BECKER MICHAEL (DE)
BESADA PEREZ VLADIMIR (CU)
CASTELLANOS SERRA LILA (CU)
FICHTNER IDUNA (DE)
BECKER MICHAEL (DE)
BESADA PEREZ VLADIMIR (CU)
CASTELLANOS SERRA LILA (CU)
| WO2001063292A2 | 2001-08-30 |
NOH DONG-YOUNG ET AL: "Overexpression of peroxiredoxin in human breast cancer" ANTICANCER RESEARCH, vol. 21, no. 3B, May 2001 (2001-05), pages 2085-2090, XP008026146 ISSN: 0250-7005
BERGGREN MARGARETA I ET AL: "Thioredoxin peroxidase-1 (peroxiredoxin-1) is increased in thioredoxin-1 transfected cells and results in enhanced protection against apoptosis caused by hydrogen peroxide but not by other agents including dexamethasone, etoposide, and doxorubicin" ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, vol. 392, no. 1, 1 August 2001 (2001-08-01), pages 103-109, XP002266115 ISSN: 0003-9861
SEITH P ET AL: "Novel estrogen and tamoxifen induced genes identified by SAGE (Serial Analysis of Gene Expression)" ONCOGENE, BASINGSTOKE, HANTS, GB, vol. 21, 23 January 2002 (2002-01-23), pages 836-843, XP002965930 ISSN: 0950-9232
HILSENBECK S G ET AL: "STATISTICAL ANALYSIS OF ARRAY EXPRESSION DATA AS APPLIED TO THE PROBLEM OF TAMOXIFEN RESISTANCE" JOURNAL OF THE NATIONAL CANCER INSTITUTE, US DEPT. OF HEALTH, EDICATIONAND WELFARE, PUBLIC HEALTH, US, vol. 91, no. 5, 26 January 1999 (1999-01-26), pages 453-459, XP009002755 ISSN: 0027-8874
KARIHTALA PEETER ET AL: "Peroxiredoxins in breast carcinoma." CLINICAL CANCER RESEARCH: AN OFFICIAL JOURNAL OF THE AMERICAN ASSOCIATION FOR CANCER RESEARCH. UNITED STATES 15 AUG 2003, vol. 9, no. 9, 15 August 2003 (2003-08-15), pages 3418-3424, XP002266133 ISSN: 1078-0432
| 1. | Method to evaluate the resistance of breast tumour cells to antiestrogen therapy, wherein a) the concentration of at least one specific target protein is determined in tumour tissue ; and b) is compared with the standard reference value of the same protein or proteins in breast tumour tissue sensitive to antiestrogen treatment, whereat a protein concentration in the sample examined which lies above the standard reference value indicates a resistance of the tumour to antiestrogen treatment, if it is a protein that is expressed at a higher level in breast tumour cells resistant to antiestrogen treatment, as compared to breast tumour cells sensitive to antiestrogen treatment, or, a protein concentration in the sample examined which lies below the standard reference value indicates a resistance of the tumour to antiestrogen treatment, if it is a protein that is expressed at a lower level in breast tumour cells resistant to antiestrogen treatment, as compared to breast tumour cells sensitive to antiestrogen treatment. |
| 2. | Method in accordance with Claim 1, wherein the following proteins: Peroxiredoxin 1 SwissProt*: Acc. No. Q06830 Locus: PDX1_HUMAN Vinculin (Metavinculin) SwissProt*: Acc. No. P18206 Locus: VINCHUMAN Lysophospholipase I, AcylProtein Thioesterase 1 NCBIREFSEQ*: Acc. No. NM006330. 2 Locus: NP006321 C80RF2Protein, Chromosome 8"open reading frame"2 NCBIREFSEQ*: Acc. No. NM007175. 2 Locus: NP009106 Glutaminehydrolysing GMP Synthase SwissProt*: Acc. No. P49915 Locus: GUAAHUMAN DJ1 Protein NCBI*: Acc. No. BAA09603 Locus: HUMDJ1 RNABinding Protein (Regulatory Subunit) NCBI*: Acc.No. CAB52550 Locus: CAB52550 (both proteins are identical) 27 kDa Heat Shock Protein (HSP27) SwissProt*: Acc. No. P04792 Locus: HS27 HUMAN Peroxiredoxin 4, Thioredoxin Peroxidase SwissProt Acc. No. Q13162 Locus: PDX4HUMAN VoltageDependent, AnionSelective Channel Protein 1, outer mitochondrial membrane protein Porin 1 SwissProt Acc. No. P21796 Locus POR1HUMAN 40S Ribosomal Protein, Laminin Receptor SwissProt Acc.No. P08865 Locus RSP4HUMAN Endothelial ActinBinding Protein SwissProt Acc. No. P21333 Locus FLNAHUMAN UbiquinolCytochrome c reductase IronSulphur subunit SwissProt Acc. No. P47985 Locus CRI HUMAI ALG2 interacting protein, programmed cell death 6 interacting protein NCBI Acc.No. NP037506 Locus PDCD6IP Cyclophilin A, Peptidylpropyl cistrans isomerase SwissProt Acc. No. P05092 Locus CYPHHUMAN 60S Acidic Ribosomal Protein PO SwissProt Acc. No. P05388 Locus RLAOJHUMAN are applied as the target proteins. |
| 3. | Method in accordance with the Claims 1 und 2, wherein at least one of the following target proteins: Peroxiredoxin 1 SwissProt*: AccNo. Q06830 Locus: PDX1 HUMAN Vinculin (Metavinculin) SwissProt*: Acc. No. P18206 Locus: VINCHUMAN Lysophospholipase I, AcylProtein Thioesterase 1 NCBIREFSEQ*: Acc. No. Nom 006330. 2 Locus: NP006321 C80RF2Protein, Chromosome 8"open reading frame"2 NCBIREFSEQ*: Acc. No. NM 007175. 2 Locus: NP009106 Peroxiredoxin 4, Thioredoxin Peroxidase SwissProt Acc.No. Q13162 Locus: PDX4HUMAN VoltageDependant, AnionSelective Channel Protein 1, outer mitochondrial membrane protein Porin 1 SwissProt Acc. No. P21796 Locus PORTHUMAIN 40S Ribosomal Protein, Laminin Receptor SwissProt Acc. No. P08865 Locus RSP4_HUMAN Endothelial ActinBinding Protein SwissProt Acc. No. P21333 Locus FLNAHUMAN UbiquinolCytochrome c Reductase IronSulphur Subunit SwissProt Acc. No. P47985 Locus UCRIHUMAN is expressed at a higher level in breast tumour cells resistant to antiestrogen treatment, as compared to breast tumour cells sensitive to antiestrogen treatment. |
| 4. | Method in accordance with Claim 3, wherein the concentration of at least one of the target proteins is at least twice as high in breast tumour cells resistant to antiestrogen treatment, as compared to breast tumour cells sensitive to antiestrogen treatment. |
| 5. | Method in accordance with Claims 1 to 2, wherein the concentration of at least one of the following target proteins: Glutaminehydrolysing GMP Synthase SwissProt*: Acc. No. P49915 Locus: GUAA HUMAN DJ1 Protein NCBI*: Acc. No. BAA09603 Locus: HUMDJ1 RNABinding Protein (Regulatory Subunit) NCBI*: Acc.No. CAB52550 Locus: CAB52550 (both proteins are identical) 27 kDa Heat Shock Protein (HSP27) SwissProt*: Acc. No. P04792 Locus: HS27 HUMAN ALG2 Interacting Protein, programmed cell death 6 interacting protein NCBI Acc.No. NP037506 Locus PDCD6IP Cyclophilin A, PeptidylPropyl cistrans Isomerase SwissProt Acc.No. P05092 Locus CYPHHUMAN 60S Acidic Ribosomal Protein PO SwissProt Acc. No. P05388 Locus LAO HUMAIN is lower in breast tumour cells resistant to antiestrogen treatment, as compared to breast tumour cells sensitive to antiestrogen treatment. |
| 6. | Method in accordance with Claim 5, wherein the concentration of at least one target protein is twofold lower in breast tumour cells resistant to antiestrogen treatment than in breast tumour cells sensitive to antiestrogen treatment. |
| 7. | Method in accordance with Claims 1 to 6, wherein the determination of the protein concentrations is performed by applying immunological methods. |
| 8. | Method in accordance with Claim 7, wherein the determination of the protein concentrations is performed by applying antibodies which are directed against the target proteins. |
| 9. | Method in accordance with Claim 8, wherein the determination of the protein concentrations is performed by applying the Western blot technique, immunohistochemistry, the ELISA technique or other methods of protein determination. |
| 10. | Method to evaluate the resistance of breast tumour cells to antiestrogen treatment, wherein a) the concentration of at least one nucleic acid segment which encodes a particular target protein is determined in the tumour cells; and b) is compared with the standard reference value of the same nucleic acid segment or segments in breast tumour cells sensitive to antiestrogen treatment, whereat a concentration of the nucleic acid segment in the sample examined that lies above the standard reference value indicates a tumour resistance to antiestrogen therapy, provided it is a segment that is expressed at a higher level in breast tumour cells resistant to antiestrogen treatment than in breast tumour cells sensitive to antiestrogen treatment, and a concentration of the nucleic acid segment in the sample examined that lies below the standard reference value indicates a tumour resistance to antiestrogen treatment, provided it is a segment that is expressed at a lower level in breast tumour cells resistant to antiestrogen treatment than in breast tumour cells sensitive to antiestrogen treatment. |
| 11. | Method in accordance with Claim 10, wherein the concentration of the nucleic acid segments is determined by PCR or other suitable methods. |
| 12. | Use of the method in accordance with Claims 1 to 11 to diagnose resistance to the treatment of breast tumours with tamoxifen. |
| 13. | Use of the method in accordance with Claims 1 to 11 for the treatment of breast tumours resistant to antihormonal treatment. |
| 14. | Use in accordance with Claim 13, wherein an increase of the concentration of the following proteins: Peroxiredoxin 1 SwissProt*: AccNo. Q06830 Locus: PDXl HUMAN Vinculin (Metavinculin) SwissProt*: Acc. No. P18206 Locus: VINCHUMAN Lysophospholipase I, AcylProtein Thioesterase 1 NCBIREFSEQ*: Acc. No. Nom 006330. 2 Locus: NP006321 C80RF2Protein, Chromosome 8"open reading frame"2 NCBIREFSEQ*: Acc.No. Nom 007175. 2 Locus: NP 009106 Peroxiredoxin 4, Thioredoxin Peroxidase SwissProt Acc.No. Q13162 Locus: PYX4 HUMAIN 'VoltageDependent, AnionSelective Channel Protein 1, outer mitochondrial membrane protein Porin 1 SwissProt Acc. No. P21796 Locus POR1 HUMAN 40S Ribosomal Protein, LamininReceptor SwissProt Acc. No. P08865 Locus RSP4HUMAN Endothelial Actinbinding Protein SwissProt Acc. No. P21333 Locus FLNAHUMAN UbiquinolCytochrome C Reductase IronSulphur Subunit SwissProt Acc.No. P47985 Locus UCRIHUMAN in the tumour cells is prevented, or an increased concentration is eliminated, and antihormonal treatment is either initiated or continued. |
| 15. | Use in accordance with Claim 14, wherein the increased concentration of the proteins is prevented by blocking protein synthesis on the level of RNA, preferentially by means of antisense oligonucleotides or ribozyme directed against the mRNA encoding these proteins. |
| 16. | Use in accordance with Claim 14, wherein the function of higher expressed target proteins is blocked or hampered by means of specific antibodies directed against these proteins. |
| 17. | Use in accordance with Claim 13, wherein an increased concentration of the proteins: Glutaminehydrolysing GMP Synthase SwissProt*: Acc. No. P49915 Locus: GUAAHUMAN DJ1 Protein NCBI*: Acc. No. BAA09603 Locus: HUMDJ1 RNABinding Protein (Regulatory Subunit) NCBI*: Acc. No. CAB52550 Locus: CAB52550 (both proteins are identical) 27 kDa Heat Shock Protein (HSP27) SwissProt*: Acc. No. P04792 Locus: HS27HUMAN ALG2 Interacting Protein, programmed cell death 6 interacting protein NCBI Acc.No. NP037506 Locus PDCD6IP Cyclophilin A, PeptidylPropyl cistrans Isomerase SwissProt Acc. No. P05092 Locus CYPH HUMAN 60S Acidic Ribosomal Protein PO SwissProt Acc. No. P05388 Locus RLAOHUMAN in the tumour cells is generated and antiestrogen treatment is either initiated or continued. |
| 18. | Use in accordance with the Claims 14 to 17, wherein antiestrogenic therapeutics, preferentially tamoxifen, are applied. |
| 19. | Testkit to determine antiestrogen treatment resistance of breast tumours, wherein it contains one or several antibodies directed against at least one of the following proteins: Peroxiredoxin 1 SwissProt*: AccNo. Q06830 Locus: PDX1_HUMAN Vinculin (Metavinculin) SwissProt*: Acc. No. P18206 Locus: VINCHUMAN Lysophospholipase I, AcylProtein Thioesterase 1 NCBIREFSEQ*: Acc. No. Nom 006330. 2 Locus: NP006321 C80RF2Protein, Chromosome 8"open reading frame"2 NCBIREFSEQ*: Acc. No. Nom 007175. 2 Locus: NP009106 Glutaminehydrolysing GMP Synthase SwissProt*: Acc.No. P49915 Locus: GUAAHUMAN DJ1 Protein NCBI*: Acc. No. BAA09603 Locus: HUMDJ1 RNABinding Protein (Regulatory Subunit) NCBI*: Acc.No. CAB52550 Locus: CAB52550 (both proteins are identical) 27 kDa Heat Shock Protein (HSP27) SwissProt*: Acc. No. P04792 Locus: HS27HUMAN Peroxiredoxin 4, Thioredoxin Peroxidase SwissProt Acc. No. Q13162 Locus: PDX4_ElUMAN 'VoltageDependant, AnionSelective Channel Protein 1, outer mitochondrial membrane protein Porin 1 SwissProt Acc. No. P21796 Locus POR1 HUMAN 40S Ribosomal Protein, LamininReceptor SwissProt Acc.No. P08865 Locus RSP4_HUMAN Endothelial ActinBinding Protein SwissProt Acc. No. P21333 Locus FLNAHUMAN UbiquinolCytochrome C Reductase IronSulphur Subunit SwissProt Acc. No. P47985 Locus UCRI HUMAN ALG2 Interacting Protein, programmed cell death 6 interacting protein NCBI Acc.No. NP037506 Locus PDCD6IP Cyclophilin A, PeptidylPropyl cistrans Isomerase SwissProt Acc. No. P05092 Locus CYPHHUMAN 60S Acidic Ribosomal Protein PO SwissProt Acc.No. P05388 Locus RLAOHUMAN 20. Testkit to determine antiestrogen treatment resistance of breast tumours, wherein it contains one or several primer pairs capable to amplify at least one of the nucleic acid sequences of the mRNA encoding the following proteins: Peroxiredoxin 1 SwissProt*: AccNo. Q06830 Locus: PDXl HUMAN Vinculin (Metavinculin) SwissProt*: Acc. No. P18206 Locus: VINCHUMAN Lysophospholipase I, AcylProtein Thioesterase 1 NCBIREFSEQ*: Acc. No. Nom 006330. 2 Locus: NP006321 C80RF2Protein, Chromosome 8"open reading frame"2 NCBIREFSEQ*: Acc. No. NM007175. 2 Locus: NP009106 Glutaminehydrolysing GMP Synthase SwissProt*: Acc. No. P49915 Locus: GUAA HCTMAN DJ1 Protein NCBI*: Acc. No. BAA09603 Locus: HUMDJ1 RNABinding Protein (Regulatory Subunit) NCBI* : Acc. No. CAB52550 Locus: CAB52550 (both proteins are identical) 27 kDa Heat Shock Protein (HSP27) SwissProt*: Acc.No. P04792 Locus: HS27HUMAN Peroxiredoxin 4, Thioredoxin Peroxidase SwissProt Acc. No. Q13162 Locus: PDX4_HUMAN VoltageDependent, AnionSelective Channel Protein 1, outer mitochondrial membrane protein Porin 1 SwissProt Acc. No. P21796 Locus PORTHUMAIN 40S Ribosomal Protein, Laminin Receptor SwissProt Acc.No. P08865 LocusRSP4 HUMAN Endothelial ActinBindingProtein SwissProt Acc. No. P21333 Locus FLNAHUMAN UbiquinolCytochrome C Reductase IronSulphur Subunit SwissProt Acc.No. P47985 Locus CRI HUMAIN ALG2 Interacting Protein, programmed cell death 6 interacting protein NCBI Acc.No. NP037506 Locus PDCD61P Cyclophilin A, PeptidylPropyl cistrans Isomerase SwissProt Acc.No. P05092 Locus CYPHHUMAN 60S Acidic Ribosomal Protein PO SwissProt Acc. No. P05388 Locus RLAOHUMAN *Swissprot and NCBI Protein Database (www. ncbi. nlm. nih. gov/Entrez) SwissProt EMBLOutstationEuropean Bioinformatics Institute Hinxton, Cambridge CB10 1SD, UK NCBI National Center for Biotechnology Information National Library of Medicine Bethesda, MD, USA. |
Breast tumours are the most frequent type of cancer among women in the western industrialized countries. The hormone-dependent growth of mammary tumours is mediated primarily by a nuclear steroid hormone receptor-the estrogen receptor (ER). As of today, prognosis and treatment strategies are determined on account of the estrogen receptor status. As approximately two-thirds of the tumours are found to dispose this receptor, anti-hormone preparations are applied as an initial medication to these patients after surgical removal of the primary tumour. The anti-hormones are supposed to competitively displace the natural ligands (estrogen) from the receptor and thus inhibit the hormone-mediated growth of the tumours.
Tamoxifen, a non-steroidal antiestrogen, is most frequently applied to treat mammary carcinomas, whereat the adjuvant application to prevent the development of metastasis is in the centre of attention (Harris 1992). Unfortunately, about one-third of the ER-positive tumours does not respond to tamoxifen therapy and a large number of patients develops resistance to the pharmaceutical drug in the course of treatment. Resistance to tamoxifen comprises a significant clinical problem to this day and its molecular cause is still unknown.
As a ligand-inducible transcription factor the estrogen receptor itself is closely involved in the cellular transcription machinery. In the complex interaction with a large number of
co-activator and co-repressor molecules it induces the expression of certain genes which, in turn, may be part of cellular signalling pathways.
The fact that nearly 15% of the ER-negative primary tumours also respond to tamoxifen, is an indication to the existence of other ER-independent cellular antiestrogen binding sites.
Therefore, resistance to tamoxifen is apparently due to more complex molecular mechanisms which are based on an impaired balance of transcription cofactors, growth factors, signal transduction pathways, or oncogenes (Clarke et al. 2001).
Concerning the optimisation of hormone therapy of breast tumours, it would be desirable to predict tumour responses prior to the respective anti-hormone therapy, in order to avoid an unnecessary therapy whose cancerogenous potential has been repeatedly subject of discussion.
The objective of the invention consisted in finding new marker proteins which could serve as a therapeutic or diagnostic target when breast tumours show antiestrogen therapy resistance.
The problem was solved by comparative investigations on a tamoxifen-sensitive mammary carcinoma xenograft (3366) and a tamoxifen-resistant sub-line (3366/TAM) created by a two-year treatment with tamoxifen (Naundorf et al. , 2000).
Proteins derived from tissue lysates of both tumour cell lines were examined by means of high-resolution two-dimensional (2D-) polyacrylamide gel-electrophoresis (examples are shown in Fig. 1).
Comparative gel evaluations were carried out with the aid of appropriate computer programs, in order to trace differentially expressed proteins, this means, proteins expressed to various degrees. Interesting protein spots displaying significant differences were punched out and in gel-digested with trypsin. Resulting mixtures of peptides were analysed by MALDI mass-spectrometry.
Surprisingly, we thus succeeded to identify several proteins that are clearly, i. e. more than two-fold, under-or overexpressed in tamoxifen-resistant tumours, as compared to tamoxifen-sensitive tumours.
The following proteins have been identified as marker proteins for antiestrogen therapy resistance of breast tumours:
Proteins expressed at higher levels in the resistant cell line: Peroxiredoxin 1 SwissProt*: Acc-No. Q06830 Locus: PDXl_HUMAN Vinculin (Metavinculin) SwissProt*: Acc. -No. P18206 Locus: VINC HUMAN . Lysophospholipase I, Acyl-Protein Thioesterase 1 NCBI-REFSEQ*: Acc. -No. NM006330. 2 Locus: NP006321 C80RF2-Protein, Chromosome 8"open reading frame"2 NCBI-REFSEQ*: Acc.-No. NM007175. 2 Locus: NP009106 Peroxiredoxin 4, Thioredoxin Peroxidase SwissProt Acc.-No. Q13162 Locus: PDX4_HUMAN Voltage-Dependent, Anion-Selective Channel Protein 1, outer mitochondrial membrane protein Porin 1 SwissProt Acc. -No. P21796 Locus POR1 HUMAN 40S Ribosomal Protein, Laminin Receptor SwissProt Acc. -No. P08865 LocusRSP4 HUMAN Endothelial actin-binding Protein SwissProt Acc. -No. P21333 Locus FLNAHUMAN Ubiquinol-Cytochrome C Reductase Iron-Sulphur Subunit SwissProt Acc. -No. P47985 Locus CRI-HUMAIN Proteins expressed at lower levels in the resistant cell line: Glutamine hydrolysing GMP Synthase SwissProt*: Acc. -No. P49915 Locus: GUAAHUMAN DJ-1 Protein NCBI*: Acc.-No. BAA09603 Locus: HUMDJ1 RNA-Binding Protein (Regulatory Subunit)
NCBI*: Acc.-No. CAB52550 Locus: CAB52550 (both proteins are identical) * 27 kDa Heat Shock Protein (HSP27) SwissProt*: Acc. -No. P04792 Locus: HS27HUMAN ALG-2 Interacting Protein, programmed cell death 6 interacting protein NCBI Acc.-No. NP037506 Locus PDCD6IP Cyclophilin A, peptidyl-propyl cis-trans isomerase SwissProt Acc. -No. P05092 Locus CYPHJHUMAN 60S Acidic Ribosomal Protein PO SwissProt Acc.-No. P05388 Locus RLAOHUMAN With the aid of these proteins (referred to as target proteins in the following) it is possible to assess tumour resistance to antiestrogen therapy.
The invention is realised in accordance with the Claims stated.
The objective of the invention is to create a method capable of assessing the resistance of breast tumour cells to antiestrogen therapy. The method is characterized by the fact that the concentration of at least one target protein is determined in the tumour tissue and is compared with the standard reference value of the same protein or proteins in breast tumour cells sensitive to antiestrogen treatment, whereat a separate standard reference value is determined once for each protein. If the protein concentration in the sample examined lies above the standard reference value, resistance of the tumour to antiestrogen treatment will be indicated, provided it is a protein which is expressed at higher levels in breast tumour cells resistant to antiestrogen treatment, as compared to breast tumour cells sensitive to antiestrogen treatment. If the protein concentration in the sample examined lies below the standard reference value, resistance of the tumour to antiestrogen treatment will be indicated, provided it is a protein which is expressed at lower levels in breast tumour cells resistant to antiestrogen treatment, as compared to breast tumour cells sensitive to antiestrogen treatment.
Determination of the protein concentration is performed by applying known immunobiological methods, preferentially the application of antibodies, such as Western blot, immunohistochemistry, ELISA, among others. Moreover, the invention comprises a test-kit to determine the concentrations of the target proteins in tumour samples.
The invention also includes the therapeutic application of target proteins for the treatment of breast tumours that are resistant to antiestrogen treatment.
Subject of the invention are also nucleic acid sequences which are either identical or complementary to the cDNA sequences of the target proteins. Experience shows that these nucleic acid sequences can be applied as primers in a method to evaluate the resistance of breast tumour cells to antiestrogen treatment, by determining the concentrations of nucleic acids encoding specific target proteins in the tumour tissue and comparing them with a standard reference value of the same nucleic acids in the breast tumour tissues that are sensitive to antiestrogen treatment, whereat a separate standard reference value is determined once for each nucleic acid fragment.
If the concentration of the nucleic acid fragment in the sample examined lies above the standard reference value, resistance of the tumour to antiestrogen treatment will be indicated, provided it is a nucleic acid segment which is expressed at a higher level in breast tumour cells resistant to antiestrogen treatment, as compared to breast tumour cells sensitive to antiestrogen treatment. If the concentration of the nucleic acid segment in the sample examined lies below the standard reference value, resistance of the tumour to antiestrogen treatment will be indicated, provided it is a nucleic acid segment which is expressed at lower levels in breast tumour cells resistant to antiestrogen treatment, as compared to breast tumour cells sensitive to antiestrogen treatment.
In addition, the invention includes the application of nucleic acid segments which are either identical with or complementary to the cDNA sequences of the target proteins, for example, in the in form of antisense oligonucleotides for the treatment of breast tumours resistant to antiestrogen therapy.
Furthermore, the invention includes the blocking of the synthesis of the target proteins on the level of RNA, preferentially by means of antisense oligonucleotides or ribozyme directed against the mRNA encoding these proteins. This blocking is also possible, according to the invention, by means of specific antibodies directed against these proteins.
Legend of Figure: Fig. 1: Examples of comparative 2D gel electrophoresis The images show the differential expression of selected proteins in three samples of tamoxifen-sensitive (above) and tamoxifen-resistant cell lines (below). a) Spot 857-Lysophospholipase I Spot 866-Peroxiredoxin I b) C80RF2-Protein (hypothetical 37. 8-kDa-Protein, function unknown) c) Ubiquinol-Cytochrome c reductase
Literature: Harris JR, Lippman ME, Veronesi U, Willett W: Breast cancer. New England J Med 327: 319-328 (1992) Clarke R, Leonessa F, Welch JM, Skaar TC: Cellular and molecular pharmacology of antiestrogen action and resistance. Pharm Rev 53: 25-71 (2001) Naundorf H, Becker M, Lykkesfeldt AE, Elbe B, Neumann C, Butter B, Fichtner I: Development and characterization of a tamoxifen-resistant breast carcinoma xenograft. Br.
J. Cancer 82 : 1844 (2000)