The low-molecular-weight heparin, nadroparin, inhibits tumour angiogenesis in a rodent dorsal skinfold chamber model

A celastrol-based nanodrug with reduced hepatotoxicity for primary and metastatic cancer treatment

BACKGROUND

Cancer is the world's leading cause of death and a key hindrance to extending life expectancy. Celastrol, a bioactive compound derived from Tripterygium wilfordii, has been shown to have excellent antitumor activity, but its poor solubility and severe organ toxicity side effects have hampered its clinical application.

METHODS

In this study, a self-assembled nanodrug (PLC-NP) was designed to deliver celastrol to tumor sites while efficiently reducing its side effects by conjugating celastrol with the bioactive material LMWH and P-selectin targeting peptide (PSN). Extensive in vitro and in vivo experiments were performed to investigate both therapeutic efficacy and adverse effects. Furthermore, the specific mechanism of the antitumor activity has also been explored.

FINDING

The PLC-NP nanodrugs were spherical in shape, with a mean particle size of 115.83 ± 6.93 nm. PLC-NP was sufficiently stable during blood circulation, with a selective target to P-selectin-highly expressed tumor cells, followed by releasing the containing celastrol under acidic environment and high levels of esterase in tumor cells. Both in vitro and in vivo results confirmed that celastrol's antitumor and anti-metastatic abilities were not attenuated and were actually strengthened after being formed into nanodrugs. More importantly, the organ toxicities of the modified celastrol nanodrug were dramatically reduced. Mechanistic study indicated that the inactivation of PI3K/Akt/mTOR signaling pathway and ROS-mediated mitochondrial dysfunction play critical roles in celastrol-mediated autophagy and apoptosis.

INTERPRETATION

Our findings could offer a potential strategy for the translation of toxic compounds into clinical therapeutic nanomedicine.

FUNDING

See a detailed list of funding bodies in the Acknowledgements section at the end of the manuscript.

Heparanase and the hallmarks of cancer

Heparanase is the only mammalian enzyme that cleaves heparan sulphate, an important component of the extracellular matrix. This leads to the remodelling of the extracellular matrix, whilst liberating growth factors and cytokines bound to heparan sulphate. This in turn promotes both physiological and pathological processes such as angiogenesis, immune cell migration, inflammation, wound healing and metastasis. Furthermore, heparanase exhibits non-enzymatic actions in cell signalling and in regulating gene expression. Cancer is underpinned by key characteristic features that promote malignant growth and disease progression, collectively termed the 'hallmarks of cancer'. Essentially, all cancers examined to date have been reported to overexpress heparanase, leading to enhanced tumour growth and metastasis with concomitant poor patient survival. With its multiple roles within the tumour microenvironment, heparanase has been demonstrated to regulate each of these hallmark features, in turn highlighting the need for heparanase-targeted therapies. However, recent discoveries which demonstrated that heparanase can also regulate vital anti-tumour mechanisms have cast doubt on this approach. This review will explore the myriad ways by which heparanase functions as a key regulator of the hallmarks of cancer and will highlight its role as a major component within the tumour microenvironment. The dual role of heparanase within the tumour microenvironment, however, emphasises the need for further investigation into defining its precise mechanism of action in different cancer settings.

A systematic review on the efficacy and safety of low molecular weight heparin as an anticancer therapeutic in preclinical animal models

OBJECTIVE

The therapeutic effects of low molecular weight heparins (LMWH) may extend past thrombosis prevention, with preclinical evidence demonstrating anti-metastatic properties. Clinical evidence on the topic, however, remains controversial. A systematic review of preclinical evidence may help elucidate reasons for this contradictory evidence. The objective of our systematic review is to assess the anti-metastatic properties of LMWHs in solid tumour animal models.

METHODS

MEDLINE, Embase, Web of Science and PubMed were searched from inception to May 12th, 2020. All articles were screened independently and in duplicate. Studies that compared LMWH to a placebo or no treatment arm in solid tumour animal models were included. The primary outcome was the burden of metastasis. Secondary outcomes included primary tumour growth and mortality. The risk of bias was assessed in duplicate using a modified Cochrane Risk of Bias tool.

RESULTS

Forty-two studies were included in the review. Administration of a LMWH was associated with a significant decrease in the burden of metastasis (SMD -2.18; 95% CI -2.66 to -1.70). Additionally, the administration of a LMWH was also associated with a significant reduction in primary tumour growth (SMD -1.95; 95% CI -2.56 to -1.34) and risk of death (RR 0.39; 95% CI 0.16-0.97). All included studies were deemed to be at an unclear risk of bias for at least one methodological criterion.

CONCLUSIONS

Our results demonstrate that LMWH can effectively reduce metastatic burden and reduce tumour growth in preclinical animal models of solid tumour malignancies. Reasons for the contradiction with clinical evidence require further exploration.

Randomised phase II trial of gemcitabine and nab-paclitaxel with necuparanib or placebo in untreated metastatic pancreas ductal adenocarcinoma

BACKGROUND

Necuparanib, a rationally engineered low-molecular-weight heparin, combined with gemcitabine/nab-paclitaxel showed an encouraging safety and oncologic signal in a phase Ib trial. This randomised multicentre phase II trial evaluates the addition of necuparanib or placebo to gemcitabine/nab-paclitaxel in untreated metastatic pancreatic ductal adenocarcinoma (PDAC).

PATIENTS AND METHODS

Eligibility included 18 years, histologically or cytologically confirmed metastatic PDAC, measurable disease and Eastern Co-Operative Oncology Group performance status of 0-1. Patients were randomly assigned to necuparanib (5 mg/kg subcutaneous injection once daily) or placebo (subcutaneous injection once daily) and gemcitabine/nab-paclitaxel on days 1, 8 and 15 of 28-day cycles. The primary end-point was median overall survival (OS), and secondary end-points included median progression-free survival, response rates and safety.

RESULTS

One-hundred ten patients were randomised, 62 to necuparanib arm and 58 to placebo arm. The futility boundary was crossed at a planned interim analysis, and the study was terminated by the Data Safety Monitoring Board. The median OS was 10.71 months (95% confidence interval [CI]: 7.95-11.96) for necuparanib arm and 9.99 months (95% CI: 7.85-12.85) for placebo arm (hazard ratio: 1.12, 95% CI: 0.66-1.89, P-value: 0.671). The necuparanib arm had a higher incidence of haematologic toxicity relative to placebo patients (83% and 70%).

CONCLUSION

The addition of necuparanib to standard of care treatment for advanced PDAC did not improve OS. Safety was acceptable. No further development of necuparanib is planned although targeting the coagulation cascade pathway remains relevant in PDAC. NCT01621243.

LMWH and its derivatives represent new rational for cancer therapy: construction strategies and combination therapy

Low-molecular-weight heparin (LMWH) has attracted increasing attention as a tumor treatment because of its board range of physiological functions. Over the past decade, diverse LMWH derivatives have increased the variety of antitumor strategies available, serving not only as anti-tumor agents, but also as drug delivery platforms. In this review, we introduce the basic strategy for structural modification of LMWH to attenuate its antitumor activity while reducing its risk of bleeding and immune responses, as well as highlighting current applications of LMWH and its derivatives in cancer therapy. We select representative drug delivery systems involving LMWH derivatives and discuss the construction principles and therapeutic effects associated with their use. We also analyze progress made in the development of antitumor combination therapies, in which LMWH has shown synergistic or combined effects with other treatment strategies.

pH-activatable polymeric nanodrugs enhanced tumor chemo/antiangiogenic combination therapy through improving targeting drug release

It was widely accepted that polymeric nanodrugs held superiority in enhancing antitumor efficacy, reducing side effect and achieving better long-term prognosis. However, there still existed disputes that whether their therapeutic efficiency was closely related to insure effective release of hydrophobic drug located in their hydrophobic core in tumor site. In order to investigate this controversy, we constructed two polymeric nanodrugs (pH-activatable sLMWH-UOA and non-sensitive LMWH-UOA) with low molecular weight heparin (LMWH) and ursolic acid (UOA) for chemo-and anti-angiogenic combination therapy in hepatocellular carcinoma. The degradation ratio of pH-activatable sLMWH-UOA increased by 33% compared with non-sensitive LMWH-UOA in in vitro degradation study. Besides, confocal microscopy captured that sLMWH-UOA could effectively release drug in acidic microenvironment of lysosome while LMWH-UOA nearly could not. More importantly, in contrast with LMWH-UOA, sLMWH-UOA presented pH-dependent cytotoxicity, indicating that promoting drug release played a key role in enhancing the cytotoxicity of polymeric nanodrugs. Additionally, in vivo pharmacodynamic evaluation showed that although non-sensitive LMWH-UOA had benefited from enhanced tumor targeting drug delivery ability to achieve absolute advantage over free drug combination therapy in antitumor combination therapy, sLMWH-UOA could acquire further optimized combined therapeutic effect with better drug release in tumor. All above, application of tumor-triggered chemical bonds to construct polymeric nanodrugs held vast prospect for improving the therapeutic efficiency for tumor cells.

Attempts to strengthen and simplify the tumor vascular normalization strategy using tumor vessel normalization promoting nanomedicines

Tumor vascular normalization theory opened the door for the rational use of antiangiogenic agents and chemotherapeutics.

Antitumor effects of nadroparin combined with radiotherapy in Lewis lung cancer models

Background

The beneficial antitumor effects of low-molecular-weight heparins (LMWHs) have previously been investigated in basic and clinical studies. In this study, the antitumor efficacy of nadroparin combined with radiotherapy was investigated in vivo.

Methods

A total of 48 tumor-bearing mice were randomly divided into six groups (n=8 per group): control group, irradiation group (X), LMWH_1,000 group, LMWH_2,000 group, LMWH_1,000+X group and LMWH_2,000+X group. Following this, tumor growth, weight and inhibitory rate, as well as the survival of mice in each group, were determined. Levels of serum interleukin (IL)-6 and transforming growth factor (TGF)-β1 were determined via enzyme-linked immunosorbent assay (ELISA) analyses. The expression levels of CD34 were investigated using immunohistochemistry analyses to represent the microvascular density (MVD) values of tumor tissues. In addition, tumor cell apoptosis was investigated using TdT-mediated dUTP nick end labeling (TUNEL) analysis post treatment. The expression levels of survivin were analyzed by Western blotting.

Results

The volumes and weights of tumors in the treatment groups were demonstrated to be significantly decreased, which was most obvious in the LMWH_2,000+X group. The tumor inhibitory rate was significantly increased in the treated mice. ELISA assays demonstrated that the concentrations of serum IL-6 and TGF-β1 were significantly decreased in the LMWH_2,000+X group. In addition, the decreased CD34 expression was found in the combined treatment groups. TUNEL assays demonstrated that the apoptosis rate was increased in treated mice, and the highest apoptosis rate was exhibited by the LMWH_2,000+X group. Results of Western blotting demonstrated that combinatory treatment with both nadroparin and X-ray irradiation significantly inhibited the expression of survivin.

Conclusion

These results demonstrated that a combinatory treatment strategy of nadroparin with fractionated irradiation had a strong synergistic antitumor effect in vivo, which may be associated with the promotion of apoptosis, inhibited secretion of TGF-β1 and IL-6 and down-regulation of CD34 and survivin expression.

A targeted nanoplatform co-delivering chemotherapeutic and antiangiogenic drugs as a tool to reverse multidrug resistance in breast cancer

Several obstacles are currently impeding the successful treatment of breast cancer, namely impaired drug accumulation into the tumor site, toxicity to normal cells and narrow therapeutic index of chemotherapy, multidrug resistance (MDR) and the metastatic spread of cancer cells through the blood and lymphatic vessels. In this regard, we designed a novel multifunctional nano-sized drug delivery system based on LyP-1 peptide-modified low-molecular-weight heparin-quercetin conjugate (PLQ). This nanosystem was developed for targeted co-delivery of multiple anticancer drugs to p32-overexpressing tumor cells and peritumoral lymphatic vessels, using LyP-1 peptide as active targeting ligand, with the aim to achieve a targeted combinatorial chemo/angiostatic therapy and MDR reversal. The cellular uptake of PLQ nanoparticles by p32-overexpressing breast cancer cells was significantly higher than nonfunctionalized nanoparticles. Besides, the anti-angiogenic activity of PLQ nanoparticles was proven by the effective inhibition of the bFGF-induced neovascularization in subcutaneous Matrigel plugs. More importantly, PLQ/GA nanoparticles with better targeting ability toward p32-positive tumors, displayed a high antitumor outcome by inhibition of tumor cells proliferation and angiogenesis. Immunohistochemistry and western blot assay showed that PLQ/GA nanoparticles significantly disrupted the lymphatic formation of tumor, and inhibited the P-glycoprotein (P-gp) expression in MCF-7 tumor cells, respectively. In conclusion, PLQ/GA nanoparticles provide a synergistic strategy for effective targeted co-delivery of chemotherapeutic and antiangiogenic agents and reversing MDR and metastasis in breast cancer.

STATEMENT OF SIGNIFICANCE

Herein, we successfully developed a novel amphiphilic nanomaterial, LyP-1-LMWH-Qu (PLQ) conjugate, consisting of a tumor-targeting moiety LyP-1, a hydrophobic quercetin (a multidrug resistance [MDR]-reversing drug) inner core, and a hydrophilic low-molecular-weight heparin (an antiangiogenic agent) outer shell for encapsulating and delivering a hydrophobic chemotherapeutic agent (gambogic acid). This versatile nanoplatform with multiple targeted features, i.e., dual chemo/angiostatic effects, destruction ability of the peritumoral lymphatic vessels, and reversal of MDR, resulted in a significantly stronger antitumor efficacy and lower toxic side effect than those of nontargeted nanoparticles and the free drug solution. Therefore, this versatile nanosystem might provide a novel insight for the treatment and palliation of breast cancer by targeted co-delivery of chemo/antiangiogenic agents and reversing MDR and metastasis.

Intracellular self-disassemble polysaccharide nanoassembly for multi-factors tumor drug resistance modulation of doxorubicin

Drug efflux induced by multidrug resistance (MDR) overexpression, as well as secondary drug resistance caused by subtoxic drug microenvironments as a result of inefficient drug release of nanoscopic drug carriers in tumor cells, are major bottlenecks for chemotherapy.

Smart Carriers and Nanohealers: A Nanomedical Insight on Natural Polymers

Biodegradable polymers are popularly being used in an increasing number of fields in the past few decades. The popularity and favorability of these materials are due to their remarkable properties, enabling a wide range of applications and market requirements to be met. Polymer biodegradable systems are a promising arena of research for targeted and site-specific controlled drug delivery, for developing artificial limbs, 3D porous scaffolds for cellular regeneration or tissue engineering and biosensing applications. Several natural polymers have been identified, blended, functionalized and applied for designing nanoscaffolds and drug carriers as a prerequisite for enumerable bionano technological applications. Apart from these, natural polymers have been well studied and are widely used in material science and industrial fields. The present review explains the prominent features of commonly used natural polymers (polysaccharides and proteins) in various nanomedical applications and reveals the current status of the polymer research in bionanotechnology and science sectors.

Anticoagulants versus cancer

Venous thromboembolism (VTE) and cancer are strongly associated, and present a major challenge in cancer patient treatment. Cancer patients have a higher risk of developing VTE, although the risk differs widely between tumour types. VTE prophylaxis is routinely given to cancer patients, in the form of vitamin K antagonists (VKA) or low molecular weight heparin (LMWH). Several studies have reported that cancer patients receiving anticoagulants show prolonged survival and this effect was more pronounced in patients with a good prognosis, although the mechanism is poorly understood. Tissue Factor (TF) is the initiator of extrinsic coagulation, but its non-haemostatic signalling via protease-activated receptors (PARs) is a potent driver of tumour angiogenesis. Furthermore, coagulation activation is strongly implicated in tumour cell migration and metastasis. This review discusses the effects of anticoagulants on cancer progression in patients, tumour cell behaviour, angiogenesis, and metastasis in in vitro and in vivo models. Inhibition of TF signalling shows great promise in curbing angiogenesis and in vivo tumour growth, but whether this translates to patients is not yet known. Furthermore, non-haemostatic properties of coagulation factors in cancer progression are discussed, which provide exciting opportunities on limiting oncologic processes without affecting blood coagulation.

Non-anticoagulant effects of low molecular weight heparins in inflammatory disorders: A review

Low molecular weight heparins (LMWHs) are produced by chemical or enzymatic depolymerization of unfractionated heparin (UFH). Besides their well-known anticoagulant effects, LMWHs have also been reported to exhibit numerous anti-inflammatory properties. Previous studies have, however, shown that different production processes result in unique structural characteristics of LMWHs. The structural variations may help explain the different therapeutic spectrums in disease treatment for non-anticoagulant effects. In the present review, we summarize major advances in understanding and exploiting the anti-inflammatory disorder activities of LMWHs, based on mechanistic studies, preclinical experiments and clinical trials. We highlight differences in these activities of commercially available LMWHs produced using different manufacturing processes. We stress the importance of structure-activity relationship (SAR) studies on the non-anticoagulant effects of LMWHs and discuss strategies for exploring new clinical indications.

Combination of nadroparin with radiotherapy results in powerful synergistic antitumor effects in lung adenocarcinoma A549 cells

Low-molecular-weight heparins (LMWHs), which are commonly used in venous thromboprophylaxis and treatment, have recently been reported to have effects on cancer metastasis in pre-clinical research studies. This study was planned to define the synergistic antitumor effects of nadroparin (a kind of LMWH) combined with radiotherapy in A549 cells. Six experimental groups were set up in our study according to the different treatment: control group; irradiation (IR) group; low dose of nadroparin group (LMWH50, L50); high dose of nadroparin group (LMWH100, L100); LMWH50+IR group; LMWH100+IR group. The viability of A549 cells was assessed by Cell Counting Kit-8 (CCK-8) assay. The apoptosis of tumor cells was analyzed by flow cytometry (FCM) after treatment. The concentration of transforming growth factor-β1 (TGF-β1) in the culture supernatants was measured by enzyme-linked immunosorbent assay (ELISA). The migration and invasion of the A549 cells were tested by the Transwell chamber assay. The expression of survivin, CD147 and matrix metalloproteinase-2 (MMP-2) was analyzed by western blotting. CCK-8 assay showed that irradiation or nadroparin alone slightly inhibited the cell viability while the combined treatments significantly inhibited the cell viability in a dose- and time-dependent manner. The apoptosis rate showed greater improvement dose- and time‑dependently in the groups receiving combination therapy of nadroparin and irradiation than the control group or the group receiving nadroparin or irradiation alone by FCM. ELISA assay showed that the decreased TGF-β1 secretion was found after combined treatments with nadroparin and irradiation compared to either treatment alone. The Transwell chamber assay showed that nadroparin not only significantly suppressed the migration and invasion of A549 cells but also inhibited the enhanced ability of migration and invasion induced by X-ray irradiation. Western blotting showed that nadroparin inhibited the upregulated effects of survivin and MMP-2 expression induced by radiation in the combined treatment groups in a dose- and time-dependent manner. Moreover, the expression level of CD147 was the lowest in the combined treatment groups. This study identified that combination of nadroparin and irradiation had a strong synergistic antitumor effect in a dose- and time-related manner in vitro, which was reflected in the inhibition of cell viability, invasion and metastasis, promotion of apoptosis, inhibited secretion level of TGF-β1 and downregulation of CD147, MMP-2 and survivin expression.

Sigma receptor-mediated targeted delivery of anti-angiogenic multifunctional nanodrugs for combination tumor therapy

The potential of low molecular weight heparin (LMWH) in anti-angiogenic therapy has been tempered by poor in vivo delivery to the tumor cell and potentially harmful side effects, such as the risk of bleeding due to heparin's anticoagulant activity. In order to overcome these limitations and further improve the therapeutic effect of LMWH, we designed a novel combination nanosystem of LMWH and ursolic acid (UA), which is also an angiogenesis inhibitor for tumor therapy. In this system, an amphiphilic LMWH-UA (LHU) conjugate was synthesized and self-assembled into core/shell nanodrugs with combined anti-angiogenic activity and significantly reduced anticoagulant activity. Furthermore, DSPE-PEG-AA-modified LHU nanodrugs (A-LHU) were developed to facilitate the delivery of nanodrugs to the tumor. The anti-angiogenic activity of A-LHU was investigated both in vitro and in vivo. It was found that A-LHU significantly inhibited the tubular formation of human umbilical vein endothelial cells (HUVECs) (p<0.01) and the angiogenesis induced by basic fibroblast growth factor (bFGF) in a Matrigel plug assay (p<0.001). More importantly, A-LHU displayed significant inhibition on the tumor growth in B16F10-bearing mice in vivo. The level of CD31 and p-VEGFR-2 expression has demonstrated that the excellent efficacy of antitumor was associated with a decrease in angiogenesis. In conclusion, A-LHU nanodrugs are a promising multifunctional antitumor drug delivery system.

Intravital Microscopy Imaging Approaches for Image-Guided Drug Delivery Systems

Rapid technical advances in the field of non-linear microscopy have made intravital microscopy a vital pre-clinical tool for research and development of imaging-guided drug delivery systems. The ability to dynamically monitor the fate of macromolecules in live animals provides invaluable information regarding properties of drug carriers (size, charge, and surface coating), physiological, and pathological processes that exist between point-of-injection and the projected of site of delivery, all of which influence delivery and effectiveness of drug delivery systems. In this Review, we highlight how integrating intravital microscopy imaging with experimental designs (in vitro analyses and mathematical modeling) can provide unique information critical in the design of novel disease-relevant drug delivery platforms with improved diagnostic and therapeutic indexes. The Review will provide the reader an overview of the various applications for which intravital microscopy has been used to monitor the delivery of diagnostic and therapeutic agents and discuss some of their potential clinical applications.

Safety studies on intravenous infusion of a potent angiogenesis inhibitor: taurocholate-conjugated low molecular weight heparin derivative LHT7 in preclinical models

CONTEXT

As a class of angiogenesis inhibitors, heparin conjugates have shown significant effectiveness in several studies.

OBJECTIVES

The purpose of our current study is to evaluate the effectiveness and safety of infusing the conjugate of low molecular weight heparin and taurocholate (LHT7), which has been developed as a potent angiogenesis inhibitor.

METHODS

To evaluate its safety, the method of intravenous infusion was compared with its i.v. bolus administration. Intravenous infusion was administered at a rate of 400 μl/min/kg of body weight for 30 min. Pharmacokinetic (PK) analysis, organ accumulation, and plasma concentration profiles of LHT7 were measured. The anticancer effect of LHT7 was evaluated in murine and human xenograft models, and preclinical studies were performed in SD rats and beagle dogs.

RESULTS

The results of the PK studies showed reduced organ accumulation in mice and the AUC(0-96 h) (area under the curve) was increased up to 1485 ± 125 h × μg/ml. The efficacy, at dose 1 mg/kg/2 d was higher for i.v. infusion than for i.v. bolus administration in both murine and human cancer models. The preclinical studies showed the safety dose of LHT7 is less than 20 mg/kg in SD rats and in the next safety analysis in beagle dogs showed that there were no organ-specific adverse effects in higher doses, such as, 12 mg/kg. LHT7 showed sustained effects with minimized adverse events when administered through i.v. infusion.

CONCLUSIONS

LHT7 (i.v. infusion) could be safely used for further clinical development as a multi-targeting anti-angiogenic agent.

Molecular imaging of tumor-associated angiogenesis using a novel magnetic resonance imaging contrast agent targeting αvβ 3 integrin

BACKGROUND

The recent introduction of biological anticancer therapy has renewed the interest in functional imaging of tumor-associated angiogenesis (TAA) as a tool to monitor early therapy response. The present study evaluated imaging of TAA using P1227, a novel, small molecular magnetic resonance imaging (MRI) probe targeting αvβ3 integrin.

METHODS

HT29 human colorectal cancers were grown in athymic mice. Dynamic MRI was performed using a three-dimensional VIBE sequence up to 110 min after injection of P1227 or gadolinium-tetraazacyclododecane tetraacetic acid (Gd-DOTA). Specificity was assessed by using P1227 1 h after intravenous administration of the αvβ3 inhibitor cilengitide. Regions of interest were drawn encompassing the tumor rim and normal muscle. Imaging data were compared with microvessel density and αvβ3 expression.

RESULTS

Using P1227, specific enhancement of the angiogenic tumor rim, but not of normal muscle, was observed, whereas Gd-DOTA enhanced tumor and normal muscle. After administering cilengitide, enhancement with P1227, but not with DOTA, was significantly suppressed during the first 20 min. When using P1227, a significant correlation was observed between normalized enhancement of the tumor rim and immunohistochemical αvβ3 integrin expression.

CONCLUSIONS

Molecular MRI using a small monogadolinated tracer targeting αvβ3 integrin and moderate magnetic field strength holds promise in assessing colorectal TAA.

Effect of bone marrow mesenchymal stem cells on hepatocellular carcinoma in microcirculation

This study aims t explore the effect and application of bone marrow mesenchymal stem cells (BMSCs) on hepatocellular carcinoma in microcirculation by observing the angiogenesis of hepatocellular carcinoma in transplanted area. BMSCs were isolated and cultured primarily using the method of whole bone marrow culture and identifying surface antigens of third-generation bone marrow-derived mesenchymal stem cells using flow cytometry. Hepatoma cells cultured with BMSCs-conditioned medium (BMSCs-CM) were assayed using the cell proliferation rate of the MTT method. Nude mice were divided into control group (group A), BMSCs cell transplantation group (group B), HepG-2 cell group (group C), and combined BMSCs and HepG-2 cell cotransplanted group (group D). The result showed that the microvascular density was not significantly different in groups A and B. However, the microvascular density at 14 days was higher than 0 day in group C (P < 0.05). In group D, the microvascular density at 14 days was higher than that of 7 and 0 days (P < 0.05) and 7 days was higher than 0 days (P < 0.05). It was showed that the microvascular density did not get significant difference at 0 and 7 days in the four groups (P > 0.05). But the microvascular density of group C was higher than groups A and B at 14 days (P < 0.05), group D was higher than groups A and B at 14 days (P < 0.05) and group D was higher than group C at 14 days (P < 0.05). BMSCs could promote the growth of microvascular in hepatoma cells in a transplanted area.

The mechanisms of nadroparin-mediated inhibition of proliferation of two human lung cancer cell lines

OBJECTIVES

Clinical data suggest that heparin treatment improves survival of lung cancer patients, but the mechanisms involved are not fully understood. We investigated whether low molecular weight heparin nadroparin, directly affects lung cancer cell population growth in conventionally cultured cell lines.

MATERIALS AND METHODS

A549 and CALU1 cells' viability was assessed by MTT and trypan blue exclusion assays. Cell proliferation was assessed using 5-bromo-2-deoxyuridine incorporation. Apoptosis and cell-cycle distribution were analysed by flow cytometry; cyclin B1, Cdk1, p-Cdk1 Cdc25C, p-Cdc25C and p21 expressions were analysed by western blotting. mRNA levels were analysed by real time RT-PCR.

RESULTS

Nadroparin inhibited cell proliferation by 30% in both cell lines; it affected the cell cycle in A549, but not in CALU-1 cells, inducing arrest in the G(2) /M phase. Nadroparin in A549 culture inhibited cyclin B1, Cdk1, Cdc25C and p-Cdc25C, while levels of p-Cdk1 were elevated; p21 expression was not altered. Dalteparin caused a similar reduction in A549 cell population growth; however, it did not alter cyclin B1 expression as expected, based on previous reports. Fondaparinux caused minimal inhibition of A549 cell population growth and no effect on either cell cycle or cyclin B1 expression.

CONCLUSIONS

Nadroparin inhibited proliferation of A549 cells by inducing G(2) /M phase cell-cycle arrest that was dependent on the Cdc25C pathway, whereas CALU-1 cell proliferation was halted by as yet not elucidated modes.

Differential effects of fondaparinux and bemiparin on angiogenic and vasculogenesis-like processes

INTRODUCTION

Conventional therapy for venous thromboembolism or acute coronary syndrome involves the administration of glycoanticoagulants (heparins) or oligosaccharides (fondaparinux). We evaluated the effects of such drugs on angiogenesis and vasculogenesis-like models.

MATERIALS AND METHODS

Human umbilical vein endothelial cells or human endothelial progenitor cells were treated with bemiparin, fondaparinux or unfractionated heparin, at concentrations reflecting the doses used in clinical practice. After 24h, cell viability, proliferation, tubule formation and angiogenic molecular mechanisms, such as activation of the serine/threonine kinase AKT, were assessed. In vivo angiogenesis was studied using a Matrigel sponge assay in mice.

RESULTS

Bemiparin gave a significant decrease of in vitro angiogenesis as shown by the reduction of endothelial cell tubule network, while both fondaparinux and unfractionated heparin did not show any significant effect. In assays of Matrigel sponge invasion in mice, unfractionated heparin was able to stimulate angiogenesis and, conversely, bemiparin inhibited angiogenesis. Furthermore, both bemiparin and fondaparinux caused a significant reduction in an in vitro vasculogenesis-like model, as demonstrated by the decrease of tubule network after co-seeding of endothelial progenitor cells and human umbilical vein endothelial cells. In addition, unfractionated heparin but not bemiparin was able to increase AKT phosphorylation.

CONCLUSIONS

In in vitro experiments, bemiparin was the only drug to show an anti-angiogenic and vasculogenic-like effect, unfractionated heparin showed only a trend to increase in angiogenesis assay and fondaparinux affected only the vasculogenesis-like model. Notably, the in vivo experiments corroborated these data. Such results are important for the choice of a patient-tailored therapy.

The impact of thromboprophylaxis on cancer survival: focus on pancreatic cancer

Pancreatic cancer is still a clinical challenge due to its predominantly late diagnosis and the chemoresistance to cytotoxic and target drugs. One of the major complications of pancreatic cancer is venous thromboembolism (VTE). Both ambulatory and hospitalized pancreatic cancer patients are at higher risk of developing VTE. Among patients with unresectable pancreatic cancer, the occurrence of VTE may be associated with a poor prognosis. Furthermore, emerging clinical data strongly suggest that anticoagulant treatment may improve patient survival by decreasing thromboembolic complications as well as by anticancer activity. Given the clinical relevance for both physicians and basic scientists, this article focuses on the experimental and clinical evidence supporting the relation between the coagulation cascade and the invasive and metastatic potential of pancreatic cancer, and suggests that anticoagulant therapy may represent a useful strategy to improve the prognosis of pancreatic cancer patients.

Intravital microscopy in the mouse dorsal chamber model for the study of solid tumors

Intra-Vital Microscopy (IVM) is used to visualize tumors in animals and analyze various aspects of cancer physiology such as tumor vascularization, cell migration and metastasis. The main advantages of IVM include the real -time analysis of dynamic processes with single-cell resolution. The application of IVM, however, is limited by the availability of animal models that carry visually accessible tumors. These models have evolved over time to become more and more relevant to human tumors. The latest step is the development of a pseudo-orthotopic, syngeneic model for tumor growth and metastasis. In this model, tissue from a variety of mouse organs are grafted in a dorsal skinfold chamber and allowed to revascularize, whereupon tumor cell spheroids are implanted. These spheroids develop into tumors that bear a much closer resemblance to human tumors than xenografts. Unlike xenografts, the vasculature is well-ordered and, because the model is syngeneic, there are no cross-species host immune reactions. The use of fluorescence-tagged pseudo-organs and tumor cells allows IVM analysis and provides real-time access to the development of tumors that closely resemble the real disease. This model can be used to test therapeutics and to image tumor development and stroma-tumor interactions.

Intravital microscopy as a tool to study drug delivery in preclinical studies

The technical developments in the field of non-linear microscopy have made intravital microscopy one of the most successful techniques for studying physiological and pathological processes in live animals. Intravital microscopy has been utilized to address many biological questions in basic research and is now a fundamental tool for preclinical studies, with an enormous potential for clinical applications. The ability to dynamically image cellular and subcellular structures combined with the possibility to perform longitudinal studies have empowered investigators to use this discipline to study the mechanisms of action of therapeutic agents and assess the efficacy on their targets in vivo. The goal of this review is to provide a general overview of the recent advances in intravital microscopy and to discuss some of its applications in preclinical studies.