Modulating Three-Dimensional Microenvironment with Hyaluronan of Different Molecular Weights Alters Breast Cancer Cell Invasion Behavior.

Hyaluronan (HA), a polymer with various molecular weights (MW) found in tumor microenvironments, is associated with malignant progression of breast cancer. Reducing the amount of high-MW HA in the microenvironment by hyaluronidase is a promising approach for breast cancer treatment. However, whether the generation of HA fragments negatively affects breast cancer cells remains to be determined. Furthermore, HA forms three-dimensional (3D) networks by cross-linking with other extracellular molecules to function. Therefore, a model mimicking the cross-linked HA network is required to determine the effect of HA fragments on breast cancer cells. To clarify the differential roles of low (HA35) versus high (HA117) MW HA on cancer cell phenotype, a 3D culture system was set up by covalently cross-linking HA with alginate and investigating the behavior of 4T-1 and SKBR3 breast cancer cells alongside a two-dimensional (2D) control. The results show the invasion and migration abilities of 4T-1 and SKBR3 cells are significantly enhanced by the presence of HA35 but inhibited by HA117 in both 2D monolayers and 3D spheroids. The differential effects of HA35 and HA117 on cancer cell epithelial-mesenchymal transition (EMT) phenotype were further confirmed in terms of differential regulation of E-cadherin and vimentin as important EMT markers at both the cellular and mRNA levels. Additional experiments show the CD44-Twist signaling pathway might be involved in the differential effects of HA35 and HA117. These results have important implications with respect to understanding the role of HA in breast cancer development and for the design of therapeutic approaches based on the eradication of HA with hyaluronidase.

An alginate-based platform for cancer stem cell research.

UNLABELLED: As the primary determinants of the clinical behaviors of human cancers, the discovery of cancer stem cells (CSCs) represents an ideal target for novel anti-cancer therapies (Kievit et al., 2014). Notably, CSCs are difficult to propagate in vitro, which severely restricts the study of CSC biology and the development of therapeutic agents. Emerging evidence indicates that CSCs rely on a niche that controls their differentiation and proliferation, as is the case with normal stem cells (NSCs). Replicating the in vivo CSC microenvironment in vitro using three-dimensional (3D) porous scaffolds can provide means to effectively generate CSCs, thus enabling the discovery of CSC biology. This paper presents our study on a novel alginate-based platform for mimicking the CSC niche to promote CSC proliferation and enrichment. In this study, we used a versatile mouse 4T1 breast cancer model to independently evaluate the matrix parameters of a CSC niche - including the material's mechanical properties, cytokine immobilization, and the composition of the extracellular matrix's (ECM's) molecular impact - on CSC proliferation and enrichment. On this basis, the optimal stiffness and concentration of hyaluronic acid (HA), as well as epidermal growth factor and basic fibroblast growth factor immobilization, were identified to establish the platform for mimicking the 4T1 breast CSCs (4T1 CSCs) niche. The 4T1 CSCs obtained from the platform show increased expression of the genes involved in breast CSC and NSC, as compared to general 2D or 3D culture, and 4T1 CSCs were also demonstrated to have the ability to quickly form a subcutaneous tumor in homologous Balb/c mice in vivo. In addition, the platform can be adjusted according to different parameters for CSC screening. Our results indicate that our platform offers a simple and efficient means to isolate and enrich CSCs in vitro, which can help researchers better understand CSC biology and thus develop more effective therapeutic agents to treat cancer. STATEMENT OF SIGNIFICANCE: As the primary determinants of the clinical behaviors of human cancers, the discovery of cancer stem cells (CSCs) represents an ideal target for novel anti-cancer therapies. However, CSCs are difficult to propagate in vitro, which severely restricts the study of CSC biology and the development of therapeutic agents. Emerging evidence indicates that CSCs rely on a niche that controls their differentiation and proliferation, as is the case with normal stem cells (NSCs). Replicating the in vivo CSC microenvironment in vitro using three-dimensional (3D) porous scaffolds can provide means to effectively generate CSCs, thus enabling the discovery of CSC biology. In our study, a novel alginate-based platform were developed for mimicking the CSC niche to promote CSC proliferation and enrichment.

An experimental test of stroke recovery by implanting a hyaluronic acid hydrogel carrying a Nogo receptor antibody in a rat model.

The objective of the study was to determine the effects of a hyaluronic-acid-based (HA-based) hydrogel implant, carrying a polyclonal antibody to the Nogo-66 receptor (NgR), on adult rats that underwent middle cerebral artery occlusion (MCAO). Behavioral tests of a forelimb-reaching task suggested that the disabled function of the impaired forelimb in this stroke model was ameliorated by the implant to a certain extent. These behavioral findings were correlated with immunohistochemical results of investigating the distribution of NgR antibody, neurofilaments (NF) and neuron-specific class III beta-tubulin (TuJ1) in the brain sections. The porous hydrogel functioned as a scaffold to deliver the NgR antibody, support cell migration and development. In addition, it was found NF-positive and TuJ1-positive expressions were distributed in the implanted hydrogel. Collectively, the results demonstrate the promise of the HA hydrogel as a scaffold material and the delivery vehicle of the NgR antibody for the repair of defects and the support of neural regeneration in the brain.

[Effect of gufuhuo decoction on local apoptosis of steroid-induced necrosis of femoral head].

OBJECTIVE: To observe the bone specimen of SANFH (steroid-induced avascular necrosis of femoral head) and the effect of Gufuhuo decoction on local apoptosis of SANFH. METHOD: Model rabbits of necrosis of femoral head, made by intragluteal injection with prednisone acetate, were killed after 6 weeks to study the apoptosis by means of TUNEL. RESULT: A great number of faded osteocytes and osteoblasts existed in specimen of SANFH. There was significant difference in apoptosis indexes between model and control group, Gufuhuo decoction and Xianlinggubao group (P < 0.05). CONCLUSION: In the course of SANFH, the necrosis results from the interaction of apoptosis and necrosis of steroid-induced osteocytes and osteoblasts. Gufuhuo decoction has some effects on improving apoptosis and necrosis of SANFH.

[Effect of gufuhuotang on hemorheology and lipid metabolism of hormonal necrosis of femoral head].

OBJECTIVE: To probe the of Gufuhuotang effect on hemorheology and lipid metabolism of hormonal necrosis of femoral head. METHOD: 32 male rabbits of New Zealand were divided at random into pathological pattern group, normal control group, low-dosage of Gufuhuotang group and high-dosage group; models of osteocyte necrosis of head of femur were made with intragluteal injection of hydroprednisone acetate; the rabbits were observed weekly and killed 6 weeks later and HE pathological section was made to observe hemorheology index and blood-liquid content, and then analysis and comparison were made. RESULT: Gufuhuotang could obviously decrease total blood low-shear viscosity, plasma viscosity, hemacocrit, serum cholesterol and triglyceride contents; under light microscope empty bone lacunas of femoral head were less, fat cells of medullary cavity were less and relatively small, and bone trabecula was sparse with no break. CONCLUSION: Gufuhuotang has a distinct preventive and curative effect on rabbits' hormonal necrosis of femoral head.