Targeting ESE3/EHF With Nifurtimox Inhibits CXCR2+ Neutrophil Infiltration and Overcomes Pancreatic Cancer Resistance to Chemotherapy and Immunotherapy.

BACKGROUND & AIMS: Because pancreatic cancer responds poorly to chemotherapy and immunotherapy, it is necessary to identify novel targets and compounds to overcome resistance to treatment. METHODS: This study analyzed genomic single nucleotide polymorphism sequencing, single-cell RNA sequencing, and spatial transcriptomics. Ehf-knockout mice, KPC (LSL-KrasG12D/+, LSL-Trp53R172H/+ and Pdx1-Cre) mice, CD45.1+ BALB/C nude mice, and CD34+ humanized mice were also used as subjects. Multiplexed immunohistochemistry and flow cytometry were performed to investigate the proportion of tumor-infiltrated C-X-C motif chemokine receptor 2 (CXCR2)+ neutrophils. In addition, multiplexed cytokines assays and chromatin immunoprecipitation assays were used to examine the mechanism. RESULTS: The TP53 mutation-mediated loss of tumoral EHF increased the recruitment of CXCR2+ neutrophils, modulated their spatial distribution, and further induced chemo- and immunotherapy resistance in clinical cohorts and preclinical syngeneic mice models. Mechanistically, EHF deficiency induced C-X-C motif chemokine ligand 1 (CXCL1) transcription to enhance in vitro and in vivo CXCR2+ neutrophils migration. Moreover, CXCL1 or CXCR2 blockade completely abolished the effect, indicating that EHF regulated CXCR2+ neutrophils migration in a CXCL1-CXCR2-dependent manner. The depletion of CXCR2+ neutrophils also blocked the in vivo effects of EHF deficiency on chemotherapy and immunotherapy resistance. The single-cell RNA-sequencing results of PDAC treated with Nifurtimox highlighted the therapeutic significance of Nifurtimox by elevating the expression of tumoral EHF and decreasing the weightage of CXCL1-CXCR2 pathway within the microenvironment. Importantly, by simultaneously inhibiting the JAK1/STAT1 pathway, it could significantly suppress the recruitment and function of CXCR2+ neutrophils, further sensitizing PDAC to chemotherapy and immunotherapies. CONCLUSIONS: The study demonstrated the role of EHF in the recruitment of CXCR2+ neutrophils and the promising role of Nifurtimox in sensitizing pancreatic cancer to chemotherapy and immunotherapy.

CD64+ fibroblast-targeted vilanterol and a STING agonist augment CLDN18.2 BiTEs efficacy against pancreatic cancer by reducing desmoplasia and enriching stem-like CD8+ T cells.

OBJECTIVE: The objective of this study is to improve the efficacy of CLDN18.2/CD3 bispecific T-cell engagers (BiTEs) as a promising immunotherapy against pancreatic ductal adenocarcinoma (PDAC). DESIGN: Humanised hCD34+/hCD3e+, Trp53R172HKrasG12DPdx1-Cre (KPC), pancreas-specific Cldn18.2 knockout (KO), fibroblast-specific Fcgr1 KO and patient-derived xenograft/organoid mouse models were constructed. Flow cytometry, Masson staining, Cell Titer Glo assay, virtual drug screening, molecular docking and chromatin immunoprecipitation were conducted. RESULTS: CLDN18.2 BiTEs effectively inhibited early tumour growth, but late-stage efficacy was significantly diminished. Mechanically, the Fc fragment of BiTEs interacted with CD64+ cancer-associated fibroblasts (CAFs) via activation of the SYK-VAV2-RhoA-ROCK-MLC2-MRTF-A-α-SMA/collagen-I pathway, which enhanced desmoplasia and limited late-stage infiltration of T cells. Molecular docking analysis found that vilanterol suppressed BiTEs-induced phosphorylation of VAV2 (Y172) in CD64+ CAFs and weakened desmoplasia. Additionally, decreased cyclic guanosine-adenosine monophosphate synthase/stimulator of interferon genes (STING) activity reduced proliferation of TCF-1+PD-1+ stem-like CD8+ T cells, which limited late-stage effects of BiTEs. Finally, vilanterol and the STING agonist synergistically boosted the efficacy of BiTEs by inhibiting the activation of CD64+ CAFs and enriching proliferation of stem-like CD8+ T cells, resulting in sustained anti-tumour activity. CONCLUSION: Vilanterol plus the STING agonist sensitised PDAC to CLDN18.2 BiTEs and augmented efficacy as a potential novel strategy.

SDCBP promotes pancreatic cancer progression by preventing YAP1 from ß-TrCP-mediated proteasomal degradation.

OBJECTIVE: Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal tumour with limited treatment options. Here, we identified syndecan binding protein (SDCBP), also known as syntenin1, as a novel targetable factor in promoting PDAC tumour progression. We also explored a therapeutic strategy for suppressing SDCBP expression. DESIGN: We used samples from patients with PDAC, human organoid models, LSL-KrasG12D/+mice, LSL-Trp53R172H/+ and Pdx1-Cre (KPC) mouse models, and PDX mouse models. Immunostaining, colony formation assay, ethynyl-2-deoxyuridine incorporation assay, real-time cell analysis, cell apoptosis assay, automated cell tracking, invadopodia detection and gelatin degradation assays, coimmunoprecipitation, and pull-down assays were performed in this study. RESULTS: The median overall survival and recurrence-free survival rates in the high-SDCBP group were significantly shorter than those in the low-SDCBP group. In vitro and in vivo studies have demonstrated that SDCBP promotes PDAC proliferation and metastasis. Mechanically, SDCBP inhibits CK1δ/ε-mediated YAP-S384/S387 phosphorylation, which further suppresses ß-TrCP-mediated YAP1 ubiquitination and proteasome degradation by directly interacting with YAP1. SDCBP interacts with the TAD domain of YAP1, mainly through its PDZ1 domain. Preclinical KPC mouse cohorts demonstrated that zinc pyrithione (ZnPT) suppresses PDAC tumour progression by suppressing SDCBP. CONCLUSIONS: SDCBP promotes the proliferation and metastasis of PDAC by preventing YAP1 from ß-TrCP-mediated proteasomal degradation. Therefore, ZnPT could be a promising therapeutic strategy to inhibit PDAC progression by suppressing SDCBP.

BZW1 Facilitates Glycolysis and Promotes Tumor Growth in Pancreatic Ductal Adenocarcinoma Through Potentiating eIF2α Phosphorylation.

BACKGROUND & AIMS: Pancreatic ductal adenocarcinoma (PDAC) is characterized by severe metabolic stress due to fibrosis and poor vascularization. BZW1 is an eIF5-mimic protein involved in tumorigenesis and progression. The aim of this study was to investigate the role of BZW1 in metabolic stress resistance in PDAC. METHODS: BZW1 expression was evaluated in human PDAC tissue microarray and PDAC cells. Glycolysis regulation of BZW1 and its correlation with glycolysis-related genes was analyzed. Tumor growth, cell proliferation, and apoptosis were evaluated in mice xenograft tumors and patient-derived organoids. RESULTS: The results of bioinformatic screening identified that BZW1 was 1 of the top 3 genes favorable for tumor progression in PDAC. The analysis of our cohort confirmed that BZW1 was overexpressed in human PDAC tissues compared with nontumor tissues, and its abnormal expression was correlated with large tumor size and poor prognosis. BZW1 promoted cell proliferation and inhibited apoptosis in both mouse xenograft models and PDAC-derived organoids via facilitating glycolysis in the oxygen-glucose-deprivation condition. Mechanically, BZW1 served as an adaptor for PKR-like endoplasmic reticulum (ER) kinase (PERK), facilitated the phosphorylation of eIF2α, promoted internal ribosome entry site-dependent translation of HIF1α and c-Myc, and thereby boosted the Warburg effect. In organoid-based xenografts with high BZW1 levels, both the PERK/eIF2α phosphorylation inhibitor GSK2606414 and ISRIB significantly suppressed tumor growth and prolonged animal survival. CONCLUSIONS: BZW1 is a key molecule in the internal ribosome entry site-dependent translation of HIF1α/c-Myc and plays crucial roles in the glycolysis of PDAC. BZW1 might serve as a therapeutic target for patients with pancreatic cancer.

ESE3/EHF, a promising target of rosiglitazone, suppresses pancreatic cancer stemness by downregulating CXCR4.

BACKGROUND AND AIMS: The crosstalk between cancer stem cells (CSCs) and their niche is required for the maintenance of stem cell-like phenotypes of CSCs. Here, we identified E26 transformation-specific homologous factor (EHF) as a key molecule in decreasing the sensitivity of pancreatic cancer (PC) cells to CSCs' niche stimulus. We also explored a therapeutic strategy to restore the expression of EHF. DESIGN: We used a LSL-KrasG12D/+mice, LSL-Trp53R172H/+ and Pdx1-Cre (KPC) mouse model and samples from patients with PC. Immunostaining, flow cytometry, sphere formation assays, anchorage-independent growth assay, in vivo tumourigenicity, reverse transcription PCR, chromatin immunoprecipitation (ChIP) and luciferase analyses were conducted in this study. RESULTS: CXCL12 derived from pancreatic stellate cells (PSCs) mediates the crosstalk between PC cells and PSCs to promote PC stemness. Tumorous EHF suppressed CSC stemness by decreasing the sensitivity of PC to CXCL12 stimulus and inhibiting the crosstalk between PC and CSC-supportive niches. Mechanically, EHF suppressed the transcription of the CXCL12 receptor CXCR4. EHF had a cell autonomous role in suppressing cancer stemness by inhibiting the transcription of Sox9, Sox2, Oct4 and Nanog. Rosiglitazone suppressed PC stemness and inhibited the crosstalk between PC and PSCs by upregulating EHF. Preclinical KPC mouse cohorts demonstrated that rosiglitazone sensitised PDAC to gemcitabine therapy. CONCLUSIONS: EHF decreased the sensitivity of PC to the stimulus from PSC-derived CSC-supportive niche by negatively regulating tumorous CXCR4. Rosiglitazone could be used to target PC stem cells and the crosstalk between CSCs and their niche by upregulating EHF.

ESE3-positive PSCs drive pancreatic cancer fibrosis, chemoresistance and poor prognosis via tumour-stromal IL-1ß/NF-κB/ESE3 signalling axis.

BACKGROUND: Desmoplastic stroma, a feature of pancreatic ductal adenocarcinoma (PDAC), contains abundant activated pancreatic stellate cells (PSCs). How PSCs promote PDAC progression remains incompletely understood. METHODS: Effect of epithelium-specific E-twenty six factor 3 (ESE3)-positive PSCs on PDAC fibrosis and chemoresistance was examined by western blot, RT-PCR, immunofluorescence, flow cytometry assay, chromatin immunoprecipitation, luciferase assay, immunohistochemistry and subcutaneous pancreatic cancer mouse model. RESULTS: ESE3 expression increased in PSCs in PDAC tissues compared with those in normal PSCs. Clinical data showed that ESE3 upregulation in PSCs was positively correlated with tumour size, pTNM stage, CA19-9, carcinoembryonic antigen and serum CA242 level. ESE3 overexpression in PSCs was an independent negative prognostic factor for disease-free survival and overall survival amongst patients with PDAC. Mechanistically, the conditional medium from the loss and gain of ESE3-expressing PSCs influenced PDAC chemoresistance and tumour growth. ESE3 directly induced the transcription of α-SMA, collagen-I and IL-1ß by binding to ESE3-binding sites on their promoters to activate PSCs. IL-1ß upregulated ESE3 in PSCs through NF-κB activation, and ESE3 was required for PSC activation by tumour cell-derived IL-1ß. CONCLUSION: Inhibiting the IL-1ß/ESE3 (PSCs)/IL-1ß-positive feedback loop is a promising therapeutic strategy to reduce tumour fibrosis and increase chemotherapeutic efficacy in PDAC.

Interleukin 35 Expression Correlates With Microvessel Density in Pancreatic Ductal Adenocarcinoma, Recruits Monocytes, and Promotes Growth and Angiogenesis of Xenograft Tumors in Mice.

BACKGROUND & AIMS: Cells of the monocyte lineage contribute to tumor angiogenesis. Interleukin 35 (IL35) is a member of the IL12 family produced by regulatory, but not effector, T cells. IL35 is a dimer comprising the IL12 alpha and IL27 beta chains, encoded by IL12A and EBI3, respectively. Expression of IL35 is increased in pancreatic ductal adenocarcinomas (PDACs) compared with normal pancreatic tissues, and promotes metastasis. We investigated the role of IL35 in monocyte-induced angiogenesis of PDAC in mice. METHODS: We measured levels of IL35 protein, microvessel density, and numbers of monocytes in 123 sequential PDAC tissues from patients who underwent surgery in China in 2010. We performed studies with the human PDAC cell lines CFPAC-1, BxPC-3, Panc-1, MIA-PaCa-2, and mouse PDAC cell line Pan02. Monocyte subsets were isolated by flow cytometry from human peripheral blood mononuclear cells. Fused human or mouse IL12A and EBI3 genes were overexpressed in PDAC cells or knocked down using small hairpin RNAs. Cells were grown as xenograft tumors in SCID mice; some mice were given injections of an IL35-neutralizing antibody and tumor growth was monitored. We performed chemotaxis assays to measure the ability of IL35 to recruit monocytes. We analyzed mRNA sequences of 179 PDACs in the Cancer Genome Atlas to identify correlations between expression of IL12A and EBI3 and monocyte markers. Monocytes incubated with IL35 or PDAC cell supernatants were analyzed in tube formation and endothelial migration assays. RESULTS: In PDAC samples from patients, levels of IL35 mRNA and protein correlated with microvessel density and infiltration of monocyte lineage cells. In cells and mice with xenograft tumors, IL35 increased recruitment of monocytes into PDAC tumors, which required CCL5. Upon exposure to IL35, monocytes increased expression of genes whose products promote angiogenesis (CXCL1 and CXCL8). IL35 activated transcription of CCL5, CXCL1, and CXCL8 by inducing GP130 signaling, via IL12RB2 and phosphorylation of STAT1 and STAT4. A combination of a neutralizing antibody against IL35 and gemcitabine significantly decreased monocyte infiltration, microvessel density, and volume of xenograft tumors grown from PDAC cells in mice. CONCLUSIONS: PDAC cells produce IL35 to recruit monocytes via CCL5 and induce macrophage to promote angiogenesis via expression of CXCL1 and CXCL8. IL35 signaling promotes angiogenesis and growth of xenograft tumors from PDAC cells in mice. IL35 might serve as a therapeutic target for patients with pancreatic cancer.

Prognostic significance of lymphovascular infiltration in overall survival of gastric cancer patients after surgery with curative intent.

OBJECTIVE: Lymphovascular infiltration (LVI) is frequently detected in gastric cancer (GC) specimens. Studies have revealed that GC patients with LVI have a poorer prognosis than those without LVI. METHODS: In total, 1,007 patients with curatively resected GC at Department of Gastric Cancer, Tianjin Medical University Cancer Institute and Hospital were retrospectively enrolled. The patients were categorized into two groups based on the LVI status: a positive group (PG; presence of LVI) and a negative group (NG; absence of LVI). The clinicopathological factors corrected with LVI and prognostic variables were analyzed. Additionally, a pathological lymphovascular-node (lvN) classification system was proposed to evaluate the superiority of its prognostic prediction of GC patients compared with that of the eighth edition of the N staging system. RESULTS: Two hundred twenty-four patients (22.2%) had LVI. The depth of invasion and lymph node metastasis were independently associated with the presence of LVI. GC patients with LVI demonstrated a significantly lower overall survival (OS) rate than those without LVI (42.8% vs. 68.9%, respectively; P<0.001). In multivariate analysis, LVI was identified as an independent prognostic factor for GC patients (hazard ratio: 1.370; 95% confidence interval: 1.094-1.717; P=0.006). Using strata analysis, significant prognostic differences between the groups were only observed in patients at stage I-IIIa or N0-2. The lvN classification was found to be more appropriate to predict the OS of GC patients after curative surgery than the pN staging system. The -2 log-likelihood of lvN classification (4,746.922) was smaller than the value of pN (4,765.196), and the difference was statistically significant (χ2=18.434, P<0.001). CONCLUSIONS: The presence of LVI influences the OS of GC patients at stage I-IIIa or N0-2. LVI should be incorporated into the pN staging system to enhance the accuracy of the prognostic prediction of GC patients.

Hypoxia Inducible Factor 1 (HIF-1) Recruits Macrophage to Activate Pancreatic Stellate Cells in Pancreatic Ductal Adenocarcinoma.

Hypoxia inducible factor 1 (HIF-1) is a transcription factor composed of two subunits, namely, HIF-1α and HIF-1ß, in which HIF-1ß is constitutively expressed. HIF-1 upregulates several hypoxia-responsive proteins, including angiogenesis factors, glycolysis solution enzymes, and cell survival proteins. HIF-1 is also associated with the degree of inflammation in the tumor region, but the exact mechanism remains unclear. This study aims to identify the molecular mechanism of recruiting monocytes/macrophages by HIF-1α in pancreatic ductal adenocarcinoma (PDAC) and the effects of macrophages on pancreatic stellate cells (PSCs). Immunohistochemistry (IHC) was performed for cluster of differentiation 68 (CD68), HIF-1α, and chemical chemokines 2 (CCL2). Western blot, real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), chromatin immunoprecipitation assay, and The Cancer Genome Atlas (TCGA) were used to verify the correlation between HIF-1α and CCL2 at protein and nucleic acid levels. Monocytes/macrophages were co-cultured with PSCs to observe their interaction. Samples showed significant correlation between CD68 and HIF-1α (t-test, p < 0.05). HIF-1α recruited monocytes/macrophages by promoting CCL2 secretion. Moreover, macrophages could accelerate the activation of PSCs. HIF-1α might promote inflammation and fibrosis of PDAC through CCL2 secretion, which may provide a novel target to treat PDAC patients.

MiR-497 Suppresses YAP1 and Inhibits Tumor Growth in Non-Small Cell Lung Cancer.

BACKGROUND/AIMS: To investigate the expression, clinical significance and the cellular effects of miR-497 in non-small cell lung cancer (NSCLC). METHODS: NSCLC cells were transiently transfected with miR-497 mimics or siRNA to up-regulate or down-regulate expression. Quantitative real-time PCR (qRT-PCR) was used to detect the mRNA level of miR-497. Luciferase assays, colony formation assays and BrdU incorporation assays were performed to identify the targets and role of miR-497 in NSCLC cells. Finally, the abundance of miR-497 was analyzed in a total of 51 NSCLC specimens. RESULTS: The transcript levels of miR-497 were significantly decreased in NSCLC tissue (25/30; 83.3%). Low miR-497 levels in tumor tissue correlated with advanced pT stage. Additionally, miR-497 transcript levels correlated with overall survival of NSCLC patients (n = 51, p = 0.022). Overexpression of miR-497 inhibited the proliferation of NSCLC cell and down-regulation of miR-497 resulted in elevated NSCLC growth. Exogenous over-expression of YAP1 partially eliminated miR-497-induced cell growth. CONCLUSION: miR-497 plays an important role in inhibiting the proliferation of NSCLC by targeting YAP1. Our results suggest that miR-497 is a potential therapeutic target in treating patients with NSCLC.

Usefulness of the neutrophil-to-lymphocyte ratio in predicting lymph node metastasis in patients with non-small cell lung cancer.

Preoperative neutrophil-to-lymphocyte ratio (NLR) is a new hotspot for its prognostic significance in many types of cancers. In this study, a novel diagnosing model-the combination of enhanced contrast computed tomography (ECCT) and NLR (COCT-NLR) was constructed to detect the lymph nodal involvement in patients with non-small cell lung cancer (NSCLC). The clinicopathological parameters and thoracic ECCT images of 353 NSCLC patients were retrospectively reviewed. The COCT-NLR model was constructed and evaluated in detecting regional lymph nodal metastasis in patients with NSCLC. Univariate and multivariate analyses of clinicopathological parameters revealed that NLR value was independently associated with regional nodal involvement rate in patients with NSCLC (odds ratio (OR) = 4.770; 95 % confidence interval (CI), 2.487-9.146; P < 0.001). Compared with ECCT and NLR, the COCT-NLR model showed the highest efficacy in predicting nodal involvement. The sensitivity and specificity of COCT-NLR were 70.59 and 74.89 %, respectively. The COCT-NLR model is a valuable tool in detecting regional lymph node metastasis in patients with NSCLC.

miR-143 inhibits NSCLC cell growth and metastasis by targeting Limk1.

MicroRNAs (miRNAs) have essential roles in carcinogenesis and tumor progression. Here, we investigated the roles and mechanisms of miR-143 in non-small cell lung cancer (NSCLC). miR-143 was significantly decreased in NSCLC tissues and cell lines. Overexpression of miR-143 suppressed NSCLC cell proliferation, induced apoptosis, and inhibited migration and invasion in vitro. Integrated analysis identified LIM domain kinase 1 (Limk1) as a direct and functional target of miR-143. Overexpression of Limk1 attenuated the tumor suppressive effects of miR-143 in NSCLC cells. Moreover, miR-143 was inversely correlated with Limk1 expression in NSCLC tissues. Together, our results highlight the significance of miR-143 and Limk1 in the development and progression of NSCLC.

Tumor-derived interleukin 35 mediates the dissemination of gemcitabine resistance in pancreatic adenocarcinoma.

Rapid development of drug resistance after chemotherapy is a major cause of treatment failure in individuals with pancreatic ductal adenocarcinoma (PDAC). In this study, we illustrate that tumor-derived interleukin 35 (IL-35) mediates the accelerated resistance of PDAC to gemcitabine (GEM). We observe that GEM resistance can spread from GEM-resistant PDAC cells to GEM-sensitive cells, and that IL-35 is responsible for the propagation of chemoresistance, which is supported by sequencing and experimental data. Additionally, we discover that GEM-resistant cells have significantly higher levels of IL-35 expression. Mechanistically, aberrantly expressed IL-35 triggers transcriptional activation of SOD2 expression via GP130-STAT1 signaling, scavenging reactive oxygen species (ROS) and leading to GEM resistance. Furthermore, GEM treatment stimulates IL-35 expression through activation of the NF-κB pathway, resulting in acquired chemoresistance. In the mouse model, a neutralizing antibody against IL-35 enhances the tumor suppressive effect of GEM. Collectively, our data suggests that IL-35 is critical in mediating GEM resistance in pancreatic cancer, and therefore could be a valuable therapeutic target in overcoming PDAC chemoresistance.

Blockade of CD73 potentiates radiotherapy antitumor immunity and abscopal effects via STING pathway.

Radiotherapy (RT) is a crucial treatment for colorectal cancer (CRC) patients, but it often fails to induce systemic antitumor immunity. CD73, an immunomodulatory factor, is upregulated after RT and associated with poor prognosis in CRC patients. This study aims to elucidate the mechanisms driving RT-induced CD73 upregulation in CRC and investigate how combining RT with CD73 blockade stimulates immune responses and induces abscopal effects. Findings revealed that RT-induced CD73 upregulation is mediated by the ataxia telangiectasia and Rad3-related (ATR) pathway and correlated with RT tolerance, as demonstrated through flow cytometry, immunofluorescence, and Western Blotting. Using flow cytometry and multicolor immunofluorescence, experiments demonstrated that in CRC subcutaneous tumor models, combination therapy reduces the infiltration of myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), and regulatory T cells (Tregs) while increasing dendritic cells (DCs) and CD8 + T cells, resulting in superior antitumor responses. Additionally, results from flow cytometry, Western Blot, and RNA sequencing demonstrated that combination therapy enhances the antigen-presenting ability of DCs and activates tumor antigen-specific CD8 + T cells, improving their function and delaying their depletion. The activation of the cGAS-STING and IFN-I pathways is crucial for this effect. In summary, the integration of RT with CD73 blockade effectively reverses the immunosuppressive TME and invigorates CD8 + T cell-driven, specific antitumor immune responses. These insights shed fresh light on the mechanisms governing the synergistic modulation of immunity by RT and CD73 blockade in CRC, offering promising avenues for the advancement of therapeutic strategies against CRC.

BICC1 drives pancreatic cancer stemness and chemoresistance by facilitating tryptophan metabolism.

Pancreatic adenocarcinoma is the fourth leading cause of malignancy-related deaths, with rapid development of drug resistance driven by pancreatic cancer stem cells. However, the mechanisms sustaining stemness and chemotherapy resistance in pancreatic ductal adenocarcinoma (PDAC) remain unclear. Here, we demonstrate that Bicaudal C homolog 1 (BICC1), an RNA binding protein regulating numerous cytoplasmic mRNAs, facilitates chemoresistance and stemness in PDAC. Mechanistically, BICC1 activated tryptophan catabolism in PDAC by up-regulating indoleamine 2,3-dioxygenase-1 (IDO1) expression, a tryptophan-catabolizing enzyme. Increased levels of tryptophan metabolites contribute to NAD+ synthesis and oxidative phosphorylation, leading to a stem cell-like phenotype. Blocking BICC1/IDO1/tryptophan metabolism signaling greatly improves the gemcitabine (GEM) efficacy in several PDAC models with high BICC1 level. These findings indicate that BICC1 is a critical tryptophan metabolism regulator that drives the stemness and chemoresistance of PDAC and thus a potential target for combinatorial therapeutic strategy against chemoresistance.

RIPK1-dependent necroptosis promotes vasculogenic mimicry formation via eIF4E in triple-negative breast cancer.

Necroptosis is a caspase-independent form of programmed cell death. Receptor interacting protein kinase 1 (RIPK1) is a key molecule in the initiation of necroptosis and the formation of the necrotic complex. Vasculogenic mimicry (VM) provides a blood supply to tumor cells that is not dependent on endothelial cells. However, the relationship between necroptosis and VM in triple-negative breast cancer (TNBC) is not fully understood. In this study, we found that RIPK1-dependent necroptosis promoted VM formation in TNBC. Knockdown of RIPK1 significantly suppressed the number of necroptotic cells and VM formation. Moreover, RIPK1 activated the p-AKT/eIF4E signaling pathway during necroptosis in TNBC. eIF4E was blocked by knockdown of RIPK1 or AKT inhibitors. Furthermore, we found that eIF4E promoted VM formation by promoting epithelial-mesenchymal transition (EMT) and the expression and activity of MMP2. In addition to its critical role in necroptosis-mediated VM, eIF4E was essential for VM formation. Knockdown of eIF4E significantly suppressed VM formation during necroptosis. Finally, through clinical significance, the results found that eIF4E expression in TNBC was positively correlated with the mesenchymal marker vimentin, the VM marker MMP2, and the necroptosis markers MLKL and AKT. In conclusion, RIPK1-dependent necroptosis promotes VM formation in TNBC. Necroptosis promotes VM formation by activating RIPK1/p-AKT/eIF4E signaling in TNBC. eIF4E promotes EMT and MMP2 expression and activity, leading to VM formation. Our study provides a rationale for necroptosis-mediated VM and also providing a potential therapeutic target for TNBC.

Selective extended dissection for pancreaticoduodenectomy is associated with better survival in pancreatic cancer patients: retrospective cohort study.

BACKGROUND: Pancreatic ductal adenocarcinoma is a highly malignant tumor with relatively poor survival. Surgery is the first choice for treating patients with early pancreatic cancer. However, the surgical approach and the extent of resection for patients with pancreatic cancer are currently controversial. METHODS: The authors optimized the procedure of standard pancreaticoduodenectomy to selective extended dissection (SED), which is based on the extrapancreatic nerve plexus potentially invaded by the tumor. The authors retrospectively analyzed the clinicopathological data of patients with pancreatic adenocarcinoma who underwent radical surgery in our center from 2011 to 2020. Patients who underwent standard dissection (SD) were matched 2:1 to those who underwent SED using propensity score matching. The log-rank test and Cox regression model were used to analyze survival data. In addition, statistical analyses were performed for the perioperative complications, postoperative pathology, and recurrence pattern. RESULTS: A total of 520 patients were included in the analysis. Among patients with extrapancreatic perineural invasion (EPNI), disease-free survival was significantly longer in those who received SED than in those who received SD (14.5 months vs. 10 months, P <0.05). The incidence of metastasis in No. 9 and No. 14 lymph nodes was significantly higher in patients with EPNI. In addition, there was no significant difference in the incidence rate of perioperative complications between the two surgical procedures. CONCLUSION: Compared with SD, SED exhibits a significant prognostic benefit for patients with EPNI. The SED procedure aiming at specific nerve plexus dissection displayed particular efficacy and safety in resectable pancreatic ductal adenocarcinoma patients.

CD73, a Promising Therapeutic Target of Diclofenac, Promotes Metastasis of Pancreatic Cancer through a Nucleotidase Independent Mechanism.

CD73, a cell surface-bound nucleotidase, facilitates extracellular adenosine formation by hydrolyzing 5'-AMP to adenosine. Several studies have shown that CD73 plays an essential role in immune escape, cell proliferation and tumor angiogenesis, making it an attractive target for cancer therapies. However, there are limited clinical benefits associated with the mainstream enzymatic inhibitors of CD73, suggesting that the mechanism underlying the role of CD73 in tumor progression is more complex than anticipated, and further investigation is necessary. In this study, CD73 is found to overexpress in the cytoplasm of pancreatic ductal adenocarcinoma (PDAC) cells and promotes metastasis in a nucleotidase-independent manner, which cannot be restrained by the CD73 monoclonal antibodies or small-molecule enzymatic inhibitors. Furthermore, CD73 promotes the metastasis of PDAC by binding to the E3 ligase TRIM21, competing with the Snail for its binding site. Additionally, a CD73 transcriptional inhibitor, diclofenac, a non-steroidal anti-inflammatory drug, is more effective than the CD73 blocking antibody for the treatment of PDAC metastasis. Diclofenac also enhances the therapeutic efficacy of gemcitabine in the spontaneous KPC (LSL-KrasG12D/+ , LSL-Trp53R172H/+ , and Pdx-1-Cre) pancreatic cancer model. Therefore, diclofenac may be an effective anti-CD73 therapy, when used alone or in combination with gemcitabine-based chemotherapy regimen, for metastatic PDAC.

BICC1 drives pancreatic cancer progression by inducing VEGF-independent angiogenesis.

VEGF inhibitors are one of the most successful antiangiogenic drugs in the treatment of many solid tumors. Nevertheless, pancreatic adenocarcinoma (PAAD) cells can reinstate tumor angiogenesis via activation of VEGF-independent pathways, thereby conferring resistance to VEGF inhibitors. Bioinformatic analysis showed that BICC1 was one of the top genes involved in the specific angiogenesis process of PAAD. The analysis of our own cohort confirmed that BICC1 was overexpressed in human PAAD tissues and was correlated to increased microvessel density and tumor growth, and worse prognosis. In cells and mice with xenograft tumors, BICC1 facilitated angiogenesis in pancreatic cancer in a VEGF-independent manner. Mechanistically, as an RNA binding protein, BICC1 bounds to the 3'UTR of Lipocalin-2 (LCN2) mRNA and post-transcriptionally up-regulated LCN2 expression in PAAD cells. When its level is elevated, LCN2 binds to its receptor 24p3R, which directly phosphorylates JAK2 and activates JAK2/STAT3 signal, leading to increased production of an angiogenic factor CXCL1. Blocking of the BICC1/LCN2 signalling reduced the microvessel density and tumor volume of PAAD cell grafts in mice, and increased the tumor suppressive effect of gemcitabine. In conclusion, BICC1 plays a pivotal role in the process of VEGF-independent angiogenesis in pancreatic cancer, leading to resistance to VEGF inhibitors. BICC1/LCN2 signaling may serve as a promising anti-angiogenic therapeutic target for pancreatic cancer patients.

Irbesartan overcomes gemcitabine resistance in pancreatic cancer by suppressing stemness and iron metabolism via inhibition of the Hippo/YAP1/c-Jun axis.

BACKGROUND: Chemoresistance is the main reason for the poor prognosis of pancreatic ductal adenocarcinoma (PDAC). Thus, there is an urgent need to screen out new targets and compounds to reverse chemotherapeutic resistance. METHODS: We established a bio-bank of human PDAC organoid models, covering a representative range of PDAC tumor subtypes. We screened a library of 1304 FDA-approved compounds to identify candidates efficiently overcoming chemotherapy resistance. The effects of the compounds were evaluated with a CellTiter-Glo-3D assay, organoid apoptosis assay and in vivo patient-derived xenograft (PDX), patient-derived organoid (PDO) and LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx1-Cre (KPC) genetically engineered mouse models. RNA-sequencing, genome editing, sphere formation assays, iron assays and luciferase assays were conducted to elucidate the mechanism. RESULTS: High-throughput drug screening of chemotherapy-resistant PDOs identified irbesartan, an angiotensin ‖ type 1 (AT1) receptor antagonist, which could synergistically enhance the ability of chemotherapy to kill PDAC cells. In vitro and in vivo validation using PDO, PDX and KPC mouse models showed that irbesartan efficiently sensitized PDAC tumors to chemotherapy. Mechanistically, we found that irbesartan decreased c-Jun expression by inhibiting the Hippo/YAP1 pathway and further overcame chemotherapy resistance in PDAC. We also explored c-Jun, a potential target of irbesartan, which can transcriptionally upregulate the expression of key genes involved in stemness maintenance (SOX9/SOX2/OCT4) and iron metabolism (FTH1/FTL/TFRC). More importantly, we observed that PDAC patients with high levels of c-Jun expression demonstrated poor responses to the current standard chemotherapy regimen (gemcitabine plus nab-paclitaxel). Moreover, patients with PDAC had significant survival benefits from treatment with irbesartan plus a standard chemotherapy regimen in two-center retrospective clinical cohorts and patients with high c-Jun expression exhibited a better response to combination chemotherapy. CONCLUSIONS: Irbesartan could be used in combination with chemotherapy to improve the therapeutic efficacy in PDAC patients with high levels of c-Jun expression. Irbesartan effectively inhibited chemotherapy resistance by suppressing the Hippo/YAP1/c-Jun/stemness/iron metabolism axis. Based on our findings, we are designing an investigator-initiated phase II clinical trial on the efficacy and safety of irbesartan plus a standard gemcitabine/nab-paclitaxel regimen in the treatment of patients with advanced III/IV staged PDAC and are hopeful that we will observe patient benefits.