Modeling the communication-satisfaction relationship in hospital patients

Objectives:

Although it has long been known that communication with medical professionals presents a strong relationship with patient satisfaction, research on this topic has been hindered by conceptual and methodological issues (e.g. single-item measures, inclusion of idiosyncratic patient characteristics, etc.). Using a more comprehensive and integrated approach, this study had two objectives: to document the multidimensional structure of the Picker Patient Experience–15, and to test a patient communication/satisfaction model that organizes its dimensions in a conceptually logical array of relationships. First, the factorial structure of the Picker Patient Experience–15 was hypothesized to comprise five dimensions: communication with patient, with family, addressing fears/concerns, preparation for discharge, and patient satisfaction. Second, the hypothesized model included positive relationships between all four communications dimensions, on the one hand, and patient satisfaction, on the other. Within communication dimensions, communication with patient was hypothesized to be the incipient factor for other dimensions, and thus to be positively associated with the other three forms of communication.

Methods:

This research is based on a single time point design, which relied on administrative and questionnaire data. The study was conducted at a large University Hospital in Switzerland. The sample included 54,686 patients who received inpatient treatment, excluding those who were cared for in the intensive and intermediate care units. Patients filled out, over a 5-year period, the Picker Patient Experience questionnaire (PPE-15) after discharge (overall response rate of 41%).

Results:

The proposed five-factor structure of the Picker Patient Experience–15 was successfully supported by the results of a confirmatory factor analysis. Moreover, the hypothesized network of associations between communication and satisfaction latent constructs was substantiated using structural equation modeling. With the exception of the association between preparation for discharge and patient satisfaction, the hypothesized model was fully corroborated.

Conclusion:

A more in-depth understanding of patient satisfaction can be achieved when it is studied as a multifaceted phenomenon.

PDGF-BB regulates splitting angiogenesis in skeletal muscle by limiting VEGF-induced endothelial proliferation

VEGF induces normal or aberrant angiogenesis depending on its dose in the microenvironment around each producing cell in vivo. This transition depends on the balance between VEGF-induced endothelial stimulation and PDGF-BB-mediated pericyte recruitment, and co-expression of PDGF-BB normalizes aberrant angiogenesis despite high VEGF doses. We recently found that VEGF over-expression induces angiogenesis in skeletal muscle through an initial circumferential vascular enlargement followed by longitudinal splitting, rather than sprouting. Here we investigated the cellular mechanism by which PDGF-BB co-expression normalizes VEGF-induced aberrant angiogenesis. Monoclonal populations of transduced myoblasts, expressing similarly high levels of VEGF alone or with PDGF-BB, were implanted in mouse skeletal muscles. PDGF-BB co-expression did not promote sprouting and angiogenesis that occurred through vascular enlargement and splitting. However, enlargements were significantly smaller in diameter, due to a significant reduction in endothelial proliferation, and retained pericytes, which were otherwise lost with high VEGF alone. A time-course of histological analyses and repetitive intravital imaging showed that PDGF-BB co-expression anticipated the initiation of vascular enlargement and markedly accelerated the splitting process. Interestingly, quantification during in vivo imaging suggested that a global reduction in shear stress favored the initiation of transluminal pillar formation during VEGF-induced splitting angiogenesis. Quantification of target gene expression showed that VEGF-R2 signaling output was significantly reduced by PDGF-BB co-expression compared to VEGF alone. In conclusion, PDGF-BB co-expression prevents VEGF-induced aberrant angiogenesis by modulating VEGF-R2 signaling and endothelial proliferation, thereby limiting the degree of circumferential enlargement and enabling efficient completion of vascular splitting into normal capillary networks despite high VEGF doses.

Implantation of Stromal Vascular Fraction Progenitors at Bone Fracture Sites: From a Rat Model to a First-in-Man Study

Stromal Vascular Fraction (SVF) cells freshly isolated from adipose tissue include osteogenic- and vascular-progenitors, yet their relevance in bone fracture healing is currently unknown. Here, we investigated whether human SVF cells directly contribute to the repair of experimental fractures in nude rats, and explored the feasibility/safety of their clinical use for augmentation of upper arm fractures in elderly individuals. Human SVF cells were loaded onto ceramic granules within fibrin gel and implanted in critical nude rat femoral fractures after locking-plate osteosynthesis, with cell-free grafts as control. After 8 weeks, only SVF-treated fractures did not fail mechanically and displayed formation of ossicles at the repair site, with vascular and bone structures formed by human cells. The same materials combined with autologous SVF cells were then used to treat low-energy proximal humeral fractures in 8 patients (64-84 years old) along with standard open reduction and internal fixation. Graft manufacturing and implantation were compatible with intraoperative settings and led to no adverse reactions, thereby verifying feasibility/safety. Biopsies of the repair tissue after up to 12 months, upon plate revision or removal, demonstrated formation of bone ossicles, structurally disconnected and morphologically distinct from osteoconducted bone, suggesting the osteogenic nature of implanted SVF cells. We demonstrate that SVF cells, without expansion or exogenous priming, can spontaneously form bone tissue and vessel structures within a fracture-microenvironment. The gained clinical insights into the biological functionality of the grafts, combined with their facile, intra-operative manufacturing modality, warrant further tests of effectiveness in larger, controlled trials. Stem Cells 2016;34:2956-2966.

VEGF dose regulates vascular stabilization through Semaphorin3A and the Neuropilin-1+ monocyte/TGF-β1 paracrine axis

VEGF is widely investigated for therapeutic angiogenesis, but while short-term delivery is desirable for safety, it is insufficient for new vessel persistence, jeopardizing efficacy. Here, we investigated whether and how VEGF dose regulates nascent vessel stabilization, to identify novel therapeutic targets. Monoclonal populations of transduced myoblasts were used to homogeneously express specific VEGF doses in SCID mouse muscles. VEGF was abrogated after 10 and 17 days by Aflibercept treatment. Vascular stabilization was fastest with low VEGF, but delayed or prevented by higher doses, without affecting pericyte coverage. Rather, VEGF dose-dependently inhibited endothelial Semaphorin3A expression, thereby impairing recruitment of Neuropilin-1-expressing monocytes (NEM), TGF-β1 production and endothelial SMAD2/3 activation. TGF-β1 further initiated a feedback loop stimulating endothelial Semaphorin3A expression, thereby amplifying the stabilizing signals. Blocking experiments showed that NEM recruitment required endogenous Semaphorin3A and that TGF-β1 was necessary to start the Semaphorin3A/NEM axis. Conversely, Semaphorin3A treatment promoted NEM recruitment and vessel stabilization despite high VEGF doses or transient adenoviral delivery. Therefore, VEGF inhibits the endothelial Semaphorin3A/NEM/TGF-β1 paracrine axis and Semaphorin3A treatment accelerates stabilization of VEGF-induced angiogenesis.

CD40 ligand-expressing recombinant vaccinia virus promotes the generation of CD8(+) central memory T cells

Central memory CD8(+) T cells (TCM ) play key roles in the protective immunity against infectious agents, cancer immunotherapy, and adoptive treatments of malignant and viral diseases. CD8(+) TCM cells are characterized by specific phenotypes, homing, and proliferative capacities. However, CD8(+) TCM -cell generation is challenging, and usually requires CD4(+) CD40L(+) T-cell "help" during the priming of naïve CD8(+) T cells. We have generated a replication incompetent CD40 ligand-expressing recombinant vaccinia virus (rVV40L) to promote the differentiation of human naïve CD8(+) T cells into TCM specific for viral and tumor-associated antigens. Soluble CD40 ligand recombinant protein (sCD40L), and vaccinia virus wild-type (VV WT), alone or in combination, were used as controls. Here, we show that, in the absence of CD4(+) T cells, a single "in vitro" stimulation of naïve CD8(+) T cells by rVV40L-infected nonprofessional CD14(+) antigen presenting cells promotes the rapid generation of viral or tumor associated antigen-specific CD8(+) T cells displaying TCM phenotypic and functional properties. These observations demonstrate the high ability of rVV40L to fine tune CD8(+) mediated immune responses, and strongly support the use of similar reagents for clinical immunization and adoptive immunotherapy purposes.

Absence of myeloperoxidase and CD8 positive cells in colorectal cancer infiltrates identifies patients with severe prognosis

Colorectal cancer (CRC) infiltration by cells expressing myeloperoxidase (MPO) or CD8 positive T lymphocytes has been shown to be independently associated with favorable prognosis. We explored the relationship occurring between CD8+ and MPO+ cell CRC infiltration, its impact on clinical-pathological features and its prognostic significance in a tissue microarray (TMA) including 1,162 CRC. We observed that CRC showing high MPO+ cell infiltration are characterized by a prognosis as favorable as that of cancers with high CD8+ T cell infiltration. However, MPO+ and CD8+ CRC infiltrating cells did not synergize in determining a more favorable outcome, as compared with cancers showing MPOhigh/CD8low or MPOlow/CD8high infiltrates. Most importantly, we identified a subgroup of CRC with MPOlow/CD8low tumor infiltration characterized by a particularly severe prognosis. Intriguingly, although MPO+ and CD8+ cells did not co-localize in CRC infiltrates, an increased expression of TIA-1 and granzyme-B was detectable in T cells infiltrating CRC with high MPO+ cell density.

Abstract 2370: Tumor-associated stromal cells increase malignancy of human colorectal cancers triggering the induction of Epithelial-to-mesenchymal transition

During tumor formation, normal tissue microenvironment is transformed in an “altered” niche, composed of non-malignant supporting cells, which influence the homeostasis of cancer cells via paracrine regulators. Tumor-associated stromal cells (TASC) are the prominent stromal elements in most types of human carcinomas including colorectal cancer (CRC). The differentiation of TASC from other cell types, such as resident stromal cells or bone marrow-derived mesenchymal stem cells (BM-MSC) is mainly mediated by factors produced during the crosstalk with malignant cells. TASC produce various extracellular matrix proteins, chemokines, and other tumor-promoting factors which affect vascularization, proliferation, tumor cell invasiveness and survival. Emerging data suggests that they also play a critical role in determining response to therapy. For instance TASC-derived factors may contribute to the development of a protective milieu by influencing cell-cell/cell-matrix interactions, cancer cell survival, and suppression of anti-tumor immune responses. Moreover, physical contact between TASC and malignant cells supports tumor cell survival via activation of anti-apoptotic pathways or inducing epithelial-to-mesenchymal transition (EMT). We previously showed that BM-MSC are capable of triggering EMT in CRC cells, leading to increased tumor cell aggressiveness in vitro and in vivo. However, the role played by the stromal component and the processes induced on CRC cells remain to be fully elucidated. For this purpose we have addressed phenotypic and functional characterization of TASC in vitro and we have analyzed TASC-mediated effects on CRC development and progression in vivo.

TASC were characterized for phenotype and differentiation capacity. Human CRC cells were cultured in the presence or absence of TASC for five days. After co-culture tumor cells were sorted by flow cytometry and evaluated for the expression of EMT-related genes by Real Time PCR and for in vitro invasiveness by chemoinvasion assay. Furthermore, their tumorigenicity was assessed upon injection in NOD/SCID mice and developing tumors were analyzed.

Our results indicate that TASC resemble BM-MSC in morphology and phenotype. They comprise a multipotent subpopulation that is able to differentiate into adipogenic and osteogenic lineage. After co-culture with CRC cells they express membrane-bound TGF-β, through which they are capable to initiate EMT in tumor cells. Moreover CRC cells acquire a more invasive phenotype after co-culture with TASC. Upon subcutaneous injection in NOD/SCID mice, tumor cells co-cultured with TASC show a significantly faster growth kinetic and develop significantly larger tumor masses as compared to tumor cells alone.

Thus our data show that the stromal component of CRC increases the tumor cells malignancy triggering EMT induction.

Citation Format: Valentina Mele, Manuele Giuseppe Muraro, Raoul Droeser, Daniel Oertli, Markus Zuber, Raffaele Rosso, Ivan Martin, Michael Heberer, Giulio C. Spagnoli, Giandomenica Iezzi. Tumor-associated stromal cells increase malignancy of human colorectal cancers triggering the induction of Epithelial-to-mesenchymal transition. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2370. doi:10.1158/1538-7445.AM2015-2370

Abstract 2490: CD40 ligand expressing recombinant vaccinia virus (rVV40L) modulation of central memory CD8-mediated immune response

In cancer immunotherapy, induction of tumor-reactive CD8+ T cells displaying phenotypic and functional profile of central memory T cells (TCM) is associated with favorable prognosis. A key element in the generation of TCM CD8+ cells is represented by the help provided by CD4+ T cells during the priming of naïve CD8+ T cells. In particular CD40 ligand (CD40L) expressed and/or secreted by activated CD4+ T cells triggers CD40 receptor expressed on antigen presenting cells (APCs) thereby enhancing their antigen presentation capacity. In order to bypass the requirement of CD4+ T cells we generated a non-replicating recombinant vaccinia virus encoding human CD40L (rVV40L) and compared its ability to shape CD8-mediated immune response to soluble CD40L recombinant protein (sCD40L).

In this regard, our data clearly underline the different biological properties of membrane-bound CD40L, as provided by rVV40L infection, as compared to its soluble form, in CD14+ APCs activation. Notably, considering expression of IL-12p40, IFN-a and -b genes, cytokines of proven relevance for memory T cell induction, rVV40L-infection was much more potent than s40L-treatment alone or combine with WT infection. In parallel, s40L-stimulation induced a much more significant expression of IL-10 and indoleamine-2, 3-dioxygenase (IDO) genes encoding immunosuppressive factors. Considering a panel of molecules involved in the generation of the immunological synapse with T cells on CD14+ cells, rVV40L appeared to promote a less intense up regulation of CD80 co-stimulatory molecules but, most importantly, only a minor increase of programmed death ligand-1 (PD-L1). Therefore, gene expression and phenotypic profiles suggested that rVV40L-infected CD14+ cells might be highly effective APC in the induction of TCM CD8+ cells. Indeed, a single in vitro stimulation of naïve CD8+ T cells by rVV40L-infected CD14+ cells, in the absence of CD4+ T cells, was able to promote the rapid generation of central memory TAA (MAGE and MART-1) specific CD8+ T cells. These TCM were characterized by the typical central memory phenotype, as indicated by co-expression of CD45RO, CD62L and IL-7Ra, and by the high proliferative potential upon antigen recognition.

Collectively our data indicate that rVV40L efficiently modulates the quality of different APC signals delivered during the formation of the immunological synapse with CD8+ T cells. These in-vitro observations validate the strong clinical potential of our recombinant vaccinia virus constructs co-expressing CD40L for cancer immunotherapies.

Citation Format: Emanuele Trella, Evangelos Panopoulos, Nermin Raafat, Chantal Mengus, Emmanuel Traunecker, Swantje Heidtmann, Michael Heberer, Daniel Oertli, Giulio Cesare Spagnoli, Paul Zajac. CD40 ligand expressing recombinant vaccinia virus (rVV40L) modulation of central memory CD8-mediated immune response. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2490. doi:10.1158/1538-7445.AM2015-2490

Abstract 328: Original microenvironment of different cancer types is maintained upon culture of primary tissues in perfused bioreactors

The development of novel three-dimensional (3D) culture systems allowing the survival/expansion of primary tumors in vitro may help to bridge the gap between conventional bi-dimensional (2D) cultures and animal models, poorly predictive of therapeutic responses.

We have investigated the suitability of a previously developed perfused bioreactor system for the in vitro culture of human primary tumor tissues.

Surgical specimens of colorectal cancer (CRC, n = 15), glioblastoma (n = 3), breast cancer (n = 3), sarcoma (n = 2), and melanoma (n = 1) were used. Tumor fragments, obtained upon mechanical mincing and enzymatic digestion, were cultured on collagen scaffolds, in medium supplemented with human serum, under alternate perfusion up to 20 days. Characterization of expanded tissues was performed by histo-morphological analysis, immunofluorescence and gene expression profiling.

CRC tissues were effectively expanded in perfused 3D cultures in 10 out of 15 cases, whereas no expansion was observed under static culture conditions. Gene profiles of expanded tumor tissues suggested a heterogeneous tissue composition, as indicated by the expression of EpCAM, CD90, CD8, CD16 and Foxp3 genes. Phenotypic analysis confirmed that expanded tissues included epithelial and stromal cells, as assessed by EpCAM and vimentin staining, respectively. Evidence of tumor cell proliferation was provided by Ki67 staining. Furthermore, infiltrating CD4+ and CD8+ lymphocytes were consistently identified within cultured tumor fragments.

The established protocol could easily be adapted to other tumor types, including breast-cancer, glioblastoma, sarcoma and melanoma, with highly effective tissue formation.

Taken together, our results indicate that culture of primary tumor fragments within perfused bioreactors can be successfully achieved over a short-time period in a reproducible manner, and results in the expansion of epithelial and interstitial cells. These ex-vivo generated tissues might mirror features of the original tumor more effectively than 2D or 3D static cultures, and of patient-derived xenografts, thus possibly representing useful tools for the evaluation of sensitivity to chemotherapies or new targeted treatments.

Citation Format: Christian Hirt, Manuele G. Muraro, Valentina Mele, Francesca Amicarella, Celeste Manfredonia, Savas D. Soysal, Simone Muenst, Luigi Mariani, Christoph Kettelhack, Michael Heberer, Giulio C. Spagnoli, Ivan Martin, Giandomenica Iezzi, Adam Papadimitropoulos. Original microenvironment of different cancer types is maintained upon culture of primary tissues in perfused bioreactors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 328. doi:10.1158/1538-7445.AM2015-328

Bioreactor-engineered cancer tissue-like structures mimic phenotypes, gene expression profiles and drug resistance patterns observed "in vivo"

Anticancer compound screening on 2D cell cultures poorly predicts "in vivo" performance, while conventional 3D culture systems are usually characterized by limited cell proliferation, failing to produce tissue-like-structures (TLS) suitable for drug testing. We addressed engineering of TLS by culturing cancer cells in porous scaffolds under perfusion flow. Colorectal cancer (CRC) HT-29 cells were cultured in 2D, on collagen sponges in static conditions or in perfused bioreactors, or injected subcutaneously in immunodeficient mice. Perfused 3D (p3D) cultures resulted in significantly higher (p < 0.0001) cell proliferation than static 3D (s3D) cultures and yielded more homogeneous TLS, with morphology and phenotypes similar to xenografts. Transcriptome analysis revealed a high correlation between xenografts and p3D cultures, particularly for gene clusters regulating apoptotic processes and response to hypoxia. Treatment with 5-Fluorouracil (5-FU), a frequently used but often clinically ineffective chemotherapy drug, induced apoptosis, down-regulation of anti-apoptotic genes (BCL-2, TRAF1, and c-FLIP) and decreased cell numbers in 2D, but only "nucleolar stress" in p3D and xenografts. Conversely, BCL-2 inhibitor ABT-199 induced cytotoxic effects in p3D but not in 2D cultures. Our findings advocate the importance of perfusion flow in 3D cultures of tumor cells to efficiently mimic functional features observed "in vivo" and to test anticancer compounds.

Abstract 2024: Resistance of colorectal cancer cells to 5-FU treatment in three dimensional cell culture models under perfusion involves BCL-2

Assessment of the effectiveness of chemotherapeutic compounds in bidimensional cell cultures poorly mimics resistance development and the tumor-microenvironment complexity in vivo. In this study we addressed the suitability of a perfused bioreactor to sustain colorectal cancer cell growth and to test established treatment regimens in an in-vitro setting as compared to normal cell culture or xenografts of the same cell line.

By culturing the HT29 colorectal cancer cell line in 3D on collagen scaffolds tissue-like structures characterized by a heterogeneous pattern of proliferating and apoptotic cells closely resembling xenografts from the same cell line as generated in immunodeficient mice could be successfully established. CDX2, a colorectal cancer tumor-marker , was expressed in 3D static and perfused cultures, but not in 2D cultures. Upon perfusion, homogeneous seeding on scaffolds could be obtained and significantly higher numbers of tumor cells were recovered, as compared to static cultures (13.7 fold increase, p&lt;0.0001).

After 48 hours treatment with clinically relevant concentrations of 5-FU no effect on numbers of cells cultured in 3D under perfusionand as xenografts was observed, as compared to a 55.8% inhibition of 2D cultures. The fraction of Ki67 negative cells (G0 cell phase), was increased after a 48 hours treatment in the 3D perfused and xenografts, but it reached again levels similar to untreated cells after 96 hours. In contrast,cells surviving n 2D cell cultures remained largely positive for Ki67. Importantly, in perfused cultures we could only observe a marginal effect on the expression of BCL-2, TRAF1, FLIP apoptosis resistance genes, as compared to a significant down regulation of their expression in 2D cell cultures and 3D static conditions. In the same line, a combination of ABT-199, a new clinically approved BCL-2 inhibitor, and 5-FU induced additional cytostatic and cytotoxic effects in 3D perfused but not in 2D cell cultures (83.3% inhibition vs. 39.8% p=0.003).

Notably, we found that BCL-2 expression in tissues from neoadjuvant treated patients with resistance to treatment was higher than in stage and grade matched colorectal cancers from untreated patients or patients responding to treatment.

Cultures in perfused bioreactors offer the possibility of generating tumour tissue-like structures over a short time period. These structures are characterized by sensitivity to chemotherapeutic treatments similar to that of xenografted tumors and significantly different from standard 2D cellular assays.In particular, our data suggest that inhibition of BCL-2 in combination with 5-FU treatment in colorectal cancer could be endowed with therapeutic potential.

Citation Format: Christian Hirt, Adam Papadimitropoulos, Evangelos Panopoulos, Valentina Mele, Manuele Muraro, Eleonora Cremonesi, Raoul Droeser, Chantal Mengus, Michael Heberer, Daniel Oertli, Giandomenica Iezzi, Paul Zajac, Serenella Eppenberger-Castori, Luigi Tornillo, Luigi Terracciano, Ivan Martin, Giulio Spagnoli. Resistance of colorectal cancer cells to 5-FU treatment in three dimensional cell culture models under perfusion involves BCL-2. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2024. doi:10.1158/1538-7445.AM2014-2024

Designing questionnaires: healthcare survey to compare two different response scales

BACKGROUND

A widely discussed design issue in patient satisfaction questionnaires is the optimal length and labelling of the answering scale. The aim of the present study was to compare intra-individually the answers on two response scales to five general questions evaluating patients' perception of hospital care.

METHODS

Between November 2011 and January 2012, all in-hospital patients at a Swiss University Hospital received a patient satisfaction questionnaire on an adjectival scale with three to four labelled categories (LS) and five redundant questions displayed on an 11-point end-anchored numeric scale (NS). The scales were compared concerning ceiling effect, internal consistency (Cronbach's alpha), individual item answers (Spearman's rank correlation), and concerning overall satisfaction by calculating an overall percentage score (sum of all answers related to the maximum possible sum).

RESULTS

The response rate was 41% (2957/7158), of which 2400 (81%) completely filled out all questions. Baseline characteristics of the responders and non-responders were similar. Floor and ceiling effect were high on both response scales, but more pronounced on the LS than on the NS. Cronbach's alpha was higher on the NS than on the LS. There was a strong individual item correlation between both answering scales in questions regarding the intent to return, quality of treatment and the judgement whether the patient was treated with respect and dignity, but a lower correlation concerning satisfactory information transfer by physicians or nurses, where only three categories were available in the LS. The overall percentage score showed a comparable distribution, but with a wider spread of lower satisfaction in the NS.

CONCLUSIONS

Since the longer scale did not substantially reduce the ceiling effect, the type of questions rather than the type of answering scale could be addressed with a focus on specific questions about concrete situations instead of general questions. Moreover, the low correlation in questions about information provision suggests that only three possible response choices are insufficient. Further investigations are needed to find a more sensitive scale discriminating high-end ratings. Otherwise, a longitudinal within-hospital or a cross-sectional between-hospital comparison of patient care is questionable.

Engineered autologous cartilage tissue for nasal reconstruction after tumour resection: an observational first-in-human trial

BACKGROUND

Autologous native cartilage from the nasal septum, ear, or rib is the standard material for surgical reconstruction of the nasal alar lobule after two-layer excision of non-melanoma skin cancer. We assessed whether engineered autologous cartilage grafts allow safe and functional alar lobule restoration.

METHODS

In a first-in-human trial, we recruited five patients at the University Hospital Basel (Basel, Switzerland). To be eligible, patients had to be aged at least 18 years and have a two-layer defect (≥50% size of alar subunit) after excision of non-melanoma skin cancer on the alar lobule. Chondrocytes (isolated from a 6 mm cartilage biopsy sample from the nasal septum harvested under local anaesthesia during collection of tumour biopsy sample) were expanded, seeded, and cultured with autologous serum onto collagen type I and type III membranes in the course of 4 weeks. The resulting engineered cartilage grafts (25 mm × 25 mm × 2 mm) were shaped intra-operatively and implanted after tumour excision under paramedian forehead or nasolabial flaps, as in standard reconstruction with native cartilage. During flap refinement after 6 months, we took biopsy samples of repair tissues and histologically analysed them. The primary outcomes were safety and feasibility of the procedure, assessed 12 months after reconstruction. At least 1 year after implantation, when reconstruction is typically stabilised, we assessed patient satisfaction and functional outcomes (alar cutaneous sensibility, structural stability, and respiratory flow rate).

FINDINGS

Between Dec 13, 2010, and Feb 6, 2012, we enrolled two women and three men aged 76-88 years. All engineered grafts contained a mixed hyaline and fibrous cartilage matrix. 6 months after implantation, reconstructed tissues displayed fibromuscular fatty structures typical of the alar lobule. After 1 year, all patients were satisfied with the aesthetic and functional outcomes and no adverse events had been recorded. Cutaneous sensibility and structural stability of the reconstructed area were clinically satisfactory, with adequate respiratory function.

INTERPRETATION

Autologous nasal cartilage tissues can be engineered and clinically used for functional restoration of alar lobules. Engineered cartilage should now be assessed for other challenging facial reconstructions.

FUNDING

Foundation of the Department of Surgery, University Hospital Basel; and Krebsliga beider Basel.

Mesenchymal stromal cells induce epithelial-to-mesenchymal transition in human colorectal cancer cells through the expression of surface-bound TGF-β

Mesenchymal stem/stromal cells (MSC) are multipotent precursors endowed with the ability to home to primary and metastatic tumor sites, where they can integrate into the tumor-associated stroma. However, molecular mechanisms and outcome of their interaction with cancer cells have not been fully clarified. In this study, we investigated the effects mediated by bone marrow-derived MSC on human colorectal cancer (CRC) cells in vitro and in vivo. We found that MSC triggered epithelial-to-mesenchymal transition (EMT) in tumor cells in vitro, as indicated by upregulation of EMT-related genes, downregulation of E-cadherin and acquisition of mesenchymal morphology. These effects required cell-to-cell contact and were mediated by surface-bound TGF-β newly expressed on MSC upon coculture with tumor cells. In vivo tumor masses formed by MSC-conditioned CRC cells were larger and characterized by higher vessel density, decreased E-cadherin expression and increased expression of mesenchymal markers. Furthermore, MSC-conditioned tumor cells displayed increased invasiveness in vitro and enhanced capacity to invade peripheral tissues in vivo. Thus, by promoting EMT-related phenomena, MSC appear to favor the acquisition of an aggressive phenotype by CRC cells.

The relationship between hospital patients' ratings of quality of care and communication

OBJECTIVE

To assess the relationship between hospital patients' quality of care ratings and their experiences with health-related information exchanges and communication during hospitalization.

DESIGN

Cross-sectional multivariate dimensional analysis of data from a quality of care experience questionnaire of hospital patients comparing scores across three levels of reported satisfaction.

SETTING AND PARTICIPANTS

Five thousand nine hundred and fifty-two patients from a Swiss University Hospital responded to the questionnaire at discharge during 2010.

MAIN OUTCOME MEASURES

Survey questions measuring patients' evaluation of quality of care, patient loyalty and overall satisfaction.

RESULTS

Different levels of reported satisfaction are associated with differing experiences of health-related information and communication during a hospital stay.

CONCLUSIONS

Patients who report lower satisfaction appear to attribute to the hospital staff enduring negative dispositions from behaviours that may be due to specific situational contexts. Negative experiences appear to influence scores on most other communication and information domains. Patients who report higher satisfaction, in contrast, appear to differentiate negative experiences and positive experiences and they appear to relativize and compartmentalize negative experiences associated with their hospital stay.

Induction of aberrant vascular growth, but not of normal angiogenesis, by cell-based expression of different doses of human and mouse VEGF is species-dependent

Therapeutic angiogenesis by vascular endothelial growth factor (VEGF) gene delivery is an attractive approach to treat ischemia. VEGF remains localized around each producing cell in vivo, and overexpression of mouse VEGF(164) (mVEGF(164)) induces normal or aberrant angiogenesis, depending strictly on its dose in the microenvironment in vivo. However, the dose-dependent effects of the clinically relevant factor, human VEGF(165) (hVEGF(165)), are unknown. Here we exploited a highly controlled gene delivery platform, based on clonal populations of transduced myoblasts overexpressing specific VEGF levels, to rigorously compare the in vivo dose-dependent effects of hVEGF(165) and mVEGF(164) in skeletal muscle of severe combined immune deficient (SCID) mice. While low levels of both factors efficiently induced similar amounts of normal angiogenesis, only high levels of mVEGF(164) caused widespread angioma-like structures, whereas equivalent or even higher levels of hVEGF(165) induced exclusively normal and mature capillaries. Expression levels were confirmed both in vitro and in vivo by enzyme-linked immunosorbent assay (ELISA) and quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). However, in vitro experiments showed that hVEGF(165) was significantly more effective in activating VEGF receptor signaling in human endothelial cells than mVEGF(164), while the opposite was true in murine endothelial cells. In conclusion, we found that, even though hVEGF is similarly efficient to the syngenic mVEGF in inducing angiogenesis at lower doses in a widely adopted and convenient mouse preclinical model, species-dependent differences in the relative activation of the respective receptors may specifically mask the toxic effects of high doses of the human factor.

Characterization and clinical relevance of ALDHbright populations in prostate cancer

PURPOSE

High aldehyde dehydrogenase (ALDH) has been suggested to selectively mark cells with high tumorigenic potential in established prostate cancer cell lines. However, the existence of cells with high ALDH activity (ALDH(bright)) in primary prostate cancer specimens has not been shown so far. We investigated the presence, phenotype, and clinical significance of ALDH(bright) populations in clinical prostate cancer specimens.

EXPERIMENTAL DESIGN

We used ALDEFLUOR technology and fluorescence-activated cell-sorting (FACS) staining to identify and characterize ALDH(bright) populations in cells freshly isolated from clinical prostate cancer specimens. Expression of genes encoding ALDH-specific isoforms was evaluated by quantitative real-time PCR in normal prostate, benign prostatic hyperplasia (BPH), and prostate cancer tissues. ALDH1A1-specific expression and prognostic significance were assessed by staining two tissue microarrays that included more than 500 samples of BPH, prostatic intraepithelial neoplasia (PIN), and multistage prostate cancer.

RESULTS

ALDH(bright) cells were detectable in freshly excised prostate cancer specimens (n = 39) and were mainly included within the EpCAM((+)) and Trop2((+)) cell populations. Although several ALDH isoforms were expressed to high extents in prostate cancer, only ALDH1A1 gene expression significantly correlated with ALDH activity (P < 0.01) and was increased in cancers with high Gleason scores (P = 0.03). Most importantly, ALDH1A1 protein was expressed significantly more frequently and at higher levels in advanced-stage than in low-stage prostate cancer and BPH. Notably, ALDH1A1 positivity was associated with poor survival (P = 0.02) in hormone-naïve patients.

CONCLUSIONS

Our data indicate that ALDH contributes to the identification of subsets of prostate cancer cells of potentially high clinical relevance.

Controlled angiogenesis in the heart by cell-based expression of specific vascular endothelial growth factor levels

Vascular endothelial growth factor (VEGF) can induce normal angiogenesis or the growth of angioma-like vascular tumors depending on the amount secreted by each producing cell because it remains localized in the microenvironment. In order to control the distribution of VEGF expression levels in vivo, we recently developed a high-throughput fluorescence-activated cell sorting (FACS)-based technique to rapidly purify transduced progenitors that homogeneously express a specific VEGF dose from a heterogeneous primary population. Here we tested the hypothesis that cell-based delivery of a controlled VEGF level could induce normal angiogenesis in the heart, while preventing the development of angiomas. Freshly isolated human adipose tissue-derived stem cells (ASC) were transduced with retroviral vectors expressing either rat VEGF linked to a FACS-quantifiable cell-surface marker (a truncated form of CD8) or CD8 alone as control (CTR). VEGF-expressing cells were FACS-purified to generate populations producing either a specific VEGF level (SPEC) or uncontrolled heterogeneous levels (ALL). Fifteen nude rats underwent intramyocardial injection of 10(7) cells. Histology was performed after 4 weeks. Both the SPEC and ALL cells produced a similar total amount of VEGF, and both cell types induced a 50%-60% increase in both total and perfused vessel density compared to CTR cells, despite very limited stable engraftment. However, homogeneous VEGF expression by SPEC cells induced only normal and stable angiogenesis. Conversely, heterogeneous expression of a similar total amount by the ALL cells caused the growth of numerous angioma-like structures. These results suggest that controlled VEGF delivery by FACS-purified ASC may be a promising strategy to achieve safe therapeutic angiogenesis in the heart.

High myeloperoxidase positive cell infiltration in colorectal cancer is an independent favorable prognostic factor

Background

Colorectal cancer (CRC) infiltration by adaptive immune system cells correlates with favorable prognosis. The role of the innate immune system is still debated. Here we addressed the prognostic impact of CRC infiltration by neutrophil granulocytes (NG).

Methods

A TMA including healthy mucosa and clinically annotated CRC specimens (n = 1491) was stained with MPO and CD15 specific antibodies. MPO+ and CD15+ positive immune cells were counted by three independent observers. Phenotypic profiles of CRC infiltrating MPO+ and CD15+ cells were validated by flow cytometry on cell suspensions derived from enzymatically digested surgical specimens. Survival analysis was performed by splitting randomized data in training and validation subsets.

Results

MPO+ and CD15+ cell infiltration were significantly correlated (p<0.0001; r = 0.76). However, only high density of MPO+ cell infiltration was associated with significantly improved survival in training (P = 0.038) and validation (P = 0.002) sets. In multivariate analysis including T and N stage, vascular invasion, tumor border configuration and microsatellite instability status, MPO+ cell infiltration proved an independent prognostic marker overall (P = 0.004; HR = 0.65; CI:±0.15) and in both training (P = 0.048) and validation (P = 0.036) sets. Flow-cytometry analysis of CRC cell suspensions derived from clinical specimens showed that while MPO+ cells were largely CD15+/CD66b+, sizeable percentages of CD15+ and CD66b+ cells were MPO−.

Conclusions

High density MPO+ cell infiltration is a novel independent favorable prognostic factor in CRC.

Clinical impact of programmed cell death ligand 1 expression in colorectal cancer

BACKGROUND

Programmed cell death 1 (PD-1) receptor triggering by PD ligand 1 (PD-L1) inhibits T cell activation. PD-L1 expression was detected in different malignancies and associated with poor prognosis. Therapeutic antibodies inhibiting PD-1/PD-L1 interaction have been developed.

MATERIALS AND METHODS

A tissue microarray (n=1491) including healthy colon mucosa and clinically annotated colorectal cancer (CRC) specimens was stained with two PD-L1 specific antibody preparations. Surgically excised CRC specimens were enzymatically digested and analysed for cluster of differentiation 8 (CD8) and PD-1 expression.

RESULTS

Strong PD-L1 expression was observed in 37% of mismatch repair (MMR)-proficient and in 29% of MMR-deficient CRC. In MMR-proficient CRC strong PD-L1 expression correlated with infiltration by CD8(+) lymphocytes (P = 0.0001) which did not express PD-1. In univariate analysis, strong PD-L1 expression in MMR-proficient CRC was significantly associated with early T stage, absence of lymph node metastases, lower tumour grade, absence of vascular invasion and significantly improved survival in training (P = 0.0001) and validation (P = 0.03) sets. A similar trend (P = 0.052) was also detectable in multivariate analysis including age, sex, T stage, N stage, tumour grade, vascular invasion, invasive margin and MMR status. Interestingly, programmed death receptor ligand 1 (PDL-1) and interferon (IFN)-γ gene expression, as detected by quantitative reverse transcriptase polymerase chain reaction (RT-PCR) in fresh frozen CRC specimens (n = 42) were found to be significantly associated (r = 0.33, P = 0.03).

CONCLUSION

PD-L1 expression is paradoxically associated with improved survival in MMR-proficient CRC.

Governance of hospital alliances: lessons learnt from 6 hospital and non-hospital cases

Hospital alliances can be a solution for the coordination that is required between providers as a result of the increasing fragmentation in health-care services. 3 hospital and 3 non-hospital alliances were studied with a qualitative case study methodology, to find common, or specific, practices with regards to the management of alliances. Striking similarities prevailed, hospital alliances are not unique and common principles of coordination were identified that appear pivotal for successful alliance management.

Klf4 transcription factor is expressed in the cytoplasm of prostate cancer cells

BACKGROUND

Cancer initiation and progression might be driven by small populations of cells endowed with stem cell-like properties. Here we comparatively addressed the expression of genes encoding putative stemness regulators including c-Myc, Klf4, Nanog, Oct4A and Sox2 genes in benign prostatic hyperplasia (BPH) and prostate cancer (PCA).

METHODS

Fifty-eight PCA and thirty-nine BPH tissues samples were used for gene expression analysis, as evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). The expression of specific Klf4 isoforms was tested by conventional PCR. Klf4 specific antibodies were used for protein detection in a tissue microarray including 404 prostate samples.

RESULTS

Nanog, Oct4A and Sox2 genes were comparably expressed in BPH and PCA samples, whereas c-Myc and Klf4 genes were expressed to significantly higher extents in PCA than in BPH specimens. Immunohistochemical studies revealed that Klf4 protein is detectable in a large majority of epithelial prostatic cells, irrespective of malignant transformation. However, in PCA, a predominantly cytoplasmic location was observed, consistent with the expression of a differentially spliced Klf4α isoform.

CONCLUSION

Klf4 is highly expressed at gene and protein level in BPH and PCA tissues but a cytoplasmic location of the specific gene product is predominantly detectable in malignant cells. Klf4 location might be of critical relevance to steer its functions during oncogenesis.

CD133+, CD166+CD44+, and CD24+CD44+ phenotypes fail to reliably identify cell populations with cancer stem cell functional features in established human colorectal cancer cell lines

Increasing evidence that cancers originate from small populations of so-called cancer stem cells (CSCs), capable of surviving conventional chemotherapies and regenerating the original tumor, urges the development of novel CSC-targeted treatments. Screening of new anticancer compounds is conventionally conducted on established tumor cell lines, providing sufficient material for high-throughput studies. Whether tumor cell lines might comprise CSC populations resembling those of primary tumors, however, remains highly debated. We have analyzed the expression of defined phenotypic profiles, including CD133+, CD166+CD44+, and CD24+CD44+, reported as CSC-specific in human primary colorectal cancer (CRC), on a panel of 10 established CRC cell lines and evaluated their correlation with CSC properties. None of the putative CSC phenotypes consistently correlated with stem cell-like features, including spheroid formation ability, clonogenicity, aldehyde dehydrogenase-1 activity, and side population phenotype. Importantly, CRC cells expressing putative CSC markers did not exhibit increased survival when treated with chemotherapeutic drugs in vitro or display higher tumorigenicity in vivo. Thus, the expression of CD133 or the coexpression of CD166/CD44 or CD24/CD44 did not appear to reliably identify CSC populations in established CRC cell lines. Our findings question the suitability of cell lines for the screening of CSC-specific therapies and underline the urgency of developing novel platforms for anticancer drug discovery.

Perspective on the evolution of cell-based bone tissue engineering strategies

Despite the compelling clinical needs in enhancing bone regeneration and the potential offered by the field of tissue engineering, the adoption of cell-based bone graft substitutes in clinical practice is limited to date. In fact, no study has yet convincingly demonstrated reproducible clinical performance of tissue-engineered implants and at least equivalent cost-effectiveness compared to the current treatment standards. Here, we propose and discuss how tissue engineering strategies could be evolved towards more efficient solutions, depicting three different experimental paradigms: (i) bioreactor-based production; (ii) intraoperative manufacturing, and (iii) developmental engineering. The described approaches reflect the need to streamline graft manufacturing processes while maintaining the potency of osteoprogenitors and recapitulating the sequence of biological steps occurring during bone development, including vascularization. The need to combine the assessment of efficacy of the different strategies with the understanding of their mechanisms of action in the target regenerative processes is highlighted. This will be crucial to identify the necessary and sufficient set of signals that need to be delivered at the injury or defect site and should thus form the basis to define release criteria for reproducibly effective engineered bone graft substitutes.

FACS-purified myoblasts producing controlled VEGF levels induce safe and stable angiogenesis in chronic hind limb ischemia

We recently developed a method to control the in vivo distribution of vascular endothelial growth factor (VEGF) by high throughput Fluorescence-Activated Cell Sorting (FACS) purification of transduced progenitors such that they homogeneously express specific VEGF levels. Here we investigated the long-term safety of this method in chronic hind limb ischemia in nude rats. Primary myoblasts were transduced to co-express rat VEGF-A₁₆₄ (rVEGF) and truncated ratCD8a, the latter serving as a FACS-quantifiable surface marker. Based on the CD8 fluorescence of a reference clonal population, which expressed the desired VEGF level, cells producing similar VEGF levels were sorted from the primary population, which contained cells with very heterogeneous VEGF levels. One week after ischemia induction, 12 × 10⁶ cells were implanted in the thigh muscles. Unsorted myoblasts caused angioma-like structures, whereas purified cells only induced normal capillaries that were stable after 3 months. Vessel density was doubled in engrafted areas, but only approximately 0.1% of muscle volume showed cell engraftment, explaining why no increase in total blood flow was observed. In conclusion, the use of FACS-purified myoblasts granted the cell-by-cell control of VEGF expression levels, which ensured long-term safety in a model of chronic ischemia. Based on these results, the total number of implanted cells required to achieve efficacy will need to be determined before a clinical application.

Abstract 3384: High ALDH activity is associated with high tumorigenicity in prostate cancer

OBJECTIVE: Tumor initiation and progression might be driven by rare populations of cells endowed with stem-properties, and therefore defined as cancer stem cells (CSC). High Aldehyde dehydrogenase (ALDH) activity has been suggested to selectively identify CSC in several tumor types including breast cancer, and, possibly, prostate cancer (PCA). In this study, we investigated presence and potential CSC characteristics of cells with high ALDH activity (ALDH bright) in PCA cell lines, fresh surgical specimens, and primary cultures. MATERIALS AND METHODS: PC3, Du145, VCaP, and LNCaP PCA cell lines were evaluated. Surgical specimens, including Benign Prostate Hyperplasia (BPH) and PCA, were used directly for gene expression studies. Surgical samples were also enzymatically digested for functional analysis and the establishment of primary cultures. ALDH activity was tested using ALDEFLUOR® technology. Cells were sorted from individual cell lines by flow cytometry and evaluated for CSC properties, including spheroid formation ability, clonogenicity, stemness-related gene expression, ALDH specific isoforms expression, and tumorigenicity upon injection in NOD/SCID mice. RESULTS: PCA cell lines and primary cultures displayed heterogeneous ALDH activity and expression of specific ALDH isoforms. Despite a higher expression of Oct4A and Klf4 stemness associated genes, ALDH bright cells isolated from Du145 and PC3 did not show improved spheroid formation or clonogenic capacity, as compared to their dim counterparts. Interestingly, however, ALDH bright cells were associated with a significantly higher tumorigenic capacity in vivo as compared to ALDH low cells. Nevertheless, ALDH bright cells lost their higher tumorigenic capacity following serial “in vivo” passages. Most importantly, a well defined ALDH bright population could also be detected in cells isolated from PCA specimens (n&gt;20). ALDH activity was consistent with a strong expression of several ALDH specific isoforms in PCA tissues. Notably, a significant increase of defined ALDH isoforms such as ALDH1A3 (p=0.001) was detectable in tissues obtained from patients with PCA as compared to BPH or normal specimens. CONCLUSIONS: ALDH bright subsets can be detected in cells isolated from fresh PCA tissue samples, PCA cell lines and primary cultures. These populations appear to be associated with increased “in vivo” tumorigenicity rather than enhanced “in vitro” stem properties in the cell lines investigated. Importantly, expression of ALDH specific isoforms appears to be increased in clinical PCA as compared to BPH and “normal” samples, thereby suggesting a putative role of ALDH in PCA tumorigenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3384. doi:1538-7445.AM2012-3384

Differential pattern and prognostic significance of CD4+, FOXP3+ and IL-17+ tumor infiltrating lymphocytes in ductal and lobular breast cancers

Background

Clinical relevance of tumor infiltrating lymphocytes (TILs) in breast cancer is controversial. Here, we used a tumor microarray including a large series of ductal and lobular breast cancers with long term follow up data, to analyze clinical impact of TIL expressing specific phenotypes and distribution of TILs within different tumor compartments and in different histological subtypes.

Methods

A tissue microarray (TMA) including 894 ductal and 164 lobular breast cancers was stained with antibodies recognizing CD4, FOXP3, and IL-17 by standard immunohistochemical techniques. Lymphocyte counts were correlated with clinico-pathological parameters and survival.

Results

CD4⁺ lymphocytes were more prevalent than FOXP3⁺ TILs whereas IL-17⁺ TILs were rare. Increased numbers of total CD4⁺ and FOXP3⁺ TIL were observed in ductal, as compared with lobular carcinomas. High grade (G3) and estrogen receptor (ER) negative ductal carcinomas displayed significantly (p < 0.001) higher CD4⁺ and FOXP3⁺ lymphocyte infiltration while her2/neu over-expression in ductal carcinomas was significantly (p < 0.001) associated with higher FOXP3⁺ TIL counts. In contrast, lymphocyte infiltration was not linked to any clinico-pathological parameters in lobular cancers. In univariate but not in multivariate analysis CD4⁺ infiltration was associated with significantly shorter survival in patients bearing ductal, but not lobular cancers. However, a FOXP3⁺/CD4⁺ ratio > 1 was associated with improved overall survival even in multivariate analysis (p = 0.033).

Conclusions

Ductal and lobular breast cancers appear to be infiltrated by different lymphocyte subpopulations. In ductal cancers increased CD4⁺ and FOXP3⁺ TIL numbers are associated with more aggressive tumor features. In survival analysis, absolute numbers of TILs do not represent major prognostic indicators in ductal and lobular breast cancer. Remarkably however, a ratio > 1 of total FOXP3⁺/CD4⁺ TILs in ductal carcinoma appears to represent an independent favorable prognostic factor.

Preventing vaccinia virus class-I epitopes presentation by HSV-ICP47 enhances the immunogenicity of a TAP-independent cancer vaccine epitope

Herpes simplex virus protein ICP47, encoded by US12 gene, strongly downregulates major histocompatibility complex (MHC) class-I antigen restricted presentation by blocking transporter associated with antigen processing (TAP) protein. To decrease viral vector antigenic immunodominance and MHC class-I driven clearance, we engineered recombinant vaccinia viruses (rVV) expressing ICP47 alone (rVV-US12) or together with endoplasmic reticulum (ER)-targeted Melan-A/MART-1(27-35) model tumor epitope (rVV-MUS12). In this study, we show that antigen presenting cells (APC), infected with rVV-US12, display a decreased ability to present TAP dependent MHC class-I restricted viral antigens to CD8+ T-cells. While HLA class-I cell surface expression is strongly downregulated, other important immune related molecules such as CD80, CD44 and, most importantly, MHC class-II are unaffected. Characterization of rVV-MUS12 infected cells demonstrates that over-expression of a TAP-independent peptide, partially compensates for ICP47 induced surface MHC class-I downregulation (30% vs. 70% respectively). Most importantly, in conditions where clearance of infected APC by virus-specific CTL represents a limiting factor, a significant enhancement of CTL responses to the tumor epitope can be detected in cultures stimulated with rVV-MUS12, as compared to those stimulated by rVV-MART alone. Such reagents could become of high relevance in multiple boost protocols required for cancer immunotherapy, to limit vector-specific responsiveness.

Generation of human adult mesenchymal stromal/stem cells expressing defined xenogenic vascular endothelial growth factor levels by optimized transduction and flow cytometry purification

Adult mesenchymal stromal/stem cells (MSCs) are a valuable source of multipotent progenitors for tissue engineering and regenerative medicine, but may require to be genetically modified to widen their efficacy in therapeutic applications. For example, overexpression of the angiogenic factor vascular endothelial growth factor (VEGF) at controlled levels is an attractive strategy to overcome the crucial bottleneck of graft vascularization and to avoid aberrant vascular growth. Since the regenerative potential of MSCs is rapidly lost during in vitro expansion, we sought to develop an optimized technique to achieve high-efficiency retroviral vector transduction of MSCs derived from both adipose tissue (adipose stromal cells, ASCs) or bone marrow (BMSCs) and rapidly select cells expressing desired levels of VEGF with minimal in vitro expansion. The proliferative peak of freshly isolated human ASCs and BMSCs was reached 4 and 6 days after plating, respectively. By performing retroviral vector transduction at this time point, >90% efficiency was routinely achieved before the first passage. MSCs were transduced with vectors expressing rat VEGF(164) quantitatively linked to a syngenic cell surface marker (truncated rat CD8). Retroviral transduction and VEGF expression did not affect MSC phenotype nor impair their in vitro proliferation and differentiation potential. Transgene expression was also maintained during in vitro differentiation. Furthermore, three subpopulations of transduced BMSCs homogeneously producing specific low, medium, and high VEGF doses could be prospectively isolated by flow cytometry based on the intensity of their CD8 expression already at the first passage. In conclusion, this optimized platform allowed the generation of populations of genetically modified MSCs, expressing specific levels of a therapeutic transgene, already at the first passage, thereby minimizing in vitro expansion and loss of regenerative potential.

Elevated levels of circulating IL-7 and IL-15 in patients with early stage prostate cancer

Background

Chronic inflammation has been suggested to favour prostate cancer (PCA) development. Interleukins (IL) represent essential inflammation mediators. IL-2, IL-7, IL-15 and IL-21, sharing a common receptor γ chain (c-γ), control T lymphocyte homeostasis and proliferation and play major roles in regulating cancer-immune system interactions. We evaluated local IL-2, IL-7, IL-15 and IL-21 gene expression in prostate tissues from patients with early stage PCA or benign prostatic hyperplasia (BPH). As control, we used IL-6 gene, encoding an IL involved in PCA progression. IL-6, IL-7 and IL-15 titres were also measured in patients' sera.

Methods

Eighty patients with BPH and 79 with early (1 to 2c) stage PCA were enrolled. Gene expression in prostate tissues was analyzed by quantitative real-time PCR (qRT-PCR). Serum IL concentrations and acute phase protein titres were evaluated by ELISA. Mann-Whitney, Wilcoxon and χ² tests were used to compare IL gene expression and serum titers in the two groups of patients. Receiver operating characteristic (ROC) curves were constructed to evaluate the possibility to distinguish sera from different groups of patients based on IL titers.

Results

IL-2 and IL-21 gene expression was comparably detectable, with low frequency and at low extents, in PCA and BPH tissues. In contrast, IL-6, IL-7 and IL-15 genes were expressed more frequently (p < 0.0001, p = 0.0047 and p = 0.0085, respectively) and to significantly higher extents (p = 0.0051, p = 0.0310 and p = 0.0205, respectively) in early stage PCA than in BPH tissues. Corresponding proteins could be detected to significantly higher amounts in sera from patients with localized PCA, than in those from patients with BPH (p = 0.0153, p = 0.0174 and p = 0.0064, respectively). Analysis of ROC curves indicates that IL-7 (p = 0.0039), but not IL-6 (p = 0.2938) or IL-15 (p = 0.1804) titres were able to distinguish sera from patients with malignancy from those from patients with benign disease. Serum titres of C reactive (CRP), high mobility group B1 (HMGB1) and serum amyloid A (SAA) acute phase proteins were similar in both groups of patients.

Conclusions

Expression IL-7 and IL-15 genes in prostate tissues and corresponding serum titres are significantly increased in patients with early stage PCA as compared with patients with BPH.

Abstract 1513: Mesenchymal stromal cells enhance the malignant potential of human colorectal cancer cells by inducing epithelial to mesenchymal transition-related phenomena

Background: Mesenchymal stromal cells (MSCs) are recruited to primary and metastatic sites of several tumour types, including colorectal cancer (CRC), and might contribute to tumour progression. The actual role played by MSCs and the mechanisms underlying MSC-tumour interactions remain to be clarified. We investigated the effects of human bone-marrow-derived MSCs (BM-MSCs) on CRC, in vitro and in vivo.

Material and methods: Human established CRC cell lines were cultured in the presence or absence of BM-MSCs, in direct contact or in transwell plates. After a five day culture, tumour cell proliferation was assessed by differential cell counts, surface molecule expression was analyzed by flow cytometry, and production of soluble factors in culture supernatants was measured by Raybio antibody array® and ELISA. Tumour cells, sorted upon co-culture by flow cytometry, were evaluated for the expression of epithelial to mesenchymal transition (EMT)-related genes by quantitative PCR and for in vitro invasiveness, by chemoinvasion assay. Furthermore, their tumorigenicity was assessed upon injection in NOD/SCID mice and developing tumours were analyzed by immunofluorescence.

Results: MSCs significantly increased tumour cell proliferation and decreased CD44 expression, independently of cell-to-cell contact. Analysis of co-culture supernatants revealed higher amounts of IL-6, MCP-1, RANTES and Angiogenin, in comparison to supernatants derived from single cultures. Moreover increased expression of several EMT-related genes, including SNAI2, TWIST, N-Cadherin, was detected on CRC cells sorted upon co-culture as compared with controls. Importantly, CRC cells co-cultured with MSCs showed higher invasive behaviour in vitro, than CRC cells cultured alone. No significant changes were observed in tumorigenicity. However, tumours originated from tumour cells co-cultured with MSCs showed a significantly higher vessel density as compared to controls.

Conclusions: MSCs reduce adhesiveness, induce expression of EMT-related genes and increase proliferation, invasiveness and angiogenic potential of CRC cells. These effects might contribute to CRC progression and spreading.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1513. doi:10.1158/1538-7445.AM2011-1513

Abstract 3658: The expression of genes encoding common gamma-chain cytokines is associated with tissue infiltration by CD8+ T cells displaying an “exhausted” phenotype in benign prostatic hyperplasia and prostate cancer

Objectives: Prostate cancer (PCA) is a leading cause of cancer related-death in men. Immunotherapy may provide alternative therapy for patients with castration-resistant PCA. Immunosuppressive mechanisms in benign prostatic hyperplasia (BPH) and PCA patients are not fully clarified. We analyzed homeostatic cytokines gene expression in tissue from patients bearing either PCA or BPH. CD8+ T cells exhaustion was assessed by evaluating Programmed Death-1 (PD-1) and its ligand PD-L1 expression in freshly isolated tissue infiltrating and peripheral blood CD8+ T cells.

Methods: 78 BPH, 93 PCA patients were enrolled. Gene expression was evaluated by Real-Time-PCR. Protein expressions were assessed by flow cytometry.

Results: IL-6, IL-7 and IL-15 gene expression were significantly increased in PCA tissues as compared to BPH (p=0.0077; p=0.0244 and p=0.0316, respectively). No significant differences were observed in IL-2, IL-17 and IL-21 gene expression.

A majority of CD8+ T cells infiltrating BPH or PCA tissues were PD-1+ (82.78±7.33% and 87.63±6.41%, respectively), whereas PD-L1 was expressed in 50.71±14.42% and 36.97±14.95% of tissue infiltrating CD8+ T cells in BPH and PCA, respectively. PD-L2 was expressed in 10.15±5.97% and 13.70±7.66% of tissue infiltrating CD8+ T cells in BPH and PCA, respectively.

In peripheral blood CD8+ T cells, PD-1, -L1 and -L2 expressions were similar in BPH (26.36±2.81%, 23.74±4.78% and 1.41±0.26%; respectively) and PCA patients (26.29±2.80, 26.56±3.23 and 4.40±1.84; respectively). CD8+PD-1+ cells were in majority effector memory and effector cells in both groups, while CD8+PD-L1+ cells were mainly effector and naïve cells.

In peripheral blood CD8+ T cells from BPH and PCA patients, %CD8+PD-L1+ cells was correlating with %CD8+CD25+ cells (p=0.011 and r=0.790, p=0.044 and r=0.646; respectively).

Percentages of CD8+PD-1+ cells from patients bearing either BPH or PCA were significantly increasing upon culture with IL-7 and IL-15. In addition, the basal level of Stat5 phosphorylation in peripheral blood CD8+ T cells from PCA patients was significantly higher as compared to BPH (p=0.045), and Stat5 activation was similarly increased upon culture with homeostatic cytokines in the both groups.

Conclusion: We demonstrated that tissues from patients bearing BPH and PCA are expressing inflammatory homeostatic cytokine genes. Percentages of tissue infiltrating and peripheral blood CD8+ T cells from both groups expressing PD-1 and ligands are high. In addition, homeostatic cytokines are able to up-regulate in vitro expression of these exhaustion molecules in peripheral blood CD8+ T cells from patients bearing either BPH or PCA.

Cytokine rich tumour environment might lead to T cell exhaustion rather than activation, thus raising the issue of the role of T cells exhaustion in PCA.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3658. doi:10.1158/1538-7445.AM2011-3658

Effect of three-dimensional expansion and cell seeding density on the cartilage-forming capacity of human articular chondrocytes in type II collagen sponges

Chondrocytes for tissue engineering strategies are typically expanded in monolayer (2D), leading to cell dedifferentiation but allowing to generate large cell numbers for seeding into scaffolds. Direct chondrocyte culture in scaffolds, instead, may support better maintenance of the differentiated phenotype but reduce the extent of proliferation and thus the resulting cell density. This study investigates whether the quality of cartilaginous tissues generated in vitro by human articular chondrocytes (HAC) on type II collagen sponges is enhanced (1) by direct expansion on the scaffolds (3D), as compared with standard 2D, or (2) by increasing cell seeding density, which in turn requires extensive 2D expansion. Three-dimensional expansion of HAC on the scaffolds, as compared with 2D expansion for the same number of doublings, better maintained the chondrocytic phenotype of the expanded cells (13.7-fold higher levels of type II collagen mRNA) but did not enhance their accumulation of glycosaminoglycan (GAG) following chondrogenic culture. Instead, increasing the HAC seeding density in the scaffolds (from 25 × 10(3) to 66 × 10(3) cells/mm(3)) significantly improved chondrogenesis (up to 3.3-fold higher GAG accumulation and up to 9.3-fold higher type II collagen mRNA), even if seeded cells had to be expanded and dedifferentiated more extensively in 2D to reach the required cell numbers. This study indicates that, under the specific conditions tested, a high-seeding density of HAC in 3D scaffolds is more critical for the generation of cartilaginous constructs than the stage of cell differentiation reached following expansion.

High-throughput flow cytometry purification of transduced progenitors expressing defined levels of vascular endothelial growth factor induces controlled angiogenesis in vivo

Delivery of therapeutic genes by genetically modified progenitors is a powerful tool for regenerative medicine. However, many proteins remain localized within or around the expressing cell, and heterogeneous expression levels can lead to reduced efficacy or increased toxicity. For example, the matrix-binding vascular endothelial growth factor (VEGF) can induce normal, stable, and functional angiogenesis or aberrant angioma growth depending on its level of expression in the microenvironment around each producing cell, and not on its total dose. To overcome this limitation, we developed a flow cytometry-based method to rapidly purify transduced cells expressing desired levels of a therapeutic transgene. Primary mouse myoblasts were transduced with a bicistronic retrovirus expressing VEGF linked to a nonfunctional, truncated form of the syngenic molecule CD8a. By using a clonal population uniformly expressing a known VEGF level as a reference, cells producing similar VEGF amounts were rapidly sorted from the primary population on the basis of their CD8a fluorescence intensity. A single round of sorting with a suitably designed gate yielded a purified population that induced robust, normal, and stable angiogenesis, and completely avoided angioma growth, which was instead always caused by the heterogeneous parent population. This clinically applicable high-throughput technique allowed the delivery of highly controlled VEGF levels in vivo, leading to significantly improved safety without compromising efficacy. Furthermore, when applied to other suitable progenitor populations, this technique could help overcome a significant obstacle in the development of safe and efficacious vascularization strategies in the fields of regenerative medicine and tissue engineering.

Abstract 1500: Modulation of recombinant vaccinia virus vector immunogenicity

Recombinant poxviruses expressing tumor associated antigens (TAAs) are evaluated since 20 years as immunogenic vaccine vector in clinical trials. Possible limitation to recombinant viral vector is due to either prior systemic immunity to poxviruses or immunodominance of viral antigens which may reduce the induction of immune response against weaker tumor antigens. To address this issue, we developed a recombinant Vaccinia virus expressing HSV type I protein ICP47. This protein down-regulates MHC class-I antigen presentation by blocking the transporter associated with antigen processing (TAP), which translocates peptides, generated by proteasomal protein degradation, into the endoplasmic reticulum for loading onto MHC class I molecule.

Herpes simplex virus (HSV) US12 gene, coding for infected cell protein 47 (ICP47) was introduced into wild type vaccinia virus and into a r.VV expressing MART-1/Melan-A27–35 HLA-A201 endoplasmic reticulum (ER)-targeted epitope. Following infection with non-replicating recombinant virus, effect of ICP47 expression on cell surface MHC-class-I, MHC class-II and co-stimulatory molecules was characterized by antibody staining and FACS analysis. Human T-lymphocytes were stimulated in vitro with autologous CD14+ cells infected with r.VV-US12, r.VV-Mart-US12 or control virus. Responsiveness of specific CD8+ and CD4+ to viral proteins and recombinant epitopes were monitored by MHC-multimer staining and interferon gamma (IFNg) expression analysis.

Cells infected with HSV-US12-r.VV, demonstrated a decreased ability of presenting MHC class-I antigens to CD8+ T cells whereas MHC-class-II restricted presentation to CD4+ T cells remained unaffected. Co-expression of ER-Melan-A/Mart-126–35 appeared to partially compensate for the ICP47 related surface MHC class-I molecule down-regulation and preserve a strong capacity to induce CTL response against the TAA derived peptide.

Thus, viral vectors expressing ICP47 confirmed a diminished TAP-dependant processing of endogenous class-I restricted epitopes while the immunogenic potential of recombinant epitopes directly targeted to the ER was enhanced. Such reagents could become of high relevance especially in multiple-boost vaccine protocol required in cancer immunotherapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1500.

Abstract 4782: Expression of programmed death-1 in CD8+ T cells from patients bearing PCA upon stimulation with common γ-chain cytokines

Prostate cancer (PCA) is a leading cause of cancer death in men. Underlying immunosuppressive mechanisms in benign prostate hyperplasia (BPH) and PCA patients are not fully clarified. We analyzed homeostatic proliferation of CD8+ T cells upon stimulation with common receptor γ chain IL-2, IL-7 and IL-15 cytokines in PCA as compared to BPH patients. CD8+ T cells exhaustion was assessed by evaluating Programmed Death-1 (PD-1) receptor and its ligand PD-L1 expression in PBMC and tissue infiltrating CD8+ T cells from PCA and BPH patients.

57 BPH and 76 PCA patients were enrolled. Gene expression was quantified by Real-Time PCR. T cell proliferation was evaluated by CFSE dilution. CD132, CD122, PD-1 and PD-Ll expression were assessed by flow cytometry.

IL-2, IL-7 and IL-15 gene expression were quantified in PCA (n=57) and BPH (n=32) tissues. IL-7 and IL-15 gene expression were significantly increased in PCA tissues as compared to BPH (p=0.024; p=0.031). No significant differences were observed for IL-2 gene expression. CD8+ cells from BPH (n=17) and PCA (n=21) patients showed a significantly decreased responsiveness to IL-7 and IL-15 (p=0.021; p=0.015) as compared to healthy donors (n=9). Response to IL-2 was similar. A trend towards a lower response to IL-15 in PCA as compared to BPH patients was detectable. Percentage of CD8+ T cells expressing the common γ chain (CD132) of homeostatic cytokines receptor is significantly decreased in PCA (n=13) and BPH (n=16) patients as compared to healthy donors (n=8) (p= 0.024; p&lt;0.001). Percentage of CD8+ T cells expressing the common β chain (CD122) is significantly decreased in PCA patients as compared to healthy donors (p=0.035). No significant differences were noticed for the expression of the α chain of homeostatic cytokine receptor. Urged by these findings, we addressed the expression of PD-1 and its ligand in CD8+ T cells from BPH and PCA patients. In BPH (n=7) and PCA (n=7), %CD8+PD-1+ and %CD8+PD-L1+ T cells are increasing upon culture with homeostatic cytokines. In freshly isolated CD8+ cells, a highly significant increase in the %CD8+PD-1+ cells was observed in PCA (n=32) and BPH (n=22) as compared to healthy donors (p&lt;0.001; p&lt;0.001). In contrast, PD-L1 expression in CD8+ cells was similar in BPH and PCA patients and in healthy donors. A large majority of CD8+ cells infiltrating BPH or PCA tissues (83±22% for BPH, n=9; 88±17% for PCA, n=7) were PD-1+, whereas PD-L1 was expressed in 51±43% and 37±39% of infiltrating CD8+ T cells in BPH and PCA, respectively.

Taken together these data indicate that both BPH and PCA patients display a decreased responsiveness to IL-7 and IL-15 homeostatic cytokines. Interestingly, high percentages of peripheral blood CD8+ T cells express PD-1 in BPH and PCA patients. Notably, PD-1 and its ligand are highly expressed in tissue infiltrating CD8+ T cells in BPH and PCA patients, thus raising the issue of the role of T cells exhaustion in PCA.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4782.

Effect of bone sialoprotein coating of ceramic and synthetic polymer materials on in vitro osteogenic cell differentiation and in vivo bone formation

In this study, we addressed whether Bone Sialoprotein (BSP) coating of various substrates could enhance the in vitro osteogenic differentiation and in vivo bone formation capacity of human Bone Marrow Stromal Cells (BMSC). Moreover, we tested whether synthetic polymer-based porous scaffolds, despite the absence of a mineral component, could support ectopic bone formation by human BMSC if coated with BSP. Adsorption of recombinant human BSP on tissue culture-treated polystyrene (TCTP), beta-tricalcium phosphate (Osteologic) or synthetic polymer (Polyactive) substrates was dose dependent, but did not consistently accelerate or enhance in vitro BMSC osteogenic differentiation, as assessed by the mRNA expression of osteoblast-related genes. Similarly, BSP coating of porous beta-tricalcium phosphate scaffolds (Skelite) did not improve the efficiency of bone tissue formation following loading with BMSC and ectopic implantation in nude mice. Finally, Polyactive foams seeded with BMSC did not form bone tissue in the same ectopic assay, even if coated with BSP. We conclude that BSP coating of a variety of substrates is not directly associated with an enhancement of osteoprogenitor cell differentiation in vitro or in vivo, and that presentation of BSP on polymeric materials is not sufficient to prime BMSC functional osteoblastic differentiation in vivo.

[Interdisciplinary centres in hospitals? A review of the literature]

The treatment of complex disease patterns demands knowledge, and hence the collaboration of many medical disciplines. Interdisciplinary approaches to treatment are thus superior to multidisciplinary ones in terms of quality and costs. To make use of those benefits, interdisciplinary centres have emerged at many hospitals. Our review of the literature has sought to answer two questions: 1) Is there any evidence for the relationship 'creation of a centre = creation of interdisciplinarity'? 2) How can interdisciplinarity be fostered in centres? Medical and economic publications were identified via key terms in PubMed, Web of Knowledge and WISO. Using their references, further publications were researched. Contributions that complied with predefined criteria were included. For 75 of the 78 publications interdisciplinarity is the means to achieve a centre's objectives in quality and cost. Almost all the positive results achieved in centres, e.g., an increase in number of cases, are attributed to the seemingly established interdisciplinarity, without any evidence to substantiate this interrelation (question 1). The recommendations for creating the requested lively interdisciplinarity are insufficient, since technical arrangements dominate and the importance of social and therewith behavioural aspects is often forgotten--the findings of the respective literature remain unappreciated (question 2). Moreover, pertinent research as well as qualitative longitudinal research designs activating the knowledge of physicians, social scientists and economists should be used to investigate the interdisciplinarity sought for in centres.

[From pay-for-effort to pay-for-performance--an analysis of the Swiss health care system with focus on the inpatient sector]

INTRODUCTION

The Swiss health care system is facing the implementation of lump compensation in the form of diagnosis related groups from 2010 on. In addition there is an increasing discussion about the quality of health care in the media. We have analyzed current remuneration in Swiss health care and their steering effects on providers in order to deduct future developments in Swiss health care remuneration.

METHODS

Based on the remuneration contracts and tariff regularities at the Basel University Hospital we conducted an internet and literature search. The identified Swiss remuneration systems were classified after remuneration scales and remuneration item using a typology of performance-related remuneration systems. The steering effects of the remuneration systems on the providers were deducted.

RESULTS

Remuneration scales can be classified in <<costs incurred>>, <<standardized costs>> or <<negotiated costs>>. Remuneration items can be classified in <<activities>>, <<cases>> or <<outcome oriented cases>>. Remuneration systems can lead to increased or decreased services or to patient selection. In the Swiss health care system we find a trend away from traditional <<pay-for-effort>> to <<pay-for-performance>> remuneration systems. In that context diagnosis related groups are identified as an intermediate step in the development of remuneration systems.

CONCLUSIONS

Future developments of medical remuneration in terms of a consideration of quality of medical performance and negotiated costs seem likely in Switzerland in the long term. Both, economics and quality should be considered adequately in a health care remuneration system.

Intranodal immunization with a vaccinia virus encoding multiple antigenic epitopes and costimulatory molecules in metastatic melanoma

Recombinant vaccinia virus (rVV) encoding tumor-associated antigens (TAAs) and adhesion or costimulatory molecules may represent important immunogenic reagents for cancer immunotherapy. Recently, intranodal (IN) antigen administration was suggested to be more immunogenic than intradermal (ID) vaccination. However, IN rVV administration has not been attempted so far. We used a rVV encoding gp100(280-288), Melan-A/MART-1(27-35) and tyrosinase(1-9) HLA-A0201 restricted epitopes and CD80 and CD86 costimulatory molecules in stage III and IV melanoma patients in a phase 1/2 trial. Of 15 patients initiating treatment, including two cycles of IN immunization, each comprising one rVV administration and three recall injections of the corresponding peptides, accompanied by subcutaneous granulocyte macrophage-colony stimulating factor supplementation, five withdrew due to progressing disease. Of 10 remaining patients seven showed evidence of induction of cytotoxic T lymphocytes (CTLs) directed against at least one epitope under investigation, as detectable by limiting dilution analysis (LDA) of specific precursors and multimer staining. Adverse reactions were mild (National Cancer Institute (NCI) grade 1-2) and mainly represented by fever, skin rashes, and pruritus. These data indicate that IN administration of rVV encoding melanoma-associated epitopes and costimulatory molecules is safe and immunogenic.

Intra-individual comparison of human ankle and knee chondrocytes in vitro: relevance for talar cartilage repair

OBJECTIVE

As compared to knee chondrocytes (KC), talar chondrocytes (TC) have superior synthetic activity and increased resistance to catabolic stimuli. We investigated whether these properties are maintained after TC are isolated and expanded in vitro.

METHODS

Human TC and KC from 10 cadavers were expanded in monolayer and then cultured in pellets for 3 and 14 days or in hyaluronan meshes (Hyaff-11) for 14 and 28 days. Resulting tissues were assessed biochemically, histologically, biomechanically and by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The proteoglycan and collagen synthesis rates in the pellets were also measured following exposure to Interleukin-1 beta (IL-1 beta).

RESULTS

After 14 days of pellet culture, TC and KC expressed similar levels of type I collagen (CI) and type II collagen (CII) mRNA and the resulting tissues contained comparable amounts of glycosaminoglycans (GAG) and displayed similar staining intensities for CII. Also proteoglycan and collagen synthesis were similar in TC and KC pellets, and dropped to a comparable extent in response to IL-1 beta. Following 14 days of culture in Hyaff-11, TC and KC generated tissues with similar amounts of GAG and CI and CII. After 28 days, KC deposited significantly larger fractions of GAG and CII than TC, although the trend was not reflected in the measured biomechanical properties.

CONCLUSION

After isolation from their original matrices and culture expansion, TC and KC displayed similar biosynthetic activities, even in the presence of catabolic stimuli. These in vitro data suggest a possible equivalence of TC and KC as autologous cell sources for the repair of talar cartilage lesions.

Cartilage tissue engineering using pre-aggregated human articular chondrocytes

In this study, we first aimed at determining whether human articular chondrocytes (HAC) proliferate in aggregates in the presence of strong chondrocyte mitogens. We then investigated if the aggregated cells have an enhanced chondrogenic capacity as compared to cells cultured in monolayer. HAC from four donors were cultured in tissue culture dishes either untreated or coated with 1% agarose in the presence of TGFbeta-1, FGF-2 and PDGF-BB. Proliferation and stage of differentiation were assessed by measuring respectively DNA contents and type II collagen mRNA. Expanded cells were induced to differentiate in pellets or in Hyaff-11 meshes and the formed tissues were analysed biochemically for glycosaminoglycans (GAG) and DNA, and histologically by Safranin O staining. The amount of DNA in aggregate cultures increased significantly from day 2 to day 6 (by 3.2-fold), but did not further increase with additional culture time. Expression of type II collagen mRNA was about two orders of magnitude higher in aggregated HAC as compared to monolayer expanded cells. Pellets generated by aggregated HAC were generally more intensely stained for GAG than those generated by monolayer-expanded cells. Scaffolds seeded with aggregates accumulated more GAG (1.3-fold) than scaffolds seeded with monolayer expanded HAC. In conclusion, this study showed that HAC culture in aggregates does not support a relevant degree of expansion. However, aggregation of expanded HAC prior to loading into a porous scaffold enhances the quality of the resulting tissues and could thus be introduced as an intermediate culture phase in the manufacture of engineered cartilage grafts.

Advanced Liposomal Vectors as Cancer Vaccines in Melanoma Immunotherapy

Malignant tumors represent a major source of disability and account for more than one of five deaths in Western countries. Among the different cancers, melanoma harbors two distinctive features. First, its has long been recognized as an immunogenic tumor, and second, an unprecedented rise in incidence is currently observed, in face of few therapeutic options. Thus, melanoma represent an ideal target for a cancer immunotherapy program. To date, a number of immunodominant epitopes from tumor associated antigens (TAA) are used as cancer vaccines in clinical trials, in spite of an acknowledged rapid degradation in vivo and low immunogenicity. However, most of the immunotherapy trials reported so far do not achieve consistent clinical results. Hence, there is an urgent need for the development of a carrier system and strong adjuvants suitable for a TAA-based cancer immunotherapy. Liposomes and their further development as virosomes with added adjuvancy may address both these issues. We report here our experience in the tailoring of dedicated advanced liposomal vectors that were developed in the context of an upcoming immunotherapy clinical trial for melanoma.