Use of selective inhibition of nuclear export (SINE) using a CRM1/XPO1 antagonist to overcome resistance to CPT-11 in colon cancer in preclinical models.

2013 ◽  
Vol 31 (4_suppl) ◽  
pp. 396-396 ◽  
Author(s):  
Hye Won Chung ◽  
Roberto A. Salas Fragomeni ◽  
Sharon Shacham ◽  
Michael Kauffman ◽  
James C. Cusack
Keyword(s):  
Colon Cancer ◽  
Catalytic Activity ◽  
Western Blot ◽  
Nuclear Export ◽  
Topoisomerase I ◽  
Immunofluorescence Microscopy ◽  
Expression Change ◽  
Colon Cancers

396 Background: Overcoming the resistance of topoisomerase I (TOP1) inhibitors has great clinical potential for treatment of advanced colon cancer. Previously, we showed a kind of novel CRM1-dependent SINEs leads to increase the anti-cancer effects of topoisomerase-1 (topo-1) inhibitor, CPT-11 (SN38), in colon cancer in vitro. However, its underlying mechanisms have not been fully understood. Here, we showed CRM1-dependent SINEs induced the sequestration of TOP1 into nucleus as well as other tumor suppressors or growth regulatory proteins. Methods: The synergism of KPT-251, a novel CRM1-dependent SINE, with SN38 were evaluated using Chou-Talalay method in both CPT-11/SN38-sensitive (SW480) and CPT-11/SN38-resistant colon cancers cells (WiDr) in vitro and animal experiments bearing CPT-sensitive and CPT-resistant cells in vivo. The expression change of TOP1, p-FOXO3a, p27, p53, p21, and IkBa in nucleus were evaluated by western blot. Nuclear trafficking of TOP1 was confirmed by immunofluorescence microscopy and measuring nuclear TOP1 catalytic activity. Increased apoptosis through TOP1 nuclear sequestration were evaluated by comet assay. Results: We found the dramatic synergism of KPT-251 with CPT-11 in both CPT-11/SN38-sensitive and CPT-11/SN38-resistant colon cancers cells in vitro and in vivo. We also found TOP1 was sequestrated into nucleus by KPT-251 through CRM1 inhibition, and this induced overcoming the resistance of CPT-11 in colon cancers, which were demonstrated by western blot, immunofluorescence microscopy, TOP1 catalytic activity, and comet assays. Conclusions: Our results suggest blocking TOP1 nuclear export by a novel CRM1-dependent SINE sensitizes colon cancer to TOP1 inhibitors. Our study supports the development of a novel treatment strategy to overcome the resistance of CPT-11 and other TOP1 inhibitors in colon and potentially other cancers.

scholarly journals Effects of Hexane Root Extract of Ferula hermonis Boiss. on Human Breast and Colon Cancer Cells: An In Vitro and In Vivo Study

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Nael Abutaha ◽  
Fahd A. Nasr ◽  
Mohammed Al-zharani ◽  
Ali S. Alqahtani ◽  
Omar M. Noman ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cancer Cells ◽  
Root Extract ◽  
Therapeutic Effects ◽  
Nuclear Staining ◽  
Colon Cancer Cells ◽  
Baccatin Iii ◽  
Colon Cancers

Breast and colon cancers are leading causes of cancer-related deaths globally. Plants are a potential source of natural products that may be used for the treatment of cancer. Ferula hermonis (FH) is reported to have diverse therapeutic effects. However, there are few reports on the in vitro anticancer potential of FH extract. Our results showed that the Ferula hermonis root hexane extract (FHRH) can induce dose-dependent cytotoxic effects in breast and colon cancer cells with MTT IC50 values of 18.2 and 25 μg/ml, respectively. The FHRH extract induced apoptosis in both breast and colon cancer cells; this was confirmed by light and nuclear staining, q-PCR, and caspase 3/7 activation. This study also demonstrated the antitumor activity of FHRH in 9,10-dimethylbenz[α]anthracene DMBA-induced rodent mammary tumor model. The GC/MS analysis revealed the presence of 3,5-Dimethylbenzenemethanol, Alpha-Bisabolol, Alpha-pinene, Beta-pinene, and Baccatin III that have various pharmacological potentials. Overall, the present study suggests that FHRH extract possesses anticancer potential which is mediated through apoptotic effects in MDA-MB-231 and LoVo cells. The present study also considered a basis for further investigations into the potential use of FHRH extract as an anticancer therapy for breast and colon cancers.

Overcoming Drug Resistance In Acute Lymphoblastic Leukemia by Inhibition of CBP/γ-Catenin

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3264-3264
Author(s):  
Enzi Jiang ◽  
Eugene Park ◽  
Cu Nguyen ◽  
James Yoon ◽  
Yao-Te Hsieh ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Western Blot ◽  
Conflicts Of Interest ◽  
Lymphoblastic Leukemia ◽  
Philadelphia Chromosome ◽  
Saline Control ◽  
Control Group ◽  
Apoptosis Protein

Abstract Abstract 3264 Survivin, an inhibitor of apoptosis protein (IAP) family, has been associated with poor prognosis in cancer including leukemia. Survivin can be downregulated in colon cancer cells by inhibition of the β-catenin/Creb-binding protein (CBP) interaction using ICG-001, a small molecule specific inhibitor of the β-catenin/CBP interaction. We have shown previously that combined ICG-001 and chemotherapy can downregulate Survivin and sensitize ALL cells to chemotherapy in vitro and in a pilot study in vivo. In this study, we determine the CBP interaction with ICG-001 in primary ALL cells and preclinically evaluate ICG-001 in vitro and in vivo as an adjuvant against primary ALL and. For this purpose, primary ALL cells were co-cultured with OP9 cells and treated for 4 days with ICG-001 (10mM, 20mM) or DMSO as vehicle control. Mean viability (trypan blue exclusion) of cells treated with ICG-001 was significantly lower (ICG-001 10mM: 75.12% ± 3.15%; 20mM: 41.18%± 7.88%) compared to cells treated with DMSO (84.99% ± 0.42%) (% cell viability relative to initial control) (p=0.03). Real time RT-PCR showed ICG-001 dose-dependent downregulation of Survivin in ALL compared to control (ICG10mM vs. control: p=0.0037 and 20mM vs. control: p=0.0031). Immunoblotting demonstrated reduction of Survivin after ICG-001 treatment. Primary ALL cells incubated with a combination of VDL (Vincristine, Dexamethasone and L-Asparaginase) and ICG-001 showed decreased viability (28.7%± 4.9%) versus VDL only (79.3%± 13.6%) (p=0.014) determined by MTT assay. To elucidate if ICG-001 interacts with β-catenin/CBP as shown previously in colon cancer, we analyzed ten primary pre-B ALL cells and found significantly greater γ-catenin and Survivin expression versus normal pre-B-Cells. β-catenin was absent or in some cases expressed only weakly. Expression of v-catenin and b-catenin in ALL xenograft cells were detected by Western blot. One primary ALL was selected and incubated with γ-catenin and β-catenin siRNA for 48hrs, followed by 6hrs incubation with Wnt3a. Wnt3a induced both of γ-catenin and β-catenin expression. Survivin was reduced by γ-catenin siRNA but not β-catenin siRNA treatment. Addition of Wnt3a partially recovered the decrease of Survivin. In addition, Survivin was knocked down in primary ALL using shRNA and non-silencing shRNA control or ICG-001 (2uM) and DMSO control. Western blot analysis showed that survivin shRNA or ICG-001 treatment lead to downregulation of Survivin and γ-catenin. Using a ChIP assay we could demonstrate occupancy of TCF4 and CBP association at the Survivin promoter, which was not altered by ICG-001 in primary ALL. Moreover, ICG-001 treatment of primary ALL cells prevents CBP but not p300 occupancy. For further preclinical in vivo evaluation of ICG-001, one Philadelphia chromosome positive ALLs (Ph+) and two Ph− primary ALL were injected into sublethally irradiated NOD/SCID IL2Rγ−/-mice and treated with ICG-001 (50mg or 100mg/kg/day per subcutaneous miniosmotic pump) with or without chemotherapy including VDL for Ph− ALL (per intraperitoneal injections) or Nilotinib for Ph+ ALL (per os). For analysis we pooled the survival of all three primary leukemias. The saline control group (n=10) (MST= 55.5.days) and the ICG-001 only groups (n=3) (MST=61 days) died rapidly. The group treated with chemotherapy (n=13) had a median survival time (MST) of 85 days. In marked contrast, the group treated with the combined chemotherapy+ICG-001 (n=15) lived significantly longer (MST=100) (p<0.05). Taken together, our data shows that Survivin transcription can be mediated by γ-catenin in primary ALL and that targeting CBP/γ-catenin by using ICG-001 ALL can sensitize ALL cells to chemotherapy in vitro and in vivo. Disclosures: No relevant conflicts of interest to declare.

In vitro and in vivo activities of KRN330, a fully human monoclonal antibody against colon cancer.

2011 ◽  
Vol 29 (4_suppl) ◽  
pp. 432-432 ◽  
Author(s):  
N. Sawada ◽  
E. Taguchi ◽  
M. Takahashi
Keyword(s):  
Colorectal Cancer ◽  
Monoclonal Antibody ◽  
Colon Cancer ◽  
Western Blot ◽  
Human Colon ◽  
Human Colorectal Cancer ◽  
Antitumor Activities ◽  
Reducing Condition

432 Background: KRN330 is a novel recombinant human IgG1 monoclonal antibody (mAb) targeting A33 surface differentiation antigen that is uniformly expressed on the surface of 95% of colorectal cancer (CRC) cells. In this study, we characterized the activity of KRN330 for its in vitro properties, as well as for its in vivo antitumor activity. Methods: A kinetic analysis of the interaction between KRN330 and recombinant human A33 was conducted using a Biacore 3000. Western blot analysis was conducted using A33 expressing COLO205 lysates under reducing and non-reducing conditions. Binding of KRN330 to human colorectal cancer tissues were investigated using FITC-labeled KRN330. We also developed more conventional staining methods of A33 and investigated A33 expression using human colon cancer tissue microarray (TMA). ADCC and CDC activities of KRN330 were assessed using a standard 51Cr release assay. A33 expression levels of 14 CRC cell lines were analyzed using flow cytometer. In vivo antitumor activities of KRN330 alone or in combination with chemotherapeutic agents against subcutaneous or intraperiotoneal human CRC (COLO205 and LS174T) models were investigated using mice and rats xenograft model. Results: A kinetic analysis revealed that KRN330 showed a high binding affinity to A33. Western blot analysis also showed that antibody recognized not any protein under reducing condition, but non-reducing condition. A33 staining of TMA with 204 different samples revealed the majority of tumor expressed A33. KRN330 exhibited ADCC activity against A33 expressing human colorectal cancer cell lines which include both K-ras wild and mutated types. KRN330 showed dose-dependent antitumor activities in vivo. KRN330 also significantly prolonged survival of human colon tumor bearing mice. In addition, combination treatment of KRN330 with irinotecan showed increased antitumor activitiy and prolongation of survival, compared to either irinotecan or KRN330 alone. Conclusions: These results suggest that KRN330 is a promising candidate of novel therapy for CRC. The phase I/II study of KRN330 plus irinotecan in patients with second line metastatic CRC is ongoing. [Table: see text]

Abstract P426: Inactivating Grk5 Impairs Basal Cardiac Function And Survival Via P53 Modulation

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Federica Marzano ◽  
Antonio Rapacciuolo ◽  
Walter J Koch ◽  
Alessandro Cannavo
Keyword(s):  
Catalytic Activity ◽  
Cardiac Function ◽  
Nuclear Export ◽  
P53 Protein ◽  
Nuclear Export Signal ◽  
P53 Gene ◽  
Mrna Levels ◽  
Cardiac Phenotype

Introduction: G protein-coupled receptor (GPCR) kinase 5 (GRK5) is a multifunctional protein and depending on its localization within the cell, it has been shown to elicit either protective or deleterious effects. For instance in the heart, when anchored to the plasma membrane, this kinase can regulate specific GPCRs via canonical phosphorylation that can confer cardioprotection. However, when it accumulates in the nucleus its non-canonical activity can drive pathological hypertrophic gene transcription. Interestingly, the latter effects may not be kinase-dependent. Hypothesis: The role played by GRK5’s catalytic activity in the heart has not been fully elucidated and for that reason we sought to assess the in vivo consequences of inactivating the catalytic site of GRK5 with an initial focus at examining the basal cardiac phenotype and response to stress. Methods: We used CRISPR/Cas9 technology to generate a novel knock-in mouse model, with the ATP binding lysine (K) 215 in the catalytic cleft replaced by arginine (R) (GRK5-K215R) resulting in mice devoid of any GRK5 catalytic activity. We studies baseline cardiac function in these mutant mice compared to wild-type (WT) littermates and then stressed them via transverse aortic constriction (TAC). In vitro, we used H9c2 cardiomyocytes and various GRK5 mutants for mechanistic studies. Results: Compared to age-matched WT littermates, GRK5-K215R mice revealed marked and early (9 weeks) deterioration of cardiac function, with augmented apoptosis and fibrosis basally. Importantly, mutant knock-in mice displayed increased p53 gene expression (both at mRNA and protein levels). Moreover, TAC induced increased dysfunction and fibrosis in GRK5-K215R mice compared to WT. Mechanistically, we transduced H9c2 cells with adenoviruses (Ad), encoding for WT GRK5 (Ad-GRK5) or a mutant GRK5 lacking its nuclear localization signal (Ad-NLS) and when GRK5 was localized only outside the nucleus, there was a significant protection against apoptosis, with reduced p53 protein and mRNA levels. Conversely, when we overexpressed a mutant GRK5 without nuclear export signal (GRK5-ΔNES) to trap GRK5 within the nucleus, we found a significant increase in apoptosis, with high p53 protein expression levels. Conclusions: Inactivating GRK5’s catalytic activity impairs its nuclear regulation of p53. This can result in higher levels of p53 mRNA and protein resulting in higher rates of apoptosis in the heart leading to significant cardiac dysfunction and an intolerance to stress.

scholarly journals Why Should DNA Topoisomerase I Have a Scaffold Activity?

Biology ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 190
Author(s):  
Francesca Di Felice ◽  
Giorgio Camilloni
Keyword(s):  
Catalytic Activity ◽  
Rna Polymerase Ii ◽  
Topoisomerase I ◽  
Ribosomal Genes ◽  
Dna Topoisomerase I ◽  
Dna Topoisomerase ◽  
Macromolecular Complexes ◽  
Rna Polymerase Ii Transcription

Since the early 1990s, in vitro studies have demonstrated that DNA topoisomerase I promotes RNA polymerase II transcription, acting as a cofactor, regardless of its catalytic activity. Recent studies, carried in vivo, using yeast as a model system, also demonstrate that DNA topoisomerase I is able to recruit, without the involvement of its catalytic activity, the Sir2p deacetylase on ribosomal genes thus contributes to achieve their silencing. In this review, the DNA topoisomerase I capability, acting as a scaffold protein, as well as its involvement and role in several macromolecular complexes, will be discussed, in light of several observations reported in the literature, pointing out how its role goes far beyond its well-known ability to relax DNA.

Radiosensitivity of glioma to Gamma Knife treatment enhanced in vitro and in vivo by RNA interfering Ku70 that is mediated by a recombinant adenovirus

2010 ◽  
Vol 113 (Special_Supplement) ◽  
pp. 228-235 ◽  
Author(s):  
Qiang Jia ◽  
Yanhe Li ◽  
Desheng Xu ◽  
Zhenjiang Li ◽  
Zhiyuan Zhang ◽  
...  
Keyword(s):  
Western Blot ◽  
Gamma Knife ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Glioma Cells ◽  
C6 Glioma ◽  
C6 Glioma Cells ◽  
C6 Cells

Object The authors sought to evaluate modification of the radiation response of C6 glioma cells in vitro and in vivo by inhibiting the expression of Ku70. To do so they investigated the effect of gene transfer involving a recombinant replication-defective adenovirus containing Ku70 short hairpin RNA (Ad-Ku70shRNA) combined with Gamma Knife treatment (GKT). Methods First, Ad-Ku70shRNA was transfected into C6 glioma cells and the expression of Ku70 was measured using Western blot analysis. In vitro, phenotypical changes in C6 cells, including proliferation, cell cycle modification, invasion ability, and apoptosis were evaluated using the MTT (3′(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide) assay, Western blot analysis, and cell flow cytometry. In vivo, parental C6 cells transfected with Ad-Ku70shRNA were implanted stereotactically into the right caudate nucleus in Sprague-Dawley rats. After GKS, apoptosis was analyzed using the TUNEL (terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling) method. The inhibitory effects on growth and invasion that were induced by expression of proliferating cell nuclear antigen and matrix metalloproteinase–9 were determined using immunohistochemical analyses. Results The expression of Ku70 was clearly inhibited in C6 cells after transfection with Ad-Ku70shRNA. In vitro following transfection, the C6 cells showed improved responses to GKT, including suppression of proliferation and invasion as well as an increased apoptosis index. In vivo following transfection of Ad-Ku70shRNA, the therapeutic efficacy of GKT in rats with C6 gliomas was greatly enhanced and survival times in these animals were prolonged. Conclusions Our data support the potential for downregulation of Ku70 expression in enhancing the radiosensitivity of gliomas. The findings of our study indicate that targeted gene therapy–mediated inactivation of Ku70 may represent a promising strategy in improving the radioresponsiveness of gliomas to GKT.

Light Chain LC and TAT-EGFP-HCS of Botulinum Toxin Expression and Biological Function in vitro and in vivo

2019 ◽  
Vol 16 (3) ◽  
pp. 175-180
Author(s):  
Fengjin Hao ◽  
Yueqin Feng ◽  
Yifu Guan
Keyword(s):  
Biological Activity ◽  
Botulinum Toxin ◽  
Cell Membrane ◽  
Western Blot ◽  
Biological Function ◽  
C6 Cells ◽  
Green Fluorescence ◽  
Bv2 Cells

Objective: To verify whether the botulinum toxin heavy chain HCS has specific neuronal targeting function and to confirm whether TAT-EGFP-LC has hydrolyzable SNAP-25 and has transmembrane biological activity. Methods: We constructed the pET-28a-TAT-EGFP-HCS/LC plasmid. After the plasmid is expressed and purified, we co-cultured it with nerve cells or tumors. In addition, we used Western-Blot to identify whether protein LC and TAT-EGFP-LC can digest the protein SNAP-25. Results: Fluorescence imaging showed that PC12, BV2, C6 and HeLa cells all showed green fluorescence, and TAT-EGFP-HCS had the strongest fluorescence. Moreover, TAT-EGFP-LC can hydrolyze intracellular SNAP-25 in PC12 cells, C6 cells, BV2 cells and HeLa, whereas LC alone cannot. In addition, the in vivo protein TAT-EGFP-HCS can penetrate the blood-brain barrier and enter mouse brain tissue. Conclusion: TAT-EGFP-HSC expressed in vitro has neural guidance function and can carry large proteins across the cell membrane without influencing the biological activity.

The Anti-tumor Activity and Mechanisms of rLj-RGD3 on Human Laryngeal Squamous Carcinoma Hep2 Cells

2020 ◽  
Vol 19 (17) ◽  
pp. 2108-2119
Author(s):  
Yang Jin ◽  
Li Lv ◽  
Shu-Xiang Ning ◽  
Ji-Hong Wang ◽  
Rong Xiao
Keyword(s):  
Wound Healing ◽  
Western Blot ◽  
Morphological Changes ◽  
In Vivo Studies ◽  
Migration And Invasion ◽  
Tunel Staining ◽  
Dna Ladder ◽  
Western Blot Assay

Background: Laryngeal Squamous Cell Carcinoma (LSCC) is a malignant epithelial tumor with poor prognosis and its incidence rate increased recently. rLj-RGD3, a recombinant protein cloned from the buccal gland of Lampetra japonica, contains three RGD motifs that could bind to integrins on the tumor cells. Methods: MTT assay was used to detect the inhibitory rate of viability. Giemsa’s staining assay was used to observe the morphological changes of cells. Hoechst 33258 and TUNEL staining assay, DNA ladder assay were used to examine the apoptotic. Western blot assay was applied to detect the change of the integrin signal pathway. Wound-healing assay, migration, and invasion assay were used to detect the mobility of Hep2 cells. H&E staining assay was used to show the arrangement of the Hep2 cells in the solid tumor tissues. Results: In the present study, rLj-RGD3 was shown to inhibit the viability of LSCC Hep2 cells in vitro by inducing apoptosis with an IC50 of 1.23µM. Western blot showed that the apoptosis of Hep2 cells induced by rLj- RGD3 was dependent on the integrin-FAK-Akt pathway. Wound healing, transwells, and western blot assays in vitro showed that rLj-RGD3 suppressed the migration and invasion of Hep2 cells by integrin-FAKpaxillin/ PLC pathway which could also affect the cytoskeleton arrangement in Hep2 cells. In in vivo studies, rLj-RGD3 inhibited the growth, tumor volume, and weight, as well as disturbed the tissue structure of the solid tumors in xenograft models of BALB/c nude mice without reducing their body weights. Conclusion: hese results suggested that rLj-RGD3 is an effective and safe suppressor on the growth and metastasis of LSCC Hep2 cells from both in vitro and in vivo experiments. rLj-RGD3 might be expected to become a novel anti-tumor drug to treat LSCC patients in the near future.

Large volume spark discharge and plasma jet-technology for generating plasma-oxidized saline targeting colon cancer in vitro and in vivo

2021 ◽  
Vol 129 (5) ◽  
pp. 053301
Author(s):  
Eric Freund ◽  
Lea Miebach ◽  
Ramona Clemen ◽  
Michael Schmidt ◽  
Amanda Heidecke ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Large Volume ◽  
Plasma Jet ◽  
Spark Discharge
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