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“Zone in with Zon”—Nanomedicine Used to Target Breast Cancer Tumors

Dr. Gerald Zon’s latest “Zone in with Zon” blog post, dated October 7, 2013, and published by TriLink BioTechnologies of San Diego, reviews some of the latest advances in breast cancer research in recognition of October as National Breast Cancer Awareness Month. Dr. Zon begins with an outline of some of the grim statistics about the deadly impact of breast cancer today and then goes on to describe existing treatments and a number of exciting and promising new therapeutic approaches that are being developed. Statistics from the NIH predict 232,340 new breast cancer cases and 39,620 deaths in 2013 in the U.S., Dr. Zon said. Nevertheless, in women diagnosed with breast cancer in the period of 1999 through 2006, the 5-year survival rate was 90%, which represents a significant improvement since the mid-1970s and is attributed to more screening and improved treatments. Among these treatments are tamoxifen and another selective estrogen receptor modulator (SERM), raloxifene, which have been approved by the FDA, and the monoclonal antibody trastuzumab, which is an accepted treatment for breast cancers that overproduce a protein called human epidermal growth factor receptor 2, or HER2. Dr. Zon also provided a description of cancer research expert Esther H. Chang, M.D., Ph.D., who has made significant achievements in specifically targeting tumors using antibody-fragment-tagged liposomal nanoparticles. Dr. Zon noted that Dr. Chang has referred to this process as involving “tiny little Fed Ex trucks.” Dr. Zon noted that tumor-targeted nanomedicine delivery of the p53 gene (SGT-53) has already successfully completed Phase I safety trials. He went on to note that nanomedicine researchers are currently seeking to develop a number of revolutionary tools. These include drug carriers that focus drug action at the site of disease to limit side effects, vaccines that are more feasible for use in areas with limited health care access, imaging agents that produce signal detectable from significant depths only in diseased tissues, and scaffolds for culturing engineered tissues that mimic the corresponding extracellular matrix and enable modulation of development over time and real-time monitoring of their activity and biochemistry. He highlighted a few particular exciting potential therapeutic approaches. One is work to develop a nanomedicine-based controllable magnetic drug delivery system for the treatment of cancer. Another is the potential development of potent antibodies to the epithelial cell adhesion molecule (EpCAM), which is over-expressed in 70-90% of carcinomas. In recent progress on this front, EpCAM RNA aptamers (“chemical antibodies”) have been developed that are specific and more sensitive than the current EpCAM antibodies. Dr. Zon closed by reporting that the FDA has determined that the benefits of Perjeta (a monoclonal antibody developed by Genentech) outweigh its risks as an initial treatment for breast cancer. Dr. Zon is an eminent nucleic acid chemist and Director of Business Development at TriLink BioTechnologies in San Diego, California. The entirety of Dr. Zon’s breast cancer blog can be viewed at the link below. [Zon blog post]