Genetic of radiation-induced toxicities in cancer patients

Cancer remains a leading cause of death globally, and radiotherapy has contributed significantly to improvements in the treatment of cancer patients. However, not every cancer responds to radiotherapy in the same way. Despite applying uniform treatment protocols for radiotherapy to minimize damage to the surrounding healthy tissue, a large patient-to-patient variability exists in radiation-induced toxicities. Many cancer patients achieve survivorship at the cost of treatment complications occurring in normal tissues. However, the solution is not to eliminate radiation exposure but to protect individuals who are the most sensitive to radiation and minimize dose and exposure to all individuals.In this thesis, I focused on uncovering the underlying genetic causes of individual variation in sensitivity to radiation in cancer patients. I applied various genetic epidemiological designs, methods, and concepts in a range of studies to identify genetic variants associated with radiation-induced toxicities in cancer patients. Eventually, this thesis identified several genomic regions associated with radiation-induced toxicities. In addition, the thesis showed for the first time, radiation-induced toxicities are mostly heritable and predictable by genetic profiles of cancer patients. The identified predictors aim to contribute to an algorithm to improve the guidelines of therapeutic decisions. Patients at high risk of developing radiation-induced toxicities may be offered an alternative treatment approach, or, for patients who have received radiotherapy, advanced planning corrections can be introduced to better-individualized radiotherapy treatment. In addition to predictive and prognostic testing, the products of the identified genes could become targets for innovative therapies in susceptible individuals

Assessment of flocculation induced by pH increase for harvesting microalgae Cyanothece sp.

One of the most important challenges lies in the microalgae mass production is the high cost of harvesting process which is the separation of a low amount of biomass consisting of small individual cells from a large volume of culture medium. Therefore, finding an efficient and cost-effective technique for harvesting microalgae is important issue. In the current study, pH-induced flocculation method was tested for microalgae Cyanothece sp. harvesting. The halophilic microalgae were cultured and grown in laboratory with hypersaline water in F/2 medium. After reaching the stationary phase, the impact of pH induction (from natural medium culture pH:8.2 to pH:11) on flocculation efficiency, chlorophyll a, chlorophyll b, total carotenoid, β-Carotene and phycocyanin component and the possibility of reuse flocculated medium of microalgae Cyanothece sp. were evaluated. The results indicated that the increasing the medium pH value by adding NaOH from pH natural at 8.2 to 9.4 increased flocculation efficiency significantly from 10 up to 90% (P<0.05), but after that remained stable up to pH: 11. Regarding the pigment content, the increase in pH value from natural pH: 8.2 to pH: 9.1 had a relatively a medium effect on pigment components, including chlorophyll a, chlorophyll b, total carotenoid, β-Carotene and phycocyanin amount of the harvested biomass of Cyanothece sp, but after that from pH: 9.4 to 11 the reduction was severe. The medium culture from pH: 8.5 to pH: 11 was reusable for new culture of microalgae. Thus, the flocculation induced by pH increase up to pH: 9.1 is a suitable method for harvesting microalgae Cyanothece sp. with no serious adverse effect on pigment component

Association of retinopathy and intima media thickness of common carotid artery in type 2 diabetic patients

Background: This study was carried out in order to evaluate the relationship between retinopathy and carotid intima-media thickness (CIMT). Materials and Methods: In a cross-sectional study, 154 diabetic patients who had a history of diabetic disease were evaluated in two equal groups of 77 patients with and without retinopathy, respectively. CIMT was evaluated in all of the patients. Results: Mean age of the patients was 59.65 +/- 9.37 years. Mean CIMT of all patients was 0.84 +/- 0.18. CIMT of patients with retinopathy was significantly greater than patients without retinopathy (P < 0.001). CIMT also correlated with age, duration of diabetes, systolic blood pressure, blood urea nitrogen, and serum creatinine. Conclusion: CIMT may be used as a simple, available and noninvasive method for screening of macro and microvascular complication of diabetic patients

The Progress and Pitfalls of Pharmacogenetics-Based Precision Medicine in Schizophrenia Spectrum Disorders:A Systematic Review and Meta-Analysis

The inadequate efficacy and adverse effects of antipsychotics severely affect the recovery of patients with schizophrenia spectrum disorders (SSD). We report the evidence for associations between pharmacogenetic (PGx) variants and antipsychotics outcomes, including antipsychotic response, antipsychotic-induced weight/BMI gain, metabolic syndrome, antipsychotic-related prolactin levels, antipsychotic-induced tardive dyskinesia (TD), clozapine-induced agranulocytosis (CLA), and drug concentration level (pharmacokinetics) in SSD patients. Through an in-depth systematic search in 2010–2022, we identified 501 records. We included 29 meta-analyses constituting pooled data from 298 original studies over 69 PGx variants across 39 genes, 4 metabolizing phenotypes of CYP2D9, and 3 of CYP2C19. We observed weak unadjusted nominal significant (p &lt; 0.05) additive effects of PGx variants of DRD1, DRD2, DRD3, HTR1A, HTR2A, HTR3A, and COMT (10 variants) on antipsychotic response; DRD2, HTR2C, BDNF, ADRA2A, ADRB3, GNB3, INSIG2, LEP, MC4R, and SNAP25 (14 variants) on weight gain; HTR2C (one variant) on metabolic syndrome; DRD2 (one variant) on prolactin levels; COMT and BDNF (two variants) on TD; HLA-DRB1 (one variant) on CLA; CYP2D6 (four phenotypes) and CYP2C19 (two phenotypes) on antipsychotics plasma levels. In the future, well-designed longitudinal naturalistic multi-center PGx studies are needed to validate the effectiveness of PGx variants in antipsychotic outcomes before establishing any reproducible PGx passport in clinical practice.</p

Network of microRNAs-mRNAs Interactions in Pancreatic Cancer

Background. MicroRNAs are small RNA molecules that regulate the expression of certain genes through interaction with mRNA targets and are mainly involved in human cancer. This study was conducted to make the network of miRNAs-mRNAs interactions in pancreatic cancer as the fourth leading cause of cancer death. Methods. 56 miRNAs that were exclusively expressed and 1176 genes that were downregulated or silenced in pancreas cancer were extracted from beforehand investigations. MiRNA-mRNA interactions data analysis and related networks were explored using MAGIA tool and Cytoscape 3 software. Functional annotations of candidate genes in pancreatic cancer were identified by DAVID annotation tool. Results. This network is made of 217 nodes for mRNA, 15 nodes for miRNA, and 241 edges that show 241 regulations between 15 miRNAs and 217 target genes. The miR-24 was the most significantly powerful miRNA that regulated series of important genes. ACVR2B, GFRA1, and MTHFR were significant target genes were that downregulated. Conclusion. Although the collected previous data seems to be a treasure trove, there was no study simultaneous to analysis of miRNAs and mRNAs interaction. Network of miRNA-mRNA interactions will help to corroborate experimental remarks and could be used to refine miRNA target predictions for developing new therapeutic approaches

A two-stage genome-wide association study of radiation-induced acute toxicity in head and neck cancer

BACKGROUND: Most head and neck cancer (HNC) patients receive radiotherapy (RT) and develop toxicities. This genome-wide association study (GWAS) was designed to identify single nucleotide polymorphisms (SNPs) associated with common acute radiation-induced toxicities (RITs) in an HNC cohort. METHODS: A two-stage GWAS was performed in 1279 HNC patients treated with RT and prospectively scored for mucositis, xerostomia, sticky saliva, and dysphagia. The area under the curve (AUC) was used to estimate the average load of toxicity during RT. At the discovery study, multivariate linear regression was used in 957 patients, and the top-ranking SNPs were tested in 322 independent replication cohort. Next, the discovery and the replication studies were meta-analyzed. RESULTS: A region on 5q21.3 containing 16 SNPs showed genome-wide (GW) significance association at P-value < 5.0 × 10-8 with patient-rated acute xerostomia in the discovery study. The top signal was rs35542 with an adjusted effect size of 0.17*A (95% CI 0.12 to 0.23; P-value <  = 3.78 × 10-9). The genome wide significant SNPs were located within three genes (EFNA5, FBXL17, and FER). In-silico functional analysis showed these genes may be involved in DNA damage response and co-expressed in minor salivary glands. We found 428 suggestive SNPs (P-value < 1.0 × 10-5) for other toxicities, taken to the replication study. Eleven of them showed a nominal association (P-value < 0.05). CONCLUSIONS: This GWAS suggested novel SNPs for patient-rated acute xerostomia in HNC patients. If validated, these SNPs and their related functional pathways could lead to a predictive assay to identify sensitive patients to radiation, which may eventually allow a more individualized RT treatment

Large-scale meta-genome-wide association study reveals common genetic factors linked to radiation-induced acute toxicities across cancer types

Meta-genome; Toxicities; CancerMetagenoma; Toxicidades; CáncerMetagenoma; Toxicitats; CàncerBackground This study was designed to identify common genetic susceptibility and shared genetic variants associated with acute radiation-induced toxicity across 4 cancer types (prostate, head and neck, breast, and lung). Methods A genome-wide association study meta-analysis was performed using 19 cohorts totaling 12 042 patients. Acute standardized total average toxicity (STATacute) was modelled using a generalized linear regression model for additive effect of genetic variants, adjusted for demographic and clinical covariates (rSTATacute). Linkage disequilibrium score regression estimated shared single-nucleotide variation (SNV—formerly SNP)–based heritability of rSTATacute in all patients and for each cancer type. Results Shared SNV-based heritability of STATacute among all cancer types was estimated at 10% (SE = 0.02) and was higher for prostate (17%, SE = 0.07), head and neck (27%, SE = 0.09), and breast (16%, SE = 0.09) cancers. We identified 130 suggestive associated SNVs with rSTATacute (5.0 × 10‒8 < P < 1.0 × 10‒5) across 25 genomic regions. rs142667902 showed the strongest association (effect allele A; effect size ‒0.17; P = 1.7 × 10‒7), which is located near DPPA4, encoding a protein involved in pluripotency in stem cells, which are essential for repair of radiation-induced tissue injury. Gene-set enrichment analysis identified ‘RNA splicing via endonucleolytic cleavage and ligation’ (P = 5.1 × 10‒6, P = .079 corrected) as the top gene set associated with rSTATacute among all patients. In silico gene expression analysis showed that the genes associated with rSTATacute were statistically significantly up-regulated in skin (not sun exposed P = .004 corrected; sun exposed P = .026 corrected). Conclusions There is shared SNV-based heritability for acute radiation-induced toxicity across and within individual cancer sites. Future meta–genome-wide association studies among large radiation therapy patient cohorts are worthwhile to identify the common causal variants for acute radiotoxicity across cancer types.E.N. was supported by a scholarship for a PhD from the University of Groningen, Groningen, The Netherlands. T.D. is funded as an Academic Clinical Fellow by the National Institute for Health Research, UK. D.J.T. is supported by a grant from The Taylor Family Foundation and Cancer Research UK [C19941/A30286]. M.L.K.C. is supported by the National Medical Research Council Singapore Clinician Scientist Award (NMRC/CSA-INV/0027/2018), National Research Foundation Proton Competitive Research Program (NRF-CRP17-2017-05), Ministry of Education Tier 3 Academic Research Fund (MOE2016-T3-1-004), the Duke-NUS Oncology Academic Program Goh Foundation Proton Research Programme, NCCS Cancer Fund, and the Kua Hong Pak Head and Neck Cancer Research Programme. G.C.B. is supported by Cancer research UK RadNet Cambridge [C17918/A28870]. RADIOGEN research was supported by Spanish Instituto de Salud Carlos III (ISCIII) funding, an initiative of the Spanish Ministry of Economy and Innovation partially supported by European Regional Development FEDER Funds (INT20/00071, INT15/00070, INT17/00133, INT16/00154; PI19/01424; PI16/00046; PI13/02030; PI10/00164); by AECC grant PRYES211091VEGA and through the Autonomous Government of Galicia (Consolidation and structuring program: IN607B). C.N.A. and L.M.H.S. received funding from the Danish Cancer Society (grant R231-A14074-B2537). T.R. was funded by a National Institutes of Health Research (NIHR) Clinical Lectureship (CL 2017-11-002) and is supported by the NIHR Leicester Biomedical Research Centre. This publication presents independent research funded by the NIHR. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. REQUITE received funding from the European Union’s Seventh Framework Programme for research, technological development, and demonstration under grant agreement No. 601826. S.G.E. is supported by the government of Catalonia 2021SGR01112. L.D. was supported by the European Union Horizon 2020 research and innovation programs BRIDGES (grant No. 634935)