Toxoplasma serotype is associated with development of ocular toxoplasmosis.

BACKGROUND: Worldwide, ocular toxoplasmosis (OT) is the principal cause of posterior uveitis, a severe, life-altering disease. A Toxoplasma gondii enzyme-linked immunoassay that detects strain-specific antibodies present in serum was used to correlate serotype with disease. METHODS: Toxoplasma serotypes in consecutive serum samples from German uveitis patients with OT were compared with non-OT seropositive patients with noninfectious autoimmune posterior uveitis. OT patients were tested for association of parasite serotype with age, gender, location, clinical onset, size, visual acuity, or number of lesions (mean follow-up, 3.8 years) to determine association with recurrences. RESULTS: A novel, nonreactive (NR) serotype was detected more frequently in serum samples of OT patients (50/114, 44%) than in non-OT patients (4/56, 7%) (odds ratio, 10.0; 95% confidence interval 3.4-40.8; P < .0001). Non-OT patients were predominantly infected with Type II strains (39/56; 70%), consistent with expected frequencies in Central Europe. Among OT patients, those with NR serotypes experienced more frequent recurrences (P = .037). Polymerase chain reaction detected parasite DNA in 8/60 OT aqueous humor specimens but failed to identify Type II strain alleles. CONCLUSIONS: Toxoplasma NR and Type II serotypes predominate in German OT patients. The NR serotype is associated with OT recurrences, underscoring the value of screening for management of disease.

A Rare Case of Persistent Multifocal Cribriform-Morular Thyroid Carcinoma.

Background/Objective: Cribriform-morular thyroid carcinoma (CMTC) was considered a variant of papillary thyroid carcinoma (PTC) but is a separate entity in the 2022 World Health Organization classification. CMTC has an association with familial adenomatous polyposis (FAP). Our objective is to report a case of CMTC who was subsequently diagnosed with FAP, to highlight these associated entities and implications for management. Case Report: A 15-year-old female with a history of iron-deficiency anemia and alpha-gal syndrome presented with several years of goiter and dysphagia. She also noted unintentional weight loss, abdominal pain, melena and hematochezia, and symptomatic anemia. Physical examination was significant for multiple thyroid nodules. Laboratory results revealed normal thyroid function and iron deficiency. Multiple nodules were visualized on thyroid ultrasound, and fine needle aspiration biopsy was consistent with PTC. Total thyroidectomy was performed with a revised diagnosis of multifocal CMTC, with administration of adjuvant radioactive iodine due to persistent disease. Genetic testing confirmed FAP and she was referred for upper endoscopy, colonoscopy, and an evaluation for colectomy. Discussion: There are no best practice guidelines for management of CMTC. Management of CMTC is guided by FAP status; sporadic cases can be managed with hemithyroidectomy, while FAP-associated cases are better managed with total thyroidectomy. Recurrence is usually managed with surgical resection. The decision to treat with adjuvant radioactive iodine is often extrapolated from management of classic PTC. Conclusion: Thyroid carcinoma in the setting of extensive family history of colorectal carcinoma should arouse suspicion for CMTC. Patients with CMTC should receive a referral for colonoscopy and genetic testing for FAP.

Sex-Specific Expression of Histone Lysine Demethylases (KDMs) in Thyroid Cancer.

BACKGROUND: The incidence of thyroid cancer in women is 3-4-fold higher than in men. To characterize sex-specific molecular alterations in thyroid cancer, we examined the expression of sex-biased genes in normal thyroids and thyroid tumors. METHODS: Ingenuity pathways analysis was used to define sex-biased gene networks using data from the Cancer Genome Atlas (TCGA). Confirmatory studies were performed through the analysis of histone lysine demethylases (KDMs) expression by real-time PCR and immunostaining. RESULTS: In normal thyroids, 44 sex-biased genes were comparatively upregulated in male and 28 in female patients. The expressions of 37/72 (51%) sex-biased genes were affected in cancer tissues compared with normal thyroids. Gene network analyses revealed sex-specific patterns in the expressions of KDM5C, KDM5D, and KDM6A. In confirmatory studies, KDM5D mRNA and protein were detected only in males, whereas KDM5C and KDM6A were detected in samples from male and female patients. Nuclear staining with anti-KDMs was found in normal thyroids, but a loss of nuclear expression with a concomitant gain of cytoplasmic staining was observed in cancer tissues. CONCLUSIONS: Normal thyroids have a sex-specific molecular signature, and the development of thyroid cancer is associated with a differential expression of sex-biased genes. The sex-specific expression of KDMs, coupled with cancer-related alterations in their intracellular localization, may contribute to mechanisms underlying sex differences in thyroid tumorigenesis.

Sex Differences in Differentiated Thyroid Cancer.

Background: Sex dimorphism strongly impacts tumor biology, with most cancers having a male predominance. Uniquely, thyroid cancer (TC) is the only nonreproductive cancer with striking female predominance with three- to four-fold higher incidence among females, although males generally have more aggressive disease. The molecular basis for this observation is not known, and current approaches in treatment and surveillance are not sex specific. Summary: Although TC has overall good prognosis, 6-20% of patients develop regional or distant metastasis, one third of whom are not responsive to conventional treatment approaches and suffer a 10-year survival rate of only 10%. More efficacious treatment strategies are needed for these aggressive TCs, as tyrosine kinase inhibitors and immunotherapy have major toxicities without demonstrable overall survival benefit. Emerging evidence indicates a role of sex hormones, genetics, and the immune system in modulation of both risk for TC and its progression in a sex-specific manner. Conclusion: Greater understanding of the molecular mechanisms underlying sex differences in TC pathogenesis could provide insights into the development of sex-specific, targeted, and effective strategies for prevention, diagnosis, and management. This review summarizes emerging evidence for the importance of sex in the pathogenesis, progression, and response to treatment in differentiated TC with emphasis on the role of sex hormones, genetics, and the immune system.

Do Molecular Profiles of Primary Versus Metastatic Radioiodine Refractory Differentiated Thyroid Cancer Differ?

Management of metastatic radioiodine refractory differentiated thyroid cancer (DTC) can be a therapeutic challenge. Generally, little is known about the paired molecular profile of the primary tumor and the metastases and whether they harbor the same genetic abnormalities. The present study compared the molecular profile of paired tumor specimens (primary tumor/metastatic sites) from patients with radioiodine refractory DTC in order to gain insight into a possible basis for resistance to radioiodine. Twelve patients with radioiodine refractory metastases were studied; median age at diagnosis of 61 years (range, 25-82). Nine patients had papillary TC (PTC), one had follicular TC (FTC), and two had Hürthle cell TC (HTC). Distant metastases were present in the lungs (n = 10), bones (n = 4), and liver (n = 1). The molecular profiling of paired tumors was performed with a panel of 592 genes for Next Generation Sequencing, RNA-sequencing, and immunohistochemistry. Digital microfluidic PCR was used to investigate TERT promoter mutations. The genetic landscape of all paired sites comprised BRAF, NRAS, HRAS, TP53, ATM, MUTYH, POLE, and NTRK genes, including BRAF and NTRK fusions. BRAF V600E was the most common point mutation in the paired specimens (5/12). TERT promoter mutation C228T was detected in one case. PD-L1 expression at metastatic sites was highly positive (95%) for one patient with HTC. All specimens were stable for microsatellite instability testing, and the tumor mutation burden was low to intermediate. Therefore, the molecular profile of DTC primary and metastatic lesions can show heterogeneity, which may help explain some altered responses to therapeutic intervention.

The p110α and p110ß isoforms of class I phosphatidylinositol 3-kinase are involved in toll-like receptor 5 signaling in epithelial cells.

BACKGROUND: Bacterial flagellin triggers inflammation in mammalian cells via Toll-like receptor (TLR) 5. Release of the chemokine IL-8 in response to flagellin involves NF-κB, p38 MAP kinase, and phosphatidylinositol 3-kinase (PI3K). However, PI3K has been reported to be either pro- or anti-inflammatory in different model systems. We hypothesized that this could be due to different activities of the p110α and ß isoforms of PI3K. RESULTS: PI3K and Akt were rapidly activated in Caco-2 colon carcinoma cells by flagellin. Using a plasmid-based shRNA delivery system and novel p110 isoform-specific inhibitors, we found that flagellin-induced IL-8 production was dependent on both p110α and p110ß. However in the mouse, inhibition of p110ß but not p110α reduced the increase of serum IL-6 levels induced by intraperitoneal injection of flagellin. CONCLUSIONS: These data demonstrate that the p110α and ß isoforms of class IA PI3K are both required for the proinflammatory response to flagellin.

Clinical, Pathological, and Molecular Profiling of Radioactive Iodine Refractory Differentiated Thyroid Cancer.

Background: Six to 20% of thyroid cancer (TC) patients develop distant metastases, and one-third become radioiodine refractory (RAIR). Available targeted therapies increase progression-free survival but are associated with toxicities. This study aims to characterize clinical, pathological, and molecular profiles of patients with RAIR TC. Methods: Data of TC patients seen during 2013-2017 at two tertiary care centers were retrospectively analyzed. Patients were considered RAIR according to American Thyroid Association guidelines. The control cohort was sex matched and age matched and had either regression or stable disease (by Response Evaluation Criteria in Solid Tumors) on follow-up at least three years after initial therapy. Molecular profiles on a subset of RAIR patients were reviewed. Results: Compared with 22 matched controls, 54 RAIR patients had an average age of 57 years (standard deviation [SD] = 13), 56% were male (41% in the control group); the average tumor size was 4 cm (SD = 2.5); tumors were multifocal in 54%, with involved surgical margins in 42%, focal invasion in 79%, and extrathyroidal extension (ETE) in 61%. Sixty-six percent had distant metastases at initial presentation with metastases to the lungs in 85%, bone in 56%, both sites in 43%, brain in 9%, and liver in 4%. There were no statistically significant differences between RAIR and controls in tumor size, focal invasion, ETE, and histology. The RAIR group received a higher cumulative radioactive iodine (RAI) dose and number of therapies compared with the controls (518 mCi vs. 302 mCi, p = 0.002 and 2.2 vs. 1.3 treatments, p = 0.001). Overall, patients >46 years had 4.5 times higher odds ratio (OR) of being RAIR; white race/ethnicity was associated with a reduced OR of RAIR disease (OR 0.33, p = 0.079). Molecular profiling data in the RAIR subgroup indicated that 50% of patients harbored mutations in the RAS/RAF pathway (11/22). Among 19 patients with a more extensive molecular panel, median tumor mutational burden was 5 megabase (range 3-16) and 26% (5/19) exhibited strong PD-L1 positivity. Conclusion: Among patients with metastatic differentiated thyroid carcinomas, patients with RAIR have similar histopathological and clinical characteristics as patients with RAI avid cancer. The risk of having RAIR TC is increased at age ≥46 and reduced in Caucasians.

Cholesterol in Alzheimer's disease.

Alzheimer's disease (AD) is the most common form of neurodegenerative dementia and affects up to 15 million people worldwide. Although no single cause of AD has been identified, recent research has suggested that several pathogenetic factors influence risk and expression. A growing amount of evidence underscores a mechanistic link between cholesterol metabolism in the brain and the formation of amyloid plaques. Excess brain cholesterol has been associated with increased formation and deposition of amyloid-beta peptide from amyloid precursor protein. Cholesterol-lowering statins have become a focus of research in AD. Genetic polymorphisms associated with pivotal points in cholesterol metabolism in brain tissues may contribute to the risk and pathogenesis of AD. In this review, we summarise current knowledge of the role of cholesterol metabolism in the pathogenesis of AD and examine the potential of statins in the prevention and treatment of AD.

Protein kinase D interaction with TLR5 is required for inflammatory signaling in response to bacterial flagellin.

Protein kinase D (PKD), also called protein kinase C (PKC)mu, is a serine-threonine kinase that is involved in diverse areas of cellular function such as lymphocyte signaling, oxidative stress, and protein secretion. After identifying a putative PKD phosphorylation site in the Toll/IL-1R domain of TLR5, we explored the role of this kinase in the interaction between human TLR5 and enteroaggregative Escherichia coli flagellin in human epithelial cell lines. We report several lines of evidence that implicate PKD in TLR5 signaling. First, PKD phosphorylated the TLR5-derived target peptide in vitro, and phosphorylation of the putative target serine 805 in HEK 293T cell-derived TLR5 was identified by mass spectrometry. Furthermore, mutation of serine 805 to alanine abrogated responses of transfected HEK 293T cells to flagellin. Second, TLR5 interacted with PKD in coimmunoprecipitation experiments, and this association was rapidly enhanced by flagellin treatment. Third, pharmacologic inhibition of PKC or PKD with Gö6976 resulted in reduced expression and secretion of IL-8 and prevented the flagellin-induced activation of p38 MAPK, but treatment with the PKC inhibitor Gö6983 had no significant effects on these phenotypes. Finally, involvement of PKD in the p38-mediated IL-8 response to flagellin was confirmed by small hairpin RNA-mediated gene silencing. Together, these results suggest that phosphorylation of TLR5 by PKD may be one of the proximal elements in the cellular response to flagellin, and that this event contributes to p38 MAPK activation and production of inflammatory cytokines in epithelial cells.