Modulation of O6-alkylguanine alkyltransferase-directed DNA repair in metastatic colon cancers.

1995 ◽  
Vol 13 (9) ◽  
pp. 2301-2308 ◽  
Author(s):  
J K Willson ◽  
J R Haaga ◽  
J E Trey ◽  
T A Stellato ◽  
N H Gordon ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Dna Repair ◽  
Mononuclear Cells ◽  
Metastatic Tumor ◽  
Colorectal Cancers ◽  
Human Colon Cancer ◽  
Peripheral Blood Mononuclear ◽  
Cancer Metastases ◽  
Clinical Resistance

PURPOSE Carmustine (BCNU) resistance has been correlated with tumor expression of the DNA repair enzyme O6-alkylguanine-DNA alkyltransferase (AT). It has been shown that streptozotocin will deplete AT activity of human colon cancer cells in vitro and potentiate BCNU cytotoxicity. This clinical trial was conducted to determine whether streptozotocin can be used as a modulator of AT in metastatic colorectal cancers and thereby overcome clinical resistance to BCNU. PATIENTS AND METHODS Fifteen patients with fluorouracil-resistant metastatic colon or rectal cancers were treated sequentially with 2 g/m2 of streptozotocin followed 5 1/2 hours later by BCNU. Sequential biopsies of metastases before and after streptozotocin were conducted to determine whether streptozotocin depletes tumor AT. Peripheral-blood mononuclear cells (PBMCs) were evaluated as a surrogate tissue for prediction of baseline AT levels and streptozotocin posttreatment modulation of the AT in metastases. RESULTS Streptozotocin treatment led to a 78% (range, 69% to 89%) decrease in the AT levels in colon cancer metastases; however, myelosuppression and hepatic toxicity limited the BCNU dose to 130 mg/m2. A similar decrease in AT levels of PBMCs was found; however, the absolute levels of AT in PBMCs at baseline and following streptozotocin were not predictive of the levels expressed in metastases from the same patient. Despite the decrease in tumor levels of AT, no clinical responses were observed. CONCLUSION Streptozotocin decreases but does not fully deplete AT activity in metastatic colorectal cancers and the residual AT level in metastases is sufficient to maintain clinical resistance to BCNU. We have also demonstrated that sequential computed tomography (CT)-directed biopsies of colorectal cancer metastases can be used to evaluate strategies to investigate modulators of AT-directed repair. AT levels of PBMCs do not predict for the AT level or degree of modulation achieved in the metastatic tumor.

scholarly journals Delivery of functional exogenous proteins by plant-derived vesicles to human cells in vitro

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luiza Garaeva ◽  
Roman Kamyshinsky ◽  
Yury Kil ◽  
Elena Varfolomeeva ◽  
Nikolai Verlov ◽  
...  
Keyword(s):  
Cell Culture ◽  
Colon Cancer ◽  
Extracellular Vesicles ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Human Cells ◽  
Bioactive Molecules ◽  
Native Plant ◽  
Peripheral Blood Mononuclear

AbstractPlant-derived extracellular vesicles (EVs) gain more and more attention as promising carriers of exogenous bioactive molecules to the human cells. Derived from various edible sources, these EVs are remarkably biocompatible, biodegradable and highly abundant from plants. In this work, EVs from grapefruit juice were isolated by differential centrifugation followed by characterization of their size, quantity and morphology by nanoparticle tracking analysis, dynamic light scattering, atomic force microscopy and cryo-electron microscopy (Cryo-EM). In Cryo-EM experiments, we visualized grapefruit EVs with the average size of 41 ± 13 nm, confirmed their round-shaped morphology and estimated the thickness of their lipid bilayer as 5.3 ± 0.8 nm. Further, using cell culture models, we have successfully demonstrated that native grapefruit-derived extracellular vesicles (GF-EVs) are highly efficient carriers for the delivery of the exogenous Alexa Fluor 647 labeled bovine serum albumin (BSA) and heat shock protein 70 (HSP70) into both human peripheral blood mononuclear cells and colon cancer cells. Interestingly, loading to plant EVs significantly ameliorated the uptake of exogenous proteins by human cells compared to the same proteins without EVs. Most importantly, we have confirmed the functional activity of human recombinant HSP70 in the colon cancer cell culture upon delivery by GF-EVs. Analysis of the biodistribution of GF-EVs loaded with 125I-labeled BSA in mice demonstrated a significant uptake of the grapefruit-derived extracellular vesicles by the majority of organs. The results of our study indicate that native plant EVs might be safe and effective carriers of exogenous proteins into human cells.

scholarly journals RSK2 phosphorylates T-bet to attenuate colon cancer metastasis and growth

2017 ◽  
Vol 114 (48) ◽  
pp. 12791-12796 ◽  
Author(s):  
Ke Yao ◽  
Cong Peng ◽  
Yuwen Zhang ◽  
Tatyana A. Zykova ◽  
Mee-Hyun Lee ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Liver Metastasis ◽  
Cancer Metastasis ◽  
Mononuclear Cells ◽  
Kinase Assay ◽  
Mrna Levels ◽  
Peripheral Blood Mononuclear ◽  
Colon Cancer Metastasis ◽  
Ribosomal S6 Kinase

Metastasis is a major cause of cancer-related deaths. Approximately 80% of patients with colorectal cancer develop liver metastasis and 20% develop lung metastasis. We found that at different stages of colon cancer, IFNγ secretion from peripheral blood mononuclear cells was decreased compared with healthy controls. The ribosomal S6 kinase (RSK) family of kinases has multiple cellular functions, and we examined their roles in this observed IFNγ decrease. Flow cytometry analysis of wild-type (WT) and RSK2 knockout (KO) mice revealed significantly lower levels of IFNγ in the RSK2 KO mice compared with the WT mice. Since IFNγ is a component of immunity, which contributes to protection against metastatic carcinomas, we conducted a colon cancer liver metastasis experiment. We found significantly greater metastasis in RSK2 KO mice compared with WT mice. Transcription factor T-bet can directly activate Ifnγ gene transcription. In vitro kinase assay results showed that RSK2 phosphorylated T-bet at serines 498 and 502. We show that phosphorylation of T-bet by RSK2 is required for IFNγ expression, because knockdown of RSK2 expression or overexpression of mutant T-bet reduces IFNγ mRNA expression. To verify the function of the phosphorylation sites, we overexpressed a constitutively active mutant T-bet (S498E/S502E) in bone marrow. Mutant T-bet restored the IFNγ mRNA levels and dramatically reduced the metastasis rate in these mice. Overall, these results indicate that phosphorylation of T-bet is required for the inhibition of colon cancer metastasis and growth through a positive regulation of RSK2/T-bet/IFNγ signaling.

Preoperative Mobilization of Circulating Dendritic Cells by Flt3 Ligand Administration to Patients With Metastatic Colon Cancer

2000 ◽  
Vol 18 (23) ◽  
pp. 3883-3893 ◽  
Author(s):  
Michael A. Morse ◽  
Smita Nair ◽  
Monica Fernandez-Casal ◽  
Yuping Deng ◽  
Michelle St Peter ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Peripheral Blood ◽  
Tumor Tissue ◽  
Mononuclear Cells ◽  
Metastatic Tumor ◽  
Delayed Type Hypersensitivity ◽  
Metastatic Colon Cancer ◽  
Flt3 Ligand ◽  
Peripheral Blood Mononuclear

PURPOSE: To evaluate preoperative dendritic cell (DC) mobilization and tumor infiltration after administration of Flt3 ligand (Flt3L) to patients with metastatic colon cancer. PATIENTS AND METHODS: Twelve patients with colon cancer metastatic to the liver or lung received Flt3L (20 μg/kg/d subcutaneously for 14 days for one to three cycles at monthly intervals) before attempted metastasectomy. The number and phenotype of DCs mobilized into peripheral-blood mononuclear cells (PBMCs) were evaluated by flow cytometry. After surgical resection, metastatic tumor tissue was evaluated for DC infiltration. In vivo immune responses to recall antigens were measured. RESULTS: After Flt3L administration, on average, the total number of leukocytes in the peripheral blood increased from 5.9 ± 1.0 × 103/mm3 to 11.2 ± 3.8 × 103/mm3 (mean ± SD, P = .0001). The percentage of CD11c+CD14− DCs in PBMCs increased from 2.4% ± 1.8% to 8.8% ± 4.7% (P = .004). Delayed-type hypersensitivity (DTH) responses to recall antigens (Candida, mumps, and tetanus) showed marginally significant increases in reactivity after Flt3L administration (P = .06, P = .03, and P = .08, respectively). An increase in the number of DCs was observed at the periphery of the tumors of patients who received Flt3L compared with those of patients who had not. CONCLUSION: Flt3L is capable of mobilizing DCs into the peripheral blood of patients with metastatic colon cancer and may be associated with increases in DC infiltration in the peritumoral regions. Flt3L mobilization is associated with a trend toward increased DTH responses to recall antigens in vivo. The use of Flt3L to increase circulating DCs for cancer immunotherapy should be considered.

scholarly journals Mushroom Polysaccharides-Alginate/κ-Carrageenan Microcapsules Trigger NK Cells-Cytotoxic Activity Against Colon Cancer: Induction of Kappa B- Alpha Inflammatory Pathway

2021 ◽  
Author(s):  
Nehal El-Deeb ◽  
M. R. El-Aassar ◽  
Mohamed M. S. Farag ◽  
Ayman A. Farrag ◽  
Mahmoud A. Mohamed
Keyword(s):  
Colon Cancer ◽  
Nk Cells ◽  
Mononuclear Cells ◽  
Nk Cell ◽  
Inhibitory Effect ◽  
Cell Populations ◽  
Peripheral Blood Mononuclear ◽  
Cytotoxic Effects ◽  
Inflammatory Pathway

Abstract PurposeThe main objective of this study is to explore the effects of the extracted mushroom polysaccharides in the form of polysaccharides-Alginate (Alg.)/kappa carrageenan (El-Aassar MR) microcapsules to activate natural killer cells (NK) against colon cancer. MethodsWater soluble polysaccharides were extracted from nine wild isolates of Egyptian Mushroom, and their safety patterns were checked on peripheral blood mononuclear cells (PBMC). The extracted Agaricus bisporus MH751906 polysaccharide was microcapsulated in Alg/κ-carrageenan microcapsules. The morphology and swelling behavior of Alg/κ-carrageenan microcapsules, Alg/κ-carrageenan*polysaccharide microcapsules was determined. Also, the in vitro release of Polysaccharide from Alg/κ-carrageenan*polysaccharide microcapsules was analyzed. The Effects of Alg/κ-carrageenan*polysaccharide microcapsules on activating NK cells against colon cancer was evaluated at both cellular and molecular levels. ResultsThe results showed that, the extracted polysaccharide from the isolate 8 (submitted to the Gen Bank as Agaricusbisporus MH751906) was the safest sample on PBMCs even at 5mg/ml. The microencapsulated polysaccharides in Alg/κ-carrageenan*polysaccharide formula showed better thermal stability at high temperature with higher hydrogel swelling rates in alkaline pH. Upon NK cells activation with microcapsules (ANK cells), a significant decrease in CD11b and CD16-CD56- and an increase in CD16+CD56+ NK cell populations were recorded. These activated NK cells showed 74.09% cytotoxic effects against CaCO-2cellswith an increase of cancer cell populations in the G0/G1 phase. Furthermore, the ANK cells-CaCo-2treated cells recorded down regulations both Bcl2 and TGF genes and up regulation of IkappaB-α expression.ConclusionA novel polysaccharides-alginate/κ-carrageenan microcapsules preparation to enhance NK cell cytotoxic effects against colon cancer cells and this inhibitory effect is associated with the regulatory effects of inflammatory pathway through the induction of IkappaB- alpha.

Discovery of Novel 2-Amino-5-(Substituted)-1,3,4-Thiadiazole Derivatives: New Utilities for Colon Cancer Treatment

2018 ◽  
Vol 18 (5) ◽  
pp. 719-738 ◽  
Author(s):  
Vinit Raj ◽  
Amit Rai ◽  
Ashok K. Singh ◽  
Amit K. Keshari ◽  
Prakruti Trivedi ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cancer Metastasis ◽  
Molecular Targets ◽  
Cancer Cell Line ◽  
Chemotherapeutic Agents ◽  
Cancer Drug ◽  
Human Colon Cancer ◽  
Thiadiazole Derivatives ◽  
Ht 29

Background: Colon cancer is one of the most widespread disease, the mortality rate is high due to cancer metastasis and the development of drug resistance. In this regards, new chemotherapeutic agents with specific mechanisms of action and significant effect on patient’s survival are the new era for the colon cancer drug development. Objective: The main objective of present study was to design, synthesize of a novel series of 1,3,4-thiadiazole derivatives (VR1 to VR35) and screen them against HT-29 human colon cancer cell line. Method: Newly 1,3,4-thiadiazole scaffold were designed, synthesized and further, characterized by FTIR, NMR (1H and 13C), MS and elemental analyses. Before the synthesis, molecular dynamic simulation and ADME studies were performed to find out the most potent lead compounds. Later, SRB assay using HT-29 cells and ELISA assays were performed to explore activity and molecular targets of VR24 and VR27 and find out whether in silico data had a similar pattern in the molecular level. Results: The results of docking study revealed that both VR24 and VR27 had interaction energy >-5 kcal/mol with various assigned molecular targets and the ligand-protein complexes were found to be stable with IL-6. The computational analysis of molecules showed good ADMET profiling. Later, the in vitro anticancer study was conducted where VR24 and VR27 were found to be active against HT-29 cells (GI50<10 µM). Finally, ELISA assays revealed that both the compounds had higher inhibition properties to various biomarker of colon cancer like IL-6 and COX-2. Conclusion: Collectively, these result suggested that VR24 and VR27 inhibited the assigned molecular targets, imparting their ameliorative effects against colon cancer. Due to these encouraging results, we concluded that both VR24 and VR27 may be effective against colon cancer therapy in future.

Preliminary Report of In vitro and In vivo Effectiveness of Dornase Alfa on SARS-CoV-2 Infection (Preprint)

2020 ◽  
Author(s):  
Hacer Kuzu Okur ◽  
Koray Yalcin ◽  
Cihan Tastan ◽  
Sevda Demir ◽  
Bulut Yurtsever ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Respiratory Tract ◽  
Mononuclear Cells ◽  
Multiple Organ ◽  
Peripheral Blood Mononuclear ◽  
Dornase Alfa ◽  
Tract Infections ◽  
Adult Peripheral Blood

UNSTRUCTURED Dornase alfa, the recombinant form of the human DNase I enzyme, breaks down neutrophil extracellular traps (NET) that include a vast amount of DNA fragments, histones, microbicidal proteins and oxidant enzymes released from necrotic neutrophils in the highly viscous mucus of cystic fibrosis patients. Dornase alfa has been used for decades in patients with cystic fibrosis to reduce the viscoelasticity of respiratory tract secretions, to decrease the severity of respiratory tract infections, and to improve lung function. Previous studies have linked abnormal NET formations to lung diseases, especially to acute respiratory distress syndrome (ARDS). Coronavirus disease 2019 (COVID-19) pandemic affected more than two million people over the world, resulting in unprecedented health, social and economic crises. The COVID-19, viral pneumonia that progresses to ARDS and even multiple organ failure, is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). High blood neutrophil levels are an early indicator of SARS-CoV-2 infection and predict severe respiratory diseases. A similar mucus structure is detected in COVID-19 patients due to the accumulation of excessive NET in the lungs. Here, we show our preliminary results with dornase alfa that may have an in-vitro anti-viral effect against SARS-CoV-2 infection in a bovine kidney cell line, MDBK without drug toxicity on healthy adult peripheral blood mononuclear cells. In this preliminary study, we also showed that dornase alfa can promote clearance of NET formation in both an in-vitro and three COVID-19 cases who showed clinical improvement in radiological analysis (2-of-3 cases), oxygen saturation (SpO2), respiratory rate, disappearing of dyspnea and coughing.

Sign in / Sign up

Export Citation Format

Share Document