scholarly journals Mouse models for BRAF-induced cancers

2007 ◽  
Vol 35 (5) ◽  
pp. 1329-1333 ◽  
Author(s):  
C. Pritchard ◽  
L. Carragher ◽  
V. Aldridge ◽  
S. Giblett ◽  
H. Jin ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Mouse Models ◽  
Human Cancer ◽  
Cre Recombinase ◽  
Genetically Engineered ◽  
Mitogen Activated Protein Kinase ◽  
Braf Mutations ◽  
Single Nucleotide Change

Oncogenic mutations in the BRAF gene are detected in ∼7% of human cancer samples with a particularly high frequency of mutation in malignant melanomas. Over 40 different missense BRAF mutations have been found, but the vast majority (>90%) represent a single nucleotide change resulting in a valine→glutamate mutation at residue 600 (V600EBRAF). In cells cultured in vitro, V600EBRAF is able to stimulate endogenous MEK [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase] and ERK phosphorylation leading to an increase in cell proliferation, cell survival, transformation, tumorigenicity, invasion and vascular development. Many of these hallmarks of cancer can be reversed by treatment of cells with siRNA (small interfering RNA) to BRAF or by inhibiting MEK, indicating that BRAF and MEK are attractive therapeutic targets in cancer samples with BRAF mutations. In order to fully understand the role of oncogenic BRAF in cancer development in vivo as well as to test the in vivo efficacy of anti-BRAF or anti-MEK therapies, GEMMs (genetically engineered mouse models) have been generated in which expression of oncogenic BRaf is conditionally dependent on the Cre recombinase. The delivery/activation of the Cre recombinase can be regulated in both a temporal and spatial manner and therefore these mouse models can be used to recapitulate the somatic mutation of BRAF that occurs in different tissues in the development of human cancer. The data so far obtained following Cre-mediated activation in haemopoietic tissue and the lung indicate that V600EBRAF mutation can drive tumour initiation and that its primary effect is to induce high levels of cyclin D1-mediated cell proliferation. However, hallmarks of OIS (oncogene-induced senescence) are evident that restrain further development of the tumour.

scholarly journals Actions and Potential Therapeutic Applications of Growth Hormone–Releasing Hormone Agonists

Endocrinology ◽  
2019 ◽  
Vol 160 (7) ◽  
pp. 1600-1612 ◽  
Author(s):  
Andrew V Schally ◽  
Xianyang Zhang ◽  
Renzhi Cai ◽  
Joshua M Hare ◽  
Riccarda Granata ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cardiac Tissue ◽  
Human Cancer ◽  
Large Body ◽  
Neuroprotective Effects ◽  
Promote Cell Proliferation ◽  
Therapeutic Applications ◽  
Human Cancer Cells

Abstract In this article, we briefly review the identification of GHRH, provide an abridged overview of GHRH antagonists, and focus on studies with GHRH agonists. Potent GHRH agonists of JI and MR class were synthesized and evaluated biologically. Besides the induction of the release of pituitary GH, GHRH analogs promote cell proliferation and exert stimulatory effects on various tissues, which express GHRH receptors (GHRH-Rs). A large body of work shows that GHRH agonists, such as MR-409, improve pancreatic β-cell proliferation and metabolic functions and facilitate engraftment of islets after transplantation in rodents. Accordingly, GHRH agonists offer a new therapeutic approach to treating diabetes. Various studies demonstrate that GHRH agonists promote repair of cardiac tissue, producing improvement of ejection fraction and reduction of infarct size in rats, reduction of infarct scar in swine, and attenuation of cardiac hypertrophy in mice, suggesting clinical applications. The presence of GHRH-Rs in ocular tissues and neuroprotective effects of GHRH analogs in experimental diabetic retinopathy indicates their possible therapeutic applications for eye diseases. Other effects of GHRH agonists, include acceleration of wound healing, activation of immune cells, and action on the central nervous system. As GHRH might function as a growth factor, we examined effects of GHRH agonists on tumors. In vitro, GHRH agonists stimulate growth of human cancer cells and upregulate GHRH-Rs. However, in vivo, GHRH agonists inhibit growth of human cancers xenografted into nude mice and downregulate pituitary and tumoral GHRH-Rs. Therapeutic applications of GHRH analogs are discussed. The development of GHRH analogs should lead to their clinical use.

scholarly journals How Genetically Engineered Mouse Tumor Models Provide Insights Into Human Cancers

2011 ◽  
Vol 29 (16) ◽  
pp. 2273-2281 ◽  
Author(s):  
Katerina Politi ◽  
William Pao
Keyword(s):  
Mouse Models ◽  
Cancer Biology ◽  
Human Cancer ◽  
Genetically Engineered ◽  
Mouse Tumor ◽  
Tumor Models ◽  
Genetically Engineered Mouse Models ◽  
Human Cancers ◽  
Chemically Induced

Genetically engineered mouse models (GEMMs) of human cancer were first created nearly 30 years ago. These early transgenic models demonstrated that mouse cells could be transformed in vivo by expression of an oncogene. A new field emerged, dedicated to generating and using mouse models of human cancer to address a wide variety of questions in cancer biology. The aim of this review is to highlight the contributions of mouse models to the diagnosis and treatment of human cancers. Because of the breadth of the topic, we have selected representative examples of how GEMMs are clinically relevant rather than provided an exhaustive list of experiments. Today, as detailed here, sophisticated mouse models are being created to study many aspects of cancer biology, including but not limited to mechanisms of sensitivity and resistance to drug treatment, oncogene cooperation, early detection, and metastasis. Alternatives to GEMMs, such as chemically induced or spontaneous tumor models, are not discussed in this review.

scholarly journals Laboratory Mice – A Driving Force in Immunopathology and Immunotherapy Studies of Human Multiple Myeloma

2021 ◽  
Vol 12 ◽  
Author(s):  
Michael Pisano ◽  
Yan Cheng ◽  
Fumou Sun ◽  
Binod Dhakal ◽  
Anita D’Souza ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Mouse Models ◽  
Plasma Cell ◽  
Plasma Cells ◽  
De Novo ◽  
Human Cancer ◽  
Tumor Development ◽  
Adaptive Immune Response ◽  
Genetically Engineered

Mouse models of human cancer provide an important research tool for elucidating the natural history of neoplastic growth and developing new treatment and prevention approaches. This is particularly true for multiple myeloma (MM), a common and largely incurable neoplasm of post-germinal center, immunoglobulin-producing B lymphocytes, called plasma cells, that reside in the hematopoietic bone marrow (BM) and cause osteolytic lesions and kidney failure among other forms of end-organ damage. The most widely used mouse models used to aid drug and immunotherapy development rely on in vivo propagation of human myeloma cells in immunodeficient hosts (xenografting) or myeloma-like mouse plasma cells in immunocompetent hosts (autografting). Both strategies have made and continue to make valuable contributions to preclinical myeloma, including immune research, yet are ill-suited for studies on tumor development (oncogenesis). Genetically engineered mouse models (GEMMs), such as the widely known Vκ*MYC, may overcome this shortcoming because plasma cell tumors (PCTs) develop de novo (spontaneously) in a highly predictable fashion and accurately recapitulate many hallmarks of human myeloma. Moreover, PCTs arise in an intact organism able to mount a complete innate and adaptive immune response and tumor development reproduces the natural course of human myelomagenesis, beginning with monoclonal gammopathy of undetermined significance (MGUS), progressing to smoldering myeloma (SMM), and eventually transitioning to frank neoplasia. Here we review the utility of transplantation-based and transgenic mouse models of human MM for research on immunopathology and -therapy of plasma cell malignancies, discuss strengths and weaknesses of different experimental approaches, and outline opportunities for closing knowledge gaps, improving the outcome of patients with myeloma, and working towards a cure.

Targeting GCK pathway: a novel and selective therapeutic strategy against RAS mutated multiple myeloma

Blood ◽  
2020 ◽  
Author(s):  
Shirong Li ◽  
Jing Fu ◽  
Jun Yang ◽  
Huihui Ma ◽  
Divaya Bhutani ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Proliferation ◽  
Growth Inhibition ◽  
Alternative Therapy ◽  
Braf Mutations ◽  
Ras Mutation ◽  
Ras Mutations ◽  
Cell Proliferation Inhibition

In multiple myeloma (MM), frequent mutations of NRAS, KRAS, or BRAF are found in up to 50% of newly diagnosed patients. The majority of the NRAS, KRAS, and BRAF mutations occur in hotspots causing constitutive activation of the corresponding proteins. Thus targeting RAS mutation in MM will increase therapeutic efficiency and potentially overcome drug-resistance. We identified Germinal Center Kinase (GCK) as a novel therapeutic target in MM with RAS mutation. GCK knockdown in MM cells demonstrated in vitro and in vivo that silencing of GCK induces MM cell growth inhibition, associated with blocked MKK4/7-JNK phosphorylation and impaired degradation of IKZF1/3, BCL-6, and c-MYC. These effects were rescued by overexpression of an shRNA-resistant GCK, thereby excluding the potential off-target effects of GCK knockdown. In contrast, overexpression of shRNA-resistant GCK kinase-dead mutant (K45A) inhibited MM cell proliferation and failed to rescue the effects of GCK knockdown on MM growth inhibition, indicating that GCK kinase activity is critical for regulating MM cell proliferation and survival. Importantly, the higher sensitivity to GCK knockdown in RASMut cells suggests that targeting GCK is effective in multiple myeloma which harbors RAS mutations. In accordance with the effects of GCK knockdown, the GCK inhibitor TL4-12 dose-dependently downregulated IKZF1 and BCL-6 and led to MM cell proliferation inhibition accompanied by induction of apoptosis. Hereby our data identify GCK as a novel target in RASMut MM cells, providing a rationale to treat RAS mutations in MM. Furthermore, GCK inhibitors might represent an alternative therapy to overcome IMiD-resistance in MM.

scholarly journals HOTAIR contributes to cell proliferation and metastasis of cervical cancer via targetting miR-23b/MAPK1 axis

2018 ◽  
Vol 38 (1) ◽  
Author(s):  
Qin Li ◽  
Yanhong Feng ◽  
Xu Chao ◽  
Shuai Shi ◽  
Man Liang ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cell Proliferation ◽  
Cancer Cells ◽  
Mitogen Activated Protein Kinase ◽  
Cancer Tissue ◽  
Tissue Samples ◽  
Downstream Target ◽  
Cervical Cancer Cells

The long non-coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR) has been found to be overexpressed in many human malignancies and involved in tumor progression and metastasis. Although the downstream target through which HOTAIR modulates tumor metastasis is not well-known, evidence suggests that miR-23b might be involved in this event. In the present study, the expressions of HOTAIR and miR-23b were detected by real-time PCR in 33 paired cervical cancer tissue samples and cervical cell lines. The effects of HOTAIR on the expressions of miR-23b and mitogen-activated protein kinase 1 (MAPK1) were studied by overexpression and RNAi approaches. We found that HOTAIR expression was significantly increased in cervical cancer cells and tissues. In contrast, the expression of miR-23b was obviously decreased. We further demonstrated that HOTAIR knockdown promoted apoptosis and inhibited cell proliferation and invasion in vitro and in vivo. Moreover, our data indicated that HOTAIR may competitively bind miR-23b and modulate the expression of MAPK1 indirectly in cervical cancer cells. Taken together, our study has identified a novel pathway through which HOTAIR exerts its oncogenic role, and provided a molecular basis for potential applications of HOTAIR in the prognosis and treatment of cervical cancer.

scholarly journals Imaging Metformin Efficacy as Add-On Therapy in Cells and Mouse Models of Human EGFR Glioblastoma

2021 ◽  
Vol 11 ◽  
Author(s):  
Silvia Valtorta ◽  
Alessia Lo Dico ◽  
Isabella Raccagni ◽  
Cristina Martelli ◽  
Valentina Pieri ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Mouse Models ◽  
Molecular Subtype ◽  
Combined Treatment ◽  
Response To Therapy ◽  
Translocator Protein ◽  
Common Mechanism ◽  
Duration Of Treatment

Glioblastoma (GBM) is a highly aggressive tumor of the brain. Despite the efforts, response to current therapies is poor and 2-years survival rate ranging from 6-12%. Here, we evaluated the preclinical efficacy of Metformin (MET) as add-on therapy to Temozolomide (TMZ) and the ability of [18F]FLT (activity of thymidine kinase 1 related to cell proliferation) and [18F]VC701 (translocator protein, TSPO) Positron Emission Tomography (PET) radiotracers to predict tumor response to therapy. Indeed, TSPO is expressed on the outer mitochondrial membrane of activated microglia/macrophages, tumor cells, astrocytes and endothelial cells. TMZ-sensitive (Gli36ΔEGFR-1 and L0627) or -resistant (Gli36ΔEGFR-2) GBM cell lines representative of classical molecular subtype were tested in vitro and in vivo in orthotopic mouse models. Our results indicate that in vitro, MET increased the efficacy of TMZ on TMZ-sensitive and on TMZ-resistant cells by deregulating the balance between pro-survival (bcl2) and pro-apoptotic (bax/bad) Bcl-family members and promoting early apoptosis in both Gli36ΔEGFR-1 and Gli36ΔEGFR-2 cells. In vivo, MET add-on significantly extended the median survival of tumor-bearing mice compared to TMZ-treated ones and reduced the rate of recurrence in the TMZ-sensitive models. PET studies with the cell proliferation radiopharmaceutical [18F]FLT performed at early time during treatment were able to distinguish responder from non-responder to TMZ but not to predict the duration of the effect. On the contrary, [18F]VC701 uptake was reduced only in mice treated with MET plus TMZ and levels of uptake negatively correlated with animals’ survival. Overall, our data showed that MET addition improved TMZ efficacy in GBM preclinical models representative of classical molecular subtype increasing survival time and reducing tumor relapsing rate. Finally, results from PET imaging suggest that the reduction of cell proliferation represents a common mechanism of TMZ and combined treatment, whereas only the last was able to reduce TSPO. This reduction was associated with the duration of treatment response. TSPO-ligand may be used as a complementary molecular imaging marker to predict tumor microenvironment related treatment effects.

scholarly journals HOX Antisense lincRNA HOXA-AS2 Promotes Tumorigenesis of Hepatocellular Carcinoma

2016 ◽  
Vol 40 (1-2) ◽  
pp. 287-296 ◽  
Author(s):  
Fuqiang Wang ◽  
Huili Yang ◽  
Zhigang Deng ◽  
Yongjie Su ◽  
QinLiang Fang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Proliferation ◽  
Biological Function ◽  
Human Cancer ◽  
Rank Test ◽  
Advanced Tumor Stage ◽  
Advanced Tumor ◽  
Hcc Cells

Background: Recent studies reveal that long non-coding RNAs (LncRNAs) play critical roles in the proliferation and migration of human cancer. Previous report has shown that LncRNA HOXA-AS2 was involved in carcinoma processes. However, the expression and biological function of HOXA-AS2 in hepatocellular carcinoma (HCC) are poorly understood. Methods: Quantitative real-time PCR (qRT-PCR) was performed to detect the expression of HOXA-AS2 in HCC tissues and cell lines. The relation between lncRNA HOXA-AS2 expression and clinicopathological characteristics was assessed by chi-square test. The prognosis was analyzed using Kaplan-Meier method, and compared differences between the two groups by log-rank test. The biological function of HOXA-AS2 on HCC cells were determined both in vitro and in vivo. Results: In the present study, we found that HOXA-AS2 expression was increased in HCC tissues and adjacent normal tissues and high HOXA-AS2 expression was associated with bigger tumor size, advanced tumor stage, and shorter survival time. Knockdown of HOXA-AS2 significantly inhibited HCC cell proliferation and invasion and resulted in an increase of apoptosis. Furthermore, inhibition of HOXA-AS2 in HCC cells significantly repressed tumorigenicity in nude mice. Conclusion: Our results indicated that the inhibition of HOXA-AS2 in HCC cells significantly inhibited cell proliferation in vitro and in vivo, which might provide a potential possibility for targeted therapy of HCC.

scholarly journals An Engineered Arginase FC Protein Inhibits Tumor GrowthIn VitroandIn Vivo

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Lihua Li ◽  
Yan Wang ◽  
Jun Chen ◽  
Bi Cheng ◽  
Jiehua Hu ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Proliferation ◽  
Amino Acid ◽  
Fusion Protein ◽  
Genetically Engineered ◽  
Arginine Deiminase ◽  
Cellular Migration ◽  
Fc Fusion Protein

Arginine is a semiessential amino acid required for the growth of melanoma and hepatocellular carcinoma, and the enzymatic removal of arginine by pegylated arginine deiminase (ADI) or arginase is being tested clinically. Here, we report a genetically engineered arginase FC fusion protein exhibiting a prolonged half-life and enhanced efficacy. The use of this enzyme to treat different tumor lines both inhibited cell proliferation and impaired cellular migrationin vitroandin vivo. Our data reinforce the hypothesis that nutritional depletion is a key strategy for cancer treatment.

scholarly journals Molecular imaging of nuclear factor-Y transcriptional activity maps proliferation sites in live animals

2012 ◽  
Vol 23 (8) ◽  
pp. 1467-1474 ◽  
Author(s):  
Frauke Goeman ◽  
Isabella Manni ◽  
Simona Artuso ◽  
Balaji Ramachandran ◽  
Gabriele Toietta ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Genetically Engineered ◽  
Hepatocyte Proliferation ◽  
Luciferase Expression ◽  
Nuclear Factor ◽  
Proliferating Cells ◽  
Nuclear Factor Y ◽  
Reporter Mice

In vivo imaging involving the use of genetically engineered animals is an innovative powerful tool for the noninvasive assessment of the molecular and cellular events that are often targets of therapy. On the basis of the knowledge that the activity of the nuclear factor-Y (NF-Y) transcription factor is restricted in vitro to proliferating cells, we have generated a transgenic reporter mouse, called MITO-Luc (for mitosis-luciferase), in which an NF-Y–dependent promoter controls luciferase expression. In these mice, bioluminescence imaging of NF-Y activity visualizes areas of physiological cell proliferation and regeneration during response to injury. Using this tool, we highlight for the first time a role of NF-Y activity on hepatocyte proliferation during liver regeneration. MITO-Luc reporter mice should facilitate investigations into the involvement of genes in cell proliferation and provide a useful model for studying aberrant proliferation in disease pathogenesis. They should be also useful in the development of new anti/proproliferative drugs and assessment of their efficacy and side effects on nontarget tissues.

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