The challenge of p53 as prognostic and predictive factor in Hodgkin's or non-Hodgkin's lymphoma

High expression of Bcl-2 predicts poor outcome in diffuse large B-cell lymphoma patients with low international prognostic index receiving R-CHOP chemotherapy

The prognostic significance of Bcl-2, Bcl-6, p53, topoisomerase II, and β-tubulin expression was evaluated in diffuse large B-cell lymphoma (DLBCL) patients treated with cyclophosphamide, doxorubicin, vincristine, prednisolone, and rituximab. Eight-year progression-free survival (PFS, P = 0.006) and overall survival (OS, P = 0.001) of patients with high Bcl-2 expression were significantly inferior to those of patients with low expression without prognostic significance of Bcl-6, p53, topoisomerase II, and β-tubulin expression. High expression of Bcl-2 was associated with poor PFS (P = 0.045) and OS (P = 0.004) only in patients with low international prognostic index (IPI). In multivariate analysis, high expression of Bcl-2 was a significant independent prognostic factor of poor PFS (P = 0.026) and OS (P = 0.007) along with high IPI. In conclusion, the expression of Bcl-2 may be a useful prognostic factor, especially in DLBCL patients with low IPI.

Expression of cell cycle regulatory proteins in eyelid sebaceous gland carcinoma: low p27 expression predicts poor prognosis

Prognosis of eyelid sebaceous gland carcinoma is largely unpredictable and there are few practically available markers for predicting patients' prognosis. Dysregulation of cell cycle progression is strongly associated with the development of cancer and the cancer prognosis. We investigated the expression of cell cycle regulatory proteins in eyelid sebaceous gland carcinoma and estimate their value as prognostic predictors. Forty-three cases of eyelid sebaceous gland carcinoma were included in this study. Immunohistochemistry for the p53, p21, p27, cyclin E, p16, cyclin D1, and phosphorylated Rb (pRb) proteins was performed using archival paraffin blocks. Correlations between clinical features and protein expression were evaluated statistically. Nine patients showed lymph node or distant metastasis, and the remaining patients showed localized disease. High expression of p21, p27, cyclin E, and p16 was found in the majority of tumor cell nuclei, whereas these proteins were rarely expressed in the normal sebaceous glands. However, pRb was focally lost in a subset of cases. Patients showing diffuse p27 expression developed metastasis less commonly than those with negative or focal p27 expression (log-rank test, p = 0.008). Aberrant expression of cell cycle regulatory proteins was observed in eyelid sebaceous gland carcinoma, suggesting that cell cycle dysregulation is involved in the pathogenesis of this tumor. Decreased p27 expression is a predictive biomarker of an unfavorable prognosis of eyelid sebaceous gland carcinoma.

No Prognostic Impact of p53 and P-Glycoprotein Expression in Patients with Diffuse Large B-Cell Lymphoma

The aim of this study was to determine the clinical significances of p53 and p-glycoprotein (P-gp) expression on outcome predictors for patients with DLBC. We assessed the immunohistochemical expression of p53 and P-gp using formalin-fixed, paraffin-embedded specimens in 108 patients diagnosed with de novo DLBC. A high expression of p53 was found in 53.7% of the patients. No expression of P-gp was demonstrated in any of the specimens. There were no significant differences in the complete remission (CR) rate (P = 0.79), overall survival (OS) (P = 0.73), or disease-free survival (DFS) (P = 31) between the p53-positive and p53-negative groups. The final model from multivariate analysis that revealed poor performance status was significantly associated with CR (P < 0.001) and OS (P < 0.001). Moreover, the advanced stage was a significant predictor of DFS (P = 0.03). This study demonstrated no impact of the expression of p53 on either response or survival rates.

Small-animal PET/CT for monitoring the development and response to chemotherapy of thymic lymphoma in Trp53-/- mice

Transgenic mouse models of human cancers represent one of the most promising approaches to elucidate clinically relevant mechanisms of action and provide insights into the treatment efficacy of new antitumor drugs. The use of Trp53 transgenic mice (Trp53 knockout [Trp53(-/-)] mice) for these kinds of studies is, so far, restricted by limitations in detecting developing tumors and the lack of noninvasive tools for monitoring tumor growth, progression, and treatment response.

METHODS

We hypothesized that quantitative small-animal PET with (18)F-FDG was able to detect the onset and location of tumor development, follow tumor progression, and monitor response to chemotherapy. To test these hypotheses, C57BL/6J Trp53(-/-) mice underwent longitudinal small-animal PET during lymphoma development and gemcitabine treatment. Trp53 wild-type (Trp53(+/+)) mice were used as controls, and histology after full necropsy served as the gold standard.

RESULTS

In Trp53(+/+) mice, the thymic standardized uptake value (SUV) did not exceed 1.0 g/mL, with decreasing (18)F-FDG uptake over time. Conversely, all Trp53(-/-) mice that developed thymic lymphoma showed increasing thymic glucose metabolism, with a mean SUV doubling time of 9.0 wk (range, 6.0-17.5 wk). Using an SUV of 3.0 g/mL as a criterion provided a sensitivity of 78% and a specificity of 100% for the detection of thymic lymphoma. Treatment monitoring with (18)F-FDG PET correctly identified all histologic responses and relapses to gemcitabine.

CONCLUSION

(18)F-FDG small-animal PET can be used to visualize onset and progression of thymic lymphomas in Trp53(-/-) mice and monitor response to chemotherapy. Thus, (18)F-FDG small-animal PET provides an in vivo means to assess intervention studies in the Trp53 transgenic mouse model.

Role of immunoexpression of nitric oxide synthases by Hodgkin and Reed-Sternberg cells on apoptosis deregulation and on clinical outcome of classical Hodgkin lymphoma

Hodgkin and Reed-Sternberg (H-RS) cells of classical Hodgkin lymphoma (cHL) present an impaired expression of immunoglobulin genes, but escape apoptotic death. We investigated whether nitric oxide synthases (NOS) are expressed by H-RS cells, studied their association with EBV status and the expression of apoptotic proteins, and investigated their relationship to the clinical outcome of 171 patients. NOS1 and NOS2 were expressed in a large number of cases, whereas NOS3 expression was not detected. Positive associations were found between NOS1 and p53, bax and NOS2, bcl-2 and NOS2, bax and p53, and between bax and fasL. Inverse correlations were established between EBV and NOS2 and between EBV and bcl-2. A shorter overall survival (OS) was associated with strong expression of NOS2. In conclusion, NOS are expressed by H-RS cells of cHL.

Over-expression of p53/BAK in aseptic loosening after total hip replacement

Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. The possible induction of apoptosis has not been addressed in great detail. Thus far, it has been shown that ceramic and polyethylene particles can induce apoptosis of macrophages in vitro. The purpose of this study was to test the hypothesis that wears debris generated from total hip arthroplasty could induce cellular damage and apoptosis in vivo. We therefore determined by immunohistochemical methods if increased expression of p53, an important transcription factor, and BAK and Bcl-2, two important regulators of apoptosis, can be found in interface membranes and capsules of hips with aseptically loose implants. Strongly positive immunohistochemical staining for p53 and BAK was found in peri-implant tissues from patients with aseptic hip implant loosening. Differentiation of various cell types showed that macrophages stained positive for p53 in all capsule and interface specimens. p53 was frequently detected in giant cells. Positive staining of BAK in macrophages and giant cells was seen in all specimens. Some positive reactions were observed in fibroblasts, only two of 19 cases stained for p53 and three cases for BAK within synovial cells. Positive macrophages and giant cells were localized around polyethylene particles. While T-lymphocytes showed a regular BAK-staining, the other leukocytes were negative. Statistical analyses showed significant positive correlations (p < 0.001) between the presence of polyethylene and metal debris and the expression of BAK and p53. Polyethylene particles were surrounded by more positive macrophages and giant cells than were metal particles, indicating that polyethylene debris may be a stronger inductor of cell cycle arrest and apoptosis than metal debris. In this study apoptosis of macrophages, giant cells and T-lymphocytes in capsules and interface membranes of patients with aseptic hip implant loosening has been demonstrated in vivo. It is possible that the apoptotic cascade could evolve as a novel therapeutic target to prevent particle-induced osteolysis.

Recent progress in predictive biomarkers for metastatic recurrence of human hepatocellular carcinoma: a review of the literature

Molecular markers (biomarkers) for hepatocellular carcinoma (HCC) metastasis and recurrence could provide additional information to that gained from traditional histopathological features. A large number of biomarkers have been shown to have potential predictive significance. One important aspect of this is to detect the transcripts of tumor-associated antigens (such as AFP, MAGEs, and CK19), which are proposed as predictive markers of HCC cells disseminated into the circulation and for metastatic recurrence. Another important aspect is to analyze the molecular markers for cellular malignancy phenotype, including DNA ploidy, cellular proliferation index, cell cycle regulators, oncogenes, and tumor suppressors (especially p53 gene), as well as telomerase activity. Molecular factors involved in the process of HCC invasion and metastasis, including adhesion molecules (E-cadherin, catenins, ICAM-1, laminin-5, CD44 variants, osteopontin), proteinases responsible for the degradation of extracellular matrix (MMPs, uPA system), as well as angiogenesis regulators (such as VEGF, intratumor MVD), have also been shown to be potential predictors for HCC metastatic recurrence and clinical outcomes. One important new trend is to widely delineate biomarkers with genomic and proteomic expression with reference to predicting metastatic recurrence, molecular diagnosis, and classification, which has been drawing more attention recently. Body fluid (particularly blood and urine) testing for biomarkers is easily accessible and more useful in clinical patients. The prognostic significance of circulating DNA in plasma or serum and its genetic alterations is another important direction. More attention should be paid to these areas in the future. As understanding of tumor biology deepens, more and more new biomarkers with high sensitivity and specificity for HCC metastatic recurrence could be found and routinely used in clinical assays. However, the combination of the pathological features and some of the biomarkers mentioned above seems to be more practical up to now.

Coexpression of p53 protein and MDR functional phenotype in leukemias: The predominant association in chronic myeloid leukemia

BACKGROUND

One of the best characterized resistance mechanisms of leukemias is multidrug resistance (MDR) mediated by P-glycoprotein (Pgp) and multidrug-resistant related protein (MRP). In addition to Pgp and MRP, p53 mutation or inactivation might play a relevant role in therapeutic failure. Some studies have demonstrated that Pgp and MRP may be activated in association with overexpression of mutant or inactivated p53 protein. The aim of this study was to investigate the association between p53 expression and MDR functional phenotype analyzed by flow cytometry (FCM).

METHODS

Rhodamine-123 assay analyzed by FCM was used to detect the MDR phenotype that was positive in 18 out of 41 (43.9%) cases of chronic myeloid leukemia (CML), 16 out of 28 (57.1%) chronic lymphoid leukemia (CLL) cases, 11 out of 28 (39.3%) acute myeloid leukemia (AML) cases, and four out of 22 (18.2%) acute lymphoid leukemia (ALL) cases.

RESULTS

Variable levels of p53 expression were observed in leukemic cells: 12 out of 41 (29.2%) in CML, nine out of 28 (32.1%) in CLL, 15 out of 28 (53.6%) in AML, and eight out of 22 (36.4%) in ALL samples.

CONCLUSIONS

In our study, no significant association between p53 expression and MDR functional phenotype was observed in ALL, CLL, and AML. On the other hand, a significant association (P = 0.0003) of the coexpression was observed in CML. The p53 overexpression was more frequently seen in the accelerated phase and the blastic phase of this disease. Our results suggest that an MDR functional phenotype could be associated with p53 mutation in the advanced stage of leukemias.

Prognostic factors in Hodgkin's lymphoma

Risk-adapted treatment strategies have constituted a major issue since the beginning of clinical research into Hodgkin's disease (HD). Various prognostic factors have been identified and several of those considered for staging procedures, resulting in strictly stage-dependent treatment recommendations for patients suffering from HD. These factors may be subdivided in host-related (e.g. age, sex) and tumour-related (e.g. number of tumour cells, growth characteristics, spread of tumour cells, resistance to apoptosis) factors. Owing to the striking improvement of the overall prognosis in HD patients it may be difficult to identify novel prognostic factors analysing the minority of patients with a fatal outcome. However, especially in advanced-stage disease, improved treatment results were achieved by the introduction of more aggressive treatment regimens, resulting in an increased toxicity rate. Thus, partially in contrast to earlier work in this field, future prognostic factors are needed for identification of those patients that have a good prognosis and might be susceptible to overtreatment. During the Fifth International Symposium on Hodgkin's Lymphoma, promising results on several new prognostic markers were presented. Furthermore, a joint effort to design new studies on large, well characterised patient groups has been initiated.

p53 immunohistochemical scoring: an independent prognostic marker for patients after hepatocellular carcinoma resection

AIM: To confirm if p53 mutation could be a routine predictive marker for the prognosis of hepatocellular carcinoma (HCC) patients.

METHODS: Two hundreds and forty-four formalin-fixed paraffin-embedded tumor samples of the patients with HCC receiving liver resection were detected for nuclear accumulation of p53. The percent of p53 immunoreactive tumor cells was scored as 0 to 3 + in p53 positive region (< 10% -, 10%-30% +, 31%-50% ++, > 50% +++). Proliferating cell nuclear antigen (PCNA) and some clinicopathological characteristics, including patients’ sex, preoperative serum AFP level, tumor size, capsule, vascular invasion (both visual and microscopic), and Edmondson grade were also evaluated.

RESULTS: In univariate COX harzard regression model analysis, tumor size, capsule status, vascular invasion, and p53 expression were independent factors that were closely related to the overall survival (OS) rates of HCC patients. The survival rates of patients with 3+ for p53 expression were much lower than those with 2+ or + for p53 expression. Only vascular invasion (P < 0.05) and capsule (P < 0.01) were closely related to the disease-free survival (DFS) of HCC patients. In multivariate analysis, p53 overexpression (RI 0.5456, P < 0.01) was the most significant factor associated with the OS rates of patients after HCC resection, while tumor size (RI 0.5209, P < 0.01), vascular invasion (RI 0.5271, P < 0.01) and capsule (RI 0.8691, P < 0.01) were also related to the OS. However, only tumor capsular status was an independent predictive factor (P < 0.05) for the DFS. No significant prognostic value was found in PCNA-LI, Edmondson’s grade, patients’ sex and preoperative serum AFP level.

CONCLUSION: Accumulation of p53 expression, as well as tumor size, capsule and vascular invasion, could be valuable markers for predicting the prognosis of HCC patients after resection. The quantitative immunohistochemical scoring for p53 nuclear accumulation might be more valuable for predicting prognosis of patients after HCC resection than the common qualitative analysis.

The prognostic molecular markers in hepatocellular carcinoma

The prognosis of hepatocellular carcinoma (HCC) still remains dismal, although many advances in its clinical study have been made. It is important for tumor control to identify the factors that predispose patients to death. With new discoveries in cancer biology, the pathological and biological prognostic factors of HCC have been studied quite extensively. Analyzing molecular markers (biomarkers) with prognostic significance is a complementary method. A large number of molecular factors have been shown to associate with the invasiveness of HCC, and have potential prognostic significance. One important aspect is the analysis of molecular markers for the cellular malignancy phenotype. These include alterations in DNA ploidy, cellular proliferation markers (PCNA, Ki-67, Mcm2, MIB1, MIA, and CSE1L/CAS protein), nuclear morphology, the p53 gene and its related molecule MD M2, other cell cycle regulators (cyclin A, cyclin D, cyclin E, cdc2, p27, p73), oncogenes and their receptors (such as ras, c-myc, c-fms, HGF, c-met, and erb-B receptor family members), apoptosis related factors (Fas and FasL), as well as telomerase activity. Another important aspect is the analysis of molecular markers involved in the process of cancer invasion and metastasis. Adhesion molecules (E-cadherin, catenins, serum intercellular adhesion molecule-1, CD44 variants), proteinases involved in the degradation of extracellular matrix (MMP-2, MMP-9, uPA, uPAR, PAI), as well as other molecules have been regarded as biomarkers for the malignant phenotype of HCC, and are related to prognosis and therapeutic outcomes. Tumor angiogenesis is critical to both the growth and metastasis of cancers including HCC, and has drawn much attention in recent years. Many angiogenesis-related markers, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived endothelial cell growth factor (PD-ECGF), thrombospondin (TSP), angiogenin, pleiotrophin, and endostatin (ES) levels, as well as intratumor microvessel density (MVD) have been evaluated and found to be of prognostic significance. Body fluid (particularly blood and urinary) testing for biomarkers is easily accessible and useful in clinical patients. The prognostic significance of circulating DNA in plasma or serum, and its genetic alterations in HCC are other important trends. More attention should be paid to these two areas in future. As the progress of the human genome project advances, so does a clearer understanding of tumor biology, and more and more new prognostic markers with high sensitivity and specificity will be found and used in clinical assays. However, the combination of some items, i.e., the pathological features and some biomarkers mentioned above, seems to be more practical for now.

Tumor suppressor genes in normal and malignant hematopoiesis

Over the last decade, a growing number of tumor suppressor genes have been discovered to play a role in tumorigenesis. Mutations of p53 have been found in hematological malignant diseases, but the frequency of these alterations is much lower than in solid tumors. These mutations occur especially as hematopoietic abnormalities become more malignant such as going from the chronic phase to the blast crisis of chronic myeloid leukemia. A broad spectrum of tumor suppressor gene alterations do occur in hematological malignancies, especially structural alterations of p15(INK4A), p15(INK4B) and p14(ARF) in acute lymphoblastic leukemia as well as methylation of these genes in several myeloproliferative disorders. Tumor suppressor genes are altered via different mechanisms, including deletions and point mutations, which may result in an inactive or dominant negative protein. Methylation of the promoter of the tumor suppressor gene can blunt its expression. Chimeric proteins formed by chromosomal translocations (i.e. AML1-ETO, PML-RARalpha, PLZF-RARalpha) can produce a dominant negative transcription factor that can decrease expression of tumor suppressor genes. This review provides an overview of the current knowledge about the involvement of tumor suppressor genes in hematopoietic malignancies including those involved in cell cycle control, apoptosis and transcriptional control.