Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The bis-indole indirubin is the active ingredient of the Traditional Chinese Medicine recipe Danggui Longhui Wan used against chronic myelocytic leukemia. We have previously shown that indirubins are potent inhibitors of cyclin-dependent kinases and glycogen synthase kinase-3. We here investigated the anti-mitotic properties of this class of compounds using the cell permeable indirubin-3'-monoxime and the HBL-100 cell line. Indirubin-3'-monoxime reversibly arrests asynchronous HBL-100 cells in G2. This arrest is not accompanied by any significant change in expression of the major cell cycle regulators. However indirubin-3'-monoxime inhibits the phosphorylation of consensus CDK phosphorylation sites as well as of nucleolin at a specific CDK1/cyclin B phosphorylation site, suggesting a direct action on the mitotic CDK1/cyclin B. When indirubin-3'-monoxime is added to HBL-100 cells synchronized in M phase by nocodazole, cells undergo an endoreplication leading to an 8n DNA content. As soon as indirubin-3'-monoxime is washed away, these polyploid cells become aneuploid and later die from necrosis. This mechanism of endoreplication followed by cell death may contribute to the anti-tumour properties of indirubins.
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PMID:Anti-mitotic properties of indirubin-3'-monoxime, a CDK/GSK-3 inhibitor: induction of endoreplication following prophase arrest. 1143 42

Many components of mitogenic signaling pathways in normal and neoplastic cells have been identified, including the large family of protein kinases, which function as components of signal transduction pathways, playing a central role in diverse biological processes, such as control of cell growth, metabolism, differentiation, and apoptosis. The development of selective protein kinase inhibitors that can block or modulate diseases caused by abnormalities in these signaling pathways is widely considered a promising approach for drug development. Because of their deregulation in human cancers, protein kinases, such as Bcr-Abl, those in the epidermal growth factor-receptor (HER) family, the cell cycle regulating kinases such as the cyclin-dependent kinases, as well as the vascular endothelial growth factor-receptor kinases involved in the neo-vascularization of tumors, are among the protein kinases considered as prime targets for the development of selective inhibitors. These drug-discovery efforts have generated inhibitors and low-molecular weight therapeutics directed against the ATP-binding site of various protein kinases that are in various stages of development (up to Phase II/III clinical trials). Three examples of inhibitors of protein kinases are reviewed, including low-molecular weight compounds targeting the cell cycle kinases; a potent and selective inhibitor of the HER1/HER2 receptor tyrosine kinase, the pyrollopyrimidine PKI166; and the 2-phenyl-aminopyrimidine STI571 (Glivec(R), Gleevec) a targeted drug therapy directed toward Bcr-Abl, the key player in chronic leukemia (CML). Some members of the HER family of receptor tyrosine kinases, in particular HER1 and HER2, have been found to be overexpressed in a variety of human tumors, suggesting that inhibition of HER signaling would be a viable antiproliferative strategy. The pyrrolo-pyrimidine PKI166 was developed as an HER1/HER2 inhibitor with potent in vitro antiproliferative and in vivo antitumor activity. Based upon its clear association with disease, the Bcr-Abl tyrosine kinase in CML represents the ideal target to validate the clinical utility of protein kinase inhibitors as therapeutic agents. In a preclinical model, STI571 (Glivec(R), Gleevec) showed potent in vitro and in vivo antitumor activity that was selective for Abl, c-Kit, and the platelet-derived growth factor-receptor. Phase I/II studies demonstrated that STI571 is well tolerated, and that it showed promising hematological and cytogenetic responses in CML and clinical responses in the c-Kit-driven gastrointestinal tumors.
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PMID:Protein kinases as targets for anticancer agents: from inhibitors to useful drugs. 1219 2

Indirubin, a 3, 2' bisindole isomer of indigo, has originally been identified as the active principle of a traditional Chinese preparation and has been proven to exhibit antileukemic effectiveness in chronic myelocytic leukemia. Indirubin was detected to represent a novel lead structure with potent inhibitory potential towards cyclin-dependent kinases (CDKs) resulting from high affinity binding into the enzymes ATP binding site. This seminal finding triggered our research to improve the pharmacological activities of the parent molecule within comprehensive structure-activity studies. Molecular modifications made novel anticancer compounds accessible with strongly improved CDK inhibitory potential and with broad spectrum antitumour activity. This novel family of compounds holds strong promise for clinical anticancer activity and might be useful also in several important noncancer indications, including Alzheimer's disease or diabetes.
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PMID:Molecular mechanisms of indirubin and its derivatives: novel anticancer molecules with their origin in traditional Chinese phytomedicine. 1534 Aug 40

Chronic myelogenous leukaemia (CML) is a clonal malignancy of the pluripotent haematopoietic stem cell, characterised by an uncontrolled proliferation and expansion of myeloid progenitors expressing a fusion oncogene, BCR-ABL, the molecular counterpart of the Ph1 chromosome. The tyrosine kinase (TK) activity of BCR-ABL is known to activate several major signalling pathways in malignant cells, including Ras, JAK/STAT and PI3K/Akt with evidence of proteasome-mediated degradation of other targets such as the DNA repair protein DNA-PKcs and cyclin-dependent kinases inhibitor p27. Targeting these abnormalities by blocking TK of BCR-ABL with STI571 provided a promising approach for the therapy of CML. The recent development of resistance to STI571 illustrates, however, that the use of other TK inhibitors could be of major interest for therapeutic purposes. To this end, the TK inhibitor Tyrphostin AG1024 was used to evaluate effect on regulation of BCR-ABL expression, inhibition of cell proliferation and tumour formation in vivo in human and murine BCR-ABL expressing cell lines. Tyrphostin AG1024 was shown to downregulate expression of BCR-ABL and P-Akt, and to upregulate DNA-PKcs expression. In addition, Tyrphostin AG1024 was able to inhibit cell proliferation, and delay tumour growth in vivo. Thus, AG1024 is able to interfere with three major targets of BCR-ABL in leukaemic cells. Interestingly, Tyrphostin AG1024 was also effective against cells resistant to STI571 by distinct mechanisms including Bcr-Abl mutation. Therefore, these data suggest that Tyrphostin AG1024 could represent the basis of a novel therapy for STI571 refractory CML.
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PMID:Tyrosine kinase inhibitor AG1024 exerts antileukaemic effects on STI571-resistant Bcr-Abl expressing cells and decreases AKT phosphorylation. 1549 18

Chronic myeloid leukemia (CML) is a bi- or triphasic disease. Molecular markers distinct for the phase evolution would be clinically helpful. For signaling transformation and proliferation activities in CML, Bcr-Abl is the pivotal protein. As downstream signals of Bcr-Abl , RAS, PI3-K, and Stat 5 may lead to cell cycle progression mediated by increased expression of cyclin Ds. We analyzed copy numbers of bcr-abl and cyclin D1 transcripts by reverse transcription (RT) and competitive PCR titration in bone marrow cells of 20 patients with CML, 10 in chronic phase (CP) and the other 10 in accelerated phase (AP). The level of bcr-abl transcripts in the AP was not significantly higher than that in the CP; in contrast, the level of cyclin D1 transcripts in the AP was significantly higher than that in the CP (p <0.001). Cyclin D1 RNA expression in the CP of CML was also found to have clinical relevance to time to AP transformation. The median time to AP transformation for the CP patients with cyclin D1 transcripts of 1.50 x 10(4)/microg RNA was significantly shorter than that for those with cyclin D1 transcripts < 1.50 x 10(4)/microg RNA (15 vs. 67 months, p=0.0354) although confirmation to conduct in a larger patient group is required. These results suggest that the expression level of cyclin D1 RNA in bone marrow cells is predictive of the phase evolution in CML and may be helpful in treatment decision-making.
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PMID:Overexpression of cyclin D1 in accelerated-phase chronic myeloid leukemia. 1562 54

Indirubin, an isomer of indigo, is a reported inhibitor of cyclin-dependent kinases (CDKs) and glycogen synthase kinase-3 (GSK-3) as well as an agonist of the aryl hydrocarbon receptor (AhR). Indirubin is the active ingredient of a traditional Chinese medicinal recipe used against chronic myelocytic leukemia. Numerous indirubin analogs have been synthesized to optimize this promising kinase inhibitor scaffold. We report here on the cellular effects of 7-bromoindirubin-3'-oxime (7BIO). In contrast to its 5-bromo- and 6-bromo- isomers, and to indirubin-3'-oxime, 7BIO has only a marginal inhibitory activity towards CDKs and GSK-3. Unexpectedly, 7BIO triggers a rapid cell death process distinct from apoptosis. 7-Bromoindirubin-3'-oxime induces the appearance of large pycnotic nuclei, without classical features of apoptosis such as chromatin condensation and nuclear fragmentation. 7-Bromoindirubin-3'-oxime-induced cell death is not accompanied by cytochrome c release neither by any measurable effector caspase activation. Furthermore, the death process is not altered either by the presence of Q-VD-OPh, a broad-spectrum caspase inhibitor, or the overexpression of Bcl-2 and Bcl-XL proteins. Neither AhR nor p53 is required during 7BIO-induced cell death. Thus, in contrast to previously described indirubins, 7BIO triggers the activation of non-apoptotic cell death, possibly through necroptosis or autophagy. Although their molecular targets remain to be identified, 7-substituted indirubins may constitute a new class of potential antitumor compounds that would retain their activity in cells refractory to apoptosis.
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PMID:7-Bromoindirubin-3'-oxime induces caspase-independent cell death. 1670 56

In traditional Chinese Medicine, the preparation Danggui Longhui Wan has been used for years in the treatment of chronic myelocytic leukemia. The compound indirubin has been shown to be the active constituent. A cell permeable derivative, indirubin-3'-monoxime, is a selective and potent inhibitor of cyclin-dependent kinases (cdk). The ability of indirubin-3'-monoxime to induce apoptosis and tumor cell death in transitional cell cancer cell lines was investigated here. The growth-inhibitory properties were evaluated by EZ4U, a cytotoxic assay; apoptosis induction was determined by immunoblotting of cleaved PARP and flow cytometry of Annexin-V/PI staining during treatment. To evaluate further the underlying molecular action of indirubin-3'-monoxime on the cell cycle, the levels of cdk-1 and survivin, a mitotic spindle checkpoint and apoptosis-regulating protein, respectively, were additionally determined by flow cytometry and immunoblotting. The results indicated that indirubin-3'-monoxime induced reversible growth arrest in all four cell lines and an increase of apoptosis in two of them. The treatment with indirubin-3'-monoxime increased the expression of survivin almost four times in the RT4 cells and more than doubled it in the RT112 and T24 cells. In the SUP cells, the expression of survivin increased more than seven-fold after 72-h incubation. No clear correlation between the low apoptosis induction rate and extent of survivin expression was found. Cdk expression was not significantly altered by indirubin-3'-monoxime. In summary, indirubin-3'-monoxime might be a promising candidate for targeted cancer therapy, however, its molecular action remains to be further evaluated.
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PMID:Indirubin-3'-monoxime, a CDK inhibitor induces growth inhibition and apoptosis-independent up-regulation of survivin in transitional cell cancer. 1682 55

It is now widely recognized that intrinsically unstructured (or disordered) proteins (IUPs or IDPs) are found in organisms from all kingdoms of life. In eukaryotes, IUPs are highly abundant and perform a wide range of biological functions, including regulation and signaling. Despite an increased level of interest in understanding the structural biology of IUPs and IDPs, questions regarding the mechanisms through which disordered proteins perform their biological function(s) remain. In other words, what are the relationships between disorder and function for IUPs? There are several excellent reviews that discuss the structural properties of IUPs and IDPs since 2005 [Receveur-Brechot, V., et al. (2006) Proteins 62, 24-45; Mittag, T., and Forman-Kay, J. D. (2007) Curr. Opin. Struct. Biol. 17, 3-14; Dyson, H. J., and Wright, P. E. (2005) Nat. Rev. Mol. Cell Biol. 6, 197-208]. Here, we briefly review general concepts pertaining to IUPs and then discuss our structural, biophysical, and biochemical studies of two IUPs, p21 and p27, which regulate the mammalian cell division cycle by inhibiting cyclin-dependent kinases (Cdks). Some segments of these two proteins are partially folded in isolation, and they fold further upon binding their biological targets. Interestingly, some portions of p27 remain flexible after binding to and inhibiting the Cdk2-cyclin A complex. This residual flexibility allows otherwise buried tyrosine residues within p27 to be phosphorylated by non-receptor tyrosine kinases (NRTKs). Tyrosine phosphorylation relieves kinase inhibition, triggering Cdk2-mediated phosphorylation of a threonine residue within the flexible C-terminus of p27. This, in turn, marks p27 for ubiquitination and proteasomal degradation, unleashing full Cdk2 activity which drives cell cycle progression. p27, thus, constitutes a conduit for transmission of proliferative signals via post-translational modifications. The term "conduit" is used here to connote a means of transmission of molecular signals which, in the case of p27, correspond to tyrosine and threonine phosphorylation, ubiquitination, and, ultimately, proteolytic degradation. Transmission of these multiple signals is enabled by the inherent flexibility of p27 which persists even after tight binding to the Cdk2-cyclin A complex. Importantly, activation of the p27 signaling conduit by oncogenic NRTKs contributes to tumorigenesis in some human cancers, including chronic myelogenous leukemia (CML) [Grimmler, M., et al. (2007) Cell 128, 269-280] and breast cancer [Chu, I., et al. (2007) Cell 128, 281-294]. Other IUPs may participate in conceptually similar molecular signaling conduits, and dysregulation of these putative conduits may contribute to other human diseases. Detailed study of these IUPs, both alone and within functional complexes, is required to test these hypotheses and to more fully understand the relationships between protein disorder and biological function.
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PMID:Regulation of cell division by intrinsically unstructured proteins: intrinsic flexibility, modularity, and signaling conduits. 1862 25

Indirubin has been identified as a component of a traditional Chinese medicine, Danggui Longhui Wan, which is used for the treatment of chronic myelogenous leukemia. Indirubin inhibits cyclin-dependent kinases (CDKs) and induces cell cycle arrest and apoptosis in cancer cells. Many indirubin derivatives have been studied for their potential anti-solid tumor activity. We have synthesized and evaluated many indirubin derivatives. In order to compare and confirm the potential of our major derivatives as anti-solid tumor agents, we examined their anti-proliferative activity in monolayers, as well as in multicellular spheroids (MCS) cultures of human colorectal cancer cells, DLD-1 and HT-29. The MCS model is an in vitro solid tumor model that is increasingly used for the evaluation of anti-solid tumor activity. 5-nitro-indirubin-3'-oxime (4c) and 5'-bromo-5-nitro-indirubin-3'-oxime (4l), compared to 5-trimethylacetamido-indirubin-3'-oxime (11) and 5-diphenylacetamido-indirubin-3'-oxime (33) showed greater anti-proliferative effects in monolayers, but lower anti-proliferative effects in MCS. Overall, our data suggest that compounds 11 and 33 may exert a significant anti-solid tumor activity via a mechanism other than CDK inhibition, different from that of 4c and 4l. These compounds are worth further investigation with respect to their anti-solid tumor activity and their mechanism of action in various solid tumor models.
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PMID:Anti-tumor activity of noble indirubin derivatives in human solid tumor models in vitro. 1955 70

It is now widely recognized that intrinsically disordered (or unstructured) proteins (IDPs, or IUPs) are found in organisms from all kingdoms of life. In eukaryotes, IDPs are highly abundant and perform a wide range of biological functions, including regulation and signaling. Despite increased interest in understanding the structural biology of IDPs, questions remain regarding the mechanisms through which disordered proteins perform their biological function(s). In other words, what are the relationships between disorder and function for IDPs? Several excellent reviews have recently been published that discuss the structural properties of IDPs.1-3 Here, we discuss two IDP systems which illustrate features of dynamic complexes. In the first section, we discuss two IDPs, p21 and p27, which regulate the mammalian cell division cycle by inhibiting cyclin-dependent kinases (Cdks). In the second section, we discuss recent results from Follis, Hammoudeh, Metallo and coworkers demonstrating that the IDP Myc can be bound and inhibited by small molecules through formation of dynamic complexes. Previous studies have shown that polypeptide segments of p21 and p27 are partially folded in isolation and fold further upon binding their biological targets. Interestingly, some portions of p27 which bind to and inhibit Cdk2/cyclin A remain flexible in the bound complex. This residual flexibility allows otherwise buried tyrosine residues within p27 to be phosphorylated by nonreceptor tyrosine kinases (NRTKs). Tyrosine phosphorylation relieves kinase inhibition, triggering Cdk2-mediated phosphorylation of a threonine residue within the flexible C-terminus of p27. This, in turn, marks p27 for ubiquitination and proteasomal degradation, unleashing full Cdk2 activity which drives cell cycle progression. p27, thus, constitutes a conduit for transmission of proliferative signals via posttranslational modifications. Importantly, activation of the p27 signaling conduit by oncogenic NRTKs contributes to tumorigenesis in some human cancers, including chronic myelogenous leukemia (CML)9 and breast cancer.10 Another IDP with important roles in human cancer is the proto-oncoprotein, Myc. Myc is a DNA binding transcription factor which critically drives cell proliferation in many cell types and is often deregulated in cancer. Myc is intrinsically disordered in isolation and folds upon binding another IDP, Max and DNA. Follis, Hammoudeh, Metallo and coworkers identified small molecules which bind disordered regions of Myc and inhibit its heterodimerization with Max. Importantly, these small molecules- through formation of dynamic complexes with Myc-have been shown to inhibit Myc function in vitro and in cellular assays, opening the door to IDP-targeted therapeutics in the future. The p21/p27 and Myc systems illustrate, from different perspectives, the role of dynamics in IDP function. Dynamic fluctuations are critical for p21/p27 signaling while the dynamic free state of Myc may represent a therapeutically approachable anticancer target. Herein we review the current state of knowledge related to these two topics in IDP research.
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PMID:Intrinsic protein flexibility in regulation of cell proliferation: advantages for signaling and opportunities for novel therapeutics. 2239 17


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