Role of microRNAs in fluoropyrimidine-related toxicity: what we know.

Although more than half a century has passed since the discovery of fluoropyrimidines, they are still used in the treatment of many types of cancer, and it is estimated that annually two million patients undergo fluoropyrimidine-based chemotherapy. The toxicity resulting from the use of fluoropyrimidines affects about 30-40% of patients, which in some cases may prove to be lethal. The key player in fluoropyrimidine toxicity is DPD activity, and patients with deficits are more likely to develop significant adverse events. In addition to genotyping DPYD variants associated with DPD deficiency, overexpression of miR-27 has also been shown to be a predictive factor for fluoropyrimidine toxicity. This review aims to relate what we know so far about the involvement of miRNA in fluoropyrimidine toxicity and to open new perspectives in this field.

The clinical implications of platelet derived growth factor B, vascular endothelial growth factor and basic fibroblast growth factor in colorectal cancer.

Colorectal cancer (CRC) remains a major health problem worldwide. Angiogenesis is a key process for tumor growth and metastasis. The conversion of tumor cells to an angiogenic phenotype involves the change in the balance of angiogenic growth factors and angiogenesis inhibitors. In our study we evaluated by qRT-PCR the level of expression of 3 growth factors involved in angiogenesis: platelet derived growth factor-B (PDGFb), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) in patients with different stages of colon cancer. Our results showed the level of VEGF increased on all tumor without difference, statistically significant according with tumor stage whereas the others the levels of bFGF and PDGF were higher, statistically significant, on tumor classified stage B compared with stage C. The early implication of these molecules in colon carcinogenesis justifies the development of new biologic individualized therapies.

Oxaliplatin in patients with metastatic colorectal cancer: efficacy and pharmacokinetics parameters.

PURPOSE: The aim of this study was to investigate the efficiency of the FOLFOX-4 regimen and to evaluate the pharmacokinetics of oxaliplatin in untreated patients with metastatic colorectal cancer. METHODS: 43 patients were enrolled in the study. Patients received oxaliplatin 85 mg/m(2) as 2-h i.v. infusion, on day 1, and bolus 5-fluorouracil (5FU) 400 mg/m(2) plus leucovorin (LV) 200 mg/m(2) followed by 5FU 600 mg/m(2) as 22-h infusion on day 1 and 2, every 2 weeks. The pharmacokinetics of oxaliplatin evaluated in 4 patients was performed in blood, plasma and ultrafiltered plasma (UFT) by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). RESULTS: The overall response rate and the median time to progression (TTP) were 53.49% and 7.1 months, respectively. Grade 3-4 toxic effects were observed in 11 (25.5%) patients. Grade 3 neuropathy was observed in 13.95% of the cases. In univariate analysis only Eastern Cooperative Oncology Group (ECOG) performance status (PS) was correlated with response. No correlation was found between grade 3-4 adverse events and the patient characteristics. The area under the time-concentration curve (AUC) in UFT was 4.8 + or - 0.72 standard deviation (SD) microg h/ml and the total clearance 30.17 + or - 7.75 l/min. The values for volume of distribution and the maximum concentration were 567 + or - 20 liters and 0.38 + or - 0.17 ug/ml, respectively. CONCLUSION: FOLFOX-4 was an effective regimen with good tolerability in previously untreated metastatic colorectal cancer patients. The pharmacokinetics of oxaliplatin was triphasic with a short initial distribution phase and a long terminal elimination phase.

p53 gene therapy using RNA interference.

p53 gene, discovered almost 35 years ago, keeps the main role in cell cycle control, apoptosis pathways and transcription. p53 gene is found mutated in more than 50% of all human cancers in different locations. Many structures from viral to non viral were designed to incorporate and deliver in appropriate conditions forms of p53 gene or its transcripts, systemically to target tumor cells and to eliminate them through apoptosis or to restore the normal tumor suppressor gene role. Each delivery system presents advantages and low performance in relation to immune system recognition and acceptance. One of the major discoveries in the last years, silencing of RNA, represents a powerful tool for inhibiting post transcriptional control of gene expression. According to several studies, the RNA silencing technology for p53 transcripts together with other carriers or transporters at nano level can be used for creating new therapeutic models. RNA interference for p53 uses different double-stranded (ds) molecules like short interfering (si) RNA and, despite the difficulty of introducing them into mammalian cells due to immune system response, it can be exploited in cancer therapy.