Abstract: Provided is a cyclic peptide which comprises: (i) a CDK4 peptide region; and (ii) a cell-penetrating region; wherein the CDK4 peptide region comprises the amino acid sequence P1R1x1y1R2P2V (SEQ ID NO: 1), in which P1 and P2 are each proline, R1 and R2 are each arginine and each of x1 and y1 are either a linker or proline, wherein if x1 is a linker then y1 is proline or if x1 is proline then y1 is a linker, or wherein x1 and y1 when taken together form a linker, and wherein V may be present or absent; and wherein the cell-penetrating region is capable of enhancing the uptake of the cyclic peptide or a part thereof into cancer cells and comprises an amphiphilic amino acid sequence; and wherein the cyclic peptide or a part thereof is cytotoxic to and/or inhibiting to the growth of a cancer cell.

Abstract: The present invention provides a peptide comprising an amino acid sequence that is part of the amino acid sequence of CDK4 protein, or homologous to part of the amino acid sequence of CDK4 protein, which peptide is cytotoxic to, and/or inhibiting to the growth of, a cancer cell and/or stimulating to the growth of a non-cancerous cell and/or a control cell. Methods of identifying such peptides and medical uses of such peptides are also disclosed.

Abstract: Provided is a cyclic peptide which comprises: (i) a CDK4 peptide region; and (ii) a cell-penetrating region; wherein the CDK4 peptide region comprises the amino acid sequence P1R1x1y1R2P2V (SEQ ID NO: 1), in which P1 and P2 are each proline, R1 and R2 are each arginine and each of x1 and y1 are either a linker or proline, wherein if x1 is a linker then y1 is proline or if x1 is proline then y1 is a linker, or wherein x1 and y1 when taken together form a linker, and wherein V may be present or absent; and wherein the cell-penetrating region is capable of enhancing the uptake of the cyclic peptide or a part thereof into cancer cells and comprises an amphiphilic amino acid sequence; and wherein the cyclic peptide or a part thereof is cytotoxic to and/or inhibiting to the growth of a cancer cell.

Abstract: The present invention provides a peptide comprising an amino acid sequence that is part of the amino acid sequence of CDK4 protein, or homologous to part of the amino acid sequence of CDK4 protein, which peptide is cytotoxic to, and/or inhibiting to the growth of, a cancer cell and/or stimulating to the growth of a non-cancerous cell and/or a control cell. Methods of identifying such peptides and medical uses of such peptides are also disclosed.

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 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.