Low Molecular Weight Apple Polysaccharides Induced Cell Cycle Arrest in Colorectal Tumor

Abstract

Dietary components play an important role in cancer prevention. Many ingredients from apples have been proven to have antitumor potency. We thus made low molecular weight apple polysaccharides (LMWAP) and evaluated the effects of it on colorectal cancer (CRC). The effects of LMWAP on human colon carcinoma cells (HT-29) were evaluated using a microarray. Then, cell-cycle distribution was measured by flow cytometric analysis. A colitis-associated colorectal cancer mouse model was used to assess the effect of LMWAP on in vivo CRC prevention. Treatment of HT-29 cells with LMWAP resulted in 333 genes expression over cutoff values (≥2-fold). Further analysis demonstrated that pathways of cell cycle were mainly influenced. At the concentrations from 0.001 to 0.1 mg/mL, LMWAP induced a G₀/G₁ phase block in HT-29 cells in a dose-dependent way. In vivo studies revealed that administration of LMWAP could protect ICR mice against CRC effectively. The results of Western blot suggested LMWAP induced cell-cycle arrest in a p53 independent manner. These data indicate that LMWAP could inhibit the development of CRC through affecting cell cycle, and it has potential for clinical prevention for colon cancer.

ACKNOWLEDGMENTS

This investigation was supported by Grant No. 2010CB 535002, from National Program on Key Basic Research Project of China (973 Program), and Grant No. 2010ZDKG-47, from the Technology Gallery of Shaanxi Province.

Yuhua Li, Lin Mei, and Yinbo Niu are co-first authors.