Identification of an aptamer targeting hnRNP A1 by tissue slide‐based SELEX

Citations Over TimeTop 10% of 2009 papers

Abstract

We report a new in situ tissue slide-based SELEX strategy targeting neoplastic tissues from breast cancer patients. The methodology, using the molecular differences between clinical specimens, can evolve aptamers to all fractions of tissue. The aptamers may be used as new molecular probes for pathological diagnosis and tumour imaging, and also to reveal the molecular differences that are responsible for the diseases. The specific aptamers were enriched by unequal length strand PCR employing a structured (-) strand primer. After 12 rounds of selection, using the paraffin tissue sections from infiltrating ductal carcinomas as targets, and using the adjacent normal tissue from the same case as controls, one of the enriched ssDNA aptamers, BC15, was selected from a nucleic acid library and characterized as recognizing breast cancer cells either within the tissue sections or from the culture medium, but only weakly binding to adjacent normal cells or immortalized breast cell line MCF10A. The calculated equilibrium dissociation constants (K(d)) of BC15 bound to MCF7 cells was 111.0 +/- 36.9 nM. Through streptavidin magnetic beads mediated affinity purification assay followed by mass spectrometry identification and western blot confirmation, the target of BC15 was characterized to be hnRNP A1, which was further verified to be specifically and highly expressed in cancerous tissues of breast by hnRNP A1 antibody immunostaining as well as western blot. BC15 aptamer was also used to probe cancer cells in tissues from other pathological types of breast cancers including lobular carcinoma, ductal carcinoma complicated with lobular carcinoma, comedo carcinoma, and lymph node metastasis of breast ductal carcinoma origin or breast lobular carcinoma origin. Therefore, tissue slide-based SELEX holds promise in identifying tumour markers and developing specific molecular probes for cancer diagnosis.

Related Papers

• → Risk of invasive breast carcinoma among women diagnosed with ductal carcinoma in situ and lobular carcinoma in situ, 1988‐2001(2006)190 cited
• → Long term clinical follow-up of atypical ductal hyperplasia and lobular carcinoma in situ in breast core needle biopsies(2015)61 cited
• → Lobular Neoplasia in Breast Core Needle Biopsy Specimens Is Not Associated With an Increased Risk of Ductal Carcinoma In Situ or Invasive Carcinoma(2002)84 cited
• → Contemporary management of ductal carcinoma in situ and lobular carcinoma in situ(2016)8 cited
• → LOBULAR CARCINOMA IN SITU OF THE BREAST WITH DUCTAL INVOLVEMENT.(1974)15 cited