Cecilia Guastadisegni

Microsatellite instability as a marker of prognosis and response to therapy: A meta-analysis of colorectal cancer survival data

BACKGROUND AND METHODS We have reviewed and pooled data from published studies to evaluate the relationship between microsatellite instability (MSI) and colorectal cancer (CRC) prognosis. Thirty-one eligible studies reporting survival in 12782 patients characterised for MSI were pooled using a fixed- or random-effects model. RESULTS The summary odds ratio (OR) estimate for overall survival (OS) associated with MSI was 0.6 (95%CI 0.53-0.69, p<0.0001), with no evidence of heterogeneity. The effect was similar for disease-free survival (DFS) (OR=0.58, 95%CI 0.47-0.72, p<0.0001). In a subset of patients treated with 5-fluorouracil (5-FU)-based chemotherapy a significant improved prognosis was found for microsatellite stable (MSS) tumours (OR=0.52, 95%CI 0.4-0.6, p<0.0001) with no heterogeneity (p=0.53; I(2)=0%). By contrast a large heterogeneity characterised the data relative to 396 patients with MSI tumours (OR=0.69, 95%CI 0.3-1.5, p=0.1; heterogeneity: p=0.03; I(2)=58%). CONCLUSIONS This study confirmed the association between MSI and favourable prognosis as determined by both OS and DFS of CRC patients. A significant beneficial effect of 5-FU therapy was found for MSS tumours whilst no clear conclusion was reached for MSI tumours due to the high inter-study heterogeneity. We propose that this inconclusive result is due to the use of a single marker, such as MSI, that cannot account alone for the complexity of the mechanisms underlying 5-FU cytotoxicity. Future studies to predict response to 5-FU chemotherapy should include additional genome stability markers.

Inflammatory mediators induced by coarse (PM2.5-10) and fine (PM2.5) urban air particles in RAW 264.7 cells

Increased incidence of mortality and morbidity due to cardiopulmonary complications has been found to associate with elevated levels of urban air particles with an aerodynamic diameter <10 micron, PM10 and <2.5 micron, PM2.5. Respirable particles reach the lower respiratory tract where they are phagocytized by alveolar macrophages. Depending on particle composition, exposed macrophages may produce inflammatory mediators. A cascade impactor sampler was used to collect size-fractionated urban air particles. Particulate matter from the city of Rome (Italy) were collected onto stainless steel plates, and recovered using alcohol. The murine monocytic/macrophagic RAW 264.7 cell line was used to compare the ability of PM2.5-10, PM2.5 and carbon black to cause cell injury, such as arachidonic acid (AA) release, tumour necrosis factor alpha (TNF alpha) and interleukin (IL)-6 production. All test particles have been used at the same concentrations 30 and 120 microg/ml. Treatment with PM2.5-10 and PM2.5 induced significant AA release after 5 h of exposure at both concentrations, while carbon black was effective only at the higher concentration. After 5 h of incubation, PM2.5-10 and PM2.5 at 120 microg/ml induced 10 times the amount of TNF alpha than carbon black particles. The urban air particles-stimulated TNF alpha production decreased after 24 h of incubation while carbon black-stimulated TNF alpha was not. IL-6 production was induced by PM2.5 and by PM2.5-10 but not by carbon black. Carbon black was consistently less effective than the urban particles, suggesting that, the contaminants adsorbed on the particles are responsible for the release of inflammatory mediators.

Toxicity of Coarse and Fine Particulate Matter from Sites with Contrasting Traffic Profiles

Residence in urban areas with much traffic has been associated with various negative health effects. However, the contribution of traffic emissions to these adverse health effects has not been fully determined. Therefore, the objective of this in vivo study is to compare the pulmonary and systemic responses of rats exposed to particulate matter (PM) obtained from various locations with contrasting traffic profiles. Samples of coarse (2.5 μm–10 μm) and fine (0.1 μm–2.5 μm) PM were simultaneously collected at nine sites across Europe with a high-volume cascade impactor. Six PM samples from various locations were selected on the basis of contrast in in vitro analysis, chemical composition, and traffic profiles. We exposed spontaneously hypertensive (SH) rats to a single dose (3 mg PM/kg body weight or 10 mg PM/kg body weight) of either coarse or fine PM by intratracheal instillation. We assessed changes in biochemical markers, cell differentials, and histopathological changes in the lungs and blood 24 h postexposure. The dose-related adverse effects that both coarse and fine PM induced in the lungs and vascular system were mainly related to cytotoxicity, inflammation, and blood viscosity. We observed clear differences in the extent of these responses to PM from the various locations at equivalent dose levels. There was a trend that suggests that samples from high-traffic sites were the most toxic. It is likely that the toxicological responses of SH rats were associated with specific PM components derived from brake wear (copper and barium), tire wear (zinc), and wood smoke (potassium).

Prostaglandin E2 synthesis is differentially affected by reactive nitrogen intermediates in cultured rat microglia and RAW 264.7 cells

We studied the effects of nitric oxide (NO) on prostanoid production, cyclooxygenase (COX‐2) expression and [3H]arachidonic acid (AA) release in RAW 264.7 macrophagic cells and rat microglial primary cultures. Inhibition of NO synthesis enhanced microglial prostanoid production without affecting that of RAW 264.7 cells. Both 3‐morpholinosydnonimine (SIN‐1), (which, by releasing NO and superoxide, leads to the formation of peroxynitrite), and S‐nitroso‐N‐acetylpenicillamine (SNAP), (which releases only NO), inhibited microglial prostanoid production, by preventing COX‐2 expression. In contrast, in RAW 264.7 cells, SIN‐1 enhanced both basal and LPS‐stimulated prostanoid production by upregulating COX‐2, while SNAP stimulated basal production and slightly inhibited the LPS‐induced production, as a cumulative result of enhanced AA release and depressed COX‐2 expression. Thus, reactive nitrogen intermediates can influence prostanoid production at distinct levels and in different way in the two cell types, and results obtained with RAW 264.7 cells can not be extrapolated to microglia.

Determinants of the proinflammatory action of ambient particulate matter in immortalized murine macrophages

Background Proximity to traffic-related pollution has been associated with poor respiratory health in adults and children. Objectives We wished to test the hypothesis that particulate matter (PM) from high-traffic sites would display an enhanced capacity to elicit inflammation. Methods We examined the inflammatory potential of coarse [2.5–10 μm in aerodynamic diameter (PM2.5–10)] and fine [0.1–2.5 μm in aerodynamic diameter (PM0.1–2.5)] PM collected from nine sites throughout Europe with contrasting traffic contributions. We incubated murine monocytic-macrophagic RAW264.7 cells with PM samples from these sites (20 or 60 μg/cm2) and quantified their capacity to stimulate the release of arachidonic acid (AA) or the production of interleukin-6 and tumor necrosis factor-α (TNFα) as measures of their inflammatory potential. Responses were then related to PM composition: metals, hydrocarbons, anions/cations, and endotoxin content. Results Inflammatory responses to ambient PM varied markedly on an equal mass basis, with PM2.5–10 displaying the largest signals and contrasts among sites. Notably, we found no evidence of enhanced inflammatory potential at high-traffic sites and observed some of the largest responses at sites distant from traffic. Correlation analyses indicated that much of the sample-to-sample contrast in the proinflammatory response was related to the content of endotoxin and transition metals (especially iron and copper) in PM2.5–10. Use of the metal chelator diethylene triamine pentaacetic acid inhibited AA release, whereas recombinant endotoxin-neutralizing protein partially inhibited TNFα production, demonstrating that different PM components triggered inflammatory responses through separate pathways. Conclusions We found no evidence that PM collected from sites in close proximity to traffic sources displayed enhanced proinflammatory activity in RAW264.7 cells.

LIVER MITOCHONDRIA ALTERATIONS IN CHLOROFORM-TREATED SPRAGUE-DAWLEY RATS

The formation of a chloroform adduct produced by the reaction of the oxidative chloroform metabolite phosgene with two molecules of phosphatidylethanolamine has been previously demonstrated in liver mitochondria of phenobarbital-pretreated Sprague-Dawley (SD) rats. The aim of our study was to assess the influence of chloroform adduct mitochondrial accumulation on the hepatic mitochondria morphology. Liver mitochondrial ultrastructural alterations were analyzed by electron microscopy in SD rats administered with increasing doses of chloroform. Variation in the morphology of mitochondria, consisting of an increase of intertwined organelles, only rarely seen in control specimens, was observed at the lowest chloroform dose (180 mg/kg). At higher doses, mitochondrial damage progressed with swelling of the organelles and formation of megamitochondria. These megamitochondria were characterized by a dilution of the matrix, and often membranous whorls were found inside the matrix. The two distinct forms of cell death, necrosis and apoptosis, were first observed at 300 mg/kg of chloroform. Our results suggest that the formation and the accumulation of a chloroform-modified phosphatidylethanolamine in mitochondria induce ultrastructural modifications of these organelles. In conclusion, mitochondria are involved in chloroform-induced hepatotoxicity.

Characterization of a Phospholipid Adduct Formed in Sprague Dawley Rats by Chloroform Metabolism: NMR Studies

The formation of a covalent adduct to a single phospholipid by the oxidative chloroform metabolite, phosgene, is demonstrated in liver mitochondria of phenobarbital‐pretreated Sprague Dawley (SD) rats treated with CHCl3. The densitometric analysis of the phosphorus stained extracted phospholipids showed that the formation of this adduct in liver mitochondria is accompanied by a decrease of phosphatidylethanolamine and cardiolipin. The characterization of this adduct was performed with a multinuclear NMR approach by comparison with the decreased phospholipids. Treatment of rats with [13C]chloroform resulted in an intense 13C NMR peak from either an esteric or amidic carbonyl. Very strong similarities in fatty acid composition were found between phosphatidylethanolamine and the phosgene‐modified PL, using 13C and 1H NMR spectroscopy. A multiplet at 3.91 ppm coupled to a signal at 3.41 ppm was shown by two‐dimensional 1H NMR in the adduct spectrum. This cross peak was interpreted as arising from the shifted resonances of the two PE head group methylene groups, due to the binding with phosgene. 31P spectrum of the adduct was identical to that of phosphatidylethanolamine. We concluded that the chloroform adduct is a modified phosphatidylethanolamine, with the phosgene‐derived carbonyl bound to the amine of the head group.

Preliminary characterization of phospholipid adducts formed by [14C]-CHCl3 reactive intermediates in hepatocyte suspensions

The adducts produced in vitro by the reactive metabolites of [14C]-chloroform with total phospholipids (PLs) of freshly isolated hepatocytes have been characterized. The radical metabolite formed several adducts with all the major PL classes. These adducts seemed very likely to result from the unspecific attack of the radical on the PL fatty acyl chains. [14C]-Chloroform-derived phosgene caused the formation of a single PL adduct characterized by a ratio 14C:P of 1:4. This adduct was tentatively identified as an adduct of phosgene with two molecules of cardiolipin.

Targeted drugs and Psycho-oncological intervention for breast cancer patients

Personalized medicine is a new field based on molecular biology and genomics in which targeted tumor therapies are administered to patients. Psycho-oncology is a complementary approach that considers social and psychological aspects of patients as part of the treatments for cancer patients.The aim of this mini-review is to weigh clinical benefits for breast cancer patients of both treatments and possibily enhance benefits by modulating the use of both interventions. We have compared and evaluated on the one hand the use of anti Vascular Endothelial Growth Factor and, on the other hand, psycho-oncological interventions in metastatic and non-metastatic breast cancer patients.Both treatments did not increase survival of metastatic breast cancer patients, while in a selected study psycho-oncological interventions extended lifespan of non-metastatic breast cancer patients and ameliorate psychological and social factors of metastatic breast cancer patients. Because the two approaches address completely different aspects of cancer patients, if the comparison is limited to the extension of survival, the value of these two treatments cannot be assessed and compared.It is likely that by comparing patients reported outcomes, possibly by using standardized Quality of Life questionnaires, both patients and health care providers can weigh the benefits of the two treatments. It is therefore important to evaluate the use of cancer patients’ quality of life measures as a mean to improve their experiences about life and treatment, and possibly to extend their survival.

Translation of Cancer Molecular Biomarkers: Ethical and Epistemological Issues

The phenomenon of high cancer mortality has been the key factor in driving drug approval processes and health-care policies. In this paper, we discuss the inconsistencies of the genetic model of cancer as applied in the case of colorectal cancer (CRC). The result of relying on a genetic model of CRC is the approval of cancer drugs based on the inhibition of the epidermal growth factor receptor. The poor clinical performance of these drugs has prompted the use of a molecular biomarker to find the respondent patients. Due to the complexity of the cancer cell biological pathways, even the use of a molecular biomarker has not improved the clinical response of treated patients. Within the clinical uncertainty derived from the limited predictive value of a cancer molecular biomarker, we analyse the patient-doctor relationship. Beyond the challenge of communicating the medical uncertainty, many influences coming from the health-care system make the medical decisions biased. We analyse the ethical justification in using drugs that, at best, extend the patients’ survival for a few weeks, then we proceed to highlight the excessive cost of these drugs that create a problem for the allocation of resources for the whole society. We hold that a sensitive evaluation before the use of costly drugs for metastatic cancers must enter into the physician-patient relationship balancing the ethical concerns of the oncologist community and the need for the development of preventive policies.