ADAM12 and ADAM17 Gene Expression in Laser-capture Microdissected and Non-microdissected Breast Tumors

Abstract

ADAM (a disintegrin and metalloprotease)12 and ADAM17 are multidomain transmembrane proteins involved in ectodomain shedding of cytokines, growth factors and adhesion molecules, with pivotal activities in the tumor microenvironment. The aim of this study was to confirm the up-regulation of ADAM17 and ADAM12 gene splicing variants in breast tumors and to delineate their expression between laser-capture microdissected (LCM) and non-microdissected breast tumors. The gene expression was analyzed by quantitative-reverse transcription-PCR in a total sample of 109 breast tumors paired with corresponding non-neoplastic breast tissues. ADAM12 and 17 proteins expression for corresponding tissue samples was confirmed by immunohistochemistry. ADAM12S, 12L and 17 genes were significantly up-regulated in either malign or benign LCM samples when compared to non-tumor controls. For non-LCM samples, it was obtained also an increased expression for ADAM12 and 17 genes in cancers, while in benign tumors only ADAM12 variants were significantly up-regulated compared to controls. When benign versus malignant tumors were compared, in LCM samples all investigated genes displayed a higher expression in cancers, whereas in non-LCM, ADAM12 variants were overexpressed in benign samples. The increased expression of ADAM12 protein in the tumor cells and stroma of benign breast diseases was immunohistochemically confirmed. These differences between LCM and non-LCM samples were explained by the contribution of the stroma to the expression of this marker. This study underlines the accuracy conferred by homogenous LCM samples on gene expression profiles and confers further evidence regarding the role of ADAM12 and 17 in the breast tumorigenesis and progression.

Erbb2 up‐regulation of ADAM12 expression accelerates skin cancer progression

“…ADAMs, a subfamily of the matrix metalloproteinases, have generated much interest in the last several years and participate in a number of cellular processes, including adhesion, extracellular matrix degradation, migration, and proliferation, processes which are important in the carcinogenesis sequence. Increased ADAM12 expression has been found in human carcinomas of the liver , bladder , breast , larynx , and lung . ADAM12 is also highly expressed in carcinoma‐associated stroma and is necessary for prostate tumor progression in mouse models .…”

Gene expression of NMDA and AMPA receptors in different facial motor neurons

“…Although the retrograde fluorescence labeling and Nissl staining complicated the microdissection and RNA extraction, our study showed that the total RNA from the two different FMNs could be effectively used for gene expression analysis by real‐time qRT‐PCR. Previous studies successfully used partially degraded input RNA with a low RIN for gene analysis . Furthermore, as we had hypothesized before the study, in the dormant and reinnervating FMNs, gene expressions of multiple ionotropic glutamate receptor subunits were different 90 days after facial‐facial anastomosis.…”

“…Previous studies successfully used partially degraded input RNA with a low RIN for gene analysis. [19][20][21] Furthermore, as we had hypothesized before the Prior studies examined the mRNA expression of ionotropic glutamate receptor subunits in the whole facial nucleus region. Nevertheless, detecting and sampling processes, including the manual collection of specimens, in situ hybridization, or regular RT-PCR, would unavoidably affect the reproducibility of results and thereby decreased the power of a study.…”

New insight into the role of the ADAM protease family in breast carcinoma progression

“…However, only ADAM12 is overexpressed in benign non-LCM tumor samples. The differences between LCM and non-LCM tumor samples were due to the influences of stroma on theses markers expression [ 57 , 94 ].…”

“…It is also termed as TACE (TGF-α converting enzyme) [ 58 ],since, it was originally recognized by its capability to cut off membrane bound TNF- α from its progenitor [ 97 , 59 ]. ADAM17 is the main sheddase for HB-EGF, TGF-α, epiregulin, and amphiregulin [ 57 , [60] , [61] , [62] ] and it was demonstrated to be elevated in human breast carcinomas [ 97 ]. ADAM17 is also implicated in several biological procedures and cleaves plenty of substrates such as TNF-α, TNF receptor, CD40, EGF receptor L, c-kit, p75NTR, c-fms, interleukin-1 receptor, interleukin-6 receptor growth hormone receptor, L-selectin, MUC1, vascular cell adhesion molecule-1, collagen VII, CX3CL-1, Notch, prion protein, and β-amyloid precursor [ 59 , [63] , [64] , [65] ].…”