Molecular biological role of epithelial splicing regulatory protein 1 in intrahepatic cholangiocarcinoma.

AIM: Epithelial splicing regulatory protein 1 (ESRP1) regulates tumor progression and metastasis through the epithelial‒mesenchymal transition by interacting with zinc finger E-box binding 1 (ZEB1) and CD44 in cancers. However, the role of ESRP1 in intrahepatic cholangiocarcinoma (iCCA) remains unclear. METHODS: Three iCCA cell lines (HuCCT-1, SSP-25, and KKU-100) were analyzed using small interfering RNA to investigate the molecular biological functions of ESRP1 and ZEB1. The association between clinicopathological features and the expression of ESRP1 and ZEB1 in iCCA tissues was analyzed immunohistochemically. Proteomic analysis was performed to identify molecules related to ESRP1 expression. RESULTS: ESRP1 expression was upregulated in HuCCT-1 and SSP-25 cells. Cell migration and invasion were enhanced, and the expression of ZEB1 and CD44s (CD44 standard) isoforms were upregulated in the ESRP1 silencing cells. Moreover, ESRP1 silencing increased the expression of N-cadherin and vimentin, indicating the presence of mesenchymal properties. Conversely, ZEB1 silencing increased the expression of ESRP1 and CD44v (CD44 variant) isoforms. Immunohistochemical analysis revealed that a lower ESRP1-to-ZEB1 expression ratio was associated with poor recurrence-free survival in patients with iCCA. Flotillin 2, a lipid raft marker related to epithelial‒mesenchymal transition, was identified as a protein related to the interactive feedback loop in proteomic analysis. CONCLUSIONS: ESRP1 suppresses tumor progression in iCCA by interacting with ZEB1 and CD44 to regulate epithelial‒mesenchymal transition.

Inhibitor for protein disulfide-isomerase family A member 3 enhances the antiproliferative effect of inhibitor for mechanistic target of rapamycin in liver cancer: An in vitro study on combination treatment with everolimus and 16F16.

mTOR is involved in the proliferation of liver cancer. However, the clinical benefit of treatment with mTOR inhibitors for liver cancer is controversial. Protein disulfide isomerase A member 3 (PDIA3) is a chaperone protein, and it supports the assembly of mTOR complex 1 (mTORC1) and stabilizes signaling. Inhibition of PDIA3 function by a small molecule known as 16F16 may destabilize mTORC1 and enhance the effect of the mTOR inhibitor everolimus (Ev). The aim of the present study was to elucidate the usefulness of combination treatment with Ev and 16F16 in liver cancer using cultured Li-7 and HuH-6 cells. The proliferation of cultured cells was examined following treatment with 0.01 µM Ev, 2 µM 16F16 or both. The expression levels and phosphorylation of S6 kinase (S6K) and 4E-binding protein 1 (4E-BP1) were examined by western blotting. Li-7 was susceptible to Ev, and proliferation was reduced to 69.5±7.2% by Ev compared with that of untreated cells. Proliferation was reduced to 90.2±10.8% by 16F16 but to 62.3±12.2% by combination treatment with Ev and 16F16. HuH-6 cells were resistant to Ev, and proliferation was reduced to 86.7±6.1% by Ev and 86.6±4.8% by 16F16. However, combination treatment suppressed proliferation to 57.7±4.0%. Phosphorylation of S6K was reduced by Ev in both Li-7 and HuH-6 cells. Phosphorylation of 4E-BP1 was reduced by combination treatment in both Li-7 and HuH-6 cells. Immunoprecipitation assays demonstrated that PDIA3 formed a complex with 4E-BP1 but not with S6K. The small molecule 16F16 increased susceptibility to Ev in cultured liver cancer cells, which are resistant to Ev. The inhibition was associated with reduction of 4E-BP1 phosphorylation, which formed a complex with PDIA3. Combination treatment with Ev and 16F16 could be a novel therapeutic strategy for liver cancer.

High Expression of p21 as a Potential Therapeutic Target in Ovarian Clear-cell Carcinoma.

BACKGROUND/AIM: DNA damage response (DDR), wherein p21 is a cell fate determinant, is a potential cancer therapeutic target. Molecular expression during DDR was explored in ovarian clear-cell carcinoma (CCC). MATERIALS AND METHODS: CHK1, CHK2, TP53 and p21 expression in DDR was examined using immunostaining in surgical sections of CCC (n=22). Molecular alterations in two types of CCC cell lines, JHOC-5 and JHOC-9, were investigated using western blot analysis. RESULTS: Expression of DDR-associated molecules was noted in most patients. While high p21 expression was found in half of the patients, the remaining patients exhibited low p21 expression. Treatment with UC2288, a p21 inhibitor, attenuated proliferation of both cell lines, more prominently in JHOC-9, resulting in reduced viability and subsequent apoptosis. CONCLUSION: p21 Inhibitor induced cell death in cells with high p21 expression, suggesting that p21 suppression can be a therapeutic strategy to treat patients with CCC.

Expression level of long noncoding RNA H19 of normotensive placentas in late pregnancy relates to the fetal growth restriction.

AIM: Infants with fetal growth restriction (FGR) are at an increased risk of perinatal morbidity and mortality. The long noncoding RNA H19 gene is expressed abundantly in placental villi and recent studies suggest that it regulates FGR. However, the role of H19 in the FGR placenta remains unclear. This study aimed to clarify the relationship between H19 expression and FGR using normotensive placentas after 34 weeks of gestation. METHODS: Formalin-fixed paraffin-embedded tissues from human placentas collected from pregnancies resulting in small for gestational age (SGA) and appropriate for gestational age (AGA) newborns were used. The histopathological features of placenta tissues, such as villous stromal fibrosis, the numbers of terminal villi, villous vessels and cytotrophoblasts were analyzed using hematoxylin and eosin, Masson's trichrome staining and immunostaining. The localization and expression of H19 in the placentas were demonstrated by in situ hybridization and reverse transcription-quantitative polymerase chain reaction (RT-qPCR), respectively. Moreover, the expression levels of H19-regulated molecules such as IGF2 and decorin (DCN) were measured by RT-qPCR. RESULTS: Histopathological features of the placental villous were not different between placentas associated with SGA and AGA. H19 localized to the villous stroma, endothelial cells and cytotrophoblasts. Moreover, the expression level of H19 in SGA placentas was significantly lower than that in AGA placentas. The expression levels of IGF2 and DCN in SGA placentas tended to be lower than those in AGA placentas similarly to H19. CONCLUSION: This study highlights the potential importance of regulatory events mediated by H19 in SGA placentas without histopathological abnormalities in late pregnancy.

In vitro and in vivo studies on the association of long non­coding RNAs H19 and urothelial cancer associated 1 with the susceptibility to 5­fluorouracil in rectal cancer.

There is no predictive biomarker for response to 5­fluorouracil (5FU)­based neoadjuvant chemotherapy (NAC) in rectal cancer. In the present study, we examined potential long non­coding RNAs (lncRNAs) linked to the susceptibility to 5FU in cultured colorectal cancer cells, and in biopsy and resected tissues of 31 human rectal cancer cases treated with NAC. Candidate lncRNAs for the prediction of susceptibility to 5FU were investigated by comprehensive analysis of expression profiles of 84 lncRNAs in cultured cells using PCR array. Bioinformatic analysis identified H19 and urothelial cancer associated 1 (UCA1) as candidate biomarkers for 5FU susceptibility. Quantitative PCR of H19 and UCA1 in cultures of colorectal cancer cells demonstrated the notable variation in expression. The ratios of changes of H19 and UCA1 expression in response to 5FU were low in cells resistant to 5FU, whereas ratios were high in cells susceptible to 5FU. In 5FU­susceptible cells, cell proliferation was inhibited by 5FU. Upregulation of H19 and UCA1 were associated with the reduction in target molecule expression, including retinoblastoma and p27kip1. In 31 cases of rectal cancer, H19 and UCA1 expression levels in biopsy and resected tissue were comparable. The ratios of H19 and UCA1 expression in resected tissue compared with biopsy samples were low in 17 cases, whereas the ratios were high in 14 cases; 11 of the 17 cases (65%) with low ratios exhibited poor response to NAC, whereas 4 of the 14 cases (29%) with high ratios showed poor response (P=0.045). The increase in H19 and UCA1 expression may represent the response to impaired cell cycle in cells susceptible to 5FU. Our results indicate that changes in H19 and UCA1 expression may be considered for predicting the susceptibility to 5FU­based NAC in rectal cancer.

Farnesoid X receptor induces cell death and sensitizes to TRAIL-induced inhibition of growth in colorectal cancer cells through the up-regulation of death receptor 5.

Farnesoid X receptor (FXR) exhibits critical anti-cancer functions in several types of cancer, including colorectal cancer, in vitro and in vivo. However, the underlying mechanism remains unclear. We evaluated pharmacological activation of FXR with the synthetic agonist GW4064 using comprehensive proteomic analysis in colorectal cancer cell lines (HCT116, SW480, and DLD1). Among the commonly detected proteins in all three cell lines, death receptor 5 (DR5) was the most up-regulated protein, and key autophagy-related proteins, such as microtubule-associated protein 1 light chain 3 alpha/beta (MLP3A/3B) and p62 sequestosome-1 (SQSTM), were also differentially expressed. Western blot analysis showed that GW4064 stimulation induced activation of the extrinsic death signaling pathway in all cell lines and induced activation of the intrinsic death signaling pathway in DLD1 cells. Western blotting showed that DR5 up-regulation was associated with inhibition of autophagic activity. These results suggest that FXR activation induced DR5 up-regulation through inhibition of autophagic activity and the DR5-related death signaling pathway. In addition, DR5 selective ligand, also known as TRAIL, has been widely used for anti-cancer treatment in several clinical trials. Co-treatment of TRAIL with GW4064 synergistically inhibited colorectal cancer cell proliferation as compared with single treatments. To the best of our knowledge, our results provide novel insights into FXR function in cancer cell lines. These findings may contribute to a new therapeutic strategy for colorectal cancer.

Toll­like receptor 4 plays a tumor­suppressive role in cutaneous squamous cell carcinoma.

Toll­like receptor 4 (TLR4), a key regulator of the innate immune system, is expressed not only in immune cells, but also in a number of cancer cells. A biological role for TLR4 in cutaneous squamous cell carcinoma (SCC), however, is unclear. In this study, we first examined TLR4 expression and localization in cases of SCC, actinic keratosis (AK) and Bowen's disease (BD) by immunohistochemistry. TLR4 expression was significantly higher in the SCC than in the AK or BD tissues. We then determined the TLR4 expression level in vivo, in 3 histological subtypes of SCC. TLR4 expression in poorly differentiated SCC was significantly lower compared with that of the moderately and well­differentiated type. In addition, the CD44 immunoreactivity tended to be high in the cell membrane of poorly differentiated SCC. Of note, poorly differentiated SCC is a risk factor of unfavorable outcomes in affected patients. We then assessed the biological role of TLR4 in HSC­1 and HSC­5 SCC cells and HaCaT human keratinocytes. TLR4 knockdown by transfection with siRNA accelerated HSC­1 and HaCaT cell migration and invasion compared to the control siRNA­transfected cells. TLR4 knockdown resulted in an increased CD44 expression and in an enhanced filopodia protrusion formation, particularly in HSC­1. On the whole, these results suggest that a reduced TLR4 expression enhances the malignant features in SCC cases and cultured SCC cell lines. TLR4 may thus play an anti­tumor role in cutaneous SCC.

Downregulation of protein disulfide­isomerase A3 expression inhibits cell proliferation and induces apoptosis through STAT3 signaling in hepatocellular carcinoma.

Protein disulfide­isomerase A3 (PDIA3) is a chaperone protein that modulates folding of newly synthesized glycoproteins and responds to endoplasmic reticulum (ER) stress. Previous studies reported that increased expression of PDIA3 in hepatocellular carcinoma (HCC) is a marker for poor prognosis. However, the mechanism remains poorly understood. The aim of the present study, therefore, was to understand the role of PDIA3 in HCC development. First, immunohistochemical staining of tissues from 53 HCC cases revealed that HCC tissues with high PDIA3 expression exhibited a higher proliferation index and contained fewer apoptotic cells than those with low expression. In addition, the knockdown of PDIA3 significantly inhibited cell proliferation and induced apoptosis in HCC cell lines. These results suggest that PDIA3 regulates cell proliferation and apoptosis in HCC. An examination of whether PDIA3 knockdown induced apoptosis through ER stress revealed that PDIA3 knockdown did not increase ER stress marker, 78 kDa glucose­regulated protein, in HCC cell lines. Furthermore, the association between PDIA3 and the signal transducer and activator of transcription 3 (STAT3) signaling pathway were investigated in vitro and in vivo. Immunofluorescence staining and co­immunoprecipitation experiments revealed colocalization and binding, respectively, of PDIA3 and STAT3 in HCC cell lines. The knockdown of PDIA3 decreased the levels of phosphorylated STAT3 (P­STAT3; Tyr705) and downstream proteins of the STAT3 signaling pathway: The anti­apoptotic proteins (Bcl­2­like protein 1, induced myeloid leukemia cell differentiation protein Mcl­1, survivin and X­linked inhibitor of apoptosis protein). In addition, PDIA3 knockdown provided little inhibitory effect on cell proliferation in HCC cell lines treated with AG490, a tyrosine­protein kinase JAK/STAT3 signaling inhibitor. Finally, an association was demonstrated between PDIA3 and P­STAT3 expression following immunostaining of 35 HCC samples. Together, the present data suggest that PDIA3 promotes HCC progression through the STAT3 signaling pathway.

Expression of protein disulfide isomerase A3 and its clinicopathological association in gastric cancer.

Protein disulfide isomerase A3 (PDIA3) is a chaperone protein that supports the folding and processing of synthesized proteins. Its expression is associated with the prognosis of laryngeal cancer, hepatocellular carcinoma, diffuse glioma and uterine cervical cancer. In the present study, the expression levels of PDIA3 and its clinicopathological association were examined in 52 cases of gastric cancer (GC). The expression of PDIA3 was examined by immunohistochemistry and scored using a semi-quantitative method. According to the score, GC samples were classified into PDIA3­High and PDIA3­Low GC. PDIA3­High GC samples were predominantly of the intestinal type. Multivariate survival analysis indicated that PDIA3 expression and cancer stage were independent factors. The overall survival of PDIA3­High GC cases was significantly favorable compared with that of PDIA3­Low GC cases, and this was more evident in cases at an advanced stage. In GC cell cultures, the PDIA3 and major histocompatibility complex (MHC) class I proteins were expressed in three out of the four assessed cell lines according to western blot analysis. Notably, the expression of MHC class I was increased by the stimulation of interferon γ. Co­immunoprecipitation assays suggested the formation of a PDIA3 and MHC class I complex. The findings suggested that PDIA3 may be involved in the immune response of carcinoma cells. The improved prognosis in PDIA3­High GC may be accounted for, in part, by sufficient antigen processing and expression of MHC class I, which can be mediated by PDIA3. It was suggested that PDIA3 serves an important role in the pathobiology of GC, and that PDIA3 is a useful marker for the prediction of prognosis.

Enhanced Sternal Healing Through Platelet-Rich Plasma and Biodegradable Gelatin Hydrogel.

Platelet-rich plasma (PRP) contains numerous growth factors and promotes bone fracture healing. The aim of this study was to evaluate the effectiveness of the controlled release of PRP from biodegradable gelatin hydrogel for promoting healing in a rabbit ischemic sternal model. PRP was prepared from the whole blood of a Japanese white rabbit. Sixteen rabbits were randomized into four groups (each n = 4) and all underwent median sternotomy and bilateral internal thoracic artery removal. Before the sternum was closed, the following solutions were applied between the sternum incisions in three of the groups: 30 mg of gelatin hydrogel incorporating 300 µL of phosphate-buffered saline, 300 µL of a solution form of PRP, or 30 mg of gelatin hydrogel incorporating 300 µL of PRP (PRP + Gel). The fourth group acted as a control. Sternal healing was evaluated by histology and microcomputed tomography 7 days after the intervention. The PRP + Gel group showed a significantly higher proportion of fibrosis within the fracture area (an indicator of sternal healing) than the other groups and a significantly higher mean intensity of osteocalcin. These results indicate that the controlled release of PRP from locally applied gelatin hydrogel was markedly effective in enhancing sternal healing in the early postoperative period. This novel therapy could potentially help prevent complications, such as deep sternal wound infection and could result in early postoperative ambulation after median sternotomy.

2-Deoxy-d-glucose increases GFAT1 phosphorylation resulting in endoplasmic reticulum-related apoptosis via disruption of protein N-glycosylation in pancreatic cancer cells.

The glycolytic inhibitor 2-deoxy-d-glucose (2DG) causes energy starvation, affecting cell viability in a wide range of cancer cell lines. To determine the action of 2DG in pancreatic cancer, we performed proteomic analysis of pancreatic cancer cell line after 2DG treatment. Eighty proteins showed differential expression and among these, proteins involved in phosphohexose metabolism were upregulated. Up-regulation of glutamine: fructose 6-phosphate aminotransferase 1 (GFAT1), which belongs to the hexosamine biosynthesis pathway (HBP) that produces uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) to maintain glycoprotein, was validated by evaluation of mRNA and protein levels. Therefore, we assessed the amounts of total N-glycoproteins. Unexpectedly, we found a reduction of total N-glycoproteins and phosphorylation of GFAT1 by AMP-activated protein kinase (AMPK). These data may shed light on HBP dysfunction. Furthermore, we found endoplasmic reticulum (ER) stress accompanied by increased expression of ER stress markers, such as glucose response protein 78 (GRP78) and C/EBP-homologous protein (CHOP), in 2DG-treated cells. Moreover, the additive activation of AMPK by metformin (Met) synergistically enhanced the reduction of protein N-glycosylation and cell growth inhibition in the presence of 2DG. These results suggest that 2DG reduces N-glycosylation of proteins following the increase of phosphorylation of GFAT1 and results in the inhibition of cell growth mediated by ER stress in pancreatic cancer cells.

Expression of DNA damage response proteins in gastric cancer: Comprehensive protein profiling and histological analysis.

Gastric cancer is the third major cause of cancer-related mortality in Japan. The aim of this study was to identify a factor implicated in the biology of gastric cancer by comprehensive protein profiling. Protein profiling was carried out by liquid chromatography-tandem mass spectrometry, using formalin-fixed paraffin-embedded specimens of 17 gastric cancer cases. Pathway analysis and orthogonal partial least square-discriminant analysis suggested the significant expression of ribonucleoproteins, heterogeneous nuclear ribonucleoproteins, interleukin binding factor 2 (ILF2), KU70 and KU80, which are involved in DNA damage response (DDR). Thus, the expression and phosphorylation levels of KU70, ILF2, CHK1 and CHK2 were examined by immunohistochemistry in 42 cases of gastric cancer. The expressions of ILF2 and CHK1 were unaffected in all cases. The expression and phosphorylation of CHK2 were absent in 2 cases. Despite the expression of proteins, the phosphorylation of KU70 and CHK2 appeared to be impaired in 1 and 4 cases, respectively. In 7 out of 42 cases (17%), DDR appeared to be impaired. Recurrence was noted in 2 out of these 7 cases (29%), whereas the recurrence was noted in 2 out of the remaining 35 cases (6%). The expression levels of KU70, ILF2, CHK1, CHK2 and TP53 were further examined in 4 gastric cancer cell lines. The expression and phosphorylation levels following exposure to ultraviolet radiation were abnormal in the 3 cell lines. The normal consecutive phosphorylation of CHK1 and CHK2, the upregulation of TP53 and an increase in apoptotic cell death following exposure to ultraviolet radiation was detected only in one cell line, suggesting that the preserved functions of DDR and TP53 are necessary for the determination of cell fate. It is thus suggested that DDR plays an important role in the pathobiology of gastric cancers.

Identification of aldolase A as a potential diagnostic biomarker for colorectal cancer based on proteomic analysis using formalin-fixed paraffin-embedded tissue.

Colorectal cancer (CRC) is one of the most common cancers worldwide, and many patients are already at an advanced stage when they are diagnosed. Therefore, novel biomarkers for early detection of colorectal cancer are required. In this study, we performed a global shotgun proteomic analysis using formalin-fixed and paraffin-embedded (FFPE) CRC tissue. We identified 84 candidate proteins whose expression levels were differentially expressed in cancer and non-cancer regions. A label-free semiquantitative method based on spectral counting and gene ontology (GO) analysis led to a total of 21 candidate proteins that could potentially be detected in blood. Validation studies revealed cyclophilin A, annexin A2, and aldolase A mRNA and protein expression levels were significantly higher in cancer regions than in non-cancer regions. Moreover, an in vitro study showed that secretion of aldolase A into the culture medium was clearly suppressed in CRC cells compared to normal colon epithelium. These findings suggest that decreased aldolase A in blood may be a novel biomarker for the early detection of CRC.

Insulin-like growth factor 2 mRNA-binding protein-3 as a marker for distinguishing between cutaneous squamous cell carcinoma and keratoacanthoma.

In the histopathological diagnosis of cutaneous tumors, the differential diagnosis of squamous cell carcinoma (SCC) with crateriform architecture and keratoacanthoma (KA) is often difficult so an accurate understanding of the biological features and the identification of reliable markers of SCC and KA are crucial issues. Insulin-like growth factor 2 mRNA-binding protein-3 (IGF2BP3, also known as IMP3) is thought of as a bona fide oncofetal protein, which is overexpressed and is involved in cell proliferation, migration, and invasion in several kinds of tumors. However, the role of IMP3 in cutaneous SCC and KA has not been well studied. Therefore, we focused on studying the biological functions of IMP3 in SCC and KA. In human skin SCC cell lines, HSC-1 and HSC-5, and the human keratinocyte cell line, HaCaT, IMP3 mRNA levels were significantly higher than that of normal human skin. The knockdown of IMP3 expression reduced the proliferation of HSC-1, and significantly reduced invasion by HSC-1 and HSC-5. In contrast, the knockdown of IMP3 did not significantly affect invasion by HaCaT cells. In immunohistochemical studies of SCC and KA tissues, the Ki-67 labeling index (LI) of the suprabasal cell layer was significantly higher in SCC, compared with KA tissues and the tumor-free margin (TFM) adjacent to SCC and KA. Most SCC tissues stained strongly positive for IMP3, but KA tissues and TFM were mostly negative for IMP3. The Ki-67 LI of the IMP3-positive group was significantly higher than that of the IMP3-negative group in the suprabasal cell layer of SCC. These results suggest that IMP3 plays an important role in proliferation and, more significantly, in the invasion of SCC, and may be a suitable marker for the histopathological diagnosis of SCC with a crateriform architecture and KA. Furthermore, IMP3 may potentially be a new therapeutic target for SCC.

Increased expression of PDIA3 and its association with cancer cell proliferation and poor prognosis in hepatocellular carcinoma.

The prognosis of hepatocellular carcinoma (HCC) is unfavorable following complete tumor resection. The aim of the present study was to identify a molecule able to predict HCC prognosis through comprehensive protein profiling and to elucidate its clinicopathological significance. Comprehensive protein profiling of HCC was performed by liquid chromatography-tandem mass spectrometry. Through the bioinformatic analysis of proteins expressed differentially in HCC and non-HCC tissues, protein disulfide-isomerase A3 (PDIA3) was identified as a candidate for the prediction of prognosis. PDIA3 expression was subsequently examined in 86 cases of HCC by immunostaining and associations between PDIA3 expression levels and clinicopathological characteristics were evaluated. The Ki-67 index and apoptotic cell death of carcinoma cells were examined by immunostaining and terminal deoxynucleotidyl transferase dUTP nick-end labeling assay in 24 cases. The results demonstrated that PDIA3 was expressed in all 86 HCC cases; 56 HCC cases (65%) exhibited high expression of PDIA3 and 30 (35%) exhibited low expression. The disease-free and overall survival times of HCC patients with high PDIA3 expression were significantly shorter than in HCC patients with low expression. Furthermore, increased expression of PDIA3 was associated with an elevated Ki-67 index, indicating increased cancer cell proliferation and a reduction in apoptotic cell death. Taken together, these results suggest that PDIA3 expression is associated with tumor proliferation and decreased apoptosis in HCC, and that increased expression of PDIA3 predicts poor prognosis. PDIA3 may therefore be a key molecule in the development of novel targeting therapies for patients with HCC.

A cross-sectional analysis of dioxins and health effects in municipal and private waste incinerator workers in Japan.

This cross-sectional study was intended to examine health effects of 678 male workers employed during an 8-yr period from 2000 to 2007 at 36 municipal and private waste incineration plants in Japan. Blood samples were obtained for analysis of concentrations of dioxins including coplanar polychlorinated biphenyls (coplanar PCBs) and evaluation of health effects. Health effects including diabetes were surveyed via a physician's interview or clinical data from blood samples. There was a certain difference in serum concentrations of polychlorinated dibenzofurans (PCDFs) between the incinerator workers and Japanese general population, although no differences in the concentrations of total dioxins or polychlorinated dibenzo-p-dioxins (PCDDs) were found between the two groups. A few positive correlations between serum levels of PCDDs and PCDFs and the results of laboratory and physiological tests were found, but coplanar PCBs showed significant relations with 14 parameters of the tests. The background serum levels of PCDDs, PCDFs and total dioxins were significantly associated with the prevalence of diabetes. No essential differences in serum concentrations of total dioxins and in prevalence of diabetes between our subjects and the general population suggested that the incinerator workers were marginally exposed to dioxins in the workplace without any recognizable adverse health effects.

Isomer pattern and elimination of dioxins in workers exposed at a municipal waste incineration plant.

The aim of this study was to clarify patterns of serum concentrations of dioxins in the employees of a waste incineration plant and to estimate elimination rates and half-lives of serum dioxin isomers, and the maximum serum concentrations of dioxin isomers at the time of plant shutdown. Sixteen subjects participating 3 times or more in annual health examinations during an 8-yr period from 2000 to 2007 were recruited for this study. Serum concentrations of dioxins expressed as TEQ/g lipid decreased gradually after plant shutdown with the highest decrease observed in polychlorinated dibenzofurans (PCDFs) followed by polychlorinated deibenzo-p-dioxins (PCDDs) and then coplanar PCBs. The serum toxic equivalency (TEQ) concentrations of PCDF and PCDD congeners in the employees were higher than those in the general population survey by the Ministry of the Environment, Japan, whereas the serum concentrations of coplanar PCBs were similar to those in the general population. The estimated half-lives and elimination rates of PCDDs and PCDFs in the highly exposed workers increased compared with the moderately exposed workers. The estimated geometric mean serum concentrations of PCDDs, PCDFs and total dioxins at the time of plant shutdown were 35, 53 and 107 pg TEQ/g lipid, respectively.

Cystatin B as a potential diagnostic biomarker in ovarian clear cell carcinoma.

Epithelial ovarian cancer (EOC) consists of four major subtypes: clear cell carcinoma (CCC), endometrioid adenocarcinoma (EA), mucinous adenocarcinoma (MA) and serous adenocarcinoma (SA). Relative to the other subtypes, the prognosis of CCC is poor due to a high recurrence rate and chemotherapy resistance, but CCC-specific biomarkers have yet to be identified. With the aim of identifying diagnostic and treatment biomarkers for CCC, we analyzed 96 cases of EOC (32 CCC, 13 EA, 19 MA, 32 SA) using liquid chromatography/mass spectrometry (LC/MS) followed by immunohistochemistry (IHC) and quantitative reverse transcription PCR (RT-qPCR). Semi-quantification of protein differences between subtypes showed upregulation of 150 proteins and downregulation of 30 proteins in CCC relative to the other subtypes. Based on hierarchical clustering that revealed a marked distinction in the expression levels of cystatin B (CYTB) and Annexin A4 (ANXA4) in CCC relative to the other subtypes, we focused the study on CYTB and ANXA4 expression in EOCs by IHC, RT-qPCR and western blot analyses using tissue specimens and cultured cells. As a result, compared to the other subtypes, CCC showed significantly high expression levels of CYTB and ANXA4 in the analyses. To examine the possibility of CYTB and ANXA4 as serum diagnostic biomarkers of CCC, we checked the protein levels in conditioned media and cell lysates using culture cells. Compared with the other subtypes, CCC cell lines showed a significantly higher level of expression of CYTB in both conditioned media and cell lysates, while ANXA4 showed a higher level of expression in cell lysates only. Our results demonstrate that CYTB and ANXA4 overexpression may be related to carcinogenesis and histopathological differentiation of CCC. CYTB may be a secreted protein, and may serve as a potential serum diagnostic biomarker of CCC, while ANXA4 may be useful as an intracellular marker.

Altered expression of fibroblast growth factor receptor 2 isoform IIIc: relevance to endometrioid adenocarcinoma carcinogenesis and histological differentiation.

Fibroblast growth factor receptor 2 (FGFR2) is activated in many cancers and considered as a potential therapeutic molecular target including for endometrial endometrioid carcinoma (EEC). Overexpression of FGFR2 isoform IIIc (FGFR2IIIc) has been shown to be associated with carcinogenesis in various cancers, but its expression in EEC has not been reported yet to the best of our knowledge. In this study, we identified roles for FGFR2IIIc in EEC carcinogenesis and demonstrated its diagnostic and prognostic values in EEC. FGFR2IIIc expression was compared between 10 normal endometrium, 10 atypical endometrial hyperplasias, and 47 EEC specimens using immunohistochemistry and quantitative real-time PCR. Atypical hyperplasia, Grade 1 (G1), and Grade 2 (G2) differentiated EEC tissues showed significantly higher FGFR2IIIc expression than normal endometrium tissue. However, as compared to G1 and G2 EECs, Grade 3 (G3) differentiated EEC tissue showed lower FGFR2IIIc expression (P<0.05). There was no significant association between FGFR2IIIc expression and patient age, lymph node metastasis, and EEC stage. These results suggest that altered FGFR2IIIc expression plays an important role in EEC carcinogenesis and may occur in precancerous tissues. However, FGFR2IIIc appears to be not related to EEC progression. Some G3 EECs may develop through different carcinogenic processes than G1 and G2 EECs.