Methods and compositions related to single chain antibody fragments that bind to tumor-associated glycoprotein 72 (TAG-72)

1. An antibody fragment which specifically binds tumor-associated glycoprotein 72 (TAG-72), wherein the antibody fragment comprises SEQ ID NO: 1 or SEQ ID NO: 2.

2. A nucleic acid sequence encoding an antibody fragment comprising SEQ ID NO: 1 or SEQ ID NO: 2.

3. A vector comprising a nucleic acid sequence encoding an antibody fragment comprising SEQ ID NO: 1 or SEQ ID NO: 2.

4. The vector according to claim 3 , wherein said vector is a bare nucleic acid segment, a carrier-associated nucleic acid segment, a nucleoprotein, a plasmid, a virus, a viroid, or a transposable element.

5. An isolated cell that produces the antibody fragment comprising SEQ ID NO: 1 or SEQ ID NO: 2.

6. A composition comprising an antibody fragment comprising SEQ ID NO: 1 or SEQ ID NO: 2 and a pharmaceutically acceptable carrier.

7. A composition comprising an antibody fragment comprising SEQ ID NO: 1 or SEQ ID NO: 2, wherein the antibody fragment is directly or indirectly attached to an effector moiety.

8. The composition of claim 7 , wherein said effector moiety is a radionuclide, therapeutic enzyme, anti-cancer drug, cytokine, cytotoxin, or anti-proliferative agent.

9. The composition of claim 7 , wherein the effector moiety is a detectable label, and the composition is suitable for detection of cancer.

10. The composition of claim 9 , wherein the detectable label is a radionuclide or an enzyme.

11. The composition of claim 9 , wherein the cancer is colon cancer, colorectal cancer, gastric cancer, an adenocarcinoma, esophageal cancer, pancreatic cancer, endometrial cancer, ovarian cancer, lung cancer, prostate cancer, and breast cancer.

12. A method of in vivo immunodetection of TAG-72-expressing cancer cells in a mammal comprising a step of administering to the mammal a diagnostically effective amount of a composition comprising an antibody fragment comprising SEQ ID NO: 1 or SEQ ID NO: 2, wherein the antibody fragment is directly or indirectly attached to a radionuclide.

13. The method of claim 12 , wherein said immunodetection is in vivo tumor imaging.

14. The method of claim 12 , wherein the radionuclide is 43 K, 52 Fe, 57 Co, 67 Cu, 67 Ga, 68 Ga, 77 Br, 81 Rb/ 81 MKr, 87M Sr, 99M Tc, 111 In, 113 In, 123 I, 124 I, 125 I, 127 Cs, 129 Cs, 131 I, 132 I, 197 Hg, 203 Pb, 64 Cu, or 206 Bi.

15. A method of treating cancer expressing TAG-72 comprising administering to a subject in need thereof a composition comprising an antibody fragment comprising SEQ ID NO: 1 or SEQ ID NO: 2, wherein the antibody fragment is directly or indirectly attached to an effector moiety.

16. The method of claim 15 , wherein the effector moiety is a chemotherapeutic agent selected from the group consisting of an anti-tumor drug, a cytokine, an anti-metabolite, an alkylating agent, a hormone, methotrexate, doxorubicin, daunorubicin, cytosine arabinoside, etoposide, 5-fluorouracil, melphalan, chlorambucil, a nitrogen mustard, cyclophosphamide, cis-platinum, vindesine, vinca alkaloids, mitomycin, bleomycin, purothionin, macromomycin, 1,4-benzoquinone derivatives, trenimon, steroids, aminopterin, anthracyclines, demecolcine, mithramycin, daunomycin, vinblastine, neocarzinostatin, macromycin, a-amanitin, and combinations thereof.

17. The method of claim 16 , further comprising administering to the subject one or more additional anti-tumor treatments.

18. The method of claim 17 , wherein the one or more additional anti-tumor treatments are selected from the group consisting of radiotherapy, chemotherapy, an additional immunotherapy, an anti-inflammatory therapy, and combinations thereof.

19. The method of claim 17 , wherein the one or more additional anti-tumor therapies comprise administering gemcitabine (4-amino-1-(2-deoxy-2,2-difluoro- -D-eiyi/7ropentofuranosyl)pyrimidin-2(1 H)-on-2′,2′-difluoro-2′-deoxycytidine) and celecoxib (4-[5-(4-methylphenyl)-3-(trifluoromethyl)pyrazol-1-yl]benzenesulfonamide), or pharmaceutically acceptable salts of either or both thereof, to the subject.