Validation of COL11A1/procollagen 11A1 expression in TGF-β1-activated immortalised human mesenchymal cells and in stromal cells of human colon adenocarcinoma

Our observations stress once more the usefulness of the DMTX1/1E8.33 mAb for cancer research, and the clinical significance of procollagen 11A1 as a very valuable biomarker to characterise cancer-associated stromal cells and to evaluate human colon adenocarcinomas.Background: The human COL11A1 gene has been shown to be up-regulated in stromal cells of colorectal tumours, but, so far, the immunodetection of procollagen 11A1, the primary protein product of COL11A1, has not been studied in detail in human colon adenocarcinomas. Some cancer-associated stromal cells seem to be derived from bone marrow mesenchymal cells; the expression of the COL11A1 gene and the parallel immunodetection of procollagen 11A1 have not been evaluated in these latter cells, either. Methods: We used quantitative RT-PCR and/or immunocytochemistry to study the expression of DES/desmin, VIM/vimentin, ACTA2/αSMA (alpha smooth muscle actin) and COL11A1/procollagen 11A1 in HCT 116 human colorectal adenocarcinoma cells, in immortalised human bone marrow mesenchymal cells and in human colon adenocarcinoma-derived cultured stromal cells. The immunodetection of procollagen 11A1 was performed with the new recently described DMTX1/1E8.33 mouse monoclonal antibody. Human colon adenocarcinomas and non-malignant colon tissues were evaluated by immunohistochemistry as well. Statistical associations were sought between anti-procollagen 11A1 immunoscoring and patient clinicopathological features. Results: Procollagen 11A1 was immunodetected in human bone marrow mesenchymal cells and in human colon adenocarcinoma-associated spindle-shaped stromal cells but not in colon epithelial or stromal cells of the normal colon. This immunodetection paralleled, in both kinds of cells, that of the other mesenchymalrelated biomarkers studied: vimentin and alpha smooth muscle actin, but not desmin. Thus, procollagen 11A1+ adenocarcinoma-associated stromal cells are similar to “activated myofibroblasts”. In the series of human colon adenocarcinomas here studied, a high procollagen 11A1 expression was associated with nodal involvement (p = 0.05), the development of distant metastases (p = 0.017), and advanced Dukes stages (p = 0.047). Conclusion: The immunodetection of procollagen 11A1 in cancer-associated stromal cells could be a useful biomarker for human colon adenocarcinoma characterisation. Keywords: Procollagen 11A1, Human bone marrow mesenchymal cells, Cancer-associated stromal cells, Human colon adenocarcinom

COL11A1/(pro)collagen 11A1 expression is a remarkable biomarker of human invasive carcinoma-associated stromal cells and carcinoma progression

The COL11A1 human gene codes for the α1 chain of procollagen 11A1 and mature collagen 11A1, an extracellular minor fibrillar collagen. Under regular conditions, this gene and its derived products are mainly expressed by chondrocytes and mesenchymal stem cells as well as osteoblasts. Normal epithelial cells and quiescent fibroblasts from diverse locations do not express them. Mesenchyme-derived tumors and related conditions, such as scleroderma and keloids, are positive for COL11A1/(pro)collagen 11A1 expression, as well as high-grade human gliomas/glioblastomas. This expression is almost absent in benign pathological processes such as breast hyperplasia, sclerosing adenosis, idiopathic pulmonary fibrosis, cirrhosis, pancreatitis, diverticulitis, and inflammatory bowel disease. By contrast, COL11A1/(pro)collagen 11A1 is highly expressed by activated stromal cells of the desmoplastic reaction of different human invasive carcinomas, and this expression is correlated with carcinoma aggressiveness and progression, and lymph node metastasis. COL11A1 upregulation has been shown to be associated to TGF-β1, Wnt, and Hh signaling pathways, which are especially active in cancerassociated stromal cells. At the front of invasive carcinomas, neoplastic epithelial cells, putatively undergoing epithelial-to-mesenchymal transition, and carcinoma-derived cells with highly metastatic capabilities, can express COL11A1. Thus, in established metastases, the expression of COL11A1/ (pro)collagen 11A1 could rely on both the metastatic epithelial cells and/or the accompanying activated stromal cells. COL11A1/(pro)collagen 11A1 expression is a remarkable biomarker of human carcinoma-associated stromal cells and carcinoma progression

Overexpression of proCOL11A1 as a stromal marker of breast cancer

Background: Our previous studies demonstrated the expression of procollagen11A1 in fibroblasts of pancreatic cancer desmoplasia and the lack of expression in fibroblasts of pancreatitis by means of the polyclonal antibody (anti-proCOL11A1 pAb) we generated. In a similar way, we decided to compare the expression of procollagen11A1 in fibroblasts of infiltrating ductal carcinoma of the breast and fibroblasts of benign sclerosing lesions of the breast, in order to validate the anti-proCOL11A1 pAb in this setting and to study how proCOL11A1 expression relates to other prognostic and predictive factors, as well as to survival. Methods: 45 core biopsies of sclerosing adenosis and 50 core biopsies of infiltrating ductal carcinoma of the breast were stained with anti-proCOL11A1 pAb, a polyclonal antibody highly specific to the less homologous fraction of proCOL11A1 (in comparison with proCOL5A1 and proCOL11A2). In addition, the expression of the proCOL11A1 gene was measured by RT-qPCR. On the other hand, the expression of proCOL11A1 was compared to the expression of estrogenic receptors, progestagen receptors, the state of the epidermal growth factor receptor 2 (HER2), the histologic grade and the stage of the disease. We also compared the immunohistochemical expression of proCol11A1 to the disease-free interval, and to overall survival. Results: The immunohistochemical analysis showed that proCOL11A1 was expressed in 100% of infiltrating ductal carcinomas, but only focally expressed in 2.2% (1 case) of sclerosing adenosis, in agreement with RT-qPCR results. ProCOL11A1 expression did not prove to have a prognostic value in relation to the disease-free interval or to overall survival in infiltrating ductal carcinoma. Conclusion: The anti-proCOL11A1 pAb is a stromal marker for breast cancer and the expression of proCOL11A1 does not seem to have a prognostic value in infiltrating ductal carcinoma of the breast