Project description:Pituitary adenomas are common benign neoplasms giving rise to disorders of growth, reproductive function and cortisol production. Although recently determined to be monoclonal, very little is known about the mechanisms regulating the development of pituitary hyperplasia and neoplasia in humans. Surgical resection is the treatment of choice for most symptomatic pituitary adenomas. The goal of surgery is the complete removal of the tumor and the success of surgery is strongly affected by the presence of local invasion. However, complete tumor removal is unlikely when there is extensive local invasion. Identifying genes that control the invasiveness and recurrence of this class of tumors will provide therapeutic targets for this class of tumors. We will determine the expression pattern of genes in recurrent and invasive and pituitary adenomas and compare those to non-invasive and non-recurrent tumors. We hypothesize that the differential expression and activation of a number of genes affect pituitary adenoma recurrence and invasiveness. Rationale: Preliminary result showed a differential expression of novel PKC isozymes in non-invasive and invasive pituitary adenomas. PMA, an activator of both novel and classical PKC isozymes increased the expression of gelatinase A (MMP-2) mRNA in human pituitary adenoma cell line. This result raises a fundamental question as to the functional role of novel PKC isozymes and proteases in the invasive phenotype of pituitary adenomas. The primary component of this Specific Aim is to determine whether specific genes are differentially expressed in recurrent or invasive adenomas when compared with control non-invasive tumors. Tissue specimens from non-invasive and invasive (dural invasion based microscopic examination) and recurrent vs non-recurrent tumors will be used for microarray analysis. Frozen pituitaryspecimens will be collected and total RNA extracted with TriZol reagent. We will provide total RNA (10 ug) from non-invasive, invasive, reoccurred and non-occurrent pituitary adenomas.

Project description:Pituitary tumors are generally considered as benign. However, many are invasive (45 to 55%) and some are described as aggressive with a high proliferation rate and short post-operative time to recurrence and 0.2% metastasize. The molecular events associated to the progression of the pituitary tumor toward an aggressive and malignant phenotype is still unresolved. To bring new hypothesis on signaling pathways associated to the tumor progression, we applied a wide genome analysis approach combining transcriptome analysis and CGH analysis on the same 13 prolactin tumours classified as non-invasive (n=5), invasive (n=2) and agressive-invasive tumors (n=6). In 5/6 agressive-invasive tumours a loss of a common region in the p arm of the chromosome 11 was detected. This region extending from position 14.9 to position 46.5 Mb harbours the cytobands 11p15.2, 11p15.1, 11p14.3, 11p14.2, 11p14.1, 11p13, 11p12 and 11p11.2. In 3 of these 5 tumours considered as carcinomas because of the presence of metastasis, an allelic loss is also observed in the 11q arm. The combination of data coming from genome structure exploration and transcriptomic analysis showed that allelic loss impact the expression of genes harbored in the imbalanced region. Data filtering strategy allowed us to highlight among the 139 genes harbored in the 11p region loss, 5 genes (DGKZ, CD44, TSG101, GTF2H1 and HTATIP2) that could be candidate gene for triggering the progression of prolactin tumour toward an aggressive and malignant phenotype. Finally, specific DNA alterations give one molecular argument more to consider agressive-invasive tumour and carcinomas as a distinct step in progression of the pituitary tumours. Copy number analysis of Affymetrix Genome-Wide Human SNP Array 6.0 was performed for 13 prolactin tumors, 6 aggressive-invasive, 2 invasive, 5 non-invasive. The same analysis was performed for one normal pituitary and one genomic DNA called "reference 103" from Affymetrix.

Project description:Pituitary adenomas are common benign neoplasms giving rise to disorders of growth, reproductive function and cortisol production. Although recently determined to be monoclonal, very little is known about the mechanisms regulating the development of pituitary hyperplasia and neoplasia in humans. Surgical resection is the treatment of choice for most symptomatic pituitary adenomas. The goal of surgery is the complete removal of the tumor and the success of surgery is strongly affected by the presence of local invasion. However, complete tumor removal is unlikely when there is extensive local invasion. Identifying genes that control the invasiveness and recurrence of this class of tumors will provide therapeutic targets for this class of tumors. We will determine the expression pattern of genes in recurrent and invasive and pituitary adenomas and compare those to non-invasive and non-recurrent tumors. We hypothesize that the differential expression and activation of a number of genes affect pituitary adenoma recurrence and invasiveness. Rationale: Preliminary result showed a differential expression of novel PKC isozymes in non-invasive and invasive pituitary adenomas. PMA, an activator of both novel and classical PKC isozymes increased the expression of gelatinase A (MMP-2) mRNA in human pituitary adenoma cell line. This result raises a fundamental question as to the functional role of novel PKC isozymes and proteases in the invasive phenotype of pituitary adenomas. The primary component of this Specific Aim is to determine whether specific genes are differentially expressed in recurrent or invasive adenomas when compared with control non-invasive tumors. Tissue specimens from non-invasive and invasive (dural invasion based microscopic examination) and recurrent vs non-recurrent tumors will be used for microarray analysis. Frozen pituitaryspecimens will be collected and total RNA extracted with TriZol reagent. We will provide total RNA (10 ug) from non-invasive, invasive, reoccurred and non-occurrent pituitary adenomas. Keywords: other

Project description:Context : Non Functioning Pituitary Adenomas (NFPAs), although typically benign, may be locally invasive. Few datas are currently available related to the molecular process of invasion in sporadic pituitary adenomas. Markers of invasiveness, important for helping the clinician in the therapeutic strategy particularly in the decision for adjuvant radiotherapy, are currently lacking. Objective: Evaluate if invasive NFPAs display a specific expression profile compared with non invasive tumors. Methods: To address this issue, we selected 40 NFPAs (38 of the gonadotroph type) and classified them as invasive (n=22) or non invasive (n=18) on the basis of MRI and surgical findings. Then we performed pangenomic analysis based on Agilent Human Whole genome Gene Expression oligonucleotide microarray (44k) Expression in order to identify genes differentially expressed between invasive and non invasive NFPA. Experiements are made in dual color with tumor samples labelled in cyanine 5 and a pool of all tumors labelled in cyanine 3.The expressions of some genes identified by microarray screening were confirmed by real-time quantitative RT-PCR. The selection of genes was made on the basis of Ingenuity networks and degree of upregulation between invasive and non invasive tumors. Moreover, some genes of interest already described in the literature were added to the analysis. Results: Prediction class analysis showed that 346 genes discriminated between invasive and non invasive NFPAs (p<0.001); 233 were up- and 113 were down-regulated between the two groups. We then tested On the basis of Ingenuity networks and degree of upregulation between invasive and non invasive tumors, a set of eight genes, including MYO5A, IGFBP5, FLT3, NFE2L1, PTTG, MMP9, NCAM and NR1H3, was tested in quantitative PCR analysis and. Results confirmed those obtained in microarrays results.analysis. At the protein level, Myosin 5A (MYO5A) demonstrated stronger immunostaining in invasive NFPAs compared to non invasive NFPAs. Conclusions: We propose a molecular signature of eight genes of grossly invasive NFPAs as compared with non invasive tumors: The product of one of these genes, MYO5A, may be a useful marker of invasive process in tumoral specimens. The role of these genes in the invasiveness process and as prognostic markers of pituitary adenomas needs to be confirmedinvestigated. Method: Microarray analyses the transcriptome of 22 invasive Non Functional Pituitary Adenomas (NFPAs) and 18 non invasive NFPAs in dual color (each sample labelled in cyanine 5 and a pool of all tumors labelled in cyanine 3).

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