Anti-Human ErbB2 Recombinant Antibody (TAB-005) (CAT#: TAB-005)

Figure 1 t-DARPP and ERBB2 are significantly overexpressed in adenocarcinomas.

left, cell viability of OE19 and OE33 cells in response to trastuzumab treatment was evaluated by Trypan blue staining. OE19 cells were 2-fold more sensitive to trastuzumab than OE33 cells (P < 0.001). D, right, Western blot analysis shows higher protein expression of ERBB2 in OE19 cells than OE33 cells. In contrast, t-DARPP expression was undetectable in OE19 cells but highly expressed in OE33 cells.

Hong, J., Katsha, A., Lu, P., Shyr, Y., Belkhiri, A., & El-Rifai, W. (2012). Regulation of ERBB2 receptor by t-DARPP mediates trastuzumab resistance in human esophageal adenocarcinoma. Cancer research.

Figure 2 t-DARPP expression blocks trastuzumab-induced apoptosis.

A, apoptosis in OE19 cells infected with control (10 MOI) or t-DARPP (10 MOI) recombinant adenoviruses after treatment with vehicle or trastuzumab (20 μg/mL) for 48 hours was determined by Annexin-V/PI staining and FACS analysis. B, Western blot analysis of caspase-3, cleaved caspase-3, and t-DARPP proteins in OE19 cells infected with control or t-DARPP adenoviruses following treatments as described in A. C, apoptosis in parental and trastuzumab-resistant OE19 cells after treatment with vehicle or trastuzumab (20 μg/mL) for 48 hours was evaluated by Annexin-V/PI staining and FACS analysis. D, Western blot analysis of caspase-3, cleaved caspase-3, and t-DARPP proteins in parental and trastuzumab-resistant OE19 cells after treatments as described in C. These data indicate that endogenous and exogenous t-DARPP expression counteracted trastuzumab-induced apoptosis in OE19 cells.

Hong, J., Katsha, A., Lu, P., Shyr, Y., Belkhiri, A., & El-Rifai, W. (2012). Regulation of ERBB2 receptor by t-DARPP mediates trastuzumab resistance in human esophageal adenocarcinoma. Cancer research.

Figure 3 t-DARPP associates with ERBB2 and interferes with trastuzumab/ERBB2 protein interaction.

A, Western blot analysis of coimmunoprecipitated exogenous t-DARPP and endogenous ERBB2 proteins with M2-flag or trastuzumab antibodies in OE19 cells infected with t-DARPP-flag adenovirus (10 MOI). These data show protein association of ERBB2 with t-DARPP. B, Western blot analysis of immunoprecipitated endogenous ERBB2 protein with trastuzumab antibody in OE19 cells infected with control (10 MOI) or t-DARPP (10 MOI) adenoviruses. Pulled-down ERBB2 band intensity was depicted as a ratio relative to input ERBB2 protein. The results show that exogenous t-DARPP expression blocked binding of trastuzumab to ERBB2 receptor relative to control. C, Western blot analysis of immunoprecipitated endogenous ERBB2 protein with trastuzumab antibody in parental or trastuzumab-resistant OE19 cells. The band intensity of immunoprecipitated ERBB2 protein was shown as a ratio relative to input ERBB2. These data indicate that endogenous t-DARPP expression in trastuzumab-resistant cells was associated with a significant decrease in trastuzumab/ERBB2 protein interaction relative to control.

Hong, J., Katsha, A., Lu, P., Shyr, Y., Belkhiri, A., & El-Rifai, W. (2012). Regulation of ERBB2 receptor by t-DARPP mediates trastuzumab resistance in human esophageal adenocarcinoma. Cancer research.

Figure 4 t-DARPP overexpression promotes tumor growth and blocks response to trastuzumab treatment in vivo.

The H&E staining at the end of trastuzumab treatment shows effectively diminished control tumors leaving necrotic and fibrotic lesions (left), whereas t-DARPP tumors were unaffected (right).

Hong, J., Katsha, A., Lu, P., Shyr, Y., Belkhiri, A., & El-Rifai, W. (2012). Regulation of ERBB2 receptor by t-DARPP mediates trastuzumab resistance in human esophageal adenocarcinoma. Cancer research.

Figure 1 Anti-ErbB2 Antibody (TAB-005) in WB

Western blot analysis of TAB-005 was performed with human ErbB2 protein.

Figure 2 Anti-ErbB2 Antibody (TAB-005) in ELISA

ELISA analysis of TAB-005 was performed by coating with human ErbB2 protein.

Figure 3 Anti-ErbB2 Antibody (TAB-005) in Dot Blot

Dot Blot analysis of TAB-005 was performed by coating with human ErbB2 protein.

Figure 4 Anti-Human ErbB2 Recombinant Antibody (Trastuzumab) (TAB-005) in HPLC

The purity of TAB-005 was greater than 95% as determined by SEC-HPLC.

Figure 5 Anti-Human ErbB2 Recombinant Antibody (Trastuzumab) (TAB-005) in SDS-PAGE

SDS-PAGE analysis of TAB-005 in reduced conditions. Gel stained for 30 minutes with Coomassie Blue. As a result of different β-mercaptoethanol-reduced proteins (Heavy chain and Light chain) migrate as about 50 kDa and 25 kDa, respectively.