Regulation of incidence of circulating single/clustered cancer cells (CCC^S/CCC^C) by Rb and CD44.

<p>(A) Fluorescent images and quantification of circulating live cancer cells and cell clusters co-isolated with mononuclear fraction from blood of animals bearing tumors. The tumors were induced by orthotopic implantation of MCF7ras cells expressing shRNAs against Rb, CD44, and their combination, along with respective controls. EGFP is expressed in cytoplasm and its presence indicates both cancer cell identity and presumably intact membrane. Number of animals in each group is depicted on the graph. Scale bar, 10 μm; unequal variance Student's t-test, ** p<0.01, *** p<0.001. (B) Fluorescent images and quantification of total circulating cancer cells (both alive and dead) detected with a human-specific antibody to a nuclear antigen. Data are presented as mean ± SEM. Scale bar, 10 μm; unequal variance Student's t-test, ** p<0.01, *** p<0.001. (C) Number of CCC^S and CCC^C in the total number of cancer cells detected with a human-specific antibody to a nuclear antigen. Data are presented as mean ± SEM; unequal variance Student's t-test, ** p<0.01, *** p<0.001. (D) Fluorescent images and quantification of CD44 positive cancer cells detected with a human-specific anti-CD44 antibody. Data are presented as mean ± SEM. Scale bar, 10 μm; unequal variance Student's t-test, ** p<0.01, *** p<0.001.