Methylation and hydroxymethylation of cytosine moieties in CpG islands of specific genes are epigenetic processes shown to be involved in the development of cervical (pre)neoplastic lesions. We ...studied global (hydroxy)methylation during the subsequent steps in the carcinogenic process of the uterine cervix by using immunohistochemical protocols for the detection of 5-methylcytosine (5-mC) and 5-hydroxymethylcytosine (5-hmC) in paraffin-embedded tissues of the normal epithelia and (pre)malignant lesions. This approach allowed obtaining spatially resolved information of (epi)genetic alterations for individual cell populations in morphologically heterogeneous tissue samples. The normal ectocervical squamous epithelium showed a high degree of heterogeneity for both modifications, with a major positivity for 5-mC in the basal and parabasal layers in the ectocervical region, while 5-hmC immunostaining was even more restricted to the cells in the basal layer. Immature squamous metaplasia, characterized by expression of SOX17, surprisingly showed a decrease of 5-hmC in the basal compartments and an increase in the more superficial layers of the epithelium. The normal endocervical glandular epithelium showed a strong immunostaining reactivity for both modifications. At the squamocolumnar junctions, a specific 5-hmC pattern was observed in the squamous epithelium, resembling that of metaplasia, with the typical weak to negative reaction for 5-hmC in the basal cell compartment. The reserve cells underlying the glandular epithelium were also largely negative for 5-hmC but showed immunostaining for 5-mC. While the overall methylation status remained relatively constant, about 20% of the high-grade squamous lesions showed a very low immunostaining reactivity for 5-hmC. The (pre)malignant glandular lesions, including adenocarcinoma in situ (AIS) and adenocarcinoma showed a progressive decrease of hydroxymethylation with advancement of the lesion, resulting in cases with regions that were negative for 5-hmC immunostaining. These data indicate that inhibition of demethylation, which normally follows cytosine hydroxymethylation, is an important epigenetic switch in the development of cervical cancer.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This study compares three different pretreatment protocols for the immunohistochemical detection of 5-methylcytosine (5-mC) and 5-hydroxymethylcytosine (5-hmC) in nuclear DNA. The human biological ...samples analyzed included formalin-fixed and paraffin-embedded (FFPE) normal squamous epithelium, ethanol-fixed cultured cells, and metaphase chromosomes. The antigen retrieval methods included low pH Citrate and high pH Tris–ethylenediaminetetraacetic acid (EDTA) protocols, as well as a method using Pepsin pretreatment combined with HCl for DNA denaturation. A gradual increase in the detection levels of 5-mC and 5-hmC was observed when going from Citrate via Tris/EDTA to Pepsin/HCl retrieval. While the Citrate retrieval protocol was the least efficient for the detection of 5-mC and 5-hmC, it did preserve nuclear morphology and enabled visualization of differences in intra- and internuclear distribution patterns in tissue and cell culture samples by single- and double-fluorescence detection. Quantification of (hydroxy)methylation levels in FFPE material demonstrated a significant heterogeneity and differences in 5-mC and 5-hmC levels within and between nuclei in the different compartments of normal squamous epithelium. It was concluded that immunohistochemical detection of 5-mC and 5-hmC enables the correlation of these DNA modifications with histomorphological features in heterogeneous tissues, but this is influenced by different pretreatment protocols that must be carefully chosen to allow an appropriate interpretation of these epigenetic switches.
Purpose: Patients with human papillomavirus (HPV)-containing oropharyngeal squamous cell carcinomas (OSCC) have a better prognosis
than patients with HPV-negative OSCC. This may be attributed to ...different genetic pathways promoting cancer.
Experimental Design: We used comparative genomic hybridization to identify critical genetic changes in 60 selected OSCC, 28 of which were associated
with HPV-16 as determined by HPV-specific PCR and fluorescence in situ hybridization analysis and positive p16 INK4A immunostaining. The results were correlated with HPV status and clinical data from patients.
Results: Two thirds of OSCC harbored gain at 3q26.3-qter irrespective of HPV status. In HPV-negative tumors this alteration was associated
with advanced tumor stage ( P = 0.013). In comparison with HPV-related OSCC, the HPV-negative tumors harbored: ( a ) a higher number of chromosomal alterations and amplifications ( P = 0.03 and 0.039, respectively); ( b ) significantly more losses at 3p, 5q, 9p, 15q, and 18q, and gains/amplifications at 11q13 ( P = 0.002, 0.03; <0.001, 0.02, 0.004, and 0.001, respectively); and ( c ) less often 16q losses and Xp gains ( P = 0.02 and 0.03). Survival analysis revealed a significantly better disease-free survival for HPV-related OSCC ( P = 0.02), whereas chromosome amplification was an unfavorable prognostic indicator for disease-free and overall survival ( P = 0.01 and 0.05, respectively). Interestingly, 16q loss, predominantly identified in HPV-related OSCC, was a strong indicator
of favorable outcome (overall survival, P = 0.008; disease-free survival, P = 0.01) and none of these patients had a tumor recurrence.
Conclusions: Genetic signatures of HPV-related and HPV-unrelated OSCC are different and most likely underlie differences in tumor development
and progression. In addition, distinct chromosomal alterations have prognostic significance.
Hypoxic-ischemic encephalopathy (HIE) in preterm infants is a severe disease for which no curative treatment is available. Cerebral inflammation and invasion of activated peripheral immune cells have ...been shown to play a pivotal role in the etiology of white matter injury, which is the clinical hallmark of HIE in preterm infants. The objective of this study was to assess the neuroprotective and anti-inflammatory effects of intravenously delivered mesenchymal stem cells (MSC) in an ovine model of HIE. In this translational animal model, global hypoxia-ischemia (HI) was induced in instrumented preterm sheep by transient umbilical cord occlusion, which closely mimics the clinical insult. Intravenous administration of 2 x 10(6) MSC/kg reduced microglial proliferation, diminished loss of oligodendrocytes and reduced demyelination, as determined by histology and Diffusion Tensor Imaging (DTI), in the preterm brain after global HI. These anti-inflammatory and neuroprotective effects of MSC were paralleled by reduced electrographic seizure activity in the ischemic preterm brain. Furthermore, we showed that MSC induced persistent peripheral T-cell tolerance in vivo and reduced invasion of T-cells into the preterm brain following global HI. These findings show in a preclinical animal model that intravenously administered MSC reduced cerebral inflammation, protected against white matter injury and established functional improvement in the preterm brain following global HI. Moreover, we provide evidence that induction of T-cell tolerance by MSC might play an important role in the neuroprotective effects of MSC in HIE. This is the first study to describe a marked neuroprotective effect of MSC in a translational animal model of HIE.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Tonsillar squamous cell carcinoma (TSCC) is frequently associated with human papillomavirus (HPV) and chromosome instability. Data from cellular model systems are, however, controversial concerning a ...relation between HPV and chromosome instability development. Here we studied this association in 77 primary TSCC with known clinical outcome and cell cycle protein expression profiles. Thirty‐two tumors (42%) showed HPV16‐integration. All 77 cases were analyzed by fluorescence in situ hybridization using chromosome 1‐ and 7‐specific centromere DNA probes to detect chromosome instability, indicated by the presence of chromosome imbalances and/or polyploidization for these chromosomes. In addition, eight HPV‐positive dysplasias, seven of which were adjacent to a carcinoma, were analyzed. Disomy for chromosome 1 and 7 was present in 29 out of 77 TSCC (38%), of which 19 were HPV16‐positive (p = 0.002). Aneusomy was observed in the remaining 48 TSCC, of which 13 were HPV‐positive. Aneusomies correlated significantly with tobacco‐ and alcohol consumption (p = 0.001 and p = 0.016, respectively) and a higher T‐stage (p = 0.018). Both HPV‐positivity and chromosome disomy were significantly associated with a favorable disease‐free survival (p = 0.001 and p = 0.025, respectively). Particularly in the HPV16‐positive group chromosome instability is a very strong indicator for an unfavorable prognosis (p = 0.032). In the dysplasias an identical HPV and chromosome copy number status was identified as in the adjacent tumors. We conclude that HPV‐positive TSCC and their precursor lesions are more often genetically stable than HPV‐negative lesions and that these tumors are associated with a favorable prognosis. Chromosome instability is an indicator for unfavorable prognosis, particularly in the HPV‐positive patient group.
What's new?
While tonsillar squamous cell carcinoma (TSCC) frequently is associated with human papillomavirus (HPV) and chromosome instability, data have been based primarily on in vitro cell model experiments. In this study, which examined tissue samples from patients with primary TSCC, HPV‐positive tumors were found to have comparatively stable genomes. Chromosome instability in these tumors was correlated with unfavorable prognosis. The findings could have clinical implications for TSCC.
SOX2 expression in high-grade cervical intraepithelial neoplasia (CIN3) and cervical squamous cell carcinoma is increased compared to that in the normal cervical epithelium. However, data on the ...expression and histological distribution of SOX2 in squamous epithelium during progression of CIN are largely lacking. We studied SOX2 expression throughout the epithelium in 53 cases of CIN1, 2, and 3. In general, SOX2 expression increased and expanded from basal/parabasal to the intermediate/superficial compartment during early stages of progression of CIN. An unexpected, specific expression pattern was found in areas classified as CIN2 and CIN3. This pattern was characterized by the absence or low expression of SOX2 in the basal/parabasal compartment and variable levels in the intermediate and superficial compartments. It was significantly associated with CIN3 (
p
= 0.009), not found in CIN1 and only seen in part of the CIN2 lesions. When the different patterns were correlated with the genetic make-up and presence of HPV, the CIN3-related pattern contained HPV-positive cells in the basal/parabasal cell compartment that were disomic. This is in contrast to the areas exhibiting the CIN1 and CIN2 related patterns, which frequently exhibited aneusomic cells. Based on their SOX2 localisation pattern, CIN1 and CIN2 could be delineated from CIN3. These data shed new light on the pathogenesis and dynamics of progression in premalignant cervical lesions, as well as on the target cells in the epithelium for HPV infection.
Aims
SOX17 expression has not been studied in glandular lesions of the uterine cervix like adenocarcinoma in situ (AIS) and invasive adenocarcinomas (AdC), whereas SOX17 promoter CpG island ...methylation has been reported. Therefore, the aim of this study was to relate the topographical distribution of SOX17 expression and SOX17 methylation status to each other, and to SOX2 expression, human papillomavirus (HPV) type, and physical status of the virus.
Methods and results
Immunohistochemistry was used in 45 cases to assess expression of SOX17 and SOX2. SOX17 promoter methylation was determined in 25 cases by means of bisulphite conversion and methylation‐specific polymerase chain reaction. SOX17 and SOX2 showed a mutually exclusive expression pattern in normal epithelium, with a sharp delineation in the squamocolumnar junction. SOX17 was found in endocervical columnar and reserve cells, whereas SOX2 was exclusively found in squamous epithelium. In both glandular lesions and cases with coexisting glandular and squamous intraepithelial components, a complex combination of SOX17 and SOX2 expression patterns was seen and mutually exclusive expression was lost. Frequently, gain of expression of SOX2 was found and expression of SOX17 was lost. Methylation of the CpG island in the SOX17 promoter was shown to be strongly associated with loss of expression of SOX17 (P = 0.0016).
Conclusions
In this study, we show for the first time a direct correlation between the topographical distribution of SOX17 expression and the methylation status of its gene promoter. This explains the heterogeneity of SOX17 expression in the glandular lesions of the cervix. No correlation was found between HPV type and physical status of the virus on the one hand and methylation status on the other.
Medical errors may be occasionally explained by inattentional blindness (IB), i.e., failing to notice an event/object that is in plain sight. We aimed to determine whether age/experience, ...restfulness/fatigue, and previous exposure to simulation education may affect IB in the anesthetic/surgical setting.PURPOSEMedical errors may be occasionally explained by inattentional blindness (IB), i.e., failing to notice an event/object that is in plain sight. We aimed to determine whether age/experience, restfulness/fatigue, and previous exposure to simulation education may affect IB in the anesthetic/surgical setting.In this multicentre/multinational study, a convenience sample of 280 anesthesiologists watched an attention-demanding video of a simulated trauma patient undergoing laparotomy and (independently/anonymously) recorded the abnormalities they noticed. The video contained four expected/common abnormalities (hypotension, tachycardia, hypoxia, hypothermia) and two prominently displayed unexpected/rare events (patient's head movement, leaky central venous line). We analyzed the participants' ability to notice the expected/unexpected events (primary outcome) and the proportion of expected/unexpected events according to age group and prior exposure to simulation education (secondary outcomes).METHODSIn this multicentre/multinational study, a convenience sample of 280 anesthesiologists watched an attention-demanding video of a simulated trauma patient undergoing laparotomy and (independently/anonymously) recorded the abnormalities they noticed. The video contained four expected/common abnormalities (hypotension, tachycardia, hypoxia, hypothermia) and two prominently displayed unexpected/rare events (patient's head movement, leaky central venous line). We analyzed the participants' ability to notice the expected/unexpected events (primary outcome) and the proportion of expected/unexpected events according to age group and prior exposure to simulation education (secondary outcomes).Anesthesiologists across all ages noticed fewer unexpected/rare events than expected/common ones. Overall, younger anesthesiologists missed fewer common events than older participants did (P = 0.02). There was no consistent association between age and perception of unexpected/rare events (P = 0.28), although the youngest cohort (< 30 yr) outperformed the other age groups. Prior simulation education did not affect the proportion of misses for the unexpected/rare events but was associated with fewer misses for the expected/common events. Self-perceived restfulness did not impact perception of events.RESULTSAnesthesiologists across all ages noticed fewer unexpected/rare events than expected/common ones. Overall, younger anesthesiologists missed fewer common events than older participants did (P = 0.02). There was no consistent association between age and perception of unexpected/rare events (P = 0.28), although the youngest cohort (< 30 yr) outperformed the other age groups. Prior simulation education did not affect the proportion of misses for the unexpected/rare events but was associated with fewer misses for the expected/common events. Self-perceived restfulness did not impact perception of events.Anesthesiologists noticed fewer unexpected/rare clinical events than expected/common ones in an attention-demanding video of a simulated trauma patient, in keeping with IB. Prior simulation training was associated with an improved ability to notice anticipated/expected events, but did not reduce IB. Our findings may have implications for understanding medical mishaps, and efforts to improve situational awareness, especially in acute perioperative and critical care settings.CONCLUSIONAnesthesiologists noticed fewer unexpected/rare clinical events than expected/common ones in an attention-demanding video of a simulated trauma patient, in keeping with IB. Prior simulation training was associated with an improved ability to notice anticipated/expected events, but did not reduce IB. Our findings may have implications for understanding medical mishaps, and efforts to improve situational awareness, especially in acute perioperative and critical care settings.
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