Objective:Side population(SP) cells may play a crucial role in tumorigenesis and the recurrence of cancer.Many kinds of cell lines and tissues have demonstrated the presence of SP cells,including several gastric cancer cell lines.This study is aimed to identify the cancer stem-like cells in the SP of gastric cancer cell line MKN-45.Methods:We used fluorescence activated cell sorting(FACS) to sort SP cells in the human gastric carcinoma cell line MKN-45(cells labeled with Hoechst 33342) and then characterized the cancer stem-like properties of SP cells.Results:This study found that the SP cells had higher clone formation efficiency than major population(MP) cells.Five stemness-related gene expression profiles,including OCT-4,SOX-2,NANOG,CD44,and adenosine triphosphate(ATP)-binding cassette transporters gene ABCG2,were tested in SP and MP cells using quantitative real-time reverse transcription polymerase chain reaction(RT-PCR).Western blot was used to show the difference of protein expression between SP and MP cells.Both results show that there was significantly higher protein expression in SP cells than in MP cells.When inoculated into non-obese diabetic/severe combined immunodeficiency(NOD/SCID) mice,SP cells show higher tumorigenesis tendency than MP cells.Conclusions:These results indicate that SP cells possess cancer stem cell properties and prove that SP cells from MKN-45 are gastric cancer stem-like cells.
Surgical resection remains the mainstay of curative treatment for gastric cancer.Laparoscopic surgery is a form of minimally invasive surgery （MIS） that has become increasingly used in the resection of gastric cancer.Laparoscopic surgery is designed to minimize surgical insults and to maximize patient survival,while not compromising oncologic clearance.
Objective To discuss the present status and progress of clinical research on recurrence of gastric cancer after surgery, including patterns, clinicopathologic factors, prognosis, detection, diagnosis, prevention, and treatment strategies. Data sources The data used in this review were mainly from PubMed articles published in English from 2000 to August 2011. The search terms were ＂gastric cancer＂ and ＂recurrence＂. Study selection Articles were selected if they involved clinicopathologic factors, detection methods, and treatment strategies of recurrence of gastric cancer. Results Peritoneal recurrence is the most common pattern in recurrence of gastric cancer. The main risk factors for recurrence of gastric cancer are tumor stage, including depth of tumor invasion and lymph node metastasis, and Borrmann classification. The prognosis of patients with recurrence is very poor, especially patients with peritoneal recurrence. Systemic chemotherapy is still the main treatment method for patients with recurrent cancer. If complete resection can be accomplished, some benefits may be obtained from surgery for recurrence. However, standard treatment for patients with recurrence has not yet been established. Conclusions Early detection and diagnosis of recurrence is quite crucial for treatment and prognosis. The optimal therapeutic strategy for recurrence should be based on a multidisciplinary assessment and the patient＇s individual state and should involve combined therapy.
LI Jing-huiZHANG Shi-wuLIU JingSHAO Ming-zheCHEN Lin
