Abstract: Provided is a method for screening for effective agents for the treatment of cancer which method comprises selecting a putative agent that is likely to disrupt a function mediated by a critical normal gene product, which function is required for the successful division and continued cell survival of cancer cells, and which function is not required for the successful division and continued cell survival of control cells, treating a cancer cell sample and a control cell sample with a purative agent and determining the cytotoxic effect of, and/or the growth inhibitory effect of the putative agent on these samples, and identifying an effective agent as an agent which is more cytotoxic to, and/or more inhibiting to the growth of the cancer cell sample than the control cell sample. This invention further provides an effective agent identified by this screening method and a method of treating a cancer patient with such an agent.

Abstract: Provided is a method for the diagnosis of a cancerous or pre-cancerous state in a subject, comprising testing a sample comprising cells or an extract therefrom for the co-elevation of CDK1 and CDK4. Also provided is a kit for the diagnosis of a cancerous or pre-cancerous state in a subject, comprising: (i) a means for testing for the elevation of CDK1; and (ii) a means for testing for the elevation of CDK4.

Abstract: Provided is a method for screening for effective agents for the treatment of cancer which method comprises testing a putative agent that is likely to disrupt a critical normal gene product present in said cancer for its cytotoxic and/or growth inhibitory effect upon a cancer cell sample, and identifying an effective agents as an agent which is cytotoxic to, and/or inhibiting to the growth of the cancer cell sample. This invention further provides an agent capable of disrupting a critical normal gene in such a manner as to be cytotoxic to, or inhibiting to the growth of a cancer cell, and a method of treating a cancer patient with such an agent.

Abstract: Provided is a method for measuring the sensitivity of a cancer cell to an anti-cancer agent, which method comprises testing a sample for the mutational status, expression, and/or function of a negative signal transduction factor (NSTF), and testing the sample for the mutational status, expression, and/or function of a positive signal transduction factor (PSTF), wherein when the method comprises measuring the radiosensitivity of wild-type p53 cancer cells by testing a sample comprising wild-type p53 cells or an extract therefrom for the abundance of Raf-1 protein by Western blotting, an antibody specific to Raf-1 protein is employed.

Abstract: Provided is a method for measuring the sensitivity of a cancer cell to an anticancer agent, which method comprises testing a sample for the mutational status, expression, and/or function of a negative signal transduction factor (NSTF), and testing the sample for the mutational status, expression, and/or function of a positive signal transduction factor (PSTF), wherein when the method comprises measuring the radiosensitivity of wild-type p53 cancer cells by testing a sample comprising wild-type p53 cells or an extract therefrom for the abundance of Raf-1 protein by Western blotting, an antibody specific to Raf-1 protein is employed.