The polymeric fluoropyrimidine CF10 overcomes limitations of 5-FU in pancreatic ductal adenocarcinoma cells through increased replication stress.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease soon to become the second leading cause of cancer deaths in the US. Beside surgery, current therapies have narrow clinical benefits with systemic toxicities. FOLFIRINOX is the current standard of care, one component of which is 5- Fluorouracil (5-FU), which causes serious gastrointestinal and hematopoietic toxicities and is vulnerable to resistance mechanisms.

Review of Prodrug and Nanodelivery Strategies to Improve the Treatment of Colorectal Cancer with Fluoropyrimidine Drugs.

Fluoropyrimidine (FP) drugs are central components of combination chemotherapy regimens for the treatment of colorectal cancer (CRC). FP-based chemotherapy has improved survival outcomes over the last several decades with much of the therapeutic benefit derived from the optimization of dose and delivery. To provide further advances in therapeutic efficacy, next-generation prodrugs and nanodelivery systems for FPs are being developed.

Enhanced Therapeutic Efficacy of the Nanoscale Fluoropyrimidine Polymer CF10 in a Rat Colorectal Cancer Liver Metastasis Model.

Combination chemotherapy regimens that include fluoropyrimidine (FP) drugs, e.g., 5-fluorouracil (5-FU), are central to the treatment of colorectal cancer liver metastases (CRLMs), a major cause of cancer mortality.

Review of 5-FU resistance mechanisms in colorectal cancer: clinical significance of attenuated on-target effects.

The emergence of chemoresistant disease during chemotherapy with 5-Fluorouracil-based (5-FU-based) regimens is an important factor in the mortality of metastatic CRC (mCRC). The causes of 5-FU resistance are multi-factorial, and besides DNA mismatch repair deficiency (MMR-D), there are no widely accepted criteria for determining which CRC patients are not likely to be responsive to 5-FU-based therapy. Thus, there is a need to systematically understand the mechanistic basis for 5-FU treatment failure and an urgent need to develop new approaches for circumventing the major causes of 5-FU resistance.

A narrative review of genetic factors affecting fluoropyrimidine toxicity.

Objective: Our objective is to document progress in developing personalized therapy with fluoropyrimidine drugs (FPs) to improve outcomes for cancer patients and to identify areas requiring further investigation.

Background: FPs including 5-fluorouracil (5-FU), are among the most widely used drugs for treating colorectal cancer (CRC) and other gastrointestinal (GI) malignancies. While FPs confer a survival benefit for CRC patients, serious systemic toxicities, including neutropenia, occur in ~30% of patients with lethality in 0.

Recent Advances in Our Knowledge of mCRC Tumor Biology and Genetics: A Focus on Targeted Therapy Development.

Metastatic colorectal cancer (mCRC) remains a highly lethal malignancy although considerable progress has resulted from characterizing molecular alterations such as mutation status and extent of microsatellite instability (MSI) to guide optimal use of available therapies. The availability of gene expression profiling, next generation sequencing technologies, proteomics analysis and other technologies provides high resolution information on individual tumors, including metastatic lesions to better define intra-tumor and inter-tumor heterogeneity. Recent literature applying this information to further customize personalized therapies is reviewed.

AraC-FdUMP[10] Is a Next-Generation Fluoropyrimidine with Potent Antitumor Activity in PDAC and Synergy with Inhibition.

AraC-FdUMP[10] (CF10) is a second-generation polymeric fluoropyrimidine that targets both thymidylate synthase (TS), the target of 5-fluorouracil (5-FU), and DNA topoisomerase 1 (Top1), the target of irinotecan, two drugs that are key components of FOLFIRNOX, a standard-of-care regimen for pancreatic ductal adenocarcinoma (PDAC). We demonstrated that F10 and CF10 are potent inhibitors of PDAC cell survival (in multiple cell lines including patient-derived lines) with ICs in the nanomolar range and are nearly 1,000-fold more potent than 5-FU. The increased potency of CF10 relative to 5-FU correlated with enhanced TS inhibition and strong Top1 cleavage complex formation.

Improved Antitumor Activity of the Fluoropyrimidine Polymer CF10 in Preclinical Colorectal Cancer Models through Distinct Mechanistic and Pharmacologic Properties.

Chemotherapy regimens that include 5-fluorouracil (5-FU) are central to colorectal cancer treatment; however, risk/benefit concerns limit 5-FU's use, necessitating development of improved fluoropyrimidine (FP) drugs. In our study, we evaluated a second-generation nanoscale FP polymer, CF10, for improved antitumor activity. CF10 was more potent than the prototype FP polymer F10 and much more potent than 5-FU in multiple colorectal cancer cell lines including HCT-116, LS174T, SW480, and T84D.

Hairpin Oligonucleotide Can Functionalize Gold Nanorods for Application Delivering Cytotoxic Nucleotides and Curcumin: A Comprehensive Study in Combination with Near-Infrared Laser.

We prepared a multimodality nanocomplex by functionalizing gold nanorods (GNRs) with a cytotoxic nucleoside, 5-fluoro-2'-deoxyuridine (FdU) containing a DNA hairpin, along with complexation of pleiotropic molecule curcumin. Conjugates were investigated for anti-tumor activity using an Ehrlich carcinoma model in combination with 808 nm laser irradiation. We demonstrated that hairpin-functionalized GNRs are suitable for intravenous administration, including delivery of cytotoxic nucleotides and curcumin.

Chemistry of Fluorinated Pyrimidines in the Era of Personalized Medicine.

We review developments in fluorine chemistry contributing to the more precise use of fluorinated pyrimidines (FPs) to treat cancer. 5-Fluorouracil (5-FU) is the most widely used FP and is used to treat > 2 million cancer patients each year. We review methods for 5-FU synthesis, including the incorporation of radioactive and stable isotopes to study 5-FU metabolism and biodistribution.

Fluoropyrimidine Modulation of the Anti-Tumor Immune Response-Prospects for Improved Colorectal Cancer Treatment.

Chemotherapy modulates the anti-tumor immune response and outcomes depend on the balance of favorable and unfavorable effects of drugs on anti-tumor immunity. 5-Florouracil (5-FU) is widely used in adjuvant chemotherapy regimens to treat colorectal cancer (CRC) and provides a survival benefit. However, survival remains poor for CRC patients with advanced and metastatic disease and immune checkpoint blockade therapy benefits only a sub-set of CRC patients.

Dysregulated Pyrimidine Biosynthesis Contributes to 5-FU Resistance in SCLC Patient-Derived Organoids but Response to a Novel Polymeric Fluoropyrimidine, CF10.

Chemo-immunotherapy is central to the treatment of small cell lung cancer (SCLC). Despite modest progress made with the addition of immunotherapy, current cytotoxic regimens display minimal survival benefit and new treatments are needed. Thymidylate synthase (TS) is a well-validated anti-cancer drug target, but conventional TS inhibitors display limited clinical efficacy in refractory or recurrent SCLC.

Entrapment of DNA topoisomerase-DNA complexes by nucleotide/nucleoside analogs.

Topoisomerases are well-validated targets for cancer chemotherapy and DNA topoisomerase 1 (Top1) is the sole target of the camptothecin (CPT) class of anticancer drugs. Over the last 20 years, multiple studies have shown Top1 activity is modulated by non-native DNA structures and this can lead to trapping of Top1 cleavage complexes (Top1cc) and conversion to DNA double strand breaks. Among the perturbations to DNA structure that generate Top1cc are nucleoside analogs that are incorporated into genomic DNA during replication including cytarabine, gemcitabine, and 5-fluoro-2'-deoxyuridine (FdU).

Prexasertib treatment induces homologous recombination deficiency and synergizes with olaparib in triple-negative breast cancer cells.

Background: Breast cancer remains as one of the most lethal types of cancer in women. Among various subtypes, triple-negative breast cancer (TNBC) is the most aggressive and hard to treat type of breast cancer. Mechanistically, increased DNA repair and cell cycle checkpoint activation remain as the foremost reasons behind TNBC tumor resistance to chemotherapy and disease recurrence.

Development of a Colorectal Cancer 3D Micro-tumor Construct Platform From Cell Lines and Patient Tumor Biospecimens for Standard-of-Care and Experimental Drug Screening.

Colorectal cancer is subject to a high rate of mutations, with late stage tumors often containing many mutations. These tumors are difficult to treat, and even with the recently implemented methods of personalized medicine at modern hospitals aiming to narrow treatments, a gap still exists. Proper modeling of these tumors may help to recommend optimal treatments for individual patients, preferably utilizing a model that maintains proper signaling in respect to the derived parent tissue.

Improved potency of F10 relative to 5-fluorouracil in colorectal cancer cells with p53 mutations.

Aim: Resistance to fluoropyrimidine drugs (FPs) is a major cause of mortality in colorectal cancer (CRC). We assessed the potency advantage of the polymeric FP F10 relative to 5-fluorouracil (5FU) in four human CRC cell lines that differ only in mutational status to determine how p53 mutations affect drug response and whether F10 is likely to improve outcomes.

Methods: HCT-116 human CRC cells (p53) and three isogenic variants (p53, R248W/+, R248W/-) were assessed for drug response.

Thymineless Death by the Fluoropyrimidine Polymer F10 Involves Replication Fork Collapse and Is Enhanced by Chk1 Inhibition.

We are developing the fluoropyrimidine polymer F10 to overcome limitations of 5-fluorouracil (5-FU) that result from inefficient metabolism to 5-fluoro-2'-deoxyuridine-5'-mono- and tri-phosphate, the deoxyribonucleotide metabolites that are responsible for 5-FU's anticancer activity. F10 is much more cytotoxic than 5-FU to colorectal cancer (CRC) cells; however, the mechanism of enhanced F10 cytotoxicity remains incompletely characterized. Using DNA fiber analysis, we establish that F10 decreases replication fork velocity and causes replication fork collapse, while 1000-fold excess of 5-FU is required to achieve similar endpoints.

Secondary Structure-Dependent Physicochemical Interaction of Oligonucleotides with Gold Nanorod and Photothermal Effect for Future Applications: A New Insight.

We investigate the physicochemical interactions of gold nanorod (GNR) with single-stranded, double-stranded, and hairpin DNA structures to improve the biological compatibility as well as the therapeutic potential, including the photothermal effect of the conjugates. Studies have demonstrated that different DNA secondary structures, containing thiol group, have different patterns of physicochemical interaction. Conjugation efficiency of paired oligonucleotides are significantly higher than that of oligonucleotides with naked bases.

Practical Guidelines for Cerenkov Luminescence Imaging with Clinically Relevant Isotopes.

Cerenkov luminescence imaging (CLI) is a relatively new imaging modality that utilizes conventional optical imaging instrumentation to detect Cerenkov radiation derived from standard and often clinically approved radiotracers. Its research versatility, low cost, and ease of use have increased its popularity within the molecular imaging community and at institutions that are interested in conducting radiotracer-based molecular imaging research, but that lack the necessary resources and infrastructure. Here, we provide a description of the materials and procedures necessary to conduct a Cerenkov luminescence imaging experiment using a variety of imaging instrumentation, radionuclides, and animal models.

Curcumin stably interacts with DNA hairpin through minor groove binding and demonstrates enhanced cytotoxicity in combination with FdU nucleotides.

We report, based on biophysical studies and molecular mechanical calculations that curcumin binds DNA hairpin in the minor groove adjacent to the loop region forming a stable complex. UV-Vis and fluorescence spectroscopy indicated interaction of curcumin with DNA hairpin. In this novel binding motif, two ɣ H of curcumin heptadiene chain are closely positioned to the A-H8 and A-H8, while G-H8 is located in the close proximity of curcumin α H.

All-atom molecular dynamics comparison of disease-associated zinc fingers.

An important regulatory domain of NF-[Formula: see text]B Essential Modulator (NEMO) is a ubiquitin-binding zinc finger, with a tetrahedral CYS3HIS1 zinc-coordinating binding site. Two variations of NEMO's zinc finger are implicated in various disease states including ectodermal dysplasia and adult-onset glaucoma. To discern structural and dynamical differences between these disease states, we present results of 48-[Formula: see text]s of molecular dynamics simulations for three zinc finger systems each in two states, with and without zinc-bound and correspondingly appropriate cysteine thiol/thiolate configurations.

All-atom MD indicates ion-dependent behavior of therapeutic DNA polymer.

Understanding the efficacy of and creating delivery mechanisms for therapeutic nucleic acids requires understanding structural and kinetic properties which allow these polymers to promote the death of cancerous cells. One molecule of interest is a 10 mer of FdUMP (5-fluoro-2'-deoxyuridine-5'-O-monophosphate) - also called F10. Here we investigate the structural and kinetic behavior of F10 in intracellular and extracellular solvent conditions along with non-biological conditions that may be efficacious in in vitro preparations of F10 delivery systems.

All-Atom MD Predicts Magnesium-Induced Hairpin in Chemically Perturbed RNA Analog of F10 Therapeutic.

Given their increasingly frequent usage, understanding the chemical and structural properties which allow therapeutic nucleic acids to promote the death of cancer cells is critical for medical advancement. One molecule of interest is a 10-mer of FdUMP (5-fluoro-2'-deoxyuridine-5'-O-monophosphate) also called F10. To investigate causes of structural stability, we have computationally restored the 2' oxygen on each ribose sugar of the phosphodiester backbone, creating FUMP[10].