Figure 2.

A3B expression in relation to cell cycle markers CCNE2 and CCNB1. (A) Levels of endogenous A3B mRNA expression during normal culture of A3B-low (MCF7), A3B-intermediate (HCC1954), and A3B-high (HCC1143) breast cancer cells (n = 3). (B) Expression of A3B, CCNE2, and CCNB1 in MCF7, HCC1954, and HCC1143 released from G₁/S arrest, induced by a double-thymidine block. The peak in CCNB1 expression denotes the G₂/M phase, whereas CCNE2 drops soon after release since CCNE2 expression is high throughout G₁. The different sampling times are chosen to accommodate the differences in the growth speed of the used cell lines. Error bar represents SD. MCF7 and HCC1954 data represent n = 2 independent experiments; HCC1143 data represent n = 6 independent experiments. (C) Cell cycle progression and A3B expression in the normal-like breast epithelial cell line MCF10A, which expresses very low levels of A3B. Data represent n = 2 independent experiments. (D) Gene expression levels of A3B and CCNB1 as measured in MCF7 breast cancer cells after varying lengths of serum deprivation. Values relative to normal growth conditions. Error bar represents SD. Data represent n = 2 independent experiments.