Cancer

E-Cadherin is a member of the cadherin superfamily and is fundamental player in a wide range of cellular processes such as development, morphology, polarity, migration and tissue integrity. Specifically, E-cadherin is an approximately 100 kDa epithelial cell glycoprotein whose extracellular domain interacts with that of other E-cadherin molecules on adjacent cells to establish cell-cell adhesion. This adhesion is Ca^2+-dependent and a variety of interactions have been identified.

Tropomyosin receptor kinase B (TrkB) is a member of the Trk receptor tyrosine kinases family consisting of TrkA, TrkB and TrkC. The sequence of these family members is highly conserved. TrK's are activated by several neurotrophins, which are small protein growth factors that play a role in survival and differentiation of distinct cell populations.

Sterol-regulatory-element-binding protein 2 (SREBP2) is a transcription factor that regulates cholesterol homeostasis by controlling enzymes involved in cholesterol synthesis and uptake, e.g. HMG-CoA.

Proliferating cell nuclear antigen (PCNA) is an evolutionarily well-conserved protein found in all eukaryotic species as well as in Archaea. PCNA was first shown to be involved in DNA replication. However PCNA functions are associated with other vital cellular processes such as chromatin remodeling, DNA repair, sister-chromatid cohesion and cell cycle control as well (1).

Nucleolin is a multifunctional phosphoprotein ubiquitously distributed in the nucleolus, nucleus and cytoplasm of the cell. Nucleolin has a bipartite nuclear localization signal sequence and is conserved across the species. Nucleolin levels are expressed in abundance in exponentially growing cells and it regulates various aspects of DNA and RNA metabolism, chromatin structure, rDNA transcription, rRNA maturation, cytokinesis, nucleogenesis, cell proliferation and growth (1).

The mammalian target of rapamycin (mTOR) is a downstream effector of the phosphatidylinositol 3-kinase (PI3K)/Akt (protein kinase B) signaling pathway that mediates cell survival and proliferation. It is increasingly apparent that mTOR signaling impacts most major cellular functions.

BrdU (5-bromo-2-deoxyuridine) is a thymidine analogue which is incorporated into the cells of DNA synthetic phase. Replicating cells undergo DNA synthesis in a highly regulated, S-phase of the cell cycle. The regulation of cell proliferation is central to tissue morphogenesis during the development of multicellular organisms. Furthermore, loss of control of cell proliferation underlies the pathology of diseases like cancer.

Increasing evidence shows that a variety of cancers arise from the transformation of normal stem cells into cancer stem cells (CSCs). CSCs are thought to sustain cancer progression, invasion, metastasis.

Ghrelin is the only potent orexigenic peptide in circulation. It stimulates food intake and leads to metabolism regulation, positive energy balance, adipogenesis, and body weight gain. However, in studies using ghrelin antibodies, the physiological significance of ghrelin in the regulation of energy homeostasis is controversial, since loss of ghrelin function in rodents does not necessarily lead to anorexia and weight loss (1).

Epigenetic alterations have come to prominence in biomedical research. In particular, hypermethylation of CpG islands located in the promoter regions of tumor-suppressor genes is now firmly established as an important mechanism for gene inactivation in cancer.