Human ADAM12 ELISA Matched Antibody Pair

ADAMs (a disintegrin and metalloproteinases) are multifunctional molecules involved in cell-cell fusion, cell adhesion, membrane protein shedding, and proteolysis. In the present study, we examined the mRNA expression of 13 different ADAM species with putative metalloproteinase activity in human astrocytic tumors, nonneoplastic brain tissues, and other intracranial tumors by, reverse transcriptase-polymerase chain reaction, and found that prototype membrane-anchored ADAM12 (ADAM12m) is predominantly expressed in glioblastomas. Real-time quantitative polymerase chain reaction indicated that the expression level of ADAM12m is remarkably at least 5.7-fold higher in ghoblastomas (it = 16) than in nonneoplastic brain tissues (it = 6), low grade (n = 7) and anaplastic astrocytic tumors (n = 9) (P < 0.05 for each group), and intracranial neurinomas (it = 5) (P < 0.01). In situ hybridization showed that glioblastoma cells are responsible for the gene expression. By immunohistochemistry, ADAM12m was predominantly immunolocalized on the cell membranes of glioblastoma cells. Immunoblotting analysis demonstrated that ADAM12m is expressed as an activated N-glycosylated form of similar to90 kd in glioblastoma tissues. There was a direct correlation between the mRNA expression levels of ADAM12m and proliferative activity (MIB1-positive cell index) of gliomas (r = 0.791, P < 0.0001; it = 32). Protein bands consistent with the soluble form of heparin-binding epidermal growth factor, a substrate of ADAM12m, were observed by immunoblotting in glioblastoma samples with the ADAM12m expression, and inhibited by treatment with ADAM inhibitor of the glioblastomas. These data demonstrate for the first time that among the 13 different ADAM species, ADAM12m is highly expressed in human glioblastomas, and suggest the possibility that ADAM12m plays a role in the prominent proliferation of the glioblastomas through shedding of heparin-binding epidermal growth factor.

Purpose Biomarkers are molecular mediators that can serve as indicators of normal biological processes, pathologic processes, and therapeutic interventions. This study aims to identify potential biomarkers in Dupuytren's disease (DD), a fibroproliferative benign tumor with an unknown etiology and high recurrence after surgery. Methods Bioinformatic analytical techniques were employed to identify candidate genes that may be differentially expressed in DD, which included gene expression analysis of microarray data and thorough literature searches in genetic linkage and other related biomolecular studies. All DD cases were males with advanced DD (n = 5, 66 years 14). RNA was extracted from biopsies and corresponding cultures of normal fascia (unaffected transverse palmar fascia), palmar nodule and cord from each patient. Real-time reverse transcriptionpolymerase chain reactions were performed to determine the gene expression levels for disease-related transcripts. Results The bioinformatic analysis revealed 25 candidate genes, which were further short-listed to 6 genes via functional annotation. The 6 selected candidate genes included: A disintegrin and metalloproteinase domain (ADAM12), aldehyde dehydrogenase I family member (ALDH1) A1, Iroquois homeobox protein 6 (IRX6), proteoglycan 4 (PRG4), tenascin C (TNC), and periostin (POSTN). The culturing treatments were shown to have significant impact on the gene expression for ALDH1A1, PRG4, and TNC. In tissue biopsies, significant fold changes were observed for ADAM12, POSTN, and TNC in the cord and/or nodule when compared with that of normal fascia. ADAM12 and POSTN are associated with accelerated or abnormal cell growth, whereas TNC has been associated with fibrotic diseases and cell migration. Conclusions This study demonstrated differential gene expression results in DD tissue biopsies compared with that of their corresponding cultures. ADAM12, POSTN, and TNC were identified from the cord and nodule biopsy samples as potential biomarkers in relation to DD development. (J Hand Surg 2009;34A:124-136. (C) 2009 Published by Elsevier Inc. on behalf of the American Society for Surgery of the Hand.)