Cyclophosphamide promotes breast cancer cell migration through CXCR4 and matrix metalloproteinases.

Cyclophosphamide is indicated for the treatment of cancerous diseases such as breast cancer and cervical cancer. Recent studies have shown that cyclophosphamide may induce cancer metastasis, but the cause of this unexpected adverse effect is not fully understood. In this study, we investigate the effect of cyclophosphamide on cancer cell migration and its correlation to chemokine (C-X-C motif) receptor 4 (CXCR4), a biomarker for cancer metastasis. Two human cancer cell lines with significant difference in endogenous CXCR4 expression, the breast cancer cell line, MDA-MB-231, and the melanoma cell line, MDA-MB-435S, were treated with various concentrations of cyclophosphamide, followed by the assessment of CXCR4 expression and cell migration. We found that the migration ability of MDA-MB-231 cells was enhanced with increasing concentrations of cyclophosphamide, which induced the cell-surface expression of CXCR4, but had no effect on the overall amount of CXCR4. In MDA-MB-435S cells, in which CXCR4 was barely detectable, cyclophosphamide was unable to activate cell-surface CXCR4, and did not promote cell migration. Studies on the mRNA expression profile of matrix metalloproteinases (MMPs) in MDA-MB-231 cells further indicate that MMP9 and MMP13 may be involved in the action of cyclophosphamide. The protein expression of both MMP9 and MMP13 was increased in the presence of cyclophosphamide. Results from this study provide the molecular basis for the possible pathway of cyclophosphamide to induce cancer metastasis.

Coexpression of CXCR4 and MMP9 predicts lung metastasis and poor prognosis in resected osteosarcoma.

Osteosarcoma is a highly aggressive bone disease with a tendency to metastasize to the lung. The 5-year survival of patients with metastatic osteosarcoma is only 20 %. Many studies have demonstrated SDF-1/CXCR4 and MMP9 play important roles in the metastasis of malignant tumors, including osteosarcoma. The aim of this study was to investigate the association of CXCR4 and MMP9 expression with clinicopathological features and pulmonary metastasis in osteosarcoma. Using tumor tissue microarrays, we analyzed the expression of CXCR4 and MMP9 among 34 primary osteosarcomas with pulmonary metastasis and 62 primary osteosarcomas without metastasis. A median time of 57.5 months (range: 6 to 171 months) follow-up was performed to evaluate tumor metastasis and the patient survival. The prognostic values were determined by univariate Kaplan-Meier survival analysis and multivariate Cox proportional hazard model analysis. The accuracy of oncologic outcome prediction was evaluated by receiver-operating characteristics (ROC) curves (AUC). The expression of CXCR4 and MMP9 was significantly correlated in tumor tissues (P = 0.026). Both CXCR4 and MMP9 were independent predictors for overall survival and metastasis-free survival by Cox multivariate analysis, and high expression for both CXCR4 and MMP9 were even more significant and better biomarkers for osteosarcoma metastasis and survival. The combination of CXCR4 and MMP9 high expression is very likely to be a valuable independent predictor of lung metastasis and survival in osteosarcoma patients.

Biocompatible Nanogold Carrier Coated with Hyaluronic Acid for Efficient Delivery of Plasmid or siRNA to Mesenchymal Stem Cells.

A fluorescein isothiocyanate (FITC)-labeled, hyaluronic acid (HA)-coated nanogld (NP-FITC) was developed to carry plasmid or siRNA into mesenchymal stem cells (MSCs). NP-FITC was characterized by scanning electron microscopy (SEM), ultraviolet-visible (UV-vis) spectroscopy, and Fourier transform infrared (FTIR) spectrophotometry. Nontoxicity of NP-FITC in both normal cells and cancer cells was confirmed by the MTT assay. The cellular uptake of NP-FITC at different time points (30 min, 2 h, and 24 h) was verified using an immunofluorescence assay. The delivery efficiency of plasmid was tested on the delivery of superoxide dismutase-1 (SOD-1) plasmid, where the protein expression of SOD-1 was analyzed by Western blots. In addition, the delivery efficiency of siRNA was tested using CXCR4 siRNA. Besides, the siRNA delivery by NP-FITC was employed to elucidate the molecular mechanism associated with the effect of vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1). The biological function of MSCs delivered with chemokine (C-X-C motif) receptor 4 (CXCR4) siRNA was examined using ELISA, gelatin zymography, and a migration assay. Finally, we evaluated the tissue distribution of NP-FITC after the direct injection in the retro orbital sinus of mice or after injection of NP-FITC internalized MSCs through the tail vein of mice. The data provided essential information for NP-FITC as a plasmid or siRNA carrier.

Tumor-tropic endothelial colony forming cells (ECFCs) loaded with near-infrared sensitive Au nanoparticles: A "cellular stove" approach to the photoablation of melanoma.

In the photothermal treatments (PTs) of tumor, the localization of a high number of near-infrared (NIR) absorbing gold nanoparticles in the tumor mass is still a challenging issue. Here, we propose a promising strategy to deliver therapeutic chitosan-coated gold nanoparticles to tumor cells as hidden cargo of Endothelial Colony Forming Cells (ECFCs) endowed with an innate tumor-tropism. Remarkably, ECFC gold enrichement doesn't affect cell viability and preserves the endothelial lineage characteristics such as capillary morphogenesis and cell migration. We demonstrate that heavily Au-doped ECFCs are able to efficiently warm up the tumor environment, and kill the cancer cells via hyperthermic heating both in vitro as well as in vivo. Thus, we show an excellent thermotransductive property of gold enriched ECFCs and their capability to kill melanoma cells at moderate NIR light intensities.

Macrophages play an essential role in the long effects of low-dose photodynamic therapy on vessel permeability.

Low-dose photodynamic therapy (L-PDT) has been used to transiently increase the permeability of tumor vessels to improve the delivery of chemotherapeutic drugs to lung tumors. However, the effects of L-PDT in a long-term on delivery of chemotherapeutic drugs are unknown. In this study, we studied this question as well as the underlying mechanisms. We found that the effects of L-PDT on tumor vessel permeability appeared to be prolonged. Moreover, L-PDT significantly increased the number of tumor associated macrophages, and appeared to induce macrophage polarization to a M1 phenotype. Further analyses showed that L-PDT upregulated stromal cell-derived factor 1 (SDF-1) in tumor to recruit macrophages through a SDF-1/Chemokine (C-X-C Motif) Receptor 4 (CXCR4) axis, which accounted for the prolonged effects of L-PDT on vessel permeability. Application of a specific CXCR4 inhibitor significantly suppressed the L-PDT-induced macrophage recruitment, resulting in abolishment of the prolonged effects of L-PDT on vessel permeability. Furthermore, the inhibitory effects of Liporubicin™ on the growth of the implanted tumor in L-PDT-treated mice were significantly attenuated by CXCR4 inhibition. Thus, our data demonstrate a previously unappreciated long-lasting effect of L-PDT on vessel permeability, and suggest that this long-lasting effects of L-PDT treatment on vessel permeability may result from modulation of macrophage recruitment and polarization. Hence, L-PDT may be a promising method to assist chemotherapeutic approaches.