Antiproliferative and Apoptotic Properties of Andrographolide Against Human Colon Cancer DLD1 Cell Line

Background: In recent years, natural products have received great attention for cancer prevention owing to their various health benefits, noticeable lack of toxicity and side effects, and the limitations of chemotherapeutic agents. Andrographolide, a labdane diterpenoid is a principal bioactive constituent of Andrographis paniculata Nees, exhibits significant anticancer activity. Objective: The efficacy of andrographolide on colon cancer cells is yet to be elucidated completely. Therefore, we investigated the anticancer efficiency of andrographolide in colon cancer DLD1 cell line. Methods: Antiproliferative activity of andrographolide on DLD1 cells was evaluated by MTT assay, LDH release assay, morphological analysis and colony formation assay. Induction of apoptosis was determined by DAPI staining, Annexin V-FITC staining assay, and caspase-3 activation assay. Role of andrographolide induced cellular reactive oxygen species (ROS) and its association with apoptosis induction in DLD1 cells was elucidated by DCFDA dye. Synergistic ability of andrographolide with 5- fluorouracil (5-FU) and paclitaxel (PTX) was evaluated by MTT assay. Results: Results of the present study indicated that andrographolide declined cell viability of DLD1 cells in a concentration and time-dependent manner. Andrographolide induced apoptosis via nuclear condensation, phosphatidylserine externalization and caspase-3 activation. It also augmented cellular ROS levels which were in turn associated with apoptosis induction in DLD1 cells. Moreover, andrographolide displayed synergistic activity with 5-FU and PTX against DLD1 cells. Conclusion: The present study showed that andrographolide demonstrated antiproliferative and apoptotic properties, moreover it also displayed synergistic effect with chemotherapeutic drugs in colon cancer DLD1 cells.

Eukaryotic initiation factor 4A2 (EIF4A2) expression in colorectal cancer and prediction of prognosis.

664 Background: Eukaryotic initiation factor 4A2(EIF4A2) is a member of the eukaryotic initiation factor 4A family and it is one of the protein-synthesis initiation factors, which are involved in the binding of messenger RNA to the ribosome. The prognostic roles of EIF4A2 in breast cancer, melanoma and lung cancer have been studied. However, the clinical significance and biologic role of EIF4A2 in colorectal cancer remain unknown. Methods: We used quantitative real-time polymerase chain reaction to compare expression of eIF4A2 mRNA between 72 paired colorectal cancer tissues and non-tumor colorectal tissues. We used immunohistochemistry to study the expression of EIF4A2 in 310 colorectal cancer patients under surgical resection, 247 of them received curative surgery. We also analyzed correlation between EIF4A2 expression and clinicopathological characteristics. The biological function of EIF4A2 on colorectal cancer cells were determined in vitro by knock-downing EIF4A2 in HCT116 and DLD1 cell lines. We performed MTT tests, colony formation assays, transwell and wound healing assays. Results: EIF4A2 mRNA was significantly higher in colorectal cancer tissues compared to the paired non-tumor colorectal tissues(P = 0.0034). Over-expression of EIF4A2 was prognostic of shorter overall survival(P = 0.002) and shorter disease-free survival(P = 0.042). Over-expression of EIF4A2 was significantly correlated with more TNM stage IV(P = 0.012). Multivariate analysis suggested EIF4A2 as an independent predictor of overall survival (hazard ratio 2.041[95% CI 1.385 to 3.008], P < 0.001) and disease-free survival (hazard ratio 1.537[95% CI 1.003 to 2.355], P = 0.049). Functionally, knockdown of EIF4A2 in HCT116 and DLD1 cell lines exerted tumor-suppressive effects by significantly inhibiting cell proliferation, colony formation,migration and invasion(P < 0.05). Conclusions: EIF4A2 is highly expressed in colorectal cancer and predicts poor prognosis. EIF4A2 could be served as a potential prognostic marker for colorectal cancer patients.