Background & Aims: The dose and duration of mesalazine treatment for ulcerative colitis (UC) is a potentially important determinant of effectiveness, with evidence suggesting that continuing... Show moreBackground & Aims: The dose and duration of mesalazine treatment for ulcerative colitis (UC) is a potentially important determinant of effectiveness, with evidence suggesting that continuing the induction dose for 6-12 months may improve outcomes; however, real-world data are lacking. We assessed mesalazine use in Dutch clinical practice, including how differences in dose and duration affected UC outcomes. Methods: Adults with mild-to-moderate UC who received oral prolonged-release mesalazine de novo or had a dose escalation for an active episode were followed for 12 months in this non-interventional study (ClinicalTrials.gov identifier: NCT02261636). The primary endpoint was time from start of treatment to dose reduction (TDR). Secondary endpoints included recurrence rate, adherence, and work productivity. Results: In total, 151 patients were enrolled, of whom 108 (71.5%) were newly diagnosed with UC. The majority (120; 79.5%) received a dose of >= 4 g/day. Nearly one-third (48; 31.8%) underwent dose reduction, with mean TDR being 8.3 months. Disease extent and endoscopic appearance did not influence duration of induction therapy, while TDR increased with higher baseline UCDAI scores. TDR was longer in patients without (mean 8.8 months) than with (4.1 months) recurrence, although not significantly (p=0.09). Patients on >= 4 g/day had a significantly lower chance of recurrence versus those on 2-<4 g/day (26.6% vs 62.5%, respectively; p=0.04). Longer treatment duration was associated with significantly reduced recurrence risk [hazard ratio >6 months vs 3-6 months: 0.19 (95%CI: 0.08-0.46); p<0.05], particularly for those on >= 4 g/day [0.15 (0.06-0.40) vs 0.26 (0.01-11.9) for 2-<4 g/day). Patients reported significantly increased work productivity, which was maintained throughout follow-up. Conclusions: Mesalazine was effective induction therapy, with treatment duration not meaningfully influenced by disease extent and endoscopic appearance at initiation. A higher induction dose of oral mesalazine (>= 4 g/day) and longer duration of treatment (>6 months) was associated with a lower recurrence risk. Show less
West, R.; Russel, M.; Bodelier, A.; Kuijvenhoven, J.; Bruin, K.; Jansen, J.; ... ; Lubbinge, H. 2022
Background and Aims: The dose and duration of mesalazine treatment for ulcerative colitis (UC) is a potentially important determinant of effectiveness, with evidence suggesting that continuing the... Show moreBackground and Aims: The dose and duration of mesalazine treatment for ulcerative colitis (UC) is a potentially important determinant of effectiveness, with evidence suggesting that continuing the induction dose for 6-12 months may improve outcomes; however, real-world data are lacking. We assessed mesalazine use in Dutch clinical practice, including how differences in dose and duration affected UC outcomes.Methods: Adults with mild-to-moderate UC who received oral prolonged-release mesalazine de novo or had a dose escalation for an active episode were followed for 12 months in this non-interventional study (ClinicalTrials.gov identifier: NCT02261636). The primary endpoint was time from start of treatment to dose reduction (TDR). Secondary endpoints included recurrence rate, adherence, and work productivity.Results: In total, 151 patients were enrolled, of whom 108 (71.5%) were newly diagnosed with UC. The majority (120; 79.5%) received a dose of ≥4 g/day. Nearly one-third (48; 31.8%) underwent dose reduction, with mean TDR being 8.3 months. Disease extent and endoscopic appearance did not influence duration of induction therapy, while TDR increased with higher baseline UCDAI scores. TDR was longer in patients without (mean 8.8 months) than with (4.1 months) recurrence, although not significantly (p=0.09). Patients on ≥4 g/day had a significantly lower chance of recurrence versus those on 2-<4 g/day (26.6% vs 62.5%, respectively; p=0.04). Longer treatment duration was associated with significantly reduced recurrence risk [hazard ratio >6 months vs 3-6 months: 0.19 (95%CI: 0.08-0.46); p<0.05], particularly for those on ≥4 g/day [0.15 (0.06-0.40) vs 0.26 (0.01-11.9) for 2-<4 g/day). Patients reported significantly increased work productivity, which was maintained throughout follow-up.Conclusions: Mesalazine was effective induction therapy, with treatment duration not meaningfully influenced by disease extent and endoscopic appearance at initiation. A higher induction dose of oral mesalazine (≥4 g/day) and longer duration of treatment (>6 months) was associated with a lower recurrence risk. Show less
West, R.; Russel, M.; Bodelier, A.; Kuijvenhoven, J.; Bruin, K.; Jansen, J.; ... ; Lubbinge, H. 2022
Background and Aims: The dose and duration of mesalazine treatment for ulcerative colitis (UC) is a potentially important determinant of effectiveness, with evidence suggesting that continuing the... Show moreBackground and Aims: The dose and duration of mesalazine treatment for ulcerative colitis (UC) is a potentially important determinant of effectiveness, with evidence suggesting that continuing the induction dose for 6-12 months may improve outcomes; however, real-world data are lacking. We assessed mesalazine use in Dutch clinical practice, including how differences in dose and duration affected UC outcomes.Methods: Adults with mild-to-moderate UC who received oral prolonged-release mesalazine de novo or had a dose escalation for an active episode were followed for 12 months in this non-interventional study (ClinicalTrials.gov identifier: NCT02261636). The primary endpoint was time from start of treatment to dose reduction (TDR). Secondary endpoints included recurrence rate, adherence, and work productivity.Results: In total, 151 patients were enrolled, of whom 108 (71.5%) were newly diagnosed with UC. The majority (120; 79.5%) received a dose of ≥4 g/day. Nearly one-third (48; 31.8%) underwent dose reduction, with mean TDR being 8.3 months. Disease extent and endoscopic appearance did not influence duration of induction therapy, while TDR increased with higher baseline UCDAI scores. TDR was longer in patients without (mean 8.8 months) than with (4.1 months) recurrence, although not significantly (p=0.09). Patients on ≥4 g/day had a significantly lower chance of recurrence versus those on 2-<4 g/day (26.6% vs 62.5%, respectively; p=0.04). Longer treatment duration was associated with significantly reduced recurrence risk [hazard ratio >6 months vs 3-6 months: 0.19 (95%CI: 0.08-0.46); p<0.05], particularly for those on ≥4 g/day [0.15 (0.06-0.40) vs 0.26 (0.01-11.9) for 2-<4 g/day). Patients reported significantly increased work productivity, which was maintained throughout follow-up.Conclusions: Mesalazine was effective induction therapy, with treatment duration not meaningfully influenced by disease extent and endoscopic appearance at initiation. A higher induction dose of oral mesalazine (≥4 g/day) and longer duration of treatment (>6 months) was associated with a lower recurrence risk. Show less
Braak, S.J. ter; Niemeijer, M.C.; Wolters, L.; Le Dévédec, S.E.; Bouwman, R.J.P.; Water, B. van de 2021
In vitro assessment of mutagenicity is an essential component in the chemical risk assessment. Given the diverse modes of action by which chemicals can induce DNA damage, it is essential that these... Show moreIn vitro assessment of mutagenicity is an essential component in the chemical risk assessment. Given the diverse modes of action by which chemicals can induce DNA damage, it is essential that these in vitro assays are carefully evaluated for their possibilities and limitations. In this study, we used a fluorescent protein HepG2 reporter test system in combination with high content imaging. To measure induction of the DNA damage response (DDR), we used three different green fluorescent protein (GFP) reporters for p53 pathway activation. These allowed for accurate quantification of p53, p21 and BTG2 (BTG anti-proliferation factor 2) protein expression and cell viability parameters at a single cell or spheroid resolution. The reporter lines were cultured as 2D monolayers and as 3D spheroids. Furthermore, liver maturity and cytochrome P450 enzyme expression were increased by culturing in an amino acid rich (AAGLY) medium. We found that culture conditions that support a sustained proliferative state (2D culturing with DMEM medium) give superior sensitivity when genotoxic compounds are tested that do not require metabolization and of which the mutagenic mode of action is dependent on replication. For compounds, which are metabolically converted to mutagenic metabolites, more differentiated HepG2 DDR reporters (e.g., 3D cultures) showed a higher sensitivity. This study stratifies how different culture methods of HepG2 DDR reporter cells can influence the sensitivity towards diverse genotoxicants and how this provides opportunities for a tiered genotoxicity testing strategy. Show less
Koedoot, E.; Wolters, L.; Smid, M.; Stoilov, P.; Burger, G.A.; Herpers, B.H.A.; ... ; Water, B. van de 2021
Screening for effective candidate drugs for breast cancer has shifted from two-dimensional (2D) to three-dimensional (3D) cultures. Here we systematically compared the transcriptomes of these... Show moreScreening for effective candidate drugs for breast cancer has shifted from two-dimensional (2D) to three-dimensional (3D) cultures. Here we systematically compared the transcriptomes of these different culture conditions by RNAseq of 14 BC cell lines cultured in both 2D and 3D conditions. All 3D BC cell cultures demonstrated increased mitochondrial metabolism and downregulated cell cycle programs. Luminal BC cells in 3D demonstrated overall limited reprogramming. 3D basal B BC cells showed increased expression of extracellular matrix (ECM) interaction genes, which coincides with an invasive phenotype not observed in other BC cells. Genes downregulated in 3D were associated with metastatic disease progression in BC patients, including cyclin dependent kinases and aurora kinases. Furthermore, the overall correlation of the cell line transcriptome to the BC patient transcriptome was increased in 3D cultures for all TNBC cell lines. To define the most optimal culture conditions to study the oncogenic pathway of interest, an open source bioinformatics strategy was established. Show less
Koedoot, E.; Wolters, L.; Water, B. van de; Dévédec, S.E.L. 2019
By regulating transcript isoform expression levels, alternative splicing provides an additional layer of protein control. Recent studies show evidence that cancer cells use different splicing... Show moreBy regulating transcript isoform expression levels, alternative splicing provides an additional layer of protein control. Recent studies show evidence that cancer cells use different splicing events to fulfill their requirements in order to develop, progress and metastasize. However, there has been less attention for the role of the complex catalyzing the complicated multistep splicing reaction: the spliceosome. The spliceosome consists of multiple sub-complexes in total comprising 244 proteins or splice factors and 5 associated RNA molecules. Here we discuss the role of splice factors in the oncogenic processes tumors cells need to fulfill their oncogenic properties (the so-called the hallmarks of cancer). Despite the fact that splice factors have been investigated only recently, they seem to play a prominent role in already five hallmarks of cancer: angiogenesis, resisting cell death, sustaining proliferation, deregulating cellular energetics and invasion and metastasis formation by affecting major signaling pathways such as epithelial-to-mesenchymal transition, the Warburg effect, DNA damage response and hormone receptor dependent proliferation. Moreover, we could relate expression of representative genes of four other hallmarks (enabling replicative mortality, genomic instability, avoiding immune destruction and evading growth suppression) to splice factor levels in human breast cancer tumors, suggesting that also these hallmarks could be regulated by splice factors. Since many splice factors are involved in multiple hallmarks of cancer, inhibiting splice factors might provide a new layer of oncogenic control and a powerful method to combat breast cancer progression. Show less
Bischoff, L.J.M.; Kuijper, I.A.; Schimming, J.P.; Wolters, L.; Braak, B. ter; Langenberg, J.P.; ... ; Water, B. van de 2018
Oxidative stress leads to the activation of the Nuclear factor-erythroid-2-related factor 2 (Nrf2) pathway. While most studies have focused on the activation of the Nrf2 pathway after single... Show moreOxidative stress leads to the activation of the Nuclear factor-erythroid-2-related factor 2 (Nrf2) pathway. While most studies have focused on the activation of the Nrf2 pathway after single chemical treatment, little is known about the dynamic regulation of the Nrf2 pathway in the context of repeated exposure scenarios. Here we employed single cell live imaging to quantitatively monitor the dynamics of the Nrf2 pathway during repeated exposure, making advantage of two HepG2 fluorescent protein reporter cell lines, expressing GFP tagged Nrf2 or sulfiredoxin 1 (Srxn1), a direct downstream target of Nrf2. High throughput live confocal imaging was used to measure the temporal dynamics of these two components of the Nrf2 pathway after repeated exposure to an extensive concentration range of diethyl maleate (DEM) and tert-butylhydroquinone (tBHQ). Single treatment with DEM or tBHQ induced Nrf2 and Srxn1 over time in a concentration-dependent manner. The Nrf2 response to a second treatment was lower than the response to the first exposure with the same concentration, indicating that the response is adaptive. Moreover, a limited fraction of individual cells committed themselves into the Nrf2 response during the second treatment. Despite the suppression of the Nrf2 pathway, the second treatment resulted in a three-fold higher Srxn1-GFP response compared to the first treatment, with all cells participating in the response. While after the first treatment Srxn1-GFP response was linearly related to Nrf2-GFP nuclear translocation, such a linear relationship was less clear for the second exposure. siRNA-mediated knockdown demonstrated that the second response is dependent on the activity of Nrf2. Several other, clinically relevant, compounds (i.e., sulphorophane, nitrofurantoin and CDDO-Me) also enhanced the induction of Srxn1-GFP upon two consecutive repeated exposure. Together the data indicate that adaptation towards pro-oxidants lowers the Nrf2 activation capacity, but simultaneously primes cells for the enhancement of an antioxidant response which depends on factors other than just Nrf2. These data provide further insight in the overall dynamics of stress pathway activation after repeated exposure and underscore the complexity of responses that may govern repeated dose toxicity. Show less
