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Background: Prostate cancer (PCa) is the most prevalent solid cancer among men in Western Countries. The clinical behavior of localized PCa is highly variable. Some cancers are aggressive leading to death, while others can even be monitored safely. Hence, there is a high clinical need for precise biomarkers for identification of aggressive disease in addition to established clinical parameters., Objective: To develop an RNA expression-based score for the prediction of PCa prognosis that facilitates clinical decision making., Design, Setting, and Participants: We assessed 233 tissue specimens of PCa patients with long-term follow-up data from fresh-frozen radical prostatectomies (RPs), from formalin-fixed and paraffin-embedded RP specimens and biopsies by transcriptome-wide next-generation sequencing and customized expression microarrays., Outcome Measurements and Statistical Analysis: We applied Cox proportional hazard models to the cohorts from different platforms and specimen types. Evidence from these models was combined by fixed-effect meta-analysis to identify genes predictive of the time to death of disease (DoD). Genes were combined by a weighted median approach into a prognostic score called ProstaTrend and transferred for the prediction of biochemical recurrence (BCR) after RP in an independent cohort of The Cancer Genome Atlas (TCGA)., Results and Limitations: ProstaTrend comprising ∼1400 genes was significantly associated with DoD in the training cohort of PCa patients treated by RP (leave-one-out cross-validation, Cox regression: p=2e-09) and with BCR in the TCGA validation cohort (Cox regression: p=3e-06). The prognostic impact persisted after multivariable Cox regression analysis adjusting for Gleason grading group (GG) ≥3 and resection status (p=0.001; DoD, training cohort) and for GG≥3, pathological stage ≥T3, and resection state (p=0.037; BCR, validation cohort)., Conclusions: ProstaTrend is a transcriptome-based score that predicts DoD and BCR in cohorts of PCa patients treated with RP., Patient Summary: ProstaTrend provides molecular patient risk stratification after radical prostatectomy., (Copyright © 2020. Published by Elsevier B.V.)

Objectives: To investigate the expression profile of miR-1258 and heparanase (HPSE) in breast cancer and to assess their clinicopathological significance., Design and Methods: The expression levels of miR-1258 and HPSE were analyzed in normal, benign and malignant breast tissues. Their serum levels were evaluated in healthy women and in patients with benign and malignant breast disease. We studied the correlation between the expression of miR-1258 and HPSE and the clinical features presented by the patients., Results: MiR-1258 was down-regulated and HPSE was up-regulated in breast cancer, with a significant inverse correlation. A reduced miR-1258 expression and an elevated HPSE expression were associated with the lymph node status, late clinical stages, a short overall survival and a short relapse-free survival. In frozen fresh tissue samples, the miR-1258 levels in breast cancer with lymph node metastasis were significantly lower than that of breast cancer without lymph node metastasis and benign disease (BD). In contrast, the HPSE levels in breast cancer with lymph node metastasis were the highest. In serum samples, the miR-1258 levels in metastatic breast cancer (M1) were lower than that of primary breast cancer (M0) and BD. However, serum HPSE levels of M1 patients were significantly higher than that of M0 patients and BD patients., Conclusions: MiR-1258 may play an important role in breast cancer development and progression by regulating the expression of HPSE, and they might be potential prognostic biomarkers for breast cancer., (Copyright © 2013 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

B-acute lymphoblastic leukemia (ALL) is the most common hematologic tumor of pediatric age. Although patient survival has been improved, some cases still relapse and need alternative therapies. In this context, the role of microRNA in cancer is actually matter of investigation due to their regulatory function implicated in human tumorigenesis since the main target mRNA transcripts are involved in proliferation, apoptosis and differentiation. On the other hand, cytokines are actually used as adjuvants in B-ALL therapy, and recent studies reported that they may also function by acting directly against leukemic cells. Here we review the current knowledge about the role of miRNA and cytokines in B-ALL, highlighting the link between cytokine activity and miRNA expression. The translational relevance of these issues will be also discussed., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objectives: To elucidate the mechanism of transforming growth factor (TGF)-β1 overexpression in prostate cancer cells., Methods: Malignant (PC3, DU145) and benign (RWPE1, BPH1) prostate epithelial cells were used. Phosphatase activity was measured using a commercial kit. Recruitment of the regulatory subunit, Bα, of protein phosphatase 2A (PP2A-Bα) by TGF-β type I receptor (TβRI) was monitored by coimmunoprecipitation. Blockade of TGF-β1 signaling in cells was accomplished either by using TGF-β-neutralizing monoclonal antibody or by transduction of a dominant negative TGF-β type II receptor retroviral vector., Results: Basal levels of TGF-β1 in malignant cells were significantly higher than those in benign cells. Blockade of TGF-β signaling resulted in a significant decrease in TGF-β1 expression in malignant cells, but not in benign cells. Upon TGF-β1 treatment (10 ng/mL), TGF-β1 expression was increased in malignant cells, but not in benign cells. This differential TGF-β1 auto-induction between benign and malignant cells correlated with differential activation of extracellular signal-regulated kinase (ERK). Following TGF-β1 treatment, the activity of serine/threonine phosphatase and recruitment of PP2A-Bα by TβRI increased in benign cells, but not in malignant cells. Inhibition of PP2A in benign cells resulted in an increase in ERK activation and in TGF-β1 auto-induction after TGF-β1 (10 ng/mL) treatment., Conclusions: These results suggest that TGF-β1 overexpression in malignant cells is caused, at least in part, by a runaway of TGF-β1 auto-induction through ERK activation because of a defective recruitment of PP2A-Bα by TβRI., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Certain lactone-containing secondary plant metabolites display potent biological effects, including anti-tumor activities. This is of particular interest as these compounds appear effective against hormone-dependent cancers, such as those of breast and prostate, of which the incidence is on the rise. The mechanisms of anti-tumor action of these compounds are largely unknown. Thirteen synthetic lactone derivatives were evaluated for effects on aromatase activity and mRNA expression in H295R human adrenocortical carcinoma cells. Aromatase (CYP19) is a key enzyme in the synthesis of estrogens from androgens. Over-expression has been associated with increased risk of developing estrogen-dependent mammary tumors, and aromatase inhibitors are effective in their treatment. The androgen receptor is implicated in mediating hormone-dependent prostate tumor growth, and androgen antagonists are effective in the treatment of these cancers. Thus the (anti)androgenic effects of the lactones were also assessed in LNCaP human prostate cancer cells transfected with human androgen receptor and an androgen receptor-responsive luciferase reporter gene. Cells were exposed to lactones (0.1-100 microM) dissolved in dimethyl sulfoxide (0.1% in medium) for 24 h prior to measurement of aromatase activity using a tritiated water-release assay. Three (competitive) inhibitors of aromatase activity were identified (potencies in decreasing order): 3-(3,4-dimethoxy-phenyl)-4-(4-methoxy-phenyl)-5H-furan-2-one (CRI-7; IC(50)=1 microM; K(i)=1.0 microM), 3,4-bis-(3,4-dimethoxy-phenyl)-5H-furan-2-one (CRI-8; IC(50)=2 microM; K(i)=1.2 microM) and 3-(3,4-dimethoxy-phenyl)-4-(3,4,5-trimethoxy-phenyl)-5H-furan-2-one (CRI-9; IC(50)=3 microM; K(i)=6.8 microM). Several concentration-dependent inducers of aromatase (>2fold) were also identified (CRI-1, CRI-4 or Vioxx, CRI-11 and CRI-13). These lactones also induced pII promoter-specific CYP19 transcripts. In transfected LNCaP cells, the three aromatase inhibitors CRI-7, 8 and 9 demonstrated concentration-dependent anti-androgenicity above 0.1 microM in the presence of either 0.1 nM of dihydrotestosterone or the synthetic androgen R1881. The other lactones showed no consistent pro- or anti-androgenic effects in these LNCaP cells. Lactone moiety-containing molecules may form the structural basis for the development of potent drugs effective against hormone-dependent cancers.

Gangliogliomas (GG) constitute the most frequent tumor entity in young patients undergoing surgery for intractable epilepsy. The histological composition of GG, with the presence of dysplastic neurons, corroborates their maldevelopmental origin. However, their histogenesis, the pathogenetic relationship with other developmental lesions, and the molecular alterations underlying the epileptogenicity of these tumors remain largely unknown. We performed gene expression analysis using the Affymetrix Gene Chip System (U133 plus 2.0 array). We used GENMAPP and the Gene Ontology database to identify global trends in gene expression data. Our analysis has identified various interesting genes and processes that are differentially expressed in GG when compared with normal tissue. The immune and inflammatory responses were the most prominent processes expressed in GG. Several genes involved in the complement pathway displayed a high level of expression compared with control expression levels. Higher expression was also observed for genes involved in cell adhesion, extracellular matrix and proliferation processes. We observed differential expression of genes as cyclin D1 and cyclin-dependent kinases, essential for neuronal cell cycle regulation and differentiation. Synaptic transmission, including GABA receptor signaling was an under-expressed process compared with control tissue. These data provide some suggestions for the molecular pathogenesis of GG. Furthermore, they indicate possible targets that may be investigated in order to dissect the mechanisms of epileptogenesis and possibly counteract the epileptogenic process in these developmental lesions.

Genome-wide oligonucleotide DNA microarrays and real time RT-PCR were used to assess differential gene expression in rat glioma and hepatoma cell lines after exposure to the aryl hydrocarbon receptor (AhR) agonist 3,3',4,4',5-pentachlorobiphenyl (penta-CB). Under maximal inducing concentrations for cytochrome P450 1A1 (CYP1A1) in H4IIE rat hepatoma cells, both H4IIE and C6 rat glioma cells were exposed to sub-micromolar concentrations of penta-CB for 24h. Differential gene expression for approximately 28,000 gene probes were computationally analyzed and compared. As expected, penta-CB potently activated CYP1A1/2 transcription in liver-derived H4IIE hepatoma cells yet did not do so in brain-derived C6 glioma cells. Additionally, we show that penta-CB causes: (1) distinct patterns of gene expression between tumor cells derived from liver or brain; (2) robust transcriptional activation of select C6 glioma gene ontologies; (3) over-expression of H4IIE hepatoma genes associated with tumor progression in liver; (4) greater than 100-fold over-expression of C6 glioma genes associated with protein processing and programmed cell death and/or metastasis; (5) tissue-selective histone deacetylase inhibition in C6 glioma, but not H4IIE hepatoma cells as signaled by galectin-1 over-expression.

Objectives: The individual recurrence-free period after primary surgery of patients with Ta urothelial cell carcinoma (UCC) cannot be predicted accurately. This study aims at discriminating between patients with primary Ta UCC and long or short recurrence-free periods., Methods: We investigated mRNA expression of 23 genes in 44 primary Ta tumours (23 and 21 tumours were from patients with long [>or=4 yr] or short [

Developmental exposure to methylmercury (MeHg) induces a spectrum of neurological impairment characterized by cognitive disturbance, sensory/motor deficit, and diffuse structural abnormalities of the brain. These alterations may arise from neural path-finding errors during brain development, resulting from disturbances in the function of morphoregulatory guidance molecules. The Eph family of tyrosine kinase receptors and their ligands, the ephrins, guide neuronal migration and neurite pathfinding mainly via repulsive intercellular interactions. The present study examined the effects of MeHg on mRNA and protein expression profiles of Ephs and ephrins in the P19 embryonal carcinoma (EC) cell line and its neuronal derivatives. Undifferentiated control P19 cells displayed low- to undetectable levels of mRNA for ephrins or Ephs, with the sole exception of EphA2 which was highly expressed. Upon differentiation into neurons, the ephrin expression increased progressively through day 10. Similarly, expression of the Ephs, including EphsA3, -A4, -A8, -B2, -B3, -B4, and -B6, increased significantly. In contrast, EphA2 expression decreased in day 2, 6 and 10 control neurons. Treatment with MeHg did not affect the expression of mRNA for ephrins or Ephs in undifferentiated P19 cells. However, treatment of differentiating neurons with MeHg for 24 h caused consistent increases in ligand mRNA expression, particularly ephrin-A5, -A6, -B1, and -B2. Similarly, MeHg induced variable increases in mRNA expression of receptors EphA2, -A3, -B3, and -B6. A trend toward a concentration-response relationship was observed for the alterations in Eph receptor mRNA expression although increases at the low and mid concentrations did not reach statistical significance. Immunoblots for ligand and receptor proteins mirrored the increases in the mRNA levels at the 0.5 and 1.5 microM MeHg concentrations but showed decreased protein levels compared to controls at the 3.0 microM concentration. Alterations in the Eph/ephrin family of repulsion molecules may represent an important mechanism in developmental MeHg neurotoxicity.

Objectives: To determine whether nucleophosmin/B23 mRNA expression in bladder carcinoma predicts recurrence, progression, and survival., Methods: Real-time reverse transcriptase-polymerase chain reaction was performed on 50 fresh cancer specimens. The change in the cycle of threshold (Ct)was the difference in the Ct values derived from the nucleophosmin/B23 gene assayed and the 18S ribosomal RNA control [Ct (18S)-Ct (nucleophosmin/B23)]., Results: Fifty patients diagnosed with bladder cancer were followed up postoperatively for a median of 24 months. Overexpression of nucleophosmin/B23 mRNA was observed in 37.1% of patients with Stage pT1 and 73.3% of those with pT2-T4 disease. Nucleophosmin/B23 overexpression was not associated with tumor grade (P = 0.163) but was associated with bladder cancer recurrence (68.2%) and progression (88.9%) when adjusted for the effects of clinical stage. Multivariate analysis revealed that the overall tumor stage and nucleophosmin/B23 mRNA overexpression were important prognostic indicators for bladder carcinoma (P <0.05). Patients with nucleophosmin/B23 mRNA overexpression were at a significantly greater risk of disease recurrence and progression than those with low expression of nucleophosmin/B23 mRNA., Conclusions: Overexpression of nucleophosmin/B23 mRNA was independently associated with bladder cancer recurrence and progression. In patients with muscular invasion disease, overexpression of nucleophosmin/B23 mRNA was associated with the greatest risk of recurrence and progression, suggesting a potential rationale for early definitive therapy in these patients.

Objectives: The Fas-Fas ligand system is an important regulator of apoptosis and is involved in tumor development. Invasive cancers downregulate Fas expression to evade antitumor immune responses. Fas is a transcriptional target of p53, which is often mutated in bladder cancers. Therefore, Fas expression and its relation to p53 mutation was investigated., Methods: Expression of Fas protein and p53 status was studied by immunohistochemistry in 83 bladder cancer specimens. In addition, mRNA levels for soluble (decoy) and membrane-bound forms of Fas were compared between 10 bladder cancer cell lines and primary uroepithelial cells by quantitative TaqMan polymerase chain reaction. Mutational analysis of the death domain of the Fas gene was performed in all cell lines., Results: Organ-confined tumors maintained specific Fas staining at the cell membrane and often also in the cytoplasm. In higher stage carcinomas, Fas expression became restricted to a smaller fraction of cells or was lacking entirely. The correlation of Fas staining with tumor stage was highly significant but no correlation to tumor grade or survival was found. Furthermore, no statistically significant relationship was observed with either the presence or lack of mutated p53 accumulation. Membrane-bound Fas mRNA was decreased in most, and soluble Fas was increased in all transitional cell carcinoma lines compared with primary uroepithelial cells. No mutations in the death domain were detected., Conclusions: Fas downregulation occurring in advanced bladder cancer is unrelated to p53 mutations. The results of immunohistochemistry and mRNA studies of soluble and membrane-bound Fas in transitional cell carcinoma lines support the hypothesis of immune evasion in advanced bladder cancer.

Objectives: To explore the expression patterns and possible involvement of leptin and its receptor in the pathogenesis of urinary bladder cancer, with a focus on transitional cell carcinoma., Methods: Using reverse transcription-polymerase chain reaction, immunoblotting, and immunohistochemistry techniques, we correlated the expression patterns of leptin and its receptor with the occurrence of transitional cell carcinoma. We also applied transient transfection followed by BrdU labeling and immunofluorescent staining to address the effect of the leptin receptor on bladder cancer cell growth., Results: Although leptin was not detected in the bladder tissue specimens, a decreased expression of the leptin receptor was observed in most cancer tissue specimens we analyzed. Furthermore, the forced expression of the leptin receptor in T24 bladder cancer cells prevented them from entering the S phase., Conclusions: Our data demonstrated for the first time that the leptin receptor is aberrantly expressed in bladder cancer tissue and is possibly involved in the carcinogenesis of bladder cancer.

Objectives: To determine quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) detection of luteinizing hormone-releasing hormone (LHRH) receptor mRNA expressing prostate cancer (CaP) and benign prostatic hyperplasia (BPH) tissue by sequence-specific detection with hybridization probes using the LightCycler. Various in vitro studies have indicated that LHRH agonists and antagonists may have a direct inhibitory effect on CaP mediated by specific LHRH receptors. The incidence of LHRH receptor mRNA expression was demonstrated in 50% to 100% of clinical CaP and BPH tissue by current RT-PCR methods. However, qualitative RT-PCR can only demonstrate the existence of a gene; an exact quantification of LHRH-receptor mRNA expression has not yet been done., Methods: Quantitative real-time RT-PCR for LHRH receptor mRNA was performed using the LightCycler system and the RNA Amplification Kit hybridization probes in 35 patients with CaP and 38 patients with BPH., Results: Thirty-one (88.6%) of the 35 patients with CaP and 36 (94.7%) of the 38 patients with BPH had positive RT-PCR for LHRH receptor mRNA. The number of positive amplifications per 1 microg total RNA was not significantly lower in CaP at 695,428 +/- 350,860 than in BPH at 1,617,654 +/- 787,874. Patients with CaP evidenced a significant negative correlation between the amplification rate for LHRH receptor mRNA and Gleason score (r = -0.476; P = 0.004)., Conclusions: In the past, the potential mechanisms acting on LHRH receptors in CaP have been identified as possible antitumor strategies for this type of cancer. Our study is the first to show that CaP does not have a higher expression of LHRH receptor mRNA expression than BPH when using quantitative sequence-specific oligonucleotide hybridization probes that only detect certain PCR products.

The in vitro effect of bestatin on Philadelphia (Ph) chromosome positive chronic myeloid leukemia (CML) was investigated using mature clonogenic cells and primitive stem cells derived from long-term culture-initiating cells (LTC-ICs). Individual colonies were grown in methycellulose culture (clonogenic cells) and after 5 weeks, LTC (colonies derived from LTC-ICs) were individually isolated. DNA isolated from these clonogenic colonies was studied by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis to detect BCR/ABL mRNA transcripts b3a2 and b2a2. At the mature hematopoietic progenitor cell level, almost all (20/21) colonies, including both erythroid and myeloid progenitors, were leukemic, i.e. BCR/ABL mRNA positive. Although normal progenitors were able to grow in the presence of bestatin, even at the most primitive progenitor cell level (LTC-ICs), the number of leukemic clones gradually decreased. Furthermore, bestatin suppressed the outgrowth of leukemic clones more frequently than control LTC without any effect on the growth of normal clones. These results indicate that bestatin, at levels that can be obtained by per os administration clinically, suppresses only Ph-positive leukemic clones without affecting normal hematopoiesis. Based on these results, we suggest that bestatin has the potential to provide another treatment for patients with CML.

The dietary isothiocyanates and cancer chemopreventive agents phenethyl isothiocyanate and allyl isothiocyanate and their cysteine conjugates inhibited the growth and induced apoptosis of human leukaemia HL60 (p53-) and human myeloblastic leukaemia-1 cells (p53+) in vitro. The median growth inhibitory concentration (GC(50)) values were in the range 1.49-3.22 microM in cultures with 10% serum. Isothiocyanates and cysteine conjugates had increased potency against HL60 cells in serum-free medium, with GC(50) values of 0.8-0. 9 microM. The potency of the compounds decreased with increased serum content of the medium, but that of the cysteine conjugates decreased more markedly. Growth inhibition and toxicity was characterised by either a rapid interaction of the isothiocyanate with the cells in the first hour of culture or exposure to isothiocyanate liberated from the cysteine conjugate in the initial 3 hr of culture, inhibition of macromolecule synthesis, and a commitment to apoptosis which developed in the initial 24 hr. Activities of caspase-3 and caspase-8 were increased during isothiocyanate-induced apoptosis, but caspase-1 activity was not. The general caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone and the specific caspase-8 inhibitor N-benzyloxycarbonyl-Ile-Glu(OMe)-Thr-Asp(OMe)-fluoromethylketone inhibited apoptosis, but specific caspase-1 and caspase-3 inhibitors did not. The antiproliferative activities were limited by hydrolysis of the isothiocyanate. This suggests that caspase-8 has a critical role, and caspase-3 a supporting role, in isothiocyanate-induced apoptosis in which p53 is not an obligatory participant. Isothiocyanate-induced apoptosis may suppress the growth of preclinical tumours and contribute to the well-established decreased cancer incidence associated with a vegetable-rich diet.

Immunoregulatory cytokines may regulate the resistance or susceptibility of a host to retroviral infection. These cytokines may be therapeutically modulated to prevent or limit the progression of infection. The non-progression to AIDS of some HIV+ patients has been related to a strong type 1 cytokine response (IL-2, IL-12, and IFNgamma). For this reason, we investigated the ability of combination therapeutics to modulate cytokines in vivo towards a type 1 cytokine response in a murine retroviral infection using Friend leukemia virus (FLV). BALB/c mice were infected with FLV and treated with either 3'-azido-3'-deoxythymidine (AZT), the immunomodulator methionine enkephalin (MENK), or a combination of both AZT and MENK starting 3 d post infection. Splenocytes were harvested on days 1, 3, 7, 14, 21 and 28 post treatment initiation and cultured with 1 microg/ml concanavalin A (ConA) for 24 h. Supernatants were examined for IL-2, IL-4, IL-10, IL-12, and IFNgamma cytokine production using cytokine specific ELISAs. The levels of type 2 cytokines were not significantly changed by any treatment group over the course of the disease. However, although decreased in all infected animals, type 1 cytokines were partially maintained by the combination treatment through day 21. RT-PCR for cytokine specific mRNA confirmed these results, with expression of the type 1 cytokines, especially IFNgamma, being maintained through day 21. Establishment of a treatment regime that can maintain protective cytokine activities against disease progression may prove applicable to other retroviral infections.

The mechanism of action of the novel tetrazepinone 8-nitro-3-methyl-benzo-1,2,3,5-tetrazepin-4(3H)-one (NIME), structurally related to the antitumour drug temozolomide, was studied in the human ovarian tumour cell line OVCAR-3. NIME preferentially inhibited DNA synthesis over protein and RNA syntheses at 3 and 24 hr post-treatment. A Maxam-Gilbert sequencing assay showed that NIME induced barely detectable levels of guanine N7 alkylation in an isolated DNA strand, in contrast to temozolomide, a strong alkylating agent containing, like NIME, a cyclic 3-methyl-1,2,3-triazene moiety. Alkaline sucrose density-gradient sedimentation, at concentrations 2- to 10-fold lower than the ones used in the DNA sequencing assay, showed significant DNA damage in OVCAR-3 cells 24 hr after treatment with NIME. This was accompanied by a significant accumulation of cells in late S and G2M. Cell cycle arrest was transient and was reversed after 2-3 days following drug treatment. This was in agreement with bivariate bromodeoxyuridine/propidium iodide analysis, which showed that at 100 microM, a concentration at which the majority of the cells arrested in late S and G2M, a significant fraction of bromodeoxyuridine positive (S-phase) cells escaped the block. In an attempt to elucidate the mechanism underlying these effects, the degradation of NIME in cell culture medium was analyzed by GC-MS (gas chromatography coupled with mass spectrometry). The results showed that, in contrast to temozolomide, NIME did not convert to an open-chain alkyltriazene in cell culture medium, but to a major benzimidazole product, which exerted a minor effect on the cell cycle. This suggests that NIME, despite containing a 3-(alkyl)-1,2,3-triazene moiety, does not act by DNA alkylation but probably by generating a short-lived genotoxic species during its degradation to 6,5-benzofused derivatives.

Mutations in the presenilin-1 gene are linked to the majority of early-onset familial Alzheimer's disease cases. We have previously shown that the expression of transforming growth factor-beta is altered in Alzheimer's patients, compared to controls. Here we examine presenilin- expression in human post-mitotic neurons (hNT cells), normal human astrocytes, and human brain tumor cell lines following treatment with three isoforms of transforming growth factor-beta, or glial cell line-derived neurotrophic factor, a member of the transforming growth factor-beta superfamily. As the NT2/D1 teratocarcinoma cell line is treated with retinoic acid to induce differentiation to hNT cells, presenilin-1 messenger RNA expression is dramatically increased. Furthermore, there is a 2-3-fold increase in presenilin-1 messenger RNA expression following treatment of hNT cells with growth factors and similar results are found by Western blotting and with immunohistochemical staining for presenilin-1 protein. However, treatment of normal human astrocytes with cytokines results in minimal changes in presenilin-1 messenger RNA and protein. Interestingly, the expression of presenilin-1 in human U87 MG astrocytoma and human SK-N-SH neuroblastoma cells is only increased when cells are treated with glial cell line-derived neurotrophic factor or transforming growth factor-beta3. These findings suggest that endogenous presenilin-1 gene expression in human neurons can be induced by growth factors present in normal and diseased brain tissue. Cytokines may play a major role in regulating expression of presenilin-1 which may affect its biological actions in physiological and pathological conditions.

The calcium ionophore, ionomycin, promotes an increase of intracellular calcium and regulates mRNA expression of gamma/delta-TcR gene in human T lymphocytes. The mechanism of this regulation is not yet clear. Thus, the regulation by intracellular calcium requires elucidation. We studied the gamma-TcR gene expression in acute lymphoblastic leukemia cell line DND41 (CD4- CD8-) by Northern blot and flow cytometric analysis. The mRNA levels of gamma-TcR increased by ionomycin, anti-CD3, and with TPA. TPA had an antagonistic effect to both ionomycin and anti-CD3. Also, TPA inhibits the increased intracellular calcium promoted by ionomycin but not the increase promoted by anti-CD3 and ionomycin. Our results suggest that intracellular calcium induces mRNA and protein expression of gamma-TcR chain. This effect is antagonized by protein kinase C-activation. Thus, we conclude that the target cells of the differential regulation on gamma-TcR mRNA expression by intracellular calcium modulators are the CD4- CD8- cells, and this is due to cytosolic calcium mobilization.

Two groups of S-[2-(N,N-dialkylamino)ethyl]isothiourea derivates which depigmented melanoma cells either with inhibition of tyrosinase (group 1, R = methyl, isopropyl) or without inhibition of tyrosinase (group 2, R = benzyl, phenyl) were studied. Treatment of human melanoma cells with non-lethal doses of group 1 drugs led to a reduction in the levels of mRNA for the pigmentation genes tyrosinase, tyrosinase-related protein-1 and Pmel 17. The group 1 drug S-[2-N,N-diisopropylamino)ethyl[isothiourea] (DINOR) (R = isopropyl) produced only moderate inhibition of DNA, RNA and protein synthesis in three cell lines during the first 24 hr of treatment, and there was no correlation between the extent of inhibition and long-term toxicity. A group 2 drug (R = benzyl) rapidly inhibited DNA synthesis in an amelanotic melanoma cell line (MM96E) sensitive to killing by the drug; association of the latter with inhibition of RNA or protein synthesis was less clear. MM96E cells were also sensitive to killing by reactive oxygen species. In pigmented melanoma cells (MM418), incorporation of [125I]thiouracil, a false precursor of melanin, increased during the first 24 hr of treatment with DINOR whereas a group 2 drug (R = phenyl) inhibited incorporation of [125I]thiouracil. Cells depigmented by treatment with drugs from either group suffered the same amount of DNA damage as pigmented cells after UVB irradiation, as judged by inhibition of DNA synthesis, but did not recover as well as pigmented cells, whether or not drug was present during recovery. The results suggested that (1) group 1 agents down-regulated message for several pigmentation genes, possibly at the transcriptional level; (2) the toxicity of group 2 drugs was related to reactive oxygen species; and (3) melanin protected cells from UVB by enhancing cellular recovery.

Rat basophilic leukemia (RBL) cells are considered to be similar to bone-marrow derived mast cells and to mucosal mast cells (MMC), the latter of which may be involved in inflammatory bowel diseases. RBL cells are not able to accumulate histamine and secretory granules under regular growing conditions. Here we show that the flavonoid quercetin, which inhibits mast cell secretion of histamine, also inhibited RBL cell proliferation and constitutive histamine release while it induced synthesis of rat mast cell protease (RMCP) II and triggered processes leading to accumulation of secretory granules. Cell viability was also retained in the presence of quercetin, whereas untreated cells did not survive past 6 days of growth. Quercetin did not affect the expression of mRNA for alpha-subunit of immunoglobulin E (IgE) receptor, but led to increased expression of mRNA for, and synthesis of RMCP II, which is a marker protein for MMC. Many of these granules showed metachromasia with toluidine blue after 3 days of growth, stained red with alcian blue counterstained with safranin after 8 days of growth, and contained electron dense material. Our results suggest that RBL cells have the capacity to progress to a more mature state and may lend themselves to further analysis of a growth regulator(s) with action similar to that of quercetin.

1. Twenty-two sea anemone samples from seven species were collected in Aleutian and Comandorskiye Islands from sub-littoral region (> 50m depth). 2. Water-ethanol extracts of sea anemones were tested using various test-systems after ethanol evaporation. 3. All sea anemones extracts inhibited DNA and most of them inhibited RNA synthesis in Ehrlich carcinoma tumor cells. 4. Extracts of most sea anemones species showed high hemolytic activity. 5. The extracts proved to be nontoxic or display low toxicity being i.p. injected into mice. 6. Some extracts precipitated virus of aleutian disease of mink. 7. None of the extracts showed activity toward Gram +ve, Gram -ve bacteria or yeast.

Gemcitabine (dFdC) is a new cytidine analogue which is active mainly by the incorporation of its triphosphate (dFdCTP) into DNA, leading to cell death. We determined incorporation of dFdC into nucleic acids of two solid tumour cell lines: the murine colon carcinoma cell line Colon 26-10, the human ovarian carcinoma cell line A2780, and the human leukemic cell line CCRF-CEM. dFdC was not only incorporated into DNA, but also into RNA. The extent of incorporation into DNA was highest in A2780 cells and lowest in CCRF-CEM cells (2-4-fold difference). The same pattern was observed for incorporation into RNA, but with a 10-20-fold difference. In A2780, incorporation into DNA was about twice that of the incorporation into RNA, in CEM cells 10-20-fold that of RNA. Incorporation into RNA was verified using two methods for separation of RNA and DNA, acid precipitation and CsCl-gradient centrifugation. Incorporation into DNA was time and concentration dependent, but incorporation into RNA seemed to be only concentration dependent. We also determined the effect of dFdC on DNA and RNA synthesis by measurement of thymidine and uridine incorporation, respectively, using similar conditions as for the incorporation studies. In all three cell lines DNA synthesis was inhibited almost completely, even at 0.1 microM dFdC and at 4-hr exposure. RNA synthesis inhibition did not exceed 50% in both solid tumour cell lines, even at 1 microM dFdC exposure for 24 hr. A clear concentration effect was only observed in the CCRF-CEM cell line and only after 24 hr exposure. At a 1 microM dFdC exposure for 24 hr, RNA synthesis was completely inhibited in these cells. Incorporation of dFdC into RNA and inhibition of RNA synthesis represent an unrecognized but possibly important mechanism of action of this drug.

The role of basic fibroblast growth factor (bFGF) in the control of teratoma cell proliferation was examined. It was found that bFGF stimulates proliferation at low concentrations but induces cell migration at higher doses. These effects could be efficiently counteracted by addition of protamine sulphate. Moreover the bFGF gene is actively transcribed in primary human testicular embryonal carcinomas but was not expressed in any other embryonic tumour examined. The biological implications of these findings will be discussed.

1. In nuclei isolated from cells of the B50 rat neuroblastoma line the stimulatory effect of methyl mercury on alpha-amanitin-sensitive RNA synthesis is very much reduced compared to the stimulatory effect in HeLa nuclei (see: Frenkel G. D. and Randles K. (1982) Specific stimulation of alpha-amanitin-sensitive RNA synthesis in isolated HeLa nuclei by methyl mercury. J. biol. Chem. 257, 6275-6279). 2. The stimulatory effect of another mercury compound, p-hydroxymercuribenzoate, was also much less pronounced in the B50 nuclei. 3. Similar results were obtained with nuclei isolated from B50 cells which had been induced to differentiate by exposure to dibutaryl cyclic AMP. 4. Nuclei isolated from cells of another rat neuroblastoma line (B35), and nuclei from cells of a human neuroblastoma line both exhibited levels of stimulation similar to that of HeLa nuclei. 5. The B50 and HeLa cells were also compared as to their sensitivity to other effects of methyl mercury.

Two human melanoma cell lines, MM96 and MM127, were found to be highly sensitive to the toxicity of adenosine (D50 100-150 micrograms/ml) compared with other melanoma lines. HeLa cells and a lymphoblastoid line (D50 greater than 500 micrograms/ml). The MM127 line was also sensitive to NAD (D50 41 micrograms/ml) compared with the other lines (D50 greater than 400 micrograms/ml), and accumulated three-fold more NAD-derived isotopic label. Nicotinamide exhibited little toxicity in any cell type (D50 greater than 400 micrograms/ml); 25-100 micrograms/ml nicotinamide greatly increased the plating efficiency of melanoma cells and fibroblasts when low levels of foetal calf serum were used. The toxicity of DNA-damaging agents (alkylating agents and u.v.) in melanoma cells was not reduced in the presence of NAD, adenosine or nicotinamide. Studies of the effects of the latter compounds upon the incorporation of deoxynucleosides showed that: (a) melanoma cells have lower purine pools than fibroblasts; (b) [3H]deoxyguanosine incorporation was inhibited more than [3H]deoxyadenosine incorporation; (c) incorporation of [3H]deoxyadenosine and [3H]deoxyguanosine into RNA was inhibited by adenosine, thus providing a method for determination of guanine-specific DNA repair; and (d) NAD enhanced thymidine incorporation in intact melanoma cells but not in fibroblasts, in a pattern similar to the release from template restriction previously reported for permeabilised tumour cells.

In an in vitro study conducted without the use of adenosine/deoxyadenosine deaminase inhibitors, two human melanoma cell lines, MM96L and MM127, were found to be highly sensitive to killing by continuous treatment with deoxyadenosine (dAdo) (D37 47 microM and 68 microM respectively) compared with fibroblasts (D37 440 microM), Hela cells (D37 1.1 mM) and other melanoma cell lines (D37 0.8 to 2.5 mM). Cross-sensitivity was found to deoxyinosine (dIno) and in part to adenosine but not to related metabolites such as inosine or hypoxanthine. Hypersensitivity to dAdo was associated with deficiency in cell membrane 5'-deoxynucleotidase but not in deaminase activity. dAdo toxicity could be prevented in MM96L by addition of the other three deoxynucleosides together but not by removing dAdo after a brief (2 hr) treatment. Resistant melanoma cells, however, required more than 24 hr dAdo treatment to produce toxicity. DNA synthesis in MM96L cells was reversibly inhibited, and cells tended to accumulate in G1/S. No DNA strand breaks were detected. These results showed that in contrast to the resistant cell line, asynchronous MM96L cells are highly sensitivity to brief treatment, toxicity resulting from an effect associated with inhibition of DNA synthesis. dAdo and dIno, either combined with a deaminase inhibitor or as deaminase-resistant derivatives, may have a favourable therapeutic index for some melanomas in vivo.

The cytotoxic activity of natural killer cells is markedly increased by interferon (IFN) and IFN inducers. Auranofin, an oral gold preparation, has an effect similar in size and rapidity to that of IFN but, in contrast, the Auranofin effect does not require RNA synthesis by the effector cells.

-Deazaadenosine (9-DAA), a novel purine analog, was found to be a potent inhibitor of the growth of nine different human solid tumor cell lines in vitro and of pancreatic carcinoma (DAN) in antithymocyte serum (ATS)-immunosuppressed mice. In culture, IC50 values ranged from 1.1 to 8.5 X 10(-8)M. Ovarian carcinoma (MR) was the only cell line in which the activity of 9-DAA was potentiated (about 10-fold) by pretreatment with the adenosine deaminase inhibitor 2'-deoxycoformycin (dCF). After incubation of cultured pancreatic DAN cells with 9-DAA (10(-5)M) for 2 hr, a peak appeared in the triphosphate region of HPLC nucleotide profiles that was identified tentatively as 9-deazaATP. Under the same incubation conditions, the incorporation of [3H]uridine into RNA and of [3H]thymidine into DNA was inhibited by 34 and 80% respectively. In vivo studies using ATS-immunosuppressed mice showed that 9-DAA at 0.4 mg/kg/day for 3 consecutive days reduced pancreatic carcinoma (DAN) tumor weights to approximately 50% of untreated controls. The nucleoside transport inhibitor p-nitrobenzyl-6-thioinosine (NBMPR) was shown to selectively protect host tissues from 9-DAA toxicity and, thereby, potentiated the antitumor activity of 9-DAA in vivo at optimal dosages.

The inhibition of protein synthesis by 8-azaguanine (azaG) in L1210 cells in culture was investigated. AzaG selectively inhibited protein synthesis at concentrations where viability was decreased significantly. AzaG altered the polyribosome sedimentation profile, increasing the numbers of monosomes and smaller polysomes and decreasing the number of larger polysomes. The reversal by cycloheximide of the alterations in the polysome profile suggested that azaG inhibited the initiation of translation. This was confirmed by the demonstration of inhibition of the formation of the 43S and 80S initiation complexes.

The cytocidal and biochemical effects of formycin and 8-azaadenosine in the presence and absence of the adenosine deaminase inhibitor, 2'-deoxycoformycin, were studied in human colon carcinoma (HT-29) cells in culture. Logarithmically growing cells were unaffected by 24-hr exposure to either 10(-6) M formycin or 8-azaadenosine, but 1 to 1.4 log reductions in colony formation were produced by 10(-5) M of each analog. In the presence of 10(-6) M 2'-deoxycoformycin, a 3- and 30-fold potentiation of the cytocidal activity of 8-azaadenosine and formycin, respectively, was produced. Inhibition of DNA synthesis but not RNA synthesis by 8-azaadenosine paralleled its cytocidal activity; however, neither variable correlated closely with the cytotoxic effects of formycin. In addition, the methylation of nuclear RNA was unaffected by both drugs while the methylation of 5-methyl-deoxy-cytidine in DNA was inhibited to a lesser extent than DNA synthesis. Measurements of the incorporation of [3H]formycin and [3H]8-azaadenosine into nuclear RNA and DNA in the presence and absence of 2'-deoxycorformycin indicated that formycin substitution in RNA and DNA was enhanced 10- and 20-fold, respectively, while [3H]8-azaadenosine incorporation into both nucleic acids was increased 6- to 7-fold. These results suggest that the incorporation of formycin into nucleic acids, particularly DNA, correlates closely with its lethal effect on cell viability. On the other hand, the cytocidal activity of 8-azaadenosine more clearly parallels its inhibitory effect on DNA synthesis rather than its substitution into nucleic acids.

The relationship between the structure and activity of aclacinomycin-A (ACM) metabolites was investigated in vitro in Friend leukaemia cells (FLC). The cytotoxic effect was related to the ease with which ACM and its metabolites accumulate in the nucleus. Cellular uptake and nuclear incorporation are influenced by the hexopyranoses linked to aklavinone (AKV) and by the two methyls linked to the L-rhodosamine amino groups. The effect of ACM and its metabolites on macromolecular synthesis depended on the drug concentrations and the exposure time. ACM was the most active in the inhibition of nucleic acid synthesis whereas it had no direct effect on protein synthesis even at high drug concentrations. When cells were treated for a short time with low drug concentrations (1 microM), RNA synthesis was inhibited to a greater extent than DNA synthesis. But when incubated for longer periods, inhibition of DNA synthesis increased further. RNA and DNA syntheses were both inhibited to about the same extent only when cells were exposed to the higher drug concentrations (10 microM). We conclude therefore that at low drug concentrations the effect on DNA synthesis is probably a consequence of RNA synthesis inhibition. The early DNA synthesis inhibition which occurs at higher drug concentrations may result from the direct action on the cellular genome.

The incorporation of 9-beta-D-arabinofuranosyl-2-fluoroadenine (F-ara-A) into HL-60 cellular nucleic acids was monitored by cesium sulfate gradient centrifugation. The results demonstrated that F-ara-A incorporated into both RNA and DNA. These findings are in contrast to those previously obtained with 1-beta-D-arabinofuranosylcytosine (ara-C) and 9-beta-arabinofuranosyladenine (ara-A) which demonstrated incorporation of these nucleosides only in DNA. F-ara-A inhibited HL-60 proliferation, and the incorporation of F-ara-A into both DNA and RNA correlated with loss of clonogenic survival. Furthermore, cytostatic concentrations of F-ara-A resulted in the appearance of a more mature phenotype, a finding consistent with the effects of other inhibitors of DNA synthesis. The incorporation of F-ara-A into RNA and DNA should provide new insights regarding the mechanism of action of this agent.

Prostaglandin D2 was found to be a potent inhibitor of B-16 melanoma cell replication in vitro. The inhibition was dose-dependent between 3x10(-9)M and 3x10(-6)M (IC50 approximately 0.3 microM after 6 days). On a molar basis, PGD2 was a better inhibitor than PGA2 or 16, 16-dimethyl-PGE2-methyl ester (di-M-PGE2) and in higher concentrations (10(-6)-10(-7)M), comparable to retinoic acid. In higher concentrations, PGD2 inhibited DNA, RNA and protein synthesis. The B-16 melanoma cell line which we used synthesized arachidonic acid metabolites which comigrated with PGA2, PGD2, PGE2, and PGF2 alpha on a thin layer chromatography system.

Recent work using isolated DNA polymerase-template complexes has shown that arabinofuranosyl derivatives con slow DNA synthesis by being incorporated into DNA. Our results suggest that these agents act by a similar mechanism in L1210 cells. The results demonstrate that inhibition of cellular DNA synthesis by cytosine arabinoside (ara-C) was significantly related to the extent of ara-C incorporation in DNA over a wide range of drug concentrations and times of exposure. Furthermore, treatment with increasing concentrations of ara-C resulted in a greater proportion of ara-C residues at the 3'-terminus of the elongating DNA chain. These observations suggest that ara-C incorporation results in poor primer termini for further chain elongation.

Various adenosine analogues, i.e. (S)-9-(2,3-dihydroxypropyl)adenine, (RS)-3-adenin-9-yl-2-hydroxypropanoic acid, carbocyclic 3-deazaadenosine and neplanocin A, which have been previously recognized as specific inhibitors of S-adenosyl-L-homocysteine (SAH) hydrolase, gained a marked increase in their cytostatic activity (against tumor cells) and antiviral activity (against vaccinia and vesicular stomatitis virus) in the presence of L-homocysteine (10(-3) M). Homocysteine did not increase the cytostatic or antiviral activity of those compounds (i.e. tubercidin, ribavirin, acyclovir or vidarabine) that do not achieve their biological activity via SAH hydrolase inhibition. The increased antiviral activity following addition of homocysteine was observed only with those viruses (i.e. vaccinia and vesicular stomatitis virus) that belong to the activity spectrum of SAH hydrolase inhibitors [Biochem Pharmacol 36: 2567-2575, 1987], and only in those cells in which the SAH hydrolase inhibitors are normally active. The enhancing effect of homocysteine on the cytostatic and antiviral activity of the SAH hydrolase inhibitors could not be attributed to a non-specific increase in the cytotoxicity of the compounds, as their effects on host cell macromolecule (DNA, RNA, protein) synthesis was not markedly altered in the presence of homocysteine. Most likely, homocysteine exerted its potentiating effect on the activity of the SAH hydrolase inhibitors through an increase in the intracellular levels of SAH, which is known to act as a product inhibitor of S-adenosyl-L-methionine (SAM)-dependent transmethylation reactions.

The effect of the purine antagonist acivicin (AT-125) on the metabolism and cytotoxicity of 6-thioguanine was examined in the murine leukemia L1210. Cells exposed to 5 X 10(-6) M acivicin for 18 hr followed by 10(-5) M [14C]-6-thioguanine for 2 hr accumulated 2.90 +/- 0.17 nmoles 6-thioguanine/10(6) cells compared to 0.69 +/- 0.07 nmoles 6-thioguanine/10(6) cells in untreated controls. Intracellular accumulation of 6-thioguanine monophosphate, a lethal 6-thioguanine metabolite, increased from 0.27 +/- 0.05 to 1.08 +/- 0.13 nmoles 6-thioguanine monophosphate/10(6) cells following the same acivicin exposure. A similar increment was observed for the formation of 6-thioguanine triphosphate. These alterations in 6-thioguanine metabolism were associated with an increase in the intracellular level of 5-phosphoribosyl-1-pyrophosphate, an obligatory substrate in 6-thioguanine activation (57.9 +/- 7.6 vs 13.4 +/- 2.3 ng 5-phosphoribosyl-1-pyrophosphate/10(6) cells). In contrast, there was a 50% reduction in the amount of 6-thioguanine incorporated into RNA and DNA following acivicin pretreatment. Cytofluorometric analysis revealed that an 18-hr exposure to 5 X 10(6) M acivicin increased the population 5-phase cells, which are more sensitive to the actions of 6-thioguanine, by 50% relative to untreated controls. In both suspension culture growth and soft agar studies, the sequential administration of acivicin followed by 6-thioguanine resulted in substantial growth inhibitory activity; in contrast, the effects of the reverse sequence were subadditive. Pretreatment of L1210 cells with acivicin potentiates the action of subsequently administered 6-thioguanine, and the mechanism may involve both biochemical as well as cytokinetic factors. In vivo studies involving the sequential administration of these agents appear warranted.