The survivin:Fas ratio is predictive of recurrent disease in neuroblastoma

Upregulation of p75NTR by Histone Deacetylase Inhibitors Sensitizes Human Neuroblastoma Cells to Targeted Immunotoxin-Induced Apoptosis

Histone deacetylase (HDAC) inhibitors are novel chemotherapy agents with potential utility in the treatment of neuroblastoma, the most frequent solid tumor of childhood. Previous studies have shown that the exposure of human neuroblastoma cells to some HDAC inhibitors enhanced the expression of the common neurotrophin receptor p75NTR. In the present study we investigated whether the upregulation of p75NTR could be exploited to render neuroblastoma cells susceptible to the cytotoxic action of an anti-p75NTR antibody conjugated to the toxin saporin-S6 (p75IgG-Sap). We found that two well-characterized HDAC inhibitors, valproic acid (VPA) and entinostat, were able to induce a strong expression of p75NTR in different human neuroblastoma cell lines but not in other cells, with entinostat, displaying a greater efficacy than VPA. Cell pretreatment with entinostat enhanced p75NTR internalization and intracellular saporin-S6 delivery following p75IgG-Sap exposure. The addition of p75IgG-Sap had no effect on vehicle-pretreated cells but potentiated the apoptotic cell death that was induced by entinostat. In three-dimensional neuroblastoma cell cultures, the subsequent treatment with p75IgG-Sap enhanced the inhibition of spheroid growth and the impairment of cell viability that was produced by entinostat. In athymic mice bearing neuroblastoma xenografts, chronic treatment with entinostat increased the expression of p75NTR in tumors but not in liver, kidney, heart, and cerebellum. The administration of p75IgG-Sap induced apoptosis only in tumors of mice that were pretreated with entinostat. These findings define a novel experimental strategy to selectively eliminate neuroblastoma cells based on the sequential treatment with entinostat and a toxin-conjugated anti-p75NTR antibody.

Analysis of apoptosis regulatory genes expression in the bone marrow (BM) of adult de novo Myelodysplastic Syndromes (MDS)

The aim of the present study was to examine caspases, granzyme B and bcl-2 family mRNA expression and the degree of apoptosis in the bone marrow (BM) of 46 Myelodysplastic Syndromes (MDS) and to correlate our findings with clinical parameters. The degree of apoptosis was determined by Annexin V, whereas expression of genes was determined using a multiprobe RNase Protection System. A positive correlation was found between caspases 8, 5, 3, 2, 1 and the level of apoptosis. bfl1 and mcl1 levels were significantly higher in patients with BM blasts >5%. Cases with ratio of bid expression >1 compared to normal pool were associated with IPSS values < or =1.

Caspase 8L, a novel inhibitory isoform of caspase 8, is associated with undifferentiated neuroblastoma

Caspase 8 is a key apoptotic factor in the receptor/ligand apoptosis-signaling cascade. Absent caspase 8 expression is shown to correlate with poor prognosis in neuroblastoma. Paradoxically, the caspase 8 gene can produce as plice variant and novel inhibitor of itself-caspase 8l. The presence of caspase 8 alone in tumors may not necessarily portend a good prognosis. We sought to determine whether caspase 8l is present in neuroblastoma and whether over-expression of this protein could inhibit caspase 8-dependent apoptosis. Six of 6 histologically undifferentiated and 2 of 5 differentiated neuroblastoma tumors expressed the caspase 8l isoform, whereas caspase 8l was absent in 3 of 3 ganglioneuromas. Seven human neuroblastoma cell lines were surveyed. Two of the 5 cell lines that expressed caspase 8 also expressed the caspase 8l isoform and both were of a less differentiated neuronal phenotype. Over-expression of caspase 8l in cell lines afforded protection against TRAIL, but not against etoposide induced apoptosis. Conversely, blockade of Caspase 8l in cells that express this splice variant made them more sensitive to apoptosis induced cell death. We demonstrate the caspase 8l isoform is present in neuroblastoma and appears to be associated with undifferentiated cell lines and tumors. Furthermore, it suppresses caspase 8-dependent apoptosis.

Classification of neuroblastoma patients by published gene-expression markers reveals a low sensitivity for unfavorable courses of MYCN non-amplified disease

Currently, Pubmed lists 385 marker genes for neuroblastoma outcome. Using a customized neuroblastoma-microarray, we evaluated the prognostic impact of the gene-expression pattern of 349 of these candidates (90.6%) in 127 neuroblastoma patients with divergent outcome. By significance analysis of microarrays (SAM) and both uncorrected and Bonferroni-corrected ANOVA, 166/349 (47.5%), 218/349 (62.5%) and 128/349 (36.4%) candidates showed significant differential expression between patients with contrasting outcome. By Prediction Analysis for Microarrays (PAM), a 38-gene-classifier was derived from all markers, which classified patients outcome with an overall accuracy of 78.5%. However, patients with unfavorable outcome of MYCN non-amplified disease were largely misclassified (accuracy: 35%), suggesting that these courses are not identified by current marker genes.

Targeting caspase 8 to reduce the formation of metastases in neuroblastoma

The clinical challenge in neuroblastoma is the presence of metastasis at diagnosis in the majority of patients. Caspase 8 is an integral protein in death receptor-associated apoptosis, and loss of caspase 8 via the epigenetic phenomenon of methylation in neuroblastoma has led to increased resistance to chemotherapy. Recent evidence suggests that caspase 8 loss may also contribute to a metastatic phenotype; thus, caspase 8 may prove to be an attractive target for therapy both in treating primary tumours as well as preventing and treating metastatic lesions. Numerous methods have been described to manipulate caspase 8 levels both in vitro and in vivo, and investigation into caspase 8 isoforms may also bring forth additional therapeutic targets.

Survivin inhibits apoptosis induced by TRAIL, and the ratio between survivin and TRAIL receptors is predictive of recurrent disease in neuroblastoma

PURPOSE

Novel treatment strategies for high-risk and disseminated neuroblastoma (NB) are actively sought because of the dismal prognosis of advanced stage disease. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a recently identified member of the tumor necrosis factor family. TRAIL is capable of inducing apoptosis in multiple tumor cell types, with little or no cytotoxicity against normal cells.

EXPERIMENTAL DESIGN

We examined the activation and regulation of TRAIL-induced apoptosis in several human NB cell lines. The effect of TRAIL was examined in the context of TRAIL receptor (TRAIL-R) and survivin (an antiapoptotic protein) expression in the cell lines. The ratio of survivin/TRAIL-R messenger RNA was determined and evaluated as a marker of recurrent disease in patients with NB.

RESULTS

TRAIL induced apoptotic cell death of NB with variable sensitivities among the cell lines tested. Compared with a sensitive cell line (early passage NB16), the resistant cell lines (NB7 and late passage NB16) expressed lesser amounts of the death-inducing TRAIL-R1 and R2, and greater levels of survivin, an inhibitor of apoptosis. TRAIL sensitivity was enhanced in resistant cell lines by treating with etoposide that concomitantly increased TRAIL-R expression and diminished survivin expression. Survivin overexpression in a TRAIL-sensitive NB line (early passage NB16) rendered it less sensitive to treatment with TRAIL. Conversely, inhibiting survivin expression in NB3 by antisense oligonucleotides enhanced TRAIL sensitivity. A high survivin/TRAIL-R ratio accurately predicted risk for recurrent disease in primary tumor specimens tested.

CONCLUSIONS

These findings suggest that TRAIL therapy in combination with specific chemotherapeutic agents may represent an effective therapeutic strategy for NB. The cell's sensitivity to TRAIL is at least partially governed by both TRAIL-R and survivin expression, whereas the ratio between these 2 factors appears to have prognostic value in patients with this disease.

Survivin mRNA levels are associated with biology of disease and patient survival in neuroblastoma: a report from the children's oncology group

Alterations in apoptotic mechanisms favoring cell survival may be vital for modifying tumor behavior. Survivin, an inhibitor of apoptosis, and caspase 8, a proapoptotic enzyme, are key players in cellular apoptotic mechanisms. We investigated whether the levels of survivin and caspase 8 and the ratio between these 2 apoptotic factors correlate with tumor biology and predicts outcome in patients with neuroblastoma. Survivin and caspase 8 levels were quantified in 38 primary tumor specimens and analyzed individually and in relation to each other. High survivin expression and high survivin:caspase 8 ratios were associated with MYCN amplification, unfavorable histology, and high-risk group of disease (P<0.0008). High survivin mRNA levels were associated with worse overall survival (P=0.02) although the median follow up was only 22.6 months with a range of 1 day to 3.3 years. Low caspase 8 expression was associated with stage 4 disease, high-risk group, MYCN amplification, and unfavorable histology. Although the survivin:caspase 8 ratio was associated with these risk factors, the ratio did not improve the predictive value of survivin alone in this small series. Quantifying multiple apoptotic genes in neuroblastoma may supplement current risk stratification. Moreover, categorizing aberrant apoptotic gene expression in neuroblastoma may translate into novel therapeutic targets.

Significance of survivin mRNA expression in prognosis of neuroblastoma

Neuroblastoma (NB) is the most common malignant solid tumor in childhood, and among all childhood malignancies is second in prevalence only to leukemia. In NB we need to both make an accurate diagnosis and rapidly analyze the expression of genetic prognostic factors such as MYCN, H-ras, and trkA. Moreover, it has recently become important to analyze the expression of survivin mRNA, a member of the inhibitor of apoptosis protein family. Expression of the survivin gene is related to tumorigenesis and inhibition of apoptosis in some malignant tumors. We investigated its expression by reverse transcription-polymerase chain reaction (RT-PCR) in NB cell lines (SK-N-SH, NB-39, and IMR-32), two normal blood cell samples, and 13 clinical NB tumor samples. All three NB cell lines had high levels of mRNA expression for this gene, but normal blood cells had no expression. We detected expression of survivin mRNA in 7 of the 13 NB tumor samples (54%). Two NB patients were in stage I disease, 6 in stage II, and 5 in stage IV(A). Quantitative analysis by RT-PCR revealed that the ratio between survivin mRNA and human glyceraldehyde-3-phosphate dehydrogenase (h-GAPDH) mRNA was very low in stages I and II (0-0.017). In contrast, in advanced NBs (stage IV(A)) the ratio was much higher (0-0.050). The prognoses of the three patients in the advanced stage who had high ratios of expression were poor. A high level of expression of survivin mRNA indicates a high grade of malignancy, high likelihood of recurrence, and poor prognosis.

Ameliorating effect of hepatocyte growth factor on inflammatory bowel disease in a murine model

Hepatocyte growth factor (HGF), a multifunctional cytokine, accelerates intestinal epithelial proliferation. We studied the effects of HGF in mice with trinitrobenzene sulfonic acid-induced colitis, which shows clinical and molecular resemblance to Crohn's disease. Mice with colitis repeatedly were transfected intramuscularly with human HGF cDNA. Weight, survival, histopathology, proinflammatory cytokine mRNAs, and leukocyte infiltration were assessed. Treatment with HGF cDNA induced tyrosine phosphorylation of intestinal c-Met/HGF receptors, inhibited apoptosis, and promoted mitosis in intestinal epithelial cells, accelerating intestinal epithelial restoration and suppressing inflammation. Transfection with HGF cDNA markedly suppressed intestinal mRNA expression of T-helper 1 cytokines such as interleukin-12 and -1beta, interferon-gamma, and tumor necrosis factor-alpha. Numbers of total and CD4-positive T cells, neutrophils, and myloperoxidase activity in intestinal epithelium were diminished by HGF gene transfer, which also prevented weight loss, and improved survival. HGF might prove useful for controlling inflammatory bowel disease.

Cloning and expression of human anti-apoptosis gene survivin in Escherchia coli

AIM: To clone and express human antiapoptosis gene-survivin (SVV) in Escherchia coli.

METHODS: The SVV cDNA was obtained by using RT-PCR method with total RNA extracted from the human gastric cancer cell line, SGC7901. Then it was cloned into the pGEM-T easy vector, and subcloned into expression vector pRSET. After proved to be correct by sequencing, recombinant expression plasmid pRSET-SVV was transformed into E.coli BL21 (DE3). The fusion protein was produced by IPTG induction.

RESULTS: The SVV cDNA was obtained and its sequence was proved to be correct by sequencing identification, a new anticipated Mr 19 500-protein band appeared on SDS-PAGE gel induced by IPTG.

CONCLUSION: Human SVV cDNA is cloned and highly expressed in E.coli. This is important for studying its functions in the carcinogenesis and progress of neoplasm.

Lack of prognostic significance of survivin, survivin-deltaEx3, survivin-2B, galectin-3, bag-1, bax-alpha and MRP-1 mRNAs in breast cancer

The expression of transcripts for anti-apoptotic (survivin, survivin-deltaEx3, survivin-2B, galectin-3, bag-1 and bcl-2) and pro-apoptotic (bax-alpha) genes, and for multiple drug resistance related protein-1 (MRP-1) gene were investigated, using RT-PCR, in 106 breast tumour biopsies. Normal breast tissue was also analysed for comparative purposes. Overall, survivin, survivin-deltaEx3, survivin-2B, bcl-2, bag-1, galectin-3, bax-alpha and MRP-1 mRNAs were detected in 68, 54.7, 9.4, 78.4, 80.9, 98.9, 97.8 and 72.8%, respectively, of tumour specimens. Uniquely among the mRNAs analysed, the expression of bcl-2 correlated significantly with disease outcome, with bcl-2 expression indicative of favourable outcome in terms of both relapse-free survival and overall survival. This suggests that bcl-2 mRNA expression may be a key prognostic marker for breast cancer and that routine analysis of expression of this transcript should be considered. The results from this study suggest, however, that the expression of survivin, survivin-deltaEx3, survivin-2B, bag-1, galectin-3, bax-alpha and MRP-1 mRNAs cannot be considered as prognostic indicators of disease outcome for patients with breast cancer.

Survivin, versatile modulation of cell division and apoptosis in cancer

Survivin is a member of the inhibitor of apoptosis (IAP) gene family that has attracted attention from several viewpoints of basic and translational research. Its cell cycle-regulated expression at mitosis and association with the mitotic apparatus have been of interest to cell biologists studying faithful segregation of sister chromatids and timely separation of daughter cells. Investigators interested in mechanisms of apoptosis have found survivin an evolving challenge: while survivin inhibits apoptosis in vitro and in vivo, this pathway may be more selective as compared to cytoprotection mediated by other IAPs. Finally, basic and translational researchers in cancer biology have converged on survivin as a pivotal cancer gene, not simply for its sharp expression in tumors and not in normal tissues, but also for the potential exploitation of this pathway in cancer diagnosis and therapy. The objective of the present contribution is to line up current evidence and emerging concepts on the multifaceted functions of survivin in cell death and cell division, and how this pathway is being pursued for novel cancer therapeutic strategies.

Survivin study: what is the next wave?

Survivin, a novel member of inhibitor of apoptosis (IAP) protein family, is aberrantly expressed in cancer but undetectable in normal, differentiated adult tissues. Current studies suggest that survivin is implicated in both control of apoptosis and regulation of cell division. However, due to some inconsistent observations on survivin subcellular localization, there is debate about survivin's function in regulating apoptosis, cell division, or both. This review will discuss concepts, experimental methods, and interesting results that unify the different notions about survivin localization and function or point out gaps of knowledge about controversial issues. The author also intends to review various aspects of survivin studies, which were not emphasized or sufficiently discussed in previous reviews on survivin, and update recent developments that may reveal new applications of disease-oriented therapeutics in the coming years.

The N-myc paradox: N-myc overexpression in neuroblastomas is associated with sensitivity as well as resistance to apoptosis

Neuroblastomas are characterized by defects in tumor necrosis factor-related apoptosis inducing ligand (TRAIL) induced apoptosis, especially down-regulation and methylation of Caspase-8 (CASP8). This defect is associated with amplification of N-myc. However, N-myc has also been implicated in induction of apoptosis, especially activation of CASP9 mediated apoptosis. Here we found that ectopic N-myc expression induces TRAIL susceptibility, both by CASP8 and CASP9 mediated apoptosis. N-myc did not modify CASP8 expression and methylation. CASP8 defects therefore represent an independent event in neuroblastoma, counteracting the N-myc induced susceptibility to apoptosis. Analysis of the CASP9 mediated route in a series of neuroblastoma cell lines, we found normal expression and no aberrant methylation of four apoptotic intermediates, including CASP9 itself.

Expression of survivin protein in human colorectal carcinogenesis

AIM: To identify the role of survivin in colorectal carcinogenesis and the relationship between Survivin and histological differentiation grade of colorectal carcinoma.

METHODS: Immunohistochemical staining of survivin by using the monoclonal antibody was performed by the standard streptavidin-peroxidase (SP) technique for the 188 paraffin sections which included 30 normal colorectal mucosas, 41 adenomas with low grade dysplasia, 30 adenomas with high grade dysplasia, and 87 colorectal carcinomas which were classified as high, middle and low differentiated subgroups which included 33, 28, 26 cases respectively.

RESULTS: Expression of survivin was observed in the cytoplasm of adenoma with dysplasia and colorectal carcinoma cells. No immunoreactivity of survivin was seen in normal mucosas. The positive rate of survivin increased in the transition from normal mucosas to adenomas with low grade dysplasia to high grade dysplasia/carcinomas (0.0%, 31.7%, 56.7% and 63.2% respectively). But the difference between high grade dysplasia and carcinomas had no statistical significance. Positive rate was not related to histological differentiation grade of colorectal carcinoma. Moreover, there was no correlation between histological differentiation grade of colorectal carcinoma and immunoreactive intensity of survivin.

CONCLUSION: The expression of survivin is the essential event in the early stage of colorectal carcinogenesis and plays an important role in the transition sequence and it is not related to histological differentiation grade of colorectal carcinoma. It thus may provide a new diagnostic and therapeutic target in colorectal cancer.