IL-8 mRNA expression in primary malignant melanoma mRNA in situ hybridization: sensitivity, specificity, and evaluation of data

Targeting intracellular signaling as an antiviral strategy: aerosolized LASAG for the treatment of influenza in hospitalized patients

Influenza has been a long-running health problem and novel antiviral drugs are urgently needed. In pre-clinical studies, we demonstrated broad antiviral activity of D, L-lysine-acetylsalicylate glycine (LASAG) against influenza virus (IV) in cell culture and protection against lethal challenge in mice. LASAG is a compound with a new antiviral mode of action. It inhibits the NF-κB signal transduction module that is essential for IV replication. Our goal was to determine whether aerosolized LASAG would also show a therapeutic benefit in hospitalized patients suffering from severe influenza. The primary endpoint was time to alleviation of clinical influenza symptoms. The primary analysis was based on the modified intention-to-treat (MITT) population. This included all patients with confirmed influenza virus infection who received at least one treatment. The per protocol (PP) analysis set included all subjects from the MITT population who underwent at least 13 inhalations. In the MITT group, 48 (41.7%) participants (29 LASAG; 19 placebo) had severe influenza. The mean time to symptom alleviation was 56.2 h in the placebo group and 43.0 h in the LASAG group. The PP set consisted of 41 patients (24 LASAG; 17 placebo). The mean time to symptom alleviation in the LASAG group (38.3 h; P = 0.0365) was lower than that in the placebo group (56.2 h). In conclusion, LASAG improved the time to alleviation of influenza symptoms in hospitalized patients. The present phase II proof-of-concept (PoC) study demonstrates that targeting an intra-cellular signaling pathway using aerosolized LASAG improves the time to symptom alleviation compared to standard treatment.

The NF-κB inhibitor SC75741 efficiently blocks influenza virus propagation and confers a high barrier for development of viral resistance

Ongoing human infections with highly pathogenic avian H5N1 viruses and the emergence of the pandemic swine-origin influenza viruses (IV) highlight the permanent threat elicited by these pathogens. Occurrence of resistant seasonal and pandemic strains against the currently licensed antiviral medications points to the urgent need for new and amply available anti-influenza drugs. The recently identified virus-supportive function of the cellular IKK/NF-κB signalling pathway suggests this signalling module as a potential target for antiviral intervention. We characterized the NF-κB inhibitor SC75741 as a broad and efficient blocker of IV replication in non-toxic concentrations. The underlying molecular mechanism of SC75741 action involves impaired DNA binding of the NF-κB subunit p65, resulting in reduced expression of cytokines, chemokines, and pro-apoptotic factors, subsequent inhibition of caspase activation and block of caspase-mediated nuclear export of viralribonucleoproteins. SC75741 reduces viral replication and H5N1-induced IL-6 and IP-10 expression in the lung of infected mice. Besides its virustatic effect the drug suppresses virus-induced overproduction of cytokines and chemokines, suggesting that it might prevent hypercytokinemia that is discussed to be an important pathogenicity determinant of highly pathogenic IV. Importantly the drug exhibits a high barrier for development of resistant virus variants. Thus, SC75741-derived drugs may serve as broadly non-toxic anti-influenza agents.

A(2B) and A(3) adenosine receptors modulate vascular endothelial growth factor and interleukin-8 expression in human melanoma cells treated with etoposide and doxorubicin

Cancer patients undergoing treatment with systemic cancer chemotherapy drugs often have abnormal growth factor and cytokine profiles. Thus, serum levels of interleukin-8 (IL-8) are elevated in patients with malignant melanoma. In addition to IL-8, aggressive melanoma cells secrete, through its transcriptional regulator hypoxia-inducible factor 1 (HIF-1), vascular endothelial growth factor (VEGF), which promotes angiogenesis and metastasis of human cancerous cells. Whether these responses are related to adenosine, a ubiquitous mediator expressed at high concentrations in cancer and implicated in numerous inflammatory processes, is not known and is the focus of this study. We have examined whether the DNA-damaging agents etoposide (VP-16) and doxorubicin can affect IL-8, VEGF, and HIF-1 expressions in human melanoma cancer cells. In particular, we have investigated whether these responses are related to the modulation of the adenosine receptor subtypes, namely, A(1), A(2A), A(2B), and A(3). We have demonstrated that A(2B) receptor blockade can impair IL-8 production, whereas blocking A(3) receptors, it is possible to further decrease VEGF secretion in melanoma cells treated with VP-16 and doxorubicin. This understanding may present the possibility of using adenosine antagonists to reduce chemotherapy-induced inflammatory cytokine production and to improve the ability of chemotherapeutic drugs to block angiogenesis. Consequently, we conclude that adenosine receptor modulation may be useful for refining the use of chemotherapeutic drugs to treat human cancer more effectively.

Tumor immunotherapy in melanoma: strategies for overcoming mechanisms of resistance and escape

The incidence of melanoma has been steadily increasing over the last 3 decades. Currently, there are several approved treatments for metastatic melanoma, including chemotherapy and biologic therapy as both single treatments and in combination, but none is associated with a significant increase in survival. The chemotherapeutic agent dacarbazine is the standard treatment for metastatic melanoma, with a response rate of 15-20%, although most responses are not sustained. One of the main problems with melanoma treatment is chemotherapeutic resistance. The mechanisms of resistance of melanoma cells to chemotherapy have yet to be elucidated. Following treatment with dacarbazine, melanoma cells activate the extracellular signal-regulated kinase pathway, which results in over-expression and secretion of interleukin (IL)-8 and vascular endothelial growth factor. Melanoma cells utilize this mechanism to escape from the cytotoxic effect of the drug. We have previously reported on the development of fully human neutralizing antibodies against IL-8 (anti-IL-8-monoclonal-antibody [ABX-IL8]). In preclinical studies, ABX-IL8 inhibited tumor growth, angiogenesis, and metastasis of human melanoma in vivo. We propose that combination treatment with dacarbazine and IL-8 will potentiate the cytotoxic effect of the drug. Furthermore, formation of metastasis is a multistep process that includes melanoma cell adhesion to endothelial cells. Melanoma cell adhesion molecule (MUC18) mediates these processes in melanoma and is therefore a good target for eliminating metastasis. We have developed a fully human antibody against MUC18 that has shown promising results in preclinical studies. Since resistance is one of the major obstacles in the treatment of melanoma, we propose that utilization of antibodies against IL-8 or MUC18 alone, or as part of a 'cocktail' in combination with dacarbazine, may be a new treatment modality for metastatic melanoma that overcomes resistance of the disease to chemotherapy and significantly improves survival of patients.

Bioimmunotherapy for melanoma using fully human antibodies targeting MCAM/MUC18 and IL-8

Metastatic melanoma is associated with high rate of patients' mortality and represents a great challenge for cancer therapies because of its notorious resistance to chemotherapeutic drugs. Considerable efforts have been made over the last 2 decades in pursuit of new treatment modalities and identification of molecular events associated with melanoma progression and development of metastases. The acquisition of the metastatic phenotype is associated with overexpression of the adhesion molecule MCAM/MUC18 and the angiogenic factor IL-8. In this review, we summarize our current knowledge on MCAM/MUC18 and IL-8, their transcriptional regulation, and their role in melanoma growth, angiogenesis and metastasis. Further, we report on the development of new fully human antibodies, anti-MCAM/MUC18 (ABX-MA1) and anti-IL-8 (ABX-IL8), and their effects on tumor growth and metastasis in animal models. Collectively, our studies suggest that ABX-MA1 and ABX-IL8 could serve as new modalities for the treatment of melanoma either alone, or in combination with conventional chemotherapy or other antitumor agents.

Identification of genes promoting angiogenesis in mouse lung by transcriptional profiling

A better understanding of the regulation of factors that promote angiogenesis may ultimately enable improved therapeutic control of this important process. In our previous studies, obstruction of the left pulmonary artery in the mouse consistently induced the formation of a new vasculature, which developed from the visceral pleura and entered the upper left lung directly within 5-6 days after ligation. No new vessels developed to the lower left lung, despite the initial ischemic stimulus being identical to that in the upper lung. Using this unique model of angiogenesis, we have determined the temporal pattern of differential gene expression from two independent regions of the same lung: one where angiogenesis is induced, and the other where angiogenesis does not occur. Microarray analysis and quantitative real-time RT-PCR were used to compare the signals from these two lung regions in the first 3 d following ischemia. The findings reveal the important roles of ELR+ CXC chemokines as proangiogenic signals. Genes involved in tissue remodeling, inflammation, and injury were also upregulated in the proangiogenic upper lung. Results also confirm that lung ischemia, rather than hypoxia, is the essential trigger for angiogenesis. These altered profiles of expression in the early stage of lung ischemia show potential roles and interactions of the most important genes involved in promoting new blood vessel formation.

Fully humanized neutralizing antibodies to interleukin-8 (ABX-IL8) inhibit angiogenesis, tumor growth, and metastasis of human melanoma

Interleukin-8 (IL-8) has recently been shown to contribute to human melanoma progression by functioning as a mitogenic and angiogenic factor. In the present study, we investigated whether targeting IL-8 by a fully human anti-IL-8 antibody (ABX-IL8) could be a potential therapeutic strategy to control angiogenesis, growth, and metastasis of melanoma. The human melanoma cells A375SM (high IL-8 producer) and TXM-13 (intermediate IL-8 producer) were injected subcutaneously into nude mice, which were then treated with ABX-IL8 (1 mg/3 times weekly, i.p., for 3 weeks). Tumor growth of both melanomas in ABX-IL8-treated mice was significantly inhibited when compared with control IgG-treated animals. ABX-IL8 treatment also suppressed experimental metastasis when the melanoma cells were injected intravenously. IL-8 blockade by ABX-IL8 significantly inhibited the promoter activity and the collagenase activity of matrix metalloproteinase-2 in human melanoma cells, resulting in decreased invasion through reconstituted basement membrane in vitro. In vivo, ABX-IL8 treatment resulted in decreased expression of matrix metalloproteinase-2, and decreased vascularization (angiogenesis) of tumors concomitant with increased apoptosis of tumor cells. Moreover, in an in vitro vessel formation assay, ABX-IL8 directly interfered with the tubule formation by human umbilical vein endothelial cells. Taken together, these results point to the potential utility of ABX-IL8 as a modality to treat melanoma and other solid tumors either alone or in combination with conventional chemotherapy or other anti-tumor agents.