Clinical implications of micro lymph node metastasis for patients with gastric cancer.

BACKGROUND: Lymph node size is considered as a criterion for possible lymph node metastasis in imageology. Micro lymph nodes are easily overlooked by surgeons and pathologists. This study investigated the influencing factors and prognosis of micro lymph node metastasis in gastric cancer. METHODS: 191 eligible gastric cancer patients who underwent D2 lymphadenectomy from June 2016 to June 2017 in the Third Surgery Department at the Fourth Hospital of Hebei Medical University were retrospectively analyzed. Specimens were resected en bloc and the postoperative retrieval of micro lymph nodes was carried out by the operating surgeon for each lymph node station. Micro lymph nodes were submitted for pathological examination separately. According to the results of pathological results, patients were divided into the "micro-LNM (micro lymph node metastasis)" group (N = 85) and the "non micro-LNM" group (N = 106). RESULTS: The total number of lymph nodes retrieved was 10,954, of which 2998 (27.37%) were micro lymph nodes. A total of 85 (44.50%) gastric cancer patients had been proven to have micro lymph node metastasis. The mean number of micro lymph nodes retrieved was 15.7. The rate of micro lymph node metastasis was 8.1% (242/2998). Undifferentiated carcinoma (90.6% vs. 56.6%, P = 0.034) and more advanced Pathological N category (P < 0.001) were significantly related to micro lymph node metastasis. The patients with micro lymph node metastasis had a poor prognosis (HR for OS of 2.199, 95% CI = 1.335-3.622, P = 0.002). For the stage III patients, micro lymph node metastasis was associated with shorter 5-year OS (15.6% vs. 43.6%, P = 0.0004). CONCLUSIONS: Micro lymph node metastasis is an independent risk factor for poor prognosis in gastric cancer patients. Micro lymph node metastasis appears to be a supplement to N category in order to obtain more accurate pathological staging.

Upregulated Vav2 in gastric cancer tissues promotes tumor invasion and metastasis.

Several studies have proved that Vav2 gene is associated with the carcinogenesis of some tumors, but the relationship between Vav2 gene and gastric cancer remains unclear. Purpose of this study is to detect the expression of Vav2 protein in gastric cancer tissues and to evaluate the clinical value of Vav2. Furthermore, both effect of Vav2 gene on invasion and metastasis of gastric cancer cells and its mechanism are investigated in vitro. Results showed that positive rate of Vav2 protein was significantly higher in gastric cancer tissues than in adjacent tissues and notably higher in metastatic lymph nodes than in gastric cancer tissues. Results of western blot were consistent with immunohistochemistry. Expression of Vav2 protein in gastric cancer tissues was related to degree of tumor differentiation, lymph node metastasis, and clinical stages. Inhibition of endogenous Vav2 in BGC823 cells led to significantly decreased cell activity, migration, and invasion ability in vitro, and expression of Rac1, MMP-2, and MMP-9 decreased, whereas expression of TIMP-1 increased. We concluded that Vav2 might promote invasion and metastasis of gastric cancer by regulating some invasion and metastasis-related genes.

Inhibition of Vav3 gene can promote apoptosis of human gastric cancer cell line MGC803 by regulating ERK pathway.

Previous studies proved that Vav3 gene was overexpressed in cancers. However, the molecular mechanism of Vav3 in apoptosis still keeps unclear; therefore, the relationship between Vav3 gene and apoptosis of gastric cancer (GC) was explored in the present study. Vav3-siRNA was transfected into MGC803 cells, and then cell activity and apoptosis rate were tested with MTT and FCM; apoptosis-related genes and proteins in MAPK signaling pathway were also tested. Results showed that Vav3 was overexpressed in GC than in adjacent normal tissues (all P < 0.05), and expression of Vav3 was related to degree of histological differentiation, cancer invasion depth, and lymphatic metastasis (Χ (2) = 7.185, P = 0.007; Χ (2) = 18.654, P < 0.001; Χ (2) = 5.058, P = 0.025). Vav3 silencing inhibited activity of MGC803 cells, and apoptosis rate of cells was affected. Vav3-siRNA transfection led to changes of apoptosis-related genes such as Survivin, xIAP, Bcl-2, caspase-3, and Bax (all P < 0.01). After transfection, ratio of phosphorylation of ERK significantly reduced. We concluded that Vav3 inhibition can suppress cell activity and promote apoptosis by regulating the apoptosis-related genes through the ERK pathway.

Regulatory mechanism of ZNF139 in multi-drug resistance of gastric cancer cells.

Our previous study found increased zinc finger protein 139 (ZNF139) expression in gastric cancer (GC) cells. Purpose of the study is to further clarify the role and mechanism of ZNF139 in multi-drug resistance (MDR) of GC cells. MTT assay, RT-PCR, Western blotting were employed to detect susceptibility of GC cells to chemotherapeutic agents (5-FU, L-OHP) in vitro, and expressions of ZNF139 and MDR associated genes MDR1/P-gp, MRP1, Bcl-2, Bax were also detected. siRNA specific to ZNF139 was transfected into MKN28 cells, then chemosensitivity of GC cells as well as changes of ZNF139 and MDR associated genes were detected. It's found the inhibition rate of 5-FU, L-OHP to well-differentiated GC tissues and cell line was lower than that in the poorly differentiated tissues and cell line; expressions of ZNF139 and MDR1/P-gp, MRP1 and Bcl-2 in well-differentiated GC tissues and cell line MKN28 were higher, while Bax expression was lower. After ZNF139-siRNA was transfected into MKN28, ZNF139 expression in GC cells was inhibited by 90%; inhibition rate of 5-FU, L-OHP to tumor cells increased, and expressions of MDR1/P-gp, MRP1 and Bcl-2 were down-regulated, while Bax was up-regulated. ZNF139 was involved in GC MDR by promoting expressions of MDR1/P-gp, MRP1 and Bcl-2 and inhibiting Bax simultaneously.

Comparative proteomics in gastric cancer cell line BGC823 after ZNF139 gene inhibited with RNA interference.

BACKGROUND/AIMS: Zinc finger protein 139 (ZNF139) gene is proved play an important role in gastric cancer. Aim of this study is to identify changes of proteins after ZNF139 gene was inhibited in gastric cancer cell line BGC823. METHODS: siRNA-specific ZNF139 was synthesized and transfected into BGC823; 2-D fluorescence difference gel electrophoresis (2-D DIGE) and liquid chromatography-mass spectrometry (LC-MS) were applied to screen, identify differentially expressed proteins, and function of these proteins was analyzed; Western blot method was applied to verify the identified proteins. RESULTS: ZNF139 expression in siRNA transfected cancer cell BGC823 decreased significantly. Results of 2-D DIGE showed eight differential protein spots, of which seven were identified with LC-MS, including switches associated protein 70, far upstream element binding protein 1, heat shock protein 60, annexin A7, small ubiquitin-like modifier 1 activating enzyme, chaperonin-containing tail-less complex protein 1 and annexin A2. These proteins were found to be associated with proliferation, apoptosis, invasion, metastasis, adhesion of gastric cancer cells with bioinformatic analysis. Western blot analysis confirmed that expressions of these proteins in BGC823 were consistent with the proteomic results. CONCLUSIONS: ZNF139 gene may influence the biological behavior of gastric cancer cells in many ways by regulating multiple proteins.

[Effect and mechanisms of TET on human gastric carcinoma cell line SGC7901 and SGC7901/ADR].

OBJECTIVE: To investigate the effect of tetrandrine (TET) on zinc finger protein 139 (ZNF139) and multidrug resistance (MDR) of human gastric carcinoma cell lines and possible mechanisms. METHODS: Cultured SGC7901 and SGC7901/ADR were treated with TET (0.5, 1.0, 1.5, 2.0, and 2.5 microg/mL), then inhibition rates were measured by MTT assay in vitro. The expressions of ZNF139, MRP-1, MDR1, and GST-pi were detected by RT-PCR. The correlation between ZNF139 and each multidrug resistance factor was analyzed using Spearman correlation analysis, and the coefficient correlation was calculated. RESULTS: The inhibition rate of TET (< or = 2.0 microg/mL) for SGC7901 and SGC7901/ADR was less than 10% with MTT assay. Expressions of ZNF139, MRP-1, MDR1, and GST-pi mRNA were higher in SGC7901/ADR than in SGC7901 (all P < 0.05). The expressions of ZNF139, MRP-1, MDR1, and GST--pi were down-regulated in SGC7901/ADR cells efficiently (all P < 0.01). Positive correlation existed between ZNF139 and MRP-1, ZNF139 and MDR1 before treated by TET in SGC7901/ADR, and this relationship also existed in SGC7901/ADR cells after treated by TET (all P < 0.05). CONCLUSION: TET could achieve MDR reversion in gastric cancer cells by down-regulating the expression of ZNF139, MRP-1, and MDR1.

A new bisphosphonate derivative, CP, induces gastric cancer cell apoptosis via activation of the ERK1/2 signaling pathway.

AIM: To investigate the effects of a new derivative of bisphosphonates, [2-(6-aminopurine-9-yl)-1-hydroxy-phosphine acyl ethyl] phosphonic acid (CP), on human gastric cancer. METHODS: Human gastric cancer cell lines (SGC-7901, BGC-823, MKN-45, and MKN-28) and human colon carcinoma cell lines (LoVo and HT-29) were tested. Cell growth was determined using the MTT assay. Flow cytometry, Western blot, caspase activity assay and siRNA transfection were used to examine the mechanisms of anticancer action. Female BALB/c nude mice were implanted with SGC-7901 cells. From d6 after inoculation, the animals were injected with CP (200 µg/kg, ip) or vehicle daily for 24 d. RESULTS: CP suppressed the growth of the 6 human cancer cell lines with similar IC50 values (3239 µmol/L). In SGC-7901 cells, CP arrested cell cycle progression at the G2/M phase. The compound activated caspase-9, increased the expression of pro-apoptotic proteins Bax and Bad, decreased the expression of anti-apoptotic protein Bcl-2. Furthermore, the compound selectively activated ERK1/2 without affecting JNK and p38 in SGC-7901 cells. Treatment of SGC-7901 cells with the specific ERK1/2 inhibitor PD98059 or ERK1/2 siRNA hampered CP-mediated apoptosis. In the human gastric cancer xenograft nude mouse model, chronic administration of CP significantly retarded the tumor growth. CONCLUSION: CP is a broad-spectrum inhibitor of human carcinoma cells in vitro, and it also exerts significant inhibition on gastric cancer cell growth in vivo. CP induces human gastric cancer apoptosis via activation of the ERK1/2 signaling pathway.

Analysis of lymph node dissection range-related factors for early gastric cancer operation.

BACKGROUND/AIMS: The purpose of comprehensive treatment for early gastric cancer (EGC) is curing tumor, prevention of recurrence or metastasis. The aim of the present study was to analyze the clinical pathological characteristics of EGC, and to find out factors which influence lymph node metastasis. METHODOLOGY: Records of 417 patients with EGC who underwent surgery from January 1996 to December 2006 were collected. The information including general characteristics, tumor relevant factors, surgical complications, clinical manifestations and pathological features, were evaluated. RESULTS: EGC accounted for 6.03% of total gastric cancer (GC) cases. In EGC subjects, mucosal cancer and sub-mucosal cancer accounted for 55.2% and 44.8%, respectively; 11.5% (48/417) of patients were found with positive lymph nodes metastasis, the incidence of lymph node metastasis was 5.64% (168/2979); 6 cases were found with liver metastasis; 96.64% of patients undertook radical surgical treatment; 5 cases with positive upper incisal margin (1.2%). Logistic regression analysis showed that multiple original tumors, lesions of over 2cm, tumor invasion to the submucosa, poor differentiation, and vascular tumor thrombus, were independent risk factors for lymph node metastasis in EGC. CONCLUSIONS: The risk factors of lymph node metastasis should be noticed and evaluated in EGC treatment.

Tumor chemosensitivity is correlated with expression of multidrug resistance associated factors in variously differentiated gastric carcinoma tissues.

BACKGROUND/AIMS: To evaluate the relationship between chemosensitivities in vitro and expressions of multidrug resistance (MDR) associated factors in differentiated gastric carcinomas. METHODOLOGY: Gastric carcinomas tissues of varying degree of differentiation (65 cases) were collected and chemosensitivities to 5-FU, HCPT, PTX, L-OHP, CDDP and eADM were detected by sulphorhodamine B (SRB) assay, and expressions of P-gp, GST-π, Topo IIα, p53, Bcl-2, Bax and Survivin were tested by immunohistochemical staining. RESULTS: Inhibition rates of 5-FU, L-OHP and CDDP for well differentiated tumors were lower than those of poorly differentiated tumors (p<0.05). Expressions of P-gp, Bcl-2 and Survivin were higher in well differentiated than in poorly differentiated carcinomas (p<0.05); while expression of Topo IIα in well differentiated carcinomas was lower than in poorly differentiated carcinomas (p<0.05). The expression of MDR factors was different between well and poorly differentiated carcinomas. CONCLUSIONS: Different MDR characteristics were exhibited in well and poorly differentiated gastric carcinomas, which may be caused by different expressed MDR associated factors in these tissues.

Technique appraisement of comparative proteomics and screening of differentiation-related protein in gastric carcinoma.

BACKGROUND/AIMS: Different differentiations of cancer have resulted in its unique biological characteristics. We screen and appraise differentially expressed proteins in different differentiated gastric adenocarcinoma with comparative proteomics technology in order to find regulatory factors of tumor differentiation related and finally reach the purpose of tumor differentiation reversal. METHODOLOGY: With two-dimensional fluorescence difference gel electrophoresis (2-D DIGE) and liquid chromatography in conjunction with tandem mass spectrometry (LC­MS/MS), the differentially expressed proteins from 8 patients with different differentiated gastric adenocarcinoma were identified and some factors identified were verified with application of QPCR and Western blot techniques. RESULTS: Significant differences in 35 protein spots were found and 48 kinds of proteins were identified. Other than structural proteins and non-specific protein, six possible proteins associated with tumor differentiation were determined - the serine protease inhibitor B1 (serine protease inhibitor, clade B, member 1, SERPINB1), calcium-phospholipid binding protein III (annexin A3), transcription factor Nm23-H1, adenine phosphoribosyl-transferase enzyme APRT (Adenine Phosphoribosyltransferase in APO and AMP), glutathione S-transferase P1-1 (GST-π-1), antimicrobial peptides Dermcidin-lL. The identified SERPINB1, annexin A3, Nm23-H1 and APRT were verified, confirming the expression of these factors was in line with proteomics identification. CONCLUSIONS: Protein expression in different differentiated gastric adenocarcinoma was varied.

[Effect of antisurvivin oligodeoxynucleotides on proliferation and apoptosis in gastric cancer cell line BGC-823 and the molecular mechanism].

OBJECTIVE: To explore the effects of antisense oligodeoxynucleotides (ASODN) on proliferation and apoptosis in gastric cancer cell line BGC-823 cells and the molecular mechanisms induced by ASODN. METHODS: survivin ASODN-1, survivin ASODN-2 and survivin ASODN-3 were transfected into BGC-823 cells by Lipofectamine(TM) 2000 transfection reagent. The growth activity of BGC-823 cells was detected by MTT assay. Apoptosis index (AI), proliferation index (PI), cell cycle and expressions of survivin, VEGF and Smac/DIABLO proteins were detected by flow cytometry (FCM). The changes of survivin mRNA, VEGF mRNA and Smac/DIABLO mRNA were detected by RT-PCR. RESULTS: The expression of survivin was down-regulated by the three ASODN sequences, especially the ASODN-2 was best. At 48 hours after transfection with 600 nmol/L survivin ASODN-2, the cells in G(1)/G(0) phase were significantly increased [(72.25 ± 2.95)%], apoptotic index increased [(11.31 ± 0.38)%], proliferation index decreased [(27.77 ± 2.97)%], compared with those in the control group [(56.25 ± 0.75)%, (1.62 ± 0.36)%, (43.80 ± 0.80)%, all P < 0.05]. The survivin mRNA and protein levels (0.523 ± 0.091, 0.733 ± 0.009) were down-regulated compared with those in the control group (0.861 ± 0.047, 0.997 ± 0.233), VEGF (0.519 ± 0.076, 0.75 ± 0.006) were down-regulated compared with those in the control group (0.779 ± 0.059, 1.000 ± 0.01), while those of Smac/DIABLO(0.899 ± 0.113, 1.637 ± 0.023)were up-regulated compared with those in the control group (0.558 ± 0.041, 1.000 ± 0.049, all P < 0.05). CONCLUSIONS: Survivin ASODN can induce apoptosis and inhibit the proliferation of gastric cancer cell line BGC-823 cells. Those effects are induced through up-regulation of Smac/DIABLO and down-regulation of survivin and VEGF expression simultaneously.

Up-regulation of KLF17 expression increases the sensitivity of gastric cancer to 5-fluorouracil.

It has been reported that the expression of Krüppel-like factor 17 (KLF17) was associated with the occurrence, development, invasion, metastasis and chemotherapy resistance of various tumors. However, the detailed mechanisms by which KLF17 promotes chemotherapy resistance in gastric cancer (GC) have not been fully investigated. In the present study, we collected the GC tissues and non-tumor tissues (matched adjacent normal tissues with corresponding GC tissues) of 60 GC patients, used qRT-PCR, Western blot and immunohistochemistry assay to analyze the relationship between the expression of KLF17 and the clinical pathological data of the patients. The effect of KLF17 on the sensitivity of GC cell lines to 5-fluorouracil (5-FU), and the potential mechanism were detected by MTS assay, Flow cytometry assay, and Western blot. Compared with non-tumor tissues, the expression level of KLF17 in GC tissue was significantly down-regulated, and the expression level of KLF17 in GES-1 cell line and GC cell lines also had a similar trend. Down-regulated expression of KLF17 is related to tumor size, invasion, regional lymph node metastasis, and TNM staging. Furthermore, through upregulating the expression of KLF17, the sensitivity of BGC-823 and SGC-7901 cell lines to 5-FU was obviously increased. Mechanistically, upregulation the expression of KLF17 can inhibit the expressions of P-glycoprotein (P-gp), multidrug resistance protein 1 (MRP1), and B-Cell lymphoma-2 (BCL-2), which have been reported to be associated with drug resistance and cell proliferation. Collectively, these data implied that KLF17 has the biological effect of inhibiting chemotherapy resistance of GC, and it could be a potential strategy for the GC chemotherapy resistance.

Expression of COX-2, survivin in regional lymph node metastases of gastric carcinoma and the correlation with prognosis.

BACKGROUND/AIMS: Little is known about the expression and significance of the proteins in regional lymph node metastases (LNMs) of gastric carcinoma (GC). In present study we intend to evaluate the expression of COX-2 and Survivin in primary tumors (PT) and LNMs of GC, keeping track of the correlation between the clinicopathologic factors, the tumor angiogenesis, patients' survival and prognosis. METHODOLOGY: Surgical specimens were obtained and paired from 65 patients with advanced GC. The gastric operational pieces have been examined with usual histological, histochemical and immunohistochemical staining. Then relationship and significance of these data were analyzed. RESULTS: Expression of COX-2 was higher in LNMs than that in PT p < 0.05 with positive correlativity of COX-2 between PT and LNMs p < 0.01 and positive correlativity also existed between COX-2 and Survivin in PT p < 0.01. The patients with strong expression of COX-2 had lower cumulative survival rate than those with weaker COX-2 expressed (p < 0.01). In LNMs, strong expression of COX-2 was an independent prognostic factor for GC in PT and LNMs while strong expression of Survivin was not that case. CONCLUSIONS: The expression of COX-2 in PT and LNMs explained for the heterogeneity of GC and it has a tight correlation with GC cell's apoptosis. Strong expression of COX-2 in LNMs was associated with poor prognosis for patients with GC.

[Proteomic identification and comparison of differentiation-related proteins in gastric carcinoma cell lines].

OBJECTIVE: To investigate the differentiation-related proteins in human gastric carcinoma cell lines by comparative proteomics. METHODS: The holoproteins of human gastric carcinoma cell lines MKN28, SGC7901 and BGC823 were measured by two-dimensional gel electrophoresis and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Some proteins identified by proteomics were tested by Western blot in the cell strains and tissues of gastric carcinoma. RESULTS: 14 differential protein spots were found in the 3 gastric carcinoma cell lines, among them 8 spots were identified by MALDI-TOF-MS. These proteins were probably thioredoxin peroxidase, glyceraldehyde-3-phosphate dehydrogenase (GAPD), beta-tubulin polypeptide, hypothetical protein, zinc finger protein (ZNF) 139, protein-tyrosine kinase, calreticulin precursor, and tropomyosin, proteins related with biological behavior of gastric carcinoma cells such as signal transduction, cellular homeostasis, glycolysis, antioxidation action, multidrug resistance(MDR), etc. The expressions of those proteins in gastric cancer cells and tissues identified by Western blot were consistent with the results obtained by proteomics. CONCLUSION: Differential proteins are found in 3 human gastric carcinoma cell lines, mainly, proteins related with cell signaling, maintenance of homeostasis, glycolysis, metabolism of anti-cancer drug and anti-oxidative injury, etc.

[The effect of caspase-3 inhibitor on the concentrations of serum inflammatory cytokines in sepsis related acute kidney injury induced by peritoneal cavity infection in mice].

OBJECTIVE: To observe the effects of caspase-3 inhibitor Ac-DEVD-CHO on the concentrations of serum inflammatory cytokines in sepsis related acute kidney injury induced by peritoneal cavity infection in mice. METHODS: One hundred and two male C57BL/6 mice were subjected to cecal ligation and puncture (CLP, a model of polymicrobial sepsis) or sham operation. The animals were assigned into three equal groups (n=34) according to random number table: sham group, model group, and caspase-3 inhibitor (CI) group. Thirty minutes before CLP, Ac-DEVD-CHO (4 µg/g) was injected subcutaneously in CI group. The levels of blood urea nitrogen (BUN) and creatinine (Cr) were determined, and the concentrations of tumor necrosis factor-α (TNF-α), interleukins (IL-6 and IL-10) were measured by enzyme linked immunosorbent assay (ELISA), the renal cell apoptosis rate was determined by flow cytometry and the expression of caspase-3 mRNA was determined by real time reverse transcription-polymerase chain reaction (RT-PCR) at 6, 12 and 24 hours after operation. The 4-day and 7-day survival rates of three groups of mice were observed. RESULTS: Compared with sham group, the concentrations of serum BUN, TNF-α, IL-6, IL-10 and the renal cell apoptosis rates, the caspase-3 mRNA expression were increased significantly at all time points after CLP, the concentrations of serum Cr were increased significantly at 6 hours, with the 4-day and 7-day survival rates were decreased significantly. Compared with model group, in CI group, the concentrations of serum BUN were decreased significantly at all time points after operation and those of Cr were decreased significantly at 6 hours, then restored to those of the sham group at 12 hours and 24 hours; the concentrations of serum TNF-α, IL-6 were decreased and those of IL-10 elevated significantly at all time points [TNF-α (µg/L) 6 hours: 436.2±64.2 vs. 653.6±8.9, 12 hours: 233.4±85.4 vs. 579.7±137.1, 24 hours: 151.0±90.3 vs. 551.0±119.8; IL-6 (µg/L) 6 hours: 1 033.2±345.8 vs. 1 595.3±159.4, 12 hours : 366.3±68.3 vs. 1 330.7±249.8, 24 hours: 241.2±208.4 vs. 815.3±572.7; IL-10 (µg/L) 6 hours : 33.6±10.4 vs. 26.6±4.5, 12 hours: 37.2±5.0 vs. 24.5±4.3, 24 hours: 38.3±5.5 vs. 18.2±1.6, all P<0.05]; the renal cell apoptosis rate and the expression of caspase-3 mRNA were decreased significantly at all time points [apoptosis rates 6 hours: (13.9±3.2)% vs. (18.3±1.4)%, 12 hours: (10.5±3.6)% vs. (15.9±3.5)%, 24 hours: (8.4±1.8)% vs. (12.5±2.1)%; caspase-3 mRNA 6 hours: 1.95±0.16 vs. 3.84±0.35, 12 hours: 1.89±0.19 vs. 3.97±0.73, 24 hours : 2.01±0.20 vs. 4.97±0.24, all P<0.05]. The 4-day survival rate of CI group was improved (80% vs. 20%), but that of 7-day did not change (20% vs. 20%). CONCLUSION: The modulation of caspase-3 inhibitor on the concentrations of serum inflammatory cytokines in sepsis related acute kidney injury induced by peritoneal cavity infection may be associated with a decrease in renal cell apoptosis by Ac-DEVD-CHO.

[Relationship of cyclooxygenase-2 and multidrug resistance associated factors to chemosensitivities in gastrointestinal carcinomas].

OBJECTIVE: To investigate the relationship of cyclooxygenase-2 (COX-2), p-glycoprotein(P-gp), glutathione S-transferase-pi (GST-pi), and topoisomerase II alpha (Topo II alpha) to chemosensitivities in gastrointestinal tract carcinomas. METHODS: The tumor tissue samples were collected from 84 specimens of gastrointestinal carcinomas. The expressions of COX-2, P-gp, GST-pi, and Topo II alpha were determined immunohistochemically. The chemosenisitivity of each sample to 9 drugs were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RESULTS: The positive rates of COX-2, P-gp, GST-pi and Topo II alpha were 48.8%, 76.2%, 78.6% and 66.7% respectively. The expression of COX-2 was correlated with the expression of P-gp and Topo II alpha significantly (r = 0.287, 0.256, both P < 0.05). In terms of relationships of four MDR-related factors expression to inhibition rate of tumor cells, the inhibition rates of PTX, eADM and OPT in COX-2 strong expression group were significantly lower than those in COX-2 weak expression group (t = 2.21, 3.11, 2.09; all P < 0.05). The inhibition rates of PTX, OXA and DDP in P-gp strong expression group were lower than those in weak group (t = 2.54, 2.47, 2.05; all P < 0.05). There were lower inhibition rates for 5-Fu in GST-pi strong expression group (t = 2.13, P < 0.05), and higher inhibition rates for VCR, PTX and eADM in TopoII alpha strong expression group (t = -2.29, -2.12, - 2.26, all P < 0.05). CONCLUSIONS: The overexpressions of MDR-related factors in gastrointestinal carcinomas were only associated with the chemosensitivity to some of the chemotherapeutic agents, but not all. MDR related factors may be not specific and accurate predictors for the clinical chemosensitivity.

Inhibitory effect of siRNA-Annexin A7 on growth, migration, and invasion in BGC823 cells and gastric cancer xenograftsin nude mice.

OBJECTIVE: To explore the inhibitory effect of siRNA-Annexin A7 on growth, migration, and invasion of transplanted gastric cancer in nude mice. METHODS: The siRNA sequence targeting to human Annexin A7 gene was designed, and based on that a pair of complementary oligonucleotides were synthesized, annealed, and cloned into plasmid pGenesil-1.1 to construct recombinant plasmid siRNA-Annexin A7. Transplanted gastric cancer model was established by injecting s.c. nude mice with human gastric cancer BGC823 cells, and siRNA-Annexin A7 was injected into the tumors formed. The nude mice were observed for clinical manifestation relying on the size and weight of transplanted tumors. The tumor tissue and angiogenesis were examined by pathologic sections. Flow cytometry was used to detect the changes of cell cycle. Western blot and qRT-PCR were used to analyze the expression of PCNA, P27, MMP-2, and TIMP-2. RESULTS: Both the size and weight of transplanted tumors of nude mice injected with siRNA-Annexin A7 were less than those of control groups (P<0.05). The examination of pathologic sections showed that, compared with in the control group, obvious necrosis of tumor cells was observed in siRNA-Annexin A7 group. The cells in stage S were fewer in siRNA-Annexin A7 group than those in the other two groups, while the cells in stage G0/G1 were much more in siRNA-Annexin A7 group. The results of western blot and qRT-PCR confirmed that the expression of PCNA and MMP-2 was down-regulated, whereas the expression of p27 was up-regulated. CONCLUSION: Gastric cancer xenografts were established in nude mice with human gastric cancer BGC823 cells. The volume and weight of tumor were decreased after inhibition of Annexin A7 expression in BGC823 cells. Tumor cells were arranged sparsely after inhibition of Annexin A7 expression in BGC823 cells. The siRNA-Annexin A7 inhibits Annexin A7 expression in transplanted gastric cancer of nude mice, and influences the growth, migration, and invasion of tumors by down-regulating the expression of PCNA and MMP-2, as well as up-regulating the expression of p27.

Downregulation of annexin A7 decreases proliferation, migration, and invasion of gastric cancer cells by reducing matrix metalloproteinase 1 and 9 expression.

High annexin A7 expression is a potential indicator of lymphatic metastasis and poor prognosis in patients with gastric cancer (GC). The mechanism underlying the effects of annexin A7 on GC cells remains unclear. In patients with GC, primary adenocarcinoma tissues had higher annexin A7 expression than adjacent non-cancerous tissues (P < 0.05). Among three human GC cell lines with high, moderate, and low levels of differentiation, respectively, the cell line with the lowest level of differentiation displayed the highest level of annexin A7 expression. We transfected cells of the human GC cell line BGC823 with short interfering RNAs (siRNAs) targeting annexin A7 and investigated the effects on signaling pathways related to cancer progression by quantitative real-time PCR and western blot. The silencing of endogenous annexin A7 suppressed the proliferation, migration, and invasion abilities of the BGC823 cells. In the cells treated with annexin A7 siRNA, the expression of p16, p21, and p27 was significantly upregulated while that of proliferating cell nuclear antigen (PCNA), cyclin A, cyclin D1, cyclin E1, matrix metalloproteinase-2 (MMP-2), MMP-9, and intercellular cell-adhesion molecule-1 (ICAM-1) was significantly downregulated compared with that in control cells. Our results suggest that the downregulation of endogenous annexin A7 inhibits GC cell proliferation, migration, and invasion by impacting cell cycle regulators and the expression of MMP-1, MMP-2, and ICAM-1. Targeting annexin A7 may represent a valuable strategy for the diagnosis and clinical treatment of GC.

Formononetin inhibits colon carcinoma cell growth and invasion by microRNA­149­mediated EphB3 downregulation and inhibition of PI3K/AKT and STAT3 signaling pathways.

Formononetin (Form), a phytoestrogen extracted from the roots of Astragalus membranaceus, is one of the fundamental herbs used in traditional Chinese medicine because of its protective effects against certain malignant tumors. However, its role in colon carcinoma cells and the underlying molecular mechanisms have not been completely elucidated. The present study aimed to demonstrate that Form significantly inhibited the proliferation and invasion of the colon carcinoma cell lines SW1116 and HCT116. Mechanistic studies have suggested that Form suppresses colon carcinoma cell growth by downregulating cell cycle­associated protein (cyclin D1) expression and arresting the cell cycle at the G0­G1 checkpoint. Further studies revealed that treatment with Form inhibits matrix metalloproteinase (MMP)2 and MMP9 expression. Aditionally, the results demonstrated that Form significantly increased microRNA (miR)­149 expression. Following miR­149 overexpression in SW1116 and HCT116 cells using an miR­149 mimic, cell viability and Ephrin type­B receptor 3 (EphB3) levels decreased. Furthermore, the inhibitory effects of Form were associated with phosphatidylinositol 3­kinase (PI3K)/protein kinase B (AKT) and signal transducer and activator of transcription 3 (STAT3) signaling pathways. These results indicated the suppressive effect of Form on colon carcinoma cell proliferation and invasion, possibly via miR­149­induced EphB3 downregulation and the inhibition of the PI3K/AKT and STAT3 signaling pathways. Overall, Form may be used as a novel candidate for the clinical treatment of colorectal cancer in the future.

Inhibitory effects of CP on the growth of human gastric adenocarcinoma BGC-823 tumours in nude mice.

Objective To investigate the potential antitumour effects of [2-(6-amino-purine-9-yl)-1-hydroxy-phosphine acyl ethyl] phosphonic acid (CP) against gastric adenocarcinoma. Methods Human BGC-823 xenotransplants were established in nude mice. Animals were randomly divided into control and CP groups, which were administered NaHCO3 vehicle alone or CP dissolved in NaHCO3 (200 µg/kg body weight) daily, respectively. Tumour volume was measured weekly for 6 weeks. Resected tumours were assayed for proliferative activity with anti-Ki-67 or anti-proliferating cell nuclear antigen (PCNA) antibodies. Cell apoptosis was examined using terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assays and with caspase-3 immunostaining. Proteins were measured by Western blotting. Results There was a significant reduction in tumour volume and a reduced percentage of Ki-67-positive or PCNA-positive cells in the CP group compared with the control group. The percentage of TUNEL-positive or caspase 3-positive cells significantly increased following CP treatment compared with the control group. Tumours from the CP group had higher levels of phosphorylated-extracellular signal-regulated kinase (p-ERK) and phosphorylated-AKT (p-AKT) compared with control tumours. Conclusion CP treatment inhibited tumour growth and induced tumour cell apoptosis in a nude mouse model of BGC-823 gastric adenocarcinoma. Activation of the AKT and ERK signalling pathways may mediate this antitumour activity.