Intrauterine growth restriction (IUGR) and preeclampsia (PE) are placental pathologies known to complicate pregnancy and cause neonatal disorders. To date, there is a limited number of studies on the genetic similarity of these conditions. DNA methylation is a heritable epigenetic process that can regulate placental development. Our objective was to identify methylation patterns in placental DNA from normal, PE and IUGR-affected pregnancies. DNA was extracted, and bisulfite was converted, prior to being hybridized for the methylation array. Methylation data were SWAN normalized and differently methylated regions were identified using applications within the USEQ program. UCSC’s Genome browser and Stanford’s GREAT analysis were used to identify gene promoters. The commonality among affected genes was confirmed by Western blot. We observed nine significantly hypomethylated regions, two being significantly hypomethylated for both PE and IGUR. Western blot confirmed differential protein expression of commonly regulated genes. We conclude that despite the uniqueness of methylation profiles for PE and IUGR, the similarity of some methylation alterations in pathologies could explain the clinical similarities observed with these obstetric complications. These results also provide insight into the genetic similarity between PE and IUGR and suggest possible gene candidates plausibly involved in the onset of both conditions.

BackgroundPembrolizumab is FDA approved for tumors with tumor mutational burden (TMB) of ≥10 mutations/megabase (mut/Mb). However, the response to immune checkpoint inhibitors (ICI) varies significantly among cancer histologies. We describe the landscape of frameshift mutations (FSs) and evaluated their role as a predictive biomarker to ICI in a clinical cohort of patients.MethodsComprehensive genomic profiling was performed on a cohort of solid tumor samples examining at least 324 genes. The clinical cohort included patients with metastatic solid malignancies who received ICI monotherapy and had tumor sequencing. Progression-free survival (PFS), overall survival, and objective response rates (ORR) were compared between the groups.ResultsWe analyzed 246,252 microsatellite stable (MSS) and 4561 samples with microsatellite instability across solid tumors. Histologies were divided into groups according to TMB and FS. MSS distribution: TMB-L (<10 mut/Mb)/FS-A (absent FS) (N=111,065, 45%), TMB-H (≥10 mut/Mb)/FS-A (N=15,313, 6%), TMB-L/FS-P (present ≥1 FS) (N=98,389, 40%) and TMB-H/FS-P (N=21,485, 9%). FSs were predominantly identified in the p53 pathway. In the clinical cohort, 212 patients were included. Groups: TMB-L/FS-A (N=80, 38%), TMB-H/FS-A (N=36, 17%), TMB-L/FS-P (N=57, 27%), TMB-H/FS-P (N=39, 18%). FSs were associated with a higher ORR to ICI, 23.8% vs 12.8% (p=0.02). TMB-L/FS-P had superior median PFS (5.1 months) vs TMB-L/FS-A (3.6 months, p<0.01). The 12-month PFS probability was 34% for TMB-L/FS-P vs 17.1% for TMB-L/FS-A.ConclusionsFSs are found in 47% of patients with MSS/TMB-L solid tumors in a pan-cancer cohort. FS may complement TMB in predicting immunotherapy responses, particularly for tumors with low TMB.

The placenta facilitates nutrient and gas exchange between the mother and the fetus. Intrauterine growth restriction (IUGR) and preeclampsia (PE) are placental pathologies known to cause pre‐term delivery and diverse disorders in neonates. Placental adversities during complicated pregnancy may cause epigenetic changes that can altered fetal development. DNA methylation is a heritable epigenetic process that can regulate important genetic mechanisms and processes critical for optimal placental and fetal development. Our objective was to determine differential placental DNA methylation from normal, PE and IUGR human patients. Placental DNA was extracted from PE, IUGR, and control patients. Extracted DNA was then bisulfite converted for DNA methylation analysis. Bisulfite‐converted DNA was hybridized to Illumina’s EPIC 850K methylation array for analysis. Methylation data was SWAN normalized and significant regions were identified using USEQ’s “methylation array scanner” and “enriched region maker” applications (with a threshold of significance of an adjusted p‐value < 0.001). UCSC’s Genome browser was used to identify potentially impacted gene promoters associated with differentially methylated regions. Additionally, Stanford’s GREAT analysis tool was used to perform a GO term analysis to find biological processes and cellular components associated with differentially methylated regions. We observed nine significantly hypomethylated regions, six for PE (including the HIST1H4L and NAPRT‐1) and three for IUGR (including CRABP1). Two regions significantly hypomethylated for both PE and IGUR gene promoters. We conclude that although we identified a unique methylation profile for both PE and IUGR, the overlap that was seen with some methylation alterations between the two pathologies could explain some of the clinical similarities observed during these obstetrics complications. Our results may provide some insights into placenta cell regulatory response to developmental syndromes. Information in these cellular components and biological pathways could be useful in determining cellular level responses to complicated diseases associated with PE and IUGR.