Tsuyoshi Ishihara

The circulating microRNA-221 level in patients with malignant melanoma as a new tumor marker

BACKGROUND MicroRNA-221 (miR-221) is known to be abnormally expressed in malignant melanoma (MM) cells, and it favors the induction of the malignant phenotype through down-modulation of p27Kip1/CDKN1B and the c-KIT receptor. This suggests that the serum level of miR-221 might increase in patients with MM and thus could be used as a new tumor marker. OBJECTIVE To evaluate the possibility that the serum miR-221 level can be a marker of MM. METHODS Serum samples were obtained from 94 MM patients and 20 healthy controls. MicroRNAs were purified from serum, and miR-221 levels were measured by quantitative real-time polymerase chain reaction. RESULTS Circulating miR-221 was detectable and could be quantified in serum samples. MM patients had significantly higher miR-221 levels than healthy controls. Among the MM patients, the miR-221 levels were significantly increased in patients with stage I-IV MM compared to those with MM in situ, and the levels were correlated with tumor thickness. Moreover, a longitudinal study revealed a tendency for the miR-221 levels to decrease after surgical removal of the primary tumor, and to increase again at recurrence. CONCLUSIONS Serum levels of miR-221 were significantly increased in MM patients and may be useful not only for the diagnosis of MM, but also for the differentiating MM in situ from stage I-IV MM, and for evaluating tumor progression and monitoring patients during the follow-up period. In addition, considering that the serum levels of miR-221 were correlated with tumor thickness, miR-221 might also be useful as a prognostic marker for patients with MM.

Down-regulation of mir-424 contributes to the abnormal angiogenesis via MEK1 and cyclin E1 in senile hemangioma: Its implications to therapy

Background Senile hemangioma, so-called cherry angioma, is known as the most common vascular anomalies specifically seen in the aged skin. The pathogenesis of its abnormal angiogenesis is still unclear. Methodology/Principal Findings In this study, we found that senile hemangioma consisted of clusters of proliferated small vascular channels in upper dermis, indicating that this tumor is categorized as a vascular tumor. We then investigated the mechanism of endothelial proliferation in senile hemangioma, focusing on microRNA (miRNA). miRNA PCR array analysis revealed the mir-424 level in senile hemangioma was lower than in other vascular anomalies. Protein expression of MEK1 and cyclin E1, the predicted target genes of mir-424, was increased in senile hemangioma compared to normal skin or other anomalies, but their mRNA levels were not. The inhibition of mir-424 in normal human dermal microvascular ECs (HDMECs) using specific inhibitor in vitro resulted in the increase of protein expression of MEK1 or cyclin E1, while mRNA levels were not affected by the inhibitor. Specific inhibitor of mir-424 also induced the cell proliferation of HDMECs significantly, while the cell number was decreased by the transfection of siRNA for MEK1 or cyclin E1. Conclusions/Significance Taken together, decreased mir-424 expression and increased levels of MEK1 or cyclin E1 in senile hemangioma may cause abnormal cell proliferation in the tumor. Senile hemangioma may be the good model for cutaneous angiogenesis. Investigation of senile hemangioma and the regulatory mechanisms of angiogenesis by miRNA in the aged skin may lead to new treatments using miRNA by the transfection into senile hemangioma.

Recent progress in studies of infantile hemangioma

A hallmark of infantile hemangioma, the most common tumor of infancy, is its dramatic growth after birth, by diffuse proliferation of immature endothelial cells, followed by spontaneous regression. The growth and involution of infantile hemangioma is quite different from other vascular anomalies, which do not regress and can occur at any time during life. Some hemangioma lesions can be extremely disfiguring and destructive to normal tissue and may even be life‐threatening. Unfortunately, existing therapeutic approaches have limited success and significant adverse effects of some treatment modalities limit their use. Better understanding of the pathogenesis of hemangioma will enable the development of better therapeutic strategies. Here, we review recent studies and new hypotheses on the pathogenesis of the tumor. Detailed mechanisms of activated vascular endothelial growth factor signaling in tumor cells, identification of their origin and characterization of multipotent stem cells that can give rise to infantile hemangioma are shedding new light on this intriguing vascular tumor.

Down-regulation of miR-124/-214 in cutaneous squamous cell carcinoma mediates abnormal cell proliferation via the induction of ERK.

Squamous cell carcinoma (SCC) is one of the most common skin cancers. Because its potential to recur and metastasize leads to a poor prognosis and significant mortality, it is necessary to develop new early diagnostic tools and new therapeutic approaches. In this study, we found protein levels of ERK1 and ERK2 were increased in SCC cell lines without changing mRNA levels and that ERK1/2 mediates abnormal cell proliferation in these cells. Then, mechanisms underlying the overexpression of ERK1/2 in SCC were investigated focusing on microRNA. We found that miR-214 is the regulator of ERK1, whereas ERK2 is regulated by miR-124 and miR-214. Expression of miR-124 and miR-214 was significantly down-regulated in SCC in vitro and in vivo. Treatment with 5-aza-deoxycytidine and trichostatin A synergistically recovered the miR-124/-214 down-regulation in SCC cell line. However, bisulphite sequencing revealed the methylation status of miR-124/-214 promoter was not increased in the SCC cell line and tumor tissue. Taken together, the down-regulation of miR-124/-214 in SCC is most likely caused, at least in part, by hypermethylation of other promoter regions rather than the miR-124/-214 promoter. Supplementation of these microRNAs in the SCC cell line reduced the abnormal cell proliferation by normalizing ERK1/2 levels. Additionally, serum concentration of miR-124 was correlated with miR-124 expression levels in the tumor tissues and inversely correlated with tumor progression. On the other hand, miR-214 was not detected in the serum. Investigation of the regulatory mechanisms of keratinocyte proliferation by microRNA may lead to develop new biomarkers and treatments using microRNA.

Management of sentinel lymph nodes in malignant skin tumors using dynamic lymphoscintigraphy and the single-photon-emission computed tomography/computed tomography combined system

BackgroundThe differentiation of true sentinel lymph nodes from nonsentinel lymph nodes is difficult in cases of multiple radiolabeled or dyed lymph nodes.MethodsWe examined the locations of sentinel lymph nodes in melanoma and other malignant skin tumors by using dynamic lymphoscintigraphy and the single-photon-emission computed tomography/computed tomography (SPECT/CT) combined system.ResultsSentinel lymph nodes were detected in 45 of the 53 patients examined using only the ordinary blue dye method (85%), and were detected in all 35 patients examined using the SPECT/CT method (100%). Twenty of the 35 patients mentioned above had one sentinel lymph node. Multiple sentinel lymph nodes were demonstrated in the head and neck areas using the SPECT/CT method. Significant differences (P = 0.0015) in the numbers of sentinel lymph nodes were found between the blue dye method only and the SPECT/CT method in the neck area. Popliteal sentinel lymph nodes were recognized in three patients, and cubital sentinel lymph nodes were recognized in two patients. Two patients had plural regional lymph nodes: one had popliteal and groin sentinel lymph nodes, while the other had cubital and axillary sentinel lymph nodes. The probe counts of the popliteus and cubitus were significantly lower (P = 0.0241) than the counts in the groin, axilla, and neck areas. Micrometastatic sentinel lymph nodes were recognized in four patients, and two patients had metastases in both sentinel and nonsentinel lymph nodes.ConclusionsDynamic lymphoscintigraphy was useful when we were concerned about cubital and popliteal lymph nodes. The SPECT/CT combined system was useful in recognizing the anatomical location of sentinel lymph nodes before biopsy. The detection rate of sentinel lymph nodes using the SPECT/CT method was always better than that with the blue dye method (P = 0.0197).

Evaluation of sentinel node biopsy for cutaneous squamous cell carcinoma.

Sentinel lymph node biopsy (SLNB) is a standard care for cutaneous melanoma but its role in cutaneous squamous cell carcinoma (SCC) has not been established. Clinical data was obtained from 54 patients with SCC who received SLNB with the usage of blue dye and radioisotope colloid methods. The positive rate of SLNB in SCC was 7.4%. If the cases were limited to more than T2, the positive rate was 12.9%. Three of 41 patients who was estimated negative LN metastasis by the preoperative tests had micrometastasis (7.3%). Among 13 patients who were suggested to have metastasis in the preoperative tests, only one patient had histological metastasis. One patient with SCC located in the lower lip showed negative SLNB and subsequently developed node recurrence. In conclusion, the efficacy of SLNB in SCC is comparable to that of melanoma in the positive rate. There are two kinds of benefit, avoidance of unnecessary complete lymph node dissection and early detection of metastasis.

WITHDRAWN; Recent progress in studies of infantile hemangioma

A hallmark of infantile hemangioma, the most common tumor of infancy, is its dramatic growth after birth, by diffuse proliferation of immature endothelial cells, followed by spontaneous regression. The growth and involution of infantile hemangioma is quite different from other vascular anomalies, which do not regress and can occur at any time during life. Some hemangioma lesions can be extremely disfiguring and destructive to normal tissue and may even be life‐threatening. Unfortunately, existing therapeutic approaches have limited success and significant adverse effects of some treatment modalities limit their use. Better understanding of the pathogenesis of hemangioma will enable the development of better therapeutic strategies. Herein, we review recent studies and new hypotheses on the pathogenesis of the tumor. Detailed mechanisms of activated vascular endothelial growth factor (VEGF) signaling in tumor cells, identification of their origin and characterization of multipotent stem cells that can give rise to infantile hemangioma are shedding new light on this intriguing vascular tumor.

Submental perforator flap: location and number of submental perforating vessels.

The sites and numbers of submental perforator vessels were examined using a Doppler probe in 21 volunteers. The subcutaneous vascular network from each perforator was studied in three cases of dissection of upper-neck lymph nodes among the volunteers. A perforator from the submental vessels was noted in all 21 volunteers: a single perforator in 13 cases, and double perforators in eight. The main perforator, which had some subdermal branches, was located 31.8 (8.3) mm in front of the facial artery that was palpated at the mandible. Five patients who presented with skin defects on the cheek and the chin had the submental perforator flap reconstructed, excluding the platysma muscle. All flaps covered the wounds. The submental perforator flap was useful for reconstructing skin defects on the cheek and the chin, because the site of the submental perforator was stable and raising the flap was easy, and the colour and texture matches were acceptable.

Acquired Coccygeal Nodule Due to Repeated Stimulation by a Bicycle Saddle

Four Japanese male students, aged 14, 16, 18 and 19, were found to have a nodule in their coccygeal regions. The typical lesion was a rugby‐ball‐shaped, normal‐colored or slightly erythematous nodule measuring 5 to 6 cm in its long axis. Histopathologically, it showed hyperplasia of collagen fibers and slight acanthosis. All four students rode to school by bicycle over long distances and long periods; three of them developed the nodule after they started bicycle riding to school. We found that the nodule shape corresponded to the saddle of the bicycle. X‐ray abnormalities included bending or anterior dislocation of the coccyx in all cases and spina bifida in two cases. These nodules may have developed as a result of irritation of this region by the saddle of the bicycle.

Giant malignant peripheral nerve sheath tumor of the scalp

Herein, we describe a rare case of giant malignant peripheral nerve sheath tumor of the head in a 38‐year‐old Japanese man. The tumor measured 210 mm at its largest diameter and was ulcerated, hemorrhagic, multilocular and non‐mobile. It should be noted that the patient stubbornly refused to see a doctor for a long time, resulting in the extreme growth of the tumor. We suspect a psychological basis for this behavior. Dermatohistopathological findings of the biopsy indicated ancient schwannoma and total excision was therefore performed. However, after 4 months, the patient developed multiple metastases and died. Post‐mortem skin biopsy revealed features of malignant peripheral nerve sheath tumor. We performed immunohistochemical studies on the primary and recurrent lesions and concluded that there was a difference in the expression of Ki67 and p16. We propose that the expressions of Ki67 and p16 should be checked for all lesions of peripheral nerve sheath tumor for distinguishing benign from malignant forms.