EGFR and VEGFR as potential target for biological therapies in HCC cells.

Hepatocellular carcinoma (HCC) is a highly malignant cancer with poor prognosis. Inhibitors of EGFR and VEGFR for HCC treatment are currently under investigation. Gefitinib and vandetanib inhibit migration of HCC cells on Laminin-5 and Fibronectin, and invasion through matrigel. Both drugs inhibit p-EGFR after short time, while their efficacy on p-Erk1/2 and p-Akt is progressive and stable over time. PI3K/Akt and MEK/Erk1/2 inhibitors, inhibit migration and invasion as well as inducing de-phosphorylation of downstream effectors. Finally, both inhibitors, vandetanib and gefitinib down-regulated the secretion of matrix metalloproteases MMP-2 and MMP-9. All these biological effects seem to depend on the activity of gefitinib and vandetanib blocking activity towards p-EGFR mediated pathways.

Laminin-5 stimulates hepatocellular carcinoma growth through a different function of alpha6beta4 and alpha3beta1 integrins.

UNLABELLED: 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 alpha3beta1 and alpha6beta4, 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 alpha3beta1 and alpha6beta4. 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 beta4 integrin phosphorylation. However, the two HCC cell lines do not proliferate in presence of Ln-5 despite beta4 integrin and Erk1/2 activation. After transfection with alpha3 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 alpha3 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 alpha6beta4 and alpha3beta1.

Alterated integrin expression in lichen planopilaris.

BACKGROUND: Lichen planopilaris (LPP) is an inflammatory disease characterized by a lymphomononuclear infiltrate surrounding the isthmus and infundibulum of the hair follicle of the scalp, that evolves into atrophic/scarring alopecia. In the active phase of the disease hairs are easily plucked with anagen-like hair-roots. In this study we focused on the expression of integrins and basement membrane components of the hair follicle in active LPP lesions. METHODS: Scalp biopsies were taken in 10 patients with LPP and in 5 normal controls. Using monoclonal antibodies against alpha3beta1 and alpha6beta4 integrins we showed the expression of these integrins and of the basement membrane components of the hair follicle in active LPP lesions and in healthy scalp skin. RESULTS: In the LPP involved areas, alpha3beta1 was distributed in a pericellular pattern, the alpha6 subunit was present with a basolateral distribution while the beta4 subunit showed discontinuous expression at the basal pole and occasionally, basolateral staining of the hair follicle. CONCLUSION: An altered distribution of the integrins in active LPP lesions can explain the phenomenon of easy pulling-out of the hair with a "gelatinous" root-sheath.

ZD6474 inhibits proliferation and invasion of human hepatocellular carcinoma cells.

Hepatocellular carcinoma (HCC) is characterized by hypervascularization, neoangiogenesis formation and blood vessel invasion. Recently, it has been demonstrated that an inhibitor of the vascular endothelial growth factor (VEGF) receptor, ZD6474, may directly inhibit the growth of tumor cells. ZD6474 effectiveness was investigated on cell growth, apoptosis, adhesion, migration and invasion and related to the drug-dependent modulation of main molecular targets on HCC cells. ZD6474 inhibited HCC cell proliferation, however, such effect was reverted by Laminin-5 (Ln-5) but not by other extracellular matrix proteins (ECM). ZD6474 also inhibited HCC cell adhesion, migration and invasion, whereas the simultaneous treatment with the drug and Ln-5 strongly recovered those effects. Under the same experimental conditions, ZD6474 inhibited the expression of phosphorylated EGFR in all cell lines while the effect on p-Erk1/2 was dependent on cellular invasive characteristics. Nonetheless, co-incubation with Ln-5 completely recovered this effect. Our results support the hypothesis that ZD6474 could represent an interesting therapeutic opportunity for patients with HCC scarcely expressing the ECM protein, Ln-5.

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.