OP0297 EFFICACY AND SAFETY OF ROMOSOZUMAB AMONG POSTMENOPAUSAL WOMEN WITH OSTEOPOROSIS AND MILD-TO-MODERATE CHRONIC KIDNEY DISEASE

Background:

Osteoporosis and renal insufficiency are coexisting disease states in a substantial proportion of postmenopausal women. Since bisphosphonates are generally contraindicated in patients with estimated glomerular filtration rate (eGFR) <35 mL/min, it is important to evaluate other osteoporosis treatments in this setting.

Objectives:

To determine if baseline renal function affects the efficacy and safety of romosozumab.

Methods:

We performed post hoc analyses of two clinical trials of romosozumab in postmenopausal women with osteoporosis. In ARCH (NCT01631214), 4,093 patients were randomised 1:1 to romosozumab 210 mg monthly or alendronate 70 mg weekly for 12 months (mean age: 74.3 years; 96.1% with prevalent vertebral fractures [VFx]). In FRAME (NCT01575834), 7,180 patients were randomised 1:1 to romosozumab 210 mg or placebo monthly for 12 months (mean age: 70.9 years; 18.3% with prevalent VFx). For these analyses, patients were categorised by baseline eGFR (mL/min/1.73m2): normal renal function (eGFR ≥90), mild renal insufficiency (eGFR 60–89), or moderate renal insufficiency (eGFR 30–59). Least squares mean (LSM) percent change from baseline in bone mineral density (BMD) at the lumbar spine, total hip, and femoral neck; incidence of new VFx and adverse events (AEs); and changes in renal function were assessed for each eGFR category at Month 12 of the double-blind treatment period.

Results:

At baseline, most patients had mild/moderate renal insufficiency: 84% in ARCH, 88% in FRAME. In both studies, change from baseline in BMD was significantly higher in the romosozumab group across baseline eGFR categories (Figure). There was an interaction between BMD increase and renal function, and although BMD increase was not as large in women with impaired renal function, differences between romosozumab and control groups remained significant (Figure). In ARCH, among patients with eGFR ≥90, 60–89, and 30–59, the incidence of new VFx (romosozumab vs alendronate) at Month 12 was 3.3% vs 7.3%, 3.2% vs 3.9%, and 3.4% vs 6.2% in ARCH. In FRAME, the incidence of new VFx (romosozumab vs placebo) at Month 12 was 0.5% vs 3.0%, 0.4% vs 1.5%, and 0.6% vs 2.1%.

In both studies, the incidences of AEs and serious AEs were similar in both treatment groups within and across eGFR categories. AEs of mild-to-moderate hypocalcaemia (investigator reported) occurred in two patients in ARCH (one romosozumab [eGFR 60–89] and one alendronate [eGFR ≥90]), and one patient in FRAME (romosozumab [eGFR 60–89]). Five patients in ARCH (all in the alendronate group) and 19 patients in FRAME (14 romosozumab, 5 placebo) had decreases in serum Ca levels (albumin adjusted); in the romosozumab group all were mild (<LLN–8.0 mg/dL) or moderate (<8.0–7.0 mg/dL). A similar percentage of patients in each group had changes in renal function over 12 months of treatment.

Conclusion:

The efficacy and safety of romosozumab vs alendronate or placebo was similar among postmenopausal women with osteoporosis and different levels of renal function.

Acknowledgments:

This study was funded by Amgen, Astellas and UCB Pharma. Editorial services were provided by Costello Medical.

Disclosure of Interests:

Paul Miller Grant/research support from: Amgen, Radius Health, Ultragenyx, Consultant of: Amgen, Radius Health, Jonathan Adachi Consultant of: Amgen, Speakers bureau: Amgen, Ben-Hur Albergaria Consultant of: Amgen Inc., Eli Lilly, Speakers bureau: Amgen Inc., Eli Lilly, Angela M Cheung Consultant of: Amgen, Eli Lilly, Arkadi Chines Shareholder of: Amgen Inc., Employee of: Amgen Inc., Evelien Gielen Consultant of: Amgen Inc., Takeda, Sandoz and UCB Pharma, Speakers bureau: Amgen Inc., Takeda, Sandoz and UCB Pharma, Bente Langdahl Grant/research support from: Amgen, NovoNordisk, Consultant of: Amgen Inc., Eli Lilly, UCB Pharma, Akimitsu Miyauchi Consultant of: Amgen Inc., Astellas BioPharma K.K., Teijin Pharma, Mary Oates Shareholder of: Amgen Inc., Employee of: Amgen Inc., Ian Reid Consultant of: Amgen Inc., Eli Lilly, Speakers bureau: Amgen Inc., Eli Lilly, Norma Ruiz Santiago Shareholder of: Amgen Inc., Employee of: Amgen Inc., Mark Vanderkelen Employee of: UCB Pharma, Wenjing Yang Shareholder of: Amgen Inc., Employee of: Amgen Inc., Zhigang Yu Shareholder of: Amgen Inc., Employee of: Amgen Inc.

Novel biallelic SZT2 mutations in 3 cases of early-onset epileptic encephalopathy

The seizure threshold 2 (SZT2) gene encodes a large, highly conserved protein that is associated with epileptogenesis. In mice, Szt2 is abundantly expressed in the central nervous system. Recently, biallelic SZT2 mutations were found in 7 patients (from 5 families) presenting with epileptic encephalopathy with dysmorphic features and/or non-syndromic intellectual disabilities. In this study, we identified by whole-exome sequencing compound heterozygous SZT2 mutations in 3 patients with early-onset epileptic encephalopathies. Six novel SZT2 mutations were found, including 3 truncating, 1 splice site and 2 missense mutations. The splice-site mutation resulted in skipping of exon 20 and was associated with a premature stop codon. All individuals presented with seizures, severe developmental delay and intellectual disabilities with high variability. Brain MRIs revealed a characteristic thick and short corpus callosum or a persistent cavum septum pellucidum in each of the 2 cases. Interestingly, in the third case, born to consanguineous parents, had unexpected compound heterozygous missense mutations. She showed microcephaly despite the other case and previous ones presenting with macrocephaly, suggesting that SZT2 mutations might affect head size.

Low-risk papillary microcarcinoma of the thyroid: A review of active surveillance trials

Papillary microcarcinoma (PMC) of the thyroid is defined as papillary thyroid carcinoma (PTC) measuring ≤1 cm. Many autopsy studies on subjects who died of non-thyroidal diseases reported latent small thyroid carcinoma in up to 5.2% of the subjects. A mass screening study for thyroid cancer in Japanese adult women detected small thyroid cancer in 3.5% of the examinees. This incidence was close to the incidence of latent thyroid cancer and more than 1000 times the prevalence of clinical thyroid cancer in Japanese women reported at that time. The question of whether it was correct to treat such PMCs surgically then arose. In 1993, according to Dr. Miyauchi's proposal, Kuma Hospital initiated an active surveillance trial for low-risk PMC as defined in the text. In 1995, Cancer Institute Hospital in Tokyo, Japan, started a similar observation trial. The accumulated data from the trials at these two institutions strongly suggest that active surveillance (i.e., observation without immediate surgery) can be the first-line management for low-risk PMC. Although our data showed that young age and pregnancy might be risk factors of disease progression, we think that these patients can also be candidates for active surveillance, because all of the patients who showed progression signs were treated successfully with a rescue surgery, and none of them died of PTC. In this review, we summarize the data regarding the active surveillance of low-risk PMC as support for physicians and institutions that are considering adopting this strategy.

Cytological features of solid variants of papillary thyroid carcinoma: a fine needle aspiration cytology study of 18 cases

OBJECTIVE

Solid variants of papillary thyroid carcinoma (SV-PTC) are rare, and there have been few reports describing the cytological findings of such variants.

METHODS

The cytological features of cellular specimens aspirated from 18 histologically confirmed SV-PTC cases were evaluated, retrospectively.

RESULTS

Solid and small papillary clusters were observed in 14 (77.8%) and 13 (72.2%) cases, respectively. The incidences of large papillary clusters (11.1%) and sheet-like arrangements (11.1%) were low. Nuclear features were consistent with conventional PTC. The background was clean, and there were no colloid materials, foamy histiocytes, multinucleated giant cells, psammoma bodies, or necrotic materials.

CONCLUSIONS

Solid clusters and small papillary clusters in conjunction with a clean background are diagnostic clues that indicate SV-PTC cytologically. It is thought that small papillary clusters reflect the micropapillary growth pattern seen within the lumen of middle-sized follicular structures. The presence of nuclear findings typical of conventional PTC and the absence of mitotic figures and necrotic materials are important for distinguishing SV-PTC from poorly differentiated carcinoma.

Association of the C–509→T polymorphism, alone or in combination with the T869→C polymorphism, of the transforming growth factor-β1 gene with bone mineral density and genetic susceptibility to osteoporosis in Japanese women

Transforming growth factor-beta1 is an important local regulator of bone metabolism, acting downstream of estrogen and cooperatively with vitamin D. The possible association of a C 509-->T polymorphism in the promoter region of the transforming growth factor-beta1 gene, alone or in combination with a T869-->C (Leu10-->Pro) polymorphism, with bone mineral density and genetic susceptibility to osteoporosis was investigated in 625 postmenopausal Japanese women. The frequencies of the CC, CT, and TT genotypes of the C-509-->T polymorphism in the study population were 24%, 49%, and 27%, respectively. A significant association of C-509-->T genotype with bone mineral density was detected: lumbar spine (L2-L4) and total body bone mineral density values were 7% and 5% lower, respectively, in individuals with the TT genotype than in those with the CT or CC genotype. The serum concentration of transforming growth factor-beta1 did not vary with C-509-->T genotype. Multivariable logistic regression analysis, with adjustment for age, height, body weight, time since menopause, smoking status, body fat mass, and lean mass, revealed a significantly higher frequency of the TT genotype of the C-509-->T polymorphism in 286 individuals with osteoporosis than in 170 normal controls. Analysis of combined C-509-->T and T869-->C genotypes showed that L2-L4 bone mineral density decreases and the prevalence of osteoporosis increases with the number of T alleles. These results suggest that the C-509-->T polymorphism, alone or in combination with the T869-->C polymorphism, of the transforming growth factor-beta1 gene is a genetic determinant of bone mass, and that the number of T alleles in the combined genotype is a risk factor for the genetic susceptibility to osteoporosis in postmenopausal Japanese women.

Diffuse sclerosing variant of papillary thyroid carcinoma: a study of fine needle aspiration cytology in 20 patients

BACKGROUND

A diffuse sclerosing variant of papillary thyroid carcinoma (DSV-PTC) is a rare variant and reports describing the cytological findings are few.

PATIENTS AND METHODS

We studied 24 cytological samples from thyroid fine needle aspirates of 20 patients with DSV-PTC. The specimens were taken from 14 non-nodular lesions and 10 nodules.

RESULTS

All aspirates taken from both non-nodular lesions and nodules had sufficient cellularity. The carcinoma cells frequently (70-100%) appeared as solid cell balls and hollow balls, and showed a hobnail pattern, squamous differentiation, septate cytoplasmic vacuoles and large unilocular vacuoles. Most of the carcinoma cells seem to be taken from the lumen of dilated lymph vessels. Ground glass nuclear chromatin, intranuclear cytoplasmic inclusions and grooved nuclei were infrequent (50% or less). In the background, a large number of lymphocytes and abundant psammoma bodies were almost always seen.

CONCLUSIONS

Cytological findings of DSV-PTC are as follows: (1) solid cell balls and/or hollow balls containing lymphocytes; (2) hobnail cells; (3) septate cytoplasmic vacuoles; (4) large unilocular vacuoles; (5) squamous differentiation; (6) abundant psammoma bodies; (7) lymphocytic background; and (8) the absence or relative lack of characteristic nuclear features of papillary carcinoma. When DSV-PTC is suspected by ultrasound examination, the aspiration cytology from a non-nodular area of the thyroid can led us to the diagnosis of the variant.

Identification of Hic-5 as a novel regulatory factor for integrin αIIbβ3 activation and platelet aggregation in mice

BACKGROUND

Integrin αIIbβ3 plays key roles in platelet aggregation and subsequent thrombus formation. Hydrogen peroxide-inducible clone-5 (Hic-5), a member of the paxillin family, serves as a focal adhesion adaptor protein associated with αIIbβ3 at its cytoplasmic strand.

OBJECTIVES

Hic-5 function in αIIbβ3 activation and subsequent platelet aggregation remains unknown. To address this question, platelets from Hic-5(-/-) mice were analyzed.

METHODS AND RESULTS

Hic-5(-/-) mice displayed a significant hemostatic defect and resistance to thromboembolism, which were explained in part by weaker thrombin-induced aggregation in Hic-5(-/-) platelets. Mechanistically, Hic-5(-/-) platelets showed limited activation of αIIbβ3 upon thrombin treatment. Morphological alteration in Hic-5(-/-) platelets after thrombin stimulation on fibrinogen plates was also limited. As a direct consequence, the quantity of actin co-immunoprecipitating with the activated αIIbβ3 was smaller in Hic-5(-/-) platelets than in wild-type platelets.

CONCLUSION

We identified Hic-5 as a novel and specific regulatory factor for thrombin-induced αIIbβ3 activation and subsequent platelet aggregation in mice.

Deletion of thyrotropin receptor residue Asp403 in a hyperfunctioning thyroid nodule provides insight into the role of the ectodomain in ligand-induced receptor activation

Somatic mutations of the TSH receptor (TSHR) gene are the main cause of autonomously functioning thyroid nodules. Except for mutations in ectodomain residue S281, all of the numerous reported activating mutations are in the TSHR membrane-spanning region. Here, we describe a patient with a toxic adenoma with a novel heterozygous somatic mutation caused by deletion of ectodomain residue Asp403 (Del-D403). Subsequent in vitro functional studies of the Del-D403 TSHR mutation demonstrated greatly increased ligand-independent constitutive activity, 8-fold above that of the wild-type TSHR. TSH stimulation had little further effect, indicating that the mutation produced near maximal activation of the receptor. In summary, we report only the second TSHR ectodomain activating mutation (and the first ectodomain deletion mutation) responsible for development of a thyroid toxic adenoma. Because Del-D403 causes near maximal activation, our finding provides novel insight into TSHR structure and function; residue D403 is more likely to be involved in the ligand-mediated activating pathway than in the ectodomain inverse agonist property.

Extent of hypoechogenic area in the thyroid is related with thyroid dysfunction after subacute thyroiditis

OBJECTIVE

To gain an insight into risk factors for hypothyroidism after subacute thyroiditis (SAT), we examined the correlation between initial laboratory and ultrasonographic findings and sequential thyroid dysfunction among treatment modalities.

PATIENTS

We reviewed retrospectively the medical records of 252 patients (26 men and 226 women) with SAT who consecutively visited our thyroid clinic at Kuma Hospital for at least 6 months from 1996 through 2004.

RESULTS

Throughout the course, 135 patients (53.6%) developed transient or permanent hypothyroidism. Levels of TSH were most often elevated (greater than 5 IU/ml) 2 months after SAT onset regardless of treatment, and 97.0% of patients who showed transient or permanent hypothyroidism clustered within 6 months from onset. During follow-up, patients treated with prednisone (PSL) were more likely to have normal thyroid function than patients not treated or those receiving anti-inflammatory drug therapy. In patients who developed hypothyroidism with PSL treatment or without treatment, the rates of bilateral hypoechogenic areas (HEA) were 6-fold higher than those of unilateral HEA. Moreover, permanent hypothyroidism occurred in 5.9% of patients, and all patients with permanent hypothyroidism presented initially with bilateral HEA and had consequently small thyroid size with or without abnormal autoimmunity.

CONCLUSIONS

The rates of thyroid dysfunction after SAT were significantly lower in patients receiving PSL. Extent of HEA in the thyroid, but not laboratory findings, may be a possible marker for developing thyroid dysfunction after SAT.

Analgesic and Chondroprotective Effects of Risedronate in Osteoarthritis Assessed by Electroalgometry and Measurement of Collagen Type II Fragments in Urine

We evaluated the effect of the bisphosphonate, risedronate, on pain and cartilage metabolism in 33 patients with osteoarthritis of the knee, randomized into two groups. Group RC was treated with risedronate (2.5 mg/day) and calcium (900 mg/day); group C received calcium (900 mg/day) alone. Pain on exercise was estimated using a subjective visual rating scale (VRS) and an electroalgometric method of measuring decrease in skin impedance, previously shown to be indicative of pain. We measured urinary excretion of cartilage-specific collagen type II fragments as a marker of cartilage degradation. Multiple regression analysis revealed that pain alleviation as measured by skin impedance, but not VRS, was associated with a decrease in collagen fragment excretion. This suggests that, for pain evaluation, reduction in skin impedance may have a greater physiological basis compared with VRS-based evaluation. We consider that the chondroprotective and analgesic effects of risedronate may be related.

Increased expression levels of tensin3 mRNA in thyroid functional adenomas as compared to non-functioning adenomas

Tensin3 is a member of tensin family which is localized in focal adhesion. In our previous study, a high level of tensin3 mRNA expression was observed in the thyroid but not in other tissues, thus, tensin3 gene was regarded as a novel thyroid-specific gene. The high expression level of tensin3 mRNA in normal thyroid tissue suggests some fundamental roles in thyroid functions. In fact, the expression level of tensin3 mRNA was low in most thyroid carcinomas and non-functioning thyroid follicular adenomas which do not produce thyroid hormone. In the present study, we measured the expression levels of tensin3 mRNA in twelve functional adenomas and compared the results with those in normal thyroid tissues, adenomatous goiters and non-functioning thyroid follicular adenomas. Tensin3 mRNA was expressed abundantly in all twelve functional adenomas at almost the same level as in normal thyroid tissues and adenomatous goiters, while its expression was significantly lower in non-functioning follicular adenomas. Considering these facts, an abundant expression of tensin3 mRNA is observed in tissues that produce thyroid hormone, which suggests some fundamental roles in basic thyroid functions.

BRAF V600E mutation in anaplastic thyroid carcinomas and their accompanying differentiated carcinomas

Frequency of a BRAF^V600E mutation in anaplastic thyroid carcinoma, which is thought to be derived mainly from papillary carcinoma by multi-step carcinogenesis, is much lower than that in papillary carcinomas. To clarify this phenomenon, we analysed BRAF^V600E mutation in 20 cases of anaplastic carcinoma and 13 accompanying differentiated carcinomas. Among twenty cases of anaplastic carcinomas, nine and four accompanied papillary and follicular carcinomas, respectively. BRAF^V600E mutation was found in four (20%) cases. BRAF^V600E mutation was found in three of nine (33.3%), none of four and one of seven (14.3%) anaplastic carcinomas with papillary carcinoma, follicular carcinoma and without differentiated components, respectively. All three papillary carcinomas accompanied by anaplastic carcinoma with a BRAF^V600E mutation were also shown to have a BRAF^V600E mutation. In summary, BRAF^V600E mutation was occasionally observed in anaplastic carcinomas with papillary carcinoma, and the low frequency of BRAF^V600E mutation in anaplastic carcinoma was thought to be due to the low frequency of anaplastic carcinomas with papillary carcinoma. These findings raise a question about the classical model of anaplastic transformation and suggest some roles of thyroid cancer stem cells in the generation of anaplastic carcinoma.

A review of 227 cases of small papillary thyroid carcinoma

AIMS

To review differences in biological aggressiveness, clinical behaviors or selected surgical treatments between the PMC and the slightly larger PTC of 1.0<T<or=2.0 cm.

METHODS

Two hundred and twenty-seven cases of papillary thyroid carcinoma not larger than 2.0 cm, diagnosed and treated at the Kuma Hospital, Kobe, Japan, with a 10-year follow-up from 1992 to 2003, were reviewed.

RESULTS

The small PTCs demonstrated excellent outcomes, and persistent/recurrent disease was identified in only nine patients (4%). None of the patients died of the disease. A multivariate analysis revealed that massive extrathyroidal extension at presentation was the only independent prognostic factor for locoregional recurrence. Subdivision into PMCs and slightly larger tumors (1<T<or=2 cm) did not affect the excellent outcomes, but the patients in the latter subgroup received more lymph node surgery and displayed more aggressive clinico-histological features such as higher rates of extrathyroidal extension, lymph node metastasis, loss of polarity, invasive growth pattern and loss of cohesiveness.

CONCLUSIONS

Small PTC not larger than 2.0 cm could be considered as favorable a prognosis as PMC.

Multiple activation of mitogen-activated protein kinases by purified independent CCN2 modules in vascular endothelial cells and chondrocytes in culture

CCN2 consists of 4 distinct modules that are conserved among various CCN family protein members. From the N-terminus, insulin-like growth factor binding protein (IGFBP), von Willebrand factor type C repeat (VWC), thrombospondin type 1 repeat (TSP1) and C-terminal cysteine-knot (CT) modules are all aligned tandem therein. The multiple functionality of CCN2 is thought to be enabled by the differential use of these modules when interacting with other molecules. In this study, we independently prepared all 4 purified module proteins of human CCN2, utilizing a secretory production system with Brevibacillus choshinensis and thus evaluated the cell biological effects of such single modules. In human umbilical vascular endothelial cells (HUVECs), VWC, TSP and CT modules, as well as a full-length CCN2, were capable of efficiently activating the ERK signal transduction cascade, whereas IGFBP was not. In contrast, the IGFBP module was found to prominently activate JNK in human chondrocytic HCS-2/8 cells, while the others showed similar effects at lower levels. In addition, ERK1/2 was modestly, but significantly activated by IGFBP and VWC in those cells. No single module, but a mixture of the 4 modules provoked a significant activation of p38 MAPK in HCS-2/8 cells, which was activated by the full-length CCN2. Therefore, the signals emitted by CCN2 can be highly differential, depending upon the cell types, which are thus enabled by the tetramodular structure. Furthermore, the cell biological effects of each module on these cells were also evaluated to clarify the relationship among the modules, the signaling pathways and biological outcomes. Our present results not only demonstrate that single CCN2 modules were potent activators of the intracellular signaling cascade to yield a biological response per se, while also providing new insight into the module-wise structural and functional relationship of a prototypic CCN family member, CCN2.

Two cases of subacute thyroiditis presenting in pregnancy

Subacute thyroiditis (SAT) is an extremely rare cause of thyrotoxicosis in pregnant women. Untreated, thyrotoxicosis may result in complications, such as prematurity and congenital malformations in the fetus. We report two cases of first trimester subacute thyroiditis, one mild and one severe. The severe case, as demonstrated by laboratory and ultrasound findings, was successfully treated with prednisolone. In this case, it was thought that the benefits of pharmacological therapy outweighed the risk of potential teratogenesis by the medication. In contrast, the milder case was managed conservatively and resolved without treatment. These cases illustrate how laboratory and ultrasound findings can be used to determine whether treatment should be initiated and, once begun, if medication levels need to be adjusted. In both cases, the pregnancies resulted in healthy full-term infants.

Restriction of dietary Iodine does not ameliorate the early effect of anti-thyroid drug therapy for Graves' disease in an area of excessive iodine intake

The close relationship between iodine intake and the effects of anti-thyroid drugs (ATD) for Graves' disease (GD) has been well established. However, it remains unknown whether restriction of dietary iodine improves the effect of ATD. This study aimed to clarify this issue in Japanese patients with GD who routinely ingest large amounts of dietary iodine. We performed a prospective clinical study in 81 patients with newly diagnosed GD who were divided into an iodine restricted group and a control group. Urinary iodine, thyroid hormones and TSH receptor antibody were measured during the first 8 weeks of ATD therapy. Urinary iodine concentrations in the iodine restricted group were significantly lower than in the control group (p=0.043). However, there were no significant differences in the decrease of thyroid hormones and TSH receptor antibody between the two groups. Restriction of dietary iodine does not ameliorate the effect of ATD therapy for GD in an area of excessive iodine intake.

Expression of S100A2 and S100A6 in thyroid carcinomas

AIMS

S100 calcium-binding proteins are known to play multiple roles in carcinoma development. In this study, we focused on two kinds of these proteins, S100A2 and S100A6, and investigated their expression in thyroid neoplasms.

METHODS AND RESULTS

We investigated S100A2 and S100A6 expression in 141 thyroid neoplasms by immunohistochemistry. S100A2 was not expressed in normal follicles or follicular tumours, with one exception. Although 89.5% of papillary carcinoma were positive for S100A2, the expression was heterogeneous except in two cases. In anaplastic carcinoma, 78.5% of cases expressed S100A2 diffusely, while the remaining cases were negative. In normal follicles, S100A6 expression was always low, while 8.3% of follicular adenomas and 39.5% of follicular carcinomas showed increased expression. In papillary carcinomas, S100A6 expression was increased in 75% of cases, but in anaplastic carcinomas it was decreased, with only 14.3% showing high expression.

CONCLUSIONS

The expression patterns of S100A2 and S100A6 in thyroid neoplasms are unique compared with those of other carcinomas, suggesting that: (i) S100A2 and S100A6 contribute to certain events in papillary carcinoma progression, and (ii) S100A2 expression is one of the biological characteristics of anaplastic carcinoma.

Tie-1 tyrosine kinase expression in human thyroid neoplasms

AIMS

To investigate tie-1 expression in human thyroid neoplasms. Recent studies have demonstrated that receptor-type tyrosine kinases (RTKs) contribute to carcinoma progression. Tie-1 is one of the RTKs and plays a role in angiogenesis, although its pathophysiological significance in human carcinoma is still to be elucidated.

METHODS AND RESULTS

Immunohistochemical expression of tie-1 was studied in various thyroid neoplasms. Tie-1 immunoreactivity was only occasionally observed in normal follicular cells. In papillary carcinoma, tie-1 was classified as positive in carcinoma cells in 55.7% of the cases and was more frequently expressed in those of smaller size with an absence of a poorly differentiated lesion. In contrast, tie-1 was positive in only 8.3% of anaplastic carcinoma and no cases of follicular carcinoma or adenoma were positive.

CONCLUSIONS

These results suggest that tie-1 has a role in thyroid tumorigenesis, especially in the early phase of papillary carcinoma, but it is not important in the progression of anaplastic carcinoma or follicular tumour.

Papillary carcinoma of the thyroid in Japan: subclassification of common type and identification of low risk group

AIMS

Papillary thyroid carcinoma (PTC) is classified into two subgroups-common type and other histological variants. Correlations between further subgrouping of the common type and patient prognosis are not well documented.

AIMS

To introduce two novel histological parameters to characterise PTC-loss of cellular polarity and loss of cellular cohesiveness. To investigate a new subgroup of common type PTC with possible prognostic value.

METHODS

In total, 213 patients with PTCs larger than 1 cm were studied. Histological characteristics of these PTCs, including tumour growth pattern, encapsulation, extrathyroidal invasion, loss of cellular polarity, and loss of cellular cohesiveness were examined and correlated with disease free survival (DFS).

RESULTS

Multivariate analysis revealed that invasive growth of unencapsulated PTC, in addition to sex (male) and tumour size (>4 cm) were significant and independent parameters for poor DFS, whereas loss of cellular polarity and cohesiveness, old age (>60 years), extrathyroid invasion, and completeness of surgery were significant only in univariate analysis. PTCs that showed expansive growth and retained cellular polarity had a favourable course, with no recurrence and no cancer related deaths. In contrast, PTCs exhibiting loss of cellular polarity and/or invasive growth with no tumour capsule had a higher risk of recurrence.

CONCLUSION

Cytological features alone cannot predict patient outcome in PTC. This study indicates for the first time that loss of cellular polarity and the tumour growth pattern are useful parameters for identifying the so called low risk group in common type PTC and in predicting patient outcome in terms of tumour recurrence and cancer related death.

Lower concentration of serum soluble CD8 in severe Hashimoto's disease

To investigate the roles of soluble CD4 (sCD4) and CD8 (sCD8) in the severity of autoimmune thyroid diseases, we examined serum concentrations of sCD4 and sCD8 in various degrees of severity of Hashimoto's disease (HD) and Graves' disease (GD) by enzyme immunoassay. The serum concentration of sCD8 was lower in euthyroid patients with HD undergoing treatment for hypothyroidism (severe HD) than in untreated, euthyroid patients with HD (mild HD), but the sCD4 concentration did not differ between patients with severe and mild HD. The serum sCD8 concentration was negatively correlated with the proportion of CD25(+) cells in CD8(+) cells in patients with severe HD. Serum sCD4 and sCD8 concentrations did not differ between euthyroid patients with GD in remission and those with intractable GD. These results indicate that serum sCD8 is involved in the severity of HD, possibly by down-regulating the function of cytotoxic T cells.

Decrease of CD154 intensity on peripheral CD4+ T cells in autoimmune thyroid disease

To clarify immunological differences among patients with Graves' disease (GD) and Hashimoto's disease (HD) at various levels of severity, we examined the expression of the CD154 molecules on peripheral T cells, which regulate B cell activation, B cell differentiation, and T-cell survival. We found decreases in the intensities of CD154 on peripheral CD4(+) cells from euthyroid patients with GD and HD, but we did not find any differences between patients with different disease severities. CD8(+) cells did not express CD154 molecules. Thus, CD154 expression on CD4(+) cells may be related to the pathogenesis of the autoimmune thyroid diseases, not to the disease severity.

High-throughput differential screening of mRNAs by serial analysis of gene expression: decreased expression of trefoil factor 3 mRNA in thyroid follicular carcinomas

To find mRNAs whose expression differs between thyroid follicular adenomas and carcinomas, a high-throughput analysis of mRNAs in these two tumours was performed. This method, named high-throughput differential screening by serial analysis of gene expression (HDSS), combines a modified method of serial analysis of gene expression (SAGE) and real-time quantitative reverse transcription polymerase chain reaction (RT-PCR). A total of 40 candidate tag sequences that showed extremely different expression levels between a follicular carcinoma and a follicular adenoma in the SAGE analysis were analysed by real-time quantitative RT-PCR, using RNAs from an additional four typical follicular carcinomas and adenomas. One sequence tag that represents trefoil factor 3 (TFF3) mRNA showed a clear difference in its expression level between adenomas and carcinomas. The expression levels of TFF3 mRNA in 48 follicular adenomas and 29 follicular carcinomas were measured by real-time quantitative RT-PCR using a specific probe for TFF3. They were significantly decreased in follicular carcinomas, especially in widely invasive types and those with evident metastases. These results indicate that the decreased expression of TFF3 mRNA is a marker of follicular carcinomas, especially those with a high risk of invasion or metastasis.

Parathyroid invasion, nodal recurrence, and lung metastasis by papillary carcinoma of the thyroid

AIMS

Parathyroid invasion by papillary thyroid carcinoma (PTC) is found in a small proportion of surgical specimens, but the clinicopathological relevance of this phenomenon is not well understood. This study investigated the possible prognostic relevance of parathyroid invasion in PTC.

METHOD

Parathyroid involvement was seen in 14 patients with PTC, and the clinicopathological characteristics and follow up data of these patients were analysed and compared with 164 patients without parathyroid involvement, in whom histological parathyroid examination had been undertaken, and 177 other patients without parathyroid examination (341 patients without parathyroid involvement in total).

RESULTS

Parathyroid invasion was found in older patients and there were more male patients in this group than in those without parathyroid invasion. These patients had more extrathyroid extension and were frequently in an advanced stage of disease. Lung metastasis was seen in two of the 14 patients, which was significantly more than that seen in control cases. Moreover, male patients with parathyroid invasion and those who were older than 55 years had reduced disease free survival compared with those without parathyroid invasion.

CONCLUSION

Parathyroid invasion seen in thyroid carcinoma may be an important histological feature indicating a greater chance of nodal recurrence and lung metastasis.

PGP9.5 mRNA could contribute to the molecular-based diagnosis of medullary thyroid carcinoma

The protein gene product 9.5 (PGP9.5) is a ubiquitin hydrolase that is widely expressed in neuronal tissues at all stages of neuronal differentiation and is a known neuroendocrine marker. Medullary thyroid carcinoma (MTC) arises from parafollicular cells and is reported to overexpress several mRNAs such as RET, calcitonin, and CEA. These markers are thought to be useful in determining a molecular-based diagnosis of MTC. We examined the expression levels of PGP9.5 mRNA in 80 thyroid tissues using real-time quantitative reverse transcription (RT-PCR) and found that PGP9.5 mRNA was overexpressed in all 11 MTCs examined, both hereditary and sporadic, but not in other histological tumour types. Furthermore, by RT-PCR, PGP9.5 mRNA was detected only in aspirates from three medullary carcinomas, and not in aspirates from other tumour types. These results demonstrate that, in addition to the expression of RET, calcitonin and CEA, PGP9.5 mRNA expression may contribute to the molecular-based diagnosis of MTCs.

Polo-like kinase 1 overexpression is an early event in the progression of papillary carcinoma

Polo-like kinase 1 (PLK1) is one of the serine threonine kinases that contributes to cell mitosis and is regarded as a marker of cellular proliferation. However, its protein expression in human carcinoma has not been studied in depth. We investigated PLK1 expression in various thyroid neoplasms in order to elucidate its physiological significance in thyroid carcinoma. Normal follicular cells only occasionally expressed PLK1. In follicular tumours and anaplastic carcinoma, PLK1 overexpression was not a common event and only 5.9% of follicular adenoma, 7.1% of follicular carcinoma, and 11.8% of anaplastic carcinoma overexpressed this protein. However, 43.7% of papillary carcinoma overexpressed PLK1. Polo-like kinase 1 overexpression was more frequently observed in smaller papillary carcinoma lesions, and 62.5% of microcarcinoma (ranging from 4 mm to 1.0 cm) and even 66.7% of incidental carcinoma (less than 4 mm) overexpressed it, whereas this phenomenon could only be seen in 20.0% of lesions larger than 4.0 cm. Furthermore, PLK1 overexpression was not related to cell-proliferating activity evaluated by Ki-67 labelling index, but it was inversely linked to UICC stage, extrathyroidal invasion, and the presence of poorly differentiated lesion as proposed by Sakamoto et al. These findings strongly suggest that, unlike other carcinomas previously studied, PLK1 does not act as a cell cycle regulator but plays a constitutive role in papillary carcinoma especially in the early phase, and may contribute to the malignant transformation of this carcinoma.

Syndecan-1 expression in thyroid carcinoma: stromal expression followed by epithelial expression is significantly correlated with dedifferentiation

AIM

To investigate the expression of syndecan-1 in thyroid neoplasia. Syndecan-1 is a proteoglycan regulating cell adhesion. Previous studies have demonstrated that decreased expression of syndecan-1 is linked to malignant progression.

METHODS AND RESULTS

Syndecan-1 expression in thyroid neoplasia was studied immunohistochemically. Syndecan-1 was expressed in stromal cells as well as neoplastic epithelial cells. Stromal syndecan-1 expression was observed more frequently in papillary carcinomas larger than 10 mm in size than in microcarcinomas and in widely invasive than in minimally invasive follicular carcinomas. Furthermore, poorly differentiated carcinomas showed this phenomenon more than well-differentiated carcinomas, but the expression in undifferentiated carcinomas was similar to that of poorly differentiated carcinomas. Epithelial syndecan-1 expression was more frequently observed in anaplastic (undifferentiated) carcinomas than in papillary and follicular carcinomas. No significant difference in epithelial expression was found between well and poorly differentiated carcinomas, but undifferentiated carcinomas expressed epithelial syndecan-1 more frequently than did poorly differentiated carcinomas.

CONCLUSIONS

These results are in contrast to those previously reported for carcinomas at other sites. It is suggested that the role of syndecan-1 in thyroid carcinomas might be unique. Stromal syndecan-1 expression followed by its epithelial expression is significantly related to progression, including dedifferentiation of thyroid carcinoma.

Cyclooxygenase-2 expression in thyroid neoplasms

AIMS

Previous studies have demonstrated that cyclooxygenase-2 (COX-2) plays a role in carcinogenesis and carcinoma development. In this study, we investigated its expression in thyroid neoplasms in order to elucidate its role.

METHODS AND RESULTS

COX-2 expression was studied immunohistochemically in 20 anaplastic (undifferentiated) carcinomas, 49 papillary carcinomas, 22 follicular carcinomas and 15 follicular adenomas. Positive staining was only occasionally seen in normal follicles or stromal cells. COX-2 over-expression was found in only 20.0% of follicular adenomas and 40.9% of follicular carcinomas. In papillary carcinomas, the incidence (81.3%) was significantly higher (P < 0.0001) than in follicular carcinomas, although COX-2 expression was reduced in cases with old age (P = 0.0190), large size (P = 0.0028), advanced stage (P = 0.0225), satellite tumours (P = 0.0363), and the presence of solid, scirrhous or trabecular growth patterns (P = 0.0018). Undifferentiated carcinomas less frequently over-expressed COX-2 (P = 0.0004), with an incidence of 40.0%.

CONCLUSIONS

These results indicate that the up-regulation of COX-2 may contribute predominantly in the early phase of papillary carcinoma progression, whereas it plays a more adjuvant role in follicular carcinoma progression.

Expression of cdc25A and cdc25B proteins in thyroid neoplasms

Cdc25B and cdc25A phosphates are prominent stimulators of cell cycle progression and recent studies have also suggested their oncogenic roles. To elucidate the role of these proteins in thyroid neoplasms, we immunohistochemically investigated their expression, and neither protein was expressed in normal follicular cells. Cdc25B was frequently overexpressed in follicular adenoma and minimally invasive follicular carcinoma, but the incidence was significantly lower in widely invasive follicular carcinoma. Furthermore, the cdc25B expression level significantly decreased with the dedifferentiation of thyroid carcinoma. Cdc25A overexpression was observed in high incidences in all types of thyroid neoplasms. These results suggest that cdc25B and cdc25A play oncogenic roles in thyroid follicules and that cdc25B works predominantly in the early phase of the progression of thyroid carcinoma, whereas cdc25A plays a fundamental role in the development of thyroid neoplasms.

Caveolin-1 overexpression is an early event in the progression of papillary carcinoma of the thyroid

Caveolin-1 is a major structural component of caveolae, which are plasma membrane microdomains implicated in the regulation of intracellular signalling pathways. Previous in vitro and in vivo studies on the function of caveolin-1 in carcinoma showed controversial results, indicating that the physiological role of caveolin-1 varies according to the origin of carcinoma. In this study, we investigated caveolin-1 expression in thyroid neoplasms by means of immunohistochemistry using a rabbit polyclonal antibody against caveolin-1. Normal follicular cells did not express caveolin-1. In papillary carcinoma, caveolin-1 expression was observed in high incidence, and especially in microcancer (less than 1.0 cm in diameter), caveolin-1 was positive in all cases except one. In undifferentiated (anaplastic) carcinoma, its incidence was significantly reduced. On the other hand, all cases of follicular carcinoma and adenoma were classified as negative for caveolin-1. These results suggest that caveolin-1 may play a role predominantly in the early phase of papillary carcinoma, whereas it has little influence on follicular tumours.

The role of calcium channels in osteocyte function

Osteocytic response to stretching, which is potentiated by PTH, is distinct from that of osteoblast to high frequency strain. A MAPK dependent signaling pathway is suggested in the osteoblast response. At least two different types of mechanotransduction pathways are present in bone cells of osteoblastic lineage.

Role of advanced glycation end products in adynamic bone disease in patients with diabetic nephropathy

Adynamic bone disease and elevated serum levels of advanced glycation end products (AGEs) often are found in patients with renal failure caused by diabetic nephropathy. To clarify the role of AGEs in adynamic bone disease, we investigated the effect of these substances on cultured human osteoblasts and parathyroid cells. After 72 hours of incubation with AGEs-bovine serum albumin (BSA) (1,000 microgram/mL), there was significant inhibition of the synthesis of type I collagen and osteocalcin in response to stimulation with 10(-10) to 10(-8) M of 1,25-dihydroxycholecalciferol. In a human osteoblastic cell line (MG 63), AGEs-BSA did not affect human osteocalcin promoter activity. In human parathyroid cells, a receptor for AGEs was detected by reverse-transcriptase polymerase chain reaction. Incubation with AGEs-BSA for 48 hours significantly inhibited parathyroid hormone secretion in response to a low calcium concentration of 0.81 mM (P < 0.01). In HEK-293 cells, expressing calcium-sensing receptors, the same AGE concentration caused a significant potentiation of the extracellular Ca(2+) induced-intracellular calcium concentration after 24 and 48 hours of incubation (P < 0.05 and P < 0.01). These data suggest that AGEs are involved in the pathogenesis of adynamic bone disease by inhibiting osteoblastic activity and by inhibiting parathyroid hormone secretion in response to hypocalcemia.

Differential expression of menin in various adrenal tumors. The role of menin in adrenal tumors

BACKGROUND

Adrenocortical tumors occur as sporadic tumors, as part of the multiple endocrine neoplasia type 1 (MEN1) syndrome, or as part of other hereditary disorders. MEN1 is a tumor suppressor gene located on chromosome 11q13 that encodes a 610-amino acid protein called menin, and plays an important role in the development of MEN1 syndrome. Recent reports indicate that heterozygous germline mutations of this gene are responsible for the disease onset of MEN1.

METHODS

To investigate the role of menin in sporadic adrenocortical tumors, the authors examined a series of adrenocortical adenoma cases and a single case of carcinoma and adrenomedulary tumors with the corresponding adjacent tumor tissues using reverse transcriptase-polymerase chain reaction (RT-PCR) for menin mRNA and Western blot analysis for menin protein. Both RNA and protein from these tumors were applied to RT-PCR and Western blot analysis, respectively, although they are not truly quantitative. Primers for RT-PCR were designed to amplify the sequence between exons 2 and 3 of the MEN1 gene. A specific antibody against menin was generated in guinea pigs immunized with the recombinant peptide from the amino acid residues 443-535 of menin made by using glutathione-S-transferase gene fusion.

RESULTS

Based on the results of RT-PCR and Western blot analysis, both MEN1 mRNA and menin protein appeared to be highly expressed in Cushing syndrome resulting from adrenocortical adenomas and carcinoma. However, their expression was found to be greatly decreased in primary aldosteronism compared with their expression in Cushing syndrome. Although weak expression of MEN1 mRNA also was detected in pheochromocytoma on RT-PCR, menin expression was not detected in any case of pheochromocytoma by Western blot analysis, possibly due to the lower sensitivity of this assay compared with RT-PCR. Neither MEN1 mRNA nor menin protein was detected in any of the corresponding adjacent tumor tissues examined.

CONCLUSIONS

The findings of the current study indicate that menin expression appears to be up-regulated in Cushing syndrome, suggesting that adrenocortical proliferation might be one of the primary lesions in the MEN1 syndrome in which menin might play a significant role in some specific cellular functions.

Spontaneous rupture of a parathyroid adenoma presenting as a massive cervical hemorrhage: report of a case

We report an unusual case of spontaneous rupture of a parathyroid adenoma causing cervical hemorrhage. A 60-year-old woman presented to our hospital after the sudden development of extensive ecchymosis of her neck and upper anterior chest wall. Computed tomography (CT) scanning revealed a hematoma in the left retrotracheal space, and laboratory examinations revealed significant hypercalcemia, hypophosphatemia, and a high level of intact parathyroid hormone. Primary hyperparathyroidism was diagnosed, but it was not until the hematoma had subsided, 4 months after her initial presentation, that a parathyroid adenoma was revealed by CT. An operation was performed, and a parathyroid adenoma with hemosiderin deposition was histologically diagnosed. Although this phenomenon is unusual, all endocrine surgeons should be well aware of the possibility of its occurrence.

Overexpression of kα1 tubulin mRNA in thyroid anaplastic carcinoma

The expression levels of (k)alpha1 tubulin in 84 benign and malignant thyroid tissues were measured by means of real-time quantitative reverse transcription-polymerase chain reaction. An increased expression of (k)alpha1 tubulin mRNA was observed in all of five anaplastic carcinomas and some of the papillary carcinomas. Expression levels of (k)alpha1 tubulin relative to thyroglobulin mRNA were slightly increased in papillary carcinomas and greatly increased in anaplastic carcinomas. Chemotherapeutic agents which are targeted to microtubules may be considered as an alternative choice for the treatment of anaplastic carcinomas and some differentiated carcinomas in which increased expression of (k)alpha1 mRNA is observed.

Quantitative measurement of thyroglobulin mRNA in peripheral blood of patients after total thyroidectomy

Previous studies have reported the clinical usefulness of reverse transcription-polymerase chain reaction (RT-PCR) detection of thyroglobulin (TG) mRNA in the peripheral blood of patients with differentiated thyroid carcinoma. To evaluate this usefulness, we measured TG mRNA in the peripheral blood of patients diagnosed with thyroid carcinoma after total thyroidectomy by real-time quantitative RT-PCR using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA as an internal control. Surprisingly, we detected TG mRNA in all samples obtained after total thyroidectomy, including those from 4 medullary carcinomas. Further, there was no statistical difference in expression levels of TG mRNA in the patients with or without metastasis, and no significant correlation was found between serum TG concentrations and the expression levels of TG mRNA. These results give rise to a question regarding the clinical applications of not only RT-PCR detection but also quantitative measurement of TG mRNA in peripheral blood.

Large-scale analysis of mutations in RET exon 16 in sporadic medullary thyroid carcinomas in Japan

Germline mutations in the RET proto-oncogene are the cause of multiple endocrine neoplasia type 2 (MEN 2A and 2B) and familial medullary thyroid carcinoma (FMTC). Some cases of sporadic medullary thyroid carcinoma (MTC) have also been reported to have mutations in the RET gene. However, two previous reports have given discrepant results on the frequency of the mutations in RET in sporadic MTCs in Japan. To clarify this problem, we analyzed mutations in RET exon 16 in 72 sporadic MTCs by means of the two methods used in the previous studies, direct sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Mutations in exon 16 were detected in only 2 of 72 cases of sporadic MTC. These results suggest that when a MTC has a mutation in RET exon 16, it is more likely to be a hereditary MTC than a sporadic one in Japan.

Extracts from tumors causing oncogenic osteomalacia inhibit phosphate uptake in opossum kidney cells

In oncogenic osteomalacia (OOM), a tumor produces an unknown substance that inhibits phosphate reabsorption in the proximal tubules. This causes urinary phosphate wasting and, as a consequence, hypophosphatemic osteomalacia. To characterize this poorly understood biological tumor activity we generated aqueous extracts from several OOM tumors. Extracts from three of four tumors inhibited, dose- and time-dependently, (32)P-orthophosphate uptake by opossum kidney (OK) cells; maximum inhibition was about 45% of untreated control. Further characterization revealed that the factor is resistant to heat and several proteases, and that it has a low molecular weight. The tumor extracts also stimulated cAMP accumulation in OK cells, but not in osteoblastic ROS 17/2.8 and UMR106 cells, or in LLC-PK1 kidney cells expressing the parathyroid hormone (PTH)/PTH-related peptide receptor or the PTH-2 receptor. HPLC separation of low molecular weight fractions of the tumor extracts revealed that the flow-through of all three positive tumor extracts inhibited (32)P uptake and stimulated cAMP accumulation in OK cells. Additionally, a second peak with inhibitory activity on phosphate transport, but without cAMP stimulatory activity, was identified in the most potent tumor extract. We have concluded that several low molecular weight molecules with the ability to inhibit phosphate transport in OK cells can be found in extracts from OOM tumors. It remains uncertain, however, whether these are related to the long-sought phosphaturic factor responsible for the phosphate wasting seen in OOM patients.

[Extremely high level of serum thyroglobulin after surgery in a patient with follicular thyroid carcinoma. Recurrence, distant metastasis, or other etiology?]

A 67-year-old female patient with a tumor of the thyroid underwent right lobectomy of the thyroid. The tumor was histologically diagnosed as a follicular carcinoma of the thyroid. Serum studies revealed very high (> 8,000 ng/ml) levels of thyroglobulin after surgery. We suspected distant metastases from follicular carcinoma or recurrence in the left lobe of the thyroid. She therefore underwent left lobectomy of the thyroid. No recurrence of follicular carcinoma was recognized in the resected thyroid tissue, but severe autoimmune thyroiditis was diagnosed histologically. Total-body 131I scintigraphy did not show abnormal distant uptake. Serum studies revealed very low levels of thyroglobulin (< 2.0 ng/ml) after the second surgery. We speculate that silent thyroiditis might have occurred after the first surgery, resulting in the high levels of serum thyroglobulin. Silent thyroiditis should be considered as a possible cause of high serum thyroglobulin levels.