Tumor region-specific microarray analysis according to trastuzumab distribution in breast cancer patient derived xenograft

Our novel drug imaging technique revealed that trastuzumab, which is representative antibody drug for breast and gastric cancer in clinical, distributed heterogeneously inside tumor even though its target receptor, HER2 (Human epidermal growth factor receptor 2) expressed homogeneously. For identifying a predominant regulator of trastuzumab tumor delivery in the tumor site, we tried tumor region-specific microarray analysis according to trastuzumab distribution in patient derived xenograft model. First, we found that trastuzumab was less distributed in stroma high density area in NCC-BCP69 PDX tumor. Then, trastuzumab poor and rich distributed area were selected respectively (each n=3 from several tumor) according to PID-drug imaging analysis and each area was cut off by laser microdissection and a small amount of mRNA was extracted for microarray. We also conducted tumor region specific microarray for the area of stroma-rich and stroma-poor in NCC-BCP69 PDX without trastuzumab treatment as a vehicle (control) experiment (each n=3 from several tumor).