IADR Abstract Archives
Comparative Study of Breast Cancer Cells and Effects of Clinically Used Bisphosphonates, Zelondronic Acid and Alendronate, in 2D Cell Culture and 3D Live Bone Microenvironment
Objectives: Over 80% of women who reached an advanced stage of breast cancer develop bone metastases. Bisphosphonates (BPs) have been used clinically as anti-cancer/metastatic agents in cancer patients with a wide range of tumor types including breast cancers. This study was designed to compare the effects of zolendronic acid (ZOL) and alendronate (ALN) on human breast cancer cells under 2D cell culture conditions and in a 3-D live bone organ microenvironment.
Methods: We have evaluated a range of concentrations (30 nM, 0.5 µM, 2 µM, 5 µM, 10 µM and 20 µM) of ZOL and ALN on breast cancer cells MDA-MB-231 and its bone-seeking variant MDA-BO in cell culture model using two different approaches with drug treatments: (a) at confluence, and (b) at the seeding time non-confluent state. Cell count was performed at days 3 and 8 to compare the drug’s effect over time. Next,the effect of BPs on the cancer-bone metastasis/interactions and bone biology was investigated utilizing 3-D live mouse calvarial bone organ co-cultures with breast cancer cells in a roller tube model systems over 8 days. These model systems under bone resorption and formation conditions were evaluated by chemical, biochemical, TRAP and ALP enzyme activities, neutral red/silver nitrate staining, histological/quantitative histomorphometric analyses of the used media and calvarial bones.
Results: The effect of ZOL and ALN on MDA-231 and MDA-BO in 2-D cell culture conditions when cells were confluent showed: (a) susceptibility of these cells to BP treatment at clinically relevant doses, and (b) there was a significant differences in the sensitivity of MDA-231 (70% dead) versus MDA-BO (40% dead) at 20 µM dose over 8 days. However, quite distinct from 2D cell culture results, in a 3D live bone microenvironment the cancer cells colonized bone, proliferated and survived without being affected.
Conclusions: These studies revealed that the effect of BPs on breast cancer cells in 2D cell culture conditions are very different as compared to 3D live bone microenvironment due to PBs being rapidly removed from the media and trapped within the mineralized bone matrix. Furthermore, in 2D cell cultures the two breast cancer cell types showed very different sensitivity towards the BP exposure with high resistance of the bone seeking/specific MDA-BO as compared to MDA-231.
Methods: We have evaluated a range of concentrations (30 nM, 0.5 µM, 2 µM, 5 µM, 10 µM and 20 µM) of ZOL and ALN on breast cancer cells MDA-MB-231 and its bone-seeking variant MDA-BO in cell culture model using two different approaches with drug treatments: (a) at confluence, and (b) at the seeding time non-confluent state. Cell count was performed at days 3 and 8 to compare the drug’s effect over time. Next,the effect of BPs on the cancer-bone metastasis/interactions and bone biology was investigated utilizing 3-D live mouse calvarial bone organ co-cultures with breast cancer cells in a roller tube model systems over 8 days. These model systems under bone resorption and formation conditions were evaluated by chemical, biochemical, TRAP and ALP enzyme activities, neutral red/silver nitrate staining, histological/quantitative histomorphometric analyses of the used media and calvarial bones.
Results: The effect of ZOL and ALN on MDA-231 and MDA-BO in 2-D cell culture conditions when cells were confluent showed: (a) susceptibility of these cells to BP treatment at clinically relevant doses, and (b) there was a significant differences in the sensitivity of MDA-231 (70% dead) versus MDA-BO (40% dead) at 20 µM dose over 8 days. However, quite distinct from 2D cell culture results, in a 3D live bone microenvironment the cancer cells colonized bone, proliferated and survived without being affected.
Conclusions: These studies revealed that the effect of BPs on breast cancer cells in 2D cell culture conditions are very different as compared to 3D live bone microenvironment due to PBs being rapidly removed from the media and trapped within the mineralized bone matrix. Furthermore, in 2D cell cultures the two breast cancer cell types showed very different sensitivity towards the BP exposure with high resistance of the bone seeking/specific MDA-BO as compared to MDA-231.