Stimulation. The cells were then washed with PBS and refreshed with mediumStable Knockdown of PKM2 and Over-expression of PKMA plasmid containing an RNA interference sequence that targeted the PKM2 gene in BGC823, SGC7901 and AGS cells was constructed. The sense oligo for the siPKM2 sequence was 59CACCGCGGCAAGATTTATGTGGAACGTGTGCTGTCCGTTCCACGTAGATCTTGCTGCTTTTT-39, and the Title Loaded From File antisense oligo was 59-GCATAAAAAGCAGCAAGATCTACGTGGAACGGACAGCACACGTTCCACATAAATCTTGCCGC-39. The BGC-823, SGC-7901 and AGS cells were transfected with pcPUR+U6-siPKM2 or pcPUR+U6-siRenilla (control) and selected as puromycin-resistant clones. Western blot analysis was performed to confirm the PKM2 suppression. A plasmid containing PKM2 cDNA sequence was obtained from Invitrogen. The BGC-823, SGC-7901 and AGS cells were transfected with pcDNA6.0-PKM2 or pcDNA6.0-mock (control) and selected as blasticidin-resistant clones. Western blot analysis was performed to confirm the PKM2 expression.PkM2 Regulates the EGF/EGFR Signalcontaining 10 FBS. Photographs were taken at 0 and 24 h. All experiments were performed in triplicate.Ethics StatementThis study was approved by the Ethics Committee (No: 20081012) at the Zhongshan Hospital Calyculin A web affiliated with Xiamen University, Xiamen, Fujian Province, China, and we obtained written consent statements from all participants involved in this study.Preparation of tissue SamplesTumor tissue specimens were collected from 15 different gastric cancer patients who underwent curative resection at the Zhongshan Hospital, Xiamen University, Xiamen, China. An independent series of corresponding adjacent noncancerous tissues from 15 of the same patients was collected at the same time. All tissue specimens were collected and divided into two parts immediately after tumor resection. One part was collected into liquid nitrogen and stored at -80uC until RNA and protein extraction. The other part was fixed in 4 formaldehyde and embedded in paraffin for histological analysis (Hematoxylin eosin and IHC staining). All specimens were confirmed by pathological diagnosis (the histopathological diagnosis was based on WHO criteria). All experimental cases were grouped accord-ing to the International Union Against Cancer Tumor-Node-Metastasis (TNM) staging system (revised in 2002).to characterize the cell motility response in the BGC823 and SGC7901 cells. A confluent layer of cells was first incubated overnight in medium, a scratch wound was introduced, medium containing the most suitable dose of EGF (100 ng/ml) was added to stimulate migration, and the percentage of wound sealing was observed after 24 h (Figure S1). The invading cells were quantified 36 h after EGF (100 ng/ml) was added to the lower chamber. The results indicate that the treatment of BGC823-sipk and SGC7901sipk cells with EGF following a scratch wound and in the transwell significantly increased the rate of wound healing (Fig. 1 C,D) and invasion (Fig. 1 E,F) compared with that of the control cells.Depletion of PKM2 Decreased E-cadherin Expression and Enhanced the Activities of the EGF/EGFR Downstream Signaling Pathways PLC-c1 and ERK1/To investigate the mechanism of changes in cell migration and invasion after the knockdown of PKM2, we analyzed the expression of members of the Ca2+-dependent cell adhesion molecules family and metalloproteinases. We found that Ecadherin protein expression levels were decreased in BGC823 and SGC7901 cells when PKM2 expression was reduced (Fig. 2A). The level of E-cadh.Stimulation. The cells were then washed with PBS and refreshed with mediumStable Knockdown of PKM2 and Over-expression of PKMA plasmid containing an RNA interference sequence that targeted the PKM2 gene in BGC823, SGC7901 and AGS cells was constructed. The sense oligo for the siPKM2 sequence was 59CACCGCGGCAAGATTTATGTGGAACGTGTGCTGTCCGTTCCACGTAGATCTTGCTGCTTTTT-39, and the antisense oligo was 59-GCATAAAAAGCAGCAAGATCTACGTGGAACGGACAGCACACGTTCCACATAAATCTTGCCGC-39. The BGC-823, SGC-7901 and AGS cells were transfected with pcPUR+U6-siPKM2 or pcPUR+U6-siRenilla (control) and selected as puromycin-resistant clones. Western blot analysis was performed to confirm the PKM2 suppression. A plasmid containing PKM2 cDNA sequence was obtained from Invitrogen. The BGC-823, SGC-7901 and AGS cells were transfected with pcDNA6.0-PKM2 or pcDNA6.0-mock (control) and selected as blasticidin-resistant clones. Western blot analysis was performed to confirm the PKM2 expression.PkM2 Regulates the EGF/EGFR Signalcontaining 10 FBS. Photographs were taken at 0 and 24 h. All experiments were performed in triplicate.Ethics StatementThis study was approved by the Ethics Committee (No: 20081012) at the Zhongshan Hospital affiliated with Xiamen University, Xiamen, Fujian Province, China, and we obtained written consent statements from all participants involved in this study.Preparation of tissue SamplesTumor tissue specimens were collected from 15 different gastric cancer patients who underwent curative resection at the Zhongshan Hospital, Xiamen University, Xiamen, China. An independent series of corresponding adjacent noncancerous tissues from 15 of the same patients was collected at the same time. All tissue specimens were collected and divided into two parts immediately after tumor resection. One part was collected into liquid nitrogen and stored at -80uC until RNA and protein extraction. The other part was fixed in 4 formaldehyde and embedded in paraffin for histological analysis (Hematoxylin eosin and IHC staining). All specimens were confirmed by pathological diagnosis (the histopathological diagnosis was based on WHO criteria). All experimental cases were grouped accord-ing to the International Union Against Cancer Tumor-Node-Metastasis (TNM) staging system (revised in 2002).to characterize the cell motility response in the BGC823 and SGC7901 cells. A confluent layer of cells was first incubated overnight in medium, a scratch wound was introduced, medium containing the most suitable dose of EGF (100 ng/ml) was added to stimulate migration, and the percentage of wound sealing was observed after 24 h (Figure S1). The invading cells were quantified 36 h after EGF (100 ng/ml) was added to the lower chamber. The results indicate that the treatment of BGC823-sipk and SGC7901sipk cells with EGF following a scratch wound and in the transwell significantly increased the rate of wound healing (Fig. 1 C,D) and invasion (Fig. 1 E,F) compared with that of the control cells.Depletion of PKM2 Decreased E-cadherin Expression and Enhanced the Activities of the EGF/EGFR Downstream Signaling Pathways PLC-c1 and ERK1/To investigate the mechanism of changes in cell migration and invasion after the knockdown of PKM2, we analyzed the expression of members of the Ca2+-dependent cell adhesion molecules family and metalloproteinases. We found that Ecadherin protein expression levels were decreased in BGC823 and SGC7901 cells when PKM2 expression was reduced (Fig. 2A). The level of E-cadh.