Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.1 (ERK)
 95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The biological behaviour of a gastrointestinal stromal tumor (GIST) cannot be easily predicted from preoperative clinical examination alone. As a result, there is little standardization in the surgical treatment of GIST. In this study, we analyzed the clinicopathology and immunohistochemistry of 20 cases of GIST to clarify factors associated with tumors showing malignant potential. Immunohistochemical analysis of KIT, CD34, vimentin, alpha-smooth muscle actin (SMA), s-100, p53, ki-67, bcl-2 and bax expression was performed on 20 surgically resected GIST. An apoptotic index (AI) was calculated for each sample using a TdT-mediated dUTP-biotin nick end-labeling method. With regard to bcl-2, t(14;18) translocations were also investigated using a polymerase chain reaction based method. Finally, the relationship between these biological results and clinicopathological data was analyzed. Of the 20 cases studied, two patients died due to lung or liver metastasis. All cases stained positive for vimentin, nine cases were positive for alpha-SMA and three cases positive for s-100. All cases were stained for both KIT and CD34, which tended to correlate with malignant potential. There was significant difference in frequency of bcl-2 overexpression (p<0.05) and trend in Ki-67 labeling index (p=0.098) between benign and malignant cases. However, with regard to bcl-2, no chromosomal t(14;18) translocations were detected in four analyzed cases. In GIST, overexpression of bcl-2 may play an important role in increasing malignant potential. Furthermore, Ki-67 L.I. and bcl-2 overexpression may be useful in predicting malignant potential, and therefore help to determine the surgical treatment, follow-up manner, and the necessity of adjuvant therapy.
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PMID:Biological analysis of gastrointestinal stromal tumors. 1237 34

Using morphological and molecular approaches, we characterized cisplatin-induced cell necrosis and apoptosis in rat kidney. Male Sprague-Dawley rats ( n=5 per group) received a single intraperitoneal injection of either cisplatin (5 mg/kg) or saline, and were killed on day 5. Functionally, cisplatin-treated rats developed polyuric acute renal failure. Morphologically, kidneys of cisplatin-treated rats showed overt tubular necrosis associated with apoptosis in the corticomedullary junction. Cell necrosis was segment-specific and was distributed in radial fashion at the corticomedullary junction. The apoptosis was limited to discrete cells in apparently intact tubules in the vicinity of the necrosed tubules. The apoptotic changes were confirmed by TUNEL (TdT-mediated deoxyuridine triphosphate nick-end labeling) and staining for cleaved caspase-3. Analysis of outer medullary tissue for apoptosis-related molecules by RNase protection assay revealed a significant increase in the expression of pro-apoptotic mRNAs (caspases 1, 2, and 8, and Bax) in cisplatin-treated rats. On the other hand, the expression of mRNA for the anti-apoptotic Bcl-2 did not change, resulting in a decrease in relative ratio of Bcl-2/Bax, and thus favoring apoptosis. The above changes were paralleled by a marked increase in caspase-3 precursor, the executioner protease. Furthermore, these pro-apoptotic molecular changes were associated with a 3-fold increase in the activity of JNK1 in the outer medulla, but not in the cortex, of cisplatin-treated rat kidneys, localizing to the site of maximal apoptosis. Upregulation of JNK1 activity in the outer medulla was not accompanied by changes in the activities of ERK or p38 kinase. In conclusion, these data suggest that cisplatin-induced apoptotic cell death in native kidney may be mediated by cooperative activation of the JNK1 pathway and Bax in the outer medulla.
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PMID:Cellular and molecular studies on cisplatin-induced apoptotic cell death in rat kidney. 1455 73

Dual inhibition of ErbB-1 (EGFR) and ErbB-2 (HER-2) tyrosine kinases has been found to exert greater biologic effects in the inhibition of signaling pathways promoting cancer cell proliferation and survival than inhibition of either receptor alone. The novel dual EGFR/ErbB-2 tyrosine kinase inhibitor lapatinib (GlaxoSmithKline; Research Triangle Park, NC) has been shown to inhibit tumor cell growth in vitro and in xenograft models for a variety of human tumors. Preliminary findings in a phase I study of lapatinib in patients with solid tumors indicate doses up to 1,800 mg per day are well tolerated. No grade 4 toxicities were observed and only two of 43 patients had grade 3 toxicity (diarrhea). Clinical activity of lapatinib was observed in these patients; nine patients with a variety of tumors remained on study for > or =4 months, one with a complete response (head and neck cancer). In a phase IB study in pretreated metastatic cancer patients with disease that could be biopsied, grade 1 or 2 diarrhea and rash were the most common adverse events. Three patients with breast cancer refractory to trastuzumab (Herceptin; Genentech, Inc.; South San Francisco, CA) had partial responses and 12 patients with a variety of tumors had stable disease. Assessment of biologic correlates in these patients indicates that increased tumor cell apoptosis on the terminal deoxynucleotide transferase-mediated dUTP nick-end labeling assay correlates with clinical response. Lapatinib currently is being evaluated in phase II and phase III trials in patients with metastatic breast cancer.
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PMID:Dual kinase inhibition in the treatment of breast cancer: initial experience with the EGFR/ErbB-2 inhibitor lapatinib. 1516 42

In the literature, sufficient attention has not been paid to the precise subcellular localization of immunohistochemical signals, the knowledge of which is essential for proper interpretation of immunostains and distinction of genuine staining from biotin-associated or other nonspecific stainings. The subcellular localization of the signals can in fact be easily deduced from the known biologic or ultrastructural characteristics of the antigens. Extracellular antigens obviously are located in the extracellular compartment. Cellular antigens fall into 3 major groups: membranous, nuclear, and cytoplasmic. Membranous antigens include cell adhesion molecules (such as E-cadherin, N-CAM), cell surface/transmembrane receptors and proteins (such as tyrosine kinase receptors, most leukocyte antigens, CD10, CEA), and molecules linking surface molecules to cytoskeleton (such as beta-catenin, dystrophin). Nuclear antigens include cell cycle-associated proteins (such as cyclins, p16, Ki-67), nuclear enzymes (such as TdT), transcription factors (such as TTF-1, CDX-2, myogenin, PAX-5), tumor suppressor gene products (such as p53, p63, WT1, Rb), steroid hormone receptors (such as ER, PR), calcium-binding proteins (such as S-100 protein, calretinin), and some viral proteins (such as CMV, herpes). Cytoplasmic antigens can take up a granular pattern due to localization in organelles, granules, or secretory vesicles (such as chromogranin, hormones, lysozyme, HMB-45), fibrillary pattern attributable to the filamentous nature of the molecules (intermediate filaments and microfilaments), or diffuse or patchy pattern due to localization in the cytosol or large vesicles (such as myoglobin, albumin, thyroglobulin). Aberrant localization of the molecules, when present, can provide important insight into disease processes and aid in their diagnosis, such as loss of membranous E-cadherin expression in lobular breast carcinoma, aberrant nuclear localization of beta-catenin in colorectal adenocarcinoma, pattern of ALK staining in anaplastic large cell lymphoma correlating with the different types of chromosomal translocations, presence of additional cytoplasmic CD10 staining in the enterocytes indicative of microvillous inclusion disease, and "reversed" staining for EMA in micropapillary mammary carcinoma.
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PMID:Subcellular localization of immunohistochemical signals: knowledge of the ultrastructural or biologic features of the antigens helps predict the signal localization and proper interpretation of immunostains. 1530 32

Drugs that inhibit the function of heat shock protein 90 (Hsp90) are of interest in the treatment of pediatric cancers because these agents deplete the cellular levels of signaling molecules that are important for the growth and survival of many childhood tumors. To generate preclinical data in anticipation of clinical trials of Hsp90 inhibitors in children, we evaluated the effects of the Hsp90 inhibitor geldanamycin (GA) alone and in combination with cis-platinum (II)-diamine dichloride (cisplatin) in pediatric tumor cells. Immunoblotting demonstrated depletion of the Hsp90 client proteins AKT and the type 1 insulin-like growth factor receptor (IGF1R) in a panel of pediatric tumor cell lines after exposure to GA. Drug exposure also led to a dramatic decrease in cell survival/proliferation in MYCN-amplified and non-amplified neuroblastoma cells. Moderate inhibition of survival/proliferation was observed in RB-deficient and wild-type osteosarcoma cells. Treatment of neuroblastoma and osteosarcoma cell lines with GA in combination with cisplatin resulted in greater than additive inhibition of survival/proliferation based on median dose analysis. Exposure to this drug combination also resulted in a marked increase in nuclear fragmentation as assessed by terminal deoxynucleotide transferase-mediated UTP nick end labeling (TUNEL) analysis. Combined exposure also abrogated the ability of GA to induce a cytoprotective heat shock response and resulted in Hsp90 adduct formation. Our findings suggest that Hsp90 inhibitors may prove useful either alone or as a component of multi-drug regimens in the treatment of neuroblastoma and osteosarcoma.
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PMID:Hsp90 inhibitors deplete key anti-apoptotic proteins in pediatric solid tumor cells and demonstrate synergistic anticancer activity with cisplatin. 1545 81

Bile reflux has been implicated in the neoplastic progression of Barrett's esophagus (BE). Bile salts increase proliferation in a Barrett's-associated adenocarcinoma cell line (SEG-1 cells) by activating ERK and p38 MAPK pathways. However, it is not clear that these findings in cancer cells are applicable to non-neoplastic cells of benign BE. We examined the effect of bile salts on three human cell lines: normal esophageal squamous (NES) cells, non-neoplastic Barrett's cells (BAR cells), and SEG-1 cells. We hypothesized that bile salt exposure activates proproliferative and antiapoptotic pathways to promote increased growth in BE. NES, BAR, and SEG-1 cells were exposed to glycochenodeoxycholic acid (GCDA) at a neutral pH for 5 min. Proliferation was measured by Coulter counter cell counts and a 5-bromo-2'-deoxyuridine (BrdU) incorporation assay. GCDA-induced MAPK activation was examined by Western blot analysis for phosphorylated ERK and p38. Apoptosis was measured by TdT-mediated dUTP nick-end labeling and annexin V staining after GCDA and UV-B exposure. Statistical significance was determined by ANOVA. NES cells exposed to 5 min of GCDA did not increase cell number. In BAR cells, GCDA exposure increased cell number by 31%, increased phosphorylated p38 and ERK levels by two- to three-fold, increased BrdU incorporation by 30%, and decreased UV-induced apoptosis by 15-20%. In conclusion, in a non-neoplastic Barrett's cell line, GCDA exposure induces proliferation by activation of both ERK and p38 MAPK pathways. These findings suggest a potential mechanism whereby bile reflux may facilitate the neoplastic progression of BE.
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PMID:Bile salt exposure increases proliferation through p38 and ERK MAPK pathways in a non-neoplastic Barrett's cell line. 1623 4

Activation of the PI3K-Akt pathway is known to induce tumor radioresistance. In the current study, we examined the ability of 17AAG, which decreases the levels of Hsp90 client proteins including components of the PI3K-Akt pathway, to sensitize radioresistant human squamous cell carcinoma cells to X-irradiation. Human squamous cell carcinoma cell lines (SQ20B, SCC61 and SCC13) were incubated for 16 h at 37 degrees C in medium containing 17AAG. Radiation sensitivity was determined by clonogenic assays, and protein levels were examined by western blotting. Apoptosis was determined in monolayer cells by AO/EB double staining and in spheroids using the TdT-mediated dUTP nick end labeling assay. 17AAG (0.2 microM) enhanced the radiosensitivity more effectively in radioresistant SQ20B and SCC13 cells than in radiosensitive SCC61 cells. However, in all three cell lines, 17AAG increased radiation-induced apoptosis by reducing the expression of EGFR and ErbB-2 and inhibiting the phosphorylation of Akt. Furthermore, 17AAG (1 microM) sensitized SQ20B spheroids to radiation, and inhibition of Akt activation by 17AAG increased radiation-induced apoptosis in spheroids. The findings suggest that 17AAG effectively sensitizes radioresistant cells to radiation by inhibiting the PI3K-Akt pathway. Targeting the PI3K-Akt pathway with 17AAG could be a useful strategy for radiosensitization of carcinomas.
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PMID:Heat shock protein 90 inhibitor 17-allylamino-17-demethoxygeldanamycin potentiates the radiation response of tumor cells grown as monolayer cultures and spheroids by inducing apoptosis. 1636 12

A combination of chromosomal translocations associated with bcl-2 re-arrangement (t(14;18)) and c-myc re-arrangement (t(8;14), t(8;22), or t(2;8)) is a rare event. We describe the first cell line exhibiting t(14;18) and t(8;22), which will enable us to study the interactions of bcl-2 and c-myc systematically. Cell culture was started with circulating lymphoma cells from the peripheral blood of an adult male Caucasian patient with Burkitt's lymphoma after the second relapse. The cells grew spontaneously without cytokines, fulfilled all criteria of a cell line and were analysed. An Epstein-Barr virus (EBV) genome-negative cell line (DoGKiT) has been established. RC-banding analysis of the chromosomes showed a complex karyotype with a modal number of 48, XY, dup(1)(q31;q44), t(8;22)(q24;q11), der(10), t(14;18)(q32;q21), add(16)(pter), dup(17)(q12q24), +der(18), +20. The combination of t(8;22)(q24;q11), a variant translocation of Burkitt's lymphoma and t(14;18)(q32;q21), typical for follicular lymphoma (FL), was confirmed by FISH and SKY-analysis. Surface marker studies of the cell line showed that the cells were positive for CALLA (CD10), CD19, cyCD22, cyCD79a and HLA-DR and negative for TdT, IgM, CD5 and CD23. To our knowledge, this is the first established cell line carrying these two translocations. In contrast to already established cell lines carrying the more common combination of t(8;14)(q24;q32) and t(14;18)(q32;q21) with both IgH alleles being involved in translocations, the cell line DoGKiT carries only one translocated IgH allele. This cell line may serve as an important tool in the study of the combination of the chromosomal translocations t(14;18) and t(8;22) and in molecular genetic studies of transformed FL.
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PMID:A human Burkitt's lymphoma cell line carrying t(8;22) and t(14;18) translocations. 1762 30

Neuroblastoma, an embryonal tumour of the peripheral sympathetic nervous system, accounts for approximately 15% of all deaths due to childhood cancer. High-risk neuroblastomas are rapidly progressive; even with intensive myeloablative chemotherapy, relapse is common and almost uniformly fatal. Here we report the detection of previously unknown mutations in the ALK gene, which encodes a receptor tyrosine kinase, in 8% of primary neuroblastomas. Five non-synonymous sequence variations were identified in the kinase domain of ALK, of which three were somatic and two were germ line. The most frequent mutation, F1174L, was also identified in three different neuroblastoma cell lines. ALK complementary DNAs encoding the F1174L and R1275Q variants, but not the wild-type ALK cDNA, transformed interleukin-3-dependent murine haematopoietic Ba/F3 cells to cytokine-independent growth. Ba/F3 cells expressing these mutations were sensitive to the small-molecule inhibitor of ALK, TAE684 (ref. 4). Furthermore, two human neuroblastoma cell lines harbouring the F1174L mutation were also sensitive to the inhibitor. Cytotoxicity was associated with increased amounts of apoptosis as measured by TdT-mediated dUTP nick end labelling (TUNEL). Short hairpin RNA (shRNA)-mediated knockdown of ALK expression in neuroblastoma cell lines with the F1174L mutation also resulted in apoptosis and impaired cell proliferation. Thus, activating alleles of the ALK receptor tyrosine kinase are present in primary neuroblastoma tumours and in established neuroblastoma cell lines, and confer sensitivity to ALK inhibition with small molecules, providing a molecular rationale for targeted therapy of this disease.
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PMID:Activating mutations in ALK provide a therapeutic target in neuroblastoma. 1892 3

A 13 year old boy presented with a huge mass on his right arm of 6 months duration. Histopathological examination revealed sheets of malignant small round blue cells with immunopositivity for LCA, CD43, CD45Ro, CD30, EMA, ALK-1 and CD99, and negativity for CD20, TdT, myogenin, myoD1, NSE, bcl-6, bcl-2 and CD10. Fluorescent In-Situ Hybridization (FISH) testing excluded the diagnosis of Ewing's sarcoma/PNET. Pathologists need to be aware of the diagnosis of a small cell variant of ALCL, as well as of the fact that CD99 expression commonly occurs in cases of ALK-positive ALCL, in order to distinguish this entity from Ewing's sarcoma/PNET.
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PMID:Small cell variant of anaplastic large cell lymphoma with positive immunoreactivity for CD99. 1894 5


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