Pietro Pantaleo

Expression of transmembrane 4 superfamily (TM4SF) proteins and their role in hepatic stellate cell motility and wound healing migration

BACKGROUND/AIMS Migration of activated hepatic stellate cells (HSC) is a key event in the progression of liver fibrosis. Little is known about transmembrane proteins involved in HSC motility. Tetraspanins (TM4SF) have been implicated in cell development, differentiation, motility and tumor cell invasion. We evaluated the expression and function of four TM4SF, namely CD9, CD81, CD63 and CD151, and their involvement in HSC migration, adhesion, and proliferation. METHODS/RESULTS All TM4SF investigated were highly expressed at the human HSC surface with different patterns of intracellular distribution. Monoclonal antibodies directed against the four TM4SF inhibited HSC migration induced by extracellular matrix proteins in both wound healing and haptotaxis assays. This inhibition was independent of the ECM substrates employed (collagen type I or IV, laminin), and was comparable to that obtained by incubating the cells with an anti-beta1 blocking mAb. Importantly, cell adhesion was unaffected by the incubation with the same antibodies. Co-immunoprecipitation studies revealed different patterns of association between the four TM4SF studied and beta1 integrin. Finally, anti-TM4SF antibodies did not affect HSC growth. CONCLUSIONS These findings provide the first characterization of tetraspanins expression and of their role in HSC migration, a key event in liver tissue wound healing and fibrogenesis.

Vitamin E protects DNA from oxidative damage in human hepatocellular carcinoma cell lines.

Expression of multiple drug resistant (MDR) phenotype and over-expression of P-glycoprotein (P-gp) in the human hepatocellular carcinoma (HCC) cell clone P1(0.5), derived from the PLC/PRF/5 cell line (P5), are associated with strong resistance to oxidative stress and a significant ( p<0.01) increase in intracellular vitamin E content as compared with the parental cell line. This study evaluates the role of vitamin E in conferring resistance to drugs and oxidative stress in P1(0.5) cells. Parental drug-sensitive cells, P5, were incubated in α-tocopherol succinate (α-TS, 5 μM for 24 h) enriched medium to increase intracellular vitamin E content to levels comparable to those observed in P1(0.5) cells at basal conditions. Susceptibility to lipid peroxidation and oxidative DNA damage were assessed by measuring the concentration of thiobarbituric-reactive substances (TBARS) and 8-hydroxy-2′-deoxyguanosine (8-OHdG) at basal and after experimental conditions. Cell capacity to form colonies and resistance to doxorubicin were also studied. P5 cells, treated with α-TS, became resistant to ADP-Fe3+ and to ionizing radiation-induced lipid peroxidation as P1(0.5) cells. Exposure to ADP-Fe3+ or ionizing radiation increased TBARS and the 8-OHdG content in the P5 cells, while vitamin E enrichment abolished these effects. Irradiation doses at 5 cGy increased TBARS and 8-OHdG. They also inhibited cell capacity to form colonies in the untreated P5 cells. Incubation with α-TS fully reverted this effect and significantly (p<0.01) reduced the inhibitory effect of cell proliferation induced by irradiation doses at >500 cGy. Resistance to doxorubicin was not affected by α-TS. These observations demonstrate the role of vitamin E in conferring protection from lipid peroxidation, ionizing radiation and oxidative DNA damage on the human HCC cell line. They also rule out any role of P-gp over-expression as being responsible for these observations in cells with MDR phenotype expression.

Farnesyltransferase Inhibitor, ABT-100, Is a Potent Liver Cancer Chemopreventive Agent

Purpose: Treatment of hepatocellular carcinoma raised on cirrhotic liver represents a major endeavor because surgery and chemotherapeutic management fail to improve the clinical course of the disease. Chemoprevention could represent an important means to inhibit the process of hepatocarcinogenesis. Farnesyltransferase inhibitors are a class of drugs blocking the growth of tumor cells with minimal toxicity towards normal cells. Experimental Design: In the present study, we investigated the effects of a novel farnesyltransferase inhibitor, ABT-100, on human liver cancer cell lines, HepG2 and Huh7, and on an animal model of hepatocarcinogenesis. Results: ABT-100 inhibited HepG2 and Huh7 cell growth as well as the invading ability of Huh7 on Matrigel. In HepG2 and Huh7 cells, ABT-100 inhibited growth factor–stimulated phosphoinositide 3-kinase and Akt/protein kinase B activity. Furthermore, ABT-100 inhibited Akt-dependent p27Kip1 phosphorylation and this event was associated with increased levels of p27Kip1 in the nucleus and reduced activity of the cyclin-dependent kinase 2. Moreover, ABT-100 treatment resulted in a significant reduction in tumor incidence and multiplicity. Conclusions: Taken together, these findings identify a mechanism of ABT-100 function and show the efficacy of ABT-100 as a chemopreventive agent of hepatocellular carcinoma.

Survival and Prognostic Factors in Patients with Hepatocellular Carcinoma Treated by Percutaneous Ethanol Injection: A 10-Year Experience

The treatment of early and intermediate stage hepatocellular carcinoma (HCC) is still debated. Surgical treatments are considered to be the only curative procedures available, and only for a minority of patients. Percutaneous ethanol injection (PEI) is an established technique for the ablation of HCC nodules, and shows survival rates similar to those of resection. The efficacy of PEI in patients with biopsy-proven viral cirrhosis and small to intermediate inoperable HCC was evaluated. One hundred twenty-seven patients (85 men, 42 women, mean age 63 years, range 51 to 92 years, 115 hepatitis C virus-positive, 12 hepatitis B virus-positive) were enrolled between January 1993 and December 2002. They all underwent a standard PEI procedure and were prospectively followed-up. Overall median survival rate was 28 months (range six to 112 months). The following parameters were associated with a significantly longer survival: nodule diameter smaller than 30 mm (P=0.0480), the presence of a perinodular boundary (P=0.0008), serum alpha-fetoprotein less than 20 ng/mL (P=0.0104), a Child-Pugh A class score (P<0.0001) or a Cancer of the Liver Italian Program score of 0 (P<0.0001) and the presence or absence of small esophageal varices (P=0.013). The 19 patients with all these favourable characteristics showed an overall median survival of 61 months. An alpha-fetoprotein below 20 ng/mL was associated with significantly longer disease-free survival (P=0.0009). The Child-Pugh and Cancer of the Liver Italian Program scores were effective in predicting prognosis of these patients. In conclusion, PEI still represents a safe and economically sound treatment for HCC.

Effects of dietary supplementation with arachidonic acid on platelet and renal function in patients with cirrhosis

Advanced cirrhosis is associated with reduced platelet function and altered renal function and sodium handling. Arachidonic acid (AA) metabolites contribute to platelet aggregation and to maintain the response to diuretics in advanced cirrhosis. In the present study, we tested the effects of a dietary supplementation for 8 weeks with a triacylglycerol (triglyceride) enriched in AA (ARASCO; 4 g/day) or oleic acid (OA) on plasma and membrane fatty acid composition, platelet aggregation and renal prostaglandin (PG) metabolism. At baseline, all patients had reduced platelet aggregation. Patients treated with AA showed a significant increase in the percentage of AA in plasma lipids and membrane phospholipids. These changes were associated with an increased platelet aggregation in response to collagen (from 55.83 +/- 20.63 to 67.67 +/- 14.44%; P<0.05). At baseline, all urinary AA metabolites, including PGE2, 6-keto-PGF1alpha, 8-epi-PGF2alpha and 11-dehydro-thromboxane B2, were elevated in cirrhotic patients when compared with a group of normal subjects. After furosemide treatment, urinary excretion of 11-dehydro-thromboxane B2 increased significantly. Supplementation with AA did not result in any significant change in urinary PG excretion either before or after diuretic administration. The results of the present study show that dietary supplementation with AA effectively increases the levels of this fatty acid in plasma and membrane phospholipids and improves platelet aggregation. These data suggest a possible novel approach to the treatment of the haemostatic defect observed in these patients.

Long-Term Survival in Metastatic Melanoma Patients Treated with Sequential Biochemotherapy: Report of a Phase II Study

The overall survival for patients with metastatic melanoma is very poor, with a median survival of 8.5 months. In this Phase II trial, we assessed the efficacy, safety, and tolerability of a sequential biochemotherapy schedule, using dacarbazine as antiblastic agent and immunomodulant doses of interleukin-2 and interferon-alfa. Thirty-one eligible patients with metastatic melanoma received dacarbazine IV as antiblastic therapy and interluekin-2, plus interferon-alfa SC as sequential immunotherapy, for 6 months. Responding and nonprogressing patients were subsequently maintained on immunotherapy treatment for further 6 months. Twenty-nine patients had an adequate trial, and were assessable for both response and toxicities, with a median follow-up of 49 months. The overall response rate was 52 percent (3 CR and 12 PR), SD was 8 (27 percent) and PD were achieved in 6 patients (21 percent). The median survival duration of responders was 28 months, significantly longer (p < 0.001) than the 16 months of nonresponders. Therapy was well tolerated and produced a significant improvement in progressive-free survival. Further studies, thus, are recommended for larger groups of patients not only to confirm these results, but also to apply this biochemotherapy regimen as adjuvant postsurgical treatment in early stages of malignant melanoma.

Metabolomic does not predict response to cardiac resynchronization therapy in patients with heart failure

Aims Metabolomic, a systematic study of metabolites, may be a useful tool in understanding the pathological processes that underlie the occurrence and progression of a disease. We hypothesized that metabolomic would be helpful in assessing a specific pattern in heart failure patients, also according to the underlining causes and in defining, prior to device implantation, the responder and nonresponder patient to cardiac resynchronization therapy (CRT). Methods In this prospective study, blood and urine samples were collected from 32 heart failure patients who underwent CRT. Clinical, electrocardiography and echocardiographic evaluation was performed in each patient before CRT and after 6 months of follow-up. Thirty-nine age and sex-matched healthy individuals were chosen as control group. For each sample, 1H-NMR spectra, Nuclear Overhauser Enhancement Spectroscopy, Carr-Purcell-Meiboom-Gill and diffusion edited spectra were measured. Results A different metabolomic fingerprint was demonstrated in heart failure patients compared to healthy controls with high accuracy level. Metabolomics fingerprint was similar between patients with ischemic and nonischemic dilated cardiomyopathy. At 6-month follow-up, metabolomic fingerprint was different from baseline. At follow-up, heart failure patients’ metabolomic fingerprint remained significantly different from that of healthy controls, and accuracy of cause discrimination remained low. Responders and nonresponders had a similar metabolic fingerprint at baseline and after 6 months of CRT. Conclusion It is possible to identify a metabolomic fingerprint characterizing heart failure patients candidate to CRT, it is independent of the different causes of the disease and it is not predictive of the response to CRT.

Gemcitabine plus irinotecan as first-line weekly therapy in locally advanced and/or metastatic pancreatic cancer.

Single-agent gemcitabine has been established as standard treatment for advanced pancreatic cancer since clinical studies have shown an improvement in overall survival and significant clinical benefit when compared to the best supportive care despite low overall objective response. Several phase II studies have tested other single agents and different gemcitabine-based regimens in pancreatic cancer, but both response and survival rates have remained low. Irinotecan, a topoisomerase I inhibitor currently approved for the treatment of metastatic colon cancer, has also demonstrated improved response rate in patients with pancreatic cancer. Our purpose was to determine the activity and toxicity of this regimen in patients with unresectable or metastatic pancreatic cancer. Patients with histologically confirmed pancreatic adenocarcinoma received gemcitabine 1000 mg/m2 plus irinotecan 100 mg/m2 IV on days 1, 8, and 15 of a 28-day cycle for 6-8 months. From February 2004 to April 2006, 33 patients were entered into this study, 32 of whom were evaluable for treatment response, toxicity, median time to progression, and median survival. Characteristics included a median age of 63 years (range 41-79), 21 males (64%), and 12 females (36%). One patient discontinued treatment due to adverse effects. The total number of cycles administered was 188 and the median number of cycles for patients was 5.6 (range 2-7). Thirty-two patients were assessable for toxicity and response. Grade 3 hematological toxicity occurred in 9% of patients and was primarily neutropenia. No grade >2 gastrointestinal toxicities or death due to treatment were observed. The most frequent nonhematological adverse event was fatigue. Ten patients responded to treatment with two complete responses (6.3%) and eight partial responses (25.0%), for an overall response rate of 31.3%; 11 patients achieved stable disease (34.3%). The median time to tumor progression and the median survival were 9.2 (95% CI: 6.0-12.4) and 11.8 (95% CI: 7.7-15.9) months, respectively, with a 2-year survival of 22%. On the basis of this trial, the combination of gemcitabine plus irinotecan, administered in a weekly schedule and at this dose, is well tolerated and offers encouraging activity in the treatment of advanced and/or metastatic pancreatic cancer.

Vascular reserve in the lower limbs of cirrhotic patients: a duplex Doppler ultrasound study

AIM To evaluate femoral artery impedance at rest and during reactive hyperaemia. PATIENTS Study population comprised 11 cirrhotic patients without ascites, 10 with ascites and 16 age- and sex-matched healthy subjects. METHODS Echocardiographic assessment of systemic haemodynamics; duplex Doppler ultrasound measurement of femoral artery pulsatility index and vascular reserve [pulsatility index rest/pulsatility index hyperaemia). RESULTS Cirrhotic patients had elevated cardiac index and low systemic vascular resistance. Pulsatility index (right femoral artery) was not statistically different either at rest or after reactive hyperaemia (controls: rest 10.6 +/- 0.4, hyperaemia 2.6 +/- 0.2; compensated cirrhosis: rest 10.1 +/- 0.8, hyperaemia 3.4 +/- 0.4; ascitic cirrhosis: rest 11.4 +/- 1.6, hyperaemia 2.9 +/- 0.4. Vascular reserve was 4.38 +/- 0.35 in controls, 3.33 +/- 0.39 in compensated and 4.70 +/- 0.89 in ascitic cirrhosis (p = not significant). No correlation was found between systemic haemodynamic parameters and either pulsatility index or vascular reserve. CONCLUSIONS The lower limb vascular reserve is preserved in cirrhosis.