Retinoblastoma, a rare childhood cancer of the retina, is characterized by loss of both alleles of the RB1 gene. However, additional mutational events are required for malignancy. CGH studies described common chromosomal changes indicating potential oncogenes and tumor suppressor genes. Previous work in the lab implicated Cadherin-11 (Cdh11) as a tumor suppressor after analysis in human retinoblastomas and in the simian virus 40 large T-antigen induced murine retinoblastoma model (TAg-RB) showed loss of Cdh11 expression. TAg-RB mice crossed with Cdh11-/- mice, revealed faster growing tumors in mice null for Cdh11. This thesis focused on defining the tumor suppressor role of Cdh11 in retinoblastoma progression. The results showed in vitro and in vivo evidence that Cdh11 was promoting apoptosis and not suppressing proliferation. We also observed an increase in invasion markers upon the loss of Cdh11. We conclude that Cdh11 acts as a tumor suppressor in retinoblastoma, through promotion of apoptosis.

Retinoblastoma, a rare childhood cancer of the retina, is characterized by loss of both alleles of the RB1 gene. However, additional mutational events are required for malignancy. CGH studies described common chromosomal changes indicating potential oncogenes and tumor suppressor genes. Previous work in the lab implicated Cadherin-11 (Cdh11) as a tumor suppressor after analysis in human retinoblastomas and in the simian virus 40 large T-antigen induced murine retinoblastoma model (TAg-RB) showed loss of Cdh11 expression. TAg-RB mice crossed with Cdh11-/- mice, revealed faster growing tumors in mice null for Cdh11. This thesis focused on defining the tumor suppressor role of Cdh11 in retinoblastoma progression. The results showed in vitro and in vivo evidence that Cdh11 was promoting apoptosis and not suppressing proliferation. We also observed an increase in invasion markers upon the loss of Cdh11. We conclude that Cdh11 acts as a tumor suppressor in retinoblastoma, through promotion of apoptosis.