Usefulness of cell block examination for the cytological diagnosis of thoracic SMARCA4-deficient undifferentiated tumor: A case report.

SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) is a high-grade malignant neoplasm showing undifferentiated or rhabdoid morphology that significantly involves the thorax of adults. It has been reported as SMARCA4-deficient thoracic sarcoma or SMARCA4-deficient non-small cell lung carcinoma according to the findings of immunohistochemical and genetic studies. We report a case of thoracic SMARCA4-UT for which cell block analysis and immunohistochemical staining were useful for the final diagnosis. A 51-year-old man had a chief complaint of left back pain and visited our hospital for further examination. Cytological examination of a left pleural effusion was performed and we also made a cell block of the pleural effusion. Cytological examination revealed polyhedral to round tumor cells. The tumor cells appeared singly or formed loosely cohesive clusters. The nuclei were round to oval, enlarged, and sometimes eccentric with prominent nucleoli with irregular borders. The nuclear chromatin was unevenly distributed. The cytoplasm was vacuolar to eosinophilic. There were no characteristic structures of tumor cells. The cell block revealed many single or loosely cohesive round to epithelioid cells. Some tumor cells often exhibited eccentrically located nuclei and lightly eosinophilic cytoplasm, showing a rhabdoid morphology. On immunohistochemistry, the tumor cells were positive for SOX-2 and they demonstrated significantly reduced SMARCA4 (BRG1) expression; SMARCA2 (BRM) and SMARCB1 (INI1) expression were retained. Accordingly, we made a diagnosis of SMARCA4-UT. This case demonstrates the importance of performing histological and immunohistochemical analysis using cell blocks for immediate diagnosis.

Novel rapid immunohistochemistry using an alternating current electric field identifies Rac and Cdc42 activation in human colon cancer FFPE tissues.

It is important to determine the activation status of Rac and Cdc42 in cancer tissues for the prediction of metastasis and patient prognosis. However, it has been impossible to detect their spatial activation on formalin-fixed paraffin embedded (FFPE) surgical specimens thus far. Here, we established a novel detection technique for activated Rac/Cdc42 in human colon cancer FFPE tissues by using a p21-activated kinase (PAK)-Rac binding domain (RBD) detection probe fused with glutathione S-transferase (GST), designated GST-PAK-RBD, and novel rapid-immunohistochemistry (R-IHC) systems using noncontact alterating-current electric field mixing, although there is a technical limitation in that it may not distinguish between Rac members and Cdc42. In 50 cases of colon cancer, various activation patterns of Rac/Cdc42 were observed, which were designated plasma membrane, cytoplasm, mixed pattern, and polarized distribution. The activity was striking in the invasive fronts of tumors and significantly correlated with tumor invasion properties evaluated by TNM classification. Of note, in tissue microarray (TMA) samples, 29 of 33 cases demonstrated higher Rac1/Cdc42 activity in the tumor area than the corresponding normal mucosa. In addition, positive correlations were detected between Rac/Cdc42 activity and clinicopathological factors such as venous and lymphatic vessel invasion. These results suggest that understanding Rac and Cdc42 activations in cancer tissues would be valuable as an option for molecular therapy as personalized medicine.

De novo development of proteolytically resistant therapeutic peptides for oral administration.

The oral administration of peptide drugs is hampered by their metabolic instability and limited intestinal uptake. Here, we describe a method for the generation of small target-specific peptides (less than 1,600 Da in size) that resist gastrointestinal proteases. By using phage display to screen large libraries of genetically encoded double-bridged peptides on protease-resistant fd bacteriophages, we generated a peptide inhibitor of the coagulation Factor XIa with nanomolar affinity that resisted gastrointestinal proteases in all regions of the gastrointestinal tract of mice after oral administration, enabling more than 30% of the peptide to remain intact, and small quantities of it to reach the blood circulation. We also developed a gastrointestinal-protease-resistant peptide antagonist for the interleukin-23 receptor, which has a role in the pathogenesis of Crohn's disease and ulcerative colitis. The de novo generation of targeted peptides that resist proteolytic degradation in the gastrointestinal tract should help the development of effective peptides for oral delivery.

Imprint cytology of biphenotypic sinonasal sarcoma of the paranasal sinus: A case report.

Biphenotypic sinonasal sarcoma (BSNS) is a rare low-grade spindle cell sarcoma that predominantly affects middle-aged women with multiple tumors in the sinonasal tract. BSNS shows biphenotypic expression of neural and myogenic markers on immunohistochemistry (IHC) with a specific chimeric PAX3-MAML3 fusion. The cytological features of BSNS have so far not been reported. Here, we describe a case of BSNS including findings of imprint cytology, histology, IHC, and genetic analysis. A 30-year-old woman presented with a nodular tumor that completely occupied the ethmoid sinus. The tumor was resected and submitted for imprint cytology, which revealed relatively bland spindle tumor cells that had mildly enlarged oval to spindle-shaped nuclei with fine nuclear chromatin and a thin nuclear rim in a clear background. Nucleoli were inconspicuous and there was no significant nuclear atypia and pleomorphism. These cytological findings were consistent with the histology of low-grade spindle cell sarcoma in BSNS. On IHC, the tumor cells were focally positive for S-100 protein and α-smooth muscle actin; nuclear ß-catenin expression was also seen. PAX3 split signals were detected in 52% of tumor cells by fluorescence in situ hybridization. Reverse transcriptase-polymerase chain reaction also identified a chimeric PAX3-MAML3 fusion gene. Based on these findings, we diagnosed the tumor as BSNS. Our findings revealed that a relatively bland spindle cell cytology with a clear background is a characteristic feature of BSNS. BSNS should therefore be differentiated from benign and bland-appearing malignant spindle cell tumors and the combination of cytology, histology, IHC, and genetic analysis facilitates the diagnosis of BSNS.

Rapid immunocytochemistry based on alternating current electric field using squash smear preparation of central nervous system tumors.

The role of intraoperative pathological diagnosis for central nervous system (CNS) tumors is crucial for neurosurgery when determining the surgical procedure. Especially, treatment of carmustine (BCNU) wafers requires a conclusive diagnosis of high-grade glioma proven by intraoperative diagnosis. Recently, we demonstrated the usefulness of rapid immunohistochemistry (R-IHC) that facilitates antigen-antibody reaction under alternative current (AC) electric field in the intraoperative diagnosis of CNS tumors; however, a higher proportion of water and lipid in the brain parenchyma sometimes leads to freezing artifacts, resulting in poor quality of frozen sections. On the other hand, squash smear preparation of CNS tumors for cytology does not affect the frozen artifacts, and the importance of smear preparation is now being re-recognized as being better than that of the tissue sections. In this study, we established the rapid immunocytochemistry (R-ICC) protocol for squash smears of CNS tumors using AC electric field that takes only 22 min, and demonstrated its usefulness for semi-quantitative Ki-67/MIB-1 labeling index and CD 20 by R-ICC for intraoperative diagnosis. R-ICC by AC electric field may become a substantial tool for compensating R-IHC and will be applied for broad antibodies in the future.

A case of cerebral astroblastoma with rhabdoid features: a cytological, histological, and immunohistochemical study.

Astroblastoma is a rare neuroepithelial neoplasm of unknown origin, usually occurring in children and young adults. Here we report a case of astroblastoma with uncommon features in an 18-year-old female. The tumor was a well-circumscribed cystic and solid mass with marked gadolinium enhancement in the right frontal lobe. Cytological examination showed polarized monopolar cells with diminished cohesiveness. Tumor cells possessed eccentric round to oval nuclei with abundant eosinophilic cytoplasm, sometimes having cytoplasmic processes. Histopathologically, the tumor showed perivascular pseudorosettes with prominent vascular sclerosis. Foam cells were frequently infiltrated around blood vessels and among tumor cells. In some areas, a solid growth pattern of plump tumor cells with abundant inclusion-like eosinophilic cytoplasm showing rhabdoid appearance was observed. The immunohistochemical study revealed strong and diffuse positivity for vimentin and epithelial membrane antigen. Tumor cells were focally positive for glial fibrillary acidic protein and cytokeratin AE1/AE3. Nuclear immunoreactivity for INI1 protein was evident. The Ki-67 labeling index was 10.8%. This tumor was finally diagnosed as low-grade astroblastoma and the patient had no evidence of recurrence without postoperative radiotherapy or chemotherapy during the last 6 months of follow-up. This report describes novel cytological, histopathological, and immunohistochemical features of the rare tumor.

Structure-Based Development of a Protein-Protein Interaction Inhibitor Targeting Tumor Necrosis Factor Receptor-Associated Factor 6.

The interactions between tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) and TNF superfamily receptors (TNFRSFs) are promising targets for rheumatoid arthritis (RA) treatment. However, due to the challenging nature of protein-protein interactions (PPIs), a potent inhibitor that surpasses the affinity of the TRAF6-TNFRSF interactions has not been developed. We developed a small-molecule PPI inhibitor of TRAF6-TNFRSF interactions using NMR and in silico techniques. The most potent compound, TRI4, exhibited an affinity higher than those of TNFRSFs and competitively inhibited a TRAF6-TNFRSF interaction. Structural characterization of the TRAF6-TRI4 complex revealed that TRI4 supplants key interactions in the TRAF6-TNFRSF interfaces. In addition, some TRAF6-TRI4 interactions extend beyond the TRAF6-TNFRSF interfaces and increase the binding affinity. Our successful development of TRI4 provides a new opportunity for RA treatment and implications for structure-guided development of PPI inhibitors.

CD133 expression: a potential prognostic marker for non-small cell lung cancers.

BACKGROUND: CD133 is a membrane glycoprotein containing five transmembrane loops. Previous reports suggest that a CD133-positive subpopulation of multipotent cells with extensive proliferative and self-renewal characteristics has biological features of a cancer stem cell. In addition, the presence of CD133-positive cells was associated with a significantly poorer prognosis for some solid tumors, compared to those with CD133-negative cells. However, the clinicopathological significance of CD133 in non-small cell lung cancer (NSCLC) remains controversial. METHODS: We conducted immunohistochemical assessment of 161 NSCLCs surgically resected at Hokkaido University Hospital between 1982 and 1994 to evaluate correlations between CD133 expression and various clinicopathological features. RESULTS: CD133 expression was significantly correlated with pathological stages (pStages) II, III, and IV for the various NSCLC types analyzed and was an independent factor for unfavorable prognosis in this population (hazard ratio = 3.157, P = 0.015). CONCLUSION: CD133 expression was correlated with pStage and was predictive of unfavorable prognosis in patients with pStages II, III, and IV NSCLC. These results suggest the possibility of using CD133 as a novel prognostic marker in these patients.

Clinicopathological analysis of early-stage gastric cancers detected after successful eradication of Helicobacter pylori.

BACKGROUND AND AIMS: The results of a randomized controlled study and meta-analysis study have recently proved that Helicobacter pylori eradication has a preventive effect against the development of metachronous and primary gastric cancer. However, gastric cancer is sometimes detected after successful eradication. There is a lack of study about gastric cancers in eradicated patients. To clarify the characteristics of gastric cancers detected after H. pylori eradication, we analyzed the clinicopathological features of these cancers. METHODS: The subjects were 18 early-stage gastric cancer specimens resected from 17 patients who had received successful eradication of H. pylori from February 1995 to March 2009. The control group consisted of 36 specimens from noneradicated patients with persistent H. pylori infection who were matched with the subjects in age, sex, and depth of invasion. Clinicopathological features and mucin phenotypes of gastric cancer were clinically and immunohistologically evaluated. RESULTS: The average diameter of gastric cancer was smaller and Ki-67 index was lower in the eradication group. The morphological distribution of depression types was significantly lower in the control group. Immunohistochemical phenotyping revealed that 72.2% of the lesions in the eradicated group were complete gastric type or gastric predominant mixed type, whereas the percentages of gastric type and intestinal type in the control group were similar. CONCLUSION: Our findings indicate that the clinicopathological characteristics of gastric cancers detected after H. pylori eradication are different from those of gastric cancers in patients with persistent H. pylori infection. H. pylori eradication may suppress intestinalization during the development of gastric cancer.

Establishment and characterization of amylase-producing lung adenocarcinoma cell line, IMEC-2.

BACKGROUND: Few studies have successfully established an amylase-producing lung cancer cell line or have examined its cytological, biochemical and biological features. PATIENTS AND METHODS: Cancer cells, isolated from pleural effusion using a gradient method, were cultivated. RESULTS: Amylase production from the newly established cell line was confirmed by positive staining for alpha-amylase and increased amylase levels in the culture supernatant. Electron microscopy revealed zymogen granule-like structures. Sialylation of salivary-type amylase was confirmed directly from the cell line by examining the neuraminidase sensitivity and amylase elution profile under high-performance liquid chromatography. Neither EGFR or KRAS mutation were found. CONCLUSION: This cell line offers a useful tool for analyzing the pathogenesis and pathophysiology of amylase-producing lung cancers. Moreover, it might be useful for probing the metastasis and invasiveness of lung cancer cells and for developing an early diagnostic method based on sialylated salivary-amylase production.

Inverted papilloma of the nasal cavity presenting with massive amounts of squamous metaplastic cells in sputum. A case report.

BACKGROUND: Squamous metaplasic cells are rarely seen in sputum of female nonsmokers. CASE: A 47-year-old female nonsmoker presented with massive amounts of squamous metaplasic cells in sputum and an elevated level of squamous cell carcinoma (SCC) antigen in serum present for months, while no causative lesion was detected either by lung computed tomography or bronchoscopy. The patient was eventually diagnosed as having inverted papilloma in the right nasal cavity. Resection of the tumor brought about disappearance of squamous metaplastic cells in sputum and return of serum SCC antigen to the normal range. CONCLUSION: This case clearly demonstrates that squamous metaplastic cells in sputum can originate in lesions in the nasal cavity, although they are rare. It should be kept in mind that the nasal cavity is a potential site producing squamous metaplastic cells in sputum.