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.

MicroRNA-873 mediates multidrug resistance in ovarian cancer cells by targeting ABCB1.

Ovarian cancer is commonly treated with cisplatin and paclitaxel combination chemotherapy; however, ovarian cancer cells often develop resistance to these drugs. Increasingly, microRNAs (miRNAs) including miR-873 have been implicated in drug resistance in many cancers, but the role of miR-873 in ovarian cancer remains unknown. MTT cell viability assays revealed that the sensitivities of ovarian cancer lines to cisplatin and paclitaxel increased following transfection with miR-873 (P < 0.05). After predicting the miR-873 binding region in the 3'-untranslated region of ABCB1, dual-luciferase reporter assay confirmed this prediction. RT-PCR and Western blotting revealed that MDR1 expression was significantly downregulated after transfection with miR-873 and upregulated after transfection with anti-miR-873 at both mRNA and protein levels compared to negative controls (P < 0.05). Experiments in a mouse xenograft model confirmed that intratumoral administration of miR-873 could enhance the efficacy of cisplatin in inhibiting tumor growth in ovarian cancer in vivo (P < 0.05). ABCB1 overexpression reduced sensitivities of ovarian cancer lines OVCAR3 and A2780 to cisplatin and paclitaxel, which can be reversed by miR-873 mimic transfection (P < 0.05). In summary, we demonstrated that overexpression of miR-873 increased the sensitivity of ovarian cancer cells to cisplatin and paclitaxel by targeting MDR1 expression. Our findings suggest that combination therapies with chemotherapy agents and miR-873 may suppress drug resistance in ovarian cancer.

Incorporating inter-relationships between different levels of genomic data into cancer clinical outcome prediction.

In order to improve our understanding of cancer and develop multi-layered theoretical models for the underlying mechanism, it is essential to have enhanced understanding of the interactions between multiple levels of genomic data that contribute to tumor formation and progression. Although there exist recent approaches such as a graph-based framework that integrates multi-omics data including copy number alteration, methylation, gene expression, and miRNA data for cancer clinical outcome prediction, most of previous methods treat each genomic data as independent and the possible interplay between them is not explicitly incorporated to the model. However, cancer is dysregulated by multiple levels in the biological system through genomic, epigenomic, transcriptomic, and proteomic level. Thus, genomic features are likely to interact with other genomic features in the different genomic levels. In order to deepen our knowledge, it would be desirable to incorporate such inter-relationship information when integrating multi-omics data for cancer clinical outcome prediction. In this study, we propose a new graph-based framework that integrates not only multi-omics data but inter-relationship between them for better elucidating cancer clinical outcomes. In order to highlight the validity of the proposed framework, serous cystadenocarcinoma data from TCGA was adopted as a pilot task. The proposed model incorporating inter-relationship between different genomic features showed significantly improved performance compared to the model that does not consider inter-relationship when integrating multi-omics data. For the pair between miRNA and gene expression data, the model integrating miRNA, for example, gene expression, and inter-relationship between them with an AUC of 0.8476 (REI) outperformed the model combining miRNA and gene expression data with an AUC of 0.8404. Similar results were also obtained for other pairs between different levels of genomic data. Integration of different levels of data and inter-relationship between them can aid in extracting new biological knowledge by drawing an integrative conclusion from many pieces of information collected from diverse types of genomic data, eventually leading to more effective screening strategies and alternative therapies that may improve outcomes.

Searching for mammary analogue [corrected] secretory carcinoma of salivary gland among its mimics.

Mammary analog secretory carcinoma of salivary gland is a recently described entity with unique morphologic, clinical, and genetic characteristics, including the characteristic t(12;15)(p13;q25) with ETV6-NTRK3 translocation found in secretory carcinomas of the breast. Before their initial description, these salivary gland tumors were generally diagnosed as acinic cell carcinoma or adenocarcinoma. For the purpose of this study, all cases of salivary gland acinic cell carcinoma, cribriform cystadenocarcinoma, and adenocarcinoma, not otherwise specified (NOS), diagnosed over a 10-year period were retrieved from our surgical pathology files. There were a total of 11 cases diagnosed as acinic cell carcinoma, 10 cases of adenocarcinoma, NOS, and 6 cases of cribriform cystadenocarcinoma. All slides were reviewed by two pathologists (AP, CGF) and tumors that show morphologic features of mammary analog secretory carcinoma according to the recent literature were selected. This process narrowed down the initial number to six cases originally diagnosed as acinic cell carcinoma, three cases originally diagnosed as adenocarcinoma, NOS, and one case originally diagnosed as cribriform cystadenocarcinoma. The 10 cases were subjected to immunohistochemistry for S-100, mammaglobin, and ANO1, as well as fluorescence in situ hybridization analysis for t(12;15)(p13;q25) with ETV6-NTRK3 fusion rearrangement. The ETV6-NTRK3 gene rearrangement was detected in three tumors. These three tumors, initially diagnosed as acinic cell carcinomas, stained positive for S-100 and mammaglobin, and negative for ANO1 by immunohistochemistry. Two of the three patients were male (2/3). In summary, mammary analog secretory carcinoma is a newly described diagnostic entity that should be in the differential diagnosis of salivary gland tumors that morphologically mimic other neoplasms, mainly acinic cell carcinomas. They differ from conventional acinic cell tumors immunohistochemically and molecularly. Positivity for mammaglobin and S-100, and negativity for ANO1 are useful screening tools before confirmatory molecular studies.

An analysis of PLAG1 and HMGA2 rearrangements in salivary duct carcinoma and examination of the role of precursor lesions.

AIMS: Salivary duct carcinoma (SDC) often arises in pleomorphic adenoma (PA). Putative precursors, including low-grade cribriform cystadenocarcinoma (LGCCC) and ductal carcinoma in-situ (DCIS), are more controversial. Rearrangement of PLAG1 or HMGA2 is seen in 50-70% of PAs, but this has not been investigated in SDC. Using a large collection of SDCs from a single institution, we aimed to study these genes by fluorescence in-situ hybridization (FISH), and to correlate the presence of precursor lesions/intraductal proliferations with gene alterations. METHODS AND RESULTS: Forty-four SDCs were stained for smooth muscle actin, CK14, and p63, and examined with PLAG1 and HMGA2 FISH. Eight cases were SDC ex-PA; ten had a hyalinized nodule (HN), which is suspicious for PA; six arose in association with LGCCC; and twenty were 'de-novo' SDCs. Ten cases had PLAG1 rearrangement/amplification (22.7%) and eight had HMGA2 (18.2%) rearrangement/amplification. The positive cases were four SDC ex-PAs, eight SDCs with an HN, and five 'de-novo' SDCs. Twenty-three SDC ex-PAs were present in total (52.3%). All six SDC ex-LGCCCs were FISH-negative. Myoepithelial staining surrounded all LGCCCs, and demonstrated DCIS in 17 cases. Eleven DCIS lesions were in SDC ex-PAs or FISH-positive 'de-novo' SDCs. These cases represent 'cancerization' of ducts. Only six FISH-negative 'de-novo' SDCs showed DCIS. CONCLUSIONS: A large proportion of SDCs arise in PAs (with or without residual evidence of a PA). A small proportion of SDCs arise in LGCCCs. Cases showing DCIS often represent cancerization.

A comparative analysis of K-ras mutation and carcinoembryonic antigen in pancreatic cyst fluid.

BACKGROUND/AIMS: Analysis of cystic fluid may be useful in distinguishing between benign and malignant cysts which has significant impact on their management. The aim of our study was to assess the diagnostic utility of carcinoembryonic antigen (CEA) and K-ras gene mutation in pancreatic cysts fluid. METHODS: The study included 56 patients with pancreatic cystic fluid collected for analysis. The cysts were classified as benign (simple cysts, pseudocysts, serous cystadenoma) - 39 patients or premalignant/malignant (mucinous cystadenoma, IPMN, cystadenocarcinoma) - 17 patients. The patients history, CEA fluid concentrations and presence of K-ras mutation were analyzed. RESULTS: CEA were higher in patients with malignant cysts (mean levels 238 ± 12.5 ng/ml; range 32.8-4985 ng/ml) compared to benign lesions (mean levels 34.5 ± 3.7 ng/ml; range 3.9-693 ng/ml; p < 0.001). K-ras mutation correctly classified 11 of 17 patients with premalignant/malignant lesions. It was also detected in 1 patient with final diagnosis of benign cyst (the sensitivity 64.7% and the specificity 97.4%; p < 0.01). If CEA and molecular analysis were combined in that cysts with either CEA level>45 ng/ml or presence of K-ras mutation, than 16 of 17 premalignant/malignant cysts were correctly identified (94.1%). CONCLUSION: Molecular analysis of pancreatic cyst fluid adds diagnostic value to the preoperative diagnosis and should be considered when cyst cytologic examination is negative for malignancy.

HMGA2: a biomarker significantly overexpressed in high-grade ovarian serous carcinoma.

Ovarian carcinoma consists of a group of histologically heterogeneous diseases involving distinct tumorigenic pathways. High-grade papillary serous carcinoma of the ovary is commonly associated with p53 mutations. HMGA2, an oncofetal protein, is found to be overexpressed in ovarian cancer. To study the function of HMGA2 in ovarian cancer, it is important to know which subtypes of ovarian cancer are associated with HMGA2 overexpression. In this study, we collected six different types of ovarian cancer and examined HMGA2 expression by immunohistochemistry, along with HMGA1, p53 and Ki-67. We found that HMGA2 overexpression was significantly higher in high-grade papillary serous carcinoma (64%) and carcinosarcoma (60%) than in other types of ovarian cancers (7-23%). HMGA2 overexpression was moderately associated with dominant p53 mutations (R=0.51). In addition, the microRNA in situ analysis revealed that let-7b, the HMGA2-negative regulators, were significantly lost in high-grade serous carcinoma. Our findings suggest that HMGA2 is an important molecular change significantly related to high-grade papillary serous carcinoma and is less common in other histological types of ovarian cancer.

Reverse painting of microdissected chromosome 19 markers in ovarian carcinoma identifies a complex rearrangement map.

Alterations of chromosome bands 19p13 and 19q13 in the form of added extra material of unknown origin are among the most frequent cytogenetic changes in ovarian carcinomas. To investigate the chromosomal composition of the 19p+ and/or 19q+ markers, we selected for examination 26 ovarian carcinomas which by G-banding had one to four 19p+ and/or 19q+, in total 37 markers. These cases were then subjected to chromosomal microdissection with subsequent reverse painting, which gave informative results on 29 markers. The breakpoints on chromosome 19 were located in both the short (p; n = 15) and the long (q; n = 10) arms, as well as in the centromeric (n = 2) and pericentromeric (n = 6) region. The analysis showed that many chromosomes added material to chromosome 19, but the chromosome arms 11q, 21q, and 22q were particularly common donors. Homogeneously staining regions (hsr) were seen in only three markers, in all of them consisting of 19p material. Eighteen markers were derived from an unbalanced translocation involving chromosome 19. In five markers, chromosome 19 was rearranged with two chromosomes. The most complex marker showed chromosome 19 rearranged with three other chromosomes, i.e., X, 13, and 16. In five markers, all of the additional material stemmed from chromosome 19 itself. This is the first large chromosome microdissection/FISH study of chromosome 19 markers in ovarian carcinomas. A detailed map of the rearrangements should provide clues to the positions of oncogenes and potential fusion genes important in ovarian carcinogenesis.

Clinicopathological study of intraductal carcinoma of the salivary gland, with emphasis on the apocrine type.

Intraductal carcinoma (IC) is a rare salivary gland tumor with low- to intermediate-grade cytological features. It is further classified into intercalated duct type and apocrine type based on its distinct histologic and immunohistochemical expression. Conventional salivary duct carcinoma (SDC) is an aggressive carcinoma with high-grade features and is usually associated with poor prognosis. In this study, immunohistochemistry and mutation analyses (including HRAS/PIK3CA mutations, RET rearrangement, and human epidermal growth factor receptor 2 [HER2] amplification) of 9 ICs (including 3 pure ICs, 6 ICs with invasive carcinoma) and 24 conventional SDCs were performed and the results were compared. Four intercalated duct-type cases were positive for SOX10 and S100 and negative for AR; five apocrine-type cases showed opposite results. All five apocrine-type cases had cysts with relatively circumscribed tumor borders and morphologically mimicking breast low-grade ductal carcinoma in situ or papillary carcinoma. RET fusion is detected in half of the 4 intercalated duct-type IC but not in the apocrine-type or conventional SDC. HER2 amplification was only observed in conventional SDC. The monoclonal antibody (clone RBT-NRAS) against NRAS Q61R is a sensitive and specific marker used for detecting HRAS Q61R mutation in the salivary gland tumors. The apocrine-type IC had different cytological grades, distinct tumor growth patterns, and no evidence of low- to high-grade transition, suggesting that apocrine-type IC should be distinguished from apocrine SDC with an in situ component.

Somatic activation of rasK gene in a human ovarian carcinoma.

A tumor isolate from a patient with serous cystadenocarcinoma of the ovary contained an activated rasK gene detected hy transfection of NIH/3T3 cells. In contrast, DNA from normal cells of the same patient lacked transforming activity, indicating that activation of this transforming gene was the consequence of somatic mutation in the neoplastic cells. The transforming gene product displayed an electrophoretic mobility in sodium dodecyl sulfate-polyacrylamide gels that differed from the mobilities of rasK transforming proteins in other tumors, indicating that a previously undescribed mutation was responsible for activation of rasK in this ovarian carcinoma.

[Effects of ARLTS1 gene on growth and apoptosis of epithelial ovarian cancer SKOV3 cells].

OBJECTIVE: To investigate the effect of ARLTS1 (ADP-ribosylation factor-like tumor suppressor gene 1) on the growth and apoptosis of ovarian cystadenocarcinoma cell line SKOV3. METHODS: The recombinant plasmid pCMV-Tag 3B-ARLTS1 was constructed and transfected into SKOV3 cells by liposome protocol. The expression of ARLTS1 mRNA and its protein were examined by RT-PCR and Western blotting. Effects of ARLTS1 gene on growth and apoptosis of the transfected cells were evaluated by MTT assay and flow cytometry (FCM). The alterations of caspase-3 and bcl-2 protein levels were examined by Western blotting. RESULTS: The stable transfection of pCMV-Tag 3B-ARLTS1 in SKOV3 cells were obtained and verified by RT-PCR and Western blotting methods. After transfected with ARLTS1, more SKOV3 cells were observed in S phase by FCM compared with those in the other two groups (P is 0.035 and 0.011, respectively). The 36.7% apoptotic index of ARLTS1 transfected cell was significantly higher than that of the other two groups (P < 0.001). The growth of ARLTS1 transfected cells was dramatically inhibited compared with cells transfected with Vector (P < 0.05). Western blotting indicated a significantly decrease in caspase-3 and bcl-2 protein levels in cells transfected with ARLTS1 compared with SKOV3 cells (P is 0.021 and 0.013, respectively). CONCLUSION: ARLTS1 transfection can inhibit proliferation and induce apoptosis of SKOV3 cells in vitro and down-regulate the expression of caspase-3 and bcl-2. ARLTS1 gene may be a candidate tumor suppressor gene in ovarian cancer.

A microRNA signature for the differential diagnosis of salivary gland tumors.

Salivary gland tumors (SGTs) are rare tumors of the head and neck with different clinical behavior. Preoperative diagnosis, based on instrumental and cytologic examinations, is crucial for their correct management. The identification of molecular markers might improve the accuracy of pre-surgical diagnosis helping to plan the proper treatment especially when a definitive diagnosis based only on cytomorphology cannot be achieved. miRNAs appear to be new promising biomarkers in the diagnosis and prognosis of cancer. Studies concerning the useful of miRNA expression in clinical decision-making regarding SGTs remain limited and controversial.The expression of a panel of 798 miRNAs was investigated using Nanostring technology in 14 patients with malignant SGTs (6 mucoepidermoid carcinomas, 4 adenoid cystic carcinomas, 1 acinic cell carcinoma, 1 ductal carcinoma, 1 cystadenocarcinoma and 1 adenocarcinoma) and in 10 patients with benign SGTs (pleomorphic adenomas). The DNA Intelligent Analysis (DIANA)-miRPath v3.0 software was used to determinate the miRNA regulatory roles and to identify the controlled significant Kyoto Encyclopedia of Genes and Genomes (KEGG) molecular pathways. Forty six miRNAs were differentially expressed (False Discovery Rate-FDR<0.05) between malignant and benign SGTs. DIANA miRPath software revealed enriched pathways involved in cancer processes as well as tumorigenesis, cell proliferation, cell growth and survival, tumor suppressor expression, angiogenesis and tumor progression. Interestingly, clustering analysis showed that this signature of 46 miRNAs is able to differentiate the two analyzed groups. We found a correlation between histological diagnosis (benign or malignant) and miRNA expression profile.The molecular signature identified in this study might become an important preoperative diagnostic tool.

Tubulocystic carcinoma of the kidney: clinicopathologic and molecular characterization.

The nature of tubulocystic carcinoma, a rare renal tumor composed of tubular and cystic structures, is poorly understood. It has been suggested that it may represent a low-grade collecting duct carcinoma of the kidney despite the lack of sufficient molecular and pathologic evidence. The aim of this study was to examine the clinical and pathologic features of 13 cases of tubulocystic carcinoma of the kidney. Furthermore, using gene expression microarray analysis, we defined the molecular signature of this tumor by comparing it with other renal tumors in our previously established molecular profile database. Histologically, all 13 tumors were composed of closely packed tubules and cysts of varying sizes separated by fibrovascular septa. The epithelial lining cells of the tubules and cysts in this tumor were characterized by abundant eosinophilic cytoplasm with prominent nucleoli often showing a hobnail appearance. Clinically, one of the 13 cases showed metastasis to the pelvic lymph nodes. Five of the 13 cases coexisted with papillary renal cell carcinoma (RCC) (n=3) or papillary adenoma (n=2). In addition, the molecular profile of tubulocystic carcinoma was similar but not identical to those of papillary RCC by clustering analysis. Through comparative genomic microarray analysis, tubulocystic carcinoma showed gains of chromosome 17, but not chromosome 7, whereas most papillary RCCs showed chromosomal gains in both 7 and 17 (trisomies). Therefore, based on its unique pathologic features and molecular signature as well as its biologic behavior to develop metastasis either by itself or in association with papillary RCC, tubulocystic carcinoma of the kidney should be recognized as a distinct subtype of RCC and be distinguished from other malignant and benign cystic lesions of the kidney.

Recurrent RET Gene Rearrangements in Intraductal Carcinomas of Salivary Gland.

Intraductal carcinoma (IC) is the World Health Organization designation for lesions previously called low-grade cribriform cystadenocarcinoma. The relationship of IC to salivary duct carcinoma (SDC) is controversial, but currently these are considered distinct entities. It is hypothesized that IC and SDC should have different genomic signatures that may be identifiable by next-generation sequencing. A total of 23 ICs were identified: 14 pure IC and 9 invasive carcinomas with an intraductal component. Five invasive carcinomas were subjected to next-generation paired-end RNA sequencing. Data analysis was performed using FusionSeq and Mutation detection algorithms (MuTect and VarScan) for variant callers. Gene fusion candidates were validated by fluorescence in situ hybridization and reverse transcription polymerase chain reaction, and mutations by Sanger sequencing. Among the 9 invasive carcinomas, all except 1 were apocrine SDCs with an intraductal component. The remaining case showed typical intercalated duct type IC with invasive adenocarcinoma. The 14 pure ICs had typical intercalated duct features (2 showed hybrid intercalated/apocrine features). RNA sequencing predicted a NCOA4-RET fusion, confirmed by reverse transcription polymerase chain reaction, in the intercalated duct type IC invasive component. Six additional cases of pure IC showed RET rearrangement by fluorescence in situ hybridization (7/15=47%). No apocrine carcinomas showed RET rearrangement. RNA sequencing and Sanger sequencing identified PIK3CA (p.E545K/p.H1047R) and/or HRAS (p.Q61R) hotspot mutations in 6 of 8 (75%) apocrine carcinomas. In conclusion, 2 distinctive types of intraductal lesions are emerging based on molecular analysis. Classic intercalated type ICs commonly harbor fusions involving RET and rarely show widespread invasion. Apocrine intraductal lesions are typically associated with widespread invasion with no pure examples and show similar PIK3CA and HRAS mutations to SDC.

PIK3CA and PTEN mutations in adenoid cystic carcinoma of the breast metastatic to kidney.

Adenoid cystic carcinoma (ACC) of the breast rarely metastasizes and has been associated with excellent prognosis. We describe a patient with renal metastasis of primary breast ACC 5 years after the mastectomy. A detailed molecular genetic analysis of the primary and metastatic tumors demonstrated somatic mutations in 2 well-known cancer genes associated with regulation of PI3K/AKT signaling pathway: (1) PIK3CA, which encodes the catalytic alpha subunit of the phosphoinositide-3-kinase, and (2) PTEN, which encodes phosphatase and tensin homolog. The mutation identified in PIK3CA (Ex1+169 A>C) predicts an amino acid change from isoleucine to methionine at codon 31 (I31M) and resides in the p85-binding domain of exon 1. The mutation identified in PTEN (IVS4-3 C>T) resides in intron 4 near the splice acceptor site of exon 5 and was associated with an aberrant PTEN transcript lacking exon 5, which is necessary for protein tyrosine phosphatase function and tumor suppressor properties of PTEN. Increased promoter methylation of PTEN was present in renal metastasis, coinciding with the decrease in the level of normal PTEN transcript. These coexistent mutations/epigenetic inactivations in PI3K/AKT pathway may be responsible for the unusually aggressive course of ACC.

15-Lipoxygenase-2 is differentially expressed in normal and neoplastic ovary.

Ovarian cancer is a major cause of lethality from gynecological malignancies, and there is a lack of reliable and specific serum markers for this disease. Eicosanoid-related enzymes have previously been implicated in the pathogenesis of various types of cancer, but little is known about the relevance of lipoxygenase isoforms in ovarian cancer and the results on cyclooxygenases are conflicting. For this study, we quantified the expression of eicosanoid-related enzymes (cyclooxygenase-1 and cyclooxygenase-2, 15-lipoxygenase-1 and lipoxygenase-2, 5-lipoxygenase) in normal and malignant human ovarian tissue by real-time polymerase chain reaction and found a 22-fold elevated expression of 15-lipoxygenase-2 in malignant specimens when compared with normal ovarian tissue (P=0.001). In ovarian carcinoma metastases, expression of the enzyme was also augmented (20-fold upregulation, P=0.004). For 15-lipoxygenase-1 and cyclooxygenase-2, we did not observe differential expression, but there was a trend for increased steady-state concentrations of cyclooxygenase-1 (P=0.1 for ovarian carcinoma, P=0.011 for metastases) and 5-lipoxygenase (P=0.1 for ovarian carcinoma, P=0.018 for metastases, respectively). These data indicate that expression of 15-lipoxygenase-2 mRNA is strongly augmented during ovarian carcinogenesis and that the enzyme may constitute a suitable candidate as a tumor marker.

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.

Incorporating PARP-inhibitors into clinical routine: A tailored treatment strategy to tackle ovarian cancer.

DNA repair mechanisms play a key role in oncogenesis and cancer progression in women with BRCA mutation-positive (BRCAm) ovarian cancer (OC). The BRCA1/2 and poly(ADP-ribose) polymerase (PARP) proteins are considered the foremost mediators among the various components of double-strand and single-strand repair, respectively. A series of new therapeutic drugs that target PARP have been developed for BRCAm OC. This class of agents provokes tumour-specific cytotoxicity with minimal side effects by inducing synthetic lethality, of which they are the first clinical example. The European Medicines Agency granted accelerated licensing approval for the first-in-class-drug that inhibits PARP, olaparib (Lynparza™, AstraZeneca). Olaparib can be used as a monotherapeutic maintenance treatment in patients with platinum-sensitive relapsed (germline and/or somatic) BRCAm high-grade serous epithelial ovarian, fallopian tube or primary peritoneal cancer responsive to platinum-based chemotherapy. Seen in light of these recent events, this review article will focus on (a) how PARP-inhibitors exploit cancer-specific defects in the homologous recombination repair apparatus and (b) how BRCA testing is implemented in routine clinical care.

Frequency of Her2/Neu Protein Expression in Ovarian Epithelial Cancers.

OBJECTIVE: To detect the frequency of Her-2/neu protein expression in epithelial ovarian cancers by immunohistochemistry. STUDY DESIGN: Descriptive cross-sectional study. PLACE AND DURATION OF STUDY: Department of Pathology, King Edward Medical University, Lahore, from July 2014 to May 2015. METHODOLOGY: Fifty-six cases diagnosed as epithelial ovarian cancer on histopathology were included in this study. Immunohistochemistry was performed to observe the pattern of HER2/neu protein expression in these cases. Association with age was determined by Chi-square test with significance at p<0.05. RESULTS: Out of these 56 cases, 38 (67.9%) were serous cystadenocarcinomas, 11 (19.6%) were endometrioid adenocarcinomas, 6 (10.7%) were mucinous cystadenocarcinomas and 1 (1.8%) was non-Brenner transitional cell carcinoma. The mean age of patients was 49.61 ±13.20 years with minimum and maximum ages of 21 years and 80 years, correspondingly. Twentyone (37.5%) out of 56 patients were found to overexpress Her-2/neu protein. CONCLUSION: Her-2/neu protein overexpression was observed in 21 (37.5%) patients. No statistically significant association was seen between age and Her-2/neu protein overexpression.

Genetic disparity between morphologically benign cysts contiguous to ovarian carcinomas and solitary cystadenomas.

BACKGROUND: Ovarian carcinomas occasionally contain large, histologically benign cysts contiguous to the clearly malignant areas (cystadenocarcinomas). The question of whether such cysts are remnants of pre-existing benign tumors (cystadenomas) or constitute integral components of the carcinomas is important in clarifying the role of cystadenomas in ovarian carcinogenesis. It is also important for our general understanding of tumor heterogeneity, a phenomenon thought to result from the gradual accumulation of genetic abnormalities in initially homogeneous tumors. This question is also pertinent to the clinical management of ovarian cystadenomas, which are frequent in women of childbearing age and are usually treated surgically based on the possibility that they may give rise to carcinomas. PURPOSE: Reasoning that molecular markers of ovarian malignancy would be confined to the histologically malignant portions of cystadenocarcinomas if the morphologically benign portions are in fact pre-existing typical cystadenomas, we sought to verify that mutations in the p53 tumor suppressor gene are markers of malignancy in ovarian tumors and to determine the distribution of such mutations in cystadenocarcinomas. METHODS: We used immunohistochemical and DNA-sequencing techniques to analyze 46 ovarian carcinomas, 21 ovarian tumors of low malignant potential, and 16 solitary cystadenomas for the presence of p53 mutations. We then used similar techniques to examine the distribution of such mutations in different portions of cystadenocarcinomas. The observed differences in mutation frequencies were analyzed by the two-tailed Fisher's exact test. RESULTS: Mutations in the p53 gene were present in 24 (52%) of the 46 carcinomas, but they were absent in the 21 tumors of low malignant potential (P < .0001) and the 16 solitary cystadenomas (P = .0002). Six of six cystadenocarcinomas with p53 mutations showed the presence of the same mutations in the adjacent, histologically benign cysts. The mutations were seen not only in cells immediately adjacent to the carcinomas, but also throughout the morphologically benign cysts. Twenty (83%) of the 24 cases showing mutation of one p53 allele also showed loss of genetic heterozygosity, suggesting that the other p53 allele was deleted. Such allelic loss, if present in morphologically malignant portions of cystadenocarcinomas, was also observed in the contiguous cysts. CONCLUSIONS: Ovarian carcinomas can be distinguished from ovarian cystadenomas and tumors of low malignant potential by p53 mutations. The fact that the mutations were present in histologically benign cysts contiguous to ovarian carcinomas suggests that such cysts are not typical cystadenomas and may carry a genetic predisposition to carcinogenesis that is not present in ordinary cystadenomas.