From the rarest to the most common: insights from progeroid syndromes into skin cancer and aging

A study of risk factors associated with the presence of oral potentially malignant disorders: a community-based study from Northeastern Thailand

BACKGROUND

The principal objective of this study is to ascertain the connections between well-known risk factors of oral cancer, including smoking (cigarette and tobacco), alcohol consumption, betel quid chewing, irritations in the oral cavity, history of head and neck cancer, and history of working outdoor more than 4 days/week, and the presence of OPMDs within the Thai population.

METHOD

349,318 subjects were recruited for initial screening, then 1,483 subjects who had at least 1 risk factor and a suspicious lesion underwent comprehensive oral examinations followed by a clinical diagnosis and then received initial treatment from either oral surgeons or oral medicine specialists. Among these subjects, individuals with at least 1 risk factor and with a clinical diagnosis of OPMDs were classified as cases, while those with at least 1 risk factor but without OPMDs were categorized as controls. The case group comprised a total of 487 subjects, whereas the control group consisted of 996 subjects. Exclusion criteria were known cases of currently having oral cancer or OPMDs.

RESULTS

The outcomes of the multivariate analysis revealed that among the variables assessed, betel quid (adjusted OR 5.12 [3.93-6.68], p < 0.001) and smoking (adjusted OR 1.46 [1.08-1.97], p = 0.013), there were an association with the presence of OPMDs. Conversely, alcohol drinking, having irritations in the oral cavity, a history of head and neck cancer, and a history of working outdoors more than 4 days/week were not associated with the presence of OPMDs. Furthermore, we also study the synergistic effect of alcohol drinking, irritations in the oral cavity, history of head and neck cancer, and history of working outdoors more than 4 days/week using subgroup analysis. The analysis showed that alcohol consumption combined with smoking or betel quid chewing expressed a significantly increased risk of OPMDs, from 1.46 to 2.03 (OR 2.03 [1.16-3.56], p = 0.014) and from 5.12 to 7.20 (OR 7.20 [3.96-13.09], p < 0.001).

CONCLUSION

Smoking and exposure to betel quid were a significant risk factors for the presence of OPMDs. The combination of alcohol with smoking or betel quid chewing was also found to increase the risk of OPMDs in this Thai northeastern population.

Defining the progeria phenome

Progeroid disorders are a heterogenous group of rare and complex hereditary syndromes presenting with pleiotropic phenotypes associated with normal aging. Due to the large variation in clinical presentation the diseases pose a diagnostic challenge for clinicians which consequently restricts medical research. To accommodate the challenge, we compiled a list of known progeroid syndromes and calculated the mean prevalence of their associated phenotypes, defining what we term the 'progeria phenome'. The data were used to train a support vector machine that is available at https://www.mitodb.com and able to classify progerias based on phenotypes. Furthermore, this allowed us to investigate the correlation of progeroid syndromes and syndromes with various pathogenesis using hierarchical clustering algorithms and disease networks. We detected that ataxia-telangiectasia like disorder 2, spastic paraplegia 49 and Meier-Gorlin syndrome display strong association to progeroid syndromes, thereby implying that the syndromes are previously unrecognized progerias. In conclusion, our study has provided tools to evaluate the likelihood of a syndrome or patient being progeroid. This is a considerable step forward in our understanding of what constitutes a premature aging disorder and how to diagnose them.

Congenital Telangiectatic Erythema: Scoping Review

BACKGROUND

Congenital telangiectatic erythema (CTE), also known as Bloom syndrome, is a rare autosomal recessive disorder characterized by below-average height, a narrow face, a red skin rash occurring on sun-exposed areas of the body, and an increased risk of cancer. CTE is one of many genodermatoses and photodermatoses associated with defects in DNA repair. CTE is caused by a mutation occurring in the BLM gene, which causes abnormal breaks in chromosomes.

OBJECTIVE

We aimed to analyze the existing literature on CTE to provide additional insight into its heredity, the spectrum of clinical presentations, and the management of this disorder. In addition, the gaps in current research and the use of artificial intelligence to streamline clinical diagnosis and the management of CTE are outlined.

METHODS

A literature search was conducted on PubMed, DOAJ, and Scopus using search terms such as "congenital telangiectatic erythema," "bloom syndrome," and "bloom-torre-machacek." Due to limited current literature, studies published from January 2000 to January 2023 were considered for this review. A total of 49 sources from the literature were analyzed.

RESULTS

Through this scoping review, the researchers were able to identify several publications focusing on Bloom syndrome. Some common subject areas included the heredity of CTE, clinical presentations of CTE, and management of CTE. In addition, the literature on rare diseases shows the potential advancements in understanding and treatment with artificial intelligence. Future studies should address the causes of heterogeneity in presentation and examine potential therapeutic candidates for CTE and similarly presenting syndromes.

CONCLUSIONS

This review illuminated current advances in potential molecular targets or causative pathways in the development of CTE as well as clinical features including erythema, increased cancer risk, and growth abnormalities. Future studies should continue to explore innovations in this space, especially in regard to the use of artificial intelligence, including machine learning and deep learning, for the diagnosis and clinical management of rare diseases such as CTE.

Hutchinson-Gilford Progeria Syndrome: An Overview of the Molecular Mechanism, Pathophysiology and Therapeutic Approach

Lamin A/C encoded by the LMNA gene is an essential component for maintaining the nuclear structure. Mutation in the lamin A/C leads to a group of inherited disorders is known as laminopathies. In the human body, there are several mutations in the LMNA gene that have been identified. It can affect diverse organs or tissues or can be systemic, causing different diseases. In this review, we mainly focused on one of the most severe laminopathies, Hutchinson-Gilford progeria syndrome (HGPS). HGPS is an immensely uncommon, deadly, metameric ill-timed laminopathies caused by the abnormal splicing of the LMNA gene and production of an aberrant protein known as progerin. Here, we also presented the currently available data on the molecular mechanism, pathophysiology, available treatment, and future approaches to this deadly disease. Due to the production of progerin, an abnormal protein leads to an abnormality in nuclear structure, defects in DNA repair, shortening of telomere, and impairment in gene regulation which ultimately results in aging in the early stage of life. Now some treatment options are available for this disease, but a proper understanding of the molecular mechanism of this disease will help to develop a more appropriate treatment which makes it an emerging area of research.

Noninvasive Analysis Using Data-Independent Acquisition Mass Spectrometry: New Epidermal Proteins That Reveal Sex Differences in the Aging Process

The development of mass spectrometry has provided a method with extremely high sensitivity and selectivity that can be used to identify protein biomarkers. Epidermal proteins, lipids, and cornified envelopes are involved in the formation of the skin epidermal barrier. The epidermal protein composition changes with age. Therefore, quantitative proteomic changes may be indicative of skin aging. We sought to utilize data-independent acquisition mass spectrometry for noninvasive analysis of epidermal proteins in healthy Chinese individuals of different age groups and sexes. In our study, we completed high-throughput protein detection, analyzed protein differences with MaxQuant software, and performed statistical analyses of the proteome. We obtained interesting findings regarding ceruloplasmin (CP), which exhibited significant differences and is involved in ferroptosis, a signaling pathway significantly associated with aging. There were also several proteins that differed between sexes in the younger group, but the sex differences disappeared with aging. These proteins, which were associated with both aging processes and sex differences, are involved in signaling pathways such as apoptosis, oxidative stress, and genomic stability and can serve as candidate biomarkers for sex differences during aging. Our approach for noninvasive detection of epidermal proteins and its application to accurately quantify protein expression can provide ideas for future epidermal proteomics studies.

Epigenetic Regulation of Skin Cells in Natural Aging and Premature Aging Diseases

Skin undergoes continuous renewal throughout an individual’s lifetime relying on stem cell functionality. However, a decline of the skin regenerative potential occurs with age. The accumulation of senescent cells over time probably reduces tissue regeneration and contributes to skin aging. Keratinocytes and dermal fibroblasts undergo senescence in response to several intrinsic or extrinsic stresses, including telomere shortening, overproduction of reactive oxygen species, diet, and sunlight exposure. Epigenetic mechanisms directly regulate skin homeostasis and regeneration, but they also mark cell senescence and the natural and pathological aging processes. Progeroid syndromes represent a group of clinical and genetically heterogeneous pathologies characterized by the accelerated aging of various tissues and organs, including skin. Skin cells from progeroid patients display molecular hallmarks that mimic those associated with naturally occurring aging. Thus, investigations on progeroid syndromes strongly contribute to disclose the causal mechanisms that underlie the aging process. In the present review, we discuss the role of epigenetic pathways in skin cell regulation during physiologic and premature aging.

Recent Developments in the Diagnosis and Management of Photosensitive Disorders

Photodermatoses occur in males and females of all races and ages. Onset can be variable in timing and influenced by genetic and environmental factors. Photodermatoses are broadly classified as immunologically mediated, chemical- and drug-induced, photoaggravated, and genetic (defective DNA repair or chromosomal instability) diseases. Advances in the field have led to improved recognition and treatment of many photodermatoses. The purpose of this focused review is to provide an update on the diagnosis and management of a variety of photodermatoses, both common and less common, with review of recent updates in the literature pertaining to their diagnosis and management.

Skin microbiota-host interactions

The skin is a complex and dynamic ecosystem that is inhabited by bacteria, archaea, fungi and viruses. These microbes-collectively referred to as the skin microbiota-are fundamental to skin physiology and immunity. Interactions between skin microbes and the host can fall anywhere along the continuum between mutualism and pathogenicity. In this Review, we highlight how host-microbe interactions depend heavily on context, including the state of immune activation, host genetic predisposition, barrier status, microbe localization, and microbe-microbe interactions. We focus on how context shapes the complex dialogue between skin microbes and the host, and the consequences of this dialogue for health and disease.

Mechanisms of vascular aging: What can we learn from Hutchinson-Gilford progeria syndrome?

Aging is the main risk factor for cardiovascular disease (CVD). The increased prevalence of CVD is partly due to the global increase in life expectancy. In this context, it is essential to identify the mechanisms by which aging induces CVD, with the ultimate aim of reducing its incidence. Both atherosclerosis and heart failure significantly contribute to age-associated CVD morbidity and mortality. Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder caused by the synthesis of progerin, which is noted for accelerated aging and CVD. This mutant form of prelamin A induces generalised atherosclerosis, vascular calcification, and cardiac electrophysiological abnormalities, leading to premature aging and death, mainly due to myocardial infarction and stroke. This review discusses the main vascular structural and functional abnormalities during physiological and premature aging, as well as the mechanisms involved in the exacerbated CVD and accelerated aging induced by the accumulation of progerin and prelamin A. Both proteins are expressed in non-HGPS individuals, and physiological aging shares many features of progeria. Research into HGPS could therefore shed light on novel mechanisms involved in the physiological aging of the cardiovascular system.

Aging in the Cardiovascular System: Lessons from Hutchinson-Gilford Progeria Syndrome

Aging, the main risk factor for cardiovascular disease (CVD), is becoming progressively more prevalent in our societies. A better understanding of how aging promotes CVD is therefore urgently needed to develop new strategies to reduce disease burden. Atherosclerosis and heart failure contribute significantly to age-associated CVD-related morbimortality. CVD and aging are both accelerated in patients suffering from Hutchinson-Gilford progeria syndrome (HGPS), a rare genetic disorder caused by the prelamin A mutant progerin. Progerin causes extensive atherosclerosis and cardiac electrophysiological alterations that invariably lead to premature aging and death. This review summarizes the main structural and functional alterations to the cardiovascular system during physiological and premature aging and discusses the mechanisms underlying exaggerated CVD and aging induced by prelamin A and progerin. Because both proteins are expressed in normally aging non-HGPS individuals, and most hallmarks of normal aging occur in progeria, research on HGPS can identify mechanisms underlying physiological aging.

Genome-wide DNA methylation analysis in blood cells from patients with Werner syndrome

Background

Werner syndrome is a progeroid disorder characterized by premature age-related phenotypes. Although it is well established that autosomal recessive mutations in the WRN gene is responsible for Werner syndrome, the molecular alterations that lead to disease phenotype remain still unidentified.

Results

To address whether epigenetic changes can be associated with Werner syndrome phenotype, we analysed genome-wide DNA methylation profile using the Infinium MethylationEPIC BeadChip in the whole blood from three patients affected by Werner syndrome compared with three age- and sex-matched healthy controls. Hypermethylated probes were enriched in glycosphingolipid biosynthesis, FoxO signalling and insulin signalling pathways, while hypomethylated probes were enriched in PI3K-Akt signalling and focal adhesion pathways. Twenty-two out of 47 of the differentially methylated genes belonging to the enriched pathways resulted differentially expressed in a publicly available dataset on Werner syndrome fibroblasts. Interestingly, differentially methylated regions identified CERS1 and CERS3, two members of the ceramide synthase family. Moreover, we found differentially methylated probes within ITGA9 and ADAM12 genes, whose methylation is altered in systemic sclerosis, and within the PRDM8 gene, whose methylation is affected in dyskeratosis congenita and Down syndrome.

Conclusions

DNA methylation changes in the peripheral blood from Werner syndrome patients provide new insight in the pathogenesis of the disease, highlighting in some cases a functional correlation of gene expression and methylation status.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-017-0389-4) contains supplementary material, which is available to authorized users.

The impact of cellular senescence in skin ageing: A notion of mosaic and therapeutic strategies

Cellular senescence is now recognized as one of the nine hallmarks of ageing. Recent data show the involvement of senescent cells in tissue ageing and some age-related diseases. Skin represents an ideal model for the study of ageing. Indeed, skin ageing varies between individuals depending on their chronological age but also on their exposure to various exogenous factors (mainly ultraviolet rays). If senescence traits can be detected with ageing in the skin, the senescent phenotype varies among the various skin cell types. Moreover, the origin of cellular senescence in the skin is still unknown, and multiple origins are possible. This reflects the mosaic of skin ageing. Senescent cells can interfere with their microenvironment, either via the direct secretion of factors (the senescence-associated secretory phenotype) or via other methods of communication, such as extracellular vesicles. Knowledge regarding the impact of cellular senescence on skin ageing could be integrated into dermatology research, especially to limit the appearance of senescent cells after photo(chemo)therapy or in age-related skin diseases. Therapeutic approaches include the clearance of senescent cells via the use of senolytics or via the cooperation with the immune system.

[Epidermal aging and anti-aging strategies]

Epithelial senescence is a complex process depending on intrinsic as well as extrinsic factors (e.g., UV or IR light, tobacco smoke) and must be seen in the context of the aging process especially of the corium and the subcutis. Morphological alterations become apparent in the form of epithelial atrophy, structural changes within the basal membrane, and a decrease in cell count of melanocytes and Langerhans cells. Signs of cellular senescence are reduced proliferation of keratinocytes, cumulation of dysplastic keratinocytes, various mutations (e.g., c-Fos/c-Jun, STAT3, FoxO1), as well as multiple lipid or amino acid metabolic aberrations (e.g., production of advanced glycation endproducts). This causes functional changes within the physical (lipid deficiency, water distribution dysfunction, lack of hygroscopic substances), chemical (pH conditions, oxygen radicals), and immunological barrier. Prophylactically, barrier-protective care products, antioxidant substances (e.g., vitamin C, B3, E, polyphenols, flavonoids), sunscreen products/measurements, and retinoids are used. For correcting alterations in aged epidermis, chemical peelings (fruit acids, β-hydroxy acid, trichloroacetic acid, phenolic compounds), non-ablative (IPL, PDL, Nd:YAG) as well as ablative (CO2, Erbium-YAG) light-assisted methods are used.

Tumors Involving Skin, Soft Tissue and Skeletal Muscle: Benign, Primary Malignant or Metastatic?

BACKGROUND

Metastatic cancer with invasion of skin, soft tissue and skeletal muscle is not common. Examples presenting as soft tissue masses could sometimes lead to misdiagnosis with delayed or inappropriate management. The purpose of current study was to investigate clinical characteristics in the involvement of metastatic cancer.

MATERIALS AND METHODS

A total of 1,097 patients complaining of skin or soft tissue masses and/or lesions were retrospectively reviewed from January 2012 to June 2013. Tumors involving skin, soft tissue and skeletal muscle of head and neck, chest wall, abdominal wall, pelvic region, back, upper and lower extremities were included in the study.

RESULTS

Fifty-seven (5.2%) patients were recognized as having malignancies on histopathological examination. The most common involvement of malignancy was basal cell carcinoma, followed by cutaneous squamous cell carcinoma, sarcoma and melanoma. The most common anatomical location in skin and soft tissue malignancies was head and neck (52.6% of the malignancies). Four (0.36%) of the malignant group were identified as metastatic cancer with the primary cancer source from lung, liver and tonsil and the most common site was upper extremities. One of them unexpectedly expired during the operation of metastatic tumor excision at the scalp.

CONCLUSIONS

Discrimination between benign and malignant soft tissue tumors is crucial. Performance of imaging study could assist in the differential diagnosis and the pre-operative risk evaluation of metastatic tumors involving skin, soft tissue and skeletal muscle.

[Experimental models of human skin aging]

The skin is a representative model for the study of human aging. Despite the high regenerative capacity of the skin, skin physiology changes over the course of life. Medical and cosmetic research is trying to prevent aging, to slow, to stop, or to reverse it. Effects of age-related DNA damage and of changing skin structure on pharmacological parameters are largely unknown. This review article summarizes the state of scientific knowledge in the field of experimental models of human skin aging and shows approaches to improve organotypic skin models, to develop predictive models of aging, and improve aging research.

Facial involvement in genodermatoses

Facial involvement represents a characteristic feature of a wide range of genodermatoses. Specific facial findings often help point to the correct diagnosis, which improves counseling and management. In particular, this can facilitate the identification and treatment of associated extracutaneous disease. The highly visible nature of facial lesions in genodermatoses and facial birthmarks can result in stigmatization and frequently leads to particular concern in patients and their family members. It is therefore critical for dermatologists to be aware of the broad spectrum of facial manifestations in genetic skin disease, especially when these findings have important implications with regard to monitoring and treatment. In this contribution, facial involvement in genodermatoses is divided into five morphologic categories based on the most prominent feature: Papules, scaling, photosensitivity/findings associated with aging (eg, telangiectasias, atrophy, lentigines), blisters/erosions, and birthmarks. Hopefully, this will provide a practical and clinically useful approach to a large and diverse assortment of genetic skin conditions.

Premature skin aging features rescued by inhibition of NADPH oxidase activity in XPC-deficient mice

Xeroderma pigmentosum type C (XP-C) is characterized mostly by a predisposition to skin cancers and accelerated photoaging, but little is known about premature skin aging in this disease. By comparing young and old mice, we found that the level of progerin and p16(INK4a) expression, β-galactosidase activity, and reactive oxygen species, which increase with age, were higher in young Xpc(-/-) mice than in young Xpc(+/+) ones. The expression level of mitochondrial complexes and mitochondrial functions in the skin of young Xpc(-/-) was as low as in control aged Xpc(+/+)animals. Furthermore, the metabolic profile in young Xpc(-/-) mice resembled that found in aged Xpc(+/+) mice. Furthermore, premature skin aging features in young Xpc(-/-) mice were mostly rescued by inhibition of nicotinamide adenine dinucleotide phosphate oxidase 1 (NOX1) activity by using a NOX1 peptide inhibitor, suggesting that the continuous oxidative stress due to overactivation of NOX1 has a causative role in the underlying pathophysiology.

XRCC3 C18067T polymorphism contributes a decreased risk to both basal cell carcinoma and squamous cell carcinoma: evidence from a meta-analysis

Background

The X-ray repair cross-complementing group 3 (XRCC3) in homologous recombination repair (HRR) pathway plays a very important role in DNA double-strand break repair (DSBR). Variations in the XRCC3 gene might lead to altered protein structure or function which may change DSBR efficiency and result in cancer. The XRCC3 C18067T polymorphism has been reported to be associated with skin cancer susceptibility, yet the results of these previous results have been inconsistent or controversial. To derive a more precise estimation of the association, we conducted a meta-analysis.

Methods

The quality of the studies was assessed according to a predefined scale. The association between the XRCC3 C18067T polymorphism and skin cancer risk was assessed by odds ratios (ORs) together with their 95% confidence intervals (CIs).

Results

Overall, no significant association was observed between XRCC3 C18067T polymorphism and skin cancer risk in any genetic model. Stratified analyses according to tumor type, significant association was found in the relationship between XRCC3 C18067T polymorphism and nonmelanoma skin cancer risk (homozygote comparison TT versus CC: OR = 0.74, 95%CI = 0.61–0.90, P = 0.003; recessive model TT versus TC/CC: OR = 0.81, 95%CI = 0.68–0.95, P = 0.01). Furthermore, significant association was also observed in XRCC3 C18067T polymorphism with both basal cell carcinoma risk (homozygote comparison TT versus CC: OR = 0.70, 95%CI = 0.53–0.92, P = 0.011; recessive model TT versus. TC/CC: OR = 0.74, 95%CI = 0.60–0.92, P = 0.007) and squamous cell carcinoma risk (heterozygote comparison TT versus .CC: OR = 0.81, 95%CI = 0.67–0.99, P = 0.04; dominant model TT/TC versus .CC: OR = 0.81, 95%CI = 0.68–0.98, P = 0.029).

Conclusion

The present meta-analysis demonstrates that XRCC3 C18067T polymorphism was not associated with risk of cutaneous melanoma but contributed a decreased risk to both basal cell carcinoma and squamous cell carcinoma.

The Fanconi anemia associated protein FAAP24 uses two substrate specific binding surfaces for DNA recognition

To maintain the integrity of the genome, multiple DNA repair systems exist to repair damaged DNA. Recognition of altered DNA, including bulky adducts, pyrimidine dimers and interstrand crosslinks (ICL), partially depends on proteins containing helix-hairpin-helix (HhH) domains. To understand how ICL is specifically recognized by the Fanconi anemia proteins FANCM and FAAP24, we determined the structure of the HhH domain of FAAP24. Although it resembles other HhH domains, the FAAP24 domain contains a canonical hairpin motif followed by distorted motif. The HhH domain can bind various DNA substrates; using nuclear magnetic resonance titration experiments, we demonstrate that the canonical HhH motif is required for double-stranded DNA (dsDNA) binding, whereas the unstructured N-terminus can interact with single-stranded DNA. Both DNA binding surfaces are used for binding to ICL-like single/double-strand junction-containing DNA substrates. A structural model for FAAP24 bound to dsDNA has been made based on homology with the translesion polymerase iota. Site-directed mutagenesis, sequence conservation and charge distribution support the dsDNA-binding model. Analogous to other HhH domain-containing proteins, we suggest that multiple FAAP24 regions together contribute to binding to single/double-strand junction, which could contribute to specificity in ICL DNA recognition.

Identification of biomarkers of human skin ageing in both genders. Wnt signalling - a label of skin ageing?

The goal of our work has been to investigate the mechanisms of gender-independent human skin ageing and examine the hypothesis of skin being an adequate model of global ageing. For this purpose, whole genome gene profiling was employed in sun-protected skin obtained from European Caucasian young and elderly females (mean age 26.7±4 years [n1 = 7] and 70.75±3.3 years [n2 = 4], respectively) and males (mean age 25.8±5.2 years [n3 = 6] and 76±3.8 years [n4 = 7], respectively) using the Illumina array platform. Confirmation of gene regulation was performed by real-time RT-PCR and immunohistochemistry. 523 genes were significantly regulated in female skin and 401 genes in male skin for the chosen criteria. Of these, 183 genes exhibited increased and 340 decreased expression in females whereas 210 genes showed increased and 191 decreased expression in males with age. In total, 39 genes were common in the target lists of significant regulated genes in males and females. 35 of these genes showed increased (16) or decreased (19) expression independent of gender. Only 4 overlapping genes (OR52N2, F6FR1OP2, TUBAL3 and STK40) showed differential regulation with age. Interestingly, Wnt signalling pathway showed to be significantly downregulated in aged skin with decreased gene and protein expression for males and females, accordingly. In addition, several genes involved in central nervous system (CNS) ageing (f.i. APP, TAU) showed to be expressed in human skin and were significanlty regulated with age. In conclusion, our study provides biomarkers of endogenous human skin ageing in both genders and highlight the role of Wnt signalling in this process. Furthermore, our data give evidence that skin could be used as a good alternative to understand ageing of different tissues such as CNS.

Effect of GSTM1 polymorphism on risks of basal cell carcinoma and squamous cell carcinoma: a meta-analysis

Glutathione S-transferases are important enzymes in the detoxification of a wide range of reactive oxygen species produced during melanin synthesis and oxidative stress processes. Glutathione S-transferase M1 (GSTM1) null genotype may be a candidate genetic polymorphism with a role in susceptibility to skin cancer such as basal and squamous cell carcinomas. We conducted a systematic review and meta-analysis to define the effect of GSTM1 null polymorphism on skin cancer risk. We searched the PubMed, Embase, and Web of Science databases to identify published case-control studies investigating the association between GSTM1 null genotype and skin cancer risk. Between-study heterogeneity was assessed using the I (2) statistic. Odds ratios (OR) with corresponding 95 % confidence intervals (95 % CI) from individual studies were pooled using fixed and random effects models. Nineteen case-control studies (4,275 cases and 4,255 controls) were considered eligible and included in the meta-analysis, and 11 of which were on basal cell carcinoma; ten, on melanoma, and seven, on squamous cell carcinoma. Overall, the GSTT1 null genotype was not associated with the risk of skin cancer (OR, 1.01; 95 % CI 0.93-1.11; P = 0.76). Subgroup analysis by histological types showed that GSTT1 null genotype was not associated with risks of basal cell carcinoma (OR, 1.06; 95 % CI 0.92-1.21; P = 0.42), squamous cell carcinoma (OR, 0.97; 95 % CI 0.76-1.24; P = 0.80), and cutaneous malignant melanoma (OR, 1.00; 95 % CI 0.88-1.14; P = 0.60). Therefore, this meta-analysis suggests that GSTM1 null polymorphism is not associated with risks of basal and squamous cell carcinomas.

Correlated alterations in genome organization, histone methylation, and DNA-lamin A/C interactions in Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is a premature aging disease that is frequently caused by a de novo point mutation at position 1824 in LMNA. This mutation activates a cryptic splice donor site in exon 11, and leads to an in-frame deletion within the prelamin A mRNA and the production of a dominant-negative lamin A protein, known as progerin. Here we show that primary HGPS skin fibroblasts experience genome-wide correlated alterations in patterns of H3K27me3 deposition, DNA-lamin A/C associations, and, at late passages, genome-wide loss of spatial compartmentalization of active and inactive chromatin domains. We further demonstrate that the H3K27me3 changes associate with gene expression alterations in HGPS cells. Our results support a model that the accumulation of progerin in the nuclear lamina leads to altered H3K27me3 marks in heterochromatin, possibly through the down-regulation of EZH2, and disrupts heterochromatin–lamina interactions. These changes may result in transcriptional misregulation and eventually trigger the global loss of spatial chromatin compartmentalization in late passage HGPS fibroblasts.

Werner's syndrome may be lost in the shadow of the scleroderma

We describe three patients with Werner's syndrome (WS), two of whom had been mistakenly diagnosed as having scleroderma. We would like to discuss briefly the importance of differentiation of these two disorders from each other.

Using VAAST to identify an X-linked disorder resulting in lethality in male infants due to N-terminal acetyltransferase deficiency

We have identified two families with a previously undescribed lethal X-linked disorder of infancy; the disorder comprises a distinct combination of an aged appearance, craniofacial anomalies, hypotonia, global developmental delays, cryptorchidism, and cardiac arrhythmias. Using X chromosome exon sequencing and a recently developed probabilistic algorithm aimed at discovering disease-causing variants, we identified in one family a c.109T>C (p.Ser37Pro) variant in NAA10, a gene encoding the catalytic subunit of the major human N-terminal acetyltransferase (NAT). A parallel effort on a second unrelated family converged on the same variant. The absence of this variant in controls, the amino acid conservation of this region of the protein, the predicted disruptive change, and the co-occurrence in two unrelated families with the same rare disorder suggest that this is the pathogenic mutation. We confirmed this by demonstrating a significantly impaired biochemical activity of the mutant hNaa10p, and from this we conclude that a reduction in acetylation by hNaa10p causes this disease. Here we provide evidence of a human genetic disorder resulting from direct impairment of N-terminal acetylation, one of the most common protein modifications in humans.

On the traces of XPD: cell cycle matters - untangling the genotype-phenotype relationship of XPD mutations

Mutations in the human gene coding for XPD lead to segmental progeria - the premature appearance of some of the phenotypes normally associated with aging - which may or may not be accompanied by increased cancer incidence. XPD is required for at least three different critical cellular functions: in addition to participating in the process of nucleotide excision repair (NER), which removes bulky DNA lesions, XPD also regulates transcription as part of the general transcription factor IIH (TFIIH) and controls cell cycle progression through its interaction with CAK, a pivotal activator of cyclin dependent kinases (CDKs). The study of inherited XPD disorders offers the opportunity to gain insights into the coordination of important cellular events and may shed light on the mechanisms that regulate the delicate equilibrium between cell proliferation and functional senescence, which is notably altered during physiological aging and in cancer.

The phenotypic manifestations in the different XPD disorders are the sum of disturbances in the vital processes carried out by TFIIH and CAK. In addition, further TFIIH- and CAK-independent cellular activities of XPD may also play a role. This, added to the complex feedback networks that are in place to guarantee the coordination between cell cycle, DNA repair and transcription, complicates the interpretation of clinical observations. While results obtained from patient cell isolates as well as from murine models have been elementary in revealing such complexity, the Drosophila embryo has proven useful to analyze the role of XPD as a cell cycle regulator independently from its other cellular functions. Together with data from the biochemical and structural analysis of XPD and of the TFIIH complex these results combine into a new picture of the XPD activities that provides ground for a better understanding of the patophysiology of XPD diseases and for future development of diagnostic and therapeutic tools.

Human variation databases

More than 100 000 human genetic variations have been described in various genes that are associated with a wide variety of diseases. Such data provides invaluable information for both clinical medicine and basic science. A number of locus-specific databases have been developed to exploit this huge amount of data. However, the scope, format and content of these databases differ strongly and as no standard for variation databases has yet been adopted, the way data is presented varies enormously. This review aims to give an overview of current resources for human variation data in public and commercial resources.

Mitochondrial dysfunction in some oxidative stress-related genetic diseases: Ataxia-Telangiectasia, Down Syndrome, Fanconi Anaemia and Werner Syndrome

Oxidative stress is a phenotypic hallmark in several genetic disorders characterized by cancer predisposition and/or propensity to premature ageing. Here we review the published evidence for the involvement of oxidative stress in the phenotypes of Ataxia-Telangiectasia (A-T), Down Syndrome (DS), Fanconi Anaemia (FA), and Werner Syndrome (WS), from the viewpoint of mitochondrial dysfunction. Mitochondria are recognized as both the cell compartment where energetic metabolism occurs and as the first and most susceptible target of reactive oxygen species (ROS) formation. Thus, a critical evaluation of the basic mechanisms leading to an in vivo pro-oxidant state relies on elucidating the features of mitochondrial impairment in each disorder. The evidence for different mitochondrial dysfunctions reported in A-T, DS, and FA is reviewed. In the case of WS, clear-cut evidence linking human WS phenotype to mitochondrial abnormalities is lacking so far in the literature. Nevertheless, evidence relating mitochondrial dysfunctions to normal ageing suggests that WS, as a progeroid syndrome, is likely to feature mitochondrial abnormalities. Hence, ad hoc research focused on elucidating the nature of mitochondrial dysfunction in WS pathogenesis is required. Based on the recognized, or reasonably suspected, role of mitochondrial abnormalities in the pathogenesis of these disorders, studies of chemoprevention with mitochondria-targeted supplements are warranted.

Lip cancer: incidence, trends, histology and survival: 1970-2006

BACKGROUND

High levels of lip cancer have been reported among Israelis over the last four decades. Epidemiological descriptions and analyses for this region have not previously been presented.

OBJECTIVES

To establish the incidence, trends and histology of lip cancer and associated demographic variables in Israel over time.

METHODS

Data for 1970-2006 were derived from the Israel National Cancer Registry. Incidence and trends over time and analyses by lip site, sex, age, origin, histology and 5-year survival were studied.

RESULTS

Of 4337 new cases, most were found among men (61.4%), people aged over 53 years (75.5%), and those with lighter skin (62.6%). Lip cancer cases were 40 times more prevalent in the external than in the inner lip. The dominant tumour type was squamous cell carcinoma at the external lower lip and intraoral lip mucosa (predominantly in men) and basal cell carcinoma (originating from skin) at the external upper lip (predominantly in women). Minor salivary gland tumours, melanoma and metastases were also reported. Slight increases in the trend of upper lip cancer and decreases for lower lip cancer were reported.

CONCLUSIONS

Men, fair-skinned individuals and those over 53 years of age were at higher risk for lip cancer. A higher incidence of external lip cancer, compared with internal, may indicate a major role for sun exposure rather than smoking. The effect of public awareness campaigns as well as occupational changes, both related to sun exposure, should be studied carefully as potential factors in the changing incidence of lip tumours.