Quality of Life in Post-Surgical Hypoparathyroidism (PoSH) in Thyroid and Parathyroid Surgery.

BACKGROUND: Post-surgical hypoparathyroidism (PoSH) is often long term, with significant associated morbidity and ongoing treatment. A recent systematic review found impaired quality of life (QoL) in patients with PoSH, despite stable treatment. Most studies did not include an appropriate control arm and further studies were recommended, taking into account underlying disease and comorbidities. This study aims to compare QoL in patients with PoSH with appropriate control groups. METHODS: This was a cross-sectional observational study using the general quality of life SF-36 tool and a hypocalcaemia symptom score (HcSS) to assess QoL in patients with PoSH and controls (who had similar surgery but without PoSH). Participants were identified from two patient groups (the Butterfly Thyroid Cancer Trust and the Association for Multiple Endocrine Neoplasia Disorders) and a single tertiary centre in the UK. RESULTS: Four hundred and thirty-nine responses (female n = 379, PoSH n = 89) were included with a median (range) age of 52 (19-92) years. Reported dates of surgery ranged from 1973 to 2019. HcSS scores showed significantly more associated symptoms in patients with PoSH than those without (p < 0.001). Although there was no overall difference in QoL between groups, patients with PoSH consistently had lower scores (p = 0.008) in the energy/fatigue subdomain of the SF-36. CONCLUSION: Patients with PoSH reported significantly more fatigue and loss of energy compared to appropriately matched controls, but overall QoL was not significantly different. Standardised QoL measures may not be sensitive enough to highlight the impact on QoL in these patients. A disease-specific tool may be required.

Mechanical Heterogeneity in the Bone Microenvironment as Characterized by Atomic Force Microscopy.

Bones are structurally heterogeneous organs with diverse functions that undergo mechanical stimuli across multiple length scales. Mechanical characterization of the bone microenvironment is important for understanding how bones function in health and disease. Here, we describe the mechanical architecture of cortical bone, the growth plate, metaphysis, and marrow in fresh murine bones, probed using atomic force microscopy in physiological buffer. Both elastic and viscoelastic properties are found to be highly heterogeneous with moduli ranging over three to five orders of magnitude, both within and across regions. All regions include extremely compliant areas, with moduli of a few pascal and viscosities as low as tens of Pa·s. Aging impacts the viscoelasticity of the bone marrow strongly but has a limited effect on the other regions studied. Our approach provides the opportunity to explore the mechanical properties of complex tissues at the length scale relevant to cellular processes and how these impact aging and disease.

Bone marrow osteoprogenitors are depleted whereas osteoblasts are expanded independent of the osteogenic vasculature in response to zoledronic acid.

Zoledronic acid (ZOL) is an antiresorptive drug used to prevent bone loss in a variety of conditions, acting mainly through suppression of osteoclast activity. There is growing evidence that ZOL can also affect cells of the mesenchymal lineage in bone. We present novel data revealing significant changes in the abundance of perivascular mesenchymal stromal cells (MSCs)/osteoprogenitors and osteoblasts following the injection of ZOL, in vivo. In young mice with high bone turnover and an abundance of perivascular osteoprogenitors, ZOL significantly (P < 0.0001) increased new bone formation. This was accompanied by a decline in osterix-positive osteoprogenitors and a corresponding increase in osteoblasts. However, these effects were not observed in mature mice with low bone turnover. Interestingly, the ZOL-induced changes in cells of the mesenchymal lineage occurred independently of effects on the osteogenic vasculature. Thus, we demonstrate that a single, clinically relevant dose of ZOL can induce new bone formation in microenvironments enriched for perivascular MSC/osteoprogenitors and high osteogenic potential. This arises from the differentiation of perivascular osterix-positive MSC/osteoprogenitors into osteoblasts at sites that are innately osteogenic. Collectively, our data demonstrate that ZOL affects multiple cell types in bone and has differential effects depending on the level of bone turnover.-Hughes, R., Chen, X., Hunter, K. D., Hobbs, J. K., Holen, I., Brown, N. J. Bone marrow osteoprogenitors are depleted whereas osteoblasts are expanded independent of the osteogenic vasculature in response to zoledronic acid.

Use of Electrical Impedance Spectroscopy for Intraoperative Tissue Differentiation During Thyroid and Parathyroid Surgery.

BACKGROUND: Electrical impedance (EI) measures tissue resistance to alternating current across several frequencies and may help identify tissue type. A recent rabbit model demonstrated that electrical impedance spectroscopy (EIS) may facilitate identification of parathyroid glands and potentially improve outcomes following surgery. This study looks at the EI patterns of soft tissues in the human neck to determine whether parathyroid tissue can be accurately identified. METHODS: This was a phase 1, single-arm interventional study involving 56 patients undergoing thyroid and/or parathyroid surgery. Up to 12 EI readings were taken from in vivo and ex vivo thyroid and parathyroid glands, adipose tissue and muscle of each patient. Each reading consists of a series of measurements over 14 frequencies from each tissue. EI patterns were analysed. Two patients were excluded due to data loss due to device malfunction. RESULTS: The median age of participants was 53.5 (range 20-85) years. Thirty-five participants had surgery for thyroid pathology, 17 for parathyroid pathology and four for both. Six hundred and six EIS spectra were reviewed for suitability. One hundred and eighty-four spectra were rejected leaving 422 spectra for analysis. The impedance patterns of the soft tissues differed by histological type. The EI ratio of low (152 Hz) to high (312 kHz) frequencies demonstrated a significant difference between the soft tissues (p = 0.006). Using appropriate thresholds, parathyroid tissue can be distinguished from thyroid tissue with a sensitivity of 76% and specificity of 60%. CONCLUSIONS: This study demonstrates the feasibility of using EIS to aid parathyroid identification and preservation. Further changes to the device and modelling of the EI patterns across the range of frequencies may improve accuracy and facilitate intraoperative use. TRIAL REGISTRATION: ClinicalTrials.gov (NCT02901873).

Use of methylene blue and near-infrared fluorescence in thyroid and parathyroid surgery.

PURPOSE: Intraoperative localisation and preservation of parathyroid glands improves outcomes following thyroid and parathyroid surgery. This can be facilitated by fluorescent imaging and methylene blue; a fluorophore is thought to be taken up avidly by parathyroid glands. This preliminary study aims to identify the optimum dose of methylene blue (MB), fluorescent patterns of thyroid and parathyroid glands and develop a protocol for the use of intravenous MB emitted fluorescence to enable parathyroid identification. METHODS: This is a phase 1b, interventional study (NCT02089542) involving 41 patients undergoing thyroid and/or parathyroid surgery. After exposure of the thyroid and/or parathyroid gland(s), intravenous boluses of between 0.05 and 0.5 mg/kg of MB were injected. Fluobeam® (a hand held fluorescence real-time imager) was used to record fluorescence from the operating field prior and up to 10 min following administration. RESULTS: The optimum dose of MB to visualise thyroid and parathyroid glands was 0.4 mg/kg body weight. The median time to onset of fluorescence was 23 and 22 s and the median time to peak fluorescence was 41.5 and 40 s, respectively. The peak fluorescence for thyroid and parathyroid glands compared to muscle were 2.6 and 4.3, respectively. Parathyroid auto-fluorescence prior to methylene blue injection was commonly observed. CONCLUSIONS: A clinical protocol for detection of fluorescence from MB during thyroid and parathyroid surgery is presented. Parathyroids (especially enlarged glands) fluoresce more intensely than thyroid glands. Auto-fluorescence may aid parathyroid detection, but MB fluorescence is needed to demonstrate viability.

Parathyroid Hormone (PTH) Increases Skeletal Tumour Growth and Alters Tumour Distribution in an In Vivo Model of Breast Cancer.

Breast cancer cells colonize the skeleton by homing to specific niches, but the involvement of osteoblasts in tumour cell seeding, colonization, and progression is unknown. We used an in vivo model to determine how increasing the number of cells of the osteoblast lineage with parathyroid hormone (PTH) modified subsequent skeletal colonization by breast cancer cells. BALB/c nude mice were injected for five consecutive days with PBS (control) or PTH and then injected with DiD-labelled breast cancer cells via the intra-cardiac route. Effects of PTH on the bone microenvironment and tumour cell colonization and growth was analyzed using bioluminescence imaging, two-photon microscopy, and histological analysis. PTH treatment caused a significant, transient increase in osteoblast numbers compared to control, whereas bone volume/structure in the tibia was unaffected. There were no differences in the number of tumour cells seeding to the tibias, or in the number of tumours in the hind legs, between the control and PTH group. However, animals pre-treated with PTH had a significantly higher number of tumour colonies distributed throughout skeletal sites outside the hind limbs. This is the first demonstration that PTH-induced stimulation of osteoblastic cells may result in alternative skeletal sites becoming available for breast cancer cell colonization.

Zoledronic acid alters hematopoiesis and generates breast tumor-suppressive bone marrow cells.

BACKGROUND: The bone-targeting agent zoledronic acid (ZOL) increases breast cancer survival in subsets of patients, but the underlying reasons for this protective effect are unknown. ZOL modulates the activity of osteoclasts and osteoblasts, which form hematopoietic stem cell niches, and therefore may affect hematopoietic cells that play a role in breast cancer progression. METHOD: Immunocompetent and immunocompromised strains of mice commonly used for breast cancer research were injected with a single, clinically relevant dose of ZOL (100 µg/kg) or vehicle control. The effects of ZOL on the bone marrow microenvironment (bone volume, bone cell number/activity, extracellular matrix composition) were established at various time points following treatment, using micro-computed tomography (µCT) analysis, histomorphometry, ELISA and immunofluorescence. The effects on peripheral blood and bone marrow hematopoietic progenitor populations were assessed using a HEMAVET® hematology analyzer and multicolor flow cytometry, respectively. Tumor support function of bone marrow cells was determined using an in vivo functional assay developed in our laboratory. RESULTS: Using multiple mouse strains, we observed transient changes in numbers of hematopoietic stem cells, myeloid-biased progenitor cells, and lymphoid-biased cells concurrent with changes to hematopoietic stem cell niches following ZOL administration. Importantly, bone marrow cells from mice treated with a single, clinically relevant dose of ZOL inhibited breast tumor outgrowth in vivo. The ZOL-induced tumor suppressive function of the bone marrow persisted beyond the time point at which numbers of hematopoietic progenitor cells had returned to baseline. CONCLUSIONS: These findings provide novel evidence that alterations to the bone marrow play a role in the anti-tumor activity of ZOL and suggest possibilities for capitalizing on the beneficial effects of ZOL in reducing breast cancer development and progression.

Influence of washing and quenching in profiling the metabolome of adherent mammalian cells: a case study with the metastatic breast cancer cell line MDA-MB-231.

Metabolome characterisation is a powerful tool in oncology. To obtain a valid description of the intracellular metabolome, two of the preparatory steps are crucial, namely washing and quenching. Washing must effectively remove the extracellular media components and quenching should stop the metabolic activities within the cell, without altering the membrane integrity of the cell. Therefore, it is important to evaluate the efficiency of the washing and quenching solvents. In this study, we employed two previously optimised protocols for simultaneous quenching and extraction, and investigated the effects of a number of washing steps/solvents and quenching solvent additives, on metabolite leakage from the adherent metastatic breast cancer cell line MDA-MB-231. We explored five washing protocols and five quenching protocols (including a control for each), and assessed for effectiveness by detecting ATP in the medium and cell morphology changes through scanning electron microscopy (SEM) analyses. Furthermore, we studied the overall recovery of eleven different metabolite classes using the GC-MS technique and compared the results with those obtained from the ATP assay and SEM analysis. Our data demonstrate that a single washing step with PBS and quenching with 60% methanol supplemented with 70 mM HEPES (-50 °C) results in minimum leakage of intracellular metabolites. Little or no interference of PBS (used in washing) and methanol/HEPES (used in quenching) on the subsequent GC-MS analysis step was noted. Together, these findings provide for the first time a systematic study into the washing and quenching steps of the metabolomics workflow for studying adherent mammalian cells, which we believe will improve reliability in the application of metabolomics technology to study adherent mammalian cell metabolism.

Electrical Impedance Spectroscopy to Aid Parathyroid Identification and Preservation in Central Compartment Neck Surgery: A Proof of Concept in a Rabbit Model.

BACKGROUND: Accurate identification of parathyroid glands during thyroid surgery is crucial to avoid postthyroidectomy hypocalcemia. Electrical impedance spectroscopy has the potential to differentiate between tissues of different morphology. The aim of this study was to determine the electrical impedance patterns of the thyroid, parathyroid, and other soft tissue structures in the rabbit neck. METHODS: The central compartments were exposed in 9 freshly culled New Zealand White rabbits. In situ and ex vivo electrical impedance was measured from thyroid lobes, external parathyroid glands, adipose tissue, and strap muscle using the APX100 device. Specimens of all identified glands were sent for histopathology examination. RESULTS: Histology confirmed correct identification of all excised thyroid and parathyroid glands. The impedance was higher for thyroid tissue at lower frequencies and for parathyroid tissue at higher frequencies. Ex vivo electrical impedance spectra were significantly higher compared with the in situ spectra across all frequencies for thyroid and parathyroid tissues (P < .001). The ratio of low to high frequency in situ impedance of thyroid, parathyroid, and muscle was significantly different (P < .001), allowing for differentiation between these tissues. CONCLUSION: The electrical impedance spectra of rabbit thyroid and parathyroid glands are distinct and different from each other and from skeletal muscle. If these results are replicated in human tissue, they have the potential to improve patient outcomes by achieving early identification and preservation of parathyroid glands.

Prostate cancer cells home to bone using a novel in vivo model: modulation by the integrin antagonist GLPG0187.

Micrometastasis is a barrier to the development of effective cancer therapies for prostate cancer metastasis to bone. The mechanisms remain incompletely characterised, primarily due to an inability to adequately monitor the initial metastatic events in vivo. This study aimed to establish a new model, allowing the tracking of prostate cancer cells homing to bone, and furthermore, to evaluate the response of this approach to therapeutic modulation, using the integrin antagonist GLPG0187. A single murine metatarsal was engrafted into a dorsal skinfold chamber implanted on a SCID mouse. Fluorescently-labeled human prostate (PC3-GFP) or oral (SCC4-GFP) cancer cells were administered via intracardiac (i.c) injection, with simultaneous daily GLPG0187 or vehicle-control treatment (i.p. 100 mg/kg/day) for the experimental duration. Metatarsal recordings were taken every 48 h for up to 4 weeks. Tissue was harvested and processed for microCT, multiphoton analysis, histology and immunohistochemistry. Cell viability, proliferation and migration in vitro were also quantified following treatment with GLPG0187. Metatarsals rapidly revascularised by inosculation with the host vasculature (day 5-7). PC3-GFP cells adhered to the microvascular endothelium and/or metatarsal matrix 3 days after administration, with adhesion maintained for the experimental duration. GLPG0187 treatment significantly (p < 0.05) reduced PC3 cell number within the metatarsal in vivo and reduced migration (p < 0.05) and proliferation (p < 0.05) but not cell viability in vitro. This new model allows evaluation of the early events of tumour-cell homing and localisation to the bone microenvironment, in addition to determining responses to therapeutic interventions.

The relationship between semaphorin 3C and microvessel density in the progression of breast and oral neoplasia.

This study aimed to identify the expression of semaphorin 3C (SEMA3C) in the normal-metastatic spectrum of breast and oral cancers, and correlate expression with microvessel density (MVD, CD31), a surrogate marker of angiogenesis. Histological analysis revealed that SEMA3C expression was reduced in the development of oral cancer from normal oral tissue (P<0.0001) and expression was inversely correlated with MVD (r=-0.394, P=0.05). In contrast, SEMA3C expression increased in the transition from normal to invasive breast disease in epithelial/tumour cells (P=0.001) and endothelial cells (P=0.006), with both correlating weakly with MVD (r=0.35, p=0.03 and r=0.243, p=0.041 respectively). Furthermore, histological analysis of a breast cancer tissue microarray revealed a weak positive correlation with tumour grade (r=0.305, P=<0.001) and biological phenotype (r=0.237, p=0.004) with tumour cell expression of SEMA3C highest in triple negative and ER-, PR-, HER2+ subtypes. These data suggest that SEMA3C expression is differentially regulated in the development and progression of breast versus oral neoplasia, and that increased expression of SEMA3C may be modulating breast cancer progression and angiogenesis, and could represent a biomarker of metastatic disease.

A peptide derived from TIMP-3 inhibits multiple angiogenic growth factor receptors and tumour growth and inflammatory arthritis in mice.

The binding of vascular endothelial growth factor (VEGF) to VEGF receptor-2 (VEGFR-2) on the surface of vascular endothelial cells stimulates many steps in the angiogenic pathway. Inhibition of this interaction is proving of value in moderating the neovascularization accompanying age-related macular degeneration and in the treatment of cancer. Tissue inhibitor of metalloproteinases-3 (TIMP-3) has been shown to be a natural VEGFR-2 specific antagonist-an activity that is independent of its ability to inhibit metalloproteinases. In this investigation we localize this activity to the C-terminal domain of the TIMP-3 molecule and characterize a short peptide, corresponding to part of this domain, that not only inhibits all three VEGF-family receptors, but also fibroblast growth factor and platelet-derived growth factor receptors. This multiple-receptor inhibition may explain why the peptide was also seen to be a powerful inhibitor of tumour growth and also a partial inhibitor of arthritic joint inflammation in vivo.

Angiopoietin-1 regulates microvascular reactivity and protects the microcirculation during acute endothelial dysfunction: role of eNOS and VE-cadherin.

The growth factor angiopoietin-1 (Ang-1) plays an essential role in angiogenesis and vascular homeostasis. Nevertheless, the role of Ang-1 in regulating vascular tone and blood flow is largely unexplored. Endothelial nitric oxide synthase (eNOS) and the junctional protein VE-cadherin are part of the complex signalling cascade initiated by Ang-1 in endothelial cells. In this study, we aimed to investigate the mechanisms underlying acute effects of Ang-1 on microvascular reactivity, permeability and blood flow, and hypothesise that eNOS and VE-cadherin underpin Ang-1 mediated vascular effects that are independent of angiogenesis and proliferation. Myography of isolated microarterioles from male C3H/HeN mice (7-10 weeks) was employed to measure vascular reactivity in vitro. Microcirculatory function in vivo was evaluated by intravital microscopy and Doppler fluximetry in dorsal window chambers. Ang-1 and its stable variant MAT.Ang-1 induced a concentration-dependent vasodilation of arterioles in vitro, which was blocked with nitric oxide (NO) synthesis inhibitor l-NAME. In vivo, MAT.Ang-1 restored to control levels l-NAME induced peripheral vasoconstriction, decreased blood flow and microvascular hyperpermeability. Tissue protein expression of VE-cadherin was reduced by NOS inhibition and restored to control levels by MAT.Ang-1, whilst VE-cadherin phosphorylation was increased by l-NAME and subsequently reduced by MAT.Ang-1 administration. Moreover, MAT.Ang-1 alone did not modulate systemic levels of angiogenetic factors. Our novel findings report that Ang-1 induces arteriolar vasodilation via release of NO, suggesting that Ang-1 is an important regulator of microvascular tone. As MAT.Ang-1 ameliorates detrimental effects on the microcirculation induced by inhibition of NO synthesis and stabilizes the endothelial barrier function through VE-cadherin, we propose that this Ang-1 variant may serve as a novel therapeutic agent to protect the microcirculation against endothelial dysfunction.

Near infrared fluorescence imaging of rabbit thyroid and parathyroid glands.

BACKGROUND: Near infrared fluorescence imaging using intravenous methylene blue (MB) is a novel technique that has potential to aid the parathyroid gland (PG) localization during thyroid and parathyroid surgery. The aim of this study was to examine MB fluorescence in the rabbit neck and determine the influence of MB dose and time following administration on fluorescence from thyroid and PGs. METHODS: Thyroid and external PGs were exposed in six New Zealand white rabbits under anesthesia. Varying doses of MB (0.025-3 mg/kg) were injected through the marginal ear vein. Near infrared fluorescence from exposed tissues was recorded at different time intervals (10-74 min) using Fluobeam 700. Specimens of identified glands were then resected for histologic assessment. RESULTS: Histology confirmed accurate identification of all excised thyroid and PGs; these were the only neck structures to demonstrate significant fluorescence. The parathyroid demonstrated lower fluorescence intensities and reduced washout times at all MB doses compared with the thyroid gland. A dose of 0.1 mg/kg MB was adequate to identify fluorescence; this also delineated the blood supply of the external PGs. CONCLUSIONS: The study demonstrates that near infrared fluorescence with intravenous MB helps differentiate between thyroid and PGs in the rabbit. This has potential to improve outcomes in thyroid and parathyroid surgery by increasing the accuracy of parathyroid identification; however, the findings require replication in human surgery. The use of low doses of MB may also avoid the side effects associated with currently used doses in humans (3-7 mg/kg).

Angiogenic growth factor expression in benign and malignant vascular tumours.

Angiosarcomas are rare malignant vascular tumours. Angiosarcoma expression of vascular endothelial growth factor (VEGF) has previously been reported, but angiosarcoma expression of other angiogenic growth factors has not been systematically studied. Non-VEGF angiogenic growth factors are a potential mechanism of resistance to VEGF-targeted therapy, but they also represent potential therapeutic targets. Immunohistochemistry analysis evaluated the expression of 13 angiogenic growth factors and receptors in 27 separate benign and malignant archived human vascular tumour samples. The expression of 55 angiogenesis-related proteins was subsequently profiled in five fresh human angiosarcoma tumour samples using antibody arrays. Angiosarcomas expressed a variety of angiogenic growth factors. Significantly higher levels of Notch1 were detected compared with benign haemangiomas (p=0.033), but lower levels of basic fibroblast growth factor (bFGF) compared to benign haemangiomas (p=0.07) and inflammatory vascular lesions (p=0.009). Vascular tumour expression of FGF receptor (FGFR)-1 correlated with angiopoietin (Ang)-2, Tie2, hepatocyte growth factor (HGF) and Notch1 expression (p=0.001, p=0.001, p<0.001 and p<0.001 respectively). Notch1 also correlated with Tie2 expression (p=0.004). In conclusion, angiosarcomas express multiple angiogenic growth factors. Treatments could be targeted at individual angiogenic growth factors. However, our findings provide a rationale for combination therapy, or for treatments that target common downstream signalling intermediaries, such as Akt, mTOR or ERK.

Critical research gaps and translational priorities for the successful prevention and treatment of breast cancer.

INTRODUCTION: Breast cancer remains a significant scientific, clinical and societal challenge. This gap analysis has reviewed and critically assessed enduring issues and new challenges emerging from recent research, and proposes strategies for translating solutions into practice. METHODS: More than 100 internationally recognised specialist breast cancer scientists, clinicians and healthcare professionals collaborated to address nine thematic areas: genetics, epigenetics and epidemiology; molecular pathology and cell biology; hormonal influences and endocrine therapy; imaging, detection and screening; current/novel therapies and biomarkers; drug resistance; metastasis, angiogenesis, circulating tumour cells, cancer 'stem' cells; risk and prevention; living with and managing breast cancer and its treatment. The groups developed summary papers through an iterative process which, following further appraisal from experts and patients, were melded into this summary account. RESULTS: The 10 major gaps identified were: (1) understanding the functions and contextual interactions of genetic and epigenetic changes in normal breast development and during malignant transformation; (2) how to implement sustainable lifestyle changes (diet, exercise and weight) and chemopreventive strategies; (3) the need for tailored screening approaches including clinically actionable tests; (4) enhancing knowledge of molecular drivers behind breast cancer subtypes, progression and metastasis; (5) understanding the molecular mechanisms of tumour heterogeneity, dormancy, de novo or acquired resistance and how to target key nodes in these dynamic processes; (6) developing validated markers for chemosensitivity and radiosensitivity; (7) understanding the optimal duration, sequencing and rational combinations of treatment for improved personalised therapy; (8) validating multimodality imaging biomarkers for minimally invasive diagnosis and monitoring of responses in primary and metastatic disease; (9) developing interventions and support to improve the survivorship experience; (10) a continuing need for clinical material for translational research derived from normal breast, blood, primary, relapsed, metastatic and drug-resistant cancers with expert bioinformatics support to maximise its utility. The proposed infrastructural enablers include enhanced resources to support clinically relevant in vitro and in vivo tumour models; improved access to appropriate, fully annotated clinical samples; extended biomarker discovery, validation and standardisation; and facilitated cross-discipline working. CONCLUSIONS: With resources to conduct further high-quality targeted research focusing on the gaps identified, increased knowledge translating into improved clinical care should be achievable within five years.

Neuropilin-1 and neuropilin-2 expression in the adenoma-carcinoma sequence of colorectal cancer.

AIMS: Neuropilin-1 (NRP1) and neuropilin-2 (NRP2) are transmembrane glycoproteins which interact with vascular endothelial growth factor (VEGF) to prevent tumour cell apoptosis and regulate angiogenesis. However, the precise role of NRP1 and NRP2 in the adenoma-carcinoma sequence (ACS) of colorectal cancer remains unclear, and we aimed to determine this in surgical specimens comprising the ACS. METHODS AND RESULTS: Histological analysis demonstrated that epithelial NRP1 expression increased significantly across the ACS (P = 0.0007), and correlated with microvessel density (MVD; r = 0.505, P = 0.0003) and weakly with VEGF (r = 0.251, P = 0.001). In contrast, although NRP2 epithelial expression was increased significantly in all carcinomas (P < 0.002), there was no correlation with MVD, VEGF or NRP1. Furthermore, patients showing coexpression of NRP1 and NRP2 had a potentially worse prognosis than those expressing a single neuropilin or neither one. Although vascular expression of NRP1 increased significantly across the ACS (P = 0.0004) and correlated with MVD (r = 0.361, P = 0.0006), NRP2 vascular expression decreased significantly (P = 0.0001) and showed an inverse correlation with MVD (r=-0.506, P = 0.0001), suggesting differential roles for neuropilins in the angiogenic process during colorectal cancer development. CONCLUSIONS: These data suggest that an increase in NRP1 and NRP2 epithelial/tumour expression, as well as in NRP1 vascular expression, may be associated with disease progression in colorectal cancer.

Combination therapy inhibits development and progression of mammary tumours in immunocompetent mice.

We have determined the effect of combining the chemotherapy agent doxorubicin and the anti-resorptive drug zoledronic acid on the early stages of spontaneous mammary tumour development using the immunocompetent PyMT mouse model that closely mimics human breast cancer development. 6-week-old PyMT mice were treated weekly for 6 weeks with PBS, 2 mg/kg doxorubicin, 100 µg/kg zoledronic acid or doxorubicin followed 24 h later by zoledronic acid (n = 15/group). Untreated, 6-week-old animals were used for comparison of tumour development. Tumour volume, apoptosis and angiogenesis were analysed on H&E, caspase 3, CD31 and CD34 stained histological sections. Proliferation was measured by BrdU incorporation and Ki67 staining and tumour macrophage infiltration assessed by F4/80 immunohistochemistry. Animals treated with doxorubicin followed by zoledronic acid did not develop palpable mammary tumours, whereas in all other treatment groups tumours progressed to late stage adenocarcinomas. Tumours from the combination treatment group were of comparable size to those in 6-week-old untreated animals, remaining pre-malignant with well-differentiated acinar arrangements and with tumour volume only reaching on average 26% of that in the PBS control group. Tumour cell apoptosis and proliferation was significantly reduced compared to control, single agent or untreated 6-week-old mice. Significantly fewer circulating tumour cells were present in animals following sequential treatment compared to all other groups. Combination treatment with doxorubicin followed by zoledronic acid inhibits development and progression of spontaneously occurring mammary tumours.

Evaluation of fluorescent plasma markers for in vivo microscopy of the microcirculation.

This study evaluated four fluorescent-protein conjugates to monitor microcirculatory variables using the murine cremaster muscle and determined acute and long-term responses to repeated administration of FITC-BSA [conjugated at the University of Sheffield (UoS)] within a dorsal microcirculatory chamber (DMC) in rats. For analysis of the cremaster muscle, male C3H/HeN mice were anaesthetized, the cremaster muscle was exteriorized, then TRITC-BSA, TRITC-dextran, FITC-BSA, FITC-BSA (UoS) or FITC-dextran (0.25 ml/100 g) were administered systemically. The microcirculation was viewed with epi-illumination every 10 min for 120 min. For analysis of the DMC, male Wistar rats were implanted with the chamber. Three weeks later, FITC-BSA (UoS) was administered systemically, and the microcirculation response was monitored using three different protocols. In addition, in vitro stability of fluorescent conjugates was measured over 8 h. With regard to the cremaster muscle, initially no differences in interstitial fluorescence or vessel diameter were observed between the four fluorescent conjugates. By the end of the study, interstitial fluorescence from TRITC-dextran, FITC-dextran and FITC-BSA (Sigma) was significantly (p < 0.05) increased compared to FITC-BSA (UoS). With regard to the DMC, there was no interstitial fluorescence leakage after 180 min or 5 weeks despite repeated administration, but a significant (p < 0.05) leak was detected between 4 and 24 h. FITC-BSA (UoS) was the most stable fluorescent conjugate both in vitro and in vivo and was comparable with other conjugates for evaluating skeletal muscle microcirculation using fluorescent in vivo microscopy.

Angiopoietin-1 variant reduces LPS-induced microvascular dysfunction in a murine model of sepsis.

INTRODUCTION: Severe sepsis is characterised by intravascular or extravascular infection with microbial agents, systemic inflammation and microcirculatory dysfunction, leading to tissue damage, organ failure and death. The growth factor angiopoietin (Ang-1) has therapeutic potential but recombinant Ang-1 tends to aggregate and has a short half-life in vivo. This study aimed to investigate the acute effects of the more stable Ang-1 variant matrilin-1-angiopoietin-1 (MAT.Ang-1) on the function of the microcirculation in an experimental model of sepsis, and whether any protection by MAT-Ang-1 was associated with modulation of inflammatory cytokines, angiogenic factors or the endothelial nitric oxide synthase (eNOS)-Akt and vascular endothelial (VE)-cadherin pathways. METHODS: Aluminium window chambers were implanted into the dorsal skinfold of male C3H/HeN mice (7 to 10 weeks old) to expose the striated muscle microcirculation. Endotoxemia was induced by intraperitoneal injection of lipopolysaccharide (LPS, 1 mg/kg at 0 and 19 hours). MAT.Ang-1 was administered intravenously 20 hours after the onset of sepsis. Microcirculatory function was evaluated by intravital microscopy and Doppler fluximetry. RESULTS: Endotoxemia resulted in macromolecular leak, which was ameliorated by MAT.Ang-1 post-treatment. LPS induced a dramatic reduction in tissue perfusion, which was improved by MAT.Ang-1. Proteome profiler array analysis of skeletal muscle also demonstrated increased inflammatory and reduced angiogenic factors during endotoxemia. MAT.Ang-1 post-treatment reduced the level of IL-1ß but did not significantly induce the expression of angiogenic factors. MAT.Ang-1 alone did not induce leak or increase angiogenic factors but did reduce vascular endothelial growth factor expression in controls. CONCLUSION: Administration of MAT.Ang-1 after the onset of sepsis protects the microcirculation from endotoxemia-induced vascular dysfunction through reducing inflammation but without pro-angiogenic actions, thus representing a novel, potential pharmacotherapeutic agent for the treatment of sepsis.