Gene involved in immortalization of human cancer cell and use thereof

A method for screening a substance for suppressing proliferation of immortalized cancer cells, comprising the steps of:

• (A) bringing a test material into contact with a cell that can express one of the immortalization-determining genes represented by SEQ ID Nos. 1 to 13;
• (B) measuring an expression amount of one of the immortalization-determining genes represented by SEQ ID Nos. 1 to 13 in the cell brought into contact with the test material;
• (C) comparing the expression amount of the immortalization-determining gene found in Step (B) with an expression amount (generically referred to as “a comparative expression amount”, hereinafter) of an immortalization-determining gene in a cell not in contact with the test material;
• and
• (D) selecting the test material as a candidate substance for suppressing proliferation of immortalized cancer cells when the expression amount found in Step (B) is lower than the comparative expression amount.

A method for screening a substance for suppressing proliferation of immortalized cancer cells, comprising the steps of:

• (A′) bringing a test material into contact with a polypeptide having one of the amino acid sequences represented by SEQ ID Nos. 14 to 26;
• (B′) measuring activity of the polypeptide having one of the amino acid sequences represented by SEQ ID Nos. 14 to 26 brought into contact with the test material;
• (C′) determining the degree of the activity of the polypeptide found in Step (B′) by comparing the activity of the polypeptide found in Step (B′) with activity (generically referred to as “a comparative activity”, hereinafter) of a polypeptide not in contact with the test material;
• and
• (D′) selecting the test material as a candidate substance for suppressing proliferation of immortalized cancer cells when the activity of the polypeptide found in Step (B′) is lower than the comparative activity.