Toyoharu Kamibeppu

Dysregulated HAI-2 Plays an Important Role in Renal Cell Carcinoma Bone Metastasis through Ligand-Dependent MET Phosphorylation

MET, a c-met proto-oncogene product and hepatocyte growth factor (HGF) receptor, is known to play an important role in cancer progression, including bone metastasis. In a previous study, we reported increased expression of MET and matriptase, a novel activator of HGF, in bone metastasis. In this study, we employed a mouse model of renal cell carcinoma (RCC) bone metastasis to clarify the significance of the HGF/MET signaling axis and the regulator of HGF activator inhibitor type-2 (HAI-2). Luciferase-transfected 786-O cells were injected into the left cardiac ventricle of mice to prepare the mouse model of bone metastasis. The formation of bone metastasis was confirmed by whole-body bioluminescent imaging, and specimens were extracted. Expression of HGF/MET-related molecules was analyzed. Based on the results, we produced HAI-2 stable knockdown 786-O cells, and analyzed invasiveness and motility. Expression of HGF and matriptase was increased in bone metastasis compared with the control, while that of HAI-2 was decreased. Furthermore, we confirmed increased phosphorylation of MET in bone metastasis. The expression of matriptase was upregulated, and both invasiveness and motility were increased significantly by knockdown of HAI-2. The significance of ligand-dependent MET activation in RCC bone metastasis is considered, and HAI-2 may be an important regulator in this system.

MP60-06 HAI-2 REGULATES THE INVASIVE GROWTH OF RCC CELLS IN BONE METASTASIS THROUGH SUPPRESSION OF MATRIPTASE-INDUCED HGF ACTIVATION

INTRODUCTION AND OBJECTIVES: We previously reported that high MET and matriptase expression in RCC cells in bone metastasis indicates their importance in bone metastasis (Mukai et al. Hum Cell, 2015). MET is a high-affinity receptor tyrosine kinase of hepatocyte growth factor (HGF). HGF is secreted as an inactive singlechain precursor, which requires proteolytic activation for conversion to an active form. Matriptase is the most efficient known cellular activator of pro-HGF. Furthermore, activation of matriptase is regulated by HGF activator inhibitor (HAI). In this study, we employed a previously reported mouse model of bone metastasis (Strube et al. Clin Exp Metastasis, 2010) to clarify the significance of the matriptase-induced HGF/MET signaling axis in RCC bone metastasis. METHODS: Luciferase-transfected 786-O cells were injected into the left cardiac ventricle of female nude mice (5 weeks old). After 6 weeks, we confirmed the formation of bone metastasis by whole-body bioluminescent imaging, and extracted specimens. Expression of matriptase, MET and HAI was analyzed by PCR, immunohistochemistry (IHC) and immunoblots. Phosphorylation of MET was also investigated. Based on the result, we produced HAI-2 (specific inhibitor of matriptase) stable knock down (KD) 786-O cells, and analyzed the difference of expression in each molecule, cell-migration assay and invasion assay. RESULTS: Expression of matriptase was increased significantly in bone metastasis compared with parent cell line, and we confirmed increased phosphorylation of MET in bone metastasis. On the other hand, decreased expression of HAI-2 was observed in bone metastasis. Interestingly, increased matriptase expression was observed by HAI-2 KD in 786-O cells. In addition, invasive activity was increased significantly by knock down of HAI-2. CONCLUSIONS: These results have suggested that matriptase contributes to the HGF-dependent MET activation in the pericellular microenvironment of bone metastasis in RCC. In addition, upregulation of matriptase and downregulation of HAI-2 may have important roles in their progression.

CT evaluation of acupuncture needles inserted into sacral foramina

Objective To use CT scanning to evaluate the precision with which acupuncture needles can be inserted into sacral foramina to establish sacral nerve modulation by electroacupuncture. Methods The subjects were five adult women (mean age 71.6 years). These five cases were divided into two groups. In the first three subjects (group A) the intention was to insert acupuncture needles in the S3 and S4 foramina; in the remaining two subjects (group B) the intention was to insert acupuncture needles in the S2 and S3 foramina. Results CT scanning showed that in subject 1 of group A, the acupuncture needle intended for insertion in S3 was actually in the S4 foramen, and the acupuncture needle intended for insertion in S4 was actually distal to the sacral body. In subjects 2 and 3, the acupuncture needles were inserted accurately in the S3 and S4 foramina. In the three subjects who had acupuncture needles inserted in the S4 foramen, the tip of the acupuncture needle was an average distance of 6.0 mm from the rectum. The acupuncture needles inserted in subjects 4 and 5 of group B were inserted accurately into the S2 and S3 foramina. Conclusions Inserting acupuncture needles into the sacral foramina of S2 and S3 at an angle of about 60° has the potential to be used for sacral nerve modulation by repeated electroacupuncture stimulation. Needling may be less accurate in subjects with higher body mass index. Because of the potential risk of perforating the rectum with the needle, this technique must be used by specialists only. Trial Registration Number 2013-026

Pure Verrucous Carcinoma of the Penis: Two Cases

Verrucous carcinoma is a rare subtype of penile verruciform squamous cell carcinoma. However, in past literature, the diagnosis of verrucous carcinoma has been confused with giant condylomas, and papillary and warty carcinomas due to the absence of critical criteria in pathological diagnosis. We experienced two cases of penile verruciform tumor occurring in a 48-year-old Japanese male and an 88-year-old Japanese male. We performed partial penectomy without lymph node dissection after biopsy. Although we initially detected small palpablelymph node swelling in the latter case, unnecessary lymph node dissection could be avoided by pathological diagnosis using preoperative biopsy. The resected specimens were diagnosed in accordance with the World Health Organization (WHO) classification and current pathological reviews. Histopathological findings and immunohistochemical appearance were compatible with a diagnosis of verrucous carcinoma.