Akinori Hashiguchi

Histopathological features and prognostic significance of the micropapillary pattern in lung adenocarcinoma

The micropapillary pattern is characterized by small papillary tufts with no fibrovascular core lying in spaces and has been reported as an aggressive variant of carcinoma in several organs. We investigated the histopathobiological properties of the micropapillary pattern with immunohistochemistry, serial sections, and electron microscopy in lung adenocarcinoma. We further analyzed its clinicopathological character and prognosis. The subjects included 383 adenocarcinoma cases, of which 184 (48%) were micropapillary pattern-positive and 199 (52%) were micropapillary pattern-negative. On histology, micropapillary tufts seemed to float in the alveolar space or spaces encased by connective tissues, whereas serial sections revealed that most tufts had continuity with other tufts and even with the main tumor. Positive staining for the adhesion molecules E-cadherin and β-catenin suggested the preservation of tight adhesion, and electron microscopy showed the existence of intercellular junctions. Negative staining for laminin and loss of basement membrane as determined by electron microscopy suggest a loss of cell–matrix contact. Positive staining for Ki-67 indicates that cells constituting micropapillary tufts retained their proliferation potency. There were no CD34-positive cells in micropapillary tufts, and the loss of the vascular core was confirmed. In micropapillary pattern-positive cases, lymphatic invasion was identified significantly more frequently than in micropapillary pattern-negative cases (P<0.001), even at stageIA (without lymph node metastasis, N=197) (P<0.001). The 5-year and 10-year overall survival rates of the micropapillary pattern-positive stageIA group were 77.6 and 67.6%, respectively, which were significantly less than those of the micropapillary pattern-negative stageIA group (98.1 and 98.1%) (P=0.001). In conclusion, cells constituting the micropapillary pattern are likely to have acquired anchorage-independent growth and a potential for high malignancy.

Synuclein-γ Is Closely Involved in Perineural Invasion and Distant Metastasis in Mouse Models and Is a Novel Prognostic Factor in Pancreatic Cancer

Purpose: Perineural invasion is associated with the high incidence of local recurrence and a dismal prognosis in pancreatic cancer. We previously reported a novel perineural invasion model and distinguished high– and low–perineural invasion groups in pancreatic cancer cell lines. This study aimed to elucidate the molecular mechanism of perineural invasion. Experimental Design: To identify key biological markers involved in perineural invasion, differentially expressed molecules were investigated by proteomics and transcriptomics. Synuclein-γ emerged as the only up-regulated molecule in high–perineural invasion group by both analyses. The clinical significance and the biological property of synuclein-γ were examined in 62 resected cases of pancreatic cancer and mouse models. Results: Synuclein-γ overexpression was observed in 38 (61%) cases and correlated with major invasive parameters, including perineural invasion and lymph node metastasis (P < 0.05). Multivariate analyses revealed synuclein-γ overexpression as the only independent predictor of diminished overall survival [hazard ratio, 3.4 (95% confidence interval, 1.51-7.51)] and the strongest negative indicator of disease-free survival [2.8 (1.26-6.02)]. In mouse perineural invasion and orthotopic transplantation models, stable synuclein-γ suppression by short hairpin RNA significantly reduced the incidence of perineural invasion (P = 0.009) and liver/lymph node metastasis (P = 0.019 and P = 0.020, respectively) compared with the control. Conclusions: This is the first study to provide in vivo evidence that synuclein-γ is closely involved in perineural invasion/distant metastasis and is a significant prognostic factor in pancreatic cancer. Synuclein-γ may serve as a promising molecular target of early diagnosis and anticancer therapy.

A histologic classification of IgA nephropathy for predicting long-term prognosis: emphasis on end-stage renal disease

BACKGROUND A multicenter case-control study on IgA nephropathy (IgAN) was conducted to develop an evidence-based clinicopathologic classification of IgAN for predicting long-term renal outcome. METHODS Two hundred and eighty-seven patients including those with isolated hematuria or very mild proteinuria were enrolled. During a median follow-up of 9.3 years after biopsy, 49 patients (17%) progressed to end stage renal disease (ESRD). The associations between pathological variables and the need for chronic dialysis was examined by multivariate logistic regression analysis separately in patients who required dialysis earlier than 5 years (Early Progressors) and those who required dialysis within 5 to 10 years (Late Progressors) after biopsy. RESULTS Independent pathological variables predicting progression to ESRD were global sclerosis, segmental sclerosis and fibrous crescents for Early Progressors, and global sclerosis and cellular/fibrocellular crescents for Late Progressors. Four histological grades, HG 1, HG 2, HG 3 and HG 4, were established corresponding to <25%, 25-49%, 50-74% and =75% of glomeruli exhibiting cellular or fibrocellular crescents, global sclerosis, segmental sclerosis or fibrous crescents. Eleven (7%) patients in HG 1, 12 (16%) in HG 2, 13 (31%) in HG 3 and 13 (68%) in HG 4 progressed to ESRD. Multivariate logistic analysis revealed that the risk of progression to ESRD was significantly higher in HG 2, 3 and 4 than in HG 1 (odds ratio, 2.4, 5.7 and 27.6 vs. 1.0). CONCLUSIONS Our evidence-based histologic classification can identify the magnitude of the risk of progression to ESRD and is useful for predicting long-term renal outcome in IgAN.

Tumor angiogenesis in the bone marrow of multiple myeloma patients and its alteration by thalidomide treatment.

Angiogenesis in solid tumors is important to tumor growth, invasion and metastasis. Recently, it has been suggested that angiogenesis plays a certain role in the development of hematopoietic malignancies, including leukemia and multiple myeloma. We evaluated tumor angiogenesis in the bone marrow (BM) of multiple myeloma (MM) patients by calculating microvessel density (MVD) in needle‐biopsy specimens obtained from 51 cases of untreated MM or monoclonal gammopathy of undetermined significance (MGUS). The MVD in the BM of donors for transplantation and patients with non‐hematological diseases was calculated as a control. There was an obvious increase in MVD in the BM of MM patients, and the MVD correlated with the grade of myeloma cell invasion of the BM in the untreated MM cases. It was recently reported that thalidomide might be effective for the treatment of MM. We assessed the effect of thalidomide on angiogenesis in BM treatment of 11 patients with refractory MM. The concentration of M‐protein in the serum or urine of seven of the 11 patients was reduced by at least 30% after thalidomide treatment, and MVD in the BM decreased in three of these seven cases in response to thalidomide. Increased plasma concentrations of basic fibroblast growth factor (FGF‐2) and vascular endothelial growth factor (VEGF) were observed in all 11 cases before thalidomide administration and both levels were reduced after treatment with thalidomide. Augmented angiogenesis in the bone marrow of MM patients was confirmed in the present study. It seems that thalidomide is effective in the treatment of MM through the impairment of angiogenesis by decreasing FGF‐2 and VEGF production. This is the first report on pathological evidence in the bone marrow of MM before and after thalidomide treatment, in Japan.

FUNCTION OF 90-kDa HEAT SHOCK PROTEIN IN CELLULAR DIFFERENTIATION OF HUMAN EMBRYONAL CARCINOMA CELLS

SummaryHeat shock proteins (HSPs) have been recognized as molecules that maintain cellular homeostasis during changes in the environment. Here we report that HSP90 functions not only in stress responses but also in certain aspects of cellular differentiation. We found that HSP90 slowed remarkably high expression in undifferentiated human embryonal carcinoma (EC) cells, which were subsequently dramatically down-regulated during in vitro cellular differentiation, following retinoic acid (RA) treatment, at the protein level. Surprisingly, heat shock treatment also triggered the down-regulation of HSP90 within 48 h at the protein level. Furthermore, the heat treatment induced cellular differentiation into neural cells. This down-regulation of HSP90 by heat treatment was shifted to an up-regulation attern after cellular differentiation in response to RA treatment. In order to clarify the functions of HSP90 in cellular differentiation, we conducted various experiments, including overexpression of HSP90 via gene transfer. We showed that the RA-induced differentiation of EC cells into a neural cell lineage was inhibited by overexpression of the HSP90α or-β isoform via the gene transfer method. On the other hand, the overexpression of HSP90β alone impaired cellular differentiation into trophoectoderm. These results show that down-regulation of HSP90 is a physiological critical event in the differentiation of human EC cells and that specific HSP90 isoforms may be involved in differentiation into specific cell lineages.

Computational grading of hepatocellular carcinoma using multifractal feature description

Cancer grading has become an important topic in the field of image interpretation-based computer aided diagnosis systems. This paper proposes a novel feature descriptor to observe the characteristics of histopathological textures in a discriminative manner. The proposed feature descriptor utilizes fractal geometric analysis with four multifractal measures to construct an eight dimensional feature space. The proposed method employed a bag-of-feature-based classification model to discriminate a set of hepatocellular carcinoma images into five categories according to Edmondson and Steiners grading system. Three feature selection methods were utilized to obtain the most discriminative features of codeword dictionary (codebook). Furthermore, we incorporated four other textural feature descriptors: Gabor-filters, LM-filters, local binary patterns, and Haralick, to obtain a benchmark of the accuracy of the classification. Two experiments were performed: (i) classifying non-neoplastic tissues and tumors and (ii) grading the hepatocellular carcinoma images into five classes. Experimental results indicated the significance of the multifractal features for describing the histopathological image texture because it outperformed other four feature descriptors. We graded a given ROI image by defining a threshold-based majority-voting rule and obtained an average correct classification rate around 95% for five classes classification.

Contrast-enhanced Ultrasonography of the Prostate with Sonazoid

OBJECTIVE The diagnosis of prostate cancer is based on the results of ultrasonography-guided needle biopsy of the prostate, but cancer foci are often not visible in conventional transrectal ultrasonography. Sonazoid is a new microbubble contrast agent. The purpose of our study was to compare areas of contrast material enhancement in the prostate at ultrasonography with whole-mount radical prostatectomy specimens to determine if the use of Sonazoid improves the detection rate of prostate cancer. METHODS Fifty patients with biopsy-proven cancer of the prostate who were scheduled to undergo radical prostatectomy were recruited for this study. The day before the operation, each patient was evaluated with ultrasonography at baseline and again during intravenous infusion of Sonazoid. A map of ultrasonography findings was created prospectively at the time of imaging. Following radical prostatectomy, independent mapping of the pathologic results was performed and the maps were compared. RESULTS Ultrasonography evaluation at baseline demonstrated that at least one focus of cancer was identified in 20 of the 50 subjects (40.0%). Meanwhile at least one cancer focus was enhanced in 31 of the 50 patients (62.0%) when Sonazoid was used. The combination of baseline grayscale imaging and contrast-enhanced imaging allowed identification of at least one focus of cancer in 40 patients (80.0%). Contrast-enhanced ultrasonography can improve sensitivity, especially for the detection of large cancer, peripheral zone cancer and highly malignant cancer. CONCLUSIONS Our study has demonstrated significantly improved detection of prostate cancer with the combination of baseline grayscale imaging and contrast-enhanced imaging compared with conventional ultrasonography techniques only, and this technique may be applicable to targeted biopsy.

Suppression of autophagy by CUB domain-containing protein 1 signaling is essential for anchorage-independent survival of lung cancer cells

CUB (C1r/C1s, urchin embryonic growth factor, BMP1) domain‐containing protein 1 (CDCP1) has been implicated in promoting metastasis of cancer cells through several mechanisms, including the inhibition of anoikis, which is cell death triggered by the loss of extracellular matrix interactions. However, the mechanism inhibiting cell death regulated by CDCP1 remains elusive. Inhibition of CDCP1 expression using small interfering RNA (siRNA) induced the cell death of suspended cancer cells without cleaving caspase‐3, a marker of apoptosis; cell death was not inhibited by a general caspase inhibitor, suggesting that the loss of CDCP1 induces caspase‐independent cell death. In contrast, knockdown of CDCP1 as well as protein kinase Cδ (PKCδ), a downstream effector of CDCP1, in a suspension culture of lung cancer cells resulted in marked induction of membranous microtubule‐associated protein 1 light chain 3 (LC3)‐II protein, a hallmark of autophagy, and caused the formation of an autophagosome structure visualized using green fluorescent protein‐tagged LC3‐II. Expression and phosphorylation of exogenous CDCP1 by Fyn kinase reduced the formation of autophagosomes and inhibited phosphorylation of CDCP1 by PP2, a Src kinase inhibitor or inhibited PKCδ by rottlerin, stimulating autophagosome formation. Moreover, death of suspended lung cancer cells induced by CDCP1 siRNA or by PKCδ siRNA was reduced by the autophagy inhibitor 3‐methyladenine. These results indicate that CDCP1‐PKCδ signaling plays a critical role in inhibiting autophagy, which is responsible for anoikis resistance of lung cancer cells.

Color correction for automatic fibrosis quantification in liver biopsy specimens

Context: For a precise and objective quantification of liver fibrosis, quantitative evaluations through image analysis have been utilized. However, manual operations are required in most cases for extracting fiber areas because of color variation included in digital pathology images. Aims: The purpose of this research is to propose a color correction method for whole slide images (WSIs) of Elastica van Gieson (EVG) stained liver biopsy tissue specimens and to realize automated operation of image analysis for fibrosis quantification. Materials and Methods: Our experimental dataset consisted of 38 WSIs of liver biopsy specimens collected from 38 chronic viral hepatitis patients from multiple medical facilities, stained with EVG and scanned at ×20 using a Nano Zoomer 2.0 HT (Hamamatsu Photonics K.K., Hamamatsu, Japan). Color correction was performed by modifying the color distribution of a target WSI so as to fit to the reference, where the color distribution was modeled by a set of two triangle pyramids. Using color corrected WSIs; fibrosis quantification was performed based on tissue classification analysis. Statistical Analysis Used: Spearman′s rank correlation coefficients were calculated between liver stiffness measured by transient elastography and median area ratio of collagen fibers calculated based on tissue classification results. Results: Statistical analysis results showed a significant correlation r = 0.61-0.68 even when tissue classifiers were trained by using a subset of WSIs, while the correlation coefficients were reduced to r = 0.40-0.50 without color correction. Conclusions: Fibrosis quantification accompanied with the proposed color correction method could provide an objective evaluation tool for liver fibrosis, which complements semi-quantitative histologic evaluation systems.

Using immunofluorescent digital slide technology to quantify protein expression in archival paraffin-embedded tissue sections

Molecularly targeted therapies require an adequate assessment of molecular expression in cancer. Immunofluorescent staining is a better method to quantify protein expression than immunohistochemistry (IHC), although the latter is currently used to score human epidermal growth factor receptor 2 (HER2) and steroid receptors. The quantification of signal intensity in IHC is still controversial. The advanced technology of virtual slides permits digitizing a whole slide image of immunofluorescence for a few minutes. We have established fluorescence‐based, immunofluorescent quantification digital slides (IQD), a method widely applicable in routine practice. The IQD were made by scanning images of formalin‐fixed, paraffin‐embedded sections and contained, not only morphological information obtained from hematoxylin‐counterstains, but also immunofluorescent signals. Assessing protein expression on IQD was carried out using the original image analysis software and was compared with the IHC score (HER2 and steroid receptors). There was a statistically significant correlation between the IQD and IHC scores. In addition, we compared IQD scores of groups classified by IHC scores. The IHC intermediate‐expression groups were not statistically different from the high, or negative‐expression groups. Immunofluorescent quantification digital slides may help pathologists to assess molecular expression in cancer tissue, and resolve the issue of scoring the intensity of brown signal on IHC slides.