No abstract

This study was undertaken to assess the prognostic effectiveness of Fuhrman nuclear grading and the individual components of this grading system, in a series of chromophobe renal cell carcinomas. Eighty-seven cases of chromophobe renal cell carcinoma were investigated. There were 47 males and 40 females, 28 to 78 years of age. The carcinomas ranged from 25 to 180 mm in size and on TNM staging there were 38 stage I, 25 stage II, 22 stage III, and 2 stage IV tumors. Whole tumor Fuhrman grading was grade 1, 6 cases; grade 2, 72 cases; grade 3, 8 cases; and grade 4, 1 case, whereas focal (single high power field) grading was grade 1, 1 case; grade 2, 62 cases; grade 3, 21 cases; and grade 4, 3 cases. On assignment of nucleolar grading using Fuhrman criteria there were 37 grade 1, 44 grade 2, and 4 grade 3 tumors on whole tumor assessment and 3 grade 1, 63 grade 2, and 21 grade 3 tumors on assessment of the high power field showing the greatest degree of nuclear pleomorphism. Measurements of nuclear size showed nuclear area to range from 26.14 to 100.74 microm2, nuclear perimeter from 19.73 to 39.28 microm, and nuclear major axis from 6.49 to 13.21 microm, whereas the ranges of measures of nuclear shape were; shape factor 0.798 to 0.890, compactness 14.260 to 15.843, and feret diameter 5.694 to 11.242. Follow-up ranged from 1 to 150 months and 8 patients died of tumor-related causes 5 to 53 months from diagnosis. On log rank testing against survival, only patient age (P=0.016) and tumor maximum diameter (P=0.0055) were significant, whereas patient sex and TNM stage were not significant. Whole tumor and focal Fuhrman grading, as well as all measures of nucleolar prominence, nuclear size, and nuclear shape showed no significant association with outcome. It is concluded that neither Fuhrman grading, nor any of the components of the Fuhrman grading system, is useful as prognostic indicators for this tumor type.

Hypochlorous acid (HOCl) is a potent oxidant produced by myeloperoxidase that causes aggregation of many proteins. Treatment of apohaemoglobin and apomyoglobin with HOCl produced a regular series of oligomer bands when the proteins were separated by SDS/PAGE under reducing conditions. Aggregation was detectable at a HOCl/protein molar ratio of 0.5:1 and was maximal at ratios of 10:1-20:1. Dimers formed within 1 min of adding HOCl, and further aggregation occurred over the next 30 min. No convincing evidence for covalent cross-linking was obtained by amino acid analysis, peptide analysis or electrospray ionization-MS of HOCl-modified apomyoglobin. The latter showed an increase in mass consistent with conversion of the two methionine residues into sulphoxides. A 5-fold excess of HOCl generated approximately three chloramines on the apomyoglobin. These underwent slow decay. Protein carbonyls were formed and were almost entirely located only on the polymer bands. Conversion of positively into negatively charged groups on the protein by succinylation caused preformed aggregates to dissociate. Treatment of apomyoglobin with taurine chloramine generated methionine sulphoxides but few protein carbonyls, and did not result in aggregation. We conclude that aggregation was due to strong, non-covalent interactions between protein chains. We propose that formation of protein carbonyls and possibly chloramines, along with methionine oxidation, alters protein folding to expose hydrophobic areas on neighbouring molecules that associate to form dimers and higher-molecular-mass aggregates. This process could lead to the formation of aggregated proteins at sites of myeloperoxidase activity and contribute to inflammatory tissue injury.

This study was undertaken to determine the validity of Fuhrman grading in a series of papillary renal cell carcinomas (PRCCs), to examine the interrelationship and prognostic significance of the individual components of the grading system, and further to determine whether any observed predictive value was independent of other prognostic indicators. Ninety cases of PRCC were studied. Fifty-nine tumors were of type 1 and 31 were of type 2. There were 33 TNM stage 1, 26 stage 2, 18 stage 3, and 12 stage 4 tumors, whereas division of cases according to pT category showed 14 pT1a, 20 pT1b, 25 pT2, 15 pT3a, 4 pT3b, and 11 pT4 tumors. Ten tumors were grade 1, 58 grade 2, and 22 grade 3 when predominant Fuhrman grade was assigned, whereas grading according to the high-power field containing the highest grade (focal grade) showed 40 grade 2, 49 grade 3, and 1 grade 4 tumors. Measurements of nuclear size (area, major axis, perimeter) and shape (shape factor, compactness) were undertaken using image analysis. Nuclear area ranged from 27.63 to 116.39 microM, major axis length 6.70 to 14.06 microM, and nuclear perimeter 20.05 to 41.77 microM. Shape factor ranged from 0.805 to 0.878 and compactness from 14.33 to 15.66. Predominant nucleolar grade using the criteria of the Fuhrman classification was nucleolar grade 1 for 13 tumors, nucleolar grade 2 for 56 tumors, and nucleolar grade 3 for 21 tumors. Focal nucleolar grade based on the high-power field showing the greatest degree of nuclear pleomorphism, was grade 2 for 38 tumors and grade 3 for 52 tumors. pT category, TNM stage, focal Fuhrman grade, and PRCC type were significantly associated with survival. Of the various measures of the components of the Fuhrman classification, only focal nucleolar grade was associated with survival, on univariate analysis. On multivariate analysis, focal nucleolar grade and tumor diameter were independently associated with survival, whereas TNM stage retained significance independent of other parameters. It is concluded that assessment of nucleolar prominence rather than Fuhrman grade is applicable for stratification of tumors within TNM stage or pT category for PRCC and that this should be based upon the high-power field showing the greatest degree of nuclear pleomorphism.

Peloruside A, isolated from the marine sponge Mycale hentscheli, has a similar mechanism of action to paclitaxel (Taxol®), a drug used clinically to treat tumors of the breast, ovary and lung. Paclitaxel and peloruside stabilize the polymerized form of tubulin and arrest cells in G₂/M of the cell cycle. We have therefore used two-dimensional electrophoresis of proteins to examine the effect of peloruside A on the human HL-60 promyeloid leukemic cell line. Our goals included investigation whether affected proteins could be mapped onto pathways that predicted the cellular effects of this compound. In response to 100 nM peloruside A treatment for 24 h, seventeen identified proteins showed significant change in abundance with fourteen increases and three decreases. Use of Ingenuity Pathways Analysis confirmed that peloruside A affected pathways consistent with the known effects on microtubules and apoptosis. Our results also indicate a potential role of c-Myc in the cellular actions of peloruside consistent with an induction of aneuploidy seen at low concentrations of peloruside.