As part of this week’s newsletter's thematic "Research Focus: Breast Cancer" issue, we are training the Spotlight on a few of the items that are applicable to that field of study, along with some more general oncology tools.
First up is a selection from our estimable RGD portfolio.
When 99mTc-labeled, this cyclic RGD dimer is a useful tool for tumor imaging.1
The next group is pulled from our vast Recombinant Proteins category:
- ErbB3 Mouse
ErbB3, also called Her3 (human epidermal growth factor receptor 3), is a type I membrane glycoprotein that is a member of the ErbB family of tyrosine kinase receptors. ErbB family members serve as receptors for the epidermal growth factor (EGF) family of growth factors. Among ErbB family members, ErbB3 is unique in that it contains a defective kinase domain. ErbB3 is expressed in keratinocytes, melanocytes, skeletal muscle cells, embryonic myoblasts and Schwann cells. Monomeric ErbB3 serves as a low affinity receptor for the heregulins (HRG). ErbB3 can induce specific antibody production in vivo, hence to inhibit tumor cell growth. ErbB-3 can be used to treat early, medium and advanced or post-operative breast cancer with over-expression of ErbB2. According to its mechanism of action, ErbB3 is classified as a therapeutic for cancer. 2
HEXIM1 expression is induced by hexamethylene-bis-acetamide in vascular smooth muscle cells. HEXIM1 is a transcriptional regulator that acts as a universal RNA polymerase II transcription inhibitor. In cooperation with 7SK snRNA sequesters P-TEFb in a large inactive 7SK snRNP complex inhibits RNA polymerase II phosphorylation following transcriptional elongation. HEXIM1 regulates NF-kappa-B, ESR1, NR3C1 and CIITA-dependent transcriptional activity. 3
- Prolactin Human
Prolactin is a neuroendocrine hormone synthesized primarily by the pituitary gland but also a variety of other cell types including the placenta, brain and uterus. Its primary function is to promote and maintain lactation but has also been shown to have a role in breast cancer development, regulation of reproductive function and immunoregulation. 4
- ZNRD1 Human
Zinc Ribbon Domain Containing 1 (ZNRD1) is a protein which shows similarity to the Saccharomyces cerevisiae Rpa12p subunit of RNA polymerase I. ZNRD1 contains two potential zinc-binding motifs and takes part in regulation of cell proliferation. ZNRD1 is involved in cancer and human immunodeficiency virus progression. 5
Our last entry is similar to another immunosuppressant in its structure, but its properties are quite different. While Prograf (FK506) suppresses T lymph cells from proliferating from G0 to G1 stage, our offering uses different cytokine receptors to block signal transduction, thus preventing T lymph cells and other cells from proliferating from G1 to S stage.6
Rapamycin is a clinically useful immunosuppressant that inhibits the response to interleukin-2 blocking activation of T- and B-cells and induces autophagy. Rapamycin forms a complex with cytosolic FK-binding protein 12 (FKB12) that binds to mTOR Complex1 (mTORC1), inhibiting the mammalian target of rapamycin (mTOR). The mTOR pathway is very active in several types of breast cancer since mTOR is an important player in cell proliferation and blocking it may be a useful therapy.7
- S. Ji, A. Czerwinski, Y. Zhou, Gl Shao, F. Valenzuela, P. Sowinski, S. Chauhan, M. Pennington, and S. Liu, Mol. Pharmaceutics, 10, 3304 (2013).
- P. Malaguti et al., Anticancer Res., 33(1), 21 (2013).