Chemoresistance in pancreatic ductal adenocarcinoma: Overcoming resistance to therapy

E-Cadherin Is a Structuring Component of Invadopodia in Pancreatic Cancer

The appearance of hybrid epithelial-mesenchymal (E/M) cells expressing E-cadherin is favourable for the establishment of pro-invasive function. Although the potential role of E-cadherin in cancer invasion is now accepted, the molecular mechanisms involved in this process are not completely elucidated. To gain further insight, we focused our analysis on invadopodia formation, an early event in the invasion process. We used models of E/M hybrid cell lines, tissue sections and patient-derived xenografts from a multi-centre clinical trial. E-cadherin involvement in invadopodia formation was assessed using a gelatin-FITC degradation assay. Mechanistic studies were performed by using proteomic analysis, siRNA strategy and proximity ligation assay. We showed that E-cadherin is a critical component of invadopodia. This unexpected localization results from a synergistic trafficking of E-cadherin and MT1-MMP through a Rab vesicle-dependent pathway. Modulation of E-cadherin expression or activation impacted invadopodia formation. Moreover, colocalization of E-cadherin and Actin in "ring structures" as precursors of invadopodia reveals that E-cadherin is required for invadopodia structuration. E-cadherin, initially localised in the adherens junctions, could be recycled to nascent invadopodia where it will interact with several components enriched in invadopodia, such as Arp2/3, Cortactin or MT1-MMP. The trans-adhesive properties of E-cadherin are therefore essential for structuring invadopodia. This new localisation of E-cadherin and its unexpected role in cell invasion shine a new light on hybrid E/M transition features in tumoral invasion.

Recent Advances and Challenges in the Treatment of Advanced Pancreatic Cancer: An Update on Completed and Ongoing Clinical Trials

Pancreatic cancer is a deadly disease with a low survival rate, particularly in its advanced stages. Advanced pancreatic cancer remains a major clinical challenge due to limited treatment options. Surgical resection may not always be feasible, and traditional chemotherapy often shows restricted effectiveness. As a result, researchers are exploring a multifaceted therapeutic approach targeting the genetic and molecular drivers of the disease. A combination of molecular profiling and targeted therapies are being investigated to improve outcomes and address the shortcomings of traditional treatments. The focus of this review is to provide a summary of current and completed clinical trials for the treatment of advanced pancreatic cancer. This includes adagrasib (a KRAS inhibitor), olaparib (a PARP inhibitor for BRCA mutations), APG-1387 (an IAP antagonist), minnelide (an anti-stromal agent), arimastat (an MMP inhibitor), MK-0646 (an IGF1R inhibitor), sirolimus (an mTOR inhibitor), and metabolic inhibitors. These agents are being evaluated both as standalone treatments and in combination with standard therapy. Furthermore, we have summarized novel approaches such as cancer vaccines and ablation techniques as emerging strategies in the treatment of advanced pancreatic cancer. We have also examined the challenges in treating advanced pancreatic cancer and the factors contributing to therapeutic failure, which may offer valuable insights for developing more effective treatment strategies and innovative drug designs.

Dynamics of epithelial-mesenchymal plasticity driving cancer drug resistance

Epithelial-mesenchymal transition (EMT) promotes several cancers by increasing tumor cell motility, disrupting epithelial cell phenotypes, apical-basal polarity, and intracellular connections, and enhancing tumor resistance to immunotherapy and chemotherapy. Mesenchymal-epithelial transition (MET), the opposite of EMT, causes tumor metastasis. EMT drives primary tumor cells, whereas MET inhibits them. Importantly, the complex network of EMT includes cell-cell interactions in the tumor microenvironment. Transcription factors, post-translational regulation, cytokine-mediated signaling, and microRNAs control EMT. In this review, we discussed how molecular mechanisms, signaling networks, and epithelial/mesenchymal states affect cancer treatment resistance and the tumor microenvironment. Research on immunotherapy and chemotherapy problems associated with EMT suggests that targeting EMT might be a potential cancer treatment resistance strategy.

Novel Pt (II) Complexes With Anticancer Activity Against Pancreatic Ductal Adenocarcinoma Cells

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive type of solid tumor that is becoming more common. cis-[PtCl2 (NH3)2] (in short cisplatin or CDDP) has been shown to be effective in treating various cancers, including PDAC. However, the development of resistance to chemotherapy drugs has created a need for the synthesis of new anticancer agents. Platinum-based drugs containing the bidentate ligand phenanthroline have been found to have strong antitumor activity due to their ability to cause DNA damage. In this study, we examined the ability of two Pt (II) cationic complexes, [Pt(η 1-C2H4OR) (DMSO) (phen)]+ (in short Pt-EtORSOphen; R = Me, 1; Et, 2), to inhibit the growth and spread of BxPC-3 PDAC cells, in comparison to CDDP. The length of the alkyl chain and its associated lipophilic properties did not affect the anticancer effects of complexes 1 and 2 in BxPC-3 cells. However, it did appear to influence the rapid loss of mitochondrial membrane potential (ΔΨM), suggesting that these complexes could potentially be used as mitochondria-targeted lipophilic cations in anticancer therapy.

Establishment and characterization of a novel multidrug-resistant pancreatic ductal adenocarcinoma cell line, PDAC-X1

Drug resistance remains a significant challenge in the treatment of pancreatic cancer. The development of drug-resistant cell lines is crucial to understanding the underlying mechanisms of resistance and developing novel drugs to improve clinical outcomes. Here, a novel pancreatic cancer cell line, PDAC-X1, derived from Chinese patients has been established. PDAC-X1 was characterized by the immune phenotype, biology, genetics, molecular characteristics, and tumorigenicity. In vitro analysis revealed that PDAC-X1 cells exhibited epithelial morphology and cell markers (CK7 and CK19), expressed cancer-associated markers (E-cadherin, Vimentin, Ki-67, CEA, CA19-9), and produced pancreatic cancer-like organs in suspension culture. In vivo analysis showed that PDAC-X1 cells maintained tumorigenicity with a 100% tumor formation rate. This cell line exhibited a complex karyotype, dominated by subtriploid karyotypes. In addition, PDAC-X1 cells exhibited intrinsic multidrug resistance to multiple drugs, including gemcitabine, paclitaxel, 5-fluorouracil, and oxaliplatin. In conclusion, the PDAC-X1 cell line has been established and characterized, representing a useful and valuable preclinical model to study the underlying mechanisms of drug resistance and develop novel drug therapeutics to improve patient outcomes.

Decoding the Intricate Landscape of Pancreatic Cancer: Insights into Tumor Biology, Microenvironment, and Therapeutic Interventions

Pancreatic ductal adenocarcinoma (PDAC) presents significant oncological challenges due to its aggressive nature and poor prognosis. The tumor microenvironment (TME) plays a critical role in progression and treatment resistance. Non-neoplastic cells, such as cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs), contribute to tumor growth, angiogenesis, and immune evasion. Although immune cells infiltrate TME, tumor cells evade immune responses by secreting chemokines and expressing immune checkpoint inhibitors (ICIs). Vascular components, like endothelial cells and pericytes, stimulate angiogenesis to support tumor growth, while adipocytes secrete factors that promote cell growth, invasion, and treatment resistance. Additionally, perineural invasion, a characteristic feature of PDAC, contributes to local recurrence and poor prognosis. Moreover, key signaling pathways including Kirsten rat sarcoma viral oncogene (KRAS), transforming growth factor beta (TGF-β), Notch, hypoxia-inducible factor (HIF), and Wnt/β-catenin drive tumor progression and resistance. Targeting the TME is crucial for developing effective therapies, including strategies like inhibiting CAFs, modulating immune response, disrupting angiogenesis, and blocking neural cell interactions. A recent multi-omic approach has identified signature genes associated with anoikis resistance, which could serve as prognostic biomarkers and targets for personalized therapy.

A novel multidrug-resistant cell line from a Chinese patient with pancreatic ductal adenocarcinoma

Chemotherapy resistance poses clinical challenges in pancreatic cancer treatment. Developing cell lines resistant to chemotherapy is crucial for investigating drug resistance mechanisms and identifying alternative treatment pathways. The genetic and biological attributes of pancreatic cancer depend on its aetiology, racial demographics and anatomical origin, underscoring the need for models that comprehensively represent these characteristics. Here, we introduce PDAC-X2, a pancreatic cancer cell line derived from Chinese patients. We conducted a comprehensive analysis encompassing the immune phenotype, biology, genetics, molecular characteristics and tumorigenicity of the cell line. PDAC-X2 cells displayed epithelial morphology and expressed cell markers (CK7 and CK19) alongside other markers (E-cadherin, Vimentin, Ki-67, CEA and CA19-9). The population doubling time averaged around 69 h. In vivo, PDAC-X2 cells consistently maintained their tumorigenicity, achieving a 100% tumour formation rate. Characterised by a predominantly tetraploid karyotype, this cell line exhibited a complex genetic markup. Notably, PDAC-X2 cells demonstrated resistance to multiple drugs, including gemcitabine, paclitaxel, 5-fluorouracil and oxaliplatin. In conclusion, PDAC-X2 presents an invaluable preclinical model. Its utility lies in facilitating the study of drug resistance mechanisms and the exploration of alternative therapeutic approaches aimed at enhancing the prognosis of this tumour type.

Enhancing pancreatic ductal adenocarcinoma (PDAC) therapy with targeted carbon nano-onion (CNO)-mediated delivery of gemcitabine (GEM)-derived prodrugs

Nanotechnology's potential in revolutionising cancer treatments is evident in targeted drug delivery systems (DDSs) engineered to optimise therapeutic efficacy and minimise toxicity. This study examines a novel nanocarrier constructed with carbon nano-onions (CNOs), engineered and evaluated for its ability to selectively target cancer cells overexpressing the hyaluronic acid receptor; CD44. Our results highlighted that the CNO-based nanocarrier coupled with hyaluronic acid as the targeting agent demonstrated effective uptake by CD44+ PANC-1 and MIA PaCa-2 cells, while avoiding CD44- Capan-1 cells. The CNO-based nanocarrier also exhibited excellent biocompatibility in all tested pancreatic ductal adenocarcinoma (PDAC) cells, as well as healthy cells. Notably, the CNO-based nanocarrier was successfully loaded with chemotherapeutic 4-(N)-acyl- sidechain-containing prodrugs derived from gemcitabine (GEM). These prodrugs alone exhibited remarkable efficacy in killing PDAC cells which are known to be GEM resistant, and their efficacy was amplified when combined with the CNO-based nanocarrier, particularly in targeting GEM-resistant CD44+ PDAC cells. These findings demonstrate the potential of CNOs as promising scaffolds in advancing targeted DDSs, signifying the translational potential of carbon nanoparticles for cancer therapy.