Genomic and in silico analyses of CRBN gene and thalidomide embryopathy in humans

Caldas-Garcia

et al. 2020

Sci Rep

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The Cereblon-CRL4 complex has been studied predominantly with regards to thalidomide treatment of multiple myeloma. Nevertheless, the role of Cereblon-CRL4 in Thalidomide Embryopathy (TE) is still not understood. Not all embryos exposed to thalidomide develop TE, hence here we evaluate the role of the CRL4-Cereblon complex in TE variability and susceptibility. We sequenced CRBN, DDB1, CUL4A, IKZF1, and IKZF3 in individuals with TE. To better interpret the variants, we suggested a score and a heatmap comprising their regulatory effect. Differential gene expression after thalidomide exposure and conservation of the CRL4-Cereblon protein complex were accessed from public repositories. Results suggest a summation effect of Cereblon variants on pre-axial longitudinal limb anomalies, and heatmap scores identify the CUL4A variant rs138961957 as potentially having an effect on TE susceptibility. CRL4-Cereblon gene expression after thalidomide exposure and CLR4-Cereblon protein conservation does not explain the difference in Thalidomide sensitivity between species. In conclusion, we suggest that CRL4-Cereblon variants act through several regulatory mechanisms, which may influence CRL4-Cereblon complex assembly and its ability to bind thalidomide. Human genetic variability must be addressed not only to further understand the susceptibility to TE, but as a crucial element in therapeutics, including in the development of pharmacogenomics strategies.

Section: Discussionsupporting

confidence: 92%

CRL4-Cereblon complex in Thalidomide Embryopathy: a translational investigation

Caldas-Garcia

et al. 2020

Sci Rep

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“…Some polymorphisms in humans can lead to higher or lower susceptibility to teratogen‐induced damage (Cassina, Salviati, Di Gianantonio, & Clementi, ). Our group has previously conducted exploratory studies in CRBN and angiogenesis‐related genes, and demonstrated that variants in these targets can help to understand TE scenario in humans (Kowalski et al, ; Vianna et al, ). In the present study, we evaluated whether a genetic predisposition to thalidomide embryopathy might be detected by analyzing polymorphisms in genes of pathways affected by this drug.…”

Section: Discussionmentioning

confidence: 99%

“…Saliva samples were collected and stored in DNA Oragene® Kits (Genotek). A sample of 135 individuals without congenital anomalies from the Brazilian population was used as a control group (Kowalski et al, , 2017Vianna et al, 2013Vianna et al, , 2016. These subjects were selected according to similar time and place of birth of the individuals with TE.…”

Section: Samplementioning

confidence: 99%

“…Our group has previously published studies in TE people who were assessed to CRBN ‐thalidomide binding region and angiogenesis‐related genes functional polymorphisms (Kowalski et al, ; Vianna et al, ), suggesting variants that could help to explain the role of molecular mechanisms in TE in humans. Here, we show results from the progress of our study about the genetic susceptibility of TE, in which we have analyzed genetic variants in genes involved in developmental processes in people with TE, comparing to people without malformations.…”

Section: Introductionmentioning

confidence: 99%

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Genetic susceptibility to thalidomide embryopathy in humans: Study of candidate development genes

Fraga

et al. 2017

Birth Defects Research

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Thalidomide is a drug used worldwide for several indications, but the molecular mechanisms of its teratogenic property are not fully understood. Studies in animal models suggest the oxidative stress, the inhibition of angiogenesis, and the binding to E3-ubiquitin ligase complex as mechanisms by which thalidomide can change the expression of genes important to embryonic development. In this study, seven polymorphisms in genes related to development (FGF8, FGF10, BMP4, SHH, TP53, TP63, and TP73) were analyzed in people with thalidomide embryopathy (TE) and compared to people without malformations. The sample consisted of 36 people with TE and 135 unrelated and nonsyndromic people who had their DNA genotyped by PCR real-time. Although no allelic or genotypic differences were observed between the groups, we hypothesized that other regions in these genes and related genes may play an important role in thalidomide teratogenesis, which is known to have a genetic contribution. Identifying such molecular mechanisms is essential for the development of a molecule that will be analogue to thalidomide but safe enough to avoid the emergence of new cases of TE.

“…without the teratogenic propriety). The embryonic genetic background is believed to act in the differential susceptibility to teratogen-induced damage 7,10–12 .…”

Section: Introductionmentioning

confidence: 99%

The role of ESCO2, SALL4 and TBX5 genes in the susceptibility to thalidomide teratogenesis

Fraga

et al. 2019

Sci Rep

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Thalidomide is widely used for several diseases; however, it causes malformations in embryos exposed during pregnancy. The complete understanding of the mechanisms by which thalidomide affects the embryo development has not yet been obtained. The phenotypic similarity makes TE a phenocopy of syndromes caused by mutations in ESCO2 , SALL4 and TBX5 genes. Recently, SALL4 and TBX5 were demonstrated to be thalidomide targets. To understand if these genes act in the TE development, we sequenced them in 27 individuals with TE; we verified how thalidomide affect them in human pluripotent stem cells (hPSCs) through a differential gene expression (DGE) analysis from GSE63935; and we evaluated how these genes are functionally related through an interaction network analysis. We identified 8 variants in ESCO2 , 15 in SALL4 and 15 in TBX5 . We compared allelic frequencies with data from ExAC, 1000 Genomes and ABraOM databases; eight variants were significantly different (p < 0.05). Eleven variants in SALL4 and TBX5 were previously associated with cardiac diseases or malformations; however, in TE sample there was no association. Variant effect prediction tools showed 97% of the variants with potential to influence in these genes regulation. DGE analysis showed a significant reduction of ESCO2 in hPSCs after thalidomide exposure.