Utility of Liquid-Based Cytology and Cell Block Procedure Obtained by Vitrectomy to Diagnose Ocular Sarcoidosis-The Significance of Epithelioid Granuloma and Epithelioid Cells.

Purpose: The eyes are one of the most frequently involved organs in sarcoidosis in Asia, including Japan. Sarcoid uveitis is the major complaint of ocular sarcoidosis. The detection of epithelioid granuloma (EG) requires histological biopsy of the uvea for the precise diagnosis of sarcoid uveitis, because it is challenging to diagnose sarcoid uveitis without a history of systemic sarcoidosis. To diagnose sarcoid uveitis, we have established novel methods. Patients and Methods: In this study, we included 30 eyes of 21 patients with granulomatous uveitis diagnosed via slit-lamp examinations, gonioscopy, fundus photography, and fluorescein angiography. Vitrectomy was performed to remove the vitreous opacity with vision loss. To examine vitreous cell components, we used liquid-based cytology (LBC). To detect EG in an intraocular irrigating solution, we collected vitreous cell components, and then the cell pellets were embedded in the cell block procedure. Results: Here, we demonstrated the usefulness of the histological detection of EG and epithelioid cells (ECs) in LBC from vitreous body specimens and in the cell block procedure from vitreous cell components in an intraocular irrigating solution. Our results showed that the detection rates of EG were 6.3% (1/16) in LBC and 9.1% (1/11) in the cell block procedure in the sarcoid uveitis-suspected group and 7.7% (1/13) in LBC and 28.6% (2/7) in the cell block procedure in the sarcoidosis group. We would discuss the specificity of the EG/EC detection of ocular sarcoidosis. Conclusion: Our methods are helpful in the precise diagnosis of ocular sarcoidosis and the control of the development of systemic sarcoidosis.

Outcomes and prognostic factors in canine epitheliotropic and nonepitheliotropic cutaneous T-cell lymphomas.

Canine cutaneous lymphoma is an uncommon lymphoma in dogs. Most canine cutaneous lymphoma cases have a T-cell origin. Canine cutaneous T-cell lymphoma (CTCL) is classified into epitheliotropic and nonepitheliotropic cutaneous lymphomas, and each type of lymphoma is subclassified into several histological subtypes. Limited information is available regarding the prognostic significance of clinical variables and histopathological subtypes in dogs with CTCL. This retrospective study aimed to investigate the influence of clinical variables and histopathological subtypes on the prognosis of dogs with CTCL. Forty-six dogs diagnosed with CTCL by histopathological examination were included. Histopathological specimens were reexamined and classified into CTCL subtypes. The influence of the type of skin lesion, histopathological subtype, haematological examination results and treatment response on the overall survival time (OS) was examined. Thirty-one dogs were diagnosed with epitheliotropic CTCL (mycosis fungoides in 28 dogs; pagetoid reticulosis in 3 dogs) and 15 dogs were diagnosed with nonepitheliotropic CTCL (anaplastic large T-cell lymphoma in 6 dogs; peripheral T-cell lymphoma, not otherwise specified, in 9 dogs). The OS of dogs diagnosed with epitheliotropic CTCL (141 days) was significantly shorter than that of dogs diagnosed with nonepitheliotropic CTCL (374 days). As clinical variables, the presence of neoplastic lymphocytes in peripheral blood, thrombocytopenia and initial chemotherapeutic response was related to prognosis. Our results demonstrated that histopathological subtype and several clinical variables were found to influence the prognosis of dogs with CTCL.

Renin-Angiotensin-Aldosterone System Inhibitors Prevent the Onset of Oxaliplatin-Induced Peripheral Neuropathy: A Retrospective Multicenter Study and in Vitro Evaluation.

Oxaliplatin (OXA) is used in chemotherapy for various cancer types and is associated with acute and chronic neurotoxicity. However, a preventive strategy for OXA-induced peripheral neuropathy (OIPN) and its underlying mechanism remain unclear. We examined the effects of renin-angiotensin-aldosterone system inhibitors (RAASIs) on OIPN by performing a retrospective multicenter study and an in vitro assay. We retrospectively evaluated electronic medical records of 976 patients who underwent one or more courses of OXA-containing regimens at Ehime, Okayama, and Tokushima University Hospitals. The primary endpoint was the incidence of OIPN during or after OXA administration. The effects of RAASIs and OXA on the neurite length in PC12 cells were determined. The combined administration of an OXA-containing regimen and RAASI significantly inhibited the cumulative incidence grade-2 or higher OIPN (log-rank test; p = 0.0001). RAASIs markedly suppressed the development of both acute and chronic OIPN (multivariate analysis; p = 0.017 and p = 0.011). In an in vitro assay, 10 µM OXA suppressed the neurite length; treatment with 1 µM aliskiren, spironolactone, 10 µM candesartan, and enalapril significantly restored neurite length to the control level. Moreover, 1 µM SCH772984 (a selective inhibitor of extracellular signal-regulated kinase, ERK1/2) and 500 µM SQ22536 (a cell-permeable adenylate cyclase (AC) inhibitor) markedly abolished neurite-extending effects of candesartan and enalapril. These results indicate that RAASIs possess preventive or therapeutic effects in acute and chronic OIPN, candesartan and enalapril may increase in the activity of ERK1/2 and AC in PC12 cells.

Surgical Outcomes of Rhegmatogenous Retinal Detachment with Different Peripheral Vitreous-Shaving Procedures.

PURPOSE: To compare the surgical outcomes of vitreous surgery for rhegmatogenous retinal detachment (RRD) after two different peripheral vitreous-shaving techniques are performed. METHODS: We reviewed 269 eyes with RRD that were treated with a 25-gauge vitrectomy by a single surgeon between June 2015 and May 2020. The exclusion criteria for the proposed air tamponade selection were as follows: more than two weeks since RRD onset, giant retinal tears, a history of complications following cataract surgery, high myopia, and proliferative vitreoretinopathy classified as grade C or higher. We examined the differences in the therapeutic effect between shaving under slit lamp microscope illumination (group A) and shaving under a wide-angle viewing system (group B). RESULTS: A total of 269 eyes were included in this study, with 146 eyes in group A and 123 eyes in group B. The primary anatomical success rates did not differ between group A (97.3%; 142/146 eyes) and group B (97.6%; 120/123 eyes; P = 0.102). However, the surgical time was significantly longer in group A (60.2 ± 17.1 min) than that in group B (46.9 ± 12.6 min) (P < 0.001). The multiple linear regression analysis revealed that surgical time was significantly correlated with using the wide-angle noncontact viewing system for vitreous shaving (adjusted R 2 = 0.248; beta [standard partial regression coefficient] = -0.447, P < 0.001), the number of retinal breaks (beta = 0.182, P = 0.001), and the quadrant of retinal detachment (beta = 0.205, P < 0.001). CONCLUSION: The surgical outcomes were similar regardless of the shaving procedure performed, and the surgical time was shortened by using the wide-angle noncontact viewing system for vitreous shaving.

Intraoperative Observation of a Macular Holes Using Optical Coherence Tomography.

PURPOSE: This study aimed to observe intraoperative changes in macular hole (MH) form using intraoperative optical coherence tomography (iOCT). METHODS: A total of 10 eyes from 10 patients with MH who underwent vitrectomy using iOCT from May 2015 to October 2015 at the Yamagata University Hospital were retrospectively evaluated. Accordingly, 25-gauge pars plana vitrectomy using iOCT with internal limiting membrane (ILM) peeling and sulfur hexafluoride gas tamponade was performed on each patient. During surgery, MHs were observed using iOCT over four points, namely, before posterior vitreous detachment (PVD) formation, after PVD formation, after ILM peeling, and after fluid-gas exchange. Thereafter, basal MH diameter and minimum aperture MH diameter were postoperatively analyzed. RESULTS: Before PVD formation, after PVD formation, after ILM peeling, and after fluid-gas exchange, the mean basal MH diameters were 690.7 ± 268.4, 683.3 ± 274.2, 683.7 ± 269.5, and 668.3 ± 261.4 µm, while the mean minimum aperture MH diameters were 278.3 ± 165.2, 283.0 ± 170.2, 257.0 ± 127.8, and 188.0 ± 105.0 µm, respectively. The mean minimum aperture MH diameter decreased significantly after fluid-gas exchange (one-way repeated measures ANOVA, p < 0.05). None of the patients exhibited intraoperative closure of the MHs. However, MH closure was confirmed in all patients after the surgery. CONCLUSION: None of the patients demonstrated intraoperative MHs closure. Accordingly, the minimum aperture MH diameter was the first change formation to close after fluid-gas exchange.

Peripheral Cystoid Degeneration Finding Using Intraoperative Optical Coherence Tomography in Rhegmatogenous Retinal Detachment.

PURPOSE: The interaction between the peripheral vitreous and retina is closely associated with the pathogenesis of rhegmatogenous retinal detachment (RRD). This study was conducted to examine the peripheral vitreous and retina in patients with RRD using intraoperative optical coherence tomography (iOCT). METHODS: This retrospective study included 50 eyes of 50 patients (mean age 59.42 ± 10.80 years) that underwent vitrectomy using iOCT for treating RRD at the Yamagata University Hospital between September 2015 and September 2016. Each patient underwent 25-gauge pars plana vitrectomy that was performed by a single surgeon. During vitreous shaving with ocular indentation, the iOCT findings of the peripheral vitreous and retina were recorded and analyzed postoperatively. RESULTS: In all patients, iOCT was able to detect the peripheral retina and vitreous around the vitreous base. Peripheral cystoid degeneration was detected on the peripheral retina of 27 eyes (54%). Furthermore, cystoid degeneration was detected around the retinal tear (5 patients), at the detached retinal area (8 patients), and at the attached retinal area (14 patients). CONCLUSION: iOCT enabled the evaluation of peripheral cystoid degeneration in patients with RRD. Cystoid degeneration might be associated with the pathogenesis of RRD.

Quantification of the peripheral vitreous after vitreous shaving using intraoperative optical coherence tomography.

OBJECTIVE: To evaluate the technique of peripheral vitreous shaving during vitrectomy, we measured the residual peripheral vitreous using intraoperative optical coherence tomography (iOCT). METHODS AND ANALYSIS: This retrospective study included 44 eyes that underwent 25-gauge pars plana vitrectomy with iOCT by a single surgeon. In all cases, the surgery was performed via ocular indentation. Cases in group A were treated with vitreous shaving under slit lamp microscope illumination, whereas cases in group B were treated with vitreous shaving under a wide-angle viewing system. Residual peripheral posterior vitreous-cortex detachment (PVD) was quantified by iOCT. RESULTS: iOCT image analysis enabled the visualisation of the angle formed between the retina and peripheral PVD around the vitreous base in all cases. After the completion of vitreous shaving, the mean length of the peripheral PVD was shorter in group A (961.7±214.7 µm) compared with group B (1925.3.7 ± 626.1 µm; p<0.01). CONCLUSION: iOCT enabled the quantification of the residual peripheral vitreous after vitreous shaving. The quantification of the residual peripheral vitreous after different shaving procedures will be important for advocating appropriate vitreous shaving in future.

Metastatic Orbital Tumor From Breast Ductal Carcinoma With Neuroendocrine Differentiation Initially Presenting as Ocular Symptoms: A Case Report and Literature Review.

Background: Orbital metastases from cancers of various organs can arise via the hematogenous route, and many originate from breast, prostate, and lung cancers. Such metastatic orbital tumors may be diagnosed before the primary tumor. We have encountered a case of breast ductal carcinoma with neuroendocrine differentiation that metastasized to the orbit and responded to chemotherapy, with improvement in visual function. Case Presentation: A woman in her fifties visited our ophthalmology department with a chief complaint of foreign body sensation and exophthalmos in her right eye. An elastic soft mass was palpated from the lateral orbit to the temporal region. A systemic examination revealed breast cancer and a metastatic orbital tumor. Excisional biopsy of the breast revealed a diagnosis of invasive ductal carcinoma with neuroendocrine differentiation, and immunohistochemical examination was negative for cytokeratin 7, making the case unusual. Chemotherapy was remarkably effective, and the tumor size decreased, resulting in improvement of visual function. Her general condition and quality of life are still good at present. We searched the PubMed English language literature focusing on metastatic orbital tumors from breast cancer in which ocular symptoms had been the initial presenting sign. No previous reports have documented neuroendocrine differentiation or cytokeratin 7 expression in isolated orbital metastases from breast cancer. Although it is not possible to be certain from this case alone, we speculated that some such cases might involve cytokeratin 7-negative invasive breast cancer with neuroendocrine differentiation. Conclusion: We have described our experience of a very rare case of cytokeratin 7 negative breast ductal carcinoma with neuroendocrine differentiation that metastasized to the orbit and formed a solitary giant tumor initially manifesting as ocular symptoms.

Preventive Effects of Renin-angiotensin System Inhibitors on Oxaliplatin-induced Peripheral Neuropathy: A Retrospective Observational Study.

PURPOSE: Oxaliplatin-induced peripheral neuropathy has remained an unresolved issue in clinical practice. Our previous study hypothesized that inhibition of the renin-angiotensin system (RAS) may produce a preventive effect on oxaliplatin-induced neuropathy. The aim of this study was to clarify whether RAS inhibitors prevent oxaliplatin-induced peripheral neuropathy. METHODS: This study retrospectively analyzed data from cancer patients who had received chemotherapy including oxaliplatin and were treated with or without RAS inhibitors. This retrospective observational study was conducted at Ehime University Hospital using electronic medical records from May 2009 to December 2016. The primary end point was the incidence of severe peripheral neuropathy during or after oxaliplatin treatment, according to the Common Terminology Criteria for Adverse Events, version 4.0. A multivariate Cox proportional hazards model analysis was used to identify risk factors. FINDINGS: A total of 150 patients were included in the study. The estimated incidence of peripheral neuropathy was 36.9% and 91.7% in the RAS inhibitor group and the non-RAS inhibitor group, respectively. The multivariate analysis using a Cox proportional hazards model showed that the RAS inhibitor group was slightly associated with a decreased risk of neurotoxicity (adjusted hazard ratio, 0.42 [95% CI, 0.18-0.99]; P = 0.048). IMPLICATIONS: The present findings suggest that RAS inhibitors have the ability to prevent oxaliplatin-induced peripheral neuropathy.

Risk factors for discontinuation of s-1 adjuvant chemotherapy for gastric cancer.

PURPOSE: The aim of this study was to clarify the risk factors for discontinuing tegafur/gimeracil/oteracil potassium (S-1) adjuvant chemotherapy following gastrectomy in patients with gastric cancer. METHODS: We retrospectively investigated patients with curatively-resected gastric cancer who received S-1 adjuvant chemotherapy. S-1 was administered orally at 80-120 mg/day, depending on body surface area, on days 1-28 every 6 weeks for 1 year. The dose and treatment schedule were modified at the clinicians' discretion, according to toxicity. RESULTS: Seventy-one patients were included in the study, 26 of whom discontinued S-1 therapy. The relapse-free survival rates in the S-1-completed and S-1-discontinuation groups at 5 years post-surgery were 88.1% and 55.8%, respectively. The overall survival rates in the S-1-completed and S-1-discontinuation groups at 5 years post-surgery were 89.4% and 59.8%, respectively. The hazard ratios for relapse and death were significantly lower in the S-1-completed group compared with those in the S-1-discontinuation group (0.18; p<0.001 and 0.19; p=0.002, respectively). Multivariate logistic regression analysis revealed that S-1 discontinuation was significantly associated with an initial overdose of S-1, having stage I cancer, creatinine clearance <66 mL/min, and a side effect of nausea. CONCLUSIONS: These results suggest that assessing renal function to avoid initial overdose of S-1, together with the early management of side effects, may support the continuation of S-1 adjuvant chemotherapy in patients with gastric cancer.

Contribution of corneal neovascularization to dendritic cell migration into the central area during human corneal infection.

Compared with the peripheral corneal limbus, the human central cornea lacks blood vessels, which is responsible for its immunologically privileged status and high transparency. Dendritic cells (DCs) are present in the central avascular area of inflamed corneas, but the mechanisms of their migration to this location are poorly understood. Here, we investigated the contribution of vessel formation to DC migration into the central cornea, and analyzed the DC chemotactic factors produced by human corneal epithelial (HCE) cells. Using human eyes obtained from surgical procedures, we then assessed vessel formation, DC distribution, and activin A expression immunohistochemically. The results demonstrated increased numbers of vessels and DCs in the central area of inflamed corneas, and a positive correlation between the number of vessels and DCs. Activin A was expressed in the subepithelial space and the endothelium of newly formed blood vessels in the inflamed cornea. In infected corneas, DCs were present in the central area but no vascularization was observed, suggesting the presence of chemotactic factors that induced DC migration from the limbal vessels. To test this hypothesis, we assessed the migration of monocyte-derived DCs toward HCE cell supernatants with or without lipopolysaccharide (LPS) stimulation of HCE cells and inflammatory cytokines (released by HCE cells). DCs migrated toward tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and activin A, as well as LPS-stimulated HCE cell supernatants. The supernatant contained elevated TNF-α, IL-6, and activin A levels, suggesting that they were produced by HCE cells after LPS stimulation. Therefore, vessels in the central cornea might constitute a DC migration route, and activin A expressed in the endothelium of newly formed vessels might contribute to corneal vascularization. Activin A also functions as a chemotactic factor, similar to HCE-produced TNF-α and IL-6. These findings enhance our understanding of the pathophysiology of corneal inflammation during infection.

"Pleats fold" technique of amniotic membrane transplantation for management of corneal perforations.

PURPOSE: The aim of this study was to examine the efficacy and surgical success rates of amniotic membrane (AM) transplantation performed for corneal perforation closure using a novel technique. METHODS: This study included 6 eyes from 6 patients with corneal perforation who had received AM transplantation between May 2011 and April 2012. The AM was collected from human placenta shortly after cesarean section. In surgery, the AM was folded into pleats and used to plug the wound using 10-0 nylon suture. The wound was then covered with an AM seal. After reepithelialization and AM scarring, sutures were removed. RESULTS: All 6 patients had successful wound closure with 1 surgery. One patient underwent optical keratoplasty later, and 1 patient required combined preserved sclera transplantation. The absolute value of astigmatism decreased to <3.50 diopters (D) 3 months after surgery and to <3.00 D 6 months after surgery in patients with peripheral AM transplants. The visual acuity gradually improved over the first 3 months after surgery, and visual acuity gains were maintained at the 6-month postoperative mark. CONCLUSIONS: The AM transplantation procedure may be an effective option for treating corneal perforations when the wound is circular or irregular, except for incised wounds. Our "Pleats Fold" AM transplantation technique can achieve definite closure and effectively repair wounds of various sizes. Postoperative astigmatic values were acceptable. Therefore, we recommend this procedure for repairing lesions <3 mm in diameter that do not involve the central cornea and that are infection free.

Association of PDGF-BB-induced thrombomodulin with the regulation of inflammation in the corneal and scleral stroma.

PURPOSE: The responses of corneal and scleral stromal cells to platelet-derived growth factor (PDGF)-BB were assessed and inflammatory reactions in the cornea and sclera were investigated. METHODS: Primary cultures of cells obtained from human subjects and strains derived from human corneal or scleral stromal cells (Cs3 and Sc1, respectively) were used. Changes in gene expression after 24 hours of exposure to 10 ng/mL PDGF-BB were analyzed with an Sc1 DNA microarray. The upregulation of several genes in Cs3 and Sc1 was confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. The expression of bioactive factors was detected immunohistochemically in nine different clinical specimens. RESULTS: DNA microarray analysis revealed that the gene encoding thrombomodulin (TM) was induced in Sc1 by PDGF-BB. RT-PCR confirmed that TM expression at the mRNA level was increased in both corneal and scleral stromal cells. At the protein level, TM expression was increased in scleral stromal cells, but not in corneal cells, and TM was detected in both the membrane and cytoplasmic compartments. TM was detected immunohistochemically in inflamed scleral and several corneal specimens. After TM stimulation, interleukin (IL)-18 transcription was increased in Sc1. CONCLUSIONS: PDGF-BB induced TM mRNA expression in scleral and corneal stromal cells, but Western blot analysis revealed the increase in TM expression only in the scleral cells. TM induced IL-18 in scleral stromal cells. A cascade involving these biologically active factors may regulate scleral and corneal inflammation. The results also reveal differences in the biological response of scleral and corneal stromal cells.

Cloning and characterization of cell strains derived from human corneal stroma and sclera.

PURPOSE: To establish human corneal stroma- and sclera-derived cells as models for studying diseases of the anterior segment of the eye. METHODS: Using a recombinant retrovirus system, we transfected human papilloma virus 16 E6 and E7 (HPV16 E6/E7) into human corneal stroma- and sclera-derived cells. The primary cells and established cell strains were characterized by assessing the mRNA expression of collagen, matrix metalloproteinase, and tissue inhibitor of metalloproteinase by reverse transcription-polymerase chain reaction. We also examined the effects of inflammatory cytokines on hyaluronan synthase expression and hyaluronan products. RESULTS: Both a corneal stroma-derived cell strain, Cs3, and a sclera-derived cell strain, Sc1, were obtained, and both cell strains could be passaged up to 25 times. The mRNA expression pattern observed in the primary cells was identical to that observed in the cell strains. Hyaluronan synthase 1 and 2 mRNAs were increased by transforming growth factor beta and platelet-derived growth factor BB. Significant differences were observed between the hyaluronan products with and without cytokine treatment. CONCLUSION: Cell strains derived from corneal stroma and sclera fibroblast cells can be established using HPV16 E6/E7 immortalized genes of the same origin. The phenotypic cell characteristics did not change after transfection, immortalization, or successive passages in culture.

Dehydroxymethylepoxyquinomicin, a novel nuclear Factor-kappaB inhibitor, enhances antitumor activity of taxanes in anaplastic thyroid cancer cells.

Nuclear factor kappaB (NF-kappaB), as an antiapoptotic factor, crucially affects the outcomes of cancer treatments, being one of the major culprits of resistance to chemotherapy. In this study, we investigated whether dehydroxymethylepoxyquinomicin (DHMEQ), a novel NF-kappaB inhibitor, can enhance antitumor activities of taxanes in anaplastic thyroid cancer (ATC) cells. Taxanes induced NF-kappaB activation in ATC cells, which could compromise the therapeutic effect of the drugs. However, DHMEQ, by inhibiting the nuclear translocation of NF-kappaB, completely suppressed the DNA binding capacities of NF-kappaB and lowered the levels of nuclear NF-kappaB protein. Compared with single treatment (either taxane or DHMEQ), the combined treatment strongly potentiated apoptosis, confirmed by cell survival assay; Western blotting for poly (ADP-ribose) polymerase, caspase 3, X-linked inhibitor of apoptosis, and survivin; and flow cytometry for annexin V. Furthermore, we also demonstrate for the first time that the combined treatment showed significantly greater inhibitory effect on tumor growth in a nude mice xenograft model. These findings suggest that taxanes are able to induce NF-kappaB activation in ATC cells, which could attenuate antitumor activities of the drugs, but inhibition of NF-kappaB by DHMEQ creates a chemosensitive environment and greatly enhances apoptosis in taxanes-treated ATC cells in vitro and in vivo. Thus, DHMEQ may emerge as an attractive therapeutic strategy to enhance the response to taxanes in ATCs.

Oncogenic role of miR-17-92 cluster in anaplastic thyroid cancer cells.

Micro RNAs (miRNAs) are non-coding small RNAs and constitute a novel class of negative gene regulators that are found in both plants and animals. Several miRNAs play crucial roles in cancer cell growth. To identify miRNAs specifically deregulated in anaplastic thyroid cancer (ATC) cells, we performed a comprehensive analysis of miRNA expressions in ARO cells and primary thyrocytes using miRNA microarrays. MiRNAs in a miR-17-92 cluster were overexpressed in ARO cells. We confirmed the overexpression of those miRNAs by Northern blot analysis in ARO and FRO cells. In 3 of 6 clinical ATC samples, miR-17-3p and miR-17-5p were robustly overexpressed in cancer lesions compared to adjacent normal tissue. To investigate the functional role of these miRNAs in ATC cells, ARO and FRO cells were transfected with miRNA inhibitors, antisense oligonucleotides containing locked nucleic acids. Suppression of miR-17-3p caused complete growth arrest, presumably due to caspase activation resulting in apoptosis. MiR-17-5p or miR-19a inhibitor also induced strong growth reduction, but only miR-17-5p inhibitor led to cellular senescence. On the other hand, miR-18a inhibitor only moderately attenuated the cell growth. Thus, we have clarified functional differences among the members of the cluster in ATC cells. In conclusion, these findings suggest that the miR-17-92 cluster plays an important role in certain types of ATCs and could be a novel target for ATC treatment.

A novel role for thyroid hormone receptor beta in cellular radiosensitivity.

Thyroid hormone receptors (THRs) widely govern cell growth, differentiation and metabolism acting in a ligand- and cofactor-dependent manner to modulate tissue-specific gene expression. Given a large variety of genes regulated by THRs and multiplicity of cellular processes potentially influenced by THRs, we addressed the role of THRB (thyroid hormone receptor beta) in cellular radiosensitivity. Wild-type and mutant THRB were overexpressed in several cell lines using an adenovirus-mediated gene delivery and their effects were examined after cell exposure to gamma-rays. Wild-type THRB decreased clonogenic survival of the cell lines with low levels of endogenous THRB, retarded their growth and synergized with radiation in decreasing proliferative potential and promoting cellular senescence. These changes were accompanied by the accumulation of p21 (CDKN1A, CIP1, WAF1) and p16 (CDKN2A, INK4a) inhibitors of cyclin-dependent kinases and by the decrease of Rb (retinoblastoma protein) phosphorylation. Mutant THRB produced a radioprotective effect, attenuated radiation-induced growth inhibition and cellular senescence. The results suggest that THRB may modulate cellular radiosensitivity and stress-induced senescence.

[Gene abnormalities in thyroid cancer].

A number of genetic abnormalities in oncogenes or anti-oncogenes have been identified in association with thyroid carcinogenesis. Especially, oncogenes such as ras mutation, ret/PTC and Braf mutation that constitutively activate MAP kinase pathway a refrequently found in papillary thyroid cancer. The p53 mutation aggravates differentiated thyroid cancers to anaplastic thyroid cancer. These gene alterations are studied not only to understand basically the mechanisms of oncogenesis but also to develop clinically genetic diagnosis or molecular target therapy. In this article, we review the genetic diagnostic methods and phenotype-genotype relationship of human thyroid cancers.

The cytoplasmic expression of MUC1 in papillary thyroid carcinoma of different histological variants and its correlation with cyclin D1 overexpression.

This study addressed the immunohistochemical expression of MUC1 in papillary thyroid carcinoma (PTC) of different histotypes, sizes, and morphological features of aggressiveness, and its correlation with the overexpression of cyclin D1, a target molecule of the Wnt pathway. MUC1 expression was examined in a total of 209 PTCs. Cytoplasmic MUC1 expression was elevated in the tall, columnar cell and oncocytic variants (100%), Warthin-like (78%), and conventional PTCs (61%), and in papillary microcarcinoma (PMC) with the conventional growth pattern (52%). On the contrary, it was low in the follicular variant (27%) of PTC and PMCs with follicular architecture (13%). Cytoplasmic MUC1 accumulation did not associate with any clinicopathological features except peritumoral lymphoid infiltration in PTCs and in PMCs with the conventional growth pattern. MUC1 staining correlated with cyclin D1 overexpression in conventional PTCs and PMCs and PMCs with follicular architecture. The results demonstrate that MUC1 expression varies broadly in different histological variants of PTC, being the lowest in tumors with follicular structure. In general, it does not prove to be a prognosticator of PTC aggressiveness. A high correlation between MUC1 and cyclin D1 implies MUC1 involvement in the Wnt cascade functioning in a large subset of human PTCs and PMCs.