Sorafenib inhibits macrophage-induced growth of hepatoma cells by interference with insulin-like growth factor-1 secretion.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) associated macrophages accelerate tumor progression by growth factor release. Therefore, tumor-associated macrophages (TAM) and their initiated signaling cascades are potential therapeutic targets. Aiming at understanding anticancer effects of systemic HCC therapy, we investigated the impact of sorafenib on macrophage function, focusing on macrophage-related growth factor secretion. METHODS: Macrophage markers, cytokine and growth factor release were investigated in CSF-1 (M1) or GMCSF (M2) maturated monocyte-derived macrophages. Macrophages were treated with sorafenib (1.2-5.0 µg/ml) and culture supernatants were transferred to hepatoma cell cultures to assess growth propagation. Insulin-like growth factor (IGF) signaling was blocked with NVP-AEW541 to confirm the role of IGF-1 in macrophage-driven hepatoma cell propagation. Macrophage activation was followed by ELISA of serum soluble mCD163 in sorafenib-treated patients with HCC. RESULTS: Alternative macrophages (M2), which showed higher IGF-1 (p=0.022) and CD163 mRNA (p=0.032) expression compared to classical macrophages (M1), increased hepatoma growth. This effect was mediated by M2-conditioned culture media. In turn, sorafenib lowered mCD163 and IGF-1 release by M2 macrophages, which decelerated M2 macrophage driven HuH7 and HepG2 proliferation by 47% and 64%, respectively. IGF-receptor blockage with NVP-AEW541 reduced growth induction by M2-conditioned culture media in a dose dependent manner. A transient mCD163 reduction during sorafenib treatment indicated a coherent M2 macrophage inhibition in patients with HCC. CONCLUSIONS: Sorafenib alters macrophage polarization, reduces IGF-1-driven cancer growth in vitro and partially inhibits macrophage activation in vivo. Thus macrophage modulation might contribute to the anti-cancer activity of sorafenib. However, more efficient macrophage-directed therapies are required.

Sorafenib perpetuates cellular anticancer effector functions by modulating the crosstalk between macrophages and natural killer cells.

UNLABELLED: Alternatively polarized macrophages (Mϕ) shape the microenvironment of hepatocellular carcinoma (HCC) and temper anticancer immune responses. We investigated if sorafenib alters the HCC microenvironment by restoring classical macrophage polarization and triggering tumor-directed natural killer (NK) cell responses. In vivo experiments were conducted with sorafenib (25 mg/kg)-treated C57BL/6 wildtype as well as hepatitis B virus (HBV) and lymphotoxin transgenic mice with and without HCC. Monocyte-derived Mϕ or tumor-associated macrophages (TAM) isolated from HCC tissue were treated with sorafenib (0.07-5.0 µg/mL) and cocultured with autologous NK cells. Mϕ and NK cell activation was analyzed by flow cytometry and killing assays, respectively. Cytokine and growth factor release was measured by enzyme-linked immunosorbent assay. Short-term administration of sorafenib triggered activation of hepatic NK cells in wildtype and tumor-bearing mice. In vitro, sorafenib sensitized Mϕ to lipopolysaccharide, reverted alternative Mϕ polarization and enhanced IL12 secretion (P = 0.0133). NK cells activated by sorafenib-treated Mϕ showed increased degranulation (15.3 ± 0.2% versus 32.0 ± 0.9%, P < 0.0001) and interferon-gamma (IFN-γ) secretion (2.1 ± 0.2% versus 8.0 ± 0.2%, P < 0.0001) upon target cell contact. Sorafenib-triggered NK cell activation was verified by coculture experiments using TAM. Sorafenib-treated Mϕ increased cytolytic NK cell function against K562, Raji, and HepG2 target cells in a dose-dependent manner. Neutralization of interleukin (IL)12 or IL18 as well as inhibition of the nuclear factor kappa B (NF-κB) pathway reversed NK cell activation in Mϕ/NK cocultures. CONCLUSION: Sorafenib triggers proinflammatory activity of TAM and subsequently induces antitumor NK cell responses in a cytokine- and NF-κB-dependent fashion. This observation is relevant for HCC therapy, as sorafenib is a compound in clinical use that reverts alternative polarization of TAM in HCC. (HEPATOLOGY 2013;57:2358-2368).

Sarcopenia as prognostic factor for survival after orthotopic liver transplantation.

BACKGROUND AND AIM: Body composition has emerged as a prognostic factor for end-stage liver disease. We therefore investigated muscle mass, body fat and other clinical-pathological variables as predictors of posttransplant survival. METHODS: A total of 368 patients, who underwent orthotopic liver transplantation (OLT) at our institution, were assessed prior to OLT and followed for a median of 9.0 years (range 2.0-10.0 years) after OLT. Psoas, erector spinae and the combined paraspinal muscle area, as well as the corresponding indices normalized by body-height squared, were quantified by a lumbar (L3) cross-sectional computed tomography. In addition, absolute body fat and bone density were estimated by the same computed tomography approach. RESULTS: Paraspinal muscle index (PSMI) (hazard ratio 0.955, P = 0.039) and hepatitis C (hazard rati 1.498, P = 0.038) were independently associated with post-OLT mortality. In contrast, body fat and bone density did not significantly affect post-OLT outcome (P > 0.05). The PSMI also predicted one-year posttransplant mortality with a receiver operating characteristics-area under the curve of 0.671 [95% confidence interval (CI) 0.589-0.753, P < 0.001) in male patients and outperformed individual psoas and erector spinae muscle group assessments in this regard. In male patients, a defined PSMI cutoff (<18.41 cm/m) was identified as suitable determinant for sarcopenia and posttransplant one-year mortality. In female OLT-recipients, however, sarcopenia was not predictive for patient survival und a women-specific cutoff could not be derived from this study. CONCLUSIONS: Taken together this analysis provides evidence, which PSMI is a relevant marker for muscle mass and that sarcopenia is an independent predictor of early post-OLT survival in male patients.