Publications by authors named "S Kuwao"

109 Publications

Filter paper-assisted cell transfer (FaCT) technique: A novel cell-sampling technique for intraoperative diagnosis of central nervous system tumors.

Cancer Cytopathol 2017 Apr 5;125(4):277-282. Epub 2017 Jan 5.

Department of Diagnostic Pathology and Cytology, Higashiyamato Hospital, Higashiyamato, Tokyo, Japan.

Background: Intraoperative diagnosis of central nervous system (CNS) tumors provides critical guidance to surgeons in the determination of surgical resection margins and treatment. The techniques and preparations used for the intraoperative diagnosis of CNS tumors include frozen sectioning and cytologic methods (squash smear and touch imprint). Cytologic specimens, which do not have freezing artifacts, are important as an adjuvant tool to frozen sections. However, if the amount of submitted tissue samples is limited, then it is difficult to prepare both frozen sections and squash smears or touch imprint specimens from a single sample at the same time. Therefore, the objective of this study was to derive cells directly from filter paper on which tumor samples are placed.

Methods: The authors established the filter paper-assisted cell transfer (FaCT) smear technique, in which tumor cells are transferred onto a glass slide directly from the filter paper sample spot after the biopsy is removed.

Results: Cell yields and diagnostic accuracy of the FaCT smears were assessed in 40 CNS tumors. FaCT smears had ample cell numbers and well preserved cell morphology sufficient for cytologic diagnosis, even if the submitted tissues were minimal. The overall diagnostic concordance rates between frozen sections and FaCT smears were 90% and 87.5%, respectively (no significant differences). When combining FaCT smears with frozen sections, the diagnostic concordance rate rose to 92.5%.

Conclusions: The current results suggest that the FaCT smear technique is a simple and effective processing method that has significant value for intraoperative diagnosis of CNS tumors. Cancer Cytopathol 2017;125:277-282. © 2016 American Cancer Society.
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April 2017

Immunohistochemical expression profiles of solute carrier transporters in alpha-fetoprotein-producing gastric cancer.

Histopathology 2016 Nov 25;69(5):812-821. Epub 2016 Jul 25.

Division of Diagnostic Pathology and Cytology, Higashiyamato Hospital, Higashiyamato, Tokyo, Japan.

Aims: Alpha-fetoprotein (AFP)-producing gastric cancer (GC) is an aggressive tumour with high rates of liver metastasis and poor prognosis, and for which a validated chemotherapy regimen has not been established. Drug uptake by solute carrier (SLC) transporters is proposed as one of the mechanisms involved in sensitivity to chemotherapy. In this study, we aimed to develop important insights into effective chemotherapeutic regimens for AFP-producing GC.

Methods And Results: We evaluated immunohistochemically the expression levels of a panel of SLC transporters in 20 AFP-producing GCs and 130 conventional GCs. SLC transporters examined were human equilibrative nucleoside transporter 1 (hENT1), organic anion transporter 2 (OAT2), organic cation transporter (OCT) 2, OCT6 and organic anion-transporting polypeptide 1B3 (OATP1B3). The rates of high expression levels of hENT1 (hENT1 ) and OAT2 (OAT2 ) were statistically higher in AFP-producing GC, compared with conventional GC. When analysing hENT1 and OAT2 in combination, hENT1 /OAT2 was the most particular expression profile for AFP-producing GC, with a greater significance than hENT1 or OAT2 alone. However, no significant differences in OCT2, OCT6 or OATP1B3 levels were detected between AFP-producing and conventional GCs. However, immunoreactivity for hENT1, OAT2 and OCT6 tended to be increased in GC tissues compared with non-neoplastic epithelia.

Conclusions: Because hENT1 and OAT2 are crucial for the uptake of gemcitabine and 5-fluorouracil, respectively, our results suggest that patients with AFP-producing GC could potentially benefit from gemcitabine/fluoropyrimidine combination chemotherapy. Increased expression of hENT1, OAT2 and OCT6 may also be associated with the progression of GC.
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November 2016

Rapid immunocytochemistry with simple heat-induced antigen retrieval technique for improvement in the quality of cytological diagnosis.

J Histochem Cytochem 2013 Dec 4;61(12):920-30. Epub 2013 Sep 4.

Section of Molecular Pathology, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Yushima, Bunkyo-ku, Tokyo, Japan (TD, MS).

Rapid immunocytochemistry (ICC) can improve the accuracy of intraoperative cytological diagnoses; however, it is usually applied without heat-induced antigen retrieval (HIAR). We established a HIAR method for rapid ICC and evaluated its efficacy and reliability. Rapidly fixed smear samples were immunostained using 35 antibodies. We compared the results of HIAR by boiling in a pot or heating in an electric kettle. The smears were incubated for 3 min with each primary antibody and immuno-enzyme polymer reagent, and for 1 min with diaminobenzidine solution. HIAR for 1 min using the kettle method yielded the best cellular integrity. For 32 out of the 35 antibodies, results achieved using rapid ICC within 11 min were comparable to that achieved using standard ICC. HIAR was essential for 13 antibodies. For two of the antibodies, HIAR was not required when standard ICC was applied, but consistent staining with rapid ICC was obtained only with HIAR. In conclusion, we established a rapid ICC procedure using a simple HIAR method, which allowed efficient immunostaining of a panel of antigens, including nuclear antigens, within only 11 min. The combined use of this rapid ICC technique with other staining techniques could be useful for improving intraoperative cytological diagnoses.
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December 2013

Differential diagnosis of reactive mesothelial cells and malignant mesothelioma cells using the cell proliferation markers minichromosome maintenance protein 7, geminin, topoisomerase II alpha and Ki-67.

Acta Cytol 2013 12;57(4):384-90. Epub 2013 Jul 12.

Department of Pathological Analysis, Division of Medical Life Sciences, Hirosaki University Graduate School of Health Sciences, Hirosaki, Japan.

Objective: The aim of this study was to evaluate whether the immunocytochemical expression of cell proliferation markers, such as minichromosome maintenance protein 7 (MCM 7), geminin, topoisomerase II alpha (topo IIα) and Ki-67, which are different types of cell proliferation markers, could be useful for their differential diagnosis in reactive mesothelial cells and malignant mesothelioma cells obtained from body cavity fluids.

Study Design: Samples diagnosed and later histologically confirmed as reactive mesothelial cells (39 cases) or malignant mesothelioma (32 cases) in body cavity fluids were examined. Immunocytochemical staining of MCM 7, geminin, topo IIα and Ki-67 was performed with the immunoperoxidase polymer method.

Results: Labeling indices (LIs) of MCM 7 (cutoff value 20.0%; sensitivity 100%; specificity 100%), geminin (cutoff value 4.5%; sensitivity 88.0%; specificity 70.0%), topo IIα (cutoff value 11.0%; sensitivity 88.0%; specificity 92.0%) and Ki-67 (cutoff value 15.3%; sensitivity 78.0%; specificity 79.0%) of malignant mesothelioma cells were significantly higher than those of reactive mesothelial cells.

Conclusion: LIs of MCM 7, geminin and topo IIα can be reliable tools for the differential diagnosis of reactive mesothelial cells and malignant mesothelioma cells.
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October 2013

Overexpression of the miR-34 family suppresses invasive growth of malignant melanoma with the wild-type p53 gene.

Exp Ther Med 2012 May 28;3(5):793-796. Epub 2012 Feb 28.

Department of Pathology, Kitasato University School of Medicine, Kanagawa;

Malignant melanoma is the most aggressive neoplasm, with severe metastatic potential. microRNAs represent a class of endogenously expressed, small non-coding RNAs that regulate gene expression. As a consequence, the translation of these mRNAs is inhibited or they are destabilized resulting in downregulation of the encoded protein. The microRNA-34 (miR-34) family, which comprises three processed microRNAs (miR-34a/b/c) was identified as the mediator of tumor suppression by p53. Many reports suggest that the miR-34s contribute to the inhibition of invasion or metastasis in various tumor types. In this study, we evaluated the expression of the miR-34 family in four human melanoma cell lines (A375, G361, C32TG and SK-MEL-24) which have the wild-type p53 gene using real-time reverse transcription PCR. We also examined their generative and invasive characteristics using the cell proliferation assay and the invasion/migration assay, respectively. All four melanoma cell lines showed significant expression of miR-34s - A375: miR-34a 0.6176, miR-34b 0.7625, miR-34c 0.7877; G361: 7.6424, 16.4127, 22.0332; C32TG: 2.1630, 2.1091, 8.4425; SK-MEL-24: 0.3621, 2.5659, 8.5907. The cell doubling times of these cell lines in h:min were as follows: A375 23:23, G361 68:24, C32TG 47:22 and SK-MEL-24 67:03. The in vitro generation times of G361 and SK-MEL-24, which showed increased expression of miR-34c, were significantly shorter than A375 with decreased expression of miR-34c (p=0.0063, ANOVA). Invasion (%) of the four cell lines was as follows: A375 44.0%, G361 22.4%, C32TG 13.8% and SK-MEL-24 45.0%. In vitro invasiveness of G361 and C32TG, which showed increased expression of miR-34a, was significantly suppressed (p= 0.005, ANOVA). These results suggest that overexpression of miR-34a and c suppresses invasive and generative potentials, respectively, in human malignant melanoma.
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May 2012