Chemotherapy-induced COX-2 upregulation by cancer cells defines their inflammatory properties and limits the efficacy of chemoimmunotherapy combinations

Integration of STING activation and COX-2 inhibition via steric-hindrance effect tuned nanoreactors for cancer chemoimmunotherapy

Integrating immunotherapy with nanomaterials-based chemotherapy presents a promising avenue for amplifying antitumor outcomes. Nevertheless, the suppressive tumor immune microenvironment (TIME) and the upregulation of cyclooxygenase-2 (COX-2) induced by chemotherapy can hinder the efficacy of the chemoimmunotherapy. This study presents a TIME-reshaping strategy by developing a steric-hindrance effect tuned zinc-based metal-organic framework (MOF), designated as CZFNPs. This nanoreactor is engineered by in situ loading of the COX-2 inhibitor, C-phycocyanin (CPC), into the framework building blocks, while simultaneously weakening the stability of the MOF. Consequently, CZFNPs achieve rapid pH-responsive release of zinc ions (Zn2+) and CPC upon specific transport to tumor cells overexpressing folate receptors. Accordingly, Zn2+ can induce reactive oxygen species (ROS)-mediated cytotoxicity therapy while synchronize with mitochondrial DNA (mtDNA) release, which stimulates mtDNA/cGAS-STING pathway-mediated innate immunity. The CPC suppresses the chemotherapy-induced overexpression of COX-2, thus cooperatively reprogramming the suppressive TIME and boosting the antitumor immune response. In xenograft tumor models, the CZFNPs system effectively modulates STING and COX-2 expression, converting "cold" tumors into "hot" tumors, thereby resulting in ≈ 4-fold tumor regression relative to ZIF-8 treatment alone. This approach offers a potent strategy for enhancing the efficacy of combined nanomaterial-based chemotherapy and immunotherapy.

Pivotal roles for cancer cell-intrinsic mPGES-1 and autocrine EP4 signaling in suppressing antitumor immunity

Tumor cell-derived prostaglandin E2 (PGE2) is a tumor cell-intrinsic factor that supports immunosuppression in the tumor microenvironment (TME) by acting on the immune cells, but the impact of PGE2 signaling in tumor cells on the immunosuppressive TME is unclear. We demonstrate that deleting the PGE2 synthesis enzyme or disrupting autocrine PGE2 signaling through EP4 receptors on tumor cells reverses the T cell-low, myeloid cell-rich TME, activates T cells, and suppresses tumor growth. Knockout (KO) of Ptges (the gene encoding the PGE2 synthesis enzyme mPGES-1) or the EP4 receptor gene (Ptger4) in KPCY (KrasG12D P53R172H Yfp CrePdx) pancreatic tumor cells abolished growth of implanted tumors in a T cell-dependent manner. Blockade of the EP4 receptor in combination with immunotherapy, but not immunotherapy alone, induced complete tumor regressions and immunological memory. Mechanistically, Ptges- and Ptger4-KO tumor cells exhibited altered T and myeloid cell attractant chemokines, became more susceptible to TNF-α-induced killing, and exhibited reduced adenosine synthesis. In hosts treated with an adenosine deaminase inhibitor, Ptger4-KO tumor cells accumulated adenosine and gave rise to tumors. These studies reveal an unexpected finding - a nonredundant role for the autocrine mPGES-1/PGE2/EP4 signaling axis in pancreatic cancer cells, further nominating mPGES-1 inhibition and EP4 blockade as immune-sensitizing therapy in cancer.

Blocking CX3CR1+ Tumor-Associated Macrophages Enhances the Efficacy of Anti-PD1 Therapy in Hepatocellular Carcinoma

The efficacy of immune checkpoint inhibitors in the treatment of hepatocellular carcinoma (HCC) remains limited, highlighting the need for further investigation into the mechanisms underlying treatment resistance. Accumulating evidence indicates that tumor-associated macrophages (TAM) within the tumor microenvironment demonstrate a key role in immune evasion and treatment resistance. This study explored the role of TAMs in the HCC tumor microenvironment. Our findings reveal that TAMs expressing CX3C motif chemokine receptor 1 (CX3CR1) induced T-cell exhaustion through IL27 secretion in orthotopic models of HCC following treatment with anti-PD1. Moreover, we identified prostaglandin E2 (PGE2), released by immune-attacked tumor cells, as a key regulator of TAM transition to a CX3CR1+ phenotype. To augment the therapeutic response to anti-PD1 therapy, we propose targeting CX3CR1+ TAMs in addition to anti-PD1 therapy. Our study contributes to the understanding of the role of TAMs in cancer immunotherapy and highlights potential clinical implications for HCC treatment. The combination of targeting CX3CR1+ TAMs with anti-PD1 therapy holds promise for enhancing the efficacy of immunotherapeutic interventions in patients with HCC.

Tumor-derived cyclooxygenase-2 fuels hypothalamic inflammation

Hypothalamic inflammation often coincides with cancer and cachexia-anorexia. Prior work established the significance of tumor-derived inflammatory factors in triggering hypothalamic inflammation, yet the precise mechanisms remained elusive. Here, we demonstrate that prostaglandin E2 (PGE2), produced in the tumor via cyclooxygenase-2 (COX-2), plays a pivotal role in this context. PGE2 itself directly exerts pro-inflammatory effects on the hypothalamus through the EP4 receptor, while also augmenting hypothalamic inflammation via NF-κB pathways in the presence of host gut-derived pathogen-associated molecular patterns (PAMPs). In tumor-bearing mice, we confirm this synergistic interaction between tumor-derived COX-2/PGE2 and host-derived lipopolysaccharide (LPS) in amplifying hypothalamic inflammation. Supporting this mechanism we find that the tumor-specific knockout of COX-2 attenuates hypothalamic inflammation and improves survival in mice. Together, these findings highlight the mechanisms of tumor-associated COX-2 in fuelling hypothalamic inflammation. They also emphasize the potential of tumor-specific COX-2 inhibition and targeting gut permeability as a novel therapeutic strategy for improving clinical outcomes in cancer patients.

Convergent inducers and effectors of T cell paralysis in the tumour microenvironment

Tumorigenesis embodies the formation of a heterotypic tumour microenvironment (TME) that, among its many functions, enables the evasion of T cell-mediated immune responses. Remarkably, most TME cell types, including cancer cells, fibroblasts, myeloid cells, vascular endothelial cells and pericytes, can be stimulated to deploy immunoregulatory programmes. These programmes involve regulatory inducers (signals-in) and functional effectors (signals-out) that impair CD8+ and CD4+ T cell activity through cytokines, growth factors, immune checkpoints and metabolites. Some signals target specific cell types, whereas others, such as transforming growth factor-β (TGFβ) and prostaglandin E2 (PGE2), exert broad, pleiotropic effects; as signals-in, they trigger immunosuppressive programmes in most TME cell types, and as signals-out, they directly inhibit T cells and also modulate other cells to reinforce immunosuppression. This functional diversity and redundancy pose a challenge for therapeutic targeting of the immune-evasive TME. Fundamentally, the commonality of regulatory programmes aimed at abrogating T cell activity, along with paracrine signalling between cells of the TME, suggests that many normal cell types are hard-wired with latent functions that can be triggered to prevent inappropriate immune attack. This intrinsic capability is evidently co-opted throughout the TME, enabling tumours to evade immune destruction.

From viruses to cancer: exploring the role of the hepatitis C virus NS3 protein in carcinogenesis

Hepatitis C virus (HCV) chronically infects approximately 170 million people worldwide and is a known etiological agent of hepatocellular carcinoma (HCC). The molecular mechanisms of HCV-mediated carcinogenesis are not fully understood. This review article focuses on the oncogenic potential of NS3, a viral protein with transformative effects on cells, although the precise mechanisms remain elusive. Unlike the more extensively studied Core and NS5A proteins, NS3's roles in cancer development are less defined but critical. Research indicates that NS3 is implicated in several carcinogenic processes such as proliferative signaling, cell death resistance, genomic instability and mutations, invasion and metastasis, tumor-related inflammation, immune evasion, and replicative immortality. Understanding the direct impact of viral proteins such as NS3 on cellular transformation is crucial for elucidating HCV's role in HCC development. Overall, this review sheds light on the molecular mechanisms used by NS3 to contribute to hepatocarcinogenesis, and highlights its significance in the context of HCV-associated HCC, underscoring the need for further investigation into its specific molecular and cellular actions.

Comprehensive Analysis of the Tumour Immune Microenvironment in Canine Urothelial Carcinoma Reveals Immunosuppressive Mechanisms Induced by the COX-Prostanoid Cascade

A comprehensive understanding of the tumour immune microenvironment (TIME) is essential for advancing precision medicine and identifying potential therapeutic targets. This study focused on canine urothelial carcinoma (cUC) recognised for its high sensitivity to cyclooxygenase (COX) inhibitors. Using immunohistochemical techniques, we quantified the infiltration of seven immune cell populations within cUC tumour tissue to identify clinicopathological features that characterise the TIME in cUC. Our results revealed several notable factors, including the significantly higher levels of CD3+ T cells and CD8+ T cells within tumour cell nests in cases treated with preoperative COX inhibitors compared to untreated cases. Based on the immunohistochemistry data, we further performed a comparative analysis using publicly available RNA-seq data from untreated cUC tissues (n = 29) and normal bladder tissues (n = 4) to explore the link between COX-prostanoid pathways and the immune response to tumours. We observed increased expression of COX-2, microsomal prostaglandin E2 synthase-1 (mPGES-1) and mPGES-2 in cUC tissues. However, only mPGES-2 showed a negative correlation with the cytotoxic T-cell (CTL)-related genes CD8A and granzyme B (GZMB). In addition, a broader analysis of solid tumours using The Cancer Genome Atlas (TCGA) database revealed similar patterns in several human tumours, suggesting a common mechanism in dogs and humans. Our results suggest that the COX-2/mPGES-2 pathway may act as a cross-species tumour-intrinsic factor that weakens anti-tumour immunity, and that COX inhibitors may convert TIME from a 'cold tumour' to a 'hot tumour' state by counteracting COX/mPGES-2-mediated immunosuppression.

A Self-Delivery Nanodrug Simultaneously Inhibits COX-2/PGE2 Mediated Inflammation and Downregulates PD-L1 to Boost Photoimmunotherapy

Phototherapy promotes anti-tumor immunity by inducing immunogenic cell death (ICD), However, the accompanying inflammatory responses also trigger immunosuppression, attenuating the efficacy of photo-immunotherapy. Herein, they co-assembled a cell-membrane targeting chimeric peptide C16-Cypate-RRKK-PEG8-COOH (CCP) and anti-inflammatory diclofenac (DA) to develop a nanodrug (CCP@DA) that both enhances the immune effect of phototherapy and weakens the inflammation-mediated immunosuppression. CCP@DA achieves cell membrane-targeting photodynamic and photothermal synergistic therapies to damage programmed death ligand 1 (PD-L1) and induce a strong ICD to activate anti-tumor response. Simultaneously, the released DA inhibits the cycoperoxidase-2 (COX-2)/prostaglandin E2 (PGE2) pathway in tumor cells to inhibit pro-tumor inflammation and further down-regulate PD-L1 expression to relieve the immunosuppressive microenvironment. CCP@DA significantly inhibited tumor growth and inflammation both in vitro and in vivo, while maintaining a potent anti-tumor immune response. Additionally, it exhibits excellent anti-metastatic capabilities and prolongs mouse survival time with a single dose and low levels of near-infrared (NIR) light exposure. This work provides a valuable strategy to control the therapy-induced inflammation for high-efficiency photoimmunotherapy.

Disaggregation-Activated pan-COX Imaging Agents for Human Soft tissue Sarcoma

Cancer stem cells are pivotal players in tumors initiation, growth, and metastasis. While several markers have been identified, there remain challenges particularly in heterogeneous malignancies like adult soft tissue sarcomas, where conventional markers are inherently overexpressed. Here, we designed BODIPY scaffold fluorescence probes (BD-IMC-1, BD-IMC-2) that activate via disaggregation targeting for cyclooxygenase (COX), a potential marker for CSCs in sarcoma in clinical pathology. Based on their structures, BD-IMC-1 showcased higher susceptibility to disaggregation compared to BD-IMC-2, consistent with their selective interaction with COX. Notably, the BD-IMC-1 revealed positive cooperativity binding to COX-2 at sub-micromolar ranges. Both probes showed significant fluorescence turn-on upon LPS or PMA triggered COX-2 upregulation in live RAW264.7, HeLa, and human sarcoma cell line (Saos-LM2) up to 2-fold increase with negligible toxicity. More importantly, the BD-IMC-1 demonstrated their practical imaging for COX-2 positive cells in paraffin-fixed human sarcoma tissue. Considering the fixed tissues are most practiced pathological sample, our finding suggests a potential of disaggregation activated chemosensor for clinical applications.

Targeting MEK/COX-2 axis improve immunotherapy efficacy in dMMR colorectal cancer with PIK3CA overexpression

PURPOSE

PIK3CA mutation or overexpression is associated with immunotherapy resistance in multiple cancer types, but is also paradoxically associated with benefit of COX-2 inhibition on patient survival of colorectal cancer (CRC) with mismatch repair deficiency (dMMR). This study examined whether and how PIK3CA status affected COX-2-mediated tumor inflammation and immunotherapy response of dMMR CRC.

METHODS

Murine colon cancer cells MC38, CT26, and CT26-Mlh1-KO were used to construct PIK3CA knockdown and overexpression models to mimic dMMR CRC with PIK3CA dysregulation, and xenograft models were used to evaluate how PIK3CA regulate COX-2 expression, CD8+ T cells infiltration, tumor growth, and therapy response to anti-PD-L1 treatment using immunocompetent mice. Western blot was carried out to delineate the signaling pathways in human and mouse cancer cells, and immunohistochemical analysis together with bioinformatics analysis using human patient samples.

RESULTS

PIK3CA upregulates COX-2 expression through MEK/ERK signaling pathway independent of AKT signaling to promote tumor inflammation and immunosuppression. PIK3CA knockdown profoundly reduced CT26 tumor growth in a CD8+ T cell-dependent manner, while PIK3CA overexpression significantly inhibited CD8+ T cells infiltration and promoted tumor growth. Furthermore, MEK or COX-2 inhibition augmented the anti-tumor activity of anti-PD-L1 immunotherapy on dMMR CRC mouse models, accompanied with increased CD8+ T cells infiltration and activated tumor microenvironment.

CONCLUSION

Our results identified that the PIK3CA hyperactivation in dMMR CRC upregulated COX-2 through MEK signaling, which inhibited CD8+ T cells infiltration and promoted tumor growth, together led to immunotherapy resistance. COX-2 or MEK inhibition may relieve therapy resistance and promote therapy efficacy of anti-PD-1/PD-L1 immunotherapy for treating dMMR CRC with PIK3CA overexpression or activating mutation.

Breaking Barriers: Modulation of Tumor Microenvironment to Enhance Bacillus Calmette-Guérin Immunotherapy of Bladder Cancer

The clinical management of bladder cancer continues to present significant challenges. Bacillus Calmette-Guérin (BCG) immunotherapy remains the gold standard of treatment for non-muscle invasive bladder cancer (NMIBC), but many patients develop recurrence and progression to muscle-invasive disease (MIBC), which is resistant to BCG. This review focuses on the immune mechanisms mobilized by BCG in bladder cancer tumor microenvironments (TME), mechanisms of BCG resistance, the dual role of the BCG-triggered NFkB/TNFα/PGE2 axis in the regulation of anti-tumor and tumor-promoting aspects of inflammation, and emerging strategies to modulate their balance. A better understanding of BCG resistance will help develop new treatments and predictive biomarkers, paving the way for improved clinical outcomes in bladder cancer patients.

Tumor Cell-Intrinsic p38 MAPK Signaling Promotes IL1α-Mediated Stromal Inflammation and Therapeutic Resistance in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a KRAS-driven inflammatory program and a desmoplastic stroma, which contribute to the profoundly chemoresistant phenotype. The tumor stroma contains an abundance of cancer-associated fibroblasts (CAF), which engage in extensive paracrine cross-talk with tumor cells to perpetuate protumorigenic inflammation. IL1α, a pleiotropic, tumor cell-derived cytokine, plays a critical role in shaping the stromal landscape. To provide insights into the molecular mechanisms regulating IL1A expression in PDAC, we performed transcriptional profiling of The Cancer Genome Atlas datasets and pharmacologic screening in PDAC cells and identified p38α MAPK as a key positive regulator of IL1A expression. Both genetic and pharmacologic inhibition of p38 MAPK significantly diminished IL1α production in vitro. Chromatin- and coimmunoprecipitation analyses revealed that p38 MAPK coordinates the transcription factors Sp1 and the p65 subunit of NFκB to drive IL1A overexpression. Single-cell RNA sequencing of a highly desmoplastic murine PDAC model, Ptf1aCre/+; LSL-KrasG12D/+; Tgfbr2flox/flox (PKT), confirmed that p38 MAPK inhibition significantly decreases tumor cell-derived Il1a and attenuates the inflammatory CAF phenotype in a paracrine IL1α-dependent manner. Furthermore, p38 MAPK inhibition favorably modulated intratumoral immunosuppressive myeloid populations and augmented chemotherapeutic efficacy to substantially reduce tumor burden and improve overall survival in PKT mice. These findings illustrate a cellular mechanism of tumor cell-intrinsic p38-p65/Sp1-IL1α signaling that is responsible for sustaining stromal inflammation and CAF activation, offering an attractive therapeutic approach to enhance chemosensitivity in PDAC.

SIGNIFICANCE

Inhibition of p38 MAPK suppresses tumor cell-derived IL1α and attenuates the inflammatory stroma and immunosuppressive tumor microenvironment to overcome chemotherapeutic resistance in pancreatic cancer.

Platinum Prodrug Nanoparticles with COX-2 Inhibition Amplify Pyroptosis for Enhanced Chemotherapy and Immune Activation of Pancreatic Cancer

Pyroptosis, an emerging mechanism of programmed cell death, holds great potential to trigger a robust antitumor immune response. Platinum-based chemotherapeutic agents can induce pyroptosis via caspase-3 activation. However, these agents also enhance cyclooxygenase-2 (COX-2) expression in tumor tissues, leading to drug resistance and immune evasion in pancreatic cancer and significantly limiting the effectiveness of chemotherapy-induced pyroptosis. Here, an amphiphilic polymer (denoted as PHDT-Pt-In) containing both indomethacin (In, a COX-2 inhibitor) and platinum(IV) prodrug (Pt(IV)) is developed, which is responsive to glutathione (GSH). This polymer self-assemble into nanoparticles (denoted as Pt-In NP) that can disintegrate in cancer cells due to the GSH responsiveness, releasing In to inhibit the COX-2 expression, hence overcoming the chemoresistance and amplifying cisplatin-induced pyroptosis. In a pancreatic cancer mouse model, Pt-In NP significantly inhibit tumor growth and elicit both innate and adaptive immune responses. Moreover, when combined with anti-programmed death ligand (α-PD-L1) treatment, Pt-In NP demonstrate the ability to completely suppress metastatic tumors, transforming "cold tumors" into "hot tumors". Overall, the sustained release of Pt(IV) and In from Pt-In NP amplifies platinum-drug-induced pyroptosis to elicit long-term immune responses, hence presenting a generalizable strategy for pancreatic cancer.

The cellular triumvirate: fibroblasts entangled in the crosstalk between cancer cells and immune cells

This review article will focus on subpopulations of fibroblasts that get reprogrammed by tumor cells into cancer-associated fibroblasts. Throughout this article, we will discuss the intricate interactions between fibroblasts, immune cells, and tumor cells. Unravelling complex intercellular crosstalk will pave the way for new insights into cellular mechanisms underlying the reprogramming of the local tumor immune microenvironment and propose novel immunotherapy strategies that might have potential in harnessing and modulating immune system responses.

The antidepressive mechanism of Longya Lilium combined with Fluoxetine in mice with depression-like behaviors

Traditional Chinese medicine is one of the most commonly used complementary and alternative medicine therapies for depression. Integrated Chinese-western therapies have been extensively applied in numerous diseases due to their superior efficiency in individual treatment. We used the meta-analysis, network pharmacology, and bioinformatics studies to identify the putative role of Longya Lilium combined with Fluoxetine in depression. Depression-like behaviors were mimicked in mice after exposure to the chronic unpredictable mild stress (CUMS). The underlying potential mechanism of this combination therapy was further explored based on in vitro and in vivo experiments to analyze the expression of COX-2, PGE2, and IL-22, activation of microglial cells, and neuron viability and apoptosis in the hippocampus. The antidepressant effect was noted for the combination of Longya Lilium with Fluoxetine in mice compared to a single treatment. COX-2 was mainly expressed in hippocampal CA1 areas. Longya Lilium combined with Fluoxetine reduced the expression of COX-2 and thus alleviated depression-like behavior and neuroinflammation in mice. A decrease of COX-2 curtailed BV-2 microglial cell activation, inflammation, and neuron apoptosis by blunting the PGE2/IL-22 axis. Therefore, a combination of Longya Lilium with Fluoxetine inactivates the COX-2/PGE2/IL-22 axis, consequently relieving the neuroinflammatory response and the resultant depression.

Yi Qi Chu Tan Formula (YQCTF) inhibited the progress of lung cancer via regulating tumor-associated neutrophil: An integrated study of network pharmacology, proteomics and pharmacodynamics

ETHNOPHARMACOLOGICAL RELEVANCE

Yi Qi Chu Tan Formula (YQCTF), a prescription consisting of eight traditional Chinese medicine for treating lung cancer, has been clinically proven to be effective in improving the life quality and prolonging the survival time of non-small cell lung cancer (NSCLC) patients.

AIM OF THE STUDY

This study aimed to evaluate the therapeutic efficacy of YQCTF on NSCLC mice model and further explore its therapeutic targets by using network pharmacology, proteomics and pharmacodynamic methodologies.

MATERIALS AND METHODS

The network pharmacology analysis was firstly conducted to screen out the potential active ingredients and therapeutic targets of YQCTF against NSCLC. Three kinds of extracts, i.e. the water extract (WE), water extraction-alcohol precipitation (WEAP) and alcohol extract (AE) of YQCTF were prepared, which chemical compositions were subsequently analyzed by using ultra-high performance liquid chromatography-mass spectrometry/mass spectrometry (UPLC-MS/MS), and which anti-neoplastic efficacy was examined on NSCLC mice model. Mice tumor tissues were collected for proteomics analysis, and the immunomodulatory effects of YQCTF extracts on the tumor microenvironment (TME) were further validated by using flow cytometry, immunofluorescence, ELISA and Western blot.

RESULTS

Network pharmacology identified 60 conjunct genes and ample cancer-related signaling pathways as potential therapeutic targets of YQCTF. Protein-protein interaction (PPI), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that YQCTF might negatively regulate cancer-related inflammation. UPLC-MS/MS analysis showed that the main components of YQCTF include at least ginsenosides, solasodine, solamargine, solasonine, peimisine, peiminine, peimine and sipeimine-3β-D-glucosihde. All kinds of YQCTF extracts significantly inhibited the growth of lung cancer allograft and regulated the ratio of immune cells in tumor tissues, i.e. upregulated the fractions of T cells, promoted the maturation of dendritic cells (DCs), increased the M1/M2 ratio of tumor-related macrophages, but reduced the number of Tregs and immunosuppressive neutrophils. Proteomics identified neutrophils to be the most prominently enriched target linked to NETs formation in mice tumor tissue, which is verified by the downregulation of neutrophil recruiting factors involving IL-6, HIF-1α and IL-8, as well as the decreases of NETs-related biomarkers including H3cit, MPO, CD18, MMP9 and ICAM-1 in immunofluorescence, ELISA and Western blot analysis.

CONCLUSION

YQCTF inhibited the progress of mice NSCLC allograft, suppressed the pro-tumorigenic tumor-associated neutrophils and improved the tumor immune microenvironment (TIME).

Lipids as mediators of cancer progression and metastasis

Metastasis formation is a complex process, involving multiple crucial steps, which are controlled by different regulatory mechanisms. In this context, the contribution of cancer metabolism to the metastatic cascade is being increasingly recognized. This Review focuses on changes in lipid metabolism that contribute to metastasis formation in solid tumors. We discuss the molecular mechanisms by which lipids induce a pro-metastatic phenotype and explore the role of lipids in response to oxidative stress and as signaling molecules. Finally, we reflect on potential avenues to target lipid metabolism to improve the treatment of metastatic cancers.

Hypoxia-Responsive Golgi-Targeted Prodrug Assembled with Anthracycline for Improved Antitumor and Antimetastasis Efficacy

Tumor metastasis is an intricate multistep process regulated via various proteins and enzymes modified and secreted by swollen Golgi apparatus in tumor cells. Thus, Golgi complex is considered as an important target for the remedy of metastasis. Currently, Golgi targeting technologies are mostly employed in Golgi-specific fluorescent probes for diagnosis, but their applications in therapy are rarely reported. Herein, we proposed a prodrug (INR) that can target and destroy the Golgi apparatus, which consisted of indomethacin (IMC) as the Golgi targeting moiety and retinoic acid (RA), a Golgi disrupting agent. The linker between IMC and RA was designed as a hypoxia-responsive nitroaromatic structure, which ensured the release of the prototype drugs in the hypoxic tumor microenvironment. Furthermore, INR could be assembled with pirarubicin (THP), an anthracycline, to form a carrier-free nanoparticle (NP) by emulsion-solvent evaporation method. A small amount of mPEG2000-DSPE was added to shield the positive charges and improve the stability of the nanoparticle to obtain PEG-modified nanoparticle (PNP). It was proved that INR released the prototype drugs in tumor cells and hypoxia promoted the release. The Golgi destructive effect of RA in INR was amplified owing to the Golgi targeting ability of IMC, and IMC also inhibited the protumor COX-2/PGE2 signaling. Finally, PNP exhibited excellent curative efficacy on 4T1 primary tumor and its pulmonary and hepatic metastasis. The small molecular therapeutic prodrug targeting Golgi apparatus could be adapted to multifarious drug delivery systems and disease models, which expanded the application of Golgi targeting tactics in disease treatment.

Cyclooxygenase-2 Blockade Is Crucial to Restore Natural Killer Cell Activity before Anti-CTLA-4 Therapy against High-Grade Serous Ovarian Cancer

Chronic inflammation influences the tumor immune microenvironment (TIME) in high-grade serous ovarian cancer (HGSOC). Specifically, cyclooxygenase-2 (COX-2) overexpression promotes cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) expression. Notably, elevated COX-2 levels in the TIME have been associated with reduced response to anti-CTLA-4 immunotherapy. However, the precise impact of COX-2, encoded by PTGS2, on the immune profile remains unknown. To address this, we performed an integrated bioinformatics analysis using data from the HGSOC cohorts (TCGA-OV, n = 368; Australian cohort AOCS, n = 80; GSE26193, n = 62; and GSE30161, n = 45). Employing Gene Set Variation Analysis (GSVA), MIXTURE and Ecotyper cell deconvolution algorithms, we concluded that COX-2 was linked to immune cell ecosystems associated with shorter survival, cell dysfunction and lower NK cell effector cytotoxicity capacity. Next, we validated these results by characterizing circulating NK cells from HGSOC patients through flow cytometry and cytotoxic assays while undergoing COX-2 and CTLA-4 blockade. The blockade of COX-2 improved the cytotoxic capacity of NK cells against HGSOC cell lines. Our findings underscore the relevance of COX-2 in shaping the TIME and suggest its potential as a prognostic indicator and therapeutic target. Increased COX-2 expression may hamper the effectivity of immunotherapies that require NK cell effector function. These results provide a foundation for experimental validation and clinical trials investigating combined therapies targeting COX-2 and CTLA-4 in HGSOC.

Possible Participation of Adenine Nucleotide Translocase ANT1 in the Cytotoxic Action of Progestins, Glucocorticoids, and Diclofenac on Tumor Cells

A comparative analysis of the cytostatic effects of progestins (gestobutanoyl, megestrol acetate, amol, dienogest, and medroxyprogesterone acetate), glucocorticoids (hydrocortisone, dexamethasone), and diclofenac on tumor cells was carried out in order to confirm their in silico predicted probabilities experimentally. The results showed the different sensitivity of HeLa, MCF-7, Hep-2, K-562, and Wi-38 cell lines to progestins, glucocorticoids, and diclofenac. The minimum IC50 was found for progestin gestobutanoyl (GB) as 18 µM for HeLa cells, and varied from 31 to 38 µM for MCF-7, Hep-2, and K-562. Glucocorticoids and diclofenac were much less cytotoxic in the HeLa, MCF-7, and Hep-2 cell lines than progestins, with IC50 values in the range of 150-3000 μM. Myelogenous leukemia K-562 cells were the least sensitive to the action of progestins and glucocorticoids but the most sensitive to diclofenac, which showed a pronounced cytotoxic effect with an IC50 of 31 μM. As we have shown earlier, progestins can uniquely modulate MPTP opening via the binding of adenine nucleotide translocase. On this basis, we evaluated the expression of adenylate nucleotide translocase ANT1 (SLC25 A4) as a possible participant in cytotoxic action in these cell lines after 48 h incubation with drugs. The results showed that progestins differently regulated ANT1 expression in different cell lines. Gestobutanoyl had the opposite effect on ANT1 expression in the HeLa, K562, and Wi-38 cells compared with the other progestins. It increased the ANT1 expression more than twofold in the HeLa and K562 cells but had no influence on the Wi-38 cells. Glucocorticoids and diclofenac increased ANT1 expression in the Wi-38 cells and decreased it in the K562, MCF-7, and Hep-2 cells. The modulation of ANT1 expression discovered in our study can be a new explanation of the cytotoxic and cytoprotective effects of hormones, which can vary depending on the cell type. ANT isoforms in normal and cancerous cells could be a new target for steroid hormone and anti-inflammatory drug action.

Apoptosis in mesenchymal stromal cells activates an immunosuppressive secretome predicting clinical response in Crohn's disease

In vivo apoptosis of human mesenchymal stromal cells (MSCs) plays a critical role in delivering immunomodulation. Yet, caspase activity not only mediates the dying process but also death-independent functions that may shape the immunogenicity of apoptotic cells. Therefore, a better characterization of the immunological profile of apoptotic MSCs (ApoMSCs) could shed light on their mechanistic action and therapeutic applications. We analyzed the transcriptomes of MSCs undergoing apoptosis and identified several immunomodulatory factors and chemokines dependent on caspase activation following Fas stimulation. The ApoMSC secretome inhibited human T cell proliferation and activation, and chemoattracted monocytes in vitro. Both immunomodulatory activities were dependent on the cyclooxygenase2 (COX2)/prostaglandin E2 (PGE2) axis. To assess the clinical relevance of ApoMSC signature, we used the peripheral blood mononuclear cells (PBMCs) from a cohort of fistulizing Crohn's disease (CD) patients who had undergone MSC treatment (ADMIRE-CD). Compared with healthy donors, MSCs exposed to patients' PBMCs underwent apoptosis and released PGE2 in a caspase-dependent manner. Both PGE2 and apoptosis were significantly associated with clinical responses to MSCs. Our findings identify a new mechanism whereby caspase activation delivers ApoMSC immunosuppression. Remarkably, such molecular signatures could implicate translational tools for predicting patients' clinical responses to MSC therapy in CD.

Targeting PTGES/PGE2 axis enhances sensitivity of colorectal cancer cells to 5-fluorouracil

Insensitivity and resistance to 5-fluorouracil (5FU) remain as major hurdles for effective and durable 5FU-based chemotherapy in colorectal cancer (CRC) patients. In this study, we identified prostaglandin E synthase (PTGES)/prostaglandin E2 (PGE2) axis as an important regulator for 5FU sensitivity in CRC cells. We found that PTGES expression and PGE2 production are elevated in CRC cells in comparison to normal colorectal epithelial cells. Depletion of PTGES significantly enhanced the inhibitory effect of 5FU on CRC cell viability that was fully reverted by exogenous supplement of PGE2. Inhibition of PTGES enzymatic function, by either inducing loss-of-function mutant or treatment with selective inhibitors, phenocopied the PTGES depletion in terms of 5FU sensitization. Mechanistically, PTGES/PGE2 axis modulates glycolysis in CRC cells, thereby regulating the 5FU sensitivity. Importantly, high PTGES expression is correlated with poor prognosis in 5FU-treated CRC patients. Thus, our study defines PTGES/PGE2 axis as a novel therapeutic target for enhancing the efficacy of 5FU-based chemotherapy in CRC.

Facts and Hopes on Neutralization of Protumor Inflammatory Mediators in Cancer Immunotherapy

In cancer pathogenesis, soluble mediators are responsible for a type of inflammation that favors the progression of tumors. The mechanisms chiefly involve changes in the cellular composition of the tumor tissue stroma and in the functional modulation of myeloid and lymphoid leukocytes. Active immunosuppression, proangiogenesis, changes in leukocyte traffic, extracellular matrix remodeling, and alterations in tumor-antigen presentation are the main mechanisms linked to the inflammation that fosters tumor growth and metastasis. Soluble inflammatory mediators and their receptors are amenable to various types of inhibitors that can be combined with other immunotherapy approaches. The main proinflammatory targets which can be interfered with at present and which are under preclinical and clinical development are IL1β, IL6, the CXCR1/2 chemokine axis, TNFα, VEGF, leukemia inhibitory factor, CCL2, IL35, and prostaglandins. In many instances, the corresponding neutralizing agents are already clinically available and can be repurposed as a result of their use in other areas of medicine such as autoimmune diseases and chronic inflammatory conditions.

IL-1β+ macrophages fuel pathogenic inflammation in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with high resistance to therapies1. Inflammatory and immunomodulatory signals co-exist in the pancreatic tumour microenvironment, leading to dysregulated repair and cytotoxic responses. Tumour-associated macrophages (TAMs) have key roles in PDAC2, but their diversity has prevented therapeutic exploitation. Here we combined single-cell and spatial genomics with functional experiments to unravel macrophage functions in pancreatic cancer. We uncovered an inflammatory loop between tumour cells and interleukin-1β (IL-1β)-expressing TAMs, a subset of macrophages elicited by a local synergy between prostaglandin E2 (PGE2) and tumour necrosis factor (TNF). Physical proximity with IL-1β+ TAMs was associated with inflammatory reprogramming and acquisition of pathogenic properties by a subset of PDAC cells. This occurrence was an early event in pancreatic tumorigenesis and led to persistent transcriptional changes associated with disease progression and poor outcomes for patients. Blocking PGE2 or IL-1β activity elicited TAM reprogramming and antagonized tumour cell-intrinsic and -extrinsic inflammation, leading to PDAC control in vivo. Targeting the PGE2-IL-1β axis may enable preventive or therapeutic strategies for reprogramming of immune dynamics in pancreatic cancer.

Tumor Metabolism-Rewriting Nanomedicines for Cancer Immunotherapy

Cancer immunotherapy has become an established therapeutic paradigm in oncologic therapy, but its therapeutic efficacy remains unsatisfactory in the majority of cancer patients. Accumulating evidence demonstrates that the metabolically hostile tumor microenvironment (TME), characterized by acidity, deprivation of oxygen and nutrients, and accumulation of immunosuppressive metabolites, promotes the dysfunction of tumor-infiltrating immune cells (TIICs) and thereby compromises the effectiveness of immunotherapy. This indicates the potential role of tumor metabolic intervention in the reinvigoration of antitumor immunity. With the merits of multiple drug codelivery, cell and organelle-specific targeting, controlled drug release, and multimodal therapy, tumor metabolism-rewriting nanomedicines have recently emerged as an attractive strategy to strengthen antitumor immune responses. This review summarizes the current progress in the development of multifunctional tumor metabolism-rewriting nanomedicines for evoking antitumor immunity. A special focus is placed on how these nanomedicines reinvigorate innate or adaptive antitumor immunity by regulating glucose metabolism, amino acid metabolism, lipid metabolism, and nucleotide metabolism at the tumor site. Finally, the prospects and challenges in this emerging field are discussed.

Chemical Profiling and Biological Activity of Psydrax dicoccos Gaertn

Breast cancer is one of the deadliest diseases in women with a mortality rate of 6.6%. Adverse effects of synthetic drugs have directed research toward safer alternatives such as natural compounds. This study focused on Psydrax dicoccos Gaertn, an evergreen tree abundantly distributed in Tamil Nadu (India) for its possible application against breast cancer cells. P. dicoccos leaf methanol extract, found within a wide range of phytochemicals, demonstrated cytotoxic effects against MCF7 breast cancer cells at IC50 of 34 μg/mL. The extract exhibited good antioxidant activities against DPPH• (62%) and ABTS•+ (80%), as well as concentration-dependent (100-800 μg/mL) anti-inflammatory potential of 18-60% compared to standards, ascorbic acid or aspirin, respectively. Moreover, even low extract concentrations (10 μg/mL) inhibited the growth of Escherichia coli (1.9 ± 0.6 mm) and Pseudomonas aeruginosa (2.3 ± 0.7 mm), thus showing high antimicrobial and anti-inflammatory potential. GC-MS and LC-MS analyses identified 31 and 16 components, respectively, of which selected compounds were used to evaluate the interaction between key receptors (AKT-1, COX-2, and HER-2) of breast cancer based on binding energy (ΔG) and inhibition constant (Ki). The results indicate that bioactive compounds from P. dicoccos have potential against breast cancer cells, but further evaluations are needed.

Activated platelets facilitate hematogenous metastasis of breast cancer by modulating the PDGFR-β/COX-2 axis

Platelets have been widely recognized as a bona fide mediator of malignant diseases, and they play significant roles in influencing various aspects of tumor progression. Paracrine interactions between platelets and tumor cells have been implicated in promoting the dissemination of malignant cells to distant sites. However, the underlying mechanisms of the platelet-tumor cell interactions for promoting hematogenous metastasis are not yet fully understood. We found that activated platelets with high expression of CD36 were prone to release a plethora of growth factors and cytokines, including high levels of PDGF-B, compared to resting platelets. PDGF-B activated the PDGFR-β/COX-2 signaling cascade, which elevated an array of pro-inflammatory factors levels, thereby aggravating tumor metastasis. The collective administration of CD36 inhibitor and COX-2 inhibitor resolved the interactions between platelets and tumor cells. Collectively, our findings demonstrated that targeting the crosstalk between platelets and tumor cells offers potential therapeutic strategies for inhibiting tumor metastasis.

Deciphering the roles of aryl hydrocarbon receptor (AHR) in regulating carcinogenesis

Aryl hydrocarbon receptor (AHR) is a ligand-dependent receptor that belongs to the superfamily of basic helix-loop-helix (bHLH) transcription factors. The activation of the canonical AHR signaling pathway is known to induce the expression of cytochrome P450 enzymes, facilitating the detoxification metabolism in the human body. Additionally, AHR could interact with various signaling pathways such as epidermal growth factor receptor (EGFR), signal transducer and activator of transcription 3 (STAT3), hypoxia-inducible factor-1α (HIF-1α), nuclear factor ekappa B (NF-κβ), estrogen receptor (ER), and androgen receptor (AR) signaling pathways. Over the past 30 years, several studies have reported that various chemical, physical, or biological agents, such as tobacco, hydrocarbon compounds, industrial and agricultural chemical wastes, drugs, UV, viruses, and other toxins, could affect AHR expression or activity, promoting cancer development. Thus, it is valuable to overview how these factors regulate AHR-mediated carcinogenesis. Current findings have reported that many compounds could act as AHR ligands to drive the expressions of AHR-target genes, such as CYP1A1, CYP1B1, MMPs, and AXL, and other targets that exert a pro-proliferation or anti-apoptotic effect, like XIAP. Furthermore, some other physical and chemical agents, such as UV and 3-methylcholanthrene, could promote AHR signaling activities, increasing the signaling activities of a few oncogenic pathways, such as the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathways. Understanding how various factors regulate AHR-mediated carcinogenesis processes helps clinicians and scientists plan personalized therapeutic strategies to improve anti-cancer treatment efficacy. As many studies that have reported the roles of AHR in regulating carcinogenesis are preclinical or observational clinical studies that did not explore the detailed mechanisms of how different chemical, physical, or biological agents promote AHR-mediated carcinogenesis processes, future studies should focus on conducting large-scale and functional studies to unravel the underlying mechanism of how AHR interacts with different factors in regulating carcinogenesis processes.

Study of the antioxidant and anti-pancreatic cancer activities of Anchusa strigosa aqueous extracts obtained by maceration and ultrasonic extraction techniques

Pancreatic cancer is a highly aggressive malignancy and a leading cause of cancer-related deaths worldwide. Moreover, the incidence and mortality rates for pancreatic cancer are projected to keep increasing. A major challenge in the treatment of pancreatic cancer is the lack of effective screening approaches, which contributes to its poor prognosis, indicating the need for new treatment regimens and alternative therapies, such as herbal medicine. The medicinal plant A. strigosa, which is widely distributed in the Eastern Mediterranean region, is a short prickly plant from the Boraginaceae family that has been widely used in traditional medicine for treating various diseases. Nevertheless, its effect on human pancreatic cancer remains poorly investigated. In the present study, we screened the phytochemical content of Anchusa strigosa aqueous extracts obtained by maceration and ultrasound-assisted methods (ASM and ASU, respectively) and evaluated their antioxidant effects. We also investigated their anticancer effects and possible underlying mechanisms. The results show that both extracts were rich in bioactive molecules, with slight differences in their composition. Both extracts exhibited remarkable antioxidant potential and potent radical-scavenging activity in vitro. Additionally, non-cytotoxic concentrations of both extracts attenuated cell proliferation in a time- and concentration-dependent manner, which was associated with a decrease in the proliferation marker Ki67 and an induction of the intrinsic apoptotic pathway. Furthermore, the extracts increased the aggregation of pancreatic cancer cells and reduced their migratory potential, with a concomitant downregulation of integrin β1. Finally, we showed that the ASM extract caused a significant decrease in the levels of COX-2, an enzyme that has been linked to inflammation, carcinogenesis, tumor progression, and metastasis. Taken together, our findings provide evidence that A. strigosa extracts, particularly the extract obtained using the maceration method, have a potential anticancer effect and may represent a new resource for the design of novel drugs against pancreatic cancer.

Dual Blockade of EP2 and EP4 Signaling is Required for Optimal Immune Activation and Antitumor Activity Against Prostaglandin-Expressing Tumors

While the role of prostaglandin E2 (PGE2) in promoting malignant progression is well established, how to optimally block the activity of PGE2 signaling remains to be demonstrated. Clinical trials with prostaglandin pathway targeted agents have shown activity but without sufficient significance or dose-limiting toxicities that have prevented approval. PGE2 signals through four receptors (EP1-4) to modulate tumor progression. EP2 and EP4 signaling exacerbates tumor pathology and is immunosuppressive through potentiating cAMP production. EP1 and EP3 signaling has the opposite effect through increasing IP3 and decreasing cAMP. Using available small-molecule antagonists of single EP receptors, the cyclooxygenase-2 (COX-2) inhibitor celecoxib, or a novel dual EP2/EP4 antagonist generated in this investigation, we tested which approach to block PGE2 signaling optimally restored immunologic activity in mouse and human immune cells and antitumor activity in syngeneic, spontaneous, and xenograft tumor models. We found that dual antagonism of EP2 and EP4 together significantly enhanced the activation of PGE2-suppressed mouse and human monocytes and CD8+ T cells in vitro as compared with single EP antagonists. CD8+ T-cell activation was dampened by single EP1 and EP3 antagonists. Dual EP2/EP4 PGE2 receptor antagonists increased tumor microenvironment lymphocyte infiltration and significantly reduced disease burden in multiple tumor models, including in the adenomatous polyposis coli (APC)min+/- spontaneous colorectal tumor model, compared with celecoxib. These results support a hypothesis that redundancy of EP2 and EP4 receptor signaling necessitates a therapeutic strategy of dual blockade of EP2 and EP4. Here we describe TPST-1495, a first-in-class orally available small-molecule dual EP2/EP4 antagonist.

Significance

Prostaglandin (PGE2) drives tumor progression but the pathway has not been effectively drugged. We demonstrate significantly enhanced immunologic potency and antitumor activity through blockade of EP2 and EP4 PGE2 receptor signaling together with a single molecule.

Entering, Linked with the Sphinx: Lysophosphatidic Acids Everywhere, All at Once, in the Oral System and Cancer

Oral health is crucial to overall health, and periodontal disease (PDD) is a chronic inflammatory disease. Over the past decade, PDD has been recognized as a significant contributor to systemic inflammation. Here, we relate our seminal work defining the role of lysophosphatidic acid (LPA) and its receptors (LPARs) in the oral system with findings and parallels relevant to cancer. We discuss the largely unexplored fine-tuning potential of LPA species for biological control of complex immune responses and suggest approaches for the areas where we believe more research should be undertaken to advance our understanding of signaling at the level of the cellular microenvironment in biological processes where LPA is a key player so we can better treat diseases such as PDD, cancer, and emerging diseases.

Feedback-Elevated Antitumor Amplifier of Self-Delivery Nanomedicine by Suppressing Photodynamic Therapy-Caused Inflammation

Inflammation activation is accompanied by tumor growth, migration, and differentiation. Photodynamic therapy (PDT) can trigger an inflammatory response to cause negative feedback of tumor inhibition. In this paper, a feedback-elevated antitumor amplifier is developed by constructing self-delivery nanomedicine for PDT and cascade anti-inflammation therapy. Based on the photosensitizer chlorin e6 (Ce6) and COX-2 inhibitor indomethacin (Indo), the nanomedicine is prepared via molecular self-assembly technology without additional drug carriers. It is exciting that the optimized nanomedicine (designated as CeIndo) possesses favorable stability and dispersibility in the aqueous phase. Moreover, the drug delivery efficiency of CeIndo is significantly improved, which could be effectively accumulated at the tumor site and internalized by tumor cells. Importantly, CeIndo not only exhibits a robust PDT efficacy on tumor cells but also drastically decreases the PDT-induced inflammatory response in vivo, resulting in feedback-elevated tumor inhibition. By virtue of the synergistic effect of PDT and cascade inflammation suppression, CeIndo tremendously reduces tumor growth and leads to a low side effect. This study presents a paradigm for the development of codelivery nanomedicine for enhanced tumor therapy through inflammation suppression.

Comprehensive characterization of HER2-low breast cancers: implications in prognosis and treatment

BACKGROUND

HER2-low cancers are heterogeneous with different degrees of HER2 expression and hormone receptor (HR) status. Currently, its analysis is mostly focused on the standard clinic-pathologic features or common biomarkers expression, without considering the heterogeneity within the category. A further characterization and understanding of this cancer subgroup will facilitate its management.

METHODS

A large cohort of HER2-negative cancers (N = 1464) was included. The HER2-low (N = 412) and HER2-zero cancers (N = 1052) were compared and correlated with a comprehensive panel of clinico-pathologic features and biomarker expression according to different HER2 expressions and HR statuses. The prognostic values of these features in HER2-low cancers were also evaluated.

FINDINGS

The characteristics of HER2-low breast cancers, as compared to HER2-zero, varied with the HR status. HER2-low luminal cancers were associated with younger age, larger tumor, high pAKT and high HLA expression. Among TNBCs, opposite trends in age and tumor size were found. Additionally, HER2-low TNBC showed less necrosis, higher pN, lower c-kit and CK14 than HER2-zero cancers. Nonetheless, regardless of HR status, HER2-low status was associated with increased COX2 and AR expression, implicated in the biology of HER2-low cancers. HER2-low cancers showed high expression of HLAs in tumors and PD-L1 in immune cells. In particular, the co-expression of HLAs was found to be associated with better survival in HER2-low cancers.

INTERPRETATION

This study revealed further characteristic of HER2-low breast cancers as compared to HER2-zero cancers, provided further insights into its prognostication and therapeutic strategies.

FUNDING

Health and Medical Research Fund (08190586), Cheng Yue Pui Charity Foundation and CUHK direct grant.

Development of a COX-2-Selective Fluorescent Probe for the Observation of Early Intervertebral Disc Degeneration

Cyclooxygenase-2 (COX-2) is a biomolecule known to be overexpressed in inflammation. Therefore, it has been considered a diagnostically useful marker in numerous studies. In this study, we attempted to assess the correlation between COX-2 expression and the severity of intervertebral disc (IVD) degeneration using a COX-2-targeting fluorescent molecular compound that had not been extensively studied. This compound, indomethacin-adopted benzothiazole-pyranocarbazole (IBPC1), was synthesized by introducing indomethacin—a compound with known selectivity for COX-2—into a phosphor with a benzothiazole-pyranocarbazole structure. IBPC1 exhibited relatively high fluorescence intensity in cells pretreated with lipopolysaccharide, which induces inflammation. Furthermore, we observed significantly higher fluorescence in tissues with artificially damaged discs (modeling IVD degeneration) compared to normal disc tissues. These findings indicate that IBPC1 can meaningfully contribute to the study of the mechanism of IVD degeneration in living cells and tissues and to the development of therapeutic agents.

Discovery of 2H-Indazole-3-carboxamide Derivatives as Novel Potent Prostanoid EP4 Receptor Antagonists for Colorectal Cancer Immunotherapy

Nowadays, small-molecule drugs have become an indispensable part of tumor immunotherapy. Accumulating evidence has indicated that specifically blocking PGE₂/EP4 signaling to induce robust antitumor immune response represents an attractive immunotherapy strategy. Herein, a 2H-indazole-3-carboxamide containing compound 1 was identified as a EP4 antagonist hit by screening our in-house small-molecule library. Systematic structure-activity relationship exploration leads to the discovery of compound 14, which displayed single-nanomolar EP4 antagonistic activity in a panel of cell functional assays, high subtype selectivity, and favorable drug-like profiles. Moreover, compound 14 profoundly inhibited the up-regulation of multiple immunosuppression-related genes in macrophages. Oral administration of compound 14, either as monotherapy or in combination with an anti-PD-1 antibody, significantly impaired tumor growth via enhancing cytotoxic CD8⁺ T cell-mediated antitumor immunity in a syngeneic colon cancer model. Thus, these results demonstrate the potential of compound 14 as a candidate for developing novel EP4 antagonists for tumor immunotherapy.

Liposomal celecoxib combined with dendritic cell therapy enhances antitumor efficacy in melanoma

Cancer vaccine efficacy is limited by the immunosuppressive nature of the tumor microenvironment created by inflammation, immune inhibitory factors, and regulatory T cells (Tregs). Inspired by the role of cyclooxygenase-2 (COX-2) in inflammation in the tumor site, we proposed that normalization of the tumor microenvironment by celecoxib as a COX-2 inhibitor might improve the efficacy of Dendritic Cell (DC) therapy in a melanoma model. In the present study, liposomal celecoxib (Lip-CLX) was combined with ex vivo generated DC vaccines pulsed with gp100 peptide (in liposomal and non-liposomal forms) for prophylactic and therapeutic evaluation in the B16F10 melanoma model. Tumor site analysis by flow cytometry demonstrated that intravenous administration of Lip-CLX at a dose of 1 mg/kg in four doses effectively normalized the tumor microenvironment by reducing Tregs and IL-10 production. Furthermore, in combination with DC vaccination (DC + Lip-peptide+Lip-CLX), it significantly increased tumor-infiltrating CD4⁺ and CD8⁺ T cells and secretion of IFN-γ. This combinatorial strategy produced an effective prophylactic and therapeutic antitumor response, which reduced tumor growth and prolonged the overall survival. In conclusion, our findings suggest that the liposomal celecoxib targets the inhibitory mechanisms of the tumor microenvironment and broadens the impact of DC therapy to improve the outcome of immunotherapy in solid tumors.

Sorafenib Alleviates Inflammatory Signaling of Tumor Microenvironment in Precancerous Lung Injuries

According to population-based studies, lung cancer is the prominent reason for cancer-related mortality worldwide in males and is also rising in females at an alarming rate. Sorafenib (SOR), which is approved for the treatment of hepatocellular carcinoma and renal cell carcinoma, is a multitargeted protein kinase inhibitor. Additionally, SOR is the subject of interest for preclinical and clinical trials in lung cancer. This study was designed to assess in vivo the possible effects of sorafenib (SOR) in diethylnitrosamine (DEN)-induced lung carcinogenesis and examine its probable mechanisms of action. A total of 30 adult male rats were divided into three groups (1) control, (2) DEN, and (3) DEN + SOR. The chemical induction of lung carcinogenesis was performed by injection of DEN intraperitoneally at 150 mg/kg once a week for two weeks. The DEN-administered rats were co-treated with SOR of 10 mg/kg by oral gavage for 42 alternate days. Serum and lung tissue samples were analyzed to determine SRY-box transcription factor 2 (SOX-2) levels. The tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β) levels were measured in lung tissue supernatants. Lung sections were analyzed for cyclooxygenase-2 (COX-2) and c-Jun N-terminal kinase (JNK) histopathologically. In addition, cyclooxygenase-2 (COX-2) and c-Jun N-terminal kinase (JNK) were analyzed by immunohistochemistry and immunofluorescence methods, respectively. SOR reduced the level of SOX-2 that maintenance of cancer stemness and tumorigenicity, and TNF-α and IL-1β levels. Histopathological analysis demonstrated widespread inflammatory cell infiltration, disorganized alveolar structure, hyperemia in the vessels, and thickened alveolar walls in DEN-induced rats. The damage was markedly reduced upon SOR treatment. Further, immunohistochemical and immunofluorescence analysis also revealed increased expression of COX-2 and JNK expression in DEN-intoxicated rats. However, SOR treatment alleviated the expression of these inflammatory markers in DEN-induced lung carcinogenesis. These findings suggested that SOR inhibits DEN-induced lung precancerous lesions through decreased inflammation with concomitant in reduced SOX-2 levels, which enables the maintenance of cancer stem cell properties.

Blockade of store-operated calcium entry sensitizes breast cancer cells to cisplatin therapy via modulating inflammatory response

Store-operated calcium entry (SOCE) is an important pathway for calcium signaling that regulates calcium influx across the plasma membrane upon the depletion of calcium stores in the endoplasmic reticulum. SOCE participates in regulating a number of physiological processes including cell proliferation and migration while SOCE dysregulation has been linked with pathophysiological conditions such as inflammation and cancer. The crosslink between cancer and inflammation has been well-established where abundant evidence demonstrate that inflammation plays a role in cancer pathophysiology and the response of cancer cells to chemotherapeutic agents including cisplatin. Indeed, the efficacy of cisplatin against cancer cells is reduced by inflammation. Interestingly, it was shown that SOCE enhances inflammatory signaling in immune cells. Therefore, the main objectives of this study are to examine the impact of SOCE inhibition on the cisplatin sensitivity of breast cancer cells and to explore its related mechanism in modulating the inflammatory response in breast cancer cells. Our findings showed that SOCE inhibitor (BTP2) enhanced cisplatin cytotoxicity against resistant breast cancer cells via inhibition of cell proliferation and migration as well as induction of apoptosis. We also found an upregulation in the gene expression of two major components of SOCE, STIM1 and ORAI1, in cisplatin-resistant breast cancer cells compared to cisplatin-sensitive breast cancer cells. In addition, cisplatin treatment increased the gene expression of STIM1 and ORAI1 in cisplatin-resistant breast cancer cells. Finally, this study also demonstrated that cisplatin therapy caused an increase in the gene expression of inflammatory mediators COX2, IL-8, and TNF-α as well as COX2 protein and upon SOCE inhibition using BTP2, the effect of cisplatin on the inflammatory mediators was reversed. Altogether, this study has proven the pivotal role of SOCE in cisplatin resistance of breast cancer cells and showed the importance of targeting this pathway in improving breast cancer therapy.

Enhanced Cytotoxic Activity of PEGylated Curcumin Derivatives: Synthesis, Structure-Activity Evaluation, and Biological Activity

Curcumin has been modified in various ways to broaden its application in medicine and address its limitations. In this study, we present a series of curcumin-based derivatives obtained by replacing the hydroxy groups in the feruloyl moiety with polyethylene glycol (PEG) chains and the addition of the BF₂ moiety to the carbonyl groups. Tested compounds were screened for their cytotoxic activity toward two bladder cancer cell lines, 5637 and SCaBER, and a noncancerous cell line derived from lung fibroblasts (MRC-5). Cell viability was analyzed under normoxic and hypoxic conditions (1% oxygen). Structure-activity relationships (SARs) are discussed, and curcumin derivatives equipped within feruloyl moieties with 3-methoxy and 4-{2-[2-(2-methoxyethoxy)ethoxy]ethoxy} substituents (5) were selected for further analysis. Compound 5 did not affect the viability of MRC-5 cells and exerted a stronger cytotoxic effect under hypoxic conditions. However, the flow cytometry studies showed that PEGylation did not improve cellular uptake. Another observation was that the lack of serum proteins limits the intracellular uptake of curcumin derivative 5. The preliminary mechanism of action studies indicated that compound 5 under hypoxic conditions induced G2/M arrest in a dose-dependent manner and increased the expression of stress-related proteins such as p21/CIP1, phosphorylated HSP27, ADAMTS-1, and phosphorylated JNK. In summary, the results of the studies indicated that PEGylated curcumin is a more potent compound against bladder cancer cell lines than the parent compound, and derivative 5 is worthy of further investigation to clarify its mechanism of anticancer action under hypoxic conditions.

Phenylsulfonimide PPARα Antagonists Enhance Nrf2 Activation and Promote Oxidative Stress-Induced Apoptosis/Pyroptosis in MCF7 Breast Cancer Cells

The NF-E2-related factor 2 transcription factor (Nrf2) orchestrates the basal and stress-inducible activation of a vast array of antioxidant genes. A high amount of reactive oxygen species (ROS) promotes carcinogenesis in cells with defective redox-sensitive signaling factors such as Nrf2. In breast cancer (BC), emerging evidence indicates that increased Nrf2 activity enhances cell metastatic potential. An interconnection between peroxisome proliferator-activated receptors (PPARs) and Nrf2 pathways in cancer has been shown. In this light, newly synthesized PPARα antagonists, namely IB42, IB44, and IB66, were tested in the BC cell line MCF7 in parallel with GW6471 as the reference compound. Our results show that the most promising compound of this phenylsulfonimide series (IB66) is able to decrease MCF7 proliferation by blocking cells at the G2/M checkpoint. The underlying mechanism has been investigated, disclosing a caspase 3/Akt-dependent apoptotic/pyroptotic pathway induced by the increased generation of oxidative stress. Moreover, the involvement of Nrf2 and COX2 in IB66-treated MCF7 cell response has been highlighted. The reported data lay the groundwork for the development of alternative targeted therapy involving the Nrf2/PPARα molecular axis, able to overcome BC cell chemoresistance and cause better clinical outcomes, promoting other forms of programmed cell death, such as pyroptosis.

Systems biology network reveals the correlation between COX-2 expression and Ch 7q copy number alterations in Ch 11q-deleted pediatric neuroblastoma tumors

Tumor-associated inflammation and chromosomal aberrations can play crucial roles in cancer development and progression. In neuroblastoma (NB), the enzyme cyclooxygenase-2 (COX-2) is associated with copy number alterations on the long arm of chromosome 11 (Ch 11q), defining an aggressive disease subset. This retrospective study included formalin-fixed paraffin-embedded tumor samples collected from nine patients during diagnosis at the pediatric Pequeno Principe Hospital, Curitiba, PR, Brazil, and post-chemotherapy (CT). COX-2 expression was evaluated using immunohistochemistry and correlated with the genome profile of paired pre- and post-CT samples, determined by array comparative genomic hybridization. A systems biology approach elucidated the PTGS2 network interaction. The results showed positive correlations between pre-CT Ch 7q gain and COX-2 expression (ρ = 0.825; p-value = 0.006) and negative correlations between Ch 7q gain and Ch 11q deletion (ρ = −0.919; p-value = 0.0005). Three samples showed Ch 11q deletion and Ch 7q gain. Network analysis identified a direct connection between CAV-1 (Ch 7q) and COX-2 in NB tumors and highlighted the connection between amplified genes in Ch 7q and deleted ones in 11q. The identification of hub-bottleneck-switch genes provides new biological insights into this connection between NB, tumorigenesis, and inflammation.

Drugging inflammation: Easier NSAID than done

In this issue of Immunity, Eisenstein, Hiliard, et al., uncover a novel mechanism of some widely used non-steroidal anti-inflammatory drugs (NSAIDs): activation of the antioxidant transcription factor NRF2 in myeloid immune cells.