Hic-5/ARA55 inhibits the growth of Lovo cells by up-regulating the expression of P27 / 中华外科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effects of Hic-5/ARA55 on the growth of the human colorectal cancer cells (Lovo cells) and its mechanism.</p><p><b>METHOD</b>Flow cytometry (FCM) was used to study the cell cycle of Lovo cells (Lovo group), Lovo cells stably transfected with empty vector (Lovo-Vector group) and the Lovo cells stably transfected with vector containing Hic-5/ARA55 (Lovo-Hic-5/ARA55 group). Western blot assay was used to detect the principal cyclins in the three groups, and Luciferase assay was used to study the mechanism between Hic-5/ARA55 and the only target cyclin. The cells from the three groups were inoculated subcutaneously into 7 nude mice (Balb/c nu/nu) respectively to observe the effects of Hic-5/ARA55 on the growth of the cells in vivo. Seven weeks later, the subcutaneous tumors were harvested and weighed. Then immunohistochemistry assay was used to detect Hic-5/ARA55 and the target cyclin in the tumors.</p><p><b>RESULTS</b>The cell cycle was obviously delayed from G0/G1 to S stage in Lovo-Hic-5/ARA55 cells. A significantly higher expression of P27 was found in Lovo-Hic-5/ARA55 cells than in the other two groups. The weight of the subcutaneous tumors of Lovo-Hic-5/ARA55 cells, Lovo cells and Lovo-Vector cells were (0.33 +/- 0.23) g, (1.20 +/- 0.39) g and (1.30 +/- 0.49) g, respectively; the tumors of Lovo-Hic-5/ARA55 cells was significantly lighter than those of the other two groups (P<0.05). Hic-5/ARA55 and P27 were both over-expressed in implanted tumors of Lovo-Hic-5/ARA55 cells, while were both expressed lower or not expressed in the other two groups. And the expressions of Hic-5/ARA55 and P27 were highly positive correlated (r=0.816, P<0.05).</p><p><b>CONCLUSION</b>Hic-5/ARA55 could inhibit the growth of Lovo cells both in vitro and in vivo by up-regulating the transcription of P27.</p>