L. Lupo

Clinical role of MMP-2/TIMP-2 imbalance in hepatocellular carcinoma

An imbalance between the proteolytic activity of matrix metalloproteinase‐2 (MMP‐2) and the tissue inhibitor of MMP‐2 (TIMP‐2) is responsible for degradation of extracellular matrix (ECM) components and plays a critical role in tumor invasion and in metastasis formation. The occurrence of intra‐hepatic metastasis, which severely affects prognosis and long‐term survival, is commonly observed in the course of hepatocellular carcinoma (HCC). We investigated the expression of MT1‐MMP in tissues, whereas both MMP‐2 and TIMP‐2 were evaluated in the sera and tissues (primary and metastatic nodules) of HCC patients with and without metastasis, whose clinical outcome was followed over a 2‐year period. MT1‐MMP expression was similar among primary nodule tissues of patients with and without metastasis. Serum and tissue levels of MMP‐2 were not statistically different between patients with and without metastasis, but MMP‐2 was concentrated at the invasive edge of the metastatic tissue. On the contrary, serum and tissue levels of TIMP‐2 were significantly higher in HCC patients without metastasis than in those with. This situation was not only observed in the primary HCC tissues, but also in the metastatic nodules. These results correlate with the clinical outcome, because more than 90% of the patients with high levels of TIMP‐2 were still alive after 2 years, whereas less than 30% with low levels of TIMP‐2 had survived. Furthermore, we found a strict correlation between tissue and serum levels of TIMP‐2, this suggesting that a MMP‐2/TIMP‐2 imbalance and in particular TIMP‐2 levels, could represent an important prognostic factor in patients with HCC.

Down‐regulation of connective tissue growth factor by inhibition of transforming growth factor β blocks the tumor–stroma cross‐talk and tumor progression in hepatocellular carcinoma

Tumor–stroma interactions in hepatocellular carcinoma (HCC) are of key importance to tumor progression. In this study, we show that HCC invasive cells produce high levels of connective tissue growth factor (CTGF) and generate tumors with a high stromal component in a xenograft model. A transforming growth factor β (TGF‐β) receptor inhibitor, LY2109761, inhibited the synthesis and release of CTGF, as well as reducing the stromal component of the tumors. In addition, the TGF‐β–dependent down‐regulation of CTGF diminished tumor growth, intravasation, and metastatic dissemination of HCC cells by inhibiting cancer‐associated fibroblast proliferation. By contrast, noninvasive HCC cells were found to produce low levels of CTGF. Upon TGF‐β1 stimulation, noninvasive HCC cells form tumors with a high stromal content and CTGF expression, which is inhibited by treatment with LY2109761. In addition, the acquired intravasation and metastatic spread of noninvasive HCC cells after TGF‐β1 stimulation was blocked by LY2109761. LY2109761 interrupts the cross‐talk between cancer cells and cancer‐associated fibroblasts, leading to a significant reduction of HCC growth and dissemination. Interestingly, patients with high CTGF expression had poor prognosis, suggesting that treatment aimed at reducing TGF‐β–dependent CTGF expression may offer clinical benefits. Conclusion: Taken together, our preclinical results indicate that LY2109761 targets the cross‐talk between HCC and the stroma and provide a rationale for future clinical trials. (HEPATOLOGY 2009.)

Single hepatocellular carcinoma ranging from 3 to 5 cm: radiofrequency ablation or resection?

BACKGROUND The optimal therapy for hepatocellular carcinoma (HCC) is transplantation. For all those patients not eligible for transplantation (or on the waiting list) among the treatments of choice used more frequently in recent years are resection (RES) and radiofrequency ablation (RFA). RFA is less efficacious for HCC ranging over 3 cm. The aim of this study was to compare RFA to RES in a restricted cohort of patients with a single naive HCC ranging from 3 to 5 cm in size and without end-stage liver disease. PATIENTS AND METHODS. A total of 102 patients who had never been treated before were enrolled. Those patients whose HCC position would have required too much parenchymal loss at RES (central or close to main vascular structures) were treated with RFA (n=60), and the others underwent RES (n=42). The two groups were similar for HCC size and liver disease status. The outcome was considered in terms of overall survival (OS) and disease-free survival (DFS) calculated by the Kaplan-Meier method. Differences among groups were validated by log-rank test. RESULTS The RES group seemed to present a better long-term OS (91%, 57%, and 43% vs 96%, 53%, and 32% at 1, 3, and 5 years, respectively) and DFS (74%, 35%, and 14% vs 68%, 18%, and 0%, respectively) but there was no statistical significance. Age, gender, virus etiology, HCC size and alpha-fetoprotein levels did not correlate with survival. Patients with recurrence within the first 12 months after treatment showed a worse long-term survival (p=0.011). Patients in Child-Pugh class B had poor prognoses compared with those in class A (p=0.047). CONCLUSION Even if RES seemed to promise better long-term results, in the medium term this difference had no statistical significance. Survival in this series was more closely related to the stage of the underlying liver disease than to treatment (RES/RFA).

Tumor‐secreted lysophostatidic acid accelerates hepatocellular carcinoma progression by promoting differentiation of peritumoral fibroblasts in myofibroblasts

Hepatocellular carcinoma (HCC) occurs in fibrotic liver as a consequence of underlying cirrhosis. The goal of this study was to investigate how the interaction between HCC cells and stromal fibroblasts affects tumor progression. We isolated and characterized carcinoma‐associated fibroblasts (CAFs) and paired peritumoral tissue fibroblasts (PTFs) from 10 different patients with HCC and performed coculture experiments. We demonstrated a paracrine mechanism whereby HCC cells secrete lysophostatidic acid (LPA), which promotes transdifferentiation of PTFs to a CAF‐like myofibroblastic phenotype. This effect is mediated by up‐regulation of specific genes related to a myo/contractile phenotype. After transdifferentiation, PTFs expressed α‐smooth muscle actin (α‐SMA) and enhanced proliferation, migration, and invasion of HCC cells occur. A pan‐LPA inhibitor (α‐bromomethylene phosphonate [BrP]‐LPA), or autotaxin gene silencing, inhibited this PTF transdifferentiation and the consequent enhanced proliferation, migration, and invasion of HCC cells. In vivo, PTFs coinjected with HCC cells underwent transdifferentiation and promoted tumor progression. Treatment with BrP‐LPA blocked transdifferentiation of PTFs, down‐regulated myofibroblast‐related genes, and slowed HCC growth and progression. Patients with larger and metastatic HCC and shorter survival displayed higher serum levels of LPA. Analysis of microdissected tissues indicated that stroma is the main target of the LPA paracrine loop in HCC. As a consequence, α‐SMA–positive cells were more widespread in tumoral compared with paired peritumoral stroma. Conclusion: Our data indicate that LPA accelerates HCC progression by recruiting PTFs and promoting their transdifferentiation into myofibroblasts. Inhibition of LPA could prove effective in blocking transdifferentiation of myofibroblasts and tumor progression. (HEPATOLOGY 2011;)

Balancing Donor and Recipient Risk Factors in Liver Transplantation: The Value of D‐MELD With Particular Reference to HCV Recipients

Donor–recipient match is a matter of debate in liver transplantation. D‐MELD (donor age × recipient biochemical model for end‐stage liver disease [MELD]) and other factors were analyzed on a national Italian database recording 5946 liver transplants. Primary endpoint was to determine factors predictive of 3‐year patient survival. D‐MELD cutoff predictive of 5‐year patient survival <50% (5yrsPS<50%) was investigated. A prognosis calculator was implemented (http://www.D‐MELD.com). Differences among D‐MELD deciles allowed their regrouping into three D‐MELD classes (A < 338, B 338–1628, C >1628). At 3 years, the odds ratio (OR) for death was 2.03 (95% confidence interval [CI], 1.44–2.85) in D‐MELD class C versus B. The OR was 0.40 (95% CI, 0.24–0.66) in class A versus class B. Other predictors were hepatitis C virus (HCV; OR = 1.42; 95% CI, 1.11–1.81), hepatitis B virus (HBV; OR = 0.69; 95% CI, 0.51–0.93), retransplant (OR = 1.82; 95% CI, 1.16–2.87) and low‐volume center (OR = 1.48; 95% CI, 1.11–1.99). Cox regressions up to 90 months confirmed results. The hazard ratio was 1.97 (95% CI, 1.59–2.43) for D‐MELD class C versus class B and 0.42 (95% CI, 0.29–0.60) for D‐MELD class A versus class B. Recipient age, HCV, HBV and retransplant were also significant. The 5yrsPS<50% cutoff was identified only in HCV patients (D‐MELD ≥ 1750). The innovative approach offered by D‐MELD and covariates is helpful in predicting outcome after liver transplantation, especially in HCV recipients.

Randomized clinical trial of radiofrequency-assisted versus clamp-crushing liver resection

Surgical resection remains the treatment of choice for primary and secondary liver cancer. Complications are mainly related to blood loss. Radiofrequency‐assisted liver resection (RF‐R) has been proposed for parenchymal division as an alternative to clamp crushing in order to reduce blood loss.

Liver Match, a prospective observational cohort study on liver transplantation in Italy: Study design and current practice of donor-recipient matching

BACKGROUND The Liver Match is an observational cohort study that prospectively enrolled liver transplantations performed at 20 out of 21 Italian Transplant Centres between June 2007 and May 2009. Aim of the study is to investigate the impact of donor/recipient matching on outcomes. In this report we describe the study methodology and provide a cross-sectional description of donor and recipient characteristics and of graft allocation. METHODS Adult primary transplants performed with deceased heart-beating donors were included. Relevant information on donors and recipients, organ procurement and allocation were prospectively entered in an ad hoc database within the National Transplant Centre web-based Network. Data were blindly analysed by an independent Biostatistical Board. RESULTS The study enrolled 1530 donor/recipient matches. Median donor age was 56 years. Female donors (n = 681, median 58, range 12-92 years) were older than males (n = 849, median 53, range 2-97 years, p < 0.0001). Donors older than 60 years were 42.2%, including 4.2% octogenarians. Brain death was due to non-traumatic causes in 1126 (73.6%) cases. Half of the donor population was overweight, 10.1% was obese and 7.6% diabetic. Hepatitis B core antibody (HBcAb) was present in 245 (16.0%) donors. The median Donor Risk Index (DRI) was 1.57 (>1.7 in 35.8%). The median cold ischaemia time was 7.3h (≥ 10 in 10.6%). Median age of recipients was 54 years, and 77.7% were males. Hepatocellular carcinoma (HCC) was the most frequent indication overall (44.4%), being a coindication in roughly 1/3 of cases, followed by viral cirrhosis without HCC (28.2%) and alcoholic cirrhosis without HCC (10.2%). Hepatitis C virus infection (with or without HCC) was the most frequent etiologic factor (45.9% of the whole population and 71.4% of viral-related cirrhosis), yet hepatitis B virus infection accounted for 28.6% of viral-related cirrhosis, and HBcAb positivity was found in 49.7% of recipients. The median Model for End Stage Liver Disease (MELD) at transplant was 12 in patients with HCC and 18 in those without. Multivariate analysis showed a slight but significant inverse association between DRI and MELD at transplant. CONCLUSIONS The deceased donor population in Italy has a high-risk profile compared to other countries, mainly due to older donor age. Almost half of the grafts are transplanted in recipients with HCC. Higher risk donors tend to be preferentially allocated to recipients with HCC, who are usually less ill and older. No other relevant allocation strategy is currently adopted at national level.

Hepatic oxidative alterations in patients with extra-hepatic cholestasis. Effect of surgical drainage

BACKGROUND/AIMS The mechanisms of liver injury in conditions of biliary obstruction are poorly understood. Hepatic oxidative injury has been observed in experimental models of cholestasis. Little is known in humans. This study aimed to gain more insights into the hepatic redox status in human cholestasis. METHODS Liver concentrations of total glutathione, protein sulfhydryls and malondialdehyde (end-product of lipid peroxidation) were measured in hepatic specimens of 12 patients with obstructive jaundice before and after the application of an external biliary drainage and in six control subjects. RESULTS Compared to control subjects, biliary obstructed patients showed significantly (P < 0.001) lower concentrations of hepatic glutathione and protein sulfhydryls, and higher (P < 0.001) levels of malondialdehyde, in the presence of comparable protein concentrations. Two-weeks after the application of external biliary drainage, cholestatic indices were significantly improved and the observed changes in glutathione, protein sulfhydryls and malondialdehyde levels, significantly decreased. CONCLUSIONS This study shows that cholestasis is associated with a decreased protein and non-protein sulfhydryl content in the liver and with an increased lipid peroxidation. These alterations reversed almost completely after biliary drainage, indicating the cholestasis itself as the determining factor for the redox status impairment observed in the liver of patients with extra-hepatic biliary obstruction.

Clinical role of tissue and serum levels of SCCA antigen in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the fifth most frequent cancer in the world and a common occurrence in patients with liver cirrhosis in western and North American countries. Ultrasound screening is a powerful technique for HCC diagnosis, whereas the only available serologic test, alpha‐fetoprotein, has poor reliability. It has been reported that the squamous cell carcinoma antigen (SCCA) is overexpressed in HCC tissue. In our study, the expression of SCCA was investigated in tumoral and peritumoral tissues and in the serum of 52 HCC patients, as well as in the serum of 48 cirrhotic patients. The results show that SCCA expression is much stronger in the tumoral than in the peritumoral tissue of HCC. Moreover, it is also evident in metastatic nodules present in the peritumoral tissue. SCCA serum levels were significantly higher in HCC samples than in cirrhotic samples. However, no correlation was found between SCCA expression and the HCC histologic degree, nor did SCCA expression correlate with tumor size, presence of metastasis or clinical outcome. In conclusion, in HCC patients, the SCCA antigen could represent a useful marker for the detection of micro‐metastasis in the tissues and for large‐scale screening of serum in patients at risk.

Laminin‐5 stimulates hepatocellular carcinoma growth through a different function of α6β4 and α3β1 integrins

Hepatocellular carcinoma (HCC) growth severely affects prognosis. Ki‐67, a known marker of cell proliferation, is a negative prognostic factor in HCC. Growth factors such as the epidermal growth factor (EGF) induce HCC cell proliferation but do not explain the great heterogeneity of HCC growth. Laminin‐5 (Ln‐5) is an extracellular matrix protein (ECM) present in the tissue microenvironment of HCC. The two main receptors for Ln‐5, integrins α3β1 and α6β4, are expressed on the cell surface of HCC cells. The aim of this study is to investigate an alternative mechanism of HCC growth whereby Ln‐5 promotes HCC cell proliferation through α3β1 and α6β4. HCC tissues containing Ln‐5 display a larger diameter and higher number of positive cells for Ki‐67, a well known proliferative index, as determined by double immunofluorescence staining and real‐time PCR on microdissected tissues. In vitro, Ln‐5, but not collagen I, collagen IV or fibronectin, induces proliferation as much as EGF does, via Erk phosphorylation as a consequence of β4 integrin phosphorylation. However, the two HCC cell lines do not proliferate in presence of Ln‐5 despite β4 integrin and Erk1/2 activation. After transfection with α3 integrin, in the presence of Ln‐5 one of these HCC cell lines acquires a proliferative activity whereas one of the proliferative HCC cell lines, knocked‐down for α3 integrin, loses its proliferative activity. Conclusions: Our study suggests a new mechanism of HCC growth whereby Ln‐5 stimulates proliferation via a different function of α6β4 and α3β1. (HEPATOLOGY 2007.)