To determine whether herpes simplex virus type 1 (HSV-1) infection causes oxidative stress and lipid peroxidation in cultured neural cells, mouse P19 embryonal carcinoma cells were differentiated...

We have investigated the recycling of apoE in livers of apoE(-)/- mice transplanted with wild type bone marrow (apoE(+/+) --> apoE(-)/-), a model in which circulating apoE is derived exclusively from macrophages. Nascent Golgi lipoproteins were recovered from livers of apoE(+/+) --> apoE(-)/- mice 8 weeks after transplantation. ApoE was identified with nascent d < 1.006 and with d 1.006-1.210 g/ml lipoproteins at a level approximately 6% that of nascent lipoproteins from C57BL/6 mice. Hepatocytes from apoE(+/+) --> apoE(-)/- mice were isolated and cultured in media free of exogenous apoE. ApoE was found in the media primarily on the d < 1.006 g/ml fraction, indicating a resecretion of internalized apoprotein. Secretion of apoE from C57BL/6 hepatocytes was consistent with constitutive production, whereas the majority of apoE secreted from apoE(+/+) --> apoE(-)/- hepatocytes was recovered in the last 24 h of culture. This suggests that release may be triggered by accumulation of an acceptor, such as very low density lipoproteins, in the media. In agreement with the in vivo data, total recovery of apoE from apoE(+/+) --> apoE(-)/- hepatocytes was approximately 6% that of the apoE recovered from C57BL/6 hepatocytes. Since plasma apoE levels in the transplanted mice are approximately 10% of control levels, the findings indicate that up to 60% of the internalized apoE may be reutilized under physiologic conditions. These studies provide definitive evidence for the sparing of apoE and its routing through the secretory pathway and demonstrate that internalized apoE can be resecreted in a quantitatively significant fashion.

Purpose. This was a pilot study conducted to examine the expression of osteopontin in uveal melanoma and to determine whether serum osteopontin can be used in detecting metastatic uveal melanoma. methods. Osteopontin mRNA was measured in three uveal melanoma cell lines of various invasive potential by real-time PCR. Tissue sections of primary and metastatic uveal melanomas were stained for osteopontin. Serum osteopontin levels were measured by ELISA assays in 15 patients with metastatic uveal melanoma and in 37 patients who were disease-free for at least 10 years after treatment of the primary tumor. Paired serum samples drawn from eight patients before and after development of metastasis were analyzed. results. By real-time PCR, highly invasive primary and metastatic uveal melanoma cells expressed 6- and 250-fold excess osteopontin mRNA, respectively, compared with poorly invasive primary uveal melanoma cells. Tissue sections of primary uveal melanomas lacking looping vasculogenic mimicry patterns either did not stain for osteopontin or exhibited weak, diffuse staining. In primary melanomas containing looping vasculogenic mimicry patterns, strong osteopontin staining was detected in the tumor periphery where patterns were located. Diffuse strong expression of osteopontin was detected in eight samples of uveal melanomas metastatic to the liver. Serum osteopontin levels were significantly higher in patients with metastatic uveal melanoma than in patients who had been disease free for at least 10 years after treatment (P = 0.0001) or in age-matched control subjects. Serum osteopontin levels were significantly higher (P = 0.008) after metastasis than before the detection of metastasis in eight patients. When a cutoff of 10 ng/mL was used, the sensitivity and specificity of serum osteopontin in detecting metastatic melanoma was 87.5%, and the area under the receiver operator characteristic curve was 96%. conclusions. Osteopontin is expressed diffusely in tissue sections of hepatic metastases from uveal melanoma, and increased serum osteopontin levels correlate with melanoma metastasis to the liver with high specificity and sensitivity.

Ture, Lacroix1 examined the issue of cross-contamination of cell lines including the well-known contamination of cell lines with HeLa cells,2 and the misidentification of the ECV304 cell line as "immortalized endothelial cells" when these cells in fact originated from T24 bladder carcinoma cells.3 Lacroix1 esti- mated that between 18% and 36% of cell lines have been misclassified. One survey at a large research institution sug- gested that fewer than 50% of researchers authenticate their cell lines.4 Nardone5 proposed recently that identification of cell lines be required of investigators before grants are awarded, and the National Institutes of Health subsequently called for researchers to authenticate cell lines as a prerequisite for grant funding.6 Cell lines are widely used in ophthalmic investigations. The authors' own research efforts have been focused on the biol- ogy of metastasis of uveal melanoma, and in the field of ocular oncology research, the use of cell lines is critical for at least two reasons. First, there are no animal models of spontaneous uveal melanoma that faithfully replicate the behavior of the human disease.7 Transgenic models of uveal melanoma do not reproduce histogenesis of human uveal melanoma, and spon- taneous uveal melanomas develop too sporadically in nature to be valuable in research,8-13 or the animal melanoma tumors vary significantly from their human counterparts.14 Therefore, uveal melanoma researchers have increasingly relied on the implantation of animal and human melanoma cell lines into animals to model the behavior of human uveal melanoma to improve imaging techniques15-17 and to investigate immuno- logic18,19 and molecular mechanisms of tumor behavior.20,21 Second, mindful of the reality that statistical associations between histologic characteristics and outcome do not always indicate causality, the availability of cell lines allows ophthal- mic researchers to advance from correlative studies to mech- anistic investigations using advanced molecular methodolo- gies. For example, All-Ericsson et al.22 identified the association between the expression of insulin-like growth factor-1 by im-