The clinical significance of the glucocorticoid receptors: Genetics and epigenetics

Phosphoproteomic analysis of the adaption of epididymal epithelial cells to corticosterone challenge

BACKGROUND

The epididymis has long been of interest owing to its role in promoting the functional maturation of the male germline. More recent evidence has also implicated the epididymis as an important sensory tissue responsible for remodeling of the sperm epigenome, both under physiological conditions and in response to diverse forms of environmental stress. Despite this knowledge, the intricacies of the molecular pathways involved in regulating the adaptation of epididymal tissue to paternal stressors remains to be fully resolved.

OBJECTIVE

The overall objective of this study was to investigate the direct impact of corticosterone challenge on a tractable epididymal epithelial cell line (i.e., mECap18 cells), in terms of driving adaptation of the cellular proteome and phosphoproteome signaling networks.

MATERIALS AND METHODS

The newly developed phosphoproteomic platform EasyPhos coupled with sequencing via an Orbitrap Exploris 480 mass spectrometer, was applied to survey global changes in the mECap18 cell (phospho)proteome resulting from sub-chronic (10-day) corticosterone challenge.

RESULTS

The imposed corticosterone exposure regimen elicited relatively subtle modifications of the global mECap18 proteome (i.e., only 73 out of 4171 [∼1.8%] proteins displayed altered abundance). By contrast, ∼15% of the mECap18 phosphoproteome was substantially altered following corticosterone challenge. In silico analysis of the corresponding parent proteins revealed an activation of pathways linked to DNA damage repair and oxidative stress responses as well as a reciprocal inhibition of pathways associated with organismal death. Corticosterone challenge also induced the phosphorylation of several proteins linked to the biogenesis of microRNAs. Accordingly, orthogonal validation strategies confirmed an increase in DNA damage, which was ameliorated upon selective kinase inhibition, and an altered abundance profile of a subset of microRNAs in corticosterone-treated cells.

CONCLUSIONS

Together, these data confirm that epididymal epithelial cells are reactive to corticosterone challenge, and that their response is tightly coupled to the opposing action of cellular kinases and phosphatases.

Diagnostic and therapeutic approaches for endometriosis: a patent landscape

OBJECTIVE

The aim of this review is to analyze the patent filings and to systematize the main technological trends in patent protection for the diagnosis and therapeutics for endometriosis. Patent literature has also been explored to identify active inventors and applicants in this field.

METHODOLOGY

Patent search was carried out in the freely accessible patent search databases namely, patentscope using various combinations of the keywords "Endometriosis OR Adenomyosis" AND "Diagnostic OR Therapeutics" were used along with wildcard search queries in the "Title", "Abstract" and "Descriptions" fields.

RESULTS

A patent search revealed 144 patents describing inventions for diagnostic and therapeutic purposes of endometriosis. These patents include 26 patent applications in the diagnostic utility and 116 patent applications under the therapeutic approaches. Out of these 116 patent applications, 43 describe traditional medicines for endometriosis. Two patent applications describe inventions that can fall into both categories.

CONCLUSION

Efforts are being made to improve current diagnostic instruments. Hormonal alteration methods is the most common field of invention, followed by surgical interventions for therapeutics. A general trend of increase in patent application filings has been observed with a slight decrease in recent years.

Glucocorticoid and Adrenergic Receptor Distribution Across Human Organs and Tissues: A Map for Stress Transduction

OBJECTIVE

Psychosocial stress is transduced into disease risk through energy-dependent release of hormones from the hypothalamic-pituitary-adrenal and sympathetic-adrenal-medullary axes. The levels of glucocorticoid and adrenergic hormones, together with the sensitivity of tissues to their signaling, define stress responses. To understand existing pathways responsible for the psychobiological transduction of stressful experiences, we provide a quantitative whole-body map of glucocorticoid and adrenergic receptor (AR) expression.

METHODS

We systematically examined gene expression levels for the glucocorticoid receptor (GR), α- and β-ARs (AR-α1B, AR-α2B AR-β2, and AR-β3), across 55 different organs using the Human Protein Atlas and Human Proteome Map datasets. Given that mitochondria produce the energy required to respond to stress, we leveraged the Human Protein Atlas and MitoCarta3.0 data to examine the link between stress hormone receptor density and mitochondrial gene expression. Finally, we tested the functional interplay between GR activation and AR expression in human fibroblast cells.

RESULTS

The GR was expressed ubiquitously across all investigated organ systems, whereas AR subtypes showed lower and more localized expression patterns. Receptor co-regulation, meaning the correlated gene expression of multiple stress hormone receptors, was found between GR and AR-α1B, as well as between AR-α1B and AR-α2B. In cultured human fibroblasts, activating the GR selectively increased AR-β2 and AR-α1B expression. Consistent with the known energetic cost of stress responses, GR and AR expressions were positively associated with the expression of specific mitochondrial pathways.

CONCLUSIONS

Our results provide a cartography of GR and AR expression across the human body. Because stress-induced GR and AR signaling triggers energetically expensive cellular pathways involving energy-transforming mitochondria, the tissue-specific expression and co-expression patterns of hormone receptor subtypes may in part determine the resilience or vulnerability of different organ systems.

Glucocorticoid Receptor Gene (NR3C1) Polymorphisms and Metabolic Syndrome: Insights from the Mennonite Population

The regulation of the hypothalamic-pituitary-adrenal (HPA) axis is associated with polymorphisms and the methylation degree of the glucocorticoid receptor gene (NR3C1) and is potentially involved in the development of metabolic syndrome (MetS). In order to evaluate the association between MetS with the polymorphisms, methylation, and gene expression of the NR3C1 in the genetically isolated Brazilian Mennonite population, we genotyped 20 NR3C1 polymorphisms in 74 affected (MetS) and 138 unaffected individuals without affected first-degree relatives (Co), using exome sequencing, as well as five variants from non-exonic regions, in 70 MetS and 166 Co, using mass spectrometry. The methylation levels of 11 1F CpG sites were quantified using pyrosequencing (66 MetS and 141 Co), and the NR3C1 expression was evaluated via RT-qPCR (14 MetS and 25 Co). Age, physical activity, and family environment during childhood were associated with MetS. Susceptibility to MetS, independent of these factors, was associated with homozygosity for rs10482605*C (OR = 4.74, pcorr = 0.024) and the haplotype containing TTCGTTGATT (rs3806855*T_ rs3806854*T_rs10482605*C_rs10482614*G_rs6188*T_rs258813*T_rs33944801*G_rs34176759*A_rs17209258*T_rs6196*T, OR = 4.74, pcorr = 0.048), as well as for the CCT haplotype (rs41423247*C_ rs6877893*C_rs258763*T), OR = 6.02, pcorr = 0.030), but not to the differences in methylation or gene expression. Thus, NR3C1 polymorphisms seem to modulate the susceptibility to MetS in Mennonites, independently of lifestyle and early childhood events, and their role seems to be unrelated to DNA methylation and gene expression.

Genetic polymorphisms of glucocorticoid receptor and their association with new-onset diabetes mellitus in kidney transplant recipients

INTRODUCTION

The variability in developing New-onset Diabetes Mellitus After Transplantation (NODAT), together with previously well-established interindividual variation in glucocorticoid sensitivity, led us to hypothesize that polymorphisms in the NR3C1 gene encoding glucocorticoid receptor may alter glucose balance in kidney transplant recipients. This study aimed to evaluate the association of three functional polymorphisms, BclI, N363S, and ER22/23EK, on the NR3C1 gene with NODAT in kidney allograft recipients.

METHODS

From Jun 2020 to July 2022 in Shiraz, 52 patients with NODAT (case group) and 52 non-diabetic kidney transplant recipients (control group) were randomly screened and recruited in this case-control study. The PCR-RFLP technique determined the genotypes of BclI, N363S, and ER22/23EK polymorphisms.

RESULTS

The allelic frequencies of the mutant alleles of BclI, N363S, and ER22/23EK polymorphisms in all patients were 0.36, 0.03, and 0.009, respectively. BclI mutant genotypes (CG and GG) were significantly associated with an increased risk of NODAT (P = 0.016), while the two other polymorphisms disclosed no significant association with NODAT development. In the case group, no significant association was detected between the onset time of NODAT and studied polymorphisms, including BclI (P = 0.43), N363S (P = 0.30), and ER22/23EK. P value was not reported for the last polymorphism because all patients with NODAT had the wild-type genotype (GG/GG) and performing statistical analysis was not feasible. Among studied demographic/clinical/paraclinical variables, factors such as higher mean trough level of tacrolimus during the first month after transplantation and higher mean daily dose of prednisolone significantly linked with NODAT development.

CONCLUSION

Our data suggested that BclI polymorphism significantly affects NODAT development among Iranian kidney allograft recipients.

[Association of the structure of the glucocorticoid receptor and single nucleotide NR3C1 gene polymorphisms with metabolic disorders]

Glucocorticoid therapy is widely used in the treatment of various pathologies. Sensitivity to glucocorticoids  (GC) has a serious impact not only on the effectiveness of their action, but also on the severity of side effects, the formation of risk factors and the development  of cardiovascular diseases (CVD). Variability of sensitivity to GC causes different phenotypes and severity of metabolic disorders underlying  CVD. Among  them, one can distinguish  a decrease in muscle mass and strength, obesity, glucose and lipid metabolism impairment, and others. Glucocorticoids carry out their effects by binding to the glucocorticoid receptor (GR), and therefore this is considered a critical point in their action. This review presents data on the significance of the glucocorticoid  receptor structure, examines the main single nucleotide polymorphisms (SNP) of the NR3C1 gene associated with hypersensitivity  or relative resistance to glucocorticoids  in the context of metabolic disorders and the development of CVD. The association of the four most studied SNP of the GR gene with metabolic risks is described in detail: BclI (rs41423247), N363S (rs56149945), ER22/23EK (rs6189/rs6190), GR-9ß (rs6198). Their determination can contribute to clarifying the prognosis of both the effectiveness of GC and the development of metabolic disorders, and subsequent early correction of CVD risk factors.

Effects of prenatal exposure to the 1944-45 Dutch famine and glucocorticoid receptor polymorphisms on later life PTSD susceptibility

Background: Exposure to adversity in utero is thought to increase susceptibility to develop posttraumatic stress disorder (PTSD) following later life trauma, due to neurobiological programming effects during critical developmental periods. It remains unknown whether effects of prenatal adversity on PTSD susceptibility are modulated by genetic variations in neurobiological pathways implicated in PTSD susceptibility.Objective: We investigated whether genetic variation in the glucocorticoid receptor (GR) modulated effects of prenatal famine exposure on late adulthood PTSD symptom severity after trauma exposure in childhood and mid-to-late adulthood.Method: We included N = 439 term-born singleton adults (mean age: 72 years, 54.2% women) from the Dutch Famine Birth Cohort, born around the time of the Dutch Famine of 1944/1945, divided into exposure and control groups based on timing of the famine during gestation. Participants filled out self-report questionnaires on childhood (Childhood Trauma Questionnaire) and mid-to-late adulthood (Life Events Checklist for DSM-5) trauma, and current PTSD symptom severity (PTSD Checklist for DSM-5). GR haplotypes were determined from four functional GR single nucleotide polymorphisms (ER22/23EK, N363S, BclI and exon 9β) in previously collected DNA. Linear regression analyses were performed to investigate associations of GR haplotype and prenatal famine exposure in conjunction with later life trauma on PTSD symptom severity.Results: We observed a significant three-way interaction between the GR Bcll haplotype, famine exposure during early gestation, and adulthood trauma exposure on PTSD symptom severity in late adulthood. Only participants exposed to famine during early gestation without the GR Bcll haplotype showed a significantly stronger positive association between adulthood trauma and PTSD symptom severity than non-exposed participants, indicating increased PTSD susceptibility.Conclusions: Our results illustrate the importance of integrated approaches considering genetics and environmental contexts throughout various life periods, including the rarely investigated prenatal environment, to elucidate how PTSD susceptibility evolves throughout life.HIGHLIGHTS Adversity during pregnancy is thought to increase offspring's PTSD risk following later life trauma, but exact neurobiological mechanisms underlying this process remain unknown.We found that effects of prenatal famine exposure on PTSD symptom severity were influenced by genetic variation in the glucocorticoid receptor, which signals effects of the stress hormone cortisol.Integrated approaches considering genetics and environmental contexts throughout both early and later life are important to understand how PTSD risk evolves throughout life.

Phase-separation: a possible new layer for transcriptional regulation by glucocorticoid receptor

Glucocorticoids (GCs) are hormones involved in circadian adaptation and stress response, and it is also noteworthy that these steroidal molecules present potent anti-inflammatory action through GC receptors (GR). Upon ligand-mediated activation, GR translocates to the nucleus, and regulates gene expression related to metabolism, acute-phase response and innate immune response. GR field of research has evolved considerably in the last decades, providing varied mechanisms that contributed to the understanding of transcriptional regulation and also impacted drug design for treating inflammatory diseases. Liquid-liquid phase separation (LLPS) in cellular processes represents a recent topic in biology that conceptualizes membraneless organelles and microenvironments that promote, or inhibit, chemical reactions and interactions of protein or nucleic acids. The formation of these molecular condensates has been implicated in gene expression control, and recent evidence shows that GR and other steroid receptors can nucleate phase separation (PS). Here we briefly review the varied mechanisms of transcriptional control by GR, which are largely studied in the context of inflammation, and further present how PS can be involved in the control of gene expression. Lastly, we consider how the reported advances on LLPS during transcription control, specially for steroid hormone receptors, could impact the different modalities of GR action on gene expression, adding a new plausible molecular event in glucocorticoid signal transduction.

Circadian clock genes as promising therapeutic targets for bone loss

The circadian clock regulates many key physiological processes such as the sleep-wake cycle, hormone release, cardiovascular health, glucose metabolism and body temperature. Recent evidence has suggested a critical role of the circadian system in controlling bone metabolism. Here we review the connection between bone metabolism and the biological clock, and the roles of these mechanisms in bone loss. We also analyze the regulatory effects of clock-related genes on signaling pathways and transcription factors in osteoblasts and osteoclasts. Additionally, osteocytes and endothelial cells (ECs) regulated by the circadian clock are also discussed in our review. Furthermore, we also summarize the regulation of circadian clock genes by some novel modulators, which provides us with a new insight into a potential strategy to prevent and treat bone diseases such as osteoporosis by targeting circadian genes.

Apoptosis Evaluation in Circulating CD34+-Enriched Hematopoietic Stem and Progenitor Cells in Patients with Abnormally Increased Production of Endogenous Glucocorticoids in Course of Cushing's Syndrome

Abnormalities in hematological parameters of peripheral blood have been noted in patients with endogenous Cushing's Syndrome (CS) in the corticotropin (ACTH)-dependent and ACTH-independent forms. Nevertheless, the exact mechanism of glucocorticoids (GCs) action on human hematopoiesis is still not entirely clear. The aim of the study was to determine whether endogenous excessive production of GCs could affect apoptosis of CD34+ cells enriched in hematopoietic stem and progenitor cells (HSPCs) collected from the peripheral blood of newly diagnosed CS patients. Flow cytometry, Annexin-V enzyme-linked immunosorbent assay, TUNEL assay, real-time quantitative PCR, and microarray RNA/miRNA techniques were used to characterize CS patients' HSPCs. We found that the glucocorticoid receptor (GR) protein expression levels in CS were higher than in healthy controls. A complex analysis of apoptotic status of CS patients' HSPC cells showed that GCs significantly augmented apoptosis in peripheral blood-derived CD34+ cells and results obtained using different methods to detect early and late apoptosis in analyzed cell population were consistent. CS was also associated with significant upregulation in several members of the BCL-2 superfamily and other genes associated with apoptosis control. Furthermore, global gene expression analysis revealed significantly higher expression of genes associated with programmed cell death control in HSPCs from CS patients. These findings suggest that human endogenous GCs have a direct pro-apoptotic activity in hematopoietic CD34+ cells derived from CS subjects before treatment.

Peripheral mRNA Expression and Prognostic Significance of Emotional Stress Biomarkers in Metastatic Breast Cancer Patients

Emotional stress is believed to be associated with increased tumor progression. Stress-induced epigenetic modifications can contribute to the severity of disease and poor prognosis in cancer patients. The current study aimed to investigate the expression profiles along with the prognostic significance of psychological stress-related genes in metastatic breast cancer patients, to rationalize the molecular link between emotional stress and cancer progression. We profiled the expression of selected stress-associated genes (5-HTT, NR3C1, OXTR, and FKBP5) in breast cancer including the stress evaluation of all participants using the Questionnaire on Distress in Cancer Patients-short form (QSC-R10). A survival database, the Kaplan-Meier Plotter, was used to explore the prognostic significance of these genes in breast cancer. Our results showed relatively low expressions of 5-HTT (p = 0.02) and OXTR (p = 0.0387) in metastatic breast cancer patients as compared to the non-metastatic group of patients. The expression of NR3C1 was low in tumor grade III as compared to grade II (p = 0.04). Additionally, the expression of NR3C1 was significantly higher in patients with positive estrogen receptor status. However, no significant difference was found regarding FKBP5 expression in breast cancer. The results suggest a potential implication of these genes in breast cancer pathology and prognosis.

Expression patterns of AMPK and genes associated with lipid metabolism in newly hatched chicks during the metabolic perturbation of fasting and refeeding

Fasting–refeeding perturbation has been extensively used to reveal specific genes and metabolic pathways that control energy metabolism in chickens. In this study, 200 chickens were randomly assigned to 2 groups after hatching: the control group (C, fed ad libitum) and the fasting–refeeding group (T, water ad libitum). The chicks in Group T were fasted for 72 h, and then fed for another 48 h. Liver, hypothalamus, and adipose samples were collected at 0 (F0), 24 (F24), 48 (F48), and 72 h (F72) after fasting and 4 (FR4), 12 (FR12), 24 (FR24), and 48 h (FR48) after refeeding, respectively. Results showed that Group T had a significantly higher number of liver vacuoles (P < 0.05 or P < 0.01) and a significantly lower gray value of Sudan IIIstained sections (P < 0.05 or P < 0.01) than Group C at F48–FR48. In addition, compared with the Group C, fasting and refeeding reduced the expression of stearoyl CoA desaturase (SCD) mRNA (P < 0.05 or P < 0.01) in the liver and adipose tissues, the expression of glucocorticoid receptor (GR) mRNA (P < 0.05 or P < 0.01) in the liver, adipose, and hypothalamus tissues, and the expression of fatty acid synthase (FAS) mRNA (P < 0.05 or P < 0.01) in the liver at F24–FR24. Moreover, relative to those in Group C, fasting and refeeding increased the mRNA expression levels of adenosine monophosphate-activated protein kinase (AMPK) α, AMPKβ, and AMPKγ in the hypothalamus (P < 0.05 or P < 0.01) at F24–FR24. In conclusion, fasting and refeeding increased the fat content of the liver, and the expression of lipolytic genes in the hypothalamus (e.g., AMPKα, AMPKβ, and AMPKγ) but decreased the expression of fat synthesis genes in the liver (e.g., SCD, GR, and FAS), adipose (SCD and GR), and hypothalamus (GR).

Immunosuppressive drugs and associated complications in abdominal organ transplantation

PURPOSE OF REVIEW

Intensive care management of patients who have undergone organ transplantation of liver, small bowel, pancreas, and/or kidney requires a basic knowledge of immunosuppression principles and the management of immunosuppressive medications. This review highlights the core principles of immunosuppression management in abdominal organ transplantation with a focus on complications arising from immunosuppressive drugs, both in the immediate postoperative period and in long-term usage.

RECENT FINDINGS

The general principles of management of immunosuppression in the abdominal organ transplant population have remained largely unchanged. Improvements in drug monitoring coupled with improvements in knowledge of pathways involved in allograft rejection have further refined immunosuppressive therapy. Infectious and central nervous system complications remain prevalent and are common complications of immunosuppressive drug therapy.

SUMMARY

For the intensive care professional who cares for abdominal organ transplant recipients, a foundational knowledge of the core principles of immunosuppression management is essential. In addition, an understanding of the common immunosuppressive drug regimens and the complications associated with these regimens is required for optimal management, risk assessment, and outcomes.

How exposure to chronic stress contributes to the development of type 2 diabetes: A complexity science approach

Chronic stress contributes to the onset of type 2 diabetes (T2D), yet the underlying etiological mechanisms are not fully understood. Responses to stress are influenced by earlier experiences, sex, emotions and cognition, and involve a complex network of neurotransmitters and hormones, that affect multiple biological systems. In addition, the systems activated by stress can be altered by behavioral, metabolic and environmental factors. The impact of stress on metabolic health can thus be considered an emergent process, involving different types of interactions between multiple variables, that are driven by non-linear dynamics at different spatiotemporal scales. To obtain a more comprehensive picture of the links between chronic stress and T2D, we followed a complexity science approach to build a causal loop diagram (CLD) connecting the various mediators and processes involved in stress responses relevant for T2D pathogenesis. This CLD could help develop novel computational models and formulate new hypotheses regarding disease etiology.

Pathophysiology of Mild Hypercortisolism: From the Bench to the Bedside

Mild hypercortisolism is defined as biochemical evidence of abnormal cortisol secretion without the classical detectable manifestations of overt Cushing’s syndrome and, above all, lacking catabolic characteristics such as central muscle weakness, adipose tissue redistribution, skin fragility and unusual infections. Mild hypercortisolism is frequently discovered in patients with adrenal incidentalomas, with a prevalence ranging between 5 and 50%. This high variability is mainly due to the different criteria used for defining this condition. This subtle cortisol excess has also been described in patients with incidentally discovered pituitary tumors with an estimated prevalence of 5%. To date, the mechanisms responsible for the pathogenesis of mild hypercortisolism of pituitary origin are still not well clarified. At variance, recent advances have been made in understanding the genetic background of bilateral and unilateral adrenal adenomas causing mild hypercortisolism. Some recent data suggest that the clinical effects of glucocorticoid (GC) exposure on peripheral tissues are determined not only by the amount of the adrenal GC production but also by the peripheral GC metabolism and by the GC sensitivity. Indeed, in subjects with normal cortisol secretion, the combined estimate of cortisol secretion, cortisone-to-cortisol peripheral activation by the 11 beta-hydroxysteroid dehydrogenase enzyme and GC receptor sensitizing variants have been suggested to be associated with the presence of hypertension, diabetes and bone fragility, which are three well-known consequences of hypercortisolism. This review focuses on the pathophysiologic mechanism underlying both the different sources of mild hypercortisolism and their clinical consequences (bone fragility, arterial hypertension, subclinical atherosclerosis, cardiovascular remodeling, dyslipidemia, glucose metabolism impairment, visceral adiposity, infections, muscle damage, mood disorders and coagulation).

Glucocorticoid-induced Changes in the Transcriptional Activity of Genes of the Innate and Adaptive Immune System in the Blood of Patients with Acute Urticaria

Background: A number of the main effects of glucocorticoids (GCs) are their direct action on T cells, mainly through the transcriptional regulation: elevated expression of immune-regulatory proteins, inhibitory receptors, and reduced expression of pro-inflammatory cytokines, co-stimulatory molecules, and cell cycle mediators. But controversies arise due to the clinical effectiveness of GCs in the treatment of acute urticaria. Methods: In our research, we applied a pathway-specific PCR array (Human Innate & Adaptive Immune Responses RT2 Profiler PCR Array, QIAGEN, Germany) to detect and verify innate & adaptive immune responses pathway-focused genes expression in the blood of patients with acute urticaria who received treatment with glucocorticoids in addition to standard therapy. Results: Adding glucocorticoids to standard therapy did not notably affect the nature of the clinical presentation of acute urticaria, which was assessed according to the UAS scale (urticaria activity score). Analysis of the transcriptional profile of peripheral blood mononuclear cells in patients with acute urticaria against the background of glucocorticoid therapy showed the induction expression of the FOXP3 and IL10 genes against the background of repression of the transcriptional activity of the genes for chemokines and cytokines CCL5, CXCL8, IFNG, IL2, IL5, IL17A, IL1B, and TNF. Glucocorticoid-induced changes in the transcriptome also manifested by pronounced repression in genes of CD40 and CD80 (B7-1) co-stimulatory molecules, transcriptional regulators of Th1-cells differentiation - TBX21 and STAT1, Th17 cells - RORC, NLRP3-inflammasome genes, and the transcription factor NFKB1 compared with the control group. Conclusions: Adding glucocorticoids to the standard therapy of acute urticaria has a pronounced immunosuppressive potential at the transcriptome level of immune response genes in the blood; however, it does not have any noticeable clinical effect.

Characterization of mouse embryonic fibroblasts derived from Rassf6 knockout mice shows the implication of Rassf6 in the regulation of NF-κB signaling

RASSF6 is a member of the tumor suppressor Ras association domain family (RASSF) proteins. We have reported using human cancer cell lines that RASSF6 induces apoptosis and cell cycle arrest via p53 and plays tumor suppressive roles. In this study, we generated Rassf6 knockout mice by CRISPR/Cas technology. Contrary to our expectation, Rassf6 knockout mice were apparently healthy. However, Rassf6-null mouse embryonic fibroblasts (MEF) were resistant against ultraviolet (UV)-induced apoptosis/cell cycle arrest and senescence. UV-induced p53-target gene expression was compromised, and DNA repair was delayed in Rassf6-null MEF. More importantly, KRAS active mutant promoted the colony formation of Rassf6-null MEF but not the wild-type MEF. RNA sequencing analysis showed that NF-κB signaling was enhanced in Rassf6-null MEF. Consistently, 7,12-dimethylbenz(a)anthracene (DMBA) induced skin inflammation in Rassf6 knockout mice more remarkably than in the wild-type mice. Hence, Rassf6 deficiency not only compromises p53 function but also enhances NF-κB signaling to lead to oncogenesis.