scholarly journals A drug targeting only p110α can block phosphoinositide 3-kinase signalling and tumour growth in certain cell types

2011 ◽  
Vol 438 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Stephen Jamieson ◽  
Jack U. Flanagan ◽  
Sharada Kolekar ◽  
Christina Buchanan ◽  
Jackie D. Kendall ◽  
...  
Keyword(s):  
Growth Factor ◽  
Cell Lines ◽  
Tumour Growth ◽  
Insulin Signalling ◽  
Cell Types ◽  
Genetic Alterations ◽  
Growth Factor Signalling ◽  
Phosphoinositide 3 Kinase ◽  
Responsive Cell

Genetic alterations in PI3K (phosphoinositide 3-kinase) signalling are common in cancer and include deletions in PTEN (phosphatase and tensin homologue deleted on chromosome 10), amplifications of PIK3CA and mutations in two distinct regions of the PIK3CA gene. This suggests drugs targeting PI3K, and p110α in particular, might be useful in treating cancers. Broad-spectrum inhibition of PI3K is effective in preventing growth factor signalling and tumour growth, but suitable inhibitors of p110α have not been available to study the effects of inhibiting this isoform alone. In the present study we characterize a novel small molecule, A66, showing the S-enantiomer to be a highly specific and selective p110α inhibitor. Using molecular modelling and biochemical studies, we explain the basis of this selectivity. Using a panel of isoform-selective inhibitors, we show that insulin signalling to Akt/PKB (protein kinase B) is attenuated by the additive effects of inhibiting p110α/p110β/p110δ in all cell lines tested. However, inhibition of p110α alone was sufficient to block insulin signalling to Akt/PKB in certain cell lines. The responsive cell lines all harboured H1047R mutations in PIK3CA and have high levels of p110α and class-Ia PI3K activity. This may explain the increased sensitivity of these cells to p110α inhibitors. We assessed the activation of Akt/PKB and tumour growth in xenograft models and found that tumours derived from two of the responsive cell lines were also responsive to A66 in vivo. These results show that inhibition of p110α alone has the potential to block growth factor signalling and reduce growth in a subset of tumours.

scholarly journals Receptor tyrosine kinases modulate distinct transcriptional programs by differential usage of intracellular pathways

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Harish N Vasudevan ◽  
Pierre Mazot ◽  
Fenglei He ◽  
Philippe Soriano
Keyword(s):  
Growth Factor ◽  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Transcriptional Response ◽  
Cell Types ◽  
Early Gene ◽  
Late Response ◽  
Intracellular Pathways ◽  
Phosphoinositide 3 Kinase

Receptor tyrosine kinases (RTKs) signal through shared intracellular pathways yet mediate distinct outcomes across many cell types. To investigate the mechanisms underlying RTK specificity in craniofacial development, we performed RNA-seq to delineate the transcriptional response to platelet-derived growth factor (PDGF) and fibroblast growth factor (FGF) signaling in mouse embryonic palatal mesenchyme cells. While the early gene expression profile induced by both growth factors is qualitatively similar, the late response is divergent. Comparing the effect of MEK (Mitogen/Extracellular signal-regulated kinase) and PI3K (phosphoinositide-3-kinase) inhibition, we find the FGF response is MEK dependent, while the PDGF response is PI3K dependent. Furthermore, FGF promotes proliferation but PDGF favors differentiation. Finally, we demonstrate overlapping domains of PDGF-PI3K signaling and osteoblast differentiation in the palate and increased osteogenesis in FGF mutants, indicating this differentiation circuit is conserved in vivo. Our results identify distinct responses to PDGF and FGF and provide insight into the mechanisms encoding RTK specificity.

Preclinical Quantification of Prostate Cancer-Associated Vascular Alterations in the Bone Microenvironment in vivo

2020 ◽  
Vol 61 (6) ◽  
pp. 188-200
Author(s):  
Malte Schroeder ◽  
Lennart Viezens ◽  
Jördis Sündermann ◽  
Svenja Hettenhausen ◽  
Gerrit Hauenherm ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Blood Flow ◽  
Flow Velocity ◽  
Cell Lines ◽  
Blood Flow Velocity ◽  
Tumour Growth ◽  
Prostate Cancer Cell ◽  
Bone Microenvironment ◽  
Prostate Cancer Cell Lines

Introduction: Prostate cancer has a special predilection to form bone metastases. Despite the known impact of the microvascular network on tumour growth and its dependence on the organ-specific microenvironment, the characteristics of the tumour vasculature in bone remain unknown. Methods: The cell lines LNCaP, DU145, and PC3 were implanted into the femurs of NSG mice to examine the microvascular properties of prostate cancer in bone. Tumour growth and the functional and morphological alterations of the microvasculature were analysed for 21 days in vivo using a transparent bone chamber and fluorescence microscopy. Results: Vascular density was significantly lower in tumour-bearing bone than in non-tumour-bearing bone, with a marked loss of small vessels. Accelerated blood flow velocity led to increased volumetric blood flow per vessel, but overall perfusion was not affected. All of the prostate cancer cell lines had similar vascular patterns, with more pronounced alterations in rapidly growing tumours. Despite minor differences between the prostate cancer cell lines associated with individual growth behaviours, the same overall pattern was observed and showed strong similarity to that of tumours growing in soft tissue. Discussion: The increase in blood flow velocity could be a specific characteristic of prostate cancer or the bone microenvironment.

scholarly journals Infection, dissemination, and transmission efficiencies of Zika virus in Aedes aegypti after serial passage in mosquito or mammalian cell lines or alternating passage in both cell types

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Lourdes G. Talavera-Aguilar ◽  
Reyes A. Murrieta ◽  
Sungmin Kiem ◽  
Rosa C. Cetina-Trejo ◽  
Carlos M. Baak-Baak ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Cell Lines ◽  
Zika Virus ◽  
Cell Types ◽  
Mosquito Cell ◽  
Cell Passage ◽  
Genetic Changes ◽  
Synonymous Substitutions ◽  
Vertebrate Cell

Abstract Background Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) with an urban transmission cycle that primarily involves humans and Aedes aegypti. Evidence suggests that the evolution of some arboviruses is constrained by their dependency on alternating between disparate (vertebrate and invertebrate) hosts. The goals of this study are to compare the genetic changes that occur in ZIKV after serial passaging in mosquito or vertebrate cell lines or alternate passaging in both cell types and to compare the replication, dissemination, and transmission efficiencies of the cell culture-derived viruses in Ae. aegypti. Methods An isolate of ZIKV originally acquired from a febrile patient in Yucatan, Mexico, was serially passaged six times in African green monkey kidney (Vero) cells or Aedes albopictus (C6/36) cells or both cell types by alternating passage. A colony of Ae. aegypti from Yucatan was established, and mosquitoes were challenged with the cell-adapted viruses. Midguts, Malpighian tubules, ovaries, salivary glands, wings/legs and saliva were collected at various times after challenge and tested for evidence of virus infection. Results Genome sequencing revealed the presence of two non-synonymous substitutions in the premembrane and NS1 regions of the mosquito cell-adapted virus and two non-synonymous substitutions in the capsid and NS2A regions of both the vertebrate cell-adapted and alternate-passaged viruses. Additional genetic changes were identified by intrahost variant frequency analysis. Virus maintained by continuous C6/36 cell passage was significantly more infectious in Ae. aegypti than viruses maintained by alternating passage and consecutive Vero cell passage. Conclusions Mosquito cell-adapted ZIKV displayed greater in vivo fitness in Ae. aegypti compared to the other viruses, indicating that obligate cycling between disparate hosts carries a fitness cost. These data increase our understanding of the factors that drive ZIKV adaptation and evolution and underscore the important need to consider the in vivo passage histories of flaviviruses to be evaluated in vector competence studies. Graphic abstract "Image missing"

scholarly journals Comparison of growth factor signalling pathway utilisation in cultured normal melanocytes and melanoma cell lines

BMC Cancer ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Ji Eun Kim ◽  
Clare Stones ◽  
Wayne R Joseph ◽  
Euphemia Leung ◽  
Graeme J Finlay ◽  
...  
Keyword(s):  
Growth Factor ◽  
Cell Lines ◽  
Melanoma Cell ◽  
Signalling Pathway ◽  
Growth Factor Signalling ◽  
Melanoma Cell Lines ◽  
Growth Factor Signalling Pathway

scholarly journals Exosomal lncRNA PVT1/VEGFA Axis Promotes Colon Cancer Metastasis and Stemness by Downregulation of Tumor Suppressor miR-152-3p

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Shiue-Wei Lai ◽  
Ming-Yao Chen ◽  
Oluwaseun Adebayo Bamodu ◽  
Ming-Shou Hsieh ◽  
Ting-Yi Huang ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Growth Factor ◽  
Cell Lines ◽  
Distant Metastasis ◽  
Cancer Metastasis ◽  
Lovo Cell ◽  
Promoting Effect ◽  
Colon Cancer Metastasis

Background. Treating advanced colon cancer remains challenging in clinical settings because of the development of drug resistance and distant metastasis. Mechanisms underlying the metastasis of colon cancer are complex and unclear. Methods. Computational analysis was performed to determine genes associated with the exosomal long noncoding (lncRNA) plasmacytoma variant translocation 1 (PVT1)/vascular endothelial growth factor A (VEGFA) axis in patients with colon cancer. The biological importance of the exosomal lncRNA PVT1/VEGFA axis was examined in vitro by using HCT116 and LoVo cell lines and in vivo by using a patient-derived xenograft (PDX) mouse model through knockdown (by silencing of PVT1) and overexpression (by adding serum exosomes isolated from patients with distant metastasis (M-exo)). Results. The in silico analysis demonstrated that PVT1 overexpression was associated with poor prognosis and increased expression of metastatic markers such as VEGFA and epidermal growth factor receptor (EGFR). This finding was further validated in a small cohort of patients with colon cancer in whom increased PVT1 expression was correlated with colon cancer incidence, disease recurrence, and distant metastasis. M-exo were enriched with PVT1 and VEGFA, and both migratory and invasive abilities of colon cancer cell lines increased when they were cocultured with M-exo. The metastasis-promoting effect was accompanied by increased expression of Twist1, vimentin, and MMP2. M-exo promoted metastasis in PDX mice. In vitro silencing of PVT1 reduced colon tumorigenic properties including migratory, invasive, colony forming, and tumorsphere generation abilities. Further analysis revealed that PVT1, VEGFA, and EGFR interact with and are regulated by miR-152-3p. Increased miR-152-3p expression reduced tumorigenesis, where increased tumorigenesis was observed when miR-152-3p expression was downregulated. Conclusion. Exosomal PVT1 promotes colon cancer metastasis through its association with EGFR and VEGFA expression. miR-152-3p targets both PVT1 and VEGFA, and this regulatory pathway can be explored for drug development and as a prognostic biomarker.

scholarly journals Chimeric RNA:DNA Donorguide Improves HDR in vitro and in vivo

2021 ◽  
Author(s):  
Brandon W Simone ◽  
Han B Lee ◽  
Camden L Daby ◽  
Santiago Restrepo-Castillo ◽  
Hirotaka Ata ◽  
...  
Keyword(s):  
Cell Types ◽  
Repair Process ◽  
Strand Break ◽  
Genetic Alterations ◽  
Precise Integration ◽  
Genetic Changes ◽  
Area Of Interest ◽  
Temporal Localization

Introducing small genetic changes to study specific mutations or reverting clinical mutations to wild type has been an area of interest in precision genomics for several years. In fact, it has been found that nearly 90% of all human pathogenic mutations are caused by small genetic variations, and the methods to efficiently and precisely correct these errors are critically important. One common way to make these small DNA changes is to provide a single stranded DNA (ssDNA) donor containing the desired alteration together with a targeted double-strand break (DSB) at the genomic target. The donor is typically flanked by regions of homology that are often ~30-100bp in length to leverage the homology directed repair (HDR) pathway. Coupling a ssDNA donor with a CRISPR-Cas9 to produce a targeted DSB is one of the most streamlined approaches to introduce small changes. However, in many cell types this approach results in a low rate of incorporation of the desired alteration and has undesired imprecise repair at the 5' or 3' junction due to artifacts of the DNA repair process. We herein report a technology that couples the spatial temporal localization of an ssDNA repair template and leverages the nucleic acid components of the CRISPR-Cas9 system. We show that by direct fusion of an ssDNA template to the trans activating RNA (tracrRNA) to generate an RNA-DNA chimera, termed Donorguide, we recover precise integration of genetic alterations, with both increased integration rates and decreased imprecision at the 5' or 3' junctions relative to an ssODN donor in vitro in HEK293T cells as well as in vivo in zebrafish. Further, we show that this technology can be used to enhance gene conversion with other gene editing tools such as TALENs.

Stem cell defects in parthenogenetic peri-implantation embryos

Development ◽  
1995 ◽  
Vol 121 (7) ◽  
pp. 2069-2077
Author(s):  
E.D. Newman-Smith ◽  
Z. Werb
Keyword(s):  
Stem Cells ◽  
Growth Factor ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Types ◽  
Insulin Like Growth Factor ◽  
Embryonic Antigen ◽  
Parietal Endoderm

Mouse embryos containing only maternal chromosomes (parthenotes) develop abnormally in vivo, usually failing at the peri-implantation stage. We have analyzed the development of parthenote embryos by using an inner cell mass (ICM) outgrowth assay that mimics peri-implantation development. ICMs from normal embryos maintained undifferentiated stem cells positive for stage-specific embryonic antigen-1 and Rex-1 while differentiating into a variety of cell types, including visceral endoderm-like cells and parietal endoderm cells. In contrast, ICMs from parthenotes failed to maintain undifferentiated stem cells and differentiated almost exclusively into parietal endoderm. This suggests that parthenote ICMs have a defect that leads to differentiation, rather than maintenance, of the stem cells, and a defect that leads to a parietal endoderm fate for the stem cells. To test the hypothesis that the ICM population is not maintained owing to a lack of proliferation of the stem cells, we investigated whether mitogenic agents were able to maintain the ICM population in parthenotes. When parthenote blastocysts were supplied with the insulin-like growth factor-1 receptor (Igf-1r) and insulin-like growth factor-2 (Igf-2), two genes not detectable in parthenote blastocysts by in situ hybridization, the ICM population was maintained. Similarly, culture of parthenote blastocysts in medium conditioned by embryonic fibroblasts and supplemented with the maternal factor leukemia inhibitory factor maintained the ICM population. However, once this growth factor-rich medium was removed, the parthenote ICM cells still differentiated predominantly into parietal endoderm.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytokine-mediated PGE2expression in human colonic fibroblasts

1998 ◽  
Vol 275 (4) ◽  
pp. C988-C994 ◽  
Author(s):  
Edward C. Kim ◽  
Yingting Zhu ◽  
Valerie Andersen ◽  
Daniela Sciaky ◽  
H. James Cao ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Cell Lines ◽  
Shape Change ◽  
Cell Types ◽  
Mrna Levels ◽  
Primary Fibroblast ◽  
Fibroblast Cultures ◽  
Epithelial Cell Lines ◽  
Factor Α

We investigated prostanoid biogenesis in human colonic fibroblasts (CCD-18Co and 5 primary fibroblast cultures) and epithelial cell lines (NCM460, T84, HT-29, and LS 174T) and the effect of PGE2 on fibroblast morphology. Cytokine-stimulated PGE2production was measured. PGH synthase-1 and -2 (PGHS-1 and -2) protein and mRNA expression were evaluated. Basal PGE2 levels were low in all cell types (0.15–6.47 ng/mg protein). Treatment for 24 h with interleukin-1β (IL-1β; 10 ng/ml) or tumor necrosis factor-α (50 ng/ml), respectively, elicited maximal 25- and 6-fold inductions of PGE2 synthesis in CCD-18Co cultures and similar results in primary fibroblast cultures; maximal inductions with IL-1β in colonic epithelial cell lines were from zero to fivefold. Treatment of CCD-18Co fibroblasts with IL-1β caused maximal 21- and 53-fold increases, respectively, in PGHS-2 protein and mRNA levels without altering PGHS-1 expression. PGE2 (0.1 μmol/l) elicited a dramatic shape change in selected fibroblasts. Colonic fibroblasts are potentially important as cytokine targets and a source of and target for colonic prostanoids in vivo.

scholarly journals Isoform-specific Ras signaling is growth factor dependent

2019 ◽  
Vol 30 (9) ◽  
pp. 1108-1117 ◽  
Author(s):  
Fiona E. Hood ◽  
Bertram Klinger ◽  
Anna U. Newlaczyl ◽  
Anja Sieber ◽  
Mathurin Dorel ◽  
...  
Keyword(s):  
Growth Factor ◽  
Cell Lines ◽  
Ectopic Expression ◽  
In Vivo Studies ◽  
Ras Signaling ◽  
Oncogenic Ras ◽  
Ras Activation ◽  
Pathway Activation ◽  
Ras Isoforms

HRAS, NRAS, and KRAS isoforms are almost identical proteins that are ubiquitously expressed and activate a common set of effectors. In vivo studies have revealed that they are not biologically redundant; however, the isoform specificity of Ras signaling remains poorly understood. Using a novel panel of isogenic SW48 cell lines endogenously expressing wild-type or G12V-mutated activated Ras isoforms, we have performed a detailed characterization of endogenous isoform-specific mutant Ras signaling. We find that despite displaying significant Ras activation, the downstream outputs of oncogenic Ras mutants are minimal in the absence of growth factor inputs. The lack of mutant KRAS-induced effector activation observed in SW48 cells appears to be representative of a broad panel of colon cancer cell lines harboring mutant KRAS. For MAP kinase pathway activation in KRAS-mutant cells, the requirement for coincident growth factor stimulation occurs at an early point in the Raf activation cycle. Finally, we find that Ras isoform-specific signaling was highly context dependent and did not conform to the dogma derived from ectopic expression studies.

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