Metastasizing aneurysmal dermatofibroma initially diagnosed as angiosarcoma confirmed by CD63::PRKCD fusion gene detection with nanopore sequencing.

Dermatofibroma (DF) is a benign tumor that forms pedunculated lesions ranging in size from a few millimeters to 2 cm, usually affecting the extremities and trunks of young adults. Histopathologically, DF is characterized by the storiform proliferation of monomorphic fibroblast-like spindle cells. In addition to neoplastic cells, secondary elements such as foamy histiocytes, Touton-type giant cells, lymphoplasmacytes, and epidermal hyperplasia are characteristic histological features. Several histological variants, including atypical, cellular, aneurysmal, and lipidized variants, have been reported; cases with variant histologies are sometimes misdiagnosed as sarcomas. We present a case of metastasizing aneurysmal DF that was initially diagnosed as an angiosarcoma on biopsy. A 26-year-old woman was referred to our hospital with a gradually enlarging subcutaneous mass in her lower left leg. Positron emission tomography-computed tomography revealed high fluorodeoxyglucose uptake not only in the tumor but also in the left inguinal region. On biopsy, ERG and CD31-positive atypical spindle cells proliferated in slit-like spaces with extravasation, leading to the diagnosis of angiosarcoma. Histology of the wide-resection specimen was consistent with DF, and lymph node metastasis was also observed. Nanopore DNA sequencing detected CD63::PRKCD fusion and copy number gain, although CD63 was not included in the target region of adaptive sampling. This report highlights the importance of recognizing the unusual clinical, radiological, and pathological features of DF to avoid misdiagnosis, and the potential diagnostic utility of nanopore sequencer.

The diagnostic utility of cytology specimen in a case of EWSR1::NFATC2 sarcoma.

EWSR1::NFATC2 sarcoma, a rare round cell sarcoma constituting the majority of EWSR1::non-ETS sarcomas, has recently been defined in the latest WHO classification. To date, the cytological findings of EWSR1::NFATC2 sarcoma remain undocumented. We present the case of a 25-year-old man with a history of polyostotic fibrous dysplasia in the right leg, referred to our hospital with left thigh pain. Cytological findings included metachromasia, minimally pleomorphic round cells, and eosinophilic infiltration. There was no precursor fibrous dysplasia and the initial diagnosis was undifferentiated pleomorphic sarcoma. Following histologic review, we successfully performed immunocytochemistry and fluorescence in situ hybridization (FISH) on archival cytology specimens. The tumor cells were positive for NKX2-2, NKX3-1, and PAX7 and showed amplified 5' single signals of EWSR1 gene. Reverse transcriptase-polymerase chain reaction revealed an in-frame fusion of EWSR1 and NFATC2. This report describes the cytological features of EWSR1::NFATC2 sarcoma and highlights the diagnostic utility of archival cytology specimens.

A case of primary pulmonary leiomyosarcoma completely resected after neoadjuvant chemotherapy.

BACKGROUND: Primary pulmonary leiomyosarcoma is a rare malignant tumor. We herein report a case of primary pulmonary leiomyosarcoma that was completely resected by surgery after neoadjuvant chemotherapy. CASE PRESENTATION: A 60-year-old man presented with cough. Chest computed tomography showed an 11-cm mass in the right upper lobe of the lung that had invaded the superior vena cava. Endobronchial ultrasound-guided transbronchial needle aspiration revealed leiomyosarcoma of the lung. We considered complete resection of the tumor to be very difficult because of the tumor invasion into the right atrium inflow of the superior vena cava, so we performed chemotherapy using doxorubicin for five cycles. After chemotherapy, the tumor size decreased to 5.6 cm, and we performed right upper lobectomy with combined resection of the superior vena cava. The tumor was completely resected by surgery. The patient is alive without recurrence 17 months postoperatively. CONCLUSIONS: We encountered a case of primary pulmonary leiomyosarcoma that was successfully treated by surgery after neoadjuvant chemotherapy. Doxorubicin monotherapy was effective in this case. Surgery combined with neoadjuvant chemotherapy should be considered for such cases, as a long-term survival can be achieved by complete resection of primary pulmonary leiomyosarcoma.

Prognostic factors and survival in Japanese patients with brain metastasis from renal cell cancer.

BACKGROUND: Patients with brain metastasis from renal cell carcinoma have poor outcomes despite recent advances in diagnosis and treatment. Moreover, factors affecting such poor outcomes are unclear. This study aimed to evaluate the prognostic factors associated with overall survival in renal cell carcinoma patients with brain metastasis. METHODS: We retrospectively reviewed the data of 50 consecutive patients with brain metastasis from renal cell carcinoma at our institution between 1988 and 2017. The evaluated prognostic factors for overall survival included clinicopathological factors at diagnosis, treatment for brain metastasis, and the Graded Prognostic Assessment score of renal cell carcinoma. The associations between preoperative clinicopathological factors and overall survival were assessed using the log-rank test and Cox proportional hazards models for univariate and multivariate analyses, respectively. RESULTS: Forty-five patients were included, among whom 39 died during follow-up. The median follow-up was 8.2 months. The median survival time was 8.2 months (95% confidence interval 5.5-13.7). A Graded Prognostic Assessment score ≤ 2 (hazard ratio 1.967; 95% confidence interval 1.024-3.892; P = 0.042), the presence of sarcomatoid components (hazard ratio 3.299; 95% confidence interval 1.424-7.193; P = 0.007), and no treatment for brain metastasis (hazard ratio 2.594; 95% confidence interval 1.033-5.858; P = 0.043) were independently associated with poor prognosis in the multivariate analysis. CONCLUSIONS: Patients with renal cell carcinoma who develop brain metastasis have poor overall survival. The Graded Prognostic Assessment score, sarcomatoid components, and treatment for brain metastasis from renal cell carcinoma were independent factors associated with prognosis.

Sendai virus-mediated expression of reprogramming factors promotes plasticity of human neuroblastoma cells.

Neuroblastoma (NB) is the most common extracranial solid tumor that originates from multipotent neural crest cells. NB cell populations that express embryonic stem cell-associated genes have been identified and shown to retain a multipotent phenotype. However, whether somatic reprogramming of NB cells can produce similar stem-cell like populations is unknown. Here, we sought to reprogram NB cell lines using an integration-free Sendai virus vector system. Of four NB cell lines examined, only SH-IN cells formed induced pluripotent stem cell-like colonies (SH-IN 4F colonies) at approximately 6 weeks following transduction. These SH-IN 4F colonies were alkaline phosphatase-positive. Array comparative genomic hybridization analysis indicated identical genomic aberrations in the SH-IN 4F cells as in the parental cells. SH-IN 4F cells had the ability to differentiate into the three embryonic germ layers in vitro, but rather formed NBs in vivo. Furthermore, SH-IN 4F cells exhibited resistance to cisplatin treatment and differentiated into endothelial-like cells expressing CD31 in the presence of vascular endothelial growth factor. These results suggest that SH-IN 4F cells are partially reprogrammed NB cells, and could be a suitable model for investigating the plasticity of aggressive tumors.

Solid variant type of serous cystadenocarcinoma of the pancreas: a case report and review of the literature.

Serous cystic neoplasms (SCN) of the pancreas are typically honeycombed microcystic masses, which are believed to be benign entity. This report describes a case of a 69-year-old man with a rare solid type of serous cystadenocarcinoma of the pancreas with liver metastases. A 6-cm well enhanced pancreatic tumor and multiple liver nodules were depicted with contrast medium on computed tomography scan. Distal pancreatectomy was performed at first operation. The cut surface of the tumor was solid and glossy appearance. Second operation of liver resection for all metastatic nodules was performed 27 months after the initial operation. The tumor cells in both the pancreas and the liver had cytoplasmic periodic acid-Schiff positive granules, which were completely digested by diastase. Eleven cases of serous cystadenocarcinoma of the pancreas have been reported in the literature. To our knowledge, this is the first case of a solid type serous cystadenocarcinoma.

NCYM, a Cis-antisense gene of MYCN, encodes a de novo evolved protein that inhibits GSK3ß resulting in the stabilization of MYCN in human neuroblastomas.

The rearrangement of pre-existing genes has long been thought of as the major mode of new gene generation. Recently, de novo gene birth from non-genic DNA was found to be an alternative mechanism to generate novel protein-coding genes. However, its functional role in human disease remains largely unknown. Here we show that NCYM, a cis-antisense gene of the MYCN oncogene, initially thought to be a large non-coding RNA, encodes a de novo evolved protein regulating the pathogenesis of human cancers, particularly neuroblastoma. The NCYM gene is evolutionally conserved only in the taxonomic group containing humans and chimpanzees. In primary human neuroblastomas, NCYM is 100% co-amplified and co-expressed with MYCN, and NCYM mRNA expression is associated with poor clinical outcome. MYCN directly transactivates both NCYM and MYCN mRNA, whereas NCYM stabilizes MYCN protein by inhibiting the activity of GSK3ß, a kinase that promotes MYCN degradation. In contrast to MYCN transgenic mice, neuroblastomas in MYCN/NCYM double transgenic mice were frequently accompanied by distant metastases, behavior reminiscent of human neuroblastomas with MYCN amplification. The NCYM protein also interacts with GSK3ß, thereby stabilizing the MYCN protein in the tumors of the MYCN/NCYM double transgenic mice. Thus, these results suggest that GSK3ß inhibition by NCYM stabilizes the MYCN protein both in vitro and in vivo. Furthermore, the survival of MYCN transgenic mice bearing neuroblastoma was improved by treatment with NVP-BEZ235, a dual PI3K/mTOR inhibitor shown to destabilize MYCN via GSK3ß activation. In contrast, tumors caused in MYCN/NCYM double transgenic mice showed chemo-resistance to the drug. Collectively, our results show that NCYM is the first de novo evolved protein known to act as an oncopromoting factor in human cancer, and suggest that de novo evolved proteins may functionally characterize human disease.

Importance of confirming HER2 overexpression of recurrence lesion in breast cancer patients.

BACKGROUND: The systemic management of metastatic breast cancer (MBC) is usually based on ER or HER2 status of the primary tumor. However, the hormonal status or the overexpression of human epidermal growth factor 2 (HER2) may change in every metastatic site because of the effects of the long-term treatment of metastatic cancer with endocrine therapy, chemotherapy, or biological agents. The purpose of this study was to investigate the frequency of change in HER2 expression in primary and distant metastatic tumors in breast cancer patients. Another objective of the study was to examine the effect of the clinical therapy on the basis of HER2 expression in a metastatic tumor. MATERIALS AND METHODS: In our hospital between 1991 to December 2010, retrospectively, 156 patients had biopsy or surgical resection of their metastatic site. All sample were analyzed pathologically to confirm metastatic disease and, second, to evaluate HER2 status by immunohistochemistry or by FISH. RESULTS: The recurrence lesions were resected from the breast or lymph node (n = 67, local lesion), brain (n = 27), lung (n = 16), liver (n = 20), bone (n = 16), and from the stomach, intestine, ovary, and uterus (n = 10). Loss, increase, or no change in HER2 overexpression was observed in 3, 5, and 92%, respectively. Positive changes of HER2 in metastatic sites were 3 (4%) local lesion, 3 (11%) brain, 1 (7%) lung, 0 (0%) liver, 2 (17%) bone, and 0 (0%) others. In 3 of these 8 patients, trastuzumab was administered. In 2 of 3 patients, trastuzumab achieved long stable disease. The negative conversion rate of HER2 expression in metastatic lesions was 37% in patients treated with trastuzumab and 6% in those not treated with trastuzumab, a significant difference between the two groups (P < 0.05). CONCLUSIONS: The results of this study emphasize the significance of confirming HER2 expression in a recurrence lesion. For patients with positive conversion of HER2 status, more treatment options may be available. On the other hand, the rate of loss of HER2 expression was high in patients treated with trastuzumab, suggesting that the results of biopsy may provide an opportunity to reconsider treatment strategies for these patients.

Fragmented hyaluronan is an autocrine chemokinetic motility factor supported by the HAS2-HYAL2/CD44 system on the plasma membrane.

Hyaluronan (HA) is synthesized by HA synthase (HAS) 1, HAS2 and HAS3, and degraded by hyaluronidase (HYAL) 1 and HYAL2 in a CD44-dependent manner. HA and HYALs are intricately involved in tumor growth and metastasis. Random cell movement is generally described as chemokinesis, and represents an important step at the beginning of tumor cell liberation from the primary site. To investigate the roles of HAS2 and HYAL2/CD44 in cell motility, we examined HeLa-S3 cells showing spontaneous chemokinesis. HeLa-S3 cells expressed HAS2 and HAS3. siRNA-mediated knockdown of HAS2 decreased spontaneous chemokinesis of HeLa-S3 cells. Although HeLa-S3 cells secreted 50 ng/ml of high molecular weight (HMW)-HA (peak: 990 kDa) into the culture supernatant after 6 h of culture, exogenously added HMW-HA did not enhance spontaneous chemokinesis of the cells. These observations suggested that HeLa-S3 cells may have a self-degrading system for HA to regulate their spontaneous chemokinesis. To examine this possibility, we investigated the effects of siRNA-mediated knockdown of HYAL2 or CD44 on the spontaneous chemokinesis of HeLa-S3 cells. Knockdown of either molecule decreased the spontaneous chemokinesis of the cells. Low molecular weight (LMW)-HA (23 kDa) reversed the HYAL2 siRNA-mediated reduction in spontaneous chemokinesis of HeLa-S3 cells to the level in control cells stimulated with the same HA. These findings indicate that the HAS2-HYAL2/CD44 system may support spontaneous chemokinesis of human cancer cells through self-degradation of HMW-HA to produce LMW-HA by an autocrine mechanism. Consequently, our study may further expand our understanding of HA functions in cancer.

Overexpression of human ortholog of mammalian enabled (hMena) is associated with the expression of mutant p53 protein in human breast cancers.

The human ortholog of mammalian enabled (hMena), a member of the enabled/vasodilator-stimulated phosphoprotein (Ena/VASP) family, is an actin regulatory protein involved in the regulation of cell motility. Increasing evidence suggests that hMena overexpression is involved in human cancers, but the upstream events that influence the expression of hMena remain to be elucidated. In this study, we performed immunohistochemical analysis of the expression of hMena protein in paraffin-embedded archival tissues of infiltrating ductal carcinomas (IDCs) obtained from 52 cases. We found that elevated hMena expression is associated with larger tumor size (>2.5 cm, p<0.01), HER2 expression (p<0.05), p53 index (p<0.03) and Ki67 index (p<0.01), suggesting that hMena is a predictor of poor prognosis in IDCs. The histological characteristics of each specimen showed that hMena was overexpressed in the tumor cells at the invasive front of IDCs, indicating that hMena expression is at least partly mediated by tumor cell-matrix interactions. To explore the role of the absence of p53 function in hMena overexpression of IDCs, wild-type p53 cDNA was introduced into SW620 cells, which originally express mutant p53. In wild-type p53-transfected cells, hMena mRNA expression was decreased to 70% of the levels in mock transfected cells (p<0.01). In conclusion, our study indicates that hMena overexpression is involved in the progression of IDCs, and raises the possibility that wild-type p53 may suppress hMena expression.

Visualization of the Activity of Rac1 Small GTPase in a Cell.

Rho family G proteins including Rac regulate a variety of cellular functions, such as morphology, motility, and gene expression. Here we developed a fluorescence resonance energy transfer-based analysis in which we could monitor the activity of Rac1. To detect fluorescence resonance energy transfer, yellow fluorescent protein fused Rac1 and cyan fluorescent protein fused Cdc42-Rac1-interaction-binding domain of Pak1 protein were used as intermolecular probes of FRET. The fluorophores were separated with linear unmixing method. The fluorescence resonance energy transfer efficiency was measured by acceptor photobleaching assisted assay. With these methods, the Rac1 activity was visualized in a cell. The present findings indicate that this approach is sensitive enough to achieve results similar to those from ratiometric fluorescence resonance energy transfer analysis.

Human Mena associates with Rac1 small GTPase in glioblastoma cell lines.

Mammarian enabled (Mena), a member of the Enabled (Ena)/Vasodilator-stimulated phosphoprotein (VASP) family of proteins, has been implicated in cell motility through regulation of the actin cytoskeleton assembly, including lamellipodial protrusion. Rac1, a member of the Rho family GTPases, also plays a pivotal role in the formation of lamellipodia. Here we report that human Mena (hMena) colocalizes with Rac1 in lamellipodia, and using an unmixing assisted acceptor depletion fluorescence resonance energy transfer (u-adFRET) analysis that hMena associates with Rac1 in vivo in the glioblastoma cell line U251MG. Depletion of hMena by siRNA causes cells to be highly spread with the formation of lamellipodia. This cellular phenotype is canceled by introduction of a dominant negative form of Rac1. A Rac activity assay and FRET analysis showed that hMena knock-down cells increased the activation of Rac1 at the lamellipodia. These results suggest that hMena possesses properties which help to regulate the formation of lamellipodia through the modulation of the activity of Rac1.

Aberrant expression of human ortholog of mammalian enabled (hMena) in human colorectal carcinomas: implications for its role in tumor progression.

The human ortholog of mammalian enabled (hMena), a family of enabled/vasodilator-stimulated phosphoprotein (Ena/VASP), is an actin regulatory protein involved in the regulation of cell motility. Increasing evidence suggests that hMena over-expression is involved in human breast cancers, whereas the significance of hMena expression in colorectal carcinomas remains to be elucidated. In this study, we assessed the relative mRNA level of hMena using real-time PCR, showing that there is a statistically significant increase of hMena transcripts in matched human colorectal carcinomas and adjacent non-neoplastic colorectal epithelium (n=6, P=0.046). We also performed immunohistochemical analysis of the expression of hMena protein in 50 cases of paraffin-embedded archival colorectal tissues, and found that an elevated hMena expression is correlated to the cases with advanced TNM stages of colorectal carcinomas (P<0.001). On further inspection of immunohistochemical features of each specimen, we observed intensified hMena staining in the invasive front of colorectal carcinomas, especially in tumor budding, a transition from glandular structure to single or small clusters of cells at the invasive front. We demonstrated that there was a significantly increased hMena staining in the tumor budding as compared with more morphologically-differentiated areas of colorectal carcinomas, indicating that hMena over-expression may have a role in the initial steps of tumor invasion from primary sites. We performed in vitro motility assays to show that transient hMena transfection markedly enhanced the chemotactic/chemokinetic activity of HeLaS3 cells (P<0.001). Taken together, these results suggest that hMena over-expression is implicated in the progression of colorectal carcinomas by positively affecting the migratory phenotype of cancer cells.

Collision of advanced gastric adenocarcinoma and gastrointestinal stromal tumour: a case report.

We present a case of an 83-year-old female patient with a collision tumour of an advanced Borrmann type 4 gastric cancer and a large gastric gastrointestinal stromal tumour (GIST). According to the deformity of the gastric wall caused by the GIST, type 4 cancer was difficult to identify by oesophagogastroduodenoscopy (OGD). The patient died of progressive gastric cancer related disease. While the mechanism of histogenesis of the simultaneous adenocarcinoma and GIST remains to be determined, the present case suggests that gastric adenocarcinoma has a more adverse effect on prognosis than does GIST. Additionally, this case suggests that thorough inspection of GIST patients is required at the OGD and at the pathology facility, in order to avoid overlooking the underlying cancer.

CD44 suppresses TLR-mediated inflammation.

The cell adhesion molecule CD44, which is the major hyaluronan receptor, has been implicated in the binding, endocytosis, and metabolism of hyaluronan. Previous studies have revealed that CD44 plays crucial roles in a variety of inflammatory diseases. In recent years, TLRs, which are ancient microbial pattern recognition receptors, have been shown to initiate an innate immune response and have been linked to a variety of inflammatory diseases. The present study shows that CD44 negatively regulates in vivo inflammation mediated by TLRs via NF-kappaB activation, which leads to proinflammatory cytokine production. Furthermore, our results show that CD44 directly associates with TLR2 when stimulated by the TLR2 ligand zymosan and that the cytoplasmic domain of CD44 is crucial for its regulatory effect on TLR signaling. This study indicates that CD44 plays a protective role in TLR-mediated inflammation and is the first to demonstrate a direct association between CD44 and a TLR.

The activity of RhoA is correlated with lymph node metastasis in human colorectal cancer.

Rho family GTPases play a pivotal role in the regulation of numerous cellular functions associated with malignant transformation and metastasis. To evaluate the role of these GTPases in colorectal cancer, the protein expression levels and activities of these proteins in matched sets of tumor and non-tumor tissues of surgical specimens were analyzed. The relationship between the protein levels and activities in tumor tissues to the clinicopathological features was also assessed. The expression levels of RhoA, active RhoA, Rac1, and active Rac1 in tumor tissues were higher than in normal tissues. The amounts of active RhoA protein in primary tumors correlated with lymph nodes metastasis. No relationship was noted between the protein expression levels and other clinicopathological findings. These findings suggest that the Rho family small GTPases are related to malignant transformation and progression of colorectal cancer and the activation of RhoA is associated with the lymph node metastasis.