Insufficiency of hepatocyte growth factor activator inhibitor-1 confers lymphatic invasion of tongue carcinoma cells.

Hepatocyte growth factor (HGF) activator inhibitor type-1 (HAI-1), encoded by the SPINT1 gene, is a transmembrane protease inhibitor that regulates membrane-anchored serine proteases, particularly matriptase. Here, we explored the role of HAI-1 in tongue squamous cell carcinoma (TSCC) cells. An immunohistochemical study of HAI-1 in surgically resected TSCC revealed the cell surface immunoreactivity of HAI-1 in the main portion of the tumor. The immunoreactivity decreased in the infiltrative front, and this decrease correlated with enhanced lymphatic invasion as judged by podoplanin immunostaining. In vitro homozygous deletion of SPINT1 (HAI-1KO) in TSCC cell lines (HSC3 and SAS) suppressed the cell growth rate but significantly enhanced invasion in vitro. The loss of HAI-1 resulted in enhanced pericellular activities of proteases, such as matriptase and urokinase-type plasminogen activator, which induced activation of HGF/MET signaling in the co-culture with pro-HGF-expressing fibroblasts and plasminogen-dependent plasmin generation, respectively. The enhanced plasminogen-dependent plasmin generation was abrogated partly by matriptase silencing. Culture supernatants of HAI-1KO cells had enhanced potency for converting the proform of vascular endothelial growth factor-C (VEGF-C), a lymphangiogenesis factor, into the mature form in a plasminogen-dependent manner. Furthermore, HGF significantly stimulated VEGF-C expression in TSCC cells. Orthotopic xenotransplantation into nude mouse tongue revealed enhanced lymphatic invasion of HAI-1KO TSCC cells compared to control cells. Our results suggest that HAI-1 insufficiency leads to dysregulated pericellular protease activity, which eventually orchestrates robust activation of protease-dependent growth factors, such as HGF and VEGF-C, in a tumor microenvironment to contribute to TSCC progression.

Protease-activated receptor-2 accelerates intestinal tumor formation through activation of nuclear factor-κB signaling and tumor angiogenesis in ApcMin/+ mice.

Hepatocyte growth factor activator inhibitor-1 (HAI-1), encoded by the SPINT1 gene, is a membrane-bound protease inhibitor expressed on the surface of epithelial cells. Hepatocyte growth factor activator inhibitor-1 regulates type II transmembrane serine proteases that activate protease-activated receptor-2 (PAR-2). We previously reported that deletion of Spint1 in ApcMin/+ mice resulted in accelerated formation of intestinal tumors, possibly through enhanced nuclear factor-κB signaling. In this study, we examined the role of PAR-2 in accelerating tumor formation in the ApcMin/+ model in the presence or absence of Spint1. We observed that knockout of the F2rl1 gene, encoding PAR-2, not only eliminated the enhanced formation of intestinal tumors caused by Spint1 deletion, but also reduced tumor formation in the presence of Spint1. Exacerbation of anemia and weight loss associated with HAI-1 deficiency was also normalized by compound deficiency of PAR-2. Mechanistically, signaling triggered by deregulated protease activities increased nuclear translocation of RelA/p65, vascular endothelial growth factor expression, and vascular density in ApcMin/+ -induced intestinal tumors. These results suggest that serine proteases promote intestinal carcinogenesis through activation of PAR-2, and that HAI-1 plays a critical tumor suppressor role as an inhibitor of matriptase, kallikreins, and other PAR-2 activating proteases.

TP53 and PTEN mutations were shared in concurrent germ cell tumor and acute megakaryoblastic leukemia.

BACKGROUND: The occurrence of a mediastinal germ cell tumor (GCT) and hematological malignancy in the same patient is very rare. Due to its rarity, there have been only two reports of the concurrent cases undergoing detailed genetic analysis with whole-exome sequencing (WES), and the possible clonal relationship between the both tumors remained not fully elucidated. METHODS: We performed whole-exome sequencing analysis of mediastinal GCT and acute myeloid leukemia (AML) samples obtained from one young Japanese male adult patient with concurrent both tumors, and investigated the possible clonal relationship between them. RESULTS: Sixteen somatic mutations were detected in the mediastinal GCT sample and 18 somatic mutations in the AML sample. Mutations in nine genes, including TP53 and PTEN both known as tumor suppressor genes, were shared in both tumors. CONCLUSIONS: All in our case and in the previous two cases with concurrent mediastinal GCT and AML undergoing with whole-exome sequencing analysis, TP53 and PTEN mutations were commonly shared in both tumors. These data not only suggest that these tumors share a common founding clone, but also indicate that associated mediastinal GCT and AML harboring TP53 and PTEN mutations represent a unique biological entity.

Possible role of combined therapy targeting MET and pro-HGF activation for renal cell carcinoma: analysis by human HGF-producing SCID mice.

MET is a high-affinity receptor tyrosine kinase of HGF (hepatocyte growth factor). HGF is secreted as an inactive single-chain precursor (pro-HGF), which requires proteolytic activation for conversion to an active form. HGF activator inhibitor (HAI)-2 is a transmembrane Kunitz-type serine protease inhibitor, which inhibits all pro-HGF-activating enzymes. In RCC, increased expression of MET and decreased expression of HAI-2 were reported to be poor prognostic factors. In the current study, we tried to inhibit the growth of RCC cells by dual inhibition of both MET phosphorylation and pro-HGF-activation using MET inhibitor and HAI-2 overexpression. A transgenic mouse model which expressed human HGF (HGF mouse) was used for in vivo analysis to evaluate the HGF/MET signaling axis accurately. Initially, doxycycline-induced HAI-2 overexpression RCC cells (786-O-HAI2) were prepared. The cells were cultured with pro-HGF, and inhibitory effect of MET inhibitor (SCC244) and HAI-2 was evaluated by phosphorylation of MET and cell proliferation. Next, the cells were subcutaneously implanted to HGF mice and the growth inhibition was determined by SCC244 and HAI-2. Single use of each inhibitor showed significant inhibition in MET phosphorylation, migration and proliferation of 786-O-HAI2 cells; however, the strongest effect was observed by combined use of both inhibitors. Although in vivo analysis also showed apparent downregulation of MET phosphorylation and growth inhibition in combined treatment, statistical significance was not observed compared with single use of MET inhibitor. Combined treatment with MET-TKI and HAI-2 suggested to consider as a candidate for new strong therapy for RCC.

Adrenomedullin alleviates mucosal injury in experimental colitis and increases claudin-4 expression in the colonic epithelium.

Adrenomedullin (AM) is a peptide with pleiotropic physiological functions that attenuates intestinal mucosal inflammation. However, the mechanism underpinning mucosal protection by AM is not fully understood, and its effect on intestinal epithelial cells remains unclear. Here, we investigated the effects of AM on junctional molecules in primary-cultured murine intestinal epithelial cells and discovered that AM upregulates claudin-4 expression. In a mouse model of dextran sulfate sodium-induced colitis, AM administration also enhanced claudin-4 expression and accelerated mucosal regeneration. Furthermore, AM reversed TNFα-mediated downregulation of claudin-4 and loss of cell-cell adhesion of the HCT116 human intestinal epithelial cell line in vitro. These results indicate that AM may enhance intestinal epithelial integrity by upregulating claudin-4 expression.

Epithelioid Angiomyolipoma with Tumor Thrombus into Inferior Vena Cava Presurgically Treated with Combination Therapy of Pembrolizumab and Axitinib: A Case Report.

Epithelioid angiomyolipoma (EAML) is a rare variant of AML with malignant potential. It is occasionally difficult to distinguish EAML from renal cell carcinoma (RCC) on imaging. A 72-year-old woman was admitted to our hospital for the treatment of a left renal tumor with relatively high blood flow and a tumor thrombus extending to the inferior vena cava, suggesting RCC. The patient underwent presurgical combination therapy with axitinib and pembrolizumab. This treatment significantly shortened the thrombus, and radical nephrectomy was performed. The pathological findings were compatible with EAML, and the treatment effects were observed. We report a case treated pre-surgically with a combined therapy of pembrolizumab and axitinib, with a favorable response as a treatment option for EAML.

Patient-Derived Organoids of Colorectal Cancer: A Useful Tool for Personalized Medicine.

Colorectal cancer is one of the most important malignancies worldwide, with high incidence and mortality rates. Several studies have been conducted using two-dimensional cultured cell lines; however, these cells do not represent a study model of patient tumors very well. In recent years, advancements in three-dimensional culture methods have facilitated the establishment of patient-derived organoids, which have become indispensable for molecular biology-related studies of colorectal cancer. Patient-derived organoids are useful in both basic science and clinical practice; they can help predict the sensitivity of patients with cancer to chemotherapy and radiotherapy and provide the right treatment to the right patient. Regarding precision medicine, combining gene panel testing and organoid-based screening can increase the effectiveness of medical care. In this study, we review the development of three-dimensional culture methods and present the most recent information on the clinical application of patient-derived organoids. Moreover, we discuss the problems and future prospects of organoid-based personalized medicine.

Role of the polycystic kidney disease domain in matriptase chaperone activity and localization of hepatocyte growth factor activator inhibitor-1.

Hepatocyte growth factor activator inhibitor-1 (HAI-1, also known as SPINT1) is an inhibitor of matriptase, a type-2 transmembrane protease widely expressed in epithelial cells. HAI-1 also functions as a chaperone to maintain the processing and localization of matriptase required for epithelial integrity. However, mechanisms underpinning the chaperone function remain to be elucidated. Here, we show that the first Kunitz domain (KD1) and the adjacent polycystic kidney disease (PKD) domain-like internal domain of HAI-1 are essential for the chaperone function. In HEK293T cells, which do not express endogenous HAI-1 or matriptase, forced matriptase overexpression was unsuccessful unless sufficient HAI-1 was co-expressed. Among mutant HAI-1 constructs, HAI-1 with inactivation mutation in KD1 (HAI-1mKD1) or HAI-1 lacking the PKD domain (HAI-1dPKD) was unable to support matriptase expression, and neither mutant formed a complex with activated matriptase. Matriptase did not localize to the cell surface when co-expressed with HAI-1dPKD. Moreover, HAI-1dPKD accumulated in the cytoplasm of HEK293T and HaCaT cells rather than localizing to the cell surface, presumably due to misfolding as judged by altered antibody recognition. On the other hand, activationlocked and activity-incompetent matriptase were stable and readily overexpressed and localized to the cell surface without HAI-1. Therefore, the observed matriptase instability was caused by its own catalytic activity in the absence of inhibitory HAI-1. The matriptase chaperone function of HAI-1 is thus mediated primarily by the inhibition of undesired intracellular matriptase activity, and the PKD domain is essential for the proper folding and trafficking of inhibitory HAI-1 and its chaperone function.

Primary cardiac angiosarcoma directly invading the right lung: An autopsy report.

We presented a difficult-to-diagnose case of cardiac angiosarcoma. The patient presented pericardial effusion, but cytology of the effusion was negative. Because cytological detection of angiosarcoma cells is difficult, a possibility of malignancy should not be excluded with negative cytological examination. Biopsy of cardiac mass is the best way for diagnosis.

Cutaneous metastasis emerging during chemotherapy and progressing during immunotherapy for urothelial carcinoma.

INTRODUCTION: Cutaneous metastasis of urothelial carcinoma is uncommon. We experienced a case of cutaneous metastasis that emerged during chemotherapy and progressed rapidly during immunotherapy for bladder tumor with lymph node metastasis. CASE PRESENTATION: A 77-year-old female patient received chemotherapy using gemcitabine and cisplatin for bladder urothelial carcinoma with para-aortic and pelvic lymph node metastases (clinical stage T2N1M1). After eight courses of chemotherapy, skin rash appeared in the lower abdomen with leg edema caused by multiple lymphadenopathy. Skin biopsy revealed cutaneous metastasis of urothelial carcinoma. The cutaneous tumor progressed rapidly and the patient died 5 weeks after the start of second-line pembrolizumab treatment. CONCLUSION: A patient with cutaneous metastasis of urothelial carcinoma that emerged during chemotherapy had poor prognosis and lack of efficacy of an immune checkpoint inhibitor.

Malignant pheochromocytoma with liver invasion treated successfully by combined retroperitoneal laparoscopic control of arterial in-flow followed by open hepatectomy: A case report.

INTRODUCTION: Pheochromocytoma surgery is generally challenging for surgeons and anesthesiologists for cardiovascular complications. PRESENTATION OF CASE: A 54-year-old Japanese man was found to have a large right pheochromocytoma infiltrating the posterior part of his liver and vena cava and multiple lung metastases. After retroperitoneal laparoscopic dissection of the dorsal side of the tumor and ligation of the feeding vessels, total resection of the primary tumor, extended posterior sectional hepatectomy, and partial vena cava resection were performed by open surgery via a thoracoabdominal approach. Abundant congestive bleeding with instability of vital signs occurred during transection. It could be finally controlled by dissect the remnant feeding artery in the inmost space. Prior control of arterial in-flow enabled successful completion of the planned surgical procedure. The patient has now survived for 27 months since resection of the primary lesion. CONCLUSION: Ligation of the feeding arteries to this hypervascular catecholamine-releasing tumor via a retroperitoneal laparoscopic approach prior to performing combined organ resection facilitated successful excision of this large malignant pheochromocytoma.

Decreased prostasin expression is associated with aggressiveness of oral squamous cell carcinoma.

Prostasin is a glycosylphosphatidylinositol-anchored serine protease widely expressed in epithelial cells, with crucial epidermal barrier functions. Evidence has suggested prostasin may have served as a tumor suppressor in various cancers, but its role in oral squamous cell carcinoma (OSCC) remains unclear. Thus, herein, we conducted an immunohistochemical prostasin study in 119 resected OSCC cases. Prostasin expression was decreased in 63% (75/119) of cases. OSCC with decreased prostasin immunoreactivity (low prostasin cases) tended to show a higher histological grade (p = 0.0088) and a more infiltrative cancer cell morphology (p = 0.0024). We then explored the role of prostasin in the OSCC cell lines: SAS and HSC-4. SAS did not express detectable prostasin levels, whereas HSC-4 expressed low but distinct levels. Prostasin overexpression suppressed the proliferation and migration of both OSCC lines in vitro. Conversely, prostasin silencing significantly enhanced growth rates of HSC-4. Finally, we analyzed the impact of prostasin expression on the prognosis of patients with OSCC; decreased expression tended to correlate with shorter overall survival (p = 0.0291) after resection. This trend was supported by our analyses using a public database (Kaplan-Meier plotter) of head and neck squamous cell carcinomas. In conclusion, we showed decreased prostasin expression was associated with aggressive features and a poorer prognosis of OSCC.

An adult case of a retroperitoneal isolated enteric duplication cyst with the imaging changes over time.

BACKGROUND: Adult cases of retroperitoneal isolated enteric duplication cyst (IEDC) are rare, with only 17 case reports in the relevant literature. We herein present a case, which was characterized by changes in intra-cystic density on computed tomography (CT), which was safely resected by laparoscopic surgery. CASE PRESENTATION: The patient was a 60-year-old male who received abdominal CT to investigate the cause of increased serum CA19-9 levels. CT revealed a unilocular cystic mass located in the lower right retroperitoneum. The size increased from 5 to 10 cm in three and a half years and the CT value decreased from 101 Hounsfield Units (HU) to 20 HU. We performed laparoscopic surgical resection, because the possibility that the enlargement of the lesion represented malignant transformation could not be denied. The large cystic mass firmly adhered to the appendix and its mesentery via the retroperitoneum, the appendix was resected en bloc with the cystic lesion. Microscopically, it had no communication with the appendix, and had an intestinal wall structure of muscularis mucosae and muscularis propria. The final pathological diagnosis was IEDC in the retroperitoneal space. There was no histological evidence of malignancy. CONCLUSION: When we encounter a retroperitoneal cystic lesion, we should consider the possibility of malignancy to determine the treatment strategy and perform a careful operation without breaking the cyst wall, irrespective of the preoperative diagnosis.

Severe Fever with Thrombocytopenia Syndrome Accompanied by Invasive Pulmonary Aspergillosis: An Autopsy Case.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tickborne infectious disease in China, Korea, and Japan caused by the SFTS virus (SFTSV). SFTS has a high mortality rate due to multiorgan failure. Recently, there are several reports on SFTS patients with mycosis. Here, we report a middle-aged Japanese SFTS patient with invasive pulmonary aspergillosis (IPA) revealed by an autopsy. A 61-year-old man with hypertension working in forestry was bitten by a tick and developed fever, diarrhea, and anorexia in 2 days. On day 4, consciousness disorder was appearing, and the patient was transferred to the University of Miyazaki Hospital. A blood test showed leukocytopenia, thrombocytopenia, as well as elevated levels of alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and creatine kinase. The SFTSV gene was detected in serum using a reverse-transcription polymerase chain reaction. On day 5, respiratory failure appeared and progressed rapidly, and on day 7, the patient died. An autopsy was performed that revealed hemophagocytosis in the bone marrow and bleeding of several organs. IPA was observed in lung specimens. SFTSV infection may be a risk factor for developing IPA. Early diagnosis and treatment of IPA may be important in patients with SFTS.

A rare association between true thymic hyperplasia and thyroid follicular tumor: a case report.

BACKGROUND: True thymic hyperplasia is a rare condition characterized by enlargement of the thymus while its normal structure is retained. True thymic hyperplasia is known to accompany Graves' disease, but no association between true thymic hyperplasia and thyroid follicular tumor has been reported so far. We report a case of true thymic hyperplasia in a patient with a thyroid follicular tumor. CASE PRESENTATION: A 52-year-old Japanese man was referred to our hospital for evaluation of a thyroid mass and a mediastinal mass. His serum thyroglobulin level was high, and hemithyroidectomy was performed to remove the thyroid mass. The resected mass was diagnosed as a follicular tumor of uncertain malignant potential. After resection of the thyroid lesion, the patient's serum thyroglobulin levels were markedly decreased. Seven months later, the patient underwent resection of the mediastinal mass. On pathological examination, the mass was found to consist of lobules, which formed a corticomedullary structure with Hassall's bodies, indicating a normal thymic mass with hyperplastic thymic tissue, less organized cellular cords, and intermingled adipose tissue. Immunostaining for cytokeratin 19 and cytokeratin 7 indicated that the lesion was consistent with thymic tissue. The lesion was diagnosed as true thymic hyperplasia, and the histological findings suggested that secondary atrophy had occurred. No evidence of recurrence was observed at 24 months after surgery. CONCLUSIONS: We present a case of a combination of true thymic hyperplasia and thyroidal follicular tumors that, to our knowledge, has not been reported previously. High serum thyroglobulin levels might play a role in hyperplasia of the thymus. Although true thymic hyperplasia is a rare disorder, it should be included in the differential diagnosis of a mediastinal mass in patients with thyroid disease.