Cancer risk after ionizing radiation (IR) is assumed to be linear with the dose; however, for low doses, definite evidence is lacking. Here, using temporal multi-omic systems analyses after a low ... Show moreCancer risk after ionizing radiation (IR) is assumed to be linear with the dose; however, for low doses, definite evidence is lacking. Here, using temporal multi-omic systems analyses after a low (LD; 0.1 Gy) or a high (HD; 1 Gy) dose of X-rays, we show that, although the DNA damage response (DDR) displayed dose proportionality, many other molecular and cellular responses did not. Phosphoproteomics uncovered a novel mode of phospho-signaling via S12-PPP1R7, and large-scale dephosphorylation events that regulate mitotic exit control in undamaged cells and the G2/M checkpoint upon IR in a dose-dependent manner. The phosphoproteomics of irradiated DNA double-strand breaks (DSBs) repair-deficient cells unveiled extended phospho-signaling duration in either a dose-dependent (DDR signaling) or independent (mTOR-ERK-MAPK signaling) manner without affecting signal magnitude. Nascent transcriptomics revealed the transcriptional activation of genes involved in NRF2-regulated antioxidant defense, redox-sensitive ERK-MAPK signaling, glycolysis and mitochondrial function after LD, suggesting a prominent role for reactive oxygen species (ROS) in molecular and cellular responses to LD exposure, whereas DDR genes were prominently activated after HD. However, how and to what extent the observed dose-dependent differences in molecular and cellular responses may impact cancer development remain unclear, as the induction of chromosomal damage was found to be dose-proportional (10-200 mGy). Show less
Zazuli, Z.; Kos, R.; Veltman, J.D.; Uyterlinde, W.; Longo, C.; Baas, P.; ... ; Zee, A.H.M. van der 2020
Aim Antineoplastic effect of cisplatin, the first line treatment in non-small cell lung cancer (NSCLC), is hindered by its nephrotoxicity and myelotoxicity. Both low-dose and high-dose regimens are... Show moreAim Antineoplastic effect of cisplatin, the first line treatment in non-small cell lung cancer (NSCLC), is hindered by its nephrotoxicity and myelotoxicity. Both low-dose and high-dose regimens are used in the management of NSCLC. The aim of this study is to assess the risk on myelotoxicity and nephrotoxicity from the daily low-dose cisplatin (DLD) treatment as compared to cyclic high-dose cisplatin (CHD). Methods A retrospective cohort study was conducted. NSCLC patients treated with cisplatin between 2011 and 2018 in the Amsterdam UMC or Antoni van Leeuwenhoek cancer hospital were studied. Myelotoxicity and nephrotoxicity were defined based on common terminology criteria (CTCAE v4.03) and categorized as >= grade 1 and >= grade 2. Modified Poisson regression and Cox proportional hazards model were used to estimate relative risks and cumulative hazard respectively. Results Of the 115 NSCLC patients receiving DLD (N=62) and CHD (N=53), 60% had >= grade 1 anemia, 33.9% leukopenia, 31.3% neutropenia, 27.8% thrombocytopenia, 32.2% acute nephrotoxicity with combined definition (Cr-electrolyte nephrotoxicity), and 58.3% chronic nephrotoxicity. The DLD group was older, had an earlier cancer stage, had more comorbidities, and had higher baseline albumin levels. In the DLD group less >= grade 2 toxicities were reported compared to the CHD group except for Cr-electrolyte nephrotoxicity. However, there was a stronger association in the DLD group with >= grade 1 leukopenia, thrombocytopenia, and Cr-electrolyte nephrotoxicity. The DLD group developed significantly more >= grade 1 leukopenia [adjusted relative risk (adjRR)=1.83, 95% CI 1.02-3.27], thrombocytopenia (adjRR=3.43, 95% CI 1.64-7.15), and >= grade 2 Cr-electrolyte nephrotoxicity (adjRR=3.02, 95% CI 1.20-7.56). The DLD group had a lower adjusted cumulative hazard for developing >= grade 2 myelotoxicity and chronic nephrotoxicity but not for Cr-electrolyte nephrotoxicity [adjusted hazard ratio (adjHR)=3.90, 95% CI 1.35-11.23]. In contrast, DLD showed protective effect to >= grade 2 nephrotoxicity when definition was restricted to the traditional creatinine-based definition (adjRR=0.07, 95% CI 0.01-0.86; adjHR=0.05, 95% CI 0.01-0.56). Conclusions Overall, the DLD regimen was safer than the CHD regimen when assessing the risk of >= grade 2 myelotoxicity and nephrotoxicity. However, this might not be the case in patients with a higher risk of electrolyte abnormalities. Show less
