Inclusion Criteria:

- Must be >- 18 years old, with a life expectancy > 8 weeks

- Histologically confirmed intracranial glioblastoma multiforme (GBM) or gliosarcoma

- Must submit an unstained paraffin block or slides from surgical procedure

- Patients without prior treatment and with prior diagnosis of lower-grade gliomas that
have been upgraded to GBM after repeated resection allowed

- At least 21 days since cranial MRI or contrast CT scan OR ≥ 96 hours since cranial
MRI or contrast CT scan for patients who underwent surgical resection

- Measurable or assessable disease

- Voluntary written informed consent obtained before performance of any study related
procedure not part of normal medical care.

- Karnofsky performance status > 60%

- WBC ≥ 3,000/mm^3

- ANC ≥ 1,500/mm^3

- Platelet count ≥ 100,000/mm^3

- Hemoglobin ≥ 10 g/dL (transfusion allowed)

- Bilirubin < 2.5 times upper limit of normal (ULN)

- SGOT < 2.5 times ULN

- Creatinine < 1.5 mg/dL

- Creatinine clearance ≥ 20 mL/minute

- Serum sodium > 130 mmol/L

- Negative pregnancy test

- Fertile patients must use effective contraception

- Patients on EIAED must be transitioned to non-EAIED for ≥ 2 weeks

- Concurrent full-dose warfarin or its equivalent (e.g., unfractionated and/or low
molecular weight heparin) allowed

Exclusion Criteria:

- peripheral neuropathy ≥ grade 2

- Myocardial infarction within the past 6 months

- NYHA class III or IV heart failure

- Uncontrolled angina

- Severe uncontrolled ventricular arrhythmias

- Electrocardiographic evidence of acute ischemia or active conduction system
abnormalities

- hypersensitivity to bortezomib, boron, or mannitol

- serious medical or psychiatric illness that would interfere with study participation
including, but not limited to, any of the following:

- Ongoing or active infection requiring IV antibiotics

- Psychiatric illness and/or social situations that would limit compliance with study
requirements

- Disorders associated with a significant immunocompromised state (e.g., HIV, systemic
lupus erythematosus)

- history of stroke within the past 6 months

- other malignancy within the past 3 years except completely resected basal cell
carcinoma or squamous cell carcinoma of the skin, an in situ malignancy (i.e.,
cervical cancer), or low-risk prostate cancer after curative therapy

- significant medical illness that, in the investigator's opinion, cannot be adequately
controlled with appropriate therapy or would compromise the patient's ability to
tolerate this therapy

- disease that will obscure toxicity or dangerously alter drug metabolism

- viral hepatitis (HBV surface antigen positive) or active hepatitis C infection

- Prior or concurrent corticosteroids, automated external defibrillator, analgesics,
and other drugs to treat symptoms or prevent complications allowed

- concurrent investigational drugs that must be stopped at least 4 months prior to
therapy.

- prior radiotherapy to the brain

- prior cytotoxic or noncytotoxic drug therapy or experimental drug therapy (including
chemotherapy, hormonal therapy, or immunotherapy) directed against the brain tumor

- prior polifeprosan 20 with carmustine implant (Gliadel wafer)

- concurrent stereotactic radiosurgery or brachytherapy

- concurrent sargramostim

- concurrent inducers of CYP450 3A4 (e.g., enzyme-inducing anti-epileptic drugs
[EIAED])