Isoform of Bruton's Tyrosine Kinase (BTK) Protein

Abstract

The use of compounds is described which are capable of functionally blocking at least one of the genes chosen from the group composed of EphAI, EphA2, EphA8, EphB2, CSF1R, VEGFR2, RAMP2, RAMP3, CLRN1, MAPK4, PIK3C2A, PIK3CG, GSK3alpha, GSK3beta, IRAK3, DAPK1, JAK1, PIM1, TRB3, BTG1, LATS1, LIMK2, MYLK, PAK1, PAK2, CDC2, BTK, PNRC2, NCOA4, NR2C1, TPR, RBBP8, TRPC7, FXYD1, ERNI, PRSS16, RPS3, CCL23 and SERPINE1, for the manufacture of a medicament destined to diminish the resistance to chemotherapeutic drugs in the therapeutic treatment of epithelial tumor pathologies. Also described is a method for the determination of the drug resistance in tumor cells, as well as a method for the identification of tumor stem cells.

What is claimed is: 
     
         1 . A method for reducing and/or reversing resistance of a tumor cell or a tumor stem cell to a chemotherapeutic drug in a tumor of a subject, the method comprising:
 providing a composition for usage in a medicament comprising compounds that inhibit and/or functionally block BTK used together with a chemotherapeutic agent.   
     
     
         2 . The method according to  claim 1 , wherein the method for reducing and/or reversing the resistance of patients' tumor cell or a tumor stem cell to a chemotherapeutic drug comprises
 (a) administering to the tumor of the subject a therapeutic amount of a composition comprising a small interfering RNA (siRNA) or a small hairpin RNA (shRNA),   wherein the tumor comprises the tumor cell or the tumor stem cell that is resistant to the chemotherapeutic drug;   wherein the small interfering RNA (siRNA) or the small hairpin RNA (shRNA) targets a 5′-untranslated region (5′-UTR) (SEQ ID NO: 1) of the messenger RNA (mRNA) encoding a shorter isoform of Bruton's Tyrosine Kinase (BTK) having the amino acid sequence of SEQ ID NO: 2, wherein the shorter isoform does not contain amino acid residues 1-88 or 2-89 of the Bruton's Tyrosine Kinase (BTK) set forth in SEQ ID NO: 3;   wherein the small interfering RNA (siRNA) inhibits expression of the messenger RNA (mRNA) encoding the shorter isoform of the Bruton's Tyrosine Kinase (BTK); and   wherein inhibition of the expression of the messenger RNA (mRNA) encoding the shorter isoform of the Bruton's Tyrosine Kinase (BTK) reverses resistance of the tumor cell or the tumor stem cell to the chemotherapeutic drug.   
     
     
         3 . The method according to  claim 2 , wherein the small interfering RNA (siRNA) comprises a double-stranded RNA comprising:
 (i) a sense polynucleotide strand having a nucleotide sequence length of from about 19 to about 23 nucleotides, wherein the sense polynucleotide strand is complementary to the 5′-untranslated region (5′-UTR) of the shorter isoform of the Bruton's Tyrosine Kinase (BTK) set forth in SEQ ID NO: 1; and   (ii) an anti-sense polynucleotide strand that is complementary to the sequence of the sense polynucleotide strand.   
     
     
         4 . The method according to  claim 2 , wherein the small hairpin RNA (shRNA) comprises:
 (i) a sense polynucleotide strand having a nucleotide sequence length of 19 to 23 nucleotides, wherein the sense polynucleotide strand is complementary to the 5′-untranslated region (5′-UTR) of the shorter isoform of the Bruton's Tyrosine Kinase (BTK) set forth in SEQ ID NO: 1;   (ii) an anti-sense polynucleotide strand that is complementary to the sequence of the sense polynucleotide strand; and   (iii) a polynucleotide linker sequence of sufficient length, wherein the polynucleotide linker sequence allows the sense polynucleotide strand and the anti-sense polynucleotide strand to fold over and hybridize to each other.   
     
     
         5 . The method according to  claim 4 , wherein the small hairpin RNA (shRNA) is expressed by an expression vector. 
     
     
         6 . The method according to  claim 5 , wherein the expression vector is a retroviral vector. 
     
     
         7 . The method according to  claim 2 , wherein the small interfering RNA (siRNA) or the small hairpin RNA (shRNA) does not affect expression of Bruton's Tyrosine Kinase (BTK) set forth in SEQ ID NO: 3. 
     
     
         8 . The method according to  claim 1 , wherein the compound capable of functionally blocking the shorter isoform of Bruton's Tyrosine Kinase (BTK) having the amino acid sequence of SEQ ID NO: 2, wherein the shorter isoform does not contain amino acid residues 1-88 or 2-89 of BTK set forth in SEQ ID NO: 3, is at least one agent selected from the group consisting of LFM-A13, AVL-292, Ibrutinib, Dasatinib, Bosutinib, and a combination thereof. 
     
     
         9 . The method according to  claim 1 , wherein the tumor is an epithelial tumor. 
     
     
         10 . The method according to  claim 9 , wherein the epithelial tumor is at least one tumor selected from the group consisting of a colon tumor, a lung tumor, a breast tumor, an ovarian tumor, a thyroid tumor, a stomach tumor, a pancreatic tumor, a liver tumor, a kidney tumor, and a combination thereof. 
     
     
         11 . The method according to  claim 1 , wherein the chemotherapeutic drug is an antimetabolite agent. 
     
     
         12 . The method according to  claim 1 , wherein the chemotherapeutic drug is a DNA-damaging agent. 
     
     
         13 . The method according to  claim 1 , wherein the DNA-damaging agent is selected from the group consisting of a topoisomerase I inhibitor, a topoisomerase II inhibitor, a platinum coordination compound, an alkylating agent, and a combination thereof. 
     
     
         14 . The method according to  claim 1 , wherein the chemotherapeutic drug is 5-fluorouracil. 
     
     
         15 . The method according to  claim 1 , wherein the chemotherapeutic drug is oxaliplatin alone or in admixture with 5-fluorouracil (5FU).