Gardner's syndrome (familial adenomatous polyposis): a cilia-related disorder. Lancet Oncol. 2009;10:727-735. [PMID: 19573802 DOI: 10.1016/S1470-2045(09)70167-6]

Emerging insights into CP110 removal during early steps of ciliogenesis

The primary cilium is an antenna-like projection from the plasma membrane that serves as a sensor of the extracellular environment and a crucial signaling hub. Primary cilia are generated in most mammalian cells, and their physiological significance is highlighted by the large number of severe developmental disorders or ciliopathies that occur when primary ciliogenesis is impaired. Primary ciliogenesis is a tightly regulated process, and a central early regulatory step is the removal of a key mother centriole capping protein, CP110 (also known as CCP110). This uncapping allows vesicles docked on the distal appendages of the mother centriole to fuse to form a ciliary vesicle, which is bent into a ciliary sheath as the microtubule-based axoneme grows and extends from the mother centriole. When the mother centriole migrates toward the plasma membrane, the ciliary sheath fuses with the plasma membrane to form the primary cilium. In this Review, we outline key early steps of primary ciliogenesis, focusing on several novel mechanisms for removal of CP110. We also highlight examples of ciliopathies caused by genetic variants that encode key proteins involved in the early steps of ciliogenesis.

Association between sulfur microbial diet and the risk of colorectal cancer precursors in older adults

Background

Sulfur microbial diet (SMD), related to the enrichment of sulfur-metabolizing gut bacteria, has been confirmed to be linked to an elevated risk of early-onset colorectal adenoma in young females. However, it remains unclear whether SMD is associated with the risk of colorectal adenoma in older people, who are at greater risk for colorectal cancer.

Methods

All data on participants in this study were retrieved from the intervention arm of the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening test. Participants' adherence to this dietary pattern was assessed using SMD score. Hazard ratios (HR) and 95% confidence intervals (CI) were adopted in Cox proportional hazards regression models to assess the link between SMD score and the incidence of colorectal adenoma in participants included in the study. Specific stratified analyses were constructed to assess whether this association changed in different conditions, whereas the robustness of the association was examined through sensitivity analyses.

Results

The mean baseline age of participants was 62.1 (SD 5.2) years (range 54.0-75.0 years). During 19,468,589 person-years of follow-up, 992 colorectal adenoma cases were documented in a total of 17,627 included participants. In a fully adjusted model, an increased risk of colorectal adenoma was determined in participants in the highest quartile of SMD score in comparison with those in the lowest quartile (HRquartile4 vs. HRquartile1 = 1.23; 95% CI: 1.02, 1.47; p = 0.017 for trend). This positive association between SMD score and adenoma risk was more evident in participants who were current or former smokers (p = 0.029 for interaction).

Conclusion

In this study, our results support a role for the SMD in the carcinogenicity of colorectal cancer precursors among older adults. Nevertheless, these results require validation through more research.

Rare Genetic Variants in Human APC Are Implicated in Mesiodens and Isolated Supernumerary Teeth

The activation of Wnt/β-catenin signalling is a prerequisite for odontogenesis. APC, a member of the AXIN-CK1-GSK3β-APC β-catenin destruction complex, functions to modulate Wnt/β-catenin signalling to establish regular teeth number and positions. APC loss-of-function mutations are associated with the over-activation of WNT/β-catenin signalling and subsequent familial adenomatous polyposis (FAP; MIM 175100) with or without multiple supernumerary teeth. The ablation of Apc function in mice also results in the constitutive activation of β-catenin in embryonic mouse epithelium and causes supernumerary tooth formation. The objective of this study was to investigate if genetic variants in the APC gene were associated with supernumerary tooth phenotypes. We clinically, radiographically, and molecularly investigated 120 Thai patients with mesiodentes or isolated supernumerary teeth. Whole exome and Sanger sequencing identified three extremely rare heterozygous variants (c.3374T>C, p.Val1125Ala; c.6127A>G, p.Ile2043Val; and c.8383G>A, p.Ala2795Thr) in APC in four patients with mesiodentes or a supernumerary premolar. An additional patient with mesiodens was compound as heterozygous for two APC variants (c.2740T>G, p.Cys914Gly, and c.5722A>T, p.Asn1908Tyr). Rare variants in APC in our patients are likely to contribute to isolated supernumerary dental phenotypes including isolated mesiodens and an isolated supernumerary tooth.

Identification of a novel missense mutation in non-syndromic familial multiple supernumerary teeth

OBJECTIVE

This study intended to evaluate the involvement of genetic factors in the etiology of non-syndromic multiple supernumerary teeth.

DESIGN

We filtered the single nucleotide polymorphisms (SNPs) of the proband and his mother with similar phenotypes through whole-genome sequencing (WGS). By integrating multiple databases related to human genome mutations and disease information for mutation annotation, we excluded the SNPs of people without supernumerary teeth. Subsequently, the bioinformatics analysis tools (Sorting Intolerant From Tolerant (SIFT) < 0.05, Polymorphism Phenotyping (PolyPhen) > 0.90) were used to screen out the most correlated SNPs of the disease, besides, Gene Ontology (GO) analysis (P<0.05, FDR<0.05) and Sanger sequencing was applied to further verify the candidate pathogenic mutation point.

RESULTS

A novel heterozygous variant in fer-1 like family member 6 (FER1L6) gene likely denoted pathogenicity in non-syndromic familial multiple supernumerary teeth. We identified a cohort of 3499 non-synonymous SNPs (nsSNPs), and only 142 nsSNPs with the score of SIFT < 0.05 and PolyPhen > 0.90 were retained. Then we got 54 nsSNPs from 31 candidate genes through GO analysis. Sanger sequencing revealed a missense variant in exon 31 of the FER1L6 gene, causing a transition from guanine to adenine in position 1447 of protein kinase C conserved region 2.

CONCLUSIONS

We identified a novel heterozygous chromosome 8q24.13 mutation of FER1L6, which was a new mutation site identified in non-syndromic familial multiple supernumerary teeth through genetic analysis of a Chinese family.

Nonmalignant Features Associated with Inherited Colorectal Cancer Syndromes-Clues for Diagnosis

Simple Summary

Familiarity with nonmalignant features and comorbidities of cancer predisposition syndromes may raise awareness and assist clinicians in the diagnosis and interpretation of molecular test results. Genetic predisposition to colorectal cancer (CRC) should be suspected mainly in young patients, in patients with significant family histories, multiple polyps, mismatch repair-deficient tumors, and in association with malignant or nonmalignant comorbidities. The aim of this review is to describe the main nonmalignant comorbidities associated with selected CRC predisposition syndromes that may serve as valuable diagnostic clues for clinicians and genetic professionals.

Abstract

Genetic diagnosis of affected individuals and predictive testing of their at-risk relatives, combined with intensive cancer surveillance, has an enormous cancer-preventive potential in these families. A lack of awareness may be part of the reason why the underlying germline cause remains unexplained in a large proportion of patients with CRC. Various extracolonic features, mainly dermatologic, ophthalmic, dental, endocrine, vascular, and reproductive manifestations occur in many of the cancer predisposition syndromes associated with CRC and polyposis. Some are mediated via the WNT, TGF-β, or mTOR pathways. However the pathogenesis of most features is still obscure. Here we review the extracolonic features of the main syndromes, the existing information regarding their prevalence, and the pathways involved in their pathogenesis. This knowledge could be useful for care managers from different professional disciplines, and used to raise awareness, enable diagnosis, and assist in the process of genetic testing and interpretation.

Recurrent CTNNB1 mutations in craniofacial osteomas

Osteoma is a benign bone forming tumor predominantly arising on the surface of craniofacial bones. While the vast majority of osteomas develops sporadically, a small subset of cases is associated with Gardner syndrome, a phenotypic variant of familial adenomatous polyposis caused by mutations in the APC gene resulting in aberrant activation of WNT/β-catenin signaling. In a sequencing analysis on a cohort of sporadic, non-syndromal osteomas, we identified hotspot mutations in the CTNNB1 gene (encoding β-catenin) in 22 of 36 cases (61.1%), harbouring allelic frequencies ranging from 0.04 to 0.53, with the known S45P variant representing the most frequent alteration. Based on NanoString multiplex expression profiling performed in a subset of cases, CTNNB1-mutated osteomas segregated in a defined "WNT-cluster", substantiating functionality of CTNNB1 mutations which are associated with β-catenin stabilization. Our findings for the first time convincingly show that osteomas represent genetically-driven neoplasms and provide evidence that aberrant WNT/β-catenin signaling plays a fundamental role in their pathogenesis, in line with the well-known function of WNT/β-catenin in osteogenesis. Our study contributes to a better understanding of the molecular pathogenesis underlying osteoma development and establishes a helpful diagnostic molecular marker for morphologically challenging cases.

Compendium of causative genes and their encoded proteins for common monogenic disorders

A compendium is presented of inherited monogenic disorders that have a prevalence of >1:20,000 in the human population, along with their causative genes and encoded proteins. "Simple" monogenic diseases are those for which the clinical features are caused by mutations impacting a single gene, usually in a manner that alters the sequence of the encoded protein. Of course, for a given "monogenic disorder", there is sometimes more than one potential disease gene, mutations in any one of which is sufficient to cause phenotypes of that disorder. Disease-causing mutations for monogenic disorders are usually passed on from generation to generation in a Mendelian fashion, and originate from spontaneous (de novo) germline founder mutations. In the past monogenic disorders have often been written off as targets for drug discovery because they sometimes are assumed to be rare disorders, for which the meager projected financial payoff of drug discovery and development has discouraged investment. However, not all monogenic diseases are rare. Here, we report that that currently available data identifies 72 disorders with a prevalence of at least 1 in 20,000 humans. For each, we tabulate the gene(s) for which mutations cause the spectrum of phenotypes associated with that disorder. We also identify the gene and protein that most commonly causes each disease. 34 of these disorders are caused exclusively by mutations in only a single gene and encoded protein.

Reawakening of Ancestral Dental Potential as a Mechanism to Explain Dental Pathologies

During evolution, there has been a trend to reduce both the number of teeth and the location where they are found within the oral cavity. In mammals, the formation of teeth is restricted to a horseshoe band of odontogenic tissue, creating a single dental arch on the top and bottom of the jaw. Additional teeth and structures containing dental tissue, such as odontogenic tumors or cysts, can appear as pathologies. These tooth-like structures can be associated with the normal dentition, appearing within the dental arch, or in nondental areas. The etiology of these pathologies is not well elucidated. Reawakening of the potential to form teeth in different parts of the oral cavity could explain the origin of dental pathologies outside the dental arch, thus such pathologies are a consequence of our evolutionary history. In this review, we look at the changing pattern of tooth formation within the oral cavity during vertebrate evolution, the potential to form additional tooth-like structures in mammals, and discuss how this knowledge shapes our understanding of dental pathologies in humans.

APC c.4621C>T variant causing Gardner's syndrome in a Han Chinese family may be inherited through maternal mosaicism

Gardner's syndrome is a rare autosomal dominant hereditary disease that is characterized by multiple colorectal polyps combined with extra-colonic presentation (such as osteoma or desmoid tumors) of familial adenomatous polyposis syndrome. Gardner's syndrome is caused by the mutation of the adenomatous polyposis coli (APC) gene, which is located at 5q21. The aim of the current study was to investigate the APC gene mutations present in a Han Chinese family diagnosed with Gardner's syndrome. The 38-year-old proband presented with clinical symptoms, and was later diagnosed with Gardner's syndrome. Genomic DNA was extracted from the peripheral venous blood of 150 normal controls as well as the family members of the proband. Analysis of the respective APC gene sequences was performed using PCR amplification and Sanger sequencing. Pathogenesis associated with the APC mutation was investigated using reverse-transcription quantitative PCR and determined through bioinformatics approaches. Haplotype analysis was performed to identify the genetic source of the mutation(s). In the initial screening for APC variants, the APC c.4621C>T variant was detected in the proband and his son, but was not detected in the proband's affected mother. The mRNA expression changed significantly according to age and the presence of the mutation in the blood of the patients. Haplotype analysis suggested the presence of maternal mosaicism for this mutation. Haplotype analysis revealed that the APC c.4621C>T variant in a patient with Gardner's syndrome was most likely derived from his mother through mosaicism. These results indicate the necessity to verify the possibility of gonadal mosaicism when a proband diagnosed with Gardner's syndrome appears to exhibit a de novo mutation.

DIAPH1 regulates ciliogenesis and trafficking in primary cilia

Primary cilia are critical hubs for several signaling pathways, and defects in ciliogenesis or cilia maintenance produce a range of diseases collectively known as ciliopathies. Ciliogenesis requires vesicle trafficking along a network of microtubules and actin filaments to the basal body. The DIAPH1 (Diaphanous-related formin) family of formins promotes both actin polymerization and EB1-dependent microtubule (MT) stability. EB1 and EB3 have previously been implicated in cilia biogenesis to carry out centrosome-related functions. However, the role of DIAPH1 proteins had not been examined. Here we show that the depletion of DIAPH1 decreased ciliogenesis, cilia length, and reduced trafficking within cilia. Additionally, both actin nucleating and microtubule-stabilizing properties of DIAPH1 are important for their cilia functions. To assess their roles in ciliogenesis in isolation, we targeted DIAPH1 specifically to the basal body, which caused an increase in cilia length and increased trafficking within cilia. Intriguingly, expression of DIAPH1 mutants associated with human deafness and microcephaly impaired ciliation and caused cilia elongation and bulb formation. These results suggest that the actin and microtubule functions of DIAPH1 proteins regulate cilia maintenance in part by regulating vesicular trafficking to the base of the primary cilia.

Jaw and Dental Abnormalities

Deviations from anthropometric norms related to facial skeletal development are a relatively normal occurrence in the dental management of the vast majority of patients. A consideration for correction is usually warranted only when there is associated morbidity, functional impairment, or psychosocial detriment. The vast majority of jaw and dental abnormalities are developmental and present themselves within a continuum of clinically conspicuous to overtly obvious. This article highlights a variety of developmental abnormalities that present with structural disharmony of the maxillomandibular complex and secondarily associated dental structures.

Endoscopic Management of a Complex Gastrojejunal and Pancreatic Leak Following Pancreaticoduodenectomy

BACKGROUND

Pancreaticoduodenectomy remains the mainstay of surgical treatment of malignant periampullary disorders. Postoperative morbidity rates are driven by postoperative pancreatic fistula. Although most can be managed conservatively or with percutaneous techniques, complex fistulas including gastroenteric leakage frequently require operative reexploration. Endoscopic therapies in this setting offer an opportunity to avoid invasive reoperation.

CASE REPORT

We present the case of a 67-year-old male individual who developed a complex intra-abdominal abscess after pancreaticoduodenectomy with confirmed pancreaticojejunal disruption, gastric staple line dehiscence, and enterocutaneous fistula. Five endoscopic sessions utilizing advanced techniques over a period of 60 days led to complete healing of the patient's external fistula, resolution of complex abdominal abscess, creation of functional communication between the gastric staple line disruption and the afferent jejunum, and return of normal gastrointestinal function. Baseline functional and dietary status was restored without gastrointestinal symptoms or necessity for supplemental tube feedings.

Identification of aggressive Gardner syndrome phenotype associated with a de novo APC variant, c.4666dup

Gardner syndrome describes a variant phenotype of familial adenomatous polyposis (FAP), primarily characterized by extracolonic lesions including osteomas, dental abnormalities, epidermal cysts, and soft tissue tumors. We describe a 2-yr-old boy presenting with a 2-cm soft tissue mass of the forehead. Pathologic evaluation revealed a nuchal-type/Gardner-associated fibroma. Sequencing of the APC gene revealed a pathologic variant c.4666dupA. Parental sequencing of both blood and buccal tissue supported the de novo occurrence of this pathologic variant. Further imaging revealed a number of additional lesions including a large lumbar paraspinal desmoid, a 1-cm palpable lesion posterior to the left knee, firm lesions on bilateral heels, and multiple subdermal lesions. Colonoscopy was negative. This case illustrates a genetic variant of Gardner syndrome resulting in an aggressive early childhood phenotype and highlights the need for an individualized approach to treatment.

Characteristics of cribriform morular variant of papillary thyroid carcinoma in post-Chernobyl affected region

The aim is to study the characteristics of cribriform morular variant of papillary thyroid carcinoma (CMV-PTC) in patients living in the radiation-affected area of Belarus. The clinical and pathological features of 35 patients with CMV-PTC from Belarus were studied and compared with those of conventional papillary thyroid carcinoma diagnosed in the same period. The patients with CMV-PTC were all females and were younger at presentation (mean age = 24) than those with conventional papillary thyroid carcinoma. Familial adenomatous polyposis (FAP) was identified in 20% of the patients with CMV-PTC. The majority of the CMV-PTCs (29/35; 83%) were staged as pT1 and were less advanced than conventional papillary thyroid carcinoma. There was no evidence of lymph node metastases or distant metastases. CMV-PTCs were positive for β-catenin, APC (adenomatous polyposis coli) and p53 proteins. No psammoma bodies were identified on microscopic examination. Over a median follow-up of 9 years, all the patients were alive, and there was no cancer recurrence or mortality related to the thyroid cancer. To conclude, CMV-PTC in patients in the radiation-affected region behaves in an indolent fashion. They had distinctive features that are different from patients with conventional papillary thyroid carcinoma living in the same region.

APC sets the Wnt tone necessary for cerebral cortical progenitor development

Nakagawa et al. show that the maintenance of appropriate β-catenin-mediated Wnt tone is necessary for the orderly differentiation of cortical progenitors and the resultant formation of the cerebral cortex.

Adenomatous polyposis coli (APC) regulates the activity of β-catenin, an integral component of Wnt signaling. However, the selective role of the APC–β-catenin pathway in cerebral cortical development is unknown. Here we genetically dissected the relative contributions of APC-regulated β-catenin signaling in cortical progenitor development, a necessary early step in cerebral cortical formation. Radial progenitor-specific inactivation of the APC–β-catenin pathway indicates that the maintenance of appropriate β-catenin-mediated Wnt tone is necessary for the orderly differentiation of cortical progenitors and the resultant formation of the cerebral cortex. APC deletion deregulates β-catenin, leads to high Wnt tone, and disrupts Notch1 signaling and primary cilium maintenance necessary for radial progenitor functions. β-Catenin deregulation directly disrupts cilium maintenance and signaling via Tulp3, essential for intraflagellar transport of ciliary signaling receptors. Surprisingly, deletion of β-catenin or inhibition of β-catenin activity in APC-null progenitors rescues the APC-null phenotype. These results reveal that APC-regulated β-catenin activity in cortical progenitors sets the appropriate Wnt tone necessary for normal cerebral cortical development.

Cribriform-morular variant of papillary thyroid carcinoma: a distinctive type of thyroid cancer

The aim of this systematic review is to study the features of cribriform-morular variant of papillary thyroid carcinoma (CMV-PTC) by analysing the 129 documented cases in the English literature. The disease occurred almost exclusively in women. The median age of presentation for CMV-PTC was 24 years. Slightly over half of the patients with CMV-PTC had familial adenomatous polyposis (FAP). CMV-PTC presented before the colonic manifestations in approximately half of the patients with FAP. Patients with FAP often have multifocal tumours in the thyroid. Microscopic examination of CMV-PTC revealed predominately cribriform and morular pattern of cancer cells with characteristic nuclear features of papillary thyroid carcinoma. Psammoma body is rare. On immunohistochemical studies, β-catenin is diffusely positive in CMV-PTC. The morular cells in CMV-PTC are strongly positive for CD10, bcl-2 and E-cadherin. Pre-operative diagnosis of CMV-PTC by fine-needle aspiration biopsy could be aided by cribriform architecture, epithelial morules and β-catenin immunostaining. Mutations of APC gene are found in the patients with CMV-PTC associated with FAP. In addition, mutations in CTNNB1, RET/PTC rearrangement and PI3K3CA mutations have been reported. BRAF mutation is negative in all CMV-PTC tested. Compared to conventional papillary thyroid carcinoma, CMV-PTC had a lower frequency of lymph node metastases at presentation (12%) and distant metastases (3%) as well as lower recurrence rates (8.5%) and patients' mortality rates (2%). To conclude, patients with CMV-PTC have distinctive clinical, pathological and molecular profiles when compared to conventional papillary thyroid carcinoma.

Outcome of surgery for primary and recurrent desmoid-type fibromatosis. A retrospective case series of 174 patients

BACKGROUND

The best management of relapsing desmoid-type fibromatosis, a benign but locally infiltrative soft-tissue tumour, is largely undecided. Our aim was to investigate the incidence and the factors influencing local relapse after surgery for primary and recurrent disease of the trunk and extremities.

PATIENTS AND METHODS

Retrospective analysis of 174 patients who had surgical treatment for desmoid-type fibromatosis. The quality of the surgical margins and use of adjuvant radiotherapy or chemotherapy were analysed regarding local recurrences in primary and recurrent disease.

RESULTS

Clear margins were achieved in 41% of cases. 10-year local control rate was 58% for clear primary resections as compared to 37% with intralesional primary resections (p = 0.030). Extremity tumours had a higher risk of local recurrence compared to trunk and pelvic ones (p < 0.001). Attempted resection of recurrent disease was associated with an approximately 90% incidence of relapse after each procedure, despite the quality of the surgical margins being equivalent to primary resections. Quality of surgical margins was not important for local control of recurrent lesions. Adjuvant treatments (radiotherapy and chemotherapy) had a no significant effect on the local control rate of recurrent disease (odds ratio 0.693 and 0.969 respectively).

CONCLUSIONS

A complete primary excision is the best window of opportunity to achieve local control of desmoid-type fibromatosis. Once the disease relapses, surgical intervention is accompanied with a high risk of failure, irrespective of the quality of the margins and adjuvant treatment given.

A case report of desmoid tumour-a forgotten aspect of FAP?

INTRODUCTION

Desmoid tumours are locally aggressive tumours which are common in Familial Adenomatous Polyposis (FAP).

PRESENTATION OF CASE

A 20-year old Familial Adenomatous Polyposis (FAP) patient presented with abdominal pain and distention. Abdominal imaging showed small bowel obstruction and hydronephrosis due to a pelvic mass. This mass showed significant enlargement on repeat imaging, and a diagnostic biopsy confirmed desmoid tumour. The mass was deemed unresectable and he was initially started on sulindac and raloxifene. Repeat imaging however showed further enlargement of the tumour, and therefore vinblastine+methotrexate chemotherapy was commenced, with a good response.

DISCUSSION

FAP is an autosomal dominant condition caused by a germline mutation in the adenomatous polyposis coli (APC) gene. Gardner's syndrome is also caused by a mutation in the APC gene, and is now considered a different phenotypic presentation of FAP. Desmoid tumours are initially kept under observation while their size remains stable. Treatment options for enlarging desmoids tumours include surgery (first-line), radiotherapy, and systemic therapy with non-cytotoxic and cytotoxic therapy.

CONCLUSION

FAP patients should be examined regularly post-panprocotocolectomy, since desmoid tumours may arise. The presence of epidermal cysts in this FAP patient suggests a diagnosis of Gardner's syndrome.

Ciliogenesis and the DNA damage response: a stressful relationship

Both inherited and sporadic mutations can give rise to a plethora of human diseases. Through myriad diverse cellular processes, sporadic mutations can arise through a failure to accurately replicate the genetic code or by inaccurate separation of duplicated chromosomes into daughter cells. The human genome has therefore evolved to encode a large number of proteins that work together with regulators of the cell cycle to ensure that it remains error-free. This is collectively known as the DNA damage response (DDR), and genome stability mechanisms involve a complex network of signalling and processing factors that ensure redundancy and adaptability of these systems. The importance of genome stability mechanisms is best illustrated by the dramatic increased risk of cancer in individuals with underlying disruption to genome maintenance mechanisms. Cilia are microtubule-based sensory organelles present on most vertebrate cells, where they facilitate transduction of external signals into the cell. When not embedded within the specialised ciliary membrane, components of the primary cilium's basal body help form the microtubule organising centre that controls cellular trafficking and the mitotic segregation of chromosomes. Ciliopathies are a collection of diseases associated with functional disruption to cilia function through a variety of different mechanisms. Ciliopathy phenotypes can vary widely, and although some cellular overgrowth phenotypes are prevalent in a subset of ciliopathies, an increased risk of cancer is not noted as a clinical feature. However, recent studies have identified surprising genetic and functional links between cilia-associated proteins and genome maintenance factors. The purpose of this mini-review is to therefore highlight some of these discoveries and discuss their implications with regards to functional crosstalk between the DDR and ciliogenesis pathways, and how this may impact on the development of human disease.

Gardner's syndrome presenting with a fibromatous tumour of the parotid

INTRODUCTION

Gardner's syndrome is the association of familial adenomatous polyposis (FAP) with an anaphase promoting complex (APC) gene mutation and several extradigestive manifestations: osteomas, epidermal cysts and desmoid tumours. Only 2 cases of FAP associated with parotid tumour have been reported in the literature: one carcinoma and one pleomorphic adenoma.

CASE REPORT

We report the case of a 23-year-old man with Gardner's syndrome presenting with a fibromatous tumour of the left parotid gland. The other clinical manifestations were an osteoma of the skull base and a mesentery desmoid tumour. Left total parotidectomy was performed, followed by gastroscopy and colonoscopy, demonstrating numerous colonic adenomas. Genetic analysis revealed an APC gene mutation, confirming the diagnosis. Total prophylactic colectomy was performed.

CONCLUSIONS

This is the first reported case of Gardner's syndrome associated with a fibromatous tumour of the parotid. Early management of FAP is essential to prevent colorectal cancer that occurs in 100% of untreated cases. The rarity of this syndrome and the parotid site can lead to delayed diagnosis.

Genetic background of supernumerary teeth

Supernumerary teeth (ST) are odontostomatologic anomaly characterized by as the existence excessive number of teeth in relation to the normal dental formula. This condition is commonly seen with several congenital genetic disorders such as Gardner's syndrome, cleidocranial dysostosis and cleft lip and palate. Less common syndromes that are associated with ST are; Fabry Disease, Ellis-van Creveld syndrome, Nance-Horan syndrome, Rubinstein-Taybi Syndrome and Trico–Rhino–Phalangeal syndrome. ST can be an important component of a distinctive disorder and an important clue for early diagnosis. Certainly early detecting the abnormalities gives us to make correct management of the patient and also it is important for making well-informed decisions about long-term medical care and treatment. In this review, the genetic syndromes that are related with ST were discussed.

Advances in therapy for pediatric sarcomas

Pediatric sarcomas are relatively rare malignancies individually. As a group they are typically approached with combination chemotherapies in addition to local control. Fortunately, these malignancies have been approached through careful clinical trial collaboration to define risk groups and appropriately deliver local control measures and systemic therapies. Although local disease is typically approached with curative intent, therapy typically lasts over 6 months and has significant associated morbidities. It is more difficult to cure metastatic disease or induce sustained remissions. In this article, we discuss recent advances in the understanding of the disease process and highlight recent and future cooperative group trials in osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, nonrhabdomyosarcoma soft tissue sarcomas, and desmoid tumor as well as discuss promising therapeutic approaches such as epigenetics and immunotherapy.

The APC tumor suppressor is required for epithelial cell polarization and three-dimensional morphogenesis

The Adenomatous Polyposis Coli (APC) tumor suppressor has been previously implicated in the control of apical-basal polarity; yet, the consequence of APC loss-of-function in epithelial polarization and morphogenesis has not been characterized. To test the hypothesis that APC is required for the establishment of normal epithelial polarity and morphogenesis programs, we generated APC-knockdown epithelial cell lines. APC depletion resulted in loss of polarity and multi-layering on permeable supports, and enlarged, filled spheroids with disrupted polarity in 3D culture. Importantly, these effects of APC knockdown were independent of Wnt/β-catenin signaling, but were rescued with either full-length or a carboxy (c)-terminal segment of APC. Moreover, we identified a gene expression signature associated with APC knockdown that points to several candidates known to regulate cell-cell and cell-matrix communication. Analysis of epithelial tissues from mice and humans carrying heterozygous APC mutations further supports the importance of APC as a regulator of epithelial behavior and tissue architecture. These data also suggest that the initiation of epithelial-derived tumors as a result of APC mutation or gene silencing may be driven by loss of polarity and dysmorphogenesis.

N-terminal truncation mutations of adenomatous polyposis coli are associated with primary cilia defects

Adenomatous polyposis coli (APC) gene is a tumor suppressor gene and its truncated mutations cause a few cilia-related diseases such as Gardner's syndrome. However, little is known about the mechanism that links APC mutations and cilia disorder. APC mutations lead to the expression of N-terminal fragments, which have dominant effects in tumors owing to loss of the C-terminal region or a gain of function. The present study investigated the impact of tumor-associated N-terminal APC fragments on primary cilia assembly and the possible molecular mechanism involved. We discovered that expression of tumor-associated N-terminal APC fragments (APC-N, APC-N1, APC-N2, and APC-N3, which contain amino acids 1-1018, 1-448, 449-781, and 782-1018 respectively), resulted in primary cilia defects. We found that a β-catenin/PI3K/AKT/GSK-3β feedback signal cascade is responsible for causing N-terminal APC fragment-induced cilia defects. In this cascade, dysfunctions of both β-catenin and GSK-3β were involved in the up-regulation of HDAC6 and subsequent decreased acetylated tubulin levels, which thereby led to cilia defects. These data suggest a mechanism for linking N-terminal APC fragments and cilia loss, thus accelerating our understanding of human cilia-related diseases such as Gardner's syndrome and their cause due to APC mutations.

Functional Analysis of KIF3A and KIF3B during Spermiogenesis of Chinese Mitten Crab Eriocheir sinensis

BACKGROUND

Spermatogenesis represents the transformation process at the level of cellular development. KIF3A and KIF3B are believed to play some roles in the assembly and maintenance of flagella, intracellular transport of materials including organelles and proteins, and other unknown functions during this process. During spermatogenesis in Eriocheir sinensis, if the sperm shaping machinery is dependent on KIF3A and KIF3B remains unknown.

METHODOLOGY/PRINCIPAL FINDINGS

The cDNA of KIF3A and KIF3B were obtained by designing degenerate primers, 3'RACE, and 5'RACE. We detected the genetic presence of kif3a and kif3b in the heart, muscle, liver, gill, and testis of E. sinensis through RT-PCR. By western blot analysis, the protein presence of KIF3A and KIF3B in heart, muscle, gill, and testis reflected the content in protein level. Using in situ hybridization and immunofluorescence, we could track the dynamic location of KIF3A and KIF3B during different developmental phases of sperm. KIF3A and KIF3B were found surrounding the nucleus in early spermatids. In intermediate spermatids, these proteins expressed at high levels around the nucleus and extended to the final phase. During the nuclear shaping period, KIF3A and KIF3B reached their maximum in the late spermatids and were located around the nucleus and concentrated in the acrosome to some extent.

CONCLUSIONS/SIGNIFICANCE

Our results revealed that KIF3A and KIF3B were involved in the nuclear and cellular morphogenesis at the levels of mRNA and protein. These proteins can potentially facilitate the intracellular transport of organelles, proteins, and other cargoes. The results represent the functions of KIF3A and KIF3B in the spermatogenesis of Crustacea and clarify phylogenetic relationships among the Decapoda.

Multiple desmoid tumors in a patient with Gardner's syndrome - Report of a case

INTRODUCTION

Desmoid tumor (DT) is a common manifestation of Gardner's Syndrome (GS), although it is a rare condition in the general population. DT in patients with GS is usually located in the abdominal wall and/or intra-abdominal cavity.

PRESENTATION OF CASE

We report a case of a 32 years-old female patient with familial adenomatous polyposis (FAP), who was already submitted to total colectomy and developed multiple DT, located in the abdominal wall and in the left breast. The patient underwent several surgical procedures, with a multidisciplinary team of surgeons. Wide surgical resections of the left breast and the abdominal wall tumors were performed in separate steps. Polypropylene mesh reconstruction and muscle flaps were needed to cover the defects of the thoracic and abdominal walls. After partial necrosis of the adipose-cutaneous flap in the abdomen that required a new skin graft, she had a satisfactory outcome with complete healing of the surgical incisions.

DISCUSSION

DT is frequent in GS, however, breast localization is very rare, with few cases reported in the literature. Recurrence of DT is not negligible, even after a wide surgical resection. GS patients must be followed up closely, and clinical examination, associated with imaging studies, should be performed to detect any signs of tumor.

CONCLUSION

DT represents one of the most significant causes of the morbidity and mortality that affects FAP patients following colectomy. In general, the surgical procedures to excise DT are highly complex, requiring a multidisciplinary team.

Cilia and cilia-associated proteins in cancer

The primary cilium is a well-established target in the pathogenesis of numerous developmental and chronic disorders, and more recently is attracting interest as a structure relevant to cancer. Here we discuss mechanisms by which changes in cilia can contribute to the formation and growth of tumors. We emphasize the cancer-relevance of cilia-dependent signaling pathways and proteins including mTOR, VHL, TSC, WNT, Aurora-A, NEDD9, and Hedgehog, and highlight the emerging role of ciliary dysfunction in renal cell carcinoma, medulloblastoma, and breast cancer.

Recurrent chromosome 22 deletions in osteoblastoma affect inhibitors of the Wnt/beta-catenin signaling pathway

Osteoblastoma is a bone forming tumor with histological features highly similar to osteoid osteoma; the discrimination between the tumor types is based on size and growth pattern. The vast majority of osteoblastomas are benign but there is a group of so-called aggressive osteoblastomas that can be diagnostically challenging at the histopathological level. The genetic aberrations required for osteoblastoma development are not known and no genetic difference between conventional and aggressive osteoblastoma has been reported. In order to identify recurrent genomic aberrations of importance for tumor development we applied cytogenetic and/or SNP array analyses on nine conventional and two aggressive osteoblastomas. The conventional osteoblastomas showed few or no acquired genetic aberrations while the aggressive tumors displayed heavily rearranged genomes. In one of the aggressive osteoblastomas, three neighboring regions in chromosome band 22q12 were homozygously deleted. Hemizygous deletions of these regions were found in two additional cases, one aggressive and one conventional. In total, 10 genes were recurrently and homozygously lost in osteoblastoma. Four of them are functionally involved in regulating osteogenesis and/or tumorigenesis. MN1 and NF2 have previously been implicated in the development of leukemia and solid tumors, and ZNRF3 and KREMEN1 are inhibitors of the Wnt/beta-catenin signaling pathway. In line with deletions of the latter two genes, high beta-catenin protein expression has previously been reported in osteoblastoma and aberrations affecting the Wnt/beta-catenin pathway have been found in other bone lesions, including osteoma and osteosarcoma.

Functional aspects of primary cilia in signaling, cell cycle and tumorigenesis

Dysfunctional cilia underlie a broad range of cellular and tissue phenotypes and can eventually result in the development of ciliopathies: pathologically diverse diseases that range from clinically mild to highly complex and severe multi-organ failure syndromes incompatible with neonatal life. Given that virtually all cells of the human body have the capacity to generate cilia, it is likely that clinical manifestations attributed to ciliary dysfunction will increase in the years to come. Disputed but nevertheless enigmatic is the notion that at least a subset of tumor phenotypes fit within the ciliopathy disease spectrum and that cilia loss may be required for tumor progression. Contending for the centrosome renders ciliation and cell division mutually exclusive; a regulated tipping of balance promotes either process. The mechanisms involved, however, are complex. If the hypothesis that tumorigenesis results from dysfunctional cilia is true, then why do the classic ciliopathies only show limited hyperplasia at best? Although disassembly of the cilium is a prerequisite for cell proliferation, it does not intrinsically drive tumorigenesis per se. Alternatively, we will explore the emerging evidence suggesting that some tumors depend on ciliary signaling. After reviewing the structure, genesis and signaling of cilia, the various ciliopathy syndromes and their genetics, we discuss the current debate of tumorigenesis as a ciliopathy spectrum defect, and describe recent advances in this fascinating field.

Mutations in LRRC50 predispose zebrafish and humans to seminomas

Seminoma is a subclass of human testicular germ cell tumors (TGCT), the most frequently observed cancer in young men with a rising incidence. Here we describe the identification of a novel gene predisposing specifically to seminoma formation in a vertebrate model organism. Zebrafish carrying a heterozygous nonsense mutation in Leucine-Rich Repeat Containing protein 50 (lrrc50 also called dnaaf1), associated previously with ciliary function, are found to be highly susceptible to the formation of seminomas. Genotyping of these zebrafish tumors shows loss of heterozygosity (LOH) of the wild-type lrrc50 allele in 44.4% of tumor samples, correlating with tumor progression. In humans we identified heterozygous germline LRRC50 mutations in two different pedigrees with a family history of seminomas, resulting in a nonsense Arg488* change and a missense Thr590Met change, which show reduced expression of the wild-type allele in seminomas. Zebrafish in vivo complementation studies indicate the Thr590Met to be a loss-of-function mutation. Moreover, we show that a pathogenic Gln307Glu change is significantly enriched in individuals with seminoma tumors (13% of our cohort). Together, our study introduces an animal model for seminoma and suggests LRRC50 to be a novel tumor suppressor implicated in human seminoma pathogenesis.

Extra-abdominal desmoid tumours: a review of the literature

Extra-abdominal desmoid lesions, otherwise known as aggressive fibromatosis, are slow-growing benign lesions which may be encountered in clinical practice. Recent controversies exist regarding their optimal treatment. Given their benign nature, is major debulking surgery justified, or is it worth administering chemotherapy for a disease process which unusually defies common teaching and responds to such medications? We present a literature review of this particular pathology discussing the aetiology, clinical presentation, and various current controversies in the treatment options.

The extracellular matrix and ciliary signaling

The primary cilium protrudes like an antenna from the cell surface, sensing mechanical and chemical cues provided in the cellular environment. In some tissue types, ciliary orientation to lumens allows response to fluid flow; in others, such as bone, ciliary protrusion into the extracellular matrix allows response to compression forces. The ciliary membrane contains receptors for Hedgehog, Wnt, Notch, and other potent growth factors, and in some instances also harbors integrin and cadherin family members, allowing receipt of a robust range of signals. A growing list of ciliopathies, arising from deficient formation or function of cilia, includes both developmental defects and chronic, progressive disorders such as polycystic kidney disease (PKD); changes in ciliary function have been proposed to support cancer progression. Recent findings have revealed extensive signaling dialog between cilia and extracellular matrix (ECM), with defects in cilia associated with fibrosis in multiple contexts. Further, a growing number of proteins have been determined to possess multiple roles in control of cilia and focal adhesion interactions with the ECM, further coordinating functionality. We summarize and discuss these recent findings.

Mechanism of action of vitamin D and the vitamin D receptor in colorectal cancer prevention and treatment

Vitamin D and its analogs are potent inhibitors of colorectal cancer growth and metastasis. A number of recent studies have defined the intersections between the β-catenin-TCF pathway (a known contributor to colorectal cancer progression) and the vitamin D receptor (VDR) pathway, shedding light on the underlying mechanisms. Vitamin D also regulates the innate immune response, and as such influences susceptibility to inflammatory bowel disease, a predisposing factor in colorectal cancer. Understanding the role of vitamin D in these different contexts will enable development of next generation vitamin D analogs that will serve as both chemopreventatives and cancer therapeutics, without the accompanying side effects of hypercalcemia usually associated with high vitamin D intake. This review summarizes the mechanisms of action of vitamin D and the VDR in the context of the gastrointestinal tract and colorectal carcinogenesis.

Osteoma of the skull base and sinuses

Osteomata of the frontal and ethmoid sinuses have traditionally been surgically removed via external approaches. However, endoscopic techniques have increasingly been used for the surgical management of selected cases. Advances in visualization and instrumentation, as well as the excellent access provided by the Draf type 3 procedure, expanded the reach of endoscopes. We describe current limits of endoscopic approaches in the removal of osteomata from the frontal sinus and our algorithms for their management. We believe that the vast majority of frontal sinus osteomata can be managed endoscopically, and that only significant anterior or extreme infero-lateral extension constitute major limiting factors.

Skin signs of systemic diseases

The skin should not be considered as an isolated organ but rather as a definite functioning system that communicates with the internal environment. Skin signs of systemic diseases occur frequently and sometimes feature the first symptoms of an internal disease; furthermore, these manifestations may be the sole expressions of otherwise asymptomatic systemic disorders. A number of dermatologic signs, symptoms, and disorders can be invaluable as markers of systemic disease. Although a plethora of specialized modern diagnostic tests are available, the skin still remains the only organ of the body that is immediately and completely accessible to direct clinical examination. This contribution reviews the skin signs of systemic diseases. The description of the clinical features of skin lesions observed in several internal diseases will be useful to general physicians, internists, and dermatologists in the diagnosis of a systemic disease.

Diarrhoea, weight loss and polyposis: think Cronkhite-Canada syndrome

A 71-year-old male presented with nausea, diarrhoea and weight loss. He had mild to moderate alopecia, paucity of eyebrow hair, erythematous non-pruritic nodular rash on the wrists, toenail onychomychosis and scalp hyperpigmentation. A colonoscopy revealed an irregular, haemorrhagic 5 cm rectosigmoid mass. Biopsies revealed mucin distended glands and focal ischemic changes. A CT scan showed numerous polypoid-like lesions in the stomach. Upper endoscopy showed mucosal erythema and nodularity with polypoid-like lesions. Biopsies showed cystic glandular dilatation, lamina propria oedema and chronic inflammation consistent with Cronkhite-Canada syndrome (CCS). The patient was started on nutrition supplementation. His skin manifestations were treated topically and with mineral supplements. He improved within 10 weeks and is currently asymptomatic. A high index of suspicion for CCS should exist in patients who present with weight loss, diarrhoea and polyposis. If diagnosed early, the disease can be treated with the goal of clinical remission.

Cilia, adenomatous polyposis coli and associated diseases

Cilium is a conservative cell organelle, found in many types of cell surfaces. Cilia are tail-like prominence protruding out of the cell surface, capable of locomotion and acting as the cell's signal transduction sensory organs with their complex structures and ingenious function. Studies have shown that ciliary pathological changes and defects are related to the development of many diseases, including renal cysts, infertility, organ reversal, obesity and so on. The inactivation and mutation of cilia-related proteins can cause tumors, such as neoplasms, intestinal cancer, myeloma, rhabdomyosarcoma and adenocarcinoma. Adenomatous polyposis coli (APC) is a kind of multifunctional protein encoded by the APC gene that participates in many vital activities of organisms. The mutation of APC can lead to familial adenomatous polyposis, and also has a role in the development of human tumors, such as gastric cancer, esophageal cancer and breast carcinoma. Recent studies indicate that the abnormal mutation of APC may lead to some diseases caused by abnormal growth of cilia. Herein, the development of studies on cilia, APC and associated diseases are summarized in brief.

Clinical features of Gardner syndrome and Turcot syndrome in Chinese population: an analysis of 93 cases

AIM: To investigate the clinical characteristics of Gardner syndrome and Turcot syndrome, two variants of familial adenomatous polyposis, in Chinese population.

METHODS: The clinical data for Chinese patients with Gardner syndrome and Turcot syndrome were retrieved from Chinese Biomedical Database and PubMed (1983-2009) to conduct a meta-analysis.

RESULTS: A total of 37 sporadic cases of Gardner syndrome and 12 pedigrees containing 50 affected individuals were identified. In contrast, only six sporadic cases of Turcot syndrome were identified. Gardner syndrome often manifests itself as gastrointestinal polyposis combined with fibroma, osteoma and soft tissue neoplasm. Twenty-eight patients with Gardner syndrome had malignant polyps in the colon. Turcot syndrome often manifests itself as gastrointestinal polyposis and neoplasms of the central nervous system. Five patients with Turcot syndrome had malignant polyps. Several cases of polyps in the stomach, duodenum and distal ileum were reported. However, an overall assessment of small intestinal lesions had not been performed. Some special clinical manifestations might be helpful for early diagnosis of the two diseases. Some patients had symptomatic response to comprehensive therapy.

CONCLUSION: Chinese patients with Gardner syndrome or Turcot syndrome have variable clinical manifestations, especially extraintestinal manifestations. Careful screening and case report standardization may promote a better understanding of the two rare disorders.

Development and progression of colorectal neoplasia

A variety of genetic and molecular alterations underlie the development and progression of colorectal neoplasia (CRN). Most of these cancers arise sporadically due to multiple somatic mutations and genetic instability. Genetic instability includes chromosomal instability (CIN) and microsatellite instability (MSI), which is observed in most hereditary non-polyposis colon cancers (HNPCCs) and accounts for a small proportion of sporadic CRN. Although many biomarkers have been used in the diagnosis and prediction of the clinical outcomes of CRNs, no single marker has established value. New markers and genes associated with the development and progression of CRNs are being discovered at an accelerated rate. CRN is a heterogeneous disease, especially with respect to the anatomic location of the tumor, race/ethnicity differences, and genetic and dietary interactions that influence its development and progression and act as confounders. Hence, efforts related to biomarker discovery should focus on identification of individual differences based on tumor stage, tumor anatomic location, and race/ethnicity; on the discovery of molecules (genes, mRNA transcripts, and proteins) relevant to these differences; and on development of therapeutic approaches to target these molecules in developing personalized medicine. Such strategies have the potential of reducing the personal and socio-economic burden of CRNs. Here, we systematically review molecular and other pathologic features as they relate to the development, early detection, diagnosis, prognosis, progression, and prevention of CRNs, especially colorectal cancers (CRCs).