Germline mutations of the PTEN gene in Cowden disease, an inherited breast and thyroid cancer syndrome

Reversible oxidation of PRL family protein-tyrosine phosphatases

Recent studies have revealed that reactive oxygen species (ROS) are actively generated in cells and function as second messengers to mediate physiological intracellular signaling. ROS exert their effects on intracellular signaling via ROS effector proteins, which are sensitively and reversibly oxidized by ROS. Among various ROS effector proteins, the protein tyrosine phosphatase (PTP) family is of special interest. In the catalytic pocket, PTP proteins commonly possess a highly reactive cysteine (Cys) residue, which is susceptible to oxidation by ROS. Phosphatase of regenerating liver (PRL) belongs to the PTP family and is oxidized by ROS to form an intramolecular disulfide bond. In general, disulfide bonds in proteins can be reduced in cells with the help of various reducing enzymes, which enables the reversible redox regulation of PRL proteins. In the case of PRL proteins, thioredoxin-related protein 32 specifically catalyzes the reducing reaction, indicating the importance of redox regulation for ROS effector proteins.

The skin: a mirror to the gut

INTRODUCTION

This review discusses the diseases with involvement of both skin and gut. GI manifestations of vesicobullous disorders and systemic diseases and syndromes involving skin and gut, dermatologic manifestations of inflammatory bowel disease (IBD), polyposis syndromes, and GI malignancies have been discussed. Diagnostic and treatment approaches towards these disorders are summarized.

CONCLUSIONS

Interaction of the skin and gut has always been an area of inquisitiveness. Gastrointestinal (GI) tract can be involved in dermatological disorders or GI diseases can have a dermatological manifestation.

PTEN regulation by the Akt/GSK-3β axis during RANKL signaling

Phosphatase and tensin homolog (PTEN) negatively regulates phosphoinositide 3-kinase (PI3K)/Akt signaling as a lipid phosphatase for the second messenger phosphatidylinositol 3,4,5-triphosphate. We discovered recently that inactivating glycogen synthase kinase-3β (GSK-3β) via Akt plays an important role in receptor activator of nuclear factor κb ligand (RANKL)-induced osteoclastogenesis. However, the signaling link between GSK-3β and PTEN in RANKL signaling has not been revealed. Downregulating PTEN by RNA interference increases Akt and GSK-3β phosphorylation levels by RANKL, thereby promoting the formation of osteoclasts. PTEN phosphorylation at threonine 366 (T366) decreased gradually during RANKL-induced osteoclastogenesis, whereas PTEN protein levels were unaffected. Interestingly, the PTEN phosphorylation defective mutant (T366A) showed increased osteoclastogenesis, which is consistent with its lower phosphatase activity, compared to that of wild-type PTEN. Moreover, treatment with the GSK-3 inhibitor SB216763 suppressed PTEN phosphorylation levels and phosphatase activity and enhanced Akt phosphorylation. These data suggest that inhibiting GSK-3β during RANKL-induced osteoclastogenesis decreases PTEN phosphorylation, leading to enhanced osteoclast differentiation through Akt activation.

Phosphatase and tensin homologue deleted on chromosome 10

Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) is a tumor suppressor gene deleted or mutated in many human cancers such as glioblastoma, spinal tumors, prostate, bladder, adrenals, thyroid, breast, endometrium, and colon cancers. They result from loss of heterozygosity (LOH) for the PTEN gene on chromosome 10q23. Previous studies reported that various drugs, chemicals, and foods can up-regulate PTEN mRNA and protein expression in different cell lines, and they may be useful in the future prevention and/or treatment of these cancers. PTEN has also been observed to have prognostic significance and is gradually being accepted as an independent prognostic factor. This will help in monitoring disease progression and/or recurrence, with a view to improving treatment outcomes and reducing the associated morbidity and mortality from these cancers. Neprilysin (NEP) is a zinc-dependent metallopeptidase that cleaves and inactivates some biologically active peptides thus switching off signal transduction at the cell surface. Decreased NEP expression in many cancers has been reported. NEP can form a complex with PTEN and enhance PTEN recruitment to the plasma membrane as well as stabilize its phosphatase activity. MicroRNA-21 (miR-21) post-transcriptionally down-regulates the expression of PTEN and stimulates growth and invasion in non-small cell lung cancer (NSCLC) (lung Ca), suggesting that this may be a potential therapeutic target in the future treatment of NSCLC. PTEN is a tumor suppressor gene associated with many human cancers. This has diagnostic, therapeutic, and prognostic significance in the management of many human cancers, and may be a target for new drug development in the future.

Germline Mutations in the Polyposis-Associated Genes BMPR1A, SMAD4, PTEN, MUTYH and GREM1 Are Not Common in Individuals with Serrated Polyposis Syndrome

Background

Recent reports have observed that individuals with serrated polyps, some of whom meet the clinical diagnostic criteria for Serrated Polyposis Syndrome (SPS), are among those who carry germline mutations in genes associated with polyposis syndromes including; (1) genes known to underlie hamartomatous polyposes (SMAD4, BMPR1A, and PTEN), (2) MUTYH-associated polyposis and (3) GREM1 in Hereditary Mixed Polyposis Syndrome (HMPS). The aim of this study was to characterise individuals fulfilling the current WHO criteria for SPS for germline mutations in these polyposis-associated genes.

Methods

A total of 65 individuals with SPS (fulfilling WHO criteria 1 or 3), were recruited to the Genetics of Serrated Neoplasia study between 2000 and 2012, through multiple Genetics or Family Cancer Clinics within Australia, or from the New Zealand Familial Gastrointestinal Cancer Service. Individuals with SPS were tested for coding mutations and large deletions in the PTEN, SMAD4, and BMPR1A genes, for the MUTYH variants in exons 7 (Y179C) and 13 (G396D), and for the duplication upstream of GREM1.

Results

We found no variants that were likely to be deleterious germline mutations in the SPS cases in the PTEN, SMAD4, and BMPR1A genes. A novel variant in intron 2 (c.164+223T>C) of PTEN was identified in one individual and was predicted by in silico analysis to have no functional consequences. One further individual with SPS was found to be mono-allelic for the MUTYH G396D mutation. No individuals carried the recently reported duplication within GREM1.

Conclusions

Genes involved in the gastrointestinal hamartomatous polyposis, Hereditary Mixed Polyposis Syndrome and MUTYH-associated polyposis syndromes are not commonly altered in individuals with SPS.

Candidate biomarkers for genetic and clinicopathological diagnosis of endometrial cancer

The recent increase in the frequency of endometrial cancer has emphasized the need for accurate diagnosis and improved treatment. The current diagnosis is still based on conventional pathological indicators, such as clinical stage, tumor differentiation, invasion depth and vascular invasion. However, the genetic mechanisms underlying endometrial cancer have gradually been determined, due to developments in molecular biology, leading to the possibility of new methods of diagnosis and treatment planning. New candidate biomarkers for endometrial cancer include those for molecular epigenetic mutations, such as microRNAs. These biomarkers may permit earlier detection of endometrial cancer and prediction of outcomes and are likely to contribute to future personalized therapy for endometrial cancer.

Identification of patients at risk for hereditary colorectal cancer

Diagnosis of hereditary colorectal cancer syndromes requires clinical suspicion and knowledge of such syndromes. Lynch syndrome is the most common cause of hereditary colorectal cancer. Other less common causes include familial adenomatous polyposis (FAP), Peutz-Jeghers syndrome (PJS), juvenile polyposis syndrome, and others. There have been a growing number of clinical and molecular tools used to screen and test at risk individuals. Screening tools include diagnostic clinical criteria, family history, genetic prediction models, and tumor testing. Patients who are high risk based on screening should be referred for genetic testing.

Assessing SNP-SNP interactions among DNA repair, modification and metabolism related pathway genes in breast cancer susceptibility

Genome-wide association studies (GWASs) have identified low-penetrance common variants (i.e., single nucleotide polymorphisms, SNPs) associated with breast cancer susceptibility. Although GWASs are primarily focused on single-locus effects, gene-gene interactions (i.e., epistasis) are also assumed to contribute to the genetic risks for complex diseases including breast cancer. While it has been hypothesized that moderately ranked (P value based) weak single-locus effects in GWASs could potentially harbor valuable information for evaluating epistasis, we lack systematic efforts to investigate SNPs showing consistent associations with weak statistical significance across independent discovery and replication stages. The objectives of this study were i) to select SNPs showing single-locus effects with weak statistical significance for breast cancer in a GWAS and/or candidate-gene studies; ii) to replicate these SNPs in an independent set of breast cancer cases and controls; and iii) to explore their potential SNP-SNP interactions contributing to breast cancer susceptibility. A total of 17 SNPs related to DNA repair, modification and metabolism pathway genes were selected since these pathways offer a priori knowledge for potential epistatic interactions and an overall role in breast carcinogenesis. The study design included predominantly Caucasian women (2,795 cases and 4,505 controls) from Alberta, Canada. We observed two two-way SNP-SNP interactions (APEX1-rs1130409 and RPAP1-rs2297381; MLH1-rs1799977 and MDM2-rs769412) in logistic regression that conferred elevated risks for breast cancer (P_interaction<7.3×10⁻³). Logic regression identified an interaction involving four SNPs (MBD2-rs4041245, MLH1-rs1799977, MDM2-rs769412, BRCA2-rs1799943) (P_permutation = 2.4×10⁻³). SNPs involved in SNP-SNP interactions also showed single-locus effects with weak statistical significance, while BRCA2-rs1799943 showed stronger statistical significance (P_{correlation/trend} = 3.2×10⁻⁴) than the others. These single-locus effects were independent of body mass index. Our results provide a framework for evaluating SNPs showing statistically weak but reproducible single-locus effects for epistatic effects contributing to disease susceptibility.

Incidence of thyroid cancer in the Kingdom of Saudi Arabia, 2000-2010

BACKGROUND

Thyroid cancer is the second most common malignancy among females at King Faisal Specialist Hospital and Research Centre (KFSH&RC) and in Saudi Arabia, accounting for about 11% of all newly diagnosed female cancers in the country in 2008. Over the past several decades, an increasing incidence of thyroid cancer has been reported in the Kingdom of Saudi Arabia. There are no comprehensive clinical epidemiological data for the trends of thyroid cancer incidence compared to the global incidence. This report reviews the thyroid cancer incidence in KFSH&RC and compares that with Saudi Arabia, the Gulf region, North America and globally from 2000 to 2010.

METHODS

Retrospective review of patients with thyroid cancer was carried out from 2000 to 2010, using the hospital Tumor Registry program as per the American College of Surgeons standards. Trends and patterns of all well-known prognostic factors were sub-stratified by age, stage and grade.

RESULTS

A total of 2292 patients with thyroid cancer were treated at KFSH&RC, Riyadh, Saudi Arabia, from 2000 to 2010. Thyroid cancer constitutes about 9% of all malignancies and 12% of all female malignancies at KFSH&RC, which are significantly higher compared to the USA, where thyroid cancer represents only 2.9% of all malignancies and 4.6% of all female malignancies. Papillary adenocarcinoma was the most common histological subtype followed by papillary carcinoma, follicular variant. Median age at diagnosis was 40 for females and 44years for males. Overall Age-Standardized Incidence Rate (ASR) was 4.4/100,000 (6.8 for female and 2/100,000 for males) in the Kingdom in 2008. Median age at diagnosis was 38years and the highest incidence was in the 30-39year age group in KFSH&RC. About 48% of patients presented in the localized stage and 60% underwent combined modality treatment consisting of surgery, radiation and hormonal therapy. There was significantly increased incidence among females as compared to males. The age-adjusted thyroid cancer incidence rates from 2000 to 2010 varied three-fold more for females than for males. Considerable geographical variations were present in thyroid cancer incidence in Saudi Arabia.

CONCLUSION

Thyroid cancer incidence rates have increased exponentially between 2000 and 2010 and there is significant geographical variation in the incidence of thyroid cancer throughout the Kingdom. Thyroid cancer has become the second most common cancer among young Saudi women with a male to female ratio at 0.3:1. Rising incidence of thyroid cancer in Saudi Arabia may be due to the increased detection and diagnosis of the thyroid cancers and not only an increase in the true occurrence of thyroid cancer. More studies are required to determine this significant difference at the molecular level.

Loss of Pten promotes angiogenesis and enhanced vegfaa expression in zebrafish

Angiogenesis, the emergence of vessels from an existing vascular network, is pathologically associated with tumor progression and is of great interest for therapeutic intervention. PTEN is a frequently mutated tumor suppressor and has been linked to the progression of many types of tumors, including hemangiosarcomas in zebrafish. Here, we report that mutant zebrafish embryos lacking functional Pten exhibit enhanced angiogenesis, accompanied by elevated levels of phosphorylated Akt (pAkt). Inhibition of phosphoinositide 3-kinase (PI3K) by LY294002 treatment and application of sunitinib, a widely used anti-angiogenic compound, suppressed enhanced angiogenesis in Pten mutants. Vegfaa has a crucial role in angiogenesis and vegfaa expression was upregulated in embryos lacking functional Pten. Interestingly, vegfaa expression was also upregulated in hemangiosarcomas from haploinsufficient adult zebrafish Pten mutants. Elevated vegfaa expression in mutant embryos lacking functional Pten was suppressed by LY294002. Surprisingly, sunitinib treatment dramatically enhanced vegfaa expression in Pten mutant embryos, which might account for tumor relapse in human patients who are treated with sunitinib. Combined treatment with suboptimal concentrations of sunitinib and LY294002 rescued enhanced angiogenesis in pten mutant embryos without the dramatic increase in vegfaa expression, suggesting a new approach for therapeutic intervention in VEGFR-signaling-dependent tumors.

Identification of a breast cancer susceptibility locus at 4q31.22 using a genome-wide association study paradigm

More than 40 single nucleotide polymorphisms (SNPs) for breast cancer susceptibility were identified by genome-wide association studies (GWASs). However, additional SNPs likely contribute to breast cancer susceptibility and overall genetic risk, prompting this investigation for additional variants. Six putative breast cancer susceptibility SNPs identified in a two-stage GWAS that we reported earlier were replicated in a follow-up stage 3 study using an independent set of breast cancer cases and controls from Canada, with an overall cumulative sample size of 7,219 subjects across all three stages. The study design also encompassed the 11 variants from GWASs previously reported by various consortia between the years 2007–2009 to (i) enable comparisons of effect sizes, and (ii) identify putative prognostic variants across studies. All SNP associations reported with breast cancer were also adjusted for body mass index (BMI). We report a strong association with 4q31.22-rs1429142 (combined per allele odds ratio and 95% confidence interval = 1.28 [1.17–1.41] and P_combined = 1.5×10⁻⁷), when adjusted for BMI. Ten of the 11 breast cancer susceptibility loci reported by consortia also showed associations in our predominantly Caucasian study population, and the associations were independent of BMI; four FGFR2 SNPs and TNRC9-rs3803662 were among the most notable associations. Since the original report by Garcia-Closas et al. 2008, this is the second study to confirm the association of 8q24.21-rs13281615 with breast cancer outcomes.

Diffuse intestinal ganglioneuromatosis in a child

A 7 year old male with a history of congenital neutropenia and growth hormone deficiency presented with abdominal pain, fevers, and diarrhea. Imaging and endoscopy revealed significant inflammation of the ascending colon with stenosis at the level of the hepatic flexure. A right hemicolectomy was performed, and pathologic findings were consistent with diffuse intestinal ganglioneuromatosis. Due to recurrent mass effect at the intestinal anastomotic site detected radiologically, a second intestinal resection was performed 7 months later. Genetic testing was negative for mutations in the RET protooncogene, NF1 and PTEN tumor suppressor genes. We report a case of diffuse intestinal ganglioneuromatosis in a child with congenital neutropenia.

Genetic mutations, molecular markers and future directions in research

Recent molecular studies have described a number of abnormalities associated with the pathogenesis of thyroid carcinoma. These distinct molecular events are often associated with specific stages of tumor development and may serve as prognostic factors and therapeutic targets. A better understanding of the mechanisms involved in thyroid cancer pathogenesis, will hopefully help translate these discoveries to improved patient care.

Is fibroid heterogeneity a significant issue for clinicians and researchers?

The clinical and scientific literature overwhelmingly deals with fibroids as a single entity or disease. This convenient assumption of homogeneity may be an important oversight given that substantial evidence exists for heterogeneity between fibroids at many levels. Failure to recognize and accommodate fibroid heterogeneity can have significant ramifications for both clinical treatment decisions and research protocol design. The aim of this article is to review the current knowledge of fibroid heterogeneity and to identify key areas where fibroid heterogeneity should be taken into consideration both clinically and when designing research protocols. Uterine leiomyomata display significant and well-documented heterogeneity in symptoms, diagnostic imaging appearance, pathology, genetic background and therapeutic requirements. Additional research is needed to better understand fibroid heterogeneity as it relates to pathogenesis, molecular targets for potential new therapies, patient symptoms and, ultimately, treatment. To this list should also be added heterogeneity of genetics, lifestyle and individual clinical characteristics of the fibroid. Increasingly, an understanding of uterine leiomyoma heterogeneity will be of importance for clinicians who see patients with this common and costly disease.

Coenzyme Q10 restores amyloid beta-inhibited proliferation of neural stem cells by activating the PI3K pathway

Neurogenesis in the adult brain is important for memory and learning, and the alterations in neural stem cells (NSCs) may be an important part of Alzheimer's disease pathogenesis. The phosphatidylinositol 3-kinase (PI3K) pathway has been suggested to play an important role in neuronal cell survival and is highly involved in adult neurogenesis. Recently, coenzyme Q10 (CoQ10) was found to affect the PI3K pathway. We investigated whether CoQ10 could restore amyloid β (Aβ)25-35 oligomer-inhibited proliferation of NSCs by focusing on the PI3K pathway. To evaluate the effects of CoQ10 on Aβ25-35 oligomer-inhibited proliferation of NSCs, NSCs were treated with several concentrations of CoQ10 and/or Aβ25-35 oligomers. BrdU labeling, Colony Formation Assays, and immunoreactivity of Ki-67, a marker of proliferative activity, showed that NSC proliferation decreased with Aβ25-35 oligomer treatment, but combined treatment with CoQ10 restored it. Western blotting showed that CoQ10 treatment increased the expression levels of p85α PI3K, phosphorylated Akt (Ser473), phosphorylated glycogen synthase kinase-3β (Ser9), and heat shock transcription factor, which are proteins related to the PI3K pathway in Aβ25-35 oligomers-treated NSCs. To confirm a direct role for the PI3K pathway in CoQ10-induced restoration of proliferation of NSCs inhibited by Aβ25-35 oligomers, NSCs were pretreated with a PI3K inhibitor, LY294002; the effects of CoQ10 on the proliferation of NSCs inhibited by Aβ25-35 oligomers were almost completely blocked. Together, these results suggest that CoQ10 restores Aβ25-35 oligomer-inhibited proliferation of NSCs by activating the PI3K pathway.

Thioredoxin and thioredoxin target proteins: from molecular mechanisms to functional significance

The thioredoxin (Trx) system is one of the central antioxidant systems in mammalian cells, maintaining a reducing environment by catalyzing electron flux from nicotinamide adenine dinucleotide phosphate through Trx reductase to Trx, which reduces its target proteins using highly conserved thiol groups. While the importance of protecting cells from the detrimental effects of reactive oxygen species is clear, decades of research in this field revealed that there is a network of redox-sensitive proteins forming redox-dependent signaling pathways that are crucial for fundamental cellular processes, including metabolism, proliferation, differentiation, migration, and apoptosis. Trx participates in signaling pathways interacting with different proteins to control their dynamic regulation of structure and function. In this review, we focus on Trx target proteins that are involved in redox-dependent signaling pathways. Specifically, Trx-dependent reductive enzymes that participate in classical redox reactions and redox-sensitive signaling molecules are discussed in greater detail. The latter are extensively discussed, as ongoing research unveils more and more details about the complex signaling networks of Trx-sensitive signaling molecules such as apoptosis signal-regulating kinase 1, Trx interacting protein, and phosphatase and tensin homolog, thus highlighting the potential direct and indirect impact of their redox-dependent interaction with Trx. Overall, the findings that are described here illustrate the importance and complexity of Trx-dependent, redox-sensitive signaling in the cell. Our increasing understanding of the components and mechanisms of these signaling pathways could lead to the identification of new potential targets for the treatment of diseases, including cancer and diabetes.

An update on male breast cancer and future directions for research and treatment

Male breast cancer is a rare disease for which treatment has been based on the evidence available from female breast cancer. The new genomic tools can better characterize the biology of breast cancer. It is hoping that these will help to clarify possible differences of breast cancer behaviour in male patients, which will have a major impact on treatment strategies and on the conduct of clinical trials in this setting. In this review we will summarize available information on epidemiology, risk factors for breast cancer in men, the new insights of the biology of this disease, current recommendations for treatment and insights for future research.

SPLUNC1 regulates cell progression and apoptosis through the miR-141-PTEN/p27 pathway, but is hindered by LMP1

Little is known about the role of the host defensive protein short palate, lung and nasal epithelium clone 1 (SPLUNC1) in the carcinogenesis of nasopharyngeal carcinoma (NPC). Here we report that SPLUNC1 plays a role at a very early stage of NPC carcinogenesis. SPLUNC1 regulates NPC cell proliferation, differentiation and apoptosis through miR-141, which in turn regulates PTEN and p27 expression. This signaling axis is negatively regulated by the EBV-coded gene LMP1. Therefore we propose that SPLUNC1 suppresses NPC tumor formation and its inhibition by LMP1 provides a route for NPC tumorigenesis.

Molecular pathogenesis and mechanisms of thyroid cancer

Thyroid cancer is a common endocrine malignancy. There has been exciting progress in understanding its molecular pathogenesis in recent years, as best exemplified by the elucidation of the fundamental role of several major signalling pathways and related molecular derangements. Central to these mechanisms are the genetic and epigenetic alterations in these pathways, such as mutation, gene copy-number gain and aberrant gene methylation. Many of these molecular alterations represent novel diagnostic and prognostic molecular markers and therapeutic targets for thyroid cancer, which provide unprecedented opportunities for further research and clinical development of novel treatment strategies for this cancer.

Germline and somatic KLLN alterations in breast cancer dysregulate G2 arrest

PTEN is a well-described predisposition gene for Cowden syndrome (CS), a familial cancer syndrome characterized by a high risk of breast and other cancers. KLLN, which shares a bidirectional promoter with PTEN, causes cell cycle arrest and apoptosis. We previously identified germline hypermethylation of the KLLN promoter in 37% of PTEN mutation-negative CS/CS-like (CSL) patients. Patients with germline KLLN hypermethylation have an increased prevalence of breast and renal cancers when compared with PTEN mutation carriers. We have consequently sought to identify and characterize germline KLLN variants/mutations in CS/CSL and in apparently sporadic breast cancer patients. KLLN variants in CS/CSL patients are rare (1 of 136, 0.007%). Interestingly, among 438 breast cancer patients, 13 (3%) have germline KLLN variants when compared with none in 128 controls (P = 0.049). Patients with KLLN variants have a family history of breast cancer when compared with those without (P = 0.02). We demonstrate that germline KLLN variants dysregulate the cell cycle at G2. Of 24 breast carcinomas analyzed, 3 (13%) have somatic KLLN hemizygous deletions, with somatic loss of the wild-type allele in a patient with germline KLLN p.Leu119Leu. Of 452 breast carcinomas in The Cancer Genome Atlas project, 93 (21%) have KLLN hemizygous or homozygous deletions. This is the first study to associate germline KLLN variants with sporadic breast cancer and to recognize somatic KLLN deletions in breast carcinomas. Our observations suggest that KLLN may be a low penetrance susceptibility factor for apparently sporadic breast cancer.

PTEN and melanomagenesis

The PI3K-PTEN-AKT signaling pathway is involved in various cellular activities, including proliferation, migration, cell growth, cell survival and differentiation during adult homeostasis as well as in tumorigenesis. It has been suggested that the constitutive activation of PI3K/AKT signaling with concurrent loss of function of the tumor suppressor molecule PTEN contributes to cancer formation. Members of the PI3K-PTEN-AKT pathway, including these proteins and mTOR, are altered in melanoma tumors and cell lines. A hallmark of activation of the pathway is the loss of function of PTEN. Indeed, loss of heterozygosity of PTEN has been observed in approximately 30% of human melanomas, implicating this signaling pathway in this cancer. PI3K signaling activation, via loss of PTEN function, can inhibit proapoptotic genes such as the FoxO family of transcription factors, while inducing cell growth- and cell survival-related elements such as p70S6K and AKT. Determining how the PI3K-PTEN-AKT signaling pathway, alone or in cooperation with other pathways, orchestrates the induction of target genes involved in a diverse range of activities is a major challenge in research into melanoma initiation and progression. Moreover, the acquisition of basic knowledge will help patient management with appropriate therapies that are already, or will shortly be, on the market.

An inducible knockout mouse to model the cell-autonomous role of PTEN in initiating endometrial, prostate and thyroid neoplasias

PTEN is one of the most frequently mutated tumor suppressor genes in human cancers. The role of PTEN in carcinogenesis has been validated by knockout mouse models. PTEN heterozygous mice develop neoplasms in multiple organs. Unfortunately, the embryonic lethality of biallelic excision of PTEN has inhibited the study of complete PTEN deletion in the development and progression of cancer. By crossing PTEN conditional knockout mice with transgenic mice expressing a tamoxifen-inducible Cre-ER^T under the control of a chicken actin promoter, we have generated a tamoxifen-inducible mouse model that allows temporal control of PTEN deletion. Interestingly, administration of a single dose of tamoxifen resulted in PTEN deletion mainly in epithelial cells, but not in stromal, mesenchymal or hematopoietic cells. Using the mT/mG double-fluorescent Cre reporter mice, we demonstrate that epithelial-specific PTEN excision was caused by differential Cre activity among tissues and cells types. Tamoxifen-induced deletion of PTEN resulted in extremely rapid and consistent formation of endometrial in situ adenocarcinoma, prostate intraepithelial neoplasia and thyroid hyperplasia. We also analyzed the role of PTEN ablation in other epithelial cells, such as the tubular cells of the kidney, hepatocytes, colonic epithelial cells or bronchiolar epithelium, but those tissues did not exhibit neoplastic growth. Finally, to validate this model as a tool to assay the efficacy of anti-tumor drugs in PTEN deficiency, we administered the mTOR inhibitor everolimus to mice with induced PTEN deletion. Everolimus dramatically reduced the progression of endometrial proliferations and significantly reduced thyroid hyperplasia. This model could be a valuable tool to study the cell-autonomous mechanisms involved in PTEN-loss-induced carcinogenesis and provides a good platform to study the effect of anti-neoplastic drugs on PTEN-negative tumors.

Should patients with Cowden syndrome undergo prophylactic thyroidectomy?

BACKGROUND

Cowden syndrome (CS) is dominantly inherited and predisposes patients to tumors in multiple organs. We characterized CS-associated malignant and benign thyroid disease.

METHODS

Of data from 3,477 prospectively recruited CS patients with known genetic analysis, we analyzed 225 PTEN mutation+ patients whose treatment occurred at our center (n = 25) or other hospitals nationwide (n = 200).

RESULTS

A total of 32 of 225 PTEN mutation+ patients (14%) had thyroid cancer: 52% papillary, 28% follicular-variant papillary, 14% follicular, and 6% anaplastic. Median age at diagnosis was 35 years compared with 49 years for Surveillance Epidemiology and End Results population data. Initial thyroid ultrasonography in 16 of 25 patients revealed thyroiditis/goiters in all >13 years age, leading to FNA in 7 (64%), thyroidectomy in 3 (27%), and new cancer diagnosis in 2 (18%). Three with severe autism required intraoperative sedation for ultrasonography. A total of 9 of 25 patients were monitored after multiple partial thyroidectomies for goiters by age 42 (n = 5), thyroiditis, or cancer detected by age 36 (n = 3).

CONCLUSION

PTEN mutation+ patients with CS have an enormous prevalence of thyroid disease. Earlier screening may be advisable because thyroiditis and nodules are seen by the time patients reach adolescence, and cancer diagnosis occurs on average 14 years earlier than expected. Furthermore, the risks observed may justify prophylactic total thyroidectomy in select, if not all, patients, particularly those with developmental disorders.

The High Mobility Group A proteins contribute to thyroid cell transformation by regulating miR-603 and miR-10b expression

The overexpression of the HMGA1 proteins is a feature of human malignant neoplasias and has a causal role in cell transformation. The aim of our study has been to investigate the microRNAs (miRNAs or miRs) regulated by the HMGA1 proteins in the process of cell transformation analyzing the miRNA expression profile of v-ras-Ki oncogene-transformed thyroid cells expressing or not HMGA1 proteins. We demonstrate that, among the miRNAs regulated by cell transformation, there are miR-10b, miR-21, miR-125b, miR-221 and miR-222 that are positively and miR-34a and miR-603 that are negatively regulated by HMGA1 expression. Then, we focused our attention on the miR-10b and miR-603 whose expression was dependent on the presence of HMGA1 also in other cell systems. We found that miR-10b is able to target the PTEN gene, whereas miR-603 targets the CCND1 and CCND2 genes coding for the cyclin D1 and cyclin D2 proteins, respectively. Moreover, functional studies showed that miR-10b and miR-603 regulate positively and negatively, respectively, cell proliferation and migration suggesting a role of their dysregulation in thyroid cell transformation.

Germline PIK3CA and AKT1 mutations in Cowden and Cowden-like syndromes

Cowden syndrome (CS) is a difficult-to-recognize multiple hamartoma syndrome with high risks of breast, thyroid, and other cancers. Germline mutations in PTEN on 10q23 were found to cause 85% of CS when accrued from tertiary academic centers, but prospective accrual from the community over the last 12 years has revealed a 25% PTEN mutation frequency. PTEN is the phosphatase that has been implicated in a heritable cancer syndrome and subsequently in multiple sporadic cancers and developmental processes. PTEN antagonizes the AKT1/PI3K signaling pathway and has roles in cell cycle, migration, cell polarity, and apoptosis. We report that 8 of 91 (8.8%) unrelated CS individuals without germline PTEN mutations carried 10 germline PIK3CA mutations (7 missense, 1 nonsense, and 2 indels) and 2 (2.2%) AKT1 mutations. These mutations result in significantly increased P-Thr308-AKT and increased cellular PIP3. Our observations suggest that PIK3CA and AKT1 are CS susceptibility genes.

Germline PIK3CA and AKT1 mutations in Cowden and Cowden-like syndromes

Cowden syndrome (CS) is a difficult-to-recognize multiple hamartoma syndrome with high risks of breast, thyroid, and other cancers. Germline mutations in PTEN on 10q23 were found to cause 85% of CS when accrued from tertiary academic centers, but prospective accrual from the community over the last 12 years has revealed a 25% PTEN mutation frequency. PTEN is the phosphatase that has been implicated in a heritable cancer syndrome and subsequently in multiple sporadic cancers and developmental processes. PTEN antagonizes the AKT1/PI3K signaling pathway and has roles in cell cycle, migration, cell polarity, and apoptosis. We report that 8 of 91 (8.8%) unrelated CS individuals without germline PTEN mutations carried 10 germline PIK3CA mutations (7 missense, 1 nonsense, and 2 indels) and 2 (2.2%) AKT1 mutations. These mutations result in significantly increased P-Thr308-AKT and increased cellular PIP3. Our observations suggest that PIK3CA and AKT1 are CS susceptibility genes.

An intronic polymorphic deletion in the PTEN gene: implications for molecular diagnostic testing

Background:

A cohort of 629 patients with suspected Bannayan–Riley–Ruvalcaba syndrome or Cowden syndrome was tested for mutations in the PTEN gene.

Methods:

Dosage analysis of PTEN was carried out using a PTEN-specific multiplex ligation-dependent probe amplification (MLPA) kit, whereas point mutation analysis was performed using direct sequencing.

Results:

Approximately 4% of the patients from the testing cohort were heterozygously deleted for the two MLPA probe-binding sites situated in intron 1. The same deletion was subsequently seen in ∼3% of 220 normal controls, and in patients from the testing cohort with a causative mutation elsewhere in the PTEN gene. Sequencing of the variant revealed an 899 bp deletion, the 3′ breakpoint of which is only 58 bp from the start of exon 2.

Conclusion:

Although all evidence suggests that the 899 bp deletion is a polymorphism with no clinical effect, it removes the binding sites of almost all published PTEN exon 2 forward primers, resulting in allelic loss during PCR.

Targeting the PI3K/AKT/mTOR pathway: biomarkers of success and tribulation

PI3K/AKT/mTOR pathway is an established oncogenic driver in humans. Targeted biologic agents against components of this pathway have shown promising activity leading to the approval of the allosteric inhibitors of mTOR, everolimus, and temsirolimus for the treatment of advanced cancers of the kidney, breast, and pancreas. Despite the established and promising activity of this therapeutic strategy, the duration and quality of benefit remains suboptimal in unselected patients. Improved understanding of the biologic consequence of altered PI3K/AKT/mTOR signaling is informing the development of protein (phosphorylated forms of S6, AKT, eIF4e) and genetic (PIK3CA mutation, PTEN loss of function, TSC1 and TSC2 mutation, PIK3CA-GS genetic profile) biomarkers to identify patients most likely to benefit from this therapeutic strategy. This review provides an overview of the biologic rational and promising results of protein and genetic biomarkers for selecting patients appropriate for therapy with inhibitors of this pathway.

Molecular diagnosis of genodermatoses

The progress of molecular genetics helps clinicians to prove or exclude a suspected diagnosis for a vast and yet increasing number of genodermatoses. This leads to precise genetic counselling, prenatal diagnosis and preimplantation genetic haplotyping for many inherited skin conditions. It is also helpful in such occasions as phenocopy, late onset and incomplete penetrance, uniparental disomy, mitochondrial inheritance and pigmentary mosaicism. Molecular methods of two genodermatoses are explained in detail, i.e. genodermatoses with skin fragility and neurofibromatosis type 1.

Non-melanoma skin cancer in mouse and man

As a frontier organ, skin is exposed to different environmental and/or occupational chemicals which cause cutaneous cancers in experimental animals. In mice, 7,12-dimethylbenz[a]anthrancene (DMBA) and the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) are frequently used as skin model tumor initiator and promoter, respectively. The sequential administration of DMBA and TPA leads to the appearance of a large number of benign papillomas, of which some convert later into invasive squamous cell carcinomas (SCC). At the molecular level, initiation of carcinogenesis in mouse skin consists in the mutational activation of the Ha-ras oncoprotein. HA-RAS mutations are rare in human SCC, but HA-RAS-mutated tumors appear in melanoma patients treated with B-raf inhibitors, indicating that initiated, HA-RAS-mutated stem cells also reside in human skin. Similarly, UV-induced human SCC show footprint mutations in the tumor suppressor gene TP53 which are also observed in UV-induced mouse SCC. Strong species differences exist with respect to phorbol ester-mediated tumor promotion. While certain mouse strains are very susceptible, other rodent species are much less sensitive. Likewise, humans appear to be much more resistant to phorbol ester-mediated skin toxicity. Papilloma formation as a result of a chemical insult is uncommon in men, questioning the relevance of this preneoplastic lesion for humans. However, skin tumorigenesis in the experimental situation and in humans appears to follow common molecular mechanisms, even though there are species differences in the morphological correlates to the preneoplastic state. Therefore, we recommend not simply labeling them as irrelevant for human risk assessment.

PTEN protein expression in malignant pleural mesothelioma

Malignant pleural mesothelioma is associated with poor prognosis and despite recent advances in chemotherapy, the median survival is still approximately 12 months. Loss of phosphatase and tensin homolog (PTEN) protein expression may lead to constitutive activation of AKT resulting in cell survival and proliferation. Small studies reported that PTEN protein expression is rarely lost in mesothelioma whilst a larger study demonstrated prognostic significance of PTEN protein expression status with absence in 62 % of cases. We aimed to analyse PTEN protein expression in mesothelioma. Immunohistochemical analysis was performed in 86 archival mesothelioma samples to determine the PTEN protein expression status and statistical analysis was performed to identify any prognostic significance. Mesothelial cells in normal pleura demonstrated positive staining for PTEN protein and served as a positive reference. For mesothelioma samples, the expression of PTEN protein was scored as 0 (negative), 1 (intensity less than that of positive normal pleura reference slide) and 2 (intensity equal to or greater than positive normal pleura reference slide). A total of 23/86 (26.7 %) scored 0, 23/86 (26.7 %) scored 1 and 40/86 (46.5 %) scored 2 for PTEN expression. Univariate analysis demonstrated that lack of PTEN expression was not associated with survival. PTEN protein expression was undetectable in 26.7 % of mesothelioma samples; however, no prognostic significance was identified. Absence of PTEN protein may result in activation of the PI3K/AKT/MTOR pathway. Targeting this pathway with inhibitors further downstream of PTEN may provide a potential therapeutic target in selected patients.

Germline PIK3CA and AKT1 mutations in Cowden and Cowden-like syndromes

Cowden syndrome (CS) is a difficult-to-recognize multiple hamartoma syndrome with high risks of breast, thyroid, and other cancers. Germline mutations in PTEN on 10q23 were found to cause 85% of CS when accrued from tertiary academic centers, but prospective accrual from the community over the last 12 years has revealed a 25% PTEN mutation frequency. PTEN is the phosphatase that has been implicated in a heritable cancer syndrome and subsequently in multiple sporadic cancers and developmental processes. PTEN antagonizes the AKT1/PI3K signaling pathway and has roles in cell cycle, migration, cell polarity, and apoptosis. We report that 8 of 91 (8.8%) unrelated CS individuals without germline PTEN mutations carried 10 germline PIK3CA mutations (7 missense, 1 nonsense, and 2 indels) and 2 (2.2%) AKT1 mutations. These mutations result in significantly increased P-Thr308-AKT and increased cellular PIP3. Our observations suggest that PIK3CA and AKT1 are CS susceptibility genes.

Targeting the PI3K/Akt/mTOR pathway for breast cancer therapy

Recent advances in genetics and genomics have revealed new pathways that are aberrantly activated in many breast cancers. Chief among these genetic changes are somatic mutations and/or gains and losses of key genes within the phosphoinositide 3-kinase (PI3K) pathway. Since breast cancer cell growth and progression is often dependent upon activation of the PI3K pathway, there has been intense research interest in finding therapeutic agents that can selectively inhibit one or more constituents of this signaling cascade. Here we review key molecules involved with aberrant PI3K pathway activation in breast cancers and current efforts to target these components for therapeutic gain.

Involvement of PTEN in TPA-mediated p53-activation in mouse skin epidermal JB6 cells

Our recent studies suggest a unique role of p53 during the early stage of cancer development. However, how p53 activation is regulated during TPA treatment remains elusive. We used murine skin epidermal JB6 promotion-sensitive (P+) and promotion resistant (P-) cells to observe differential expression of PTEN during TPA-induced p53 activation. Total PTEN expression was decreased in only P+ cells. Nuclear expression of PTEN increased and complex formation between PTEN and p53 occurred in P+ cells treated with TPA. Knocking down PTEN expression via siRNA inhibited TPA-induced Bax expression. Similar effects were seen with the p53 inhibitor, pifithrin-alpha. Cells that were transfected with siRNA to PTEN exhibited enhanced tumorigenicity. Our findings suggest PTEN mediates TPA-induced p53 activation.

The clinical consequences of hemizygosity across 2 MB of 10q23 are restricted to Cowden syndrome

Cowden syndrome is caused by germline mutations in PTEN and clinically characterized by hamartomas, macrocephaly, classic dermatologic stigmata, and an estimated 85 % lifetime risk of female breast cancer. A young woman with macrocephaly, tricholemmomas, AV malformations, and mammary papillomatosis was found to be hemizygous for PTEN in her germline DNA. Using MLPA, comparative genomic hybridization, and DNA sequencing, we identified a 2-Mb deletion in chromosome 10 spanning 344-kb centromeric and 1.7-Mb telomeric of PTEN. Her father who has a clinical history including macrocephaly, Hashimoto's thyroiditis, colonic polyposis, acral keratoses, and goiter was also found to have the same deletion. In benign breast tissue from the hemizygous female, PTEN protein expression was significantly reduced in luminal and stromal cells but present in the myoepithelium. Compared with a typical papilloma of the breast which had intense cytoplasmic PTEN staining, the majority of the patient's papilloma had significantly decreased PTEN expression while some cells had mislocalized perinuclear PTEN expression. In addition to PTEN, 22 other protein-coding genes were deleted including two predicted haploinsufficient genes and five additional genes that have previously been associated with hereditary predispositions to certain diseases. However, because all significant clinical features of the proband and her father are common to patients with genetic alterations in PTEN, the other 22 hemizygous protein-coding genes appear to be haplosufficient.

PTPN14 is required for the density-dependent control of YAP1

Through an shRNA-mediated loss-of-function screen, we identified PTPN14 as a potential tumor suppressor. PTPN14 interacts with yes-associated protein 1 (YAP1), a member of the hippo signaling pathway. We showed that PTPN14 promotes the nucleus-to-cytoplasm translocation of YAP1 during contact inhibition and thus inhibits YAP1 transactivation activity. Interestingly, PTPN14 protein stability was positively controlled by cell density. We identified the CRL2(LRR1) (cullin2 RING ubiquitin ligase complex/leucine-rich repeat protein 1) complex as the E3 ligase that targets PTPN14 for degradation at low cell density. Collectively, these data suggest that PTPN14 acts to suppress cell proliferation by promoting cell density-dependent cytoplasmic translocation of YAP1.

New mutation in the PTEN gene in a Brazilian patient with Cowden's syndrome

Cowden syndrome is characterized by hamartomatous polyps, trichilemmomas, increased risk of developing neoplasms, and is associated with germline mutations in the PTEN gene. We searched for germline mutations in PTEN in a 49-year-old female patient who presented trichilemmoma with previous history of breast carcinoma, and thyroidectomy for a thyroid nodule. We also searched for somatic mutations in breast and thyroid tumoral tissues. DNA was extracted from peripheral leukocytes, paraffin samples of breast carcinoma, and cytological smears of thyroid nodule fine-needle aspiration biopsy, whose final histopathological diagnosis was adenomatous goiter. PTEN was amplified and sequenced. We identified a novel mutation, due to a T>A inversion at position 159 and A>T inversion at position 160, leading to valine-to-aspartic acid substitution at position 53. The p.Val53Asp was also found in homozygous state in samples obtained from adenocarcinoma breast and thyroid biopsy, denoting loss of heterozygosity. Here, we demonstrated a novel germline mutation in PTEN, as well as somatic loss of the wild-type PTEN allele in breast and thyroid tumors in a patient with Cowden syndrome. Arq Bras Endocrinol Metab. 2012;56(8):592-6

PTEN lipid phosphatase activity and proper subcellular localization are necessary and sufficient for down-regulating AKT phosphorylation in the nucleus in Cowden syndrome

CONTEXT

Germline mutations in PTEN are associated with phosphatase and tensin homolog deleted on chromosome 10 (PTEN) hamartoma tumor syndrome including Cowden syndrome (CS) and Cowden-like syndrome (CSL) that predisposes to high risks of benign and malignant tumors of thyroid and breast.

OBJECTIVE

The objective of the study was to analyze the subcellular pattern of phosphorylated (P)-AKT expression in nonmedullary thyroid cancers from PTEN hamartoma tumor syndrome patients and to investigate whether the lack of PTEN in the nucleus and/or lack of proper PTEN function in the nucleus affect(s) nuclear AKT activity in CS patients.

DESIGN

In all, 664 patients with CS/CSL were screened for PTEN germline mutations and nonmedullary thyroid cancers. Twenty-two patients who have both pathogenic PTEN germline mutations and nonmedullary thyroid cancers were selected. Thyroid samples from these patients were stained for PTEN and P-AKT. In our in vitro study, PTEN was knocked down or overexpressed in both thyroid cancer cells and breast cancer cells, and nuclear P-AKT was compared with the control.

RESULTS

Loss of PTEN protein was found in thyroid adenomas and carcinomas from all 22 (100%) PTEN(Mut+) CS/CSL patients. AKT activation was identified in 17 of 22 (77.3%) thyroid adenoma/carcinoma specimens, and most patients (63.7%) have activated nuclear AKT. Knockdown of PTEN in cells containing wild-type PTEN enhanced nuclear P-AKT, whereas expression of wild-type PTEN, but not phosphatase-dead mutants (C124S or G129E), markedly reduced nuclear P-AKT in PTEN null cells. We also showed that in breast cancer but not thyroid cancer cells, PTEN suppresses nuclear P-AKT mainly through decreasing P-AKT nuclear translocation by reducing the PIP3/P-AKT reservoir in the cytoplasm. In thyroid cancer cells, PTEN suppresses phosphorylation of AKT already resident in the nucleus.

CONCLUSIONS

PTEN is necessary and sufficient for inhibiting AKT activation in the nucleus through its intact lipid phosphatase activity and proper subcellular localization.

An atypical patient with Cowden syndrome and PTEN gene mutation presenting with cortical malformation and focal epilepsy

We report the case of a girl with Cowden syndrome (CS) presenting with unilateral perisylvian dysplasia and with drug resistant focal seizures carrying a novel missense mutation 385G>A (G129R) in the PTEN gene. CS has been rarely reported in association with a cortical malformation or epilepsy. These cases suggest that cortical dysplasia needs to be suspected when a CS patient presents with drug-resistant seizures.

Cowden disease and multicystic dysplastic kidney: increased risk of renal cancer?

Unilateral multicystic dysplastic kidney is one of the most frequently identified urinary tract abnormalities in children. Although it can be an isolated finding, it is often associated with other anomalies of the kidney and urinary tract. It has also been described in association with other multisystemic disorders of known genetic aetiologies. Cowden disease (CD) is a rare autosomal-dominant disorder with age-related penetrance characterized by benign and malignant hamartomatous lesions affecting derivatives of all three germ cell layers. Hamartomas can emerge in virtually every organ, but are mostly found in the skin and gastrointestinal tract. We report a 7-year-old patient presenting with unilateral multicystic dysplastic kidney and CD, a hitherto unknown association in paediatrics, which raises the question of an increased risk of renal cancer.

A new case with 10q23 interstitial deletion encompassing both PTEN and BMPR1A narrows the genetic region deleted in juvenile polyposis syndrome

We report on a patient with a contiguous interstitial germline deletion of chromosome 10q23, encompassing BMPR1A and PTEN, with clinical manifestations of juvenile polyposis and minor symptoms of Cowden syndrome (CS) and Bannayan-Riley-Ruvalcaba syndrome (BRRS). The patient presented dysmorphic features as well as developmental delay at the age of 5 months. Multiple polyps along all parts of the colon were diagnosed at the age of 3 years, following an episode of a severe abdominal pain and intestinal bleeding. The high-resolution comparative genomic hybridisation revealed a 3.7-Mb deletion within the 10q23 chromosomal region: 86,329,859-90,035,024. The genotyping with four polymorphic microsatellite markers confirmed a de novo 10q deletion on the allele with a paternal origin, encompassing both PTEN and BMPR1A genes. The karyotype analysis additionally identified a balanced translocation involving chromosomes 5q and 7q, and an inversion at chromosome 2, i.e. 46,XY,t(5;7)(q13.3-q36), inv(2)(p25q34). Although many genetic defects were detected, it is most likely that the 10q23 deletion is primarily the cause for the serious phenotypic manifestations. The current clinical findings and deletion of BMPR1A indicate a diagnosis of severe juvenile polyposis, but the existing macrocephaly and PTEN deletion also point to either CS or BRRS, which cannot be ruled out at the moment because of their clinical manifestation later in life and the de novo character of the deletion. The deletion detected in our patient narrows the genetic region deleted in all reported cases with juvenile polyposis by 0.04 Mb from the telomeric side, mapping it to the region chr10:88.5-90.03Mb (GRCh37/hg19), with an overall length of 1.53 Mb.

A new case with 10q23 interstitial deletion encompassing both PTEN and BMPR1A narrows the genetic region deleted in juvenile polyposis syndrome

We report on a patient with a contiguous interstitial germline deletion of chromosome 10q23, encompassing BMPR1A and PTEN, with clinical manifestations of juvenile polyposis and minor symptoms of Cowden syndrome (CS) and Bannayan-Riley-Ruvalcaba syndrome (BRRS). The patient presented dysmorphic features as well as developmental delay at the age of 5 months. Multiple polyps along all parts of the colon were diagnosed at the age of 3 years, following an episode of a severe abdominal pain and intestinal bleeding. The high-resolution comparative genomic hybridisation revealed a 3.7-Mb deletion within the 10q23 chromosomal region: 86,329,859-90,035,024. The genotyping with four polymorphic microsatellite markers confirmed a de novo 10q deletion on the allele with a paternal origin, encompassing both PTEN and BMPR1A genes. The karyotype analysis additionally identified a balanced translocation involving chromosomes 5q and 7q, and an inversion at chromosome 2, i.e. 46,XY,t(5;7)(q13.3-q36), inv(2)(p25q34). Although many genetic defects were detected, it is most likely that the 10q23 deletion is primarily the cause for the serious phenotypic manifestations. The current clinical findings and deletion of BMPR1A indicate a diagnosis of severe juvenile polyposis, but the existing macrocephaly and PTEN deletion also point to either CS or BRRS, which cannot be ruled out at the moment because of their clinical manifestation later in life and the de novo character of the deletion. The deletion detected in our patient narrows the genetic region deleted in all reported cases with juvenile polyposis by 0.04 Mb from the telomeric side, mapping it to the region chr10:88.5-90.03Mb (GRCh37/hg19), with an overall length of 1.53 Mb.