Purpose: Extracellular matrix metalloprotease inducer (EMMPRIN) is a tumor surface protein that promotes growth and is overexpressed in head and neck cancer.These features make it a potential therapeutic target for monoclonal antibody (mAb)^based therapy. Because molecular therapy is considered more effective whendelivered with conventionalcytotoxic agents, anti-EMMPRINtherapy was assessed alone andin combination with external beam radiation. Experimental Design: Using a murine flank model, loss of EMMPRIN function was achieved by transfection with a small interfering RNA against EMMPRIN or treatment with a chimeric anti-EMMPRIN blocking mAb. Cytokine expression was assessed for xenografts, tumor cells, fibroblasts, and endothelial cells. Results: Animals treated with anti-EMMPRIN mAb had delayed tumor growth compared with untreated controls, whereas treatment with combination radiation and anti-EMMPRIN mAb showed the greatest reduction in tumor growth (P = 0.001). Radiation-treated EMMPRIN knockdown xenografts showed a reduction in tumor growth compared with untreated knockdown controls (P = 0.01), whereas radiation-treated EMMPRIN^expressing xenografts did not show a delay in tumor growth. Immunohistochemical evaluation for Ki67 and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) resulted in a reduction in proliferation (P = 0.007) and increased apoptosis in anti-EMMPRIN mAb^treated xenografts compared with untreated controls (P = 0.087). In addition, we provide evidence that EMMPRIN suppression results in decreased interleukin 1h (IL-1h), IL-6, and IL-8 cytokine production, in vitro and in vivo. Conclusions: These data suggest that anti-EMMPRIN antibody inhibits tumor cell proliferation in vivo and may represent a novel targeted treatment option in head and neck squamous cell carcinoma.

Introduction Merck's MK-2206 is an orally active, allosteric inhibitor of AKT; a component of the phosphatidylinositol-3 kinase (PI3K) pathway. The PI3K-AKT pathway is a downstream signaling pathway that has recently been found to play an important role in head and neck squamous cell carcinoma (HNSCC). Here we examine the role AKT inhibitors may play in preventing metastasis in HNSCC. Methods Cell migration after 24 hour treatment with sub-therapeutic doses of MK-2206 was assessed using an ELISA assay in 4 HNSCC cell lines: CAL27, FaDu, SCC-1 and SCC-5). In vitro effect of MK-2206 on cell migration was assessed by making linear scratches in culture plates after cell lines were grown to confluency. Images were taken at 8, 16 and 24 hours. In vivo analysis was performed on Nude mice with human SCC1-orthotopic tongue tumors. After tumors were allowed to grow for 7 days, mice were treated with oral dosing of 120 mg/kg of MK-2206 every other day for 2 weeks. Tumor size was assessed after each treatment using a pair of digital calipers. At the end of the treatment period, mice were sacrificed and cervical lymph nodes were assessed for metastasis using flourescent imaging of tumor cell markers. Results Sub-therapeutic doses of MK-2206 was sufficient to significantly reduce cell migration a in FaDu, SCC-1 and SCC-5 cell lines (p<0.001) but not in Cal27 (p=0.09). In vitro scratch test results in SCC-1 cells yielded significant reduction in cell movement at 8, 16 and 14 hours (p<0.001). In vivo orthotopic model yielded significant reduction in primary tumor size (p=0.04) and reduction in positive cervical lymph nodes (p=0.01) between treatment and control mice. In addition we found 100% survival of MK-2206 treated mice after two weeks of treatment compared with 70 % survival in our control group (p=0.03). Conclusions Treatment with MK-2206 is sufficient to inhibit HNSCC chemotaxis and migration in vitro. In an orthotopic model, treatment with MK-2206 reduces primary tumor size and cervical metastasis while improving survival. MK-2206 currently being used in phase II clinical trials for combination treatment of metastatic solid tumors and may be useful for treating HNSCC as well.

Background The significance of EGFR expression in advanced cutaneous squamous cell carcinoma (cSCC) of the head and neck remains poorly understood. Methods Retrospective review of patients with advanced stage (Stage III or IV) cSCC of the head and neck (n = 56). Results The majority of patients (91%) had stage III disease, with 54% having regional metastasis and 9% with distant metastasis. Two-year survival was 64% and the 5-year survival was 56%. EGFR was found to be overexpressed in 56% of primary tumors and 58% of regional metastatic disease. Overall survival did not correlate with EGFR (p = 0.47) expression in primary lesions nor was it associated with an increase in regional (p = 0.74) or distant metastasis (p = 0.56). Furthermore, there was no correlation between clinicopathologic characteristics and EGFR expression Conclusion This data does not suggest upregulation of EGFR is associated with poor survival or aggressive disease.

Targeting the molecular pathways associated with carcinogenesis remains the greatest opportunity to reduce treatment-related morbidity and mortality. Extracellular matrix metalloproteinase inducer (EMMPRIN), also known as CD147, is a cell surface molecule known to promote tumor growth and angiogenesis in preclinical studies of head and neck carcinoma making it an excellent therapeutic target. To evaluate the feasibility of anti-EMMPRIN therapy, an ex-vivo human head and neck cancer model was established using specimens obtained at the time of surgery (n=22). Tumor slices were exposed to varying concentrations of anti-EMMPRIN monoclonal antibody and cetuximab for comparison purposes. Cetuximab is the only monoclonal antibody currently approved for the treatment of head and neck carcinoma. After treatment, tumor slices were assessed by immunohistochemistry and western blot analysis for apoptosis (TUNEL) and EMMPRIN expression. Of the tumor specimens 33% showed a significant reduction in mean ATP levels after treatment with cetuximab compared with untreated controls, whereas 58% of the patients responded to anti-EMMPRIN therapy (P<0.05). Samples, which showed reactivity to anti-EMMPRIN, also had greater EMMPRIN expression based on immunohistochemistry staining (49%) when compared with nonresponders (25%, P=0.06). In addition, TUNEL analysis showed a larger number of cells undergoing apoptosis in antibody-treated tumor slices (77%) compared with controls (30%, P<0.001) with activation of apoptotic proteins, caspase 3 and caspase 8. This study shows the potential of anti-EMMPRIN to inhibit proliferation and promote apoptosis and suggests its future role in the targeted treatment of head and neck carcinoma.

The objective of this study was to evaluate extracelluar matrix metalloproteinase (EMMPRIN) as a novel target in orthotopic pancreatic-cancer murine models. MIA PaCa-2 human pancreatic tumor cells were implanted in groups 1 and 3-7, while MIA PaCa-2 EMMPRIN knockdown cells were implanted in group 2. Dosing with anti-EMMPRIN antibody started immediately after implantation for groups 1-3 (residual tumor model) and at 21 days after cell implantation for groups 4-7 (established tumor model). Groups 3, 5, and 7 were treated with anti-EMMRPIN antibody (0.2-1.0 mg) twice weekly for 2-3 weeks, while the other groups served as the control. In residual tumor model, tumor growth of anti-EMMPRIN treated group was successfully arrested for 21 days (15±4 mm3), significantly lower than that of EMMPRIN knockdown group (80±15 mm3; p=0.001) or control group (240±41 mm3; p<0.001). In established tumor model, anti-EMMPRIN therapy lowered tumor-volume increase about 40% compared with control regardless of dose amount. Ki67-expressed cell densities of group 5 was 939±150 mm−2, significantly lower than that of group 4 (1709±145 mm−2; p=0.006). Microvessel density of group 5 (30±6 mm−2) was also significantly lower than that of group 4 (53±5 mm−2; p=0.014), while the microvessel size of group 5 (191±22 μm2) was significantly larger than that of group 4 (113±26 μm2; p=0.049). These data show the high potential of anti-EMMPRIN therapy for pancreatic cancer, and support its clinical translation.