Epigenetic Regulation of Carbonic Anhydrase 9 Expression by Nitric Oxide in Human Small Airway Epithelial Cells.

DNA methylation is a crucial epigenetic modification that regulates gene expression and determines cell fate; however, the triggers that alter DNA methylation levels remain unclear. Recently, we showed that S-nitrosylation of DNA methyltransferase (DNMT) induces DNA hypomethylation and alters gene expression. Furthermore, we identified DBIC, a specific inhibitor of S-nitrosylation of DNMT3B, to suppress nitric oxide (NO)-induced gene alterations. However, it remains unclear how NO-induced DNA hypomethylation regulates gene expression and whether this mechanism is maintained in normal cells and triggers disease-related changes. To address these issues, we focused on carbonic anhydrase 9 (CA9), which is upregulated under nitrosative stress in cancer cells. We pharmacologically evaluated its regulatory mechanisms using human small airway epithelial cells (SAECs) and DBIC. We demonstrated that nitrosative stress promotes the recruitment of hypoxia-inducible factor 1 alpha to the CA9 promoter region and epigenetically induces CA9 expression in SAECs. Our results suggest that nitrosative stress is a key epigenetic regulator that may cause diseases by altering normal cell function.

Potential utility of pretreatment serum miRNAs for optimal treatment selection in advanced high-grade serous ovarian cancer.

OBJECTIVE: The primary treatment of patients with advanced ovarian cancer is selected from whether primary debulking surgery or neoadjuvant chemotherapy. We investigated whether pretreatment serum microRNA profiles are useful for selecting patients with advanced high-grade serous ovarian cancer who obtain better outcomes from undergoing primary debulking surgery or neoadjuvant chemotherapy. METHODS: Consecutive patients with clinical stage IIIB-IVB and serum microRNA data were selected. Patients who underwent primary debulking surgery or neoadjuvant chemotherapy were subjected to 1:1 propensity score matching before comparing their progression-free survival using Cox modelling. Progression-free probabilities for the selected microRNA profiles were calculated, and the estimated progression-free survival with the recommended primary treatment was determined and compared with the actual progression-free survival of the patients. RESULTS: Of the 108 patients with stage IIIB-IVB disease, the data of 24 who underwent primary debulking surgery or neoadjuvant chemotherapy were compared. Eleven and three microRNAs were independent predictors of progression-free survival in patients who underwent primary debulking surgery and neoadjuvant chemotherapy, respectively. Two microRNAs correlated significantly with complete resection of the tumours in primary debulking surgery. No differences were found between the actual and estimated progression-free survival in the primary debulking surgery and neoadjuvant chemotherapy groups (P > 0.05). The recommended and actual primary treatments were identical in 27 (56.3%) of the 48 patients. The median improved survival times between recommended and actual treatment were 11.7 and 32.6 months for patients with actual primary debulking surgery and neoadjuvant chemotherapy, respectively. CONCLUSIONS: Pretreatment microRNA profiles could be used to select subgroups of patients who benefited more from primary debulking surgery or neoadjuvant chemotherapy and might contribute to selecting the optimal primary treatment modality in advanced high-grade serous ovarian cancer patients.

Attenuation of protein arginine dimethylation via S-nitrosylation of protein arginine methyltransferase 1.

Upregulation of nitric oxide (NO) production contributes to the pathogenesis of numerous diseases via S-nitrosylation, a post-translational modification of proteins. This process occurs due to the oxidative reaction between NO and a cysteine thiol group; however, the extent of this reaction remains unknown. S-Nitrosylation of PRMT1, a major asymmetric arginine methyltransferase of histones and numerous RNA metabolic proteins, was induced by NO donor treatment. We found that nitrosative stress leads to S-nitrosylation of cysteine 119, located near the active site, and attenuates the enzymatic activity of PRMT1. Interestingly, RNA sequencing analysis revealed similarities in the changes in expression elicited by NO and PRMT1 inhibitors or knockdown. A comprehensive search for PRMT1 substrates using the proximity-dependent biotin identification method highlighted many known and new substrates, including RNA-metabolizing enzymes. To validate this result, we selected the RNA helicase DDX3 and demonstrated that arginine methylation of DDX3 is induced by PRMT1 and attenuated by NO treatment. Our results suggest the existence of a novel regulatory system associated with transcription and RNA metabolism via protein S-nitrosylation.

Methyl vinyl ketone and its analogs covalently modify PI3K and alter physiological functions by inhibiting PI3K signaling.

Reactive carbonyl species (RCS), which are abundant in the environment and are produced in vivo under stress, covalently bind to nucleophilic residues such as Cys in proteins. Disruption of protein function by RCS exposure is predicted to play a role in the development of various diseases such as cancer and metabolic disorders, but most studies on RCS have been limited to simple cytotoxicity validation, leaving their target proteins and resulting physiological changes unknown. In this study, we focused on methyl vinyl ketone (MVK), which is one of the main RCS found in cigarette smoke and exhaust gas. We found that MVK suppressed PI3K-Akt signaling, which regulates processes involved in cellular homeostasis, including cell proliferation, autophagy, and glucose metabolism. Interestingly, MVK inhibits the interaction between the epidermal growth factor receptor and PI3K. Cys656 in the SH2 domain of the PI3K p85 subunit, which is the covalently binding site of MVK, is important for this interaction. Suppression of PI3K-Akt signaling by MVK reversed epidermal growth factor-induced negative regulation of autophagy and attenuated glucose uptake. Furthermore, we analyzed the effects of the 23 RCS compounds with structures similar to MVK and showed that their analogs also suppressed PI3K-Akt signaling in a manner that correlated with their similarities to MVK. Our study demonstrates the mechanism of MVK and its analogs in suppressing PI3K-Akt signaling and modulating physiological functions, providing a model for future studies analyzing environmental reactive species.

Pivotal role for S-nitrosylation of DNA methyltransferase 3B in epigenetic regulation of tumorigenesis.

DNA methyltransferases (DNMTs) catalyze methylation at the C5 position of cytosine with S-adenosyl-L-methionine. Methylation regulates gene expression, serving a variety of physiological and pathophysiological roles. The chemical mechanisms regulating DNMT enzymatic activity, however, are not fully elucidated. Here, we show that protein S-nitrosylation of a cysteine residue in DNMT3B attenuates DNMT3B enzymatic activity and consequent aberrant upregulation of gene expression. These genes include Cyclin D2 (Ccnd2), which is required for neoplastic cell proliferation in some tumor types. In cell-based and in vivo cancer models, only DNMT3B enzymatic activity, and not DNMT1 or DNMT3A, affects Ccnd2 expression. Using structure-based virtual screening, we discovered chemical compounds that specifically inhibit S-nitrosylation without directly affecting DNMT3B enzymatic activity. The lead compound, designated DBIC, inhibits S-nitrosylation of DNMT3B at low concentrations (IC50 ≤ 100 nM). Treatment with DBIC prevents nitric oxide (NO)-induced conversion of human colonic adenoma to adenocarcinoma in vitro. Additionally, in vivo treatment with DBIC strongly attenuates tumor development in a mouse model of carcinogenesis triggered by inflammation-induced generation of NO. Our results demonstrate that de novo DNA methylation mediated by DNMT3B is regulated by NO, and DBIC protects against tumor formation by preventing aberrant S-nitrosylation of DNMT3B.

[Molecular mechanism of EGFR signaling evoked by environmental pollutant 1,2-naphthoquinone].

The epidermal growth factor receptor (EGFR) is the most extensively examined receptor tyrosine kinase. Several EGFR mutations and modifications have been shown to induce self-activation, which plays a central role in carcinogenesis. Recently, environmental chemicals such as PM2.5 can also activate EGFR and become risk factors for cancer. Although, the detailed mechanism remains unknown. In this study, we focused on 1,2-naphthoquinone (1,2-NQ) which is a secondary metabolite of naphthalene. Humans are exposed to 1,2-NQ through the combustion of fossil and diesel fuel and from tobacco smoke and PM2.5. Here, we demonstrate that 1,2-NQ is a novel EGFR-specific activator. We found that 1,2-NQ forms a covalent bond called N-arylation with EGFR Lys80 which is in the extracellular domain by LC-MS/MS. This modification activates the EGFR-Akt signaling pathway, which inhibits serum deprivation-induced apoptosis in A549 cells. Our study reveals an original mode of EGFR activation via covalent binding. We propose the correlation between EGFR activation without ligands and environmental pollutant-associated diseases such as cancer.

Covalent N-arylation by the pollutant 1,2-naphthoquinone activates the EGF receptor.

The epidermal growth factor receptor (EGFR) is the most intensively investigated receptor tyrosine kinase. Several EGFR mutations and modifications have been shown to lead to abnormal self-activation, which plays a critical role in carcinogenesis. Environmental air pollutants, which are associated with cancer and respiratory diseases, can also activate EGFR. Specifically, the environmental electrophile 1,2-naphthoquinone (1,2-NQ), a component of diesel exhaust particles and particulate matter more generally, has previously been shown to impact EGFR signaling. However, the detailed mechanism of 1,2-NQ function is unknown. Here, we demonstrate that 1,2-NQ is a novel chemical activator of EGFR but not other EGFR family proteins. We found that 1,2-NQ forms a covalent bond, in a reaction referred to as N-arylation, with Lys80, which is in the ligand-binding domain. This modification activates the EGFR-Akt signaling pathway, which inhibits serum deprivation-induced cell death in a human lung adenocarcinoma cell line. Our study reveals a novel mode of EGFR pathway activation and suggests a link between abnormal EGFR activation and environmental pollutant-associated diseases such as cancer.

Unique prognostic features of grade 3 endometrioid endometrial carcinoma: Findings from 101 consecutive cases at a Japanese tertiary cancer center.

OBJECTIVE: The prognosis of and optimal treatment for grade 3 endometrioid endometrial carcinoma (G3EEC) currently remain unclear. This study aimed to clarify the baseline recurrence risk in patients with early-stage (stage I-II) G3EEC without adjuvant therapy and the prognosis of patients with advanced-stage (stage III-IV) G3EEC. MATERIALS AND METHODS: A total of 101 patients with pathologically confirmed G3EEC from 1997 to 2018 were identified. Their clinicopathological characteristics and survival outcomes were reviewed retrospectively. Disease-free survival and overall survival values were estimated according to the Kaplan-Meier method and compared using a log-rank test. RESULTS: Recurrence was observed in eight (13%) of 63 patients with early-stage G3EEC, none of whom had received adjuvant therapy. The 5-year disease-free survival and 5-year overall survival rates for these patients were 86.7% and 96.4%, respectively. Recurrence was also observed in 12 (41%) of 29 patients with stage III G3EEC. The 5-year overall survival rates for stage III patients who underwent adjuvant chemotherapy and adjuvant radiotherapy were 85.6% and 42.9%, respectively. The 3-year overall survival rate among stage IVB patients was only 12.7% despite multidisciplinary treatment provision. CONCLUSION: Our study newly demonstrates that patients with early-stage G3EEC have a favorable prognosis and a low recurrence rate in the absence of adjuvant therapy. In patients with stage III G3EEC, adjuvant chemotherapy was more beneficial than adjuvant radiotherapy. The poor prognosis of patients with stage IV G3EEC indicates the need for more effective treatments. Unique therapeutic approaches based on staging are recommended for treatment of G3EEC.

Pelvic seromucinous borderline tumor 26 years after ovarian seromucinous borderline tumor managed with post-treatment estrogen replacement therapy.

•A 56-year-old woman developed two seromucinous borderline tumors 26 years apart.•The second cyst was diagnosed as a seromucinous borderline tumor associated with pelvic endometriosis.•The first ovarian cancer was re-diagnosed as an ovarian seromucinous borderline tumor after a pathological slide review.•Seromucinous borderline tumors can re-occur several years after post-treatment estrogen replacement therapy.•Post-treatment estrogen replacement therapy for seromucinous borderline tumors should be provided carefully.

Efficacy of ascitic fluid cell block for diagnosing primary ovarian, peritoneal, and tubal cancer in patients with peritoneal carcinomatosis with ascites.

OBJECTIVE: To compare the efficacy of ascitic fluid cell block (ACB) with that of core needle biopsy (CNB) or the CA125/CEA ratio in diagnosing primary tubo-ovarian cancer in female patients with peritoneal carcinomatosis (PC) with ascites. METHODS: This retrospective study examined female patients with PC with ascites who had available results for ACB, peritoneal tumor CNB, and the CA125/CEA ratio. Several measures of the accuracy of ACB and the CA125/CEA ratio were calculated and compared, with CNB as the reference standard. RESULTS: Of 81 patients with available results, 57 were clinically diagnosed with primary tubo-ovarian cancer. Overall, 52, 47, and 64 patients were diagnosed via CNB, ACB, and CA125/CEA ratio > 25, respectively. CNB and ACB identified the cancer origin in 91.4% and 82.7% cases, respectively. The concordance ratio of the immunohistochemical findings between ACB and CNB was 93.6%. Two patients with inconclusive CNB results were diagnosed with primary tubo-ovarian cancer via ACB. The sensitivity, specificity, positive predictive value, negative predictive value, and positive likelihood ratio were 86.5%, 93.1%, 95.7%, 79.4%, and 12.5, respectively, for ACB and 94.2%, 48.3%, 76.6%, 82.4%, and 1.82, respectively, for CA125/CEA ratio > 25. CONCLUSIONS: ACB is not inferior to CNB in diagnosing primary tubo-ovarian cancer; the two methods complement each other. ACB can substitute CNB in diagnosing primary tubo-ovarian cancer in selected PC patients. ACB is superior to a CA125/CEA ratio of >25 in diagnosing primary tubo-ovarian cancer. ACB is effective, reliable, and convenient for diagnosing primary tubo-ovarian cancer in PC patients with ascites.

S-Nitrosylation at the active site decreases the ubiquitin-conjugating activity of ubiquitin-conjugating enzyme E2 D1 (UBE2D1), an ERAD-associated protein.

S-Nitrosylation of protein cysteine thiol is a post-translational modification mediated by nitric oxide (NO). The overproduction of NO causes nitrosative stress, which is known to induce endoplasmic reticulum (ER) stress. We previously reported that S-nitrosylation of protein disulfide isomerase (PDI) and the ER stress sensor inositol-requiring enzyme 1 (IRE1) decreases their enzymatic activities. However, it remains unclear whether nitrosative stress affects ER-associated degradation (ERAD), a separate ER stress regulatory system responsible for the degradation of substrates via the ubiquitin-proteasomal pathway. In the present study, we found that the ubiquitination of a known ERAD substrate, serine/threonine-protein kinase 1 (SGK1), is attenuated by nitrosative stress. C-terminus of Hsc70-interacting protein (CHIP) together with ubiquitin-conjugating enzyme E2 D1 (UBE2D1) are involved in this modification. We detected that UBE2D1 is S-nitrosylated at its active site, Cys85 by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Furthermore, in vitro and cell-based experiments revealed that S-nitrosylated UBE2D1 has decreased ubiquitin-conjugating activity. Our results suggested that nitrosative stress interferes with ERAD, leading to prolongation of ER stress by co-disruption of various pathways, including the molecular chaperone and ER stress sensor pathways. Given that nitrosative stress and ER stress are upregulated in the brains of patient with Parkinson's disease (PD) and of those with Alzheimer's disease (AD), our findings may provide further insights into the pathogenesis of these neurodegenerative disorders.

A case of cervical adenocarcinoma arising from endometriosis in the absence of human papilloma virus infection.

Endometriosis-related cervical neoplasms are rare, and their clinicopathological features and association with human papilloma virus infection are unclear. A postmenopausal woman with recently diagnosed cervical adenocarcinoma was referred to our hospital. After further investigation, we suspected a stage IIB neoplasm that originated from endometriosis of the cervix or left parametrium. A radical hysterectomy was performed, and pathological examination confirmed a stage IIB cervical endometrioid carcinoma arising from the endometriosis in the cervix to the left parametrium that invaded the cervix; human papilloma virus infection of tumor cells was not detected. Endometriosis-related neoplasms can occur in the cervix or parametrium and present as cervical cancer. The neoplasm described here was not associated with human papilloma virus infection.

[Ifosfamide and Paclitaxel for Recurrent or Metastatic Uterine Carcinosarcoma].

AIM: This study aimed to retrospectively evaluate the efficacy and safety of ifosfamide plus paclitaxel(IT)in Japanese patients with recurrent or metastatic uterine carcinosarcoma. METHODS: This study included 15 patients who received IT(ifosfamide [1.6 g/m / 2 on days 1-3]and paclitaxel[135mg/m2 on day 1]every 3 weeks)for recurrent or metastatic uterine carcinosarcoma. RESULTS: The overall response rate was 38.4%, and the disease control rate was 92.3%. The median progression- free survival was 7.0 months, and the median overall survival was 9.0 months after initiation of IT therapy. The most common hematological adverse event was Grade 1-2 neutropenia. Peripheral neuropathy of Grade 1 or 2 was observed in 33.3% of cases. There was no treatment-related death. CONCLUSION: IT therapy showed good efficacy and tolerability in Japanese patients with recurrent or metastatic uterine carcinosarcoma.

Serum microRNA profile enables preoperative diagnosis of uterine leiomyosarcoma.

Uterine leiomyosarcoma (ULMS) is the major subtype of uterine sarcoma (US) and contributes to uterine cancer deaths. Although preoperative diagnosis of US remains challenging, frequent application of laparoscopic surgery for benign uterine leiomyomas (ULM) requires precise exclusion of US. MicroRNAs are stably present in the bloodstream, and the application of circulating miRNAs as disease biomarkers has been recognized. In the present study, we aimed to identify diagnostic biomarkers for distinguishing US from ULM by focusing on circulating miRNAs. All serum samples were collected preoperatively between 2009 and 2017, and all cases were histopathologically diagnosed. Whole miRNA profiles were obtained using a miRNA microarray. By analyzing expression levels of the miRNAs, candidate miRNAs were selected based on diagnostic performance in discriminating US from ULM, and a diagnostic model was then constructed. A total of 90 serum samples were analyzed, and clustering analyses revealed that the profiles of ULMS were distinct from those of controls. Based on leave-one-out cross-validation, seven miRNAs were selected as biomarker candidates. Based on model construction, the optimal model consisted of two miRNAs (miR-1246 and miR-191-5p), with an area under the receiver operating characteristic curve (AUC) for identifying ULMS of 0.97 (95% confidence interval [CI], 0.91-1.00). In contrast, serum lactate dehydrogenase had an AUC of only 0.64 (95% CI, 0.34-0.94). Seven serum miRNAs with high diagnostic performance for preoperative US screening were detected, and a promising diagnostic model for ULMS was generated.

Treatment strategies for patients with advanced ovarian cancer undergoing neoadjuvant chemotherapy: interval debulking surgery or additional chemotherapy?

OBJECTIVE: To treat advanced ovarian cancer, interval debulking surgery (IDS) is performed after 3 cycles each of neoadjuvant chemotherapy (NAC) and postoperative chemotherapy (IDS group). If we expect that complete resection cannot be achieved by IDS, debulking surgery is performed after administering additional 3 cycles of chemotherapy without postoperative chemotherapy (Add-C group). We evaluated the survival outcomes of the Add-C group and determined their serum cancer antigen 125 (CA125) levels to predict complete surgery. METHODS: A retrospective chart review of all stage III and IV ovarian, fallopian tube, and peritoneal cancer patients treated with NAC in 2007-2016 was conducted. RESULTS: About 117 patients comprised the IDS group and 26 comprised the Add-C group. Univariate and multivariate analyses revealed that Add-C group had an equivalent effect on progression-free survival (PFS; p=0.09) and overall survival (OS; p=0.94) compared with the IDS group. Multivariate analysis revealed that patients who developed residual disease after surgery had worse PFS (hazard ratio [HR]=2.18; 95% confidence interval [CI]=1.45-3.28) and OS (HR=2.33; 95% CI=1.43-3.79), and those who received <6 cycles of chemotherapy had worse PFS (HR=5.30; 95% CI=2.56-10.99) and OS (HR=3.05; 95% CI=1.46-6.38). The preoperative serum CA125 cutoff level was 30 U/mL based on Youden index method. CONCLUSIONS: Administering 3 additional cycles of chemotherapy followed by debulking surgery exhibited equivalent effects on survival as IDS followed by 3 cycles of postoperative chemotherapy. Preoperative serum CA125 levels of ≤30 U/mL may be a useful predictor of achieving complete surgery.

Prognostic impact of intraoperative peritoneal cytology in interval debulking surgery for pelvic high-grade serous carcinoma.

BACKGROUND AND OBJECTIVES: The aim of this study was to determine whether peritoneal washing cytology (PWC) during interval debulking surgery (IDS) could predict the prognosis of patients with pelvic high-grade serous carcinoma (HGSC) achieving R0 status. METHODS: Between January 2007 and May 2018, 110 patients with ovarian/tubal/primary peritoneal HGSC received platinum-based neo-adjuvant chemotherapy, followed by IDS at National Cancer Center Hospital, Japan. All the patients achieved R0 debulking status, defined as no macroscopic residual tumor in the peritoneal cavity at the completion of IDS. PWC was performed before debulking during IDS. The survival outcomes were compared between the PWC-positive and PWC-negative groups. RESULTS: The median progression free survival (PFS) for the entire cohort was 17 months (range, 5-133 months). The median PFS for the PWC-positive group was significantly shorter than that of the PWC-negative group (16 vs 19 months, HR 2.04, 95% CI 1.22-3.41, P-value < 0.01). Increased risk of progression was observed on both univariate and multivariate analyses, including age and FIGO stage (HR 2.28; 95% CI 1.35-3.84, P < 0.01). CONCLUSIONS: The positive PWC during IDS was found to predict earlier disease recurrence in patients with pelvic HGSC achieving R0 status. As performing PWC during IDS becomes standard practice, prospective validation should be conducted in the future.

Attenuation of Macrophage Migration Inhibitory Factor-Stimulated Signaling via S-Nitrosylation.

Nitric oxide (NO) is a key signaling molecule that has various effects via S-nitrosylation, a reversible post-translational modification that affects the enzymatic activity, localization, and metabolism of target proteins. As chronic nitrosative stress correlates with neurodegeneration, the targets have received focused attention. Macrophage migration inhibitory factor (MIF) plays a pivotal role in the induction of gene expression to control inflammatory responses. MIF acts as a ligand for CD74 receptor and activates the Src-p38 mitogen-activated protein kinase (MAPK) cascade. MIF also elevates the expression of brain-derived neurotrophic factor (BDNF), which contributes to the viability of neurons. Here, we show that MIF is S-nitrosylated by a physiological NO donor. Interestingly, the induction of S-nitrosylation resulted in a loss of MIF activity following stimulation of the Src and p38 MAPK signaling pathways and the induction of BDNF expression. Our results shed light on the pathogenic mechanisms of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease.

Primary Clear Cell Adenocarcinoma of the Vulva: A Case Study With Mutation Analysis and Literature Review.

Primary vulvar clear cell carcinoma (CCC) is extremely rare. In this article, we report a primary vulvar CCC along with immunohistochemical and gene mutation analyses results and literature review to discuss the clinicopathological features and tumorigenesis of this rare tumor. A 70-year-old (gravida 2 para 2) Japanese woman complained of bleeding from a vulvar mass at a past episiotomy site. A 1.8 × 1.8 × 0.5 cm exophytic sessile mass was present on the vestibular area inside the left labium minora. Radical local excision of the tumor and resection of the inguinal lymph nodes on both sides were performed. Histopathology revealed a vulvar CCC with immunohistochemical positivity for PAX8, HNF-1ß, ER, and CA125, and negativity for p16, CD10, GATA3, PTEN, and PAX2, suggesting its Müllerian origin. No lymph node metastasis was observed. The tumor was a 5-mm exophytic growth without deep stromal invasion; thus, it was difficult to measure the invasion depth assuming a squamous cell carcinoma. To investigate pathogenic/oncogenic mutations in 50 cancer-related genes, we used the AmpliSeq Cancer Hotspot Panel. However, no pathogenic/oncogenic mutations were detected. Literature review revealed that most cases of vulvar CCC are associated with vulvar endometriosis. In particular, cases with clinically evident endometriosis at the episiotomy scar should be carefully observed. Evidence-based pathological stages of vulvar adenocarcinoma including CCC remain to be established owing to its rarity, with nationwide or global accumulation of cases required in future.

Metachronous occurrence of two different histological subtypes of endometriosis-related neoplasms.

A solitary pelvic tumor after treating a primary endometriosis-related neoplasm is usually considered a recurrence but may actually be a primary endometriosis-related peritoneal neoplasm. A Japanese woman in her late 60s was referred to our hospital for a solitary pelvic tumor. The tumor was suspected as a recurrence of a previously treated stage IA ovarian clear-cell carcinoma, and resected. Pathological analysis revealed that the tumor was a peritoneal seromucinous carcinoma associated with pelvic endometriosis. Both tumors displayed distinct histopathologies, although both neoplasms were endometriosis related. An apparent recurrent tumor after treating of an endometriosis-related neoplasm might not be a true recurrent tumor but a second primary endometriosis-related neoplasm. Histological confirmation is indicated in such cases.

Antipsychotic drugs scavenge radiation-induced hydroxyl radicals and intracellular ROS formation, and protect apoptosis in human lymphoma U937 cells.

Antioxidant activity has been reported for some atypical antipsychotic drugs; however, the detailed mechanism is not well known. Here, we investigated the effects of atypical antipsychotic drugs on •OH radical formation, intracellular reactive oxygen species (ROS), and apoptosis induced by ionising radiation. The reaction rate constants with •OH radicals were determined for five antipsychotic drugs as follows, in descending order: olanzapine, aripiprazole, clozapine, haloperidol, and risperidone. Experiments with aminophenyl fluorescein, a fluorescent dye, showed that olanzapine and clozapine could scavenge intracellular ROS. However, experiments with hydroxyphenyl fluorescein showed that only olanzapine inhibited ROS generation. X-irradiation-induced apoptosis in human lymphoma U937 cells was inhibited by clozapine at relatively low concentrations and by olanzapine at higher concentrations. Clozapine inhibited caspase-8 and caspase-3 activation and prevented loss of mitochondrial membrane potential. In contrast, olanzapine inhibited X-irradiation-induced p-JNK activation. Although the atypical antipsychotic drugs used here have relatively high reaction rate constants with •OH radicals in aqueous solutions, inhibition of intracellular ROS was not due to •OH radical scavenging. In addition, suppression of X-irradiation-induced apoptosis was not directly linked with intracellular ROS scavenging. When apoptosis signalling pathways were studied, clozapine-mediated inhibition of apoptosis was dependent on caspase-3 and caspase-8. In contrast, olanzapine inhibited apoptosis via down regulation of X-irradiation-induced p-JNK. These results suggested that both olanzapine and clozapine have antioxidative and antiapoptotic activities via distinct pathways, and provide useful information for better understanding of drug characteristics.