MMP-13 stimulates osteoclast differentiation and activation in tumour breast bone metastases

INTRODUCTION: The increased bone degradation in osteolytic metastases depends on stimulation of mature osteoclasts and on continuous differentiation of new pre-osteoclasts. Metalloproteinases (MMP)-13 is expressed in a broad range of primary malignant tumours and it is emerging as a novel biomarker. Recent data suggest a direct role of MMP-13 in dissolving bone matrix complementing the activity of MMP-9 and other enzymes. Tumour-microenvironment interactions alter gene expression in malignant breast tumour cells promoting osteolytic bone metastasis. Gene expression profiles revealed that MMP-13 was among the up-regulated genes in tumour-bone interface and its abrogation reduced bone erosion. The precise mechanism remained not fully understood. Our purpose was to further investigate the mechanistic role of MMP-13 in bone osteolytic lesions. METHODS: MDA-MB-231 breast cancer cells that express MMP-13 were used as a model for in vitro and in vivo experiments. Conditioned media from MDA-MB-231 cells were added to peripheral blood mononuclear cultures to monitor pre-osteoclast differentiation and activation. Bone erosion was evaluated after injection of MMP-13-silenced MDA-MB-231 cells into nude mice femurs. RESULTS: MMP-13 was co-expressed by human breast tumour bone metastases with its activator MT1-MMP. MMP-13 was up-regulated in breast cancer cells after in vitro stimulation with IL-8 and was responsible for increased bone resorption and osteoclastogenesis, both of which were reduced by MMP inhibitors. We hypothesized that MMP-13 might be directly involved in the loop promoting pre-osteoclast differentiation and activity. We obtained further evidence for a direct role of MMP-13 in bone metastasis by a silencing approach: conditioned media from MDA-MB-231 after MMP-13 abrogation or co-cultivation of silenced cells with pre-osteoclast were unable to increase pre-osteoclast differentiation and resorption activity. MMP-13 activated pre-MMP-9 and promoted the cleavage of galectin-3, a suppressor of osteoclastogenesis, thus contributing to pre-osteoclast differentiation. Accordingly, MMP-13 abrogation in tumour cells injected into the femurs of nude mice reduced the differentiation of TRAP positive cells in bone marrow and within the tumour mass as well as bone erosion. CONCLUSIONS: These results indicate that within the inflammatory bone microenvironment MMP-13 production was up-regulated in breast tumour cells leading to increased pre-osteoclast differentiation and their subsequent activation

Quantification of tumor cellularity and mitotic index in invasive ductal carcinoma of the breast

OBJECTIVE: To evaluate the use of stereologically estimated tumor cell counts in the mitotic index as well as to investigate its correlation with the currently used method and test the reproducibility of the method

Angioleiomyoma of Broad Ligament

Angioleiomyoma is an uncommon benign mesenchymal neoplasm that originates from smooth muscle cells and contains numerous thick-walled blood vessels. Here, we are presenting a case report of a huge broad ligament angioleiomyoma because of its rarity

Protective Effects of Silymarin against Doxorubicin-induced Toxicity

Objectives: The aim of the present study was to investigate the effect of silymarin on doxorubicin-induced toxicity to the rat kidney, heart, and liver. Materials and methods: A single dose of 10 mg/kg doxorubicin was injected intraperitoneally (ip) in the doxorubicin group. The silymarin group received silymarin (100 mg/kg) every other day. In the doxorubicin + silymarin group, silymarin was injected ip at 100 mg/kg dose for 5 days before doxorubicin administration (10 mg/kg, single ip injection) and then continued daily thereafter until euthanization. On the seventh day after doxorubicin injection, eight animals from each group were decapitated and liver and heart samples were obtained. The remaining eight animals of each group continued to receive silymarin every other day, till euthanized on the twenty first day. Serum was separated for determination of superoxide dismutase (SOD), glutathione peroxidase (GSHPx), catalase (CAT), malondialdehyde (MDA), nitric oxide (NO), creatinine, urea, AST, ALT, lactate dehydrogenase (LDH) and creatinine phosphokinase (CPK) activities. Histopathological and electron microscopic examinations of heart, kidney and liver sections were also performed. Results: Doxorubicin caused a significant increase in serum NO levels compared to controls. Silymarin pretreatment group lowered these. Histopathological and electron microscopic examinations of kidney, heart, and liver sections showed doxorubicin to cause myocardial and renal injury which was levv evident in silymarin treated rats. Conclusion(s): Results of the present study indicate that silymarin significantly protected doxorubicin-induced toxicities to the rat kidney, heart, and liver, thus suggesting its administration as a supportive care agent during anti-cancer treatment featuring doxorubicin

Expression of transforming growth factor-beta-1 and p27(Kip1) in pancreatic adenocarcinomas: relation with cell-cycle-associated proteins and clinicopathologic characteristics

Background: The purpose of our study was to investigate the immunohistochemical expression of TGF-beta 1 and p27 in pancreatic adenocarcinomas and to compare the findings with the clinicopathological features and survival. We also aimed to evaluate the expression of TGF-beta 1 and p27 in the context of other cell cycle and proliferation markers such as cyclin D1 and Ki-67