Proton Beam Therapy versus Radiofrequency Ablation for Patients with Treatment-Naïve Single Hepatocellular Carcinoma: A Propensity Score Analysis

Introduction

Proton beam therapy (PBT) is known to be an effective locoregional treatment for hepatocellular carcinoma (HCC). However, few comparative studies in treatment-naïve cases have been reported. The aim of this study was to compare the survival outcomes of PBT with those of radiofrequency ablation (RFA) in patients with treatment-naïve solitary HCC.

Methods

Ninety-five consecutive patients with treatment-naïve HCC, a single nodule measuring ≤5 cm in diameter, and a Child-Pugh score of ≤8 who were treated with PBT at the University of Tsukuba Hospital between 2001 and 2013 were enrolled in the study. In addition, 836 patients with treatment-naïve HCC treated by RFA at the University of Tokyo Hospital during the same period were analyzed as controls. Recurrence-free survival (RFS) and overall survival (OS) were compared in 83 patient pairs after propensity score matching.

Results

The 1-year, 3-year, and 5-year RFS rates were 86.6%, 49.5%, and 35.5%, respectively, in the PBT group and 59.5%, 34.0%, and 20.9% in the RFA group (p = 0.058); the respective OS rates were 97.6%, 77.8%, and 57.1% in the PBT group and 95.1%, 81.7%, and 67.7% in the RFA group (p = 0.16). Regarding adverse effects, no grade 3 or higher adverse events were noted in the PBT; however, two grade 3 adverse events occurred within 30 days of RFA in the RFA group: one hemoperitoneum and one hemothorax.

Discussion

After propensity score matching, PBT showed no significant difference in RFS and OS compared to RFA. PBT can be an alternative for patients with solitary treatment-naïve HCC.

Inhibiting SCAP/SREBP exacerbates liver injury and carcinogenesis in murine nonalcoholic steatohepatitis

Enhanced de novo lipogenesis mediated by sterol regulatory element-binding proteins (SREBPs) is thought to be involved in nonalcoholic steatohepatitis (NASH) pathogenesis. In this study, we assessed the impact of SREBP inhibition on NASH and liver cancer development in murine models. Unexpectedly, SREBP inhibition via deletion of the SREBP cleavage-activating protein (SCAP) in the liver exacerbated liver injury, fibrosis, and carcinogenesis, despite markedly reduced hepatic steatosis. These phenotypes were ameliorated by restoring SREBP function. Transcriptome and lipidome analyses revealed that SCAP-SREBP pathway inhibition altered the fatty acid (FA) composition of phosphatidylcholines due to both impaired FA synthesis and disorganized FA incorporation into phosphatidylcholine via lysophosphatidylcholine acyltransferase 3 (LPCAT3) downregulation, which led to endoplasmic reticulum (ER) stress and hepatocyte injury. Supplementation of phosphatidylcholines significantly improved liver injury and ER stress induced by SCAP deletion. The activity of SCAP-SREBP-LPCAT3 axis was found inversely associated with liver fibrosis severity in human NASH. SREBP inhibition also cooperated with impaired autophagy to trigger liver injury. Thus, excessively strong and broad lipogenesis inhibition was counterproductive for NASH therapy, which will have important clinical implications in NASH treatment.

Cell fate analysis of zone 3 hepatocytes in liver injury and tumorigenesis

Background & Aims

Liver lobules are typically subdivided into 3 metabolic zones: zones 1, 2, and 3. However, the contribution of zonal differences in hepatocytes to liver regeneration, as well as to carcinogenic susceptibility, remains unclear.

Methods

We developed a new method for sustained genetic labelling of zone 3 hepatocytes and performed fate tracing to monitor these cells in multiple mouse liver tumour models.

Results

We first examined changes in the zonal distribution of the Wnt target gene Axin2 over time using Axin2-Cre^ERT2;Rosa26-Lox-Stop-Lox-tdTomato mice (Axin2;tdTomato). We found that following tamoxifen administration at 3 weeks of age, approximately one-third of total hepatocytes that correspond to zone 3 were labelled in Axin2;tdTomato mice; the tdTomato⁺ cell distribution closely matched that of the zone 3 marker CYP2E1. Cell fate analysis revealed that zone 3 hepatocytes maintained their own lineage but rarely proliferated beyond their liver zonation during homoeostasis; this indicated that our protocol enabled persistent genetic labelling of zone 3 hepatocytes. Using this system, we found that zone 3 hepatocytes generally had high neoplastic potential, which was promoted by constitutive activation of Wnt/β-catenin signalling in the pericentral area. However, the frequency of zone 3 hepatocyte-derived tumours varied depending on the regeneration pattern of the liver parenchyma in response to liver injury. Notably, Axin2-expressing hepatocytes undergoing chronic liver injury significantly contributed to liver regeneration and possessed high neoplastic potential. Additionally, we revealed that the metabolic phenotypes of liver tumours were acquired during tumorigenesis, irrespective of their spatial origin.

Conclusions

Hepatocytes receiving Wnt/β-catenin signalling from their microenvironment have high neoplastic potential, and Wnt/β-catenin signalling is a potential drug target for the prevention of hepatocellular carcinoma.

Lay summary

Lineage tracing revealed that zone 3 hepatocytes residing in the pericentral niche have high neoplastic potential. Under chronic liver injury, hepatocytes receiving Wnt/β-catenin signalling broadly exist across all hepatic zones and significantly contribute to liver tumorigenesis as well as liver regeneration. Wnt/β-catenin signalling is a potential drug target for the prevention of hepatocellular carcinoma.

•

We developed a new method for sustained genetic labelling of Zone 3 hepatocytes.

•

Lineage tracing revealed that Zone 3 hepatocytes generally have high neoplastic potential.

•

The frequency of Zone 3 hepatocyte-derived tumours varied depending on the regeneration pattern of liver parenchyma.

•

Under chronic liver injury, hepatocytes receiving Wnt/β-catenin signalling significantly contributed to tumorigenesis.

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Wnt/β-catenin signalling is a potential drug target for the prevention of HCC.

Post-treatment cell-free DNA as a predictive biomarker in molecular-targeted therapy of hepatocellular carcinoma

BACKGROUND

Liquid biopsies, particularly those involving circulating tumor DNA (ctDNA), are rapidly emerging as a non-invasive alternative to tumor biopsies. However, clinical applications of ctDNA analysis in hepatocellular carcinoma (HCC) have not been fully elucidated.

METHODS

We measured the amount of plasma-derived cell-free DNA (cfDNA) in HCC patients before (n = 100) and a few days after treatment (n = 87), including radiofrequency ablation, transarterial chemoembolization, and molecular-targeted agents (MTAs), and prospectively analyzed their associations with clinical parameters and prognosis. TERT promoter mutations in cfDNA were analyzed using droplet digital PCR. Furthermore, we performed a comprehensive mutational analysis of post-treatment cfDNA via targeted ultra-deep sequencing (22,000× coverage) in a panel of 275 cancer-related genes in selected patients.

RESULTS

Plasma cfDNA levels increased significantly according to HCC clinical stage, and a high cfDNA level was independently associated with a poor prognosis. TERT promoter mutations were detected in 45% of all cases but were not associated with any clinical characteristics. cfDNA levels increased significantly a few days after treatment, and a greater increase in post-treatment cfDNA levels was associated with a greater therapeutic response to MTAs. The detection rate of TERT mutations increased to 57% using post-treatment cfDNA, suggesting that the ctDNA was enriched. Targeted ultra-deep sequencing using post-treatment cfDNA after administering lenvatinib successfully detected various gene mutations and obtained promising results in lenvatinib-responsive cases.

CONCLUSIONS

Post-treatment cfDNA analysis may facilitate the construction of biomarkers for predicting MTA treatment effects.

Axin2+ Peribiliary Glands in the Periampullary Region Generate Biliary Epithelial Stem Cells That Give Rise to Ampullary Carcinoma

BACKGROUND & AIMS

Peribiliary glands (PBGs), clusters of epithelial cells residing in the submucosal compartment of extrahepatic bile ducts, have been suggested as biliary epithelial stem/progenitor cell niche; however, evidence to support this claim is limited because of a lack of PBG-specific markers. We therefore sought to identify PBG-specific markers to investigate the potential role of PBGs as stem/progenitor cell niches, as well as an origin of cancer.

METHODS

We examined the expression pattern of the Wnt target gene Axin2 in extrahepatic bile ducts. We then applied lineage tracing to investigate whether Axin2-expressing cells from PBGs contribute to biliary regeneration and carcinogenesis using Axin2-Cre^ERT mice.

RESULTS

Wnt signaling activation, marked by Axin2, was limited to PBGs located in the periampullary region. Lineage tracing showed that Axin2-expressing periampullary PBG cells are capable of self-renewal and supplying new biliary epithelial cells (BECs) to the luminal surface. Additionally, the expression pattern of Axin2 and the mature ductal cell marker CK19 were mutually exclusive in periampullary region, and fate tracing of CK19⁺ luminal surface BECs showed gradual replacement by CK19^- cells, further supporting the continuous replenishment of new BECs from PBGs to the luminal surface. We also found that Wnt signal enhancer R-spondin3 secreted from Myh11-expressing stromal cells, corresponding to human sphincter of Oddi, maintained the periampullary Wnt signal-activating niche. Notably, introduction of PTEN deletion into Axin2⁺ PBG cells, but not CK19⁺ luminal surface BECs, induced ampullary carcinoma whose development was suppressed by Wnt inhibitor.

CONCLUSION

A specific cell population receiving Wnt-activating signal in periampullary PBGs functions as biliary epithelial stem/progenitor cells and also the cellular origin of ampullary carcinoma.

Discovery of a Vitamin D Receptor-Silent Vitamin D Derivative That Impairs Sterol Regulatory Element-Binding Protein In Vivo

Vitamin D₃ metabolites inhibit the expression of lipogenic genes by impairing sterol regulatory element-binding protein (SREBP), a master transcription factor of lipogenesis, independent of their canonical activity through a vitamin D receptor (VDR). Herein, we designed and synthesized a series of vitamin D derivatives to search for a drug-like small molecule that suppresses the SREBP-induced lipogenesis without affecting the VDR-controlled calcium homeostasis in vivo. Evaluation of the derivatives in cultured cells and mice led to the discovery of VDR-silent SREBP inhibitors and to the development of KK-052 (50), the first vitamin D-based SREBP inhibitor that has been demonstrated to mitigate hepatic lipid accumulation without calcemic action in mice. KK-052 maintained the ability of 25-hydroxyvitamin D₃ to induce the degradation of SREBP but lacked in the VDR-mediated activity. KK-052 serves as a valuable compound for interrogating SREBP/SCAP in vivo and may represent an unprecedented translational opportunity of synthetic vitamin D analogues.

GPR30-Expressing Gastric Chief Cells Do Not Dedifferentiate But Are Eliminated via PDK-Dependent Cell Competition During Development of Metaplasia

BACKGROUND & AIMS

Gastric chief cells, a mature cell type that secretes digestive enzymes, have been proposed to be the origin of metaplasia and cancer through dedifferentiation or transdifferentiation. However, studies supporting this claim have had technical limitations, including issues with the specificity of chief cell markers and the toxicity of drugs used. We therefore sought to identify genes expressed specifically in chief cells and establish a model to trace these cells.

METHODS

We performed transcriptome analysis of Mist1-CreERT-traced cells, with or without chief cell depletion. Gpr30-rtTA mice were generated and crossed to TetO-Cre mice, and lineage tracing was performed after crosses to R26-TdTomato mice. Additional lineage tracing experiments were performed using Mist1-CreERT, Kitl-CreERT, Tff1-Cre, and Tff2-Cre mice crossed to reporter mice. Mice were given high-dose tamoxifen or DMP-777 or were infected with Helicobacter pylori to induce gastric metaplasia. We studied mice that expressed mutant forms of Ras in gastric cells, using TetO-Kras^G12D, LSL-Kras^G12D, and LSL-Hras^G12V mice. We analyzed stomach tissues from GPR30-knockout mice. Mice were given dichloroacetate to inhibit pyruvate dehydrogenase kinase (PDK)-dependent cell competition.

RESULTS

We identified GPR30, the G-protein-coupled form of the estrogen receptor, as a cell-specific marker of chief cells in gastric epithelium of mice. Gpr30-rtTA mice crossed to TetO-Cre;R26-TdTomato mice had specific expression of GPR30 in chief cells, with no expression noted in isthmus stem cells or lineage tracing of glands. Expression of mutant Kras in GPR30⁺ chief cells did not lead to the development of metaplasia or dysplasia but, instead, led to a reduction in labeled numbers of chief cells and a compensatory expansion of neck lineage, which was derived from upper Kitl⁺ clones. Administration of high-dose tamoxifen, DMP-777, or H pylori decreased the number of labeled chief cells. Chief cells were eliminated from epithelia via GPR30- and PDK-dependent cell competition after metaplastic stimuli, whereas loss of GRP30 or inhibition of PDK activity preserved chief cell numbers and attenuated neck lineage cell expansion.

CONCLUSIONS

In tracing studies of mice, we found that most chief cells are lost during metaplasia and therefore are unlikely to contribute to gastric carcinogenesis. Expansion of cells that coexpress neck and chief lineage markers, known as spasmolytic polypeptide-expressing metaplasia, does not occur via dedifferentiation from chief cells but, rather, through a compensatory response from neck progenitors to replace the eliminated chief cells.

Intermolecular interactions of tetrabenzoporphyrin- and phthalocyanine-based charge-transfer complexes

The effect of molecular modification on the intermolecular interactions in tetrabenzoporphyrin-based charge transfer complexes is reported. TPP[Fe^III(tbp)Cl₂]₂, TPP[Co^III(tbp)Cl₂]₂ and TPP[Co^III(tbp)Br₂]₂ (TPP = tetraphenylphosphonium and tbp = tetrabenzoporphyrin) were synthesized and their crystal structures were compared to those of the reported TPP[M^III(tbp)(CN)₂]₂, TPP[Fe^III(tbp)Br₂]₂ and TPP[M^III(Pc)L₂]₂ complexes (Pc = phthalocyanine; and L = CN, Cl or Br). The prepared CT complexes were isostructural to reported systems. However, their intermolecular interactions were found to depend on the combination of the macrocyclic (Mc) and axial ligands (L). In Pc-based systems, the overlap integral between HOMOs of Pc decreased with the increase in the size of the axial ligand, which indicated that the intermolecular interactions in Pc-based systems were dominated by repulsive interactions. On the other hand, in tbp-based systems, attractive and repulsive interactions competed with each other. Furthermore, charge transport properties were found to depend on the central metal ion as well as the combination of Mc and L, which suggested that minor molecular modifications to porphyrin complexes will cause drastic changes in both inter- and intramolecular interactions.

Three types of metaplasia model through Kras activation, Pten deletion, or Cdh1 deletion in the gastric epithelium

Chronic inflammation and intestinal metaplasia are strongly associated with gastric carcinogenesis. Kras activation and Pten deletion are observed in intestinal-type gastric cancer, and Cdh1 mutation is associated with diffuse-type gastric cancer. Although various mouse models of gastric carcinogenesis have been reported, few mouse lines enable gene manipulation selectively in the stomach. Here we established a Tff1-Cre bacterial artificial chromosome transgenic mouse line in an attempt to induce gene modification specifically in the gastric pit lineage. In the stomach, Tff1-Cre-mediated recombination was most evident in the pit lineage in the corpus and in entire antral glands; recombination was also observed in a few gastric chief and parietal cells. Outside the stomach, recombination was patchy throughout the intestines, and particularly frequently in the duodenum (Brunner glands), cecum, and proximal colon. In the stomachs of Tff1-Cre;LSL-Kras^G12D mice, proliferating cell clusters expanded throughout the corpus glands, with foveolar cell expansion with ectopic Alcian blue-positive mucins, oxyntic atrophy, and pseudopyloric changes with spasmolytic polypeptide-expressing metaplasia; however, gastric cancer was not observed even at 12 months of age. Corpus-derived organoids from Tff1-Cre;LSL-Kras^G12D mice exhibited accelerated growth and abnormal differentiation with a loss of chief and parietal cell markers. Tff1-Cre;Pten^flox/flox mice displayed similar changes to those seen in Tff1-Cre;LSL-Kras^G12D mice, both with aberrant ERK activation within 3 months. In contrast, Tff1-Cre;Cdh1^flox/flox mice initially showed signet ring-like cells that were rapidly lost with disruption of the mucosal surface, and later developed gastric epithelial shedding with hyperproliferation and loss of normal gastric lineages. Eventually, the glandular epithelium in Tff1-Cre;Cdh1^flox/flox mice was completely replaced by squamous epithelium which expanded from the forestomach. Tff1-Cre mice offer an additional useful tool for studying gastric carcinogenesis both in vivo and in vitro. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Lipid Metabolic Reprogramming in Hepatocellular Carcinoma

Metabolic reprogramming for adaptation to the local environment has been recognized as a hallmark of cancer. Although alterations in fatty acid (FA) metabolism in cancer cells have received less attention compared to other metabolic alterations such as glucose or glutamine metabolism, recent studies have uncovered the importance of lipid metabolic reprogramming in carcinogenesis. Obesity and nonalcoholic steatohepatitis (NASH) are well-known risk factors of hepatocellular carcinoma (HCC), and individuals with these conditions exhibit an increased intake of dietary FAs accompanied by enhanced lipolysis of visceral adipose tissue due to insulin resistance, resulting in enormous exogenous FA supplies to hepatocytes via the portal vein and lymph vessels. This “lipid-rich condition” is highly characteristic of obesity- and NASH-driven HCC. Although the way in which HCC cells adapt to such a condition and exploit it to aid their progression is not understood, we recently obtained new insights into this mechanism through lipid metabolic reprogramming. In addition, accumulating evidence supports the importance of lipid metabolic reprogramming in various situations of hepatocarcinogenesis. Thus, in this review, we discuss the latest findings regarding the role of FA metabolism pathways in hepatocarcinogenesis, focusing on obesity- and NASH-driven lipid metabolic reprogramming.

CPT2 downregulation adapts HCC to lipid-rich environment and promotes carcinogenesis via acylcarnitine accumulation in obesity

OBJECTIVE

Metabolic reprogramming of tumour cells that allows for adaptation to their local environment is a hallmark of cancer. Interestingly, obesity-driven and non-alcoholic steatohepatitis (NASH)-driven hepatocellular carcinoma (HCC) mouse models commonly exhibit strong steatosis in tumour cells as seen in human steatohepatitic HCC (SH-HCC), which may reflect a characteristic metabolic alteration.

DESIGN

Non-tumour and HCC tissues obtained from diethylnitrosamine-injected mice fed either a normal or a high-fat diet (HFD) were subjected to comprehensive metabolome analysis, and the significance of obesity-mediated metabolic alteration in hepatocarcinogenesis was evaluated.

RESULTS

The extensive accumulation of acylcarnitine species was seen in HCC tissues and in the serum of HFD-fed mice. A similar increase was found in the serum of patients with NASH-HCC. The accumulation of acylcarnitine could be attributed to the downregulation of carnitine palmitoyltransferase 2 (CPT2), which was also seen in human SH-HCC. CPT2 downregulation induced the suppression of fatty acid β-oxidation, which would account for the steatotic changes in HCC. CPT2 knockdown in HCC cells resulted in their resistance to lipotoxicity by inhibiting the Src-mediated JNK activation. Additionally, oleoylcarnitine enhanced sphere formation by HCC cells via STAT3 activation, suggesting that acylcarnitine accumulation was a surrogate marker of CPT2 downregulation and directly contributed to hepatocarcinogenesis. HFD feeding and carnitine supplementation synergistically enhanced HCC development accompanied by acylcarnitine accumulation in vivo.

CONCLUSION

In obesity-driven and NASH-driven HCC, metabolic reprogramming mediated by the downregulation of CPT2 enables HCC cells to escape lipotoxicity and promotes hepatocarcinogenesis.

Peribiliary Glands as the Cellular Origin of Biliary Tract Cancer

The identification of the cellular origin of cancer is important for our understanding of the mechanisms regulating carcinogenesis, thus the cellular origin of cholangiocarcinoma (CCA) is a current topic of interest. Although CCA has been considered to originate from biliary epithelial cells, recent studies have suggested that multiple cell types can develop into CCA. With regard to the hilar and extrahepatic bile ducts, peribiliary glands (PBGs), a potential stem cell niche of biliary epithelial cells, have attracted attention as the cellular origin of biliary tract cancer. Recent histopathological and experimental studies have suggested that some kinds of inflammation-induced CCA and intraductal papillary neoplasms of the bile duct are more likely to originate from PBGs. During inflammation-mediated cholangiocarcinogenesis, the biliary epithelial injury-induced regenerative response by PBGs is considered a key process. Thus, in this review, we discuss recent advances in our understanding of cholangiocarcinogenesis from the viewpoint of inflammation and the cellular origin of CCA, especially focusing on PBGs.

Mature gastric chief cells are not required for the development of metaplasia

During human gastric carcinogenesis, intestinal metaplasia is frequently seen in the atrophic stomach. In mice, a distinct type of metaplasia known as spasmolytic polypeptide-expressing metaplasia (SPEM) is found in several inflammatory and genetically engineered models. Given the diversity of long- and short-term models of mouse SPEM, it remains unclear whether all models have a shared or distinct molecular mechanism. The origin of SPEM in mice is presently under debate. It is postulated that stem or progenitor cells acquire genetic alterations that then supply metaplastic cell clones, whereas the possibility of transdifferentiation or dedifferentiation from mature gastric chief cells has also been suggested. In this study, we report that loss of chief cells was sufficient to induce short-term regenerative SPEM-like lesions that originated from chief cell precursors in the gastric neck region. Furthermore, Lgr5⁺ mature chief cells failed to contribute to both short- and long-term metaplasia, whereas isthmus stem and progenitor cells efficiently contributed to long-term metaplasia. Interestingly, multiple administrations of high-dose pulsed tamoxifen induced expansion of Lgr5 expression and Lgr5-CreERT recombination within the isthmus progenitors apart from basal chief cells. Thus we conclude that short-term SPEM represents a regenerative process arising from neck progenitors following chief cell loss, whereas true long-term SPEM originates from isthmus progenitors. Mature gastric chief cells may be dispensable for SPEM development. NEW & NOTEWORTHY Recently, dedifferentiation ability in gastric chief cells during metaplasia development has been proposed. Our findings reveal that lesions that were thought to be acute metaplasia in fact represent normal regeneration supplied from neck lineage and that isthmus stem/progenitors are more responsible for sustained metaplastic changes. Cellular plasticity in gastric chief cells may be more limited than recently highlighted.

Anti-glutamate ∊2 receptor antibody-positive and anti-N-methyl-d-aspartate receptor antibody-negative lobar encephalitis presenting as global aphasia and swallowing apraxia

Background

Little is known about the difference between anti-N-methyl-D-aspartate receptor (NMDAR) antibody-positive encephalitis and anti-glutamate receptor (GluR) antibody-positive encephalitis.

Objectives

To characterize anti-GluR antibody-positive encephalitis.

Methods

We report a 33-year-old man with nonparaneoplastic anti-GluR ∊2, ζ1 and δ2 antibody-positive and anti-NMDAR antibody-negative encephalitis, using neuropsychological tests and imaging studies including magnetic resonance imaging and single photon emission computed tomography (SPECT) with a ^99mTc-ethylcysteinate dimer.

Results

The patient exhibited global aphasia and swallowing apraxia (inability to transfer food to the pharyngeal cavity without sialorrhea). He was treated with 3 courses of corticosteroid pulse therapy and had recovered markedly 3 weeks after onset. Magnetic resonance diffusion-weighted images revealed hyperintensity in the bilateral frontal and left parietal cortices. Seven months later, a small area of hyperintensity in the left supramarginal gyrus remained. SPECT revealed hypoperfusion in extensive regions of the bilateral frontal lobes and left supramarginal gyrus. Thirteen months later, blood flow reduction was restricted to diffuse areas in the frontal lobes.

Conclusions

Frontal lobar encephalitis without medial temporal involvement, marked cognitive impairment with a relatively preserved level of consciousness, and a favorable response to corticosteroid therapy, with nearly reversible cortical damage, may characterize anti-GluR antibody-positive encephalitis.

Hepatotoxicity of sub-nanosized platinum particles in mice

Nano-sized materials are widely used in consumer products, medical devices and engineered pharmaceuticals. Advances in nanotechnology have resulted in materials smaller than the nanoscale, but the biologic safety of the sub-nanosized materials has not been fully assessed. In this study, we evaluated the toxic effects of sub-nanosized platinum particles (snPt) in the mouse liver. After intravenous administration of snPt (15 mg/kg body weight) into mice, histological analysis revealed acute hepatic injury, and biochemical analysis showed increased levels of serum markers of liver injury and inflammatory cytokines. In contrast, administration of nano-sized platinum particles did not produce these abnormalities. Furthermore, snPt induced cytotoxicity when directly applied to primary hepatocytes. These data suggest that snPt have the potential to induce hepatotoxicity. These findings provide useful information on the further development of sub-nanosized materials.

Photoinduced Volume Transition in Liquid Crystalline Polymer Gels Swollen by a Nematic Solvent

Nematic liquid crystalline (LC) cross-linked polymer gel sheets containing 3 mol % azobenzene (Az) unit were prepared and swollen by a nematic solvent of 4'-pentyl-4-cyanobiphenyl (5CB). This 5CB-swollen gel sheet exhibited a discontinuous volume change around the nematic-isotoropic phase transition temperature of the LC gel (T_NI^G). UV irradiation at a temperature slightly lower than T_NI^G provoked a large volume transition (expansion) due to a loss of nematic order within the gel sheet caused by the trans-to-cis photoisomerization of Az. The volume was reverted by irradiation with 436 nm light. By templating the colloidal crystal film of monodispersed silica particles, a LC gel sheet possessing a microporous structure was also prepared. Due to the facilitated diffusion of 5CB, the microporous LC gel exhibited significant enhancements in the extent and rate of the photoinduced volume transition.

Relationship between immunological rejection and matrix GLA protein in cryopreserved vascular allografts

INTRODUCTION

Cryopreserved tissue allografts used for cardiovascular diseases become calcified as a late complication after transplantation, probably caused by immunological rejection. Recent attention has been focused on the inhibitory effect of matrix Gla protein (MGP) on ectopic vascular calcification, but the behavior of MGP in cryopreserved allografts is uncertain. In this study we examined the relationship between immunological rejection and MGP in cryopreserved rat aortic grafts after transplantation.

METHODS

Cryopreserved rat aortae were isografted or allografted intraperitoneally. Fresh isografts were also tested. The grafts were retrieved 9 days after transplantation and the intragraft MGP mRNA was measured by a real-time quantitative PCR method. The effect of daily administration of FK506 on MGP mRNA levels in cryopreserved isografts and allografts after transplantation was also evaluated.

RESULTS

There was no significant difference in intragraft MGP mRNA levels between fresh and cryopreserved isografts 9 days after transplantation. MGP expression levels in cryopreserved allografts were significantly lower as compared to those in cryopreserved isografts (P < .01). Daily administration of FK506 enhanced intragraft MGP mRNA (ninefold) in cryopreserved allografts (P < .01), but not in cryopreserved isografts.

CONCLUSIONS

Immunological rejection is likely to inhibit MGP expression in cryopreserved vascular allografts, resulting in late-onset calcification.

Karyotyping of Female and Male Hediste japonica (Polychaeta, Annelida) in Comparison with Those of Two Closely Related Species, H. diadroma and H. atoka

Karyotypes of females and males of the brackish-water polychaete Hediste japonica sensu stricto, collected from the Ariake Sea, Japan, were examined by using regenerating tails. We used the Giemsa staining method and a computer-assisted image-analyzing system for the identification of each chromosome pair. The somatic chromosome number was 2n=28. The presence of an XX-XY (male heterogametic) sex chromosome system was determined from well-spread metaphase plates of somatic cells. The type of sex chromosomes related with phenotype exactly. The metacentric Y chromosome was much larger than the submetacentric X chromosome. All autosomes were metacentric. The karyotype of this species was compared with those of the other two closely related species (H. diadroma and H. atoka). The karyotypes of all the three species were similar to one another.

Meta-analysis of adjuvant immunochemotherapy using OK-432 in patients with resected non-small-cell lung cancer

The benefits of immunochemotherapy with a penicillin-treated, lyophilized preparation of Streptococcus pyogenes, OK-432 (Picibanil), were reassessed in patients with resected non-small-cell lung cancer through a meta-analysis based on data from 1,520 patients enrolled in 11 randomized clinical trials. All 11 trials were started before 1991, and the subjects had been followed up for at least 5 years after surgery and randomization. In these trials, standard chemotherapy was compared with the same therapy plus OK-432. The endpoint of interest was overall survival, and analysis was based on intent-to-treat population without patient exclusion. Data were analyzed using the Mantel-Haenszel method. The 5-year survival rate for all eligible patients in the 11 trials was 51.2% in the immunochemotherapy group versus 43.7% in the chemotherapy group. The odds ratio (OR) for overall survival was 0.70 (95% CI = 0.56-0.87, p = 0.0010). Analysis of four trials in which central randomization was performed also reconfirmed a significantly longer survival time for the immunochemotherapy group (OR = 0.66, 95% CI = 0.44-1.00, p = 0.049). Based on these results of meta-analysis, it is postulated that postoperative adjuvant immunochemotherapy using OK-432 might improve the survival of patients after resection of non-small-cell lung cancer.

Oligomeric regulation of gastric H+,K+-ATPase

The H+,K+-ATPase of intact gastric vesicles has two Km values for ATP hydrolysis, 7 and 80 microM. Irradiation of vesicles with ultraviolet light in the presence of 1 mM ATP resulted in K+-ATPase activity that shows only the low affinity ATP binding. The irradiation stimulated or inhibited proton uptake rate compared with control vesicles at high or low ATP concentrations, respectively. The relation between proton uptake rate and K+-ATPase activity at different ATP concentrations was linear with irradiated vesicles and nonlinear with control vesicles. These results indicate that hydrolysis at the high affinity ATP binding site regulates the energy-transport coupling in negative and positive manners at high and low ATP concentrations, respectively. The complete inhibition of K+-ATPase by a specific proton pump inhibitor E3810 (rabeprazole) (2-([4-(3-methoxypropoxy)-3-methylpyridin-2-yl]methylsulf i nyl)-1H-benzimidazole sodium salt) occurred when E3810 bound to half of the alpha-subunit of H+,K+-ATPase in unirradiated vesicles at both 200 and 10 microM ATP, whereas the complete inhibition of proton uptake occurred when E3810 bound to half or a quarter of the alpha-subunit at 200 or 10 microM ATP, respectively. These results suggest that dimeric interaction between the alpha-subunits is necessary for the enzyme activity at all ATP concentrations and that dimeric or tetrameric interaction is necessary for proton transport at high or low ATP concentrations, respectively.

Cooperative clinical trial of photodynamic therapy with photofrin II and excimer dye laser for early gastric cancer

BACKGROUND AND OBJECTIVE

Photodynamic therapy (PDT) is a recently developed endoscopic method for treating malignant tumors. For obtaining more photodynamic action with less thermal effect, we employed as the excitation light source for PDT an excimer dye laser, which is a pulsed laser with extremely high peak power, instead of an argon dye laser, which is a continuous wave laser and has been used conventionally.

STUDY DESIGN/MATERIALS AND METHODS

The effect of PDT using Photofrin II and the excimer dye laser was evaluated in 27 patients with early gastric cancer.

RESULTS

Complete responses (CR) were obtained in 88% of 24 assessable patients and the response rate was 100%. CR was observed in all cases of lesions of superficial depressed type without ulceration and/or with tumor diameter less than 2 cm. Regarding toxicity, mild cutaneous reaction and photosensitivity were seen and lasted several weeks. There were no serious abnormalities in laboratory tests.

CONCLUSION

We conclude that PDT is a promising modality for early gastric cancer.

Photodynamic therapy for multiple primary bronchogenic carcinoma

In recent years, multiple primary lung cancers have been reported with greater frequency, partly as a result of technologic advances in the detection of lung cancer and therapeutic achievements in its management. Photodynamic therapy (PDT) is a relatively new therapy used with increasing frequency in the treatment of a wide variety of malignancies, including central lung cancers. In PDT, the differential retention of an injected photosensitizer by malignant tissue is exploited by treatment with a low-power laser beam delivered endoscopically. Since 1980, 145 patients with central lung cancers, including 35 cases of endoscopically evaluated early-stage lesions were treated with PDT at Tokyo Medical College. Thirteen of these 145 patients had multiple primary bronchogenic carcinomas, five cases of which were synchronous with the rest, metachronous. Three of 13 patients with multiple tumors had early-stage lesions and were treated with endoscopic PDT alone. In the other ten cases, PDT was used to treat accessible early-stage foci although operative excision was required for advanced lesions. Mean survival after PDT, alone or in combination with surgery, was 38 months (range, 14 to 87 months), and seven patients remain alive to date. It was concluded that PDT is useful in extending the therapeutic options for, and improving the prognosis of patients with, multiple primary bronchogenic carcinomas.

The present status of bronchoscopic Nd:YAG laser

In Japan, the first bronchoscopic Nd:YAG laser applied clinically was performed in our institute 10 years ago, and based on this decade of experience, the indications, effectiveness, and limitations were studied. Between 1980 and 1989, a total of 202 cases were treated by Nd:YAG laser in our institute. Among them, 94 (46.5%) cases were primary lung cancers, 10 (5.0%) cases were primary tracheal malignancies, 56 (27.7%) cases were metastatic tracheal tumors, 6 (3.0%) cases were benign tracheal tumors, and 36 (17.8%) cases were nontumorous tracheal lesions. The indications for Nd:YAG laser therapy were defined as emergency widening of airway, curative treatment, reduction of tumor size, nontumorous benign lesions, and hemostasis. The desired therapeutic effects were obtained in 55/58 (94.8%) for emergency airway widening, 22/27 (81.5%) for curative treatment, 69/88 (78.4%) for reduction of tumor size, and 48/68 (70.6%) for nontumorous benign lesions. While performing Nd:YAG laser treatment, some limitations, such as poor residual pulmonary function, tumor size, tumor depth, cartilage structure, granulation, and stricture length, were encountered. Since bronchoscopic Nd:YAG laser treatment has become a well-established therapeutic modality for tracheobroncheal lesions, areas to be addressed in the future are the training of bronchoscopic laser therapists and research on the extension of applications. To increase the range of clinical applications, it is hoped that makers of laser systems will provide tunable wavelength machines at reduced cost.

Association of point mutation in c-Ki-ras oncogene in lung adenocarcinoma with particular reference to cytologic subtypes

The correlation between clinicopathologic findings and point mutation in codon 12 of c-Ki-ras gene was examined in primary lung adenocarcinomas using polymerase chain reaction and oligonucleotide hybridization techniques. The mutation was detected in ten of 67 cases (15%). Microscopically, mutation-positive cases revealed a tendency to be well differentiated (P less than 0.01). Especially, the incidence of the mutation-positive cases was significantly higher in goblet cell type (three of four) than in other types (five of 56) (P less than 0.001). None of 21 cases of pure Clara cell type showed the mutation (P less than 0.05). The mutation was detected frequently in tumors with no lymph node metastasis (P less than 0.05), with larger tumor size (P = 0.01), and T2 cases (P less than 0.01). Cigarette smoking was not always a contributing factor for mutation. This study revealed that the point mutation of c-Ki-ras codon 12 in lung adenocarcinoma has been associated with the cytologic subtype.

Photodynamic diagnosis in respiratory tract malignancy using an excimer dye laser system

Equipment has been developed for the early-stage diagnosis and treatment of cancer using an excimer dye laser. The excimer laser beam is obtained by exciting XeCl. A 405 nm beam tuned by DPS dye is used for tumour localization and a 630 nm beam obtained with a rhodamine B dye is used for treatment. The equipment was applied clinically on the basis of extensive experimental research. Effectiveness for cancer localization was examined in 11 cases: four were early stage (three lung cancer and one vocal cord cancer), four were stage I, two were stage III and one was stage IV. All cases were squamous cell carcinoma except for one case of adenocarcinoma. Fluorescence was recognized in all lesions and the equipment was effective for localization.

Change in a complex translocation involving band 7q34 and 9p- in a case of T-cell lymphoblastic lymphoma

The authors report a case of T-cell type non-Hodgkin's lymphoma (NHL) in which neoplastic cells possessed a three-way translocation involving chromosomal bands 3q21, 7q34, and 22q11, as well as partial monosomy of the short arm of chromosome 9. In the literature, most reported cases of 7q32-q36 abnormalities had T-cell type leukemia/lymphoma and were younger than 20 years. Two NHL cases, including the current case, were diagnosed as having lymphoblastic lymphoma with a leukemic transformation. The neoplastic cells of the reported cases commonly showed CD2 (E-rosette receptors) and CD38. All 17 patients but three manifested a mediastinal mass at diagnosis and seven had central nervous system lesions or pleural infiltration. Furthermore, five of the 19 reported cases also showed 9p- change.

[Clinical studies on reconstruction procedure of total layer chest wall resection]

The results of clinical studies on 16 reconstruction procedure after total layer chest wall resection in 14 cases of malignant tumor of the chest wall were reported. The 14 cases consisted of two cases with recurrent primary chest wall tumor, two cases of primary breast cancer, seven cases of recurrent breast cancer, and others. The reconstruction procedure after total layer chest wall resection was conducted using only various myocutaneous flaps (eight cases using latissimus dorsi of the resected side, three cases using the abdominitis of the resected side, three cases using latissimus dorsi of the non-resected side, and two cases using a pectoralis major myocutaneous flap of the non-resected side). reconstruction only using a myocutaneous flap proved to be satisfactory for preventing early stage postoperative respiratory distress and maintaining the stability of the chest wall and respiratory function during prolonged observation. Namely, use of myocutaneous flap is the best approach of reconstruction the chest wall after total layer chest wall resection. We confirmed that reconstruction with latissimus dorsi myocutaneous free flap of the non-resected side with microvascular anastomosis of thoracodorsal vessels was useful for posterior chest wall tumors invading the latissimus dorsi muscle. Also, our results demonstrated the insertion of an omental flap under the myocutaneous flap was useful for cases with secondary chest wall infection or vascular damage caused by preoperative high dose irradiation.

[A case report of mediastinal malignant lymphoma with long survival following combination chemotherapy using adriamycin, vincristine and cyclophosphamide]

Mediastinal B-cell malignant lymphoma of a 22-year-old female was successfully treated by combination chemotherapy including Adriamycin, Vincristine and Cyclophosphamide. She suffered from dyspnea and axillary tumor in September 1984. Roentgenological examination revealed a large anterior mediastinal tumor. Biopsy of the axillary tumor yielded a diagnosis of metastatic undifferentiated carcinoma from thymus by hematoxylin and eosin. Radiotherapy and chemotherapy including CDDP and ACNU resulted in a symptom-free period of only 2 months. Superior vena cava syndrome and massive pleural effusion recurred. Salvage chemotherapy including Adriamycin, Vincristine and Cyclophosphamide resulted in rapid therapeutic effect. Six courses of chemotherapy were administered, and she is alive and well 4 years after the first salvage chemotherapy. A definitive diagnosis of B-cell lymphoma was made after review of biopsy specimens using immunohistochemical procedures. To select adequate treatment for mediastinal malignant lymphoma, reliable diagnostic procedures including immunohistochemistry are needed. Intensive chemotherapy with appropriate drugs may obtain good response even in advanced cases, such as this.

[A clinico-pathological study of resected lung cancer cases accompanied by pleural dissemination]

A total of 26 lung cancer cases accompanied by pleural dissemination were resected between June 1977 and June 1988. Of these 16 cases were male and 10 cases were female. Their age was 34-78, and the average age was 56.7 years. The histologic type was adenocarcinoma in 23 cases, 1 was large cell carcinoma, 1 was combined adenosquamous cell carcinoma, and 1 was combined adeno-small cell carcinoma. Of these 23 adenocarcinoma cases, 15 were well differentiated, 7 were moderately differentiated, and 1 was poorly differentiated. There was no correlation between tumor size and pleural dissemination. Pleural effusion was observed in 8, 5 had bloody effusion and the other 3 had yellow effusion. Exact preoperative diagnosis and evaluation of extent was very difficult in pleural dissemination cases except for the pleural effusion cases. Concerning the operation method in these cases pleuropneumonectomy was performed in 10, pleurolobectomy in 6, and lobectomy in 10. Prognosis of cases of resected pleural dissemination was very poor. The median survival time was 16 months, The 1-year survival rate was 56.3%, the 2-year survival rate was 23.2%, the 3-year survival rate was 15.4%, and the 4-year survival rate was 7.7%. There was no 5-year survivor in lung cancer cases of this group. Malignant pleural effusion cases had a poorer prognosis, with 6 of 8 cases dying within 1 year from operation. No remarkable therapeutic effects were achieved by adjuvant chemotherapy. In the single case of preoperative hyperthermia, histological therapeutic effect (Ef 2) was recognized. These results suggest that there is no indication of operation in malignant pleural effusion cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of a novel antigen (1G12) on the surface of peripheral blood mononuclear cells from cancer patients by a sensitive radioimmunoassay. A possible marker for the early diagnosis of cancer

A murine monoclonal antibody designated 1G12 has been produced by immunizing mice with A549 human lung adenocarcinoma. Using radiolabeled monoclonal antibody 1G12, a sensitive radioimmunoassay to detect 1G12 antigen has been developed. The antigen was detected on the surface of peripheral blood mononuclear cells (PBMC). A study was performed to examine the frequency of distribution of this antigen on the surface of PBMC from healthy donors and patients with cancer. An antigen level of above 30 units per 1 x 10(6) PBMC was considered positive. None of 41 healthy donors (0%) and 16 of 96 patients (16.7%) with benign diseases of the lung, ovary, and uterus were positive. In contrast, 27 of 41 patients (65.8%) with lung cancer, 14 of 18 patients (77.8%) with ovarian cancer, and 16 of 27 patients (59.2%) with uterine cervical cancer had elevated levels of 1G12 antigen. When patients were grouped by stages of cancer, PBMC from patients in relatively early stages (stages I and II) also gave positive results, i.e., 9 of 17 patients (59.2%) with lung cancer, 6 of 10 patients (60%) with ovarian cancer, and 11 of 22 patients (50%) with uterine cervical cancer of these stages were positive. These results suggest that the detection of 1G12 antigen on PBMC of patients may be useful for early diagnosis of cancers.

A cell kinetic study of pulmonary adenocarcinoma by an immunoperoxidase procedure after bromodeoxyuridine labeling

By in vitro labeling with bromodeoxyuridine (BrdU) and immunohistochemical staining with anti-BrdU monoclonal antibody, the tumor cell kinetics were investigated in 52 resected pulmonary adenocarcinomas. The values of the BrdU labeling index (LI) varied widely among cases of adenocarcinoma in comparison with four cases of small cell carcinoma and ten cases of squamous cell carcinoma examined as controls. The LI was below 3.0 in 60% of the adenocarcinomas. When the LI was analyzed according to the cytologic subtypes of adenocarcinoma, the values were low for goblet cell type and type II alveolar cell type, whereas the values for the bronchial surface epithelial cell type varied widely (average, 5.2) and those for the Clara cell type were intermediate (average, 1.8). A comparison of the LI with TNM classification, histologic differentiation, degree of nuclear atypia, and mitotic cell count showed a correlation between the LI and each of these prognostic factors. Thus, the possibility of the BrdU LI being a useful new prognostic factor of pulmonary adenocarcinomas was suggested.

[A case of omental pedicle flap plombage for fungus ball type pulmonary aspergillosis]

The usual surgical treatment for fungus ball type pulmonary aspergillosis is lobectomy, but in cases of aspergillosis located in a post-lobectomy space a second lobectomy is difficult because of the accompanying inflammatory process. A 53-year-old male underwent left upper lobectomy for pulmonary tuberculosis eight years ago. Six year postoperatively, he developed fungus ball type aspergillosis in the post-lobectomy space with bronchopleural fistula and recurrent hemoptysis. We performed an omental pedicle flap plombage via the post-sternal route to resect the pleural cavity fungus ball. The post operative course was uneventful and clinically the bronchopleural fistula was closed.

[Direct current therapy with chemotherapy for the local control of lung cancer]

Direct current therapy (DC therapy), consisting of the application of electric current directly to the lesion, with chemotherapy using BLM was performed in 4 advanced inoperable lung cancer patients in whom chemotherapy and radiotherapy were not effective or could not be performed. Fluoroscopically two electrodes were inserted percutaneously into the tumor under local anesthesia. The distance between the two electrodes was about 3-4 cm. About 10 volts of direct current for 1 hour (totally over 40 coulombs) was passed between them using a DC treatment processor model 85 (Inter Nova Co., Ltd.), and simultaneously 15-30 mg of BLM was administered intravenously according to the general condition of the patient. The histologic type was adenocarcinoma in 3 cases and there was 1 large cell carcinoma. This treatment was performed once in 3 cases and twice in another. A reduction of tumor size was recognized in 3 cases (2 adenocarcinomas and 1 large cell carcinoma). In another adenocarcinoma case it was not measurable in size because of infiltrative shadow but histologically tumor destruction was recognized within a short period after DC therapy. The complications were mainly slight fever and light pain during the procedure. There was one small amount of hemoptysis and one pneumothorax but it was not necessary to perform special treatment for these complications. DC therapy with chemotherapy is based on our basic experimental experience that some anticancer agents accumulate around the electrodes in lung tissue when direct current is passed. In addition, current itself has cytocidal effects in some cases. Our clinical experience suggested the usefulness of this therapy to treat lung cancer lesions locally.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunohistochemical and immunoblot analyses of ras-p21 expression in lung carcinomas

Immunohistochemical and immunoblot analyses were performed on 49 cases of surgically resected primary lung carcinoma to examine the expression of ras oncogene product using monoclonal antibodies to ras-p21. Two different monoclonal antibodies, NCC-RAS-001 and RAP-5 were used for immunohistochemical study. Cancer cells of 16 cases (33%) and 15 cases (31%) were strongly positive for NCC-RAS-001 and RAP-5, respectively. The staining pattern of antibodies was heterogenous among cancer cells, even in the same case. Among various histologic type of lung cancers, squamous cell carcinomas and well-differentiated adenocarcinomas had a tendency to react more intensively than other histologic types of carcinoma. Immunoblot analysis using monoclonal antibody NCC-RAS-004 revealed the presence of ras-p21 not only in cancer tissues but also in non-cancerous tissues in all cases analysed. In 13 cases (27%), cancer tissue expressed more than twice as much ras-p21 as non-cancerous tissues. Our study showed that the over-expression of ras-p21 in lung carcinomas compared with non-cancerous tissues was a relatively common phenomenon, especially in squamous cell carcinomas and adenocarcinomas.

[One-stage resected case of dumbbell type tumor of the posterior mediastinum]

We reported a dumbbell type tumor of the posterior mediastinum. The patient was an asymptomatic 40-year-old male. An abnormal shadow in the right lower lung field was pointed out in a mass survey. We recognized a dumbbell type tumor in the posterior mediastinum by chest CT and MRI. The tumor invaded the intervertebral canal through the spinal foramen. It was most clearly seen by MRI myelography. Operation was performed with the patient in a prone position and with an L-shaped skin incision of the back and 11th intracostal thoracotomy and Th11 laminectomy. The dumbbell type tumor was completely removed by this operation. The pathological diagnosis was Schwannoma. The post operative course was good. The one-stage operation is useful for dumbbell type tumors of the posterior mediastinum.