No abstract

No abstract

Abstract. Cancer is the leading cause of death worldwide. Although cancer occurs as a localized disease, its morbidity and mortality rates remain high due to the ability of cancer cells to break-off from the primary tumor and spread to distant organs. Currently, chemotherapy is the main treatment for cancer; however, the increase in proportion of drug-resistant cancer cells and unpleasant side-effects of chemotherapy are still the major challenges in cancer therapy. Curcumin is a natural polyphenol compound and the main bioactive constituent of Indian spice turmeric, widely used in Indian and Chinese medicines. Curcumin has well-known therapeutic actions, including antiinflammatory, anti-microbial, anti-oxidant and anti-cancer properties. Curcumin induces cancer cell apoptosis through regulating various signaling pathways and arresting tumor cell cycle. Curcumin's therapeutic/ preventative actions on metastatic cancers have not been yet fully understood and studied. The present review explores the potential anti-metastatic mechanisms of curcumin, including inhibition of transcription factors and their signaling pathways (e.g., inflammatory cytokines (e.g., CXCL1, CXCL2, multiple proteases (e.g., uPA, MMPs), multiple protein kinases (e.g., MAPKs, FAK), regulation of miRNAs (e.g., miR21, miR181b) and heat shock proteins (HLJ1). In addition, possible synergistic actions of combination therapy of curcumin with current chemotherapies are discussed in this review.Despite all recent advances in oncology, cancer is still one of the deadliest diseases around the world (1). Cancer occurs as a localized disease but can spread to distant organs through migration, invasion and metastasis (2). Metastatic cancer is one of the major causes of death in cancer patients. Metastasis is a complex process involving multiple steps: (i) local migration through degrading basement membrane and extracellular matrix (ECM), (ii) intravasation into blood and/or lymphatic vessels, (iii) circulating to the target organ site, (iv) extravasation into target organ tissue and, finally, (v) multiplication in the target organ (2, 3). These steps are mediated by various factors, including growth factors, proteolysis degradation of extracellular matrix, cell-cell adhesion, cytoskeleton remodeling and changes of genes' expressions (2, 3). Metastasis is a non-random process that means each metastatic cancer type has its own preferred site of metastasis. For example, breast cancer cells preferentially metastasize to regional lymph nodes, liver, lungs and bone (4). Nowadays, there are different therapeutic approaches available for patients with metastatic cancers, including surgery, radiotherapy and chemotherapy. Chemotherapy remains the main treatment modality for cancer patients because of its ability of preventing invasion and metastasis. However, the morbidity and mortality rates in patients with metastatic cancer still remain high since current chemotherapy agents fail to selectively and effectively kill cancer cells without destroying normal ce...

No abstract

No abstract

Although bone graft is still considered as the gold standard method, bone tissue engineering offers promising alternatives designed to mimic the extracellular matrix (ECM) and to guide bone regeneration process. In this attempt, due to their similarity to the ECM and their low toxicity/immunogenicity properties, growing attention is paid to natural polymers. In particular, considering the early critical role of fracture hematoma for bone healing, fibrin, which constitutes blood clot, is a candidate of choice. Indeed, in addition to its physiological roles in bone healing cascade, fibrin biochemical characteristics make it suitable to be used as a multipurpose platform for bioactive agents’ delivery. Thus, taking advantage of these key assets, researchers and clinicians have the opportunity to develop composite systems that might further improve bone tissue reconstruction, and more generally prevent/treat skeletal disorders.

Background and purpose: Gallium (Ga) has been shown to be effective in the treatment of disorders associated with accelerated bone loss, including cancer-related hypercalcemia and Paget's disease. These clinical applications suggest that Ga could reduce bone resorption. However, few studies have studied the effects of Ga on osteoclastic resorption. Here, we have explored the effects of Ga on bone cells in vitro. Experimental approach:In different osteoclastic models [osteoclasts isolated from long bones of neonatal rabbits (RBC), murine RAW 264.7 cells and human CD14-positive cells], we have performed resorption activity tests, staining for tartrate resistant acid phosphatase (TRAP), real-time polymerase chain reaction analysis, viability and apoptotic assays. We also evaluated the effect of Ga on osteoblasts in terms of proliferation, viability and activity by using an osteoblastic cell line (MC3T3-E1) and primary mouse osteoblasts. Key results: Gallium dose-dependently (0-100 mM) inhibited the in vitro resorption activity of RBC and induced a significant decrease in the expression level of transcripts coding for osteoclastic markers in RAW 264.7 cells. Ga also dramatically reduced the formation of TRAP-positive multinucleated cells. Ga down-regulated in a dose-dependant manner the expression of the transcription factor NFATc1. However, Ga did not affect the viability or activity of primary and MC3T3-E1 osteoblasts. Conclusions and implications:Gallium exhibits a dose-dependent anti-osteoclastic effect by reducing in vitro osteoclastic resorption, differentiation and formation without negatively affecting osteoblasts. We provide evidence that this inhibitory mechanism involves down-regulation of NFATc1 expression, a master regulator of RANK-induced osteoclastic differentiation.

Calcium phosphate biomaterials such as calcium deficient apatite (CDA) have been contemplated as carrier for delivery of bisphosphonate in bone tissues. In the present work, we have investigated the in vitro biological properties of Zoledronate-loaded CDA. CDA was loaded with zoledronate according to a previously described coating process. 31P MAS NMR spectra demonstrated the effective loading of zoledronate onto CDA. Using 14C labeled zoledronate, we then demonstrated the in vitro release of zoledronate from CDA. In a first set of experiments, we confirmed that Zoledronate reduced the number of TRAP-, vitronectin receptor-, and F-actin ring-positive cells as well as the resorption activity of osteoclasts obtained from a total rabbit bone cell culture. Interestingly, Zoledronate-loaded CDA and its extractive solutions decreased the osteoclastic resorption. Finally, zoledronate-loaded CDA did not affect the viability and alkaline phosphatase activity of primary osteoblastic cells. These data demonstrate that CDA is effective for loading and release of zoledronate. The released zoledronate inhibited osteoclastic resorption without affecting osteoblasts. Our findings therefore suggest that such a drug delivery system would allow an increase in the efficiency of bisphosphonates by being locally available. Further experiments are now required to evaluate the in vivo antiresorptive activity of this concept.