-
Hereditas Dec 2023Dyskeratosis congenita 1 (DKC1), a critical component of telomerase complex, is highly expressed in a variety of human cancers. However, the association of DKC1 with...
BACKGROUND
Dyskeratosis congenita 1 (DKC1), a critical component of telomerase complex, is highly expressed in a variety of human cancers. However, the association of DKC1 with cancer occurrence and development stages is not clear, making a pan-cancer analysis crucial.
METHODS
We conducted a study using various bioinformatic databases such as TIMER, GEPIA, UALCAN, and KM plotter Analysis to examine the different expressions of DKC1 in multiple tissues and its correlation with pathological stages. Through KEGG analysis, GO enrichment analysis and Venn analysis, we were able to reveal DKC1-associated genes and signaling pathways. In addition, we performed several tests including the CCK, wound healing assay, cell cycle arrest assay, transwell assay and Sa-β-gal staining on DKC1-deleted MDA-231 cells.
RESULTS
Our study demonstrates that DKC1 has relatively low expression specificity in different tissues. Furthermore, we found that in ACC, KICH, KIRP and LIHC, the expression level of DKC1 is positively correlated with pathological stages. Conversely, in NHSC, KIRP, LGG, LIHC, MESO and SARC, we observed a negative influence of DKC1 expression level on the overall survival rate. We also found a significant positive correlation between DKC1 expression and Tumor Mutational Burden in 14 tumors. Additionally, we observed a significantly negative impact of DKC1 DNA methylation on gene expression at the promoter region in BRCA. We also identified numerous phosphorylation sites concentrated at the C-terminus of the DKC1 protein. Our GO analysis revealed a correlation between DKC1 and ribosomal biosynthesis pathways, and the common element UTP14A was identified. We also observed decreased rates of cell proliferation, migration and invasion abilities in DKC1-knockout MDA-MB-231 cell lines. Furthermore, DKC1-knockout induced cell cycle arrest and caused cell senescence.
CONCLUSIONS
Our findings suggest that the precise expression of DKC1 is closely associated with the occurrence and developmental stages of cancer in multiple tissues. Depletion of DKC1 can inhibit the abilities of cancer cells to proliferate, migrate, and invade by arresting the cell cycle and inducing cell senescence. Therefore, DKC1 may be a valuable prognostic biomarker for the diagnosis and treatment of cancer in various tissues.
Topics: Humans; Prognosis; Cell Cycle Proteins; Dyskeratosis Congenita; Neoplasms; Biomarkers; Nuclear Proteins
PubMed: 38082360
DOI: 10.1186/s41065-023-00302-y -
Blood Mar 2022Dyskeratosis congenita related telomere biology disorders (DC/TBDs) are characterized by very short telomeres caused by germline pathogenic variants in telomere biology...
Dyskeratosis congenita related telomere biology disorders (DC/TBDs) are characterized by very short telomeres caused by germline pathogenic variants in telomere biology genes. Clinical presentations can affect all organs, and inheritance patterns include autosomal dominant (AD), autosomal recessive (AR), X-linked (XLR), or de novo. This study examined the associations between mode of inheritance with phenotypes and long-term clinical outcomes. Two hundred thirty-one individuals with DC/TBDs (144 male, 86.6% known genotype, median age at diagnosis 19.4 years [range 0 to 71.6]), enrolled in the National Cancer Institute's Inherited Bone Marrow Failure Syndrome Study, underwent detailed clinical assessments and longitudinal follow-up (median follow-up 5.2 years [range 0 to 36.7]). Patients were grouped by inheritance pattern, considering AD-nonTINF2, AR/XLR, and TINF2 variants separately. Severe bone marrow failure (BMF), severe liver disease, and gastrointestinal telangiectasias were more prevalent in AR/XLR or TINF2 disease, whereas pulmonary fibrosis developed predominantly in adults with AD disease. After adjusting for age at DC/TBD diagnosis, we observed the highest cancer risk in AR/XLR individuals. At last follow-up, 42% of patients were deceased with a median overall survival (OS) of 52.8 years (95% confidence interval [CI] 45.5-57.6), and the hematopoietic cell or solid organ transplant-free median survival was 45.3 years (95% CI 37.4-52.1). Significantly better OS was present in AD vs AR/XLR/TINF2 disease (P < .01), while patients with AR/XLR and TINF2 disease had similar survival probabilities. This long-term study of the clinical manifestations of DC/TBDs creates a foundation for incorporating the mode of inheritance into evidence-based clinical care guidelines and risk stratification in patients with DC/TBDs. This trial was registered at www.clinicaltrials.gov as #NCT00027274.
Topics: Biology; Disease Progression; Dyskeratosis Congenita; Humans; Male; Telomerase; Telomere; Telomere Shortening
PubMed: 34852175
DOI: 10.1182/blood.2021013523 -
Familial Cancer Jan 2023TINF2 is a critical subunit of the shelterin complex, which protects and maintains the length of telomeres. Pathogenic missense and truncating TINF2 mutations are...
TINF2 is a critical subunit of the shelterin complex, which protects and maintains the length of telomeres. Pathogenic missense and truncating TINF2 mutations are causative for dyskeratosis congenita (DC), a rare, dominantly inherited bone marrow failure syndrome characterized by mucocutaneous abnormalities and cancer predisposition. Recent reports indicate that specific TINF2 truncating mutations act as high penetrance cancer predisposition alleles outside DC context, including breast cancer in their tumor spectrum. Here, we have evaluated the role of germline mutations in TINF2 and other shelterin genes in inherited breast cancer susceptibility using exome sequencing data from 98 Northern Finnish breast cancer cases with indication of inherited disease predisposition as a discovery cohort. A single protein truncating variant, TINF2 p.Tyr312Ter, was identified in one of the cases (1/98), and four more carriers were observed in the subsequently genotyped unselected breast cancer cohort (4/1904). None of the carriers were reported to have DC. TINF2 p.Tyr312Ter resulted in stable short form of mRNA transcript, and normal telomere length has been indicated by a recent report. Although recurrent in cases (total of 5/2095), TINF2 p.Tyr312Ter is also present in Finnish population controls (8/12,517), and the observed 4-fold higher frequency in cases falls at most into the range of moderate breast cancer risk alleles (OR 3.74, 95% CI 1.22-11.45, p = 0.029). Current results indicate that not all TINF2 truncating variants are high cancer risk alleles and add further evidence that different TINF2 mutations can have very diverse effects on the disease phenotype.
Topics: Humans; Shelterin Complex; Telomere; Mutation; Dyskeratosis Congenita; Genotype; Neoplasms; Telomere-Binding Proteins
PubMed: 35590014
DOI: 10.1007/s10689-022-00295-z -
Oxford Medical Case Reports Nov 2021Dyskeratosis congenita (DC) is an inherited disease characterized by the triad of abnormal skin pigmentation, nail dystrophy and mucosal leukoplakia. Non-cutaneous...
Dyskeratosis congenita (DC) is an inherited disease characterized by the triad of abnormal skin pigmentation, nail dystrophy and mucosal leukoplakia. Non-cutaneous abnormalities (dental, gastrointestinal, genitourinary, neurological, ophthalmic, pulmonary and skeletal) have also been reported. Bone marrow failure (BMF) is the main cause of early mortality, with an additional predisposition to malignancy. DC results from an anomalous progressive shortening of telomeres resulting in DNA replication problems inducing replicative senescence. Men are more affected than women are and X-linked recessive, autosomal dominant and autosomal recessive forms of the disease are recognized. There are no targeted therapies for DC. Patients treated with androgens had a hematological response. We herein describe case of a 32-year-old man, presented with several characteristic systemic features of this condition, including the classic triad of lesions, dysplastic bone marrow, epiphora and liver cirrhosis with grade I esophageal varices. Therefore, a prophylactic propranolol was started in additional to danazol. Three-week later, the patient had subsequent increases in his platelet, red cell and white cell counts.
PubMed: 34858620
DOI: 10.1093/omcr/omab041 -
H/ACA Small Ribonucleoproteins: Structural and Functional Comparison Between Archaea and Eukaryotes.Frontiers in Microbiology 2021During ribosome synthesis, ribosomal RNA is modified through the formation of many pseudouridines and methylations which contribute to ribosome function across all... (Review)
Review
During ribosome synthesis, ribosomal RNA is modified through the formation of many pseudouridines and methylations which contribute to ribosome function across all domains of life. In archaea and eukaryotes, pseudouridylation of rRNA is catalyzed by H/ACA small ribonucleoproteins (sRNPs) utilizing different H/ACA guide RNAs to identify target uridines for modification. H/ACA sRNPs are conserved in archaea and eukaryotes, as they share a common general architecture and function, but there are also several notable differences between archaeal and eukaryotic H/ACA sRNPs. Due to the higher protein stability in archaea, we have more information on the structure of archaeal H/ACA sRNPs compared to eukaryotic counterparts. However, based on the long history of yeast genetic and other cellular studies, the biological role of H/ACA sRNPs during ribosome biogenesis is better understood in eukaryotes than archaea. Therefore, this review provides an overview of the current knowledge on H/ACA sRNPs from archaea, in particular their structure and function, and relates it to our understanding of the roles of eukaryotic H/ACA sRNP during eukaryotic ribosome synthesis and beyond. Based on this comparison of our current insights into archaeal and eukaryotic H/ACA sRNPs, we discuss what role archaeal H/ACA sRNPs may play in the formation of ribosomes.
PubMed: 33776984
DOI: 10.3389/fmicb.2021.654370 -
Frontiers in Aging 2021Telomeres are specialized nucleoprotein structures that form protective caps at the ends of chromosomes. Short telomeres are a hallmark of aging and a principal defining... (Review)
Review
Telomeres are specialized nucleoprotein structures that form protective caps at the ends of chromosomes. Short telomeres are a hallmark of aging and a principal defining feature of short telomere syndromes, including dyskeratosis congenita (DC). Emerging evidence suggests a crucial role for critically short telomere-induced DNA damage signaling and mitochondrial dysfunction in cellular dysfunction in DC. A prominent factor linking nuclear DNA damage and mitochondrial homeostasis is the nicotinamide adenine dinucleotide (NAD) metabolite. Recent studies have demonstrated that patients with DC and murine models with critically short telomeres exhibit lower NAD levels, and an imbalance in the NAD metabolome, including elevated CD38 NADase and reduced poly (ADP-ribose) polymerase and SIRT1 activities. CD38 inhibition and/or supplementation with NAD precursors reequilibrate imbalanced NAD metabolism and alleviate mitochondrial impairment, telomere DNA damage, telomere dysfunction-induced DNA damage signaling, and cellular growth retardation in primary fibroblasts derived from DC patients. Boosting NAD levels also ameliorate chemical-induced liver fibrosis in murine models of telomere dysfunction. These findings underscore the relevance of NAD dysregulation to telomeropathies and demonstrate how NAD interventions may prove to be effective in combating cellular and organismal defects that occur in short telomere syndromes.
PubMed: 35822010
DOI: 10.3389/fragi.2021.785171 -
Frontiers in Pediatrics 2023Dyskeratosis congenita (DC) is a multisystem and ultra-rare hereditary disease characterized by somatic involvement, bone marrow failure, and predisposition to cancer....
BACKGROUND
Dyskeratosis congenita (DC) is a multisystem and ultra-rare hereditary disease characterized by somatic involvement, bone marrow failure, and predisposition to cancer. The main objective of this study is to describe the natural history of DC through a cohort of patients diagnosed in childhood and followed up for a long period of time.
MATERIAL AND METHODS
Multicenter, retrospective, longitudinal study conducted in patients followed up to 24 years since being diagnosed in childhood (between 1998 and 2020).
RESULTS
Fourteen patients were diagnosed with DC between the ages of 3 and 17 years (median, 8.5 years). They all had hematologic manifestations at diagnosis, and nine developed mucocutaneous manifestations during the first decade of life. Seven presented severe DC variants. All developed non-hematologic manifestations during follow-up. Mutations were identified in 12 patients. Thirteen progressed to bone marrow failure at a median age of 8 years [range, 3-18 years], and eight received a hematopoietic stem cell transplant. Median follow-up time was 9 years [range, 2-24 years]. Six patients died, the median age was 13 years [range, 6-24 years]. As of November 2022, eight patients were still alive, with a median age of 18 years [range, 6-32 years]. None of them have developed myeloblastic syndrome or cancer.
CONCLUSIONS
DC was associated with high morbidity and mortality in our series. Hematologic manifestations appeared early and consistently. Non-hematologic manifestations developed progressively. No patient developed cancer possibly due to their young age. Due to the complexity of the disease multidisciplinary follow-up and adequate transition to adult care are essential.
PubMed: 37593443
DOI: 10.3389/fped.2023.1182476 -
British Journal of Haematology Jun 2021Reproductive health may be adversely impacted in women with dyskeratosis congenita (DC) and related telomere biology disorders (TBD). We evaluated gynaecological... (Clinical Trial)
Clinical Trial
Reproductive health may be adversely impacted in women with dyskeratosis congenita (DC) and related telomere biology disorders (TBD). We evaluated gynaecological problems, fertility, and pregnancy outcomes in 39 females aged 10-81 years who were followed longitudinally in our DC/TBD cohort. Twenty-six had bone marrow failure and 12 underwent haematopoietic cell transplantation. All attained menarche at a normal age. Thirteen women reported menorrhagia; ten used hormonal contraception to reduce bleeding. Nine experienced natural normal-aged menopause. Gynaecological problems (endometriosis = 3, pelvic varicosities = 1, cervical intraepithelial neoplasia = 1, and uterine prolapse = 2) resulted in surgical menopause in seven. Twenty-five of 26 women attempting fertility carried 80 pregnancies with 49 (61%) resulting in livebirths. Ten (38%) women experienced 28 (35%) miscarriages, notably recurrent pregnancy loss in five (19%). Preeclampsia (n = 6, 24%) and progressive cytopenias (n = 10, 40%) resulted in maternal-fetal compromise, including preterm (n = 5) and caesarean deliveries (n = 18, 37%). Gynaecological/reproductive problems were noted mainly in women with autosomal-dominant inheritance; others were still young or died early. Although women with TBDs had normal menarche, fertility, and menopause, gynaecological problems and pregnancy complications leading to caesarean section, preterm delivery, or transfusion support were frequent. Women with TBDs will benefit from multidisciplinary, coordinated care by haematology, gynaecology and maternal-fetal medicine.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Dyskeratosis Congenita; Female; Fertility; Humans; Middle Aged; Pre-Eclampsia; Pregnancy; Premature Birth; Reproductive Health; Uterine Diseases
PubMed: 34019708
DOI: 10.1111/bjh.17545 -
Stem Cells Translational Medicine Dec 2021Chronic lung disease has been attributed to stem cell aging and/or exhaustion. We investigated these mechanisms using mouse and human tracheobronchial tissue-specific...
Chronic lung disease has been attributed to stem cell aging and/or exhaustion. We investigated these mechanisms using mouse and human tracheobronchial tissue-specific stem cells (TSC). In mouse, chromatin labeling and flow cytometry demonstrated that naphthalene (NA) injury activated a subset of TSC. These activated TSC continued to proliferate after the epithelium was repaired and a clone study demonstrated that ~96% of activated TSC underwent terminal differentiation. Despite TSC attrition, epithelial repair after a second NA injury was normal. The second injury accelerated proliferation of previously activated TSC and a nucleotide-label retention study indicated that the second injury recruited TSC that were quiescent during the first injury. These mouse studies indicate that (a) injury causes selective activation of the TSC pool; (b) activated TSC are predisposed to further proliferation; and (c) the activated state leads to terminal differentiation. In human TSC, repeated proliferation also led to terminal differentiation and depleted the TSC pool. A clone study identified long- and short-lived TSC and showed that short-lived TSC clones had significantly shorter telomeres than their long-lived counterparts. The TSC pool was significantly depleted in dyskeratosis congenita donors, who harbor mutations in telomere biology genes. The remaining TSC had short telomeres and short lifespans. Collectively, the mouse and human studies support a model in which epithelial injury increases the biological age of the responding TSC. When applied to chronic lung disease, this model suggests that repeated injury accelerates the biological aging process resulting in abnormal repair and disease initiation.
Topics: Animals; Cell Differentiation; Cells, Cultured; Lung Diseases; Mice; Reinjuries; Stem Cells
PubMed: 34546001
DOI: 10.1002/sctm.21-0032 -
Cells Nov 2019Dyskerin is a protein involved in the formation of small nucleolar and small Cajal body ribonucleoproteins. These complexes participate in RNA pseudouridylation and are...
Dyskerin is a protein involved in the formation of small nucleolar and small Cajal body ribonucleoproteins. These complexes participate in RNA pseudouridylation and are also components of the telomerase complex required for telomere elongation. Dyskerin mutations cause a rare disease, X-linked dyskeratosis congenita, with no curative treatment. The social amoeba contains a gene coding for a dyskerin homologous protein. In this article mutant strains that have mutations corresponding to mutations found in dyskeratosis congenita patients are described. The phenotype of the mutant strains has been studied and no alterations were observed in pseudouridylation activity and telomere structure. Mutant strains showed increased proliferation on liquid culture but reduced growth feeding on bacteria. The results obtained indicated the existence of increased DNA damage response and reactive oxygen species, as also reported in human Dyskeratosis congenita cells and some other disease models. These data, together with the haploid character of vegetative cells, that resemble the genomic structure of the human dyskerin gene, located in the X chromosome, support the conclusion that can be a good model system for the study of this disease.
Topics: Amino Acid Sequence; Animals; Cell Cycle Proteins; Cell Proliferation; Cells, Cultured; DNA Damage; Dictyostelium; Dyskeratosis Congenita; Gene Expression Regulation; Gene Knock-In Techniques; Humans; Mutation; Nuclear Proteins; Oxidative Stress; Reactive Oxygen Species; Signal Transduction; Telomere
PubMed: 31717312
DOI: 10.3390/cells8111406