scholarly journals Synergistic or Antagonist Effects of Different UV Ranges Analyzed by the Combination Index: Application to DNA Photoproducts

2021 ◽  
Author(s):  
Thierry Douki ◽  
Arnaud Buhot
Keyword(s):  
Combination Index ◽  
Dna Photoproducts

scholarly journals A Yes-Associated Protein (YAP) and Insulin-Like Growth Factor 1 Receptor (IGF-1R) Signaling Loop Is Involved in Sorafenib Resistance in Hepatocellular Carcinoma

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3812
Author(s):  
Mai-Huong T. Ngo ◽  
Sue-Wei Peng ◽  
Yung-Che Kuo ◽  
Chun-Yen Lin ◽  
Ming-Heng Wu ◽  
...  
Keyword(s):  
Nuclear Translocation ◽  
Combination Index ◽  
Specific Inhibitor ◽  
In Vivo Model ◽  
Mrna Levels ◽  
Margin Distribution ◽  
Related Proteins ◽  
Emt Markers

The role of a YAP-IGF-1R signaling loop in HCC resistance to sorafenib remains unknown. Method: Sorafenib-resistant cells were generated by treating naïve cells (HepG2215 and Hep3B) with sorafenib. Different cancer cell lines from databases were analyzed through the ONCOMINE web server. BIOSTORM–LIHC patient tissues (46 nonresponders and 21 responders to sorafenib) were used to compare YAP mRNA levels. The HepG2215_R-derived xenograft in SCID mice was used as an in vivo model. HCC tissues from a patient with sorafenib failure were used to examine differences in YAP and IGF-R signaling. Results: Positive associations exist among the levels of YAP, IGF-1R, and EMT markers in HCC tissues and the levels of these proteins increased with sorafenib failure, with a trend of tumor-margin distribution in vivo. Blocking YAP downregulated IGF-1R signaling-related proteins, while IGF-1/2 treatment enhanced the nuclear translocation of YAP in HCC cells through PI3K-mTOR regulation. The combination of YAP-specific inhibitor verteporfin (VP) and sorafenib effectively decreased cell viability in a synergistic manner, evidenced by the combination index (CI). Conclusion: A YAP-IGF-1R signaling loop may play a role in HCC sorafenib resistance and could provide novel potential targets for combination therapy with sorafenib to overcome drug resistance in HCC.

scholarly journals Dasatinib (BMS-35482) Interacts Synergistically With Docetaxel, Gemcitabine, Topotecan, and Doxorubicin in Ovarian Cancer Cells With High SRC Pathway Activation and Protein Expression

2014 ◽  
Vol 24 (2) ◽  
pp. 218-225 ◽  
Author(s):  
Angeles Alvarez Secord ◽  
Deanna Teoh ◽  
Jingquan Jia ◽  
Andrew B. Nixon ◽  
Lisa Grace ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Protein Expression ◽  
Cancer Cells ◽  
Combination Index ◽  
Chemotherapeutic Agents ◽  
Cytotoxic Agents ◽  
Ovarian Cancer Cells ◽  
Response Curves ◽  
Pathway Activation ◽  
Skov3 Cells

PurposeThis study aimed to explore the activity of dasatinib in combination with docetaxel, gemcitabine, topotecan, and doxorubicin in ovarian cancer cells.MethodsCells with previously determined SRC pathway and protein expression (SRC pathway/SRC protein IGROV1, both high; SKOV3, both low) were treated with dasatinib in combination with the cytotoxic agents. SRC and paxillin protein expression were determined pretreatment and posttreatment. Dose-response curves were constructed, and the combination index (CI) for drug interaction was calculated.ResultsIn the IGROV1 cells, dasatinib alone reduced phospho-SRC/total SRC 71% and p-paxillin/t-paxillin ratios 77%. Phospho-SRC (3%–33%; P = 0.002 to 0.04) and p-paxicillin (6%–19%; P = 0.01 to 0.05) levels were significantly reduced with dasatinib in combination with each cytotoxic agent. The combination of dasatinib and docetaxel, gemcitabine, or topotecan had a synergistic antiproliferative effect (CI, 0.49–0.68), whereas dasatinib combined with doxorubicin had an additive effect (CI, 1.08).In SKOV3 cells, dasatinib resulted in less pronounced reductions of phospho-SRC/total SRC (49%) and p-paxillin/t-paxillin (62%). Phospho-SRC (18%; P < 0.001) and p-paxillin levels (18%; P = 0.001; 9%; P = 0.007) were significantly decreased when dasatinib was combined with docetaxel and topotecan (p-paxillin only). Furthermore, dasatinib combined with the cytotoxics in the SKOV3 cells produced an antagonistic interaction on the proliferation of these cells (CI, 1.49–2.27).ConclusionsDasatinib in combination with relapse chemotherapeutic agents seems to interact in a synergistic or additive manner in cells with high SRC pathway activation and protein expression. Further evaluation of dasatinib in combination with chemotherapy in ovarian cancer animal models and exploration of the use of biomarkers to direct therapy are warranted.

scholarly journals The binary, ternary and quaternary mixture toxicity of benzo[a]pyrene, arsenic, cadmium and lead in HepG2 cells

2016 ◽  
Vol 5 (2) ◽  
pp. 703-713 ◽  
Author(s):  
Sasikumar Muthusamy ◽  
Cheng Peng ◽  
Jack C. Ng
Keyword(s):  
Heavy Metal ◽  
Hepg2 Cells ◽  
Combination Index ◽  
Mixture Toxicity ◽  
Quaternary Mixture ◽  
Cadmium And Lead

The toxicity of multi-component mixtures of B[a]P and heavy metal/loid(s) was determined in HepG2 cells. Concentration dependent synergism, additivity or antagonism was predicted by the combination-index isobologram method.

Solar Radiation Induced Skin Cancer and DNA Photoproducts in Humans

1990 ◽  
pp. 83-94
Author(s):  
Paul T. Strickland ◽  
Benjamin C. Vitasa ◽  
Magnus Bruze ◽  
Edward A. Emmett ◽  
Sheila West ◽  
...  
Keyword(s):  
Skin Cancer ◽  
Solar Radiation ◽  
Radiation Induced ◽  
Dna Photoproducts

scholarly journals Intragenomic variability and extended sequence patterns in the mutational signature of ultraviolet light

2019 ◽  
Vol 116 (41) ◽  
pp. 20411-20417 ◽  
Author(s):  
Markus Lindberg ◽  
Martin Boström ◽  
Kerryn Elliott ◽  
Erik Larsson
Keyword(s):  
Uv Light ◽  
Promoter Regions ◽  
Additional Information ◽  
Pyrimidine Dimers ◽  
Genome Wide ◽  
Extended Sequence ◽  
Dna Photoproducts ◽  
Sequence Characteristics ◽  
Mutational Processes ◽  
Mutational Process

Mutational signatures can reveal properties of underlying mutational processes and are important when assessing signals of selection in cancer. Here, we describe the sequence characteristics of mutations induced by ultraviolet (UV) light, a major mutagen in several human cancers, in terms of extended (longer than trinucleotide) patterns as well as variability of the signature across chromatin states. Promoter regions display a distinct UV signature with reduced TCG > TTG transitions, and genome-wide mapping of UVB-induced DNA photoproducts (pyrimidine dimers) showed that this may be explained by decreased damage formation at hypomethylated promoter CpG sites. Further, an extended signature model encompassing additional information from longer contextual patterns improves modeling of UV mutations, which may enhance discrimination between drivers and passenger events. Our study presents a refined picture of the UV signature and underscores that the characteristics of a single mutational process may vary across the genome.

The in vitro antimalarial interaction of 9-hydroxycalabaxanthone and α-mangostin with mefloquine/artesunate

2014 ◽  
Vol 60 (1) ◽  
Author(s):  
Wanna Chaijaroenkul ◽  
Kesara Na-Bangchang
Keyword(s):  
Plasmodium Falciparum ◽  
Multidrug Resistance ◽  
Drug Concentration ◽  
Combination Index ◽  
Antimalarial Drugs ◽  
Antagonistic Effect ◽  
Parasite Growth ◽  
Major Health Problem ◽  
Major Health

AbstractMultidrug resistance Plasmodium falciparum is the major health problem in Thailand. Discovery and development of new antimalarial drugs with novel modes of action is urgently required. The aim of the present study was to investigate the antimalarial interaction of 9-hydroxycalabaxanthone and α-mangostin with the standard antimalarial drugs mefloquine and artesunate in chloroquine sensitive (3D7) and chloroquine resistant (K1) P. falciparum clones in vitro. Median (range) IC50 (drug concentration which produces 50% parasite growth inhibition) values of the 9-hydroxycalabaxanthone, α-mangostin, artesunate and mefloquine for 3D7 vs K1 clones were 1.5 (0.9-2.1) vs 1.2 (1.1-1.6) μM, 17.9 (15.7.0-20.0) vs 9.7 (6.0-14.0) μM, 1.0 (0.4-3.0) vs 1.7 (1.0-2.5) nM, and 13.3 (11.1-13.3) vs 7.1 (6.7-12.2) nM, respectively. Analysis of isobologram and combination index (CI) of 9-hydroxycalabaxanthone with artesunate or mefloquine showed synergistic and indifference antimalarial interaction, respectively. α-mangostin-artesunate combination exhibited a slight antagonistic effect of antimalarial interaction, whereas α-mangostin and mefloquine combination showed indifference interaction in both clones. The combination of 9-hydroxycalabaxanthone with α-mangostin showed the synergistic antimalarial interaction in both clones

scholarly journals The Protective Effect of Silybin against Lasalocid Cytotoxic Exposure on Chicken and Rat Cell Lines

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Lidia Radko ◽  
Wojciech Cybulski ◽  
Wojciech Rzeski
Keyword(s):  
Cell Lines ◽  
Combination Index ◽  
Protective Effects ◽  
Cytoprotective Effect ◽  
Silybum Marianum ◽  
Considerable Decrease ◽  
Combined Use ◽  
Herbal Compound ◽  
Mtt Reduction ◽  
Coomassie Brilliant

Lasalocid, an ionophore coccidiostat, extensive use implies a risk of toxicological impacts. Protective effects of silybin, a herbal compound ofSilybum marianum, are reported elsewhere. The aim of this study was to compare effects of the combined use of lasalocid and silybin in chicken hepatoma cells (LMH) and rat myoblasts (L6) cell lines cultures. The cytoprotective effect resulting from an interaction of both pharmaceuticals was measured with the help of MTT reduction and, coomassie brilliant blue binding (CBB) and LDH release assays. Isobolography and the combination index (CI) estimated the nature and scale of interaction. In all performed tests, the lowest lasalocid EC50-values were obtained for chicken hepatocytes. In the rat myoblasts cultures, the lowest lasalocid EC50-values were found with LDH test. Simultaneously, a lack of silybin cytotoxic effect was proven for the studied cell lines. An interaction between both substances led to a considerable decrease of lasalocid cytotoxicity. The isobolograms and combination index showed a significant antagonistic nature of silybin effect in the course of lasalocid cytotoxicity. It is concluded that the mechanism of cytoprotection results from complex reaction at biochemical and biophysical endpoints during chicken hepatocytes and rat myoblasts cell lines exposure to silybin and lasalocid co-action.

Sign in / Sign up

Export Citation Format

Share Document