Blocking Notch1 signaling by RNA interference can induce growth inhibition in HeLa cells

2007 ◽  
Vol 17 (2) ◽  
pp. 511-516 ◽  
Author(s):  
H. Yu ◽  
X. Zhao ◽  
S. Huang ◽  
L. Jian ◽  
G. Qian ◽  
...  

The Notch proteins constitute a family of transmembrane receptors that play a pivotal role in cellular differentiation, proliferation, and apoptosis. RNA interference of Presenilin1 (PS1) and Notch1 was carried out in this research to determine whether it could block Notch signaling and induce growth inhibition in HeLa cells. We transfected synthesized target small interfering RNA (siRNA) into HeLa cells, and blocking of Notch signaling was detected by C-promoter binding factor-1 (CBF1) reporter. We then conducted cell proliferation assay. Cells transfected with PS1 and Notch1 siRNA showed great inhibition in proliferation compared to the controls in vitro and in vivo. We conclude that RNA interference of PS1 or Notch1 can block Notch signaling and consequently induce growth inhibition of HeLa cells.

Tumor Biology ◽  
2017 ◽  
Vol 39 (5) ◽  
pp. 101042831769431
Author(s):  
Sheng-Jia Yu ◽  
Zi-Wen Long

This study aimed to investigate the effect of SOCS1 silencing on the proliferation and apoptosis of melanoma cells by in vivo and in vitro studies. Immunohistochemical staining was used to detect SOCS1 expression in melanoma tissues and pigmented nevi. Quantitative real-time polymerase chain reaction and western blotting were applied to detect the messenger RNA and protein expressions of SOCS1 in primary human melanocytes and malignant melanoma cell lines (A375, SK-MEL-5, M14, and MV3). Melanoma cells were assigned into mock, negative small interfering RNA, and SOCS1-small interfering RNA groups. The proliferation, cell cycle and apoptosis, and messenger RNA expression of SOCS1 in MV3 and A375 cells were detected using MTT assay, flow cytometry, and quantitative real-time polymerase chain reaction, respectively. The expressions of SOCS1 protein, extracellular signal–regulated kinase, and janus kinase signal transduction and activators of transcription signaling pathways–related proteins were detected using western blotting. After the establishment of subcutaneous xenograft tumor models in nude mice, the latent period, size, volume and growth speed of xenograft tumors in the mock, negative small interfering RNA, and SOCS1-small interfering RNA groups were examined and compared. The results indicated that positive expression rate of SOCS1 was higher in malignant melanoma tissues than in pigmented nevi. MV3 cells had the highest messenger RNA and protein expressions of SOCS1, followed by A357 cells. Compared with the mock and negative small interfering RNA groups, SOCS1-small interfering RNA group showed lower cell viability, elevated cell apoptosis, more cells in G0/G1 phase and less cells in S and G2/M phases, and decreased messenger RNA and protein expressions of SOCS1, p-ERK1/2, p-JAK2, p-STAT1, and p-STAT3. Compared with the mock and negative small interfering RNA groups, the SOCS1-small interfering RNA group showed longer latent period of tumor, smaller tumor size and volume, and smoother tumor growth curve. To conclude, SOCS1 silencing can inhibit proliferation and induce apoptosis of MV3 and A357 melanoma cells in vivo and in vitro by inhibiting extracellular signal–regulated kinase and janus kinase signal transduction and activators of transcription signaling pathways.


2008 ◽  
Vol 149 (4) ◽  
pp. 153-159 ◽  
Author(s):  
Zsuzsanna Rácz ◽  
Péter Hamar

A genetikában új korszak kezdődött 17 éve, amikor a petúniában felfedezték a koszuppressziót. Később a koszuppressziót azonosították a növényekben és alacsonyabb rendű eukariótákban megfigyelt RNS-interferenciával (RNSi). Bár a növényekben ez ősi vírusellenes gazdaszervezeti védekezőmechanizmus, emlősökben az RNSi élettani szerepe még nincs teljesen tisztázva. Az RNSi-t rövid kettős szálú interferáló RNS-ek (short interfering RNA, siRNS) irányítják. A jelen cikkben összefoglaljuk az RNSi történetét és mechanizmusát, az siRNS-ek szerkezete és hatékonysága közötti összefüggéseket, a célsejtbe való bejuttatás virális és nem virális módjait. Az siRNS-ek klinikai alkalmazásának legfontosabb akadálya az in vivo alkalmazás. Bár a hidrodinamikus kezelés állatokban hatékony, embereknél nem alkalmazható. Lehetőséget jelent viszont a szervspecifikus katéterezés. A szintetizált siRNS-ek ismert mellékhatásait szintén tárgyaljuk. Bár a génterápia ezen új területén számos problémával kell szembenézni, a sikeres in vitro és in vivo kísérletek reményt jelentenek emberi betegségek siRNS-sel történő kezelésére.


Blood ◽  
1990 ◽  
Vol 76 (6) ◽  
pp. 1250-1255 ◽  
Author(s):  
S Whitehead ◽  
TE Peto

Abstract Deferoxamine (DF) has antimalarial activity that can be demonstrated in vitro and in vivo. This study is designed to examine the speed of onset and stage dependency of growth inhibition by DF and to determine whether its antimalarial activity is cytostatic or cytocidal. Growth inhibition was assessed by suppression of hypoxanthine incorporation and differences in morphologic appearance between treated and control parasites. Using synchronized in vitro cultures of Plasmodium falciparum, growth inhibition by DF was detected within a single parasite cycle. Ring and nonpigmented trophozoite stages were sensitive to the inhibitory effect of DF but cytostatic antimalarial activity was suggested by evidence of parasite recovery in later cycles. However, profound growth inhibition, with no evidence of subsequent recovery, occurred when pigmented trophozoites and early schizonts were exposed to DF. At this stage in parasite development, the activity of DF was cytocidal and furthermore, the critical period of exposure may be as short as 6 hours. These observations suggest that iron chelators may have a role in the treatment of clinical malaria.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Siamak Salehi ◽  
Oliver D. Tavabie ◽  
Augusto Villanueva ◽  
Julie Watson ◽  
David Darling ◽  
...  

AbstractRegulated cell proliferation is an effector mechanism of regeneration, whilst dysregulated cell proliferation is a feature of cancer. We have previously identified microRNA (miRNA) that regulate successful and failed human liver regeneration. We hypothesized that these regulators may directly modify tumor behavior. Here we show that inhibition of miRNAs -503 and -23a, alone or in combination, enhances tumor proliferation in hepatocyte and non-hepatocyte derived cancers in vitro, driving more aggressive tumor behavior in vivo. Inhibition of miRNA-152 caused induction of DNMT1, site-specific methylation with associated changes in gene expression and in vitro and in vivo growth inhibition. Enforced changes in expression of two miRNA recapitulating changes observed in failed regeneration led to complete growth inhibition of multi-lineage cancers in vivo. Our results indicate that regulation of regeneration and tumor aggressiveness are concordant and that miRNA-based inhibitors of regeneration may constitute a novel treatment strategy for human cancers.


Author(s):  
Letizia Mondani ◽  
Giorgio Chiusa ◽  
Paola Battilani

AbstractThe aim of the study was to test in vitro and in vivo the efficacy of triazoles and biocontrol agents (BCAs) against Fusarium proliferatum and F. oxysporum, the former signaled as the main causal agent of garlic dry rot and the latter also involved. In vitro trials were organized using potato dextrose agar with added chemicals or BCAs inoculated with selected F. proliferatum and F. oxysporum. Garlic cloves were dipped before sowing in suspensions prepared with the fungicides showing the best performances in vitro; then they were dipped in Fusaria suspension before sowing. In in vitro trials, the maximum Fusaria growth inhibition was performed by Propiconazole + Prochloraz (100%), followed by Tebuconazole (88.9%). BCAs showed great capacity to control Fusaria, with a maximum growth inhibition of 80% (Trichoderma harzianum + T. gamsii). In vivo bacterial BCAs showed a similar capacity to control F. proliferatum and F. oxysporum compared to chemical products (mean of severity index 18.6% and 11.7%, respectively). In vivo results confirmed the in vitro performances, except for Trichoderma, which had the worst performances in vivo. Therefore, the results are preliminary but promising for future field application.


npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Rachel Tanner ◽  
Andrew D. White ◽  
Charelle Boot ◽  
Claudia C. Sombroek ◽  
Matthew K. O’Shea ◽  
...  

AbstractWe present a non-human primate mycobacterial growth inhibition assay (MGIA) using in vitro blood or cell co-culture with the aim of refining and expediting early tuberculosis vaccine testing. We have taken steps to optimise the assay using cryopreserved peripheral blood mononuclear cells, transfer it to end-user institutes, and assess technical and biological validity. Increasing cell concentration or mycobacterial input and co-culturing in static 48-well plates compared with rotating tubes improved intra-assay repeatability and sensitivity. Standardisation and harmonisation efforts resulted in high consistency agreements, with repeatability and intermediate precision <10% coefficient of variation (CV) and inter-site reproducibility <20% CV; although some systematic differences were observed. As proof-of-concept, we demonstrated ability to detect a BCG vaccine-induced improvement in growth inhibition in macaque samples, and a correlation between MGIA outcome and measures of protection from in vivo disease development following challenge with either intradermal BCG or aerosol/endobronchial Mycobacterium tuberculosis (M.tb) at a group and individual animal level.


Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 106
Author(s):  
Yeongji Yu ◽  
Hyejin Kim ◽  
SeokGyeong Choi ◽  
JinSuh Yu ◽  
Joo Yeon Lee ◽  
...  

The elimination of the cancer stem cell (CSC) population may be required to achieve better outcomes of cancer therapy. We evaluated stearoyl-CoA desaturase 1 (SCD1) as a novel target for CSC-selective elimination in colon cancer. CSCs expressed more SCD1 than bulk cultured cells (BCCs), and blocking SCD1 expression or function revealed an essential role for SCD1 in the survival of CSCs, but not BCCs. The CSC potential selectively decreased after treatment with the SCD1 inhibitor in vitro and in vivo. The CSC-selective suppression was mediated through the induction of apoptosis. The mechanism leading to selective CSC death was investigated by performing a quantitative RT-PCR analysis of 14 CSC-specific signaling and marker genes after 24 and 48 h of treatment with two concentrations of an inhibitor. The decrease in the expression of Notch1 and AXIN2 preceded changes in the expression of all other genes, at 24 h of treatment in a dose-dependent manner, followed by the downregulation of most Wnt- and NOTCH-signaling genes. Collectively, we showed that not only Wnt but also NOTCH signaling is a primary target of suppression by SCD1 inhibition in CSCs, suggesting the possibility of targeting SCD1 against colon cancer in clinical settings.


2006 ◽  
Vol 173 (2) ◽  
pp. 241-251 ◽  
Author(s):  
Malika Ahras ◽  
Grant P. Otto ◽  
Sharon A. Tooze

In neuroendocrine PC12 cells, immature secretory granules (ISGs) mature through homotypic fusion and membrane remodeling. We present evidence that the ISG-localized synaptotagmin IV (Syt IV) is involved in ISG maturation. Using an in vitro homotypic fusion assay, we show that the cytoplasmic domain (CD) of Syt IV, but not of Syt I, VII, or IX, inhibits ISG homotypic fusion. Moreover, Syt IV CD binds specifically to ISGs and not to mature secretory granules (MSGs), and Syt IV binds to syntaxin 6, a SNARE protein that is involved in ISG maturation. ISG homotypic fusion was inhibited in vivo by small interfering RNA–mediated depletion of Syt IV. Furthermore, the Syt IV CD, as well as Syt IV depletion, reduces secretogranin II (SgII) processing by prohormone convertase 2 (PC2). PC2 is found mostly in the proform, suggesting that activation of PC2 is also inhibited. Granule formation, and the sorting of SgII and PC2 from the trans-Golgi network into ISGs and MSGs, however, is not affected. We conclude that Syt IV is an essential component for secretory granule maturation.


2005 ◽  
Vol 280 (16) ◽  
pp. 16019-16029 ◽  
Author(s):  
Archana Jalota ◽  
Kamini Singh ◽  
Lakshminarasimhan Pavithra ◽  
Ruchika Kaul-Ghanekar ◽  
Shahid Jameel ◽  
...  

Various stresses and DNA-damaging agents trigger transcriptional activity of p53 by post-translational modifications, making it a global regulatory switch that controls cell proliferation and apoptosis. Earlier we have shown that the novel MAR-associated protein SMAR1 interacts with p53. Here we delineate the minimal domain of SMAR1 (the arginine-serine-rich domain) that is phosphorylated by protein kinase C family proteins and is responsible for p53 interaction, activation, and stabilization within the nucleus. SMAR1-mediated stabilization of p53 is brought about by inhibiting Mdm2-mediated degradation of p53. We also demonstrate that this arginine-serine (RS)-rich domain triggers the various cell cycle modulating proteins that decide cell fate. Furthermore, phenotypic knock-down experiments using small interfering RNA showed that SMAR1 is required for activation and nuclear retention of p53. The level of phosphorylated p53 was significantly increased in the thymus of SMAR1 transgenic mice, showingin vivosignificance of SMAR1 expression. This is the first report that demonstrates the mechanism of action of the MAR-binding protein SMAR1 in modulating the activity of p53, often referred to as the “guardian of the genome.”


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