Abstract Tumor cells shape the immunosuppressive tumor microenvironment (TME) through coordinated interactions with tumor-associated macrophages (TAMs), regulatory T cells (Tregs), immune checkpoint pathways and suppressive cytokines, thereby limiting the efficacy of immunotherapy across diverse cancer types. Phospholipase D (PLD) enzymes, particularly the PLD1 and PLD2 isoforms, have been implicated in oncogenic signaling and tumor progression; however, their tumor-intrinsic roles in modulating the immune landscape remain largely undefined. Here we demonstrated that both genetic ablation and pharmacological inhibition of PLD1 and PLD2 reprogram the TME and enhance antitumor immunity in a syngeneic melanoma model. Elevated PLD expression is associated with increased infiltration of M2-like TAMs, decreased ‘eat me’ signals and enhanced ‘don’t eat me’ signals. Conversely, loss or inhibition of PLD1 and PLD2 reduced Treg recruitment and enhanced infiltration of Th1, Th17 and cytotoxic CD8⁺ T cells, accompanied by downregulation of immune checkpoint molecules and restoration of T cell effector function. Depletion studies revealed that PLD-driven TAM polarization critically impairs CD8⁺ T cell-mediated antitumor responses. Mechanistically, PLD1 and PLD2 enhance CCL19 secretion, promote macrophage polarization toward an immunosuppressive phenotype and induce programmed death-ligand 1 (PD-L1) expression by activating the PI3K–Akt–NF-κB signaling axis, thereby promoting tumor immune evasion. Notably, PLD inhibition reduced CCL19 production, abrogated IFN-γ- or CCL19-induced PD-L1 expression, decreased TAM infiltration and increased CD8⁺ T cell infiltration, collectively shifting the TME toward an immune-activated state. These findings suggest that tumor-intrinsic PLD1 and PLD2 function as modulators of immune suppression and that PLD inhibition represents a promising strategy to overcome resistance to cancer immunotherapy.

The tumor microenvironment (TME) is a complex ecosystem composed of not only malignant cells but also diverse stromal and immune cell populations that collectively shape tumor behavior. Metabolism is a central regulator of the TME, orchestrating intercellular communication through altered nutrients and signaling pathways to influence both the metabolic plasticity of cancer cells and functional balance of immune populations, ultimately determining tumor progression and antitumor immunity. Although tumor-intrinsic metabolic programs have been extensively characterized, emerging evidence highlights stromal metabolism as the dominant force sculpting immune responses within the TME. Among the nonmalignant stromal constituents, cancer-associated fibroblasts and cancer-associated adipocytes have emerged as metabolically active hubs that release and redistribute key metabolites, such as lactate, fatty acids and amino acids, to modulate the activity of both tumor and immune cells. Here we integrate recent advances in the understanding of stromal-immune metabolic crosstalk and elucidates how diverse metabolic mechanisms, including nutrient competition, mitochondrial remodeling, redox imbalance and immunometabolic rewiring, collectively reinforce an immunosuppressive TME and drive therapeutic resistance. Our study highlights the emerging strategies for selectively reprogramming these metabolic networks as potential therapeutic avenues. Deciphering these multilayered interactions will establish a conceptual and mechanistic foundation for reprogramming TME, restoring immune competence and enhancing the efficacy of current immunotherapies through metabolism-targeted interventions.

Ethnopharmacological relevance Morinda citrifolia (Noni) is a traditional medicinal plant widely utilized in tropical regions for its antioxidant and anti-inflammatory properties. While its traditional applications extend to skin and hair health, its specific pharmacological effects on hair follicle biology—particularly when its phytochemical profile and bioavailability are enhanced through fermentation—remain largely unexplored. Aim of the study This study aimed to investigate the pro-regenerative effects and underlying molecular mechanisms of fermented M. citrifolia extract (FME) as a potential therapeutic intervention for hair loss. Materials and methods The pharmacological effects of FME were evaluated using human dermal papilla cells (hDPCs) and ex vivo human hair follicle organ cultures. Assessments included cell viability, cell cycle progression, protein expression analysis, hair shaft elongation, and transcriptomic profiling. Results FME significantly enhanced hDPC viability and promoted cell cycle progression into the S-phase. Mechanistically, FME activated Wnt/β-catenin signaling by stabilizing β-catenin, thereby increasing the secretion of key hair growth factors (VEGF, bFGF, IGF2) and enhancing antioxidant defense. In ex vivo cultures, FME induced dose-dependent hair shaft elongation, prolonged the anagen phase, and preserved hair bulb architecture. Transcriptomic profiling revealed that FME upregulated stemness-related and hair structure pathways while downregulating matrix remodeling enzymes and pro-inflammatory signaling networks. Conclusions FME promotes hair growth through the activation of dermal papilla cells and modulation of follicular signaling networks, primarily via the Wnt/β-catenin axis. These findings provide mechanistic evidence supporting FME as a promising and safe therapeutic candidate for alopecia.

BACKGROUND:Late-onset hypogonadism (LOH) is an age-associated condition characterized by a progressive decline in testosterone levels. It manifests as reduced libido, infertility, muscle loss, and cognitive impairment in middle-aged men. Although testosterone replacement therapy is effective, its associated side effects highlight the need for safer alternatives. Previously, we have demonstrated the efficacy of the fermented Morinda citrifolia extract (FME) in ameliorating LOH symptoms in vitro. The present study aimed to assess the in vivo efficacy of FME in mitigating LOH symptoms using an aged rat model. METHODS:Thirty-three-week-old male Sprague-Dawley rats were administered either Testofen or FME daily for four weeks. Serum levels of total and free testosterone, sex hormone-binding globulin (SHBG), dihydrotestosterone, and metabolic hormones were measured. Testicular gene expression and protein expression related to steroidogenesis were also assessed. Muscle mass, physical performance (evaluated using treadmill test), and sperm quality were also assessed. RESULTS:FME treatment significantly increased serum testosterone levels, reduced SHBG and dihydrotestosterone concentrations, and enhanced the expression of testosterone biosynthesis-related proteins. FME downregulated degradation enzymes such as 5α-reductase and aromatase. FME also improved sperm production, progressive motility, muscle mass, and treadmill running capacity. Histological analyses confirmed tissue recovery in the testes and muscles. CONCLUSION:FME alleviated LOH-related symptoms in aged rats by modulating testosterone metabolism, enhancing reproductive and physical health, and maintaining a favorable safety profile. These findings validate the in vivo efficacy of FME and highlight its potential as a natural therapeutic candidate for managing LOH and related conditions.

BACKGROUND AND AIM:Late-onset hypogonadism (LOH) is an age-related condition characterized by declining testosterone levels and impaired reproductive and metabolic functions. Fermented Morinda citrifolia extract (FME) has demonstrated therapeutic potential against LOH; however, its active constituents and underlying mechanisms remain unclear. The aim of this study was to identify the key bioactive compounds in FME and evaluate their efficacies and mechanisms of action in alleviating LOH. METHODS:High-performance liquid chromatography (HPLC) was used to quantify the iridoids and coumarins in FME. Among these four candidates, monotropein (MON) was selected for functional evaluation. In vitro assays using TM3 Leydig cells were used to assess the effects of MON on steroidogenic gene and protein expression under oxidative stress. In vivo studies involved oral administration of MON (40 mg/kg/day) to aged Sprague-Dawley rats for 4 weeks. Hormonal, histological, reproductive, metabolic, and safety parameters were measured. RESULTS:MON significantly restored testosterone production and upregulated key steroidogenic enzymes (StAR, 3β-HSD2, 17,20-desmolase, and 17β-HSD3) in vitro and in vivo. It improved serum testosterone levels, spermatogenesis, and sperm motility in aged rats. MON also reduced age-associated increases in total cholesterol and triglyceride levels without altering luteinizing hormone, follicle-stimulating hormone, or estradiol, and without inducing hepatic, renal, or prostate toxicity. CONCLUSION:MON was identified as the principal active compound of FME responsible for its LOH-alleviating effects. MON enhanced testicular steroidogenesis and improved reproductive and metabolic outcomes without causing systemic toxicity, supporting its potential as a targeted phytotherapeutic agent against age-related androgen deficiency.

Phospholipase D6 (PLD6) is a critical enzyme involved in mitochondrial fusion with a key role in spermatogenesis. However, the role of PLD6 in cancer remains unknown. Notably, Wnt signaling, energy metabolism and mitochondrial function show complex interactions in colorectal cancer (CRC) progression. Here we found that PLD6 is highly expressed in CRC and positively correlated with poor prognosis. We present a novel function of PLD6 in activating Wnt/β-catenin signaling by enhancing mitochondrial metabolism. PLD6 depletion suppresses the oncogenic properties of CRC cells and impairs mitochondrial respiration, leading to reduced mitochondrial length, membrane potential, calcium levels and reactive oxygen species. PLD6 depletion also disrupts mitochondrial metabolic reprogramming by inhibiting the tricarboxylic acid cycle and mitochondrial oxidative phosphorylation, resulting in altered intracellular levels of citrate and acetyl-CoA-both key modulators of Wnt/β-catenin activation. PLD6-mediated acetyl-CoA production enhances β-catenin stability by promoting its acetylation via the acetyltransferases CREB-binding protein and P300/CREB-binding-protein-associated factor. Consequently, PLD6 ablation reduces cancer stem cell-associated gene expression downstream of Wnt/β-catenin signaling, suppressing stem-like traits and chemoresistance to 5-fluorouracil. Furthermore, PLD6 depletion attenuates CRC tumorigenesis in both subcutaneous and orthotopic tumor models. Overall, PLD6 acts as an oncogenic switch by promoting mitochondria-mediated retrograde signaling, thereby regulating Wnt signaling in CRC.

The mitochondrial glutamine transporter SLC1A5_var plays a central role in the metabolic reprogramming of cancer cells by facilitating glutamine import into mitochondria for energy production and redox homeostasis. Despite its critical function, the development of effective and selective inhibitors targeting SLC1A5_var has remained a significant challenge. Here, we introduce iMQT_020, a selective allosteric inhibitor identified through structure-based screening. iMQT_020 disrupts the trimeric assembly of SLC1A5_var, causing metabolic crisis in cancer cells and selectively suppressing their growth. Mechanistically, iMQT_020 reduces glutamine anaplerosis and oxidative phosphorylation, resulting in a broad disruption of cancer metabolism. Additionally, iMQT_020 treatment epigenetically upregulates PD-L1 expression, enhancing the efficacy of combination therapies with anti-PD-L1 immune checkpoint inhibitors. These findings highlight the therapeutic potential of targeting SLC1A5_var as a critical metabolic vulnerability in cancer and demonstrate that targeting allosteric interprotomer interactions is a novel and promising therapeutic strategy for cancer treatment.

Background/Objectives: Late-onset hypogonadism (LOH), characterized by declining testosterone levels with age, negatively affects the health of men, causing physical, psychological, and sexual dysfunction. Conventional testosterone replacement therapies have side effects, which has led to interest in natural alternatives. We investigated the effects of a standardized fermented Morinda citrifolia extract (FME) on oxidative stress-induced damage in TM3 Leydig and TM4 Sertoli cells. The cells were treated with H2O2 to simulate oxidative stress, followed by the FME treatment. Methods: Cytotoxicity assays, testosterone measurements, and gene and protein expression analyses were conducted to evaluate the restorative properties of FME. Results: The H2O2 treatment significantly decreased the cell viability, testosterone production, and the expression of proteins involved in testosterone synthesis and spermatogenesis, and the FME treatment improved testosterone production and restored the luteinizing hormone receptor, steroidogenic acute regulatory protein, CYP11A1, 3β-hydroxysteroid dehydrogenase, 17,20 desmolase, and 17β-hydroxysteroid dehydrogenase levels in the TM3 Leydig cells. It also reduced the expression of testosterone-degrading enzymes, aromatase and 5α-reductase. The FME treatment restored the levels of the androgen receptor and follicle-stimulating hormone receptor in the TM4 Sertoli cells. Conclusions: FME alleviates oxidative stress-induced damage in Leydig and Sertoli cells by promoting testosterone synthesis and spermatogenesis while regulating testosterone metabolism. These findings suggest that FME could be a promising candidate for the management of LOH symptoms.

Abstract The development of chemoresistance is a major challenge in the treatment of several types of cancers in clinical settings. Stemness and chemoresistance are the chief causes of poor clinical outcomes. In this context, we hypothesized that understanding the signaling pathways responsible for chemoresistance in cancers is crucial for the development of novel targeted therapies to overcome drug resistance. Among the aberrantly activated pathways, the PI3K-Akt/Wnt/β-catenin signaling pathway is clinically implicated in malignancies such as colorectal cancer (CRC) and glioblastoma multiforme (GBM). Aberrant dysregulation of phospholipase D (PLD) has been implicated in several malignancies, and oncogenic activation of this pathway facilitates tumor proliferation, stemness, and chemoresistance. Crosstalk involving the PLD and Wnt/β-catenin pathways promotes the progression of CRC and GBM and reduces the sensitivity of cancer cells to standard therapies. Notably, both pathways are tightly regulated and connected at multiple levels by upstream and downstream effectors. Thus, gaining deeper insights into the interactions between these pathways would help researchers discover unique therapeutic targets for the management of drug-resistant cancers. Here, we review the molecular mechanisms by which PLD signaling stimulates stemness and chemoresistance in CRC and GBM. Thus, the current review aims to address the importance of PLD as a central player coordinating cross-talk between the PI3K/Akt and Wnt/β-catenin pathways and proposes the possibility of targeting these pathways to improve cancer therapy and overcome drug resistance.

This study explored novel immunomodulatory approaches for cancer treatment, with a specific focus on lung cancer, the leading cause of cancer-related deaths worldwide. We synthesized indole-based phospholipase D (PLD) inhibitors with various substituents to improve anticancer efficacy. Through structure-activity relationship studies, the key compound was identified that significantly inhibiting PLD, suppressing cell growth, viability, and migration in vitro, while inducing apoptosis of lung cancer cells. In silico docking studies confirmed its binding to the PLD1 active site, highlighting the role of specific residues in inhibiting PLD1 activity. The inhibitor modulated oncogenic pathways and immune evasion in lung cancer cells, showing potential for immunotherapy. In vivo experiments in a mouse model showed tumor reduction and immune response alteration. Combining these inhibitors with gemcitabine, an anticancer drug, synergistically enhanced inhibition of lung cancer cell apoptosis and proliferation. This research offers new insights into PLD inhibitor as potential cancer therapeutics.

Pancreatic ductal adenocarcinoma (PDAC) exhibits severe hyp-oxia, which is associated with chemoresistance and worse patient outcome. It has been reported that hypoxia induces metabolic reprogramming in cancer cells. However, it is not well known whether metabolic reprogramming contributes to hypoxia. Here, we established that increased glutamine catabolism is a fundamental mechanism inducing hypoxia, and thus chemoresistance, in PDAC cells. An extracellular matrix component-based in vitro three-dimensional cell printing model with patient-derived PDAC cells that recapitulate the hypoxic status in PDAC tumors showed that chemoresistant PDAC cells exhibit markedly enhanced glutamine catabolism compared with chemoresponsive PDAC cells. The augmented glutamine metabolic flux increased the oxygen con-sumption rate via mitochondrial oxidative phosphorylation (OXPHOS), promoting hypoxia and hypoxia-induced chemoresis-tance. Targeting glutaminolysis relieved hypoxia and improved chemotherapy efficacy in vitro and in vivo. This work suggests that targeting the glutaminolysis-OXPHOS-hypoxia axis is a novel therapeutic target for treating patients with chemoresistant PDAC.

Supplementary Figure S1. PLD1 inactivation promotes apoptosis under serum deprived condition. Supplementary Figure S2. Scatter diagrams of gene expression microarray by depletion of PLD1. Supplementary Figure S3. PLD1 inactivation decreases RB1 expression in the tumor tissues from ApcMin/+ mice. Supplementary Figure S4. Loss of PLD1 decreases RB1 expression in the tumor tissues from AOM/DSS mice. Supplementary Figure S5. Epigenetic regulation of RB1 promoter is not affected by depletion and inhibition of PLD1. Supplementary Figure S6. Pre-miR-4465 and -192 decrease RB1 mRNA level. Supplementary Figure S7. IEC-specific PLD1 overexpression in ApcMin/+ mice increases the levels of RB1 and p-Akt. Supplementary Figure S8. PLD1 inhibition decreases Akt phosphorylation in AOM/DSS mice. Supplementary Figure S9. Effect of depletion of p27KIP1, Bim, or NOXA on E2F1-induced apoptosis. Supplementary Figure S10. Effect of RB1, Akt, and anti-miR-4496/-192 on PLD1 inhibition-repressed beta-catenin and c-Myc expression. Supplementary Figure S11. Multivariate survival analysis between expression of PLD1 and proapoptotic E2F1 target genes in CRC patients.

Supplementary Methods, Figure Legends 1-6 from Phospholipase D1 Drives a Positive Feedback Loop to Reinforce the Wnt/β-Catenin/TCF Signaling Axis

Supplementary Figure 2 from Phospholipase D1 Drives a Positive Feedback Loop to Reinforce the Wnt/β-Catenin/TCF Signaling Axis

Supplementary Table S1. Primer sets for Q-RT-PCR. Supplementary Table S2. Sequences of the promoter-specific primers used in ChIP assay Supplementary Table S3. Primer sets for mice genotype Supplementary Table S4. Factors of multivariates variables, gender, age, organ, tumor stage, and the protein pairs using Cox's proportional hazards model.

1. Plasmids, shRNAs and miRNA. 2. Promoter reporter constructs. 3. 3Â'UTR reporter constructs and site-directed mutagenesis. 4. Viral production and infection. 5. Reagents 6. Transient transfection and reporter gene assay. 7. Real-time quantitative PCR. 8. Quantification of mature miRNA. 9. ChIP assay. 10. mRNA microarray analysis. 11. EpiTect Methyl q-PCR Assay. 12. Mice genotype. 13. PLD activity assay. 14. In vitro limiting dilution assays (LDAs). 15. Additive statistical analysis.

Phospholipase D1 (PLD1), which catalyzes the hydrolysis of phosphatidylcholine to phosphatidic acid and choline, plays multiple roles in inflammation. We investigated the therapeutic effects of the newly developed PLD1 inhibitors A2998, A3000, and A3773 in vitro and in vivo rheumatoid arthritis (RA) model. A3373 reduced the levels of LPS-induced TNF-α, IL-6, and IgG in murine splenocytes in vitro. A3373 also decreased the levels of IFN-γ and IL-17 and the frequencies of Th1, Th17 cells and germinal-center B cells, in splenocytes in vitro. A3373 ameliorated the severity of collagen-induced arthritis (CIA) and suppressed infiltration of inflammatory cells into the joint tissues of mice with CIA compared with vehicle-treated mice. Moreover, A3373 prevented systemic bone demineralization in mice with CIA and suppressed osteoclast differentiation and the mRNA levels of osteoclastogenesis markers in vitro. These results suggest that A3373 has therapeutic potential for RA.

BACKGROUND/AIMS Despite significant advances in diagnostic and operative techniques, lung cancer remains one of the most lethal malignancies worldwide. Since prostaglandins such as prostaglandin D2 (PGD2) is involved in various pathophysiological process, including inflammation and tumorigenesis, this study aims to investigate the role of PGD2 during the process of epithelial-mesenchymal transition (EMT) in A549 cells. METHODS A549 cells were stimulated with PGD2 and expression of EMT markers was analyzed by immunoblotting and immunofluorescence. EMT-related gene, Slug expression was evaluated using quantitative real-time polymerase chain reaction (qPCR). Migration and invasion abilities of A549 cells were determined in chemotaxis and Matrigel invasion assays, respectively. We also inhibited the TGF/Smad signaling pathway using a receptor inhibitor or silencing of TGF-β1 and TGFβ type I receptor (TGFβRI), and protein expression was assessed by immunoblotting and immunofluorescence. RESULTS Here, we found that stimulation of A549 cells with PGD2 resulted in morphological changes into a mesenchymal-like phenotype under low serum conditions. Stimulation of A549 cells with PGD2 resulted in a significant reduction in proliferation, whereas invasion and migration were enhanced. The expression of E-cadherin was markedly downregulated, while Vimentin expression was upregulated after treatment of A549 cells with PGD2. Slug expression was markedly upregulated by stimulating A549 cells with PGD2, and stimulation of A549 cells with PGD2 significantly enhanced TGF-β1 expression, and silencing of TGF-β1 significantly blocked PGD2-induced EMT and Smad2 phosphorylation. In addition, PGD2-induced Smad2 phosphorylation and EMT were significantly abrogated by either pharmacological inhibition or silencing of TGFβRI. PGD2-induced expression of Slug and EMT were significantly augmented in low nutrient and low serum conditions. Finally, the subsequent culture of mesenchymal type of A549 cells under normal culture conditions reverted the cell's phenotype to an epithelial type. CONCLUSION Given these results, we suggest that tumor microenvironmental factors such as PGD2, nutrition, and growth factors could be possible therapeutic targets for treating metastatic cancers.

Muscle regeneration includes proliferation and differentiation of muscle satellite cells, which involves the mammalian target of rapamycin (mTOR). We identified the C-terminal unique attached sequence motif (UNE) domain of leucyl-tRNA synthetase (LRS-UNE-L) as an mTORC1 (mTOR complex1)-activating domain that acts through Vps34 and phospholipase D1 (PLD1) when introduced in the form of a muscle-enhancing peptide. In vitro Vps34 lipid kinase assay, phosphatidylinositol 3-phosphate (PI(3)P) measurement, in vivo PLD1 assay, and western blot assay were performed in HEK293 cells to test the effect of the LRS-UNE-L on the Vps34-PLD1-mTOR pathway. Adeno-associated virus (AAV)-LRS-UNE-L was transduced in C2C12 cells in vitro , in BaCl 2 -injured tibialis anterior (TA) muscles, and in 18-month-old TA muscles to analyse its effect on myogenesis, muscle regeneration, and aged muscle, respectively. The muscle-specific cell-permeable peptide M12 was fused with LRS-UNE-L and tested for cell integration in C2C12 and HEK293 cells using FACS analysis and immunocytochemistry. Finally, M12-LRS-UNE-L was introduced into BaCl 2 -injured TA muscles of 15-week-old Pld1 +/+ or Pld1 −/− mice, and its effect was analysed by measurement of cross-sectional area of regenerating muscle fibres. The LRS-UNE-L expression restored amino acid-induced S6K1 phosphorylation in LRS knockdown cells in a RagD GTPases-independent manner (421%, P  = 0.007 vs. LRS knockdown control cells). The LRS-UNE-L domain was directly bound to Vps34; this interaction was accompanied by increases in Vps34 activity (166%, P  = 0.0352), PI(3)P levels (146%, P  = 0.0039), and PLD1 activity (228%, P  = 0.0294) compared with amino acid-treated control cells, but it did not affect autophagic flux. AAV-delivered LRS-UNE-L domain augmented S6K1 phosphorylation (174%, P  = 0.0013), mRNA levels of myosin heavy chain (MHC) (122%, P  = 0.0282) and insulin-like growth factor 2 (IGF2) (146%, P  = 0.008), and myogenic fusion (133%, P  = 0.0479) in C2C12 myotubes. AAV-LRS-UNE-L increased the size of regenerating muscle fibres in BaCl 2 -injured TA muscles (124%, P  = 0.0279) ( n  = 9–10), but it did not change the muscle fibre size of TA muscles in old mice. M12-LRS-UNE-L was preferentially delivered into C2C12 cells compared with HEK293 cells and augmented regeneration of BaCl 2 -injured TA muscles in a PLD1-dependent manner (116%, P  = 0.0022) ( n  = 6). Our results provide compelling evidence that M12-LRS-UNE-L could be a muscle-enhancing protein targeting mTOR.

Phospholipase D (PLD) is a potential therapeutic target against cancer. However, the contribution of PLD inhibition to the antitumor response remains unknown. We developed a potent and selective PLD1 inhibitor based on computer-aided drug design. The inhibitor enhanced apoptosis in colorectal cancer (CRC) cells but not in normal colonic cells, and in vitro cardiotoxicity was not observed. The inhibitor downregulated the Wnt/β-catenin signaling pathway and reduced the migration, invasion, and self-renewal capacity of CRC cells. In cancer, therapeutic engagement of immunogenic cell death (ICD) leads to more effective responses by eliciting the antitumor immunity of T cells. The CRC cells treated with the inhibitor showed hallmarks of ICD, including downregulation of "do not eat-me" signals (CD24, CD47, programmed cell death ligand 1 [PD-L1]), upregulation of "eat-me" signal (calreticulin), release of high-mobility group Box 1, and ATP. PLD1 inhibition subsequently enhanced the phagocytosis of cancer cells by macrophages through the surface expression of costimulatory molecules; as a result, the cancer cells were more susceptible to cytotoxic T-cell-mediated killing. Moreover, PLD1 inhibition attenuated colitis-associated CRC and orthotopically injected tumors, probably by controlling multiple pathways, including Wnt signaling, phagocytosis checkpoints, and immune signaling. Furthermore, combination therapy with a PLD1 inhibitor and an anti-PD-L1 antibody further enhanced tumor regression via immune activation in the tumor environment. Collectively, in this study, PLD1 was identified as a critical regulator of the tumor microenvironment in colorectal cancer, suggesting the potential of PLD1 inhibitors for cancer immunotherapy based on ICD and immune activation. PLD1 inhibitors may act as promising immune modulators in antitumor treatment via ICD.