Method and kit for detection of cancer, and therapeutic agent for cancer

Abstract

The object aims to comprehensively analyze miRNA that undergoes epigenetic silencing in cancer to identify miRNA associated with cancer, elucidate the role of the identified miRNA in cancer, and develop a novel method for detecting cancer and a novel therapeutic agent for cancer both of which relate to the miRNA. Disclosed is a method for detecting cancer in a subject, which comprises detecting methylated CpG in a CpG island located in a promoter region of a microRNA 34b gene and/or a microRNA 34c gene in a biological sample collected from the subject. Also disclosed is a therapeutic agent for cancer, which comprises a nucleic acid encoding a BTG4 gene or BTG4, or comprises a nucleic acid encoding a miR-34b gene and/or an miR-34c gene or miR-34b and/or miR-34c.

1 . Method of detecting a cancer in a subject, comprising:
 detecting a methylated CpG in a CpG island in a promoter region of microRNA34b gene and/or microRNA34c gene in a biological sample obtained from the subject.   
     
     
         2 . The method according to  claim 1 , wherein the cancer is detected according to a criteria that the methylated CpG in the CpG island in the promoter region of microRNA34b and/or microRNA34c gene in the biological sample obtained from the subject is at least more than 10% of all CpGs in the CpG island in the promoter region of microRNA34b gene and/or microRNA34c gene in said biological sample obtained from the subject. 
     
     
         3 . The method according to  claim 1 , wherein the CpG island in the promoter region of microRNA34b gene and/or microRNA34c gene is a DNA region having a nucleotide sequence that is identical to or substantially identical to the nucleotide sequence of SEQ ID NO:5. 
     
     
         4 . The method according to  claim 1 , wherein the cancer is colorectal cancer, gastric cancer, pancreatic cancer or breast cancer. 
     
     
         5 . The method according to  claim 1 , wherein the biological sample is one or more selected from a group consisting of serum, stool, colon tissue, gastric lavage fluid, pancreatic juice and bile. 
     
     
         6 . The method according to  claim 1 , wherein the methylated CpG is detected using one or more procedures selected from the group consisting of methylation-specific PCR, bisulfite sequencing, pyro-sequencing, COBRA, and MethyLight. 
     
     
         7 . The method according to  claim 6 , wherein the methylated CpG is detected using a sense primer comprising successive 15 to 40 nucleotides of a nucleotide sequence that is identical to or substantially identical to the nucleotide sequence of SEQ ID NO:5, and an antisense primer comprising successive 15 to 40 nucleotides of a nucleotide sequence that is complementary to a nucleotide sequence that is identical to or substantially identical to the nucleotide sequence of SEQ ID NO:5. 
     
     
         8 . The method according to  claim 6 , wherein the methylated CpG is detected using an oligonucleotide having a nucleotide sequence of any one of SEQ ID NO:10, 11, 13, 14, 15, 17, 18, 19 and 20. 
     
     
         9 . A kit for detecting cancer, for predicting the stage of cancer, for predicting a risk of carcinogenesis, and/or for predicting a risk of recurrence, comprising:
 (i) a sense primer comprising successive 15 to 40 nucleotides of a nucleotide sequence that is identical to or substantially identical to the nucleotide sequence of SEQ ID NO:5, and an antisense primer comprising successive 15 to 40 nucleotides of a nucleotide sequence that is complementary to a nucleotide sequence that is identical to or substantially identical to the nucleotide sequence of SEQ ID NO:5; or   (ii) an oligonucleotide having a nucleotide sequence of any one of SEQ ID NOs:10, 11, 13, 14, 15, 17, 18, 19 and 20.   
     
     
         10 . (canceled) 
     
     
         11 . A kit for cancer detection for detecting a cancer by the method according to  claim 1 , comprising:
 (i) a sense primer comprising successive 15 to 40 nucleotides of a nucleotide sequence that is identical to or substantially identical to the nucleotide sequence of SEQ ID NO:5, and an antisense primer comprising successive 15 to 40 nucleotides of a nucleotide sequence that is complementary to a nucleotide sequence that is identical to or substantially identical to the nucleotide sequence of SEQ ID NO:5: or   (ii) an oligonucleotide having a nucleotide sequence of any one of SEQ ID NOs:10, 11, 13, 14, 15, 17, 18, 19 and 20.   
     
     
         12 - 20 . (canceled) 
     
     
         21 . The method according to  claim 1 , wherein the method is practiced using the kit according to  claim 9 .