Heat stress causes spatially-distinct membrane re-modelling in K562 leukemia cells

Cellular membranes respond rapidly to various environmental perturbations. Previously we showed that modulations in membrane fluidity achieved by heat stress (HS) resulted in pronounced membrane organization alterations which could be intimately linked to the expression and cellular distribution of heat shock proteins. Here we examine heat-induced membrane changes using several visualisation methods. With Laurdan two-photon microscopy we demonstrate that, in contrast to the enhanced formation of ordered domains in surface membranes, the molecular disorder is significantly elevated within the internal membranes of cells preexposed to mild HS. These results were compared with those obtained by anisotropy, fluorescence lifetime and electron paramagnetic resonance measurements. All probes detected membrane changes upon HS. However, the structurally different probes revealed substantially distinct alterations in membrane heterogeneity. These data call attention to the careful interpretation of results obtained with only a single label. Subtle changes in membrane microstructure in the decision-making of thermal cell killing could have potential application in cancer therapy

Traditional and new prognosticators in breast cancer. Nottingham index, Mib-1 and estrogen receptor signaling relmain the best predictors of relapse and survival in a series of 289 cases.

7Histopathological and immunohistochemical findings on tissue microarrays, overall survival (OS), disease-free survival (DFS) and incidence of relapses (R) were recorded and statistically analyzed in 289 breast cancers. A higher R and a shorter DFS were significantly related to larger tumors, lymph node invasion, higher tumor grade, absence of estrogen receptors (ER), triple negative tumors, and presence of lymphovascular invasion (LVI). Longer OS was observed to be significantly associated with smaller tumor size (T), lymph node negativity, lower tumor grade, absence of LVI, lower Mib-1 expression and with the presence of ER. At multivariate analysis, only T for DFS and lymph node status and triple negativity either for DFS or OS had independent prognostic value. In the 194 lymph node-negative women DFS and OS were inversely related to tumor grade, absence of ER, Mib-1 expression in more than 15% of neoplastic cells and, only for DFS, presence of LVI. In the 95 lymph node-positive the number of involved nodes was the most discriminating parameter either for DFS or OS; T, Her-2 status and presence of LVI were significantly related to DFS. ER negativity was related to higher grade, progesterone receptors (PR) negativity, Her-2 negativity, hence to triple negativity, to basal-like type, Mib-1expression over 15% of neoplastic cells. Her-2 positivity was related to higher grade, ER positivity and PR positivity. Basal-like type was not an independent prognosticator, while triple negative type has a significant relation to shorter OS. The Nottingham prognostic index accurately identifies prognostic groupings and Mib-1 expression and ER signaling are the key biological predictors even in single cases.reservedmixedMEGHA T; NERI A; MALAGNINO V; CARUSO S; ONORATI M; F. ROVIELLO; TOSI PMegha, T; Neri, Alessandro; Malagnino, Valeria; Caruso, Stefano; Onorati, M; Roviello, Franco; Tosi, Pier

Diffuse centrocytic and/or centroblastic malignant non-Hodgkin's lymphomas: comparison of mitotic and pyknotic (apoptotic) indices

Mitotic indices (Mls) and pyknotic (apoptotic) indices (Pls) were assessed in diffuse centrocytic (CC, n = 10), centroblastic/centrocytic (CB/CC, n = 18) and centroblastic (CB, n = 20) malignant non-Hodgkin's lymphomas (NHL). Significant differences were observed. MIs were lowest in CC (median: 0.07%), intermediate in CB/CC (0.18%) and highest in CB (0.43%) NHLs. The PIs exhibited a similar pattern. The PIs of CC (0.11%) and CB/CC (0.17%) NHLs were significantly different from those of CB lymphoma (0.62%). The ratios MI/PI per case, as well as MIs and PIs per case, varied greatly and showed considerable overlapping, thus documenting a marked inter-case and inter-group heterogeneity. MIs tended to loosely correlate with PIs in a non-linear fashion, which raises the question of feedback mechanisms. More information is needed on mitotic time (T(M)) and apoptotic time (T(A)), in order to estimate cell doubling time from data on MIs and PIs

Anaplastic large cell lymphomas and Hodgkin's disease: distinctive growth features and expression of p34cdc2 /cyclin B-1

The clinical aggressiveness of a neoplastic process is largely determined by its growth, which results from cell production minus cell loss. We evaluated the potential of growth- related parameters in the differential diagnosis of Hodgkin's disease (HD), anaplastic large cell lymphoma, common type (ALCL-C), and its Hodgkin's like variant (ALCL-HL). These three conditions share some common properties, e.g. CD30 positivity. Highly significant differences were found between HD and ALCL-C. In particular, CD30+ cells in HD exhibited markedly higher mitotic indices (MI), multinucleation indices (MNI), DNA fragmentation indices (DFI, comparable to apoptotic indices) and percentages of mummified elements (MF), but distinctly lower ana-telophase indices (ATI, index of supposedly successful mitoses) than those in ALCL-C. Interestingly, the percentages of Ki-67 (MIB-1)+ large atypical cells (LAC), often referred to as " growth fractions", did not differ significantly among the three lymphomas types tested. In view of the disturbed mitotic process of CD30 cells in HD, special attention was paid to the two major proteins regulating the G2-M phases of the cell cycle: distinctly lower percentages of LAC expressing cyclin B-l (shortly: cyclin-B) in cytoplasm and nucleus (BCN) were registered in HD than in ALCL-C, while the reverse was true for the presence of p34cdc2 (shortly, p34). As regards the above parameters, ALCL-HL took a somewhat intermediate position between HD an ALCL-C, but was closer to the latter. A stepwise discriminant analysis revealed the following order of discriminant power of the parameters used to differentiate between the lymphomas: BCN > MNI > p34 > ATI > MF > MI. The other parameters tested, including the percentages of Ki 67+ CD30+ cells, were of little or no importance in this respect. Thus, anti-cyclin-B and anti-p34 antibodies may be useful tools in an immunohistochemical distinction of HD and ALCL