Ferret Systemic Coronavirus in Alpha-1 Antitrypsin Knockout Ferrets.

Ferret systemic coronavirus (FRSCV) causes a highly fatal disease of ferrets (Mustela putorius furo). It is believed to be a mutated variant of ferret enteric coronavirus (FRECV) and has a clinical presentation similar to that of feline infectious peritonitis virus (FIPV) in cats. The interplay of infectious diseases and host genetics will become a greater issue in the research environment as genetically modified species other than rodents become available due to advances in gene editing technology. In this case series, we present the clinical and histopathologic features of a FRSCV outbreak that affected 5 out of 10 ferrets with α-1 antitrypsin knockout (AAT KO) over an approximately 1-y period. Clinical features varied, with the affected ferrets presenting with some combination of wasting, hind limb paralysis, incontinence or sudden death. Multiple ferrets had gross pathologic lesions consistent with FRSCV, but the lesions were typically mild. Microscopic pyogranulomatous inflammation was present in 4 ferrets. Immunohistochemistry using an anti-feline coronavirus antibody that cross reacts with ferret coronavirus confirmed infection of intralesional macrophages in 4 out of 5 animals with suspected FRSCV infection. PCR testing of formalin fixed tissue was negative for all ferrets. PCR testing of feces from healthy wild-type ferrets indicated that the endemic presence of FRECV genotype 2, while PCR surveillance testing of other in-house AAT KO ferrets revealed both enteric coronavirus genotypes 1 and 2. This case series highlights the potential for greater disease incidence in the future as genetically modified ferrets are used more often, and may support exclusion of FRECV and similar viruses from highly susceptible ferret genotypes.

Extracelluar matrix metalloproteinase as a novel target for pancreatic cancer therapy.

The objective of this study was to evaluate extracellular 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, whereas 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, whereas the other groups served as the control. In the residual tumor model, tumor growth of anti-EMMPRIN-treated group was successfully arrested for 21 days (15 ± 4 mm(3)), which was significantly lower than that of the EMMPRIN knockdown group (80 ± 15 mm(3); P=0.001) or the control group (240 ± 41 mm(3); P<0.001). In the established tumor model, anti-EMMPRIN therapy lowered tumor volume increase by approximately 40% compared with the control, regardless of the dose amount. Ki67-expressed cell density of group 5 was 939 ± 150 mm(-2), which was 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), whereas the microvessel size of group 5 (191 ± 22 µm(2)) was significantly larger than that of group 4 (113 ± 26 µm(2); P=0.049). These data show the high potential of anti-EMMPRIN therapy for pancreatic cancer and support its clinical translation.

Anti-EMMPRIN antibody treatment of head and neck squamous cell carcinoma in an ex-vivo model.

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.

EGFR expression in advanced head and neck cutaneous squamous cell carcinoma.

BACKGROUND: The significance of epidermal growth factor receptor (EGFR) expression in advanced cutaneous squamous cell carcinoma (SCC) of the head and neck remains poorly understood. METHODS: We performed a retrospective review of patients with advanced-stage (stage III or stage IV) cutaneous SCC 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 = .47) expression in primary lesions, nor was it associated with an increase in regional (p = .74) or distant metastasis (p = .56). Furthermore, there was no correlation between clinicopathologic characteristics and EGFR expression CONCLUSIONS: These data do not suggest upregulation of EGFR is associated with poor survival or aggressive disease.

Disruption of the AKT pathway inhibits metastasis in an orthotopic model of head and neck squamous cell carcinoma.

OBJECTIVES/HYPOTHESIS: 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). The objective of this study is to examine the role AKT inhibition may play in treatment of HNSCC. STUDY DESIGN: In vivo and in vitro study. METHODS: Cell migration after 24-hour treatment with subtherapeutic doses of MK-2206 was assessed using an enzyme-linked immunosorbent assay in four 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 fluorescent imaging of tumor cell markers. RESULTS: Subtherapeutic doses of MK-2206 were sufficient to significantly reduce cell migration in FaDu, SCC-1, and SCC-5 cell lines (P < .001) but not in Cal27 (P = .09). In vitro scratch test results in SCC-1 cells yielded significant reduction in cell movement at 8, 16, and 14 hours (P < .001). In vivo orthotopic model yielded significant reduction in primary tumor size (P = .04) and reduction in positive cervical lymph nodes (P = .01) between treatment and control mice. In addition we found 100% survival of MK-2206 treated mice after 2 weeks of treatment compared with 70% survival in our control group (P = .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 is being used in phase II clinical trials for combination treatment of metastatic solid tumors and may be useful for treating HNSCC as well.

Optical imaging predicts tumor response to anti-EGFR therapy.

To evaluate cetuximab treatment in head and neck squamous cell carcinoma xenografts and cell lines, we investigated a preclinical model of head and neck squamous cell carcinoma. Head and neck squamous cell carcinoma cell lines SCC-1, FaDu, CAL27, UM-SCC-5 and UM-SCC-22A were used to generate subcutaneous flank xenografts in SCID mice. Mice were divided into control and cetuximab treatment groups, mice in the latter group received 250 µg cetuximab once weekly for four weeks. After completion of therapy, SCC-1 (p < 0.001), UM-SCC-5 (p < 0.001), UM-SCC-22A (p = 0.016) and FaDu (p = 0.007) tumors were significantly smaller than control, while CAL27 tumors were not different from controls (p = 0.90). Mice were systemically injected with 50 µg of the Cy5.5-cetuximab bioconjugate and imaged by stereomicroscopy to determine if tumor fluorescence predicted tumor response. Intact tumor fluorescence did not predict response. Tissue was harvested from untreated xenografts to evaluate ex vivo imaging. Cell lines were then evaluated in vitro for fluorescence imaging after Cy5.5-cetuximab bioconjugate labeling. The location of fluorescence observed in labeled cells was significantly different for cell lines that responded to treatment, relative to unresponsive cells. Tumors from cell lines that showed low internalized signal in vitro responded best to treatment with cetuximab. This preclinical model may aid in determining which cancer patients are best suited for cetuximab therapy.

EMMPRIN expression is required for response to bevacizumab therapy in HNSCC xenografts.

The HNSCC cell line, FaDu was stably transfected with control vector (FaDu) or with plasmid expressing small interfering RNA against EMMPRIN (FaDu/siE). Tumor cells were treated with bevacizumab (0, 25, 50, and 75 ng/ml) in vitro, and then cell counts were performed at 72 h. For in vivo analysis, tumor cells were xenografted onto the flank of SCID mice, and were treated with 100 microg bevacizumab twice weekly for three weeks. Xenograft samples from the control and treatment groups were analyzed for microvessel density. Escalating doses of bevacizumab had no effect on the growth of tumor cells in vitro (P.or=0.086). However, tumor xenografts expressing EMMPRIN responded to bevacizumab treatment (P=0.0013), whereas the EMMPRIN knockdown cell line did not (P=0.7942). Immunohistochemical analysis demonstrated that microvascular density was reduced in the treated FaDu tumors (P=0.005), but not in the FaDu/siE tumors (P=0.48). Currently there is limited information on biomarkers to predict response to bevacizumab. By demonstrating effectiveness of bevacizumab therapy in tumors that express EMMPRIN, but not in tumors with silenced EMMPRIN expression, this study suggests that EMMPRIN may serve as a biomarker for response to bevacizumab treatment.

Anti-EMMPRIN monoclonal antibody as a novel agent for therapy of head and neck cancer.

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 when delivered with conventional cytotoxic agents, anti-EMMPRIN therapy was assessed alone and in 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 1beta (IL-1beta), 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.