Breast Cancer

Centromere protein F (CENPF), also named mitosin, is a large human protein of 3113 amino acid residues. Its expression and localization are cell cycle-dependent. The protein levels are low in G1 phase but elevated from S to early M phase. CENPF is a nuclear matrix protein in interphase but is relocated to the kinetochore, the major site of microtubule attachment on chromosome, in M phase (1).

Beclin 1 is the mammalian orthologue of the yeast Apg6/Vps30 gene. Beclin 1 can complement the defect in autophagy present in apg6 yeast strains and stimulate autophagy when overexpressed in mammalian cells (1) and can bind to Bcl2, an important regulator of apoptosis (2) suggesting a role in two fundamentally important cellular pathways: autophagy and apoptosis.

The polycomb group (PcG) protein, enhancer of zeste homolog 2 (EZH2) is a methyl-transferase that plays a key role in transcriptional gene repression. EZH2 is frequently overexpressed in several malignant tumors, and is often associated with advanced disease stage in many solid tumors.

E-cadherin is a calcium-regulated adhesion molecule expressed in most normal epithelial tissues. E-cadherin is also associated with gland formation, stratification, and epithelial polarization, while loss of E-cadherin can cause dedifferentiation and invasiveness in several human carcinomas (1). In a recent study, human breast cancer tissues were stained immunohistochemistry (IHC) by anti- E-Cadherin antibodies.

EGF (epidermal growth factor) stimulates differentiation, proliferation and cell growth by binding to its receptor, EGFR. EGF was first discovered in the mouse submandibular gland in 1986 by Stanley Cohen of Vanderbilt University, leading to a Nobel Prize in Physiology and Medicine. Since then, EGF has been found in many tissues of the human body (including urine, saliva, plasma, milk, macrophages and platelets) and has been the subject of intense study in many areas of clinical research due to its many abilities.

Nucleolin is an abundant, 106 kDa nucleolar phosphoprotein that is a major protein in actively dividing cells. The stability of nucleolin is heavily cell proliferation-dependent, as nucleolin antibody studies have shown that degraded forms are relatively abundant in quiescent non-dividing cells, while nonexist in actively dividing cells.

The myeloid differentiation protein MyD88 (myeloid differentiation primary response protein) was originally identified and characterized as a primary upregulated response gene in interleukin-6 mediated myeloid differentiation.

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.

The transcription factor beta protein 1 (BP1) is a member of the homeobox gene family and the distal-less subfamily. Expression of BP1 is highly tissue-specific and developmentally restricted. Among different human tissues, BP1 is found to be highly expressed in placenta, kidney and at lower levels in fetal liver (1). Such restricted pattern of expression is compatible with a specific gene function in development and/or differentiation.

Epithelial-to-mesenchymal transition (EMT) is a critical event in the induction of cell motility and increased survival both under physiological situations like wound healing or development, as well as in malignant cells undergoing invasion and metastasis. Vimentin is an intermediate filament protein which is characteristically upregulated in cells undergoing EMT. Recent studies support the notion that vimentin functions as a positive regulator of EMT and upregulation of vimentin appears to be a prerequisite for EMT induction (1).