MTMR4, a phosphoinositide-specific 3\u27-phosphatase, regulates TFEB activity and the endocytic and autophagic pathways.

金沢大学医薬保健研究域医学系Phosphatidylinositol 3-phosphate (PI(3)P) is the predominant phosphoinositide species in early endosomes and autophagosomes, in which PI(3)P dictates traffic of these organelles. Phosphoinositide levels are tightly regulated by lipid-kinases and -phosphatases; however, a phosphatase that converts PI(3)P back to phosphatidylinositol in the endosomal and autophagosomal compartments is not fully understood. We investigated the subcellular distribution and functions of myotubularin-related protein-4 (MTMR4), which is distinct among other MTMRs in that it possesses a PI(3)P-binding FYVE domain, in lung alveolar epithelium-derived A549 cells. MTMR4 was localized mainly in late endosomes and autophagosomes. MTMR4 knockdown markedly suppressed the motility, fusion, and fission of PI(3)P-enriched structures, resulting in decreases in late endosomes, autophagosomes, and lysosomes, and enlargement of PI(3)P-enriched early and late endosomes. In amino acid- and serum-starved cells, MTMR4 knockdown decreased both autophagosomes and autolysosomes and markedly increased PI(3)P-containing autophagosomes and late endosomes, suggesting that the fusion with lysosomes of autophagosomes and late endosomes might be impaired. Notably, MTMR4 knockdown inhibited the nuclear translocation of starvation stress responsive transcription factor-EB (TFEB) with reduced expression of lysosome-related genes in starved cells. These findings indicate that MTMR4 is essential for the integrity of endocytic and autophagic pathways. © 2018 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.Embargo Period 12 month

Immunohistochemical molecular expression profile of metastatic brain tumor for potent personalized medicine

Recent progress in molecule-targeting therapy may yield personalized therapeutic strategies for patients with metastatic brain tumors (MBT), the most frequently encountered intracranial tumors. For this purpose, we investigated the molecular expression profile of MBT to establish the pathological basis for personalized diagnosis. We studied 166 MBT specimens including 70 cases of lung cancer and 34 cases of breast cancer, and performed immunostaining for EGFR, COX-2, and O-6-methylguanine-DNA methyltransferase (MGMT), among others, which could be target molecules for therapeutic agents or enable prediction of drug efficacy. Loss of MGMT expression was observed in approximately 20–40 % of MBT derived from lung, breast, and gastrointestinal cancers, indicating the possibility of treatment of MBT patients with temozolomide. In addition, MBT expressed a variety of receptor tyrosine kinases, for example EGFR and HER2, and signal transduction molecules, for example phospho-mTOR and COX-2, irrespective of tumor origin, enabling individualized medication with molecule-targeting drugs. We also identified alteration of molecular expression profile in 4 MBT cases during recurrence. Our results not only reveal the molecular characteristics of MBT but also suggest the possibility of potent personalized medicine for MBT patients

Clinicopathological evaluation of cyclooxygenase-2 expression in meningioma: immunohistochemical analysis of 76 cases of low and high-grade meningioma

Tumorigenic activity of cyclooxygenase-2 (COX-2), a rate-limiting enzyme in the production of prostaglandins (PGs), has been proved for some types of cancer, including brain tumors. We evaluated expression of COX-2 in meningioma, one of the most common intracranial tumors in adults which accounts for 24-30 % of intracranial tumors. We performed immunostaining for COX-2 in 76 cases of meningioma consisting of 44 cases of low-grade (WHO Grade I) and 32 cases of high-grade (29 cases of Grade II and 3 cases of Grade III) meningioma, and evaluated COX-2 expression levels on the basis of staining intensity and proportion in tumor cells. The expression level of COX-2 in meningioma cells was significantly correlated with WHO grade (P = 0.0153). In addition, COX-2 expression was significantly correlated with MIB-1 labeling index for all 76 cases of meningioma (P = 0.0075), suggesting tumor promotion by COX-2 in meningioma progression. Our results may indicate the therapeutic value of non-steroidal anti-inflammatory drugs against meningioma, especially for patients with elevated proliferation, to regulate the tumorigenic activity of COX-2 in meningioma cells

Clinical impact of targeted amplicon sequencing for meningioma as a practical clinical-sequencing system

Recent genetic analyses using next-generation sequencers have revealed numerous genetic alterations in various tumors including meningioma, which is the most common primary brain tumor. However, their use as routine laboratory examinations in clinical applications for tumor genotyping is not cost effective. To establish a clinical sequencing system for meningioma and investigate the clinical significance of genotype, we retrospectively performed targeted amplicon sequencing on 103 meningiomas and evaluated the association with clinicopathological features. We designed amplicon-sequencing panels targeting eight genes including NF2 (neurofibromin 2), TRAF7, KLF4, AKT1, and SMO. Libraries prepared with genomic DNA extracted from PAXgenefixed paraffin-embedded tissues of 103 meningioma specimens were sequenced using the Illumina MiSeq. NF2 loss in some cases was also confirmed by interphase-fluorescent in situ hybridization. We identified NF2 loss and/or at least one mutation in NF2, TRAF7, KLF4, AKT1, and SMO in 81 out of 103 cases (79%) by targeted amplicon sequencing. On the basis of genetic status, we categorized meningiomas into three genotype groups: NF2 type, TRAKLS type harboring mutation in TRAF7, AKT1, KLF4, and/or SMO, and 'not otherwise classified' type. Genotype significantly correlated with tumor volume, tumor location, and magnetic resonance imaging findings such as adjacent bone change and heterogeneous gadolinium enhancement, as well as histopathological subtypes. In addition, multivariate analysis revealed that genotype was independently associated with risk of recurrence. In conclusion, we established a rapid clinical sequencing system that enables final confirmation of meningioma genotype within 7 days turnaround time. Our method will bring multiple benefits to neuropathologists and neurosurgeons for accurate diagnosis and appropriate postoperative management

Esophageal Cancer with Bone Marrow Hyperplasia Mimicking Bone Metastasis: Report of a Case

A 63-year-old man visited the clinic with numbness in the right hand. Magnetic resonance imaging demonstrated multiple low-intensity lesions in the cervical vertebrae and sacrum, which was suspicious of cervical bone metastasis. Fluorodeoxyglucose positron emission tomography/computed tomography revealed areas of increased fluorodeoxyglucose uptake in the thoracic esophagus, sternum and sacrum. A flat, elevated esophageal cancer was identified by upper gastrointestinal endoscopy, and the macroscopic appearance indicated early-stage disease. From the cervical, thoracic and abdominal computed tomography images, there were no metastatic lesions except for the bone lesions. To confirm whether the bone lesions were metastatic, we performed bone biopsy. The histopathological diagnosis was bone marrow hyperplasia. It was crucial for treatment planning to establish whether the lesions were distant metastases. Here, we report a case of esophageal cancer with bone marrow hyperplasia mimicking bone metastasis

Complete laparoscopic total mesorectal excision with an intersphincteric resection and coloplasty pouch anal anastomosis for lower rectal cancer

This pilot study aimed to develop a new technique, complete laparoscopic total mesorectal excision (TME) with an intersphincteric resection (ISR) and coloplasty pouch anal anastomosis to avoid any further abdominal incision other than laparoscopic port sites, and to assess the impact on short-quality of life and oncological outcomes of this technique. After laparoscopic TME, large bowel was dissected at the level of the promontory. Then, laparoscopic construction of the coloplasty pouch was performed. Simultaneously, a rectal specimen with ISR was excised using the transanal approach. Coloplasty pouch was gently pulled from pelvic thorough anal and a hand-sewn coloplasty pouch anal anastomosis was created. We had performed 8 surgeries using the new technique. Though one patient developed pelvic infections, but intestinal continuity could be maintained and no local and distant recurrence was recognized in other patients. We foresee this novel approach to have significant clinical potential for lower rectal cancer patients with ISR