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)

HER2 overexpression is observed in 5-25% of gastric cancers. Lapatinib is a dual inhibitor of the epidermal growth factor receptor and HER2 tyrosine kinase. We examined the antitumor effect of lapatinib in gastric cancer cell lines. Lapatinib induced selective and potent growth inhibition in two HER2-amplified gastric cancer cell lines (SNU-216 and NCI-N87). Lapatinib inhibited the phosphorylation of HER2, EGFR and downstream signaling proteins, resulting in G1 arrest in both cell lines with down-regulation of cMyc and induction of p27kip1. Lapatinib also induced apoptosis in NCI-N87 which has high HER2 amplification ratio. Lapatinib combined with 5-fluorouracil, cisplatin, oxaliplatin or paclitaxel showed an additive or synergistic effect. These results provide a rationale for the future clinical trials of lapatinib combined with cytotoxic drugs in the treatment of HER2-positive gastric cancer.
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PMID:The growth inhibitory effect of lapatinib, a dual inhibitor of EGFR and HER2 tyrosine kinase, in gastric cancer cell lines. 1877 37

In various loading methods of whole tumor cells or their derivatives, cells fusion of dendritic cells (DCs) and tumor cells have some advantages for antigen presentation, and could up-regulate cytotoxic T cells (CTL) for multiple tumor antigens, including unknown antigens. However, the mechanisms of strong CTL productivity of fusion cells (FCs) are still unknown. Heat shock proteins (HSPs) are molecular chaperones that cross-present chaperoned antigenic peptides with MHC class I molecules. Herein, we focused on clarifying the potential of FCs for CTL production from the comparison of DCs pulsed with two kinds of tumor cell lysates, such as soluble tumor cell lysates or freeze-thawed tumor cell lysates. DCs, CD8+ T cells and tumor cells were prepared from ten patients with gastric cancer, and paired autologous tumor cells were used in all experiments. FCs of OK432-treated DCs and heat-stressed tumor cells (modified FCs) showed significant up-regulation of tumor-associated CEA and HER-2 antigen, and DC-related HLA-DR and co-stimulatory molecules (CD83 and CD86). FCs showed significantly higher IFN-gamma and CTL productivity of CD8+ T cells than DCs pulsed with soluble or freeze-thawed tumor cell lysates. IFN-gamma and CTL productivity of FCs was significantly increased by the heat stress of tumor cells. HSP70 mRNA levels and production of HSP70 protein of modified FCs increased significantly as compared with those of DCs pulsed with soluble or freeze-thawed tumor cell lysates. DCs pulsed with HSP70.PC extracted from modified FCs could enhance CTL productivity significantly more than that of DCs pulsed with HSP70.PC from soluble or freeze-thawed tumor cell lysate pulsed-DCs. The significant up-regulation of HSP70 mRNA and protein levels of modified FCs was related to the potential of CTL productivity. These results suggest that modified FCs possess stronger ability for MHC-restricted CTL production than DCs loaded with soluble or freeze-thawed tumor cell lysates.
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PMID:Efficient CTL productivity of modified fusion cells by increase of heat shock protein 70. 1921 34

Her-2 is the molecular target for antibody-based treatment of breast cancer (trastuzumab). The potential benefit of anti-Her-2 therapy is currently investigated in several other HER-2-amplified cancers including gastric cancer. Although HER-2 amplification occurs in more than 10% of gastric cancers, potential heterogeneity of HER-2 amplification and overexpression could represent a major drawback for anti-Her-2 therapy. To address the potential applicability of trastuzumab in gastric cancer, tissue microarray sections of 166 gastric adenocarcinomas and 69 lymph node metastases were analyzed for Her-2 overexpression and amplification using Food and Drug Administration-approved reagents for immunohistochemistry and fluorescence in situ hybridization. HER-2 amplification was seen in 27 (16%) of 166 gastric adenocarcinomas. Amplification was typically high level with more than 20 HER-2 copies per tumor cell and a HER-2/centromere 17 ratio >3. Amplification was associated with intestinal tumor phenotype but unrelated to survival, grading, pT, pN, or pM. Identical HER-2 status was found in primary tumor and their matched lymph node metastases. Moreover, HER-2 and Topoisomerase IIalpha coamplification analysis of 3 to 16 large sections from 8 Her-2-positive gastric cancers did not reveal any heterogeneity of the amplicon site. The high level of HER-2 amplification in combination with the homogeneity of its expression in primary and metastatic tumors argues for a possible therapeutic utility of trastuzumab in HER-2-amplified gastric adenocarcinomas.
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PMID:HER-2 amplification is highly homogenous in gastric cancer. 2157 Nov 26

Curcumin (diferuloylmethane), is a natural chemopreventive agent known to inhibit the proliferation of several cancer cell lines. It has been previously demonstrated that curcumin is a potent inhibitor of EGF-receptor (EGFR) tyrosine kinase, but its inhibitive effect on p21-activated kinase 1 (PAK1), a downstream protein of EGFR, has not been defined. In this paper we found that curcumin repressed the expression of HER2 and inhibited the kinase activity of PAK1 without affecting its expression. Silencing HER2 in gastric cancer cells showed that even if PAK1 activity was transiently strengthened by EGF, curcumin still had a strong inhibitive effect. It should be emphasized that kinase assay in vitro showed that curcumin could act as an ATP-competitive inhibitor, which was supported by computer-aided molecular modeling. Curcumin also downregulated the mRNA and the protein expression of cyclin D1 and suppressed transition of the cells from G(1) to S phase. Therefore, curcumin inhibited the proliferation and invasion of gastric cancer cells. Overall, these results provided novel insights into the mechanisms of curcumin inhibition of gastric cancer cell growth and potential therapeutic strategies for gastric cancer.
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PMID:Curcumin suppresses proliferation and invasion in human gastric cancer cells by downregulation of PAK1 activity and cyclin D1 expression. 1944 98

Members of the human epidermal receptor (HER) family are frequently associated with aggressive disease and poor prognosis in multiple malignancies. Lapatinib is a dual tyrosine kinase inhibitor targeting the epidermal growth factor receptor (EGFR) and HER-2. This study evaluated the therapeutic potential of lapatinib, alone and in combination with SN-38, the active metabolite of irinotecan (CPT-11), in colon and gastric cancer cell lines. Concentration-dependent antiproliferative effects of both lapatinib and SN-38 were observed in all colon and gastric cancer cell lines tested but varied significantly between individual cell lines (lapatinib range 0.08-11.7 muM; SN-38 range 3.6-256 nM). Lapatinib potently inhibited the growth of a HER-2 overexpressing gastric cancer cell line and demonstrated moderate activity in gastric and colon cancer cells with detectable HER-2 expression. The combination of lapatinib and SN-38 interacted synergistically to inhibit cell proliferation in all colon and gastric cancer cell lines tested. Cotreatment with lapatinib and SN-38 also resulted in enhanced cell cycle arrest and the induction of apoptosis with subsequent cellular pharmacokinetic analysis demonstrating that lapatinib promoted the increased intracellular accumulation and retention of SN-38 when compared to SN-38 treatment alone. Finally, the combination of lapatinib and CPT-11 demonstrated synergistic antitumor efficacy in the LoVo colon cancer mouse xenograft model with no apparent increase in toxicity compared to CPT-11 monotherapy. These results provide compelling preclinical rationale indicating lapatinib to be a potentially efficacious chemotherapeutic combination partner for irinotecan in the treatment of gastrointestinal carcinomas.
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PMID:The dual EGFR/HER-2 tyrosine kinase inhibitor lapatinib sensitizes colon and gastric cancer cells to the irinotecan active metabolite SN-38. 1953 76

The optimal adjuvant treatment for gastric cancer remains controversial. We compared the efficacy of a docetaxel and platinum adjuvant chemotherapy regimen, in patients with high-risk gastric cancer, with that of the same chemotherapy plus radiation therapy (RT). In addition, we evaluated the prognostic and/or predictive value of a panel of molecular markers. Patients with histologically proven, radically resected gastric cancer, stage > or =T3 and/or N+ were randomized to 6 cycles of docetaxel with cisplatin, both at 75 mg/m2 every 3 weeks (arm A) or the same treatment with RT (arm B; 45 Gy). Due to excessive nausea and vomiting, cisplatin was substituted by carboplatin at AUC (area under the curve) of 5 after the first 45 patients (22 group A, 23 group B). The prognostic value of EGFR, ERCC1, HER2, MET/HGFR, MAP-Tau, and PTEN expression was also studied in a subset of 67 patients using immunohistochemistry on tissue microarrays (TMAs). A total of 147 patients were randomized. After a median follow-up of 53.7 months, no differences in overall (OS) and disease-free survival (DFS) were found between the two arms. The most common grade 3/4 toxicities for arms A and B (excluding alopecia) were non-febrile neutropenia (11 and 17%, respectively), febrile neutropenia (9 and 7%) and diarrhea (7 and 4%, respectively). Patients with ERCC1 positive tumors had significantly longer median DFS (33.1 vs. 11.8 months, Wald P = 0.016) and OS (63.2 vs. 18.8 months, Wald P = 0.046). Our results indicate that the addition of RT to platinum/docetaxel adjuvant chemotherapy does not appear to improve survival in high-risk, radically resected gastric cancer. However, the possibility that a benefit by the addition of RT was not detected due to decreased power of the study should not be excluded.
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PMID:A randomized phase III study of adjuvant platinum/docetaxel chemotherapy with or without radiation therapy in patients with gastric cancer. 2115 23

Amplification of the HER2 gene and over-expression of the HER2 protein in gastric cancer have been shown in a large number of studies. HER2 positivity can be detected in approximately 20% of patients, which is a characteristic associated with poor prognosis. Preclinical in vitro and in vivo studies have demonstrated that both trastuzumab and lapatinib are effective in different gastric cancer models and have thus lead to the initiation of clinical studies. In the first phase III study, the ToGA trial, HER2-positive patients with advanced gastroesophageal and gastric adenocarcinoma were randomized to receive 5-fluorouracil/capecitabine and cisplatin either alone or in combination with trastuzumab. A statically significant gain in overall survival was seen in the patients who received the combined treatment of trastuzumab and chemotherapy. It is expected that the encouraging results from the ToGA trial will have an immediate impact on the management of patients and that routine HER2 testing of patients with advanced gastric cancer will be initiated within a relatively short period of time.
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PMID:Targeted HER2 treatment in advanced gastric cancer. 2018 38

HER2 is highly expressed in a significant proportion of breast cancer, ovarian cancer, and gastric cancer. Since the discovery of its role in tumorigenesis, HER2 has received great attention in cancer research during the past two decades. Successful development of the humanized monoclonal anti-HER2 antibody (Trastuzumab) for the treatment of breast cancer further spurred scientists to develop various HER2 specific antibodies, dimerization inhibitors and kinase inhibitors for cancer therapy. On the other hand, the high expression of HER2 and the accessibility of its extracellular domain make HER2 an ideal target for the targeted delivery of anti-tumor drugs as well as imaging agents. Although there is no natural ligand for HER2, artificial ligands targeting HER2 have been developed and applied in various targeted drug delivery systems. The emphasis of this review is to elucidate the roles of HER2 in cancer therapy and targeted drug delivery. The structure and signal pathway of HER2 will be briefly described. The role of HER2 in tumorigenesis and its relationship with other tumor markers will be discussed. For the HER2 targeted cancer therapy, numerous strategies including the blockage of receptor dimerization, inhibition of the tyrosine kinase activity, and interruption of the downstream signal pathway will be summarized. For the targeted drug delivery to HER2 positive tumor cells, various targeting ligands and their delivery systems will be described in details.
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PMID:The role of HER2 in cancer therapy and targeted drug delivery. 2038 84

A large phase III study on the use of the HER2 antibody trastuzumab in locally advanced or metastatic gastric cancer has now been completed. Patients whose tumors were either scored on immunohistochemistry (IHC) as 3+ (independently of the result of fluorescence in situ hybridization (FISH)) or as IHC2+ and FISH+ were found, in a planned subgroup analysis, to have a median overall survival time of 16.0 months--versus 11.8 months when trastuzumab was not given. In light of these data, trastuzumab was therefore approved by the European Medicines Agency (EMEA) for metastasizing patients with this HER2 test result. It should be noted that the IHC scoring system for gastric cancer was modified compared to that for breast cancer. If the same criteria as are used for breast cancer were used for gastric cancer, this would lead to a large number of false negatives; around half of the patients who would benefit from trastuzumab would not be identified. Workshops for pathologists and round robin tests are being carried out to introduce the new scoring system.
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PMID:[HER2 testing and targeted therapy in advanced gastric cancer]. 2043 10

HER2 overexpression is associated with metastasis-the main cause of death in individuals with gastric cancer. In this study, we demonstrated that vector-based shRNA significantly knocked down the expression of HER2 and considerably inhibited both the migration and invasion of gastric cancer cells. HER2 knockdown resulted in the downregulation of the expression of MMP-1, while HER2 overexpression improved the transcription of MMP-1 through the activation of an MMP-1 promoter. The promoter region of MMP-1 between -2500 and -2000 bp was found to be crucial for the upregulation of HER2-mediated transcription. Furthermore, a truncated promoter (-70 to+63) did not display any transcriptional activity. Cell invasion activity was almost completely inhibited when MMP-1 was knocked down. Conversely, the overexpression of MMP-1 partly rescued the invasion ability of cell strains with knocked-down HER2. These findings help further understanding of the molecular mechanisms through which HER2 promotes malignancy, and suggest that targeting both HER2 and MMP-1 may be required to effectively block HER2 signaling in gastric cancer therapy.
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PMID:HER2-mediated upregulation of MMP-1 is involved in gastric cancer cell invasion. 2046 98


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