Continental variations in preoperative and postoperative management of patients with anterior cruciate ligament repair

AIM

Surgeon decision making for non-operative anterior cruciate ligament (ACL) treatment and postoperative rehabilitation is influenced by a myriad of factors. The aim of this study was to investigate intercontinental differences in surgeon decision making for care of the ACL deficient patient. The authors hypothesized that significant variation in clinical decision of ACL deficient patients existed among surgeons in different continents.

METHODS

This study involved a survey design, which met the checklist for reporting results of internet e-surveys (CHERRIES) guidelines. The survey was administered to orthopedic surgeons in 15 countries and involved standardized follow up and design. Questions related to non-operative care management and postoperative/rehabilitative management were provided to each respondent. Statistical analyses included multivariate comparisons among continents and regression findings for likelihood of targeting longer term non-operative treatment.

RESULTS

Over six hundred (634) surgeons completed the survey, representing six continents. Continental variations were found in non-operative surgical decision making and postoperative/rehabilitative management. Significant differences were noted in nearly all clinical decision making categories.

CONCLUSION

Variations do exist across continents in the non-operative and postoperative/rehabilitative management of patients with an ACL tear. Continental variations and disparate emphases such as activity level, age during injury, and bracing influenced treatment decision making, which could lead to variations in outcomes, costs, and appropriate care.

Is PAMPA a useful tool for discovery?

Experimental PAMPA data generated for 40 low molecular weight commercial drugs is reviewed in the context of its utility in the drug discovery process. Several experimental variables that have been introduced in the literature as additions or improvements to the PAMPA were also evaluated. The relationship between PAMPA data and both calculated and measured octanol/water distribution coefficients was examined. From this assessment, it was concluded that the PAMPA yields information about the lipophilicity as measured by the octanol/water partitioning of a compound, but that this same information could be derived in a simpler manner from calculated log D values.

Sepsis atypique à Bacillus cereus dans les fractures de jambe

OBJECTIVE

To investigate leg fractures infected with Bacillus cereus in a traumatology-orthopedic ward of a university hospital.

METHODS

All B. cereus strains isolated from patients with leg fracture hospitalized in the traumatology-orthopedic ward between 1995 and 2004 were included in this retrospective study.

RESULTS

Five hundred and four patients had leg fracture during this period. Thirty-four patients were included in this retrospective study. B. cereus strains clinical isolates were mainly isolated from patients who had initially leg fractures with telluric contamination (wound contamination with terrestrial environments) before admission. Betalactam antibiotics used for prophylactic chemotherapy were not effective against B. cereus.

CONCLUSION

In this study, we underscore the significance of Sfar recommendations concerning prophylactic chemotherapy. However, B. cereus could be termed an emerging pathogen and physicians need to be aware of its potential importance in trauma cases. In this purpose, a systematic screening for B. cereus at admission should be necessary in front of patients with open fractures associated with telluric contamination. Furthermore, if B. cereus is isolated, chemotherapy should be based upon ciprofloxacin during 2 or 6 weeks.

Co-chaperone potentiation of vitamin D receptor-mediated transactivation: a role for Bcl2-associated athanogene-1 as an intracellular-binding protein for 1,25-dihydroxyvitamin D3

The constitutively expressed member of the heat shock protein-70 family (hsc70) is a chaperone with multiple functions in cellular homeostasis. Previously, we demonstrated the ability of hsc70 to bind 25-hydroxyvitamin D3 (25-OHD3) and 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). Hsc70 also recruits and interacts with the co-chaperone Bcl2-associated athanogene (BAG)-1 via the ATP-binding domain that resides on hsc70. Competitive ligand-binding assays showed that, like hsc70, recombinant BAG-1 is able to bind 25-OHD3 (Kd=0.71+/-0.25 nM, Bmax 69.9+/-16.1 fmoles/microg protein) and 1,25(OH)2D3 (Kd=0.16+/-0.07 nM, Bmax = 38.1+/-3.5 fmoles/microg protein; both n=3 separate binding assays, P<0.001 for Kd and Bmax). To investigate the functional significance of this, we transiently overexpressed the S, M, and L variants of BAG-1 into human kidney HKC-8 cells stably transfected with a 1,25(OH)2D3-responsive 24-hydroxylase (CYP24) promoter-reporter construct. As HKC-8 cells also express the enzyme 1alpha-hydroxylase, both 25-OHD3 (200 nM) and 1,25(OH)2D3 (5 nM) were able to induce CYP24 promoter activity. This was further enhanced following overexpression of all the three BAG-1 isoforms. By contrast, BAG-1 isoforms had no effect on metabolism of 25-OHD3 by HKC-8 cells (either via 1alpha- or 24-hydroxylase activities). Further studies showed that a mutant form of BAG-1S exhibited decreased binding of 1,25(OH)2D3 and this resulted in a concomitant loss of potentiation of CYP24 promoter transactivation. Similar effects were not observed for 25-OHD3. These data highlight a novel role for BAG-1 as an intracellular-binding protein for 1,25(OH)2D3 and further suggest that BAG-1 is able to potentiate vitamin D receptor-mediated transactivation by acting as a nuclear chaperone for 1,25(OH)2D3.

Splice variants of the CYP27b1 gene and the regulation of 1,25-dihydroxyvitamin D3 production

The cytochrome P450 25-hydroxyvitamin D3-1alpha-hydroxylase (CYP27b1) plays a pivotal role in vitamin D physiology by catalyzing synthesis of active 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. In common with other P450s, CYP27b1 is known to exhibit alternative splicing. Here we have cloned and sequenced several novel intron 2-containing, noncoding splice variant mRNAs for CYP27b1 in 1,25(OH)2D3-producing HKC-8 human proximal tubule and THP-1 monocytic cells. Regulation of 1,25(OH)2D3 synthesis in these cell lines by calciotropic and noncalciotropic factors was associated with altered expression of the CYP27b1 splice variants. To assess the functional significance of this, HKC-8 cells were transfected with short hairpin RNA (shRNA) to inhibit mRNAs containing sequences from intron 2. This resulted in a significant increase in the expression of CYP27b1 protein and synthesis of 1,25(OH)2D3 by HKC-8 cells compared with control cells for two different intron 2-containing shRNAs (both P<0.001). shRNA to intron 2 had no significant effect on the levels of wild-type CYP27b1 mRNA, suggesting a posttranscriptional mechanism of action. By contrast, shRNA to wild-type CYP27b1 suppressed transcription and activity of the enzyme by 70 and 31%, respectively (both P<0.01). These data indicate that noncoding splice variants of CYP27b1 are functionally active and may play a significant role in the regulation of 1,25(OH)2D3 synthesis during normal physiology.

AMG 386, a selective angiopoietin 1/2-neutralizing peptibody, in combination with chemotherapy in adult patients with advanced solid tumors

14033

Introduction: AMG 386 is a selective angiopoietin 1 /2-neutralizing peptibody that inhibits angiogenesis by preventing interaction between angiopoietins and Tie2 receptors. This open-label study evaluated the safety, pharmacokinetics (PK), and antitumor activity of AMG 386 in combination with FOLFOX-4 (F), carboplatin + paclitaxel (CP), or docetaxel (D) in adult patients (pts) with advanced solid tumors. Methods: Three cohorts of 6–9 pts received 1 full cycle of chemotherapy (2 weeks of F or 3 weeks of D 75 mg/m2 or CP). Administration of AMG 386 10 mg/kg IV weekly was started on day 1 of cycle 2 for patients who did not experience a dose-limiting toxicity (DLT) to chemotherapy during cycle 1, and continued until disease progression or intolerance. Safety and tolerability, tumor response (RECIST every 8 weeks), PK profiles of AMG 386 and chemotherapy agents, and formation of antibodies to AMG 386 were assessed. Results: As of October 2, 2006, 16 pts have received AMG 386: 6 pts in the F cohort, 5 in CP, and 5 in D; 7 pts were men, median age 59.5 years (range, 44- 75 years). No AMG 386-related serious AEs or DLTs were reported. AEs related to chemotherapy + AMG 386 in = 2 pts were neutropenia (n = 3), thrombocytopenia (n=2), diarrhea (n=2), and vomiting (n=2). No neutralizing antibodies were observed. F, CP, and D coadministered with AMG 386 did not appear to affect the PK profile of AMG 386, and AMG 386 had no apparent effect on the PK profile of 5 FU, leucovorin, C, P, or D. Tumor response data are available for 6 pts. One pt receiving CP+ AMG 386 for bladder cancer refractory to gemcitabine/cisplatin had a complete response (CR) at week 8, confirmed at week 16. Stable disease in 4 pts and progressive disease in 1 pt were also observed. Conclusions: Weekly administration of AMG 386 in combination with F, CP, or D appears to be safe and well tolerated. A CR in bladder cancer suggests promising antitumor activity of AMG 386 in combination with chemotherapy. Further clinical studies of AMG 386 in combination with chemotherapy and other targeted agents are warranted.

[Table: see text]

First-in-human study of AMG 386, a selective angiopoietin1/2-neutralizing peptibody, in adult patients with advanced solid tumors

3522

Introduction: AMG 386 is a selective angiopoietin1/2-neutralizing peptibody that inhibits angiogenesis by preventing interaction of angiopoietins with Tie2 receptors. This first-in-human study evaluated the safety, pharmacokinetics (PK), and tumor response of AMG 386 in adults with advanced solid tumors. Methods: Patients (pts) in sequential cohorts received weekly IV AMG 386 at 0.3, 1, 3, 10, and 30 mg/kg. Safety assessments were adverse events (AEs), laboratory data, vital signs, ECGs, and anti-AMG 386 antibodies. Tumor response was assessed via RECIST criteria, DCE-MRI, FDG-PET, and volumetric CT. Results: As of Oct. 2, 2006, enrollment is complete with 32 pts (15 men, mean [SD] age 58 [12] years). One dose-limiting toxicity was seen at 30 mg/kg: respiratory arrest likely related to tumor burden, deemed possibly related to AMG 386. Other treatment-related toxicities were all = Grade 2; those observed in = 2 pts were fatigue (n=8), nausea (n=2), and peripheral edema (n=4). PK was dose-linear (mean terminal half-life, 3.1 to 6.3 days). AMG 386 appeared to reach a steady state after 3 doses, with minimal accumulation. Two pts developed binding antibodies to AMG 386; in 1 pt, they disappeared at wk 6. No neutralizing antibodies were seen. Sixteen pts had stable disease (4–52 wks, median 8 wks); 13 had progressive disease; 3 were not evaluable. One pt with ovarian cancer remains active at 52 weeks with 27% tumor shrinkage and investigator-reported reduction in serum CA-125 from 217 U/ml pretreatment to 73 U/ml (wk 4) and 31 U/ml (wk 48). A significant vascular effect (> 20% reduction) was seen by DCE-MRI in 7 of 12 (58%) evaluable subjects. Reduction in SUVmax (FDG-PET) accompanied reduction in IAUC (DCE-MRI) in 5 of 6 evaluable patients. Conclusions: Weekly administration of AMG 386 appeared to be generally well tolerated, with 1 AE > Grade 2 and no reports of the toxicities associated with VEGF blockade (hypertension, proteinuria, bleeding/clotting). Half of pts experienced stable disease; 1 has a sustained minor clinical response accompanied by a biologic response. Further clinical studies of AMG 386 in combination with chemotherapy and other targeted agents are warranted.

No significant financial relationships to disclose.

A phase I pharmacokinetic and pharmacodynamic study of AMG 479, a fully human monoclonal antibody against insulin-like growth factor type 1 receptor (IGF-1R), in advanced solid tumors

3002

Background: Increased IGF-1 signaling mediates tumor proliferation, reduces apoptosis, and correlates with higher incidence and progression of common cancers. AMG 479, a fully human monoclonal antibody against IGF-1R, exhibited broad antitumor activity in xenograft models, both as a monotherapy and with chemotherapy. Methods: Patients (pts) entered escalating dose cohorts of AMG 479 (from 1 to 20 mg/kg administered intravenously [IV] every two weeks [Q2W]). Study objectives were to determine safety, maximum tolerated dose (MTD), pharmacokinetic (PK) parameters, pharmacodynamic (PD) parameters of tumor glucose metabolism (FDG PET/CT), human anti- AMG 479 antibody formation, IGF-1R occupancy in neutrophils, and tumor response (CT RECIST, and PET/CT criteria). Results: Sixteen pts with advanced malignancies were treated with doses from 1 to 20 mg/kg. The median number of cycles was 3 (range 1 to 16). Grade 3 thrombocytopenia was considered dose limiting in 1 pt at 20 mg/kg. Other grade 3/4 non-hematologic toxicities were observed in 2 pts; no hyperglycemia greater than grade 2 was observed. Anti-AMG 479 antibodies, but not neutralizing antibodies, were detected in 1 pt. One pt had an infusion reaction (grade 2 chills/rigors resolving in 15 minutes) but could be retreated following premedication. AMG 479 exhibited dose-linear PK in the dose range from 1 to 20 mg/kg, reaching steady state after 3 doses; mean terminal t1/2 ranged from 7 to 11 days; mean serum clearance ranged from 9 to 14 mL/day/kg; Css exceeded IC90 measured in preclinical models. PD results indicated a trend to dose-proportional occupancy of IGF-1R in neutrophils and increased levels of serum IGF-1 and IGF-BP3 (40% and 20% on day 3, respectively). By CT RECIST criteria, 1 pt with a neuroendocrine tumor had a confirmed partial response and 5 pts had durable stable disease. By FDG-PET/CT criteria, 1 pt with breast cancer had a mixed response. Conclusions: AMG 479 appears to be well tolerated at doses up to 20 mg/kg IV Q2W; dose escalation is complete. AMG 479 administration resulted in PK values adequate for activity in preclinical models, saturable binding of IGF-1R in neutrophils, and preliminary anti-tumor activity.

[Table: see text]

Evaluation of oral versus intravenous dose of vinorelbine to achieve equivalent blood exposures in patients with solid tumours

Patient's preference is for oral chemotherapy when both oral and i.v. are available, provided that efficacy is equivalent. Reliable switch from oral to i.v. is possible if correspondence between respective doses has been established. Vinorelbine oral was developed as a line extension of VRL i.v. on the basis that similar AUCs result in similar activities. From a first crossover study on 24 patients receiving VRL 25 mg/m2 i.v. and 80 mg/m2 oral data extrapolation concluded on AUCs bioequivalence between Vinorelbine 30 mg/m2 i.v. and 80 mg/m2 oral. A new trial was performed to support this calculation. In a crossover design study on patients (PS 0-1) with advanced solid tumours (44% breast carcinoma), VRL was administered (30 mg/m2 i.v., 80 mg/m2 oral) with a standard meal and 5-HT3 antagonists, at 2 weeks interval. Pharmacokinetics was performed over 168 h and VRL was measured by LC-MS/MS. Statistics included bioequivalence tests. Forty-eight patients were evaluable for PK: median age 58 years (25-71), PS0/PS1: 20/28, M/F: 11/37. Mean AUCs were 1,230 +/- 290 and 1,216 +/- 521 ng/ml for i.v. and oral, respectively. The confidence interval of the AUC ratio (0.83-1.03) was within the required regulatory range (0.8-1.25) and proved the bioequivalence between the two doses. The absolute bioavailability was 37.8 +/- 16.0%, and close to the value from the first study (40%). Patient tolerability was globally comparable between both forms with no significant difference on either haematological or non-haematological toxicities (grade 3-4). This new study, conducted on a larger population, confirmed the reliable dose correspondence previously established between vinorelbine 80 mg/m2 oral and 30 mg/m2 i.v.

Prospective validation of a novel IV busulfan fixed dosing for paediatric patients to improve therapeutic AUC targeting without drug monitoring

INTRODUCTION

Oral busulfan clearance is age-dependent and children experience a wide variability in plasma exposure. BSA- or age-based dosing is used with therapeutic drug monitoring (TDM) to reduce this variability.

PURPOSE

A new intravenous (IV) dosing of busulfan (Bu) based on body weight, designed to improve AUC targeting without TDM and dose-adjustment, was prospectively evaluated.

METHOD

Bu was administered as a 2 h IV infusion every 6 h over 4 days (16 administrations). Five dose levels were defined on body weight as follows: 1.0 mg/kg for <9 kg; 1.2 mg/kg for 9 to <16 kg; 1.1 mg/kg for 16-23 kg; 0.95 mg/kg for >23-34 kg; 0.80 mg/kg for >34 kg. Bu treatment was followed by Cyclophosphamide or Melphalan prior to allogeneic or autologous transplantation in 55 children aged 0.3-17.2 years (median 5.6 years).

RESULTS

No difference in AUC values was observed between weight strata (mean +/- SD 1248 +/- 205 micromol.min), whereas a significant difference in Bu clearance was demonstrated. This new dosing enabled to achieve a mean exposure comparable to that in adults. At dose 1, 91% of patients achieved the targeted AUC range (900-1500 micromol.min) while no patients were underexposed. At doses 9 and 13, over 75% of patients remained within that target whilst most of the others were slightly above. Successful engraftment was achieved in all patients. In conclusion, from infants to adults this new dosing enabled, without TDM and dose adjustment, to successfully target a therapeutic AUC window.

[p27Kip1 independently promotes neuronal differentiation and migration in the cerebral cortex]

The generation of glutamatergic neurons by stem and progenitor cells is a complex process involving the tight coordination of multiple cellular activities, including cell cycle exit, initiation of neuronal differentiation and cell migration. The mechanisms that integrate these different events into a coherent program are not well understood. Here we show that the cyclin-dependent kinase inhibitor p27Kip1 plays an important role in neurogenesis in the mouse cerebral cortex, by promoting the differentiation and radial migration of cortical projection neurons. Importantly, p27Kip1 promotes neuronal differentiation and neuronal migration via two distinct mechanisms, which are themselves independent of the cell cycle regulatory function of p27Kip1. p27Kip1 inactivation by gene targeting or RNA interference results in neuronal differentiation and radial migration defects, demonstrating that p27Kip1 regulates cell migration in vivo. The differentiation defect, but not the migration defect, is rescued by overexpression of the proneural gene Neurogenin 2. p27Kip1 acts by stabilizing Neurogenin 2 protein, an activity carried by the N-terminal half of the protein. The migration defect resulting from p27Kp1 inactivation is rescued by blocking RhoA signalling, an activity that resides in the c-terminal half of p27Kip1. Thus, p27Kip1 plays a key role in cortical development, acting as a modular protein that independently regulates and couples multiple cellular pathways contributing to neurogenesis.

Reaching and treating Spanish-speaking smokers through the National Cancer Institute's cancer information service

Although the prevalence of smoking is lower among Hispanics than among the general population, smoking still levies a heavy public health burden on this underserved group. The current study, Adiós al Fumar (Goodbye to Smoking), was designed to increase the reach of the Spanish-language smoking cessation counseling service provided by the National Cancer Institute's Cancer Information Service (CIS) and to evaluate the efficacy of a culturally sensitive, proactive, behavioral treatment program among Spanish-speaking smokers. Adiós was a 2-group randomized clinical trial evaluating a telephone-based smoking cessation intervention. Spanish-speaking smokers (N = 297) were randomized to receive either standard counseling or enhanced counseling (EC). Paid media was used to increase the reach of the Spanish-language smoking cessation services offered by the CIS. The Adiós sample was of very low socioeconomic status (SES), and more than 90% were immigrants. Calls to the CIS requesting smoking cessation help in Spanish increased from 0.39 calls to 17.8 calls per month. The unadjusted effect of EC only approached significance (OR = 2.4, P = .077), but became significant after controlling for demographic and tobacco-related variables (OR = 3.8, P = .048). Adiós al Fumar demonstrated that it is possible to reach, retain, and deliver an adequate dose of treatment to a very low SES population that has traditionally been viewed as difficult to reach and hard to follow. Moreover, the findings suggest that a proactive, telephone-counseling program, based on the Treating Tobacco Use and Dependence Clinical Practice Guideline and adapted to be culturally appropriate for Hispanics, is effective. Cancer 2007. (c) 2006 American Cancer Society.

[Organization of urgent blood transfusion in France: analysis of practice patterns in centers involved in care delivery to multiple trauma patients]

OBJECTIVE

To describe the organization of medical and transfusion services within the framework of hospital admission for multiple trauma.

STUDY DESIGN

National survey in France.

MATERIAL AND METHODS

All French hospitals caring for multiple trauma patients were sent a questionnaire. Organization of the medical and transfusion services, and their related resources were evaluated.

RESULTS

Among 372 questionnaires sent, 116 replies were received from structures which care for 18 (1-500) multiple trauma patients each year. An orthopaedic and an abdominal surgery unit were widely available whereas a neurosurgeon was available in 21% of responding centers. A transfusion site was found in 43%, whereas others have either a deposit for distribution to specific patients (40%) or a small deposit to cover urgent situations (17%). Comparison with legal or expert based rules of adequate transfusion process disclosed a variable incidence of practice dysfunctions (2-49%) depending on the parameter assessed.

CONCLUSION

The French organization of multiple trauma patients' care and blood transfusion delivered for these patients is not homogenous. Dysfunctions were found in all types of hospitals. Recommendations describing good practice seem necessary to be built at the national level.

Gene expression analytics identify tissue of origin of unspecified metastatic cancers

20082

Background: Identification of the tissue of origin for unspecified metastatic cancers is associated with improved outcomes. To aid in determining the origin of these cancers, we designed a semi-quantitative test that uses proprietary analytics and a companion genomic microarray to compare the expression signature of a biopsy specimen with those of the following types of cancers: bladder, breast, colorectal, gastroesophageal, germ line, hepatocellular, kidney, lung, lymphoma, melanoma, ovarian, pancreatic, prostate, soft tissue-sarcoma, and thyroid. More than 5,500 human specimens processed on Affymetrix HG U133A microarrays were analyzed to determine the test’s standardization algorithm. Methods: Studies across nine different laboratories were conducted to demonstrate the reproducibility required to support the potential clinical application of the test. Biopsy specimens of 604 metastatic cancers of known origin (by conventional pathological testing) were used to “train” the algorithm. An additional 636 samples then were tested. Diagnostic odds ratio (OR), sensitivity, specificity, positive likelihood ratio (LR+), and negative likelihood ratio (LR−) were determined for individual all-against-one tests. Results: Robust standardization, which involves 121 “house-keeping genes”, enabled the tissue of origin test to demonstrate reproducibility across nine different laboratories. Identification of the correct tissue of origin was associated with OR values ranging from 23 to >500, with averages for sensitivity of 83%, specificity of 99%, LR+ of 210, and LR− of 0.17. Conclusions: The PathWork Oncology Suite: Tissue of Origin (POS:TOO) test uses methods that are reproducible across laboratories. By analyzing microarray data with the POS:TOO algorithm, the test can identify the origin of metastatic tumors. Preparations for clinical validation studies are in progress and results will be submitted to FDA for clearance.

[Table: see text]

Aberrant promoter methylation and silencing of the POU2F3 gene in cervical cancer

POU2F3 (OCT11, Skn-1a) is a keratinocyte-specific POU transcription factor whose expression is tied to squamous epithelial stratification. It is also a candidate tumor suppressor gene in cervical cancer (CC) because it lies in a critical loss of heterozygosity region on 11q23.3 in that cancer, and its expression is lost in more than 50% of CC tumors and cell lines. We now report that the loss of POU2F3 expression is tied to the hypermethylation of CpG islands in the POU2F3 promoter. Bisulfite sequencing analysis revealed that methylation of specific CpG sites (-287 to -70 bp) correlated with POU2F3 expression, which could be reactivated with a demethylating agent. Combined bisulfite restriction analysis revealed aberrant methylation of the POU2F3 promoter in 18 of 46 (39%) cervical tumors but never in normal epithelium. POU2F3 expression was downregulated and inversely correlated with promoter hypermethylation in 10 out of 11 CC cell lines. Immunohistochemical analysis on a cervical tissue microarray detected POU2F3 protein in the epithelium above the basal layer. As the disease progressed, expression also decreased, especially in invasive squamous cell cancer (70% loss). Thus, aberrant DNA methylation of the CpG island in POU2F3 promoter appears to play a key role in silencing this gene expression in human CC. The results suggested that POU2F3 might be one of the CC-related tumor suppressor genes, which are disrupted by both epigenetic and genetic mechanisms.

Herpes simplex virus type-1 amplicon vectors for vaccine generation in acute lymphoblastic leukemia

For leukemia vaccine generation, high-efficiency gene transfer is required to express immunomodulatory molecules that stimulate potent antileukemic immune responses. In this context, herpes simplex virus type-1 (HSV-1)-derived vectors have proven to be a promising tool for genetic modification of lymphoblastic leukemia cells. Yet, vector-associated viral protein expression might inadvertently modulate vaccine efficacy facilitating both immune evasion and immune stimulation. To explore the issue of immune-stimulation versus immune-suppression in immature lymphoblastic leukemia cells, two types of HSV-1 amplicon vectors, helper virus-dependent and helper virus-free that express the immunomodulatory molecules CD70 and IL-2, were compared with regard to their vector-associated immunomodulatory potential. We first established that lymphoblastic cell lines and primary acute lymphoblastic leukemia (ALL) cells express HSV receptor genes. Lymphoblastic cell lines were transduced with high efficiency, and in primary ALL cells high gene transfer rates of 47+/-15 and 42+/-14% were obtained with helper virus-dependent and -free HSV-1 amplicon vectors, respectively. The efficacy of the two amplicon vectors to induce antineoplastic responses was assessed in a vaccine setting in mice with pre-existing highly malignant lymphoblastic disease. Treatment of mice with vaccine cells transgenically expressing CD70+IL2 significantly suppressed lymphoblastic cell proliferation and improved survival. Of note, when helper virus-dependent HSV-1 amplicon vectors were used for vaccine preparation, the high immunogenic potential of the vector itself, in the absence of transgenic CD70+IL2 expression, seemed to be sufficient to mediate protection comparable to the antineoplastic response achieved by expression of immunomodulatory molecules. Thus for vaccine generation in B lymphoblastic leukemia, the immunogenic potential of HSV-1 helper virus-dependent amplicon vectors does provide additional benefit to the high transduction efficiency of HSV-1-derived vectors.