[0056] cDNAs can be synthesized on a substrate. Synthesis on the surface of a substrate may be accomplished using a
chemical coupling procedure and a piezoelectric printing apparatus as described by Baldeschweiler et al. (PCT publication WO95 / 251116). Alternatively, the cDNAs can be synthesized on a
substrate surface using a self-addressable electronic device that controls when reagents are added as described by Heller et al. (U.S. Pat. No. 5,605,662). cDNAs can be synthesized directly on a substrate by sequentially dispensing reagents for their synthesis on the
substrate surface or by dispensing preformed
DNA fragments to the
substrate surface. Typical dispensers include a micropipette delivering solution to the substrate with a robotic
system to control the position of the micropipette with respect to the substrate. There can be a multiplicity of dispensers so that reagents can be delivered to the reaction regions efficiently.
[0070] The full length cDNAs or fragment thereof may be used to produce purified proteins using
recombinant DNA technologies described herein and taught in Ausubel et al. (supra; Units 16.1-16.62). One of the advantages of producing proteins by these procedures is the ability to obtain highly-enriched sources of the proteins thereby simplifying purification procedures.
[0096] A
gene expression profile comprises a plurality of cDNAs and a plurality of detectable hybridization complexes, wherein each complex is formed by hybridization of one or more probes to one or more complementary sequences in a sample. The cDNA composition of the invention is used as elements on a
microarray to analyze
gene expression profiles. In one embodiment, the
microarray is used to monitor the progression of
prostate cancer. Researchers can assess and catalog the differences in
gene expression between healthy and diseased tissues or cells. By analyzing changes in patterns of
gene expression, prostate cancer can be diagnosed at earlier stages before the patient is symptomatic. The invention can be used to formulate a prognosis and to design a
treatment regimen. The invention can also be used to monitor the
efficacy of treatment. For treatments with known side effects, the
microarray is employed to improve the
treatment regimen. A dosage is established that causes a change in genetic expression patterns indicative of successful treatment. Expression patterns associated with the onset of undesirable side effects are avoided. This approach may be more sensitive and rapid than waiting for the patient to show inadequate improvement, or to manifest side effects, before altering the course of treatment.
[0097] In another embodiment, animal models which mimic a
human disease can be used to characterize expression profiles associated with a particular condition, disorder or
disease; or treatment of the condition, disorder or
disease. Novel treatment regimens may be tested in these animal models using microarrays to establish and then follow expression profiles over time. In addition, microarrays may be used with
cell cultures or tissues removed from animal models to rapidly screen large numbers of candidate
drug molecules, looking for ones that produce an expression profile similar to those of known therapeutic drugs, with the expectation that molecules with the same expression profile will likely have similar therapeutic effects. Thus, the invention provides the means to rapidly determine the molecular
mode of action of a
drug.
[0105] Additionally, any of the proteins, or their ligands, or complementary
nucleic acid sequences may be administered as pharmaceutical compositions or in combination with other appropriate therapeutic agents. Selection of the appropriate agents for use in
combination therapy may be made by one of ordinary skill in the art, according to conventional pharmaceutical principles. The combination of therapeutic agents may act synergistically to affect the treatment or prevention of the conditions and disorders associated with an immune response. Using this approach, one may be able to achieve therapeutic
efficacy with lower dosages of each agent, thus reducing the potential for adverse side effects. Further, the therapeutic agents may be combined with pharmaceutically-acceptable carriers including excipients and auxiliaries which facilitate
processing of the active compounds into preparations which can be used pharmaceutically. Further details on techniques for formulation and administration used by doctors and pharmacists may be found in the latest edition of Remington's
Pharmaceutical Sciences (Maack Publishing, Easton Pa.).
[0107] Animal models may be used as bioassays where they exhibit a phenotypic response similar to that of humans and where
exposure conditions are relevant to human exposures. Mammals are the most common models, and most
infectious agent, cancer,
drug, and
toxicity studies are performed on rodents such as rats or nice because of low cost, availability, lifespan, reproductive potential, and abundant reference literature. Inbred and outbred
rodent strains provide a convenient model for investigation of the physiological consequences of underexpression or overexpression of genes of interest and for the development of methods for diagnosis and treatment of diseases. A
mammal inbred to overexpress a particular gene (for example, secreted in milk) may also serve as a convenient source of the
protein expressed by that gene.