Cartilage-derived growth factor and antitumor factor: past, present, and future studies

Functional Anatomy and Oncologic Barriers of the Larynx

Laryngeal barriers to tumor spread are a product of laryngeal development, anatomic barriers, and enzymatic activity. Supraglottic and glottic/subglottic development is distinct and partially explains the metastatic behavior of laryngeal carcinoma. Dense connective tissues and elastic fibers provide anatomic barriers within the larynx. Laryngeal cartilage contains dense cartilage, enzyme inhibitors, and an intact perichondrium making it relatively resistant to tumor invasion; however, focal areas of vulnerability are created by ossified cartilage and natural interruptions in the perichondrium. Local inflammation and the enzymatic interplay between tumor and host are important factors in the spread of laryngeal tumor.

Co-localization of chondromodulin-I (ChM-I) and bone morphogenetic protein-6 (BMP-6) in myoepithelial cells of canine mammary tumors

To compare the roles of chondromodulin-I (ChM-I) and bone morphogenetic protein-6 (BMP-6) in ectopic mesenchymal tissue formation in canine mammary gland tumors, 33 tumors and 2 normal mammary glands were examined. Immunohistochemical analysis revealed co-expression of ChM-I and BMP-6 in canine mammary tumors. In mixed tumors, newly formed woven bone with ossified cartilage matrix was observed in 4/9 cases. The osteoblasts lining the woven bone showed moderate immunoreactivity to ChM-I and BMP-6. Almost all chondrocytes and proliferative myoepithelial cells within the basement membrane showed intense immunoreactivity to both, and the myoepithelial cells adjacent to the mature cartilage showed the most intense immunoreactivity. The immunoreactivity to ChM-I and BMP-6 of the interstitial myoepithelial cells in the myxomatous stroma varied in each focus of mixed tumors. Similar findings were found in complex adenomas. In simple adenomas, hyperplasic myoepithelial cells within the basement membrane showed moderate immunoreactivity to both markers. Western blot analysis detected a 25 kDa band of ChM-I in fresh tissue samples from three mixed tumors. Our results support the hypothesis that proliferating myoepithelial cells with ChM-I and BMP-6 expression play important roles in mesenchymal metaplasia in canine mammary tumors.

Chondromodulin-I and tenomodulin: a new class of tissue-specific angiogenesis inhibitors found in hypovascular connective tissues

In tissues and/or organs of mesenchymal origin, the vasculature is usually well developed. However, there are certain hypovascular tissues that exhibit powerful anti-angiogenic resistance, implying the presence of tissue-type specific inhibitors of angiogenesis. Hyaline cartilage is one example, and several anti-angiogenic factors have been purified from cartilage. We previously identified chondromodulin-I (ChM-I) as a tissue-specific inhibitor of angiogenesis in fetal bovine cartilage. ChM-I is specifically expressed in the avascular regions of the growth-plate and cartilaginous bone rudiments in embryos. Recently, we cloned a novel type II transmembrane protein, tenomodulin (TeM), having a domain homologous to ChM-I at its C-terminus. TeM turned out to be expressed specifically in other hypovascular structures in the mesenchyme, such as the epimysium, tendon, and ligaments. In this overview, we discuss the structural characteristics of this class of anti-angiogenic molecules and their pathophysiological role in the control of vascularity.

Bovine Cartilage, Coenzyme Q10, and Wheat Grass Therapy for Primary Peritoneal Cancer

The accepted postsurgical first-line therapy for primary peritoneal cancer has been a regime of chemotherapy. This paper reports the case of an 89-year-old female who refused chemotherapy but accepted a nutritional alternative. Results after more than 4 years of the nutritional regime have been encouraging with regards to objective and subjective measures.

Cartilage-specific matrix protein, chondromodulin-I (ChM-I), is a strong angio-inhibitor in endochondral ossification of human neonatal vertebral tissues in vivo: relationship with angiogenic factors in the cartilage

Although cartilage contains many angiogenic factors during endochondral ossification, it is an avascular tissue. The cartilage-specific non-collagenous matrix protein chondromodulin-I (ChM-I) has been shown to be a strong angio-inhibitor. To elucidate whether ChM-I plays an essential role in angio-inhibition during endochondral ossification in man, we investigated the expression and localization of ChM-I in comparison with those of angiogenic factors and the endothelial cell marker CD34 in human neonatal vertebral tissues. Although invasion of CD34-positive endothelial cells was observed in primary subchondral spongiosa, expression of the marker of endothelial cells, CD34, was not found in neonatal vertebral cartilage matrix. Type II collagen was deposited in all matrices during endochondral ossification, whereas aggrecan was deposited in the matrix of hypertrophic cartilage, especially around lacunae. Vascular endothelial growth factor (VEGF), which is known to be a strong angiogenic factor, was localized in chondrocytes in mature to hypertrophic cartilage and also in bone marrow. Fibroblast growth factor-2 (FGF-2; basic fibroblast growth factor), which is also known to be a strong angiogenic factor, was localized in the cytoplasm of chondrocytes of mature cartilage in human vertebral cartilage tissues. Transforming growth factor (TGF)-beta has been reported to have many functions including angiogenesis, and TGF-beta1 was also localized in mature chondrocytes in endochondral tissues undergoing ossification. On the other hand, the novel cartilage-specific matrix protein ChM-I was localized in interterritorial regions of the matrix in mature to hypertrophic cartilage, especially around lacunae. In conclusion, these observations indicate that ChM-I may serve as a barrier against the angiogenic properties of VEGF, FGF-2 and TGF-beta1 during endochondral ossification, and this matrix molecule may play an essential role in determining the avascular nature of cartilage in vivo.

BRICHOS: a conserved domain in proteins associated with dementia, respiratory distress and cancer

A novel domain (the BRICHOS domain) of approximately 100 amino acids has been identified in several previously unrelated proteins that are linked to major diseases. These include BRI(2), which is related to familial British and Danish dementia (FBD and FDD); Chondromodulin-I (ChM-I), related to chondrosarcoma; CA11, related to stomach cancer; and surfactant protein C (SP-C), related to respiratory distress syndrome (RDS). In several of these, the conserved BRICHOS domain is located in the propeptide region that is removed after proteolytic processing. Experimental data suggest that the role of this domain could be related to the complex post-translational processing of these proteins.

Post-translational processing of bovine chondromodulin-I

Chondromodulin-I (ChM-I) is a small glycoprotein that is abundant in fetal cartilage. Mature chondromodulin-I is processed from a larger precursor form, presumably at a proteolytic site RERR-ELVR. The precursor, mature chondromodulin-I and two processed products, the remnant left after removal of mature chondromodulin-I and a smaller, unglycosylated form, were identified using antipeptide antisera. The products of chondromodulin-I precursor processing were seen in cultured chondrocytes, a stable long-term culture chondrosarcoma cell line, as well as Chinese hamster ovary (CHO) cells transfected with an expression plasmid that contained cDNA coding for the chondromodulin-I precursor. Pulse-chase analysis allowed a processing pathway to be analyzed for chondromodulin-I. To further dissect the processing events, three constructs that express recombinant wild-type or mutant chondromodulin-I were transfected into CHO cells. We showed that chondromodulin-I is cleaved intracellularly at the predicted cleavage site, and that the mature glycopeptide is rapidly secreted immediately after processing. The chondromodulin-1 precursor has a short half-life and is not readily apparent in tissue samples, suggesting that chondromodulin is not a member of the juxtacrine family of growth factors, despite some similarities. The smaller unglycosylated form of chondromodulin-I was only observed in cartilage and not in short-term cultures or transfected cells, suggesting an extracellular processing event. No processing occurred when the precursor cleavage site was mutated to RERQ-SLVR or when precursor chondromodulin-I was expressed in the furin-deficient CHO cell line, suggesting the involvement of furin in processing.