Autopsy case with concurrent transthyretin and immunoglobulin amyloidosis.

An 85-year-old man with a history of aortic dissection suddenly fainted, underwent cardiac heart arrest, and died. An autopsy was performed, but the cause of death was not grossly identified. Congo red staining detected amyloid deposits in systemic organs, including the heart, lungs, liver, and kidneys. Immunohistochemical (IHC) analysis revealed immunoglobulin (Ig) λ light chain (-λ) in systemic blood vessels and transthyretin (TTR) in the heart and lungs. Ig-λ was predominantly positive in the blood vessels of the lungs, while TTR was detected in the alveolar septum. In the heart, Ig-λ was positive in the endocardium and blood vessels, and TTR was positive in nodular deposits between cardiomyocytes. The concurrent deposition of Ig-λ and TTR in the heart was further substantiated by laser microdissection (LMD)-liquid chromatography-tandem mass spectrometry (LC-MS/MS) at each deposition site. Despite systemic deposition of Ig-λ, bone marrow biopsy findings were not diagnostic for multiple myeloma. In summary, we present an autopsy case of concurrent Ig-λ and TTR deposition as revealed by IHC and LC-MS/MS. When Congo red staining and IHC results are indeterminate due to the deposition of multiple amyloid proteins, LMD-LC-MS/MS is useful for determining the precursor protein.

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.

DNA Adductome Analysis Identifies N-Nitrosopiperidine Involved in the Etiology of Esophageal Cancer in Cixian, China.

Esophageal cancer is prevalent in Cixian, China, but the etiology of this disease remains largely unknown. Therefore, we explored this by conducting a DNA adductome analysis. Both tumorous and nontumorous tissues were collected from patients who underwent surgical procedures at Cixian Cancer Hospital and the Fourth Hospital of Hebei Medical University, which is in a low-incidence area. N2-(3,4,5,6-Tetrahydro-2H-pyran-2-yl)deoxyguanosine (THP-dG) was the major adduct detected in samples from esophageal cancer patients in Cixian. The precursor of THP-dG, N-nitrosopiperidine (NPIP), exhibited a strong mutagenic activity under metabolic activation in the Ames test and a significant dose-dependent increase in mutation frequency during an in vivo mutagenicity test with guanine phosphoribosyltransferase (gpt) delta rats. The NPIP-induced mutation was dominated by A:T to C:G transversions, followed by G:C to A:T and A:T to G:C transitions, in the liver and esophagus of animal samples. A similar mutational pattern was observed in the mutational signature of esophageal cancer patients that demonstrated weak correlation with THP-dG levels. These findings suggested that NPIP exposure is partly involved in the development of esophageal cancer in Cixian residents.

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.

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.

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.

Suppressive effects of the NADPH oxidase inhibitor apocynin on intestinal tumorigenesis in obese KK-A(y) and Apc mutant Min mice.

Obesity is a risk factor for colorectal cancer. The accumulation of abdominal fat tissue causes abundant reactive oxygen species production through the activation of NADPH oxidase due to excessive insulin stimulation. The enzyme NADPH oxidase catalyzes the production of reactive oxygen species and evokes the initiation and progression of tumorigenesis. Apocynin is an NADPH oxidase inhibitor that blocks the formation of the NADPH oxidase complex (active form). In this study, we investigated the effects of apocynin on the development of azoxymethane-induced colonic aberrant crypt foci in obese KK-A(y) mice and on the development of intestinal polyps in Apc mutant Min mice. Six-week-old KK-A(y) mice were injected with azoxymethane (200 µg/mouse once per week for 3 weeks) and given 250 mg/L apocynin or 500 mg/L apocynin in their drinking water for 7 weeks. Six-week-old Min mice were also treated with 500 mg/L apocynin for 6 weeks. Treatment with apocynin reduced the number of colorectal aberrant crypt foci in KK-A(y) mice by 21% and the number of intestinal polyps in Min mice by 40% compared with untreated mice. Both groups of mice tended to show improved oxidation of serum low-density lipoprotein and 8-oxo-2'-deoxyguanosine adducts in their adipose tissues. In addition, the inducible nitric oxide synthase mRNA levels in polyp tissues decreased. Moreover, apocynin was shown to suppress nuclear factor-κB transcriptional activity in vitro. These results suggest that apocynin and other NADPH oxidase inhibitors may be effective colorectal cancer chemopreventive agents.

P16-positive continuous minimal deviation adenocarcinoma and gastric type adenocarcinoma in a patient with Peutz-Jeghers syndrome.

We report a case of Peutz-Jeghers syndrome (PJS) in a 33-year-old female patient with synchronous uterine cervical minimal deviation adenocarcinoma (MDA) and gastric type adenocarcinoma (GTA). The patient was diagnosed with PJS at the age of 10. At the time of consultation, she complained of watery discharge. Magnetic resonance imaging of the pelvis showed a poorly circumscribed mass in the uterine cervix. Histologically, both MDA and GTA components, as well as their transitional area, were observed. Both components were diffusely positive for MUC6, CK7 and, robustly, for p16. Moreover, the components were negative for ER, PgR and CEA, while HIK1083 and CK20 positive cells were found focally. Ki-67 labeling index in the MDA component was 5% while that in the GTA component was 50%. This case of GTA accompanied by MDA in a patient with PJS is distinct from the single previously-reported comparable case of which we are aware, with respect to the overexpression of p16 protein, an event considered rare in these tumors, and the continuity between the MDA and GTA components. This continuity favors the hypothesis that GTA arises from the dedifferentiation of MDA.

Comprehensive DNA adduct analysis reveals pulmonary inflammatory response contributes to genotoxic action of magnetite nanoparticles.

Nanosized-magnetite (MGT) is widely utilized in medicinal and industrial fields; however, its toxicological properties are not well documented. In our previous report, MGT showed genotoxicity in both in vitro and in vivo assay systems, and it was suggested that inflammatory responses exist behind the genotoxicity. To further clarify mechanisms underlying the genotoxicity, a comprehensive DNA adduct (DNA adductome) analysis was conducted using DNA samples derived from the lungs of mice exposed to MGT. In total, 30 and 42 types of DNA adducts were detected in the vehicle control and MGT-treated groups, respectively. Principal component analysis (PCA) against a subset of DNA adducts was applied and several adducts, which are deduced to be formed by inflammation or oxidative stress, as the case of etheno-deoxycytidine (εdC), revealed higher contributions to MGT exposure. By quantitative-LC-MS/MS analysis, εdC levels were significantly higher in MGT-treated mice than those of the vehicle control. Taken together with our previous data, it is suggested that inflammatory responses might be involved in the genotoxicity induced by MGT in the lungs of mice.

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.

Human DNA glycosylase enzyme TDG repairs thymine mispaired with exocyclic etheno-DNA adducts.

Lipid peroxidation directly reacts with DNA and produces various exocyclic etheno-base DNA adducts, some of which are considered to contribute to carcinogenesis. However, the system for repairing them in humans is largely unknown. We hypothesized that etheno-DNA adducts are repaired by base excision repair initiated by DNA glycosylase. To test this hypothesis, we examined the activities of the DNA glycosylase proteins OGG1, SMUG1, TDG, NEIL1, MUTYH, NTH1, MPG, and UNG2 against double-stranded oligonucleotides containing 1,N(6)-ethenoadenine (εA), 3,N(4)-ethenocytosine (εC), butanone-ethenocytosine (BεC), butanone-ethenoguanine (BεG), heptanone-ethenocytosine (HεC), or heptanone-ethenoguanine (HεG) using a DNA cleavage assay. We found that TDG is capable of removing thymine that has mispaired with εC, BεC, BεG, HεC, or HεG in vitro. We next examined the effect of TDG against etheno-DNA adducts in human cells. TDG-knockdown cells exhibited the following characteristics: (a) higher resistance to cell death caused by the induction of etheno-DNA adducts; (b) lower repair activity for εC; and (c) a modest acceleration of mutations caused by εC, compared with the rate in control cells. All these characteristics suggest that TDG exerts a repair activity against etheno-DNA adducts in human cells. These results suggest that TDG has novel repair activities toward etheno-DNA adducts.