Search results for "uracil"

On the N1-H and N3-H Bond Dissociation in Uracil by Low Energy Electrons: A CASSCF/CASPT2 Study.

2015

The dissociative electron-attachment (DEA) phenomena at the N1-H and N3-H bonds observed experimentally at low energies (<3 eV) in uracil are studied with the CASSCF/CASPT2 methodology. Two valence-bound π(-) and two dissociative σ(-) states of the uracil anionic species, together with the ground state of the neutral molecule, are proven to contribute to the shapes appearing in the experimental DEA cross sections. Conical intersections (CI) between the π(-) and σ(-) are established as the structures which activate the DEA processes. The N1-H and N3-H DEA mechanisms in uracil are described, and experimental observations are interpreted on the basis of two factors: (1) the relative energy of …

Therapeutic drug monitoring as a tool to optimize 5-FU-based chemotherapy in gastrointestinal cancer patients older than 75 years.

2019

Abstract Aims Most clinical trials exclude elderly people, leading to a limited understanding of the benefit-to-risk ratio in this population. Despite existing data regarding the oncological management of elderly receiving fluorouracil (5-FU)-based regimen, our objective was to investigate 5-FU exposure/toxicity relationship in patients ≥75 years and compare the effectiveness of 5-FU therapeutic drug monitoring between elderly and younger patients. Methods Hundred fifty-four patients (31 of whom are older than 75 years) with gastrointestinal cancers, who were to receive 5-FU–based regimens, were included in our study. At cycle 1 (C1), the 5-FU dose was calculated using patient's body surfac…

Introduction of WT-TP53 into pancreatic cancer cells alters sensitivity to chemotherapeutic drugs, targeted therapeutics and nutraceuticals

2018

Abstract Pancreatic ductal adenocarcinoma (PDAC) is an aggressive, highly metastatic malignancy and accounts for 85% of pancreatic cancers. PDAC patients have poor prognosis with a five-year survival of only 5–10%. Mutations at the TP53 gene are readily detected in pancreatic tumors isolated from PDAC patients. We have investigated the effects of restoration of wild-type (WT) TP53 activity on the sensitivity of pancreatic cancer cells to: chemotherapy, targeted therapy, as well as, nutraceuticals. Upon introduction of the WT-TP53 gene into the MIA-PaCa-2 pancreatic cancer cell line, the sensitivity to drugs used to treat pancreatic cancer cells such as: gemcitabine, fluorouracil (5FU), cisp…

A common SNP in the UNG gene decreases ovarian cancer risk in BRCA2 mutation carriers

2018

Single nucleotide polymorphisms (SNPs) in DNA glycosylase genes involved in the base excision repair (BER) pathway can modify breast and ovarian cancer risk in BRCA1 and BRCA2 mutation carriers. We previously found that SNP rs34259 in the uracil-DNA glycosylase gene (UNG) might decrease ovarian cancer risk in BRCA2 mutation carriers. In the present study, we validated this finding in a larger series of familial breast and ovarian cancer patients to gain insights into how this UNG variant exerts its protective effect. We found that rs34259 is associated with significant UNG downregulation and with lower levels of DNA damage at telomeres. In addition, we found that this SNP is associated with…

Physiological concentrations of phytosterols enhance the apoptotic effects of 5-fluorouracil in colon cancer cells

2018

Abstract Combining natural products as co-adjuvants in 5-fluorouracil (5-FU) chemotherapy might enhance the effectiveness of 5-FU by avoiding a high dosage and/or reducing treatment times. We explored the anticancer efficacy of the phytosterols (PS) at concentrations achievable in the human colon, as well as their potential as sensitizing agents of human colon cancer cells (Caco-2 and HT-29) to 5-FU treatment. Cells proliferation, combination index, cell cycle, apoptosis, caspases activation, ROS production, and ΔΨm were determined. Co-treatment (PS+5-FU) had an antiproliferative additive effect, and moreover, in general a significantly improved efficacy was observed on cell cycle arrest at…

Cisplatin/5-fluorouracil +/- panitumumab for patients with non-resectable, advanced or metastatic esophageal squamous cell cancer : A randomized phas…

2018

Phase II study of necitumumab plus modified FOLFOX6 as first-line treatment in patients with locally advanced or metastatic colorectal cancer

2016

Background:This single-arm phase II study investigated the EGFR monoclonal antibody necitumumab plus modified FOLFOX6 (mFOLFOX6) in first-line treatment of locally advanced or metastatic colorectal cancer (mCRC).Methods:Patients received 800-mg intravenous necitumumab (day 1; 2-week cycles), followed by oxaliplatin 85 mg m -2, folinic acid 400 mg m -2, and 5-fluorouracil (400 mg m -2 bolus then 2400 mg m -2 over 46 h). Radiographic evaluation was performed every 8 weeks until progression. Primary endpoint was objective response rate.Results:Forty-four patients were enrolled and treated. Objective response rate was 63.6% (95% confidence interval 47.8-77.6); complete response was observed in …

Predictive and prognostic value of magnesium serum level in FOLFIRI plus cetuximab or bevacizumab treated patients with stage IV colorectal cancer: r…

2020

Magnesium wasting is a frequent side effect of epidermal growth factor receptor (EGFR)-antibody treatment as magnesium-absorption mechanisms are dependent on EGFR signaling. EGFR-inhibition results in decreased renal reabsorption. There is evidence that hypomagnesemia during cetuximab treatment correlates with response. The prognostic role of hypomagnesemia during bevacizumab treatment has not been studied yet. Here, we evaluate the prognostic value of hypomagnesemia in patients with metastatic colorectal cancer treated with FOLFIRI plus cetuximab or bevacizumab as first-line therapy. A total of 391 of 752 patients of the firstline irinotecan study population had magnesium levels measured a…

Impact of BRAF and RAS mutations on first-line efficacy of FOLFIRI plus cetuximab versus FOLFIRI plus bevacizumab: analysis of the FIRE-3 (AIO KRK-03…

2017

Abstract Background RAS and BRAF mutations have been identified as negative prognostic factors in metastatic colorectal cancer. Efficacy of 5-fluorouracil, leucovorin, irinotecan (FOLFIRI) plus bevacizumab in patients with RAS-mutant tumours needs to be further evaluated. Whether to treat patients with BRAF-mutant tumours with either bevacizumab or anti-epidermal growth factor receptor (EGFR) antibodies remains unclear. Methods Patients treated within the FIRE-3 trial were retrospectively tested for BRAF and RAS mutations using formalin fixated paraffin embedded (FFPE) tumour material applying pyrosequencing for KRAS and NRAS exon 2, 3 and 4 mutations as far as for BRAF mutations. Survival …

Cetuximab, fluorouracil and cisplatin with or without docetaxel for patients with recurrent and/or metastatic squamous cell carcinoma of the head and…

2019

Abstract Background The combination of cisplatin, 5-fluorouracil (5-FU) and cetuximab (PFC) is the reference first-line treatment for recurrent/metastatic (R/M) squamous cell carcinoma of the head and neck (SCCHN). We analysed whether treatment intensification by the addition of docetaxel to PFC improved efficacy in R/M SCCHN. Methods A total of 180 patients with R/M SCCHN (1:1) were assigned to receive either cisplatin (40 mg/m2), docetaxel (40 mg/m2) and 5-FU (2000 mg/m2) at days 1 and 8 and cetuximab (400/250 mg/m2) at days 1, 8 and 15 (DPFC) or standard cisplatin (100 mg/m2) at day 1, 5-FU (1000 mg/m2) at days 1–4 and cetuximab (400/250 mg/m2) at days 1, 8 and 15 (PFC). Chemotherapy was…