Biomedical subjects

Takashi Uruno

Publications and source records attributed to Takashi Uruno.

46 records · Page 3Linked to original sources

PubMed2003

Y-box binding protein expression in thyroid neoplasms: its linkage with anaplastic transformation.

Recent studies have demonstrated that Y-box binding protein (YB-1) regulates the transcription of genes linked to carcinoma progression. In this study, we investigated the expression of this protein in thyroid neoplasms to elucidate its significance. The expression of YB-1 was immunohistochemically investigated using the monoclonal antibody for various thyroid neoplasms. Normal follicles did not overexpress YB-1, and only moderate overexpression of YB-1 was observed in some follicular tumors and papillary carcinoma, especially those of a larger size. In contrast, 92.9% of anaplastic carcinoma strongly overexpressed YB-1. YB-1 immunoreactivity was seen in both cytoplasms and cell nuclei, but the former was more predominant. These findings suggest that YB-1 plays a role in regulating the transcription as well as translation of genes contributing to the anaplastic transformation of thyroid carcinoma.

Adenocarcinoma, Follicular↗

PubMed2003

KAI1 expression in thyroid neoplasms: its linkage with clinicopathologic features in papillary carcinoma.

KAI1 is a metastasis suppressor gene located on human chromosome 11p11.2. Previous studies have shown that the down-regulation of KAI1 mRNA and decreased expression of its gene product are significantly linked to carcinoma progression, including metastatic ability. In this study, we investigated KAI1 protein expression in thyroid neoplasms. KAI1 overexpression was observed in 64.0% of papillary carcinoma cases, and the incidence was significantly higher than in cases of follicular carcinoma (20.0%) (p = 0.0001). In papillary carcinomas, decreased KAI1 expression was frequently observed in cases invading beyond the thyroid capsule (p = 0.001), as well as in lymph node metastases (p = 0.0047) and poorly differentiated lesions (p = 0.0299). Furthermore, in anaplastic carcinoma, the incidence of KAI1 overexpression was lower than in papillary carcinoma (p < 0.0001), and only 4.2% of the cases overexpressed this gene. These results suggest that KAI1 down-regulation is significantly related to the progression of papillary carcinoma, including lymph node metastasis, and its anaplastic transformation.

Adenocarcinoma, Follicular↗

PubMed2003

An observation trial without surgical treatment in patients with papillary microcarcinoma of the thyroid.

The recent prevalence of ultrasound-guided fine-needle aspiration biopsy has resulted in a marked increase in the number of patients with papillary microcarcinoma (maximum diameter, </= 10 mm) of the thyroid detected by this sophisticated tool. On the other hand, it is debatable whether patients with papillary microcarcinoma should always undergo surgery after diagnosis, because a high incidence of occult papillary carcinoma has been observed in autopsy studies. Thus, we proposed observation without surgical therapy as a treatment option in 732 patients diagnosed with papillary microcarcinoma by the above technique from 1993 to 2001. One hundred sixty-two patients chose observation and were classified as the observation group. During the follow-up period for patients in the observation group, more than 70% of tumors either did not change or decreased in size compared to their initial size at diagnosis. They enlarged by more than 10 mm in 10.2%, and lymph node metastasis in the lateral compartments appeared in only 1.2% of patients during follow-up. On the other hand, 570 patients chose surgical treatment at diagnosis and 56 patients in the observation group who underwent surgery after a period of follow-up were classified as the surgical treatment group. Of these 626 patients, lymph node dissection was performed in 594 patients, and metastasis was confirmed histologically in 50.5%. Multiple tumor formation was seen in 42.8% of patients. In this group, the rate of recurrence was 2.7% at 5 years and 5.0% at 8 years after surgery. Our preliminary data suggest that papillary microcarcinomas do not frequently become clinically apparent, and that patients can choose observation while their tumors are not progressing, although they are pathologically multifocal and involve lymph nodes in high incidence.

Adolescent↗

PubMed2003

Changes in serum TSH receptor antibody (TRAb) values in patients with Graves' disease after total or subtotal thyroidectomy.

TSH receptor antibodies (TRAb) are generally regarded as mediators of thyroid stimulation in Graves' disease. In addition, a high serum TRAb value during pregnancy is one of the risk factors for intrauterine death, prematurity, and fetal or neonatal hyperthyroidism. Recently, correlations between a high serum TRAb value and endocrine opthalmopathy were also suggested. Surgical resection of the thyroid is usually followed by a reduction of serum TRAb levels in variable degrees. The relation between the extent of the thyroidectomy and the degree of reduction is still controversial. In addition, the changes in the TRAb value after total thyroidectomy (TT) over a long period of time have never been studied. We studied the changes in serum TRAb values after TT and subtotal thyroidectomy (ST) for more than 7 years. Forty-one patients with Graves' disease underwent TT, and 99 patients underwent ST. The serum TRAb values and the ratio of the patients who achieved normal values among each group (normalization rates of TRAb) at 3 and 6 months, 1, 3, 5 and 7 years after surgery were compared between the TT group and ST group. The mean preoperative TRAb values were not significantly different between the TT and ST groups, and the mean TRAb values measured 3, 6 and 12 months after surgery were not significantly different between the groups. However, the TRAb values measured 3, 5 and 7 years after surgery were significantly (p<0.05) lower in the TT group than in the ST group (16.7 +/- 3.3% vs 28.0 +/- 2.6%, 12.6 +/- 3.4% vs 29.3 +/- 3.8%, 5.6 +/- 0.9% vs 25.4 +/- 4.1%, respectively). The normalization rates of TRAb were not significantly different between the groups until 1 year after surgery. However, the normalization rates 3, 5 and 7 years after surgery were significantly (p<0.05) higher in the TT group than in the ST group (65.7% vs 42.4%, 77.3% vs 46.7%, 100% vs 59.1%, respectively). The surgical complication rates of TT were similar to ST except for permanent hypoparathyroidism. TT is a treatment option for Graves' disease, especially in patients with a high TRAb value who wish to have children or who have Graves' opthalmopathy.

Adolescent↗

PubMedDate not supplied

Survivin expression is significantly linked to the dedifferentiation of thyroid carcinoma.

Survivin is a novel member of the apoptosis protein inhibitors, but according to previous reports, it is also significantly linked to cell proliferating activity. In this study, we investigated the expression of survivin in thyroid neoplasms. Survivin was only occasionally expressed in normal follicular cells, whereas in follicular and papillary carcinomas, about 20% of cases were positive for survivin. The incidence was significantly higher in advanced stage papillary carcinoma (p=0.0080) and papillary and follicular carcinomas with poorly differentiated lesions (p=0.0150). In anaplastic carcinoma, survivin positivity was observed in 84% of the cases, which was in significantly higher incidence than in papillary or follicular carcinoma (p<0.0001). These results suggest that survivin is strongly related to the dedifferentiation of thyroid carcinoma.

Adenocarcinoma, Follicular↗

PubMedDate not supplied

Decreased expression of cyclin G2 is significantly linked to the malignant transformation of papillary carcinoma of the thyroid.

BACKGROUND: Cyclin G2 is a novel cyclin negatively regulating the cell cycle progression, contrary to the characteristics of conventional cyclins. However, little is known about the cyclin G2 expression in human carcinomas. We thus investigated cyclin G2 expression in human thyroid neoplasms. MATERIALS AND METHODS: We immunohistochemically examined cyclin G2 expression in 40 normal thyroids and 80 thyroid neoplasms. RESULTS: Normal thyroids expressed cyclin G2 in more than 5% of follicular cells. Of 30 papillary carcinomas including 6 microcarcinoma, cyclin G2 expression was not, or only occasionally, observed in carcinoma cells, indicating its expression decreased in all these cases. On the other hand, in 16 of the 24 follicular adenomas (66.7%) and 5 of the 23 follicular carcinomas (21.7%), cyclin G2 expression was retained (more than 5% of neoplastic cells were positive), and adenomas more frequently (p = 0.0032) retained cyclin G2 expression than carcinomas. CONCLUSION: Our results suggest that lack of cyclin G2 plays an important role in the malignant transformation of papillary carcinoma. Also, it may play an adjuvant role in the transformation of follicular adenoma to carcinoma. This is the first study of the expression of cyclin G2, a novel cyclin having a role opposite to that of conventional cyclins, in human carcinoma.

Carcinoma↗

PubMedDate not supplied

Decreased expression of p107 is correlated with anaplastic transformation in papillary carcinoma of the thyroid.

BACKGROUND: Previous studies have demonstrated that two members of the Rb family, pRb and p130, are expressed in thyroid neoplasms. However, our knowledge about the expression and physiological role of the third member of this family, p107, remains poor. We therefore investigated p107 expression in various thyroid neoplasms. MATERIALS AND METHODS: We immunohistochemically investigated p107 expression in 16 anaplastic carcinomas, 50 papillary carcinomas, 15 follicular carcinomas and 17 follicular adenomas using a rabbit polyclonal antibody against p107. RESULTS: Normal follicular cells only occasionally expressed p107. In papillary carcinoma, p107 was positive in 84.0% of the cases, regardless of various biological characteristics. Follicular carcinoma less frequently expressed p107 than follicular adenoma (p = 0.0278). Furthermore, only 12.5% of anaplastic carcinomas were p107-positive and the incidence was significantly less than that in papillary carcinoma (p < 0.0001). CONCLUSION: Our findings suggest that p107 plays a constitutive role in the progression of papillary carcinoma and that decreased p107 expression may contribute to the transformation from follicular adenoma to follicular carcinoma and anaplastic transformation.

Carcinoma↗

PubMedDate not supplied

Telomerase activity in thyroid neoplasms evaluated by the expression of human telomerase reverse transcriptase (hTERT).

BACKGROUND: The recent availability of a monoclonal antibody against human telomerase reverse transcriptase (hTERT) has enabled us to investigate the telomerase activity of tissue specimens more easily than by classical TRAP assay. In this study, we studied teromerase activity in thyroid tumors using this antibody. MATERIALS AND METHODS: We immunohistochemically investigated hTERT expression in 166 thyroid neoplasms. RESULTS: Normal follicular cells did not express hTERT. In papillary carcinoma, high hTERT expression was observed in 34.5% of cases and it was directly linked to stage and the presence of lymph node metastasis. In follicular carcinoma, 39.2% were classified as the high hTERT expression group, showing a significantly higher incidence than that in follicular adenoma, 9.8%. In anaplastic carcinoma, 73.7% were regarded as the high hTERT expression group, which was larger than the percentages in papillary and follicular carcinomas. We investigated the diagnostic usefulness of hTERT measurement for discriminating follicular carcinoma from adenoma. Its specificity and positive predictive value were high at 90.2% and 83.3%, respectively, while the sensitivity and negative predictive value were low. CONCLUSION: These results suggest that: i) telomerase activity contributes to anaplastic transformation of differentiated carcinoma and ii) hTERT measurement may contribute to diagnosing follicular carcinoma, but whether it can be applied to preoperative diagnosis by fine-needle aspiration biopsy specimens remains unclear.

Adenocarcinoma, Follicular↗

PubMedDate not supplied

Expression of p8 protein in breast carcinoma; an inverse relationship with apoptosis.

BACKGROUND: P8 is a transcription factor and its expression is elevated in response to apoptotic stimuli. However, p8 in human carcinoma tissue has not been investigated in depth. In this study, we investigated p8 expression in breast carcinoma. MATERIALS AND METHODS: We immunohistochemically investigated p8 expression in 50 cases of breast carcinoma, including 7 non-invasive ductal carcinomas. RESULTS: High expression of p8 was observed in 60% of cases, which was inversely related to tumor size and UICC stage. All non-invasive ductal carcinomas diffusely expressed p8. Furthermore, in tumors of 2 cm or larger, the p8 expression was inversely linked to the apoptotic index. CONCLUSION: These results suggest that p8 plays a role in the early phase of breast carcinoma progression and especially in tumors of larger size, acting as an inhibitor of apoptosis of breast carcinoma cells.

Apoptosis↗

PubMedDate not supplied

Expression of p8 protein in medullary thyroid carcinoma.

BACKGROUND: The p8 protein is involved in various cells under cellular stress, such as apoptotic stimuli. In this study, p8 protein expression was investigated in human medullary thyroid carcinoma. in order to elucidate its physiological significance. MATERIALS AND METHODS: We immunohistochemically investigated p8 expression in 69 cases of medullary thyroid carcinoma. RESULTS: Thirty cases (43.4%) were regarded as a high group of p8 expression with a labelling index of 50% or higher. The p8 expression level was directly linked to lymph node metastasis, extrathyroid extension and UICC stage. Furthermore, there were no cases showing low p8 expression, but 24.8% of those with high p8 expression showed recurrence. However, p8 expression was not linked to the apoptotic index. CONCLUSION: These findings suggest that p8 expression plays an important role in the progression of medullary carcinoma, but does not have an anti-apoptotic function.

Adolescent↗