An Aqueous Extract of Marine Microalgae Exhibits Antimetastatic Activity through Preferential Killing of Suspended Cancer Cells and Anticolony Forming Activity

Figure 3

Microalgal extract inhibits metastasis of PC-3 prostate cancer cells. (a) Representative Ki67 IHC images showing metastatic foci in the lungs of treated and untreated mice carrying xenografts of PC-3 prostate cancer cells. (b) The graph shows the metastatic foci counts (>0.05 mm) in the lungs of both untreated and treated mice and their statistical comparison results. Bars, 100 μm. (c) Primary tumors in control mice and microalgal extract-treated mice were stained with human Ki67 antibody as a cell proliferation biomarker. (d) The percentage of Ki67-positive PC-3 cells in each group was quantitated as a bar graph (right) by counting cells in 20x high-power fields of each tumor sample ( tumors per group). ((e) and (f)) Representative Ki67 IHC images show the degree of the primary tumor’s local tissue invasiveness at the boundary between the primary tumor and the host kidney. Arrow heads show highly invasive growth patterns of the primary tumors in both the control and the microalgae extract-treated mice. Mean values ± SD (error bars) are shown. n.s.: not significant.

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