Driver gene combinations dictate cutaneous squamous cell carcinoma disease continuum progression.

The molecular basis of disease progression from UV-induced precancerous actinic keratosis (AK) to malignant invasive cutaneous squamous cell carcinoma (cSCC) and potentially lethal metastatic disease remains unclear. DNA sequencing studies have revealed a massive mutational burden but have yet to illuminate mechanisms of disease progression. Here we perform RNAseq transcriptomic profiling of 110 patient samples representing normal sun-exposed skin, AK, primary and metastatic cSCC and reveal a disease continuum from a differentiated to a progenitor-like state. This is accompanied by the orchestrated suppression of master regulators of epidermal differentiation, dynamic modulation of the epidermal differentiation complex, remodelling of the immune landscape and an increase in the preponderance of tumour specific keratinocytes. Comparative systems analysis of human cSCC coupled with the generation of genetically engineered murine models reveal that combinatorial sequential inactivation of the tumour suppressor genes Tgfbr2, Trp53, and Notch1 coupled with activation of Ras signalling progressively drives cSCC progression along a differentiated to progenitor axis. Taken together we provide a comprehensive map of the cSCC disease continuum and reveal potentially actionable events that promote and accompany disease progression.

Transcriptomic analysis of cutaneous squamous cell carcinoma reveals a multigene prognostic signature associated with metastasis.

BACKGROUND: Metastasis of cutaneous squamous cell carcinoma (cSCC) is uncommon. Current staging methods are reported to have sub-optimal performances in metastasis prediction. Accurate identification of patients with tumors at high risk of metastasis would have a significant impact on management. OBJECTIVE: To develop a robust and validated gene expression profile signature for predicting primary cSCC metastatic risk using an unbiased whole transcriptome discovery-driven approach. METHODS: Archival formalin-fixed paraffin-embedded primary cSCC with perilesional normal tissue from 237 immunocompetent patients (151 nonmetastasizing and 86 metastasizing) were collected retrospectively from four centers. TempO-seq was used to probe the whole transcriptome and machine learning algorithms were applied to derive predictive signatures, with a 3:1 split for training and testing datasets. RESULTS: A 20-gene prognostic model was developed and validated, with an accuracy of 86.0%, sensitivity of 85.7%, specificity of 86.1%, and positive predictive value of 78.3% in the testing set, providing more stable, accurate prediction than pathological staging systems. A linear predictor was also developed, significantly correlating with metastatic risk. LIMITATIONS: This was a retrospective 4-center study and larger prospective multicenter studies are now required. CONCLUSION: The 20-gene signature prediction is accurate, with the potential to be incorporated into clinical workflows for cSCC.

Topical treatment of actinic keratoses in organ transplant recipients: a feasibility study for SPOT (Squamous cell carcinoma Prevention in Organ transplant recipients using Topical treatments).

BACKGROUND: The risk of cutaneous squamous cell carcinoma (cSCC) is significantly increased in organ transplant recipients (OTRs). Clearance of actinic keratoses (AKs) is generally regarded as a surrogate biomarker for cSCC prevention. OTR-cSCC chemoprevention with topical AK treatments has not been investigated in randomized controlled trials (RCTs), although there is evidence that 5% 5-fluorouracil (5-FU) may be chemoprotective in immunocompetent patients. OBJECTIVES: To assess the feasibility, activity and evaluation outcomes relevant to the design of a future phase III RCT of topical cSCC chemoprevention in OTRs. METHODS: OTRs with 10 or more AKs in predefined areas were randomized 1 : 1 : 1 to topical 5-FU, 5% imiquimod (IMIQ) or sunscreen (sun-protective factor 30+) in a phase II, open-label RCT over 15 months. Feasibility outcomes included proportions of eligible OTRs randomized, completing treatment and willing to be re-treated. AK activity [AK clearance, new AK development, patient-centred outcomes (toxicity, health-related quality of life, HRQoL)] and evaluation methodology (clinical vs. photographic) were assessed. RESULTS: Forty OTRs with 903 AKs were randomized. All feasibility outcomes were met (56% of eligible OTRs were randomized; 89% completed treatment; 81% were willing to be re-treated). AK activity analyses found 5-FU and IMIQ were superior to sunscreen for AK clearance and prevention of new AKs. 5-FU was more effective than IMIQ in AK clearance and prevention in exploratory analyses. Although toxicity was greater with 5-FU, HRQoL outcomes were similar. CONCLUSIONS: Trials of topical AK treatments in OTRs for cSCC chemoprevention are feasible and AK activity results support further investigation of 5-FU-based treatments in future phase III trials. What is already known about this topic? Cutaneous squamous cell carcinoma (cSCC) is significantly more common in immunocompromised individuals including organ transplant recipients (OTRs) compared with immunocompetent populations. cSCC chemoprevention activity of sunscreen and 5-fluorouracil-based (5-FU) actinic keratosis (AK) treatments has been demonstrated in randomized controlled trials (RCTs) in immunocompetent populations but not in OTRs. AKs are cSCC precursors and their clearance and prevention are generally regarded as surrogate endpoint biomarkers for potential cSCC chemoprevention activity. What does this study add? SPOT (SCC Prevention in OTRs using Topical treatments) has confirmed that RCTs of OTR-cSCC chemoprevention with topical AK treatments are feasible. It also suggests that topical 5-FU may be superior to 5% imiquimod and sunscreen in AK clearance and prevention. Together with recent evidence from several RCTs in the general population, these data provide a compelling rationale for further studies of intervention with 5-FU-based topical chemoprevention approaches in OTR-cSCC prevention.

The Genomic Landscape of Actinic Keratosis.

Actinic keratoses (AKs) are lesions of epidermal keratinocyte dysplasia and are precursors for invasive cutaneous squamous cell carcinoma (cSCC). Identifying the specific genomic alterations driving the progression from normal skin to skin with AK to skin with invasive cSCC is challenging because of the massive UVR-induced mutational burden characteristic at all stages of this progression. In this study, we report the largest AK whole-exome sequencing study to date and perform a mutational signature and candidate driver gene analysis on these lesions. We demonstrate in 37 AKs from both immunosuppressed and immunocompetent patients that there are significant similarities between AKs and cSCC in terms of mutational burden, copy number alterations, mutational signatures, and patterns of driver gene mutations. We identify 44 significantly mutated AK driver genes and confirm that these genes are similarly altered in cSCC. We identify azathioprine mutational signature in all AKs from patients exposed to the drug, providing further evidence for its role in keratinocyte carcinogenesis. cSCCs differ from AKs in having higher levels of intrasample heterogeneity. Alterations in signaling pathways also differ, with immune-related signaling and TGFß signaling significantly more mutated in cSCC. Integrating our findings with independent gene expression datasets confirms that dysregulated TGFß signaling may represent an important event in AK‒cSCC progression.

Interventions for basal cell carcinoma of the skin.

BACKGROUND: Basal cell carcinoma (BCC) is the commonest cancer affecting white-skinned individuals, and worldwide incidence is increasing. Although rarely fatal, BCC is associated with significant morbidity and costs. First-line treatment is usually surgical excision, but alternatives are available. New published studies and the development of non-surgical treatments meant an update of our Cochrane Review (first published in 2003, and previously updated in 2007) was timely. OBJECTIVES: To assess the effects of interventions for BCC in immunocompetent adults. SEARCH METHODS: We updated our searches of the following databases to November 2019: Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and LILACS. SELECTION CRITERIA: Randomised controlled trials (RCTs) of interventions for BCC in immunocompetent adults with histologically-proven, primary BCC. Eligible comparators were placebo, active treatment, other treatments, or no treatment. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Primary outcome measures were recurrence at three years and five years (measured clinically) (we included recurrence data outside of these time points if there was no measurement at three or five years) and participant- and observer-rated good/excellent cosmetic outcome. Secondary outcomes included pain during and after treatment, early treatment failure within six months, and adverse effects (AEs). We used GRADE to assess evidence certainty for each outcome. MAIN RESULTS: We included 52 RCTs (26 new) involving 6690 participants (median 89) in this update. All studies recruited from secondary care outpatient clinics. More males than females were included. Study duration ranged from six weeks to 10 years (average 13 months). Most studies (48/52) included only low-risk BCC (superficial (sBCC) and nodular (nBCC) histological subtypes). The majority of studies were at low or unclear risk of bias for most domains. Twenty-two studies were industry-funded: commercial sponsors conducted most of the studies assessing imiquimod, and just under half of the photodynamic therapy (PDT) studies. Overall, surgical interventions have the lowest recurrence rates. For high-risk facial BCC (high-risk histological subtype or located in the facial 'H-zone' or both), there may be slightly fewer recurrences with Mohs micrographic surgery (MMS) compared to surgical excision (SE) at three years (1.9% versus 2.9%, respectively) (risk ratio (RR) 0.64, 95% confidence interval (CI) 0.16 to 2.64; 1 study, 331 participants; low-certainty evidence) and at five years (3.2% versus 5.2%, respectively) (RR 0.61, 95% CI 0.18 to 2.04; 1 study, 259 participants; low-certainty evidence). However, the 95% CI also includes the possibility of increased risk of recurrence and no difference between treatments. There may be little to no difference regarding improvement of cosmetic outcomes between MMS and SE, judged by participants and observers 18 months post-operatively (one study; low-certainty evidence); however, no raw data were available for this outcome. When comparing imiquimod and SE for nBCC or sBCC at low-risk sites, imiquimod probably results in more recurrences than SE at three years (16.4% versus 1.6%, respectively) (RR 10.30, 95% CI 3.22 to 32.94; 1 study, 401 participants; moderate-certainty evidence) and five years (17.5% versus 2.3%, respectively) (RR 7.73, 95% CI 2.81 to 21.3; 1 study, 383 participants; moderate-certainty evidence). There may be little to no difference in the number of participant-rated good/excellent cosmetic outcomes (RR 1.00, 95% CI 0.94 to 1.06; 1 study, 326 participants; low-certainty evidence). However, imiquimod may result in greater numbers of good/excellent cosmetic outcomes compared to SE when observer-rated (60.6% versus 35.6%, respectively) (RR 1.70, 95% CI 1.35 to 2.15; 1 study, 344 participants; low-certainty evidence). Both cosmetic outcomes were measured at three years. Based on one study of 347 participants with high- and low-risk primary BCC of the face, radiotherapy may result in more recurrences compared to SE under frozen section margin control at three years (5.2% versus 0%, respectively) (RR 19.11, 95% CI 1.12 to 325.78; low-certainty evidence) and at four years (6.4% versus 0.6%, respectively) (RR 11.06, 95% CI 1.44 to 84.77; low-certainty evidence). Radiotherapy probably results in a smaller number of good participant- (RR 0.76, 95% CI 0.63 to 0.91; 50.3% versus 66.1%, respectively) or observer-rated (RR 0.48, 95% CI 0.37 to 0.62; 28.9% versus 60.3%, respectively) good/excellent cosmetic outcomes compared to SE, when measured at four years, where dyspigmentation and telangiectasia can occur (both moderate-certainty evidence). Methyl-aminolevulinate (MAL)-PDT may result in more recurrences compared to SE at three years (36.4% versus 0%, respectively) (RR 26.47, 95% CI 1.63 to 429.92; 1 study; 68 participants with low-risk nBCC in the head and neck area; low-certainty evidence). There were no useable data for measurement at five years. MAL-PDT probably results in greater numbers of participant- (RR 1.18, 95% CI 1.09 to 1.27; 97.3% versus 82.5%) or observer-rated (RR 1.87, 95% CI 1.54 to 2.26; 87.1% versus 46.6%) good/excellent cosmetic outcomes at one year compared to SE (2 studies, 309 participants with low-risk nBCC and sBCC; moderate-certainty evidence). Based on moderate-certainty evidence (single low-risk sBCC), imiquimod probably results in fewer recurrences at three years compared to MAL-PDT (22.8% versus 51.6%, respectively) (RR 0.44, 95% CI 0.32 to 0.62; 277 participants) and five years (28.6% versus 68.6%, respectively) (RR 0.42, 95% CI 0.31 to 0.57; 228 participants). There is probably little to no difference in numbers of observer-rated good/excellent cosmetic outcomes at one year (RR 0.98, 95% CI 0.84 to 1.16; 370 participants). Participant-rated cosmetic outcomes were not measured for this comparison. AEs with surgical interventions include wound infections, graft necrosis and post-operative bleeding. Local AEs such as itching, weeping, pain and redness occur frequently with non-surgical interventions. Treatment-related AEs resulting in study modification or withdrawal occurred with imiquimod and MAL-PDT. AUTHORS' CONCLUSIONS: Surgical interventions have the lowest recurrence rates, and there may be slightly fewer recurrences with MMS over SE for high-risk facial primary BCC (low-certainty evidence). Non-surgical treatments, when used for low-risk BCC, are less effective than surgical treatments, but recurrence rates are acceptable and cosmetic outcomes are probably superior. Of the non-surgical treatments, imiquimod has the best evidence to support its efficacy. Overall, evidence certainty was low to moderate. Priorities for future research include core outcome measures and studies with longer-term follow-up.

A Static Self-Directed Method for Generating Brain Organoids from Human Embryonic Stem Cells.

Human brain organoids differentiated from embryonic stem cells offer the unique opportunity to study complicated interactions of multiple cell types in a three-dimensional system. Here we present a relatively straightforward and inexpensive method that yields brain organoids. In this protocol human pluripotent stem cells are broken into small clusters instead of single cells and grown in basic media without a heterologous basement membrane matrix or exogenous growth factors, allowing the intrinsic developmental cues to shape the organoid's growth. This simple system produces a diversity of brain cell types including glial and microglial cells, stem cells, and neurons of the forebrain, midbrain, and hindbrain. Organoids generated from this protocol also display hallmarks of appropriate temporal and spatial organization demonstrated by brightfield images, histology, immunofluorescence and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). Because these organoids contain cell types from various parts of the brain, they can be utilized for studying a multitude of diseases. For example, in a recent paper we demonstrated the use of organoids generated from this protocol for studying the effects of hypoxia on the human brain. This approach can be used to investigate an array of otherwise difficult to study conditions such as neurodevelopmental handicaps, genetic disorders, and neurologic diseases.

Comparative transcriptome analysis of hESC- and iPSC-derived lentoid bodies.

The ocular lens serves as an excellent system to investigate the intricate details of development and differentiation. Generation of lentoid bodies or lens-like structures using pluripotent stem cells is important for understanding the processes critical for lens morphogenesis and the mechanism of cataractogenesis. We previously reported the generation of peripheral blood mononuclear cell (PBMC)-originated, induced pluripotent stem cells (iPSCs). Here, we report generation of lentoid bodies from human embryonic stem cells (hESCs) and (PBMC)-originated, iPSCs employing the "fried egg" method with brief modifications. The ultrastructure analysis of hESC- and iPSC-derived lentoid bodies identified closely packed lens epithelial- and differentiating fiber-like cells. In addition, we performed RNA sequencing (RNA-Seq) based transcriptome profiling of hESC- and iPSC-derived lentoid bodies at differentiation day 25. Next-generation RNA sequencing (RNA-Seq) of hESC- and iPSC-derived lentoid bodies detected expression (≥0.659 RPKM) of 13,975 and 14,003 genes, respectively. Comparative transcriptome analysis of hESC- and iPSC-derived lentoid bodies revealed 13,563 (>96%) genes common in both datasets. Among the genes common in both transcriptome datasets, 12,856 (~95%) exhibited a quantitatively similar expression profile. Next, we compared the mouse lens epithelial and fiber cell transcriptomes with hESC- and iPSC-derived lentoid bodies transcriptomes and identified > 96% overlap with lentoid body transcriptomes. In conclusion, we report first-time comparative transcriptome analysis of hESC- and iPSC-derived lentoid bodies at differentiation day 25.

How is the term haemangioma used in the literature? An evaluation against the revised ISSVA classification.

BACKGROUND/OBJECTIVES: The International Society for the Study of Vascular Anomalies (ISSVA) classification separates vascular anomalies into vascular malformations and vascular tumors. However, misdiagnoses and misperceptions still persist around the use of the term "hemangioma." We assessed whether the term "haemangioma" (British spelling) was used as part of ISSVA terminology in the literature. METHODS: We searched PubMed for all English-language publications containing the British spelling "haemangioma" in the title or abstract from January 1, 2015 to December 31, 2016. Each paper was judged by two independent reviewers, with conflicts resolved by senior review. RESULTS: By the standard of the 2014 ISSVA classification, 126/195 (64.6%) publications used incorrect terminology for vascular anomalies. This was reduced to 118/195 (60.5%) when using the 2018 ISSVA classification. The most commonly misused terms were cavernous haemangioma (27.1%), haemangioma without further specification (26.3%), and hepatic/liver haemangioma (12.7%). Age was a significant predictor of accuracy of terminology (P = 0.01), with a higher accuracy in children. Correct usage also varied by the site of the vascular anomaly, being highest for lesions of the skin (76.5%) followed by muscle (58.3%), soft tissue (23.5%), bone (21.4%), viscera (7.7%), and eye (0.0%) (P = 0.02). CONCLUSIONS: The term "haemangioma" is frequently used incorrectly by the standards of the 2014 and 2018 ISSVA classifications. Correct terminology is important as the natural history and treatment options vary depending on the type of vascular anomaly.

The Role of the Immune System in Cutaneous Squamous Cell Carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer. In immunosuppressed populations it is a source of considerable morbidity and mortality due to its enhanced recurrence and metastatic potential. In common with many malignancies, leucocyte populations are both protective against cancer development and also play a role in 'sculpting' the nascent tumor, leading to loss of immunogenicity and tumor progression. UV radiation and chronic viral carriage may represent unique risk factors for cSCC development, and the immune system plays a key role in modulating the response to both. In this review, we discuss the lessons learned from animal and ex vivo human studies of the role of individual leucocyte subpopulations in the development of cutaneous SCC. We then discuss the insights into cSCC immunity gleaned from studies in humans, particularly in populations receiving pharmacological immunosuppression such as transplant recipients. Similar insights in other malignancies have led to exciting and novel immune therapies, which are beginning to emerge into the cSCC clinical arena.

The genomic landscape of cutaneous SCC reveals drivers and a novel azathioprine associated mutational signature.

Cutaneous squamous cell carcinoma (cSCC) has a high tumour mutational burden (50 mutations per megabase DNA pair). Here, we combine whole-exome analyses from 40 primary cSCC tumours, comprising 20 well-differentiated and 20 moderately/poorly differentiated tumours, with accompanying clinical data from a longitudinal study of immunosuppressed and immunocompetent patients and integrate this analysis with independent gene expression studies. We identify commonly mutated genes, copy number changes and altered pathways and processes. Comparisons with tumour differentiation status suggest events which may drive disease progression. Mutational signature analysis reveals the presence of a novel signature (signature 32), whose incidence correlates with chronic exposure to the immunosuppressive drug azathioprine. Characterisation of a panel of 15 cSCC tumour-derived cell lines reveals that they accurately reflect the mutational signatures and genomic alterations of primary tumours and provide a valuable resource for the validation of tumour drivers and therapeutic targets.

Generation and Proteome Profiling of PBMC-Originated, iPSC-Derived Corneal Endothelial Cells.

Purpose: Corneal endothelial cells (CECs) are critical in maintaining clarity of the cornea. This study was initiated to develop peripheral blood mononuclear cell (PBMC)-originated, induced pluripotent stem cell (iPSC)-derived CECs. Methods: We isolated PBMCs and programmed the mononuclear cells to generate iPSCs, which were differentiated to CECs through the neural crest cells (NCCs). The morphology of differentiating iPSCs was examined at regular intervals by phase contrast microscopy. In parallel, the expression of pluripotent and corneal endothelium (CE)-associated markers was investigated by quantitative real-time PCR (qRT-PCR). The molecular architecture of the iPSC-derived CECs and human corneal endothelium (hCE) was examined by mass spectrometry-based proteome sequencing. Results: The PBMC-originated, iPSC-derived CECs were tightly adherent, exhibiting a hexagonal-like shape, one of the cardinal characteristics of CECs. The CE-associated markers expressed at significantly higher levels in iPSC-derived CECs at days 13, 20, and 30 compared with their respective levels in iPSCs. It is of importance that only residual expression levels of pluripotency markers were detected in iPSC-derived CECs. Cryopreservation of iPSC-derived CECs did not affect the tight adherence of CECs and their hexagonal-like shape while expressing high levels of CE-associated markers. Mass spectrometry-based proteome sequencing identified 10,575 proteins in the iPSC-derived CEC proteome. In parallel, we completed proteome profiling of the hCE identifying 6345 proteins. Of these, 5763 proteins were identified in the iPSC-derived CECs, suggesting that 90.82% of the hCE proteome overlaps with the iPSC-derived CEC proteome. Conclusions: We have successfully developed a personalized approach to generate CECs that closely mimic the molecular architecture of the hCE. To the best of our knowledge, this is the first report describing the development of PBMC-originated, iPSC-derived CECs.

Human papillomavirus and posttransplantation cutaneous squamous cell carcinoma: A multicenter, prospective cohort study.

Organ transplant recipients (OTRs) have a 100-fold increased risk of cutaneous squamous cell carcinoma (cSCC). We prospectively evaluated the association between ß genus human papillomaviruses (ßPV) and keratinocyte carcinoma in OTRs. Two OTR cohorts without cSCC were assembled: cohort 1 was transplanted in 2003-2006 (n = 274) and cohort 2 was transplanted in 1986-2002 (n = 352). Participants were followed until death or cessation of follow-up in 2016. ßPV infection was assessed in eyebrow hair by using polymerase chain reaction-based methods. ßPV IgG seroresponses were determined with multiplex serology. A competing risk model with delayed entry was used to estimate cumulative incidence of histologically proven cSCC and the effect of ßPV by using a multivariable Cox regression model. Results are reported as adjusted hazard ratios (HRs). OTRs with 5 or more different ßPV types in eyebrow hair had 1.7 times the risk of cSCC vs OTRs with 0 to 4 different types (HR 1.7, 95% confidence interval 1.1-2.6). A similar risk was seen with high ßPV loads (HR 1.8, 95% confidence interval 1.2-2.8). No significant associations were seen between serum antibodies and cSCC or between ßPV and basal cell carcinoma. The diversity and load of ßPV types in eyebrow hair are associated with cSCC risk in OTRs, providing evidence that ßPV is associated with cSCC carcinogenesis and may present a target for future preventive strategies.

Dimethadione embryotoxicity in the rat is neither correlated with maternal systemic drug concentrations nor embryonic tissue levels.

Pregnant rats treated with dimethadione (DMO), the N-demethylated metabolite of the anticonvulsant trimethadione, produce offspring having a 74% incidence of congenital heart defects (CHD); however, the incidence of CHD has high inter-litter variability (40-100%) that presents a challenge when studying the initiating events prior to the presentation of an abnormal phenotype. We hypothesized that the variability in CHD incidence was the result of differences in maternal systemic concentrations or embryonic tissue concentrations of DMO. To test this hypothesis, dams were administered 300 mg/kg DMO every 12h from the evening of gestational day (GD) 8 until the morning of GD 11 (six total doses). Maternal serum levels of DMO were assessed on GD 11, 12, 13, 14, 15, 18 and 21. Embryonic tissue concentrations of DMO were assessed on GD 11, 12, 13 and 14. In a separate cohort of GD 12 embryos, DMO concentrations and parameters of growth and development were assessed to determine if tissue levels of DMO were correlated with these endpoints. Embryos were exposed directly to different concentrations of DMO with whole embryo culture (WEC) and their growth and development assessed. Key findings were that neither maternal systemic concentrations nor tissue concentrations of DMO identified embryos that were sensitive or resistant to DMO in vivo. Direct exposure of embryos to DMO via WEC also failed to show correlations between embryonic concentrations of DMO with developmental outcomes in vitro. We conclude that neither maternal serum nor embryonic tissue concentrations of DMO predict embryonic outcome.

PHACE syndrome misdiagnosed as a port-wine stain.

We present the case of a boy born with a large macular, segmental vascular anomaly over the left face, initially diagnosed as a capillary malformation (port-wine stain) by the postnatal paediatric team. The vascular anomaly in the face then grew rapidly during the first few weeks of life and started to occlude the left eye, causing parental concerns about the infant's vision. A dermatological opinion established that the lesion was a segmental infantile haemangioma (IH). This, in combination with the posterior fossa malformation previously detected on antenatal scanning and confirmed by an MRI postnatally, satisfied the criteria for Posterior fossa abnormalities, Haemangiomas, Arterial abnormalities, Cardiac abnormalities and Eye abnormalities (PHACE) syndrome: a rare cutaneous neurovascular syndrome. This case highlights the diagnostic challenge posed by early phenotypes of haemangiomas as well as the importance of correctly diagnosing PHACE syndrome.

Noninvasive high-resolution ultrasound reveals structural and functional deficits in dimethadione-exposed fetal rat hearts in utero.

BACKGROUND: We previously showed dimethadione (DMO), the N-demethylated metabolite of the anticonvulsant trimethadione, induces ventricular septation defects (VSD) and other heart anomalies in rat (Weston et al., 2011). Because of the relationship between cardiac structure and function, we hypothesized that DMO-induced structural defects of the heart are associated with in utero functional deficits. To test the hypothesis, the goals were (1) define the parameters for ultrasound in the rat conceptus, and; (2) use ultrasound to identify structural and functional deficits following DMO treatment. METHODS: Different ultrasound modes (B-mode, M-mode, and Pulse-wave Doppler) using four high-resolution ultrasound transducer heads of varying frequency (25-40 MHz) were tested on gestational day (GD) 14, 15, 16, 17, and 21. Having identified the optimal conditions, pregnant Sprague-Dawley rats were administered six 300 mg/kg doses of DMO every 12 hr beginning at 19:00 hr on GD 8 to generate conceptuses with a high incidence of VSD. RESULTS: The three ultrasound modalities were used to identify VSD and several novel and rare structural heart anomalies (cardiac effusions and bifurcated septum) in live rat fetuses. DMO-treated hearts had an array of functional deficits including a decrease in mean heart rate, ejection fraction, and cardiac output and increased incidence of bradycardia and dysrhythmia. CONCLUSIONS: The ultrasound biomicroscope is an effective tool for the real-time characterization of the structure and function of embryo/fetal rat hearts. DMO causes significant deficits to in utero heart function for up to ten days (GD 21) following its final administration, suggesting long-term or possible permanent changes cardiac function.

Not a walk in the park: the ECVAM whole embryo culture model challenged with pharmaceuticals and attempted improvements with random forest design.

BACKGROUND: The European Committee for the Validation of Alternative Methods (ECVAM) supported the development of a linear discriminant embryotoxicity prediction model founded on rat whole embryo culture (Piersma et al. (2004). Altern Lab Anim 32:275­307). Our goals were to (1) assess the accuracy of this model with pharmaceuticals, and (2) to use the data to develop a more accurate prediction model. METHODS: Sixty-one chemicals of known in vivo activity were tested. They were part of the ECVAM validation set (N513), commercially available pharmaceuticals (N531), and Pfizer chemicals that did not reach the market, but for which developmental toxicity data were available (N517). They were tested according to the ECVAM procedures. Fifty-seven of these chemicals were used for Random Forest modeling to develop an alternate model with the goal of using surrogate endpoints for simplified assessments and to improve the predictivity of the model. RESULTS: Using part of the ECVAM chemical test set, the ECVAM prediction model was 77% accurate. This approximated what was reported in the validation study (80%; Piersma et al. (2004). Altern Lab Anim 32:275­307). However, when confronted with novel chemicals, the accuracy of the linear discriminant model dropped to 56%. In an attempt to improve this performance, we used a Random Forest model that provided rankings and confidence estimates. Although the model used simpler endpoints, its performance was no better than the ECVAM linear discriminant model. CONCLUSIONS: This study confirms previous concerns about the applicability of the ECVAM prediction model to a more diverse chemical set, and underscores the challenges associated with developing embryotoxicity prediction models.

Assessment of the Embryonic Stem Cell Test and application and use in the pharmaceutical industry.

BACKGROUND: The European Centre for the Validation of Alternative Methods (ECVAM) designed the Embryonic Stem Cell Test (EST) as a tool for classifying developmentally toxic compounds. An in vitro tool to assess developmental toxicity would be of great value to the pharmaceutical industry to help with toxicity-associated attrition. METHODS: ECVAM's EST protocol was used, but employing a different mouse embryonic stem cell (ESC) line and an alternative differentiation medium. A subset of the compounds used to validate the EST assay along with a number of in-house pharmaceutical compounds plus marketed pharmaceutical compounds were used to assess the EST performance with receptor-mediated compounds. RESULTS: Our results with ECVAM compounds mirrored ECVAM's. Compounds that were developmentally toxic in vivo were classified by the EST as moderate risk. Overall, the accuracy was 75% with the current set of data and the predictivity of low-, moderate-, and high-risk compounds was 90, 71, and 60% while the precision was 59, 86, and 100%, respectively. Interestingly, a number of the non-developmentally toxic compounds had values for the 3T3 IC(50) values, which were lower than the ESC IC(50) and ID(50), a situation not taken into account by ECVAM when designing the EST algorithm. CONCLUSIONS: The assay as currently constructed has a significant false-positive rate (approximately 40%), but a very low false-negative rate (approximately 7%). Additional moderate- and high-risk compounds need to be assessed to increase confidence, accuracy, and understanding in the EST's predictivity.