<i>CCNE2</i> is a direct target of miR-30b in breast cancer cells.

<p>6A: A diagram of the 3′UTR-containing reporter constructs for <i>CCNE2</i>, <i>CCNA1</i>, and <i>CDC7</i> and their derivatives. The 3′UTRs of the three genes were inserted just downstream of the firefly luciferase gene in the pGL4.13 vector (wt). Next, the mutated derivatives (mut1, mut2, and mut1+2) of CCNE2-wt were generated by inserting mutations into two putative binding sites corresponding to the seed-sequence of miR-30b. 6B and 6C: SKBR3 and BT474 cells were co-transfected with reporter constructs, internal control vector (pGL4.73), and synthetic miR-30b oligomer. 6D: assessment of endogenous microRNA's inhibitory effects to <i>CCNE2</i>. Only reporter constructs and pGL4.73 were transfected into SKBR3 and BT474 cells. Twenty-four hours after the transfection, the reporter luciferase activity was measured. The data were shown as the luciferase activity relative to that of vehicle (pGL4.13+pGL4.73) transfection. All bars and error bars represent means ± SEM (n = 3). *: p<0.05, **: p<0.005.