Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: UMLS:C0699790 (colon cancer)
28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

17-Allylamino-17-demethoxygeldanamycin (17AAG) is a first-in-class heat shock protein 90 (Hsp90) molecular chaperone inhibitor to enter clinical trials. The downstream molecular and cellular consequences of Hsp90 inhibition are not well defined. 17AAG has shown activity against human colon cancer in cell culture and xenograft models. In this study, we demonstrated that in addition to depleting c-Raf-1 and inhibiting ERK-1/2 phosphorylation in human colon adenocarcinoma cells, 17AAG also depleted N-ras, Ki-ras, and c-Akt and inhibited phosphorylation of c-AKT: A consequence of these events was the induction of cell line-dependent cytostasis and apoptosis, although the latter did not result from dephosphorylation of proapoptotic BAD: One cell line, KM12, did not exhibit apoptosis and in contrast to the other cell lines overexpressed Bag-1, but did not express BAX: Taken together with other determinants of 17AAG sensitivity, these results should contribute to a more complete understanding of the molecular pharmacology of 17AAG, which in turn should aid the future rational clinical development and use of the drug in colon and other tumor types.
...
PMID:Inhibition of signal transduction by the Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin results in cytostasis and apoptosis. 1135 18

Benzamide riboside, a recently discovered inhibitor of IMP dehydrogenase (IMPDH) exhibits oncolytic activity. IMPDH is the key enzyme of de novo guanylate biosynthesis and was shown to be linked with proliferation. Therefore, IMPDH is a very good target for antitumor therapy. In order to be active, benzamide riboside has to be converted to BAD, an NAD analogue that binds to the NAD site on IMPDH. Inhibition of the enzyme by benzamide riboside selectively inhibits tumor cell growth and induces apoptosis in various human tumor cell lines. In this manuscript we describe the induction of the CD71 transferrin receptor in human promyelocytic leukemia HL-60 cells following treatment with benzamide riboside. The results indicate a possible involvement of the iron metabolism in the action of this new compound. Benzamide riboside might be clinically used in the treatment of leukemia and solid tumors, alone or as part of combination therapy. Since transferrin receptors are overexpressed in certain cancers, such as glioma and colon cancer, a combination therapy that includes benzamide riboside in transferrin-coupled liposomes will not only target cancer cells but also leads to suicidal action because benzamide riboside will upregulate transferrin receptors on cancer cells thereby make it accessible to dose-intensive chemotherapy. We therefore believe that benzamide riboside itself or derivatives of benzamide riboside might become an important addition for the treatment to diseases that are otherwise fatal.
...
PMID:Benzamide riboside, a recent inhibitor of inosine 5'-monophosphate dehydrogenase induces transferrin receptors in cancer cells. 1196 39

Studies on chemoprevention of colorectal cancer have generated increasing interest. The mechanisms involved in NSAIDs chemopreventive action are not fully elucidated. In this study, we examined in human colon cancer cells the effect of indomethacin and NS-398 (a pre-clinical selective COX-2 inhibitor) on expression of 96 genes of the EGF/PDGF signaling pathways essential for cell proliferation, migration, and survival. We found that indomethacin and NS-398 treatment significantly upregulated expression of the tumor suppressor gene, PTEN, the MAP kinase phosphatase-3, MKP-3, and the protein tyrosine phosphatase, SHP2. Additionally, NS-398 treatment increased expression of apoptotic genes such as BAD, STAT1, and CASP3. These results suggest that as a consequence of increased expression of phosphatases such as PTEN and the resulting dephosphorylation of kinases, NSAIDs can negatively regulate the EGF/PDGF pathways in colon cancer cells-a novel mechanism for NSAIDs' chemopreventive actions.
...
PMID:NSAIDs activate PTEN and other phosphatases in human colon cancer cells: novel mechanism for chemopreventive action of NSAIDs. 1524 Jan 29

Cancer cells generally exhibit increased glycolysis for ATP generation (the Warburg effect) due in part to mitochondrial respiration injury and hypoxia, which are frequently associated with resistance to therapeutic agents. Here, we report that inhibition of glycolysis severely depletes ATP in cancer cells, especially in clones of cancer cells with mitochondrial respiration defects, and leads to rapid dephosphorylation of the glycolysis-apoptosis integrating molecule BAD at Ser(112), relocalization of BAX to mitochondria, and massive cell death. Importantly, inhibition of glycolysis effectively kills colon cancer cells and lymphoma cells in a hypoxic environment in which the cancer cells exhibit high glycolytic activity and decreased sensitivity to common anticancer agents. Depletion of ATP by glycolytic inhibition also potently induced apoptosis in multidrug-resistant cells, suggesting that deprivation of cellular energy supply may be an effective way to overcome multidrug resistance. Our study shows a promising therapeutic strategy to effectively kill cancer cells and overcome drug resistance. Because the Warburg effect and hypoxia are frequently seen in human cancers, these findings may have broad clinical implications.
...
PMID:Inhibition of glycolysis in cancer cells: a novel strategy to overcome drug resistance associated with mitochondrial respiratory defect and hypoxia. 1569 6

Numerous dietary and pharmacological agents have been proposed as alternative strategies for treatment and prevention of colorectal cancer. Curcumin, an active ingredient of turmeric, that inhibits growth of malignant neoplasms, has a promising role in the prevention and treatment of colorectal cancer. EGF-R related protein (ERRP), a recently identified pan-erbB inhibitor, is a potential therapeutic agent for colorectal cancer. Here we examine whether curcumin together with ERRP will cause a greater inhibition of growth of colon cancer cells than either agent alone and the mechanisms of this inhibition. Human colon cancer HCT-116 or HT-29 cells were incubated with increasing doses of curcumin (up to 10 microM) or ERRP (up to 5 microg/ml), or a combination of both for 48 h. We observed that the cell growth inhibition and stimulation of apoptosis in response to the combinatorial treatment was significantly greater than that caused by either agent alone. These changes were associated with decreased activation (tyrosine phosphorylation) of EGFR, ErbB-2, ErbB-3, and/or IGF-1R. Whereas curcumin inhibited constitutive activation of both EGFR and IGF-1R, ERRP decreased activation of EGFR, ErbB-2, and ErbB-3 but had no effect on IGF-1R. Further, the combination therapy caused a greater attenuation of downstream effectors such as NF-kappaB, Akt and BAD activation, and down-regulation of procaspase-3 than that noted with either agent alone. The superior effects of the combinatorial treatment could partly be attributed to inhibition of constitutive activation of EGFRs and IGF-1R signaling pathways.
...
PMID:Mechanisms of curcumin- and EGF-receptor related protein (ERRP)-dependent growth inhibition of colon cancer cells. 1704 74

Recent studies indicate that secondary bile acids promote colon cancer cell proliferation but their role in maintaining cell survival has not been explored. We found that deoxycholyltaurine (DCT) markedly attenuated both unstimulated and TNF-alpha-stimulated programmed cell death in colon cancer cells by a phosphatidylinositol 3-kinase (PI3K)-dependent mechanism. To examine the role of bile acids and PI3K signaling in maintaining colon cancer cell survival, we explored the role of signaling downstream of bile acid-induced activation of the epidermal growth factor receptor (EGFR) in regulating both apoptosis and proliferation of HT-29 and H508 human colon cancer cells. DCT caused dose- and time-dependent Akt (Ser(473)) phosphorylation, a commonly used marker of activated PI3K/Akt signaling. Both EGFR kinase and PI3K inhibitors attenuated DCT-induced Akt phosphorylation and Akt activation, as demonstrated by reduced phosphorylation of a GSK-3-paramyosin substrate. Transfection of HT-29 cells with kinase-dead EGFR (K721M) reduced DCT-induced Akt phosphorylation. In HT-29 cells, EGFR and PI3K inhibitors as well as transfection with dominant negative AKT attenuated DCT-induced cell proliferation. DCT-induced PI3K/Akt activation resulted in downstream phosphorylation of GSK-3 (Ser(21/9)) and BAD (Ser(136)), and nuclear translocation (activation) of NF-kappaB, thereby confirming that DCT-induced activation of PI3K/Akt signaling regulates both proproliferative and prosurvival signals. Collectively, these results indicate that DCT-induced activation of post-EGFR PI3K/Akt signaling stimulates both colon cancer cell survival and proliferation.
...
PMID:Deoxycholyltaurine rescues human colon cancer cells from apoptosis by activating EGFR-dependent PI3K/Akt signaling. 1806 5

Human BFK (BCL-2 family kin) is a novel pro-apoptotic BCL-2 family member specifically expressed in the gastrointestinal tract. BFK has the characteristic BH3 domain, which was shown to be essential for the apoptosis-inducing activity of pro-apoptotic BCL-2 family members. When overexpressed, BFK interacts with BCL-XL and BCL-W but not BCL-2 or BAD in co-immunoprecipitations studies. We find that BFK exhibits striking similarity to BID in the way it is activated through cleavage during apoptosis. The endogenous and cleaved versions of BFK are readily recognized by the rabbit and mouse sera raised against human BFK. An ideal caspase 3 or 7 target sequence, DEVD (amino acids 38-41), is evident N-terminal to the BH3 domain. A recombinant version of the protein containing all residues downstream of the putative caspase cleavage site induces apoptosis in human colon cancer cells, HCT116, and in wild-type mouse embryonic fibroblasts (MEFs), which can be reversed by co-expression of BCL-XL or BCL-W. BFK becomes activated through caspase-dependent cleavage during DNA damage-induced apoptosis. The cleaved form of the protein is dependent on the presence of BAX or BAK for its ability to induce apoptosis, since BAX(-/-)-BAK(-/-) double-knockout MEFs are completely resistant to BFK-induced apoptosis.
...
PMID:A putative role for human BFK in DNA damage-induced apoptosis. 1955

Mcl-1 inhibits apoptosis in well-differentiated cells by sequestering BAD, BID, and BAX and other apoptotic molecules. pAKT blocks apoptotsis by facilitating the interaction of BAD with BCL-XL. Expression of pAKT and Mcl-1 have been described in colon cancer, however, the relationship between pAKT and Mcl-1 has not. Mcl-1 and pAKT immunohistochemistry was performed using colorectal cancer tissue microarray (TMA). The Holm step-down method was used to adjust for multiple testing. Mcl-1 and pAKT scores, stage, and grade were compared using Spearman's correlation coefficient. Metastasis and no metastasis groups were compared using the Wilcoxon rank sum test. Mcl-1 and pAKT scores were compared for normal colorectal mucosa (NR), adenoma (AD), and colorectal cancer (CRC) cohorts. The mean (SD) pAKT expression in NR (14) was 2.0 (1.4), in AD (8) was 3.0 (1.7), and in CRC (101) was 5.6 (2.4). These differences were statistically significant. For Mcl-1 the mean (SD) expression was 4.1 (1.7) in NR, 3.2 (1.2) in AD, and 3.3 (2.6) in CRC. Mcl-1 and pAKT scores were directly correlated during various stages of colon car-cinogenesis (p = 0.04). Mcl-1 showed direct correlation with tumor grade (p = 0.001) and tumor stage (p = 0.02) and with presence of metastasis (p = 0.008). We report the correlation of Mcl-1 protein expression with higher grade and stage in colorectal cancer. Mcl-1 correlated also with pAKT expression. We also report the up regulation of pAKT during the transition from NR to CRC.
...
PMID:Correlation between Mcl-1 and pAKT protein expression in colorectal cancer. 2115 90

The aim of this study was to characterize peptides present in common bean non-digestible fractions (NDF) produced after enzymatic digestion and determine their antiproliferative action on human colorectal cancer cells. Five NDF peptides represented 70% of total protein (GLTSK, LSGNK, GEGSGA, MPACGSS and MTEEY) with antiproliferative activity on human colon cancer cells. Based on the antiproliferative effect, HCT116 cell line was most sensitive to bean Azufrado Higuera (IC50=0.53 mg/ml) and RKO to Bayo Madero (IC50=0.51 mg/ml) peptide extracts. Both cultivars increased significantly (p<0.05) the expression of p53 in HCT116 by 76% and 68%, respectively. Azufrado Higuera modified the expression of cell cycle regulation proteins p21 and cyclin B1. Bayo Madero modified the expression of mitochondrial activated apoptotic proteins BAD, cytC, c-casp3, Survivin, BIRC7. Results suggest that peptides present in common bean NDF contributed to the antiproliferative effect on human colorectal cancer cells by modifying molecules involved in either cell cycle arrest or apoptosis.
...
PMID:Peptides in common bean fractions inhibit human colorectal cancer cells. 2467 90

There are no effective therapies for the ~30% of human malignancies with mutant RAS oncogenes. Using a kinome-centered synthetic lethality screen, we find that suppression of the ERBB3 receptor tyrosine kinase sensitizes KRAS mutant lung and colon cancer cells to MEK inhibitors. We show that MEK inhibition results in MYC-dependent transcriptional upregulation of ERBB3, which is responsible for intrinsic drug resistance. Drugs targeting both EGFR and ERBB2, each capable of forming heterodimers with ERBB3, can reverse unresponsiveness to MEK inhibition by decreasing inhibitory phosphorylation of the proapoptotic proteins BAD and BIM. Moreover, ERBB3 protein level is a biomarker of response to combinatorial treatment. These data suggest a combination strategy for treating KRAS mutant colon and lung cancers and a way to identify the tumors that are most likely to benefit from such combinatorial treatment.
...
PMID:Intrinsic resistance to MEK inhibition in KRAS mutant lung and colon cancer through transcriptional induction of ERBB3. 2468 32


1 2 Next >>

---