The role of oncogenes in pituitary tumorigenesis remains elusive since few genetic changes have been identi®ed so far in pituitary tumors. Pituitary tumortransforming gene (pttg) has been recently cloned from rat GH4 pituitary tumor cells. We have previously isolated and characterized hpttg from human thymus. In the present study, we analyse the expression of hpttg mRNA in a series of human pituitary adenomas. We show that hpttg is highly expressed in the majority of pituitary adenomas while only very low levels of mRNA can be detected in normal pituitary gland by Northern blot analysis. hPTTG protein was immunolocalized mainly in the cytoplasm of adenoma cells. Other common extra-cranial malignant tumors were also analysed by immunohistochemistry. Interestingly, strong hPTTG immunoreactivity was detected in most adenocarcinomas of mammary and pulmonary origins.

Purpose:Tumors of the Ewing family are characterized by chromosomal translocations that yield chimeric transcription factors, such as EWS/FLI1, which regulate the expression of specific genes that contribute to the malignant phenotype. In the present study, we show that cholecystokinin (CCK) is a new target of the EWS/FLI1oncoprotein and assess its functional role in Ewing tumor pathogenesis. Experimental Design: Relevant EWS/FLI1 targets were identified using a combination of cell systems with inducible EWS/FLI1expression, Ewing tumors and cell lines, microarrays, and RNA interference with doxycycline-inducible small hairpin RNA (shRNA) vectors. A doxycyclineinducible CCK-shRNA vector was stably transfected in A673 and SK-PN-DW Ewing cell lines to assess the role of CCK in cell proliferation and tumor growth. Results: Microarray analysis revealed that CCK was up-regulated by EWS/FLI1 in HeLa cells. CCK was overexpressed in Ewing tumors as compared with other pediatric malignancies such as rhabdomyosarcoma and neuroblastoma, with levels close to those detected in normal tissues expressing the highest levels of CCK. Furthermore, EWS/FLI1 knockdown in A673 and SK-PN-DW Ewing cells using two different doxycycline-inducible EWS/FLI1-specific shRNA vectors down-regulated CCK mRNA expression and diminished the levels of secreted CCK, showing that CCK is a EWS/FLI1 specific target gene in Ewing cells. A doxycycline-inducible CCK-specific shRNA vector successfully down-regulated CCK expression, reduced the levels of secreted CCK in Ewing cell lines, and inhibited cell growth and proliferation in vitro and in vivo. Finally, we show that Ewing cell lines and tumors express CCK receptors and that the growth inhibition produced by CCK silencing can be rescued by culturing the cells with medium containing CCK. Conclusions: Our data support the hypothesis that CCK acts as an autocrine growth factor stimulating the proliferation of Ewing cells and suggest that therapies targeting CCK could be promising in the treatment of Ewing tumors.Ewing family of tumors is a group of highly malignant tumors arising mainly in bone that most often affects children and young adults in the first two decades of life. Despite the use of multimodal therapy (chemotherapy, radiation therapy, and surgery), the long-term disease-free survival rate of Ewing tumor patients is still disappointingly low, particularly in the high-risk groups with metastasis at diagnosis or unfavorable localization (reviewed in ref. 1). The lack of new effective drugs in the treatment of Ewing tumors, together with the side effects that high-dose regimens have on young patients who have a long life expectancy, supports the need for innovative therapeutic strategies that should mainly include targeted therapies against molecules critical for the pathogenesis and progression of these tumors.The molecular hallmark of Ewing family of tumors is the presence of balanced chromosomal translocations leading to the formation of chimeric transcription factors. These aberrant...

The histochemical patterns of mucosubstances in 1.010 intestinal metaplasia (IM) foci in stomachs removed during surgery for benign ulcer and carcinoma has been studied. Two kinds of IM were characterized: the complete and the incomplete types, with the first one subdivided in Small intestine Type I, Small intestine Type II, and Colonic type, based on their similarity of mucosubstances, with those found in normal small intestine and colon, and the second one divided in two groups, depending on the presence or absence of sulfomucins. The incomplete type with sulfomucins was significantly more frequent in patients with carcinoma than in benign ulcer cases (P < 0.001) as well as, in stomachs bearing intestinal type of carcinoma than in stomachs with diffuse type of carcinoma (P < 0.005). The significance of the different types of IM, in relation to the gastric pathologic findings is discussed.

Pituitary tumor-transforming gene (pttg) is a distinct proto-oncogene which is expressed in certain normal tissues with high proliferation rate and in a variety of tumors. PTTG is the vertebrate analog of yeast securins Pds1 and Cut2 with a key role in the regulation of sister chromatid separation during mitosis. Impairment of PTTG regulated functions is expected to lead to chromosomal instability and aneuploidy. Human pttg (hpttg) is abundantly expressed in Jurkat T lymphoblastic lymphoma cells but not in normal peripheral blood leukocytes. To obtain additional data on the potential role of hpttg in lymphomagenesis we selected 150 cases of lymphoid tumors for the assessment of hpttg expression in tumor tissues. Immunohistochemical studies on formalin-fixed, paraffin-embedded tissues revealed hPTTG in 38.8% of B-cell lymphomas, 70.2% of Tcell lymphomas, and 73.1% of Hodgkin's lymphomas. Among B-cell lymphomas, the most frequently immunostained tumors were plasma cell tumors, diffuse large cell lymphomas, and follicle center cell lymphomas. In Hodgkin's disease, immunoreactivity was mainly noted in Reed-Sternberg cells. In conclusion, the frequent overexpression of hpttg in many histological subtypes of lymphoma suggests the involvement of this protooncogene in lymphomagenesis.

Hirschsprung disease (HSCR, OMIM 142623) is a developmental disorder characterized by the absence of ganglion cells along variable lengths of the distal gastrointestinal tract, which results in tonic contraction of the aganglionic colon segment and functional intestinal obstruction. The RET proto-oncogene is the major gene associated to HSCR with differential contributions of its rare and common, coding and noncoding mutations to the multifactorial nature of this pathology. In addition, many other genes have been described to be associated with this pathology, including the semaphorins class III genes SEMA3A (7p12.1) and SEMA3D (7q21.11) through SNP array analyses and by next-generation sequencing technologies. Semaphorins are guidance cues for developing neurons implicated in the axonal projections and in the determination of the migratory pathway for neural-crest derived neural precursors during enteric nervous system development. In addition, it has been described that increased SEMA3A expression may be a risk factor for HSCR through the upregulation of the gene in the aganglionic smooth muscle layer of the colon in HSCR patients. Here we present the results of a comprehensive analysis of SEMA3A and SEMA3D in a series of 200 Spanish HSCR patients by the mutational screening of its coding sequence, which has led to find a number of potentially deleterious variants. RET mutations have been also detected in some of those patients carrying SEMAs variants. We have evaluated the A131T-SEMA3A, S598G-SEMA3A and E198K-SEMA3D mutations using colon tissue sections of these patients by immunohistochemistry. All mutants presented increased protein expression in smooth muscle layer of ganglionic segments. Moreover, A131T-SEMA3A also maintained higher protein levels in the aganglionic muscle layers. These findings strongly suggest that these mutants have a pathogenic effect on the disease. Furthermore, because of their coexistence with RET mutations, our data substantiate the additive genetic model proposed for this rare disorder and further support the association of SEMAs genes with HSCR.