Disturbed expression of the anti-apoptosis gene, survivin, and EPR-1 in hematological malignancies

The application, safety, and future of ex vivo immune cell therapies and prognosis in different malignancies

Introduction

Immunotherapy has revolutionized how cancer is treated. Many of these immunotherapies rely on ex vivo expansion of immune cells, classically T cells. Still, several immunological obstacles remain, including tumor impermeability by immune cells and the immunosuppressive nature of the tumor microenvironment (TME). Logistically, high costs of treatment and variable clinical responses have also plagued traditional T cell-based immunotherapies.

Methods

To review the existing literature on cellular immunotherapy, the PubMed database was searched for publications using variations of the phrases "cancer immunotherapy", "ex vivo expansion", and "adoptive cell therapy". The Clinicaltrials.gov database was searched for clinical trials related to ex vivo cellular therapies using the same phrases. The National Comprehensive Cancer Network guidelines for cancer treatment were also referenced.

Results

To circumvent the challenges of traditional T cell-based immunotherapies, researchers have developed newer therapies including tumor infiltrating lymphocyte (TIL), chimeric antigen receptor (CAR), T cell receptor (TCR) modified T cell, and antibody-armed T cell therapies. Additionally, newer immunotherapeutic strategies have used other immune cells, including natural killer (NK) and dendritic cells (DC), to modulate the T cell immune response to cancers. From a prognostic perspective, circulating tumor cells (CTC) have been used to predict cancer morbidity and mortality.

Conclusion

This review highlights the mechanism and clinical utility of various types of ex vivo cellular therapies in the treatment of cancer. Comparing these therapies or using them in combination may lead to more individualized and less toxic chemotherapeutics.

Peripheral blood marker of residual acute leukemia after hematopoietic cell transplantation using multi-plex digital droplet PCR

Background

Relapse remains the primary cause of death after hematopoietic cell transplantation (HCT) for acute leukemia. The ability to identify minimal/measurable residual disease (MRD) via the blood could identify patients earlier when immunologic interventions may be more successful. We evaluated a new test that could quantify blood tumor mRNA as leukemia MRD surveillance using droplet digital PCR (ddPCR).

Methods

The multiplex ddPCR assay was developed using tumor cell lines positive for the tumor associated antigens (TAA: WT1, PRAME, BIRC5), with homeostatic ABL1. On IRB-approved protocols, RNA was isolated from mononuclear cells from acute leukemia patients after HCT (n = 31 subjects; n = 91 specimens) and healthy donors (n = 20). ddPCR simultaneously quantitated mRNA expression of WT1, PRAME, BIRC5, and ABL1 and the TAA/ABL1 blood ratio was measured in patients with and without active leukemia after HCT.

Results

Tumor cell lines confirmed quantitation of TAAs. In patients with active acute leukemia after HCT (MRD+ or relapse; n=19), the blood levels of WT1/ABL1, PRAME/ABL1, and BIRC5/ABL1 exceeded healthy donors (p<0.0001, p=0.0286, and p=0.0064 respectively). Active disease status was associated with TAA positivity (1+ TAA vs 0 TAA) with an odds ratio=10.67, (p=0.0070, 95% confidence interval 1.91 - 59.62). The area under the curve is 0.7544. Changes in ddPCR correlated with disease response captured on standard of care tests, accurately denoting positive or negative disease burden in 15/16 (95%). Of patients with MRD+ or relapsed leukemia after HCT, 84% were positive for at least one TAA/ABL1 in the peripheral blood. In summary, we have developed a new method for blood MRD monitoring of leukemia after HCT and present preliminary data that the TAA/ABL1 ratio may may serve as a novel surrogate biomarker for relapse of acute leukemia after HCT.

Immunotherapy of Relapsed and Refractory Solid Tumors With Ex Vivo Expanded Multi-Tumor Associated Antigen Specific Cytotoxic T Lymphocytes: A Phase I Study

PURPOSE

Tumor-associated antigen cytotoxic T cells (TAA-Ts) represent a new, potentially effective and nontoxic therapeutic approach for patients with relapsed or refractory solid tumors. In this first-in-human trial, we investigated the safety of administering TAA-Ts that target Wilms tumor gene 1, preferentially expressed antigen of melanoma, and survivin to patients with relapsed/refractory solid tumors.

MATERIALS AND METHODS

TAA-T products were generated from autologous peripheral blood and infused over three dose levels: 1, 2, and 4 × 10⁷ cells/m². Patients were eligible for up to eight infusions administered 4 to 7 weeks apart. We assessed dose limiting toxicity during the first 45 days after infusion. Disease response was determined within the context of a phase I trial.

RESULTS

There were no dose-limiting toxicities. Of 15 evaluable patients, 11 (73%) with stable disease or better at day 45 postinfusion were defined as responders. Six responders remain without progression at a median of 13.9 months (range, 4.1 to 19.9 months) after initial TAA-Ts. Patients who were treated at the highest dose level showed the best clinical outcomes, with a 6-month progression-free survival of 73% after TAA-T infusion compared with a 38% 6-month progression-free survival with prior therapy. Antigen spreading and a reduction in circulating tumor-associated antigens using digital droplet polymerase chain reaction was observed in patients after TAA-T infusion.

CONCLUSION

TAA-Ts safely induced disease stabilization, prolonged time to progression, and were associated with antigen spreading and a reduction in circulating tumor-associated antigen DNA levels in patients with relapsed/refractory solid tumors without lymphodepleting chemotherapy before infusion. TAA-Ts are a promising new treatment approach for patients with solid tumors.

Critical testing and parameters for consideration when manufacturing and evaluating tumor-associated antigen-specific T cells

The past year has seen remarkable translation of cellular and gene therapies, with U.S. Food and Drug Administration (FDA) approval of three chimeric antigen receptor (CAR) T-cell products, multiple gene therapy products, and the initiation of countless other pivotal clinical trials. What makes these new drugs most remarkable is their path to commercialization: they have unique requirements compared with traditional pharmaceutical drugs and require different potency assays, critical quality attributes and parameters, pharmacological and toxicological data, and in vivo efficacy testing. What's more, each biologic requires its own unique set of tests and parameters. Here we describe the unique tests associated with ex vivo-expanded tumor-associated antigen T cells (TAA-T). These tests include functional assays to determine potency, specificity, and identity; tests for pathogenic contaminants, such as bacteria and fungus as well as other contaminants such as Mycoplasma and endotoxin; tests for product characterization, tests to evaluate T-cell persistence and product efficacy; and finally, recommendations for critical quality attributes and parameters associated with the expansion of TAA-Ts.

Dysregulation of the intrinsic apoptotic pathway mediates megakaryocytic hyperplasia in myeloproliferative neoplasms

AIMS

Megakaryocyte expansion in myeloproliferative neoplasms (MPNs) is due to uncontrolled proliferation accompanied by dysregulation of proapoptotic and antiapoptotic mechanisms. Here we have investigated the intrinsic and extrinsic apoptotic pathways of megakaryocytes in human MPNs to further define the mechanisms involved.

METHODS

The megakaryocytic expression of proapoptotic caspase-8, caspase-9, Diablo, p53 and antiapoptotic survivin proteins was investigated in bone marrow specimens of the MPNs (n=145) and controls (n=15) using immunohistochemistry. The megakaryocyte percentage positivity was assessed by light microscopy and correlated with the MPN entity, JAK2V617F/CALR mutation status and platelet count.

RESULTS

The proportion of megakaryocytes in the MPNs expressing caspase-8, caspase-9, Diablo, survivin and p53 was significantly greater than controls. A greater proportion of myeloproliferative megakaryocytes expressed survivin relative to its reciprocal inhibitor, Diablo. Differences were seen between myelofibrosis, polycythaemia vera and essential thrombocythaemia for caspase-9 and p53. CALR-mutated cases had greater megakaryocyte p53 positivity compared to those with the JAK2V617F mutation. Proapoptotic caspase-9 expression showed a positive correlation with platelet count, which was most marked in myelofibrosis and CALR-mutated cases.

CONCLUSIONS

Disruptions targeting the intrinsic apoptotic cascade promote megakaryocyte hyperplasia and thrombocytosis in the MPNs. There is progressive dysfunction of apoptosis as evidenced by the marked reduction in proapoptotic caspase-9 and accumulation of p53 in myelofibrosis. The dysfunction of caspase-9, which is necessary for proplatelet formation, may be the mechanism for the excess thrombocytosis associated with CALR mutations. Survivin seems to be the key protein mediating the megakaryocyte survival signature in the MPNs and is a potential therapeutic target.

Prognostic and biological significance of survivin expression in patients with diffuse large B-cell lymphoma treated with rituximab-CHOP therapy

Survivin, a member of the inhibitor of apoptosis protein family, is overexpressed in a variety of human neoplasms. The prognostic significance of survivin expression in diffuse large B-cell lymphoma patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) is unclear. We used standard immunohistochemistry methods to quantify survivin expression in 463 patients with de novo diffuse large B-cell lymphoma who received the R-CHOP. Of the 463 patients, 269 (58%) had survivin overexpression with a cutoff of >25%, associated with an International Prognostic Index score of >2 (P=0.015), disease in ≥2 extranodal sites (P=0.011), and a high Ki-67 index (P<0.0001). Among patients with activated B cell-like disease, the overall survival rate of survivin-positive patients was significantly lower than that of survivin-negative patients (P=0.033); multivariate analysis confirmed that in these patients, survivin overexpression was an independent prognostic factor for survival. Among patients with wild-type p53 overexpression, the overall survival and progression-free survival rates of the survivin-positive group were significantly lower than those of the survivin-negative group (P=0.035 and P=0.04 respectively). In STAT3-positive patients, survivin overexpression was associated with significantly better survival. Among patients with activated B cell-like disease, survivin-positive compared with survivin-negative groups had significantly different gene expression signatures, including genes involved in mitosis or tumor cell proliferation. Our results indicate that survivin is an independent prognostic factor for poor outcome in patients with activated B cell-like disease treated with the R-CHOP regimen, and patients with survivin-positive activated B cell-like diffuse large B-cell lymphoma seem to benefit less from this treatment and may require additional novel agents.

Study of survivin and X-linked inhibitor of apoptosis protein (XIAP) genes in acute myeloid leukemia (AML)

Apoptosis deregulation is important for cancer development, chemotherapy response, and prognosis. Survivin and X-linked inhibitor of apoptosis protein (XIAP) are 2 members of the inhibitor of apoptosis proteins family (IAP). We used semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) to determine the levels of expression of survivin and XIAP in 30 patients with de novo acute myeloid leukemia (AML) and 20 age- and sex-matched healthy volunteers. Survivin and XIAP overexpression were detected in 36.7% and 43.3% of cases, respectively. Patients with overexpression of either survivin or XIAP showed unfavorable response to chemotherapy in 81.2% and 91.7%, respectively. Also, these cases showed shorter median survival time (30 days) compared to patients with normal expression of either survivin or XIAP (150 days and 180 days). Patients with overexpression of both survivin and XIAP showed unfavorable response to induction therapy in 100% of the patients and the shortest median survival (30 days). These findings suggest that survivin and XIAP may have a role in leukemogenesis and provide prognostic information.

Survivin isoforms and clinicopathological characteristics in colorectal adenocarcinomas using real-time qPCR

AIM: To investigate three isoforms of survivin in colorectal adenocarcinomas.

METHODS: We used the LightCycler Technology (Roche), along with a common forward primer and reverse primers specific for the splice variants and two common hybridization probes labeled with fluorescein and LightCycler-Red fluorophore (LC-Red 640). Real time quantitative polymerase chain reaction (PCR) was performed on cDNAs from 52 tumor specimens from colorectal cancer patients and 10 unrelated normal colorectal tissues. In the patients group, carcinoembryonic antigen (CEA) and CA19-9 tumor markers were also measured immunochemically.

RESULTS: Wild type survivin mRNA isoform was expressed in 48% of the 52 tumor samples, survivin-2b in 38% and survivin-ΔΕx3 in 29%, while no expression was found in normal tissues. The mRNA expression of wild type survivin presented a significant correlation with the expression of the ratio of survivin-2b, survivin-ΔΕx3, survivin-2b/wild type survivin and survivin-ΔΕx3/wild type survivin (P < 0.001). The mRNA expression of wild-survivin and survivin-ΔΕx3 was related with tumor size and invasion (P = 0.006 and P < 0.005, respectively). A significant difference was found between survivin-2b and morphologic cancer type. Also, the ratio of survivin-ΔEx3/wild-survivin was significantly associated with prognosis. No association was observed between the three isoforms and grade, metastasis, Dukes stage and gender. The three isoforms were not correlated with CEA and CA19-9.

CONCLUSION: Survivin isoforms may play a role in cell apoptosis and their quantification could provide information about clinical management of patients suffering from colorectal cancer.

Survivin isoform expression patterns in CML patients correlate with resistance to imatinib and progression, but do not trigger cytolytic responses

Tyrosine-kinase inhibitors are very effective in patients with CML, but in most cases the disease relapses after their discontinuation. As a result, novel approaches should be considered, such as anti-survivin treatment or anti-survivin-based immunotherapy. To gain insight into the roles of survivin isoform expression and specific CD8(+) T cells in CML, we investigated 51 patients at different stages, both at diagnosis and during treatment. We demonstrated that (i) patients at advanced-stage displayed an increased expression of the standard-survivin form along with a significant decrease of survivin-2B and -ΔEx3 levels, (ii) patients in chronic phase with higher expression of the standard-survivin exhibited a 3.5-fold increased probability not to achieve an optimal response to imatinib (p=0.048), (iii) responders displayed a significant up-regulation of all survivin isoforms in bone marrow, and (iv) anti-survivin CD8(+) T cells were undetectable both at diagnosis and during treatment. Accordingly, our results question the validity of immunotherapeutic approaches targeting survivin in CML.

Down-regulation of Stat3 decreases invasion activity and induces apoptosis of human glioma cells

Gliomas are the most common type of primary brain tumors. Despite the improvement in current treatments for gliomas, including surgical resection, radiation, and chemotherapy, there has been very little progress in curing this kind of disease. Stat3 is a member of signal transducer and activator of transcription family. It plays an important role in regulating cell survival, invasion, and apoptosis. This study investigated the influence of low-level expression of Stat3 on invasion and apoptosis in U251 cells. Our data showed that Stat3 is constitutively expressed in human gliomas cell line U251. The invasion activity in U251 cells was weakened and the apoptosis in U251 cells was induced after down-regulation of Stat3. In addition, down-regulation of Stat3 can suppress the expression of MMP-2, Bcl-xL and survivin but not 67LR. These results further indicate that Stat3 plays a key role in the invasion and apoptosis of human glioma cell line U251.

K562/GM-CSF immunotherapy reduces tumor burden in chronic myeloid leukemia patients with residual disease on imatinib mesylate

PURPOSE

Chronic myeloid leukemia (CML) can be responsive to T-cell-mediated immunity. K562/granulocyte macrophage-colony stimulating factor (GM-CSF) is a GM-CSF producing vaccine derived from a CML cell line that expresses several CML-associated antigens. A pilot study was developed to determine if K562/GM-CSF immunotherapy could improve clinical responses to imatinib mesylate (IM) in patients with chronic myeloid leukemia.

EXPERIMENTAL DESIGN

Patients with chronic phase CML who achieved at least a major cytogeneic response but remained with persistent, measurable disease despite one or more years on imatinib mesylate were eligible. Each was given a series of four vaccines administered in three-week intervals, with or without topical imiquimod, while remaining on a stable dose of imatinib mesylate. CML disease burden was measured serially before and after vaccination.

RESULTS

Nineteen patients were vaccinated, with a median duration of previous imatinib mesylate therapy of 37 (13-53) months. Mean PCR measurements of BCR-ABL for the group declined significantly following the vaccines (P = 0.03). Thirteen patients had a progressive decline in disease burden, 8 of whom had increasing disease burden before vaccination. Twelve patients achieved their lowest tumor burden measurements to date following vaccine, including seven subjects who became PCR-undetectable.

CONCLUSIONS

K562/GM-CSF vaccine appears to improve molecular responses in patients on imatinib mesylate, including achieving complete molecular remissions, despite long durations of previous imatinib mesylate therapy.

Expression of BIRC7 protein and mRNA in non-Hodgkin's lymphoma

Studies have shown that BIRC7, a new member of inhibitor of the apoptosis protein family, is expressed in fetal tissues and most solid tumors in humans. However, there are no reported data concerning BIRC7 expression in lymphomas. We investigated the expression of BIRC7, survivin, Bcl-2, Bax, p53 and p170 proteins in 167 cases of non-Hodgkin's lymphoma (NHL) and 10 cases of non-specific lymphadenitis by tissue microarray-based immunohistochemistry. BIRC7 mRNA in three cell lines and 16 cases of NHL were detected by reverse transcriptase-polymerase chain reaction. BIRC7 protein was exhibited in the cytoplasm of cells in 25 (31%) of 80 cases of B-NHLs, 32 (37%) of 87 cases of T-NHLs, and none in non-specific lymphadenitis. The positive rate of BIRC7 was lower than that of survivin in almost all types of NHL with no significant differences, and similar to that of Bcl-2, Bax or p53. There was no correlation of protein expression between BIRC7 and any other detected markers, except p170 in T-NHL (P < 0.001). BIRC7 expression did not correlate with clinic pathologic factors such as sex, age, stage and grade, but overexpression of BIRC7 was positively correlated with aggression of NHL cells (P < 0.05). BIRC7 mRNA expressed in six (38%) of 16 cases of NHLs. BIRC7 mRNA expression was approximately consistent with BIRC7 protein in NHL. Our results indicate that the BIRC7 gene might play a role in the development and aggression of NHL and that the inhibition of BIRC7 expression may be important in NHL treatment.

Both strands of siRNA have potential to guide posttranscriptional gene silencing in mammalian cells

Despite the widespread application of RNA interference (RNAi) as a research tool for diverse purposes, the key step of strand selection of siRNAs during the formation of RNA-induced silencing complex (RISC) remains poorly understood. Here, using siRNAs targeted to the complementary region of Survivin and the effector protease receptor 1 (EPR-1), we show that both strands of the siRNA duplex can find their target mRNA and are equally eligible for assembly into Argonaute 2 (Ago2) of RISC in HEK293 cells. Transfection of the synthetic siRNA duplexes with different thermodynamic profiles or short hairpin RNA (shRNA) vectors that generate double-stranded RNAs (dsRNAs), permitting processing specifically from either the 5' or 3' end of the incipient siRNA, results in the degradation of the respective target mRNAs of either strand of the siRNA duplex with comparable efficiencies. Thus, while most RNAi reactions may follow the thermodynamic asymmetry rule in strand selection, our study suggests an exceptional mode for certain siRNAs in which both strands of the duplex are competent in sponsoring RNAi, and implies additional factors that might dictate the RNAi targets.

Quantitative detection of survivin in malignant pleural effusion for the diagnosis and prognosis of lung cancer

In the present study, pleural effusions are the first time to be used as the specimens for detection of survivin expression in lung cancer patients. We demonstrated that by quantifying survivin expression with enzyme-linked immunosorbent assay (ELISA) in the 80 effusion samples exhibited a diagnostic power of 85% and 75% in sensitivity and specificity, respectively. A multivariate analysis with the Cox regression model revealed that both high survivin expression and cancer cells of stage IV were the indicators for poor prognosis of lung cancer. In conclusion, quantitative assay of survivin in pleural effusion could be useful both in diagnosis and prognosis for lung cancer.

Survivin-derived peptide epitopes and their role for induction of antitumor immunity in hematological malignancies

The immune system's ability to detect and destroy tumor cells offers an attractive approach to broaden the spectrum of cancer therapies. Survivin, a member of the apoptosis inhibitor protein family, is a tumor antigen, overexpressed in human cancers giving rise to peptides eliciting spontaneous CD8+ and CD4+ responses. Due to its dual function, blockade of apoptosis and regulation of cell division, survivin is directly associated with tumor survival and therefore regarded as an ideal target structure for immunotherapeutic approaches. Strong evidence that survivin acts as a T-cell activating antigen has been collected in recent years and the first clinical trials using survivin-based vaccines aim to prove its therapeutic efficacy in the clinic. We focus on the role of survivin in hematological malignancies, including a list of survivin-derived peptides eliciting potent immune responses.

Transcriptional expression of survivin and its splice variants in cervical carcinomas

The objective of this study was to evaluate transcriptional expression of survivin and the two splice variants (survivin-2B and survivin-ΔEx3) in cervical carcinomas. The gene expression levels of survivin and its splice variants in 11 human cervical carcinoma cell lines and 20 malignant and 12 normal cervical tissue samples were analyzed using quantitative reverse transcription–polymerase chain reaction analysis. Gene expression levels of survivin and survivin-ΔEx3 in cell lines were higher than those in normal cervical tissues (P= 0.0193 and 0.0489). Transcript levels of survivin and survivin-ΔEx3 in carcinoma tissues were also higher than those in normal controls (P= 0.0016 and 0.0011). Gene expression levels of survivin and survivin-ΔEx3 in adenocarcinomas were statistically higher than those in squamous cell carcinomas (P= 0.0260 and 0.0487). There was no significant difference in survivin-2B gene expression between malignant and normal cervical samples or different histologic types. The ratios of survivin-2B/survivin and survivin-ΔEx3/survivin in carcinoma tissues were higher than those in normal controls (P= 0.0288 and 0.0081). Interestingly, the ratio of survivin-2B/survivin was increased in the patients with higher stages and with pelvic lymph node metastasis (P= 0.0205 and 0.0437), respectively. We conclude that survivin and its splice variants might be involved in the pathogenesis and development of cervical carcinomas.

Survivin and EPR-1 expression in acute leukemias: prognostic significance and review of the literature

The aim of this study is to detect the biologic and/or prognostic significance of survivin (S) and effector protease receptor 1: EPR-1 (E) expression in acute leukemias (34 ALL and 40 AML) by using RT-PCR. S and E expressions were found in 83.8 and 20.3% of the cases, respectively. S was detected in 90%, 76.5% and E was detected in 17.5%, 23.5% of the cases with AML and ALL, respectively. There was a significant correlation between S and E (r=0.30 p=0.01). Mortality rate was higher in E(-) cases than E(+) cases (83.1 % versus 66.7%) (p=0.04). The median DFS and OS rates were shorter in S(+) and E(-) cases. In subgroup analysis, there was not a significant difference for OS between S(-) and S(+) cases and E(-) and E(+) cases in ALL group. The median OS rate was significantly longer in S(-) cases than S(+) cases, and longer in E(+) cases than E(-) in AML groups (p=0.04, 0.001, respectively). OS and DFS rates were longest in S(-) E(+) cases and shortest in S(+) E(-) cases (p=0.04 and 0.03, respectively). In multivariate analyses EPR1 negativity was found to be an independent poor risk factor for survival (OR: 2.4, p=0.02). In conclusion S expression is a bad prognostic indicator in cases with acute leukemia especially in AML. S negativity and E positivity show good clinical outcome in acute leukemias. E expression is important due to its property of the possible natural anti-sense of the S.

CD34 cells from patients with trisomy 8 myelodysplastic syndrome (MDS) express early apoptotic markers but avoid programmed cell death by up-regulation of antiapoptotic proteins

CD34 cells from patients with trisomy 8 myelodysplastic syndrome (MDS) are distinguished from other MDS cells and from normal hematopoietic cells by their pronounced expression of apoptotic markers. Paradoxically, trisomy 8 clones can persist in patients with bone marrow failure and expand following immunosuppression. We previously demonstrated up-regulation of c-myc and CD1 by microarray analysis. Here, we confirmed these findings by real-time polymerase chain reaction (PCR), demonstrated up-regulation of survivin, c-myc, and CD1 protein expression, and documented comparable colony formation by annexin(+) trisomy 8(-) CD34(+) and annexin(-) CD34 cells. There were low levels of DNA degradation in annexin(+) trisomy 8 CD34 cells, which were comparable with annexin(-) CD34 cells. Trisomy 8 cells were resistant to apoptosis induced by gamma irradiation. Knock-down of survivin by siRNA resulted in preferential loss of trisomy 8 cells. These results suggest that trisomy 8 cells undergo incomplete apoptosis and are nonetheless capable of colony formation and growth.

Detection of Survivin-expressing circulating cancer cells in the peripheral blood of breast cancer patients by a RT-PCR ELISA

Survivin mRNA expression was detected in 69.2%-93.8% of primary breast carcinomas, but is rarely expressed in normal breast tissues and hematopoietic cells. The objective of this study was to investigate the significance that the detection of Survinin-expressing circulating breast cancer cells in the peripheral blood has on clinical outcomes. The detection method was based on a RT-PCR ELISA technique developed in our laboratory. Sixty-seven breast cancer patients in various stages and 135 normal healthy women were investigated. Survivin-expressing circulating cancer cells were detected in the peripheral blood samples from 34 (50.7%) out of 67 breast cancer patients, but not in the healthy women that were used as controls. The presence of Survivin-expressing circulating breast cancer cells was found to be significantly associated with various clinicopathological parameters such as vessel infiltration, histological grade, tumor size, nodal status, ER/PgR status, Her-2 status and clinical stages of the disease (P < 0.01). During a follow-up period of 36 months, 9 out of 11 (81.8%) breast cancer patients that had a positive Survivin-expressing at the time of the initial assay test suffered a relapse of the disease, whereas recurrence was only found in 2 out of 6 (33.3%) breast cancer patients that had a negative Survivin-expression. Thus, the detection of circulating cancer cells expressing Survivin mRNA could provide valuable information for the prediction of metastasis and recurrence of breast cancer.

Survivin expression, apoptosis and proliferation in chronic myelomonocytic leukemia

We analyzed the expression of the inhibitor of apoptosis survivin by immunocytochemistry in bone marrow cells from patients with chronic myelomonocytic leukemia (CMML) to evaluate possible abnormalities in comparison with other myelodysplastic (MDS) and myeloproliferative syndromes, and to investigate a possible correlation between survivin expression and altered apoptosis or proliferation, or relevant laboratory and clinical findings. Thirty-four patients with CMML [18 MDS-CMML and 16 myeloproliferative disorder (MPD)-CMML], 90 with MDS, 41 with acute myeloid leukemia (AML), 19 with chronic MPD and 25 control subjects were studied. In normal samples survivin was never detectable. In CMML survivin levels higher than in MDS and AML (P < 0.0001), but similar to those found in MPD were observed. In CMML and MDS apoptosis was significantly higher compared to normal controls and all other subtypes of leukemias (P < 0.0001). Proliferation did not differ significantly in normal controls, MDS and CMML; the lowest levels were observed in AML and MPD (P < 0.0001). In CMML there was no correlation between survivin expression and blast cell percentage, apoptosis or proliferation, FAB or WHO subgroup. Proliferation was higher in MDS-CMML and tended to correlate with overall survival. CMML-2 cases with higher survivin expression showed higher evolution rate and shorter survival. In conclusion, CMML is characterized by high proliferation and apoptosis. Survivin overexpression, by disrupting the balance between cell proliferation/differentiation and apoptosis, may play an important role in its pathophysiology. The detection of survivin-deregulated expression may provide a useful tool for diagnosis, prognosis and a possible target for experimental treatments.

Overcoming Fas-mediated apoptosis accelerates Helicobacter-induced gastric cancer in mice

The initiating molecular events in Helicobacter-induced gastric carcinogenesis are not known. Early in infection, Fas antigen-mediated apoptosis depletes parietal and chief cell populations, leading to architectural distortion. As infection progresses, metaplastic and dysplastic glands appear, which are resistant to Fas-mediated apoptosis. These abnormal lineages precede, and are thought to be the precursor lesions of, gastric cancer. Acquisition of an antiapoptotic phenotype before transformation of cells suggests that loss of Fas sensitivity may be an early required trait for gastric cancer. We reasoned that forced Fas-apoptosis resistance would result in earlier and more aggressive gastric cancer in our mouse model. Fas antigen-deficient (lpr) mice or C57BL/6 wild-type mice were irradiated and reconstituted with C57BL/6 marrow forming partial lpr/wt chimera or wt/wt control mice, extending the life span of the lpr and ensuring a competent immune response to Helicobacter felis infection. Infected lpr/wt mice developed gastric cancer as early as 7 months after infection (compared with 15 months in wt/wt mice). At 10 months (90%) and 15 months (100%), mice developed aggressive invasive lesions. This earlier onset and more aggressive histology strongly argues that Fas-apoptosis resistance is an early and important feature of gastric cancer formation.

Do Bcl-2 and survivin help distinguish benign from malignant B-cell lymphoid aggregates in bone marrow biopsies?

Bcl-2 and survivin are cellular proteins that are known to be inhibitors of apoptosis and are commonly found in malignant tissues, including lymphomas. In previous studies, it has been shown that staining for bcl-2 can help distinguish between benign and malignant lymphoid aggregates in bone marrow biopsies. To determine whether staining for survivin expression in lymphoid aggregates can aid investigators in making this clinically important distinction, we stained bone marrow biopsies from 10 patients with benign lymphoid aggregates, and 15 malignant ones derived from B cells (six mantle cell, four follicular cells, two diffuse large cell, two small lymphocytic cell, and one marginal zone lymphoma) with antibodies to CD3, CD20, bcl-2, and survivin by an indirect immunoperoxidase technique. Whereas staining for bcl-2 was significantly stronger in the malignant lymphoid aggregates (P=0.001), both the control and malignant cases were almost uniformly negative for survivin expression. Only three cases (two mantle cell and one small lymphocytic lymphoma) showed very faint expression of survivin. Although bcl-2 and survivin both act to inhibit apoptosis, their expressions do not parallel each other. Survivin is not significantly expressed in either benign or malignant bone marrow aggregates, and therefore measuring its expression does not help distinguish benign from malignant B-cell bone marrow lymphoid aggregates.

Survivin and Leukemia

Survivin is a unique member of the inhibitor-of-apoptosis family. Survivin plays a role in the proliferation and survival of normal hematopoietic cells. Survivin expression is aberrantly enhanced in most cancers and hematopoietic malignancies. Survivin is an attractive therapeutic target, and various approaches to targeting survivin have been tested in vitro and in vivo. We review here progress in survivin research.

Erythroid-induced commitment of K562 cells results in clusters of differentially expressed genes enriched for specific transcription regulatory elements

Understanding regulation of fetal and embryonic hemoglobin expression is critical, since their expression decreases clinical severity in sickle cell disease and beta-thalassemia. K562 cells, a human erythroleukemia cell line, can differentiate along erythroid or megakaryocytic lineages and serve as a model for regulation of fetal/embryonic globin expression. We used microarray expression profiling to characterize transcriptomes from K562 cells treated for various times with hemin, an inducer of erythroid commitment. Approximately 5,000 genes were expressed irrespective of treatment. Comparative expression analysis (CEA) identified 899 genes as differentially expressed; analysis by the self-organizing map (SOM) algorithm clustered 425 genes into 8 distinct expression patterns, 322 of which were shared by both analyses. Differential expression of a subset of genes was validated by real-time RT-PCR. Analysis of 5'-flanking regions from differentially expressed genes by PAINT v3.0 software showed enrichment in specific transcription regulatory elements (TREs), some localizing to different expression clusters. This finding suggests coordinate regulation of cluster members by specific TREs. Finally, our findings provide new insights into rate-limiting steps in the appearance of heme-containing hemoglobin tetramers in these cells.

HLA-B35-restricted immune responses against survivin in cancer patients

Two HLA-A2 restricted epitopes have recently been identified from the broadly expressed tumor antigen survivin, and several vaccination trials in cancer patients based on these survivin-derived peptides have been initiated. Consequently, there is a crucial need for the identification of survivin epitopes restricted to other HLA-molecules in order to extend the proportion of patients that can enter these ongoing clinical trials. In the present study, we characterized 2 survivin-derived epitopes, which are restricted to HLA-B35. Specific T-cell reactivity against these survivin-derived epitopes was found in the peripheral blood from patients with different B-cell malignancies and melanoma. Substitution of the C-terminal anchor residue of the survivin-derived peptides improved the recognition by tumor-infiltrating lymphocytes from melanoma patients. Furthermore, we demonstrated spontaneous cytotoxic T-cell responses to survivin in a primary melanoma lesion. The characterization of these epitopes allows more patients can be included in the ongoing peptide-based survivin vaccination trials against cancer.

Transcriptional expression of survivin and its splice variants in brain tumors in humans

OBJECT

Survivin, one of the apoptosis inhibitor proteins, has been detected in most cancers in humans. In addition, two splice variants (survivin-2B and survivin-deltaEx3) have been identified. The authors investigated the transcription levels of survivin messenger (m)RNA and its splice variants in nine tumor cell lines, including gliomas, and in 25 brain tumor samples, by performing quantitative reverse transcription-polymerase chain reaction. The correlation between transcript expression levels and pathological findings were also analyzed.

METHODS

Transcription levels were measured using primer pairs specific for survivin and either of its splice variants and were normalized to the glyceraldehyde 6-phosphate dehydrogenase. Among the tumor cell lines tested, glioblastoma cell lines showed the highest levels of survivin expression. Among brain tumor samples studied, survivin was preferentially expressed in malignant brain tumors and gliomas. The relative expression level of survivin-deltaEx3/survivin was significantly higher in malignant than in benign brain tumor samples. Expression patterns were dominant for survivin-deltaEx3 in malignant brain tumors and dominant for survivin-2B in benign ones. A significant linear correlation between survivin mRNA expression and MIB-1 labeling index was demonstrated in all brain tumor samples.

CONCLUSIONS

The authors' results indicate that quantifying the levels of survivin and its splice variants is useful for the prediction of the cell biological malignancy of gliomas, independent of their pathological features.

Cellular and molecular themes in apoptosis

Apoptosis, an active mechanism of cell death, is of central importance in many biological scenarios. Research in this area has the potential to contribute to our understanding of many diseases and raises several potential therapeutic opportunities. Given this potential and the speed with which our understanding of this field has advanced over recent years, it is timely to introduce the clinician to the background on which the clinical implications of this research will be built. This review begins with contrasting apoptosis with the other mechanism of cell death, necrosis, and then outlines the features by which apoptosis may be recognised. With a view to understanding the level at which this process may be involved in disease and therapeutics, it is important to be aware of the basic mechanistic features of the induction and execution of apoptosis. In this, surface molecules such as CD95 (Fas) and the cascade of intracellular enzymes involved at many levels in apoptosis, the caspases, are of central importance. In all this, the mitochondrion is crucial to the induction of apoptosis and the regulation of the whole process. In the last part of this review, we attempt to draw out the clinical relevance of all this information. It is clear that apoptosis has an important role in the pathophysiology of malignancy, particularly with respect to haematological cancers, but also other oncological diseases. Apoptosis is also very important in autoimmune disease and viral infection. Finally, it is clear that apoptosis may be manipulated therapeutically to the benefit of patients in various scenarios. This is clearly an exciting area for future development, but one which clearly depends on a thorough mechanistic understanding.

Survivin and aven: two distinct antiapoptotic signals in acute leukemias

BACKGROUND

Antiapoptotic signals are important in the development, progression and prognosis of malignant tumors. The aim of this study was to determine the two distinct antiapoptotic signals-survivin and aven-in acute leukemias and compare them with clinical and hematological findings and response to therapy. Real-time quantitative PCR was used and survivin and aven were detected at the messenger (m)RNA level.

PATIENTS AND METHODS

Sixty-five patients with acute leukemia [37 with acute myeloblastic leukemia (AML) and 28 with acute lymphoblastic leukemia (ALL)] were used as the study group and 10 healthy subjects were used as the control group.

RESULTS

Survivin was between 0.0 and 0.829 copy number/cell (median 0.0721, mean 0.5424301909 +/- 0.139799488589) and aven was between 0.0 and 0.853 copy number/cell (median 0.0124, mean 0.070335542 +/- 0.1524685709). We found an important association between survivin and aven (P = 0.000). Both survivin and aven were higher in the study group than in the controls (P = 0.001 and 0.035, respectively). When we compared survivin and aven with other clinical and hematological parameters, there was an important association between survivin and extramedullary involvement (P = 0.033), survivin and alkaline phosphatase (P = 0.06), white blood cell (WBC) count and lactate dehydrogenase (LDH) (P = 0.000), WBC count and uric acid (P = 0.074), hemoglobin level and LDH (P = 0.072), LDH and uric acid (P = 0.057), CD7 expression and survivin (P = 0.097), and CD34 expression and aven (P = 0.058). Response to therapy was evaluated according to the survivin and aven levels. Survivin level was lower in refractory patients as compared with complete responders (P = 0.085). Aven level was higher in patients with relapse as compared with non-relapse patients (P = 0.04). There was no important association between survivin or aven and performance status, lymphadenopathy or organomegaly.

CONCLUSIONS

Both survivin and aven are important antiapoptotic signals in acute leukemias, and the association between extramedullary involvement, CD7 expression and CD34 expression, which are important poor prognostic indicators in acute leukemias, suggests that survivin and/or aven may be novel prognostic indicators in acute leukemias. Further studies with a higher number of patients will be more informative.

Myeloproliferative disease in transgenic mice expressing P230 Bcr/Abl: longer disease latency, thrombocytosis, and mild leukocytosis

P230 Bcr/Abl has been associated with indolent myeloproliferative disease (MPD). We generated transgenic mice expressing P230Bcr/Abl driven by the promoter of the long terminal repeat of the murine stem cell virus of the MSCV neo P230 BCR/ABL vector. Two founder mice exhibited mild granulocytosis and marked thrombocytosis and developed MPD. The disease of one founder mouse, no. 13, progressed to extramedullary myeloblastic crisis in the liver at 12 months old. The other founder mouse, no. 22, was found to have chronic-phase MPD with large populations of megakaryocytes and granulocytes in an enlarged spleen. The transgenic progeny of no. 22 clearly exhibited MPD at 15 months old. These results showed that P230Bcr/Abl had leukemogenic properties and induced MPD. The phenotype of the MPD caused by P230Bcr/Abl was characterized by mild granulocytosis, a high platelet count, infiltration of megakaryocytes in some organs, and a longer disease latency compared with the MPD caused by P210Bcr/Abl.

A flow cytometric method to detect apoptosis-related protein expression in minimal residual disease in acute myeloid leukemia

Minimal residual disease (MRD) cells are thought to be responsible for the persistence and relapse of acute myeloid leukemia (AML). Flow cytometric MRD detection by the establishment of a leukemia-associated phenotype (LAP) at diagnosis can be used in 80% of AML patients, allowing detection and functional characterization of MRD in follow-up bone marrow. One of the mechanisms contributing to inefficient chemotherapy is apoptosis resistance. Measuring apoptosis parameters in MRD cells will help to unravel the importance of apoptosis resistance in AML. We therefore developed a four-color flow cytometry method that enables establishment of apoptosis-related protein expression such as Bcl-2, Bcl-x(L), Mcl-1 and Bax at diagnosis and in MRD. Firstly, validation of this assay using Western blot analysis in five leukemia cell lines showed a significant correlation (R=0.70: P<0.0001). Secondly, the influence of the permeabilization procedure on LAP expression was investigated in 38 AML samples at diagnosis and in 42 MRD samples. Quantification of the frequency of LAP+ cells with and without permeabilization showed no significant differences (diagnosis: P= 0.57, follow-up: P= 0.43). The flow cytometric protocol thus enables analysis of apoptosis-related proteins at different stages of the disease, which will lead to a better understanding of the role of apoptosis resistance in the emergence of MRD in AML.

High numbers of active caspase 3-positive Reed-Sternberg cells in pretreatment biopsy specimens of patients with Hodgkin disease predict favorable clinical outcome

In vitro studies suggest that resistance to the apoptosis-inducing effect of chemotherapy might explain poor responses to therapy in fatal instances of Hodgkin disease (HD). Execution of apoptosis depends on proper functioning of effector caspases, in particular caspase 3, which is activated on the induction of apoptosis through either the stress-induced pathway or the death receptor-mediated pathway. Thus, high levels of caspase 3 activation should reflect proper functioning of one or both identified apoptosis pathways, resulting in chemotherapy-sensitive neoplastic cells and thus a favorable clinical response to chemotherapy. We tested this hypothesis by quantifying active caspase 3-positive tumor cells in primary biopsy specimens of HD and compared these numbers to clinical outcomes. Using an immunohistochemical assay, activation of caspase 3 was detected in 0% to 13% of neoplastic cells. High numbers of active caspase 3-positive tumor cells (5% or more) correlated with excellent clinical prognosis; 0 of 22 patients with 5% or more active caspase 3-positive cells died compared with 11 of 41 patients with less than 5% positive cells (P =.007). Proper functioning of active caspase 3 was demonstrated by the detection of one of its cleaved substrates, PARP-1/p89, in similar percentages of neoplastic cells. High levels of active caspase 3-positive neoplastic cells were associated with the expression of p53 and its downstream effector molecule p21, suggesting proper functioning of the stress-induced apoptosis pathway. In conclusion, high numbers of active caspase 3-positive neoplastic cells predict a highly favorable clinical outcome in HD patients, supporting the notion that an (at least partially) intact apoptosis cascade is essential for the cell killing effect of chemotherapy.

Increased survivin transcript levels: an independent negative predictor of survival in soft tissue sarcoma patients

Survivin, a recently identified inhibitor of apoptosis protein (IAP), is expressed in diverse embryonic tissues and in various human cancers. We have investigated the quantitative expression of survivin mRNA by a sensitive TaqMan-based RT-PCR assay in tissue samples from 94 patients with soft tissue sarcomas (STS). Survivin transcript levels were measured and normalized to GAPDH transcripts. By using a multivariate Cox regression analysis, we found an inverse correlation between the level of survivin mRNA (ratio >2 zmol survivin/amol GAPDH) and the rate of overall survival (p = 0.009, RR = 2.7). Survivin transcript variants as detected by qualitative RT-PCR analysis were revealed in 36 of 56 STS patients (64%). Only survivin DeltaEx3 and/or full-length survivin variants but not survivin 2B were identified. Our results suggest that a higher level of survivin mRNA is an independent predictor of survival for STS patients.

Heightened expression of survivin in activated T lymphocytes from patients with multiple sclerosis

The perpetuation of the inflammatory process in multiple sclerosis (MS) may arise from the failure to eliminate potentially pathogenic autoreactive lymphocytes by programmed cell death (apoptosis). Such impairment may be caused by multiple abnormalities of apoptosis regulatory proteins. In this study, we investigated the expression of survivin, a recently described cell cycle-regulated antiapoptosis protein, in lymphocytes from patients with active relapsing-remitting MS and appropriate controls. Survivin reactivity was detected in intrathecal lymphocytes from some MS patients, but not in resting peripheral lymphocytes. However, mitogen stimulation of resting lymphocytes induced survivin expression, which was significantly higher in stimulated intrathecal and peripheral T lymphocytes from MS patients when compared to controls. In contrast, cellular expression of the antiapoptosis protein Bcl-2 was relatively similar between MS patients and the control groups. Moreover, heightened survivin expression in MS patients correlated with T lymphocyte resistance to apoptosis, and was independent of cellular expression of the death receptor Fas. These findings suggest that upregulation of the antiapoptotic protein survivin in mitogen-stimulated T lymphocytes is a feature of multiple sclerosis.