Molecular and cellular mechanisms of chemoresistance in pancreatic cancer

Ferroptosis-inducing compounds synergize with docetaxel to overcome chemoresistance in docetaxel-resistant non-small cell lung cancer cells

Development of resistance to therapy-induced cell death is a major hurdle in the effective treatment of advanced solid tumors. Erastin and RSL3 were originally found to induce synthetic lethality by induction of a novel form of cell death termed ferroptosis. Emerging evidence suggests that ferroptosis inducers enhance chemosensitivity of classic therapeutic agents by triggering ferroptotic cell death. In this study we evaluated the effects of erastin and RSL3 on the resistance of docetaxel, doxorubicin, and cisplatin, and revealed a mechanism whereby these ferroptosis inducers augment docetaxel efficacy in non-small cell lung cancer by regulating redox signaling to promote ferroptosis. Transcriptome analysis revealed that combination treatment modulated not only p53 signaling pathway but also immune responses and several signaling pathways including MAPK, NF-κB and PI3K/Akt. Considering that glutathione peroxidase 4 (GPX4) serves as the main effector to protect cells from ferroptosis, this study identified three novel non-covalent GPX4 inhibitors with the aid of pharmacophore-based virtual screening. The new ferroptosis-inducing compounds synergized with docetaxel to increase the cytotoxicity by promoting ferroptotic cell death in docetaxel-resistant A549/DTX cells. Collectively, the induction of ferroptosis contributed to docetaxel-induced cytotoxic effects and overcame drug resistance in A549/DTX cells. Ferroptosis has a great potential to become a new approach to attenuate resistance to some classic therapeutic drugs in cancer patients.

Cannabidiol exhibits potent anti-cancer activity against gemcitabine-resistant cholangiocarcinoma via ER-stress induction in vitro and in vivo

BACKGROUND

Failure of treatment with gemcitabine in most cholangiocarcinoma (CCA) patients is due to drug resistance. The therapeutic potential of natural plant secondary compounds with minimal toxicity, such as cannabidiol (CBD), is a promising line of investigation in gemcitabine-resistant CCA. We aim to investigate the effects of CBD on gemcitabine-resistant CCA (KKU-213BGemR) cells in vitro and in vivo.

MATERIALS

In vitro, cell proliferation, colony formation, apoptosis and cell cycle arrest were assessed using MTT assay, clonogenicity assay and flow cytometry. The effect of CBD on ROS production was evaluated using the DCFH-DA fluorescent probe. The mechanism exerted by CBD on ER stress-associated apoptosis was investigated by western blot analysis. A gemcitabine-resistant CCA xenograft model was also used and the expression of PCNA and CHOP were evaluated by immunohistochemical analysis.

RESULTS

The IC50 values of CBD for KKU-213BGemR cells ranged from 19.66 to 21.05 µM. For a non-cancerous immortalized fibroblast cell line, relevant values were 18.29 to 19.21 µM. CBD suppressed colony formation by KKU-213BGemR cells in a dose-dependent manner in the range of 10 to 30 µM. CBD at 30 µM significantly increased apoptosis at early (16.37%) (P = 0.0024) and late (1.8%) stages (P < 0.0001), for a total of 18.17% apoptosis (P = 0.0017), in part by increasing ROS production (P < 0.0001). Multiphase cell cycle arrest significantly increased at G0/G1 with CBD 10 and 20 µM (P = 0.004 and P = 0.017), and at G2/M with CBD 30 µM (P = 0.005). CBD treatment resulted in increased expression of ER stress-associated apoptosis proteins, including p-PERK, BiP, ATF4, CHOP, BAX, and cytochrome c. In xenografted mouse, CBD significantly suppressed tumors at 10 and 40 mg/kg·Bw (P = 0.0007 and P = 0.0278, respectively), which was supported by an increase in CHOP, but a decrease in PCNA expression in tumor tissues (P < 0.0001).

CONCLUSION

The results suggest that CBD exhibits potent anti-cancer activity against gemcitabine-resistant CCA in vitro and in vivo, in part via ER stress-mediated mechanisms. These results indicate that clinical explorative use of CBD on gemcitabine-resistant CCA patients is warranted.

Neoadjuvant chemo- or chemo-radiation-therapy of pancreatic ductal adenocarcinoma differentially shift ECM composition, complement activation, energy metabolism and ribosomal proteins of the residual tumor mass

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal cancer, often diagnosed at stages that dis-qualify for surgical resection. Neoadjuvant therapies offer potential tumor regression and improved resectability. Although features of the tumor biology (e.g., molecular markers) may guide adjuvant therapy, biological alterations after neoadjuvant therapy remain largely unexplored. We performed mass spectrometry to characterize the proteomes of 67 PDAC resection specimens of patients who received either neoadjuvant chemo (NCT) or chemo-radiation (NCRT) therapy. We employed data-independent acquisition (DIA), yielding a proteome coverage in excess of 3500 proteins. Moreover, we successfully integrated two publicly available proteome datasets of treatment-naïve PDAC to unravel proteome alterations in response to neoadjuvant therapy, highlighting the feasibility of this approach. We found highly distinguishable proteome profiles. Treatment-naïve PDAC was characterized by enrichment of immunoglobulins, complement and extracellular matrix (ECM) proteins. Post-NCT and post-NCRT PDAC presented high abundance of ribosomal and metabolic proteins as compared to treatment-naïve PDAC. Further analyses on patient survival and protein expression identified treatment-specific prognostic candidates. We present the first proteomic characterization of the residual PDAC mass after NCT and NCRT, and potential protein candidate markers associated with overall survival. We conclude that residual PDAC exhibits fundamentally different proteome profiles as compared to treatment-naïve PDAC, influenced by the type of neoadjuvant treatment. These findings may impact adjuvant or targeted therapy options.

Perineural invasion score system and clinical outcomes in resected pancreatic cancer patients

BACKGROUND/OBJECTIVES

Perineural invasion (PNI), classified according to its presence or absence in tumor specimens, is recognized as a poor prognostic factor in pancreatic ductal adenocarcinoma (PDAC) patients. Herein, we identified five histological features of PNI and investigated their impact on survival outcomes of PDAC resected patients.

METHODS

Five histopathological features of PNI (diameter, number, site, sheath involvement, and mitotic figures within perineural invasion) were combined in an additional final score (ranging from 0 to 8), and clinical data of PDAC patients were retrospectively analyzed. PNI + patients were stratified in two categories according to the median score value (<6 and ≥ 6, respectively). Impact of PNI on disease-free survival (DFS) and overall survival (OS) were analyzed.

RESULTS

Forty-five patients were enrolled, of whom 34 with PNI (PNI+) and 11 without PNI (PNI-). The DFS was 11 months vs. not reached (NR) (p = 0.258), while the OS was 19 months vs. NR (p = 0.040) in PNI+ and PNI- patients, respectively. A ≥6 PNI was identified as an independent predictor of worse OS vs. <6 PNI + patients (29 vs. 11 months, p < 0.001) and <6 PNI+ and PNI- patients (43 vs. 11 months, p < 0.001). PNI ≥6 was an independent negative prognostic factor of DFS vs. <6 PNI+ and PNI- patients (13 vs. 6 months, p = 0.022).

CONCLUSIONS

We report a PNI scoring system that stratifies surgically-treated PDAC patients in a graded manner that correlates with patient prognosis better than the current dichotomous (presence/absence) definition. However, further and larger studies are needed to support this PNI scoring system.

The Multifaceted Role of miR-21 in Pancreatic Cancers

With the lack of specific signs and symptoms, pancreatic ductal adenocarcinoma (PDAC) is often diagnosed at late metastatic stages, resulting in poor survival outcomes. Among various biomarkers, microRNA-21 (miR-21), a small non-coding RNA, is highly expressed in PDAC. By inhibiting regulatory proteins at the 3' untranslated regions (UTR), miR-21 holds significant roles in PDAC cell proliferation, epithelial-mesenchymal transition, angiogenesis, as well as cancer invasion, metastasis, and resistance therapy. We conducted a systematic search across major databases for articles on miR-21 and pancreatic cancer mainly published within the last decade, focusing on their diagnostic, prognostic, therapeutic, and biological roles. This rigorous approach ensured a comprehensive review of miR-21's multifaceted role in pancreatic cancers. In this review, we explore the current understandings and future directions regarding the regulation, diagnostic, prognostic, and therapeutic potential of targeting miR-21 in PDAC. This exhaustive review discusses the involvement of miR-21 in proliferation, epithelial-mesenchymal transition (EMT), apoptosis modulation, angiogenesis, and its role in therapy resistance. Also discussed in the review is the interplay between various molecular pathways that contribute to tumor progression, with specific reference to pancreatic ductal adenocarcinoma.

Conquering chemoresistance in pancreatic cancer: Exploring novel drug therapies and delivery approaches amidst desmoplasia and hypoxia

Pancreatic cancer poses a significant challenge within the field of oncology due to its aggressive behaviour, limited treatment choices, and unfavourable outlook. With a mere 10% survival rate at the 5-year mark, finding effective interventions becomes even more pressing. The intricate relationship between desmoplasia and hypoxia in the tumor microenvironment further complicates matters by promoting resistance to chemotherapy and impeding treatment efficacy. The dense extracellular matrix and cancer-associated fibroblasts characteristic of desmoplasia create a physical and biochemical barrier that impedes drug penetration and fosters an immunosuppressive milieu. Concurrently, hypoxia nurtures aggressive tumor behaviour and resistance to conventional therapies. a comprehensive exploration of emerging medications and innovative drug delivery approaches. Notably, advancements in nanoparticle-based delivery systems, local drug delivery implants, and oxygen-carrying strategies are highlighted for their potential to enhance drug accessibility and therapeutic outcomes. The integration of these strategies with traditional chemotherapies and targeted agents reveals the potential for synergistic effects that amplify treatment responses. These emerging interventions can mitigate desmoplasia and hypoxia-induced barriers, leading to improved drug delivery, treatment efficacy, and patient outcomes in pancreatic cancer. This review article delves into the dynamic landscape of emerging anticancer medications and innovative drug delivery strategies poised to overcome the challenges imposed by desmoplasia and hypoxia in the treatment of pancreatic cancer.

CD200 is overexpressed in the pancreatic tumor microenvironment and predictive of overall survival

Pancreatic cancer is an aggressive disease with a 5 year survival rate of 13%. This poor survival is attributed, in part, to limited and ineffective treatments for patients with metastatic disease, highlighting a need to identify molecular drivers of pancreatic cancer to target for more effective treatment. CD200 is a glycoprotein that interacts with the receptor CD200R and elicits an immunosuppressive response. Overexpression of CD200 has been associated with differential outcomes, depending on the tumor type. In the context of pancreatic cancer, we have previously reported that CD200 is expressed in the pancreatic tumor microenvironment (TME), and that targeting CD200 in murine tumor models reduces tumor burden. We hypothesized that CD200 is overexpressed on tumor and stromal populations in the pancreatic TME and that circulating levels of soluble CD200 (sCD200) have prognostic value for overall survival. We discovered that CD200 was overexpressed on immune, stromal, and tumor populations in the pancreatic TME. Particularly, single-cell RNA-sequencing indicated that CD200 was upregulated on inflammatory cancer-associated fibroblasts. Cytometry by time of flight analysis of PBMCs indicated that CD200 was overexpressed on innate immune populations, including monocytes, dendritic cells, and monocytic myeloid-derived suppressor cells. High sCD200 levels in plasma correlated with significantly worse overall and progression-free survival. Additionally, sCD200 correlated with the ratio of circulating matrix metalloproteinase (MMP) 3: tissue inhibitor of metalloproteinase (TIMP) 3 and MMP11/TIMP3. This study highlights the importance of CD200 expression in pancreatic cancer and provides the rationale for designing novel therapeutic strategies that target this protein.

Heteronemin promotes iron-dependent cell death in pancreatic cancer

The marine environment has been recognized as a prolific source of potent bioactive compounds with significant anticancer properties. Among these, heteronemin, a sesterterpenoid-type natural product, has shown promise. This study delves into the potential of heteronemin as a ferroptotic agent against pancreatic cancer, using the Panc-1 cell line as a model. The cytotoxic potential of heteronemin was assessed using cell viability assays. Furthermore, its effect on lipid peroxidation was determined spectrophotometrically, while the changes it induced in autophagy- and ferritin-related protein expressions were evaluated using immunoblotting techniques. Various cell-based tests were employed to scrutinize its anticancer efficacy. Heteronemin displayed a notable cytotoxic effect, reducing cell viability by 50% at a concentration of 55 nM. This cytotoxicity was discernibly linked to ferroptosis, as evidenced by the reversal of cell death upon treatment with the ferroptosis inhibitor, ferrostatin-1. Heteronemin treatment led to a marked increase in ferroptosis markers and malondialdehyde (MDA) levels. Conversely, the expression of glutathione peroxidase-4 (GPX4), a key anti-ferroptotic protein, was suppressed. Furthermore, significant modulations in the expression of ferritinophagy- and iron-related proteins such as Atg5, Atg7, FTL, STEAP3, and DMT-1 were evident post-treatment (p < 0.05). This study underscores the potential of heteronemin as a ferroptosis inducer in pancreatic cancer cells. Given its robust cytotoxicity, heteronemin emerges as a promising lead compound for further exploration in cancer therapeutics.

Synergistic Anticancer Activity of Plumbagin and Xanthohumol Combination on Pancreatic Cancer Models

Among diverse cancers, pancreatic cancer is one of the most aggressive types due to inadequate diagnostic options and treatments available. Therefore, there is a necessity to use combination chemotherapy options to overcome the chemoresistance of pancreatic cancer cells. Plumbagin and xanthohumol, natural compounds isolated from the Plumbaginaceae family and Humulus lupulus, respectively, have been used to treat various cancers. In this study, we investigated the anticancer effects of a combination of plumbagin and xanthohumol on pancreatic cancer models, as well as the underlying mechanism. We have screened in vitro numerous plant-derived extracts and compounds and tested in vivo the most effective combination, plumbagin and xanthohumol, using a transgenic model of pancreatic cancer KPC (KrasLSL.G12D/+; p53R172H/+; PdxCretg/+). A significant synergistic anticancer activity of plumbagin and xanthohumol combinations on different pancreatic cancer cell lines was found. The combination treatment of plumbagin and xanthohumol influences the levels of B-cell lymphoma (BCL2), which are known to be associated with apoptosis in both cell lysates and tissues. More importantly, the survival of a transgenic mouse model of pancreatic cancer KPC treated with a combination of plumbagin and xanthohumol was significantly increased, and the effect on BCL2 levels has been confirmed. These results provide a foundation for a potential new treatment for pancreatic cancer based on plumbagin and xanthohumol combinations.

Glycogen synthase kinase 3β: the nexus of chemoresistance, invasive capacity, and cancer stemness in pancreatic cancer

The treatment of pancreatic cancer remains a significant clinical challenge due to the limited number of patients eligible for curative (R0) surgery, failures in the clinical development of targeted and immune therapies, and the pervasive acquisition of chemotherapeutic resistance. Refractory pancreatic cancer is typified by high invasiveness and resistance to therapy, with both attributes related to tumor cell stemness. These malignant characteristics mutually enhance each other, leading to rapid cancer progression. Over the past two decades, numerous studies have produced evidence of the pivotal role of glycogen synthase kinase (GSK)3β in the progression of over 25 different cancer types, including pancreatic cancer. In this review, we synthesize the current knowledge on the pathological roles of aberrant GSK3β in supporting tumor cell proliferation and invasion, as well as its contribution to gemcitabine resistance in pancreatic cancer. Importantly, we discuss the central role of GSK3β as a molecular hub that mechanistically connects chemoresistance, tumor cell invasion, and stemness in pancreatic cancer. We also discuss the involvement of GSK3β in the formation of desmoplastic tumor stroma and in promoting anti-cancer immune evasion, both of which constitute major obstacles to successful cancer treatment. Overall, GSK3β has characteristics of a promising therapeutic target to overcome chemoresistance in pancreatic cancer.

Tephrosin Suppresses the Chemoresistance of Paclitaxel-Resistant Ovarian Cancer via Inhibition of FGFR1 Signaling Pathway

Ovarian cancer is the leading cause of death among gynecologic cancers. Paclitaxel is used as a standard first-line therapeutic agent for ovarian cancer. However, chemotherapeutic resistance and high recurrence rates are major obstacles to treating ovarian cancer. We have found that tephrosin, a natural rotenoid isoflavonoid, can resensitize paclitaxel-resistant ovarian cancer cells to paclitaxel. Cell viability, immunoblotting, and a flow cytometric analysis showed that a combination treatment made up of paclitaxel and tephrosin induced apoptotic death. Tephrosin inhibited the phosphorylation of AKT, STAT3, ERK, and p38 MAPK, all of which simultaneously play important roles in survival signaling pathways. Notably, tephrosin downregulated the phosphorylation of FGFR1 and its specific adapter protein FRS2, but it had no effect on the phosphorylation of the EGFR. Immunoblotting and a fluo-3 acetoxymethyl assay showed that tephrosin did not affect the expression or function of P-glycoprotein. Additionally, treatment with N-acetylcysteine did not restore cell cytotoxicity caused by a treatment combination made up of paclitaxel and tephrosin, showing that tephrosin did not affect the reactive oxygen species scavenging pathway. Interestingly, tephrosin reduced the expression of the anti-apoptotic factor XIAP. This study demonstrates that tephrosin is a potent antitumor agent that can be used in the treatment of paclitaxel-resistant ovarian cancer via the inhibition of the FGFR1 signaling pathway.

Genomic analysis reveals HDAC1 regulates clinically relevant transcriptional programs in Pancreatic cancer

Novel strategies are needed to combat multidrug resistance in pancreatic ductal adenocarcinoma (PDAC). We applied genomic approaches to understand mechanisms of resistance in order to better inform treatment and precision medicine. Altered function of chromatin remodeling complexes contribute to chemoresistance. Our study generates and analyzes genomic and biochemical data from PDAC cells overexpressing HDAC1, a histone deacetylase involved in several chromatin remodeling complexes. We characterized the impact of overexpression on drug response, gene expression, HDAC1 binding, and chromatin structure using RNA-sequencing and ChIP-sequencing for HDAC1 and H3K27 acetylation. Integrative genomic analysis shows that HDAC1 overexpression promotes activation of key resistance pathways including epithelial to mesenchymal transition, cell cycle, and apoptosis through global chromatin remodeling. Target genes are similarly altered in patient tissues and show correlation with patient survival. We also demonstrate that direct targets of HDAC1 that also show altered chromatin are enriched near genes associated with altered GTPase activity. HDAC1 target genes identified using in vitro methods and observed in patient tissues were used to develop a clinically relevant nine-transcript signature associated with patient prognosis. Integration of multiple genomic and biochemical data types enables understanding of multidrug resistance and tumorigenesis in PDAC, a disease in desperate need of novel treatment strategies.

A Comparative Analysis of Orthotopic and Subcutaneous Pancreatic Tumour Models: Tumour Microenvironment and Drug Delivery

Pancreatic ductal adenocarcinoma (PDAC) remains a challenging malignancy, mainly due to its resistance to chemotherapy and its complex tumour microenvironment characterised by stromal desmoplasia. There is a need for new strategies to improve the delivery of drugs and therapeutic response. Relevant preclinical tumour models are needed to test potential treatments. This paper compared orthotopic and subcutaneous PDAC tumour models and their suitability for drug delivery studies. A novel aspect was the broad range of tumour properties that were studied, including tumour growth, histopathology, functional vasculature, perfusion, immune cell infiltration, biomechanical characteristics, and especially the extensive analysis of the structure and the orientation of the collagen fibres in the two tumour models. The study unveiled new insights into how these factors impact the uptake of a fluorescent model drug, the macromolecule called 800CW. While the orthotopic model offered a more clinically relevant microenvironment, the subcutaneous model offered advantages for drug delivery studies, primarily due to its reproducibility, and it was characterised by a more efficient drug uptake facilitated by its collagen organisation and well-perfused vasculature. The tumour uptake seemed to be influenced mainly by the structural organisation and the alignment of the collagen fibres and perfusion. Recognising the diverse characteristics of these models and their multifaceted impacts on drug delivery is crucial for designing clinically relevant experiments and improving our understanding of pancreatic cancer biology.

Genome, Metabolism, or Immunity: Which Is the Primary Decider of Pancreatic Cancer Fate through Non-Apoptotic Cell Death?

Pancreatic ductal adenocarcinoma (PDAC) is a solid tumor characterized by poor prognosis and resistance to treatment. Resistance to apoptosis, a cell death process, and anti-apoptotic mechanisms, are some of the hallmarks of cancer. Exploring non-apoptotic cell death mechanisms provides an opportunity to overcome apoptosis resistance in PDAC. Several recent studies evaluated ferroptosis, necroptosis, and pyroptosis as the non-apoptotic cell death processes in PDAC that play a crucial role in the prognosis and treatment of this disease. Ferroptosis, necroptosis, and pyroptosis play a crucial role in PDAC development via several signaling pathways, gene expression, and immunity regulation. This review summarizes the current understanding of how ferroptosis, necroptosis, and pyroptosis interact with signaling pathways, the genome, the immune system, the metabolism, and other factors in the prognosis and treatment of PDAC.

Targeting mitochondrial transcription factor A sensitizes pancreatic cancer cell to gemcitabine

BACKGROUND

The survival of pancreatic cancer cells, particularly cancer stem cells which are responsible for tumor relapse, depends on mitochondrial function. Mitochondrial transcription factor A (TFAM) is critical for the regulation of mitochondrial DNA and thus mitochondrial function. However, the possible involvement of TFAM in pancreatic cancer is unknown.

METHODS

Human samples were obtained from pancreatic cancers and their adjacent tissues; human pancreatic cell lines were cultured in RPMI1640 medium. TFAM expressions in pancreatic tissues and cultured cells were determined using immunohistochemistry, ELISA, and reverse transcription polymerase chain reaction (RT-PCR). The effect of TFAM on cell growth, migration, colony formation and apoptosis were evaluated. Mitochondrial biogenesis in pancreatic cancer and normal cells were examined.

RESULTS

The majority of pancreatic cancer tissues exhibited higher TFAM expression compared to the adjacent counterparts. Consistently, TFAM mRNA and protein levels were higher in pancreatic cancer cell lines than in immortalized normal pancreatic epithelial cells. There was no difference on TFAM level between gemcitabine-sensitive and resistant pancreatic cancer cells. Functional analysis demonstrated that TFAM overexpression activated pancreatic normal and tumor cells whereas TFAM inhibition effectively inhibited the growth of pancreatic cancer cells. TFAM inhibition enhanced gemcitabine's cytotoxicity and suppressed growth, anchorage-independent colony formation and survival of gemcitabine-resistant pancreatic cancer cells. Mechanistic studies showed that TFAM inhibition resulted in remarkable mitochondrial dysfunction and energy crisis followed by oxidative stress. The basal mitochondrial biogenesis level correlated well with TFAM level in pancreatic cancer cells.

CONCLUSIONS

TFAM played essential roles in pancreatic cancer via regulating mitochondrial functions which highlighted the therapeutic value of inhibiting TFAM to overcome gemcitabine resistance.

Exosomes: Emerging Modulators of Pancreatic Cancer Drug Resistance

Pancreatic cancer (PaC) is one of the most lethal tumors worldwide, difficult to diagnose, and with inadequate therapeutical chances. The most used therapy is gemcitabine, alone or in combination with nanoparticle albumin-bound paclitaxel (nab-paclitaxel), and the multidrug FOLFIRINOX. Unfortunately, PaC develops resistance early, thus reducing the already poor life expectancy of patients. The mechanisms responsible for drug resistance are not fully elucidated, and exosomes seem to be actively involved in this phenomenon, thanks to their ability to transfer molecules regulating this process from drug-resistant to drug-sensitive PaC cells. These extracellular vesicles are released by both normal and cancer cells and seem to be essential mediators of intercellular communications, especially in cancer, where they are secreted at very high numbers. This review illustrates the role of exosomes in PaC drug resistance. This manuscript first provides an overview of the pharmacological approaches used in PaC and, in the last part, focuses on the mechanisms exploited by the exosomes released by cancer cells to induce drug resistance.

Enhancing chemotherapy for pancreatic cancer through efficient and sustained tumor microenvironment remodeling with a fibroblast-targeted nanosystem

Pancreatic cancer (PC) carries a poor prognosis among all malignancies and poses great challenges to clinical drug accessibility due to the severely fibrotic and hypoxic tumor microenvironment (TME). Therein, cancer-associated fibroblasts (CAFs), which are extremely abundant in PC, play a key role in forming the complex PC microenvironment. Therefore, a highly efficient TME reprogramming therapeutic paradigm that can specifically inhibit CAF function is urgently needed. Herein, we successfully developed a novel CAF-tailored nanosystem (Dex-GP-DOCA, DPD) loaded with a potent anti-fibrosis flavonoid compound (Quercetin, QUE), which possesses biological responsiveness to fibroblast activation protein alpha (FAP-α), prolonged TME remodeling and enhancement of clinical chemotherapeutics. Specifically, DPD/QUE allowed for extracellular matrix (ECM) reduction, vessel normalization, hypoxia-induced drug resistance reversal, and blockade of Wnt16 paracrine in CAFs. More importantly, this chemotherapy conducive microenvironment persisted for at least 8 days following treatment with DPD/QUE. It should also be noted that the effective and prolonged microenvironment modulation induced by DPD/QUE significantly improved the chemotherapy sensitivity of Abraxane and gemcitabine, the first-line chemotherapeutic drugs for PC, with inhibition rates increasing from 37.5% and 40.0% to 87.5% and 85.2%, respectively. Overall, our CAFs-targeted nanosystem showed promising prospects for remodeling the TME and facilitating chemotherapy for refractory pancreatic cancer.

Should oncologists trust cannabinoids?

Cannabis enjoyed a "golden age" as a medicinal product in the late 19th, early 20th century, but the increased risk of overdose and abuse led to its criminalization. However, the 21st century have witnessed a resurgence of interest and a large body of literature regarding the benefits of cannabinoids have emerged. As legalization and decriminalization have spread around the world, cancer patients are increasingly interested in the potential utility of cannabinoids. Although eager to discuss cannabis use with their oncologist, patients often find them to be reluctant, mainly because clinicians are still not convinced by the existing evidence-based data to guide their treatment plans. Physicians should prescribe cannabis only if a careful explanation can be provided and follow up response evaluation ensured, making it mandatory for them to be up to date with the positive and also negative aspects of the cannabis in the case of cancer patients. Consequently, this article aims to bring some clarifications to clinicians regarding the sometimes-confusing various nomenclature under which this plant is mentioned, current legislation and the existing evidence (both preclinical and clinical) for the utility of cannabinoids in cancer patients, for either palliation of the associated symptoms or even the potential antitumor effects that cannabinoids may have.

A randomized phase II study of full dose gemcitabine versus reduced dose gemcitabine and nab-paclitaxel in vulnerable patients with non-resectable pancreatic cancer (DPCG-01)

BACKGROUND

According to current evidence, the best treatment for fit patients with non-resectable pancreatic cancer (PC) is combination chemotherapy, whereas frail patients are recommended gemcitabine (Gem) monotherapy. Randomized controlled trials in colorectal cancer and a post-hoc analysis of gemcitabine and nab-paclitaxel (GemNab) in PC suggest, however, that reduced dose of combination chemotherapy may be feasible and more efficient compared to monotherapy in frail patients. The aim of this study is to investigate whether reduced dose GemNab is superior to full dose Gem in patients with resectable PC, who are not candidates for full dose combination chemotherapy in first line.

METHODS

The Danish Pancreas Cancer Group (DPCG)-01 trial is a national multicenter prospective randomized phase II trial. A total of 100 patients in ECOG performance status 0-2 with non-resectable PC, not candidate for full dose combination chemotherapy in first line, but eligible for full dose Gem, will be included. Patients are randomized 1:1 to either full dose Gem or GemNab in 80% of recommended dose. The primary endpoint is progression-free survival. Secondary endpoints are overall survival, overall response rate, quality of life, toxicity and rate of hospitalizations during treatment. The correlation between blood inflammatory markers, including YKL-40 and IL-6, circulating tumor DNA, and tissue biomarkers of resistance to chemotherapy and outcome will be explored. Finally, the study will include measures of frailty (G8, modified G8, and chair-stand-test) to assess whether scoring would enable a personalized allocation to different treatments or indicates a possibility for interventions.

DISCUSSION

Single-drug treatment with Gem has for frail patients with non-resectable PC been the main treatment option for more than thirty years, but the impact on outcome is modest. If improved results and sustained tolerability with reduced dose combination chemotherapy can be shown, this could change the future practice for this increasing group of patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05841420. Secondary Identifying No: N-20210068. EudraCT No: 2021-005067-52.

PROTOCOL VERSION

1.5, 16-MAY-2023.

Can the molecules carried by extracellular vesicles help to diagnose pancreatic cancer early?

BACKGROUND

Pancreatic cancer is a deadly malignancy mainly because of its asymptomatic onset which prevents the implementation of the primary tumour's resection surgery, leading to metastatic spread resistant to chemotherapy. Early-detection of this cancer in its initial stage would represent a game changer in the fight against this disease. The few currently available biomarkers detectable in patients' body fluids lack sensitivity and specificity.

SCOPE OF REVIEW

The recent discovery of extracellular vesicles and their role in promoting cancer's advancement, has boosted interest in researching their cargo, to find reliable early detection biological markers. This review examines the most recent discoveries in the analysis of potential extra vesicle-carried biological markers for the early detection of pancreatic cancer.

MAJOR CONCLUSIONS

Despite the advantages of using extracellular vesicles for early diagnosis, and the promising findings of extracellular vesicle-carried molecules possibly functional as biomarkers, until now there are no validated markers derived from extracellular vesicles available to be used in the clinic.

GENERAL SIGNIFICANCE

Further studies in this direction are urgently required to provide what would be a major asset for defeating pancreatic cancer.

Serum thrombospondin-1 serves as a novel biomarker and agonist of gemcitabine-based chemotherapy in intrahepatic cholangiocarcinoma

BACKGROUND

At present, the first-line treatment for advanced intrahepatic cholangiocarcinoma (ICC) is gemcitabine combined with cisplatin, but a considerable portion of ICC patients exhibit resistance to gemcitabine. Therefore, finding sensitisers for gemcitabine chemotherapy in ICC patients and predicting molecular markers for chemotherapy efficacy have become urgent needs.

METHODS

In this study, PDX models were established to conduct gemcitabine susceptibility tests. The selected PDX tissues of the chemotherapy-sensitive group and drug-resistant group were subjected to transcriptome sequencing and protein chip technology to identify the key genes. Sixty-one ICC patients treated with gemcitabine chemotherapy were recruited for clinical follow-up validation.

RESULTS

We found that thrombospondin-1 (TSP1) can predict gemcitabine chemosensitivity in ICC patients. The expression level of TSP1 could reflect the sensitivity of ICC patients to gemcitabine chemotherapy. Functional experiments further confirmed that TSP1 can increase the efficacy of gemcitabine chemotherapy for ICC. A mechanism study showed that TSP1 may affect the intake of oleic acid by binding to the CD36 receptor.

CONCLUSIONS

In summary, we found a key molecule-TSP1-that can predict and improve the sensitivity of ICC patients to gemcitabine chemotherapy, which is of great significance for the treatment of advanced cholangiocarcinoma.

The combination of gemcitabine and ginsenoside Rh2 enhances the immune function of dendritic cells against pancreatic cancer via the CARD9-BCL10-MALT1 / NF-κB pathway

Cold tumor immune microenvironment (TIME) of pancreatic cancer (PC) with minimal dendritic cell (DC) and T cell infiltration can result in insufficient immunotherapy and chemotherapy. While gemcitabine (GEM) is a first-line chemotherapeutic drug for PC, its efficacy is reduced by immunosuppression and drug resistance. Ginsenoside Rh2 (Rh2) is known to have anti-cancer and immunomodulatory properties. Combining GEM with Rh2 may thus overcome immunosuppression and induce lasting anti-tumor immunity in PC. Here, we showed that after GEM-Rh2 therapy, there was significantly greater tumor infiltration by DCs. Caspase recruitment domain-containing protein 9 (CARD9), a central adaptor protein, was strongly up-regulated DCs with GEM-Rh2 therapy and promoted anti-tumor immune responses by DCs. CARD9 was found to be a critical target for Rh2 to enhance DC function. However, GEM-Rh2 treatment did not achieve the substantial anti-PC efficacy in CARD9^-/- mice as in WT mice. The adoptive transfer of WT DCs to DC-depleted PC mice treated with GEM-Rh2 elicited strong anti-tumor immune responses, although CARD9^-/- DCs were less effective than WT DCs. Our results showed that GEM-Rh2 may reverse cold TIME by enhancing tumor immunogenicity and decreasing the levels of immunosuppressive factors, reactivating DCs via the CARD9-BCL10-MALT1/ NF-κB pathway. Our findings suggest a potentially feasible and safe treatment strategy for PC, with a unique mechanism of action. Thus, Rh2 activation of DCs may remodel the cold TIME and optimize GEM chemotherapy for future therapeutic use.

Genetics, Genomics and Emerging Molecular Therapies of Pancreatic Cancer

The number of cases of pancreatic cancers in 2019 in Poland was 3852 (approx. 2% of all cancers). The course of the disease is very fast, and the average survival time from the diagnosis is 6 months. Only <2% of patients live for 5 years from the diagnosis, 8% live for 2 years, and almost half live for only about 3 months. A family predisposition to pancreatic cancer occurs in about 10% of cases. Several oncogenes in which somatic changes lead to the development of tumours, including genes BRCA1/2 and PALB2, TP53, CDKN2A, SMAD4, MLL3, TGFBR2, ARID1A and SF3B1, are involved in pancreatic cancer. Between 4% and 10% of individuals with pancreatic cancer will have a mutation in one of these genes. Six percent of patients with pancreatic cancer have NTRK pathogenic fusion. The pathogenesis of pancreatic cancer can in many cases be characterised by homologous recombination deficiency (HRD)-cell inability to effectively repair DNA. It is estimated that from 24% to as many as 44% of pancreatic cancers show HRD. The most common cause of HRD are inactivating mutations in the genes regulating this DNA repair system, mainly BRCA1 and BRCA2, but also PALB2, RAD51C and several dozen others.

Development of doped ZnO-based biomimicking and tumor-targeted nanotheranostics to improve pancreatic cancer treatment

Despite different nanomaterials were developed so far against cancer, their potential drawbacks are still scarcely considered. The off-target delivery of a therapeutic compound, as well as the non-specific uptake of these nanomaterials by healthy tissues or organs, and their potential immunogenicity are some of the major issues that still have to be faced prior to a successful clinical translation. This work aims to develop an innovative theranostic, biocompatible, and drug-loaded nanoconstruct based on Gadolinium-doped Zinc Oxide (ZnO-Gd) nanocrystals (NCs), focusing on one of the most lethal diseases, i.e., pancreatic cancer. The use of zinc oxide is motivated by the huge potential of this nanomaterial already demonstrated for in vitro and in vivo applications, while the Gadolinium doping confers magnetic properties useful for diagnostics. Furthermore, an innovative biomimetic shell is here used to coat the NCs: it is composed of a lipid bilayer made from extracellular vesicles (EVs) combined with other synthetic lipids and a peptide targeting the pancreatic tumor microenvironment. To complete the nanoconstruct therapeutic function, Gemcitabine, a first-line drug for pancreatic cancer treatment, was adsorbed on the ZnO-Gd NCs prior to the coating with the above-mentioned lipidic shell. The aim of this work is thus to strongly enhance the therapeutic capability of the final nanoconstruct, providing it with high biocompatibility, colloidal stability in biological media, efficient cargo loading and release properties, as well as active targeting for site-selective drug delivery. Furthermore, the magnetic properties of the ZnO-Gd NCs core can in future allow efficient in situ bioimaging capabilities based on Magnetic Resonance Imaging technique. The obtained nanoconstructs were tested on two different pancreatic cancer cell lines, i.e., BxPC-3 and the metastatic AsPC-1, proving high cell internalization levels, mediated by the targeting peptide exposed on the nanoconstruct. Cellular cytotoxicity assay performed on both cell lines dictated ~ 20% increased cell killing efficacy of Gemcitabine when delivered through the nanoconstruct rather than as a free drug. Taken together, our designed theranostic nanoconstruct can have a significant impact on the standard treatment of pancreatic cancer.

Neutrophil membrane-coated nanoparticles for enhanced nanosecond pulsed electric field treatment of pancreatic cancer

OBJECTIVE

Pancreatic cancer is one of the leading causes of cancer-related deaths worldwide. Poor prognosis and low survival rates have driven the development of novel therapeutic strategies. Nanosecond pulsed electric field has emerged as a novel, minimal invasive and non-thermal treatment for solid tumors. It is of great significance to study the combination therapy of nsPEF and other treatment strategies for pancreatic cancer.

METHODS

We developed neutrophil membrane-wrapped liposomal nanoparticles loaded with gemcitabine (NE/Lip-GEM) and investigated their use as a complementary agent for nsPEF treatment.

RESULTS

Our results showed that neutrophil-mediated delivery of liposomal-gemcitabine (NE/Lip-GEM) efficiently inhibited the growth of pancreatic tumors in mice whose has been treated with incomplete nsPEF ablation.

CONCLUSIONS

The combination of nsPEF and NE/Lip-GEM may be a promising synergistic strategy for pancreatic cancer therapy.

Pancreatic intra-arterial infusion chemotherapy for the treatment of patients with advanced pancreatic carcinoma: A pilot study

Objective

To preliminarily evaluate the efficacy and safety of pancreatic intra-arterial infusion chemotherapy (PAIC) with nab-paclitaxel in patients with advanced pancreatic carcinoma.

Methods

Fifteen patients with advanced pancreatic carcinoma received monthly, inpatient, 3-h, continuous PAIC of nab-paclitaxel at 180 mg/m², combined with 60 mg oral tegafur gimeracil oteracil potassium capsule for 2 weeks. The therapeutic courses were repeated every 4 weeks. All patients had a preliminary diagnosis based on clinical symptoms, imaging data (computed tomography or magnetic resonance imaging or positron emission tomography/computed tomography), and tumor markers. The adverse effects, clinical benefit response (CBR), objective response rate (ORR), median progression free survival (mPFS), and median overall survival (mOS) were monitored.

Results

Fifteen patients with advanced pancreatic carcinoma were enrolled in this study, including 10 male and 5 female patients. The mean age at the time of treatment was 66.3 years (53-84 years). A total of 49 cycles of PAIC (mean = 3.27 cycles/patient) were performed. The most common treatment-related toxicities were alopecia, diarrhea, and nausea/vomiting. No procedure-related complications were observed. The longest overall survival observed was 22 months and the maximum number of treatments for the same patient was six cycles. PAIC contributed a high rate (13/15 [86.67%]) and fast (10/15 [66.67%]) easement of pain, with apparent symptom relief within 24 h, especially local pain symptom. The pain anesis rate was 13 (86.67%). CBR was achieved in 13 (86.67%) patients (95%CI [59.54,98.34]). ORR was achieved in four (26.67%) patients (95%CI [7.79,55.10]). Disease Control Rate was achieved in 14 (93.33%) patients. The mPFS was 5.22 months (interquartile range [IQR], 4.27-7.85 months). The mOS was 8.97 months (IQR, 5.65-13.70 months).

Conclusions

In this study, the dose of the chemotherapeutics and the schedule of the transcatheter pancreatic arterial chemotherapy perfusion were shown to be safe, well-tolerated, and effective for the relief of clinical symptoms and CBR. These advantages can quickly establish the treatment belief and improve patient quality of life. This regimen requires further investigation in patients with advanced pancreatic carcinoma.

Perineural Invasion in Pancreatic Ductal Adenocarcinoma: From Molecules towards Drugs of Clinical Relevance

Pancreatic ductal adenocarcinoma is one of the most threatening solid malignancies. Molecular and cellular mediators that activate paracrine signalling also regulate the dynamic interaction between pancreatic cancer cells and nerves. This reciprocal interface leads to perineural invasion (PNI), defined as the ability of cancer cells to invade nerves, similar to vascular and lymphatic metastatic cascade. Targeting PNI in pancreatic cancer might help ameliorate prognosis and pain relief. In this review, the modern knowledge of PNI in pancreatic cancer has been analysed and critically presented. We focused on molecular pathways promoting cancer progression, with particular emphasis on neuropathic pain generation, and we reviewed the current knowledge of pharmacological inhibitors of the PNI axis. PNI represents a common hallmark of PDAC and correlates with recurrence, poor prognosis and pain in pancreatic cancer patients. The interaction among pancreatic cancer cells, immune cells and nerves is biologically relevant in each stage of the disease and stimulates great interest, but the real impact of the administration of novel agents in clinical practice is limited. It is still early days for PNI-targeted treatments, and further advanced studies are needed to understand whether they could be effective tools in the clinical setting.

FOLFIRINOX Pharmacodynamic Interactions in 2D and 3D Pancreatic Cancer Cell Cultures

The multi-drug combination regime, FOLFIRINOX, is a standard of care chemotherapeutic therapy for pancreatic cancer patients. However, systematic evaluation of potential pharmacodynamic interactions among multi-drug therapy has not been reported previously. Here, pharmacodynamic interactions of the FOLFIRINOX agents (5-fluorouracil (5-FU), oxaliplatin (Oxa) and SN-38, the active metabolite of irinotecan) were assessed across a panel of primary and established pancreatic cancer cells. Inhibition of cell proliferation was quantified for each drug, alone and in combination, to obtain quantitative, drug-specific interaction parameters and assess the nature of drug interactions. The experimental data were analysed assuming Bliss independent interactions, and nonlinear regression model fitting was conducted in SAS. Estimates of the drug interaction term, psi (ψ), revealed that the Oxa/SN-38 combination appeared synergistic in PANC-1 (ψ = 0.6, 95% CI = 0.4, 0.9) and modestly synergistic, close to additive, in MIAPaCa-2 (ψ = 0.8, 95% CI = 0.6, 1.0) in 2D assays. The triple combination was strongly synergistic in MIAPaCa-2 (ψ = 0.2, 95% CI = 0.1, 0.3) and modestly synergistic/borderline additive in PANC-1 2D (ψ = 0.8, 95% CI = 0.6, 1.0). The triple combination showed antagonistic interactions in the primary PIN-127 and 3D PANC-1 model (ψ > 1). Quantitative pharmacodynamic interactions have not been described for the FOLFIRINOX regimen; this analysis suggests a complex interplay among the three chemotherapeutic agents. Extension of this pharmacodynamic analysis approach to clinical/translational studies of the FOLFIRINOX combination could reveal additional pharmacodynamic interactions and guide further refinement of this regimen to achieve optimal clinical responses.

Long non-coding RNA SNHG16 decreased SMAD4 to induce gemcitabine resistance in pancreatic cancer via EZH2-mediated epigenetic modification

Gemcitabine resistance (GR) in pancreatic cancer (PC) results in poor patient outcomes. SMAD family member (Smad4) dysregulation is a significant role of GR in PC, and EZH2 is involved in Smad4 expression in tumor progression. Interestingly, lncRNA small nucleolar RNA host gene 16 (SNHG16) might interact with EZH2, indicating a potential pathway to overcome gemcitabine-resistant PC progression. We investigated the role of the SNHG16/EZH2/Smad4 pathway in gemcitabine-resistant PC cells (PANC-1/GR and SW1990/GR). First, we found that SNHG16 was upregulated both in wild-type PC cells and in gemcitabine-resistant PC cells. SNHG16 overexpression reduced gemcitabine cytotoxicity and apoptosis in PC cells. Meanwhile, SNHG16 upregulation caused p-Akt elevation and Smad4 reduction. However, SNHG16 silencing induced the opposite trend. Then, we found that EZH2 was enriched in SNHG16 based on RIP and RNA pulldown. In particular, SNHG16 overexpression promoted the interaction between EZH2 and the Smad4 promoter according to Chromatin immunoprecipitation-quantitative polymerase chain reaction. Finally, both EZH2 inhibition and Smad4 upregulation increased gemcitabine cytotoxicity and apoptosis in PC cells during SNHG16 overexpression. Moreover, both treatments decreased p-Akt and increased Smad4. Collectively, lncRNA SNHG16 decreased Smad4 to induce GR in PC via EZH2-mediated epigenetic modification.

The trilogy of P21 activated kinase, autophagy and immune evasion in pancreatic ductal adenocarcinoma

Pancreatic Ductal Adenocarcinoma (PDA) is one of the most lethal types of cancer with a dismal prognosis. KRAS mutation is a commonly identified oncogene in PDA tumorigenesis and P21-activated kinases (PAKs) are its downstream mediator. While PAK1 is more well-studied, PAK4 also attracted increasing interest. In PDA, PAK inhibition not only reduces cancer cell viability but also sensitises it to chemotherapy. While PDA remains resistant to existing immunotherapies, PAK inhibition has been shown to increase cancer immunogenicity of melanoma, glioblastoma and PDA. Furthermore, autophagy plays an important role in PDA immune evasion, and accumulating evidence has pointed to a connection between PAK and cancer cell autophagy. In this literature review, we aim to summarize currently available studies that have assessed the potential connection between PAK, autophagy and immune evasion in PDA biology to guide future research.

CDK7 inhibition augments response to multidrug chemotherapy in pancreatic cancer

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a dismal prognosis. Although combined treatment with gemcitabine and albumin-bound paclitaxel has improved the prognosis of PDAC, both intrinsic and acquired chemoresistance remain as severe hurtles towards improved prognosis. Thus, new therapeutic targets and innovative strategies are urgently needed.

METHODS

In this study, we used the KPC mouse model-derived PDAC cell line TB32047 to perform kinome-wide CRISPR-Cas9 loss-of-function screening. Next-generation sequencing and MAGeCK-VISPR analysis were performed to identify candidate genes. We then conducted cell viability, clonogenic, and apoptosis assays and evaluated the synergistic therapeutic effects of cyclin-dependent kinase 7 (CDK7) depletion or inhibition with gemcitabine (GEM) and paclitaxel (PTX) in a murine orthotopic pancreatic cancer model. For mechanistic studies, we performed genome enrichment analysis (GSEA) and Western blotting to identify and verify the pathways that render PDAC sensitive to GEM/PTX therapy.

RESULTS

We identified several cell cycle checkpoint kinases and DNA damage-related kinases as targets for overcoming chemoresistance. Among them, CDK7 ranked highly in both screenings. We demonstrated that both gene knockout and pharmacological inhibition of CDK7 by THZ1 result in cell cycle arrest, apoptosis induction, and DNA damage at least predominantly through the STAT3-MCL1-CHK1 axis. Furthermore, THZ1 synergized with GEM and PTX in vitro and in vivo, resulting in enhanced antitumor effects.

CONCLUSIONS

Our findings support the application of CRISPR-Cas9 screening in identifying novel therapeutic targets and suggest new strategies for overcoming chemoresistance in pancreatic cancer.

Coix seed oil regulates mitochondrial functional damage to induce apoptosis of human pancreatic cancer cells via the PTEN/PI3K/AKT signaling pathway

BACKGROUND

Coix seed oil (CSO) has a wide range of anticancer effects. However, the mechanism of action against pancreatic cancer (PC) and regulation of mitochondria in vitro is still unclear.

MATERIALS AND RESULTS

This research investigated the possible mechanism of CSO induction of PC cell apoptosis and regulating mitochondrial functional damage. Proliferation of PC cells, mitochondrial membrane potential (MMP), qualitative and quantitative analysis of PC cell apoptosis, openness of mitochondrial permeability transition pore, related protein expression, generation of reactive oxygen species (ROS), and gene expression were determined by cell counting kit-8, JC-1 staining, acridine orange and ethidium bromide staining, flow cytometry, calcein-AM/cobalt staining, western blotting, dichlorofluorescein diacetate probe, and quantitative real-time reverse transcription-polymerase chain reaction, respectively. We confirmed that PTEN protein was involved in CSO-induced PANC-1 cell apoptosis and mitochondrial functional damage. CSO induced depolarization of MMP, increased opening of the mitochondrial permeability transition pore, increased ROS production, and further increased mitochondrial damage. Additionally, CSO downregulated expression of p-AKT and p-PI3K proteins; upregulated protein expression of cleaved caspase-9, Bax, cleaved caspase-3 and cytochrome c; and downregulated expression of Bcl-2 by upregulating the PTEN gene. The corresponding protein expression was consistent with the gene expression level. Furthermore, the loss of function of PTEN protein reduces the ability of CSO to induce apoptosis of PANC-1 cells and damage to mitochondrial function.

CONCLUSIONS

CSO induces apoptosis of PANC-1 PC cells by modulating mitochondrial functional impairment and related apoptotic molecules via PTEN, which may be closely related to the PI3K/AKT signaling pathway.

MARK2 regulates chemotherapeutic responses through class IIa HDAC-YAP axis in pancreatic cancer

Despite paclitaxel's wide use in cancer treatment, patient response rate is still low and drug resistance is a major clinical obstacle. Through a Phos-tag-based kinome-wide screen, we identified MARK2 as a critical regulator for paclitaxel chemosensitivity in PDAC. We show that MARK2 is phosphorylated by CDK1 in response to antitubulin chemotherapeutics and in unperturbed mitosis. Phosphorylation is essential for MARK2 in regulating mitotic progression and paclitaxel cytotoxicity in PDAC cells. Mechanistically, our findings also suggest that MARK2 controls paclitaxel chemosensitivity by regulating class IIa HDACs. MARK2 directly phosphorylates HDAC4 specifically during antitubulin treatment. Phosphorylated HDAC4 promotes YAP activation and controls expression of YAP target genes induced by paclitaxel. Importantly, combination of HDAC inhibition and paclitaxel overcomes chemoresistance in organoid culture and preclinical PDAC animal models. The expression levels of MARK2, HDACs, and YAP are upregulated and positively correlated in PDAC patients. Inhibition of MARK2 or class IIa HDACs potentiates paclitaxel cytotoxicity by inducing mitotic abnormalities in PDAC cells. Together, our findings identify the MARK2-HDAC axis as a druggable target for overcoming chemoresistance in PDAC.

Gemcitabine-Loaded Nanocarrier of Essential Oil from Pulicaria crispa: Preparation, Optimization, and In Vitro Evaluation of Anticancer Activity

The limitations of gemcitabine (GEM) in cancer therapy are due to its poor pharmacokinetics, which cause undesired adverse effects. The current study was aimed at investigating the anticancer effect and apoptotic mechanism of synthesized nanoemulsion (NE) containing Pulicaria crispa essential oil (PC-EO) and GEM (PC-NE:GEM) on MCF-7 and Hep-G2 cancer cell lines. An optimized NE formulation was selected based on the Box–Behnken method. The droplet size of the optimized PC-NE was 9.93 ± 0.53 nm, but after GEM loading, it was increased to 11.36 ± 0.0.21 nm. Results from FTIR revealed that GEM was successfully loaded onto PC-NE. The antineoplastic effect of PC-NE:GEM on MCF-7 and Hep-G2 cancer cells was increased more than 100-fold relative to that of GEM. A combination index and isobologram based on CompuSyn software revealed the synergistic effect of the formulation produced by a 1:1 ratio combination of PC-NE and GEM. These findings were confirmed by examination of cellular morphologies. The combination formulation strongly induced about 4.48-fold and 2.95-fold increases in apoptosis in MCF-7 and Hep-G2 cells, respectively, when compared with GEM. Moreover, PC-NE:GEM produced a synergistic increase in ROS production in MCF-7 cells (15.23%) and Hep-G2 cells (31.69%), when compared with GEM. In addition, PC-NE:GEM enhanced the activation of the intrinsic apoptosis pathway through upregulation of expressions of p53 and Caspase-3, and downregulation of Bcl-2 expression in MCF-7 cells, while the expressions of Caspase-3, Bax, and p53 were upregulated in HepG2 cells. These results indicate that the GEM-loaded NE containing PC-EO may reduce the dose of GEM and eliminate the associated side effects.

Lipocalin 2 may be a key factor regulating the chemosensitivity of pancreatic cancer to gemcitabine

Owing to the high heterogeneity of pancreatic cancer, patient-derived xenografts (PDX) can compensate for the defects of cell line-derived xenografts (CDX) and also better preserve the heterogeneity and tumor microenvironment of primary tumors. Further, gemcitabine, which is used for the treatment of various cancers, is prone to tumor drug resistance, and this limits its sustained efficacy. Therefore, in this study, our objective was to screen appropriate individual therapeutic drugs for pancreatic cancer. To this end, we established pancreatic cancer PDX models from different patients and screened gemcitabine sensitivity regulatory molecules via high-throughput transcriptome sequencing and bioinformatics analysis. Based on the results obtained, gemcitabine was identified as the most suitable chemotherapeutic drug in a variety of PDX models. Additionally, our results indicated that Lipocalin 2 (LCN 2) may play an important role in the sensitivity of pancreatic cancer to gemcitabine treatment. Thus, the study provides a new potential intervention target for the treatment of pancreatic cancer in clinical practice.

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PDX model plays an important role in the screening of chemotherapeutic agents for pancreatic cancer.

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Gemcitabine is the most suitable chemotherapeutic drug in a variety of PDX models of pancreatic cancer.

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Lcn2 may be involved in the sensitivity of gemcitabine in the treatment of pancreatic cancer and the change of Lipocalin 2 levels determines the gemcitabine therapeutic output.

An anti-bacterial and anti-cancer fibrous membrane with multiple therapeutic effects for prevention of pancreatic cancer recurrence

Adjuvant systemic chemotherapy with gemcitabine (GEM) is recognized as the standard of care to improve the prognosis of patients with resected pancreatic cancer (PC); however, it is greatly limited by poor absorption of chemotherapy agents. Moreover, surgical site infection and Gammaproteobacteria-induced GEM resistance further decrease the chemotherapy efficacy and increase the risk of recurrence and even mortality. Here, we develop an implantable anti-bacterial and anti-cancer fibrous membrane (AAFM) to inhibit PC recurrence in a well-coordinated manner. Our AAFM can be readily prepared via simple co-electrospinning of GEM and poly-L-lactic acid (PLLA) and subsequent tannic acid (TA)-mediated in-situ generation of silver nanoparticles (AgNPs). The resultant membrane presents highly porous fibrous morphology and appropriate mechanical performance. Most importantly, we find the surface-deposited TA/AgNP complexes can exert multiple therapeutic effects: (1) they can act as a fence to extend GEM diffusion route, achieving a sustained drug release; (2) they can fight the pathogenic microorganisms in the local microenvironment and prevent infectious complications and alleviate Gammaproteobacteria-induced chemotherapy resistance; (3) they can combat residual cancer cells to synchronously strengthen the effectiveness of GEM-based chemotherapy. Altogether, our AAFM provides a proof-of-concept demonstration of the integrated anti-cancer and anti-bacterial strategy for enhanced therapeutic efficacy and will inspire the design of other high-performance implants for prevention of tumor relapse.

The Role of Nonapoptotic Programmed Cell Death — Ferroptosis, Necroptosis, and Pyroptosis — in Pancreatic Ductal Adenocarcinoma Treatment

Pancreatic ductal adenocarcinoma (PDAC) is the most lethal cancer, with a dismal 5-year survival rate of less than 10%. It is estimated that approximately 80% of pancreatic ductal carcinoma (PDAC) patients are diagnosed at an advanced or metastatic stage. Hence, most patients are not appropriate candidates for surgical resection and therefore require systemic chemotherapy. However, it has been reported that most patients develop chemoresistance within several months, partly because of antiapoptotic mechanisms. Hence, inducing alternative programmed cell death (PCD), including ferroptosis, necroptosis or pyroptosis, seems to be a promising strategy to overcome antiapoptosis-mediated chemoresistance. In this review, we shed light on the molecular mechanisms of ferroptosis, necroptosis and pyroptosis and suggest several potential strategies (e.g., compounds and nanoparticles [NPs]) that are capable of triggering nonapoptotic PCD to suppress PDAC progression. In conclusion, these strategies might serve as adjuvants in combination with clinical first-line chemotherapies to improve patient survival rates.

Exploration of the System-Level Mechanisms of the Herbal Drug FDY003 for Pancreatic Cancer Treatment: A Network Pharmacological Investigation

Pancreatic cancer (PC) is the most lethal cancer with the lowest survival rate globally. Although the prescription of herbal drugs against PC is gaining increasing attention, their polypharmacological therapeutic mechanisms are yet to be fully understood. Based on network pharmacology, we explored the anti-PC properties and system-level mechanisms of the herbal drug FDY003. FDY003 decreased the viability of human PC cells and strengthened their chemosensitivity. Network pharmacological analysis of FDY003 indicated the presence of 16 active phytochemical components and 123 PC-related pharmacological targets. Functional enrichment analysis revealed that the PC-related targets of FDY003 participate in the regulation of cell growth and proliferation, cell cycle process, cell survival, and cell death. In addition, FDY003 was shown to target diverse key pathways associated with PC pathophysiology, namely, the PIK3-Akt, MAPK, FoxO, focal adhesion, TNF, p53, HIF-1, and Ras pathways. Our network pharmacological findings advance the mechanistic understanding of the anti-PC properties of FDY003 from a system perspective.

Thymidine phosphorylase induction by ionizing radiation antagonizes 5-fluorouracil resistance in human ductal pancreatic adenocarcinoma

Chemoresistance in pancreatic ductal adenocarcinoma (PDAC) frequently contributes to failure of systemic therapy. While the radiosensitizing properties of 5-fluorouracil (FU) are well known, it is unknown whether ionizing radiation (IR) sensitizes towards FU cytotoxicity. Here, we hypothesize that upregulation of thymidine phosphorylase (TP) by IR reverses FU chemoresistance in PDAC cells. The FU resistant variant of the human PDAC cell line AsPC-1 (FU-R) was used to determine the sensitizing effects of IR. Proliferation rates of FU sensitive parental (FU-S) and FU-R cells were determined by WST-1 assays after low (0.05 Gy) and intermediate dose (2.0 Gy) IR followed by FU treatment. TP protein expression in PDAC cells before and after IR was assessed by Western blot. To analyze the specificity of the FU sensitizing effect, TP was ablated by siRNA. FU-R cells showed a 2.7-fold increase of the half maximal inhibitory concentration, compared to FU-S parental cells. Further, FU-R cells showed a concomitant IR resistance towards both doses applied. When challenging both cell lines with FU after IR, FU-R cells had lower proliferation rates than FU-S cells, suggesting a reversal of chemoresistance by IR. This FU sensitizing effect was abolished when TP was blocked by anti-TP siRNA before IR. An increase of TP protein expression was seen after both IR doses. Our results suggest a TP dependent reversal of FU-chemoresistance in PDAC cells that is triggered by IR. Thus, induction of TP expression by low dose IR may be a therapeutic approach to potentially overcome FU chemoresistance in PDAC.

Challenges and Opportunities Associated With Platelets in Pancreatic Cancer

Pancreatic cancer is one of the most common malignant tumors in the digestive system with a poor prognosis. Accordingly, better understanding of the molecular mechanisms and innovative therapies are warranted to improve the prognosis of this patient population. In addition to playing a crucial role in coagulation, platelets reportedly contribute to the growth, invasion and metastasis of various tumors, including pancreatic cancer. This narrative review brings together currently available evidence on the impact of platelets on pancreatic cancer, including the platelet-related molecular mechanisms of cancer promotion, pancreatic cancer fibrosis, immune evasion, drug resistance mechanisms, thrombosis, targeted platelet therapy, combined radiotherapy and chemotherapy treatment, platelet combined with nanotechnology treatment and potential applications of pancreatic cancer organoids. A refined understanding of the role of platelets in pancreatic cancer provides the foothold for identifying new therapeutic targets.

HDAC Inhibitor Sodium Butyrate Attenuates the DNA Repair in Transformed but Not in Normal Fibroblasts

Many cancer therapy strategies cause DNA damage leading to the death of tumor cells. The DNA damage response (DDR) modulators are considered as promising candidates for use in combination therapy to enhance the efficacy of DNA-damage-mediated cancer treatment. The inhibitors of histone deacetylases (HDACis) exhibit selective antiproliferative effects against transformed and tumor cells and could enhance tumor cell sensitivity to genotoxic agents, which is partly attributed to their ability to interfere with DDR. Using the comet assay and host-cell reactivation of transcription, as well as γH2AX staining, we have shown that sodium butyrate inhibited DNA double-strand break (DSB) repair of both endo- and exogenous DNA in transformed but not in normal cells. According to our data, the dysregulation of the key repair proteins, especially the phosphorylated Mre11 pool decrease, is the cause of DNA repair impairment in transformed cells. The inability of HDACis to obstruct DSB repair in normal cells shown in this work demonstrates the advantages of HDACis in combination therapy with genotoxic agents to selectively enhance their cytotoxic activity in cancer cells.

B-Lymphocytes in the Pathophysiology of Pancreatic Adenocarcinoma

Pancreatic adenocarcinoma is highly infiltrated by B lymphocytes but the relevance of these immune cells in tumor development has been surprisingly overlooked until recently. Based on available evidence from other solid tumors, interaction between B lymphocytes and neoplastic cells is probably not uniformly stimulatory or inhibitory. Although presentation of tumor antigens to T cells and production of antitumor immunoglobulins might intuitively suggest a prominent tumor suppressive activity, specific subsets of B lymphocytes can secrete growth factors for neoplastic cells and immunosuppressive cytokines thus promoting escape from immunosurveillance and cancer progression. Because many of these mechanisms might also be implicated in the development of PDAC, and immune-modulation of B-cell activity is nowadays possible at different levels, determining the role of B-lymphocytes in this lethal cancer becomes of utmost importance to design novel therapeutic strategies. This review aims to discuss the emerging role of B cells in PDAC tumorigenesis, progression, and associated stromal reaction.

Association of the Microbiota and Pancreatic Cancer: Opportunities and Limitations

The human body is thoroughly colonized by a wide variety of microorganisms, termed microbiota. Pancreatic cancer, one of the most aggressive forms of cancer, is no exception. The microbiota of pancreatic cancer largely influences and even dominates the occurrence, development and outcome of pancreatic cancer in many ways. Studies have shown that microbiota could change the malignant phenotype and prognosis of pancreatic cancer by stimulating persistent inflammation, regulating the antitumor immune system, changing the tumor microenvironment and affecting cellular metabolism. This is why the association of the microbiota with pancreatic cancer is an emerging area of research that warrants further exploration. Herein, we investigated the potential microbial markers of pancreatic cancer, related research models, the mechanism of action of microbiota in pancreatic cancer, and pancreatic cancer-microbiota-related treatment.

Targeting the Endocannabinoidome in Pancreatic Cancer

Pancreatic Ductal adenocarcinoma (PDAC), the most common malignancy of the pancreas, is an aggressive and lethal form of cancer with a very high mortality rate. High heterogeneity, asymptomatic initial stages and a lack of specific diagnostic markers result in an end-stage diagnosis when the tumour has locally advanced or metastasised. PDAC is resistant to most of the available chemotherapy and radiation therapy treatments, making surgery the most potent curative treatment. The desmoplastic tumour microenvironment contributes to determining PDAC pathophysiology, immune response and therapeutic efficacy. The existing therapeutic approaches such as FDA-approved chemotherapeutics, gemcitabine, abraxane and folfirinox, prolong survival marginally and are accompanied by adverse effects. Several studies suggest the role of cannabinoids as anti-cancer agents. Cannabinoid receptors are known to be expressed in pancreatic cells, with a higher expression reported in pancreatic cancer patients. Therefore, pharmacological targeting of the endocannabinoid system might offer therapeutic benefits in pancreatic cancer. In addition, emerging data suggest that cannabinoids in combination with chemotherapy can increase survival in transgenic pancreatic cancer murine models. This review provides an overview of the regulation of the expanded endocannabinoid system, or endocannabinoidome, in PDAC and will explore the potential of targeting this system for novel anticancer approaches.

Paclitaxel Restores Sensitivity to Chemotherapy in Preclinical Models of Multidrug-Resistant Intrahepatic Cholangiocarcinoma

The treatment of unresectable cholangiocarcinoma (CCA) is limited by the development of resistance to conventional first-line chemotherapy based on gemcitabine (GEM). In addition, a prior treatment with GEM frequently induces cross-resistance to other drugs employed in the second-line. Paclitaxel (PTX) is now emerging as an alternative option for the management of advanced/metastatic CCA. In the present work, we evaluate the antitumor activity of PTX in preclinical models of multidrug-resistant intrahepatic cholangiocarcinoma (iCCA). In vitro, PTX decreases tumor cell viability by affecting the cell cycle and inducing apoptosis and impairs the stem cell compartment. In vivo, a therapeutic regimen containing albumin-bound nanoparticle (Nab)-PTX overcomes drug resistance resulting in delayed tumor growth, impaired organization of the tumor vasculature, and reduced glucose uptake. Together, our results provide a rationale to consider PTX-based regimens in patients with iCCA who became refractory to conventional therapies.

The Establishment of Quantitatively Regulating Expression Cassette with sgRNA Targeting BIRC5 to Elucidate the Synergistic Pathway of Survivin with P-Glycoprotein in Cancer Multi-Drug Resistance

Quantitative analysis and regulating gene expression in cancer cells is an innovative method to study key genes in tumors, which conduces to analyze the biological function of the specific gene. In this study, we found the expression levels of Survivin protein (BIRC5) and P-glycoprotein (MDR1) in MCF-7/doxorubicin (DOX) cells (drug-resistant cells) were significantly higher than MCF-7 cells (wild-type cells). In order to explore the specific functions of BIRC5 gene in multi-drug resistance (MDR), a CRISPR/Cas9-mediated knocking-in tetracycline (Tet)-off regulatory system cell line was established, which enabled us to regulate the expression levels of Survivin quantitatively (clone 8 named MCF-7/Survivin was selected for further studies). Subsequently, the determination results of doxycycline-induced DOX efflux in MCF-7/Survivin cells implied that Survivin expression level was opposite to DOX accumulation in the cells. For example, when Survivin expression was down-regulated, DOX accumulation inside the MCF-7/Survivin cells was up-regulated, inducing strong apoptosis of cells (reversal index 118.07) by weakening the release of intracellular drug from MCF-7/Survivin cells. Also, down-regulation of Survivin resulted in reduced phosphorylation of PI3K, Akt, and mTOR in MCF-7/Survivin cells and significantly decreased P-gp expression. Previous studies had shown that PI3K/Akt/mTOR could regulate P-gp expression. Therefore, we speculated that Survivin might affect the expression of P-gp through PI3K/Akt/mTOR pathway. In summary, this quantitative method is not only valuable for studying the gene itself, but also can better analyze the biological phenomena related to it.

The Urokinase Plasminogen Activation System in Pancreatic Cancer: Prospective Diagnostic and Therapeutic Targets

Pancreatic cancer is a highly aggressive malignancy that features high recurrence rates and the poorest prognosis of all solid cancers. The urokinase plasminogen activation system (uPAS) is strongly implicated in the pathophysiology and clinical outcomes of patients with pancreatic ductal adenocarcinoma (PDAC), which accounts for more than 90% of all pancreatic cancers. Overexpression of the urokinase-type plasminogen activator (uPA) or its cell surface receptor uPAR is a key step in the acquisition of a metastatic phenotype via multiple mechanisms, including the increased activation of cell surface localised plasminogen which generates the serine protease plasmin. This triggers multiple downstream processes that promote tumour cell migration and invasion. Increasing clinical evidence shows that the overexpression of uPA, uPAR, or of both is strongly associated with worse clinicopathological features and poor prognosis in PDAC patients. This review provides an overview of the current understanding of the uPAS in the pathogenesis and progression of pancreatic cancer, with a focus on PDAC, and summarises the substantial body of evidence that supports the role of uPAS components, including plasminogen receptors, in this disease. The review further outlines the clinical utility of uPAS components as prospective diagnostic and prognostic biomarkers for PDAC, as well as a rationale for the development of novel uPAS-targeted therapeutics.