Hiroomi Funahashi

Characterization of intracellular signals via tyrosine 1062 in RET activated by glial cell line-derived neurotrophic factor.

Glial cell line derived neurotrophic factor (GDNF) signals through a multicomponent receptor complex consisting of RET receptor tyrosine kinase and a member of GDNF family receptor α (GFRα). Recently, it was shown that tyrosine 1062 in RET represents a binding site for SHC adaptor proteins and is crucial for both RAS/mitogen activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3-K)/AKT signaling pathways. In the present study, we characterized how these two pathways diverge from tyrosine 1062, using human neuroblastoma and primitive neuroectodermal tumor cell lines expressing RET at high levels. In response to GDNF stimulation, SHC bound to GAB1 and GRB2 adaptor proteins as well as RET, and SHC and GAB1 were highly phosphorylated on tyrosine. The complex formation consisting of SHC, GAB1 and GRB2 was almost abolished by replacement of tyrosine 1062 in RET with phenylalanine. Tyrosine-phosphorylated GAB1 was also associated with p85 subunit of PI3-K, resulting in PI3-K and AKT activation, whereas SHC-GRB2-SOS complex was responsible for the RAS/ERK signaling pathway. These results suggested that the RAS and PI3-K pathways activated by GDNF bifurcate mainly through SHC bound to tyrosine 1062 in RET. Furthermore, using luciferase reporter-gene assays, we found that the RAS/ERK and PI3-K signaling pathways are important for activation of CREB and NF-κB in GDNF-treated cells, respectively.

A case-controlled study of laparoscopic compared with open lateral adrenalectomy.

BACKGROUND Few studies have been done regarding laparoscopic transperitoneal lateral adrenalectomy compared with open transretroperitoneal lateral adrenalectomy in a case-controlled fashion. METHODS A case-controlled study of 40 laparoscopic and 40 open adrenalectomies was done in patients who were matched for age, gender, endocrine disorder, side and size of tumor, and area of body surface. Follow-up was complete in 92.5% of the patients, with a mean follow-up period of 30 months. RESULTS Statistically significant differences (P <0.05) were present (laparoscopic versus open) when the following results were compared: estimated blood loss (40 g versus 172 g), operating time (147 versus 79 minutes), analgesic equivalents (2.9 versus 5.2 times), hospital stay (12 versus 18 days), and late morbidity (0% versus 47.5%). There were no statistically significant differences between the laparoscopic and open groups with regard to time to oral intake, time to walking, intraoperative and early complications, and total cost. CONCLUSIONS Laparoscopic adrenalectomy is a safe technique that results in greater patient comfort, decrease in estimated blood loss, and earlier discharge than open adrenalectomy, with no increase in cost. It should be adopted as the technique of choice for the removal of functioning adenomas and for adrenal masses less than 6 cm in diameter.

Inhibition of NF-κB Activity Decreases the VEGF mRNA Expression in MDA-MB-231 Breast Cancer Cells

VEGF (vascular endothelial growth factor) secreted from tumor cells including breast cancer serves as a potent angiogenic factor which favors tumor growth and metastasis. Indeed, a higher concentration of serum VEGF has been shown to associate with a poorer prognosis in patients with breast cancer. On the other hand, constitutive expression of a transcription factor, NF-κB was correlated with progression and metastasis in a number of human breast cancers, suggesting a possible regulation of VEGF expression by NF-κB. We thus investigated the relationship between the expression of VEGF and constitutive NF-κB activity in three breast cancer cell lines, MCF-7, T47D, and MDA-MB-231. The basal levels of VEGF mRNA expression correlated with those of nuclear NF-κB activity in these cell lines. The highest NF-κB activity in MDA-MB-231 cells was associated with the highest expression of VEGF mRNA, while the activity and the mRNA levels were moderate in MCF cells and the lowest in T47D cells. In MDA-MB-231 cells, inhibition of NF-κB by adenovirus-mediated expression of a dominant negative NF-κB or by a proteasome inhibitor, MG132, decreased the VEGF mRNA. These results suggest that NF-κB is involved in the upregulation of VEGF mRNA and inhibition of the activity could be a new approach for the treatment of breast cancer by preventing angiogenesis.

Preoperative staging of thyroid papillary carcinoma with ultrasonography

OBJECTIVE To evaluate the usefulness of ultrasonography including Doppler flow imaging for the preoperative staging of thyroid papillary carcinoma. MATERIALS AND METHODS In 77 patients with thyroid papillary carcinoma who underwent total thyroidectomy, the accuracy of ultrasonography in preoperative clinical staging was assessed with use of pathologic examination on the basis of TNM classification by the International Union Against Cancer (UICC). RESULTS In 63 (81.8%) cases, T categories were estimated accurately. The sensitivity in depicting tumor extension into the prethyroidal muscle and/or the sternocleidomastoid muscle was 77.8%, whereas the sensitivity for invasion into the trachea and the esophagus was 42.9 and 28.6%, respectively. In 37 (48.1%) cases, N categories were underestimated, and the sensitivity in the detection of regional lymph node metastasis was 36.7%. Doppler flow imaging was performed in 36 patients, and no correlation was found between flow patterns and the presence of local invasion or regional lymph node metastasis. CONCLUSION Ultrasonography was useful for preoperative investigation of thyroid papillary carcinoma, but several limitations existed, especially in evaluating extracapsular invasion to deep locations and regional lymph node metastasis.

Seaweed Prevents Breast Cancer

To investigate the chemopreventive effects of seaweed on breast cancer, we have been studying the relationship between iodine and breast cancer. We found earlier that the seaweed, wakame, showed a suppressive effect on the proliferation of DMBA (dimethylbenz(a)anthracene)‐induced rat mammary tumors, possibly via apoptosis induction. In the present study, powdered mekabu was placed in distilled water, and left to stand for 24 h at 4°C. The filtered supernatant was used as mekabu solution. It showed an extremely strong suppressive effect on rat mammary carcinogenesis when used in daily drinking water, without toxicity. In vitro, mekabu solution strongly induced apoptosis in 3 kinds of human breast cancer cells. These effects were stronger than those of a chemothera‐peutic agent widely used to treat human breast cancer. Furthermore, no apoptosis induction was observed in normal human mammary cells. In Japan, mekabu is widely consumed as a safe, inexpensive food. Our results suggest that mekabu has potential for chemoprevention of human breast

Wakame seaweed suppresses the proliferation of 7,12-dimethylbenz(a)-anthracene-induced mammary tumors in rats.

We examined the anti‐tumor proliferation effects of wakame seaweed on 7,12‐dimethylbenz(a)‐anthracene (DMBA)‐induced rat mammary tumor. DMBA was administered to 8‐week‐old female Sprague‐Dawley rats, and rats which developed mammary tumors were assigned randomly to three groups. Commercial rat feed was used in a control group (group I‐A), and two feed mixtures were prepared, which contained commercial rat feed blended with wakame at 1.0% (group I‐B) and 5.0% (group I‐C) by weight. The respective feeds were given to each group for 8 weeks, and changes in mammary tumor size were compared. At the end of the experiment, mammary tumors and thyroid glands were resected to compare their weights. Serum total iodine and thyroxin (T4) levels were measured. Immunohistochemical studies for bromodeoxyuridine (BrdU) labeling, transforming growth factor (TGF)‐β, and apoptosis were carried out in the resected tumor. Significant suppression of tumor growth was observed in groups I‐B and I‐C compared with I‐A. In groups I‐B and I‐C, the weights of resected mammary tumors were significantly lower and serum total iodine concentration was significantly higher than in I‐A. BrdU indices were significantly lower in groups I‐B and I‐C, compared with I‐A. TGF‐β and apoptotic index were inversely related to BrdU. These results suggest that iodine is transported from the serum into mammary tissues and induces apoptosis through the expression of TGF‐β. In conclusion, wakame suppressed the proliferation of DMBA‐induced mammary tumors.

Laparoscopic partial adrenalectomy

AbstractBackground: Most laparoscopic adrenalectomies involve total removal of the whole adrenal gland, and reports of laparoscopic partial adrenalectomies have been very few. The criteria for performing a laparoscopic partial adrenalectomy have not been described. Methods: (a) Patients with functioning adrenal tumors smaller than 3 cm in diameter were selected. (b) The solitary adrenal tumors were evaluated by preoperative thin-slice computed tomography (CT) scan. (c) Solitary lesions were reconfirmed with intraoperative ultrasonography. (d) Partial adrenalectomy was performed with at least a 5-mm margin using a vascular stapler. Results: Laparoscopic partial adrenalectomy was performed in five patients using the vascular stapler. Hemostasis was perfect in all five patients. The tumor was located in the inferior part of the right adrenal gland in three cases and in the upper pole of the left adrenal gland in two cases. The postoperation pathologic diagnosis was adrenocortical adenoma in all five patients, and excessive hormonal levels or symptoms all disappeared. Conclusions: Laparoscopic partial adrenalectomy can be performed safely using a vascular stapler.

Role of ultrasonography in the detection of intraductal spread of breast cancer: correlation with pathologic findings, mammography and MR imaging

Abstract. The purpose of this study was to assess the role of US in the detection of intraductal spread of breast cancer in comparison with mammography (MMG) and MRI. In 46 patients with breast cancer, US features of the intraductal component were classified as ductal type or distorted type. Histopathologically, 29 of 46 (63 %) cases had intraductal components, and the sensitivity, specificity, and accuracy rates in detection of intraductal spread were 89, 76, and 85 %, respectively. Each US pattern demonstrated good correspondence to the histologic components, and the distorted type correlated well with comedo-type carcinoma. Mammography was performed in all cases, and the sensitivity, specificity, and accuracy rates in detection of intraductal spread were 55, 100, and 72 %, respectively. In comedo type, MMG could diagnose the extent of intraductal spread more accurately compared with US examination. Magnetic resonance imaging comparison was available in 25 cases. Magnetic resonance imaging depicted intraductal extension as an enhanced area during the early phase of a contrast enhancement study with a sensitivity of 93 %. Ultrasound and MRI were closely related in terms of morphologic characteristics: the ductal type of US image correlated well with linear enhancement on MRI, whereas the distorted type correlated with regional or segmental enhancement. Current US examination is useful in depicting the intraductal spread of breast cancer; however, US has a tendency to underestimate intraductal component of comedo type compared with MMG and MRI.

C-erbB-2 protein in the sera of breast cancer patients

SummaryThe c-erbB-2 protein was measured in sera of patients with breast cancer or benign breast diseases to study the significance of this protein as a tumor marker. The mean value and positive rate for this protein (assuming 20 U/ml as the cut-off value) were 11.8 U/ml (0%) in benign breast disease (n=30), 11.8 U/ml (3.1%) in stage I/II primary breast cancer (n=64), 38.2 U/ml (29.4%) in stage III/IV primary breast cancer (n=17), 17.9 U/ml (33.3%) in locally recurrent breast cancer (n=12), 298.4 U/ml (51.0%) in recurrent breast cancer with distant metastases (n=51), and 12.9 U/ml (0%) in those with no evidence of recurrence (n=57). Thus, the serum c-erbB-2 protein level was significantly higher in the distant metastatic group. In patients with distant metastases, there was a close association between expression of c-erbB-2 protein in the primary tumor and the serum c-erbB-2 protein level. On the basis of these results, serum c-erbB-2 protein was thought to be useful as a tumor marker for postoperative monitoring of breast cancer, especially in patients positive for expression of this protein in primary cancer tissue.

Adrenalectomy for Treatment of Cushing Syndrome: Results in 122 Patients and Long-Term Follow-up Studies

Abstract. Patients with Cushing syndrome (n = 122) who underwent adrenalectomy from 1957 through 1993 were reviewed for survival and complications. Of the 122 patients, 70 had adrenocortical adenoma, 30 Cushing’s disease, 6 primary pigmented nodular adrenocortical disease (PPNAD), 7 other types of primary nodular hyperplasia, 5 adrenocortical carcinoma, and 4 ectopic ACTH syndrome. Sixty-five patients with adrenocortical adenoma are alive, and the survival rate was equal to the age-matched control population, when patients who died of the postoperative complication were excluded. Of the patients with Cushing’s disease, 20 are alive; and 10 of 16 patients (63%) who were followed-up and evaluated had skin pigmentation. Four of sixteen patients (25%) developed Nelson’s syndrome. Four PPNAD patients and five with other types of nodular hyperplasia are alive. Most of these patients underwent bilateral total adrenalectomy, but some patients remitted after unilateral adrenalectomy. All of five adrenocortical carcinoma patients and four with ectopic ACTH syndrome died within 2 years after operation. The prognosis for patients with adrenocortical adenoma after unilateral adrenalectomy is excellent, though it is important to avoid operative complications. The rapid cure of signs and symptoms of glucocorticoid excess after total adrenalectomy is ensured, and prognosis is satisfactory under careful glucocorticoid replacement, making total adrenalectomy an alternative treatment for Cushing’s disease.