Effects of endogenous nitric oxide induced by 5-fluorouracil and L-Arg on liver carcinoma in nude mice

5-Fluorouracil, capecitabine and vasospasm: a scoping review of pathogenesis, management options and future research considerations

BACKGROUND

5-Fluorouracil (5-FU) is a widely used chemotherapeutic agent that can cause cardiotoxicity manifesting, among others, as chest pain. Capecitabine is an oral prodrug of 5-FU, with reported preferential activation in malignant cells that may also cause cardiotoxic reactions. Standard treatment of 5-FU and capecitabine induced chest pain with vasodilators is mostly effective, but there are several cases of patients unresponsive to these agents.

METHODS

We performed a PubMed search on 31st May 2020. We used a three keyword search strategy using Boolean search operators. More specifically, we included fluorouracil or 5-FU or capecitabine and chest pain or angina and mechanism or treatment or management. We included primary reports of clinical and non-clinical data, as well as systematic reviews. Narrative reviews, expert opinions, letters to the editor and other forms of non-primary literature were excluded.

RESULTS

Our search yielded a total of 1595 reports. Of these, 1460 were narrative reviews or irrelevant to the topic and were excluded. A total of 135 reports were used for our review. We used 81 reports for data extraction, which included 13 clinical trials, 4 retrospective reports, 61 case reports, and 3 systematic reviews.

CONCLUSION

We report the incidence and predisposing factors, the value of available diagnostic procedures, and standard medical and invasive treatments. We also speculate on the potential benefit of arginine as a promising option both in prevention as well as treatment of 5-FU-induced chest pain. Finally, gaps of evidence are identified and proposals are made in terms of future research.

Gliclazide Prevents 5-FU-Induced Oral Mucositis by Reducing Oxidative Stress, Inflammation, and P-Selectin Adhesion Molecules

Oral mucositis (OM) is one of the main side effects of the head and neck cancer treatment, particularly radiotherapy and/or chemotherapy. OM is characterized by ulcers, erythema, dysphagia, xerostomia, and increased susceptibility to opportunistic infections. In the perspective of finding pharmacological therapies to prevent inflammation and ulceration of OM, the investigation of the pleiotropic effect of commercial drugs is needed, among them gliclazide, an antidiabetic drug. This study aimed to evaluate the effect of gliclazide in an experimental OM model induced by 5-fluorouracil. Male hamsters were pre-treated with oral gliclazide (1, 5, or 10 mg/kg) for 10 days. Cheek pouch samples were subjected to histopathological and immunohistochemical analysis (COX₂, iNOS, MMP-2, NFκB P65, GPx) and imunofluorescence (P-selectin). IL-1β and TNF-α levels, Myeloperoxidase activity (MPO) and malondialdehyde (MDA) levels were investigated by ultraviolet-visible spectroscopy analysis. NFκB NLS P50 protein levels were analyzed by western blotting. The group treated with gliclazide at a dose of 10 mg/kg showed presence of erythema, no evidence of erosion, and absence of mucosal ulceration with a score of 1 (1–2) (p < 0.01). Histopathological data for the group treated with gliclazide 10 mg/kg showed re-epithelialization, discrete mononuclear inflammatory infiltrate and absence of hemorrhage, edema, ulcers and abscesses with a score of 1 (1–1) (p < 0.01). Treatment with gliclazide 10 mg/kg reduced MPO activity (p < 0.001), MDA levels (p < 0.001) and NFκB NLS P50 (p < 0.05) protein levels, resulting in low immunostaining to Cox-2, iNOS (p < 0.05), NFκB P65 (p < 0.05), and negative immunoreaction to MMP-2 (p < 0.001). However, it appeared that for Gpx1, the staining was restored in the GLI 10-FUT group compared with 5FUT/saline (p < 0.05). Immunofluorescence revealed decreased levels of P-selectin (p < 0.001) after treatment with gliclazide 10 mg/kg (p < 0.05). In summary, gliclazide accelerated mucosal recovery and reduced oxidative stress and inflammation in the 5-FU-induced OM in hamsters.

Dynamin 3 suppresses growth and induces apoptosis of hepatocellular carcinoma cells by activating inducible nitric oxide synthase production

Dynamin 3 (DNM3) is candidate tumor suppressor against hepatocellular carcinoma (HCC). Downregulation of DNM3 is more frequently identified in HCC tissues than in normal liver tissues. However, the mechanism underlying DNM3-mediated inhibition of HCC remains unclear. The present study demonstrated that DNM3 expression was decreased in human HCC tissues and cell lines. The downregulation of DNM3 promoted cell proliferation by increasing cell cycle-associated proteins, including cyclin D1, cyclin-dependent kinase (CDK) 2 and CDK4. The upregulation of DNM3 induced HCC cell apoptosis and inhibited tumor growth. The present study also revealed that overexpression of DNM3 induced nitric oxide (NO) production and intracellular reactive oxygen species (ROS) accumulation. DNM3 overexpression also increased the protein expression level of inducible nitric oxide synthase (iNOS) in HCC cells and subcutaneous HCC tumor xenografts. The inhibition of iNOS by L-canavanine attenuated the DNM3-induced ROS accumulation and apoptotic cell death. In conclusion, the results indicate that DNM3 overexpression may induce apoptosis and inhibit tumor growth of HCC by activating iNOS production and the subsequent NO-ROS signaling pathways.

Elevated nitric oxide levels associated with hepatic cell apoptosis during liver injury

Hepatic injury is a major event in liver surgery such as liver transplantation and it always leads to hepatic cell apoptosis. Nitric oxide (NO) is a key signaling regulation molecule. Many researchers have shown that increased NO level can influence liver cell apoptosis by promoting or inhibiting the relative signaling pathways that are involved in the caspase family, Bax/Bcl-2, mitochondria, oxidative stress, death receptors, and mitogen-activated protein kinases. Elucidating the relationships between NO and hepatic cell apoptosis is necessary for ameliorating prognosis of liver surgery. This article reviews the newest research progress in the relationships between higher NO levels and hepatic cell apoptosis in liver injury.

5-Fluorouracil: mechanisms of resistance and reversal strategies

The purpose of this work is to review the published studies on the mechanisms of action and resistance of 5-fluorouracil. The review is divided into three main sections: mechanisms of anti-tumor action, studies of the resistance to the drug, and procedures for the identification of new genes involved in resistance with microarray techniques. The details of the induction and reversal of the drug resistance are also described.