Notch/Wnt cross-signalling regulates stemness of dental pulp stem cells through expression of neural crest and core pluripotency factors.

Dental pulp stem cells (DPSCs) from adult teeth express neural crest (NC) markers together with core transcriptional factors associated with stem cell pluripotency, such as Oct4a, Sox2, c-Myc, Rex1, Stella/Dppa3, Ssea1/Fut4, Lin28 and Nanog. The possibility to boost the natural stemness features of DPSCs by mild methods, that do not involve gene and/or chromatin modification or gene transfection, is highly desirable for cell therapy. Canonical Wnt and Notch are two highly conserved developmental signalling pathways that are involved in NC emergence and stem cell self-renewal. We determined that both pathways coordinate to regulate the expression of core pluripotency and NC factors in DPSCs. Pharmacological inhibition of the Notch pathway for 48 h, by the γ-secretase inhibitor N-[N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT), abolished the expression of NC and core factors. In addition, it induced a silencing of the canonical Wnt signalling and a clear reduction in the stemness potential of DPSCs, as shown by a reduced ability to generate mature, fully differentiated osteoblasts and adipocytes. Conversely, pharmacological activation of the Wnt pathway for 48 h, by either the glycogen synthase kinase 3 beta (GSK3-ß) inhibitor 6-bromoindirubin-3´-oxime (BIO) or the human recombinant protein Wnt-3a, not only largely increased the expression of NC and core factors, but also increased the efficiency of DPSCs to differentiate into mature osteoblasts and adipocytes. These results showed that a short preconditioning activation of Wnt/Notch signalling by small molecules and/or recombinant proteins enhanced the stemness and potency of DPSCs in culture, which could be useful for optimising the therapeutic use of these and other tissue-specific stem cells.

Circulating tumor cells (CTCs) in metastatic breast cancer (MBC): prognosis, drug resistance and phenotypic characterization.

BACKGROUND: the expression of ATP-binding cassette transporters on circulating tumor cells (CTCs) is predictive of response to chemotherapy in cancer patients. We tested the hypothesis that drug-resistant CTCs might have predictive value in metastatic breast cancer (MBC) and possibly retain stem-like properties. PATIENTS AND METHODS: CTCs obtained from 42 MBC patients were evaluated for multidrug-resistance-related proteins (MRPs), aldehyde dehydrogenase 1 (ALDH1), estrogen receptor α (ERα) and human epidermal growth factor receptor 2 (HER2/neu). Primary objective was to evaluate the prognostic and predictive value of CTCs profile. Secondary end points were the level of concordance in ERα and HER2/neu status between primary tumors and CTCs and the correlation in CTCs between ALDH1, drug resistance profile and number of MRPs. RESULTS: A difference in progression-free survival (PFS) was found between CTCs-positive and CTCs-negative patients. PFS was shorter in patients with a 'drug resistance' CTCs profile and in patients whose CTCs expressed two or more MRPs. No correlation was found between tumor characteristics and ALDH1. ALDH1 correlated to negative ERα and positive HER2/neu status in CTCs. The correlation between the number of MRPs expressed in CTCs and ALDH1 was statistically significant. CONCLUSION: in MBC, the presence of CTCs expressing MRPs and ALDH1 is predictive of response to chemotherapy.

Increased metastatic lymph node 64 and CYP17 expression are associated with high stage prostate cancer.

The metastatic lymph node 64 (MLN64), which is localized in the human chromosome 17, encodes a protein with strong homology with steroidogenic acute regulatory protein. Its overexpression in human breast carcinomas and MLNs led to the hypothesis that this protein could be involved in intraneoplastic steroidogenesis. In the present study, we investigated the expression of MLN64 in prostate cancer, another hormone-dependent tumor, and compared its expression with that of CYP17, the gene encoding for the key enzyme of androgen synthesis. We investigated by RT-PCR the expression of MLN64 and CYP17 in 60 prostatic tumors and compared their expression with the stage of disease and the appearance of relapses in a follow-up of 24 months. We found MLN64 and CYP17 expressed in all samples examined, with significantly higher expression in neoplastic tissues with respect to normal tissues (NTs). Moreover, only in neoplastic but not in NTs, a positive linear correlation was found between MLN64 and CYP17 gene expression. MLN64 and CYP17 expression seems to correlate with high stage, high Gleason score and short relapse-free time. These data, for the first time, demonstrate the presence of MLN64 and CYP17 expression in both normal and neoplastic prostatic tissues. The biological role of MLN64 in human prostate and, particularly, in neoplastic tissue is still unclear. Our findings concerning MLN64 and CYP17 gene expression and their significant positive correlation in human prostate cancer may suggest their possible role in intraneoplastic autonomous steroidogenesis.

Detection of epidermal growth factor receptor mRNA in peripheral blood: a new marker of circulating neoplastic cells in bladder cancer patients.

Despite the large number of studies performed in solid tumors, few attempts at molecular detection of urothelial cells in blood have been made. Specifically, only uroplakin II (UP-II) and cytokeratin 20 (CK-20) have been suggested as tumor markers in the blood of bladder cancer patients. Epidermal growth factor receptor (EGFR) mRNA expression was found in the blood of patients with some types of carcinoma; nevertheless, its expression has been never investigated in the blood of patients with urothelial tumors. We used a EGFR-based reverse transcription-PCR assay for the detection of tumoral cells in the blood of 27 patients with bladder cancer, in 30 healthy donors, and in 9 patients with cystitis. EGFR expression was compared with that of known markers of circulating epithelial cells, CK-19 and CK-20, and to a urothelial-specific marker, UP-II. Analysis by reverse transcription-PCR and Southern blot hybridization showed no evidence of EGFR and UP-II mRNA expression in any of the samples used as controls. Analysis of healthy donors showed mRNA expression for CK-19 and CK-20 in 6 of 30 and in 4 of 30 samples, respectively. All patients with cystitis resulted negative for EGFR expression, whereas 3 of 9, 2 of 9, and 3 of 9 were found expressing CK-19, CK-20, and UP-II, respectively. Among blood samples from tumoral patients, 74% had EGFR mRNA and 41% had positive signals for CK-19, whereas positivity for CK-20 and UP-II was found in 15% and 37% of patients, respectively. These results seem to indicate that EGFR mRNA in the blood may be a useful tumor marker in bladder cancer patients, as well as in other patients with epithelial tumors.

High levels of transforming growth factor-alpha (TGF-alpha) mRNA may predict local relapses in early stage urinary bladder cancer.

Elevated expression of transforming growth factor-alpha (TGF-alpha) gene has been previously reported in some types of human neoplasms, but its role in the pathogenesis of bladder cancer has still not been investigated. In the present study, we analysed 28 samples of early stage bladder tumours for the presence of TGF-alpha mRNA using reverse transcription-polymerase chain reaction (RT-PCR). We detected TGF-alpha mRNA in 71% (20/28) of these samples. When we related the expression levels of TGF-alpha with local relapses of patients during a follow-up of 2 years, we found that a high TGF-alpha expression level in bladder cancer was significantly associated with local relapses in patients with early stage tumours. The appearance of early relapses in tumours with high TGF-alpha expression levels may suggest the existence of an additional marker in the prediction of local relapses in patients with superficial disease.

A rapid and sensitive assay for proviral sequences of a human retrovirus (HTLV) in leukemic cells.

Whole cells of cellular DNA from leukemia patients were used in blot hybridization to cloned probes of a human retrovirus HTLV. The results demonstrated the facility of screening large numbers of samples of limited material for the presence of low copy number of HTLV sequences.

Detection of basic fibroblast growth factor mRNA in urinary bladder cancer: correlation with local relapses.

Natural history of bladder cancer is characterized by high risk of disease progression even for patients with a clinical diagnosis of superficial disease; in these tumors, the occurrence of local relapse is known to be dependent on the angiogenesis rate. Basic fibroblast growth factor (bFGF), has been described to be elevated in urine and serum of patients with bladder cancer. We investigated the expression of bFGF at mRNA level in a panel of 32 transitional cell tumors of the urinary bladder and in normal bladder tissues used as controls. Expression of bFGF was found elevated in most tumors of high stage, where its presence was found correlated with the occurrence of early local relapses. Furthermore, bFGF was found highly expressed in the majority of tumors showing a high bcl-2 expression rate. Our data suggest that bFGF expression could contribute to the progression of disease; it may provide a prognostic indicator in the identification of patients with high risk for occurrence of local relapses.

Involvement of bcl-2 and bax gene expression in apoptosis and differentiation of the non-tumorigenic murine hematopoietic cell line, 32DC13(G).

32DCl3(G) is an interleukin-3 (IL-3) dependent, non-tumorigenic murine hematopoietic cell line which undergoes terminal differentiation into granulocytes when exposed to granulocyte-colony stimulating factor (G-CSF). This line therefore offers a convenient system to study the expression of genes involved in apoptosis and differentiation. In our experiments we have acquired evidence that during the differentiation pathway, likewise in apoptosis induced by IL-3 deprivation, detectable levels of bax mRNA appear, while bcl-2 expression decreases. These events are under the control of the p53 tumor-suppressor gene. In these cells, an overexpression of exogenous wild-type p53 leads to a decrease in bcl-2 mRNA and to the appearance of box mRNA, which instead is absent in the parental cells growing in IL-3 conditioned medium. Furthermore, results from experiments on p53 transfected cells demonstrate that excess wild-type p53 activity, on its own, fails to elicit apoptosis as long as IL-3 is present and does not induce differentiation if G-CSF is not added to the culture medium. We conclude that in apoptosis and differentiation of 32DCl3(G) the alterate ratio of bcl-2 and box gene expression, modulated by p53, is an early event dependent on IL-3 withdrawal and that the appearance of bax and the decrease of bcl-2 expression are necessary, but not sufficient for the acquisition of a completely mature granulocytic phenotype.

Human immunodeficiency virus (HIV) and Epstein-Barr virus (EBV) antigens and genome in lymph nodes of HIV-positive patients affected by persistent generalized lymphadenopathy (PGL).

The presence of human immunodeficiency virus (HIV) and Epstein-Barr virus (EBV) antigens and genome has been investigated in 50 lymph nodes involved by persistent generalized lymphadenopathy (PGL). All the patients were HIV infected and most of them (42 of 50) also had anti-EBV serum antibodies. At lymph node level, HIV and EBV antigens were studied by immunohistochemistry using monoclonal antibodies directed against viral core proteins. The HIV p24 protein was detected in 43 of 50 lymph nodes within the B-cell germinal centers with a reticular pattern. Few cells with positive results for EBV antigens were found in only 2 of 50 lymph nodes. These rare EBV-positive centrocyte-like cells were mainly located in the germinal centers. The presence of HIV and EBV genome was also studied in lymph nodes involved by PGL, with the use of in situ and Southern blot hybridization. A positive reaction for HIV genome was detected in only 1 of 14 lymph nodes with the Southern blot hybridization, and the presence of EBV genome was never demonstrated in these lymph nodes with the use of both in situ and Southern blot hybridization. The expression of EBV antigens and genome was also investigated in the peripheral blood of 15 patients with PGL in which cells with positive results for EBV antigens were detected in a single case with a frequency of 1 X 10(-4). No evidence of EBV genome was found with the use of the in situ hybridization. These results suggest that EBV is not present in lymph nodes during the PGL phase and that its possible implication in the pathogenesis of acquired immune deficiency syndrome (AIDS)-associated lymphoma might be a late event.

Follicle-stimulating hormone, testosterone, and hypoxia differentially regulate UDP-glucuronosyltransferase 1 isoforms expression in rat sertoli and peritubular myoid cells.

Uridine diphosphoglucuronosyltransferases (UGTs) are detoxifying enzymes responsible for the metabolism of endogenous and xenobiotics compounds. UGT isoforms are widely distributed in rat tissues showing a constitutive and inducible gene expression. However, little information is available concerning UGTs expression in testis. The UGT1A1, UGT1A2, and UGT1B1 mRNAs expression in whole rat testis, in Sertoli and peritubular myoid cells in basal conditions, and after hormonal and hypoxic stimulation were investigated by reverse transcriptase-polymerase chain reaction (RT-PCR). Constitutive expression of each UGT1 isoform was present in rat testis with higher levels of UGT1A2. UGT transcripts were also detected in Sertoli and peritubular myoid cells. After FSH stimulation, Sertoli cells showed an increase in UGT1B1 mRNA expression, whereas the levels of UGT1A1 and UGT1A2 resulted unmodified. The main effect induced by testosterone was a decrease of UGT1B1 mRNA expression in peritubular myoid cells, whereas in Sertoli cells an increase in UGT1A1 and UGT1B1 was observed. In hypoxic conditions, a reduction in UGTs mRNA levels was detected in both cell types. These findings suggest that rat UGT1 isoforms are regulated in testis by hormonal and environmental factors. Thus, it was speculated that alterations in UGTs expression and/or activity may be involved in the pathogenesis of testis injury.

Immunoglobulin M specific for measles in serum and cerebrospinal fluid of patients with multiple sclerosis and other neurological diseases.

Serum and cerebrospinal fluid of patients with multiple sclerosis, subacute sclerosing panencephalitis and other neurological disease have been tested by the indirect fluorescent antibody method for immunoglobulin M specific for measles. Only sera of three patients were positive. This feature is of little statistical importance. Nevertheless the authors emphasize the role of a possible viral infection in the pathogenesis of multiple sclerosis.

Clinical and hormonal effects of gonadotropin-releasing hormone agonist plus an oral contraceptive in severely hirsute patients with polycystic ovary disease.

OBJECTIVE: To evaluate the therapeutic effects of a GnRH agonist (GnRH-a), leuprolide acetate (LA) plus a pill containing ethinyl E2 plus cyproterone acetate (CPA) in a group of women with severe hirsutism who were unresponsive to oral contraceptive (OC) therapy. DESIGN: Twenty-four patients suffering from severe hirsutism secondary to polycystic ovary disease (PCOD) were treated for 12 months with 3.75 mg IM LA every 28 days in association with 0.035 mg/d ethinyl E2 plus 2 mg/d CPA (Diane; Schering, Berlin, Germany) for 21 d/mo. SETTING: Patients were recruited in the Institute of Obstetrics and Gynecology, St. Bambino Hospital, University of Catania, Catania, Italy. Hormonal assays were performed in the Hormone Laboratories of St. Bambino Hospital, University of Catania, Catania, Italy. MAIN OUTCOME MEASURES: Every 3 months the hirsutism score was evaluated. Mean serum concentrations of LH, FSH, E2, total and free T, androstenedione (A), sex hormone-binding globulin (SHBG), and DHEAS were determined. Every 6 months a vaginal ultrasound examination was performed. RESULTS: In all patients after 6 and 12 months of treatment with LA plus OC, the hirsutism score improved significantly. Serum levels of LH, FSH, E2, total and free T, A, and DHEAS decreased significantly, whereas SHBG showed a marked increase. A significant reduction in the ovarian size was observed. CONCLUSION: Gonadotropin-releasing hormone agonist, associated with a pill containing CPA, reduced the hirsutism in severely affected women with PCOD who are unresponsive to OC treatment alone.

Treatment of hirsutism with flutamide and a low-dosage oral contraceptive in polycystic ovarian disease patients.

OBJECTIVE: To evaluate the clinical and hormonal response of the antiandrogen flutamide (Eulexin, Schering Plough, Milan, SA, Italy) associated with a low dosage oral contraceptive (OC) in a group of hirsute women who were unresponsive to OC treatment. DESIGN: Twenty-two polycystic ovarian disease (PCOD) patients with hirsutism were treated with flutamide (250 mg twice/d) in association with ethinyl-E2 (0.030 mg/d) plus desogestrel (0.150 mg/d) (Practil 21; Organon, Rome, Italy) for 21 d/mo. SETTING: Patients were recruited in the Institute of Obstetrical and Gynaecological Pathology, St. Bambino Hospital, University of Catania, Italy. Hormonal assays were performed in the Hormone Laboratories of St. Bambino Hospital, University of Catania, Catania, Italy. MAIN OUTCOME MEASURE: Every 2 months the hirsutism score was evaluated using the Ferriman-Gallwey hair density index. Mean plasma concentrations of LH, FSH, E2, total T, dihydrotestosterone (DHT), androstenedione (A), sex hormone-binding globulin, DHEAS were determined. RESULTS: After 8 months treatment with flutamide and low dosage OC, the Ferriman-Gallwey score improved in all patients, mean values decreasing from 25.4 +/- 3.96 to 14.6 +/- 1.92. Plasma levels of total T and E2 were unchanged, whereas LH, FSH, A, and DHT values decreased significantly. Sex hormone-binding globulin levels showed a marked increase. CONCLUSION: Flutamide, associated with low dosage OC, favorably influence the hirsutism in PCOD women who are unresponsive to OC treatment alone.

Amplifications of multiple regions of the HTLV-I genome from DNA of an Italian spastic paraparesis patient but not from DNA of multiple sclerosis patients.

We searched for evidence of infection by the human T-cell lymphoma/leukemia virus type I (HTLV-I) in patients with multiple sclerosis (40 cases); brainstem encephalitis (1 case); Friedreich's ataxia (1 case); spastic paraparesis of unknown etiology (1 case). All patients were from the region of Abruzzo, Italy. Sera were all negative for anti-HTLV-I reactivity by the Western blotting (WB) analysis. DNAs from peripheral blood mononuclear cells were amplified using the polymerase chain reaction (PCR) technique with primers specific for the HTLV-I gag, pol, and env proviral regions. HTLV-I sequences were amplified only in the patient with spastic paraparesis of unknown etiology. In this case, HTLV-I infection might have been related to blood transfusions received 2 years prior to the onset of the neurologic symptoms. Members of the patient's family were negative for HTLV-I by PCR and WB. These data indicate that HTLV-I associated myelopathy is present also in Italy, but fail to substantiate an association of HTLV-I with multiple sclerosis.

Variable levels of bcl-2, bcl-x and bax mRNA in bladder cancer progression.

We investigated the expression of the anti-apoptotic genes bcl-2 and bcl-X and the pro-apoptotic gene bax in bladder tumors and normal samples from urinary bladder, using RT-PCR analysis. Bcl-2 mRNA was not detected in any of the normal samples, while it was found expressed in 66% of the low stage tumors and in 100% of the high stage tumors. Bax expression had an inverse progress, being present in 62% of the normal tissues examined, in 16% of the low stage tumors and in 14% of the high stage. Bcl-X gene expression was quite variable among all samples (37% in normal tissues, 50% in the low stage tumors and 14% in the high stage). bcl-X mRNA was only found in the isoform bcl-XL, with anti-apoptotic functions, whereas no sample expressed the isoform bcl-XS, which is known to suppress bcl-2 functions. Most samples expressing bcl-2 did not express bcl-X, and vice versa. These results, besides confirming the potential role of these genes in the pathogenesis of low stage bladder cancer strengthen the hypothesis concerning their possible interaction in the progression of disease.

Tissue-specific expression of two alternatively spliced isoforms of the human insulin receptor protein.

Two insulin receptor mRNA species are expressed in human tissues as a result of alternative splicing of exon 11. This event is regulated in a tissue-specific manner. To date, there is little information about the relative abundance of the two receptor protein isoforms on the cell surface. The aim of the present investigation was to assess whether the tissue-specific expression of the two insulin receptor mRNA species is paralleled by a similar pattern of expression of the two receptor protein isoforms. To this end, we assessed the relative distribution of the two receptor variants in various human tissues at the mRNA and protein levels. A PCR-based technique was used to measure the relative abundance of the two mRNA species, and two immunological assays were used to measure the relative steady-state expression of the two receptor protein isoforms. The expression of the two insulin receptor protein isoforms followed the tissue-specific pattern of expression of the two mRNA species.

LTB4 as marker of 5-LO inhibitory activity of two new N-omega-ethoxycarbonyl-4-quinolones.

The supposed 5-LO inhibitory activity of two N-omega-ethoxycarbonyl-4-quinolones was tested determining leukotriene B4 (LTB4) in RBL-1 cell cultures, pretreated with the two compounds of interest. LTB4, obtained by solid-phase extraction (SPE) from cell cultures supernatants, was determined by micellar electrokinetic chromatography (MEKC). The analysis was performed using an uncoated capillary, filled with borate buffer at pH 8.3, containing 12.5 mM SDS as micelles generator. Therefore, following the decreasing of LTB4 it was possible to verify the 5-LO inhibitory activity of two quinolone derivatives. To asses the suitability of the use of LTB4 as marker of the activity of the new compounds, the analysis was repeated using quercetin, a well known 5-LO inhibitor.

The quinoline imidoselenocarbamate EI201 blocks the AKT/mTOR pathway and targets cancer stem cells leading to a strong antitumor activity.

Methylimidoselenocarbamates have previously proven to display potent antitumor activities. In the present study we show that these compounds act as multikinase inhibitors. We found that the most effective compound, quinoline imidoselenocarbamate EI201, inhibits the PI3K/AKT/mTOR pathway, which is persistently activated and contributes to malignant progression in various cancers. EI201 blocked the phosphorylation of AKT, mTOR and several of its downstream regulators (p70S6K and 4E-BP1) and ERK1/2 in PC-3, HT-29 and MCF-7 cells in vitro, inducing both autophagy and apoptosis. EI201 also contributes to the loss of maintenance of the selfrenewal and tumorigenic capacity of cancer stem cells (CSCs). 0.1 µmol/L EI201 triggered a reduction in size and number of tumorspheres in PC-3, HT-29 and MCF-7 cells and 4 µmol/L induced the elimination of almost all the tumorspheres in the three studied cell lines. In addition, EI201 suppressed almost 80% prostate tumor growth in vivo (p < 0.01) compared to controls at a relatively low dose (10 mg/kg) in a mouse xenograft model. There was a significant decrease in the subcutaneous primary tumor [18F]-FDG uptake (76.5% reduction, p < 0.05) and in the total tumor burden (76.8% reduction, p < 0.05) after EI201 treatment compared to vehicle control, without causing toxicity in mice. Taken together, our results support further development of EI201 as a novel multi-kinase inhibitor that may be useful against cancers with aberrant upregulation of PI3K/AKT and MAPK signaling pathways.

Tyrosinase expression as a molecular marker for investigating the presence of circulating tumor cells in melanoma patients.

In 1991, Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) was introduced to assess the expression of Tyrosinase in the peripheral blood of melanoma patients, in order to identify the presence of Circulating Melanoma Cells. To date, hundreds of studies, some of which are reviewed here, were performed to assess the clinical value of tyrosinase expression alone, and/or, in addition to other molecular markers. Unfortunately no consensus on the utility of tyrosinase detection exists. In this paper, we underline the presence of too many variables that may interfere with the detection of circulating melanoma cells: from withdrawal and RNA extraction, to Reverse Transcriptase-Polymerase Chain Reaction and the assays used for the analysis of amplification products.