Jean-Claude Barbare

EGFR activation is a potential determinant of primary resistance of hepatocellular carcinoma cells to sorafenib

Sorafenib is currently the medical treatment of reference for hepatocellular carcinoma (HCC), but it is not known whether sorafenib is equally active in all HCC. Here, our aim was to explore intrinsic differences in the response of HCC cells to sorafenib, to identify potential mechanisms leading to primary resistance to this treatment. We analyzed a panel of six human HCC cell lines and compared the activity of the main oncogenic kinase cascades, their clonogenic potential, proliferation and apoptosis upon exposure to sorafenib. We report that HCC cells present important differences in their response to sorafenib, and that some cell lines are more resistant to the actions of sorafenib than others. We identify the activated epidermal growth factor receptor (EGFR) as a parameter that promotes the resistance of HCC cells to sorafenib. In resistant cells, the efficacy of sorafenib was increased when EGFR was inhibited, as was demonstrated using two chemical inhibitors (erlotinib or gefitinib), a monoclonal antibody directed against EGFR (cetuximab), and RNA interference directed against EGFR. A combination of EGFR inhibitors and sorafenib affords a better control over HCC proliferation, most likely through an improved blockade of the RAF kinases. Our findings therefore confirm the importance of RAF kinases as therapeutic targets in HCC, and identify EGFR as a determinant of the sensitivity of HCC cells to sorafenib. Our findings bear possible implications for the improvement of the efficacy of sorafenib in HCC, and might be useful for the identification of predictive biomarkers in this context.

Iron-dependent cell death of hepatocellular carcinoma cells exposed to sorafenib

The multikinase inhibitor sorafenib is currently the treatment of reference for advanced hepatocellular carcinoma (HCC). In our report, we examined the cytotoxic effects of sorafenib on HCC cells. We report that the depletion of the intracellular iron stores achieved by using the iron chelator deferoxamine (DFX) strikingly protects HCC cells from the cytotoxic effects of sorafenib. The protective effect of the depletion of intracellular iron stores could not be explained by an interference with conventional forms of programmed cell death, such as apoptosis or autophagic cell death. We also found that DFX did not prevent sorafenib from reaching its intracellular target kinases. Instead, the depletion of intracellular iron stores prevented sorafenib from inducing oxidative stress in HCC cells. We examined the possibility that sorafenib might exert a cytotoxic effect that resembles ferroptosis, a form of cell death in which iron‐dependent oxidative mechanisms play a pivotal role. In agreement with this possibility, we found that pharmacological inhibitors (ferrostatin‐1) and genetic procedures (RNA interference against IREB‐2) previously reported to modulate ferroptosis, readily block the cytotoxic effects of sorafenib in HCC cells. Collectively, our findings identify ferroptosis as an effective mechanism for the induction of cell death in HCC. Ferroptosis could potentially become a goal for the medical treatment of HCC, thus opening new avenues for the optimization of the use of sorafenib in these tumors.

Treatment of advanced hepatocellular carcinoma with long-acting octreotide: a phase III multicentre, randomised, double blind placebo-controlled study.

BACKGROUNDnA previous study reported a significant survival benefit for octreotide compared with no treatment in patients with advanced hepatocellular carcinoma (HCC). This was investigated further in this multicentre study.nnnPATIENTS AND METHODSnTwo hundred and seventy two patients with HCC who were ineligible for curative treatments or had relapsed following potentially curative therapies were randomised to receive long-acting octreotide, 30 mg as an intramuscular injection once every 4 weeks for up to 2 years, or placebo.nnnRESULTSnAt the time of the final analysis, median overall survival (OS) was 6.53 months (95% confidence interval [CI], 4.8-8.3) for octreotide versus 7.03 months (95% CI, 5.43-8.53) for placebo (p=0.34). Progression-free survival (p=0.26) also did not differ significantly between the two treatment groups. No objective responses were achieved in the octreotide group but 33% of patients achieved disease stabilisation for a mean time of 5.5 months (95% CI, 1.1-9.9). The median time until definitive global health score deterioration (according to QLQ-C30) was 2.3 months (95% CI, 1.4-3.7) in the octreotide and 4 months (95% CI, 2.2-5.7) in the placebo group (p=0.09). There were four objective responses in the placebo group. Octreotide was well tolerated; seven patients reported severe adverse events possibly related to octreotide and there were no cases of haematoma or cholecystitis.nnnCONCLUSIONSnIn patients with advanced HCC, octreotide has a favourable safety profile but does not improve OS and could have a negative impact on quality of life.

The retinoblastoma (Rb) protein regulates ferroptosis induced by sorafenib in human hepatocellular carcinoma cells

Sorafenib is the treatment of reference for advanced hepatocellular carcinoma (HCC), the most frequent form of primary liver tumour. The loss of function of the retinoblastoma (Rb) protein is an important event during liver carcinogenesis, but it is unclear whether the Rb status modulates the response of HCC cells to sorafenib. Here, we examined this question in HCC cells with reduced levels of Rb achieved through stable RNA interference. We show that HCC cells with reduced levels of Rb exhibit a two- to threefold increase in cell death induction upon exposure to sorafenib compared with controls. Sorafenib treatment of Balb/c nude mice that received tumour xenografts derived from HCC cells with reduced Rb levels resulted in complete tumour regression in 50% of the animals treated, compared with tumour stabilization in mice that received control cells. We show that, upon exposure to sorafenib, the Rb-negative status of HCC cells promotes the occurrence of ferroptosis, a form of oxidative necrosis. The findings highlight the role of Rb in the response of HCC cells to sorafenib and the regulation of ferroptosis.

BAD, a proapoptotic member of the BCL2 family, is a potential therapeutic target in hepatocellular carcinoma.

Proteins of the BCL2 family are key regulators of apoptosis. Their expression levels are frequently altered in cancers, enabling tumor cells to survive. To gain insight into the pathogenesis of hepatocellular carcinoma (HCC), we performed a comprehensive survey of the expression of the members of the BCL2 family in samples obtained from surgically resected HCCs. Here, we report the occurrence of a new molecular anomaly, consisting of a strong reduction in the expression of the proapoptotic protein BAD in HCC compared with surrounding nontumoral tissue. We investigate the function of BAD in a panel of HCC cell lines. Using gene overexpression and RNA interference, we show that BAD is involved in the cytotoxic effects of sorafenib, a multikinase blocker, which is currently the sole therapeutic drug effective for the treatment of HCC. Finally, we report that ABT-737, a compound that interacts with proteins of the BCL2 family and exhibits a BAD-like reactivity, sensitizes HCC cells toward sorafenib-induced apoptosis. Collectively, our findings indicate that BAD is a key regulator of apoptosis in HCC and an important determinant of HCC cell response to sorafenib. Mol Cancer Res; 8(8); 1116–25. ©2010 AACR.

New biological perspectives for the improvement of the efficacy of sorafenib in hepatocellular carcinoma.

Sorafenib, an orally-available kinase inhibitor, is the only medical treatment with a proven efficacy against Hepatocellular Carcinoma (HCC). Although the overall clinical efficacy of sorafenib is modest, recent experimental results have uncovered new potential strategies that may increase its clinical benefits. The potential implication of Receptor Tyrosine Kinases (RTKs), such as the Epidermal Growth Factor Receptor (EGFR), in the development of resistance to sorafenib highlights the importance of the RAF kinase pathway. Various strategies aiming to optimize the control exerted over this pathway by combining sorafenib with other targeted molecules (such as anti-EGFR, anti-MEK) are under investigation. Increasing the cytotoxicity of sorafenib in HCC, either through apoptosis or through new forms of non-apoptotic cell death, such as ferroptosis, may also promote more sustained tumour regression. Finally, the heterogeneity of individual responses to sorafenib is increasingly recognised, even though clinically-applicable biomarkers remain to be identified. Here, we discuss how molecular genetics and complementary approaches such as short term culture of tumour samples could help to personalize the use of sorafenib.

The added value of quality of life (QoL) for prognosis of overall survival in patients with palliative hepatocellular carcinoma

BACKGROUND & AIMSnSeveral prognostic classifications (PCs) have been developed for use in palliative care in patients with hepatocellular carcinoma (HCC). We have recently suggested that CLIP combined with WHO PS has the greatest discriminative power. We evaluated the prognostic value of quality of life (QoL) data and whether the latter could improve classification of palliative HCC patients.nnnMETHODSnThis was a reanalysis from the CHOC trial with an evaluation of the discriminative power for overall survival (OS) of the established CLIP/GRETCH/BCLC/BoBar prognostic systems alone and then in association with each of the following groups of parameters: selected clinical factors, QoL as continuous variables, dichotomized QoL, selected clinical factors and continuous QoL, selected clinical factors and dichotomized QoL. Baseline QoL was assessed using the EORTC QLQ-C30. Discriminative power was evaluated with the Harrells C-index and net reclassification improvement.nnnRESULTSnQuality of life was available in 79% of the patients (n=271). Univariate analysis revealed that better role functioning (HR=0.991 [0.987-0.995]) and better physical functioning (0.991 [0.984-0.997]) scores were associated with longer survival. In contrast, poorer score for fatigue (1.011 [1.006-1.015]) and diarrhoea (1.008 [1.002-1.013]) were associated with shorter survival. After adjustment for clinical and sociodemographic variables, only better role functioning score (0.993 [0.988-0.998]) was associated with longer survival. Adding oedema, hepatomegaly, fatigue and diarrhoea QoL scales to CLIP resulted in the best performance.nnnCONCLUSIONSnOur results confirm that QoL scales are independent prognostic factors of OS in palliative HCC patients. Incorporation of QoL data improved all the studied PCs.

Alpha-foetoprotein (AFP): A multi-purpose marker in hepatocellular carcinoma.

Alpha-foetoprotein (AFP), one of the first protein tumour markers discovered, is widely used today in clinical practice. Its application for the screening and diagnosis of hepatocellular carcinoma (HCC), the most frequent form of primary liver tumour, is a matter of extensive debate. In addition to the studies focused on the role of the AFP in the diagnosis of HCC, in recent years AFP has been used to guide the therapeutic choice in HCC and monitor the treatment. Here, we summarize the latest studies that show the interest of AFP quantification in determining the suitability of liver transplantation or to follow-up on patients receiving the targeted treatment sorafenib. We also highlight the recent studies showing the active role of AFP in tumour progression, and the new modes of regulation of this tumour marker. Among these is the regulation of AFP through tumour proteostasis and the Unfolded Protein Response (UPR). We discuss the implications of this new knowledge in the therapeutic context, in terms of interpreting serum levels of AFP, and the new perspectives offered by AFP for the study of tumour proteostasis.

Development and validation of a new prognostic score of death for patients with hepatocellular carcinoma in palliative setting.

BACKGROUND & AIMSnPatients with hepatocellular carcinoma (HCC) in a palliative setting have a poor prognosis despite recent therapeutic progress. Several prognostic scores, such as the BCLC and the CLIP, have been shown to be useful in helping select treatment options ranging from transplantation to palliative care. However, the discriminatory ability of these scores is inadequate in palliative settings, which concern about 70% of HCC patients. In this paper, we propose and validate a new prognostic score for patients in the palliative setting.nnnMETHODSnThe prognostic score was developed on a set of 416 patients from a negative randomized clinical trial conducted by the Fédération Francophone de Cancers Digestifs. It was then subsequently validated on a second set of 271 patients from another negative trial. Backward selection was used to identify independent baseline characteristics. Measures of discrimination and predictive values were computed to assess the quality of the developed score. Comparisons with the BCLC and the CLIP - with and without the WHO performance status (PS) score - were performed.nnnRESULTSnTumour morphology, portal vein obstruction, metastasis, ascites, jaundice, alpha-foetoprotein, and serum alkaline phosphatase were included in the final score. From the training dataset, three groups of increasing risk were defined, and these were associated with hazard ratios (HR) of 2.13 and HR = 5.72. Similar results were obtained on the validation dataset. This score provides a better discriminatory ability than BCLC and CLIP in this setting. Unfortunately, absolute performances for these scores remain poor.nnnCONCLUSIONSnThe new prognostic score and CLIP + PS are recommended in palliative settings. However, new prognostic variables are necessary.

Prevalence of hepatitis C infection and risk factors in hospitalized diabetic patients: results of a cross-sectional study.

Objectives Although there may exist a nosocomial risk of hepatitis C virus (HCV) infection in patients with type 1 or type 2 diabetes, this risk has not been fully investigated thus far and its magnitude is unknown. The aim of this multicenter cross-sectional study was to evaluate the prevalence of, and risk factors for, hepatitis C infection in consecutive hospitalized patients with diabetes and to assess the nosocomial risk and magnitude of HCV infection in these patients. Patients and methods Consecutive hospitalized patients with diabetes seen in 11 French hepatogastroenterology and diabetology departments were studied. The prevalence of anti-HCV antibodies was compared with that observed in healthy blood donors and individuals seen during routine medical checkup. Diabetic patients with anti-HCV antibodies were compared with patients without anti-HCV antibodies for assessment of risk factors. Results In total 1561 patients were studied. Independent risk factors for HCV infection were assessed through multivariate analysis. Thirty-three patients (2.11%) had anti-HCV antibodies and 21 (63.70%) had HCV identified risk factors. The prevalence of HCV infection was higher in patients with diabetes than in blood donors (0.08%) or healthy controls (0.20%) (P<0.001). Multivariate analysis identified four independent risk factors for HCV infection: blood transfusion before 1991 [odds ratio (OR)=2.88, P=0.033], intravenous drug use (OR=21.37, P=0.012), treatment in a hepatogastroenterology center (OR=4.17, P=0.002) and a high number (>2) of previous admissions since the onset of diabetes (OR=2.52, P=0.039). Conclusion A nosocomial source of HCV infection in hospitalized diabetic patients is suggested by the increased risk of HCV infection associated with the number of hospitalizations. This may account for at least 36% of cases of HCV infection.