Purpose: Human cell lines are useful for studying cancer biology and preclinically modeling cancer therapy, but can be misidentified and cross-contamination is unfortunately common. The purpose of this study was to develop a panel of validated head and neck cell lines representing the spectrum of tissue sites and histologies that could be used for studying the molecular, genetic, and phenotypic diversity of head and neck cancer. Methods: A panel of 122 clinically and phenotypically diverse head and neck cell lines from head and neck squamous cell carcinoma, thyroid cancer, cutaneous squamous cell carcinoma, adenoid cystic carcinoma, oral leukoplakia, immortalized primary keratinocytes, and normal epithelium was assembled from the collections of several individuals and institutions. Authenticity was verified by carrying out short tandem repeat analysis. Human papillomavirus (HPV) status and cell morphology were also determined. Results: Eighty-five of the 122 cell lines had unique genetic profiles. HPV-16 DNA was detected in 2 cell lines. These 85 cell lines included cell lines from the major head and neck primary tumor sites, and close examination shows a wide range of in vitro phenotypes. Conclusions: This panel of 85 genomically validated head and neck cell lines represents a valuable resource for the head and neck cancer research community that can help advance understanding of the disease by providing a standard reference for cell lines that can be used for biological as well as preclinical studies. Clin Cancer Res; 17(23); 7248–64. ©2011 AACR.

Purpose: Aberrant expression of inflammatory molecules, such as inducible nitric oxide (NO) synthase (iNOS), has been linked to cancer, suggesting that their inhibition is a rational therapeutic approach. Whereas iNOS expression in melanoma and other cancers is associated with poor clinical prognosis, in vitro and in vivo studies suggest that iNOS and NO can have both protumor and antitumor effects. We tested the hypothesis that targeted iNOS inhibition would interfere with human melanoma growth and survival in vivo in a preclinical model. Experimental Design: We used an immunodeficient non-obese diabetic/severe combined immunodeficient xenograft model to test the susceptibility of two different human melanoma lines to the orally-given iNOS-selective small molecule antagonist N⁶-(1-iminoethyl)-l-lysine-dihydrochloride (L-nil) with and without cytotoxic cisplatin chemotherapy. Results: L-nil significantly inhibited melanoma growth and extended the survival of tumor-bearing mice. L-nil treatment decreased the density of CD31+ microvessels and increased the number of apoptotic cells in tumor xenografts. Proteomic analysis of melanoma xenografts with reverse-phase protein array identified alterations in the expression of multiple cell signaling and survival genes after L-nil treatment. The canonical antiapoptotic protein Bcl-2 was downregulated in vivo and in vitro after L-nil treatment, which was associated with increased susceptibility to cisplatin-mediated tumor death. Consistent with this observation, combination therapy with L-nil plus cisplatin in vivo was more effective than either drug alone, without increased toxicity. Conclusions: These data support the hypothesis that iNOS and iNOS-derived NO support tumor growth in vivo and provide convincing preclinical validation of targeted iNOS inhibition as therapy for solid tumors. Clin Cancer Res; 16(6); 1834–44

Purpose: To characterize tumor growth and metastatic potential in head and neck squamous cell carcinoma (HNSCC) cell lines in an orthotopic murine model of oral tongue cancer and to correlate TP53 mutation status with these findings. Experimental Design: Cells from each of 48 HNSCC cell lines were orthotopically injected into the oral tongues of nude mice. Tumor volume, cervical lymph node metastasis, and mouse survival were recorded. Direct sequencing of the TP53 gene and Western blot analysis for the p53 protein after induction with 5-fluorouracil was conducted. Cell lines were categorized as either mutant TP53 or wild-type TP53, and lines with TP53 mutation were further categorized on the basis of type of mutation (disruptive or nondisruptive) and level of p53 protein expression. The behavior of tumors in these different groups was compared. Results: These 48 HNSCC cell lines showed a wide range of behavior from highly aggressive and metastatic to no tumor formation. Mice injected with cells harboring disruptive TP53 mutations had faster tumor growth, greater incidence of cervical lymph node metastasis, and shorter survival than mice injected with cells lacking these mutations. Conclusions: HNSCC cell lines display a wide spectrum of behavior in an orthotopic model of oral cancer. Cell lines with disruptive TP53 mutations are more aggressive in this system, corroborating clinical reports that have linked these mutations to poor patient outcome. Clin Cancer Res; 17(21); 6658–70. ©2011 AACR.

Head and neck cancers are among the most prevalent tumors in the world. Despite advances in the treatment of head and neck tumors, the survival of patients with these cancers has not markedly improved over the past several decades because of our inability to control and our poor understanding of the regional and distant spread of this disease. One of the factors contributing to our poor understanding may be the lack of reliable animal models of head and neck cancer metastasis. The earliest xenograft models in which human tumor cells were grown in immunosuppressed mice involved subcutaneous implantation of human head and neck cancer cell lines. Subcutaneous xenograft models have been popular because they are easy to establish, easy to manage, and lend themselves to ready quantitation of the tumor burden. More recently, orthotopic xenograft models, in which the tumor cells are implanted in the tumor site of origin, have been used with greater frequency in animal studies of head and neck cancers. Orthotopic xenograft models are advantageous for their ability to mimic local tumor growth and recapitulate the pathways of metastasis seen in human head and neck cancers. In addition, recent innovations in cell labeling techniques and small-animal imaging have enabled investigators to monitor the metastatic process and quantitate the growth and spread of orthopically implanted tumors. This review summarizes the progress in the development of murine xenograft models of head and neck cancers. We then discuss the advantages and disadvantages of each type of xenograft model. We also discuss the potential for these models to help elucidate the mechanisms of regional and distant metastasis, which could improve our ability to treat head and neck cancers.