The forkhead box M1 transcription factor contributes to the development and growth of mouse colorectal cancer.

Background & Aims: In this study, we used Forkhead Box m1b (Foxm1b) transgenic mice and conditional Foxm1 knock-out mice to examine the role of Foxm1 in colon cancer development and proliferation.

Methods: To induce mouse colorectal cancer, we used a single intraperitoneal injection of azoxymethane (AOM) followed by three 1-week cycles of 2.5% dextran sodium sulfate (DSS) water, each cycle separated by 2 weeks.

The Forkhead Box m1 transcription factor stimulates the proliferation of tumor cells during development of lung cancer.

The proliferation-specific Forkhead Box m1 (Foxm1 or Foxm1b) transcription factor (previously called HFH-11B, Trident, Win, or MPP2) regulates expression of cell cycle genes essential for progression into DNA replication and mitosis. Expression of Foxm1 is found in a variety of distinct human cancers including hepatocellular carcinomas, intrahepatic cholangiocarcinomas, basal cell carcinomas, ductal breast carcinomas, and anaplastic astrocytomas and glioblastomas. In this study, we show that human Foxm1 protein is abundantly expressed in highly proliferative human non-small cell lung cancers (NSCLC) as well as in mouse lung tumors induced by urethane.

The forkhead box m1 transcription factor is essential for embryonic development of pulmonary vasculature.

Transgenic and gene knock-out studies demonstrated that the mouse Forkhead Box m1 (Foxm1 or Foxm1b) transcription factor (previously called HFH-11B, Trident, Win, or MPP2) is essential for hepatocyte entry into mitosis during liver development, regeneration, and liver cancer. Targeted deletion of Foxm1 gene in mice produces an embryonic lethal phenotype due to severe abnormalities in the development of liver and heart. In this study, we show for the first time that Foxm1(-/-) lungs exhibit severe hypertrophy of arteriolar smooth muscle cells and defects in the formation of peripheral pulmonary capillaries as evidenced by significant reduction in platelet endothelial cell adhesion molecule 1 staining of the distal lung.

The mouse Forkhead Box m1 transcription factor is essential for hepatoblast mitosis and development of intrahepatic bile ducts and vessels during liver morphogenesis.

Conditional deletion of the mouse Forkhead Box (Fox) m1b targeted allele in adult hepatocytes (Foxm1, previously called HFH-11B, Trident, Win, or MPP2) demonstrated that the Foxm1b transcription factor is essential for hepatocyte mitosis during liver regeneration. To determine the role of Foxm1b in liver development, we have generated Foxm1b -/- mice that deleted the Foxm1b exons encoding the winged helix DNA binding and transcriptional activation domains. Here, we show that all of the Foxm1b -/- embryos died in utero by 18.

Foxm1b transcription factor is essential for development of hepatocellular carcinomas and is negatively regulated by the p19ARF tumor suppressor.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide. Here, we provide evidence that the Forkhead Box (Fox) m1b (Foxm1b or Foxm1) transcription factor is essential for the development of HCC. Conditionally deleted Foxm1b mouse hepatocytes fail to proliferate and are highly resistant to developing HCC in response to a Diethylnitrosamine (DEN)/Phenobarbital (PB) liver tumor-induction protocol.

Foxf1 haploinsufficiency reduces Notch-2 signaling during mouse lung development.

The forkhead box (Fox) f1 transcription factor is expressed in the mouse splanchnic (visceral) mesoderm, which contributes to development of the liver, gallbladder, lung, and intestinal tract. Pulmonary hemorrhage and peripheral microvascular defects were found in approximately half of the newborn Foxf1(+/-) mice, which expressed low levels of lung Foxf1 mRNA [low-Foxf1(+/-) mice]. Microvascular development was normal in the surviving newborn high-Foxf1(+/-) mice, which compensated for pulmonary Foxf1 haploinsufficiency and expressed wild-type Foxf1 levels.

Ubiquitous expression of the forkhead box M1B transgene accelerates proliferation of distinct pulmonary cell types following lung injury.

The delayed early transcription factor Forkhead Box M1B (FoxM1B) is expressed in proliferating cells, but its expression is extinguished in cells undergoing terminal differentiation. Liver regeneration studies with genetically altered mice that either prematurely expressed FoxM1B in hepatocytes or contained a hepatocyte-specific deletion of the Foxm1b allele demonstrated that FoxM1B is critical for regulating the expression of cell cycle genes required for hepatocyte proliferation. Furthermore, preventing the decline in hepatocyte FoxM1B levels during aging was sufficient to increase regenerating hepatocyte proliferation and expression of cell cycle genes to levels found in young regenerating mouse liver.