Chondromodulin-1 functions as a tumor suppressor in gastric adenocarcinoma

Chondromodulin-1 and vascular endothelial growth factor-A expression in esophageal squamous cell carcinoma: accelerator and brake theory for angiogenesis at the early stage of cancer progression

BACKGROUND

Magnifying endoscopy has demonstrated dramatic morphologic changes in the surface microvasculature of superficial esophageal squamous cell carcinoma (ESCC) according to the depth of invasion. We investigated the mechanism of angiogenesis in early-stage ESCC by examining the expression of vascular endothelial growth factor (VEGF)-A and chondromodulin (ChM)-1.

METHODS

Using 41 samples of superficial esophageal cancer (EP and LPM 19 cases, MM or deeper 22 cases) and 7 samples of regenerative squamous epithelium, the expression of VEGF-A and ChM-1 was examined in relation to the histological grade or morphology of the surface microvasculature demonstrated by magnifying endoscopy (types A, B, and C correspond to types A, B1, and B2 and B3 of the magnifying endoscopic classification of the Japan Esophageal Society, respectively). We also investigated the correlation between CD31-positive microvessel density (MVD) and VEGF-A or ChM-1 expression.

RESULTS

In normal squamous epithelium, regenerative squamous epithelium, EP and LPM cancer, and MM or deeper cancer, the positivity rates for VEGF-A and ChM-1 were 0%, 85.7%, 52.6% and 90.9%, respectively, and 48.5%, 71.4%, 73.7% and 23.8%, respectively. The VEGF-A and ChM-1 positivity rates in type B or type C vasculature were 70.0% and 76.2%, respectively, and 75.0% and 19.0%, respectively. The expression of neither VEGF-A nor ChM-1 in cancer cells was correlated with MVD (P = 0.19 and 0.68, respectively), whereas that of VEGF-A in stromal mononuclear cells (SMCs) was significantly correlated with MVD (P = 0.04).

CONCLUSION

Angiogenesis at the early stage of ESCC progression is configured by the balance between accelerator (angiogenic factors from both cancer cells and SMCs) and brake (angiogenic inhibitor) factors.

Chondromodulin-1 in health, osteoarthritis, cancer, and heart disease

The human chondromodulin-1 (Chm-1, Chm-I, CNMD, or Lect1) gene encodes a 334 amino acid type II transmembrane glycoprotein protein with characteristics of a furin cleavage site and a putative glycosylation site. Chm-1 is expressed most predominantly in healthy and developing avascular cartilage, and healthy cardiac valves. Chm-1 plays a vital role during endochondral ossification by the regulation of angiogenesis. The anti-angiogenic and chondrogenic properties of Chm-1 are attributed to its role in tissue development, homeostasis, repair and regeneration, and disease prevention. Chm-1 promotes chondrocyte differentiation, and is regulated by versatile transcription factors, such as Sox9, Sp3, YY1, p300, Pax1, and Nkx3.2. Decreased expression of Chm-1 is implicated in the onset and progression of osteoarthritis and infective endocarditis. Chm-1 appears to attenuate osteoarthritis progression by inhibiting catabolic activity, and to mediate anti-inflammatory effects. In this review, we present the molecular structure and expression profiling of Chm-1. In addition, we bring a summary to the potential role of Chm-1 in cartilage development and homeostasis, osteoarthritis onset and progression, and to the pathogenic role of Chm-1 in infective endocarditis and cancers. To date, knowledge of the Chm-1 receptor, cellular signalling, and the molecular mechanisms of Chm-1 is rudimentary. Advancing our understanding the role of Chm-1 and its mechanisms of action will pave the way for the development of Chm-1 as a therapeutic target for the treatment of diseases, such as osteoarthritis, infective endocarditis, and cancer, and for potential tissue regenerative bioengineering applications.

Angiogenic approaches to meniscal healing

Meniscal injuries commonly result in osteoarthritis causing long term morbidity, lifelong treatment, joint replacement and significant financial burden to the Canadian healthcare system. Injuries to the outer third of the meniscus often heal well due to adequate blood supply. Healing of injuries in the inner two thirds of the meniscus are often critically retarded due to a lack of blood flow necessitating partial meniscectomy in many instances. Localized angiogenesis in the inner meniscus has yet to be achieved despite a belief that vascularization of these lesions corresponds with meniscal healing. This review briefly summarizes the growth factors that have been assessed for a role in meniscal healing and points to a significant knowledge gap in our understanding of meniscal healing.

Chondromodulin‑I suppresses tumorigenesis of human osteosarcoma cells

Osteosarcoma is the most common type of bone cancer, and accounts for ~3% of cancers that occurring in children. Chondromodulin‑I (ChM-I) is a 25 kDa glycoprotein that is expressed mainly in cartilage. ChM-I demonstrates anti‑angiogenic activity and has been suggested to inhibit endothelial cells from invading cartilage, and then has been shown to be an inhibitor of tumorigenesis. However, it remains unclear if ChM‑I has any direct anti‑tumorigenesis role on osteosarcoma. Therefore, the present study aimed to identify whether ChM‑I has any direct inhibit effect on human osteosarcoma cells. A bromodeoxyuridine incorporation assay was performed on the Saos‑2 human osteosarcoma cell line treated with or without recombinant human ChM‑I, to evaluate its impact on DNA synthesis. An adenovirus carrier for the expression of ChM‑I was constructed and transfected into tumor cells in vitro to evaluate the effect of ChM‑I on tumor cells. Additionally, ChM‑I was knocked down by using small interfering RNA to downregulate the expression of ChM‑I. Cell invasion, migration and cell‑colony formation assays, and xenograft tumor experiments were performed to evaluate the effects of ChM‑I on tumor cells in vitro and in vivo. The results demonstrated that ChM‑I could suppress DNA synthesis of human osteosarcoma cells, and it also exerted an inhibitory effect on the proliferation and colony formation abilities of human osteosarcoma cells. In addition, ChM‑I inhibited cell invasion and migration in vitro and suppressed osteosarcoma cell growth significantly in vivo. In conclusion, ChM‑I directly suppressed the proliferation and growth of osteosarcoma cells in an anchorage‑independent manner, and may therefore be a promising drug for the treatment of osteosarcoma.