Inclusion Criteria:

- Histologically confirmed soft tissue sarcoma or mesothelioma.

- Ineligible for other high priority national or institutional study.

- Non-pregnant, non-lactating.

- Recurrent or progressive disease defined as an increase in size of any existing tumor
mass, or the development of new tumor mass or masses, which is not amenable to
definitive surgical therapy.

- Measurable disease defined as lesions that can be measured in at least one dimension
by physical examination or by means of medical imaging techniques. Ascites and
pleural effusions will not be considered measurable disease.

- Prior chemotherapy is allowed with the exception of prior treatment with Temozolomide
or Azacitidine. Patients must have received prior 1st line therapy. There is no upper
limit to the number of prior therapies received. Prior treatment with an alkylating
agent is acceptable.

- Prior radiation therapy is allowed.

- At least 4 weeks since prior chemotherapy or at least 6 weeks since prior radiation
therapy.

- Patients may have had another cancer but there must be convincing clinical evidence
that the sarcoma is the disease requiring therapeutic intervention. (i.e. Several
sarcoma patients have had had a prior cancer [Hodgkin's disease or breast cancer]
treated years previously and then developed a clinically active sarcoma.)

- Clinical parameters: Life expectancy > 3 months, Age > 18 years, Performance
Karnofsky performance status of greater than or equal to 60%.

- Required initial laboratory data:

- Absolute neutrophil count > 1,500/mm3

- Hemoglobin > 10.0 g/dl

- Platelet count > 100,000/mm3

- Total Bilirubin < 1.5 times upper limit of normal (ULN) for the laboratory.

- Transaminases: aspartate aminotransferase (AST) or alanine aminotransferase
(ALT) levels must be < 2 x ULN. If there is known hepatic metastasis,
transaminases may be < 5 times upper limit of normal.

- Serum creatinine levels < 1.5 x ULN.

- Women of child-bearing potential must have a negative serum pregnancy test prior
to initiation of treatment.

- Men and women of child-bearing potential must be willing to consent to using
effective contraception while on treatment and for a reasonable period thereafter
(approximately 3 months).

- Capable of providing written, informed consent. Each patient must be completely
aware of the nature of his/her disease process and must willingly give consent after
being informed of the procedure to be followed, the experimental nature of the
therapy, alternatives, potential benefits, side-effects, risks and discomforts.

- No serious medical or psychiatric illness preventing informed consent or intensive
treatment (e.g. serious infection).

- No uncontrolled central nervous system metastases.

Exclusion Criteria:

- Known or suspected hypersensitivity to azacitidine or mannitol

- Pregnant or breast-feeding

- Histology other than soft-tissue sarcoma or mesothelioma

- Active or uncontrolled infection or other serious systemic disease

- Prior treatment with temozolomide or azacitidine

- Pregnant or lactating women

- Uncontrolled central nervous system metastases

- Liver metastases

- Patients will not be excluded if they do not wish to participate in the second biopsy
for tissue evaluation

- Subjects who have not had prior chemotherapy.