Identification of a JAK2 mutation involved in Vaquez Polyglobulia
View Patent ↗The present invention concerns the V617F variant of the protein-tyrosine kinase JAK2, said variant being responsible for Vaquez Polyglobulia. The invention also relates to a first intention diagnostic method for erythrocytosis and thrombocytosis allowing their association with myeloproliferative disorders, or to the detection of the JAK2 V617F variant in myeloproliferative disorders allowing their reclassification in a new nosological group, and to the identification of specific inhibitors and siRNA.
1. An isolated variant of human JAK2 (Janus kinase 2) protein, wherein the variant has a V617F mutation, and has the sequence shown in SEQ ID NO 1.
2. An isolated nucleotide sequence encoding the isolated variant of human JAK2 protein according to claim 1 .
3. A cloning and/or viral expression vector, either plasmid or in naked DNA form, characterized in that it comprises the nucleotide sequence according to claim 2 under the control of a promoter in mammalian cells.
4. A recombinant mammalian cell expressing the isolated variant of human JAK2 protein according to claim 1 .
5. An isolated nucleic acid consisting essentially of at least 12 consecutive nucleotides of sequence SEQ ID NO 3 or 4, wherein the isolated nucleic acid comprises the nucleotide t 261 in SEQ ID NO 3 or t 50 in SEQ ID NO 4, wherein the isolated nucleic has the functional properties of a probe or primer.
6. The isolated nucleic acid according to claim 5 , wherein said isolated nucleic acid is SEQ ID NO: 11 with a g 21 t mutation.
7. A kit for detecting a G 1849 T mutation in the human JAK2 gene in a human tumor, wherein the kit comprises one or more primers or probes, as defined in claim 5 , for the specific detection of the presence or absence of the G 1849 T mutation in the human JAK2 gene, wherein the G 1849 T mutation is nucleotide t 261 in SEQ ID NO 3 or t 50 in SEQ ID NO 4.
8. A kit for determining whether a patient is suffering from a myeloproliferative disorder involving a G 1849 T mutation of the human JAK2 gene, wherein the kit comprise one or more probes or primers, as defined in claim 5 , for the specific detection of the presence or absence of the G 1849 T mutation in the human JAK2 gene.
9. The kit according to claim 7 also containing at least one element chosen from among a heat resistant polymerase for PCR amplification, one or more solutions for amplification and/or hybridisation and any reagent allowing said specific detection.
10. An isolated siRNA capable of reducing, by more than 50%, the expression of the variant of human JAK2 protein according to claim 1 in an isolated cell system, wherein the siRNA is 19 to 25 nucleotides in length, with the sequence of a first strand being identical and the sequence of a second strand being complementary to sequence (i) SEQ ID NO 3, (ii) SEQ ID NO 4, or (iii) SEQ ID NO 11 with a g 21 t mutation.
11. The siRNA according to claim 10 , characterized in that it is chosen from the group consisting of:
UGGAGUAUGUUUCUGUGGA
(SEQ ID NO 29)
GGAGUAUGUUUCUGUGGAG
(SEQ ID NO 30)
and
GAGUAUGUUUCUGUGGAGA
(SEQ ID NO 31).
12. A composition comprising the siRNA according to claim 10 and a pharmaceutically acceptable vehicle.
13. The isolated nucleic acid according to claim 5 , wherein said nucleic acid consists essentially of 15 to 30 consecutive nucleotides of sequence SEQ ID NO 3 or 4, wherein the nucleic acid comprises the nucleotide t 261 in SEQ ID NO 3 or t 50 in SEQ ID NO 4.
14. The isolated nucleic acid according to claim 5 , wherein said nucleic acid consists essentially of at least 15 consecutive nucleotides.
15. The isolated nucleic acid according to claim 5 , wherein said nucleic acid consists of at least 12 consecutive nucleotides.
16. The isolated nucleic acid according to claim 5 , wherein said nucleic acid consists of at least 15 consecutive nucleotides.