A rat-based preclinical platform facilitating transcatheter hepatic arterial infusion in immunodeficient rats with liver xenografts of patient-derived pancreatic ductal adenocarcinoma.

Liver metastases from pancreatic ductal adenocarcinoma (PDAC) are highly fatal. A rat-based patient-derived tumor xenograft (PDX) model is available for transcatheter therapy. This study aimed to create an immunodeficient rat model with liver xenografts of patient-derived primary PDAC and evaluate efficacy of hepatic arterial infusion chemotherapy with cisplatin in this model. Three patient-derived PDACs were transplanted into the livers of 21 rats each (totally, 63 rats), randomly assigned into hepatic arterial infusion, systemic venous infusion, and control groups (n = 7 each) four weeks post-implantation. Computed tomography evaluated tumor volumes before and four weeks after treatment. Post-euthanasia, resected tumor specimens underwent histopathological examination. A liver-implanted PDAC PDX rat model was established in all 63 rats, with first CT identifying all tumors. Four weeks post-treatment, arterial infusion groups exhibited significantly smaller tumor volumes than controls for all three tumors on second CT. Xenograft tumors histologically maintained adenocarcinoma features compared to original patient tumors. Ki67 expression was significantly lower in arterial infusion groups than in the other two for the three tumors, indicating reduced tumor growth in PDX rats. A liver-implanted PDAC PDX rat model was established as a rat-based preclinical platform. Arterial cisplatin infusion chemotherapy represents a potential therapy for PDAC liver metastasis.

LncRNAs as nodes for the cross-talk between autophagy and Wnt signaling in pancreatic cancer drug resistance.

Pancreatic cancer is a malignancy with high mortality. In addition to the few symptoms until the disease reaches an advanced stage, the high fatality rate is attributed to its rapid development, drug resistance and lack of appropriate treatment. In the selection and research of therapeutic drugs, gemcitabine is the first-line drug for pancreatic cancer. Solving the problem of gemcitabine resistance in pancreatic cancer will contribute to the progress of pancreatic cancer treatment. Long non coding RNAs (lncRNAs), which are RNA transcripts longer than 200 nucleotides, play vital roles in cellular physiological metabolic activities. Currently, our group and others have found that some lncRNAs are aberrantly expressed in pancreatic cancer cells, which can regulate the process of cancer through autophagy and Wnt/ß-catenin pathways simultaneously and affect the sensitivity of cancer cells to therapeutic drugs. This review presents an overview of the recent evidence concerning the node of lncRNA for the cross-talk between autophagy and Wnt/ß-catenin signaling in pancreatic cancer, together with the practicability of lncRNAs and the core regulatory factors as targets in therapeutic resistance.

Tumor Microenvironment Modulates Invadopodia Activity of Non-Selected and Acid-Selected Pancreatic Cancer Cells and Its Sensitivity to Gemcitabine and C18-Gemcitabine.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease with high mortality due to early metastatic dissemination and high chemoresistance. All these factors are favored by its extracellular matrix (ECM)-rich microenvironment, which is also highly hypoxic and acidic. Gemcitabine (GEM) is still the first-line therapy in PDAC. However, it is quickly deaminated to its inactive metabolite. Several GEM prodrugs have emerged to improve its cytotoxicity. Here, we analyzed how the acidic/hypoxic tumor microenvironment (TME) affects the response of PDAC cell death and invadopodia-mediated ECM proteolysis to both GEM and its C18 prodrug. METHODS: For this, two PDAC cell lines, PANC-1 and Mia PaCa-2 were adapted to pHe 6.6 or not for 1 month, grown as 3D organotypic cultures and exposed to either GEM or C18 in the presence and absence of acidosis and the hypoxia inducer, deferoxamine. RESULTS: We found that C18 has higher cytotoxic and anti-invadopodia activity than GEM in all culture conditions and especially in acid and hypoxic environments. CONCLUSIONS: We propose C18 as a more effective approach to conventional GEM in developing new therapeutic strategies overcoming PDAC chemoresistance.

Rutinosides-derived from Sarocladium strictum 6-O-α-rhamnosyl-ß-glucosidase show enhanced anti-tumoral activity in pancreatic cancer cells.

BACKGROUND: Low targeting efficacy and high toxicity continue to be challenges in Oncology. A promising strategy is the glycosylation of chemotherapeutic agents to improve their pharmacodynamics and anti-tumoral activity. Herein, we provide evidence of a novel approach using diglycosidases from fungi of the Hypocreales order to obtain novel rutinose-conjugates therapeutic agents with enhanced anti-tumoral capacity. RESULTS: Screening for diglycosidase activity in twenty-eight strains of the genetically related genera Acremonium and Sarocladium identified 6-O-α-rhamnosyl-ß-glucosidase (αRßG) of Sarocladium strictum DMic 093557 as candidate enzyme for our studies. Biochemically characterization shows that αRßG has the ability to transglycosylate bulky OH-acceptors, including bioactive compounds. Interestingly, rutinoside-derivatives of phloroglucinol (PR) resorcinol (RR) and 4-methylumbelliferone (4MUR) displayed higher growth inhibitory activity on pancreatic cancer cells than the respective aglycones without significant affecting normal pancreatic epithelial cells. PR exhibited the highest efficacy with an IC50 of 0.89 mM, followed by RR with an IC50 of 1.67 mM, and 4MUR with an IC50 of 2.4 mM, whereas the respective aglycones displayed higher IC50 values: 4.69 mM for phloroglucinol, 5.90 mM for resorcinol, and 4.8 mM for 4-methylumbelliferone. Further, glycoconjugates significantly sensitized pancreatic cancer cells to the standard of care chemotherapy agent gemcitabine. CONCLUSIONS: αRßG from S. strictum transglycosylate-based approach to synthesize rutinosides represents a suitable option to enhance the anti-proliferative effect of bioactive compounds. This finding opens up new possibilities for developing more effective therapies for pancreatic cancer and other solid malignancies.

Significant elevation of serum CA19-9 and CA242 levels induced by dulaglutide.

The use of dulaglutide, a common medication for managing type 2 diabetes, rarely causes elevated pancreatic tumour markers. Here, we report the case of a woman in her mid-60s with diabetes for over 10 years. The patient presented with markedly elevated serum CA19-9 and CA242 levels revealed during a routine health examination despite being asymptomatic. She had been receiving dulaglutide injections for 16 months. Imaging and interventional assessments did not reveal any hepatobiliary, gastrointestinal or pancreatic neoplasm. After excluding alternate diagnoses, the patient was determined to exhibit an adverse reaction to dulaglutide use. Management involved the discontinuation of dulaglutide, which resulted in normalisation of serum CA19-9 and CA242 levels within 6 weeks. This case underscores the importance of discontinuing dulaglutide and monitoring changes in the biomarker levels in asymptomatic patients receiving dulaglutide, rather than immediately resorting to imaging and endoscopic examinations.

Analysis of chemoresistance characteristics and prognostic relevance of postoperative gemcitabine adjuvant chemotherapy in pancreatic cancer.

AIM: To investigate the relationship between chemoresistance in pancreatic cancer patients receiving postoperative gemcitabine adjuvant therapy and specific clinical/pathological characteristics, as well as its impact on patient prognosis. METHODS: From June 2018 to June 2021, clinical and pathological data of 148 pancreatic cancer patients were collected, and 101 patients were followed up for tumor recurrence/metastasis and survival status. The correlation between chemoresistance and specific clinical/pathological characteristics or patient prognosis was retrospectively analyzed. RESULTS: Of the 148 patients, 78 were in the chemoresistance group and 70 in the non-chemoresistance group. Univariate analysis showed that the development of chemoresistance may be related to patient age, combined diabetes, preoperative CA19-9 level, tumor size, AJCC stage, vascular invasion, and positive lymph node ratio. Furthermore, subsequent multivariate analysis incorporating these variables indicated that tumor size may be a key factor influencing chemoresistance (p < 0.001, OR = 1.584). Log-rank test showed patients in the chemoresistance group had worse overall survival (OS) (HR = 2.102, p = 0.018) and progression free survival (PFS) (HR = 3.208, p = 0.002) than patients in the non-chemoresistance group; and patients with smaller size tumors (diameter ≤3 cm) had significantly better OS (HR = 2.923, p < 0.001) and PFS (HR = 2.930, p = 0.003) than those with larger size tumors (diameter >3 cm). CONCLUSIONS: Patients with pancreatic cancer receiving postoperative gemcitabine adjuvant therapy are more likely to develop chemoresistance when their tumor sizes are larger (diameter >3 cm). Development of chemoresistance exacerbates the prognosis of patients with pancreatic cancer, and larger tumor size is also a risk factor for poor prognosis in these patients.

Physical function as a predictor of chemotherapy-induced peripheral neuropathy in patients with pancreatic cancer.

BACKGROUND: A growing body of research indicates that poor functional status before chemotherapy may be correlated with the severity of chemotherapy-induced peripheral neuropathy (CIPN) after the neurotoxic treatment. However, little is known about the associations between pre-chemotherapy physical function and CIPN in patients with pancreatic cancer. PURPOSE: To identify the predictors of CIPN in relation to pre-chemotherapy physical function in patients with pancreatic cancer. METHODS: This secondary analysis included data from patients with pancreatic cancer who participated in a longitudinal research study at National Cheng Kung University Hospital, Tainan, Taiwan. Four physical function tests (i.e., grip strength, Timed Up and Go (TUG), 2-minute step test (2MST), and Romberg test) and two questionnaires (The European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 [EORTC QLQ-C30] and Chemotherapy-Induced Peripheral Neuropathy Module [CIPN20]) were assessed at baseline (i.e., before first chemotherapy session) and 2-, 3-, 4-, and 6-month follow-up. Multiple linear regression with adjustment for confounding factors was used to assess the associations between the four functional tests at baseline and the CIPN20 total score and individual subscale scores (sensory, motor, and autonomic) at 6-month follow-up. RESULTS: Data from a total of 209 pancreatic cancer patients (mean age: 64.4 years, 54.5% male) were analyzed. The findings showed that the severity of CIPN at 6-month follow-up was significantly associated with the baseline TUG completion time (ß = 0.684, p = 0.003). The TUG completion time was also positively correlated with the 6-month CIPN sensory and autonomic subscales. In addition, a baseline positive Romberg test (ß = 0.525, p = 0.009) was a significant predictor of the severity of motor neuropathy at 6-month follow-up. CONCLUSION: The TUG completion time and positive Romberg test before chemotherapy may be predictive factors of the CIPN severity 6 months after the commencement of chemotherapy. Accordingly, the incorporation of TUG and Romberg tests into the clinical assessment protocol emerges as imperative for individuals diagnosed with pancreatic carcinoma undergoing chemotherapy regimens.

Effect of chemotherapy on prognosis in patients with primary pancreatic signet ring cell carcinoma: A large real-world study based on machine learning.

BACKGROUND: Primary pancreatic signet ring cell carcinoma (PSRCC), an extremely rare histologic variant of pancreatic cancer, has a poor prognosis. This study aimed to investigate the prognostic value of chemotherapy in PSRCC. METHODS: Patients with PSRCC between 2000 and 2019 were identified using the Surveillance Epidemiology and End Results (SEER) database. The main outcomes in this study were cancer-specific survival (CSS) and overall survival (OS). The baseline characteristics of patients were compared using Pearson's Chi-square test. Kaplan-Meier analysis was used to generate the survival curves. Least absolute shrinkage and selection operator (LASSO), univariate and multivariate Cox regression models, and Random Survival Forest model were used to analyze the prognostic variables for OS and CSS. The variance inflation factors (VIFs) were used to analyze whether there was an overfitting problem. RESULTS: A total of 588 patients were identified. Chemotherapy was an independent prognostic factor for OS and CSS, and significantly associated with OS (HR = 0.33, 95% CI = 0.27-0.40, P <0.001) and CSS (HR = 0.32, 95% CI = 0.26-0.39, P <0.001). CONCLUSIONS: Chemotherapy showed beneficial effects on OS and CSS in patients with PSRCC and should be recommended in clinical practice.

Adjuvant chemotherapy omission after pancreatic cancer resection: a French nationwide study.

BACKGROUND: Adjuvant chemotherapy (AC) improves the prognosis after pancreatic ductal adenocarcinoma (PDAC) resection. However, previous studies have shown that a large proportion of patients do not receive or complete AC. This national study examined the risk factors for the omission or interruption of AC. METHODS: Data of all patients who underwent pancreatic surgery for PDAC in France between January 2012 and December 2017 were extracted from the French National Administrative Database. We considered "omission of adjuvant chemotherapy" (OAC) all patients who failed to receive any course of gemcitabine within 12 postoperative weeks and "interruption of AC" (IAC) was defined as less than 18 courses of AC. RESULTS: A total of 11 599 patients were included in this study. Pancreaticoduodenectomy was the most common procedure (76.3%), and 31% of the patients experienced major postoperative complications. OACs and IACs affected 42% and 68% of the patients, respectively. Ultimately, only 18.6% of the cohort completed AC. Patients who underwent surgery in a high-volume centers were less affected by postoperative complications, with no impact on the likelihood of receiving AC. Multivariate analysis showed that age ≥ 80 years, Charlson comorbidity index (CCI) ≥ 4, and major complications were associated with OAC (OR = 2.19; CI95%[1.79-2.68]; OR = 1.75; CI95%[1.41-2.18] and OR = 2.37; CI95%[2.15-2.62] respectively). Moreover, age ≥ 80 years and CCI 2-3 or ≥ 4 were also independent risk factors for IAC (OR = 1.54, CI95%[1.1-2.15]; OR = 1.43, CI95%[1.21-1.68]; OR = 1.47, CI95%[1.02-2.12], respectively). CONCLUSION: Sequence surgery followed by chemotherapy is associated with a high dropout rate, especially in octogenarian and comorbid patients.

QbD Enabled Development and Evaluation of Pazopanib Loaded Nanoliposomes for PDAC Treatment.

Pancreatic ductal adenocarcinoma (PDAC) is one of the highly fatal types of cancer with high mortality/incidence. Considering the crucial role of vascular endothelial growth factor (VEGF) in PDAC progression, its inhibition can be a viable strategy for the treatment. Pazopanib, a second-generation VEGF inhibitor, is approved for the treatment of various oncological conditions. However, due to associated limitations like low oral bioavailability (14-39%), high inter/intra-subject variability, stability issues, etc., high doses (800 mg) are required, which further lead to non-specific toxicities and also contribute toward cancer resistance. Thus, to overcome these challenges, pazopanib-loaded PEGylated nanoliposomes were developed and evaluated against pancreatic cancer cell lines. The nanoliposomes were prepared by thin-film hydration method, followed by characterization and stability studies. This QbD-enabled process design successfully led to the development of a suitable pazopanib liposomal formulation with desirable properties. The % entrapment of PZP-loaded non-PEGylated and PEGylated nanoliposomes was found to be 75.2% and 84.9%, respectively, whereas their particle size was found to be 129.7 nm and 182.0 nm, respectively. The developed liposomal formulations exhibited a prolonged release and showed desirable physicochemical properties. Furthermore, these liposomal formulations were also assessed for in vitro cell lines, such as cell cytotoxicity assay and cell uptake. These studies confirm the effectiveness of developed liposomal formulations against pancreatic cancer cell lines. The outcomes of this work provide encouraging results and a way forward to thoroughly investigate its potential for PDAC treatment.

Blockade of histamine receptor H1 augments immune checkpoint therapy by enhancing MHC-I expression in pancreatic cancer cells.

BACKGROUND: Although immune checkpoint blockade (ICB) therapy has proven to be extremely effective at managing certain cancers, its efficacy in treating pancreatic ductal adenocarcinoma (PDAC) has been limited. Therefore, enhancing the effect of ICB could improve the prognosis of PDAC. In this study, we focused on the histamine receptor H1 (HRH1) and investigated its impact on ICB therapy for PDAC. METHODS: We assessed HRH1 expression in pancreatic cancer cell (PCC) specimens from PDAC patients through public data analysis and immunohistochemical (IHC) staining. The impact of HRH1 in PCCs was evaluated using HRH1 antagonists and small hairpin RNA (shRNA). Techniques including Western blot, flow cytometry, quantitative reverse transcription polymerase chain reaction (RT-PCR), and microarray analyses were performed to identify the relationships between HRH1 and major histocompatibility complex class I (MHC-I) expression in cancer cells. We combined HRH1 antagonism or knockdown with anti-programmed death receptor 1 (αPD-1) therapy in orthotopic models, employing IHC, immunofluorescence, and hematoxylin and eosin staining for assessment. RESULTS: HRH1 expression in cancer cells was negatively correlated with HLA-ABC expression, CD8+ T cells, and cytotoxic CD8+ T cells. Our findings indicate that HRH1 blockade upregulates MHC-I expression in PCCs via cholesterol biosynthesis signaling. In the orthotopic model, the combined inhibition of HRH1 and αPD-1 blockade enhanced cytotoxic CD8+ T cell penetration and efficacy, overcoming resistance to ICB therapy. CONCLUSIONS: HRH1 plays an immunosuppressive role in cancer cells. Consequently, HRH1 intervention may be a promising method to amplify the responsiveness of PDAC to immunotherapy.

Genomic Profiling of Rare Undifferentiated Sarcomatoid Subtypes of Pancreatic Carcinomas: In Search of Therapeutic Targets.

PURPOSE: The highly aggressive undifferentiated sarcomatoid carcinoma (USC) subtype of pancreatic ductal adenocarcinoma (PDAC) remains poorly characterized because of its rarity. Previous case reports suggest that immune checkpoint inhibitors could be a promising treatment strategy, but the prevalence of established predictive biomarkers of response is largely unknown. The objective of this study was to leverage comprehensive genomic profiling of USC PDAC tumors to determine the prevalence of biomarkers associated with potential response to targeted therapies. METHODS: USC tumors (n = 20) underwent central pathology review by a board-certified gastrointestinal pathologist to confirm the diagnosis. These samples were compared with non-USC PDAC tumors (N = 5,562). Retrospective analysis of DNA and RNA next-generation sequencing data was performed. RESULTS: USC PDACs were more frequently PD-L1+ by immunohistochemistry than non-USC PDAC (63% v 16%, respectively, P < .001). Furthermore, USC PDAC had an increase in neutrophils (8.99% v 5.55%, P = .005) and dendritic cells (1.08% v 0.00%, q = 0.022) and an increased expression of PDCD1LG2 (4.6% v 1.3%, q = 0.001), PDCD1 (2.0% v 0.8%, q = 0.060), and HAVCR2 (45.9% v 21.7%, q = 0.107) than non-USC PDAC. Similar to non-USC PDAC, KRAS was the most commonly mutated gene (86% v 90%, respectively, P = 1). CONCLUSION: To our knowledge, this work represents the largest molecular analysis of USC tumors to date and showed an increased expression of immune checkpoint genes in USC tumors. These findings provide evidence for further investigation into immune checkpoint inhibitors in USC tumors.

Circadian transcriptome of pancreatic adenocarcinoma unravels chronotherapeutic targets.

Pancreatic ductal adenocarcinoma (PDA) is a lethal cancer characterized by a poor outcome and an increasing incidence. A significant majority (>80%) of newly diagnosed cases are deemed unresectable, leaving chemotherapy as the sole viable option, though with only moderate success. This necessitates the identification of improved therapeutic options for PDA. We hypothesized that there are temporal variations in cancer-relevant processes within PDA tumors, offering insights into the optimal timing of drug administration - a concept termed chronotherapy. In this study, we explored the presence of the circadian transcriptome in PDA using patient-derived organoids and validated these findings by comparing PDA data from The Cancer Genome Atlas with noncancerous healthy pancreas data from GTEx. Several PDA-associated pathways (cell cycle, stress response, Rho GTPase signaling) and cancer driver hub genes (EGFR and JUN) exhibited a cancer-specific rhythmic pattern intricately linked to the circadian clock. Through the integration of multiple functional measurements for rhythmic cancer driver genes, we identified top chronotherapy targets and validated key findings in molecularly divergent pancreatic cancer cell lines. Testing the chemotherapeutic efficacy of clinically relevant drugs further revealed temporal variations that correlated with drug-target cycling. Collectively, our study unravels the PDA circadian transcriptome and highlights a potential approach for optimizing chrono-chemotherapeutic efficacy.

Exploiting the ferroaddiction of pancreatic cancer cells using Fe-doped nanoparticles.

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with poor survival rates. Here, we evaluated iron-doped hydroxyapatite (FeHA) as a potential nanomedicine-based approach to combat PDAC. FeHA, in combination with a sublethal dose of the glutathione peroxidase 4 (GPX4) inhibitor RSL3, was found to trigger ferroptosis in KRAS mutant PANC-1 cells, but not in BxPC3 cells, while sparing normal human cells (fibroblasts and peripheral blood mononuclear cells). These findings were recapitulated in 3D spheroids generated using PDAC cells harboring wild-type versus mutant KRAS. Moreover, ferroptosis induction by FeHA plus RSL3 was reversed by the knockdown of STEAP3, a metalloreductase responsible for converting Fe3+ to Fe2+. Taken together, our data show that FeHA is capable of triggering cancer cell death in a KRAS-selective, STEAP3-dependent manner in PDAC cells.

Nuclear MAST4 Suppresses FOXO3 through Interaction with AKT3 and Induces Chemoresistance in Pancreatic Ductal Carcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is highly malignant, with a 5-year survival rate of less than 10%. Furthermore, the acquisition of anticancer drug resistance makes PDAC treatment difficult. We established MIA-GEM cells, a PDAC cell line resistant to gemcitabine (GEM), a first-line anticancer drug, using the human PDAC cell line-MIA-PaCa-2. Microtubule-associated serine/threonine kinase-4 (MAST4) expression was increased in MIA-GEM cells compared with the parent cell line. Through inhibitor screening, dysregulated AKT signaling was identified in MIA-GEM cells with overexpression of AKT3. MAST4 knockdown effectively suppressed AKT3 overexpression, and both MAST4 and AKT3 translocation into the nucleus, phosphorylating forkhead box O3a (FOXO3) in MIA-GEM cells. Modulating FOXO3 target gene expression in these cells inhibited apoptosis while promoting stemness and proliferation. Notably, nuclear MAST4 demonstrated higher expression in GEM-resistant PDAC cases compared with that in the GEM-sensitive cases. Elevated MAST4 expression correlated with a poorer prognosis in PDAC. Consequently, nuclear MAST4 emerges as a potential marker for GEM resistance and poor prognosis, representing a novel therapeutic target for PDAC.

Minocycline and photodynamic priming significantly improve chemotherapy efficacy in heterotypic spheroids of pancreatic ductal adenocarcinoma.

The prognosis for patients with advanced-stage pancreatic ductal adenocarcinoma (PDAC) remains dismal. It is generally accepted that combination cancer therapies offer the most promise, such as Folforinox, despite their associated high toxicity. This study addresses the issue of chemoresistance by introducing a complementary dual priming approach to attenuate the DNA repair mechanism and to improve the efficacy of a type 1 topoisomerase (Top1) inhibitor. The result is a regimen that integrates drug-repurposing and nanotechnology using 3 clinically relevant FDA-approved agents (1) Top1 inhibitor (irinotecan) at subcytotoxic doses (2) benzoporphyrin derivative (BPD) as a photoactive molecule for photodynamic priming (PDP) to improve the delivery of irinotecan within the cancer cell and (3) minocycline priming (MNP) to modulate DNA repair enzyme Tdp1 (tyrosyl-DNA phosphodiesterase) activity. We demonstrate in heterotypic 3D cancer models that incorporate cancer cells and pancreatic cancer-associated fibroblasts that simultaneous targeting of Tdp1 and Top1 were significantly more effective by employing MNP and photoactivatable multi-inhibitor liposomes encapsulating BPD and irinotecan compared to monotherapies or a cocktail of dual or triple-agents. These data are encouraging and warrant further work in appropriate animal models to evolve improved therapeutic regimens.

Calix[6]arene dismantles extracellular vesicle biogenesis and metalloproteinases that support pancreatic cancer hallmarks.

Many challenges are faced in pancreatic cancer treatment due to late diagnosis and poor prognosis because of high recurrence and metastasis. Extracellular vesicles (EVs) and matrix metalloproteinases (MMPs), besides acting in intercellular communication, are key players in the cancer cell plasticity responsible for initiating metastasis. Therefore, these entities provide valuable targets for the development of better treatments. In this context, this study aimed to evaluate the potential of calix[6]arene to disturb the release of EVs and the activity of MMPs in pancreatic cancer cells. We found a correlation between the endocytic-associated mediators and the prognosis of pancreatic cancer patients. We observed a more active EV machinery in the pancreatic cancer cell line PANC-1, which was reduced three-fold by treatment with calix[6]arene at subtoxic concentration (5 µM; p ã€ˆ0,001). We observed the modulation of 186 microRNAs (164 miRNAs upregulated and 22 miRNAs downregulated) upon calix[6]arene treatment. Interestingly, some of them as miR-4443 and miR-3909, regulates genes HIF1A e KIF13A that are well known to play a role in transport of vesicles. Furthermore, Calix[6]arene downmodulated matrix metalloproteinases (MMPs) -2 and - 9 and disturbed the viability of pancreatic organoids which recapitulate the cellular heterogeneity, structure, and functions of primary tissues. Our findings shed new insights on calix[6]arene's antitumor mechanism, including its intracellular effects on vesicle production and trafficking, as well as MMP activity, which may harm the tumor microenvironment and contribute to a reduction in cancer cell dissemination, which is one of the challenges associated with high mortality in pancreatic cancer.

Neoadjuvant chemotherapy is associated with suppression of the B cell-centered immune landscape in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is typically diagnosed at advanced stages and associated with early distant metastasis and poor survival. Besides clinical factors, the tumor microenvironment (TME) emerged as a crucial determinant of patient survival and therapy response in many tumors, including PDAC. Thus, the presence of tumor-infiltrating lymphocytes and the formation of tertiary lymphoid structures (TLS) is associated with longer survival in PDAC. Although neoadjuvant therapy (NeoTx) has improved the management of locally advanced tumors, detailed insight into its effect on various TME components is limited. While a remodeling towards a proinflammatory state was reported for PDAC-infiltrating T cells, the effect of NeoTx on B cell subsets, including plasma cells, and TLS formation is widely unclear. We thus investigated the frequency, composition, and spatial distribution of PDAC-infiltrating B cells in primary resected (PR) versus neoadjuvant-treated patients using a novel multiplex immunohistochemistry panel. The NeoTx group displayed significantly lower frequencies of pan B cells, GC B cells, plasmablasts, and plasma cells, accompanied by a reduced abundance of TLS. This finding was supported by bulk RNA-sequencing analysis of an independent fresh frozen tissue cohort, which revealed that major B cell pathways were downregulated in the NeoTx group. We further observed that plasma cells frequently formed aggregates that localized close to TLS and that TLS+ patients displayed significantly higher plasma cell frequencies compared to TLS- patients in the PR group. Additionally, high densities of CD20+ intratumoral B cells were significantly associated with longer overall survival in the PR group. While CD20+ B cells held no prognostic value for NeoTx patients, an increased frequency of proliferating CD20+Ki67+ B cells emerged as an independent prognostic factor for longer survival in the NeoTx group. These results indicate that NeoTx differentially affects PDAC-infiltrating immune cells and may have detrimental effects on the existing B cell landscape and the formation of TLS. Gaining further insight into the underlying molecular mechanisms is crucial to overcome the intrinsic immunotherapy resistance of PDAC and develop novel strategies to improve the long-term outcome of PDAC patients.

Disruption of the pro-oncogenic c-RAF-PDE8A complex represents a differentiated approach to treating KRAS-c-RAF dependent PDAC.

Pancreatic ductal adenocarcinoma (PDAC) is considered the third leading cause of cancer mortality in the western world, offering advanced stage patients with few viable treatment options. Consequently, there remains an urgent unmet need to develop novel therapeutic strategies that can effectively inhibit pro-oncogenic molecular targets underpinning PDACs pathogenesis and progression. One such target is c-RAF, a downstream effector of RAS that is considered essential for the oncogenic growth and survival of mutant RAS-driven cancers (including KRASMT PDAC). Herein, we demonstrate how a novel cell-penetrating peptide disruptor (DRx-170) of the c-RAF-PDE8A protein-protein interaction (PPI) represents a differentiated approach to exploiting the c-RAF-cAMP/PKA signaling axes and treating KRAS-c-RAF dependent PDAC. Through disrupting the c-RAF-PDE8A protein complex, DRx-170 promotes the inactivation of c-RAF through an allosteric mechanism, dependent upon inactivating PKA phosphorylation. DRx-170 inhibits cell proliferation, adhesion and migration of a KRASMT PDAC cell line (PANC1), independent of ERK1/2 activity. Moreover, combining DRx-170 with afatinib significantly enhances PANC1 growth inhibition in both 2D and 3D cellular models. DRx-170 sensitivity appears to correlate with c-RAF dependency. This proof-of-concept study supports the development of DRx-170 as a novel and differentiated strategy for targeting c-RAF activity in KRAS-c-RAF dependent PDAC.