Widespread somatic L1 retrotransposition in normal colorectal epithelium.

Throughout an individual's lifetime, genomic alterations accumulate in somatic cells1-11. However, the mutational landscape induced by retrotransposition of long interspersed nuclear element-1 (L1), a widespread mobile element in the human genome12-14, is poorly understood in normal cells. Here we explored the whole-genome sequences of 899 single-cell clones established from three different cell types collected from 28 individuals. We identified 1,708 somatic L1 retrotransposition events that were enriched in colorectal epithelium and showed a positive relationship with age. Fingerprinting of source elements showed 34 retrotransposition-competent L1s. Multidimensional analysis demonstrated that (1) somatic L1 retrotranspositions occur from early embryogenesis at a substantial rate, (2) epigenetic on/off of a source element is preferentially determined in the early organogenesis stage, (3) retrotransposition-competent L1s with a lower population allele frequency have higher retrotransposition activity and (4) only a small fraction of L1 transcripts in the cytoplasm are finally retrotransposed in somatic cells. Analysis of matched cancers further suggested that somatic L1 retrotransposition rate is substantially increased during colorectal tumourigenesis. In summary, this study illustrates L1 retrotransposition-induced somatic mosaicism in normal cells and provides insights into the genomic and epigenomic regulation of transposable elements over the human lifetime.

HIGH PLOIDY2-mediated SUMOylation of transcription factor ARR1 controls two-component signaling in Arabidopsis.

Cytokinins regulate plant growth, development, and responses to environmental stresses such as cold via phosphorelay from cytokinin receptors to the ARABIDOPSIS RESPONSE REGULATORs (ARRs). However, the molecular mechanisms underlying the activation of type-B ARR transcriptional activity in Arabidopsis (Arabidopsis thaliana) remain unclear. Here, we show that the E3 SUMO ligase HIGH PLOIDY2 SUMOylates ARR1, a type-B ARR, at K236, triggering its activation. Cold- or cytokinin-induced phosphorylation of ARR1 at D89 is crucial for its interaction with HPY2. Lysine 236 is critical for ARR1's transactivation without compromising its DNA-binding ability, while D89 is crucial for ARR1's binding to target gene promoters. Cytokinin enhances ARR1's chromatin binding, but cold does not. ARR1 K236 plays a critical role in promoting histone H3 acetylation in response to both cytokinin and cold without affecting chromatin binding. The K236R mutation in ARR1 reduces target gene expression and alters cytokinin and cold response phenotypes. This study unveils a mechanism of ARR1 activation wherein phosphorylated ARR1 interacts with HPY2 and binds to chromatin in response to cytokinin. Cold triggers a phosphorelay targeting chromatin-bound ARR1. HPY2 then catalyzes ARR1 SUMOylation at K236, enhancing histone H3 acetylation and leading to transcriptional activation of ARR1 in response to both cold and cytokinin.

Base-resolution analysis of 5-hydroxymethylcytosine in the mammalian genome.

The study of 5-hydroxylmethylcytosines (5hmC) has been hampered by the lack of a method to map it at single-base resolution on a genome-wide scale. Affinity purification-based methods cannot precisely locate 5hmC nor accurately determine its relative abundance at each modified site. We here present a genome-wide approach, Tet-assisted bisulfite sequencing (TAB-Seq), that when combined with traditional bisulfite sequencing can be used for mapping 5hmC at base resolution and quantifying the relative abundance of 5hmC as well as 5mC. Application of this method to embryonic stem cells not only confirms widespread distribution of 5hmC in the mammalian genome but also reveals sequence bias and strand asymmetry at 5hmC sites. We observe high levels of 5hmC and reciprocally low levels of 5mC near but not on transcription factor-binding sites. Additionally, the relative abundance of 5hmC varies significantly among distinct functional sequence elements, suggesting different mechanisms for 5hmC deposition and maintenance.

Quantitative Lipid Imaging Reveals a New Signaling Function of Phosphatidylinositol-3,4-Bisphophate: Isoform- and Site-Specific Activation of Akt.

Activation of class I phosphatidylinositol 3-kinase (PI3K) leads to formation of phosphatidylinositol-3,4,5-trisphophate (PIP3) and phosphatidylinositol-3,4-bisphophate (PI34P2), which spatiotemporally coordinate and regulate a myriad of cellular processes. By simultaneous quantitative imaging of PIP3 and PI34P2 in live cells, we here show that they have a distinctively different spatiotemporal distribution and history in response to growth factor stimulation, which allows them to selectively induce the membrane recruitment and activation of Akt isoforms. PI34P2 selectively activates Akt2 at both the plasma membrane and early endosomes, whereas PIP3 selectively stimulates Akt1 and Akt3 exclusively at the plasma membrane. These spatiotemporally distinct activation patterns of Akt isoforms provide a mechanism for their differential regulation of downstream signaling molecules. Collectively, our studies show that different spatiotemporal dynamics of PIP3 and PI34P2 and their ability to selectively activate key signaling proteins allow them to mediate class I PI3K signaling pathways in a spatiotemporally specific manner.

Liver X receptor controls follicular helper T cell differentiation via repression of TCF-1.

Liver X receptor (LXR) is a critical regulator of cholesterol homeostasis that inhibits T cell receptor (TCR)-induced proliferation by altering intracellular sterol metabolism. However, the mechanisms by which LXR regulates helper T cell subset differentiation remain unclear. Here, we demonstrate that LXR is a crucial negative regulator of follicular helper T (Tfh) cells in vivo. Both mixed bone marrow chimera and antigen-specific T cell adoptive cotransfer studies show a specific increase in Tfh cells among LXRß-deficient CD4+ T cell population in response to immunization and lymphocytic choriomeningitis mammarenavirus (LCMV) infection. Mechanistically, LXRß-deficient Tfh cells express augmented levels of T cell factor 1 (TCF-1) but comparable levels of Bcl6, CXCR5, and PD-1 in comparison with those of LXRß-sufficient Tfh cells. Loss of LXRß confers inactivation of GSK3ß induced by either AKT/Extracellular signal-regulated kinase (ERK) activation or Wnt/ß-catenin pathway, leading to elevated TCF-1 expression in CD4+ T cells. Conversely, ligation of LXR represses TCF-1 expression and Tfh cell differentiation in both murine and human CD4+ T cells. LXR agonist significantly diminishes Tfh cells and the levels of antigen-specific IgG upon immunization. These findings unveil a cell-intrinsic regulatory function of LXR in Tfh cell differentiation via the GSK3ß-TCF1 pathway, which may serve as a promising target for pharmacological intervention in Tfh-mediated diseases.

α-Hemolysin promotes uropathogenic E. coli persistence in bladder epithelial cells via abrogating bacteria-harboring lysosome acidification.

There is a growing consensus that a significant proportion of recurrent urinary tract infections are linked to the persistence of uropathogens within the urinary tract and their re-emergence upon the conclusion of antibiotic treatment. Studies in mice and human have revealed that uropathogenic Escherichia coli (UPEC) can persist in bladder epithelial cells (BECs) even after the apparent resolution of the infection. Here, we found that, following the entry of UPEC into RAB27b+ fusiform vesicles in BECs, some bacteria escaped into the cytoplasmic compartment via a mechanism involving hemolysin A (HlyA). However, these UPEC were immediately recaptured within LC3A/B+ autophagosomes that matured into LAMP1+ autolysosomes. Thereafter, HlyA+ UPEC-containing lysosomes failed to acidify, which is an essential step for bacterial elimination. This lack of acidification was related to the inability of bacteria-harboring compartments to recruit V-ATPase proton pumps, which was attributed to the defragmentation of cytosolic microtubules by HlyA. The persistence of UPEC within LAMP1+ compartments in BECs appears to be directly linked to HlyA. Thus, through intravesicular instillation of microtubule stabilizer, this host defense response can be co-opted to reduce intracellular bacterial burden following UTIs in the bladder potentially preventing recurrence.

Diverse regulatory pathways modulate bet hedging of competence induction in epigenetically-differentiated phase variants of Streptococcus pneumoniae.

Despite enabling Streptococcus pneumoniae to acquire antibiotic resistance and evade vaccine-induced immunity, transformation occurs at variable rates across pneumococci. Phase variants of isolate RMV7, distinguished by altered methylation patterns driven by the translocating variable restriction-modification (tvr) locus, differed significantly in their transformation efficiencies and biofilm thicknesses. These differences were replicated when the corresponding tvr alleles were introduced into an RMV7 derivative lacking the locus. RNA-seq identified differential expression of the type 1 pilus, causing the variation in biofilm formation, and inhibition of competence induction in the less transformable variant, RMV7domi. This was partly attributable to RMV7domi's lower expression of ManLMN, which promoted competence induction through importing N-acetylglucosamine. This effect was potentiated by analogues of some proteobacterial competence regulatory machinery. Additionally, one of RMV7domi's phage-related chromosomal island was relatively active, which inhibited transformation by increasing expression of the stress response proteins ClpP and HrcA. However, HrcA increased competence induction in the other variant, with its effects depending on Ca2+ supplementation and heat shock. Hence the heterogeneity in transformation efficiency likely reflects the diverse signalling pathways by which it is affected. This regulatory complexity will modulate population-wide responses to synchronising quorum sensing signals to produce co-ordinated yet stochastic bet hedging behaviour.

Lactobacillus crispatus Limits Bladder Uropathogenic E. coli Infection by Triggering a Host Type I Interferon Response.

Many urinary tract infections (UTIs) are recurrent because uropathogens persist within the bladder epithelial cells (BECs) for extended periods between bouts of infection. Because persistent uropathogens are intracellular, they are often refractive to antibiotic treatment. The recent discovery of endogenous Lactobacillus spp. in the bladders of healthy humans raised the question of whether these endogenous bacteria directly or indirectly impact intracellular bacterial burden in the bladder. Here, we report that in contrast to healthy women, female patients experiencing recurrent UTIs have a bladder population of Lactobacilli that is markedly reduced. Exposing infected human BECs to L. crispatus in vitro markedly reduced the intracellular uropathogenic Escherichia coli (UPEC) load. The adherence of Lactobacilli to BECs was found to result in increased type I interferon (IFN) production, which in turn enhanced the expression of cathepsin D within lysosomes harboring UPECs. This lysosomal cathepsin D-mediated UPEC killing was diminished in germ-free mice and type I IFN receptor-deficient mice. Secreted metabolites of L. crispatus seemed to be responsible for the increased expression of type I IFN in human BECs. Intravesicular administration of Lactobacilli into UPEC-infected murine bladders markedly reduced their intracellular bacterial load suggesting that components of the endogenous microflora can have therapeutic effects against UTIs.

Human papillomavirus infection and cardiovascular mortality: a cohort study.

BACKGROUND AND AIMS: High-risk human papillomavirus (HR-HPV) infection-a well-established risk factor for cervical cancer-has associations with cardiovascular disease (CVD). However, its relationship with CVD mortality remains uncertain. This study examined the associations between HR-HPV infection and CVD mortality. METHODS: As part of a health examination, 163 250 CVD-free Korean women (mean age: 40.2 years) underwent HR-HPV screening and were tracked for up to 17 years (median: 8.6 years). National death records identified the CVD mortality cases. Hazard ratios (HRs) and 95% confidence intervals (CIs) for CVD mortality were estimated using Cox proportional hazard regression analyses. RESULTS: During 1 380 953 person-years of follow-up, 134 CVD deaths occurred, with a mortality rate of 9.1 per 105 person-years for HR-HPV(-) women and 14.9 per 105 person-years for HR-HPV(+) women. After adjustment for traditional CVD risk factors and confounders, the HRs (95% CI) for atherosclerotic CVD (ASCVD), ischaemic heart disease (IHD), and stroke mortality in women with HR-HPV infection compared with those without infection were 3.91 (1.85-8.26), 3.74 (1.53-9.14), and 5.86 (0.86-40.11), respectively. The association between HR-HPV infection and ASCVD mortality was stronger in women with obesity than in those without (P for interaction = .006), with corresponding HRs (95% CI) of 4.81 (1.55-14.93) for obese women and 2.86 (1.04-7.88) for non-obese women. CONCLUSIONS: In this cohort study of young and middle-aged Korean women, at low risks for CVD mortality, those with HR-HPV infection had higher death rates from CVD, specifically ASCVD and IHD, with a more pronounced trend in obese individuals.

Inhibition of the Alternative Complement Pathway May Cause Secretion of Factor B, Enabling an Early Detection of Pancreatic Cancer.

This study aims to elucidate the cellular mechanisms behind the secretion of complement factor B (CFB), known for its dual roles as an early biomarker for pancreatic ductal adenocarcinoma (PDAC) and as the initial substrate for the alternative complement pathway (ACP). Using parallel reaction monitoring analysis, we confirmed a consistent ∼2-fold increase in CFB expression in PDAC patients compared with that in both healthy donors (HD) and chronic pancreatitis (CP) patients. Elevated ACP activity was observed in CP and other benign conditions compared with that in HD and PDAC patients, suggesting a functional link between ACP and PDAC. Protein-protein interaction analyses involving key complement proteins and their regulatory factors were conducted using blood samples from PDAC patients and cultured cell lines. Our findings revealed a complex control system governing the ACP and its regulatory factors, including Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation, adrenomedullin (AM), and complement factor H (CFH). Particularly, AM emerged as a crucial player in CFB secretion, activating CFH and promoting its predominant binding to C3b over CFB. Mechanistically, our data suggest that the KRAS mutation stimulates AM expression, enhancing CFH activity in the fluid phase through binding. This heightened AM-CFH interaction conferred greater affinity for C3b over CFB, potentially suppressing the ACP cascade. This sequence of events likely culminated in the preferential release of ductal CFB into plasma during the early stages of PDAC. (Data set ID PXD047043.).

Reducing Domain Density Enhances Conversion Efficiency in GeTe.

Incorporating dilute doping and controlled synthesis provides a means to modulate the microstructure, defect density, and transport properties. Transmission electron microscopy (TEM) and geometric phase analysis (GPA) have revealed that hot-pressing can increase defect density, which redistributes strain and helps prevent unwanted Ge precipitates formation. An alloy of GeTe with a minute amount of indium added has shown remarkable TE properties compared to its undoped counterpart. Specifically, it achieves a maximum figure-of-merit zT of 1.3 at 683 K and an exceptional TE conversion efficiency of 2.83% at a hot-side temperature of 723 K. Significant zT and conversion efficiency improvements are mainly due to domain density engineering facilitated by an effective hot-pressing technique applied to lightly doped GeTe. The In-GeTe alloy exhibits superior TE properties and demonstrates notable stability under significant thermal gradients, highlighting its promise for use in mid-temperature TE energy generation systems.

Saliva-based Proteinase K method: A rapid and reliable diagnostic tool for the detection of SARS-COV-2 in children.

Early and accurate detection of viruses in children might help prevent transmission and severe diseases. In this study, the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) detection in children was evaluated using saliva specimens with a Proteinase K (PTK)-based RNA preparation, as saliva collection is a simple and noninvasive procedure, even in young children, with fewer concerns about sample contamination. The saliva-based PTK and the conventional paired nasopharyngeal aspiration (NPA)-based detection methods were compared between COVID-19-positive and -negative children. In addition, the detection rate for SARS-COV-2 and the difference between admission and discharge by the saliva-based PTK method was tested in COVID-19 patients. The diagnostic accuracy of the saliva-based PTK method was 98.8% compared to NP swab-based reverse transcriptase polymerase chain reaction. Saliva samples showed high sensitivity (94.1%) and specificity (100%) when using the PTK method. Furthermore, the saliva-based PTK method significantly reduced the test processing time by 2 h. Notably, Ct values at discharge increased in saliva samples compared with those at admission, which might indicate patients' clinical conditions or virus activity. In conclusion, the saliva-based PTK implemented in this study streamlines RNA extraction, making the process faster, safer, and more cost-effective, demonstrating that this method is a rapid and reliable diagnostic tool for SARS-CoV-2 detection in children.

Risk Factor Analysis of Lymph Node Metastasis for Rectal Neuroendocrine Tumors: Who Needs a Radical Resection in Rectal Neuroendocrine Tumors Sized 1-2 cm?

BACKGROUND: Rectal neuroendocrine tumors (NETs) have malignant potential, and lymph node (LN) or distant metastases can occur; however, treatment of NETs 1-2 cm in size is controversial. OBJECTIVE: This study aimed to identify predictive factors for LN metastasis and prognostic factors for recurrence of rectal NETs, especially tumors 1‒2 cm in size. METHODS: Between October 2004 and November 2020, 453 patients underwent endoscopic or surgical treatment for rectal NETs in Seoul National University Hospital. The data on these patients were prospectively collected in our database and reviewed retrospectively. In cases of local excision, we evaluated LN metastasis with radiologic imaging, including computed tomography or magnetic resonance imaging before treatment and during the follow-up periods. RESULTS: LN metastasis was observed in 40 patients (8.8%). A higher rate of LN metastasis was observed in larger-sized tumors, advanced T stage, lymphovascular invasion (LVI), perineural invasion (PNI), and high tumor grade. In multivariable analysis, the significant risk factors for LN metastasis were tumor size (1 ≤ size < 2 cm: hazard ratio [HR] 64.07; size ≥2 cm: HR 102.37, p < 0.001) and tumor grade (G2: HR 3.63, p = 0.034; G3: HR 5.09, p = 0.044). In multivariable analysis for tumors 1-2 cm in size, the risk factor for LN metastasis was tumor grade (G2: HR 6.34, p = 0.013). CONCLUSIONS: Tumor grade and size are important predictive factors for LN metastasis. In NETs 2 cm in size, tumor grade is also important for LN metastasis, and radical resection should be considered.

The prediction of liver decompensation using hepatic collagen deposition assessed by computer-assisted image analysis with Masson's trichrome stain.

BACKGROUND & AIM: The current pathologic system classifies structural deformation caused by hepatic fibrosis semi-quantitatively, which may lead to a disagreement among pathologists. We measured hepatic fibrosis quantitatively using collagen proportionate area (CPA) in compensated cirrhotic patients and assessed its impact on predicting the development of liver decompensation. METHOD: From January 2010 to June 2018, we assessed 101 patients who went through liver biopsy and received diagnosis as compensated cirrhosis with digital image analysis of CPA. Clinical and laboratory data were collected at the baseline and at the time of the last follow-up or progression to liver decompensation (LD). RESULT: The mean age was 50.8 ± 10.5 years, and the most common etiology of liver disease was chronic hepatitis B (48.5%), followed by alcoholic hepatitis (18.8%). The mean CPA was 16.91 ± 9.60%. The mean CPA values were different in patients with and without LD development (21.8 ± 11.1 vs. 15.2 ± 8.5). During the median follow-up of 60.0 months, 26 out of 101 patients experienced LD. Older age (hazard ratio [HR],1.069; p = 0.015), prolonged international normalized ratio (HR, 6.449; p = 0.019) and higher CPA (HR, 1.049; p = 0.040) were independent predictors of liver decompensation on multivariate cox-regression analysis. When patients were divided according to the optimal CPA threshold (26.8%), higher CPA predicted LD better than lower CPA. (Log-rank test: p < 0.001). CONCLUSION: CPA could be a useful quantitative prognostic value for patients with compensated cirrhosis.

Enhancing anti-cancer capacity: Novel class I/II HDAC inhibitors modulate EMT, cell cycle, and apoptosis pathways.

Cancer has been a leading cause of death over the last few decades in western countries as well as in Taiwan. However, traditional therapies are limited by the adverse effects of chemotherapy and radiotherapy, and tumor recurrence may occur. Therefore, it is critical to develop novel therapeutic drugs. In the field of HDAC inhibitor development, apart from the hydroxamic acid moiety, 2-aminobenzamide also functions as a zinc-binding domain, which is shown in well-known HDAC inhibitors such as Entinostat and Chidamide. With recent successful experiences in synthesizing 1-(phenylsulfonyl)indole-based compounds, in this study, we further combined two features of the above chemical compounds and generated indolyl benzamides. Compounds were screened in different cancer cell lines, and enzyme activity was examined to demonstrate their potential for anti-HDAC activity. Various biological functional assays evidenced that two of these compounds could suppress cancer growth and migration capacity, through regulating epithelial-mesenchymal transition (EMT), cell cycle, and apoptosis mechanisms. Data from 3D cancer cells and the in vivo zebrafish model suggested the potential of these compounds in cancer therapy in the future.

Potential role of Fibrosis-4 score in hepatocellular carcinoma screening: The Kangbuk Samsung Health Study.

AIM: Hepatocellular carcinoma (HCC) is a major cause of cancer-related death, with low survival rates worldwide. Fatty liver disease (FLD) significantly contributes to HCC. We studied the screening performance of different methods for identifying HCC in patients with FLD or with metabolic risk factors for FLD. METHODS: Korean adults (n = 340 825) without a prior HCC diagnosis were categorized into four groups: normal (G1), ≥2 metabolic risk factors (G2), FLD (G3), and viral liver disease or liver cirrhosis (G4). The National Cancer Registry data were used to identify HCC cases within 12 months. We assessed the area under the receiver operating characteristic curve, sensitivity, specificity, and positive and negative predictive values of individual or combined screening methods. RESULTS: In 93 HCC cases, 71 were identified in G4, whereas 20 cases (21.5%) in G2 and G3 combined where ultrasound and Fibrosis-4 performed similarly to alpha-fetoprotein and ultrasound. In G2, Fibrosis-4 and ultrasound had the highest area under the receiver operating characteristic curve (0.93 [0.87-0.99]), whereas in G3, the combined screening methods had the highest area under the receiver operating characteristic curve (0.98 [0.95-1.00]). The positive predictive value was lower in G2 and G3 than in G4, but was >5% when restricted to a high Fibrosis-4 score. CONCLUSIONS: More than 21% of HCC cases were observed in patients with diagnosed FLD or at risk of FLD with metabolic risk factors. Nevertheless, screening for HCC in individuals without cirrhosis or viral hepatitis yielded very low results, despite the potential value of the Fibrosis-4 score in identifying individuals at high risk of HCC.

Traditional Korean diet high in one-carbon nutrients increases global DNA methylation: implication for epigenetic diet.

PURPOSE: DNA methylation is a major epigenetic phenomenon through which diet affects health and disease. This study aimed to determine the epigenetic influence of the traditional Korean diet (K-diet) on global DNA methylation via one-carbon metabolism. METHODS: A crossover study was conducted on 52 women. Two diets, a K-diet, high in plant foods and low in calories and animal fat, and a control diet, similar to the diet currently consumed in Korea, were provided to all subjects alternately for 4 weeks with a 4-week washout period. Clinical parameters were measured before and after each dietary intervention. Nutrient intake was calculated by using a computer-aided nutritional analysis program. One-carbon metabolites in the serum and global DNA methylation in peripheral mononuclear cells were determined using ultra-performance liquid chromatography-tandem mass spectrometry. RESULTS: The K-diet group consumed more folate (669.9 ± 6.7 µg vs. 502.7 ± 3.0, p < 0.001), B6, B12, serine, and choline, and less methionine (992.6 ± 63 vs. 1048.3 mg ± 34.1, p < 0.0001) than the control group did. In the K-diet group, the increment of plasma 5-methyltetrahydrofolate (0.08 µg/mL ± 0.11 vs 0.02 ± 0.10, p < 0.009) and decrement of L-homocysteine (- 70.7 ± 85.0 vs - 39.3 ± 69.4, p < 0.0168) were greater than those of the control group. Global DNA methylation was significantly increased in the K-diet group (6.70 ± 3.02% to 9.45 ± 3.69, p < 0.0001) but not in the control group. CONCLUSIONS: A K-diet high in one-carbon nutrients can enhance the global DNA methylation status, suggesting an epigenetic mechanism by which the K-diet conveys health effects. Trial registration Korean Clinical Trial Registry (trial number: KCT0005340, 24/08/2020, retrospectively registered).

Are sporadic colorectal cancers in young patients distinct from those in elderly patients?

AIM: The aim of this study was to compare the clinicopathological and oncological characteristics of sporadic colorectal cancer (CRC) between young and elderly patients without any genetic mutations that cause hereditary CRC. METHOD: In this cross-sectional, retrospective study conducted at three tertiary referral hospitals, we enrolled 1599 patients with CRC who underwent surgery between January 2010 and December 2017, including 157 young patients (age ≤ 40 years; yCRC) and 1442 elderly patients (age ≥ 70 years; eCRC). The clinicopathological and oncological outcomes were compared between the two groups. RESULTS: The median age at diagnosis was 37 years in the yCRC group (range 33.0-39.2 years) and 76 years in the eCRC group (range 72.0-79.0 years). The yCRC group did not present with advanced stages at diagnosis compared with the eCRC group, and the distribution of tumour stages was similar between the two groups. Microsatellite instability (MSI) testing revealed no difference in the frequency of tumours with high MSI (7.8% in yCRC, 5.8% in eCRC), and the frequency of mutations in the KRAS, NRAS and BRAF genes was also similar. The 3-year overall survival was better in the yCRC group than in the eCRC group (97.4% vs. 83.5%, p < 0.001); however, no such difference was observed in cancer-specific survival. CONCLUSION: Genetically proven sporadic CRCs did not differ significantly between young and elderly patients in terms of tumour stage, tumour location and various molecular features. CLINICAL TRIAL REGISTRATION NUMBER: The study was retrospectively registered with Clinical Trials.gov (no. NCT05601609).

Single-Molecule Imaging Reveals that Rad4 Employs a Dynamic DNA Damage Recognition Process.

Nucleotide excision repair (NER) is an evolutionarily conserved mechanism that processes helix-destabilizing and/or -distorting DNA lesions, such as UV-induced photoproducts. Here, we investigate the dynamic protein-DNA interactions during the damage recognition step using single-molecule fluorescence microscopy. Quantum dot-labeled Rad4-Rad23 (yeast XPC-RAD23B ortholog) forms non-motile complexes or conducts a one-dimensional search via either random diffusion or constrained motion. Atomic force microcopy analysis of Rad4 with the ß-hairpin domain 3 (BHD3) deleted reveals that this motif is non-essential for damage-specific binding and DNA bending. Furthermore, we find that deletion of seven residues in the tip of ß-hairpin in BHD3 increases Rad4-Rad23 constrained motion at the expense of stable binding at sites of DNA lesions, without diminishing cellular UV resistance or photoproduct repair in vivo. These results suggest a distinct intermediate in the damage recognition process during NER, allowing dynamic DNA damage detection at a distance.

Successful pregnancy outcome via in-vitro fertilization and laparoscopic resection of non-communicating rudimentary horn pregnancy containing early pregnancy: a case report.

BACKGROUND: Non-communicating rudimentary horn pregnancy (NCRHP) lead to life-threatening condition for both mother and fetus. Early diagnosis of NCRHP and laparoscopic resection is important to prevent catastrophic conditions. However, delayed diagnosis until the second or third trimester makes it difficult to accurately diagnose between NCRHP and bicornuate uterine pregnancy, as both conditions present uterine rupture and massive hemoperitoneum. Furthermore, these rare cases are challenging in pregnancy trials and associated with adverse outcomes in subsequent pregnancies. CASE PRESENTATION: A 31-year-old gravida 1 para 0 Korean woman visited our infertility center with a confirmed positive urine pregnancy test after timed intercourse. Before she was scheduled to have timed intercourse, a unicornuate uterus with a non-communicating right uterine horn was suspected based on an ultrasound scan and hysterosalpingography during the initial infertility workup. A gestational sac was observed in the right non-communicating rudimentary horn at 5 weeks of gestation. Serum beta-human chorionic gonadotropin (b-hCG) level was 2052.0mIU/mL. An elective laparoscopic resection of the right rudimentary horn containing a gestational sac, along with ipsilateral salpingectomy, was performed with no adverse event. After 3-month of recovery period and three cycles of conceptional trials involving timed intercourse and intrauterine insemination, in-vitro fertilization (IVF) was performed using the antagonist protocol, and successful pregnancy was confirmed. The patient had been hospitalized from 21 + 6 weeks to 35 + 6 weeks of gestation, underwent cerclage placement and tocolytics with corticosteroid treatment. She delivered an early-term male baby by cesarean section. CONCLUSION: In this rare case, the successful pregnancy achieved through IVF following the appropriate management of NCRHP under laparoscopy underscores the critical importance of early diagnosis and intervention in cases of NCRHP. Timely identification and management of NCRHP are vital to prevent the occurrence of catastrophic conditions and to enhance the prognosis of a successful pregnancy through assisted reproductive technology (ART). Therefore, a high index of suspicion for NCRHP is important and employs a range of diagnostic modalities.