• Asian Pacific Journal of Cancer Prevention
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• 제15권8호
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• pp.3581-3586
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• 2014

Aim: To investigate the effects of tetramethypyrazine (TMP) on proliferation and apoptosis of the human gastric carcinoma cell line 7901 and its possible mechanism of action. Methods: The viability of TMP-treated 7901 cells was measured with a 3-(4, 5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT) and cell apoptosis was analyzed by flow cytometry. The distribution of cells in different phases of cell cycle after exposure of TMPs was analyzed with flow cytometry. To investigate the molecular mechanisms of TMP-mediated apoptosis, the expression of NF-${\kappa}Bp65$, cyclinD1 and p16 in SGC-7901 cells was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. Results: TMP inhibited the proliferation of human gastric carcinoma cell line 7901 in dose and time dependent manners. Cell growth was suppressed by TMP at different concentrations (0.25, 0.5, 1.0, 2.0 mg/ml), the inhibition rate is 0.46%, 4.36%, 14.8%, 76.1% (48h) and 15.5%, 18.5%, 41.2%, 89.8% (72h) respectively. When the concentration of TMPs was 2.0mg/ml, G1-phase arrest in the SGC-7901 cells was significant based on the data for cell cycle distribution. RT-PCR demonstrated that NF-${\kappa}Bp65$ and cyclin D1 mRNA expression was significantly down-regulated in 7901 cells treated with 2.0 mg/ml TMP for 72h (p<0.05), while the p16 mRNA level was up-regulated (p<0.05). The protein expression of NF-${\kappa}Bp65$ and cyclin D1 decreased gradually with the increase in TMP concentration, compared with control cells (p<0.05), while expression of protein p16 was up-regulated (p<0.01). Conclusion: TMP exhibits significant anti-proliferative and pro-apoptotic effects on the human gastric carcinoma cell line SGC-7901. NF-${\kappa}Bp65$, cyclinD1 and p16 may also play important roles in the regulation mechanisms.

• Asian Pacific Journal of Cancer Prevention
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• 제14권8호
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• pp.4685-4688
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• 2013

We aimed to investigate the mechanism and effects of autophagy on cisplatin (DDP)-induced apoptosis in human gastric cancer cell line SGC7901. After SGC7901 cells were treated with DDP and/or chloroquine, cell proliferation was measured using MTT assay; cell apoptosis was determined by flow cytometry; autophagy and apotosis-related proteins expression were detected by Western blot; and quantitative analysis of autophagy after monodansylcadaverine (MDC) staining was performed using fluorescence microscopy. We found after treatment with 5 mg/L DDP for 24 h, the rates of cell apoptosis were ($21.07{\pm}2.12$)%. Autophagy, characterized by an increase in the number of autophagic vesicles and the level of LC3-II protein was observed in cells treated with DDP. After inhibition of autophagy by chloroquine, the rates of cell apoptosis were increased to ($30.16{\pm}3.54$)%, and the level of Caspase-3 and P53 protein were increased, and Bcl-2 protein was decreased. Therefore, autophagy protects human gastric cancer cell line SGC7901 against DDP-induced apoptosis, inhibition of autophagy can promote apoptosis, and combination therapy with DDP and chloroquine may be a promising therapeutic strategy for gastric cancer.

• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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• pp.1817-1821
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• 2016

Objectives: To observed the effects of ginsenoside -Rh2 (GS-Rh2) on proliferation and apoptosis of side population (SP) human gastric cancer SGC-7901 cells. Materials and Methods: SGC-7901 SP and Non-SP cells were sorted by flow cytometry and assessed using the cck-8 method. Expression of apoptosis-related proteins Bax and Bcl-2 of SP before and after the intervention was determined by Western-blotting. Results: It was found that the proliferation of SP was significantly faster than that of NSP (P<0.05). In addition, GS-Rh2 inhibited proliferation of gastric cancer SP cells, induced cell cycle arrest and cell apoptosis, and changed the expression of BAX/Bcl-2 proteins in a time-dependent and concentration-dependent manner (P<0.05). Conclusions: With increase of GS-Rh2 dose, GS-Rh2 gradually inhibit the proliferation of SGC-7901 SP cells, which have high proliferation rate, through G1/G0 phase arrest, followed by apoptosis which involves the up-regulation of Bax and the down-regulation of Bcl-2.

• Asian Pacific Journal of Cancer Prevention
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• 제13권11호
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• pp.5619-5625
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• 2012

Gastric carcinoma is a leading cause of cancer death in the world and multi-drug resistance (MDR) is an essential aspect of gastric carcinoma chemotherapy failure. Recent studies have shown that integrin-linked kinase (ILK) is involved in metastasis of human tumors, expression silencing of ILK inhibiting the metastasis of several types of cultured human cancer cells. However, the role and potential mechanism of ILK to reverse the multi-drug resistance in human gastric carcinoma is not fully clear. In this report, we focused on roles of expression silencing of ILK in multi-drug resistance reversal of human gastric carcinoma SGC7901/DDP cells, including increased drug sensitivity to cisplatin, cell apoptosis rates, and intracellular accumulation of Rhodamine-123, and decreased mRNA and protein expression of multi-drug resistance gene (MDR1), multi-drug resistance-associated protein (MRP1), excision repair cross-complementing gene 1 (ERCC1), glutathione S-transferase -${\pi}$ (GST-${\pi}$) and RhoE, and transcriptional activation of AP-1 and NF-${\kappa}B$ in ILK silenced SGC7901/DDP cells. We also found that there was a decreased level of p-Akt and p-ERK. The results indicated that ILK might be used as a potential therapeutic strategy to combat multi-drug resistance through blocking PI3K-Akt and MAPK-ERK pathways in human gastric carcinoma.

• Asian Pacific Journal of Cancer Prevention
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• 제15권22호
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• pp.9593-9597
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• 2014

Ursolic acid, extracted from the traditional Chinese medicine bearberry, can induce apoptosis of gastric cancer cells. However, its pro-apoptotic mechanism still needs further investigation. More and more evidence demonstrates that mitochondrial translocation of cofilin-1 appears necessary for the regulation of apoptosis. Here, we report that ursolic acid (UA) potently induces the apoptosis of gastric cancer SGC-7901 cells. Further mechanistic studies revealed that the ROCK1/PTEN signaling pathway plays a critical role in UA-mediated mitochondrial translocation of cofilin-1 and apoptosis. These findings imply that induction of apoptosis by ursolic acid stems primarily from the activation of ROCK1 and PTEN, resulting in the translocation of cofilin-1 from cytoplasm to mitochondria, release of cytochrome c, activation of caspase-3 and caspase-9, and finally inducing apoptosis of gastric cancer SGC-7901 cells.

• Asian Pacific Journal of Cancer Prevention
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• 제15권21호
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• pp.9153-9157
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• 2014

Background: Capparis spinosa L., a Uygur medicine, had been shown to have anti-tumor activity in our early experiments with an N-butanol extract (CSBE) as its active fraction. However, the mechanisms responsible for its effects are not clearly understood. Here, we report that treatment of SGC-7901 cells with CSBE resulted in dose-dependent reduction of cell viability and induction of apoptosis. Materials and Methods: To observe the inhibitory and killing effects of CSBE on SGC-7901, the SRB method was adopted, apoptosis being observed by electron microscopy. To clarify the mechanisms of apoptosis, Western blot and enzyme-labeled methods were used to examine the release of cytochrome c (Cyt c) and the activation of the caspase cascade. Results: By electron microscopy, apoptotic morphologic changes were detectable after CSBE administration. In this study, it was also demonstrated that CSBE induced apoptosis in SGC-7901 cells by inhibiting mPTP open, mitochondrial cytochrome c release, caspase-9 and caspase-3 activation. Conclusions: The findings indicated that CSBE induces aap optosis through mitochondrial pathway.

• Asian Pacific Journal of Cancer Prevention
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• 제13권5호
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• pp.1845-1849
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• 2012

Objective: Tissue factor (TF) is expressed abnormally in certain types of tumor cells, closely related to invasion and metastasis. The aim of this study was to construct a human gastric cancer cell line SGC7901 stably-transfected with human TF, and observe effects on oxaliplatin-dependent inhibition of invasion and the apoptosis induction. Methods: The target gene TF was obtained from human placenta by nested PCR and introduced into the human gastric cell line SGC7901 through transfection mediated by lipofectamine. Stably-transfected cells were screened using G418. Examples successfully transfected with TF-pcDNA3 recombinant (experimental group), and empty vector pcDNA3 (control group) were incubated with oxaliplatin. Transwell chambers were used to show change in invasive ability. Caspase-3 activity was detected using a colorimetric method and annexin-V/PI double-staining was applied to detect apoptosis. Results: We generated the human gastric cancer cell line SGC7901/TF successfully, expressing TF stably and efficiently. Compared with the control group, invasion increased, whereas caspase-3 activity and apoptosis rate were decreased in the experimental group. Conclusion: TF can enhance the invasive capacity of gastric cancer cells in vitro. Its increased expression may reduce invasion inhibition and apoptosis-inducing effects of oxaliplatin and therefore may warrant targeting for improved chemotherapy.

• Asian Pacific Journal of Cancer Prevention
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• 제13권2호
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• pp.633-636
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• 2012

Purpose: PRIL (proliferation-inducing ligand) is a newly identified member of the tumor necrosis factor (TNF) family and modulates death ligand-induced apoptosis. Here, we investigated the effect of PRIL on cellular characteristics relating to tumor progression in human gastric cancer. Method: Recombinant lentivirus containing PRIL siRNA was constructed and then infected MGC803 and SGC7901 gastric cancer cells. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] colony formation and cell cycle analysis were used to study the effect of PRIL knockdown on gastric cancer cell proliferation. Results: PRIL expression in lentivirus infected cells was significantly reduced as evidenced by quantitative real-time PCR. Cell viability and colony formation of MGC803 and SGC7901 cells were significantly hampered in PRIL knock-down cells. Moreover, the cell cycle was arrested at G2/M phase, elucidating the mechanism underlying the inhibitory effect of siRNA on cell proliferation. Conclusions: Our study indicated that PRIL functions in promoting cell growth, and lentivirus-mediated PRIL gene knockdown might be a promising strategy in the treatment of gastric cancer.

• Asian Pacific Journal of Cancer Prevention
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• 제14권10호
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• pp.6007-6012
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• 2013

ANXA2, a member of the annexin family, is overexpressed and plays important roles in tumor development. However, the significance of ANXA2 expression in gastric carcinoma has not been clarified.To elucidate its roles in growth of gastric cancer, ANXA2 expression in SGC-7901 cells was inhibited with a designated siRNA, then cell proliferation, cell cycling, apoptosis and motility were determined by MTT assay, flow cytometry, Hoechst 33342 staining and wound healing assay, respectively. To further assess the behavior of ANXA2 deleted SGC-7901 cells, changes of microstructures were observed under fluorescence microscopy, laser scanning confocal microscopy and electron microscopy. We found that inhibition of ANXA2 expression caused cell proliferation to decrease significantly with G1 arrest, motility to be reduced with changes in pseudopodia/filopodia structure and F-actin and ${\beta}$-tubulin expression, and apoptosis to be enhanced albeit without significance. At the same time, ANXA2 deletion resulted in fewer pseudopodia/filopodia, non-stained areas were increased, contact inhibition among cells reappeared, and expression of F-actin and ${\beta}$-tubulin was decreased, with induction of polymerized disassembled forms. Taken together, these data suggest that ANXA2 overexpression is important to maintain the malignancy of cancer cells, and this member of the annexin family has potential to be considered as a target for the gene therapy of gastric carcinoma.

• Asian Pacific Journal of Cancer Prevention
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• 제15권24호
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• pp.10825-10830
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• 2015

The present study was conducted to investigate effects and mechanisms of action of phenolic alkaloids of Menispermum dauricum (PAMD) on gastric cancer in vivo. In vitro, cell apoptosis of human gastric cancer cell line SGC-7901 was observed using fluorescence staining. In vivo, a mice model was constructed to observe tumor growth with different doses. Cell apoptosis was examined using flow cytometry and K-RAS protein expression using Western blotting. The mRNA expression of P53, BCL-2, BAX, CASPASE-3, K-RAS was examined by real-time PCR. PAMD significantly suppressed tumor growth in the xenograft model of gastric cancer in a dose-dependent manner (p<0.01). Functionally, PAMD promoted cell apoptosis of the SGC-7901 cells and significantly increased the rate of cell apoptosis of gastric tumor cells (p<0.05). Mechanically, PAMD inhibited the expression of oncogenic K-RAS both at the mRNA and protein levels. In addition, PAMD affected the mRNA expression of the cell apoptosis-related genes (P53, BCL-2, BAX, CASPASE-3). PAMD could suppress gastric tumor growth in vivo, possibly through inhibiting oncogenic K-RAS, and induce cell apoptosis possibly by targeting the cell apoptosis-related genes of P53, BCL-2, BAX, CASPASE-3.