Correlation between Cancer Stem Cells, Inflammation and Malignant Transformation in a DEN-Induced Model of Hepatic Carcinogenesis.

Chronic inflammation and cancer stem cells are known risk factors for tumorigenesis. The aetiology of hepatocellular carcinoma (HCC) involves a multistep pathological process that is characterised by chronic inflammation and hepatocyte damage, but the correlation between HCC, inflammation and cancer stem cells remains unclear. In this study, we examined the role of hepatic progenitor cells in a mouse model of chemical-induced hepatocarcinogenesis to elucidate the relationship between inflammation, malignant transformation and cancer stem cells. We used diethylnitrosamine (DEN) to induce liver tumour and scored for H&E and reticulin staining. We also scored for immunohistochemistry staining for OV-6 expression and analysed the statistical correlation between them. DEN progressively induced inflammation at week 7 (40%, 2/5); week 27 (75%, 6/8); week 33 (62.5%, 5/8); and week 50 (100%, 12/12). DEN progressively induced malignant transformation at week 7 (0%, 0/5); week 27 (87.5%, 7/8); week 33 (100%, 8/8); and week 50 (100%, 12/12). The obtained data showed that DEN progressively induced high-levels of OV-6 expression at week 7 (20%, 1/5); week 27 (37.5%, 3/8); week 33 (50%, 4/8); and week 50 (100%, 12/12). DEN-induced inflammation, malignant transformation and high-level OV-6 expression in hamster liver, as shown above, as well as applying Spearman's correlation to the data showed that the expression of OV-6 was significantly correlated to inflammation (p = 0.001) and malignant transformation (p < 0.001). There was a significant correlation between the number of cancer stem cells, inflammation and malignant transformation in a DEN-induced model of hepatic carcinogenesis in the hamster.

Continuous bioelectricity generation through treatment of Victoria blue R: A novel microbial fuel cell operation.

A novel two-chamber microbial fuel cell (MFC) operation with a continuous anaerobic-aerobic decolorization system was developed to improve the degradation of the triphenylmethane dye, Victoria blue R (VBR). In addition, bioelectricity was generated during the VBR degradation process, and the operation parameters were optimized. The results indicated that the VBR removal efficiency and electricity generation were affected by the VBR concentration, liquid retention time (LRT), external resistance, gas retention time (GRT), and shock loading. The optimal operation parameters were as follows: VBR concentration, 600 mg L-1; LRT, 24 h; external resistance, 3300 Ω; and GRT, 60 s. Under these operating conditions, the VBR removal efficiency, COD removal efficiency, and power density were 98.2% ± 0.3%, 97.6% ± 0.5%, and 30.6 ± 0.4 mW m-2, respectively. According to our review of the relevant literature, this is the first paper to analyze the electrical characteristics of a continuous two-chamber MFC operation and demonstrate the feasibility of the simultaneous electricity generation and decolorization of VBR.

Arsenic-induced disruption of circadian rhythms and glutamine anaplerosis in human urothelial carcinoma.

Inorganic arsenic (iAs)-induced urothelial carcinoma (UC) develops into a poor-prognosis malignancy. Arsenic-induced oxidative stress contributes to circadian rhythm disruption altered metabolism. Glutamine anaplerosis is a common metabolic feature of rapidly proliferating malignant cells, in which glutaminase (GLS) is a key enzyme in this process. Therefore, this study intends to determine if arsenic-induced oxidative stress can alter circadian rhythms and promote glutamine anaplerosis. Exonic expression of core circadian molecules (CLOCK, ARNTL, and NR1D1) and GLS in varying grades of UC were assessed using 423 bladder cancer samples from the TCGA Urothelial Bladder Cancer (BLCA) dataset. The levels of circadian proteins and metabolic markers in 44 UC patients from non-black foot disease (BFD) and BFD areas were detected by immunohistochemistry. In vitro and in vivo experiments elucidated the regulatory mechanisms of arsenic-mediated circadian disturbance and metabolic alteration. Public database analysis showed that ARNTL, NR1D1, and GLS exhibited greater expression in more high-grade UC. Strong immunoreactivity for BMAL1, GLS, and low levels of NR1D1 were found in malignant urothelial lesions, especially in arsenic-exposed UC. Arsenic-induced overexpression of BMAL1 and GLS involves activation of NADH: quinone oxidoreductase 1 (NQO1), continuously altering the NADH oscillations to promote glutamate metabolism in SV-HUC-1, T24 and BFTC-905 cells. These phenomenon were also demonstrated in the urothelium of arsenic-exposed animals. The present findings highlight the potential clinical significance of BMAL1 and GLS in UC in the BFD region. Furthermore, these results suggest that arsenic interferes with circadian rhythm and glutamine anaplerosis by NADH oscillatory imbalance in urothelial cells and urothelial cancer cells, predisposing them to malignant development.

Reduced WWOX protein expression in human astrocytoma.

The WW domain-containing oxidoreductase (WWOX) functions as a tumor suppressor by interacting with various proteins in numerous important signaling pathways. WWOX silencing via homozygous deletion of its locus and/or promoter hypermethylation has been observed in various human cancers. However, the relationship between WWOX and tumors in the central nervous system has not been fully explored. In this study, the expression levels of WWOX protein in astrocytomas from 38 patients with different tumor grades were retrospectively analyzed by immunohistochemical staining. The results showed that 19 (50.0%) samples had highly reduced WWOX protein expression when compared with normal controls, while 14 (36.8%) and five (13.2%) cases exhibited moderate and mild decreases in WWOX expression, respectively. Reduction of the expression of WWOX protein correlated with patient age, supra-tentorial localization of the tumor and severity of the symptoms. Furthermore, loss of WWOX expression inversely correlated with survival time. No significant correlation was observed between the loss of WWOX expression and the gender of patients or the difference in pre-operative and post-operative karnofsky performance status scores. Surprisingly, there was no significant correlation between the loss of WWOX protein expression and overall tumor grades. Nevertheless, it was found that 63.6% (7/11) of the grade II astrocytomas had highly reduced WWOX expression and 36.4% (4/11) showed moderately reduced WWOX expression, while none of the samples exhibited mild reductions. Similar results were also found in grade III astrocytomas. The results from this small-size sample pilot study suggest that the loss of WWOX expression may be an early event in the pathogenesis of human astrocytoma.

Effect of Artocarpus communis Extract on UVB Irradiation-Induced Oxidative Stress and Inflammation in Hairless Mice.

Administration of antioxidants and anti-inflammatory agents is an effective strategy for preventing ultraviolet (UV) irradiation-induced skin damage. Artocarpus communis possesses several pharmacological activities, such as antioxidant, anticancer and anti-inflammation. However, the photoprotective activity of methanol extract of A. communis heartwood (ACM) in ultraviolet irradiation-induced skin damage has not yet been investigated. The present study was performed using ultraviolet absorption, histopathological observation, antioxidant and anti-inflammation assays to elucidate the mechanism of the photoprotective activity of ACM. Our results indicated that ACM displayed a UVA and UVB absorption effect and then effectively decreased scaly skin, epidermis thickness and sunburn cells during ultraviolet irradiation in hairless mice. ACM not only decreased ultraviolet irradiation-mediated oxidative stress, including lowering the overproduction of reactive oxygen species and lipid peroxidation (p < 0.05), but also reduced the levels of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin 1ß. Additionally, ACM can decrease the synthesis of cytosolic phospholipase A2, cyclooxygenase, inducible nitric oxide synthase and vascular cell adhesion molecular-1 via inhibiting TNF-α-independent pathways (p < 0.05) in UVB-mediated inflammation and formation of sunburn cells. Consequently, we concluded that ACM extract has a photoprotective effect against UVB-induced oxidative stress and inflammation due to its sunscreen property, and its topical formulations may be developed as therapeutic and/or cosmetic products in further studies.

Upregulation of phosphorylated HSP27, PRDX2, GRP75, GRP78 and GRP94 in acquired middle ear cholesteatoma growth.

Cholesteatoma is a destructive and expanding growth of keratinizing squamous epithelium in the middle ear or petrous apex. The molecular and cellular processes of the pathogenesis of acquired middle ear cholesteatoma have not been fully understood. In this study, comparative proteomic analysis was conducted to investigate the roles of specific proteins in the pathways regarding keratinocyte proliferation in cholesteatoma. The differential proteins were detected by comparing the two-dimension electrophoresis (2-DE) maps of the epithelial tissues of 12 attic cholesteatomas with those of retroauricular skins. There were 14 upregulated proteins in the epithelial tissues of cholesteatoma in comparison with retroauricular skin. The modulation of five crucial proteins, HSP27, PRDX2, GRP75, GRP78 and GRP94, was further determined by RT-PCR, Western blot and immunohistochemistry. Phosphorylation of HSP27 at Ser-82 was identified by mass spectroscopy. The results of this study suggested that phosphorylated HSP27 is the end expression of two potential signal-transduction pathways, and together with PRDX2, they are very likely involved in the proliferation of keratinocytes in cholesteatoma. Upregulations of GRP75, GRP78 and GRP94 in keratinocytes may be able to counter endoplasmic reticulum stress, to inhibit cell apoptosis, to prevent protein unfolding and to promote cholesteatoma growth.

Rates of cutaneous metastases from different internal malignancies: experience from a Taiwanese medical center.

BACKGROUND: Previous reports regarding the rates at which various internal tumors metastasize to the skin have been limited and have only included the Caucasian population. Moreover, the mechanisms that predispose certain internal malignancies to metastasize to the skin have rarely been discussed in the scientific literature. OBJECTIVES: We determined the frequencies with which various internal malignancies metastasize to the skin in patients from a Taiwanese medical center. We also evaluated whether expressions of chemokine receptors CCR10 and CXCR4 by tumor cells correlate with cutaneous metastatic ability. METHODS: Clinical records from Kaohsiung Medical University Hospital, Kaohsiung, Taiwan, during 20 years (1986-2006) were reviewed and cases of biopsy-proven primary internal malignancies and cutaneous metastases were identified. Immunohistochemical staining with antibodies to CCR10 and CXCR4 was performed on a selected number of internal malignancies with and without skin metastases. RESULTS: From 12,146 patients with internal malignancies, we found 124 cases (1.02%) with cutaneous metastases. The highest rates of skin metastases were found to occur from carcinoma of the breast, followed by the lung, oral mucosa, colon and rectum, stomach, and esophagus. However, the rate of cutaneous metastasis from breast cancer was much lower compared with previous studies involving Caucasians. In general, adenocarcinomas gave rise to cutaneous metastases at a higher frequency compared with other histologic subtypes. In addition, the expressions of CCR10 and CXCR4 by tumor cells did not correlate well with the presence or absence of skin metastases. LIMITATION: This study is retrospective in nature. CONCLUSIONS: Different internal malignancies metastasize to the skin with different frequencies, and the rates at which different malignancies metastasize to cutaneous sites differ between the Taiwanese and Caucasian populations. The mechanisms responsible for the cutaneous metastatic ability of certain malignancies likely involve factors other than chemokine receptors CCR10 and CXCR4, because their expressions by tumor cells are neither necessary nor sufficient for the formation of skin metastases.

Immunoexpression and prognostic role of hTERT and cyclin D1 in urothelial carcinoma.

The aim was to investigate the expression of human telomerase reverse transcriptase (hTERT) and cyclin D1 in correlation with clinicopathologic features of urothelial carcinoma (UC). Tissue microarrays (TMA) were constructed from paraffin-embedded specimens of 94 UC patients and immunohistochemical staining was used. High hTERT expression was found in 50 (53%) of the 94 tumors and was significantly associated with tumor invasiveness and tumor grade (P=0.008 and 0.0190, respectively). High cyclin D1 expression was found in 69 (73%) of the 94 tumors and was significantly associated with non-invasiveness and smaller tumor size, but there was no correlation with tumor grade. Kaplan-Meier analysis indicated that patients with low hTERT and high cyclin D1 levels had longer local recurrence-free survival (P=0.0482 and 0.0123, respectively). In addition, patients with high cyclin D1 levels had longer disease-free survival (P=0.0195). In conclusion, this study demonstrated that hTERT and cyclin D1 may be of recurrence predictive value for UC, thus providing clinicians with ancillary information when deciding on suitable therapeutic strategies in UC.

SOCS-3 is associated with vascular invasion and overall survival in hepatocellular carcinoma.

AIMS: Alteration of the suppressor of cytokine signalling-3 (SOCS-3) has been observed in certain human cancers. However, the clinical role of this short-lived protein in hepatocellular carcinoma (HCC) is not well established. Therefore, we aimed to explore the potential role of SOCS-3 proteins in HCC. METHODS: Paraffin embedded sections from 87 HCC patients were included in this study. The expression patterns of SOCS-3 proteins were analysed using immunohistochemistry and the results were correlated with clinicopathological characteristics and overall survival of the HCC patients. RESULTS: The SOCS-3 expression of HCC lesions and the adjacent non-tumourous liver tissues was significantly correlated (p = 0.035), while the SOCS-3 expression in HCC lesions was significantly and positively correlated with vascular invasion and histological grading (p = 0.034 and 0.032, respectively). The Kaplan-Meier survival curve showed that the HCC patients with high SOCS-3 expression were associated with a poor overall survival rate in the HCC subgroup with positive vascular invasion (p = 0.014). Furthermore, a multivariate Cox regression model showed that SOCS-3 expression was also a significant determinant of the overall survival for HCC (p = 0.006). CONCLUSIONS: Our results indicate that altered SOCS-3 expression is associated with the overall survival in a subset of HCC patients with positive vascular invasion. Constitutive and altered SOCS-3 expression may have potential roles in a subset of HCC patients.

Expression of D2-40 in adjunct diagnosis of papillary thyroid carcinoma.

The clinical pathologic criteria for nuclear features of papillary thyroid carcinoma are subjective and sometimes cannot distinguish carcinoma from adenomatous goiter and follicular neoplasms. No single antibody has demonstrated high sensitivity or specificity in making these distinctions. Using quantitative analysis of immunohistochemical staining with D2-40, a recently available monoclonal antibody used as a lymphatic endothelial marker, we examined 72 cases of papillary carcinoma. Controls included 36 follicular adenomas, 36 follicular carcinomas, and 20 adenomatous goiters with papillary hyperplasia. Cytoplasmic D2-40 immunoreactivity was present in 60 of 72 papillary carcinomas, 2 cases of follicular adenoma and 2 cases of follicular carcinoma, whereas no adenomatous goiter or normal thyroid glands contained positive epithelial cells. Overexpression of D2-40 in papillary thyroid carcinomas thus has potential diagnostic utility in differentiating these tumors from their potential histologic mimics.

Expression of human telomerase reverse transcriptase and cyclin-D1 in olfactory neuroblastoma.

Olfactory neuroblastoma is an uncommon neoplasm. Typically, these tumors are indolent with long-standing symptomatology, but the fact that the lesions are indeed malignant has been proven by the repeated demonstration that they can metastasize to distant organs. Suitable prognostic factors are lacking and therapeutic strategy still remains controversial. Expression of human telomerase reverse transcriptase (hTERT) is associated with most human malignancies and high levels have been correlated with poor prognosis in many cancers. In comparison, overexpression of cyclin-D1 occurs in several malignancies and has been associated with aggressive tumor behavior and poorer prognosis. In this study, we collected 16 olfactory neuroblastomas from the Kaohsiung Medical University Hospital. The aim was to investigate the value of immunoexpression of hTERT and cyclin-D1 in correlation with clinicopathologic features of olfactory neuroblastoma. Low and high cyclin-D1 expression was found in 6 and 10 cases, respectively. For hTERT, low and high protein expression was detected in 5 and 11 tumors, respectively. Cyclin-D1 expression was not correlated with selected parameters. However, high hTERT expression was significantly correlated with high Kadish stage. In conclusion, high hTERT expression can be considered a potential indicator of aggressive olfactory neuroblastoma.

Absence of Epstein-Barr virus in olfactory neuroblastoma.

AIMS: The sinonasal region is a frequent site for Epstein-Barr virus (EBV) related tumours, including nasopharyngeal carcinoma, sinonasal undifferentiated carcinoma and malignant lymphoma. Olfactory neuroblastoma is a rare neoplasm, arises from olfactory epithelium, is found in the upper nasal cavity, and may be confused morphologically with the above tumours. Our aim was to determine whether EBV is associated with olfactory neuroblastoma. METHODS: We collected tissue samples for 16 olfactory neuroblastomas over an 11-year period at Kaohsiung Medical University Hospital. Diagnoses were confirmed from pathological review and immunohistochemistry. We used in situ hybridisation for EBV encoded small RNAs in those tumours. RESULTS: None of the epithelial cells in the 16 cases of olfactory neuroblastoma was positive for EBV. CONCLUSIONS: EBV does not play a major role in the aetiology of olfactory neuroblastoma.

Expression of STAT3 and Bcl-6 oncoprotein in sodium arsenite-treated SV-40 immortalized human uroepithelial cells.

Arsenic is widely distributed in the environment, and it is a proven toxic and carcinogenic agent. On the southwest coast of Taiwan, an endemic occurrence of chronic arsenical poisoning due to a high concentration of arsenic in artesian-well water has been reported. However, the mechanisms of its carcinogenic action are still unclear. The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway is an essential cascade for mediating normal functions of different cytokines in the development of the hematopoietic and immune systems. In this study, the substantial morphological changes observed in SV-40 immortalized human uroepithelial cells (SV-HUC-1) after treatment of various concentrations of arsenite were examined, and the expression of Bcl-6, Jak-2 and p-STAT3 (Tyr 705) were evaluated by immunocytochemistry and Western blotting. Our results showed that the expression of Bcl-6 increased dose-dependently in arsenite-treated urothelial cells. Sodium arsenite treatment reduced Jak-2 protein expression in a dose-dependent manner. However, treatment of SV-HUC-1 cells with arsenite at concentration ranges from 2 and 4microM for 48h dramatically increased p-STAT3 (Tyr 705), but the levels decreased at 8-40microM of arsenite. Our data suggest that arsenic-mediated inactivation of the JAK-STAT signaling pathway might be caused by Bcl-6 interaction with JAK tyrosine kinase or STAT. In conclusion, our findings indicate that arsenic inhibits JAK tyrosine kinase protein expression and suggest the interference in the JAK-STAT pathway might be through Bcl-6 playing an important role in arsenic-associated carcinogenesis.

Arsenic salts induced autophagic cell death and hypermethylation of DAPK promoter in SV-40 immortalized human uroepithelial cells.

Arsenic is a well-known toxic and carcinogenic agent, and associated with various human malignancies, including skin, lung and bladder cancers. Paradoxically, arsenic trioxide has been used successfully in the treatment of patients with acute promyelocytic leukemia. In addition, arsenic could induce cell apoptosis or autophagy in malignant cells. However, the underlying mechanism of arsenic-induced carcinogenesis is still unclear. In this study, we demonstrated an increase of autophagosomes was produced in arsenic-treated SV-HUC-1 cells by using electron microscopy. In addition, increase of Beclin-1, an important regulator for the formation of autophagosome, protein expression in a dose-dependent manner was also found. By using methylation specific PCR, we revealed hypermethylation of CpG sites in the promoter region with decreased DAPK protein expression in arsenic-treated SV-HUC-1 cells. As epigenetic silencing of tumor suppressor genes by promoter hypermethylation has been found in a variety of malignancies including bladder cancer, our results provide new insights for the understanding of the mechanism of arsenic-induced carcinogenesis in urothelial cells.

p-Phenylenediamine induced DNA damage in SV-40 immortalized human uroepithelial cells and expression of mutant p53 and COX-2 proteins.

p-Phenylenediamine (p-PD) is the main aromatic amine used in the formulation of hair dyes. Some epidemiologic studies have suggested that the use of p-PD-based hair dyes might be related to increased risk of human malignant tumors including bladder cancer and hematopoietic cancers. However, the toxicity and genotoxicity of p-PD on urothelial cells has not been reported yet. Therefore, we investigated the genotoxicity of p-PD on human urothelial cells and study its association with the expression of oncoproteins p53 and cyclooxygenase-2 (COX-2). Our results revealed that p-PD was able to induce DNA damage determined by Comet assay. In addition, our immunocytochemical and Western blotting results showed that p-PD induced overexpression of mutant p53 and COX-2 in a dose-dependent manner. The relationship between mutant p53 and COX-2 expression shows strong correlation. Furthermore, the accumulation of mutant p53 was linearly correlated with Comet scores. These results suggest that p-PD can induce DNA damage and accumulation of mutant p53 and COX-2 proteins; this may be one of the possible mechanisms that cause genotoxic carcinogenesis in the urothelial cells.

Treatment of idiopathic prurigo nodularis in Taiwanese patients with low-dose thalidomide.

Prurigo nodularis is an intensely pruritic dermatosis characterized by lichenified and excoriated papules and nodules. The course of prurigo nodularis is often chronic, and some patients respond very poorly to the standard therapeutic modalities. Because the pathogenesis of this disease remains obscure, the treatment of prurigo nodularis can be disappointing and frustrating for both the patients and physicians. Thalidomide, a tumor necrosis factor-alpha antagonist, has been suggested as an alternative treatment option for recalcitrant prurigo nodularis. In the past, the regimen for treatment of prurigo nodularis often required thalidomide at 200 mg/day. We recruited patients with intractable prurigo nodularis and treated them with low-dose thalidomide. Six patients with idiopathic prurigo nodularis were successfully treated with low-dose thalidomide (50-100 mg/day) without clinical development of peripheral neuropathy. In summary, our preliminary results suggest that low-dose thalidomide may be a safe and effective treatment option for patients with recalcitrant idiopathic prurigo nodularis.

Absence of CD66a expression is associated with high microvessel density and high histologic grade in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a primary malignancy of the liver. Patients with HCC usually have poor prognosis and high mortality. It has been shown that carcinoembryonic antigen-related cell adhesion molecule 1 (CD66a) regulates cell signaling, proliferation, and tumor growth. The aim of this study is to analyze the expression and possible role of CD66a in HCC. Immunohistochemical staining of CD66a was performed on 86 HCC cases, and microvessel density was evaluated by CD34 immunostaining. The results were further correlated with clinicopathological parameters. For 47 of 86 HCC cases, the CD66a expression showed diffuse membrane or cytoplasmic staining. The other 39 HCC cases revealed loss of CD66a expression. Loss of CD66a expression was statistically significantly associated with large tumor size (p=0.016), fatty change (p=0.039), patients with transcatheter arterial embolization (p=0.007), and high microvessel density (p=0.036). CD34 expression had no significant association with tumor size, virus infection, histological grade, and capsular invasion. The diffuse and cytoplasmic expression of CD66a may involve the early stage of the HCC, and the loss of CD66a expression indicates tumor progression.

Heat-killed and live Lactobacillus reuteri GMNL-263 exhibit similar effects on improving metabolic functions in high-fat diet-induced obese rats.

Our objective was to investigate and compare the effects of heat-killed (HK) and live Lactobacillus reuteri GMNL-263 (Lr263) on insulin resistance and its related complications in high-fat diet (HFD)-induced rats. Male Sprague-Dawley rats were fed with a HFD with either HK or live Lr263 for 12 weeks. The increases in the weight gain, serum glucose, insulin, and lipid profiles in the serum and liver observed in the HFD group were significantly reduced after HK or live Lr263 administration. Feeding HK or live Lr263 reversed the decreased number of probiotic bacteria and increased the number of pathogenic bacteria induced by high-fat treatment. The decreased intestinal barrier in the HFD group was markedly reversed by HK or live Lr263 treatments. The elevations of pro-inflammatory associated gene expressions in both adipose and hepatic tissues by high-fat administration were markedly decreased by HK or live Lr263 treatments. The increased macrophage infiltration noticed in adipose tissue after high-fat treatment was effectively suppressed by HK or live Lr263 consumption. The insulin resistance associated gene expressions in both adipose and hepatic tissues, which were downregulated in the HFD group, were markedly enhanced after HK or live Lr263 administration. HK or live Lr263 consumption significantly decreased hepatic lipogenic gene expressions stimulated by high-fat treatment. Administration of HK or live Lr263 significantly reduced hepatic oil red O staining and ameliorated the hepatic steatosis observed in high-fat treated rats. Our data suggested that similar to live Lr263, HK Lr263 exerted significant effects on attenuating obesity-induced metabolic abnormalities by reducing insulin resistance and hepatic steatosis formation.

Targeted next-generation sequencing for molecular diagnosis of endometriosis-associated ovarian cancer.

UNLABELLED: Recent molecular and pathological studies suggest that endometriosis may serve as a precursor of ovarian cancer (endometriosis-associated ovarian cancer, EAOC), especially of the endometrioid and clear cell subtypes. Accordingly, this study had two cardinal aims: first, to obtain mutation profiles of EAOC from Taiwanese patients; and second, to determine whether somatic mutations present in EAOC can be detected in preneoplastic lesions. Formalin-fixed paraffin-embedded (FFPE) tissues were obtained from ten endometriosis patients with malignant transformation. Macrodissection was performed to separate four different types of cells from FFPE sections in six patients. The four types of samples included normal endometrium, ectopic endometriotic lesion, atypical endometriosis, and carcinoma. Ultra-deep (>1000×) targeted sequencing was performed on 409 cancer-related genes to identify pathogenic mutations associated with EAOC. The most frequently mutated genes were PIK3CA (6/10) and ARID1A (5/10). Other recurrently mutated genes included ETS1, MLH1, PRKDC (3/10 each), and AMER1, ARID2, BCL11A, CREBBP, ERBB2, EXT1, FANCD2, MSH6, NF1, NOTCH1, NUMA1, PDE4DIP, PPP2R1A, RNF213, and SYNE1 (2/10 each). Importantly, in five of the six patients, identical somatic mutations were detected in atypical endometriosis and tumor lesions. In two patients, genetic alterations were also detected in ectopic endometriotic lesions, indicating the presence of genetic alterations in preneoplastic lesion. Genetic analysis in preneoplastic lesions may help to identify high-risk patients at early stage of malignant transformation and also shed new light on fundamental aspects of the molecular pathogenesis of EAOC. KEY MESSAGES: Molecular characterization of endometriosis-associated ovarian cancer genes by targeted NGS. Candidate genes predictive of malignant transformation were identified. Chromatin remodeling, PI3K-AKT-mTOR, Notch signaling, and Wnt/ß-catenin pathway may promote cell malignant transformation.