If you are in Groups 2, 3, or 4, the dose of MK-0646 and/or dasatinib you receive will depend on when you joined this study. The first set of participants in each group will receive the lowest dose level of MK-0646 and/or dasatinib. Each new set will receive a higher dose of MK-0646 and/or dasatinib than the set before it, if no intolerable side effects were seen. This will continue until the highest tolerable dose of MK-0646 and/or dasatinib is found. This is called the Phase I portion of the study.