A method of screening for a candidate compound for treating or preventing cancer or inhibiting cancer cell growth, said method comprising the steps of: (a) contacting a test compound with a polypeptide encoded by PRMT1 gene, wherein said polypeptide is selected from the group consisting of: (i) a polypeptide comprising the amino acid sequence set forth in SEQ ID NO:2, (ii) a polypeptide that has a biological activity equivalent to the polypeptide comprising the amino acid sequence set forth in SEQ ID NO:2, wherein said polypeptide comprises an amino acid sequence in which one or more amino acids are substituted, deleted, added or inserted to the amino acid sequence of SEQ ID NO:2, (iii) a polypeptide that has a biological activity equivalent to the polypeptide comprising the amino acid sequence set forth in SEQ ID NO:2, wherein said polypeptide is composed of an amino acid sequence having at least 90% of sequence identity to the amino acid sequence set forth in SEQ ID NO:2, (iv) a polypeptide that has a biological activity equivalent to the polypeptide comprising the amino acid sequence set forth in SEQ ID NO:2, wherein said polypeptide is encoded by a polynucleotide that hybridizes under stringent condition to the polynucleotide consisting of the nucleic acid sequence set forth in SEQ ID NO:1; (b) detecting the biological activity of the polypeptide of step (a); and (c) selecting the test compound that suppresses the biological activity of the polypeptide in comparison with the biological activity detected in the absence of the test compound, wherein the cancer is selected from the group consisting of bladder cancer, gastric cancer, colorectal cancer, esophageal cancer, lung cancer, lymphoma, pancreatic cancer and testicular cancer. (a) contacting a test compound with a polypeptide encoded by PRMT1 gene, wherein said polypeptide is selected from the group consisting of: (i) a polypeptide comprising the amino acid sequence set forth in SEQ ID NO:2, (ii) a polypeptide that has a biological activity equivalent to the polypeptide comprising the amino acid sequence set forth in SEQ ID NO:2, wherein said polypeptide comprises an amino acid sequence in which one or more amino acids are substituted, deleted, added or inserted to the amino acid sequence of SEQ ID NO:2, (iii) a polypeptide that has a biological activity equivalent to the polypeptide comprising the amino acid sequence set forth in SEQ ID NO:2, wherein said polypeptide is composed of an amino acid sequence having at least 90% of sequence identity to the amino acid sequence set forth in SEQ ID NO:2, (iv) a polypeptide that has a biological activity equivalent to the polypeptide comprising the amino acid sequence set forth in SEQ ID NO:2, wherein said polypeptide is encoded by a polynucleotide that hybridizes under stringent condition to the polynucleotide consisting of the nucleic acid sequence set forth in SEQ ID NO:1; (i) a polypeptide comprising the amino acid sequence set forth in SEQ ID NO:2, (ii) a polypeptide that has a biological activity equivalent to the polypeptide comprising the amino acid sequence set forth in SEQ ID NO:2, wherein said polypeptide comprises an amino acid sequence in which one or more amino acids are substituted, deleted, added or inserted to the amino acid sequence of SEQ ID NO:2, (iii) a polypeptide that has a biological activity equivalent to the polypeptide comprising the amino acid sequence set forth in SEQ ID NO:2, wherein said polypeptide is composed of an amino acid sequence having at least 90% of sequence identity to the amino acid sequence set forth in SEQ ID NO:2, (iv) a polypeptide that has a biological activity equivalent to the polypeptide comprising the amino acid sequence set forth in SEQ ID NO:2, wherein said polypeptide is encoded by a polynucleotide that hybridizes under stringent condition to the polynucleotide consisting of the nucleic acid sequence set forth in SEQ ID NO:1; (b) detecting the biological activity of the polypeptide of step (a); and (c) selecting the test compound that suppresses the biological activity of the polypeptide in comparison with the biological activity detected in the absence of the test compound, wherein the cancer is selected from the group consisting of bladder cancer, gastric cancer, colorectal cancer, esophageal cancer, lung cancer, lymphoma, pancreatic cancer and testicular cancer.