The present invention aims to elucidate a miRNA involved in cellular senescence and to provide a method of use thereof. The senescence marker of the present invention comprises a gene transcript of miR-22. Further, the method for evaluating a senescence inhibitor of the present invention comprises the step of measuring the expression level of a gene transcript of miR-22 in a sample in the presence of a test compound and in the absence of the test compound and the step of comparing the expression level of the gene transcript of miR-22 in the sample in the presence of the test compound with the expression level of the gene transcript of miR-22 in the sample in the absence of the test compound. Further, the cancer inhibitor of the present invention comprises as an effective component a gene transcript of miR-22, which cancer inhibitor promotes cellular senescence and inhibits invasion and/or metastasis of cancer.
