Abstract
Oral cancer is characterized by high morbidity and mortality with a predisposition to metastasize to different tissues, including lung, liver, and bone. Despite progress in the understanding of mutational profiles and deregulated pathways in oral cancer, patient survival has not significantly improved over the past decades. Therefore, there is a need to establish in vivo models that recapitulate human oral cancer metastasis to evaluate therapeutic potential of novel drugs. Here we report orthotopic tongue cancer nude mouse models to study oral cancer growth and metastasis using human metastatic (UMSCC2) and non-metastatic (CAL27) cell lines, respectively. Transduction of these cell lines with lentivirus expressing red fluorescent protein (DsRed) followed by injection into tongues of immunodeficient mice generated orthotopic tongue tumors that could be monitored for growth and metastasis by fluorescence measurement with an in vivo Imaging System (IVIS 200). The growth rates of CAL27-DsRed induced tumors were higher than UMSCC2-DsRed tumors after day 15, while UMSCC2-DsRed tumors revealed metastasis beginning on day 21. Importantly, UMSCC2 tumors metastasized to a number of tissues including the submandibular gland, lung, kidney, liver, and bone. Further, immunohistochemical analyses of tongue tumors induced by CAL27 and UMSCC2 cells revealed elevated expression of components of protumorigenic pathways deregulated in human cancers, including Cyclin D1, PCNA, Ki-67, LSD1, LOXL2, MT-MMP1, DPAGT1, E-cadherin, OCT4A, and H3K4me1/2. These orthotopic mouse models are likely to be useful tools for gaining insights into the activity and mechanisms of novel oral cancer drug candidates.