RNA Activation-A Novel Approach to Therapeutically Upregulate Gene Transcription.

RNA activation (RNAa) is a mechanism whereby RNA oligos complementary to genomic sequences around the promoter region of genes increase the transcription output of their target gene. Small activating RNA (saRNA) mediate RNAa through interaction with protein co-factors to facilitate RNA polymerase II activity and nucleosome remodeling. As saRNA are small, versatile and safe, they represent a new class of therapeutics that can rescue the downregulation of critical genes in disease settings. This review highlights our current understanding of saRNA biology and describes various examples of how saRNA are successfully used to treat various oncological, neurological and monogenic diseases. MTL-CEBPA, a first-in-class compound that reverses CEBPA downregulation in oncogenic processes using CEBPA-51 saRNA has entered clinical trial for the treatment of hepatocellular carcinoma (HCC). Preclinical models demonstrate that MTL-CEBPA reverses the immunosuppressive effects of myeloid cells and allows for the synergistic enhancement of other anticancer drugs. Encouraging results led to the initiation of a clinical trial combining MTL-CEBPA with a PD-1 inhibitor for treatment of solid tumors.

Anti-inflammatory Activity of MTL-CEBPA, a Small Activating RNA Drug, in LPS-Stimulated Monocytes and Humanized Mice.

Excessive or inappropriate inflammatory responses can cause serious and even fatal diseases. The CCAAT/enhancer-binding protein alpha (CEBPA) gene encodes C/EBPα, a transcription factor that plays a fundamental role in controlling maturation of the myeloid lineage and is also expressed during the late phase of inflammatory responses when signs of inflammation are decreasing. MTL-CEBPA, a small activating RNA targeting for upregulation of C/EBPα, is currently being evaluated in a phase 1b trial for treatment of hepatocellular carcinoma. After dosing, subjects had reduced levels of pro-inflammatory cytokines, and we therefore hypothesized that MTL-CEBPA has anti-inflammatory potential. The current study was conducted to determine the effects of C/EBPα saRNA - CEBPA-51 - on inflammation in vitro and in vivo after endotoxin challenge. CEBPA-51 led to increased expression of the C/EBPα gene and inhibition of pro-inflammatory cytokines in THP-1 monocytes previously stimulated by E. coli-derived lipopolysaccharide (LPS). Treatment with MTL-CEBPA in an LPS-challenged humanized mouse model upregulated C/EBPα mRNA, increased neutrophils, and attenuated production of several key pro-inflammatory cytokines, including TNF-α, IL-6, IL-1ß, and IFN-γ. In addition, a Luminex analysis of mouse serum revealed that MTL-CEBPA reduced pro-inflammatory cytokines and increased the anti-inflammatory cytokine IL-10. Collectively, the data support further investigation of MTL-CEBPA in acute and chronic inflammatory diseases where this mechanism has pathogenic importance.

Development and Mechanism of Small Activating RNA Targeting CEBPA, a Novel Therapeutic in Clinical Trials for Liver Cancer.

Small activating RNAs (saRNAs) are short double-stranded oligonucleotides that selectively increase gene transcription. Here, we describe the development of an saRNA that upregulates the transcription factor CCATT/enhancer binding protein alpha (CEBPA), investigate its mode of action, and describe its development into a clinical candidate. A bioinformatically directed nucleotide walk around the CEBPA gene identified an saRNA sequence that upregulates CEBPA mRNA 2.5-fold in human hepatocellular carcinoma cells. A nuclear run-on assay confirmed that this upregulation is a transcriptionally driven process. Mechanistic experiments demonstrate that Argonaute-2 (Ago2) is required for saRNA activity, with the guide strand of the saRNA shown to be associated with Ago2 and localized at the CEBPA genomic locus using RNA chromatin immunoprecipitation (ChIP) assays. The data support a sequence-specific on-target saRNA activity that leads to enhanced CEBPA mRNA transcription. Chemical modifications were introduced in the saRNA duplex to prevent activation of the innate immunity. This modified saRNA retains activation of CEBPA mRNA and downstream targets and inhibits growth of liver cancer cell lines in vitro. This novel drug has been encapsulated in a liposomal formulation for liver delivery, is currently in a phase I clinical trial for patients with liver cancer, and represents the first human study of an saRNA therapeutic.

Treatment of Liver Cancer by C/EBPA saRNA.

The prognosis for hepatocellular carcinoma (HCC) remains poor and has not improved in over two decades. Most patients with advanced HCC who are not eligible for surgery have limited treatment options due to poor liver function or large, unresectable tumors. Although sorafenib is the standard-of-care treatment for these patients, only a small number respond. For the remaining, the outlook remains bleak. A better approach to target "undruggable" molecular pathways that reverse HCC is therefore urgently needed. Small activating RNAs (saRNAs) may provide a novel strategy to activate expression of genes that become dysregulated in chronic disease. The transcription factor CCAAT/enhancer-binding protein alpha (C/EBPα), a critical regulator of hepatocyte function, is suppressed in many advanced liver diseases. By using an saRNA to activate C/EBPα, we can exploit the cell's own transcription machinery to enhance gene expression without relying on exogenous vectors that have been the backbone of gene therapy. saRNAs do not integrate into the host genome and can be modified to avoid immune stimulation. In preclinical models of liver disease, treatment with C/EBPα saRNA has shown reduction in tumor volume and improvement in serum markers of essential liver function such as albumin, bilirubin, aspartate aminotransferase (AST), and alanine transaminase (ALT). This saRNA that activates C/EBPα for advanced HCC is the first saRNA therapy to have entered a human clinical trial. The hope is that this new tool will help break the dismal 20-year trend and provide a more positive prognosis for patients with severe liver disease.

Integrated molecular analysis to investigate the role of microRNAs in pancreatic tumour growth and progression.

BACKGROUND: MicroRNAs (miRNAs) are small non-coding RNAs involved in the post-transcriptional regulation of mRNAs and are aberrantly expressed in cancer with important roles in tumorigenesis. A broad analysis of the combined effects of altered activities of miRNAs in pancreatic ductal adenocarcinoma (PDAC) has not been done, and how miRNAs might affect tumour progression or patient outcomes is unclear. METHODS: We combined data from miRNA and mRNA expression profiles from PDAC and normal pancreas samples (each n=9) and used bioinformatic analyses to identify a miRNA-mRNA regulatory network in PDAC. We validated our findings in PDAC cell-lines (PANC-1, MIA PaCa-2, LPc006, and LPc167), subcutaneous PDAC xenografts in mice, and laser capture microdissected PDACs from patients (n=91). We used this information to identify miRNAs that contributed most to tumorigenesis. FINDINGS: We identified three miRNAs (miR-21, miR-23a, and miR-27a) that acted as cooperative repressors of a network of tumour suppressor genes that included PDCD4, BTG2, and NEDD4L. Inhibition of miR-21, miR-23a, and miR-27a had synergistic effects in reducing proliferation of PDAC cells in culture and the growth of xenograft tumours. The level of inhibition was greater than that of silencing oncomiR-21 alone. In PDACs from patients, high levels of the combination of miR-21, miR-23a, and miR-27a was a strong independent predictor of short overall survival after surgical resection (hazard ratio 3·21, 95% CI 1·78-5·78). High expression of this combination was also associated with a more aggressive tumour phenotype: more microscopic tumour infiltration at resection margin and increased perineural invasion. INTERPRETATION: In an integrated data analysis, we identified functional miRNA-mRNA interactions that contribute to PDAC growth. These findings indicate that miRNAs act together to promote tumour progression and that future therapeutic strategies might require inhibition of several miRNAs. Furthermore, high tumour expression of the miR-21, miR-23a, and miR-27a combination could have potential use in the future as a prognostic signature for patients with PDAC. FUNDING: Peel Medical Research Trust, Alliance Family Foundation, Action Against Cancer, National Institute for Health Research, Association for International Cancer Research, Jason Boas Fellowship, Imperial Biomedical Research Centre, Rosetrees Trust, Joseph Ettedgui Charitable Foundation.

Oncological Outcomes of Major Liver Resection Following Portal Vein Embolization: A Systematic Review and Meta-analysis.

BACKGROUND: Preoperative portal vein occlusion with either percutaneous portal vein embolization (PVE) or portal vein ligation is routinely used to induce liver hypertrophy prior to major liver resection in patients with hepatic malignancy. While this increases the future liver remnant, and hence the number of patients suitable for resection, recent evidence suggests that induction of liver hypertrophy preoperatively may promote tumor growth and increase recurrence rates. The aims of this current study were to evaluate the impact of PVE on hepatic recurrence rate and survival in patients with colorectal liver metastases (CRLM). METHODS: The MEDLINE, EMBASE and Web of Science databases were searched to identify studies assessing the oncological outcomes of patients undergoing major liver resection for CRLM following PVE. Studies comparing patients undergoing one-stage liver resection with or without preoperative PVE were included. The primary outcome was postoperative hepatic recurrence (PHR), while secondary outcomes were 3- and 5-year overall survival (OS). RESULTS: Of the 2131 studies identified, six non-randomized studies (n = 668) met the eligibility criteria, comparing outcomes of patients undergoing major liver resection with or without PVE (n = 182 and n = 486, respectively). No significant difference was observed in PHR (odds ratio [OR] 0.78; 95 % confidence interval [CI] 0.42-1.44), 3-year OS (OR 0.80; 95 % CI 0.56-1.14) or 5-year OS (OR 1.12; 95 % CI 0.40-3.11). CONCLUSIONS: PVE does not have any adverse effect on PHR or OS in patients undergoing major liver resection for CRLM. Further studies based on individual patient data are needed to provide definitive answers.

MicroRNAs cooperatively inhibit a network of tumor suppressor genes to promote pancreatic tumor growth and progression.

BACKGROUND & AIMS: There has not been a broad analysis of the combined effects of altered activities of microRNAs (miRNAs) in pancreatic ductal adenocarcinoma (PDAC) cells, and it is unclear how these might affect tumor progression or patient outcomes. METHODS: We combined data from miRNA and messenger RNA (mRNA) expression profiles and bioinformatic analyses to identify an miRNA-mRNA regulatory network in PDAC cell lines (PANC-1 and MIA PaCa-2) and in PDAC samples from patients. We used this information to identify miRNAs that contribute most to tumorigenesis. RESULTS: We identified 3 miRNAs (MIR21, MIR23A, and MIR27A) that acted as cooperative repressors of a network of tumor suppressor genes that included PDCD4, BTG2, and NEDD4L. Inhibition of MIR21, MIR23A, and MIR27A had synergistic effects in reducing proliferation of PDAC cells in culture and growth of xenograft tumors in mice. The level of inhibition was greater than that of inhibition of MIR21 alone. In 91 PDAC samples from patients, high levels of a combination of MIR21, MIR23A, and MIR27A were associated with shorter survival times after surgical resection. CONCLUSIONS: In an integrated data analysis, we identified functional miRNA-mRNA interactions that contribute to growth of PDACs. These findings indicate that miRNAs act together to promote tumor progression; therapeutic strategies might require inhibition of several miRNAs.

Novel RNA oligonucleotide improves liver function and inhibits liver carcinogenesis in vivo.

UNLABELLED: Hepatocellular carcinoma (HCC) occurs predominantly in patients with liver cirrhosis. Here we show an innovative RNA-based targeted approach to enhance endogenous albumin production while reducing liver tumor burden. We designed short-activating RNAs (saRNA) to enhance expression of C/EBPα (CCAAT/enhancer-binding protein-α), a transcriptional regulator and activator of albumin gene expression. Increased levels of both C/EBPα and albumin mRNA in addition to a 3-fold increase in albumin secretion and 50% decrease in cell proliferation was observed in C/EBPα-saRNA transfected HepG2 cells. Intravenous injection of C/EBPα-saRNA in a cirrhotic rat model with multifocal liver tumors increased circulating serum albumin by over 30%, showing evidence of improved liver function. Tumor burden decreased by 80% (P = 0.003) with a 40% reduction in a marker of preneoplastic transformation. Since C/EBPα has known antiproliferative activities by way of retinoblastoma, p21, and cyclins, we used messenger RNA (mRNA) expression liver cancer-specific microarray in C/EBPα-saRNA-transfected HepG2 cells to confirm down-regulation of genes strongly enriched for negative regulation of apoptosis, angiogenesis, and metastasis. Up-regulated genes were enriched for tumor suppressors and positive regulators of cell differentiation. A quantitative polymerase chain reaction (PCR) and western blot analysis of C/EBPα-saRNA-transfected cells suggested that in addition to the known antiproliferative targets of C/EBPα, we also observed suppression of interleukin (IL)6R, c-Myc, and reduced STAT3 phosphorylation. CONCLUSION: A novel injectable saRNA-oligonucleotide that enhances C/EBPα expression successfully reduces tumor burden and simultaneously improves liver function in a clinically relevant liver cirrhosis/HCC model.

Exploiting human CD34+ stem cell-conditioned medium for tissue repair.

Despite the progress in our understanding of genes essential for stem cell regulation and development, little is known about the factors secreted by stem cells and their effect on tissue regeneration. In particular, the factors secreted by human CD34+ cells remain to be elucidated. We have approached this challenge by performing a cytokine/growth factor microarray analysis of secreted soluble factors in medium conditioned by adherent human CD34+ cells. Thirty-two abundantly secreted factors have been identified, all of which are associated with cell proliferation, survival, tissue repair, and wound healing. The cultured CD34+ cells expressed known stem cell genes such as Nanog, Oct4, Sox2, c-kit, and HoxB4. The conditioned medium containing the secreted factors prevented cell death in liver cells exposed to liver toxin in vitro via inhibition of the caspase-3 signaling pathway. More importantly, in vivo studies using animal models of liver damage demonstrated that injection of the conditioned medium could repair damaged liver tissue (significant reduction in the necroinflammatory activity), as well as enable the animals to survive. Thus, we demonstrate that medium conditioned by human CD34+ cells has the potential for therapeutic repair of damaged tissue in vivo.

Cell-free DNA for the detection of pancreatic, liver and upper gastrointestinal cancers: has progress been made?

Detecting alterations in blood cell-free DNA (cfDNA) is hoped to be a novel, noninvasive method for diagnosing, prognosing and monitoring cancer patients. Several studies have assessed the usefulness of measuring tumor-specific genetic and epigenetic changes of cfDNA, such as loss of heterozygosity, frequency of mutations, alterations of microsatellites and the methylation of genes in patient blood samples. However, few well-designed trials have been carried out to translate these findings effectively. In this review, we have assessed the clinical utility of cfDNA in pancreatic, liver and upper gastrointestinal malignancies.

Reactive lymphoid hyperplasia of the pancreas: a clinical conundrum.

CONTEXT: Localized reactive lymphoid hyperplasia is a rare condition characterized by the presence of lymphoid follicles. CASE REPORT: We describe a case of a 60-year-old woman who presented with right upper quadrant pain and was found to have a reactive nodular hyperplasia of the pancreas involving the uncinate process, body and tail of the gland. Due to the multifocal distribution of these hypoechoic vascular lesions, a total pancreatectomy was performed since malignancy could not be safely excluded. CONCLUSION: There have been a handful of cases reporting reactive lymphoid hyperplasia affecting the pancreas; however, it is uncommon to perform such a radical pancreatic resection for this benign condition.

Enhancing SIRT1 Gene Expression Using Small Activating RNAs: A Novel Approach for Reversing Metabolic Syndrome.

Metabolic syndrome (MetS) is a pathological condition characterized by abdominal obesity, insulin resistance, hypertension, and hyperlipidemia. Sirtuin 1 (SIRT1), a highly conserved histone deacetylase, is characterized as a key metabolic regulator and protector against aging-associated pathologies, including MetS. In this study, we investigate the therapeutic potential of activating SIRT1 using small activating RNAs (saRNA), thereby reducing inflammatory-like responses and re-establishing normal lipid metabolism. SIRT1 saRNA significantly increased SIRT1 messenger RNA (mRNA) and protein levels in both lipopolysaccharide-stimulated and nonstimulated macrophages. SIRT1 saRNA significantly decreased inflammatory-like responses, by reducing mRNA levels of key inflammatory cytokines, such as Tumor Necrosis Factor alpha, Interleukin 1 beta (IL-1ß), Interleukin 6 (IL-6), and chemokines Monocyte Chemoattractant Protein-1 and keratinocyte chemoattractant. SIRT1 overexpression also significantly reduced phosphorylation of nuclear factor-κB and c-Jun N-terminal kinase, both key signaling molecules for the inflammatory pathway. To investigate the therapeutic effect of SIRT1 upregulation, we treated a high-fat diet model with SIRT1 saRNA conjugated to a transferrin receptor aptamer for delivery to the liver and cellular internalization. Animals in the SIRT1 saRNA treatment arm demonstrated significantly decreased weight gain with a significant reduction in white adipose tissue, triglycerides, fasting glucose levels, and intracellular lipid accumulation. These suggest treatment-induced changes to lipid and glucose metabolism in the animals. The results of this study demonstrate that targeted activation of SIRT1 by saRNAs is a potential strategy to reverse MetS.

Two-stage resection for bilobar colorectal liver metastases: R0 resection is the key.

BACKGROUND: Two-stage liver resection (2-SLR) is used clinically in conjunction with portal vein embolization for bilobar disease to increase the number of patients suitable for liver resection. The long-term outcomes after 2-SLR for multiple bilobar colorectal liver metastases (CLM) was examined. METHODS: Patients who sought care between November 2003 and April 2006 with multiple CLM considered suitable for 2-SLR were prospectively followed. Clinicopathological data were collected. Surgical outcomes were defined as complete clearance of tumor (R0/R1/R2), postoperative morbidity (within 3 months), 30 day mortality, disease-free survival (DFS), and overall survival (OS). RESULTS: A total of 131 patients with CLM underwent liver resection during the study period, 38 of whom were planned for a 2-SLR for multiple bilobar disease. Only 33 (87%) completed the 2-SLR with a curative intent. Five patients did not undergo stage II resection because of disease progression. The postoperative morbidity was 11 and 33% after stage I and stage II liver resections, respectively. Five patients (13%) encountered postoperative complications specific to liver surgery. The median interval from stage II resection to disease recurrence in the R0 group was 18 months versus 3 months in the R1/R2 group (P < 0.001). R0 resection with curative intent versus R1/R2 noncurative resection has a significantly longer period of DFS (P < 0.001) and OS (P = 0.04). CONCLUSIONS: The 2-SLR combined with portal vein embolization is an effective and safe method for resecting previously unresectable multiple bilobar CLM. However, a positive resection margin leads to poor DFS and OS.

Upregulation of C/EBPα Inhibits Suppressive Activity of Myeloid Cells and Potentiates Antitumor Response in Mice and Patients with Cancer.

PURPOSE: To evaluate the mechanisms of how therapeutic upregulation of the transcription factor, CCAAT/enhancer-binding protein alpha (C/EBPα), prevents tumor progression in patients with advanced hepatocellular carcinoma (HCC) and in different mouse tumor models. EXPERIMENTAL DESIGN: We conducted a phase I trial in 36 patients with HCC (NCT02716012) who received sorafenib as part of their standard care, and were given therapeutic C/EBPα small activating RNA (saRNA; MTL-CEBPA) as either neoadjuvant or adjuvant treatment. In the preclinical setting, the effects of MTL-CEBPA were assessed in several mouse models, including BNL-1ME liver cancer, Lewis lung carcinoma (LLC), and colon adenocarcinoma (MC38). RESULTS: MTL-CEBPA treatment caused radiologic regression of tumors in 26.7% of HCC patients with an underlying viral etiology with 3 complete responders. MTL-CEBPA treatment in those patients caused a marked decrease in peripheral blood monocytic myeloid-derived suppressor cell (M-MDSC) numbers and an overall reduction in the numbers of protumoral M2 tumor-associated macrophages (TAM). Gene and protein analysis of patient leukocytes following treatment showed CEBPA activation affected regulation of factors involved in immune-suppressive activity. To corroborate this observation, treatment of all the mouse tumor models with MTL-CEBPA led to a reversal in the suppressive activity of M-MDSCs and TAMs, but not polymorphonuclear MDSCs (PMN-MDSC). The antitumor effects of MTL-CEBPA in these tumor models showed dependency on T cells. This was accentuated when MTL-CEBPA was combined with checkpoint inhibitors or with PMN-MDSC-targeted immunotherapy. CONCLUSIONS: This report demonstrates that therapeutic upregulation of the transcription factor C/EBPα causes inactivation of immune-suppressive myeloid cells with potent antitumor responses across different tumor models and in cancer patients. MTL-CEBPA is currently being investigated in combination with pembrolizumab in a phase I/Ib multicenter clinical study (NCT04105335).

Impact of portal vein embolization on expression of cancer stem cell markers in regenerated liver and colorectal liver metastases.

OBJECTIVE: Little is known about the expression of stem cell markers in normal liver and colorectal liver metastases (CLM). The aim of this paper is to assess whether patterns of stem cell marker expression differ between normal liver tissue and CLM and to determine whether a clinical model of liver regeneration induced by portal vein embolization (PVE) has any influence on these patterns of expression in both regenerated liver tissue and cancer. MATERIALS AND METHODS: Immunohistochemistry was used to provide semi-quantitative analysis of patterns of expression in tissue samples of liver and tumor tissue pre- and post-PVE in 23 patients with CLM. CD133, CD44 and Oct4 were studied. RESULTS: There was no expression of CD133, CD44 or Oct4 in normal liver tissue before PVE but there was high expression of CD133 and CD44 in CLM. PVE had no significant influence on stem cell marker expression either in regenerated liver tissue or in tumor when compared with pre-PVE samples. CONCLUSION: Liver regeneration following PVE does not seem to involve stem cells. Stem cell marker expression by CLM supports the stem cell theory of carcinogenesis which is not influenced by PVE.

Liver Activation of Hepatocellular Nuclear Factor-4α by Small Activating RNA Rescues Dyslipidemia and Improves Metabolic Profile.

Non-alcoholic fatty liver disease (NAFLD) culminates in insulin resistance and metabolic syndrome. Because there are no approved pharmacological treatment agents for non-alcoholic steatohepatitis (NASH) and NAFLD, different signaling pathways are under investigation for drug development with the focus on metabolic pathways. Hepatocyte nuclear factor 4-alpha (HNF4A) is at the center of a complex transcriptional network where its disruption is directly linked to glucose and lipid metabolism. Resetting HNF4A expression in NAFLD is therefore crucial for re-establishing normal liver function. Here, small activating RNA (saRNA) specific for upregulating HNF4A was injected into rats fed a high-fat diet for 16 weeks. Intravenous delivery was carried out using 5-(G5)-triethanolamine-core polyamidoamine (PAMAM) dendrimers. We observed a significant reduction in liver triglyceride, increased high-density lipoprotein/low-density lipoprotein (HDL/LDL) ratio, and decreased white adipose tissue/body weight ratio, all parameters to suggest that HNF4A-saRNA treatment induced a favorable metabolic profile. Proteomic analysis showed significant regulation of genes involved in sphingolipid metabolism, fatty acid ß-oxidation, ketogenesis, detoxification of reactive oxygen species, and lipid transport. We demonstrate that HNF4A activation by oligonucleotide therapy may represent a novel single agent for the treatment of NAFLD and insulin resistance.

Generation in vivo of peptide-specific cytotoxic T cells and presence of regulatory T cells during vaccination with hTERT (class I and II) peptide-pulsed DCs.

BACKGROUND: Optimal techniques for DC generation for immunotherapy in cancer are yet to be established. Study aims were to evaluate: (i) DC activation/maturation milieu (TNF-alpha +/- IFN-alpha) and its effects on CD8+ hTERT-specific T cell responses to class I epitopes (p540 or p865), (ii) CD8+ hTERT-specific T cell responses elicited by vaccination with class I alone or both class I and II epitope (p766 and p672)-pulsed DCs, prepared without IFN-alpha, (iii) association between circulating T regulatory cells (Tregs) and clinical responses. METHODS: Autologous DCs were generated from 10 patients (HLA-0201) with advanced cancer by culturing CD14+ blood monocytes in the presence of GM-CSF and IL-4 supplemented with TNF-alpha [DCT] or TNF-alpha and IFN-alpha [DCTI]. The capacity of the DCs to induce functional CD8+ T cell responses to hTERT HLA-0201 restricted nonapeptides was assessed by MHC tetramer binding and peptide-specific cytotoxicity. Each DC preparation (DCT or DCTI) was pulsed with only one type of hTERT peptide (p540 or p865) and both preparations were injected into separate lymph node draining regions every 2-3 weeks. This vaccination design enabled comparison of efficacy between DCT and DCTI in generating hTERT peptide specific CD8+ T cells and comparison of class I hTERT peptide (p540 or p865)-loaded DCT with or without class II cognate help (p766 and p672) in 6 patients. T regulatory cells were evaluated in 8 patients. RESULTS: (i) DCTIs and DCTs, pulsed with hTERT peptides, were comparable (p = 0.45, t-test) in inducing peptide-specific CD8+ T cell responses. (ii) Class II cognate help, significantly enhanced (p < 0.05, t-test) peptide-specific CD8+T cell responses, compared with class I pulsed DCs alone. (iii) Clinical responders had significantly lower (p < 0.05, Mann-Whitney U test) T regs, compared with non-responders. 4/16 patients experienced partial but transient clinical responses during vaccination. Vaccination was well tolerated with minimal toxicity. CONCLUSION: Addition of IFN-alpha to ex vivo monocyte-derived DCs, did not significantly enhance peptide-specific T cell responses in vivo, compared with TNF-alpha alone. Class II cognate help significantly augments peptide-specific T cell responses. Clinically favourable responses were seen in patients with low levels of circulating T regs.

Pilot study for a new bipolar radiofrequency ablation/aspirator device in the management of primary and secondary liver cancers.

BACKGROUND: In the US, the thermal ablation workload for cancer involving the liver is predicted to more than double in the next 5 years, emphasising the need to develop and improve the current technology. STUDY DESIGN: A multicentre nonrandomised prospective clinical trial (NCT00514930) was undertaken, to assess the efficacy and safety of a new bipolar radiofrequency ablation/aspirator device, in the treatment of primary and secondary cancers of the liver. RESULTS: A total of 34 lesions in 16 patients were ablated at laparotomy and followed up at 4 weeks. The mean diameter of lesion before ablation was 3.2+/-2.22 (range 1-10) cm, the mean volume aspirated during ablation was 9.25+/-7.3 (range 0-25) ml and the mean operative time was 145.95+/-40.7 (range 60-215) min. There was one major complication of a pleural effusion, which required drainage. The mean length of stay was 8+/-3.2 (range 3-14) days. In 11 patients, the ablated tumour was resected. On histological assessment, there was no evidence of viable cancer at the tumour edge. On follow-up computed tomography, the ablation zone fully encompassed the targeted tumour and there were no local complications related to ablation. CONCLUSION: Initial analysis of the data from this small cohort, with only a short-term follow-up, shows this device to be safe and effective.

Endoscopic radiofrequency ablation in colorectal cancer: initial clinical results of a new bipolar radiofrequency ablation device.

PURPOSE: There are a number of alternative approaches to palliate cancers of the rectosigmoid, which may not be well tolerated or produce effective symptom relief. Therefore, there is a continuing need to develop alternative techniques for palliation. This paper reports our initial assessment of a new bipolar radiofrequency probe (Endoblate). METHODS: Twelve patients with rectosigmoid tumors were treated with Endoblate during transanal endoscopic microsurgery. In ten patients, this was followed by surgical resection and two patients were treated with Endoblate alone. This study was designed to assess the technical utility of the device, immediate complications, and histologic effect. RESULTS: There were no technical problems. In the patients who had resection of the tumor immediately after ablation (n = 10), there were no local complications evident at surgery. Histology of the resected specimens showed that, on average, 82 (range, 60-99) percent of the tumor mass was destroyed in the ablation zone. In the remaining two patients, Endoblate alone was used successfully to stop bleeding from the tumor. CONCLUSIONS: These preliminary results illustrate the evolution and endoscopic application of bipolar radiofrequency technology. Endoblate showed potential as a useful and safe tool for the palliation of lower gastrointestinal malignancy.