DNA demethylase activity maintains intestinal cells in an undifferentiated state following loss of APC.

Although genome-wide hypomethylation is a hallmark of many cancers, roles for active DNA demethylation during tumorigenesis are unknown. Here, loss of the APC tumor suppressor gene causes upregulation of a DNA demethylase system and the concomitant hypomethylation of key intestinal cell fating genes. Notably, this hypomethylation maintained zebrafish intestinal cells in an undifferentiated state that was released upon knockdown of demethylase components. Mechanistically, the demethylase genes are directly activated by Pou5f1 and Cebpß and are indirectly repressed by retinoic acid, which antagonizes Pou5f1 and Cebpß. Apc mutants lack retinoic acid as a result of the transcriptional repression of retinol dehydrogenase l1 via a complex that includes Lef1, Groucho2, Ctbp1, Lsd1, and Corest. Our findings imply a model wherein APC controls intestinal cell fating through a switch in DNA methylation dynamics. Wild-type APC and retinoic acid downregulate demethylase components, thereby promoting DNA methylation of key genes and helping progenitors commit to differentiation.

A two-step model for colon adenoma initiation and progression caused by APC loss.

Aberrant Wnt/beta-catenin signaling following loss of the tumor suppressor adenomatous polyposis coli (APC) is thought to initiate colon adenoma formation. Using zebrafish and human cells, we show that homozygous loss of APC causes failed intestinal cell differentiation but that this occurs in the absence of nuclear beta-catenin and increased intestinal cell proliferation. Therefore, loss of APC is insufficient for causing beta-catenin nuclear localization. APC mutation-induced intestinal differentiation defects instead depend on the transcriptional corepressor C-terminal binding protein-1 (CtBP1), whereas proliferation defects and nuclear accumulation of beta-catenin require the additional activation of KRAS. These findings suggest that, following APC loss, CtBP1 contributes to adenoma initiation as a first step, whereas KRAS activation and beta-catenin nuclear localization promote adenoma progression to carcinomas as a second step. Consistent with this model, human FAP adenomas showed robust upregulation of CtBP1 in the absence of detectable nuclear beta-catenin, whereas nuclear beta-catenin was detected in carcinomas.

Thyroid eye disease presenting with superior rectus/levator complex enlargement.

Purpose: To describe the demographic and clinical characteristics of patients with thyroid eye disease (TED) who present with predominate superior rectus/levator complex involvement.Methods: A multi-institutional retrospective review was performed to identify patients with TED who presented with superior isolated or predominate rectus/levator involvement. Baseline and subsequent visits were reviewed to characterize the clinical course.Results: Nineteen patients were identified. All patients had imaging demonstrating an enlarged levator/superior rectus complex. At presentation, the mean clinical activity score (CAS) was 2.1 (range: 0-5). Nineteen (100%) patients had proptosis on the affected side. Lid abnormalities, including upper/lower eyelid retraction and ptosis were higher on affected side compared to the unaffected side. Eleven (58%) patients had vertical misalignment. Mean thyroid stimulating immunoglobulin (TSI) was 3.7 (range: 1-7.1). Mean follow-up time was 18 months (range: 0-60 months). At last follow-up, the mean CAS was 1.3 (range 0-5). Ten (53%) patients had proptosis. Eleven (58%) patients had vertical misalignment. Repeat imaging in eight patients showed interval enlargement of other extraocular muscles.Conclusions: The presentation of TED with superior rectus/levator complex enlargement may be under-appreciated. Orbital imaging, as well as laboratory evaluation, may help support a diagnosis of TED. In the setting of abnormal TSI and/or thyrotropin receptor antibody, presence of upper eyelid retraction, and an otherwise unremarkable laboratory and systemic evaluation, a presumptive diagnosis of TED may be made, and the patient can be followed closely, as he/she is likely to develop involvement of other extraocular muscles, consistent with a more typical presentation of TED.

Minimally invasive brow lifting techniques.

PURPOSE OF REVIEW: Aesthetic concerns about upper eyelid and brow position are very common in ophthalmic practice. Management of brow descent and devolumization requires an approach customized to each patient taking into consideration preoperative examination and patient desires. This article will review several minimally invasive techniques that can be used to address the needs of patients with mild-to-moderate brow ptosis. RECENT FINDINGS: Recent publications describe and analyse efficacy of several variations of browpexy techniques. SUMMARY: Browpexy techniques provide a minimally invasive way to provide stabilization and modest elevation of the lateral brow. They can enhance outcomes of upper eyelid surgery in patients with both functional and cosmetic brow ptosis, who desire to avoid the cost and morbidity of more formal brow lifting techniques.

A Survey of Current Blepharospasm Treatment Patterns Among Oculoplastic Surgeons.

PURPOSE: To determine the current practice pattern of ASOPRS members injecting onabotulinumtoxinA for Blepharospasm. METHODS: An invitation to participate in a web-based, anonymous survey was sent to current members of American Society of Ophthalmic Plastic and Reconstructive Surgeons (ASOPRS) via e-mail. The survey consisted of 9 questions and used the Research Electronic Data Capture online application. Institutional Review board approval was obtained for this study. RESULTS: Forty-one percent of ASOPRS members invited responded to the survey. The mean initial dose of onabotulinumtoxinA used was 22.5 units per side and the most common number of injection sites was greater than 7 per side. Only 12 of the 247 responding surgeons who treat benign essential blepharospasm with onabotulinumtoxinA reported that their initial injection pattern is with 3 or fewer sites per side as per the Food and Drug Administration (FDA)-approved recommendations. CONCLUSIONS: Survey of current trends in the management of blepharospasm with onabotulinumtoxinA by ASOPRS members showed that the mean initial dose used to treat blepharospasm patients was 22.5 (standard deviation ± 9.5 units, range 2.5 to 50 units per side). There is significant variation in the treatment doses. The majority of ASOPRS members do not follow the FDA-approved recommendation for dosing.

A 10-Year Review of the Management of Ocular Mucous Membrane Pemphigoid: A Private Practice Experience.

PURPOSE: Ocular mucous membrane pemphigoid (OcMMP) is a rare and potentially blinding condition for which consensus treatment guidelines do not exist. The purpose of this study was to assess the effectiveness and safety of various immunomodulatory agents in the treatment of OcMMP in a private practice setting. METHODS: We conducted a 10-year retrospective chart review of patients managed with OcMMP (n = 22). The median age at diagnosis was 73 (range: 35-91) years, and 59% (13/22) of patients were female. Visual acuity, Foster stage, and adverse effects (AEs) were documented. Treatment outcomes for each treatment episode were qualified at 3 months as complete response (CR), response (R), or failure (F). After 3 months, CR was then further subqualified as sustained CR, reactivation after initial CR, or AE after initial CR. The Fisher exact test P values were calculated for each outcome in comparison with mycophenolate. RESULTS: Twenty patients were treated with an immunomodulatory agent for a total of 55 treatment episodes. In comparison to dapsone, mycophenolate was more likely to achieve sustained CR (50% vs. 0%, P = 0.022) and R (100% vs. 50%, P = 0.007), and less likely to fail (0% vs. 50%, P = 0.007). Dapsone was also more likely to be discontinued because of AEs than mycophenolate (40% vs. 6%, P = 0.041). CONCLUSIONS: Mycophenolate is a superior first-line agent to dapsone in the treatment of OcMMP. Although not statistically significant, mycophenolate trends toward superiority over methotrexate as well. Mycophenolate is very effective when used in combination with rituximab. Azathioprine remains a reasonable second-line agent.

Erotic asphyxiation: May have you seeing double.

PURPOSE: If not recognized and treated promptly, nontraumatic orbital subperiosteal hemorrhage (NTSOH) can have serious sequelae including compressive optic neuropathy and permanent vision loss. The following case establishes erotic asphyxiation as a cause of NTSOH. OBSERVATIONS: A 29 year-old patient presented with diplopia and periorbital edema and ecchymosis. Complete ophthalmologic exam showed no optic neuropathy. Computed tomography of the orbits revealed a subperiosteal fluid collection in the right orbit. The patient had no risk factors for NTSOH, but after detailed questioning she admitted to participating in erotic asphyxiation prior to the onset of her symptoms. She was observed and subsequently lost to follow up. CONCLUSIONS AND IMPORTANCE: To the authors' knowledge, erotic asphyxiation as a cause of orbital subperiosteal hematoma has not been previously reported. Lack of knowledge about erotic asphyxiation amongst healthcare providers may contribute to hesitance to directly question patients about the practice. Clinicians should be aware of erotic asphyxiation as a potential cause of orbital subperiosteal hemorrhage.

Primary Epithelioid Sarcoma of Orbit: A Case Report and Review of the Literature.

Epithelioid sarcoma is a rare high-grade malignancy identified by Enzinger in 1970. It accounts for 1% of all reported soft tissue sarcomas and presents most commonly in distal upper extremities in young adults with a male predominance. At this time, there are only 5 previously reported cases of primary epithelioid sarcoma of the orbit. We present a primary orbital epithelioid sarcoma case of a patient who underwent orbital exenteration followed by external beam radiation treatment. Because the literature is limited, this is to our knowledge the largest descriptive analysis of cases of orbital epithelioid sarcoma. We also provide a detailed review of all the previously reported primary orbital epithelioid sarcoma cases, as well as a discussion on the use of postoperative radiation therapy for patients with epithelioid sarcoma. Surgical resection followed by adjuvant radiation therapy appears to be a safe option for local treatment of this rare malignancy, but further future studies are needed of this rare clinical situation in order to better understand and optimize treatment for patients with orbital epithelioid sarcoma.

Socioeconomic and Ethnic Disparities in Periocular Cutaneous Malignancies.

Cutaneous malignancies make up the majority of periocular tumors diagnosed and treated by ophthalmologists. In this review, we examine literature regarding ethnic and socioeconomic disparities in incidence and clinical outcomes of the three most common cutaneous periocular tumors: basal cell carcinoma, squamous cell carcinoma, and melanoma. In all three tumor types, the literature shows an increased incidence among two groups: those with lightly pigmented skin and those of higher socioeconomic status. While incidence is high in these groups, clinical outcomes for these patients tend to be good. Those with lower socioeconomic status and ethnic minorities, on the other hand, have a low incidence but are more likely to have poor clinical outcomes. These disparities are likely the result of both biologic and behavioral differences between patients and could provide opportunities for intervention to change risk perception and improve outcomes.

New perspectives on APC control of cell fate and proliferation in colorectal cancer.

Aberrant Wnt/beta-catenin signaling following loss of the tumor suppressor adenomatous polyposis coli (APC) is thought to initiate colon adenoma formation. Considerable evidence for this model has come from mouse models of Apc truncation where nuclear beta-catenin is detectable soon after loss of Apc. However, examination of tumors from familial adenomatous polyposis coli (FAP) patients has failed to confirm the presence of nuclear beta-catenin in early lesions following APC loss despite robust staining in later lesions. This observation presents the possibility that colon adenomas arise through a beta-catenin-independent function of APC. Additionally, there is a well established role for inflammation and specifically COX-2 and prostaglandin E2 in the progression of colorectal cancer. Here we review the current literature regarding the functions of APC in regulating WNT/beta-catenin signaling as well as its control of intestinal cell fate and differentiation. Further, we provide a brief commentary on our current understanding of the role that inflammation plays in colorectal tumorigenesis and how it fits in with APC dysfunction. Though there are currently contrasting models to explain colon tumorigenesis, our goal is to begin to reconcile data from multiple different model systems and provide a functional view into the initiation and progression of colon cancer.

Dual roles for adenomatous polyposis coli in regulating retinoic acid biosynthesis and Wnt during ocular development.

Congenital hypertrophy/hyperplasia of the retinal pigmented epithelium is an ocular lesion found in patients harboring mutations in the adenomatous polyposis coli (APC) tumor suppressor gene. We report that Apc-deficient zebrafish display developmental abnormalities of both the lens and retina. Injection of dominant-negative Lef reduced Wnt signaling in the lens but did not rescue retinal differentiation defects. In contrast, treatment of apc mutants with all-trans retinoic acid rescued retinal differentiation defects but had no apparent effect on the lens. We identified Rdh5 as a retina-specific retinol dehydrogenase controlled by APC. Morpholino knockdown of Rdh5 phenocopied the apc mutant retinal differentiation defects and was rescued by treatment with exogenous all-trans retinoic acid. Microarray analyses of apc mutants and Rdh5 morphants revealed a profound overlap in the transcriptional profile of these embryos. These findings support a model wherein Apc serves a dual role in regulating Wnt and retinoic acid signaling within the eye and suggest retinoic acid deficiency as an explanation for APC mutation-associated retinal defects such as congenital hypertrophy/hyperplasia of the retinal pigmented epithelium.

Prevention of toxin-induced intestinal ion and fluid secretion by a small-molecule CFTR inhibitor.

BACKGROUND & AIMS: The cystic fibrosis transmembrane conductance regulator (CFTR) provides an important apical route for Cl(-) secretion across intestinal epithelia. A thiazolidinone-type CFTR blocker (CFTR(inh)-172) reduced cholera toxin-induced fluid accumulation in mouse intestinal loops. Here, we characterize the efficacy and pharmacodynamics of CFTR(inh)-172 in blocking cAMP and cGMP induced Cl(-)/fluid secretion in rodent and human intestine. METHODS & RESULTS: CFTR(inh)-172 inhibited cAMP and cGMP agonist induced short-circuit current by >95% in T84 colonic epithelial cells (K(I) approximately 3 micromol/L) and in mouse and human intestinal sheets (K(I) approximately 9 micromol/L). A single intraperitoneal injection of CFTR(inh)-172 (200 microg) blocked intestinal fluid secretion in a rat closed-loop model by >90% for cholera toxin and >70% for STa Escherichia coli toxin. In mice, CFTR(inh)-172 (20 microg) inhibited cholera toxin-induced intestinal fluid secretion by 90% (persistence t(1/2) approximately 10 hours, K(I) approximately 5 microg) and STa toxin by 75% (K(I) approximately 10 microg). Tissue distribution and pharmacokinetic studies indicated intestinal CFTR(inh)-172 accumulation facilitated by enterohepatic circulation. An oral CFTR(inh)-172 preparation reduced fluid secretion by >90% in a mouse open-loop cholera model. CONCLUSIONS: A small molecule CFTR blocker markedly reduced intestinal ion and fluid secretion caused by cAMP/cGMP-dependent bacterial enterotoxins. CFTR inhibition may thus reduce fluid secretion in infectious secretory diarrheas.