Background:The HER-2/neu oncogene and its p185 receptor protein are indicators of a more aggressive form of breast cancer. HER-2/neu status guides Herceptin therapy, specifically directed to the extracellular domain (ECD) of the HER-2/neu oncoprotein. The HER-2/neu ECD is shed from cancer cells into the circulation and is measurable by immunoassay. Methods: We performed a systematic review of the peer-reviewed literature on circulating ECD with respect to prevalence, prognosis, prediction of response to therapy, and monitoring of breast cancer. Results: The prevalence of increased ECD in patients with primary breast cancer varied between 0% and 38% (mean, 18.5%), whereas in metastatic disease the range was from 23% to 80% (mean, 43%). Some women with HER-2/neu-negative tumors by tissue testing develop increased ECD concentrations in metastatic disease. Increased ECD has been correlated with indicators of poor prognosis, e.g., overall survival and disease-free survival. Increased ECD predicts a poor response to hormone therapy and some chemotherapy regimens but can predict improved response to combinations of Her-

The level of DNA methylation in adenovirus type 2 (Ad2) and type 12 (Ad12) DNA was determined by comparing the cleavage patterns generated by the isoschizomeric restriction enzymes HpaII and MspI. As previously reported virion DNA of Ad2 and Ad12 is not methylated. Parental or newly synthesized Ad2 DNA in productively infected human KB or HEK cells is not methylated either, nor is the integrated form of Ad2 DNA in productively infected cells. Hamster cells and Muntiacus muntjak cells are abortively infected by Ad12. We have not detected methylation of Ad12 DNA in hamster or Muntiacus muntjak cells. An inverse correlation between the level of methylation and the extent of expression of viral DNA in Ad12-transformed hamster cells has been described earlier. A similar relation has been found for the EcoRI fragment B of Ad2 DNA which is not methylated but is expressed as the Ad2 DNA-binding (72K) protein in the Ad2-transformed hamster line HE1. Conversely, the same segment is completely methylated in lines HE2 and HE3, and there is apparently no evidence for the expression of the 72K protein in these cell lines.

Purpose: The present pilot study was performed to elucidate whether early changes in serum Her-2/neu extracellular domain (ECD) levels during trastuzumab-based treatment would predict the clinical course of disease in patients with metastatic breast cancer.Experimental Design: Sera from 55 patients with Her-2/neu-overexpressing metastatic breast cancer obtained immediately before each weekly administration of trastuzumab were analyzed by a serum Her-2/neu ELISA.Results: Whereas response rates were significantly higher in patients with elevated (>15 ng/ml) ECD levels before initiation of treatment (35% versus 7%, P ‫؍‬ 0.045), progression-free and overall survival did not differ significantly between patients with normal and elevated ECD levels. In patients responding to treatment, ECD levels decreased significantly as early as from day 8 of treatment onwards (all P for weekly measurements versus baseline <0.001). In contrast, no significant change in ECD levels was observed in patients with progressive disease. Multiple logistic regression analyses identified kinetics of ECD levels as the only factor that allowed for the accurate prediction of response likelihood as early as from day 8 of trastuzumabbased treatment onwards (P ‫؍‬ 0.020). In addition, determination of serial ECD levels allowed for the prediction of the risk for disease progression within the observed period as early as day 15 of treatment (P ‫؍‬ 0.010).Conclusions: Serial monitoring of the ECD may represent a valuable tool for early prediction of the probability of response and progression-free survival to trastuzumabbased treatment and is thus likely to contribute to an optimization of treatment and resource allocation.

Erythropoietin (EPO) formation in kidneys of 18 patients with autosomal dominant polycystic kidney disease (ADPKD) was investigated. In 12 patients on hemodialysis and in 6 patients with preterminal renal failure serum, EPO was 29±7 and 16±1.5 mU/mI and hemoglobin concentrations were 11.0±0.6 and 12.7±1.2 g/dl, respectively. Cyst fluid from a total of 357 renal cysts was obtained by either in vivo aspiration or immediately after nephrectomy. The cysts contained variable concentrations of bioactive EPO from undectable values up to 3.2 U/ml. A pronounced enrichment of EPO was observed in cysts with sodium concentrations > 100 mmol/liter, suggesting an association with proximal tubular malformations. The EPO concentrations in the cysts were neither c orrelated with the protein concentration nor with the oxygen pressure of the cyst fluid. Using a cDNA probe for human EPO, mRNA for EPO was localized in stroma cells of the cyst walls by an in situ hybridization technique. Our findings suggest that single interstitial cells juxtaposed to proximal tubular cysts may produce EPO independent of the oxygen pressure inside the cysts, which ameliorates the anemia during end-stage polycystic kidney disease.

No abstract

Background: HER-2 status is generally determined by immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH). Both methods are only semiquantitative, require a tumor sample, and can be difficult to reproduce. We compared these methods with 2 quantitative approaches, one measuring HER-2 gene copy number in tissue by real-time quantitative PCR (qPCR), and the other measuring shed HER-2 protein in serum by ELISA in patients with metastatic disease. Methods: We analyzed 52 cases of metastatic breast cancer for which both serum collected at the diagnosis of metastasis and stored primary breast tumor specimens were available. The within-and between-run imprecision of real-time qPCR and ELISA were evaluated according to Clinical and Laboratory Standards Institute (formerly known as NCCLS) recommendations. Concordance among the 4 methods was assessed by calculating the statistic and its 95% confidence interval (95% CI).

human EPO to rats 12 h, 6 h, or immediately before hypoxic exposure to mimic the early increase in EPO levels did not affect endogenous EPO formation during a subsequent hypoxic exposure of 12 h. These results indicate that the early decrease in EPO production at continuous hypoxia is not mediated by a negative feedback control through the effect of EPO on its production sites or target cells. Although the reduction in EPO production rate occurs independent of the amount of EPO produced, the magnitude of the decline appears to be related to the degree of the preceding stimulation. normobaric hypoxia; kinetics; messenger RNA; half-life TO ADAPT RED CELL MASS to oxygen demand of the organism, the glycoprotein hormone erythropoietin (EPO) is produced by the kidneys in inverse correlation with the oxygen content of arterial blood. Following acute hypoxic hypoxia, an increase in renal EPO mRNA has been demonstrated after 1 h (27), and circulating EPO increases within 1.5-2 h (27). Interestingly, it has been demonstrated that EPO levels reach maximal values after 6-24 h in rodents (1,5,15,17, 20,22,26, 31) and within 48 h in humans (1,24) and thereafter decline despite continued hypoxia. This early decrease in EPO levels occurs before red cell mass and therewith blood oxygen content has increased significantly (1,17,20,26).The mechanisms of this early decline have not been clarified but several hypotheses have been developed. Because circulating EPO levels are determined by the production rate and the clearance rate of the hormone, possible alterations in both have to be considered. One concept has early been proposed suggesting that EPO consumption might be increased by activated erythropoietic tissue (31). This has been supported by some clearance studies (21, 25) but others found no difference in EPO clearance rate in animals with hypo-or hyperplastic bone marrow (23) or any change in clearance rate after hypoxia (13). Alternatively, the proliferating erythron might also exert a feedback inhibition on EPO production by mechanisms that would have to be independent of circulating red cell mass. Support for this concept comes from observations suggesting that EPO titers are higher in patients with bone marrow hypoplasia than in comparably anemic patients with active erythropoiesis (9, 28). Other factors that were considered to possibly reduce EPO production independent of erythroid stimulation include a lowered blood oxygen affinity at prolonged hypoxia due to acidosis (8, 20,26, 32) and malnutrition during continuous hypoxic stress. The latter appears, however, not to be the primary mechanism because EPO titers in fed and food-deprived rats were found to increase similarly on repeated hypoxia exposure (18). A further possibility is that EPO production is reduced as a result of a direct feedback inhibition through the hormone itself.The present study in rats was therefore performed to address some of these possibilities and confine the potential mechanisms by which the early decline in EPO levels is brought about. ...

No abstract