Does the degree of intratumoural microvessel density and VEGF expression have prognostic significance in osteosarcoma?

The role of angiogenesis as a prognostic indicator in cancer has been extensively studied in recent times with several studies demonstrating a positive correlation for various malignant tumours. However, the role of angiogenesis in osteosarcoma remains a topic of debate. In this study, we aim to evaluate the significance of intratumoural microvessel density (MVD) and the degree of vascular epithelial growth factor (VEGF) expression as markers of angiogenesis and correlate this with disease outcome.

Outcome of patients with osteosarcoma over 40 years of age: is angiogenesis a marker of survival?

Background: Osteosarcoma predominantly afflicts young people in their second and third decades of life. When osteosarcoma arises in patients older than 40 years, the prognosis is usually poorer compared to their younger counterparts. Although the clinical, histopathologic features and prognostic indicators are well defined for young patients, much less is known about affected adults.

Localization of pigment epithelium-derived factor in growing mouse bone.

Pigment epithelium-derived factor (PEDF) is a potent anti-angiogenic factor found in a wide range of fetal and adult tissues, where it is thought to play a role in the regulation of angiogenesis during development. The temporal expression of PEDF during endochondral bone formation has not previously been reported. In this study, we analysed the expression pattern of PEDF in growing mouse hindlimbs from newborn day one through to maturation at week 9, using immunohistochemistry and in situ hybridization.

Resistance of epiphyseal cartilage to invasion by osteosarcoma is likely to be due to expression of antiangiogenic factors.

Objectives: Epiphyseal cartilage is a barrier to osteosarcoma invasion, however the mechanisms behind this resistance remain unclear. The aim of this study was to examine the chronological and spatial patterns of osteosarcoma growth and invasion of local tissue structures including epiphyseal cartilage.

Methods: We used an in vivomouse model of osteosarcoma to histologically examine tumors at different stages of disease progression.

An algal nucleus-encoded subunit of mitochondrial ATP synthase rescues a defect in the analogous human mitochondrial-encoded subunit.

Unlike most organisms, the mitochondrial DNA (mtDNA) of Chlamydomonas reinhardtii, a green alga, does not encode subunit 6 of F(0)F(1)-ATP synthase. We hypothesized that C. reinhardtii ATPase 6 is nucleus encoded and identified cDNAs and a single-copy nuclear gene specifying this subunit (CrATP6, with eight exons, four of which encode a mitochondrial targeting signal).

Rescue of a deficiency in ATP synthesis by transfer of MTATP6, a mitochondrial DNA-encoded gene, to the nucleus.

A T-->G transversion at nt 8993 in mitochondrial DNA of MTATP6 (encoding ATPase 6 of complex V of the respiratory chain) causes impaired mitochondrial ATP synthesis in two related mitochondrial disorders: neuropathy, ataxia and retinitis pigmentosa and maternally inherited Leigh syndrome. To overcome the biochemical defect, we expressed wildtype ATPase 6 protein allotopically from nucleus-transfected constructs encoding an amino-terminal mitochondrial targeting signal appended to a recoded ATPase 6 gene (made compatible with the universal genetic code) that also contained a carboxy-terminal FLAG epitope tag. After transfection of human cells, the precursor polypeptide was expressed, imported into and processed within mitochondria, and incorporated into complex V.