Figure 7

Protein interaction partners of CCND1: Different gene expression in MCL subgroups. The colors red, blue and grey mean "over expressed", "down regulated" (in "b") and "not available in the data set". FOS encodes for a leucine zipper protein and plays a role in regulation of cell proliferation, differentiation, transformation and tumorigenesis [58]. The JUN protein interacts directly with specific target DNA sequences to regulate gene expression [59] and is involved in tumorigenesis by cooperating with oncogenic alleles of Ras, an activator of the mitogen activated protein kinases [60]. MYC and MYBL2 play a role in cell cycle progression and act as transcription factors. MYC is also associated with apoptosis, cellular transformation, cell growth, proliferation, differentiation, and a variety of hematopoietic tumors, leukemias and lymphomas [61, 62, 63], and was part of the original proliferation signature [6]. MYBL2 has been shown to play a role in the G1/S transition [64] and proliferation [65] and is known to be regulated by CCND1 [66, 67]. CDK4 and CDK6 are important regulators of cell cycle transition from G1 to S, phosphorylate, and thus regulate the activity of tumor suppressor protein Rb [68].