scholarly journals PIK3CA Mutation Correlates With mTOR Pathway Expression But Not Clinical and Pathological Features in Fibro-Adipose Vascular Anomaly (FAVA)

2021 ◽  
Author(s):  
Yumiko Hori ◽  
Katsutoshi Hirose ◽  
Michio Ozeki ◽  
Kenji Hata ◽  
Daisuke Motooka ◽  
...  
Keyword(s):  
Direct Sequencing ◽  
Venous Malformation ◽  
Pik3ca Mutation ◽  
Vascular Anomaly ◽  
Mtor Pathway ◽  
Clinicopathological Features ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Immunohistochemical Expression ◽  
Mutational Status

Abstract BackgroundFibro-adipose vascular anomaly (FAVA) is a rare and new entity of vascular anomaly. Activating mutations in the phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) gene were identified at a frequency of 62.5% in FAVA cases. The PIK3CA mutations excessively activate mammalian target of rapamycin (mTOR) pathway, which promotes angiogenesis and lymphangiogenesis, implying that PIK3CA mutations may act as drivers of FAVAs. This study investigated the correlations between PIK3CA mutational status, clinicopathological features and immunohistochemical expression of the mTOR pathway in a series of FAVA.MethodsWe retrospectively evaluated the clinical and pathological findings of five FAVA cases. We performed next-generation sequencing (NGS) with a custom panel of genes associated with the mTOR pathway and genes responsible for other vascular anomalies, direct sequencing and immunohistochemical analysis of the mTOR pathway.ResultsTwo PIK3CA-mutation cases and three PIK3CA-wild-type (wt) cases exhibited similar typical clinical features of FAVA. Histological analysis revealed venous malformation, lymphatic malformation, nerves containing enlarged abnormal vessels and fibrofatty tissue were observed regardless of PIK3CA mutational status. In contrast to clinical and histological findings, the immunohistochemical expression of activated AKT and mTOR that are upstream of the mTOR pathway was detected in abnormal vessels of PIK3CA-mutation cases but not in those of PIK3CA-wt cases. However, activated eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1) and ribosomal protein S6 kinase 1 (S6K1), both of which are downstream effectors of the mTOR pathway, were expressed in abnormal vessels of both PIK3CA-mutation and PIK3CA-wt cases. Furthermore, targeting NGS did not find any common genetic mutations involved in the mTOR pathway among PIK3CA-wt cases.ConclusionThere was no significant association between the presence of PIK3CA mutations and the clinicopathological features of FAVA, suggesting that the PIK3CA gene is not necessarily involved in the onset of FAVA. FAVAs lacking PIK3CA mutations would be caused by other gene mutations that activate 4EBP1 and S6K1.

scholarly journals Importance of Arginine 20 of the Swine Vesicular Disease Virus 2A Protease for Activity and Virulence

2005 ◽  
Vol 79 (1) ◽  
pp. 428-440 ◽  
Author(s):  
Toru Inoue ◽  
Soren Alexandersen ◽  
Angela T. Clark ◽  
Ciara Murphy ◽  
Melvyn Quan ◽  
...  
Keyword(s):  
Disease Virus ◽  
Direct Sequencing ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Internal Ribosome Entry ◽  
Virus Growth ◽  
Swine Vesicular Disease Virus ◽  
2A Protease ◽  
Viral Polyprotein ◽  
Vesicular Disease

ABSTRACT A major virulence determinant of swine vesicular disease virus (SVDV), an Enterovirus that causes an acute vesicular disease, has been mapped to residue 20 of the 2A protease. The SVDV 2A protease cleaves the 1D-2A junction in the viral polyprotein, induces cleavage of translation initiation factor eIF4GI, and stimulates the activity of enterovirus internal ribosome entry sites (IRESs). The 2A protease from an attenuated strain of SVDV (Ile at residue 20) is significantly defective at inducing cleavage of eIF4GI and the activation of IRES-dependent translation compared to the 2A protease from a pathogenic strain (J1/73, Arg at residue 20), but the two proteases have similar 1D-2A cleavage activities (Y. Sakoda, N. Ross-Smith, T. Inoue, and G. J. Belsham, J. Virol. 75:10643-10650, 2001). Residue 20 has now been modified to every possible amino acid, and the activities of each mutant 2A protease has been analyzed. Selected mutants were reconstructed into full-length SVDV cDNA, and viruses were rescued. The rate of virus growth in cultured swine kidney cells reflected the efficiency of 2A protease activity. In experimentally infected pigs, all four of the mutant viruses tested displayed much-reduced virulence compared to the J1/73 virus but a significant, albeit reduced, level of viral replication and excretion was detected. Direct sequencing of cDNA derived from samples taken early and late in infection indicated that a gradual selection-reversion to a more efficient protease occurred. The data indicated that extensive sequence change and selection may introduce a severe bottleneck in virus replication, leading to a decreased viral load and reduced or no clinical disease.

scholarly journals A detailed immunohistochemical analysis of the PI3K/AKT/mTOR pathway in lung cancer: Correlation with PIK3CA, AKT1, K-RAS or PTEN mutational status and clinicopathological features

2013 ◽  
Vol 30 (2) ◽  
pp. 623-636 ◽  
Author(s):  
ELENI ANDRIANA TRIGKA ◽  
GEORGIA LEVIDOU ◽  
ANGELICA A. SAETTA ◽  
ILENIA CHATZIANDREOU ◽  
PERIKLIS TOMOS ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Immunohistochemical Analysis ◽  
Mtor Pathway ◽  
Clinicopathological Features ◽  
Mutational Status

scholarly journals PIK3CA Mutation Assessment in HR+/HER2− Metastatic Breast Cancer: Overview for Oncology Clinical Practice

2021 ◽  
Vol 2 (1) ◽  
pp. 42-54
Author(s):  
Carmen Criscitiello ◽  
Antonio Marra ◽  
Giuseppe Curigliano
Keyword(s):  
Breast Cancer ◽  
Endocrine Therapy ◽  
Pik3ca Mutation ◽  
Metastatic Breast ◽  
Mtor Pathway ◽  
Diagnostic Methods ◽  
Phase Iii ◽  
Testing Procedures ◽  
Mutational Status ◽  
Droplet Pcr

Activation of the PI3K–AKT–mTOR pathway occurs in several human cancers, including hormone receptor (HR)-positive breast cancer (BC) where is associated with resistance to endocrine therapy and disease progression. In BC, the most common PI3K–AKT–mTOR pathway alteration is represented by PIK3CA oncogenic mutations. These mutations can occur throughout several domains of the p110α catalytic subunit, but the majority are found in the helical and kinase domains (exon 9 and 20) that represent the “hotspots”. Considering the central role of the PI3K–AKT–mTOR pathway in HR-positive BC, several inhibitors (both pan-PI3K and isoform-specific) have been developed and tested in clinical trials. Recently, the PI3Kα-selective inhibitor alpelisib was the first PI3K inhibitor approved for clinical use in HR-positive metastatic BC based on the results of the phase III SOLAR-1 trial. Several methods to assess PIK3CA mutational status in tumor samples have been developed and validated, including real-time polymerase chain reaction (PCR), digital droplet PCR (ddPCR), BEAMing assays, Sanger sequencing, and next-generation sequencing (NGS) panels. Several new challenges will be expected once alpelisib is widely available in a clinical setting, including the harmonization of testing procedures for the detection of PI3K–AKT–mTOR pathway alterations. Herein, we provide an overview on PI3K–AKT–mTOR pathway alterations in HR-positive BC, discuss their role in determining prognosis and resistance to endocrine therapy and highlight practical considerations about diagnostic methods for the detection of PI3K–AKT–mTOR pathway activation status.

scholarly journals Intratumoral Heterogeneity Determines the Expression of mTOR-pathway Proteins in Prostate Cancer

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Giorgio Ivan Russo ◽  
Jörg Hennenlotter ◽  
Ulrich Vogel ◽  
Ursula Kühs ◽  
Thomas Manfred Wurm ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Meta Analysis ◽  
Mtor Pathway ◽  
Intratumoral Heterogeneity ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Clinicopathological Parameters ◽  
Tissue Samples ◽  
Benign Tissue ◽  
Tumor Center

The aim of this study was to evaluate the expression of mammalian target of rapamycin (mTOR), phosphorylated-mTOR (p-mTOR), and eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) in prostate cancer (PCa) in order to assess intratumoral heterogeneity and correlation with clinicopathological parameters. Tissue samples from 115 patients undergoing radical prostatectomy were included in a tissue microarray comprising (A) tissue from the tumor center, (B) malignant border of the tumor, (C) tumor-adjacent benign tissue, and (D) tumor-distant benign prostatic tissue. Immune reactive scores 0-12 were correlated with clinical data in reference to localization. A meta-analysis of studies investigating the association between biochemical recurrence (BCR) and parameters of the mTOR pathway was conducted. Regardless of the location within the tumor, cancer tissue showed higher expression of mTOR, p-mTOR, and 4EB-P1 compared to benign tissue (p<0.01). Significant differences in expression between tissue samples from groups C and D were observed for mTOR and p-mTOR. When considering expression according to the pathological stage, we observed lower p-mTOR expression in pT3 vs. pT2 (7.9 and 6.3; p=0.01). After a median follow-up of 74.5 months (IQR 65.0-84.0), 27 patients (23.47%) developed BCR. Weak staining of mTOR was associated with shorter time to BCR (HR: 2.0; p=0.049) after correcting for PSA and T stage. However, a significant association of mTOR expression with BCR was found for specimens from the malignant border of the tumor (B) but not the tumor center (A) (p=0.0034 log rank). In a meta-analysis, we found that the expressions of mTOR (RR=0.70; 95% CI 0.43-1.12; p=0.13) and 4E-BP1 (RR=0.86; p=0.53) were not statistically associated with BCR, while strong staining of p-mTOR was associated with a lower risk of BCR (RR=0.57; p=0.002). All 3 markers showed stronger expression in PCa and exhibited local gradients in relation to the border of tumor and healthy tissue. Our results suggest an important role of intratumor heterogeneity for the use of mTOR parameters as biomarkers in PCa.

Immunohistochemical Analysis of mTOR Pathway-Related Proteins in Kaposiform Hemangioendothelioma

Dermatology ◽  
2020 ◽  
Vol 236 (3) ◽  
pp. 262-270 ◽  
Author(s):  
Zuopeng Wang ◽  
Chao Zheng ◽  
Hongqiang Sun ◽  
Wei Yao ◽  
Kai Li ◽  
...  
Keyword(s):  
Vascular Endothelial Cells ◽  
Mtor Inhibitors ◽  
Immunohistochemical Analysis ◽  
Mtor Pathway ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Vascular Tumors ◽  
Kaposiform Hemangioendothelioma ◽  
Significant Difference ◽  
Related Proteins

Background: Mammalian target of rapamycin (mTOR) inhibitors have been shown to have excellent effects in the management of kaposiform hemangioendothelioma (KHE); however, the mechanism of action is unclear. This study identified the expressions of mTOR pathway-related proteins in different vascular tumors to provide insight into the pathogenesis of KHE. Methods: We retrospectively reviewed the pathologic specimens of 30 patients (KHE, 15; tufted angioma [TA], 5; infantile hemangioma [IH], 5; and lymphatic malformation [LM], 5). The immunohistochemical expression of mTOR-related proteins tuberous sclerosis complex 2 (TSC2), phosphatase and tensin homologue (PTEN), phosphorylated eukaryotic translation initiation factor 4E binding protein 1 (p-4EBP1), phosphorylated mTOR (p-mTOR), and phosphorylated ribosomal protein S6 kinase B1 (p-P70S6K) were analyzed using Image-Pro Plus software. KHE had the following pattern of expression in the spindle vascular endothelial cells: TSC2 (–); PTEN (–); p-4EBP1 (+); p-mTOR (+); and p-P70S6K (+). Results: All 3 patients treated with sirolimus had good responses. The TA results were similar to KHE with no significant differences (p-4EBP1: p = 0.0687; p-mTOR: p = 0.0832). The expressions of TSC2, PTEN, p-4EBP1, p-mTOR, and p-P70S6K were negative or weakly positive in IH with a statistically significant difference compared to KHE (p-4EBP1: p < 0.001; p-mTOR: p < 0.001; p-P70S6K: p < 0.001). LM had no significant differences when compared to KHE. Conclusions: The absence of TSC2 and PTEN caused abnormal activation of the mTOR signaling pathway and may be involved in the pathogenesis of KHE. The expression of mTOR-related proteins in TA and LM was similar to KHE, unlike IH. The KHE pattern of expression [PTEN (–), TSC2 (–), p-mTOR (+), p-P70S6K (+), and p-4EBP1 (+)] suggested that sirolimus may be a good therapeutic choice.

Constitutive Activation of FRAP/mTOR Pathway in Pediatric Anaplastic Large Cell Lymphomas: Potential Role as a Therapeutic Target.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 290-290 ◽  
Author(s):  
Megan S. Lim ◽  
Charles Seiler ◽  
Sheryl Tripp ◽  
Sherrie L. Perkins ◽  
Mitchell S. Cairo ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Western Blot ◽  
Ribosomal Protein ◽  
Translation Initiation ◽  
Large Cell ◽  
Mtor Pathway ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Alk Positive

Abstract Constitutive expression of the chimeric NPM/ALK fusion protein encoded by the t(2;5)(p23;q35) is a key oncogenic event in the majority of pediatric anaplastic large cell lymphomas (ALCL). To determine the pathogenetic mechanisms involved in NPM/ALK-mediated lymphomagenesis we employed a mass spectrometry (MS)-based proteomics approach to identify changes in protein expression caused by the overexpression of NPM/ALK. We identified many proteins which were downstream targets of the FRAP/mTOR pathway including ribosomal S6 kinase (1.6-fold), translational initiation factor eIF (4.8-fold), ribosomal protein L11 (4.8-fold), eukaryotic translation initiation factor 3 (3.2-fold), translation initiation factor IF-2 homolog (4.3-fold) and translation initiation factor eIF-2alpha kinase (3.4-fold). The FRAP/mTOR pathway plays a key role in the regulation of cell growth and proliferation and positively regulates translation and ribosome biogenesis and is selectively inhibited by rapamycin. To determine the feasibility of targeting the FRAP/mTOR pathway by rapamycin for treatment of pediatric ALCLs, we determined the prevalence of expression of key proteins in the FRAP/mTOR pathway in pediatric ALCLs and correlated its expression with that of the ALK protein. In addition we determined the in vitro effect of rapamycin on the viability of cell lines derived from t(2;5)-positive ALCLs. We used formalin-fixed paraffin-embedded tissues of ALK-positive ALCLs (n=18) obtained from the Children’s Oncology Group clinical trials (CCG5941 and ANHL0131) and determined the expression of phospho-mTOR, phospho-70S6Kinase and phospho-S6 ribosomal protein using immunohistochemistry. The effect of rapamycin on the viability of cell lines derived from t(2;5)-positive ALCLs was determined by MTT assay and cell cycle analysis. Western blot analysis was performed to determine the effect of rapamycin on cell cycle proteins and apoptosis. Immunohistochemical studies demonstrated diffuse strong nuclear expression of phospho-mTOR in 17/18 cases, and nuclear and cytoplasmic phospho-70S6kinase expression in 15/18 cases. In addition, cytoplasmic expression of phospho-S6 ribosomal protein was observed in 18/18 (100%) of cases. Importantly, the reactive lymphocytes demonstrated negligible expression of all three proteins. Furthermore, rapamycin potently decreased the viability of SUDHL-1 cells (30% reduction by 10nM at 48 hours) and resulted in G1 cell cycle arrest without induction of caspase-3 activity. Western blot analysis demonstrated a reduction in the level of phospho-p70S6Kinase as well as 4EBP-1 levels. Our studies demonstrate overexpression of many proteins in the FRAP/mTOR pathway in NPM/ALK-positive ALCLs. Our data indicate that the majority of pediatric ALCLs express proteins in the FRAP/mTOR pathway and are constitutively activated. Furthermore, our in vitro data support the use of rapamycin as a therapeutic agent in ALK-positive ALCLs.

Albumin-induced epithelial-mesenchymal transition and ER stress are regulated through a common ROS-c-Src kinase-mTOR pathway: effect of imatinib mesylate

2011 ◽  
Vol 300 (5) ◽  
pp. F1214-F1222 ◽  
Author(s):  
Ji Young Lee ◽  
Jai Won Chang ◽  
Won Seok Yang ◽  
Soon Bae Kim ◽  
Su Kil Park ◽  
...  
Keyword(s):  
Er Stress ◽  
Mrna Expression ◽  
Imatinib Mesylate ◽  
Epithelial Mesenchymal Transition ◽  
Src Kinase ◽  
Mtor Pathway ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Dependent Manner ◽  
Mesenchymal Transition

The epithelial-mesenchymal transition (EMT) and endoplasmic reticulum (ER) stress induced by urinary protein, particularly albumin, play an important role in tubulointerstitial injury. However, signaling pathways regulating both albumin-induced EMT and ER stress are not precisely known. We postulated that reactive oxygen species (ROS), c-Src kinase, and mammalian target of rapamysin (mTOR) would act as upstream signaling molecules. We further examined the effect of imatinib mesylate on these processes. All experiments were performed using HK-2 cells, a human proximal tubular cell line. Protein and mRNA expression were measured by Western blot analysis and real-time PCR, respectively. Exposure of tubular cells to albumin (5 mg/ml) for up to 5 days induced EMT in a time-dependent manner, as shown by conversion to the spindle-like morphology, loss of E-cadherin protein, and upregulation of α-smooth muscle actin mRNA and protein. Albumin also induced ER stress as evidenced by phosphorylation of eukaryotic translation initiation factor-2α and increased expression of GRP78 mRNA and protein. Albumin induced ROS, c-Src kinase, and mTOR as well. Antioxidants, c-Src kinase inhibitor (PP2), and mTOR inhibitor (rapamycin) suppressed the albumin-induced EMT and ER stress. Antioxidants and PP2 inhibited the albumin-induced c-Src kinase and mTOR, respectively. Imatinib suppressed the albumin-induced EMT and ER stress via inhibition of ROS and c-Src kinase. Imatinib also inhibited the albumin-induced mRNA expression of MCP-1, VCAM-1, transforming growth factor (TGF)-β1, and collagen I (α1). In conclusion, the ROS-c-Src kinase-mTOR pathway played a central role in the signaling pathway that linked albumin to EMT and ER stress. Imatinib might be beneficial in attenuating the albumin-induced tubular injury.

Sign in / Sign up

Export Citation Format

Share Document