Multi-omics data of gastric cancer cell lines.

OBJECTIVES: Gastric cancer (GC) is the fourth most common cancer worldwide, with the highest incidence and mortality regardless of sex. Despite technological advances in diagnosing and treating gastric cancer, GC still has high incidence and mortality rates. Therefore, continuous research is needed to overcome GC. In various studies, cell lines are used to find and verify the cause of specific diseases. Large-scale genomic studies such as ENCODE and Roadmap epigenomic projects provide multiomics data from various organisms and samples. However, few multi-omics data for gastric tissues and cell lines have been generated. Therefore, we performed RNA-seq, Exome-seq, and ChIP-seq with several gastric cell lines to generate a multi-omics data set in gastric cancer. DATA DESCRIPTION: Multiomic data, such as RNA-seq, Exome-seq, and ChIP-seq, were produced in gastric cancer and normal cell lines. RNA-seq data were generated from nine GC and one normal gastric cell line, mapped to a human reference genome (hg38) using the STAR alignment tool, and quantified with HTseq. Exome sequence data were produced in nine GC and two normal gastric lines. Sequenced reads were mapped and processed using BWA-MEM and GATK, variants were called by stralka2, and annotation was performed using ANNOVAR. Finally, for the ChIP-seq, nine GC cell lines and four GC cell lines were used in two experimental sets; chip-seq was performed to confirm changes in H3K4me3 and H3K27me3. Data was mapped to human reference hg38 with BWA-MEM, and peak calling and annotation were performed using the Homer tool. Since these data provide multi-omics data for GC cell lines, it will be useful for researchers who use the GC cell lines to study.

Building an ensemble learning model for gastric cancer cell line classification via rapid raman spectroscopy.

Cell misuse and cross-contamination can affect the accuracy of cell research results and result in wasted time, manpower and material resources. Thus, cell line identification is important and necessary. At present, the commonly used cell line identification methods need cell staining and culturing. There is therefore a need to develop a new method for the rapid and automated identification of cell lines. Raman spectroscopy has become one of the emerging techniques in the field of microbial identification, with the advantages of being rapid and noninvasive and providing molecular information for biological samples, which is beneficial in the identification of cell lines. In this study, we built a library of Raman spectra for gastric mucosal epithelial cell lines GES-1 and gastric cancer cell lines, such as AGS, BGC-823, HGC-27, MKN-45, MKN-74 and SNU-16. Five spectral datasets were constructed using spectral data and included the full spectrum, fingerprint region, high-wavelength number region and Raman background of Raman spectra. A stacking ensemble learning model, SL-Raman, was built for different datasets, and gastric cancer cell identification was achieved. For the gastric cancer cells we studied, the differentiation accuracy of SL-Raman was 100% for one of the gastric cancer cells and 100% for six of the gastric cancer cells. Additionally, the separation accuracy for two gastric cancer cells with different degrees of differentiation was 100%. These results demonstrate that Raman spectroscopy combined with SL-Raman may be a new method for the rapid and accurate identification of gastric cancer. In addition, the accuracy of 94.38% for classifying Raman spectral background data using machine learning demonstrates that the Raman spectral background contains some useful spectral features. These data have been overlooked in previous studies.

LncRNA FAM230B Promotes Gastric Cancer Growth and Metastasis by Regulating the miR-27a-5p/TOP2A Axis.

AIM: Long non-coding RNAs serve as key components of competing endogenous RNA (ceRNA) networks that underlie tumorigenesis. We investigated the pathogenic roles of lncRNA FAM230B and its molecular mechanism in gastric cancer (GC). METHOD: The levels of FAM230B expression in five gastric cancer cell lines and in human gastric mucosal cells were compared by quantitative RT-PCR. To analyze the function of FAM230B in GC, we overexpressed FAM230B in AGS cells, silenced FAM230B in MGC-803 cells, and tested the effect of FAM230B on tumor growth in nude mice. The interaction between miR-27a-5p and FAM230B was predicted by a bioinformatics analysis and then verified with a dual-luciferase reporter assay. We also further investigated the role and mechanism of FAM230B by forcing overexpression of miR-27a-5p in MGC-803 gastric cancer cells. RESULTS: We found that FAM230B was highly expressed in gastric cancer cell lines and mainly located in the cytoplasm. FAM230B overexpression promoted the proliferation, migration, and invasion of AGS cells and repressed their apoptosis; it also facilitated tumor growth in vivo. In contrast, FAM230B knockdown suppressed the proliferation, migration, and invasion of MGC0803 cells, but enhanced their apoptosis and inhibited tumor growth in vivo. MiR-27a-5p expression was suppressed by FAM230B overexpression in AGS cells. MiR-27a-5p inhibited the proliferation, migration, and invasion of gastric cancer cells, and promoted the apoptosis of gastric cancer cells by reducing TOP2A (topoisomerase 2 alpha) expression. CONCLUSION: Our study showed that lncRNA FAM230B might function to promote GC. FAM230B functioned as a ceRNA by sponging miR-27a-5p and enhancing TOP2A expression.

Verteporfin-photodynamic therapy is effective on gastric cancer cells.

Photodynamic therapy (PDT) induces photochemical reactions, resulting in the destruction of tumor cells via singlet (S1) oxygen production. This cellular destruction occurs specifically in tumor cells, following selective accumulation of a photosensitizer and its excitation by a specific wavelength. Verteporfin (VP) is a second-generation photosensitizer that is currently being used worldwide in PDT to treat age-related macular degeneration. In addition, clinical trials with VP-PDT demonstrated anti-tumor efficacy and overall safety when used to treat locally advanced pancreatic cancer. In the present study, we examined the anti-tumor effect of VP-PDT on gastric cancer (GC) cell lines in vitro to conduct an initial assessment of its potential clinical applicability to this specific type of cancer. We evaluated the viability of MKN45 and MKN74 cancer cell lines after VP-PDT exposure and calculated the half maximal effective concentration (EC50) values for VP. Apoptosis in VP-PDT-exposed GC cells was observed. Furthermore, the EC50 values for a 30-min treatment with VP (2.5 J/cm2 of 660 nm LED light) were 0.61 and 1.21 µM for MKN45 and MKN74, respectively. When VP treatment times were increased, the EC50 values decreased. In conclusion, VP-PDT may be developed as an effective treatment for GC.

Targeting Autophagy Facilitates T Lymphocyte Migration by Inducing the Expression of CXCL10 in Gastric Cancer Cell Lines.

Autophagy is a type of cellular catabolic degradation process that occurs in response to nutrient starvation or metabolic stress, and is a valuable resource for highly proliferating cancer cells. Autophagy also facilitates the resistance of cancer cells to antitumor therapies. However, the involvement of autophagy in regulating CXCL10 expression in gastric cancer (GC) cells and T lymphocyte migration remains unclear. In this study, we aimed to investigate the effect of autophagy inhibition on CXCL10 expression and T lymphocyte infiltration in GC and elucidate the underlying mechanism. Analysis of public databases revealed a positive correlation between CXCL10 expression and both prognosis of patients with GC and the expression profile of T lymphocyte markers in the GCs. Chemotaxis and spheroid infiltration assays revealed that CXCL10 induced T lymphocyte migration and infiltration into GC spheroids, an in vitro three-dimensional cell culture model. In addition, in vitro autophagy inhibition in GC cells increased CXCL10 expression under both normal and hypoxic culture conditions. Further investigation on the underlying mechanism showed that in vitro autophagy inhibition suppressed the JNK signaling pathway and further enhanced CXCL10 expression in GC cells. Collectively, our results provide novel insights for understanding the role of autophagy in regulation of intra-tumor immunity.

Low-density lipoprotein receptor expression is involved in the beneficial effect of photodynamic therapy using talaporfin sodium on gastric cancer cells.

Photodynamic therapy (PDT) is a therapeutic method used to destroy tumor tissue via reactive oxygen. Notably, reactive oxygen is induced by a combination of photosensitizers, including talaporfin sodium (TS) and laser light. Gastric cancer cell lines, MKN45 and MKN74, were used to evaluate the effect of TS-PDT in vitro. The antitumor effect of TS-PDT, which was evaluated via cellular viability assay, on MKN74 was weaker than that on MKN45 cells, suggesting that MKN74 cell could be resistant to TS-PDT. However, using a higher TS concentration or setting a longer treatment time (24 h) resulted in effective TS-PDT treatment on MKN74 cells. In addition, when irradiation power of LED was raised up to 5.06 J/cm2, TS-PDT was able to induce an antitumor effect on MKN74 cells. This suggested that the difference in TS-PDT efficacy between MKN45 and MKN74 cells is based on the difference in cellular uptake of TS. As expected, uptake of TS by MKN74 cells was lower than that by MKN45 cells. The expression levels of low-density lipoprotein (LDL) receptor in MKN74 cells were lower than those in MKN45 cells. With GW3965 treatment, an agonist/activator of Liver X Receptor, LDL receptor expression was reduced, weakening the TS-PDT effect. Furthermore, as a hydroxymethylglutaryl-Coenzyme A reductase inhibitor, treatment using simvastatin increased LDL receptor expression, leading to enhancement of the TS-PDT effect on MKN74 cells. In conclusion, the difference in LDL receptor expression between the two gastric cell lines could influence TS-PDT efficacy; simvastatin may enhance the antitumor effect of TS-PDT through upregulating the LDL receptor even on PDT-resistant gastric cancer cells.

Effect of diterpenoid kaurenoic acid on genotoxicity and cell cycle progression in gastric cancer cell lines.

The goal of our study was to evaluate the effect of kaurenoic acid, obtained from copaiba oil resin, in gastric cancer (GC) and a normal mucosa of stomach (MNP01) cell lines. The compound was tested at concentrations of 2.5, 5, 10, 30 and 60µg/mL. Comet and micronucleus assays were used to access its potential genotoxicity in vitro. Moreover, we evaluated the effect of kaurenoic acid in cell cycle progression and in the transcription of genes involved in the control of the cell cycle: MYC, CCND1, BCL2, CASP3, ATM, CHK2 and TP53. Kaurenoic acid induced an increase on cell DNA damage or micronucleus frequencies on GC cell lines in a dose-dependent manner. The GC and MNP01 cell lines entering DNA synthesis and mitosis decreased significantly with kaurenoic acid treatment, and had an increased growth phase compared with non-treated cells. The treatment induced apoptosis (or necrosis) even at a concentration of 2.5µg/mL in relation to non-treated cells. GC cell lines presented reduced MYC, CCND1, BCL2 and CASP3 transcription while ATM, CHK2 and TP53 increased in transcription in relation to non-treated cells, especially at a concentration above 10µg/mL. The gene transcription in the MNP01 (non-treated non-cancer cell line) was designated as a calibrator for all the GC cell lines. In conclusion, our results showed that kaurenoic acid obtained from Copaifera induces DNA damage and increases the micronuclei frequency in a dose-dependent manner in GC cells, with a significant genotoxicity observed above the concentration of 5µg/mL. Moreover, this compound seems to be able to induce cell cycle arrest and apoptosis in GC cells.

Inhibitory effects of bevacizumab monoclonal antibodies in combination with chemotherapy in different time sequences on a human gastric carcinoma cell line.

OBJECTIVE: This study investigated the inhibitory effects of bevacizumab monoclonal antibodies in combination with chemotherapy in different time sequences on a human gastric cancer cell line (MGC-803). METHODS: Cultured MGC-803 human gastric cancer cells were treated with bevacizumab in combination with chemotherapy treatment in different time sequences. The effects on cell growth inhibition were determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell cycle distribution and the rate of cell apoptosis were determined by propidium iodide staining followed by flow cytometry. RESULTS: Drug administration for different time sequences significantly inhibited the growth of MGC-803 cells. Based on group comparisons (P < 0.01), the effect of 24 h bevacizumab treatment prior to combination 5-fluorouracil and cisplatin (FP) was the strongest (F = 241.313, 246.856, all P values <0.001). Treating MGC-803 cells with bevacizumab for 24 h before combination FP induced significant G2/M phase arrest (F = 231.991, P < 0.001) and significantly increased gastric cancer cell apoptosis. Bevacizumab in combination with chemotherapy significantly inhibits the proliferation of MGC-803 gastric cancer cells. CONCLUSIONS: The mechanism may be related to cell cycle arrest at S phase and the induction of apoptosis in MGC-803 gastric cancer cells.

Anti-proliferation effects of dammar-24-ene-3β-acetate-20S-ol on gastric cancer cells / 医学研究生学报

Objective Based on the previous research that the ethanolic extract from traditional Chinese medicine fructus forsythiae (Lianqiao) can obviously inhibit cancer cells in vitro, the article aimed to investigate the anti-proliferation effects of dammar-24-ene-3β-acetate-20S-ol (DM) extracted from fructus forsythiae on gastric cancer cells and its mechanism.Methods MTT assay was used to assess the anti-proliferation effects of DM on gastric cancer cells including SGC-7901, BGC-823, and MKN-45 in vitro.There were MKN-45 control group and its low dose and high dose groups, BGC-823 control group and its low dose and high dose groups, SGC-7901 control group and its low dose and high dose groups in the experiment.Flow cytometry was used to analyze the cell apoptosis rate.Cellquest software was used to analyze the results and record the ratio of cells at different cycles.DCFH-DA probe was applied to detect the ROS levels of blank control group, docetaxol group and DM group.The reaction system of microtubule assembly test was set with 10?mol/L docetaxol, 50 or 100 μmol/L DM final density and no medicine in blank control group.The readings of UV spectrophotometer were recorded.Microtubule assembly assay and microtubule immunofluorescence staining were applied to investigate the effects of DM on microtubule system.Results The inhibition ratio of 50 μg/L DM on the proliferation three gastric cell lines were all above 80%, with IC50s of MKN-45 11.72±1.35 μg/mL, BGC-823 17.19±0.82 μg/mL, SGC-7901 7.55±0.79 μg/mL.8 days′ low density culturing at 48 hours after 2 μg/mL DM treatment, compared with control group, the number of cell clones significantly reduced without much change in clone size, while 48 hours after 10 μg/mL DM treatment, besides a few clones of BGC-823, there were just several megascopic clones of SGC-7901 and MKN-45.In comparison with apoptotic cell ratio in MKN-45 control group[(21.1±2.5)%], its low dose group and high dose group resulted in significant rise of apoptotic cell ratio[(25.1±1.3)% and (55.2±2.3)%] (P0.05).In comparison with MKN-45 control group, the ratio of cells at S phase decreased in its low dose group[(14.5±2.7)% vs (12.3±3.3)%,P>0.05].In comparison with BGC-823 control group, the ratio of cells at S phase increased in its low dose group[(12.2±5.4)% vs (20.2±2.1)%,P<0.05].In comparison with SGC-7901 control group, the ratio of cells at S phase increased in its low dose group[(21.5±3.8)% vs (31.3±2.6)%,P<0.05].From the detection of intracellular active oxygen after DM treatment, dose-dependent ROS level increased in all three cell lines 48 hours after 10μg/mL and 50μg/mL DM treatment.From the results of microtubule immunofluorescence staining, 48 hours after the treatment of IC50 docetaxol and 10μg/mL DM, the fluorescence signals were in local concentration and disorder.Conclusion Dammar-24-ene-3β-acetate-20S-ol demonstrated anti-proliferation effects due to the apoptosis induced by cell cycle arrest at S phase.

Inhibition effects of fungal immunomodulatory proteins from Ganoderma spp .on different gastric cancer cell lines in vit ro / 药学实践杂志

Objective To study the cell proliferative effects of fungal immunomodulatory proteins from Ganoderma spp . on 26 gastric cancer cell lines in vitro .Method 26 human gastric cancer cell lines were treated with FIPs by MTS assay .The average optical density (OD) in 490 nm and inhibition rate (GI50 )was counted by Universal Microplate Spectrophotometer . Results Three FIPs showed similar profiling in 26 human gastric cancer cell lines after 72 h treatment in cell proliferation as-say ,which except for NUGC-4 and OCUM-1 did not showed obvious anti-proliferative effect ,the other 24 human gastric cell lines showed some anti-proliferative effects ,especially for 7 cell lines(NUGC-3 ,GTL-16 ,HGC-27 ,IM95m ,SNU-638 ,SNU-216 and SNU-5) showing strong potency ,with their GI50 less than 50 μg/ml .Conclusion FIPs showed strong anti-prolifera-tive effects in some human gastric cancer cell lines in vitro ,which had potential to be further developed as anti-gastric cancer drugs .

Effect and mechanism of rmhTNF on gastric cancer cell lines with differentΔ133p53 status / 中国癌症杂志

Background and purpose: Little about the function of p53 isoforms in gastric cancer was reported. This study was designed to explore the role ofΔ133p53 in the effect of recombinant mutant human tumor necrosis factor (rmhTNF) on gastric cancer cells, and provide a new basis for the diagnostics and therapeutics of gastric carcinoma. Methods: MKN45 (withΔ133p53 expression) or SGC7901 (withoutΔ133p53 expression) cells were treated with rmhTNF of different concentrations only or combined with 5-FU (a traditional gastric cancer cellular killer), and the growth inhibition rate and apoptosis was detected by CCK-8 and lfow cytometry. mRNA expressions ofΔ133p53, Gadd45αand CyclinB1 were measured by nested reverse transcription-polymerase chain reaction (nRT-PCR) or real-time polymerase chain reaction(RT-PCR). Results:On MKN-45 cells with positiveΔ133p53 expression, the inhibitory effect of rmhTNF was signiifcant, the inhibition rates of 50 and 500 IU/mL rmhTNF were 24.82%, 72.33%after culturing for 24 h (t=-9.558, P0.05). In apoptosis test, the apopto-sis-enhancing effect of rmhTNF was signiifcant on MKN45 cells, and the apoptosis-enhancing effect of 5-FU was fur-ther promoted signiifcantly by rmhTNF, the apoptosis of rmhTNF (50 IU/mL), rmhTNF (50 IU/mL) combined with 5-FU (25 μg/mL), rmhTNF (500 IU/mL) combined with 5-FU (25 μg/mL) were 18.20%, 48.66%, 59.83%, separately, after culturing for 24 h (F=123.931, P<0.05). In mRNA measurement, down-regulation ofΔ133p53 and CyclinB1, up-regula-tion of Gadd45αwere signiifcant in MKN45 cells treated by rmhTNF alone or combined with 5-FU. In nRT-PCR anal-ysis, the mRNA levels ofΔ133p53 were relatively 0.886, 0.499, 0.330, 0.161 (F=240.927, P<0.01);In real-time PCR analysis, the mRNA levels of Gadd45αwere 1.227, 1.694, 3.394, and the mRNA levels of CyclinB1 were 1.221, 0.722, 0.316, relatively. The expression ofΔ133p53 was positively related to CyclinB1 (r=0.977, P<0.01), but negatively re-lated to Gadd45α(r=-0.950, P<0.01). Conclusion:InΔ133p53 positively expressed MKN45 cells, rmhTNF showed as an effective tumor inhibitor and an enhancer of 5-FU as well, and this effect might be helped by two p53 down-stream molecules CyclinB1 and Gadd45α. The results suggest thatΔ133p53 might be a key target for the biological effect of rmhTNF against gastric cancer.

Establishment of new intraperitoneal paclitaxel-resistant gastric cancer cell lines and comprehensive gene expression analysis.

BACKGROUND: Intraperitoneal (i.p.) chemotherapy with paclitaxel is a potential therapeutic modality for patients with peritoneal metastasis of gastric cancer. To overcome paclitaxel resistance, which is a major clinical problem with this modality, prediction of i.p. paclitaxel resistance is critically important. MATERIALS AND METHODS: We developed three new i.p. paclitaxel-resistant cell lines from parental gastric cancer cell lines by an in vivo selection method using i.p. paclitaxel chemotherapy. With these cell lines, we performed gene expression profiling analysis to select up-regulated genes in i.p. paclitaxel-resistant cells and validated the genes with clinical samples. RESULTS: We successfully isolated nine up-regulated genes in i.p. paclitaxel-resistant cell lines compared with parental cells by microarray analysis, followed by confirmation with quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Among these, we identified four genes, namely kinesin family member-23 (KIF23), ERBB2 interacting protein (ERBB2IP), ATPase family, AAA domain containing-2 (ATAD2) and PHD finger protein (PHF19) as candidate genes for paclitaxel resistance after validation with clinical samples derived from responders and non-responders to paclitaxel treatment. CONCLUSION: These i.p. paclitaxel-resistant cell lines are ideal models for understanding the mechanism of resistance to i.p. paclitaxel and development of a new therapeutic modality. Four up-regulated genes may be potential new predictive markers for resistance to i.p. paclitaxel in patients with peritoneal metastasis of gastric cancer.

Sequence Analyses of Aberrant FHIT Transcripts in Gastric Cancer Cell Lines / 대한소화기학회지

BACKGROUND/AIMS: The fragile histidine triad (FHIT) gene located at chromosome 3p14.2, is a candidate tumor suppressor gene often involved in various tumors. Homozygous deletions, lack or reduced expression of FHIT protein, and alteration of its transcription were frequently observed in several types of primary human cancers and cell lines. In the present study, we examined the expression profiles of aberrant FHIT transcripts to explore the role of FHIT gene in gastric carcinogenesis. METHODS: In 6 gastric cancer cell lines, nested reverse transcription-polymerase chain reaction (RT-PCR) and cDNA sequence analyses were performed to detect and characterize the aberrant FHIT transcripts. RESULTS: In addition to the wild-type FHIT transcript, small-sized transcripts with various numbers and lengths were observed in all of the cell lines examined. cDNA sequence analysis confirmed that different types of truncated transcripts included exonic deletions, insertions of intron 5 sequences between exons, and combinations of both. Most of these transcripts lacked exon 5 in which translation initiation codon is located. Aberrant transcripts with partial exonic deletions due to activation of cryptic splice sites were also observed in 5 cell lines. Additionally, multi-step splice patterns indicative of additional downstream processing, were observed in several cancer lines. CONCLUSIONS: These results suggest that the aberrant FHIT transcripts in gastric cancer cell lines results from faulty splicing, including exon skipping, selection of cryptic splice site, and additional downstream splice processing.

CpG methylation as a basis of specific loss of normal epithelial cell-specific-1 gene in gastric tumor / 中华消化杂志

Objective To investigate the expression of normal epithelial cell-specific-1(NES1) gene in normal gastric epithelial cells and different gastric cancer cell lines and the effects of 5-aza-2-de- oxycytidine(5-aza-dC)on the expression of NES1 gene.Methods Expression of NES1 mRNA in five gastric cancer cell lines(MKN-28,SGC-7901,AGS,MKN-45 and HGC-27)and normal human gastric epithelial cells were detected by real-time PCR.After treatment with 5-aza-dC,a DNA methyltransferase inhibitor,the expression of NES1 mRNA in gastric cancer cell lines was detected by real-time PCR. DNA methylation status of NES1 gene was assayed by methylation-specific PCR(MSP).Results The expression of NES1 mRNA was decreased in all gastric cancer cell lines.A strong correlation between ex on 3 hypermethylation and loss of NES1 mRNA expression in gastric cancer cell lines was noted.5-aza dC treatment of NES1-nonexpressing tumor cell lines resulted in a dose-dependent induction(SGC-7901, MKN-45,MKN-28 and AGS)and increase (HGC-27) of NES1mRNA expression in gastric cancer cells. Conclusions The study suggested that hypermethylation was a responsible factor for tumor-specific loss of NES1 gene expression in gastric cancer cells.Treatment of gastric cancer cell lines with a demethylating agent led to reexpression of NES1 suggesting an important role of hypermethylation in loss of NES1 gene expression.

Chromosomal Alterations in Gastric Cancer Cell Lines Detected by Comparative Genomic Hybridization / 대한암학회지

PURPOSE: There are only a few cytogenetic studies in gastric cancer and so far no consistent specific chromosomal abnormalities have been described. In this study, we have used comparative genomic hybridization (CGH), a powerful molecular cytogenetic technique for detecting changes of the copy number throughout the genome, to screen for genetic alterations in gastric cancer cell lines. The CGH results were compared with those derived from G-banding and chromosome painting. MATERIALS AND METHODS: Conventional cytogenetic analysis was performed on five human gastric cancer cell lines, AGS, SNU-1, SNU-16, SNU-620, and SNU-719, by a G-banding staining technique. In CGH, equal amounts of differently labeled DNA from the cell lines and normal reference DNA were hybridized simultaneously to normal metaphase chromosomes. They were visualized by different fluorochromes, and the signal intensities were quantitated separately as gray levels along the single chromosomes. The over- and under- represented DNA segments were determined by computation of ratio images and average ratio profiles. To confirm the CGH results, fluorescence in situ hybridization (FISH) with chromosome specific painting was performed using indirectly labeled chromosome specific paints. RESULTS: Complex unbalanced chromosomal aberrations that could not be identified reliably by conventional cytogenetics in gastric cancer cell lines were successfully resolved by CGH analysis. CGH results were validated by using FISH with chromosome specific probes. In gastric cancer cell lines, gains of DNA copy number were more common than losses. Gains were detected on 1p, 1q, 2p, 3q, 6p, 7q, 10q, 11p, and 19q, and losses were observed on 4p, 4q, 5q, 12p, 12q, and 18q. Interestingly, all the five gastric cancer cell lines tested showed gain of DNA copy number on the chromosome 20, suggesting an existence of oncogene. CONCLUSION: Conventional cytogenetics, CGH, and FISH using painting probes represent complementary approaches that, when employed in combination, could greatly facilitate the comprehensive analysis of chromosomal imbalances in gastric cancer cell lines. Our results suggest the existence of an oncogene or oncogenes on chromosome 20 that play a role in the development and/or the progression of gastric carcinogenesis.

Antitumor mechanism of ursolic acid on human gastric cancer cell lines SGC7901 in vitro / 中草药

Objective To investigate the potential mechanism of inhibition of ursolic acid(UA) on growth of human gastric cancer cell lines SGC7901 in vitro.Methods SGC7901 cells were cultured in vitro,MTT assay was used to observe the effect of UA on growth of SGC7901 cells in various concentrations for different times.After SGC7901 cells were treated by 0—40 ?mol/L UA for 24 h,morphological changes were observed by inverted microscope.Apoptotic changes were detected by fluorescence microscopy and flow cytometry (FCM).Protein expressions of Bcl-2 and Bax were determined by Western blotting.Results UA(20—40 ?mol/L) could significantly inhibit the growth of SGC7901 cells in a(dose-and) time-dependent manner,the IC_(50) value of UA for SGC7901 cells for 12,24,36,and 48 h were((57.50?)1.18),(34.28?2.05),(27.54?1.11),and(24.83?1.02) ?mol/L,respectively.After UA((20—)40 ?mol/L) treatment for 24 h,SGC7901 cells turned round and floated at different levels;SGC7901 cells were arrested at G_0/G_1 phase and apoptosis was induced,and the apoptotic rate was increased along with the increase of UA concentration.Meanwhile Bcl-2 protein expression decreased,whereas Bax protein expression unchanged.Conclusion UA has a stronger antitumor effect on SGC7901 cells.Cytotoxic effect,proliferation inhibition,and apoptosis may be involoved in the mechanism of UA,and the apoptosis caused by UA may be enhanced by decrease of Bcl-2 protein expression.