ERK1/2, JNK and STAT3 activation and correlation with tumor differentiation in oral SCC.

Signal transducer and activator of transcription 3 (STAT3) and mitogen activated protein kinases (MAPKs), including ERK and JNK, have been implicated in oral squamous cell carcinoma (OSCC) development and progression. Our purpose was to evaluate the levels of activated STAT3, ERK1/2 and JNK by immunohistochemistry in OSCC and to investigate possible correlations of these molecules with each other as well as with the degree of tumor differentiation. Immunohistochemical assessment of the phosphorylated levels of STAT3(tyrosine/ serine), ERK1/2 and JNK was performed in 60 OSCC, including well, moderately and poorly differentiated tumors. Semiquantitative scoring system was used, by calculating intensity of immunostaining, percentage of positive cells and combined scores. Statistics included Fisher's test, Student's T-Test and Kruskal-Wallis analysis, Spearman's correlation coefficient and multivariate logistic regression analyses. Immunohistochemical levels of both pSTAT3(tyr) and pERK1/2 showed statistically significant differences between well and poorly differentiated tumors with the latter receiving higher mean percentage, intensity and total scores. On the other hand, pJNK showed statistically significantly higher intensity levels in moderately compared to poorly differentiated tumors. pSTAT3(ser) immunoexpression did not appear to correlate with tumor differentiation. Between different molecules, more pronounced, pERK1/2 levels exhibited statistically significant positive correlation with pSTAT3(ser), pSTAT3(tyr) and pJNK expression. ERK1/2 and STAT3 activation (as assessed by tyrosine but not serine phosphorylation) could contribute to a less differentiated phenotype in OSCC, while JNK activation may have an opposite, although possibly less pronounced, effect. Positive correlations between MAPK and STAT3 levels may indicate a direct crosstalk and/or regulation by common upstream pathways.

Immunohistochemical evaluation of the mTOR pathway in intra-oral minor salivary gland neoplasms.

OBJECTIVES: The aim of this study was to investigate the expression of upstream and downstream molecules of the oncogenic mTOR signaling pathway in intra-oral minor salivary gland tumors (SGTs). MATERIALS AND METHODS: Tissue samples consisted of 39 malignant and 13 benign minor SGTs, and 8 controls of normal minor salivary glands (NMSG). An immunohistochemical analysis for phosphorylated Akt, 4EBP1 and S6 (total and phosphorylated), and eIF4E was performed. RESULTS: Expression of pAkt and 4EBP1 was observed in all SGTs and in most NMSG. p4EBP1 was detected in almost all SGT cases, NMSG being negative. S6 immunoreactivity was observed in 37.5% of NMSG, 92.3% of benign and 100% of malignant SGTs, while pS6 expression was observed in 77% of benign and 95% of malignant SGTs, but not in NMSG. Finally, eIF4E was expressed in 12.5% of NMSG, 69.2% of benign, and 76.9% of malignant tumors. All molecules studied had statistically significantly lower expression in NMSG compared with SGTs. Moreover, malignant neoplasms received higher scores compared with benign tumors for all molecules with the exception of eIF4E. CONCLUSION: The mTOR signaling pathway is activated in SGTs, especially in malignancies. Therefore, the possible therapeutic role of targeting the mTOR pathway by rapamycin analogs in SGTs needs further investigation.

Constitutive control of AKT1 gene expression by JUNB/CJUN in ALK+ anaplastic large-cell lymphoma: a novel crosstalk mechanism.

Anaplastic lymphoma kinase-positive (ALK+) anaplastic large-cell lymphoma (ALCL) is an aggressive T-cell non-Hodgkin lymphoma characterized by the t(2;5), resulting in the overexpression of nucleophosmin (NPM)-ALK, which is known to activate the phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway, resulting in cell cycle and apoptosis deregulation. ALK+ ALCL is also characterized by strong activator protein-1 (AP-1) activity and overexpression of two AP-1 transcription factors, CJUN and JUNB. Here, we hypothesized that a biologic link between AP-1 and AKT kinase may exist, thus contributing to ALCL oncogenesis. We show that JUNB and CJUN bind directly to the AKT1 promoter, inducing AKT1 transcription in ALK+ ALCL. Knockdown of JUNB and CJUN in ALK+ ALCL cell lines downregulated AKT1 mRNA and promoter activity and was associated with lower AKT1 protein expression and activation. We provide evidence that this is a transcriptional control mechanism shared by other cell types even though it may operate in a way that is cell context-specific. In addition, STAT3 (signal transducer and activator of transcription 3)-induced control of AKT1 transcription was functional in ALK+ ALCL and blocking of STAT3 and AP-1 signaling synergistically affected cell proliferation and colony formation. Our findings uncover a novel transcriptional crosstalk mechanism that links AP-1 and AKT kinase, which coordinate uncontrolled cell proliferation and survival in ALK+ ALCL.

Activation of the p53 pathway by the MDM2 inhibitor nutlin-3a overcomes BCL2 overexpression in a preclinical model of diffuse large B-cell lymphoma associated with t(14;18)(q32;q21).

p53 is frequently wild type (wt) in diffuse large B-cell lymphoma (DLBCL) associated with t(14;18)(q32;q21) that overexpresses BCL2. Nutlin-3a is a small molecule that activates the p53 pathway by disrupting p53-MDM2 interaction. We show that nutlin-3a activates p53 in DLBCL cells associated with t(14;18)(q32;q21), BCL2 overexpression and wt p53, resulting in cell cycle arrest and apoptosis. Nutlin-3a treatment had similar effects on DLBCL cells of activated B-cell phenotype with wt p53. Cell cycle arrest was associated with upregulation of p21. Nutlin-3a-induced apoptosis was accompanied by BAX and PUMA upregulation, BCL-XL downregulation, serine-70 dephosphorylation of BCL2, direct binding of BCL2 by p53, caspase-9 upregulation and caspase-3 cleavage. Cell death was reduced when p53-dependent transactivation activity was inhibited by pifithrin-α (PFT-α), or PFT-µ inhibited direct p53 targeting of mitochondria. Nutlin-3a sensitized activation of the intrinsic apoptotic pathway by BCL2 inhibitors in t(14;18)-positive DLBCL cells with wt p53, and enhanced doxorubicin cytotoxicity against t(14;18)-positive DLBCL cells with wt or mutant p53, the latter in part via p73 upregulation. Nutlin-3a treatment in a xenograft animal lymphoma model inhibited growth of t(14;18)-positive DLBCL tumors, associated with increased apoptosis and decreased proliferation. These data suggest that disruption of the p53-MDM2 interaction by nutlin-3a offers a novel therapeutic approach for DLBCL associated with t(14;18)(q32;q21).

Essential roles of Jab1 in cell survival, spontaneous DNA damage and DNA repair.

Jun activation domain-binding protein 1 (JAB1) is a multifunctional protein that participates in the control of cell proliferation and the stability of multiple proteins. JAB1 overexpression has been implicated in the pathogenesis of human cancer. JAB1 regulates several key proteins and thereby produces varied effects on cell cycle progression, genome stability and cell survival. However, the biological significance of JAB1 activity in these cellular signaling pathways is unclear. Therefore, we developed mice that were deficient in Jab1 and analyzed the null embryos and heterozygous cells. This disruption of Jab1 in mice resulted in early embryonic lethality due to accelerated apoptosis. Loss of Jab1 expression sensitized both mouse primary embryonic fibroblasts and osteosarcoma cells to γ-radiation-induced apoptosis, with an increase in spontaneous DNA damage and homologous recombination (HR) defects, both of which correlated with reduced levels of the DNA repair protein Rad51 and elevated levels of p53. Furthermore, the accumulated p53 directly binds to Rad51 promoter, inhibits its activity and represents a major mechanism underlying the HR repair defect in Jab1-deficient cells. These results indicate that Jab1 is essential for efficient DNA repair and mechanistically link Jab1 to the maintenance of genome integrity and to cell survival.

The therapeutic potential of p53 reactivation by nutlin-3a in ALK+ anaplastic large cell lymphoma with wild-type or mutated p53.

p53 is expressed frequently, but is rarely mutated in anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) tumours. Nutlin-3a is a recently developed small molecule that targets Mdm2, a critical negative regulator of p53, and disrupts the p53-Mdm2 interaction resulting in p53 stabilization and activation. We show that nutlin-3a activates p53 in ALK+ ALCL cells carrying a wild type (wt) or mutated but partially functional p53 gene resulting in p53-dependent cell-cycle arrest and apoptosis. Cell-cycle arrest was associated with upregulation of the cyclin-dependent kinase inhibitor p21. Nutlin-3a-induced apoptotic cell death was accompanied by Bax and Puma upregulation, downregulation of Bcl-xl, survivin, and caspase-3 cleavage, and this was reduced when p53-dependent transactivation activity was inhibited by pifithrin-alpha, or when pifithrin-mu was used to inhibit direct p53 targeting of mitochondria. Nutlin-3a sensitized the activation of the extrinsic apoptotic pathway in wt-p53 ALK+ ALCL cells, in part, through upregulation of DR-5 and downregulation of c-Flip(S/L), and was synergistic with TRAIL in cell death induction. In addition, nutlin-3a treatment enhanced doxorubicin cytotoxicity against ALK+ ALCL cells harbouring mt p53, and this was associated with p73 upregulation. These data suggest that disruption of the p53-mdm2 interaction by nutlin-3a offers a novel therapeutic approach for ALK+ ALCL patients.

Stabilization and activation of p53 downregulates mTOR signaling through AMPK in mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a clinically aggressive B-cell non-Hodgkin lymphoma characterized by the t(11;14)(q13;q32) and overexpression of cyclin D1. A high proportion of MCL tumors harbor wild-type (wt) and potentially functional p53 gene. We show here that stabilization and activation of wt-p53 using a recently developed potent MDM2 inhibitor, nutlin 3A, results in significant p53-dependent G1-S cell cycle arrest and apoptosis in MCL cells through regulation of p53 target genes. As mTOR signaling is activated in MCL and may control cyclin D1 levels, we show that p53 activation may downregulate the AKT/mTOR pathway through a mechanism involving AMP kinase (AMPK). Despite the non-genotoxic mode of nutlin 3A treatment, we show evidence that stabilization of p53 is associated with its phosphorylation at serine 15 residue and activation of AMPK. Stimulation of AMPK kinase activity using AICAR inhibits phosphorylation of critical downstream effectors of mTOR signaling, such as 4E-BP1 and rpS6. Pharmacologic inhibition of AMPK using compound C in nutlin-3A-treated MCL cells harboring wt-p53 did not affect the level of (ser15)p-p53, suggesting that the (ser15)p-p53 --> AMPK is the direction involved in the p53/AMPK/mTOR cross talk. These data establish a p53 --> AMPK --> mTOR mechanism in MCL and uncover a novel biologic effect of potent MDM2 inhibitors in preclinical models of MCL.

Leukotriene B4 receptor inhibitor LY293111 induces cell cycle arrest and apoptosis in human anaplastic large-cell lymphoma cells via JNK phosphorylation.

Anaplastic large-cell lymphoma (ALCL) is a heterogeneous lymphoma category in which a subset of cases carry the t(2;5)(p23;q35) or variant translocations resulting in overexpression of anaplastic lymphoma kinase (ALK). LY293111 (2-[2-propyl-3-[3-[2-ethyl-4-(4-fluorophenyl)-5-hydroxyphenoxy]-propoxy]-phenoxy] benzoic acid sodium salt) is a leukotriene B4 receptor antagonist, which was found to be safe and tolerable in Phase I clinical trials. In this study, we investigated the potential therapeutic effects and mechanisms of action of LY293111 in ALCL cell lines. LY293111 inhibited proliferation of both ALK(+) and ALK(-) ALCL cell in a dose-dependent fashion and induced complete G(1)-S cell cycle arrest, which was accompanied by upregulation of p27 and downregulation of cyclin E. Pretreatment with LY293111 for 4 h resulted in profound inhibition of serum-induced phosphorylation of extracellular-regulated kinases-1 and 2 and Akt and a concomitant increase in the phosphorylation of the stress-activated kinase c-jun N-terminal kinases (JNK). Simultaneously, LY293111 induced caspase-dependent apoptosis via activation of the intrinsic pathway, including early loss of mitochondrial inner transmembrane potential and the production of reactive oxygen species (ROS), cleavage of caspases-9, -3, poly ADP-ribose polymerase (PARP) and X-linked inhibitor of apoptosis. The phospho-JNK inhibitor SP600125 partially protected Sup-M2 cells from LY293111-induced apoptosis, PARP cleavage and ROS generation, suggesting a role for JNK in LY293111-induced cell death. These results warrant further studies of LY293111 in ALCL.

p53 gene mutations are uncommon but p53 is commonly expressed in anaplastic large-cell lymphoma.

Anaplastic large-cell lymphoma (ALCL), as defined in the World Health Organization, is a heterogeneous category in which a subset of cases is associated with the t(2;5)(p23;q35) or variant translocations resulting in overexpression of anaplastic lymphoma kinase (ALK). p53 has not been assessed in currently defined subsets of ALCL tumors. In this study, we assessed ALK+ and ALK- ALCL tumors for p53 gene alterations using PCR, single-strand conformation polymorphism and direct sequencing methods. We also immunohistochemically assessed ALCL tumors for p53 expression. Three of 36 (8%) ALCL tumors (1/14 ALK+, 2/22 ALK-) with adequate DNA showed p53 gene mutations. By contrast, p53 was overexpressed in 36 of 55 (65%) ALCL tumors (16 ALK+, 20 ALK-). p21, a target of p53, was expressed in 15 of 31 (48%) ALCL tumors including seven of 15 (47%) p53-positive tumors. p21 expression in a subset of ALCL suggests the presence of functional p53 protein. Apoptotic rate was significantly higher in p53-positive than p53-negative tumors (mean 2.78 vs 0.91%, P = 0.0003). We conclude that the p53 gene is rarely mutated in ALK+ and ALK- ALCL tumors. Nevertheless, wild-type p53 gene product is commonly overexpressed in ALCL and may be functional in a subset of these tumors.

Suppressor of cytokine signaling 3 expression in anaplastic large cell lymphoma.

Using a cDNA microarray, we found that suppressor of cytokine signaling 3 (SOCS3) is highly expressed in anaplastic lymphoma kinase (ALK)+ anaplastic large cell lymphoma (ALCL) cell lines. As SOCS3 is induced by activated signal transducer and activator of transcription 3 (STAT3), and ALK activates STAT3, we hypothesized that SOCS3 may play a role in ALK+ ALCL pathogenesis via the Janus kinase 3 (JAK3)-STAT3 pathway. Using ALCL cell lines, we show by coimmunoprecipitation experiments that SOCS3 physically binds with JAK3 in vitro, and that JAK3 inhibition by WHI-P154 downregulates SOCS3 expression. Western blot analysis confirmed expression of SOCS3 and also showed coexpression of phosphorylated (activated) STAT3 (pSTAT3). Direct sequencing of the SOCS3 gene showed no mutations or alternative splicing. In ALCL tumors that were assessed by immunohistochemistry, nine of 12 (75%) ALK+ tumors were SOCS3 positive and eight (67%) coexpressed pSTAT3. In comparison, 18 of 25 (72%) ALK-- tumors were SOCS3 positive and seven (28%) coexpressed pSTAT3. These results show that SOCS3 is overexpressed in ALCL, attributable to JAK3-STAT3 activation and likely related to ALK in ALK+ tumors. However, SOCS3 is also expressed in tumors that lack STAT3 and ALK suggesting alternative mechanisms of upregulation.

Trimetrexate in relapsed T-cell lymphoma with skin involvement.

PURPOSE: Methotrexate (MTX) is active against lymphomas, but transport or polyglutamylation mutations confer MTX resistance. Because trimetrexate (TMTX) enters cells by passive diffusion and is not polyglutamylated, its activity in relapsed T-cell lymphoma was investigated. PATIENTS AND METHODS: Eligible patients had histologically confirmed relapsed T-cell lymphoma involving the skin, had received more than one previous regimen, were older than 16 years, had normal organ function, and had no CNS disease or serious infections, including human immunodeficiency virus. TMTX (200 mg/m(2)) was given intravenously every 14 days without topical or systemic corticosteroids. Patients who responded received up to 12 doses. RESULTS: Twenty patients were assessable for response. Median age was 59 years (range, 45 to 87 years); 13 patients were men. Three patients had anaplastic large-cell lymphoma, 15 had mycosis fungoides or Sézary syndrome (14 with large-cell transformation), and two had peripheral T-cell lymphoma. Serum lactate dehydrogenase was high in 35%, and beta-2 microglobulin was more than 3.0 mg/L in 35% of patients. The median number of previous regimens was three (range, two to 15) and included MTX in five patients. Disease was refractory to the regimen immediately preceding TMTX in 85% of patients. Responses were complete in one and partial in eight patients (overall response rate, 45%). Two of five patients previously treated with MTX responded. Grade 3 or 4 mucositis was observed after 4%, infection after 3%, neutropenic fever after 6%, neutrophils less than 100/microL after 4%, and platelets less than 10,000/microL after 3% of TMTX doses. CONCLUSION: TMTX is active with acceptable toxicity in this population and merits further investigation.

Anaplastic lymphoma kinase (ALK) is not expressed in Hodgkin's disease: results with ALK-11 antibody in 327 untreated patients.

The t(2;5)(p23;q35) or other rare chromosomal abnormalities involving 2p23 upregulate the ALK gene, which is not expressed in normal lymphocytes. Thus, detection of ALK protein is presumptive evidence of these 2p23 abnormalities. The t(2;5) and ALK immunoreactivity are common in anaplastic large cell lymphoma of T/null-cell lineage. However, a small subset of cases of Hodgkin's disease (HD) have been reported to either carry the t(2;5) or express ALK. In this study, we have immunohistochemically evaluated 327 cases of HD with the ALK-11 antibody. ALK-11 is a well characterized polyclonal antibody raised against an intracellular portion of the ALK protein. We detected ALK-11 immunoreactivity in 8 (2.4%) cases of HD. We further studied these positive cases with ALK-1 monoclonal antibody, which reacts with an intracellular portion of ALK, similar to ALK-11. All 8 ALK-11 positive cases were negative for ALK-1. These results indicate that rare cases of HD may react with ALK-11 antibody, similar to previous reports by others using different polyclonal anti-ALK antibodies. However, the absence of ALK-1 expression in these HD cases suggests that ALK protein is not truly present and that polyclonal anti-ALK antibodies may rarely yield non-specific cross reactivity. These results further support the use of anti-ALK antibodies in the differential diagnosis of HD from ALCL.

Differential expression of BCL-2 family proteins in ALK-positive and ALK-negative anaplastic large cell lymphoma of T/null-cell lineage.

Anaplastic large-cell lymphoma (ALCL) of T- or null-cell lineage, as defined in the revised European-American lymphoma classification, includes a subset of tumors that carry the t(2;5)(p23;q35) resulting in overexpression of anaplastic lymphoma kinase (ALK). Patients with ALK+ ALCL are reported to have a better prognosis than patients with ALK- ALCL. Because the mechanisms for this survival difference are unknown, we investigated the hypothesis that apoptotic pathways may be involved. We therefore assessed expression levels of the anti-apoptotic proteins BCL-2 and BCL-XL and the pro-apoptotic proteins BAX and BCL-XS in T/null-cell ALCL using immunohistochemical methods and correlated the findings with ALK expression and apoptotic rate (AR), the latter assessed by a modified Tdt-mediated dUTP nick-end labeling assay. ALK was detected in 21 of 66 (31.8%) ALCLs. BCL-2 was not detected in 21 ALK+ ALCLs but was present in 26 of 45 (57.8%) ALK- ALCLs (P < 0.0001). ALK+ and ALK- ALCLs also showed significant differences in expression of BCL-XL, BAX, and BCL-XS. ALK+ tumors less commonly had a high level of BCL-XL (1 of 17 versus 14 of 35, P = 0.01), and more commonly had high levels of BAX (13 of 18 versus 15 of 36, P = 0.05), and BCL-XS (11 of 16 versus 12 of 31, P = 0.05) compared with ALK- tumors. ALK+ tumors also had a higher mean AR than ALK- tumors (3.4% versus 1.1%, P = 0.0002). Differential expression of BCL-2 family proteins may be responsible for the higher AR observed in ALK+ ALCL and provides a possible biological explanation for the better prognosis reported for patients with ALK+ ALCL.

Alterations of the 16q22.1 and 16q24.3 chromosomal loci in sporadic invasive breast carcinomas: correlation with proliferative activity, ploidy and hormonal status of the tumors.

BACKGROUND: Breast cancer is characterized by complex genetic alterations found in multiple chromosomal regions, most commonly losses of 17p, 16q, 8p and others. A number of tumor suppressor genes mapped on these loci have been investigated in mammary tumors, whereas other gene products are of unclear function and await identification. MATERIALS AND METHODS: We analyzed the loss of heterozygosity (LOH) of two chromosomal loci: a. 16q24.3 using the genetic markers D16S303, D16S3026 and D16S3407 and b. 16q22.1, the locus of E-cadherin gene, using the microsatelite markers D16S503, D16S752 and D16S512, in a series of 63 sporadic invasive breast carcinomas consisting of 56 ductal, 4 lobular and 3 tumors of mixed type. Our findings were correlated with proliferative activity, ploidy and hormonal status of the tumors. RESULTS: Fourteen (22.2%) tumors demonstrated LOH of 16q24.3. Allelic imbalance of the 16q22.1 locus was found in 19 of 61 informative cases (31%) and commonly coexisted with LOH of 16q24.3. A significant association was observed between LOH of D16S752 and the absence of progesterone receptors in tumor cells (p = 0.005). CONCLUSIONS: LOH of 16q24.3 and 16q22.1 are frequent genetic alterations in breast cancer and they do not seem to correlate with tumor cell proliferation or ploidy. The statistical association between LOH of 16q24.3 and progesterone receptors need to be further investigated in larger series.

Serum interleukin-10 levels are an independent prognostic factor for patients with Hodgkin's lymphoma.

BACKGROUND AND OBJECTIVES: Interleukin-10 (IL-10) is a pleiotropic cytokine which increases bcl-2 levels and protects cells from steroid or doxorubicin-induced apoptosis. Hodgkin and Reed-Sternberg (HRS) cells bear functional IL-10 receptors. Thus serum IL-10 (sIL-10) might inhibit apoptosis in HRS cells, which could occur as a result of either chemotherapy or the crippled immunoglobulin genes. DESIGN AND METHODS: We determined sIL-10 levels in 122 patients with Hodgkin's lymphoma (HL), treated with ABVD or equivalent regimens with or without radiotherapy, and correlated them with presenting clinical and laboratory features, as well as failure-free survival (FFS) and overall survival. RESULTS: Elevated sIL-10 levels ( > or = 10 pg/mL) were detected in 55 patients (45%), and were correlated with advanced stage and elevated serum b2-microglobulin levels. At 7 years FFS was 85% vs. 63% for patients with normal vs. elevated sIL-10 levels, respectively (p=0.01); overall survival was 97% vs. 73% (p=0.005). Multivariate analysis with Cox's proportional hazards model demonstrated that elevated sIL-10 levels were the strongest independent predictor of FFS, and were also associated with inferior overall survival. INTERPRETATION AND CONCLUSIONS: We conclude that sIL-10 levels are elevated in 45% of patients with HL, and are associated with inferior FFS and overall survival, independently of other established prognostic factors.

Evaluation of DNA topoisomerase IIalpha expression provides independent prognostic information in non-Hodgkin's lymphomas.

AIMS: In view of the dual role that DNA topoisomerase IIa (TopoIIa) plays as a cell proliferation marker and as a possible indicator of chemosensitivity, we investigated its expression in non-Hodgkin's lymphomas (NHL) in relation to conventional clinicopathological parameters, cell proliferation (as defined by Ki67 immunoreactivity), response to therapy and patient outcome. METHODS AND RESULTS: Formalin-fixed paraffin-embedded tissues from 153 patients with NHL were immunohistochemically stained for TopoIIalpha. Patients were followed up until death (n = 63) or for an average of 68 months (median 64 months, n = 90). The percentage of TopoIIalpha positive cells (TopoIIalpha LI) increased with grade (P < 0.001), extranodal location (P = 0.05) and Ki67 LI (P = 0.01, r = 0.673). In most cases (58%), Ki67 LI exceeded TopoIIalpha LI (TopoIIalpha/Ki67 < 1), especially within the indolent group (P < 0.001). TopoIIalphaLI, Ki67LI and TopoIIalpha/Ki67 ratio were all adversely related to overall survival in univariate analysis, though their significance was not maintained after adjustment for grade. In multivariate analysis high TopoIIalpha/Ki67 ratio and high TopoIIalpha LI independently predicted shortened overall and post-relapse survival, respectively. Most importantly, low TopoIIalpha/Ki67 ratio was the only independent predictor of diminished disease-free survival. However, there was no relationship between TopoIIalpha expression and response. CONCLUSIONS: Our results suggest that evaluation of TopoIIalpha expression and TopoIIalpha/Ki67 ratio as cell proliferation markers provides independent prognostic information in relation to post-relapse and overall survival. Furthermore, TopoIIalpha/Ki67 ratio appears to play a key role in the identification of patients prone to early relapse.

Analysis of proliferating cell fraction determined by monoclonal antibody to M1-subunit ribonucleotide reductase and Ki-67 in relation to p53 protein expression in fine-needle aspirates from non-Hodgkin's lymphomas.

The purpose of this study was to analyse the proliferative fraction with the monoclonal antibody M1-R-R to M1-subunit ribonucleotide reductase and with MIB-1 to Ki-67 antigen in relation to p53 protein expression in fine needle aspirates from B-cell non-Hodgkin's lymphomas. One hundred and thirty-seven cases, previously diagnosed and sub-typed according to the Kiel classification and characterized by immunophenotyping, were included in the study. The M-1 subunit ribonucleotide reductase (M1-R-R), Ki-67 and p53 antigens were detected using monoclonal antibodies on stored cytospin preparations. There was a good correlation (r = 0.72) between Ki-67 and M1-R-R positive cell fraction in both high and low grade lymphomas. High-grade lymphomas had a median percentage of M1-R-R/MIB-1 positive cells of 53.0/73.0 for lymphoblastic, 61.0/52.0 for immunoblastic and 33.5/41.0 for centroblastic lymphomas, respectively. In low grade lymphomas figures of median percentage of M1-R-R/MIB-1 were 9.0/15.0 for centroblastic/centrocytic, 11.0/9.5 for chronic lymphocytic leukaemia, 16.0/27.0 for centrocytic and 12.0/9.0 for immunocytomas, respectively. The median percentages of M1-R-R/MIB-1 for high and low grade lymphomas were 37.0/50.5 and 11.0/12.0, respectively. In the p53 positive cases the proliferation rate as measured by staining for M1-R-R and MIB-1 was higher than in p53 negative cases, but the difference was not statistically significant. The results show that cytospin material obtained by fine needle aspiration and stored at -70 degrees C for years can be used reliably for both peroxidase-avidin-biotin and three-step alkaline phosphatase immunocytochemical staining. In addition, proliferation fraction determined by M1-R-R monoclonal antibody staining correlates well with that measured by an established marker for cell proliferation, the Ki-67 antibody. However, the proliferation fraction as measured by the two antibodies differs in the various subtypes of non-Hodgkin's lymphoma which indicates that they may contribute different prognostic information.

Altered expression of the cell cycle regulatory molecules pRb, p53 and MDM2 exert a synergetic effect on tumor growth and chromosomal instability in non-small cell lung carcinomas (NSCLCs).

BACKGROUND: Recent in vitro studies provide evidence that the cell cycle molecules pRb, p53 and MDM2 form a tightly regulated protein network. In this study, we examined the relationship of this protein network in a series of non-small cell lung carcinomas (NSCLCs), with the kinetic parameters, including proliferative activity or proliferation index (PI) and apoptotic index (AI), and ploidy status of the tumors. MATERIAL AND METHODS: A total of 87 NSCLCs were examined using immunohistochemical and molecular methods in order to estimate the status of the pRb-p53-MDM2 network. The kinetic parameters and the ploidy status of the tumors were assessed by in situ assays. The possible associations between alterations of the network, kinetic parameters and ploidy status of the carcinomas were assessed with a series of statistical methods. RESULTS: Aberrant expression of pRb (Ab) and overexpression of p53 (P) and MDM2 (P) proteins were observed in 39%, 57%, and 68% of the carcinomas, respectively. The comprehensive analysis revealed that concurrent alterations in all three cell cycle regulatory molecules were the most frequent pattern, pRb(Ab)/p53(P)/MDM2(P); this "full abnormal" phenotype represented approximately 27% of the cases. This immunoprofile obtained the highest PI/AI value; whereas, the "normal" phenotype was the lowest one (p = 0.004). Furthermore, the pattern pRb(Ab)/p53(P)/MDM2(P) acquired the highest PI (p < 0.001) and lowest AI (p < 0.001) scores. Interestingly, the groups of carcinomas with impaired expression of one or two molecules attained PI/AI ratio values clustered in a narrow range placed in the middle of the scores exhibited by the "normal" and "full abnormal" phenotypes. These tumors had significantly lower AI, but similar PI values, compared with those noticed in the normal pattern. In addition, it was observed that the pRb(Ab)/p53(P)/MDM2(P) phenotype was also significantly associated with aneuploidy (p = 0.002) and a tendency was observed when the expression of two components was altered (p = 0.055). CONCLUSIONS: Our findings suggest that simultaneous deregulation of all members of the pRb-p53-MDM2 network confers an additive effect on tumor growth. The apoptotic pathway seems to be more susceptible to its defects than the cell proliferation machinery. The findings of the ploidy analysis, which are in parallel with those regarding the proliferative activity and the apoptotic rate study, further support the concept that these molecules constitute a tightly regulated network participating in cell cycle control and chromosomal stability.