Neoadjuvant Dasatinib and Radical Cystectomy for Transitional Cell Carcinoma of the Bladder

Inclusion Criteria: * Histological proof of muscle-invasive transitional cell carcinoma of the bladder (stage II-IVa) with no evidence of metastatic disease (focal squamous and/or adenocarcinoma differentiation defined as ≤ 10% of tumor volume allowed, sarcomatoid and small-cell components not allowed). Patient with any degree of fixation of the pelvic sidewall are not eligible. * Patients must be willing to undergo a Cystoscopy, prior to registration on study if tumor block is not available. * Eligible for radical cystectomy as per the attending urologist. * All patients must be willing to forego neoadjuvant cisplatin-based combination chemotherapy and understand it is an option post-surgery or must be deemed ineligible for cisplatin-based combination chemotherapy by the attending medical oncologist. * Prior radiation therapy is allowed provided that no radiation therapy was administered to the urinary bladder. * Written informed consent and HIPAA authorization for release of personal health information. * Age \> 18 years at the time of consent. * Females of childbearing potential and males must be willing to use an effective method of contraception (hormonal or barrier method of birth control; abstinence) from the time consent is signed until 4 weeks after treatment discontinuation. * Females of childbearing potential must have a negative pregnancy test within 7 days prior to being registered for protocol therapy. * Females must not be breastfeeding. * Ability to take oral medication (dasatinib must be swallowed whole). Exclusion Criteria: * No prior malignancy is allowed except for adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, Gleason \< grade 7 prostate cancers, or other cancer for which the patient has been disease-free for at least 5 years. * No treatment with any investigational agent within 30 days prior to being registered for protocol therapy. * No prior systemic chemotherapy for transitional cell carcinoma of the bladder( prior intravesical therapy is allowed). Any other prior chemotherapy must have been completed \> 5 years prior to initiation of therapy. * Following concomitant medications must be discontinued 7 days prior to registration on study and for the duration of dasatinib therapy: Bisphosphonates - due to risk of hypocalcemia; Drugs that are generally accepted to have a risk of causing Torsades de Pointes; any prohibited CYP3A4 inhibitors/inducers/substrates; Anti-coagulation and/or anti-platelet therapies to avoid potential bleeding risks. * No clinically significant infections as judged by the treating investigator. * No pleural or pericardial effusion of any grade. * history of diagnosed congenital bleeding disorders (e.g., von Willebrand's disease) * No history of diagnosed acquired bleeding disorder (e.g., acquired anti-factor VIII antibodies) within one year prior to registration on protocol therapy. * No history of ongoing or recent (within \<3 months prior to registration on protocol therapy) significant gastrointestinal bleeding. * No known history of hypokalemia that cannot be corrected prior to registration on protocol therapy. * No known history of hypomagnesemia that cannot be corrected prior to registration on protocol therapy.