, and significantly restored gut barrier function. Transcriptomic profiling revealed that PZH inhibited PI3K–Akt, interleukin-17, tumor necrosis factor, and cytokine–chemokine signaling. Notably, the chemopreventive effect of PZH involved both microbiota-dependent and -independent mechanisms. Fecal microbiota transplantation from PZH-treated mice to germ-free mice partly recapitulated the chemopreventive effects of PZH. PZH components ginsenoside-F2 and ginsenoside-Re demonstrated inhibitory effects on CRC cells and primary organoids, and PZH also inhibited tumorigenesis in azoxymethane plus dextran sulfate sodium–treated germ-free mice. PZH manipulated gut microbiota and metabolites toward a more favorable profile, improved gut barrier function, and suppressed oncogenic and pro-inflammatory pathways, thereby suppressing colorectal carcinogenesis.

Copy number alterations are crucial for the development of gastric cancer (GC). Here, we identified Transmembrane Protein 65 (TMEM65) amplification by genomic hybridization microarray to profile copy-number variations in GC. TMEM65 mRNA level was significantly up-regulated in GC compared to adjacent normal tissues, and was positively associated with TMEM65 amplification. High TMEM65 expression or DNA copy number predicts poor prognosis (P < 0.05) in GC. Furtherly, GC patients with TMEM65 amplification (n = 129) or overexpression (n = 78) significantly associated with shortened survival. Ectopic expression of TMEM65 significantly promoted cell proliferation, cell cycle progression and cell migration/invasion ability, but inhibited apoptosis (all P < 0.05). Conversely, silencing of TMEM65 in GC cells showed opposite abilities on cell function in vitro and suppressed tumor growth and lung metastasis in vivo (all P < 0.01). Moreover, TMEM65 depletion by VNP-encapsulated TMEM65-siRNA significantly suppressed tumor growth in subcutaneous xenograft model. Mechanistically, TMEM65 exerted oncogenic effects through activating PI3K-Akt-mTOR signaling pathway, as evidenced of increased expression of key regulators (p-Akt, p-GSK-3β, p-mTOR) by Western blot. YWHAZ (Tyrosine 3-Monooxygenase/Tryptophan 5-Monooxygenase) was identified as a direct downstream effector of TMEM65. Direct binding of TMEM65 with YWHAZ in the cytoplasm inhibited ubiquitin-mediated degradation of YWHAZ. Moreover, oncogenic effect of TMEM65 was partly dependent on YWHAZ. In conclusion, TMEM65 promotes gastric tumorigenesis by activating PI3K-Akt-mTOR signaling via cooperating with YWHAZ. TMEM65 overexpression may serve as an independent new biomarker and is a therapeutic target in GC.

Abstract Immune checkpoint blockade (ICB) therapy demonstrated limited efficacy in colorectal cancer (CRC), and identification of intrinsic factors modulating immune suppression in CRC is an unmet need. Here, we revealed that Chromosome 8 open reading frame 76 (C8orf76) drives immunosuppression and is a molecular target to boost ICB therapy in CRC. C8orf76 is upregulated in primary CRCs compared to adjacent normal tissues in 2 independent CRC cohorts and its expression predicts poor patient survival. Intestine-specific C8orf76 knockin in mice exacerbated AOM/DSS-induced CRC, accompanied by increased intratumoral myeloid-derived suppressor cells (MDSCs) but reduced IFN-γ+ and granzyme B+ CD8+ T cells, inferring that C8orf76 promotes immunosuppression in CRC. Consistently, genetic depletion of C8orf76 augmented antitumour immunity in CT26 (MSS-CRC) and MC38 (MSI-H-CRC) allograft models. Integrated RNA-seq and ChIP-seq revealed that C8orf76 functions as a transcription factor to drive NDST1 expression, which activates the PI3K-Akt-NF-κB signaling cascade. Activated NF-κB in turn promotes the expression and secretion of CXCL1, a major chemoattractant for MDSCs. Consequently, C8orf76-induced CXCL1 mediates the recruitment of MDSCs via CXCR2 to antagonize functional CD8+ T cells in tumor immune microenvironment of CRC. Confirming this, targeting NDST1 or CXCR2 could reverse C8orf76 induced immunosuppression in vivo. Finally, we tested the translational value of C8orf76 using genetic ablation or vesicle-like nanoparticles (VNPs)-encapsulated C8orf76-siRNA. In line with our hypothesis, we demonstrated that targeting C8orf76 by genetic ablation or VNPs-encapsulated C8orf76-siRNA potentiated the anti-PD1 efficacy in both MSI-H and MSS CRC models. In summary, C8orf76 drives immunosuppression through a NDST1-CXCL1/CXCR2 axis, and targeting C8orf76 is a promising approach to boost ICB therapy efficacy in CRC. Citation Format: Hongyan Gou, Shang Guo, Xiaohong Wang, Xia Jiang, Chi Chun Wong, Huarong Chen, Chunxian Wei, Lingxue Shi, Zengren Zhao, Jun Yu. C8orf76 promotes colorectal tumorigenesis by promoting an immunosuppressive microenvironment and is a therapeutic target for boosting anti-PD-1 efficacy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_2):Abstract nr LB132.