Secretory Granules and Granulogenic Factors as a Target for Cancer Treatment

Abstract

The present invention relates to a method for screening a cancer therapeutic agent, comprising the steps of: (a) contacting a test substance of interest with a cell containing a granulogenic factor-encoding nucleotide sequence; and (b) analyzing expression of the granulogenic factor or production of secretory granules, wherein the test substance is determined as the cancer therapeutic agent where it inhibits the expression of the granulogenic factor or the production of secretory granules. In the present invention, the expression of the granulogenic factor contributes to induction of secretory granule formation in non-secretory cells, and inhibition of the granulogenic factor expression leads to inhibition of secretory granule formation in secretory cells. In addition, the secretory granules produced by the present granulogenic factor change cell activities via the IP3-dependent cellular Ca2+ regulatory mechanism, and the changes of cellular Ca2+ homeostasis will affect the development and proliferation of cancer cells. Therefore, a pharmaceutical composition containing as an active ingredient a substance which inhibits expression of a granulogenic factor gene, production of secretory granules, or activity of the granulogenic factor may be utilized in cancer prophylaxis or treatment, and also be used as a kit for identifying a cancer.

Dependencies are inferred from the claim text.