Over-expression and knockdown of KLF5

Activation of the Ras/Erk pathway upregulates expression of the Kruppel-like Factor 5 (KLF5) transcription factor, and KLF5 is a downstream mediator of Ras oncogenic signaling. Specifically, in bladder and colon cancer cell lines KLF5 upregulates the Ras-pathway target gene cyclin D1, and facilitates entry into the S phase of the cell cycle. Ras mutations are common in lung cancer, but a role for KLF5 in lung tumorigenesis has not been defined. To this end, we manipulated KLF5 expression in four Ras-mutant human lung adenocarcinoma cell lines to find that KLF5 significantly modulates anchorage-independent growth, a mutant Ras phenotype. However, in a mouse model of human lung adenocarcinoma, K-RasG12D does not critically require Klf5 to mediate oncogenesis or induce cyclin D1 expression.

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Meyer SE, Hasenstein JR, Baktula A, Velu CS, Xu Y, Wan H, Whitsett JA, Gilks CB, Grimes HL