Recent studies of 5-fluorouracil resistance in pancreatic cancer

Development of novel pyrimidine nucleoside analogs as potential anticancer agents: Synthesis, characterization, and In-vitro evaluation against pancreatic cancer

The present study proposed modification of 5-FU by conjugation with an acyl chloride and a 5-membered heterocyclic ring to improve its in-vitro cytotoxicity and metabolic stability. XYZ-I-71 and XYZ-I-73 were synthesized by introducing a tetrahydrofuran ring on 5-fluorocytosine (a precursor of 5-FU) and conjugation with octanoyl chloride and lauroyl chloride, respectively. The structure of the synthesized compounds was validated using NMR and micro-elemental analysis. The antiproliferative activity of the analogs was determined against MiaPaCa-2, PANC-1, and BxPC-3 pancreatic cancer cells. The analog's stability in human liver microsomes was quantified by HPLC. We found that the XYZ-I-73 (IC50 3.6 ± 0.4 μM) analog was most effective against MiaPaCa-2 cells compared to XYZ-I-71(IC50 12.3 ± 1.7 μM), GemHCl (IC50 24.2 ± 1.3 μM), Irinotecan (IC50 10.1 ± 1.5 μM) and 5-FU (IC50 13.2 ± 1.1 μM). The antiproliferative effects of this analog in Miapaca-2 cells is evident based on it having a 7-fold,3-fold, and 4-fold increased cytotoxic effect over Gem-HCl, Irinotecan, and 5-FU, respectively. On the other hand, XYZ-I-71 exhibited a 2-fold increased cytotoxic effect over Gem-HCl but a comparable cytotoxic effect to 5-FU and Irinotecan in MiaPaCa-2 cells. A similar trend of higher XYZ-I-73 inhibition was observed in PANC-1 and BxPC-3 cultures. For 48-h MiaPaCa-2 cell migration studies, XYZ-I-73 (5 μM) significantly reduced migration (# of migrated cells, 168 ± 2.9), followed by XYZ-I-71(315±2.1), Gem-HCl (762±3.1) and 5-FU (710 ± 3.2). PARP absorbance studies demonstrated significant inhibition of PARP expression of XYZ-I-73 treated cells compared to 5-FU, GemHCl, and XYZ-I-71. Further, BAX and p53 expressions were significantly increased in cells treated with XYZ-I-73 compared to 5-FU, GemHCl, and XYZ-I-71. In-vitro, metabolic stability studies showed that 80 ± 5.9% of XYZ-I-71 and XYZ-I-73 remained intact after 2 h exposure in liver microsomal solution compared to 5-FU. The XYZ-I-73 analog demonstrated a remarkable cytotoxic effect and improved in-vitro metabolic stability over the selected standard drugs and may have potential anticancer activity against pancreatic cancer.

LncRNA FOXD1-AS1 regulates pancreatic cancer stem cell properties and 5-FU resistance by regulating the miR-570-3p/SPP1 axis as a ceRNA

Cancer stem cells (CSCs) play a pivotal role in the pathogenesis of human cancers. Previous studies have highlighted the role of long non-coding RNA (lncRNA) in modulating the stemness of CSCs. In our investigation, we identified an upregulation of lncRNA FOXD1-AS1 in CSCs. The enforced expression of lncRNA FOXD1-AS1 promotes tumorigenesis and self-renewal in pancreatic cancer CSCs. Conversely, the knockdown of lncRNA FOXD1-AS1 inhibits tumorigenesis and self-renewal in pancreatic cancer CSCs. Furthermore, our findings reveal that lncRNA FOXD1-AS1 enhances self-renewal and tumorigenesis in pancreatic cancer CSCs by up-regulating osteopontin/secreted phosphoprotein 1(SPP1) and acting as a ceRNA to sponge miR-570-3p in pancreatic cancer (PC) CSCs. Additionally, lncRNA FOXD1-AS1 depleted pancreatic cancer cells exhibit heightened sensitivity to 5-FU-indued cell growth inhibition and apoptosis. Analysis of patient-derived xenografts (PDX) indicates that a low level of lncRNA FOXD1-AS1 may serve as a predictor of 5-FU benefits in PC patients. Moreover, the introduction of SPP1 can reverse the sensitivity of lncRNA FOXD1-AS1-knockdown PC cells to 5-FU-induced cell apoptosis. Importantly, molecular studies have indicated that the elevated levels of lncRNAFOXD1-AS1 in PC are facilitated through METTL3 and YTHDF1-dependent m6A methylation. In summary, our results underscore the critical functions of lncRNA FOXD1-AS1 in the self-renewal and tumorigenesis of pancreatic cancer CSCs, positioning lncRNA FOXD1-AS1 as a promising therapeutic target for PC.

The Critical Function of microRNAs in Developing Resistance against 5- Fluorouracil in Cancer Cells

Although there have been significant advancements in cancer treatment, resistance and recurrence in patients make it one of the leading causes of death worldwide. 5-fluorouracil (5-FU), an antimetabolite agent, is widely used in treating a broad range of human malignancies. The cytotoxic effects of 5-FU are mediated by the inhibition of thymidylate synthase (TYMS/TS), resulting in the suppression of essential biosynthetic activity, as well as the misincorporation of its metabolites into RNA and DNA. Despite its huge benefits in cancer therapy, the application of 5-FU in the clinic is restricted due to the occurrence of drug resistance. MicroRNAs (miRNAs) are small, non-coding RNAs that act as negative regulators in many gene expression processes. Research has shown that changes in miRNA play a role in cancer progression and drug resistance. This review examines the role of miRNAs in 5-FU drug resistance in cancers.

TRPV6 Channel Is Involved in Pancreatic Ductal Adenocarcinoma Aggressiveness and Resistance to Chemotherapeutics

Pancreatic ductal adenocarcinoma (PDAC) stands as a highly aggressive and lethal cancer, characterized by a grim prognosis and scarce treatment alternatives. Within this context, TRPV6, a calcium-permeable channel, emerges as a noteworthy candidate due to its overexpression in various cancers, capable of influencing the cell behavior in different cancer entities. Nonetheless, the exact expression pattern and functional significance of TRPV6 in the context of PDAC remains enigmatic. This study scrutinizes the expression of TRPV6 in tissue specimens obtained from 46 PDAC patients across distinct stages and grades. We manipulated TRPV6 expression (knockdown, overexpression) in the human PDAC cell lines Panc-1 and Capan-1. Subsequently, we analyzed its impact on multiple facets, encompassing Ca2+ influx, proliferation, apoptosis, migration, chemoresistance, and tumor growth, both in vitro and in vivo. Notably, the data indicate a direct correlation between TRPV6 expression levels, tumor stage, and grade, establishing a link between TRPV6 and PDAC proliferation in tissue samples. Decreasing TRPV6 expression via knockdown hampered Ca2+ influx, resulting in diminished proliferation and viability in both cell lines, and cell cycle progression in Panc-1. The knockdown simultaneously led to an increase in apoptotic rates and increased the susceptibility of cells to 5-FU and gemcitabine treatments. Moreover, it accelerated migration and promoted collective movement among Panc-1 cells. Conversely, TRPV6 overexpression yielded opposing outcomes in terms of proliferation in Panc-1 and Capan-1, and the migration of Panc-1 cells. Intriguingly, both TRPV6 knockdown and overexpression diminished the process of tumor formation in vivo. This intricate interplay suggests that PDAC aggressiveness relies on a fine-tuned TRPV6 expression, raising its profile as a putative therapeutic target.

Activity-Based Protein Profiling in Methicillin-Resistant Staphylococcus aureus Reveals the Broad Reactivity of a Carmofur-Derived Probe

Activity-based protein profiling is a powerful chemoproteomic technique to detect active enzymes and identify targets and off-targets of drugs. Here, we report the use of carmofur- and activity-based probes to identify biologically relevant enzymes in the bacterial pathogen Staphylococcus aureus. Carmofur is an anti-neoplastic prodrug of 5-fluorouracil and also has antimicrobial and anti-biofilm activity. Carmofur probes were originally designed to target human acid ceramidase, a member of the NTN hydrolase family with an active-site cysteine nucleophile. Here, we first profiled the targets of a fluorescent carmofur probe in live S. aureus under biofilm-promoting conditions and in liquid culture, before proceeding to target identification by liquid chromatography/mass spectrometry. Treatment with a carmofur-biotin probe led to enrichment of 20 enzymes from diverse families awaiting further characterization, including the NTN hydrolase-related IMP cyclohydrolase PurH. However, the probe preferentially labeled serine hydrolases, thus displaying a reactivity profile similar to that of carbamates. Our results suggest that the electrophilic N-carbamoyl-5-fluorouracil scaffold could potentially be optimized to achieve selectivity towards diverse enzyme families. The observed promiscuous reactivity profile suggests that the clinical use of carmofur presumably leads to inactivation of a number human and microbial enzymes, which could lead to side effects and/or contribute to therapeutic efficacy.

Synthesis, Computational, and Anticancer In Vitro Investigations of Aminobenzylnaphthols Derived from 2-Naphtol, Benzaldehydes, and α-Aminoacids via the Betti Reaction

Multicomponent reactions have emerged as an important approach for the synthesis of diverse and complicated chemical compounds. They have various advantages over two-component reactions, including the convenience of one-pot procedures and the ability to modify the structure of agents. Here, we employed in vitro and in silico studies to explore the anticancer potential of novel aminobenzylnaphthols derived from the Betti reaction (MMZ compounds). MTT assay was used to explore the cytotoxic activity of the compounds in pancreatic (BxPC-3 cells) and colorectal (HT-29) cancer cell lines or normal human lung fibroblasts (WI-38 cells). Proapoptotic properties of two derivatives MMZ-45AA and MMZ-140C were explored using AO/EB and annexin V-FITC/PI staining. In silico studies including ADMET profiling, molecular target prediction, docking, and dynamics were employed. The compounds exhibited cytotoxic properties and showed proapoptotic properties in respective IC50 concentrations. As indicated by in silico investigations, anticancer activity of MMZs can be attributed to the inhibition of ADORA1, CDK2, and TRIM24. Furthermore, compounds exhibited favorable ADMET properties. MMZs constitute an interesting scaffold for the potential development of new anticancer agents.

The p53 reactivator PRIMA-1MET synergises with 5-fluorouracil to induce apoptosis in pancreatic cancer cells

Pancreatic cancer (PC) is one of the deadliest malignancies; p53 is mutated in approximately 75% of PC patients. Hence, the protein derived from mutant/wild-type TP53 may represent a therapeutic target. Interestingly, a p53 reactivator (PRIMA-1MET) showed promise in clinical trials of haematological malignancies; therefore, it warrants an in vitro evaluation in PC cell lines. To evaluate the antiproliferative effects of PRIMA-1MET, either alone or combined with the common chemotherapy 5-fluorouracil (5-FU), against mutated and wild-type p53 PC cell lines. This study involved p53-mutant (AsPC-1) and p53-wild type (Capan-2) PC cell lines. The cytotoxicity of PRIMA-1MET alone or in combination with 5-FU was evaluated by MTT assay. Synergism was assessed by calculating the combination index (CI) via CalcuSyn software. Fluorescence microscopy was used to analyse apoptosis following acridine orange/ethidium bromide (AO/EB) staining. Morphological changes were investigated with an inverted microscope. Quantitative reverse transcription PCR (RT‒qPCR) was used to measure gene expression. Both PC cell lines were sensitive to PRIMA-1MET monotherapy. Furthermore, PRIMA-1MET and 5-FU had a synergistic effect (CI < 1), reflected by significant enhancement of apoptosis and morphological changes in the combination vs. monotherapy treatments. Moreover, the RT‒qPCR results indicated increased expression of the NOXA and TP73 genes in combination-treated cells. Our data suggested that PRIMA-1MET, whether alone or combined with 5-FU, has an antiproliferative effect on PC cell lines regardless of p53 mutational status. The synergism of the combination was associated with significant apoptosis induction through p53-dependent and p53-independent pathways. Preclinical confirmation of these data in in vivo models is highly recommended.

Silencing of IGHG1 reverses the resistance of pancreatic cancer to multidrug chemotherapy by modulating autophagy

BACKGROUND

Pancreatic cancer is one of the most aggressive tumors with a high-mortality rate. First-line drugs include 5-fluorouracil (5-FU), gemcitabine (GEM), and oxaliplatin (OXA). Resistance to 5-FU, GEM, and OXA is a major challenge. Immunoglobulin heavy chain F1 (IGHG1) participates in the regulation of cancer progression. It is still unclear how IGHG1 affects 5-FU, GEM, and OXA in pancreatic cancer.

METHODS

The expression status of IGHG1 in pancreatic cancer was analyzed through bioinformatics tools. IGHG1 expression in pancreatic cancer tissues and cells was determined via RT-qPCR. Cell counting kit 8 assays, and flow cytometry analysis were utilized to detect the impact of IGHG1,5-FU, GEM, and OXA on cell proliferation and apoptosis. Western blotting was utilized to detect changes in the levels of the autophagy-associated proteins LC3, Beclin-1, p62, and ATG5. Immunofluorescence assays were employed to determine LC3 expression in cells. Xenograft experiments were conducted on nude mice to study tumor growth.

RESULTS

IGHG1 was overexpressed in pancreatic cancer cells and tissues. IGHG1 expression was downregulated by 5-FU, GEM, or OXA treatment in cells. Treatment with 5-FU, GEM, or OXA repressed viability and promoted apoptosis and autophagy in pancreatic cancer cells. IGHG1 silencing exhibited the same results. Furthermore, IGHG1 depletion notably strengthened the effects of 5-FU, GEM, and OXA on pancreatic cancer cell viability, apoptosis, and autophagy. The combination of IGHG1 depletion with 5-FU, GEM, or OXA significantly reduced tumor growth in vivo.

CONCLUSION

Silencing of IGHG1 could enhance 5-FU, GEM, or OXA function in pancreatic cancer and reverse resistance by regulating apoptosis and autophagy.

7-geranyloxycoumarin enhanced radiotherapy effects on human gastric adenocarcinoma cells

Background

Gastric adenocarcinoma (GA) is a serious malignancy with growing incidence and mortality rate worldwide. The objective of the present study was to determine whether 7-geranyloxycoumarin, a natural monoterpene coumarin, could induce anticancer effects, in single use and/or in combination with anticancer drugs and ionizing radiation, on GA cells.

Materials and Methods

7-geranyloxycoumarin was synthesized by a reaction between 7-hydroxycoumarin and transgeranyl bromide. MKN45 cells were treated with 7-geranyloxycoumarin, and the viability of cells was determined by resazurin. Apoptosis was then evaluated by flow cytometric analysis using annexin V and propidium iodide, and the expression of P53 and BCL2 was analyzed by quantitative polymerase chain reaction (qPCR). Combinatorial effects of 7-geranyloxycoumarin with 5-fluorouracil (5-FU), cisplatin (CDDP), and X radiation were also evaluated.

Results

Assessment of cell viability indicated that 7-geranyloxycoumarin induced its toxic effects in a time- and dose-dependent manner. This was confirmed by the detection of apoptotic cells, and qPCR results revealed a significant downregulation in BCL2 expression. Although combinatorial use of 7-geranyloxycoumarin + 5-FU or + CDDP did not improve cytotoxicity of anticancer drugs, significant increase in the effectiveness of applied radiations was detected upon pretreatment with 7-geranyloxycoumarin.

Conclusion

Our findings provide valuable insights into single and combinatorial effects of 7-geranyloxycoumarin on the GA cells.

Nanodiamond Mediated Molecular Targeting in Pancreatic Ductal Adenocarcinoma: Disrupting the Tumor-stromal Cross-talk, Next Hope on the Horizon?

Pancreatic ductal adenocarcinoma (PDAC) is one of the foremost causes of cancer-related morbidities worldwide. Novel nanotechnology-backed drug delivery stratagems, including molecular targeting of the chemotherapeutic payload, have been considered. However, no quantum leap in the gross survival rate of patients with PDAC has been realized. One of the predominant causes behind this is tumor desmoplasia, a dense and heterogenous stromal extracellular matrix of the tumor, aptly termed tumor microenvironment (TME). It plays a pivotal role in the tumor pathogenesis of PDAC as it occupies most of the tumor mass, making PDAC one of the most stromal-rich cancers. The complex crosstalk between the tumor and dynamic components of the TME impacts tumor progression and poses a potential barrier to drug delivery. Understanding and deciphering the complex cascade of tumorstromal interactions are the need of the hour so that we can develop neoteric nano-carriers to disrupt the stroma and target the tumor. Nanodiamonds (NDs), due to their unique surface characteristics, have emerged as a promising nano delivery system in various pre-clinical cancer models and have the potential to deliver the chemotherapeutic payload by moving beyond the dynamic tumor-stromal barrier. It can be the next revolution in nanoparticle-mediated pancreatic cancer targeting.

Recognition and release of uridine and hCNT3: From multivariate interactions to molecular design

As a vital target for the development of novel anti-cancer drugs, human concentrative nucleoside transporter 3 (hCNT3) has been widely concerned. Nevertheless, the lack of a comprehensive understanding of molecular interactions and motion mechanism has greatly hindered the development of novel inhibitors against hCNT3. In this paper, molecular recognition of hCNT3 with uridine was investigated with molecular docking, conventional molecular dynamics (CMD) simulations and adaptive steered molecular dynamics (ASMD) simulations; and then, the uridine derivatives with possibly highly inhibitory activity were designed. The result of CMD showed that more water-mediated H-bonds and lower binding free energy both explained higher recognition ability and transported efficiency of hCNT3. While during the ASMD simulation, nucleoside transport process involved the significant side-chain flip of residues F321 and Q142, a typical substrate-induced conformational change. By considering electronegativity, atomic radius, functional group and key H-bonds factors, 25 novel uridine derivatives were constructed. Subsequently, the receptor-ligand binding free energy was predicted by solvated interaction energy (SIE) method to determine the inhibitor c8 with the best potential performance. This work not only revealed molecular recognition and release mechanism of uridine with hCNT3, but also designed a series of uridine derivatives to obtain lead compounds with potential high activity.

Synthesis, characterization, and anticancer evaluation of 1,3-bistetrahydrofuran-2yl-5-FU as a potential agent for pancreatic cancer

The failure of current chemotherapeutic agents for pancreatic cancer (PCa) makes it the most aggressive soft tissue tumor with a 5-year survival of slightly above 10% and is estimated to be the second leading cause of cancer death by 2030.

OBJECTIVE

The main aim was to synthesize, characterize and evaluate the anticancer activity of 1,3-bistetrahydrofuran-2yl-5FU (MFU).

METHODS

MFU was synthesized by using 5-fluorouracil (5-FU) and tetrahydrofuran acetate, and characterized by nuclear magnetic resonance (NMR), micro-elemental analysis, high-performance liquid chromatography (HPLC), and liquid chromatography with mass spectrophotometry (LC-MS). MFU and Gemcitabine hydrochloride (GemHCl) were tested for antiproliferative activity against MiaPaca-2 and Panc-1 cell lines.

RESULTS

The half-minimum inhibitory concentration (IC50) of MFU was twice lower than that of GemHCl when used in both cell lines. MiaPaca-2 cells (MFU-IC50 = 4.5 ± 1.2 μM vs. GemHCl-IC50 = 10.3 ± 1.1 μM); meanwhile similar trend was observed in Panc-1 cells (MFU-IC50 = 3.0 ± 1 μM vs. GemHCl-IC50 = 6.1 ± 1.03 μM). The MFU and GemHCl effects on 3D spheroids showed a similar trend (IC50-GemHCl = 14.3 ± 1.1 μM vs. IC50-MFU = 7.2 ± 1.1 μM) for MiaPaca-2 cells, and (IC50-GemHCl = 16.3 ± 1.1 μM vs. IC50-MFU = 9.2 ± 1.1 μM) for Panc-1 cells. MFU significantly inhibited clonogenic cell growth, and induced cell death via apoptosis. Cell cycle data showed mean PI for GemHCl (48.5-55.7) twice higher than MFU (24.7 to 27.9) for MiaPaca-2 cells, and similarly to Panc-1 cells. The in-vivo model showed intensely stained EGFR (stained brown) in all control, GemHCl and MFU-treated mice bearing subcutaneous PDX tumors, however, HER2 expression was less stained in MFU-treated tumors compared to GemHCl-treated tumors and controls. Mean tumor volume of MFU-treated mice (361 ± 33.5 mm3) was three-fold lower than GemHCl-treated mice (1074 ± 181.2 mm3) bearing pancreatic PDX tumors.

CONCLUSION

MFU was synthesized with high purity and may have potential anticancer activity against PCa.

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.

Laminarin Attenuates ROS-Mediated Cell Migration and Invasiveness through Mitochondrial Dysfunction in Pancreatic Cancer Cells

Background: Pancreatic ductal adenocarcinoma (PDAC) is a notoriously aggressive type of cancer with a high metastasis rate. It is conventionally treated by surgical resection and neoadjuvant chemotherapy. However, continuous chemotherapy leads to relapse in most PDAC patients due to chemical resistance. Therefore, novel anticancer agents need to be identified and developed. The antitumor activities of laminarin extracted from brown algae against hepatocarcinoma, lung, and colon cancer have been established. However, its effects on pancreatic cancer have remained obscure. Purpose: Our study identified the anticancer effects of laminarin on pancreatic cancer cells and tried to explain its intracellular mechanisms. Methods: We assessed the cell viability of PANC-1 and MIA PaCa-2 cells using MTT assay. Hanging drop method was used for the spheroid formation. Flow cytometry was conducted to evaluate the several intracellular alterations including apoptosis, ROS production, mitochondrial membrane potential (MMP), and calcium concentration induced by laminarin. An invasion test was performed to assess the inhibitory effect of laminarin on cell migration and the invasive genes were evaluated by RT-qPCR. Signaling pathway related with anticancer effects of laminarin was analyzed by western blot. Results: We report that inhibiting laminarin increased the proliferation and viability of the representative pancreatic cancer cell lines, MIA PaCa-2 and PANC-1. Laminarin triggered apoptosis and mitochondrial impairment as evidenced by depolarized mitochondrial membranes, disrupted calcium, and suppressed cell migration caused by reactive oxygen species production and related intracellular signaling pathways. Moreover, laminarin showed synergistic effects when combined with 5-FU, a standard anticancer agent for PDAC. Conclusion: The present study is the first to report that laminarin exerts anticancer effect through ROS production in pancreatic cancer cells. Laminarin shows potential to serve as a new anticancer agent for treating PDAC.

Antitumor Effects of Cannabinoids in Human Pancreatic Ductal Adenocarcinoma Cell Line (Capan-2)-Derived Xenograft Mouse Model

Background

Pancreatic cancer is considered a rare type of cancer, but the mortality rate is high. Cannabinoids extracted from the cannabis plant have been interested as an alternative treatment in cancer patients. Only a few studies are available on the antitumor effects of cannabinoids in pancreatic cancer. Therefore, this study aims to evaluate the antitumor effects of cannabinoids in pancreatic cancer xenografted mouse model.

Materials and Methods

Twenty-five nude mice were subcutaneously transplanted with a human pancreatic ductal adenocarcinoma cell line (Capan-2). All mice were randomly assigned into 5 groups including negative control (gavage with sesame oil), positive control (5 mg/kg 5-fluorouracil intraperitoneal administration), and cannabinoids groups that daily received THC:CBD, 1:6 at 1, 5, or 10 mg/kg body weight for 30 days, respectively. Xenograft tumors and internal organs were collected for histopathological examination and immunohistochemistry.

Results

The average tumor volume was increased in all groups with no significant difference. The average apoptotic cells and caspase-3 positive cells were significantly increased in cannabinoid groups compared with the negative control group. The expression score of proliferating cell nuclear antigen in positive control and cannabinoids groups was decreased compared with the negative control group.

Conclusions

Cannabinoids have an antitumor effect on the Capan-2-derived xenograft mouse model though induce apoptosis and inhibit proliferation of tumor cells in a dose-dependent manner.

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.

Triazole Modified Tetraiodothyroacetic Acid Conjugated to Polyethylene Glycol, a Thyrointegrin αvβ3 Antagonist as a Radio- and Chemo-Sensitizer in Pancreatic Cancer

Thyroid hormone L thyroxine stimulates pancreatic carcinoma cell proliferation via thyrointegrin αvβ3 receptors, and antagonist tetraiodothyroacetic acid (tetrac) inhibits cancer cell growth. Chemically modified bis-triazole-tetrac conjugated with polyethylene glycol (P-bi-TAT) has higher binding affinity to αvβ3 receptors compared to tetrac. We investigated the antiproliferation effect of P-bi-TAT in pancreatic cancer cells (SUIT2) and its radio- and chemo-sensitizing roles in a mouse model of pancreatic cancer. P-bi-TAT treatment increased tumor-targeted radiation-induced cell death and decreased tumor size. P-bi-TAT acted as a chemo-sensitizer and enhanced the 5-fluorouracil (5FU) effect in decreasing pancreatic tumor weight compared to 5FU monotherapy. Withdrawal of treatment continued the tumor regression; however, the 5FU group showed tumor regrowth. The mechanisms of the anti-cancer activity of P-bi-TAT on SUIT2 cells were assessed by microarray experiments, and genome-wide profiling identified significant alterations of 1348 genes’ expression. Both down-regulated and up-regulated transcripts suggest that a molecular interference at the signaling pathway-associated gene expression is the prevalent mode of P-bi-TAT anti-cancer activity. Our data indicate that non-cytotoxic P-bi-TAT is not only an anti-cancer agent but also a radio-sensitizer and chemo-sensitizer that acts on the extracellular domain of the cell surface αvβ3 receptor.

INSIDIA 2.0 High-Throughput Analysis of 3D Cancer Models: Multiparametric Quantification of Graphene Quantum Dots Photothermal Therapy for Glioblastoma and Pancreatic Cancer

Cancer spheroids are in vitro 3D models that became crucial in nanomaterials science thanks to the possibility of performing high throughput screening of nanoparticles and combined nanoparticle-drug therapies on in vitro models. However, most of the current spheroid analysis methods involve manual steps. This is a time-consuming process and is extremely liable to the variability of individual operators. For this reason, rapid, user-friendly, ready-to-use, high-throughput image analysis software is necessary. In this work, we report the INSIDIA 2.0 macro, which offers researchers high-throughput and high content quantitative analysis of in vitro 3D cancer cell spheroids and allows advanced parametrization of the expanding and invading cancer cellular mass. INSIDIA has been implemented to provide in-depth morphologic analysis and has been used for the analysis of the effect of graphene quantum dots photothermal therapy on glioblastoma (U87) and pancreatic cancer (PANC-1) spheroids. Thanks to INSIDIA 2.0 analysis, two types of effects have been observed: In U87 spheroids, death is accompanied by a decrease in area of the entire spheroid, with a decrease in entropy due to the generation of a high uniform density spheroid core. On the other hand, PANC-1 spheroids' death caused by nanoparticle photothermal disruption is accompanied with an overall increase in area and entropy due to the progressive loss of integrity and increase in variability of spheroid texture. We have summarized these effects in a quantitative parameter of spheroid disruption demonstrating that INSIDIA 2.0 multiparametric analysis can be used to quantify cell death in a non-invasive, fast, and high-throughput fashion.

The Impact of Biomarkers in Pancreatic Ductal Adenocarcinoma on Diagnosis, Surveillance and Therapy

Simple Summary

Pancreatic ductal adenocarcinoma is a leading cause of cancer death worldwide. Due to the frequently late diagnosis, early metastasis and high therapy resistance curation is rare and prognosis remains poor overall. To provide early diagnostic and therapeutic predictors, various molecules from blood, tissue and other origin e.g., saliva, urine and stool, have been identified as biomarkers. This review summarizes current trends in biomarkers for diagnosis and therapy of pancreatic ductal adenocarcinoma.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is still difficult to treat due to insufficient methods for early diagnosis and prediction of therapy response. Furthermore, surveillance after curatively intended surgery lacks adequate methods for timely detection of recurrence. Therefore, several molecules have been analyzed as predictors of recurrence or early detection of PDAC. Enhanced understanding of molecular tumorigenesis and treatment response triggered the identification of novel biomarkers as predictors for response to conventional chemotherapy or targeted therapy. In conclusion, progress has been made especially in the prediction of therapy response with biomarkers. The use of molecules for early detection and recurrence of PDAC is still at an early stage, but there are promising approaches in noninvasive biomarkers, composite panels and scores that can already ameliorate the current clinical practice. The present review summarizes the current state of research on biomarkers for diagnosis and therapy of pancreatic cancer.

Recent Updates on Mechanisms of Resistance to 5-Fluorouracil and Reversal Strategies in Colon Cancer Treatment

5-Fluorouracil (5-FU) plus leucovorin (LV) remain as the mainstay standard adjuvant chemotherapy treatment for early stage colon cancer, and the preferred first-line option for metastatic colon cancer patients in combination with oxaliplatin in FOLFOX, or irinotecan in FOLFIRI regimens. Despite treatment success to a certain extent, the incidence of chemotherapy failure attributed to chemotherapy resistance is still reported in many patients. This resistance, which can be defined by tumor tolerance against chemotherapy, either intrinsic or acquired, is primarily driven by the dysregulation of various components in distinct pathways. In recent years, it has been established that the incidence of 5-FU resistance, akin to multidrug resistance, can be attributed to the alterations in drug transport, evasion of apoptosis, changes in the cell cycle and DNA-damage repair machinery, regulation of autophagy, epithelial-to-mesenchymal transition, cancer stem cell involvement, tumor microenvironment interactions, miRNA dysregulations, epigenetic alterations, as well as redox imbalances. Certain resistance mechanisms that are 5-FU-specific have also been ascertained to include the upregulation of thymidylate synthase, dihydropyrimidine dehydrogenase, methylenetetrahydrofolate reductase, and the downregulation of thymidine phosphorylase. Indeed, the successful modulation of these mechanisms have been the game plan of numerous studies that had employed small molecule inhibitors, plant-based small molecules, and non-coding RNA regulators to effectively reverse 5-FU resistance in colon cancer cells. It is hoped that these studies would provide fundamental knowledge to further our understanding prior developing novel drugs in the near future that would synergistically work with 5-FU to potentiate its antitumor effects and improve the patient's overall survival.

A novel view on an old drug, 5-fluorouracil: an unexpected RNA modifier with intriguing impact on cancer cell fate

5-Fluorouracil (5-FU) is a chemotherapeutic drug widely used to treat patients with solid tumours, such as colorectal and pancreatic cancers. Colorectal cancer (CRC) is the second leading cause of cancer-related death and half of patients experience tumour recurrence. Used for over 60 years, 5-FU was long thought to exert its cytotoxic effects by altering DNA metabolism. However, 5-FU mode of action is more complex than previously anticipated since 5-FU is an extrinsic source of RNA modifications through its ability to be incorporated into most classes of RNA. In particular, a recent report highlighted that, by its integration into the most abundant RNA, namely ribosomal RNA (rRNA), 5-FU creates fluorinated active ribosomes and induces translational reprogramming. Here, we review the historical knowledge of 5-FU mode of action and discuss progress in the field of 5-FU-induced RNA modifications. The case of rRNA, the essential component of ribosome and translational activity, and the plasticity of which was recently associated with cancer, is highlighted. We propose that translational reprogramming, induced by 5-FU integration in ribosomes, contributes to 5-FU-driven cell plasticity and ultimately to relapse.

Combating pancreatic cancer chemoresistance by triggering multiple cell death pathways

Pancreatic cancer is the fourth most common cause of cancer-associated death in western countries, where the incidence and number of deaths are increasing every year. Intrinsic or acquired resistance of tumor cells to chemotherapy agents is the major reason for failure of traditional cancer treatment. Several factors are implicated in this impressive resistance; however, of these, it is important to highlight the extensive cellular heterogeneity of these tumors. This heterogeneity is linked to a wide range of sensitivity that different clones in the same tumor display to chemotherapeutic agents. Accordingly, recent findings in this field have discovered new therapeutic targets in order to develop new combinatory treatments, as well as to induce several cell death pathways and reduce therapy-threshold and likelihood of future resistance. Accordingly, recent research has focused on targeting mitochondria, an organelle with key roles regulating cell death signaling pathways, such as apoptosis, necroptosis, autophagy, ferroptosis, or parthanatos. These findings - identifying new compounds, alone or in combination, that can target pancreatic ductal adenocarcinoma cell resistance - could be the key to future treatments.

Galactosyltransferase B4GALT1 confers chemoresistance in pancreatic ductal adenocarcinomas by upregulating N-linked glycosylation of CDK11p110

Aberrant glycosylation in pancreatic cancer has been linked to cancer development, progression and chemoresistance. However, the role of glycogene, such as galactosyltransferase, in pancreatic cancer remains unknown. Herein, we establish beta-1.4-galactosyltransferase 1 (B4GALT1) as a clinical marker and regulator of chemoresistance. Clinically, high B4GALT1 expression correlates with poor survival, enhanced tumor size, increased lymph node metastasis, elevated cancer progression and enhanced incidence of relapse in PDAC patients. Expression of B4GALT1 is up-regulated in gemcitabine resistant patient derived organoids as well as chemoresistant cancer cell lines, while genetic perturbation of its expression in PDAC cell lines regulates cancer progression and chemoresistance. Mechanistically, we show that elevated p65 activity transcriptionally up-regulates B4GALT1 expression, which then interacts with and stabilizes cyclin dependent kinase 11 isomer CDK11^p110 protein via N-linked glycosylation, in order to promote cancer progression and chemoresistance. Finally, depletion of B4GALT1 rescues the response of chemoresistant cells to gemcitabine in an orthotopic PDAC model. Overall, our data uncovers a mechanism by which p65-B4GALT1-CDK11^p110 signalling axis determines cancer progression and chemoresistance, providing a new therapeutic target for an improved pancreatic cancer treatment.

Cancer-Specific Targeting of Taurine-Upregulated Gene 1 Enhances the Effects of Chemotherapy in Pancreatic Cancer

Overcoming drug resistance is one of the biggest challenges in cancer chemotherapy. In this study, we examine whether targeting the long noncoding RNA taurine upregulated gene 1 (TUG1) could be an effective therapeutic approach to overcome drug resistance in pancreatic ductal adenocarcinoma (PDAC). TUG1 was expressed at significantly higher levels across 197 PDAC tissues compared with normal pancreatic tissues. Overall survival of patients with PDAC who had undergone 5-FU-based chemotherapy was shorter in high TUG1 group than in low TUG1 group. Mechanistically, TUG1 antagonized miR-376b-3p and upregulated dihydropyrimidine dehydrogenase (DPD). TUG1 depletion induced susceptibility to 5-FU in BxPC-3 and PK-9 pancreatic cell lines. Consistently, the cellular concentration of 5-FU was significantly higher under TUG1-depleted conditions. In PDAC xenograft models, intravenous treatment with a cancer-specific drug delivery system (TUG1-DDS) and 5-FU significantly suppressed PDAC tumor growth compared with 5-FU treatment alone. This novel approach using TUG1-DDS in combination with 5-FU may serve as an effective therapeutic option to attenuate DPD activity and meet appropriate 5-FU dosage requirements in targeted PDAC cells, which can reduce the systemic adverse effects of chemotherapy. SIGNIFICANCE: Targeting TUG1 coupled with a cancer-specific drug delivery system effectively modulates 5-FU catabolism in TUG1-overexpressing PDAC cells, thus contributing to a new combinatorial strategy for cancer treatment. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/7/1654/F1.large.jpg.

The Role of Mitochondria in the Chemoresistance of Pancreatic Cancer Cells

The first-line chemotherapies for patients with unresectable pancreatic cancer (PC) are 5-fluorouracil (5-FU) and gemcitabine therapy. However, due to chemoresistance the prognosis of patients with PC has not been significantly improved. Mitochondria are essential organelles in eukaryotes that evolved from aerobic bacteria. In recent years, many studies have shown that mitochondria play important roles in tumorigenesis and may act as chemotherapeutic targets in PC. In addition, according to recent studies, mitochondria may play important roles in the chemoresistance of PC by affecting apoptosis, metabolism, mtDNA metabolism, and mitochondrial dynamics. Interfering with some of these factors in mitochondria may improve the sensitivity of PC cells to chemotherapeutic agents, such as gemcitabine, making mitochondria promising targets for overcoming chemoresistance in PC.

5-Fluorouracil (5-FU) resistance and the new strategy to enhance the sensitivity against cancer: Implication of DNA repair inhibition

5-Fluorouracil (5-FU) has been an important anti-cancer drug to date. With an increase in the knowledge of its mechanism of action, various treatment modalities have been developed over the past few decades to increase its anti-cancer activity. But drug resistance has greatly affected the clinical use of 5-FU. Overcoming this chemoresistance is a challenge due to the presence of cancer stem cells like cells, cancer recurrence, metastasis, and angiogenesis. In this review, we have systematically discussed the mechanism of 5-FU resistance and advent strategies to increase the sensitivity of 5-FU therapy including resistance reversal. Special emphasis has been given to the cancer stem cells (CSCs) mediated 5-FU chemoresistance and its reversal process by different approaches including the DNA repair inhibition process.

Targeting laryngeal cancer cells with 5-fluorouracil and curcumin using mesoporous silica nanoparticles

Objective:

To explore the inhibitory and synergistic effects of 5-fluorouracil and curcumin on Hep-2 laryngeal cancer cells and clarify the effect of mesoporous silica nanoparticles as drug carriers.

Methods:

The inhibitory effects of 5-fluorouracil and curcumin on Hep-2 cells were detected using the CCK-8 assay. CompuSyn was used to calculate the synergistic effect of the 2 drugs. Flow cytometry was used to detect apoptosis and cell cycle arrest induced by 5-fluorouracil and curcumin. The drugs were loaded into mesoporous nanoparticles. Western blotting was used to detect the expression of related proteins after treatment. The growth of subcutaneous tumors in BALB/c nude after the intraperitoneal injection with drug-loaded mesoporous silica nanoparticles was recorded.

Results:

5-Fluorouracil and curcumin synergistically induced apoptosis and cell cycle arrest in Hep-2 cells. Mesoporous silica nanoparticles as drug carriers enhanced the therapeutic effects of 5-fluorouracil and curcumin.

Conclusions:

Mesoporous silica nanoparticles are expected to be effective drug carriers that enhance the synergistic effects of 5-fluorouracil and curcumin on laryngeal cancer.

Noncoding RNAs in drug-resistant pancreatic cancer: A review

Pancreatic cancer is the fourth-leading cause of cancer-related deaths and is expected to be the second-leading cause of cancer-related deaths in Europe and the United States by 2030. The high fatality rate of pancreatic cancer is ascribed to untimely diagnosis, early metastasis and limited responses to both chemotherapy and radiotherapy. Although gemcitabine, 5-fluorouracil and some other drugs can profoundly improve patient prognosis, most pancreatic cancer patients eventually develop drug resistance, leading to poor clinical outcomes. The underlying mechanisms of pancreatic cancer drug resistance are complicated and inconclusive. Interestingly, accumulating evidence has demonstrated that different noncoding RNAs (ncRNAs), such as microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), play a crucial role in pancreatic cancer resistance to chemotherapy reagents. In this paper, we systematically summarize the molecular mechanism underlying the influence of ncRNAs on the generation and development of drug resistance in pancreatic cancer and discuss the potential role of ncRNAs as prognostic markers and new therapeutic targets for pancreatic cancer.

Pancreatic Adenocarcinoma Invasiveness and the Tumor Microenvironment: From Biology to Clinical Trials

Pancreatic adenocarcinoma (PDAC) originates in the glandular compartment of the exocrine pancreas. Histologically, PDAC tumors are characterized by a parenchyma that is embedded in a particularly prominent stromal component or desmoplastic stroma. The unique characteristics of the desmoplastic stroma shape the microenvironment of PDAC and modulate the reciprocal interactions between cancer and stromal cells in ways that have profound effects in the pathophysiology and treatment of this disease. Here, we review some of the most recent findings regarding the regulation of PDAC cell invasion by the unique microenvironment of this tumor, and how new knowledge is being translated into novel therapeutic approaches.

Next generation sequencing and functional pathway analysis to understand the mechanism of action of copper-tolfenamic acid against pancreatic cancer cells

Anti-cancer activity of tolfenamic acid (TA) in preclinical models for pancreatic cancer (PaCa) is well established. Since the dosage for anti-cancer actions of TA is rather high, we recently demonstrated that IC₅₀ values of Copper-TA are 30-80% less than TA in 12 cancer cell lines. This study elucidates the underlying mechanisms of Copper-TA in PaCa cells. Control and Copper-TA (IC₅₀) treated PaCa cells were processed by next-generation sequencing (NGS) to determine differentially expressed genes using HTG EdgeSeq Oncology Biomarker panel. Ingenuity Pathway Analysis (IPA®) was used to identify functional significance of altered genes. The conformational studies for assessing the expression of key regulators and genes were conducted by Western blot and qPCR. IPA® identified several networks, regulators, as well as molecular and cellular functions associated with cancer. The top 5 molecular and cellular functions affected by Cu-TA treatment were cell death and survival, cellular development, cell growth and proliferation, cell cycle and cellular movement. The expression of top upstream regulators was confirmed by Western blot analysis while qPCR results of selected genes demonstrated that Copper-TA is efficacious at lower doses than TA. Results suggest that Copper-TA alters genes/key regulators associated with cancer and potentially serve as an effective anti-cancer agent.

Metabolic Adaptation during nab-Paclitaxel Resistance in Pancreatic Cancer Cell Lines

Pancreatic ductal adenocarcinoma (PDAC) correlates with high mortality and is about to become one of the major reasons for cancer-related mortality in the next decades. One reason for that high mortality is the limited availability of effective chemotherapy as well as the intrinsic or acquired resistance against it. Here, we report the impact of nab-paclitaxel on the cellular metabolome of PDAC cell lines. After establishment of nab-paclitaxel resistant cell lines, comparison of parental and resistant PDAC cell lines by metabolomics and biochemical assessments revealed altered metabolism, enhanced viability and reduced apoptosis. The results unveiled that acute nab-paclitaxel treatment affected primary metabolism to a minor extent. However, acquisition of resistance led to altered metabolites in both cell lines tested. Specifically, aspartic acid and carbamoyl-aspartic acid were differentially abundant, which might indicate an increased de novo pyrimidine synthesis. This pathway has already shown a similar behavior in other cancerous entities and thus might serve in the future as vulnerable target fighting resistance acquisition occurring in common malignancies.

Irreversible JNK1-JUN inhibition by JNK-IN-8 sensitizes pancreatic cancer to 5-FU/FOLFOX chemotherapy

Over 55,000 people in the United States are diagnosed with pancreatic ductal adenocarcinoma (PDAC) yearly, and fewer than 20% of these patients survive a year beyond diagnosis. Chemotherapies are considered or used in nearly every PDAC case, but there is limited understanding of the complex signaling responses underlying resistance to these common treatments. Here, we take an unbiased approach to study protein kinase network changes following chemotherapies in patient-derived xenograft (PDX) models of PDAC to facilitate design of rational drug combinations. Proteomics profiling following chemotherapy regimens reveals that activation of JNK-JUN signaling occurs after 5-fluorouracil plus leucovorin (5-FU + LEU) and FOLFOX (5-FU + LEU plus oxaliplatin [OX]), but not after OX alone or gemcitabine. Cell and tumor growth assays with the irreversible inhibitor JNK-IN-8 and genetic manipulations demonstrate that JNK and JUN each contribute to chemoresistance and cancer cell survival after FOLFOX. Active JNK1 and JUN are specifically implicated in these effects, and synergy with JNK-IN-8 is linked to FOLFOX-mediated JUN activation, cell cycle dysregulation, and DNA damage response. This study highlights the potential for JNK-IN-8 as a biological tool and potential combination therapy with FOLFOX in PDAC and reinforces the need to tailor treatment to functional characteristics of individual tumors.

Fluorouracil sensitivity in a head and neck squamous cell carcinoma with a somatic DPYD structural variant

Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers worldwide and represents a heterogeneous group of tumors, the majority of which are treated with a combination of surgery, radiation, and chemotherapy. Fluoropyrimidine (5-FU) and its oral prodrug, capecitabine, are commonly prescribed treatments for several solid tumor types including HNSCC. 5-FU-associated toxicity is observed in ∼30% of treated patients and is largely caused by germline polymorphisms in DPYD, which encodes dihydropyrimidine dehydrogenase, a key enzyme of 5-FU catabolism and deactivation. Although the association of germline DPYD alterations with toxicity is well-described, the potential contribution of somatic DPYD alterations to 5-FU sensitivity has not been explored. In a patient with metastatic HNSCC, in-depth genomic and transcriptomic integrative analysis on a biopsy from a metastatic neck lesion revealed alterations in genes that are associated with 5-FU uptake and metabolism. These included a novel somatic structural variant resulting in a partial deletion affecting DPYD, a variant of unknown significance affecting SLC29A1, and homozygous deletion of MTAP. There was no evidence of deleterious germline polymorphisms that have been associated with 5-FU toxicity, indicating a potential vulnerability of the tumor to 5-FU therapy. The discovery of the novel DPYD variant led to the initiation of 5-FU treatment that resulted in a rapid response lasting 17 wk, with subsequent relapse due to unknown resistance mechanisms. This suggests that somatic alterations present in this tumor may serve as markers for tumor sensitivity to 5-FU, aiding in the selection of personalized treatment strategies.

Baohuoside I Inhibits the Proliferation of Pancreatic Cancer Cells via mTOR/S6K1-Caspases/Bcl2/Bax Apoptotic Signaling

Background

Although the incidence of pancreatic cancer has increased markedly, the 5-year survival rate for this disease is considerably low compared with other types of cancer. Moreover, the mortality rate of pancreatic cancer is similar to its incidence rate. Current therapeutic agents exhibit a lack of specificity for pancreatic cancer. Baohuoside I is traditionally used to treat orgasmic disorder and inflammation. However, its role in pancreatic cancer is unknown.

Objective

To explore the effects of Baohuoside I on pancreatic cancer and to study the potential-related molecular mechanism.

Materials and methods

In the present study, the antineoplastic effect of Baohuoside I was investigated with regard to pancreatic cancer via colony formation, transwell and migration assay. The energy metabolism changes of pancreatic cancer were tested by flow cytometry analysis and oxidative phosphorylation and glycolysis assay. The target signaling members were analyzed by Western blot.

Results

Baohuoside I inhibited the cell growth of pancreatic cancer cells. In addition, it affected intracellular energy metabolism to induce cancer cell apoptosis via the mTOR/S6K1 and the caspase/Bcl2/Bax signaling pathways.

Conclusion

The present data provide further insight into the development of novel drugs against pancreatic cancer.

New Uracil Analogs with Exocyclic Methylidene Group as Potential Anticancer Agents

BACKGROUND

Hybrid molecules combining uracil skeleton with methylidene exo-cyclic group were designed in the search for novel anticancer drug candidates.

OBJECTIVE

Two series of racemic 5-methylidenedihydrouracils, either 1,3-disubstituted or 1,3,6-trisubstituted were synthesized and tested for their possible cytotoxic activity against two cancer cell lines (HL-60 and MCF-7) and two healthy cell lines (HUVEC and MCF-10A). The most cytotoxic analogs were re-synthesized as pure enantiomers. The analog designated as U-332 [(R)-3-(4-bromophenyl)-1-ethyl-5-methylidene-6-phenyldihydrouracil], which had a very low IC50 value in HL-60 cell line (0.77μM) and was the most selective towards cancer cells was chosen for further experiments on HL-60 cell line, in order to determine the possible mechanism involved in its antineoplastic action.

METHODS

Cytotoxic activities of compound was assessed by the MTT assay. In order to explore the mechanism of U-332 activity, we performed quantitative real-time PCR analysis of p53 and p21 genes. Apoptosis, cell proliferation and DNA damage in HL-60 cells were determined using the flow cytometry. The ability of U-332 to determine GADD45ɑ protein level in HL-60 cells incubated with U-332 was analyzed by ELISA test.

RESULTS

U-332 was shown to generate excessive DNA damage (70% of the cell population), leading to p53 activation, resulting in p21 down-regulation and a significant increase of GADD45α protein, responsible for the cell cycle arrest in G2/M phase.

CONCLUSION

U-332 can be used as a potential lead compound in the further development of novel uracil analogs as anticancer agents.

Wnt-11 Expression Promotes Invasiveness and Correlates with Survival in Human Pancreatic Ductal Adeno Carcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest forms of cancer, proving difficult to manage clinically. Wnt-11, a developmentally regulated gene producing a secreted protein, has been associated with various carcinomas but has not previously been studied in PDAC. The present study aimed to elucidate these aspects first in vitro and then in a clinical setting in vivo. Molecular analyses of Wnt-11 expression as well as other biomarkers involved qRT-PCR, RNA-seq and siRNA. Proliferation was measured by MTT; invasiveness was quantified by Boyden chamber (Matrigel) assay. Wnt-11 mRNA was present in three different human PDAC cell lines. Wnt-11 loss affected epithelial-mesenchymal transition and expression of neuronal and stemness biomarkers associated with metastasis. Indeed, silencing Wnt-11 in Panc-1 cells significantly inhibited their Matrigel invasiveness without affecting their proliferative activity. Consistently with the in vitro data, human biopsies of PDAC showed significantly higher Wnt-11 mRNA levels compared with matched adjacent tissues. Expression was significantly upregulated during PDAC progression (TNM stage I to II) and maintained (TNM stages III and IV). Wnt-11 is expressed in PDAC in vitro and in vivo and plays a significant role in the pathophysiology of the disease; this evidence leads to the conclusion that Wnt-11 could serve as a novel, functional biomarker PDAC.

An integrated epigenome and transcriptome analysis identifies PAX2 as a master regulator of drug resistance in high grade pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is notoriously difficult to treat due to its aggressive, ever resilient nature. A major drawback lies in its tumor grade; a phenomenon observed across various carcinomas, where highly differentiated and undifferentiated tumor grades, termed as low and high grade respectively, are found in the same tumor. One eminent problem due to such heterogeneity is drug resistance in PDAC. This has been implicated to ABC transporter family of proteins that are upregulated in PDAC patients. However, the regulation of these transporters with respect to tumor grade in PDAC is not well understood. To combat these issues, a study was designed to identify novel genes that might regulate drug resistance phenotype and be used as targets. By integrating epigenome with transcriptome data, several genes were identified based around high grade PDAC. Further analysis indicated oncogenic PAX2 transcription factor as a novel regulator of drug resistance in high grade PDAC cell lines. It was observed that silencing of PAX2 resulted in increased susceptibility of high grade PDAC cells to various chemotherapeutic drugs. Mechanistically, the study showed that PAX2 protein can bind and alter transcriptionally; expression of many ABC transporter genes in high grade PDAC cell lines. Overall, the study indicated that PAX2 significantly upregulated ABC family of genes resulting in drug resistance and poor survival in PDAC.

Redox-Mediated Mechanism of Chemoresistance in Cancer Cells

Cellular reactive oxygen species (ROS) status is stabilized by a balance of ROS generation and elimination called redox homeostasis. ROS is increased by activation of endoplasmic reticulum stress, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase family members and adenosine triphosphate (ATP) synthesis of mitochondria. Increased ROS is detoxified by superoxide dismutase, catalase, and peroxiredoxins. ROS has a role as a secondary messenger in signal transduction. Cancer cells induce fluctuations of redox homeostasis by variation of ROS regulated machinery, leading to increased tumorigenesis and chemoresistance. Redox-mediated mechanisms of chemoresistance include endoplasmic reticulum stress-mediated autophagy, increased cell cycle progression, and increased conversion to metastasis or cancer stem-like cells. This review discusses changes of the redox state in tumorigenesis and redox-mediated mechanisms involved in tolerance to chemotherapeutic drugs in cancer.

Enhance the efficiency of 5-fluorouracil targeted delivery by using a prodrug approach as a novel strategy for prolonged circulation time and improved permeation

Due to the toxicity and resistance to treatment with anticancer drugs, various methods are used to improve their efficacy in cancer treatment. In this present study, in order to overcome the limitation of 5-Fluorouracil (5-FU), prodrug strategy has been pursued with using density functional theory (DFT) and molecular dynamics simulation (MDs). The main objective of this study is to examine the mechanisms of drug release from its prodrug form by using the intrinsic reaction coordinate (IRC) calculations. The reaction mechanisms of 5-FU prodrug (EMC-5-FU) in the presence of lactic acid (LA) and water molecule were theoretically studied. The IRC calculations were carried out at the M06-2X/6-311G** level in the aqueous phase through the mechanism of ester hydrolysis to obtain energies, the geometry optimization of all stationary points along the potential energy surfaces (PES), and also to determine the harmonic vibrational frequencies. The results herein presented suggest that three reaction pathways and transition states TS1 to TS2 are involved along the calculated potential energy surface. We found that the drug molecule is released in the third step and this occurs by separation CH₂O group in the presence of water molecule with the highest energy barrier about 25.9 kcal/mol. Since the carbon nanotubes (CNTs) can act as drug delivery vehicles and deliver anticancer drugs directly to the target cells. Therefore in DFT section, the interaction mechanism of CNTs with 5-FU prodrug is studied by means of DFT method. The atoms in molecules (AIM) and the non-covalent interactions (NCI) between the CNTs and prodrug are used in order to examine the strength and type of interaction between them. The result of negative binding energy values of CNT-prodrug interaction show the stability of these complexes. Our theoretical results show that the more favorable interaction occurs when the prodrug is located inside the carbon nanotube. Furthermore, for design and development of intracellular drug delivery systems, steered molecular dynamics (SMD) simulations was used to investigate the possibility of encapsulated prodrug-CNT penetration through a (1-palmitoyl-2-oleoyl phosphatidylcholine) POPC lipid bilayer. For this purpose, the forces of penetration and the free energies of rupture of POPC bilayer with a Prodrug-CNT were studied. Our simulation results show that encapsulated prodrug-carbon nanotube does not permanently destroy the POPC membrane structure.

What "The Cancer Genome Atlas" database tells us about the role of ATP-binding cassette (ABC) proteins in chemoresistance to anticancer drugs

Introduction: Chemotherapy remains the only option for advanced cancer patients when other alternatives are not feasible. Nevertheless, the success rate of this type of therapy is often low due to intrinsic or acquired mechanisms of chemoresistance. Among them, drug extrusion from cancer cells through ATP-binding cassette (ABC) proteins plays an important role. ABC pumps are primary active transporters involved in the barrier and secretory functions of many healthy cells. Areas covered: In this review, we have used The Cancer Genome Atlas (TCGA) database to explore the relationship between the expression of the major ABC proteins involved in cancer chemoresistance in the most common types of cancer, and the drugs used in the treatment of these tumors that are substrates of these pumps. Expert opinion: From unicellular organisms to humans, several ABC proteins play a major role in detoxification processes. Cancer cells exploit this ability to protect themselves from cytostatic drugs. Among the ABC pumps, MDR1, MRPs and BCRP are able to export many antitumor drugs and are expressed in several types of cancer, and further up-regulated during treatment. This event results in the enhanced ability of tumor cells to reduce intracellular drug concentrations and hence the pharmacological effect of chemotherapy.

Pharmacogenetics of treatments for pancreatic cancer

Introduction: Despite clinical efforts, pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis. The scarcity of effective therapies can be reflected by the lack of reliable biomarkers to adapt anticancer drugs prescription to tumors' and patients' features. Areas covered: Pharmacogenetics should provide the way to select patients who may benefit from a specific therapy that best matches individual and tumor genetic profile, but it has not yet led to gains in outcome. This review describes PDAC pharmacogenetics findings, critically reappraising studies on polymorphisms and -omics profiles correlated to response to gemcitabine, FOLFIRINOX, and nab-paclitaxel combinations, as well as limitations of targeted therapies. Further, we question whether personalized approaches will benefit patients to any significant degree, supporting the need of new strategies within well-designed trials and validated genomic tests for treatment decision-making. Expert opinion: A major challenge in PDAC is the identification of subgroups of patients who will benefit from treatments. Minimally-invasive tests to analyze biomarkers of drug sensitivity/toxicity should be developed alongside anticancer treatments. However, progress might fall below expectations because of tumor heterogeneity and clonal evolution. Whole-genome sequencing and liquid biopsies, as well as prospective validation in selected cohorts, should overcome the limitations of traditional pharmacogenetic approaches.

How Cancer Cells Resist Chemotherapy: Design and Development of Drugs Targeting Protein-Protein Interactions

Background:

Resistance toward chemotherapeutics is one of the main obstacles on the way to effective cancer treatment. Personalization of chemotherapy could improve clinical outcome. However, despite preclinical significance, most of the potential markers have failed to reach clinical practice partially due to the inability of numerous studies to estimate the marker’s impact on resistance properly.

Objective:

The analysis of drug resistance mechanisms to chemotherapy in cancer cells, and the proposal of study design to identify bona fide markers.

Methods:

A review of relevant papers in the field. A PubMed search with relevant keywords was used to gather the data. An example of a search request: drug resistance AND cancer AND paclitaxel.

Results:

We have described a number of drug resistance mechanisms to various chemotherapeutics, as well as markers to underlie the phenomenon. We also proposed a model of a rational-designed study, which could be useful in determining the most promising potential biomarkers.

Conclusion:

Taking into account the most reasonable biomarkers should dramatically improve clinical outcome by choosing the suitable treatment regimens. However, determining the leading biomarkers, as well as validating of the model, is a work for further investigations.

Lycopene Inhibits Reactive Oxygen Species-Mediated NF-κB Signaling and Induces Apoptosis in Pancreatic Cancer Cells

Generation of excess quantities of reactive oxygen species (ROS) caused by mitochondrial dysfunction facilitates rapid growth of pancreatic cancer cells. Elevated ROS levels in cancer cells cause an anti-apoptotic effect by activating survival signaling pathways, such as NF-κB and its target gene expression. Lycopene, a carotenoid found in tomatoes and a potent antioxidant, displays a protective effect against pancreatic cancer. The present study was designed to determine if lycopene induces apoptosis of pancreatic cancer PANC-1 cells by decreasing intracellular and mitochondrial ROS levels, and consequently suppressing NF-κB activation and expression of NF-κB target genes including cIAP1, cIAP2, and survivin. The results show that the lycopene decreased intracellular and mitochondrial ROS levels, mitochondrial function (determined by the mitochondrial membrane potential and oxygen consumption rate), NF-κB activity, and expression of NF-κB-dependent survival genes in PANC-1 cells. Lycopene reduced cell viability with increases in active caspase-3 and the Bax to Bcl-2 ratio in PANC-1 cells. These findings suggest that supplementation of lycopene could potentially reduce the incidence of pancreatic cancer.

Mechanisms of Anticancer Drug Resistance in Hepatoblastoma

The most frequent liver tumor in children is hepatoblastoma (HB), which derives from embryonic parenchymal liver cells or hepatoblasts. Hepatocellular carcinoma (HCC), which rarely affects young people, causes one fourth of deaths due to cancer in adults. In contrast, HB usually has better prognosis, but this is still poor in 20% of cases. Although more responsive to chemotherapy than HCC, the failure of pharmacological treatment used before and/or after surgical resection is an important limitation in the management of patients with HB. To advance in the implementation of personalized medicine it is important to select the best combination among available anti-HB drugs, such as platinum derivatives, anthracyclines, etoposide, tyrosine-kinase inhibitors, Vinca alkaloids, 5-fluorouracil, monoclonal antibodies, irinotecan and nitrogen mustards. This requires predicting the sensitivity to these drugs of each tumor at each time because, it should be kept in mind, that cancer chemoresistance is a dynamic process of Darwinian nature. For this goal it is necessary to improve our understanding of the mechanisms of chemoresistance involved in the refractoriness of HB against the pharmacological challenge and how they evolve during treatment. In this review we have summarized the current knowledge on the multifactorial and complex factors responsible for the lack of response of HB to chemotherapy.

Molecular Mechanism of Inhibition of Acid Ceramidase by Carmofur

Human acid ceramidase (AC) is a lysosomal cysteine amidase, which has received a great deal of interest in recent years as a potential target for the development of new therapeutics against melanoma and glioblastoma tumors. Despite the strong interest in obtaining structural information, only the structures of the apo-AC enzyme in its zymogen and activated conformations are available. In this work, the crystal structure of AC in complex with the covalent carmofur inhibitor is presented. Carmofur is an antineoplastic drug containing an electrophilic carbonyl reactive group that targets the catalytic cysteine. This novel structural data explains the basis of the AC inhibition, provides insights into the enzymatic properties of the protein, and is a great aid toward the structure-based drug design of potent inhibitors for AC, providing the detailed mechanism, which has eluded the scientific community for more than 30 years, of carmofur's mysterious 5-fluorouracil-independent antitumor activity.

Making way for suppressing the FGF19/FGFR4 axis in cancer

FGF19 is a noncanonical FGF ligand that can control a broad spectrum of physiological responses, which include bile acid homeostasis, liver metabolism and glucose uptake. Many of these responses are mediated by FGF19 binding to its FGFR4/β-klotho receptor complex and controlling activation of an array of intracellular signaling events. Overactivation of the FGF19/FGFR4 axis has been implicated in tumorigenic formation, progression and metastasis, and inhibitors of this axis have recently been developed for single agent use or in combination with other anticancer drugs. Considering the critical role of this receptor complex in cancer, this review focuses on recent developments and applications of FGF19/FGFR4-targeted therapeutics.

Bevacizumab-enhanced antitumor effect of 5-fluorouracil via upregulation of thymidine phosphorylase through vascular endothelial growth factor A/vascular endothelial growth factor receptor 2-specificity protein 1 pathway

Bevacizumab (Bv) can be used synergistically with fluoropyrimidine-based chemotherapy to treat colorectal cancer. Whether and how it affects the delivery of fluoropyrimidine drugs is unknown. The present study aimed to explore the effect of Bv on the delivery of 5-fluorouracil (5-FU) to tumors and the underlying mechanism from metabolic perspective. Bv enhanced the anti-tumor effects of 5-FU in LoVo colon cancer xenograft mice and increased the 5-FU concentration in tumors without affecting hepatic 5-FU metabolism. Interestingly, Bv remarkably upregulated thymidine phosphorylase (TP) in tumors, which mediated the metabolic activation of 5-FU. Although TP is reported to promote angiogenesis and resistance, the combination of Bv and 5-FU resulted in anti-angiogenesis and vessel normalization in tumors, indicating that the elevated TP mainly contributed to the enhanced response to 5-FU. Bv also induced TP upregulation in LoVo cancer cells. Treatment with vascular endothelial growth factor receptor 2 (VEGFR2) antagonist apatinib and VEGFR2 silencing further confirmed TP upregulation. Bv and apatinib both enhanced the cytotoxicity of 5-FU in LoVo cells, but there was no synergism with adriamycin and paclitaxel. We further demonstrated that the effect of Bv was dependent on VEGFR2 blockade and specificity protein 1 activation via MDM2 inhibition. In summary, Bv enhanced the accumulation of 5-FU in tumors and the cytotoxicity of 5-FU via TP upregulation. We provide data to better understand how Bv synergizes with 5-FU from metabolic perspective, and it may give clues to the superiority of Bv in combination with fluoropyrimidine drugs compared to other chemotherapeutic drugs in colon cancer.

A Novel PAA Derivative with Enhanced Drug Efficacy in Pancreatic Cancer Cell Lines

Nanoparticles have been shown to be effective drug carriers in cancer therapy. Pancreatic cancer forms dense tumours which are often resistant to drug molecules. In order to overcome such multidrug resistance, new drug entities, novel delivery systems and combination therapy strategies are being explored. In this paper, we report the design and synthesis of a poly(allylamine)-based amphiphile modified with hydrophobic naphthalimido pendant groups. Bisnaphthalimide compounds have been shown to possess anticancer activity. The potential of this polymer to encapsulate, solubilize and enhance drug (5-fluorouricil and bis-(naphthalimidopropyl)-diaminooctane) cytotoxicity in BxPC-3 cells was evaluated. Our studies showed that the insoluble drugs could be formulated up to 4.3 mg mL-1 and 2.4 mg mL-1 inside the amphiphiles, respectively. Additionally, the novel poly(allylamine)-naphthalimide carrier resulted in an amplification of cytotoxic effect with drug treatment after 24 h, and was capable of reduction of 50% cell population at concentrations as low as 3 μg mL-1.

Investigational agents to enhance the efficacy of chemotherapy or radiation in pancreatic cancer

Pancreatic cancer (PC) continues to be a fatal malignancy. With standard treatments having modest impact, alternative courses of actions are being investigated such as enhancing the efficacy of standard treatment through sensitization of PC cells to chemotherapy or radiation. This review emphasizes investigational agents that increase the responses to chemotherapy or radiation in PC models. Our group has extensively investigated on Curcumin (Cur), analogs (EF31, UBS109, and L49H37), nanoparticles and a small molecule Tolfenamic acid (TA) for enhancing therapeutic efficacy in both in vitro and in vivo assays. Cur has a low level of toxicity and promising anti-cancer activity, however, its clinical development has been limited by low bioavailability. Cur analogs and nanoparticles were synthesized to improve Cur's efficacy and bioavailability. These compounds were found to be effective in enhancing the therapeutic effects of chemotherapy in pre-clinical models. Small molecules such as NSAIDs have also been tested for the anti-cancer activity and induction of response of chemotherapy and radiation. Interest in TA, a NSAID, has recently increased due to promising preclinical data demonstrating its anti-cancer properties with minimum toxicity. TA also synergistically increased the response of XRT in PC cells and in an orthotropic mouse model. With strong preclinical evidence, research aimed at developing less toxic therapies for PC using Cur analogues or TA is ready for translation into clinical testing.