Histopathological evaluation of minor salivary gland papillary-cystic tumours: focus on genetic alterations in sialadenoma papilliferum and intraductal papillary mucinous neoplasm.

AIMS: Minor salivary gland tumours showing a predominant papillary-cystic structure are rare, and constitute a mixture of various types of neoplasm; thus, the histopathological assessment of these tumours poses a significant diagnostic challenge. We aimed to delineate the histological characteristics of these tumours and further mutational aspects with a particular focus on sialadenoma papilliferum (SP) and intraductal papillary mucinous neoplasm (IPMN). METHODS AND RESULTS: We retrieved 28 papillary-cystic tumours of the minor salivary glands, and performed histological re-evaluation and mutation analyses of several key oncogenes. The histological classifications were as follows: SP (n = 10), SP-like intraductal papillary tumour (SP-IPT) (n = 2), IPMN (n = 9), intraductal papilloma, cystadenoma, and cystadenocarcinoma (two, three and two respectively). Whereas SP typically consisted of a combination of exophytic squamous epithelium and endophytic intraductal papillary infoldings, SP-IPT lacked the exophytic component. SP and SP-IPT frequently harboured BRAF V600E mutations (75.0%), which were identified in both squamous and ductal components. IPMN was characterised by a well-demarcated cystic lesion filled exclusively with a papillary proliferation of mucinous cells and a high rate of AKT1 E17K mutations (88.9%). Intraductal papillomas were unilocular cystic lesions with intraluminal papillary growth of bland columnar cells. In contrast, both cystadenomas and cystadenocarcinomas showed a multicystic appearance with a papillary configuration. Cystadenocarcinomas invaded the surrounding tissue and were composed of markedly atypical tumour cells. CONCLUSION: The appropriate interpretation of histological findings and specific genetic alterations (e.g. BRAF V600E and AKT1 E17K in SP and IPMN) would be useful for the correct diagnosis of minor salivary gland papillary-cystic tumours.

Mechanism of cytokinesis failure in ovarian cystadenomas with defective BRCA1 and P53 pathways.

We previously described an in vitro model in which serous ovarian cystadenomas were transfected with SV40 large T antigen, resulting in loss of RB and P53 functions and thus mimicking genetic defects present in early high-grade serous extra-uterine Müllerian (traditionally called high-grade serous ovarian) carcinomas including those associated with the BRCA1 mutation carrier state. We showed that replicative aging in this cell culture model leads to a mitotic arrest at the spindle assembly checkpoint. Here we show that this arrest is due to a reduction in microtubule anchoring that coincides with decreased expression of the BUB1 kinase and of the phosphorylated form of its substrate, BUB3. The ensuing prolonged mitotic arrest leads to cohesion fatigue resulting in cell death or, in cells that recover from this arrest, in cytokinesis failure and polyploidy. Down-regulation of BRCA1 to levels similar to those present in BRCA1 mutation carriers leads to increased and uncontrolled microtubule anchoring to the kinetochore resulting in overcoming the spindle assembly checkpoint. Progression to anaphase under those conditions is associated with formation of chromatin bridges between chromosomal plates due to abnormal attachments to the kinetochore, significantly increasing the risk of cytokinesis failure. The dependence of this scenario on accelerated replicative aging can, at least in part, account for the site specificity of the cancers associated with the BRCA1 mutation carrier state, as epithelia of the mammary gland and of the reproductive tract are targets of cell-nonautonomous consequences of this carrier state on cellular proliferation associated with menstrual cycle progressions.

Impact of next-generation sequencing on the clinical diagnosis of pancreatic cysts.

BACKGROUND AND AIMS: The value of next-generation sequencing (NGS) of pancreatic cyst fluid relative to the clinical and imaging impression has not been well-studied. The aim of this study was to assess the impact of NGS on the clinical diagnosis from imaging and carcinoembryonic antigen (CEA) and thus the management of pancreatic cysts. METHODS: Ninety-two pancreatic cyst fluids from 86 patients were analyzed by cytology, CEA, and targeted NGS. Cysts were classified by imaging as nonmucinous, mucinous, or not specified. NGS results were compared with the imaging impression stratified by CEA and cytology. RESULTS: NGS impacted the clinical diagnosis by defining a cyst as mucinous in 48% of cysts without elevated CEA levels. The VHL gene in 2 intraductal papillary mucinous neoplasms (IPMNs) supported a serous cystadenoma. Twenty percent of cysts that were nonmucinous by imaging were mucinous by NGS. Of the 14 not-specific cysts, CEA levels were not elevated in 12 (86%), and NGS established a mucinous etiology in 3 (25%). A KRAS or GNAS mutation supported an IPMN with nonmucinous CEA in 71%. A KRAS mutation reclassified 19% of nonneoplastic cysts with nonmucinous CEA as mucinous. Seven cyst fluids (8%) had either a TP53 mutation or loss of CDKN2A or SMAD4 in addition to KRAS and/or GNAS mutations; 5 of 7 (71%) were clinically malignant, and high-grade cytology was detected in all 5. Overall, CEA was more specific for a mucinous etiology (100%), but NGS was more sensitive (86% vs 57%). CONCLUSIONS: NGS of pancreatic cyst fluid impacts clinical diagnosis and patient management by defining, supporting, or changing the clinical diagnosis based on imaging and CEA. NGS was most valuable in identifying mucinous cysts with nonmucinous CEA. An added benefit is the potential to detect mutations late in the progression to malignancy that may increase the risk classification of the cyst based on imaging and cytology.

Elafin is downregulated during breast and ovarian tumorigenesis but its residual expression predicts recurrence.

INTRODUCTION: Elafin is an endogenous serine protease inhibitor. The majority of breast cancer cell lines lack elafin expression compared to human mammary epithelial cells. In this study, we hypothesized that elafin is downregulated during breast and ovarian tumorigenesis. METHODS: We examined elafin expression by immunohistochemistry (IHC) in specimens of normal breast tissue (n = 24), ductal carcinoma in situ (DCIS) (n = 54), and invasive breast cancer (n = 793). IHC analysis of elafin expression was also performed in normal fallopian tube tissue (n = 20), ovarian cystadenomas (n = 9), borderline ovarian tumors (n = 21), and invasive ovarian carcinomas (n = 216). To understand the significance of elafin in luminal breast cancer cell lines, wild-type or M25G elafin (lacking the protease inhibitory function) were exogenously expressed in MCF-7 and T47D cells. RESULTS: Elafin expression was downregulated in 24% of DCIS and 83% of invasive breast tumors when compared to elafin expression in the normal mammary epithelium. However, the presence of elafin-positive cells in invasive breast tumors, even at low frequency, correlated with poor recurrence-free survival (RFS), reduced overall survival (OS), and clinicopathological markers of aggressive tumor behavior. Elafin-positive cells were an especially strong and independent prognostic marker of reduced RFS in IHC-defined luminal A-like tumors. Elafin was also downregulated in 33% of ovarian cystadenomas, 43% of borderline ovarian tumors, and 86% of invasive ovarian carcinomas when compared to elafin expression in the normal fallopian tube. In ovarian tumors, elafin-positive cells were correlated with reduced RFS, OS and disease-specific survival (DSS) only in stage I/II patients and not in stage III/IV patients. Notably, exogenous expression of elafin or elafin M25G in the luminal breast cancer cell lines MCF-7 and T47D significantly decreased cell proliferation in a protease inhibitory domain-independent manner. CONCLUSIONS: Elafin predicts poor outcome in breast and ovarian cancer patients and delineates a subset of endocrine receptor-positive breast cancer patients susceptible to recurrence who could benefit from more aggressive intervention. Our in vitro results suggest that elafin arrests luminal breast cancer cells, perhaps suggesting a role in tumor dormancy.

Spectrum of magnetic resonance imaging findings in pancreatic and other abdominal manifestations of Von Hippel-Lindau disease in a series of 23 patients: a pictorial review.

CONTEXT: Von Hippel Lindau disease is a rare autosomal dominantly inherited multisystem disorder characterized by development of benign and malignant tumors. The abdominal manifestation of the syndrome are protean. Magnetic resonance plays an important role in identification of abdominal abnormalities and follow-up of lesions. OBJECTIVE: To describe magnetic resonance imaging findings and patterns of pancreatic and other principal abdominal manifestations in a series of von Hippel-Lindau (VHL) disease patients and to review literature. METHODS: We retrospectively reviewed abdominal magnetic resonance studies performed in 23 patients (10 males, 13 females) diagnosed of VHL. RESULTS: In all examined patients abdominal involvement was present. The pancreatic imaging findings detected were: unilocular cystic lesions (6/23: 26.1%); serous cystadenomas (11/23: 47.8%), including diffuse lesions (8/23: 34.8%); solid neuroendocrine tumors (8/23: 34.8%); cystic neuroendocrine tumors (1/23: 4.3%). The renal findings detected were: simple renal cysts (18/23: 78.3%); complex renal cysts (13/23: 56.5%), including benign lesions (10/23: 43.5%) and malignant lesions (3/23: 13.0%); renal carcinomas (11/23: 47.8%) and 5 of these (45.5%) were multiple and bilateral. Five patients (21.7%) presented pheochromocytoma (4 of these were bilateral; 80.0%) and 1 patient (4.3%) presented cystadenoma of the epididymis. CONCLUSIONS: In VHL disease patients, magnetic resonance imaging plays an essential role in the identification of pancreatic and other abdominal lesions, in their follow-up, in the screening of asymptomatic gene carriers, and in their long-term surveillance.

Dissecting microenvironment in cystadenomas and hepatic cysts based on single nucleus RNA-sequencing data.

Hepatic cystadenoma is a rare disease, accounting for about 5% of all cystic lesions, with a high tendency of malignant transformation. The preoperative diagnosis of cystadenoma is difficult, and some cystadenomas are easily misdiagnosed as hepatic cysts at first. Hepatic cyst is a relatively common liver disease, most of which are benign, but large hepatic cysts can lead to pressure on the bile duct, resulting in abnormal liver function. To better understand the difference between the microenvironment of cystadenomas and hepatic cysts, we performed single-nuclei RNA-sequencing on cystadenoma and hepatic cysts samples. In addition, we performed spatial transcriptome sequencing of hepatic cysts. Based on nucleus RNA-sequencing data, a total of seven major cell types were identified. Here we described the tumor microenvironment of cystadenomas and hepatic cysts, particularly the transcriptome signatures and regulators of immune cells and stromal cells. By inferring copy number variation, it was found that the malignant degree of hepatic stellate cells in cystadenoma was higher. Pseudotime trajectory analysis demonstrated dynamic transformation of hepatocytes in hepatic cysts and cystadenomas. Cystadenomas had higher immune infiltration than hepatic cysts, and T cells had a more complex regulatory mechanism in cystadenomas than hepatic cysts. Immunohistochemistry confirms a cystadenoma-specific T-cell immunoregulatory mechanism. These results provided a single-cell atlas of cystadenomas and hepatic cyst, revealed a more complex microenvironment in cystadenomas than in hepatic cysts, and provided new perspective for the molecular mechanisms of cystadenomas and hepatic cyst.

MicroRNA from pancreatic duct aspirate differentiates cystic lesions of the pancreas.

INTRODUCTION: Prognostication for cystic neoplasms of the pancreas continues to evolve. Beyond simple size and cystic fluid CEA determination, microRNA (miRNA) detection holds great promise as molecular diagnostics for cancer risk. In this study, we sought to identify miRNAs that could predict malignant potential of pancreatic cystic lesions. METHODS: RNA was harvested from the pancreatic duct aspirate of 72 cystic neoplasms of the pancreas. Samples with adequate RNA concentration (≥ 3 ng/µL) were selected for qRTPCR profiling using assays to 379 of the most common miRNAs. miRNA profiles were correlated with histopathology from resected specimens and grouped by benign (serous cystadenomas), premalignant (intraductal papillary mucinous neoplasms and mucinous cystadenomas), or malignant lesions (adenocarcinoma). RESULTS: Adequate RNA for analysis was obtained from 42 (58.3 %) of the samples. Malignant lesions were more likely to have adequate RNA (n = 17, 81 %) than either benign (n = 6, 33 %) or premalignant lesions (n = 19, 59 %; p = 0.011). Nine miRNA were identified as differentially expressed between benign and premalignant/malignant lesions (p < 0.05). A significant correlation was found between the number of differentially expressed miRNA and the likelihood of a premalignant/malignant lesion. All premalignant or malignant lesions expressed at least one miRNA surpassing the threshold of mean miRNA expression, whereas no benign lesions had more than one miRNA surpassing the threshold. CONCLUSIONS: The presence of RNA in the duct aspirate from patients with pancreatic cystic neoplasms may be a predictor of premalignancy or malignancy. miRNA may be utilized to further differentiate between benign, premalignant, and malignant cystic lesions of the pancreas.

A combined blood based gene expression and plasma protein abundance signature for diagnosis of epithelial ovarian cancer--a study of the OVCAD consortium.

BACKGROUND: The immune system is a key player in fighting cancer. Thus, we sought to identify a molecular 'immune response signature' indicating the presence of epithelial ovarian cancer (EOC) and to combine this with a serum protein biomarker panel to increase the specificity and sensitivity for earlier detection of EOC. METHODS: Comparing the expression of 32,000 genes in a leukocytes fraction from 44 EOC patients and 19 controls, three uncorrelated shrunken centroid models were selected, comprised of 7, 14, and 6 genes. A second selection step using RT-qPCR data and significance analysis of microarrays yielded 13 genes (AP2A1, B4GALT1, C1orf63, CCR2, CFP, DIS3, NEAT1, NOXA1, OSM, PAPOLG, PRIC285, ZNF419, and BC037918) which were finally used in 343 samples (90 healthy, six cystadenoma, eight low malignant potential tumor, 19 FIGO I/II, and 220 FIGO III/IV EOC patients). Using new 65 controls and 224 EOC patients (thereof 14 FIGO I/II) the abundances of six plasma proteins (MIF, prolactin, CA125, leptin, osteopondin, and IGF2) was determined and used in combination with the expression values from the 13 genes for diagnosis of EOC. RESULTS: Combined diagnostic models using either each five gene expression and plasma protein abundance values or 13 gene expression and six plasma protein abundance values can discriminate controls from patients with EOC with Receiver Operator Characteristics Area Under the Curve values of 0.998 and bootstrap .632+ validated classification errors of 3.1% and 2.8%, respectively. The sensitivities were 97.8% and 95.6%, respectively, at a set specificity of 99.6%. CONCLUSIONS: The combination of gene expression and plasma protein based blood derived biomarkers in one diagnostic model increases the sensitivity and the specificity significantly. Such a diagnostic test may allow earlier diagnosis of epithelial ovarian cancer.

A study of the methylation status of opioid binding protein/cell adhesion molecule-like gene in ovarian cancer using nested methylation-specific polymerase chain reaction detection.

BACKGROUND: The goal was to improve the methylation-specific PCR (MSP) method and investigate the methylation status of the OPCML gene in carcinoma tissues from ovarian cancer patients. METHODS: MSP and nested MSP methods were used to examine the methylation status of the OPCML gene promoter in ovarian cancer, borderline tumor, and normal ovary tissues. RESULTS: Methylation of the OPCML gene was detected in 58.3% (14/24) and 83.3% (20/24) of the specimens from ovarian cancer patients using MSP and nested MSP methods, respectively. No methylation was observed in normal ovarian tissues using either method. CONCLUSIONS: The modified nested MSP method showed better sensitivity. The methylation of the OPCML gene was significantly higher in ovarian cancer than in normal tissue. The detection of OPCML gene methylation could serve as one of the molecular markers for the diagnosis of ovarian cancer.

Emerging Entities in Salivary Pathology: A Practical Review of Sclerosing Microcystic Adenocarcinoma, Microsecretory Adenocarcinoma, and Secretory Myoepithelial Carcinoma.

In recent years, increased molecular testing and improved immunohistochemical panels have facilitated more specific classification of salivary gland carcinomas, leading to recognition of several novel tumor types and unique histologic variants. Sclerosing microcystic adenocarcinoma, microsecretory adenocarcinoma, and secretory myoepithelial carcinoma are three such recently described entities that demonstrate low-grade cytology, production of prominent secretory material, and variable amounts of sclerotic stroma. This review provides a practical overview of these important and overlapping emerging entities in salivary gland pathology with a focus on distinctive histologic features and helpful ancillary studies that differentiate them from a wide range of familiar morphologic mimics.

Sclerosing Polycystic Adenoma.

Sclerosing polycystic adenoma (SPA) is the more appropriate name for sclerosing polycystic adenosis. SPA is an uncommon salivary gland lesion with a constellation of unusual histologic findings that were originally interpreted as analogous to breast fibrocystic changes. The histologic findings in SPA include fibrosis, cystic alterations, apocrine metaplasia, and proliferations of ducts, acini, and myoepithelial cells in variable proportions. Because of its unusual mixed histology, SPA may be confused with a variety of lesions, ranging from reactive conditions to benign or even malignant neoplasms. The features of SPA are reviewed, with an emphasis on resolving its differential diagnosis.

ABC transporter gene expression in benign and malignant ovarian tissue.

OBJECTIVE: ATP-binding Cassette (ABC) transporters are thought to cause multiple drug resistance (MDR) in various carcinomas. Gene expression data from individual transporters in ovarian cancer tissue is contradictory and also scarce for some of them. RNA levels of a panel of ABC transporters were collected and analyzed to get a more detailed overview which transporters are of importance in resistance to chemotherapeutic agents in ovarian carcinoma. METHODS: Real-time PCR was used to determine RNA expression levels of 9 ABC transporters in 50 benign tissue samples and 50 recurrent ovarian cancer samples. Genes exhibiting a significant difference between those two groups were further evaluated in 50 primary cancer samples. Data were analyzed with receiver operating characteristic (ROC) curves and multiple Wilcoxon-Mann-Whitney U-tests with Shaffer correction. RESULTS: Gene expression of four transporters (ABCC1, ABCC2, ABCC3, and ABCB3) was significantly elevated in recurrent cancer lesions compared to benign tissue. Expression levels of these 4 ABC transporters were further analyzed in primary ovarian cancer lesions. A significant difference between primary and recurrent tumor tissue was found in all four genes. Changes in gene expression between benign samples and primary lesions were minor and not relevant. CONCLUSIONS: Four of the examined ABC transporters are likely to play a role in the MDR of ovarian carcinoma. Gene expression of these transporters seems only up regulated through chemotherapy. The thesis that MDR in ovarian cancer is acquired through therapy itself and not present ab initio is supported by these findings.

Expression and amplification of eIF-5A2 in human epithelial ovarian tumors and overexpression of EIF-5A2 is a new independent predictor of outcome in patients with ovarian carcinoma.

OBJECTIVES: Our previous study has suggested an oncogenic role of eIF-5A2 in ovarian tumorigenesis. Abnormalities of eIF-5A2 and its clinical/prognostic significance, however, in ovarian carcinoma are unclear. METHODS: In this study, we examined expression of EIF-5A2, using immunohistochemistry, in 30 normal ovaries, 30 ovarian cystadenomas, 30 borderline ovarian tumors and 110 ovarian carcinomas. The amplification status of eIF-5A2 in each ovarian carcinoma was assessed by fluorescence in situ hybridization. RESULTS: Overexpression of EIF-5A2 was detected in none of the normal ovaries, 7% cystadenomas, 30% borderline tumors, and 53% invasive ovarian carcinomas, respectively. Amplification of eIF-5A2 was detected in 16% of informative ovarian carcinomas. In ovarian carcinomas, significant positive associations were found between overexpression of EIF-5A2 and the tumors ascending grade, later pT/pN and FIGO stages, as well as increased positive rate of Ki-67 (p<0.05). In univariate survival analysis of the ovarian carcinoma cohorts, a significant association of overexpression of EIF-5A2 with shortened patient survival (mean 39.0 months vs 69.5 months, p<0.001) was demonstrated. Importantly, EIF-5A2 expression provided significant independent prognostic parameters in multivariate analysis (p=0.043). CONCLUSIONS: These findings suggest that increased expression of EIF-5A2 in ovarian carcinoma may represent an acquired malignant phenotypic feature of tumor cells, and the overexpression of EIF-5A2, as detected by immunohistochemistry, is an independent molecular marker for shortened survival time of patients with ovarian carcinoma.

The expression and significance of Dickkopf-1 in epithelial ovarian carcinoma.

The aim of this study was to investigate the presence and prognostic value of Dickkopf-1 (DKK1) in epithelia ovarian carcinoma. The expression of DKK1 was determined in 56 epithelial ovarian carcinoma tissues, 35 benign ovarian cystadenoma tissues, and 12 normal ovarian tissues by quantitative real-time PCR and immunohistochemistry. The DKK1 mRNA level in the carcinoma tissues was upregulated (5.5+/-2.7-fold increase) compared with that in the normal tissues (p<0.0001). The mRNA level of DKK1 in the cystadenoma tissues (1.1+/-0.4-fold increase) was not statistically different from that in the normal tissues (p=0.486). DKK1 protein expression in the carcinoma tissues was also higher (89.29%) than in cystadenoma (65.71%) and normal tissues (58.33%) (p=0.006 and p=0.009, respectively). In epithelial ovarian carcinoma, DKK1 gene and protein overexpression was associated with advanced FIGO stage (p=0.007, p=0.004) and poor differentiation grade (p=0.027, p=0.010). Elevated DKK1 protein levels in ovarian carcinoma samples were associated with a poor outcome in univariate and multivariate analysis (p<0.0001 and p<0.0001, respectively). The study indicated that DKK1 maymbe a useful prognostic and diagnostic indicator for epithelial ovarian carcinoma.

Rapamycin weekly maintenance dosing and the potential efficacy of combination sorafenib plus rapamycin but not atorvastatin or doxycycline in tuberous sclerosis preclinical models.

BACKGROUND: Tuberous sclerosis complex (TSC) is an autosomal dominant tumor suppressor syndrome, characterized by hamartomatous growths in the brain, skin, kidneys, lungs, and heart, which lead to significant morbidity. TSC is caused by mutations in the TSC1 or TSC2 genes, whose products, hamartin and tuberin, form a tumor suppressor complex that regulates the PI3K/Akt/mTOR pathway. Early clinical trials show that TSC-related kidney tumors (angiomyolipomas) regress when treated with the mammalian target of rapamycin (mTOR) inhibitor, rapamycin (also known as sirolimus). Although side effects are tolerable, responses are incomplete, and tumor regrowth is common when rapamycin is stopped. Strategies for future clinical trials may include the investigation of longer treatment duration and combination therapy of other effective drug classes. RESULTS: Here, we examine the efficacy of a prolonged maintenance dose of rapamycin in Tsc2+/- mice with TSC-related kidney tumors. Cohorts were treated with rapamycin alone or in combination with interferon-gamma (IFN-g). The schedule of rapamycin included one month of daily doses before and after five months of weekly doses. We observed a 94.5% reduction in kidney tumor burden in Tsc2+/- mice treated (part one) daily with rapamycin (8 mg/kg) at 6 months

Serum and tissue LDH levels in patients with breast/gynaecological cancer and benign diseases.

BACKGROUND: Lactate dehydrogenase A (LDHA) is involved in anaerobic glycolysis. In cancer patients, serum total lactate dehydrogenase (LDH) levels are often increased, and the gene for one of its isoenzymes, LDHA, is up-regulated. These features have been linked to poor prognosis in several studies. METHODS: We investigated comparatively the total serum LDH activity and tissue isoenzyme LDH5 and hypoxia-inducible factor 1alpha (HIF1alpha) levels in patients with breast (n = 18) and gynaecological (n = 23) malignancies and benign diseases (n =54). RESULTS: The serum LDH levels were significantly higher in patients with endometrial adenocarcinoma (349 +/- 100 IU/l) and ovarian cystadenocarcinomas (383 +/- 116 IU/l) compared to healthy controls (256 +/- 68 IU/l) (p values 0.01 and 0.006, respectively). This difference did not reach significance in patients with breast cancer (328 +/- 169 IU/l; p = 0.17)). Uterine leiomyoma patients showed intermediate LDH levels (310 +/- 81 IU/l), while patients with breast fibroadenomas and ovarian cystadenomas had LDH serum levels close to carcinomas (308 +/- 60 and 348 +/- 135 IU/l, respectively). LDH5 isoenzyme was strongly expressed in cancer cells, exhibiting a mixed cytoplasmic/nuclear subcellular pattern. Interestingly, a high LDH5 content in tissue sections was not invariably accompanied by high LDH serum levels. High HIF1alpha tissue expression was linked to high tissue LDH5 expression. CONCLUSION: Serum and tissue LDH is up-regulated in gynaecologic and breast malignancies and in a subset of benign conditions such as fibro- and cystadenomas. The release of LDH, however, in the bloodstream is partly related to the LDHA gene up-regulation.

[Serous genital carcinoma: molecular pathogenesis and the role of tubal fimbria]. / Seröse Genitalkarzinome: Molekularpathogenese und Rolle des Fimbrientrichters.

Serous carcinomas develop at various sites of the Mullerian system, in particular, the ovaries, the peritoneum, the uterus and the fallopian tubes. Currently, two distinctive molecular genetic pathways are distinguished for serous tumorigenesis: type I tumors are typically well differentiated and gradually develop from cystadenoma through borderline tumor to low grade carcinoma and are characterized by B-raf and K-ras mutations, whereas the poorly differentiated type II tumors develop from intraepithelial carcinoma and show p53 mutations. Infrequently, p53 mutations occur as a late event in the type I pathway and lead to a high grade tumor phenotype. A histologically inconspicuous possible precursor lesion of the intraepithelial carcinoma is the p53 signature that shows p53 overexpression without cell cycle deregulation. Whereas in the ovaries both pathways may occur and develop from inclusions of the surface epithelium, the fallopian tube has recently been described as an important site for the type II pathway. High grade serous carcinomas and intraepithelial carcinomas of the tubal fimbria are particularly found in patients with BRCA1/BRCA2 germ line mutations. Since an advanced tumor stage is frequent and often makes the determination of the origin impossible, the term pelvic serous carcinoma was recently proposed for high grade serous (adeno)carcinomas involving multiple sites.

Integrated transcriptomic and epigenomic analysis of ovarian cancer reveals epigenetically silenced GULP1.

Many epigenetically inactivated genes involved in ovarian cancer (OC) development and progression remain to be identified. In this study we undertook an integrated approach that consisted of identification of genome-wide expression patterns of primary OC samples and normal ovarian surface epithelium along with a pharmacologic unmasking strategy using 3 OC and 3 immortalized normal ovarian epithelial cell lines. Our filtering scheme identified 43 OC specific methylated genes and among the 5 top candidates (GULP1, CLIP4, BAMBI, NT5E, TGFß2), we performed extended studies of GULP1. In a training set, we identified GULP1 methylation in 21/61 (34%) of cases with 100% specificity. In an independent cohort, the observed methylation was 40% (146/365) in OC, 12.5% (2/16) in borderline tumors, 11% (2/18) in cystadenoma and 0% (0/13) in normal ovarian epithelium samples. GULP1 methylation was associated with clinicopathological parameters such as stage III/IV (p = 0.001), poorly differentiated grade (p = 0.033), residual disease (p < 0.0003), worse overall (p = 0.02) and disease specific survival (p = 0.01). Depletion of GULP1 in OC cells led to increased pro-survival signaling, inducing survival and colony formation, whereas reconstitution of GULP1 negated these effects, suggesting that GULP1 is required for maintaining cellular growth control.

Nuclear-mitochondrial genomic profiling reveals a pattern of evolution in epithelial ovarian tumor stem cells.

Analyses of genome orthologs in cancer on the background of tumor heterogeneity, coupled with the recent identification that the tumor propagating capacity resides within a very small fraction of cells (the tumor stem cells-TSCs), has not been achieved. Here, we describe a strategy to explore genetic drift in the mitochondrial genome accompanying varying stem cell dynamics in epithelial ovarian cancer. A major and novel outcome is the identification of a specific mutant mitochondrial DNA profile associated with the TSC lineage that is drastically different from the germ line profile. This profile, however, is often camouflaged in the primary tumor, and sometimes may not be detected even after metastases, questioning the validity of whole tumor profiling towards determining individual prognosis. Continuing mutagenesis in subsets with a mutant mitochondrial genome could result in transformation through a cooperative effect with nuclear genes - a representative example in our study is a tumor suppressor gene viz. cAMP responsive element binding binding protein. This specific profile could be a critical predisposing step undertaken by a normal stem cell to overcome a tightly regulated mutation rate and DNA repair in its evolution towards tumorigenesis. Our findings suggest that varying stem cell dynamics and mutagenesis define TSC progression that may clinically translate into increasing tumor aggression with serious implications for prognosis.

Gene expression analysis of pancreatic cystic neoplasm in SV40Tag transgenic mice model.

AIM: To study the gene expression changes in pancreatic cystic neoplasm in SV40Tag transgenic mice model and to provide information about the prevention, clinical diagnosis and therapy of pancreatic cancer. METHODS: Using the pBC-SV40Tag transgenic mice model of pancreatic cystic neoplasm, we studied the gene expression changes by applying high-density microarrays. Validation of part gene expression profiling data was performed using real-time PCR. RESULTS: By using high-density oligonucleotide microarray, of 14113 genes, 453 were increased and 760 decreased in pancreatic cystic neoplasm, including oncogenes, cell-cycle-related genes, signal transduction-related genes, skeleton-related genes and metabolism-related genes. Among these, we confirmed the changes in Igf, Shh and Wnt signal pathways with real-time PCR. The results of real-time PCR showed similar expression changes in gene chip. CONCLUSION: all the altered expression genes are associated with cell cycle, DNA damage and repair, signal pathway, and metabolism. SV40Tag may cooperate with several proteins in promoting tumorigenesis.