RAS and Leukemia: From Basic Mechanisms to Gene-Directed Therapy

1999 ◽  
Vol 17 (3) ◽  
pp. 1071-1071 ◽  
Author(s):  
Darrin M. Beaupre ◽  
Razelle Kurzrock

PURPOSE AND DESIGN: The purpose of this review is to provide an overview of the literature linking Ras signaling pathways and leukemia and to discuss the biologic and potential therapeutic implications of these observations. A search of MEDLINE from 1966 to October 1998 was performed. RESULTS: A wealth of data has been published on the role of Ras pathways in cancer. To be biologically active, Ras must move from the cytoplasm to the plasma membrane. Importantly, a posttranslational modification—addition of a farnesyl group to the Ras C-terminal cysteine—is a requisite for membrane localization of Ras. Farnesylation of Ras is catalyzed by an enzyme that is designated farnesyltranferase. Recently, several compounds have been developed that can inhibit farnesylation. Preclinical studies indicate that these molecules can suppress transformation and tumor growth in vitro and in animal models, with little toxicity to normal cells. CONCLUSION: An increasing body of data suggests that disruption of Ras signaling pathways, either directly through mutations or indirectly through other genetic aberrations, is important in the pathogenesis of a wide variety of cancers. Molecules such as farnesyl transferase inhibitors that interfere with the function of Ras may be exploitable in leukemia (as well as in solid tumors) as novel antitumor agents.

2004 ◽  
Vol 11 (2) ◽  
pp. 191-205 ◽  
Author(s):  
R M O'Regan ◽  
F R Khuri

The ras family of proto-oncogenes are upstream mediators of several essential cellular signal transduction pathways involved in cell proliferation and survival. Point mutations of ras oncogenes result in constitutively active Ras and have been shown to be oncogenic. However, ras activation can occur in the absence of ras mutations secondary to upstream receptor activation. The first important step in Ras activation is farnesylation by farnesyl transferase, and inhibitors of this enzyme have been demonstrated to inhibit Ras signaling, and have anti-tumor effects. However, it is now clear that farnesyl transferase inhibitors (FTIs) have activity independent of Ras, most likely due to effects on prenylated proteins downstream of Ras, which explains their activity in several malignancies, including breast cancer, where ras mutations are rare. Several FTIs are in clinical development for the treatment of solid tumors. Preclinical evidence suggests that FTIs can inhibit breast cancers in vitro and in vivo, and a phase II trial of the FTI, R115777, in patients with advanced breast cancer produced encouraging results. Based on prior successful outcomes with agents targeting the estrogen and epidermal growth factor receptor pathways in breast cancer, the FTIs, used alone or more likely with other agents, may be the next exciting targeted therapy in breast cancer.


The role of vitamin D is implicated in carcinogenesis through numerous biological processes like induction of apoptosis, modulation of immune system inhibition of inflammation and cell proliferation and promotion of cell differentiation. Its use as additional adjuvant drug with cancer treatment may be novel combination for improved outcome of different cancers. Numerous preclinical, epidemiological and clinical studies support the role of vitamin D as an anticancer agent. Anticancer properties of vitamin D have been studied widely (both in vivo and in vitro) among various cancers and found to have promising results. There are considerable data that indicate synergistic potential of calcitriol and antitumor agents. Possible mechanisms for modulatory anticancer activity of vitamin D include its antiproliferative, prodifferentiating, and anti-angiogenic and apoptic properties. Calcitriol reduces invasiveness and metastatic potential of many cancer cells by inhibiting angiogenesis and regulating expression of the key molecules involved in invasion and metastasis. Anticancer activity of vitamin D is synergistic or additive with the antineoplastic actions of several drugs including cytotoxic chemotherapy agents like paclitaxel, docetaxel, platinum base compounds and mitoxantrone. Benefits of addition of vitamin D should be weighed against the risk of its toxicity.


Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3312
Author(s):  
Matjaž Weiss ◽  
Marko Anderluh ◽  
Martina Gobec

The O-GlcNAcylation is a posttranslational modification of proteins regulated by O-GlcNAc transferase (OGT) and O-GlcNAcase. These enzymes regulate the development, proliferation and function of cells, including the immune cells. Herein, we focused on the role of O-GlcNAcylation in human monocyte derived dendritic cells (moDCs). Our study suggests that inhibition of OGT modulates AKT and MEK/ERK pathways in moDCs. Changes were also observed in the expression levels of relevant surface markers, where reduced expression of CD80 and DC-SIGN, and increased expression of CD14, CD86 and HLA-DR occurred. We also noticed decreased IL-10 and increased IL-6 production, along with diminished endocytotic capacity of the cells, indicating that inhibition of O-GlcNAcylation hampers the transition of monocytes into immature DCs. Furthermore, the inhibition of OGT altered the maturation process of immature moDCs, since a CD14medDC-SIGNlowHLA-DRmedCD80lowCD86high profile was noticed when OGT inhibitor, OSMI-1, was present. To evaluate DCs ability to influence T cell differentiation and polarization, we co-cultured these cells. Surprisingly, the observed phenotypic changes of mature moDCs generated in the presence of OSMI-1 led to an increased proliferation of allogeneic T cells, while their polarization was not affected. Taken together, we confirm that shifting the O-GlcNAcylation status due to OGT inhibition alters the differentiation and function of moDCs in in vitro conditions.


2014 ◽  
Vol 10 (7) ◽  
pp. 1881-1889 ◽  
Author(s):  
Sarah Schwartz Baxter ◽  
Christopher F. Dibble ◽  
Warren C. Byrd ◽  
Jim Carlson ◽  
Charles Russell Mack ◽  
...  

Anin vitroproteomics and systems biology of cerebral cavernous malformation.


2021 ◽  
Vol 28 ◽  
Author(s):  
Lucia M. Balsa ◽  
Enrique J. Baran ◽  
Ignacio E. León

: Copper is an essential element for most aerobic organisms, with an important function as a structural and catalytic cofactor, and in consequence, it is implicated in several biological actions. The relevant aspects of chemistry and biochemistry and the importance of copper compounds in medicine give us a comprehensive knowledge of the multifaceted applications of copper in physiology and physiopathology. In this review, we present an outline of the chemistry and the antitumor properties of copper complexes on breast, colon, and lung cancer cells focus on the role of copper in cancer, the relationship between structure-activity, molecular targets, and the study of the mechanism of action involved in its anticancer activity. This overview is expected to contribute to understanding the design, synthesis, uses of copper complexes as antitumor agents in the most common cancers.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Brianna J. Klein ◽  
Suk Min Jang ◽  
Catherine Lachance ◽  
Wenyi Mi ◽  
Jie Lyu ◽  
...  

Abstract Acetylation of histone H3K23 has emerged as an essential posttranslational modification associated with cancer and learning and memory impairment, yet our understanding of this epigenetic mark remains insufficient. Here, we identify the native MORF complex as a histone H3K23-specific acetyltransferase and elucidate its mechanism of action. The acetyltransferase function of the catalytic MORF subunit is positively regulated by the DPF domain of MORF (MORFDPF). The crystal structure of MORFDPF in complex with crotonylated H3K14 peptide provides mechanistic insight into selectivity of this epigenetic reader and its ability to recognize both histone and DNA. ChIP data reveal the role of MORFDPF in MORF-dependent H3K23 acetylation of target genes. Mass spectrometry, biochemical and genomic analyses show co-existence of the H3K23ac and H3K14ac modifications in vitro and co-occupancy of the MORF complex, H3K23ac, and H3K14ac at specific loci in vivo. Our findings suggest a model in which interaction of MORFDPF with acylated H3K14 promotes acetylation of H3K23 by the native MORF complex to activate transcription.


2005 ◽  
Vol 51 (12) ◽  
pp. 2348-2353 ◽  
Author(s):  
Markus Herrmann ◽  
Thomas Widmann ◽  
Graziana Colaianni ◽  
Silvia Colucci ◽  
Alberta Zallone ◽  
...  

Abstract Background: Increased plasma homocysteine (HCY) may be an independent risk factor for osteoporotic fractures and therefore may also adversely affect bone metabolism. We analyzed the effect of HCY on human osteoclast (OC) activity. Methods: We cultured peripheral blood mononuclear cells from 17 healthy male donors [median (SD) age, 30 (5) years] for 20 days with 25 μg/L macrophage-colony-stimulating factor (days 0–11), 20 μg/L receptor-activator of nuclear factor-κB ligand (days 6–20), and 4 different concentrations of HCY (0, 10, 50, and 100 μmol/L; days 0–20). For control purposes, cysteine and glutathione were tested in equimolar concentrations. OCs were identified as large, multinucleated cells with tartrate-resistant acid phosphatase (TRAP) activity and surface vitronectin receptors. We quantified OC activity by measuring TRAP activity. We analyzed cathepsin K (CP-K) activity in 9 donor samples and estimated the dentine-resorbing activity on standard dentine slices in 3 samples. Results: After 20 days of culture, most cells were fully differentiated OCs. TRAP activity increased with increasing HCY concentrations (P <0.001). HCY concentrations of 10, 50, and 100 μmol/L stimulated TRAP activity by 20%, 15%, and 42%. Additionally, HCY stimulated CP-K activity (P = 0.005): in the presence of 100 μmol/L HCY, CP-K activity was ∼38% higher than in controls (P = 0.002). Bone-resorbing activity was significantly increased in cultures with 50 and 100 μmol/L HCY. Cysteine and glutathione significantly decreased TRAP and CP-K activity. Conclusions: Increased HCY concentrations specifically stimulate OC activity in vitro, suggesting a mechanistic role of HCY for bone resorption. Future studies clarifying the mechanistic role of increased HCY concentrations in osteoporosis could have interesting therapeutic implications.


2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Hong-li Jiao ◽  
Bin-shu Weng ◽  
Shan-shan Yan ◽  
Zi-mo Lin ◽  
Shu-yang Wang ◽  
...  

AbstractOxysterol-binding protein like protein 3 (OSBPL3) has been shown involving in the development of several human cancers. However, the relationship between OSBPL3 and colorectal cancer (CRC), particularly the role of OSBPL3 in the proliferation, invasion and metastasis of CRC remains unclear. In this study, we investigated the role of OSBPL3 in CRC and found that its expression was significantly higher in CRC tissues than that in normal tissues. In addition, high expression of OSBPL3 was closely related to poor differentiation, advanced TNM stage and poor prognosis of CRC. Further experiments showed that over-expression of OSBPL3 promoted the proliferation, invasion and metastasis of CRC in vitro and in vivo models. Moreover, we revealed that OSBPL3 promoted CRC progression through activation of RAS signaling pathway. Furthermore, we demonstrated that hypoxia induced factor 1 (HIF-1A) can regulate the expression of OSBPL3 via binding to the hypoxia response element (HRE) in the promoter of OSBPL3. In summary, Upregulation of OSBPL3 by HIF1A promotes colorectal cancer progression through activation of RAS signaling pathway. This novel mechanism provides a comprehensive understanding of both OSBPL3 and the RAS signaling pathway in the progression of CRC and indicates that the HIF1A–OSBPL3–RAS axis is a potential target for early therapeutic intervention in CRC progression.


Author(s):  
Hongfang Wang ◽  
Jinlian Fu ◽  
Aiguo Wang

Obesity has become a global health problem. Research suggests that leptin, a hormone that responds to fat deposition, may be involved in mammalian reproduction; however, its precise role in embryo implantation is poorly understood. Here, primary porcine endometrium epithelium cells (PEECs) were cultured in vitro and used to evaluate the regulatory role of different leptin levels on β3-integrin, MMP9, HB-EGF, and IL-1β, which are, respectively, involved in four critical steps of embryo implantation. Results showed that only 0.01 nM leptin significantly improved β3-integrin mRNA expression (p < 0.05). MMP9 and HB-EGF mRNA expressions were upregulated by 0.10–10.00 nM leptin (p < 0.05). The IL-1β expression level was only increased by 10.00 nM leptin (p < 0.05). β3-integrin, MMP9, HB-EGF, and IL-1β mRNA and protein have a similar fluctuant response to increased leptin. Leptin’s influence on β3-integrin, MMP9, HB-EGF, and IL-1β disappeared when the JAK2, PI(3)K, or MAPK signaling pathways were blocked, respectively. In conclusion, leptin affected porcine implantation by regulating the expression of β3-integrin, MMP9, HB-EGF, and IL-1β in a dose-dependent manner. The signaling pathways of JAK2, PI(3)K, and MAPK may participate in this regulatory process. These findings will contribute to further understanding the mechanisms of reproductive disorders in obesity.


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