Anticancer Effects of Sinocrassulosides VI/VII from Silene viscidula on HeLa Cells.

Natural products are becoming increasingly important in chemoprevention and for cancer therapy. Silene viscidula (S. viscidula), a traditional Chinese herb, has long been used as an anti-inflammatory and neuroleptic agent. However, the anticancer activity of S. viscidula has remained unclear. In this study, 16 compounds were extracted from S. viscidula. Among those compounds, sinocrassulosides VI/VII, an inseparable isomer mixture, possess the strongest inhibitory activity on HeLa cells with the IC50 value of 2.37 µM. Mechanism studies found that sinocrassulosides VI/VII downregulated the expression of cyclin D1 and decreased retinoblastoma (Rb) phosphorylation, which arrested HeLa cells in the G1 phase. Also, sinocrassulosides VI/VII could induce senescence via the upregulation of p16 and a significant increase of ß-galactosidase (ß-gal) staining. Our results suggest that sinocrassulosides VI/VII may be a new therapeutic potential agent for cervical cancer. In addition, we explored the structure-activity relationships of three groups of the configurational isomer with similar chemical structure from S. viscidula. We first demonstrated that the length of the ester chains linked to the carboxyl group of the glucuronic acid residue could affect the potent cytotoxicity. This finding will open new avenues for developing effective anticancer compounds by modifying the components derived from plants in nature.

Establishment of a gastric cancer subline with high metastatic potential using a novel microfluidic system.

Metastasis is an important hallmark of malignant tumors. In this study, we developed a microfluidic system to screen highly metastatic sublines via differential resolution of cell invasiveness. The system was composed of a PDMS-glass device connected with a syringe pump and a Petri dish. To facilitate the selection process, a long-term cell invasion driving force based on a chemotactic factor gradient was created using the Petri dish-based liquid supply pattern, and the invasive cells were collected for round-by-round selection via an open region in the chip. Using the system, we established an SGC-7901/B2 subline from the human gastric cancer SGC-7901 cell line by only two rounds of selection. In vitro assays showed that the SGC-7901/B2 cells were superior to the parental cells in proliferation and invasiveness. Furthermore, an in vivo tumorigenicity assay demonstrated that compared with the parental cells, the subline had stronger spontaneous metastatic and proliferative capability, which led to a shorter survival duration. Additionally, the protein expression differences including E-cadherin and Smad3 between the subline and parental cells were revealed. In conclusion, this microfluidic system is a highly effective tool for selecting highly metastatic sublines, and SGC-7901/B2 cells could serve as a potential model for tumor metastasis research.