EDIL3 promotes epithelial-mesenchymal transition and paclitaxel resistance through its interaction with integrin αVß3 in cancer cells.

Epithelial-mesenchymal transition (EMT) has recently been associated with tumor progression, metastasis, and chemotherapy resistance in several tumor types. We performed a differential gene expression analysis comparing paclitaxel-resistant vs. paclitaxel-sensitive breast cancer cells that showed the upregulation of EDIL3 (EGF Like Repeats and Discoidin I Like Domains Protein 3). This gene codifies an extracellular matrix protein that has been identified as a novel regulator of EMT, so we studied its role in tumor progression and paclitaxel response. Our results demonstrated that EDIL3 expression levels were increased in paclitaxel-resistant breast and prostate cancer cells, and in subsets of high-grade breast and prostate tumors. Moreover, we observed that EDIL3 modulated the expression of EMT markers and this was impaired by cilengitide, which blocks the EDIL3-integrin αVß3 interaction. EDIL3 knockdown reverted EMT and sensitized cells to paclitaxel. In contrast, EDIL3 overexpression or the culture of cells in the presence of EDIL3-enriched medium induced EMT and paclitaxel resistance. Adding cilengitide resensitized these cells to paclitaxel treatment. In summary, EDIL3 may contribute to EMT and paclitaxel resistance through autocrine or paracrine signaling in cancer cells. Blockade of EDIL3-integrin αVß3 interaction by cilengitide restores sensitivity to paclitaxel and reverts EMT in paclitaxel-resistant cancer cells. Combinations of cilengitide and taxanes could be beneficial in the treatment of subsets of breast and prostate cancers.

A cellular and molecular basis for the selective desmopressin-induced ACTH release in Cushing disease patients: key role of AVPR1b receptor and potential therapeutic implications.

CONTEXT: Desmopressin is a synthetic agonist of vasopressin receptors (AVPRs). The desmopressin stimulation test is used in the diagnosis and postsurgery prognosis of Cushing disease (CD). However, the cellular and molecular mechanisms underlying the desmopressin-induced ACTH increase in patients with CD are poorly understood. OBJECTIVE: The objectives of this study were to determine, for the first time, whether desmopressin acts directly and exclusively on pituitary corticotropinoma cells to stimulate ACTH expression/release and to elucidate the cellular and molecular mechanisms involved in desmopressin-induced ACTH increase in CD. DESIGN: A total of 8 normal pituitaries (NPs), 23 corticotropinomas, 14 nonfunctioning pituitary adenomas, 17 somatotropinomas, and 3 prolactinomas were analyzed for AVPR expression by quantitative real-time RT-PCR. Primary cultures derived from corticotropinomas, nonfunctioning pituitary adenomas, somatotropinomas, prolactinomas, and NPs were treated with desmopressin, and ACTH secretion/expression, [Ca(2+)]i kinetics, and AVPR expression and/or proliferative response were evaluated. The relationship between AVPR expression and plasma adrenocorticotropin/cortisol levels obtained from desmopressin tests was assessed. RESULTS: Desmopressin affects all functional parameters evaluated in corticotropinoma cells but not in NPs or other pituitary adenomas cells. These effects might be due to the dramatic elevation of AVPR1b expression levels found in corticotropinomas. In line with this notion, the use of an AVPR1b antagonist completely blocked desmopressin stimulatory effects. Remarkably, only AVPR1b expression was positively correlated with elevated plasma adrenocorticotropin levels in corticotropinomas. CONCLUSIONS: The present results provide a cellular and molecular basis to support the desmopressin stimulation test as a reliable, specific test for the diagnosis and postsurgery prognosis of CD. Furthermore, our data indicate that AVPR1b is responsible for the direct/exclusive desmopressin stimulatory pituitary effects observed in CD, thus opening the possibility of exploring AVPR1b antagonists as potential therapeutic tools for CD treatment.

PTPL1 and PKCδ contribute to proapoptotic signalling in prostate cancer cells.

PTPL1 is a non-receptor protein tyrosine phosphatase involved in apoptosis regulation, although controversial findings have been reported in different cancer types. We report here a proapoptotic role for PTPL1 in PC3 and LNCaP prostate cancer cells, as its absence induces apoptosis resistance upon treatment with different drugs. In PC3 cells, PTPL1 silencing by small interfering RNA influences the expression levels of Bcl-xL and Mcl-1(S) proteins as well as final events in the apoptotic process such as activation of caspases and caspase-mediated cleavage of proteins like Mcl-1 or poly (ADP-ribose) polymerase. We have identified PKCδ as an intermediary of PTPL1-mediated apoptotic signalling and that phosphorylation status of NF-κB and IκBα is influenced by PTPL1 and PKCδ. Furthermore, the loss of PTPL1 and PKCδ expression in poorly differentiated, more aggressive human prostate cancers also indicate that their absence could be related to apoptosis resistance and tumour progression.

Adenoma de célula madre acidófila: variante infrecuente de tumor hipofisario / Acidophil stem cell adenoma: an uncommon pituitary tumor

El adenoma de célula madre acidófila es un tumor hipofisario parcialmente diferenciado derivado del precursor común de células productoras de hormona de crecimiento y prolactina. Son poco frecuentes y clínicamente pueden presentarse como no funcionantes o asociar hiperprolactinemia. Se analizaron los hallazgos clínicos, inmunohistoquímicos y ultrastructurales de 3 casos de este tipo de adenoma hipofisario. Dos de ellos (2 varones, casos 1 y 3), comenzaron con clínica de compresión local y panhipopituitarismo, y el restante (mujer, caso 2), con amenorrea secundaria. Eran 3 macroadenomas hipofisarios, y en el caso 3 había invasión del seno cavernoso. En todos se detectó hiperprolactinemia y sólo en 1 (caso 3) se asociaba acromegalia. Dos de los pacientes fueron intervinenidos con abordaje transesfenoidal con extirpación completa, y no existió recidiva tumoral en el seguimiento posterior. El estudio inmunohistoquímico y la microscopia electrónica confirmaron el diagnóstico. La presentación clínica de nuestros casos es heterogénea. La extirpación completa del adenoma, si es posible, es el principal factor pronóstico (AU)

Acidophil stem cell adenoma is an incompletely differentiated pituitary neoplasm consisting of a single cell type, assumed to be a common progenitor of somatotropes and lactotropes. These tumors are uncommon and may appear clinically as non-functioning adenomas; varying degrees of hyperprolactinemia are present in most cases. In this series, clinical, histopathological, immunohistochemical and ultrastructural characteristics of three cases of stem cell adenoma are described. Two patients (two males, cases 1 and 3) presented with symptoms of local compression and panhypopituitarism. In the remaining patient (female, case 2) the pituitary tumor was detected because of secondary amenorrhea. The tumors consisted of three pituitary macroadenomas with invasion of the cavernous sinus only in case 3. Hyperprolactinemia was present in all three patients. Acromegaly was evident in one patient (case 3). Complete transsphenoidal removal was achieved in two patients who have shown no evidence of tumoral recurrence in subsequent follow-up. The diagnosis was confirmed by electron microscopy and immunohistochemical characteristics. In our series, the clinical features of the tumors were heterogeneous. If is possible, complete surgical removal confers a better prognosis (AU)

Structural normalization of the lymphoid tissue in asymptomatic HIV-infected patients after 48 weeks of potent antiretroviral therapy.

BACKGROUND: The hallmark of HIV infection is the involution and destruction of lymphoid tissue. However, very little information exists on the effect of highly active antiretroviral therapy (HAART) on lymphoid tissue structure. OBJECTIVE: To evaluate the effect of a HAART regimen after 48 weeks on the architecture and cell regeneration of tonsil lymphoid tissue in HIV-infected patients with CD4 T cell counts > or = 500/microl. METHODS: From June 1997 to February 1998 all asymptomatic HIV-infected patients with CD4 T cell counts > or = 500/microl seen at our unit were offered quadruple antiretroviral therapy. Tonsil biopsies were obtained at baseline and at 48 weeks. Tonsil tissue sections were examined to evaluate structural and immunohistochemical changes by two blinded and independent pathologists. Cell numbers were counted for selected markers in T-dependent zones. RESULTS: Eleven patients were evaluable, six were excluded because of insufficient or inadequate sampling in at least one of the biopsies. Cellular depletion, plasma cell accumulation and prominent vessels were observed in all cases; three excluded patients with evaluable baseline biopsies showed similar tissue lesions. Follow-up biopsies demonstrated some degree of improvement in all patients. Germinal centres appeared in seven cases that were not seen at baseline. CD4 cell counts increased and CD8 cell counts decreased significantly in lymphoid tissue. An increase in CD45RA+ cells was observed; however, the proportion of CD45+Ki67+ cells did not differ between baseline and 48 weeks. CONCLUSION: This study shows an unexpected range of moderate to severe lymphoid tissue lesions in mildly immunosuppressed HIV-infected patients, which was partly restored after 48 weeks of HAART.

Mucinous (colloid) adenocarcinomas secrete distinct O-acylated forms of sialomucins: a histochemical study of gastric, colorectal and breast adenocarcinomas.

AIMS: Mucinous (colloid) adenocarcinomas represent a distinct group of tumours defined by the presence of large amounts of extracellular mucins. By using histochemical methods, we analysed mucins secreted by mucinous versus non-mucinous adenocarcinomas and looked for differential secretion profiles. METHODS AND RESULTS: Sixty-four adenocarcinomas were studied (23 colorectal, 17 gastric, and 24 breast tumours). Thirty-two tumours were of the colloid type. The following methods were applied to paraffin tissue sections: (i) Alcian blue (pH 2.5) and periodic acid-Schiff (PAS); (ii) high iron diamine and Alcian blue (pH 2.5); (iii) periodic acid borohydride, potassium hydroxide, and PAS; (iv) periodic acid-thionine Schiff, potassium hydroxide, and PAS; and (v) periodic acid-borohydride and PAS. Most adenocarcinomas secreted acidic mucins, with sialomucins predominating over sulfomucins, except for non-mucinous adenocarcinomas of the breast which showed predominant neutral mucins. All mucinous adenocarcinomas contained C9-O-acyl sialic acid as mono, di(C8,C9)-, or tri(C7,C8,C9)-O-acyl forms. Acidic mucins secreted by the majority of non-colloid adenocarcinomas consisted of non-O-acylated sialomucins. CONCLUSIONS: C9-O-acylation of sialic acid is a characteristic feature of mucinous adenocarcinomas and can be readily detected by histochemical methods.

hpttg is over-expressed in pituitary adenomas and other primary epithelial neoplasias.

The role of oncogenes in pituitary tumorigenesis remains elusive since few genetic changes have been identified so far in pituitary tumors. Pituitary tumor-transforming 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.

Expression of basic fibroblast growth factor and its receptors FGFR1 and FGFR2 in human benign prostatic hyperplasia treated with finasteride.

BACKGROUND: The development of benign prostatic hyperplasia (BPH) is an androgen-dependent process which may be mediated by a number of locally produced growth factors. One of these, the basic fibroblast growth factor (bFGF or FGF2), has a mitogenic effect on prostatic stroma. High expression levels of bFGF have been reported in BPH. FGFR1 and FGFR2 receptors, that exhibit affinity for bFGF, have been identified in normal and hyperplastic prostate. Finasteride, a 5alpha-reductase inhibitor, is an effective drug in the treatment of BPH, inducing regressive changes in the prostate of treated patients, even though its mechanisms of action are not yet completely elucidated. This study was designed to assess the effects of finasteride on the expression levels of bFGF, FGFR1, and FGFR2 in patients with BPH. METHODS: The expression levels of bFGF, FGFR1, and FGFR2 in 9 patients with prostatic hyperplasia treated with finasteride were assessed by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) analysis of mRNA expression and were compared with those of 9 control patients with untreated BPH. RESULTS: Immunohistochemistry showed strong bFGF immunoreactivity in the prostatic stroma of untreated patients, this being somewhat weaker in the epithelium. In treated patients, epithelial immunoreactivity was practically negative, and a considerable reduction in stromal immunoreactivity was seen. These findings were also confirmed by RT-PCR. FGFR1 showed a weak immunoreactivity in the stroma and in basal epithelial cells. FGFR1 showed a weak immunoreactivity in the stroma and in basal epithelial cells. FGFR2 exhibited strong stromal immunoreactivity, becoming weaker in the basal epithelium. No differences were seen in the expression of both receptors between the groups of treated and untreated patients. CONCLUSIONS: A marked reduction in bFGF levels is seen in BPH treated with finasteride in comparison to untreated BPH. In our opinion, finasteride may act as a negative regulator of bFGF expression, counteracting the role of bFGF in the development of BPH.

Regressive changes in finasteride-treated human hyperplastic prostates correlate with an upregulation of TGF-beta receptor expression.

BACKGROUND: Prostatic atrophy has been documented histologically as a consequence of finasteride action on human hyperplastic prostates. An increase in apoptotic rates has also been reported in androgen-deprived hyperplastic prostates. Transforming growth factor beta (TGF-beta) signaling is implicated in apoptotic cell death. TGF-betas have been detected in normal and diseased human prostate. In the normal prostate, TGF-beta acts as a predominantly negative growth regulator. TGF-beta signaling receptors TbetaRI and TbetaRII have been shown to be negatively regulated by androgens. METHODS: We studied the histological changes in 9 selected finasteride-treated patients with benign prostatic hyperplasia (BPH), and analyzed the levels of expression and localization of TGF-beta receptor types TbetaRI and TbetaRII in these patients as compared to selected BPH controls. RESULTS: The prostatic epithelial compartment seemed to be a primary target site for finasteride action, since we observed moderate to severe glandular atrophy after 4-6 months of treatment. TGF-beta receptors were upregulated in treated cases. We assessed a twofold increase in TbetaRII mRNA levels in treated cases as compared to controls. An increase in both TbetaRI and TbetaRII at the protein level by immunostaining was observed, which also provided a helpful means for detecting glands undergoing regression. CONCLUSIONS: We conclude that finasteride may modulate the TGF-beta signaling system to promote changes leading to apoptosis of epithelial cells and prostatic glandular atrophy.

Sialomucins are characteristically O-acylated in poorly differentiated and colloid prostatic adenocarcinomas.

Mucinous glycoproteins are secreted by prostatic adenocarcinomas and might play important roles in tumor invasion and metastasis. Their histochemical properties on routine biopsy specimens have not been fully characterized. We present a histochemical study of mucin in 21 prostatic adenocarcinomas, with particular focus on the demonstration of different types of sialomucins. We applied the following histochemical techniques to routinely processed, formalin-fixed, paraffin-embedded tissue sections: Alcian blue (pH 2.5) and periodic acid-Schiff to reveal both acidic and neutral mucins; high iron diamine and Alcian blue (pH 2.5) to show sulfated and acidic nonsulfated mucosubstances simultaneously; periodic acid borohydride, potassium hydroxide, and periodic acid-Schiff to demonstrate O-acylated sialic acids; periodic acid thionine-Schiff, potassium hydroxide, and periodic acid-Schiff to differentiate pre-existing glycols from those revealed after saponification procedures; and periodic acid borohydride and periodic acid-Schiff to show C9-O-acylated sialic acid. These techniques are useful tools for demonstrating neutral and acidic (sialo- and sulfo-) mucins and di(C8,C9- or C7,C9-)-O-acylated, tri(C7,C8,C9-)-O-acylated and mono(C9)-O-acylated sialomucins. Most prostatic adenocarcinomas showed acidic mucins, with sialomucins predominating over sulfomucins. Well-differentiated and moderately differentiated noncolloid tumors had non-O-acylated sialomucins. Poorly differentiated tumors contained mono-O-acylated (C9) sialomucins, and colloid-type tumors secreted mono-, di-, and tri-O-acylated sialoglycoproteins. Acidic mucins, mainly sialomucins, constitute the major secretory component in prostatic adenocarcinomas, and our results show that the O-acylation of these sialoglycoproteins inversely correlates with tumor differentiation. Well-differentiated and moderately differentiated tumors are not O-acylated, whereas the poorly differentiated ones characteristically have O-acylated sialomucins in C9. Adenocarcinomas of the colloid type, thought to bear a poor prognosis, are the most heavily O-acylated.

In situ hybridization analysis of anterior pituitary hormone gene expression during fetal mouse development.

We used 35S-labeled oligonucleotides and cRNAs (riboprobes) to detect the temporal order and spatial pattern of anterior pituitary hormone gene expression in (B6CBF1 x B6CBF1)F2 fetal mice from embryonic Day 9.5 (E9.5) to postnatal Day 1 (P1). Pro-opiomelanocortin (POMC) mRNA was expressed in the basal diencephalon on Day E10.5, in the ventromedial zone of the pars distalis on Day E12.5, and in the pars intermedia on Day E14.5. The common alpha-glycoprotein subunit (alpha-GSU) mRNA first appeared in the anterior wall of Rathke's pouch on Day E11.5 and extended to the pars tuberalis and ventromedial zone of the pars distalis on Day E12.5. Thyroid-stimulating hormone-beta (TSH beta) subunit mRNA was expressed initially in both the pas tuberalis and ventromedial pars distalis on Day E14.5, with an identical spatial distribution to alpha-GSU at the time. In contrast, luteinizing hormone-beta (LH beta) subunit and follicle-stimulating hormone beta (FSH beta) subunit mRNAs were detected initially only in the ventromedial pars distalis on Days E16.5 and E17.5, respectively, in an identical distribution to each other. POMC-, alpha-GSU-, TSH beta, LH beta-, and FSH beta-positive cells within the pars distalis all increased in number and autoradiographic signal with differing degrees of spatial expansion posteriorly, laterally, and dorsally up to Day P1. POMC expression was typically the most intense and extended circumferentially to include the entire lateral and dorsal surfaces of the pars distalis. The expression of both growth hormone (GH) and prolactin (PRL) started coincidentally on Day E15.5. However PRL cells localized in the ventromedial area similarly to POMC and the glycoprotein hormone subunits, whereas GH cells were found initially in a more lateral and central distribution within the lobes of the pars distalis. Somatotrophs increased dramatically in number and autoradiographic signal, extending throughout the pars distalis except for the most peripheral layer of cells on Day E17.5. Mammotrophs also increased in number but less abundantly than somatotrophs, and PRL expression remained more confined to central-medial and ventrolateral areas of the pars distalis up to Day P1. These data demonstrate distinctive patterns of expression for each of the major anterior pituitary hormone genes during development of the mouse pituitary gland and suggest that different groups of committed cells are the immediate precursors to the terminally differentiated hormone-secreting cell types.

Introduction of a point mutation into the mouse genome by homologous recombination in embryonic stem cells using a replacement type vector with a selectable marker.

The introduction of small mutations instead of null alleles into the mouse genome has broad applications to the study of protein structure-function relationships and the creation of animal models of human genetic diseases. To test a simple mutational strategy we designed a targeting vector for the mouse proopiomelanocortin (POMC) gene containing a single nucleotide insertion that converts the initial tyrosine codon of beta-endorphin 1-31 to a premature translational termination codon and introduces a unique Hpal endonuclease restriction site. The targeting vector also contains a neo cassette immediately 3' to the last POMC exon and a herpes simplex virus thymidine kinase cassette to allow positive and negative selection. Homologous recombination occurred at a frequency of 1/30 clones of electroporated embryonic stem cells selected in G418 and gancyclovir. 10/11 clones identified initially by a polymerase chain reaction (PCR) strategy had the predicted structure without evidence of concatemer formation by Southern blot analysis. We used a combination of Hpa I digestion of PCR amplified fragments and direct nucleotide sequencing to further confirm that the point mutation was retained in 9/10 clones. The POMC gene was transcriptionally silent in embryonic stem cells and the targeted allele was not activated by the downstream phosphoglycerate kinase-1 promoter that transcribed the neo gene. Under the electroporation conditions used, we have demonstrated that a point mutation can be introduced with high efficiency and precision into the POMC gene using a replacement type vector containing a retained selectable marker without affecting expression of the allele in the embryonic stem cells. A similar strategy may be useful for a wide range of genes.

Primary pure choriocarcinoma of the liver.

We report a pure choriocarcinoma of the liver studied at necropsy. The tumour was diagnosed ante-mortem and treated by chemotherapy with no satisfactory response. Previous cases of hepatic choriocarcinoma are reviewed and criteria to diagnose this extragonadal neoplasm are recommended.