Transcription Factor KLF15 Inhibit Cell Growth Through Up-regulating Cell Cycle Regulator P21

KLF15 is a member of KLF family, its carboxyl terminal has three zinc fingers and can bind DNA fragments that are rich in GC, Since KLF 15 has the ability of activating or inhibiting gene’s expression on the level of transcription. KLF15 plays an important role on cardiac pathology, regulation of blood sugar, adipose cell differentiation. As an important cell cycle regulator, p21 has a great effect on various physiological function.We discover that KLF15 can activate p21 promoter intensively and then up-regulate its protein expression. This is an p53-independent process. KLF15 can activate not only the level of p21 transcription but also the level of p27 transcription. Since both of p21 and p27 are important regulators of cell cycle, they can suppress the function of CDK/cyclin and thus inhibit the normal cell growth. Over-expression of KLF 15 will suppress cell cycle at G1 phase.As another important activator of p21, KLF 15 will probably have an significant function on tumor therapy. We will has a further knowledge of p21 oncogenesis mechanism for its cell cycle regulator. However, impacts of KLF15 on cell cycle need further study. Along with further investigation, KLF15 will provide a new way of p21 mediating tumor therapy.