1. Department of Internal Medicine, Harbin Medical University Cancer Hospital, Haping Road 150 of Nangang District, Harbin, Heilongjiang Province, 150081, China.
2. Department of Radiotherapy, Harbin Medical University Cancer Hospital, Haping Road 150 of Nangang District, Harbin, Heilongjiang Province, 150081, China.
3. Gastrointestinal Surgical Ward, Harbin Medical University Cancer Hospital, Haping Road 150, Harbin, Heilongjiang, 150081, China.
4. Department of Pathology, The Affiliated First Hospital, Heilongjiang University of Chinses Medicine, Heping Road 24 of Xiangfang District, Harbin, Heilongjiang Province, 150081, China.
5. Department of Medical Oncology, Fujin Central Hospital, Heilongjiang Province, 156100, China.
*Jiarong Zhang and Jinli Zhang contributed equally to this work.
Background: In the past few decades, natural products have become an increasingly important source of potential anti-cancer agents. The green walnut husk(GWH) extracts have been reported to inhibit multiple tumor cells and might be a promising chemopreventive agent in human neoplasia. However, it is not clear whether GWH extracts inhibit gastric cancer.
Methods: Proliferation, invasion, and migration of gastric cancer cells were assessed by the CCK-8, wound-healing, and Transwell assay. The apoptotic rate was detected by flow cytometry(FCM). The expressions of Bcl-2, Bax, and Caspase-3 proteins were examined by Western blot. Moreover, the growth of gastric cancer cells was assessed using orthotopic xenograft models, and related proteins expressions were evaluated using immunohistochemistry. Finally, the Gene expression profile of gastric cancer treated with GWH extracts was evaluated by using High-throughput RNA sequencing(RNA-seq).
Results: GWH extracts effectively inhibited gastric cancer cell growth in vitro and in vivo. In vivo, GWH extracts inhibited the survival of gastric cancer cells in a dose and time-dependent manner, inhibited the migration and invasion of gastric cancer cells, regulated the expressions of apoptosis-related proteins, and induced apoptosis of gastric cancer cells. In vitro, GWH extracts inhibited the growth of mouse xenografted tumors. A total of differentially expressed genes, of which 41 genes were up-regulated, and 610 genes were down-regulated, were identified by RNA-seq. GO, and KEGG analysis showed that these differentially expressed genes might be related to the mechanism of the anti-gastric cancer effect of GWH extracts.
Conclusion: GWH extracts played an anti-gastric cancer effect by inducing apoptosis and inhibiting invasion. Secondly, the differential expression of many genes, multiple signal pathways, and metabolic pathways in gastric cancer play an essential role in the anti-gastric cancer effect of GWH extracts. The results suggested that GWH extracts are expected to be a low toxic drug for the treatment of gastric cancer in the future.
Keywords: The green walnut husk, Anticancer, Gastric cancer, Cell apoptosis