Induction of the fibrinolytic system by cartilage extract mediates its antiangiogenic effect in mouse glioma

[A plasminogen regulation system in brain tumors]

INTRODUCTION

Tumor progression and neovascularization during malignant processes are believed to be associated with plasminogen activators and the PAI-1 inhibitor, but their role and interactions in various types of brain tumors have been studied insufficiently.

AIM

To conduct a comparative study of plasminogen regulation in optic nerve sheath meningiomas, glioblastomas, and brain metastases of breast cancer, as well as in perifocal tissues surrounding the tumors.

MATERIAL AND METHODS

Tumors and perifocal areas of 19 breast cancer (BC) metastases, 24 glioblastomas, and 13 meningiomas without perifocal edema were investigated by ELISA in 56 patients aged 35-72 years. Histological control was carried out in each case.

RESULTS

Significant differences were found in the levels of urokinase (uPA), tissue plasminogen activator (tPA), and PAI-1 inhibitor between glioblastomas and breast cancer metastases and the histologically unaltered (relatively intact) tissue around meningioma lesions (p≤0.05 in all cases). The levels of uPA-AG and uPA-act in meningioma were higher than those in the relatively intact tissue, while the levels of both tPA forms were reduced. The levels of uPA-AG and uPA-act in both malignant tumors and their perifocal areas were elevated compared to those in the relatively intact tissue. The levels of both tPA forms were reduced in all other tissues, except for glioblastoma. The level of PAI-1 inhibitor in malignant tissues was higher (being predominant in tumors) compared to that in the intact tissue surrounding meningioma, as well as relative to that in meningioma. The study proves that uPA and its inhibitor PAI-1 are directly involved in the metabolism of malignant gliomas and brain metastases of breast cancer. The role of tPA is to protect meningiomas; tPA activation in malignant brain tumors is suppressed.

Depletion of mucin in mucin-producing human gastrointestinal carcinoma: Results from in vitro and in vivo studies with bromelain and N-acetylcysteine

Aberrant expression of membrane-associated and secreted mucins, as evident in epithelial tumors, is known to facilitate tumor growth, progression and metastasis, and to provide protection against adverse growth conditions, chemotherapy and immune surveillance. Emerging evidence provides support for the oncogenic role of MUC1 in gastrointestinal carcinomas and relates its expression to an invasive phenotype. Similarly, mucinous differentiation of gastrointestinal tumors, in particular increased or de novo expression of MUC2 and/or MUC5AC, is widely believed to imply an adverse clinicopathological feature. Through formation of viscous gels, too, MUC2 and MUC5AC significantly contribute to the biology and pathogenesis of mucin-secreting gastrointestinal tumors. Here, we investigated the mucin-depleting effects of bromelain (BR) and N-acetylcysteine (NAC), in nine different regimens as single or combination therapy, in in vitro (MKN45, KATOIII and LS174T cell lines) and in vivo (female nude mice bearing intraperitoneal MKN45 and LS174T) settings. The inhibitory effects of the treatment on cancer cell growth and proliferation were also evaluated in vivo. Our results suggest that a combination of BR and NAC with dual effects on growth and mucin products of mucin-expressing tumor cells is a promising candidate towards the development of novel approaches to gastrointestinal malignancies with the involvement of mucin pathology. This capability supports the use of this combination formulation in locoregional approaches for reducing the adverse effects of the aberrantly secreted gel-forming mucins, as in pseudomyxoma peritonei and similar pathologies with ectopic production of mucin.

Jurassic surgery and immunity enhancement by alkyglycerols of shark liver oil

Background

Shark liver oil (SLO) contains both alkylglycerols (AKG) and squalene and is an ancient remedy among the fishermen on the west coast of Norway and Sweden. Literature reports showed that alkyglycerols enhance Fc–receptor mediated phagocytosis, increase humoral immune response and delay hypersensitivity reactions.

Methods

On this background we performed an open spontaneous study on 40 very old aged surgical patients preoperatively treated with alkyglycerols (500 mg twice a day for 4 weeks), in order to reduce the risks of operation, counteracting the postoperative inflammatory and anergic conditions thus achieving quick and plain recovery. To better understand the possible therapeutic impact of alkyglycerols we compared on a case/control basis treated versus untreated patients submitted contemporarily to the identical operation and exposed to the same environmental and seasonal risks.

Results

The onset of complications was reduced in the alkyglycerols treated group and the compliance to the natural treatment was excellent without any serious adverse effect. WBC count and IgG significant increase (respectively p <0.05 and p <0.001) might explain some sort of protection against infectious agents and wound repair adverse events. Also lymphocytes concentration significantly increased in the AKG treated group (p <0.001) whereas a slight decrease was observed in the control group. Conversely neutrophils significantly decreased in the AKG treated group (p <0.001) meaning that patients have no more infections and have re-established their physiologic state. However a significant increase was observed in the control group (p <0.05). CRP significantly decreased in the group receiving AKG (p <0.05), thus evidencing a slight antiinflammtory effect of the product. Also ESR decreased from a baseline in the group receiving AKG.

Conclusions

In conclusion we suggest the opportunity to introduce this nutraceutical product in dosages of 500 mg twice a day to very old people before surgical treatment for an effective modulation of leukocytes and soluble immune reactivity according with the shark liver oil consumption trend in the northern Europe countries folk medicine. For this reason it might be advisable a wider study on a substantially bigger patients cohort focused on the complication rate prevention or control.

Shark cartilage extract induces cytokines expression and release in endothelial cells and induces E-selectin, plasminogen and t-PA genes expression through an antioxidant-sensitive mechanism

Neovastat® is a standardized extract of marine cartilage, an avascular tissue, which contains many biologically active molecules and has multiple antiangiogenic properties. In addition to VEGFR2 and MMPs inhibition, shark cartilage extract (SCE) has recently been shown to induce tissue plasminogen activator gene (PLAT) expression in bovine endothelial cells in a TNF like manner, by inducing the typical mediators NF-κB and JNK. There is now compelling evidences that the NF-κB and JNK pathways are activated by cytokines induced generation of reactive oxygen species (ROS). We used macroarray genes expression analysis on human umbilical vein endothelial cells, to investigate if that mechanism could mediate the effect of SCE. Transcriptomic results showed that SCE induced expression of several cytokines. Their impact must be important, given that treatment of endothelial cells with the cytokine TNF-α was able to reproduce most of the effects of cartilage extract on genes expression. In addition, most of the genes, known to be inducible by NF-κB or JNK following cytokines stimulation, were less induced by SCE when endothelial cells were pretreated with the antioxidant N-Acetylcysteine (NAC), suggesting a role of ROS in endothelial cell activation by SCE. Finally, the possible effects of PLAT, PLG, SELE, IL8 and PRDX2 (those validated by q-PCR) on angiogenesis, will also be discussed.

Antiangiogenic and anticancer molecules in cartilage

Cartilage is one of the very few naturally occurring avascular tissues where lack of angiogenesis is the guiding principle for its structure and function. This has attracted investigators who have sought to understand the biochemical basis for its avascular nature, hypothesising that it could be used in designing therapies for treating cancer and related malignancies in humans through antiangiogenic applications. Cartilage encompasses primarily a specialised extracellular matrix synthesised by chondrocytes that is both complex and unique as a result of the myriad molecules of which it is composed. Of these components, a few such as thrombospondin-1, chondromodulin-1, the type XVIII-derived endostatin, SPARC (secreted protein acidic and rich in cysteine) and the type II collagen-derived N-terminal propeptide (PIIBNP) have demonstrated antiangiogenic or antitumour properties in vitro and in vivo preclinical trials that involve several complicated mechanisms that are not completely understood. Thrombospondin-1, endostatin and the shark-cartilage-derived Neovastat preparation have also been investigated in human clinical trials to treat several different kinds of cancers, where, despite the tremendous success seen in preclinical trials, these molecules are yet to show success as anticancer agents. This review summarises the current state-of-the-art antiangiogenic characterisation of these molecules, highlights their most promising aspects and evaluates the future of these molecules in antiangiogenic applications.