(625.5) Specificity of Antibodies for the Identification of Annexin 1 (ANXA1) Protein in Various Types of Cancer

Poster Board Number: E669

Karyn Olascuaga-Castillo (Universidad Nacional de Trujillo), Susana Rubio-Guevara (Universidad Nacional de Trujillo), Elena Cáceres-Andonaire (Universidad Privada Antenor Orrego), Dan Altamirano-Sarmiento (Universidad Privada Antenor Orrego), Elena Mantilla-Rodríguez (Universidad Nacional de Trujillo), Julio Hilario-Vargas (Universidad Nacional de Trujillo), José Morgado-Díaz (Instituto Nacional de Cancer), Maxim Berezovski (University of Ottawa)

Annexins are a well-characterized multigene family of phospholipid-binding and membrane-bound proteins that are Ca2+-regulated. ANXA1 expression is variable in tumor cells, ranging from high levels to none, which is why it is helpful to know the staining potential of various antibodies against the protein. Our research aims to evaluate the specificity of five antibodies used to detect ANXA1 expression in selecting different types of cancer and normal tissue and the differential specificity between the two groups. We examined a data set composed of 2177 samples from The Human Protein Atlas (HPA) as mentioned, cancer patients:1904 samples, and healthy persons: 273 samples. We examined the specificity of five different antibody types of detecting ANXA1 expression (HPA011271, HPA011272, CAB013023, CAB035987, and CAB058693). The specificity of each antibody against ANXA1 protein was evaluated using a staining scale of 0 - 3.00, where 0 indicates no staining, 0.01-1.0 low staining, 1.01 - 2.0 medium staining, and 2.01 - 3.00 high staining.

Results: CAB013023 had the highest staining values for both cancer and healthy samples; thyroid cancer and endometrial cancer had the highest staining values (2.75 and 2.80, respectively). Breast, head and neck, and bladder normal tissues stained the most intensely in healthy samples (3.00 in all three cases). The antibodys specificity for identifying ANXA1 expression suggests that this may be used as a prognosis and treatment marker in cancer.

This research was funded by the Doctoral Program in Pharmacy and Biochemistry of the National University of Trujillo. Peru and the National Council of Science and Technology - Peru (CONCYTEC) in cooperation with the World Bank (Contract N 07-2018-FONDECYT-BM-IADT-MU).