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Here, we present a novel case of a patient with chronic lymphocytic leukemia (CLL) who received CTLA-4 and then PD-1 immune-checkpoint blockade (ICB) as treatment for concomitant metastatic melanoma. Whereas the metastatic melanoma was responsive to ICB, the CLL rapidly progressed (but responded to ICB cessation and ibrutinib). There were no new genetic mutational drivers to explain the altered clinical course. PD-1/PD-L1/PD-L2 and CTLA-4/CD80/CD86 expression was not increased in CLL B cells, CD8+ or CD4+ T-cell subsets, or monocytes. The patient’s CLL B cells demonstrated strikingly prolonged in vitro survival during PD-1 blockade, which was not observed in samples taken before or after ICB, or with other patients. To our knowledge, a discordant clinical course to ICB coupled with these biological features has not been reported in a patient with dual malignancies.

Supplementary Figure 1 - PDF files 2472K, Expression of cell surface markers throughout CLL PBMC

Purpose: Despite advances in the treatment of chronic lymphocytic leukemia (CLL), the disease remains incurable with standard therapies and relapse is inevitable. A growing body of evidence indicates that alterations in the adhesion properties of neoplastic cells play a pivotal role in the development and progression of CLL.Experimental Design: The expression of 71 cell surface molecules was examined on CLL peripheral blood mononuclear cells (PBMCs) over 3 weeks in culture. The most highly upregulated marker, CD62L, was examined further for expression on CD5+/CD19+ CLL cells in vitro and in lymph node and bone marrow biopsies. The prosurvival role of CD62L was examined using a functional blocking antibody and therapeutic potential evaluated by comparison with current chemotherapy agents.Results: Blocking CD62L resulted in apoptosis of CLL cells but not PBMCs from healthy donors suggesting a novel role for CD62L in CLL cell survival. The beneficial effect of coculturing CLL cells with bone marrow stromal cells or endothelial cells does not protect CLL cells from anti-CD62L–related toxicity. Moreover, combining fludarabine or mafosfamide with the anti-CD62L in vitro produced an additive effect both with and without stromal cells.Conclusion: This is the first reported data showing that blocking the activation and homing marker, CD62L, regulates CLL cell survival in vitro. These data also suggest that therapeutic antibodies against CD62L may provide additional clinical benefit to patients with CLL receiving current standard chemotherapy protocols. Clin Cancer Res; 19(20); 5675–85. ©2013 AACR.

Supplementary Figure Legends - PDF files 57K, Figure Legends

Supplementary Table 2 - PDF files 77K, CD markers used in phenotype screen

Supplementary Figure 3 - PDF files 1469K, Correlation of CD62L antibody toxicity and clinical parameters

Supplementary Table 1 - PDF files 69K, Patient Data

Resistance, to therapeutic antibodies used to treat chronic lymphocytic leukemia (CLL) patients is common. Monocyte-derived macrophages (MDMs) are a major effector of antitumour responses to therapeutic antibodies and we have previously reported that resistance to therapeutic antibodies, by MDMs, increases as CLL disease progresses. In this study, we examine the effect of a Class IIa-selective HDAC inhibitor (TMP195) on the phagocytic response to opsonised tumor cells or non-opsonised targets by MDMs derived from CLL patients. We report that TMP195 enhances phagocytic responses to antibody-opsonised CLL cells and E. coli within 30 min of treatment. The enhanced response is phenocopied by knockdown of the Class IIa HDAC, HDAC7, or by low concentrations of the pan-HDAC inhibitor, vorinostat. HDAC7 knockdown and inhibition induces hyperacetylation and hyperphosphorylation of Bruton’s tyrosine kinase (BTK). Moreover, BTK inhibitors abrogated the enhanced response to HDAC7 inhibition. Our data show that HDAC7 is an actionable driver of resistance to therapeutic antibodies by MDMs derived from CLL patients.

Antibody therapies are important treatment options for Chronic lymphocytic leukemia (CLL). Monocyte-derived-macrophages (MDMs) are thought to be a major immune effector that clears leukaemic cells ...

There is an increasing interest in studying the crosstalk between tumor-associated adipose tissue and tumor progression. In proximity to the primary site of kidney tumors, perinephric adipose tissue has direct contact with cancer cells when kidney cancer becomes invasive. To mimic the perinephric adipose tissue microenvironment, we applied the liquid overlay-based technique, which cost-effectively generated functional adipocyte spheroids using mesenchymal stem cells isolated from human perinephric adipose tissue. Thereafter, we co-cultured adipocyte spheroids with unpolarized macrophages and discovered an M2 phenotype skew in macrophages. Moreover, we discovered that, in the presence of adipocyte spheroids, M2 macrophages exhibited stronger invasive capacity than M1 macrophages. We further showed that the perinephric adipose tissue sampled from metastatic kidney cancer exhibited high expression of M2 macrophages. In conclusion, the liquid overlay-based technique can generate a novel three-dimensional platform enabling investigation of the interactions of adipocytes and other types of cells in a tumor microenvironment.

Fcγ receptor (FcγR) signalling in monocyte derived macrophages from chronic lymphocytic leukaemia (CLL) patients is poorly understood. This signalling pathway is the key determinant of the ability of the macrophages to respond to therapeutic antibodies in current clinical use for CLL. Muted FcγR signalling activity accompanies disease progression and results in resistance to therapeutic antibodies. The molecular mechanisms controlling FcγR signalling and resistance are unknown. Here, we demonstrate that the class I phosphoinositide 3-kinase (PI3K) catalytic subunit p110δ is essential for CLL-derived macrophages to respond to therapeutic antibodies. Inhibition of p110δ in the macrophages reduces FcγR-mediated antibody immune responses. Surprisingly, our studies indicated that FcγR downstream signalling is independent of SYK and BTK activity. Thus, we show that FcγR antibody responses occur via a previously unidentified p110δ-dependent pathway, which is independent of the previously described SYK/BTK activation pathway. These data provide novel insights into the effectors of antibody responses. Our data also provide mechanistic insights into therapy resistance in CLL.

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) comprises 5% of all Hodgkin lymphomas (HL). Its biology remains poorly characterized. Like classical HL (cHL), it contains minimal malignant cells embedded within a T cell rich intra-tumoral microenvironment (TME). Unlike cHL, it can transform to diffuse large B cell lymphoma (DLBCL). Immune-checkpoint blockade is effective in cHL but has minimal activity in DLBCL. No data is currently available regarding the potential to reactivate host anti-tumoral activity via immune-checkpoint blockade in NLPHL. Diagnostic FFPE samples from 49 NLPHL patients retrospectively collected from 4 Australian centres were interrogated. Inclusion criteria were sample availability and centrally confirmed histological NLPHL. Characteristics were in line with the literature: median age 45 years, range 13-82 years; F:M 1:3.5; stage I/II 55%, III/IV 35% (10% stage unknown) with the majority of cases were of immuno-architectural types A or C. RNA was digitally quantified using the NanoString 770-gene PanCancer Immune panel. Multi-spectral immunofluorescent (mIF) microscopy, plasma soluble PD-1 quantification, cell sorting, T cell receptor (TCR) repertoire analysis and functional immuno-assays were also performed. Results were compared with samples from 38 cHL and 35 DLBCL patients. We initially compared gene expression of NLPHL and cHL, looking for molecular similarities and differences. Ten non-lymphomatous nodes (NLN) were included as controls. Unsupervised clustering showed all but 3 NLPHL cases segregated from the cHL cluster. All NLN congregated in a discrete sub-cluster. As expected, RNA analysis showed significant enrichment for CD20 in NLPHL and CD30 in HL. Volcano plots (Fig. 1a), corrected for false-discovery showed marked variation in gene expression. For NLPHL (vs. cHL) there were 105 upregulated and 337 down regulated genes. Strikingly, the most significantly differentially over-expressed genes in NLPHL were all T cell related (CD247: CD3 zeta chain; CD3D: CD3 delta chain; GZMK: granzyme K; EOMES: marker of CD8 + T cell tolerance; and the immune checkpoints PDCD1: encodes for PD-1; and TIGIT). CD8B expression was increased in NLPHL. For cHL, the most over-expressed genes included macrophage-derived chemokines CCL17 and CCL22. Gene set enrichment analysis revealed activation of the PD-L1 expression and PD-1 checkpoint pathway and 9 of the top 10 Gene Ontology (GO) term enrichment scores involved lymphocyte signalling in NLPHL (Fig. 1b). To better appreciate the impact of the relevant immune checkpoints on their signalling axis, we compared gene ratios for PD-1 and TIGIT receptors with their ligands (PD-L1/L2 and PVR, respectively). NLPHL showed the highest enrichment ratios of these signalling pathways vs. cHL, DLBCL and NLN (Fig. 1c). Although it is known that CD4 +PD-1 +T cells form rosettes around NLPHL cells, the differential cellular localization of immune proteins has not been compared between HL entities. Using mIF, the proportion of intra-tumoral PD-1 + was markedly higher for CD4 + (~7-fold; p Finally, we developed a functional assay using PD-L1/PD-L2 expressing NLPHL and cHL cell lines. These were co-cultured with genetically engineered PD-1 +CD4 + T cells that express a luciferase reporter. Similar levels of heightened T cell activation were seen with immune-checkpoint blockade for both HL entities, indicating that immune-checkpoint inhibition may also be of benefit in NLPHL. In conclusion, our multi-faceted analysis of the immunobiological features of the TME in NLPHL, provides a compelling rationale for early phase clinical studies that incorporate immune-checkpoint blockade in NLPHL. Figure 1 Figure 1. Disclosures Hawkes: Bristol Myers Squib/Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Specialised Therapeutics: Consultancy; Merck KgA: Research Funding; Merck Sharpe Dohme: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Antigene: Membership on an entity's Board of Directors or advisory committees; Regeneron: Speakers Bureau; Janssen: Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Other: Travel and accommodation expenses, Research Funding, Speakers Bureau. Swain: Janssen: Other: Travel expenses paid; Novartis: Other: Travel expenses paid. Keane: BMS: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy; Karyopharm: Consultancy; MSD: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Talaulikar: Takeda: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Jansenn: Honoraria, Research Funding; Roche: Honoraria, Research Funding; EUSA Pharma: Honoraria, Research Funding. Gandhi: janssen: Research Funding; novartis: Honoraria.

Prognosis of CLL patients has historically been determined by categorization into Rai or Binet risk groups based on physical examination and blood counts, however given heterogeneity within Rai or ...

Fcγ receptor (FcγR) signalling in monocyte derived macrophages from chronic lymphocytic leukaemia (CLL) patients is poorly understood. This signalling pathway is the key determinant of the ability of the macrophages to respond to therapeutic antibodies in current clinical use for CLL. Muted FcγR signalling activity accompanies disease progression and results in resistance to therapeutic antibodies. The molecular mechanisms controlling FcγR signalling and resistance are unknown. Here, we demonstrate that the class I phosphoinositide 3-kinase (PI3K) catalytic subunit p110δ is essential for CLL-derived macrophages to respond to therapeutic antibodies. Inhibition of p110δ in the macrophages reduces FcγR-mediated antibody immune responses. Surprisingly, our studies indicated that FcγR downstream signalling is independent of SYK and BTK activity. Thus, we show that FcγR antibody responses occur via a previously unidentified p110δ-dependent pathway, which is independent of the previously described SYK/BTK activation pathway. These data provide novel insights into the effectors of antibody responses. Our data also provide mechanistic insights into therapy resistance in CLL.

Osteosarcoma (OS) accounts for 56% of malignant bone cancers in children and adolescents. Patients with localized disease rarely develop metastasis; however, pulmonary metastasis occurs in approximately 50% of patients and leads to a 5-year survival rate of only 10-20%. Therefore, identifying the genes and pathways involved in metastasis, as new therapeutic targets, is crucial to improve long-term survival of OS patients. Novel markers that define metastatic OS were identified using comparative transcriptomic analyses of two highly metastatic (C1 and C6) and two poorly metastatic clonal variants (C4 and C5) isolated from the metastatic OS cell line, KHOS. Using this approach, we determined that the metastatic phenotype correlated with overexpression of thioredoxin reductase 2 (TXNRD2) or vascular endothelial growth factor (VEGF). Validation in patient biopsies confirmed TXNRD2 and VEGF targets were highly expressed in 29-42% of metastatic OS patient biopsies, with no detectable expression in non-malignant bone or samples from OS patients with localised disease. Auranofin (AF) was used to selectively target and inhibit thioredoxin reductase (TrxR). At low doses, AF was able to inhibit TrxR activity without a significant effect on cell viability whereas at higher doses, AF could induce ROS-dependent apoptosis. AF treatment, in vivo, significantly reduced the development of pulmonary metastasis and we provide evidence that this effect may be due to an AF-dependent increase in cellular ROS. Thus, TXNRD2 may represent a novel druggable target that could be deployed to reduce the development of fatal pulmonary metastases in patients with OS.

Chronic lymphocytic leukaemia (CLL) is the most common adult leukaemia and, in some patients, is accompanied by resistance to both chemotherapeutics and immunotherapeutics. In this review we will discuss the role of tumour associated macrophages (TAMs) in promoting CLL cell survival and resistance to immunotherapeutics. In addition, we will discuss mechanisms by which TAMs suppress T-cell mediated antitumour responses. Thus, targeting macrophages could be used to i) reduce the leukaemic burden via the induction of T-cell-mediated antitumour responses, ii) to reduce pro-survival signalling and enhance response to conventional chemotherapeutics or iii) enhance the response to therapeutic antibodies in current clinical use.

Chronic lymphocytic leukemia (CLL) is predominantly a disease of accumulation rather than rapid proliferation. To date, no cell lines exist, as CLL cells undergo rapid apoptosis when cultured in vitro, suggesting that a favorable in vivo microenvironment is required. To identify survival signals we cultured primary CLL peripheral blood mononuclear cells (PBMCs) at high density, which has previously been shown to dramatically improve survival. Using antibody arrays we measured the level of 42 cytokines in culture supernatants and showed that inerleukin-6 (IL-6), IL-8, CXCL2 and CCL2 were highly up-regulated in culture. This is the first report to describe a role for CCL2 and CXCL2 in CLL cell survival. Importantly, CXCL2, IL-6 and IL-8 were significantly up-regulated in primary patient plasma. The addition of either CXCL2 or CCL2 enhanced CLL cell survival, while antibodies blocking these chemokines reduced survival. Co-culture of CLL cells and PBMC accessory cells separated by transwells provided a similar degree of survival protection compared to normal culture, whereas CLL cells cultured alone died rapidly. Interestingly, CCL2 and CXCL2 appeared to be produced by CLL cells but only when co-cultured with accessory cells. Thus, we speculate that accessory cells release soluble factors that promote the production of these pro-survival chemokines from CLL cells and physical interactions are not required. Our data support the concept that the CLL microenvironment is critical, and suggests that soluble factors are more important than physical interactions.

There is a continued reliance on antibody therapies for treating chronic lymphocytic leukaemia (CLL). Whilst the inclusion of antibody therapies in many standard treatment regimes results in good outcomes, acquired resistance remains a significant clinical challenge for many CLL patients resulting in insensitivity to the antibody treatment. Thus, understanding the mechanisms driving treatment resistance is likely to lead to therapies to reverse resistance and improve patient outcomes. Earlier studies from our laboratory have shown that resistance to therapeutic antibodies, in CLL, is due to a reduced ability of monocyte derived macrophages (MDMs) to participate in FcγR-dependent antitumour responses (e.g. ADCC and antibody-dependent phagocytosis (ADP). In this regard, we recently showed that SYK and BTK activation are downstream of the FcγRs (Oncogene, 36(17):2366-2376, 2017). Moreover, we showed that signalling through the FcγR pathway was reduced in antibody-resistant MDMs and could be reversed using inhibitors of SHIP1. These studies indicated that knowledge of FcγR signalling could exploited to reverse resistance. Unfortunately, knowledge of the exact signalling events controlling FcγR activity in MDMs from CLL patients is unclear. In this study we investigated the involvement of PI3K isoforms in FcγR-dependent ADCC and ADP in MDMs from CLL patients. PI3K isoforms have been shown to be important pathway regulators for immune-receptor function in various immune cells such as T cells, B cells and NK cells as well as in cancerous cells. In the first instance, I examined the expression of PI3K isoforms in MDMs from CLL patients. This showed that PI3Kα, β, and δ are expressed in MDMs whereas PI3Kγ is below the limit of detection. Next, I examined the involvement of the different PI3K isoforms to contribute to FcγR-dependent ADCC by MDMs. For this we used a suite of isoform-selective inhibitors to target each PI3K isoform and examined their effect on ADCC responses by MDMs. The PI3Kδ-selective inhibitor, idelalisib and the pan PI3K inhibitor BKM120 (Buparlisib) were able to inhibit ADCC responses to the CD20-targeting therapeutic antibody, obinutuzumab. Similarly, both buparlisib and idelalisib were able to inhibit AKT phosphorylation at concentrations that also inhibited ADCC. In contrast. None of the other isoform-selective inhibitors were able to suppress ADCC responses to obinutuzumab. These studies have been repeated using isoform-specific siRNAs. This is the first report to show that PI3Kδ is involved in FcγR signalling in MDMs from CLL patients or in MDMs from any tumour type. Based on these findings we conclude that PI3Kδ is a critical effector molecule for antitumour responses to therapeutic antibodies in CLL. Disclosures Mollee: Amgen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Gill:Pharma: Membership on an entity's Board of Directors or advisory committees.

Although small interfering RNA (siRNA) treatment holds great promise for the treatment of cancers, the field has been held back by the availability of suitable delivery vehicles. For cervical cancer the E6 and E7 oncogenes are ideal siRNA targets for treatment. The purpose of the present study was to explore the potential of dendrosomes for the delivery of siRNA targeting E6 and E7 proteins of cervical cancer cells in vitro. Optimization of dendrimer generation and nitrogen-to-phosphate (N/P) ratio was carried out using dendrimer-fluorescein isothiocyanate oligo complexes. The optimized N/P ratios were used in formulating complexes between dendrimers and siRNA targeting green fluorescence protein (siGFP). Although formulation 4D100 (dendrimer-siRNA complex) displayed the highest GFP knockdown, it was also found to be highly toxic to cells. In the final formulation 4D100 was encapsulated into dendrosomes so as to mask these toxic effects. The optimized dendrosomal formulation (DF), DF3 was found to possess a siGFP-entrapment efficiency of 49.76% ± 1.62%, vesicle size of 154 ± 1.73 nm, and zeta potential of +3.21 ± 0.07 mV. The GFP knockdown efficiency of DF3 (dendrosome) was found to be almost identical to that of 4D100, but the former was completely nontoxic to the cells. DF3 containing siRNA against E6 and E7 was found to knock down the target genes considerably, as compared with the other formulations tested. Our results imply that dendrosomes hold potential for the delivery of siRNA and that a suitable targeting strategy could be useful for applications in vivo. From the Clinical Editor: siRNA treatment holds great promise for the treatment of cancers, but overall, the availability of suitable delivery vehicles remains a major issue. The purpose of this study was to explore the potential of dendrosomes for the delivery of siRNA targeting specific proteins in cervical cancer cells in vitro. The results suggest that dendrosomes hold potential for the delivery of siRNA and a suitable targeting strategy could be useful for applications in vivo. © 2010 Elsevier Inc. All rights reserved.

Recent studies on Hodgkin’s lymphoma (HL) have indicated that patients with active disease display functional impairment of Ag-specific CD8+ T cells due to expansion of regulatory T cells at sites of disease and in the peripheral blood. Adoptive cellular immunotherapy based on EBV-specific CD8+ T cells has been explored with limited success to date. It has been proposed that improved targeting of these CD8+ T cells toward viral Ags that are expressed in HL may enhance future therapeutic vaccine strategies. In this study, we have developed a novel replication-deficient adenoviral Ag presentation system that is designed to encode glycine alanine repeat-deleted EBV nuclear Ag 1 covalently linked to multiple CD8+ T cell epitopes from latent membrane proteins 1 and 2. A single stimulation of CD8+ T cells from healthy virus carriers, and patients with HL with this adenoviral construct in combination with IL-2, was sufficient to reverse the functional T cell impairment and restored both IFN-γ production and cytolytic function. More importantly, these activated CD8+ T cells responded to tumor cells expressing membrane proteins and recognized novel EBNA1 epitopes. Flow cytometric analysis revealed that a large proportion of T cells expanded from patients with HL were CD62Lhigh and CD27high, and CCR7low, consistent with early to mid effector T cells. These findings provide an important platform for translation of Ag-specific adoptive immunotherapy for the treatment of EBV-associated malignancies such as HL and nasopharyngeal carcinoma.

The aim of this study was to investigate methods for the synthesis of highly pure, well-characterized analogues of the lipid core peptide (LCP) system. Difficulties synthesizing and purifying conventional LCP systems have led to the requirement for a technique to produce highly pure, LCP-based vaccines for potential use in human clinical trials. The current study describes methods for the attachment of lipophilic adjuvants onto multi-epitopic peptide vaccines. Described is the synthesis, using native chemical ligation, of a highly pure, tri-epitopic, group A streptococcal (GAS) lipopeptide vaccine candidate. Intranasal immunization of the described tri-epitopic GAS lipopeptide with the mucosal adjuvant cholera toxin B subunit induced high serum IgG antibody titers specific for each of the incorporated peptide epitopes.

Synthesis of a tri-epitopic Group A streptococcal lipopeptide vaccine was achieved using native chemical ligation. The vaccine was administered intranasally to B10.BR mice, (H-2 k ) with cholera toxin B-subunit (CTB) or sterile phosphate-buffered saline. Following five boosts, blood was collected for ELISA. Significant IgG antibody titres were observed to the included peptide epitopes following administration with CTB. However, no significant IgG titres were observed in the absence of CTB.

Purpose: Despite advances in the treatment of chronic lymphocytic leukemia (CLL), the disease remains incurable with standard therapies and relapse is inevitable. A growing body of evidence indicates that alterations in the adhesion properties of neoplastic cells play a pivotal role in the development and progression of CLL. Experimental Design: The expression of 71 cell surface molecules was examined on CLL peripheral blood mononuclear cells (PBMCs) over 3 weeks in culture. The most highly upregulated marker, CD62L, was examined further for expression on CD5+/CD19+ CLL cells in vitro and in lymph node and bone marrow biopsies. The prosurvival role of CD62L was examined using a functional blocking antibody and therapeutic potential evaluated by comparison with current chemotherapy agents. Results: Blocking CD62L resulted in apoptosis of CLL cells but not PBMCs from healthy donors suggesting a novel role for CD62L in CLL cell survival. The beneficial effect of coculturing CLL cells with bone marrow stromal cells or endothelial cells does not protect CLL cells from anti-CD62L–related toxicity. Moreover, combining fludarabine or mafosfamide with the anti-CD62L in vitro produced an additive effect both with and without stromal cells. Conclusion: This is the first reported data showing that blocking the activation and homing marker, CD62L, regulates CLL cell survival in vitro. These data also suggest that therapeutic antibodies against CD62L may provide additional clinical benefit to patients with CLL receiving current standard chemotherapy protocols. Clin Cancer Res; 19(20); 5675–85. ©2013 AACR.

RNA interference (RNAi) may provide a therapeutic solution to many pulmonary epithelium diseases. However, the main barrier to the clinical use of RNAi remains the lack of efficient delivery vectors. Research has mainly concentrated on the intranasal route of delivery of short interfering RNA (siRNA) effector molecules for the treatment of respiratory diseases. However, this may be complicated in a diseased state due to the increased fluid production and tissue remodeling. Therefore, we investigated our hydration of a freeze-dried matrix (HFDM) formulated liposomes for systemic delivery to the lung epithelium. Here, we show that 45 ± 2% of epithelial murine lung cells receive siRNA delivery upon intravenous (IV) liposomal administration. Furthermore, we demonstrate that liposomal siRNA delivery resulted in targeted gene and protein knockdown throughout the lung, including lung epithelium. Taken together, this is the first description of lung epithelial delivery via cationic liposomes, and provides a proof of concept for the use of IV liposomal RNAi delivery to specifically knockdown targeted genes in the respiratory system. This approach may provide an attractive alternate therapeutic delivery strategy for the treatment of lung epithelium diseases.Molecular Therapy - Nucleic Acids (2013) 2, e96; doi:10.1038/mtna.2013.22; published online 4 June 2013.

The controlled release of siRNA or DNA complexes from cationic polymers is an important parameter design in polymer-based delivery carriers. In this work, we use the self-catalyzed degradable poly(2-dimethylaminoethyl acrylate) (PDMAEA) to strongly bind, protect, and then release oligo DNA (a mimic for siRNA) without the need for a cellular or external trigger. This self-catalyzed hydrolysis process of PDMAEA forms poly(acrylic acid) and N,N'-dimethylamino ethyl ethanol, both of which have little or no toxicity to cells, and offers the advantage of little or no toxicity to off-target cells and tissues. We found that PDMAEA makes an ideal component of a delivery carrier by protecting the oligo DNA for a sufficiently long period of time to transfect most cells (80% transfection after 4 h) and then has the capacity to release the DNA inside the cells after ~10 h. The PDMAEA formed large nanoparticle complexes with oligo DNA of ~400 nm that protected the oligo DNA from DNase in serum. The nanoparticle complexes showed no toxicity for all molecular weights at a nitrogen/phosphorus (N/P) ratio of 10. Only the higher molecular weight polymers at very high N/P ratios of 200 showed significant levels of cytotoxicity. These attributes make PDMAEA a promising candidate as a component in the design of a gene delivery carrier without the concern about accumulated toxicity of nanoparticles in the human body after multiadministration, an issue that has become increasingly more important.

RNA interference (RNAi)-based gene silencing is widely used in laboratories for gene function studies and also holds a great promise for developing treatments for diseases. However, in vivo delivery of RNAi therapy remains a key issue. Lentiviral vectors have been employed for stable gene transfer and gene therapy and therefore are expected to deliver a stable and durable RNAi therapy. But this does not seem to be true in some disease models. Here, we showed that lentivirus delivered short-hairpin RNA (shRNA) against human papillomavirus (HPV) E6/E7 oncogenes were effective for only 2 weeks in a cervical cancer model. However, using this vector to carry two copies of the same shRNA or two shRNAs targeting at two different but closely related genes (HPV E6 and vascular endothelial growth factor) was more effective at silencing the gene targets and inhibiting cell or even tumor growth than their single shRNA counterparts. The cancer cells treated with dual shRNA were also more sensitive to chemotherapeutic drugs than single shRNA-treated cells. These results suggest that a multi-shRNA strategy may be a more attractive approach for developing an RNAi therapy for this cancer.

Small interfering RNA (siRNA) shows great promise in cancer therapy, but its effectiveness in vivo still remains a crucial issue for its transition into the clinics. Although the successful use of polyethylene glycol (PEG)ylated lipidic delivery systems have already been reported, most of the formulation procedures used are labour intensive and also result in unstable end products. We have previously developed a simple yet efficient hydration-of-freeze-dried-matrix (HFDM) method to entrap siRNA within lipid particles, in which the products exhibited superior stability. Here, we show that these HFDM-formulated particles are stable in the presence of serum and can deliver siRNA efficiently to tumours after intravenous administration. Using these particles, around 50% knockdown of the target gene expression was observed in tumours. With the use of siRNA targeting the E6/7 oncogenes expressed in cervical cancer, we showed a 50% reduction in tumour size. This level of tumour growth suppression was comparable to that achieved from cisplatin at the clinically used dose. Overall, our results demonstrate the feasibility of using HFDM-formulated particles to systematically administer E6/7-targeted siRNA for cervical cancer treatment. The simplicity of preparation procedure along with superior product stability obtained from our method offers an innovative approach for the in vivo delivery of siRNA.

Sustained vaginal delivery of siRNA has been precluded by the mucosal barrier lining the vaginal tract. In contrast to prior reports, we showed that conventional lipoplexes administered intravaginally are unable to reach the vaginal epithelium under normal physiological conditions. Here we have developed a novel alginate scaffold system containing muco-inert PEGylated lipoplexes to provide a sustained vaginal presence of lipoplexes in vivo and to facilitate the delivery of siRNA/oligonucleotides into the vaginal epithelium. These PEGylated lipoplex-entrapped alginate scaffolds (PLAS) were fabricated using a freeze-drying method and the entrapment efficiency, release rate, and efficacy were characterized. We demonstrated that the PLAS system had an entrapment efficiency of ~ 50%, which released PEGylated lipoplexes gradually both in vitro and in vivo. While the presence of alginate diminished the cell uptake efficiency of PEGylated lipoplexes in vitro, as expected, we showed a six-fold increase their uptake into the vaginal epithelium compared to existing transfection systems following intravaginal administration in mice. A significant knockdown of Lamin A/C level was also observed in vaginal tissues using siLamin A/C-containing PLAS system in vivo. Overall, our results indicated the potential of the biodegradable PLAS system for the sustained delivery of siRNA/oligonucleotides to vaginal epithelium.

Background CLL cells have prolonged survival in vivo, but rapidly undergo apoptosis when cultured ex vivo indicating the importance of the tumour microenvironment in resistance to apoptosis. Chemokines and their receptors have been identified as playing a critical role in the CLL microenvironment and we have previously identified CCL2, CXCL2, IL-6 and IL-8 as pro-survival factors in our in vitro long-term CLL culture model. We examined the in vivo significance of these and other chemokines by examining serum levels in a cohort of uniformly treated patients with CLL. Methods Serum samples were collected from 32 Australian patients participating in the German CLL Study Group CLL8 trial prior to treatment and were assessed for circulation levels of several cytokines and chemokines. Serum samples from 7 age matched healthy donors were used as controls. Serum concentration of CCL21, CXCL12, CXCL13, CCL19 and CXCL2 were examined using enzyme-linked immunosorbent assays (ELISA) and levels of CCL2, CCL3, CCL4, sCD54, sCD178, IL6 and IL-8 were examined using flex sets of BD Cytometric Bead Arrays System. Levels of these cytokines and chemokines were compared both to the healthy donor control samples and correlated with known prognostic and clinical factors. The levels were also evaluated in respect to response to therapy, progression-free survival (PFS) and overall survival (OS). Results 32 patients were studied: median age 62yrs, 84% male, Binet stage B 63%, stage C 37%. 15 received FCR and 17 FC with a median PFS of 45 months and median OS not reached. Compared to controls, patients with CLL had significantly higher serum levels of CXCL13 (117pg/ml vs 15pg/ml, p=0.0001), CCL3 (273pg/ml vs 103pg/ml, p=0.0007), CCL4 (13pg/ml vs 0pg/ml, p=0.0057), CD178 (45pg/ml vs 26pg/ml, p=0.01) and IL-6 (5pg/ml vs 0, p=0.02) and significantly lower levels of CXCL12 (803pg/ml vs 1177pg/ml, p=0.003) and sCD154 (345pg/ml vs 2121pg/ml p=0.0004). CCL2 levels did not correlate with any baseline clinical feature, response to therapy, PFS or OS. CXCL2 levels reduced with more advanced Rai stage disease (p=0.0083) but did not predict PFS or OS. CD178 levels did not correlate with any baseline clinical feature but predicted response to therapy with lower levels predicting improved response (p=0.04). Higher CD178 also strongly predicted worse PFS (HR 1.026, p Conclusion Baseline serum levels of CD178 (soluble FasL) may be a useful predictor of response to therapy and outcome in CLL. Further studies to confirm these findings and to define the biological mechanism of FasL overexpression and function are required. Acknowledgments We thank the German CLL Study Group and Roche for access to patient samples and data from the CLL8 study, and the Leukaemia Foundation of Australia for grant support. Disclosures: Mollee: Roche Australia: Sponsorship for attending ICML Lugano 2013 Other.

Aim. Investigate the in vitro culture conditions that would allow the long-term culture of primary CLL cells and Identify cytokines responsible for B-CLL survival in vitro Method. Blood and/or bone marrow was collected, after informed consent, from patients with CLL. Diagnosis of CLL was made according to NCI criteria. Mononuclear cells were cultured at various cell densities in RPMI 1640 medium + 10% heat inactivated FCS. Human cytokine array was performed at baseline day 0 and on supernatant of B-CLL cells which had been cultured in complete media for 7 days using ChemiArray system (Human Cytokine Antibody Array III, Chemicon) Results. Samples were cultured from 19 CLL patients (9 females, 10 males with median age of 60 years; range 44–90). Patients were predominately untreated, early stage with only 3 patients at Binet stage C or Rai stage 4. The overall trend was that 80% of the total cell population died rapidly leaving a resident population of CD19+CD5+ cells (Fig 1). By increasing the initial seeding cell density to high levels (≥5×107/ml) CLL cells can be cultured out to approximately 90 days without additional stromal cells support from another source. Decreasing the seeding cell densities resulted in reduced cell survival. The surviving cells belonged to the malignant clone and were all CD5+/19+, EBV negative and mostly quiescent, with only 3.5% of the CLL B cells actively dividing. Certain patients’ cells exhibited much better in vitro survival than others but no correlation was found with any clinical parameters including clinical stage (Rai or Binet), lymphocyte doubling time, time to treatment, CD38 positivity, IgVH mutation status or LDH levels. Two novel soluble factors, the chemokines CCL2 (MCP-1) and CXCL2 (GROb), were identified in the culture media which appear to enhance survival of CLL B cells. Addition of exogenous CCL2 and CXCL2 resulted in improved in vitro survival of CLL B cells, while blocking these growth factors with specific antibodies resulted in decreased survival (Fig 2). By immunohistochemistry and intracytoplasmic flow cytometry, the CCL2 chemokine appears to be predominately secreted by the stromal cells. Conclusion. This study demonstrates the prolonged survival of B-CLL in vitro without additional stromal cell support. Furthermore, novel cytokines CCL2 and CXCL2 appear to prolong the survival of B-CLL cells in vitro. This culture system and these chemokines may allow us to gain insight into factors modulating B-CLL survival and potentially could lead to targeted therapy as well as serve as an appropriate model to test new therapies. Figure Figure Figure Figure