Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024623 (gastric cancer)
 36,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We often use hepatic arterial infusion chemotherapy to control recurrence of metastatic cancer of liver. Recently, we encountered a case of common bile duct fistula caused by hepatic arterial infusion chemotherapy. A 61-year-old man had undergone right hepatic lobectomy for liver metastasis of gastric cancer, 7 months after total gastrectomy. A hepatic arterial infusion catheter was placed. Since then he has received continuous and/or bolus hepatic artery infusion of 5-FU, ADR and CDDP+5-FU. There was a recurrence of gastric cancer in segment 2 of the liver. On his second admission, when we administered contrast medium to the infusion port, a common bile duct was found.
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PMID:[Common bile duct fistula caused by hepatic arterial infusion chemotherapy]. 885 6

For the cancer cells which have overcome the second mitotic clock (M2), activated telomerase is essential and used as another marker of immortality. Many trials had been initiated to target telomerase, which is known to be specific to tumors. To determine the best in vitro cell system for testing the efficacy of telomerase inhibitors, we evaluated the telomerase activity of various cancer cell lines and measured their telomere lengths. We also treated some cancer cell lines with adriamycin and measured the changes of telomerase activity. Telomerase activity was evaluated in various cell lines with the TRAP (telomeric repeat amplification protocol) assay. Telomerase activity was calculated and translated into arbitrary units by computer-assisted densitometry with the control of telomerase activity in the 293 control cell line. Also, terminal restriction fragment lengths were measured using Southern blotting. We also measured telomerase activity and telomere lengths in 11 benign breast tumor tissues and 19 paired stomach cancer and normal tissues. Cancer cell lines treated with adriamycin we evaluated for changes of telomerase activity and the cell proliferation by MTT assay and dye exclusion test. Telomerase activity of cell lines was 95.3 24.1 unit with a range of 27.6-129.6 unit, while the telomere lengths of those cell lines were variable from 5.0 to 10.4 kbp with a median of 6 kbp. In 11 cancer cell lines which were not yet firmly established, we could not detect any telomerase activity. Low telomerase activity was detected in only 2 benign tumor tissues of breast with a median telomere length of 8.8 (7-10.5) kbp. Among paired 19 gastric cancer and normal tissues, only 7 cancer tissues showed weak telomerase activity. After adriamycin treatment, telomerase activity in YCC-S-1, YCC-S-3, MCF-7 and MCF-7/ADR was decreased in accordance with the changes of the cell numbers. Telomerase is specific to cancer tissues and is expressed differently from organ to organ. Telomerase activity by TRAP assay could be used as a chemosensitivity assay.
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PMID:Telomerase activity and telomere lengths in various cell lines: changes of telomerase activity can be another method for chemosensitivity evaluation. 968 83

To determine whether the expression of p53, p21, bcl-2 or Ki-67 in cancer cells is predictive of chemosensitivity, immunohistochemical examination of these factors and chemosensitivity assays were performed on colon and gastric cancer specimens. Chemosensitivity tests were performed using CDDP, 5-FU, MMC, or ADR and inhibition rate (IR) was calculated by MTT assay. Before exposure to anticancer drugs, the samples were investigated immunohistochemically for expression of the above factors and after anticancer drug exposure by TUNNEL staining, for the presence of apoptotic cells. With 5-FU and MMC, the apoptotic index was well correlated with IR, so their effects were related to apoptosis. Moreover, with these two agents, the p53 labeling index (LI) was inversely correlated with IR and p21-LI showed a good correlation with IR. We therefore concluded that immunohistochemical studies for p53 and p21 were useful for predicting the chemosensitivities of colon and gastric cancer to MMC and 5-FU.
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PMID:Correlation of immunohistochemical p53 labeling index with inhibition rate in chemosensitivity test in gastric and colon cancer. 1129 39

BACKGROUND: Because chemosensitivity tests usually require a large amount of tissue, they are not used routinely in patients with unresectable gastric cancer. The aim of this study was to investigate whether apoptosis can be used as a sensitivity assay for chemosensitivity in small gastric cancer specimens.METHODS: Apoptosis, detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick labeling (TUNEL), was investigated in small specimens of the MKN-1, MKN-45, and TMK-1 human gastric cancer cell lines as a marker of chemosensitivity following exposure to antineoplastic agents.RESULTS: Doxorubicin (DXR), SN-38 (active metabolite of irinotecan), and paclitaxel (Taxol) induced DNA fragmentation in MKN-45 and TMK-1 cells, but not in MKN-1. In contrast, neither 5-fluorouracil (5-FU) nor cisplatin (CDDP) induced DNA fragmentation in any of the three cell lines. Small pieces cut from tumors implanted in nude mice were exposed to the antineoplastic agents in culture medium for 24 h, and the percentage of TUNEL-positive cancer cells (TUNEL positivity) was examined. TUNEL positivity in all three cancers increased after exposure to DXR, SN-38, and Taxol, but not after exposure to CDDP or 5-FU. MKN-45 showed the highest TUNEL positivity with SN-38 and Taxol, and TMK-1 TUNEL positivity was highest with DXR. MKN-45 and TMK-1 were the most sensitive to these three antineoplastic agents in vitro, while MKN-1, with the lowest TUNEL positivity, was the least sensitive to these three antineoplastic agents. TUNEL positivity after exposure to Taxol correlated with the antitumor effects of this compound in an animal model.CONCLUSION: These results suggest that, in small gastric cancer specimens where apoptosis is implicated, TUNEL positivity may be applicable to a chemosensitivity test.
Gastric Cancer 2000 Aug 04
PMID:A model chemosensitivity test examining apoptosis in small specimens of gastric cancer. 1198 8

In our previous work, cellular prion protein (PrPc) was identified as an upregulated gene in adriamycin-resistant gastric carcinoma cell line SGC7901/ADR compared to its parental cell line SGC7901. Here we investigate the expression of PrPc in gastric cancer and whether it was involved in multidrug resistance (MDR) of gastric cancer. We demonstrated that PrPc was ubiquitously expressed in gastric cancer cell lines and tissues. PrPc conferred resistance of both P-glycoprotein (P-gp)-related and P-gp-nonrelated drugs on SGC7901, which was accompanied by decreased accumulation and increased releasing amount of adriamycin in PrPc-overexpressing cell line. Inhibition of PrPc expression by antisense or RNAi technology could partially reverse multidrug-resistant phenotype of SGC7901/ADR. PrPc significantly upregulated the expression of the classical MDR-related molecule P-gp but not multidrug resistance associated protein and glutathione S-transferase pi. The PrPc-induced MDR could be partially reversed by P-gp inhibitor verapamil. PrPc could also suppress adriamycin-induced apoptosis and alter the expression of Bcl-2 and Bax, which might be another pathway contributing to PrPc-related MDR. The further study of the biological functions of PrPc may be helpful for understanding the mechanisms of occurrence and development of clinical gastric carcinoma and PrPc-related MDR and developing possible strategies to treat gastric cancer.
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PMID:Overexpression and significance of prion protein in gastric cancer and multidrug-resistant gastric carcinoma cell line SGC7901/ADR. 1538 5

Ribosomal proteins (RP) L6 was previously identified as an up-regulated gene in multidrug-resistant gastric cancer cells SGC7901/ADR comparing to its parental cells SGC7901 by subtractive hybridization. The aim of this study was to explore the roles of RPL6 in multidrug resistance (MDR) in gastric cancer cells. Northern and Western blot analysis confirmed that RPL6 was overexpressed in SGC7901/ADR cells. By gene transfection, RPL6 was genetically upregulated in SGC7901 or down-regulated in SGC7901/ ADR cells. Upregulation of RPL6 was associated with enhanced resistance to multiple anticancer drugs (adriamycin, vincristine, etoposide, 5-fluorouracil and cisplatin) and to adriamycin-induced apoptosis. Downregulation of RPL6 reversed MDR and sensitized cells to adriamycin-induced apoptosis. Alteration of RPL6 showed no obvious influence on intracellular adriamycin accumulation, glutathione content and expression of glutathione S-transferase. RPL6 could upregulate Bcl-2 and downregulate Bax in cells. Together, this work demonstrates that RPL6 could regulate MDR in gastric cancer cells by suppressing drug-induced apoptosis.
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PMID:Regulation of multidrug resistance by ribosomal protein l6 in gastric cancer cells. 1584 68

Gastric cancer is most chemosensitive among gastrointestinal tumors. However, the role of chemotherapy in advanced disease and its advantage over best supportive care has been adequately addressed only in the last decade. First generation regimens, such as 5-Fluorouracil (5-FU), Doxorubicin, Mitomycin C (FAM) have been used until early 90's, when evidence from randomized studies came up in favour of second generation regimens, such as 5-FU, Doxorubicin, high-dose Methotrexate (FAMTX), which in turn was proven less active than a third generation regimen, such as epirubicin, cisplatin, continuous infusion 5-FU (ECF) in a randomized study. Newer treatment options came up over last years. The Swiss Group for Clinical Cancer Research has carried out a randomized three-arm phase II study with ECF or docetaxel, cisplatin (TC), or docetaxel, cisplatin, 5-FU (TCF) in advanced gastric cancer. TCF has been selected as the combination to be further evaluated in a formal comparison with ECF. Oxaliplatin is being tested in advanced gastric cancer. Two recently published phase II studies of biweekly infusional 5-FU, folinic acid, and oxaliplatin have shown a considerable therapeutic activity. Irinotecan is another drug under investigation in advanced gastric cancer, both as single agent and in combination. A randomized phase II-III study of irinotecan plus cisplatin or irinotecan plus folinic acid/5-FU has recently been completed; the latter arm was proven worth undergoing a formal comparison with a standard CF regimen. Oral fluoropyrimidines represent a suitable therapeutic option in selected groups of patients. Marimastat is a matrix metalloproteinase inhibitor, whose main toxicity is musculoskeletal. A randomized phase III study of marimastat versus placebo as maintenance therapy in advanced gastric cancer has shown a significant survival advantage for the marimastat arm, both in the total patient population and in the subgroup of patients who had previously received chemotherapy. Since a clear gold standard for advanced gastric cancer does not yet exist, the inclusion of patients in well designed clinical trials is to be considered the best treatment option.
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PMID:Gastric cancer. Treatment of advanced disease and new drugs. 1597 May 66

Mad2beta is an alternative splicing variant of spindle checkpoint gene mad2, which was previously found by us and was related to the drug resistance in gastric cancer cells. In this paper, we explored the molecular mechanisms that Mad2beta variant promoted the formation of multidrug resistance in gastric cancer cells. We found that Mad2beta variant was detected only in the two human drug resistant gastric cancer cell sublines SGC7901/VCR and SGC7901/ADR, and it did not appear in its parental cell line SGC7901 and other detected gastric cancer cell lines. Expressions of Mad2 mRNA and protein in SGC7901 cells transfected with Mad2beta, SGC7901/VCR and SGC7901/ADR were significantly lower than that in SGC7901 cells. Moreover, SGC7901 cells overexpressing Mad2beta variant became more resistant to adriamycin, vincristine and mitomycin by abrogating mitotic arrest and apoptosis. This suggests that expression of Mad2beta variant decreases the relative expression of efficient MAD2, which may help gastric cancer cells to develop the phenotype of multidrug resistance.
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PMID:Mad2beta, an alternative variant of Mad2 reducing mitotic arrest and apoptosis induced by adriamycin in gastric cancer cells. 1621 81

Voltage-gated potassium (Kv) channels have been reported to be involved in the proliferation of many types of cells, including tumor cells. The overexpression of the Kv channels and related channel activity are involved in the neoplastic process. Our previous study has shown the existence of delayed rectifier potassium (I(K)) current in gastric cancer cells SGC7901. However, the expression and function of most delayed rectifier potassium (K(D)) channel subunits in gastric cancer cells are not completely resolved. Here we examine expression of K(D) channel subunits in Kv1-Kv3 families in immortalized gastric epithelial cells GES and various gastric cancer cells (including AGS, KATOIII, MKN28, MKN45, MGC803, SGC7901, SGC7901/ADR and SGC7901/VCR), and their roles in cell proliferation. RT-PCR analysis reveals that all cell lines examined express Kv1.3, Kv1.5, Kv1.6, Kv2.1 and Kv2.2. However, Kv1.2 and Kv3.2 genes are barely detectable in any given cancer cell lines. Kv1.5 protein, high mRNA levels in all cell lines examined, is also expressed in some cancer cells lines and more frequently detected in gastric cancer tissues. Downregulation of the expression of Kv1.5 in SGC7901 with RNA interference significantly inhibited the proliferation and tumorigenicity of SGC7901 cells. Moreover, in Ca(2+)-containing rather than Ca(2+)-free medium, KCl (50mM) stimulated a rapid increase in the concentration of cytosolic calcium in empty vector transfected cells that was blocked by verapamil. Likewise, decrease the expression of Kv1.5 with short interfering RNA also blocked the depolarization-induced influx of Ca(2+). This finding suggests that more than one kind of K(D) channel subunits are expressed in various gastric cancer cell lines. Kv1.5 may be involved in tumor cells proliferation by controlling Ca(2+) entry, and the interference of K(D) channels expression and/or activity could provide a novel strategy to reverse the malignant phenotype of gastric cancer cells.
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PMID:Expression of delayed rectifier potassium channels and their possible roles in proliferation of human gastric cancer cells. 1625 62

In a previous study, we observed that cytokine-induced apoptosis inhibitor 1 (CIAPIN1), a newly identified apoptosis inhibitor, was upregulated at the mRNA level in a multidrug-resistant gastric cancer cell line SGC7901/VCR. The aim of this study was to explore the role of CIAPIN1 in the development of multidrug resistance (MDR) in gastric cancer cells. Upregulation of CIAPIN1 in MDR gastric cancer cells was confirmed by semiquantitative RT-PCR and Western blotting. Using cDNA transfection and RNA interference, we successfully established stable transfectants with upregulation (i.e., SGC7901-pCIAPIN1) or downregulation (i.e., SGC7901-pSiCIAPIN1 and SGC7901/ADR-pSiCIAPIN1) of CIAPIN1 expression, respectively. In vitro drug sensitivity assay demonstrated that overexpression of CIAPIN1 conferred MDR in SGC7901 cells whereas downregulation of CIAPIN1 sensitized SGC7901 and SGC7901/ADR cells to anticancer drugs. CIAPIN1 protected both SGC7901 and SGC7901/ADR cells from ADR-induced apoptosis and reduced intracellular accumulation and retention of adriamycin. Moreover, expression of P-glycoprotein (P-gp or MDR-1, a product of MDR-1 gene) and MDR-related protein-1 (MRP-1) was upregulated by CIAPIN1. In addition, Western blotting revealed that CIAPIN1 decreased the expression of Bcl-2, Bax and p53. Therefore, it is concluded that CIAPIN1 confers MDR in gastric cancer cells, likely by upregulating MDR-1 and MRP-1.
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PMID:CIAPIN1 confers multidrug resistance by upregulating the expression of MDR-1 and MRP-1 in gastric cancer cells. 1641 Jul 21


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