Stefano Iacobelli

Galectins and their ligands: amplifiers, silencers or tuners of the inflammatory response?

Recent evidence has implicated galectins and their ligands as master regulators of immune cell homeostasis. Whereas some members of this family, such as galectin-3, behave as amplifiers of the inflammatory cascade, others, such as galectin-1, trigger homeostatic signals to shut off T-cell effector functions. These carbohydrate-binding proteins, identified by shared consensus amino acid sequences and affinity for beta-galactoside-containing sugars, participate in the homeostasis of the inflammatory response, either by regulating cell survival and signaling, influencing cell growth and chemotaxis, interfering with cytokine secretion, mediating cell-cell and cell-matrix interactions or influencing tumor progression and metastasis. The current wealth of new information promises a future scenario in which individual members of the galectin family or their ligands will be used as powerful anti-inflammatory mediators and selective modulators of the immune response.

Elevated Serum Cytokines Correlated with Altered Behavior, Serum Cortisol Rhythm, and Dampened 24-Hour Rest-Activity Patterns in Patients with Metastatic Colorectal Cancer

Purpose: Incapacitating symptom burden in cancer patients contributes to poor quality of life (QOL) and can influence treatment outcomes because of poor tolerance to therapy. In this study, the role of circulating cytokines in the production symptoms in cancer patients is evaluated. Experimental Design: Eighty patients with metastatic colorectal cancer with either normal (group I, n = 40) or dampened (group II, n = 40) 24-hour rest/activity patterns measured by actigraphy were identified. Actigraphy patterns were correlated with QOL indices, serum cortisol obtained at 8:00 a.m. and 4:00 p.m. and with serum levels of transforming growth factor-α, tumor necrosis factor-α, and interleukin 6 (IL-6) obtained at 8:00 a.m. and analyzed in duplicate by ELISA. Cytokine levels and survival were also correlated. Results: Group II patients had significantly higher pre treatment levels of all three cytokines, displayed significantly poorer emotional and social functioning, had higher fatigue, more appetite loss, and poorer performance status compared with group I patients. Transforming growth factor-α (TGF-α) and IL-6 were significantly increased in the patients with WHO performance status >1 and in those with appetite loss. Fatigue was significantly associated with elevated TGF-α only. IL-6 was increased in those patients with extensive liver involvement and multiple organ replacement, and it was significantly correlated with dampened cortisol rhythm. In a multivariate analysis, IL-6 was correlated with poor treatment outcome. Conclusions: Significant correlations were found between serum levels of TGF-α and IL-6, circadian patterns in wrist activity and serum cortisol and tumor-related symptoms in patients with metastatic colorectal cancer. These data support the hypothesis that some cancer patients symptoms of fatigue, poor QOL, and treatment outcome are related to tumor or host generated cytokines and could reflect cytokine effects on the circadian timing system. This interplay between cytokine signaling pathways, the hypothalamic-pituitary-adrenal axis, the autonomic nervous system, and efferent pathways of the suprachiasmatic nucleus that control circadian physiology, opens the way to new rational interventions for symptom management in cancer patients.

Galectin‐3 overexpression protects from apoptosis by improving cell adhesion properties

Galectin‐3 is a carbohydrate‐binding protein endowed with affinity for β‐galactosides. It plays a role in cell–cell and cell–matrix interactions. Furthermore, it has been hypothesized to be involved in tumor progression and metastasis. To address the role of galectin‐3 in the invasive and metastatic processes, we stably overexpressed galectin‐3 in human breast carcinoma cell lines, and we evaluated the influence of elevated galectin‐3 expression on several cell features, including cellular homotypic and heterotypic interactions and cell survival. No differences in various parameters related with cell growth features and proliferation were detected. By contrast, we found that galectin‐3 overexpressing cells, with respect to low galectin‐3 expressing cells, exerted: (1) a significantly enhanced adhesion to laminin, fibronectin and vitronectin exerted both directly or via increased expression of specific integrins, e.g., alpha‐4 and beta‐7; (2) a remodeling of those cytoskeletal elements associated with cell spreading, i.e., microfilaments; (3) an enhanced survival upon exposure to different apoptotic stimuli, such as cytokine and radiation. Collectively, our results indicate that overexpression of galectin‐3 may play a role in tumor cell invasion and metastasis by specifically influencing cell adhesion to the extracellular matrix. This may confer selective survival advantage and resistance to the particular homeless‐induced apoptosis called anoikia. Int. J. Cancer 85:545–554, 2000.

Oxaliplatin activity against metastatic colorectal cancer. A phase II study of 5-day continuous venous infusion at circadian rhythm modulated rate.

Oxaliplatin (L-OHP) is a non-nephrotoxic third generation platinum complex with proven antitumoral activity and minimal haematological toxicity. Circadian scheduling has allowed significant increases in L-OHP dosage and dose intensity and decreases in its toxicities. This phase II trial has tested the antitumour activity of a 5-day circadian schedule of continuous venous infusion of L-OHP against metastatic colorectal cancer. Initial dose was 150 mg/m2/course. An intrapatient dose escalation scheme by 25 mg/m2/course was planned up to 200 mg/m2/course, according to toxicity criteria. The delivery rate of L-OHP was sinusoidally modulated along the 24-h time scale, and was highest at 1600 h. A programmable-in-time ambulatory pump was used, so that all patients could receive their treatment at home. 29 of 30 patients registered were eligible. 25 had failed previous chemotherapy. Three objective responses were observed (response rate: 10%), in patients progressive while on chemotherapy with 5-fluorouracil and folinic acid. Toxicity was moderate. Dose-limiting toxicities were diarrhoea and peripheral sensitive neuropathy. The latter adverse effect appeared to be cumulative. L-OHP, as delivered under this circadian schedule, exhibits clinical antitumour activity against metastatic colorectal cancer. These results, which await further confirmation, support the place of L-OHP in combination regimens including 5-fluorouracil.

Increased Levels of Soluble P-Selectin in Hypercholesterolemic Patients

BACKGROUND Hypercholesterolemia is considered a major risk factor for the development of atherosclerosis. Enhanced lipid peroxidation and persistent platelet activation can be observed in vivo in hypercholesterolemic patients and may have pathophysiological implications in the occurrence of cardiovascular events. P-selectin may play an important role in the pathogenesis of multicellular events, including atherosclerosis. We studied the impact of hypercholesterolemia and oxidative stress on plasma levels of P-selectin. METHODS AND RESULTS Plasma levels of P-selectin were measured by means of an enzyme immunoassay in 20 hypercholesterolemic patients with no clinical evidence of cardiovascular disease and in 20 sex- and age-matched normocholesterolemic subjects. Hypercholesterolemic patients had higher levels of P-selectin compared with that of control subjects (98+/-61 versus 56+/-14 ng/mL; P=.001). They also displayed increased von Willebrand Factor (vWF) levels (176+/-22 versus 119+/-12%; P=.0001). A direct correlation was observed between P-selectin and LDL cholesterol levels (p=.453). Administration of vitamin E (600 mg/d for 2 weeks) to hypercholesterolemic patients significantly reduced plasma P-selectin (40%), and an inverse correlation was observed between vitamin E and P-selectin plasma levels (p=-.446). CONCLUSIONS Hypercholesterolemia is associated with elevated plasmatic P-selectin. Altered oxidative processes leading to endothelial dysfunction and persistent platelet activation may contribute to increased soluble P-selectin levels. P-selectin may be proposed as a marker of endothelial dysfunction in hypercholesterolemic patients.

Phase III Trial Comparing 4-Day Chronomodulated Therapy Versus 2-Day Conventional Delivery of Fluorouracil, Leucovorin, and Oxaliplatin As First-Line Chemotherapy of Metastatic Colorectal Cancer: The European Organisation for Research and Treatment of Cancer Chronotherapy Group

PURPOSE In two previous randomized trials, the adjustment of chemotherapy delivery to circadian rhythms improved tolerability and anticancer activity compared with constant-rate infusion during 5 days in patients with metastatic colorectal cancer. PATIENTS AND METHODS For this multicenter randomized trial, it was hypothesized that a chronomodulated infusion of fluorouracil, leucovorin, and oxaliplatin for 4 days (chronoFLO4) would improve survival by 10% compared with conventional 2-day delivery of the same drugs (FOLFOX2). Patients were treated every 2 weeks with intrapatient dose escalation. RESULTS Baseline characteristics were similar in both arms for the 564 patients (36 institutions, 10 countries). Median survival was 19.6 months (95% confidence limit [CL] = 18.2, 21.2) with chronoFLO4 and 18.7 months with FOLFOX2 (95% CL = 17.7, 21.0; P = .55). The main dose-limiting toxicities were diarrhea for chronoFLO4 and neutropenia for FOLFOX2. The analysis of survival predictors showed that sex was the single most important factor (P = .001). In women, the risk of an earlier death with chronoFLO4 was increased by 38% compared with FOLFOX2, with median survival times of 16.3 and 19.1 months (P = .03), respectively. In men, the risk of death was decreased by 25% with chronoFLO4 compared with FOLFOX2, with median survival times of 21.4 and 18.3 months (P = .02), respectively. CONCLUSION Both regimens achieved similar median survival times more than 18 months with an acceptable toxicity. The chronomodulated schedule produced a survival advantage over FOLFOX in men. The strong sex dependency of optimal scheduling of fluorouracil, leucovorin, and oxaliplatin calls for translational investigations of determinants related to the patients molecular clock.

Galectin‐3 overexpression protects from cell damage and death by influencing mitochondrial homeostasis

Galectins are a family of proteins involved in several cell processes, including their survival and death. Galectin‐3 has in particular been described as an anti‐apoptotic molecule entangled with a number of subcellular activities including anoikis resistance. In this work we partially address the mechanisms underlying this activity pointing at two key factors in injury progression: the alteration of mitochondrial membrane potential and the formation of reactive oxygen species. Overexpression of galectin‐3 appears in fact to exert a protective effect towards both these events. On the basis of these data, we propose a reappraisal of the role of galectin‐3 as a regulator of mitochondrial homeostasis.

Circadian Rhythm in Rest and Activity: A Biological Correlate of Quality of Life and a Predictor of Survival in Patients with Metastatic Colorectal Cancer

The rest-activity circadian rhythm (CircAct) reflects the function of the circadian timing system. In a prior single-institution study, the extent of CircAct perturbation independently predicted for survival and tumor response in 192 patients receiving chemotherapy for metastatic colorectal cancer. Moreover, the main CircAct parameters correlated with several health-related quality of life (HRQoL) scales. In this prospective study, we attempted to extend these results to an independent cohort of chemotherapy-naive metastatic colorectal cancer patients participating in an international randomized phase III trial (European Organisation for Research and Treatment of Cancer 05963). Patients were randomized to receive chronomodulated or conventional infusion of 5-fluorouracil, leucovorin, and oxaliplatin as first-line treatment for metastatic colorectal cancer. Patients from nine institutions completed the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-C30 and wore a wrist accelerometer (actigraph) for 3 days before chemotherapy delivery. Two validated parameters (I<O and r24) were used to estimate CircAct. Of 130 patients with baseline CircAct assessments, 96 had baseline HRQoL data. I<O was confirmed to correlate with global quality of life, physical functioning, social functioning, fatigue, and appetite loss (r > |0.25|; P < 0.01). I<O further independently predicted for overall survival with a hazard ratio of 0.94 (P < 0.0001). The associations between CircAct parameters, HRQoL, and survival, which were shown in this international study involving previously untreated metastatic colorectal cancer patients, confirm prior single-institution findings in mostly pretreated metastatic colorectal cancer patients. The circadian timing system constitutes a novel therapeutic target. Interventions that normalize circadian timing system dysfunction may affect quality of life and survival in cancer patients.

90K (Mac-2 BP) and galectins in tumor progression and metastasis.

Galectins and their ligands have been implicated in cell transformation and cancer metastasis, and found to have prognostic value. Mac-2 BP, also known as 90K, is a highly glycosylated, secreted protein extensively studied in human cancer, which binds galectin-1, galectin-3 and galectin-7. High expression levels of 90K are associated with a shorter survival, the occurrence of metastasis or a reduced response to chemotherapy in patients with different types of malignancy. The mechanisms underlying the prognostic significance of 90K and galectins in cancer are far from being understood, although they may be related to the ability of these proteins to interact and, to some extent, modulate cell-cell and cell-matrix adhesion and apoptosis. The resulting scenario is even more complex, as data have been presented that all these proteins might be associated with either a positive or a negative outcome of the patients. It is hypothesised that different galectins and galectin ligands with overlapping or opposite functions, expressed in different tumors during the different steps of the metastatic cascade might play a crucial role in tumor progression. Published in 2004.

Inhibition of the Phosphatidylinositol 3-Kinase/Akt Pathway by Inositol Pentakisphosphate Results in Antiangiogenic and Antitumor Effects

The purpose of this study was to investigate the antiangiogenic and in vivo properties of the recently identified phosphatidylinositol 3-kinase (PI3K)/Akt inhibitor Inositol(1,3,4,5,6) pentakisphosphate [Ins(1,3,4,5,6)P5]. Because activation of the PI3K/Akt pathway is a crucial step in some of the events leading to angiogenesis, the effect of Ins(1,3,4,5,6)P5 on basic fibroblast growth factor (FGF-2)-induced Akt phosphorylation, cell survival, motility, and tubulogenesis in vitro was tested in human umbilical vein endothelial cells (HUVEC). The effect of Ins(1,3,4,5,6)P5 on FGF-2-induced angiogenesis in vivo was evaluated using s.c. implanted Matrigel in mice. In addition, the effect of Ins(1,3,4,5,6)P5 on growth of ovarian carcinoma SKOV-3 xenograft was tested. Here, we show that FGF-2 induces Akt phosphorylation in HUVEC resulting in antiapoptotic effect in serum-deprived cells and increase in cellular motility. Ins(1,3,4,5,6)P5 blocks FGF-2-mediated Akt phosphorylation and inhibits both survival and migration in HUVEC. Moreover, Ins(1,3,4,5,6)P5 inhibits the FGF-2-mediated capillary tube formation of HUVEC plated on Matrigel and the FGF-2-induced angiogenic reaction in BALB/c mice. Finally, Ins(1,3,4,5,6)P5 blocks the s.c. growth of SKOV-3 xenografted in nude mice to the same extent than cisplatin and it completely inhibits Akt phosphorylation in vivo. These data definitively identify the Akt inhibitor Ins(1,3,4,5,6)P5 as a specific antiangiogenic and antitumor factor. Inappropriate activation of the PI3K/Akt pathway has been linked to the development of several diseases, including cancer, making this pathway an attractive target for therapeutic strategies. In this respect, Ins(1,3,4,5,6)P5, a water-soluble, natural compound with specific proapoptotic and antiangiogenic properties, might result in successful anticancer therapeutic strategies.