Inclusion Criteria:

- Histologic diagnosis of transitional cell carcinoma (TCC) of the bladder, urethra,
ureter or renal pelvis; histologic documentation of metastatic/recurrent disease is
not required; clinical staging, but not pathological staging, is required

- All patients must have received only one prior systemic chemotherapy regimen for
advanced or metastatic disease (which must have included at least one of the
following chemotherapy agents: cisplatin, carboplatin, paclitaxel, docetaxel or
gemcitabine), with progression documented during or after that treatment; neoadjuvant
as well as adjuvant combination chemotherapy is considered a systemic chemotherapy;
radiosensitizing single agent chemotherapy is not considered prior systemic therapy

- Patients must have completed radiotherapy (RT) or chemotherapy >= 4 weeks prior to
registration on this trial; patients must have recovered from previous treatments or
returned to their baseline in the judgment of the enrolling physician

- No Prior treatment with PS-341 or other proteasome inhibitors

- No prior treatment with investigational agents as single agent therapy; however, the
incorporation of an investigational agent into the prior systemic chemotherapy
regimen is allowed

- Patients must have measurable disease;

- Measurable Disease is defined as lesions that can be accurately measured in at
least one dimension (longest diameter to be recorded) as > 20 mm with
conventional techniques or as >10 mm with spiral CT scan

- Non-measurable disease: Patients with ONLY non-measurable disease are not
eligible for this trial

- Nonmeasurable disease is defined as all other lesions, including small
lesions (longest diameter <20 mm with conventional techniques or < 10 mm
with spiral CT scan) and truly non-measurable lesions, which include the
following:

- Bone lesions;

- Leptomeningeal disease;

- Ascites;

- Pleural/pericardial effusion;

- Inflammatory breast disease;

- Lymphangitis cutis/pulmonis;

- Abdominal masses that are not confirmed and followed by imaging
techniques;

- Cystic lesions

- Primary bladder masses

- CTC (ECOG) performance status =< 2

- Patients must have =< grade 1 peripheral neuropathy at baseline

- No known active brain metastases; patients may not have evidence of active brain
metastases; screening CT or MRI is not required, unless there is clinical suspicion
of brain metastases

- Pregnant and/or nursing women are not eligible for this trial as chemotherapy is
thought to present substantial risk to the fetus/infant; men and women of
reproductive potential may not participate unless they have agreed to use an
effective contraceptive method while in this study; pregnant and/or nursing women are
not eligible for this trial as chemotherapy is thought to present substantial risk to
the fetus/infant; men and women of reproductive potential may not participate unless
they have agreed to use an effective contraceptive method while in this study

- Creatinine =< 2.5 mg/dl or measured or calculated creatinine clearance > 30 ml/min)

- ALT and AST =< 2.5 x ULN

- Total bilirubin =< 1.8 mg/dL

- Granulocytes >= 1500/mm^3

- Platelets >= 100,000/mm^3

- Hemoglobin >= 8 g/dl