M J Carmena

University of Alcalá, Cómpluto, Madrid, Spain

Are you M J Carmena?

Claim your profile

Publications (85)243.87 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Vasoactive intestinal peptide (VIP) decreases cell proliferation through PI3K signalling and prevents tumour progression in clear renal cell carcinoma (RCC). Here we analyzed the signalling pathways that mediate such VIP effects by using human RCC A498 cells. The effects of treatment with 1 μM VIP and/or specific protein kinase inhibitors such as H89, Wortmannin and PD98059 were studied by cell adhesion assay, ELISA of VEGF165 and ROS production assays. Semiquantitative RT-PCR and western blot were performed to study p53 expression. VIP increased cell adhesion and ROS production, and decreased VEGF165 secretion through PI3K signalling. Moreover, VIP increased nuclear expression of tumour suppressor p53. VIP effects could be blocked by cell incubation with a specific p53 inhibitor, cyclin pifithrin-α hydrobromide (CPFT-αH). In conclusion, this study provides a p53-dependent mechanism by which VIP regulates cell proliferation in RCC development. It supports a potential usefulness of VIP in new therapies of RCC.
    The International Journal of Biochemistry & Cell Biology. 01/2014; 53:295–301.
  • [Show abstract] [Hide abstract]
    ABSTRACT: We studied antitumor effect of VIP in human renal cell carcinoma (RCC) (A498 cells xenografted in immunosuppressed mice). VIP-treated cells gave resulted in p53 upregulation and decreased nuclear β-catenin translocation and NFκB expression, MMP-2 and MMP-9 activities, VEGF levels and CD-34 expression. VIP led to a more differentiated tubular organization in tumours and less metastatic areas. Thus, VIP inhibits growth of A498-cell tumours acting on the major issues involved in RCC progression such as cell proliferation, microenvironment remodelling, tumour invasion, angiogenesis and metastatic ability. These antitumoral effects of VIP offer new therapeutical possibilities in RCC treatment.
    Cancer letters 05/2013; · 5.02 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Molecular mechanisms involved in progression of clear-cell renal-cell carcinomas (ccRCCs) are poorly understood. A common genetic mutation found in ccRCC is the loss of the von Hippel-Lindau (VHL) gene, which contributes to cancer progression and metastasis. We investigated VIP effects on metastatic and angiogenic factors in human VHL-null A498 ccRCC and HK2 renal cells. VIP increased adhesion but decreased expression of metalloproteinases, MMP2 and MMP9, as well as cell migration and VEGF expression and secretion in A498 but not in HK2 cells. VIP enhanced ROS levels and decreased nuclear levels of β-catenin and NFκB p50-subunit in A498 cells, suggesting neuropeptide involvement in the observed decrease of metastatic ability in clear-cell carcinoma. VIP effects in A498 cells were blocked by the VPAC(1/2)-receptor antagonist JV-1-53. In conclusion, present data point to a role of VIP in preventing invasion and metastasis in ccRCCs and support its potential therapeutic usefulness in this disease.
    Molecular and Cellular Endocrinology 10/2012; · 4.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Oxidative stress is a major mediator of tissue and cell injuries. The injury in chronic nephrotic syndrome, acute renal failure, myeloma kidney injury and other kidney diseases is initiated by oxidative stress. We have previously demonstrated that vasoactive intestinal peptide (VIP) acts as an antiproliferative agent in renal cancer cells. This study was designed to evaluate the renoprotective activity of VIP against H(2)O(2)-induced oxidative damage in a proximal tubule kidney cell line (human, non-tumor, HK2 cells) in order to investigate the potential usefulness of this peptide in the treatment of oxidative-stress related kidney diseases. HK2 cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Propidium iodide was used to identify cells undergoing apoptosis. Western blotting was performed with anti-Bcl-2, anti-Bax and anti-formyl peptide receptor (low-affinity variant FPRL-1) monoclonal antibodies whereas 2,7-dichlorofluorescein diacetate was used for measurement of levels of intracellular reactive oxygen species (ROS). HK2 cells were injured with H(2)O(2) in order to induce apoptosis: the effect was time- and dose-dependent. VIP increased the levels of the antiapoptotic protein Bcl-2 and decreased those of the proapoptotic protein Bax. VIP decreased the intracellular ROS levels reached by H(2)O(2)-induced oxidative stress. VIP effect on ROS levels involved FPLR-1 but not VPAC(1,2) receptors as evidenced by the use of the respective antagonists WRW4 and JV-1-53. Thus, VIP protects HK2 cells from apoptosis by increasing Bcl-2 levels and this effect is initiated through FPLR1 receptor. In conclusion, VIP might exert a renoprotective effect by the suppression of oxidative stress.
    Peptides 09/2012; 38(2):275-81. · 2.52 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Vasoactive intestinal peptide (VIP) is a potent inductor of cyclooxygenase-2 (COX-2) expression in human prostate cancer cell lines. There are conflicting data regarding the role of COX-2 in the progression of this disease. Here we examined the expression of VIP receptors (VPAC1 and VPAC2) and COX-2 in prostate cancer specimens. Correlations among protein levels and various clinicopathological factors and prognosis of patients were statistically analyzed. For these purposes, formaldehyde-fixed, paraffin-embedded prostate tissue specimens from 63 patients with prostate cancer and 9 control samples were used. The expression of VPAC1 and VPAC2 receptors and COX-2 was analyzed at mRNA levels by quantitative reverse transcriptase-PCR. The corresponding expression at protein level was studied by immunohistochemistry, scored as negative, weak, moderate, or strong, and correlated with different clinicopathological factors by means of multivariate analysis. 88% of prostate cancer tissues overexpressed VPAC1-receptor at mRNA level, 72% VPAC2-receptor and 77% COX-2. Simultaneous overexpression of the three genes was seen in 52% of patients. Similar overexpression patterns were observed at protein level. The correlation between VPAC1 and VPAC2 receptor protein levels was statistically significant. However, no significant correlations existed among protein levels of VPAC receptors and COX-2 with patient age, prostate-specific antigen (PSA) levels, tumor stage, Gleason score and survival time. The overexpression of VPAC1 and VPAC2 receptors and COX-2 in cancer tissue gives them a potential role as targets for diagnosis of prostate cancer but results do not support a clear value as biomarkers for the clinical prognosis of this disease.
    Histology and histopathology 08/2012; 27(8):1093-101. · 2.28 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: New approaches are needed to the therapy of advanced prostate cancer. This study determined the effect of growth hormone-releasing hormone (GHRH) antagonists, JMR-132 and JV-1-38 on growth of PC3 tumors as well as on angiogenesis and metastasis through the evaluation of various factors that contribute largely to the progression of prostate cancer. Human PC3 androgen-independent prostate cancer cells were injected subcutaneously into nude mice. The treatment with JMR-132 (10 μg/day) or JV-1-38 (20 μg/day) lasted 41 days. We also evaluated the effects of JMR-132 and JV-1-38 on proliferation, cell adhesion and migration in PC-3 cells in vitro. Several techniques (Western blot, reverse transcription polymerase chain reaction, immunohistochemistry, ELISA and zymography) were used to evaluate the expression levels of GHRH receptors and its splice variants, GHRH, vascular endothelial growth factor (VEGF), hypoxia inducible factor (HIF)-1α, metalloproteinases (MMPs) -2 and -9, β-catenin and E-cadherin. GHRH antagonists suppressed the proliferation of PC-3 cells in vitro and significantly inhibited growth of PC3 tumors. After treatment with these analogues, we found an increase in expression of GHRH receptor accompanied by a decrease of GHRH levels, a reduction in both VEGF and HIF-1α expression and in active forms of MMP-2 and MMP-9, a significant increase in levels of membrane-associated β-catenin and a significant decline in E-cadherin. These results support that the blockade of GHRH receptors can modulate elements involved in angiogenesis and metastasis. Consequently, GHRH antagonists could be considered as suitable candidates for therapeutic trials in the management of androgen-independent prostate cancer.
    International Journal of Cancer 07/2012; · 6.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Clear renal cell carcinoma (cRCC) is an aggressive and fatal neoplasm. The present work was undertaken to investigate the antiproliferative potential of vasoactive intestinal peptide (VIP) exposure on non-tumoral (HK2) and tumoral (A498, cRCC) human proximal tubular epithelial cell lines. Reverse transcription and semiquantitative PCR was used at the VIP mRNA level whereas enzyme immunoanalysis was performed at the protein level. Both renal cell lines expressed VIP as well as VIP/pituitary adenylate cyclase-activating peptide (VPAC) receptors whereas only HK2 cells expressed formyl peptide receptor-like 1 (FPRL-1). Receptors were functional, as shown by VIP stimulation of adenylyl cyclase activity. Treatment with 0.1μM VIP (24h) inhibited proliferation of A498 but not HK2 cells as based on a reduction in the incorporation of [(3)H]-thymidine and BrdU (5'-Br-2'-deoxyuridine), PCNA (proliferating-cell nuclear antigen) expression and STAT3 (signal transducer and activator of transcription 3) expression and activation. VPAC(1)-receptor participation was established using JV-1-53 antagonist and siRNA transfection. Growth-inhibitory response to VIP was related to the cyclic adenosine monophosphate (cAMP)/exchange protein directly activated by cAMP (EPAC)/phosphoinositide 3-kinase (PI3-K) signaling systems as shown by studies on adenylate cyclase stimulation, and using the EPAC-specific compound 8CPT-2Me-cAMP and specific kinase inhibitors such as H89, wortmannin and PD98059. The efficacy of VIP on the prevention of tumor progression was confirmed in vivo using xenografted athymic mouse. These actions support a potential role of this peptide and its agonists in new therapies for cRCC.
    Biochimica et Biophysica Acta (BBA) - Molecular Cell Research 06/2012; 1823(10):1676-85. · 4.81 Impact Factor
  • Ana Valdehita, María J Carmena, Ana M Bajo, Juan C Prieto
    [Show abstract] [Hide abstract]
    ABSTRACT: We used small-interference RNA (siRNA) to explore the mechanisms of some vasoactive intestinal peptide (VIP) actions on human breast cancer cells. Transfection of estrogen-dependent (T47D) and estrogen-independent (MDA-MB-468) breast cancer cells with VPAC(1)-receptor siRNA completely abolished VIP stimulatory effect on secretion of the main angiogenic factor, vascular endothelial growth factor (VEGF), and transactivation of epidermal growth factor receptor (EGFR or HER1) and HER2, two members of HER family of tyrosine-kinase receptors. The silencing procedure suggested the involvement of EGFR and HER2 transactivation in VIP-stimulated VEGF secretion. It was further supported by blocking tyrosine kinase activity by the selective HER inhibitors AG-1478 (EGFR) and AG-825 (HER2). Results give value to the specific signaling of VIP through VPAC(1) receptor in human breast cancer cells and support the potential use of VPAC(1)-receptor antagonists in combined targeted therapies for breast cancer. Molecular therapies involving RNA interference of VPAC(1)-receptor expression could also be considered.
    Molecular and Cellular Endocrinology 08/2011; 348(1):241-6. · 4.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The carcinogenic potential of vasoactive intestinal peptide (VIP) was analyzed in non-tumor human prostate epithelial cells (RWPE-1) and in vivo xenografts. VIP induced morphological changes and a migratory phenotype consistent with stimulation of expression/activity of metalloproteinases MMP-2 and MMP-9, decreased E-cadherin-mediated cell-cell adhesion, and increased cell motility. VIP increased cyclin D1 expression and cell proliferation that was blocked after VPAC(1)-receptor siRNA transfection. Similar effects were seen in RWPE-1 tumors developed by subcutaneous injection of VIP-treated cells in athymic nude mice. VIP acts as a cytokine in RWPE-1 cell transformation conceivably through epithelial-mesenchymal transition (EMT), reinforcing VIP role in prostate tumorigenesis.
    Cancer letters 12/2010; 299(1):11-21. · 5.02 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Vasoactive intestinal peptide (VIP) and its receptors (VPACs) are involved in proliferation, survival, and differentiation in human breast cancer cells. Its mechanism of action is traditionally thought to be through specific plasma membrane receptors. There is compelling evidence for a novel intracrine mode of genomic regulation by G-protein-coupled receptors (GPCRs) that implies both endocytosis and nuclear translocation of peripheral GPCR and/or the activation of nuclear-located GPCRs by endogenously-produced, non-secreted ligands. Regarding to VPAC receptors, which are GPCRs, there is only a report suggesting them as a dynamic system for signaling from plasma membrane and nuclear membrane complex. In this study, we show that VPAC(1) receptor is localized in cell nuclear fraction whereas VPAC(2) receptor presents an extranuclear localization and its protein expression is lower than that of VPAC(1) receptor in human breast tissue samples. Both receptors as well as VIP are overexpressed in breast cancer as compared to non-tumor tissue. Moreover, we report the markedly nuclear localization of VPAC(1) receptors in estrogen-dependent (T47D) and independent (MDA-MB-468) human breast cancer cell lines. VPAC(1) receptors are functional in plasma membrane and nucleus as shown by VIP stimulation of cAMP production in both cell lines. In addition, VIP increases its own intracellular and extracellular levels, and could be involved in the regulation of VPAC(1)-receptor traffic from the plasma membrane to the nucleus. These results support new concepts on function and regulation of nuclear GPCRs which could have an impact on development of new therapeutic drugs.
    Peptides 11/2010; 31(11):2035-45. · 2.52 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Bombesin (BN) and gastrin-releasing peptide (GRP) have been shown to stimulate the growth of human prostate cancer in vivo and in vitro by mechanisms initiated by binding of the peptide to BN/GRP receptor (GRPR). GRPR is overexpressed in a variety of human cancers, including human prostatic carcinoma. This led us to evaluate the effectiveness of blocking GRPR and of chemotherapy targeted to GRPR in androgen-dependent (LNCaP) and androgen-independent (PC-3) prostate cancer cells, which exhibit different features of disease progression. Thus, we used a cytotoxic BN/GRP analog, AN-215, consisting of 2-pyrrolinodoxorubicin (AN-201) linked to BN-like carrier peptide, and a BN/GRP receptor antagonist, RC-3095. Semiquantitative RT-PCR and Western blotting revealed that mRNA and protein levels for GRPR increased in prostate cancer cells as compared with nonneoplastic RWPE-1 cells. Immunofluorocytochemistry and Western blot assays revealed that AN-215 was the most effective analog decreasing both the expression of epidermal growth factor receptor family members and the activation of epidermal growth factor receptor and HER-2, which are associated to a poor prognosis. Furthermore, analogs targeted to BN/GRP receptors, AN-215 and RC-3095, blocked the effect of BN on cell growth in RWPE-1, LNCaP and PC-3 cells. These findings shed light on the mechanisms of action of these analogs and support the view that the use of AN-215 and RC-3095 for blocking BN/GRP receptors for targeted therapy may be of benefit for treatment of advanced prostate cancer.
    International Journal of Cancer 10/2010; 127(8):1813-22. · 6.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We used an in vivo model of human experimental prostate cancer in order to shed a new light on the effects of vasoactive intestinal peptide (VIP) on tumor growth as well as its pro-metastatic potential in this disease. We used nude mice subcutaneously injected with prostate cancer androgen-independent PC3 cells for 30 days. The regulatory role of VIP on cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) expression as well as on matrix metalloproteinase-2 and 9 (MMP-2 and 9) activities was examined. A selective COX-2 inhibitor, NS-398, and curcumin were used to block VIP effects. Xenografts of VIP-treated PC3 prostate cancer cells in nude mice gave tumors that grew significantly faster than those in the untreated group. It is conceivably a result of both the trophic effect of VIP on prostate cancer cells and the proangiogenic action of the neuropeptide in the growing tumor. We show the overexpression at mRNA and/or protein levels of VIP, its main receptor VPAC(1), the major angiogenic factor VEGF, and the pro-inflammatory enzyme COX-2 as well as the increased activity of MMP-2 and 9 in tumors derived from VIP-treated PC3 cells as compared with control group. The overexpression of the above biomarkers was suppressed in tumors derived from VIP-treated PC3 cells that had been previously incubated with curcumin or NS-398. Thus, the potential therapeutic role of curcumin and selective COX-2 inhibitors in combination with available VIP antagonists should be considered in prostate cancer therapy as supported by their inhibitory activities on tumor cell growth.
    Peptides 09/2009; 30(12):2357-64. · 2.52 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: There is little known on the involvement of vasoactive intestinal peptide (VIP) in the metastatic cascade of human prostate cancer, that is, cell proliferation, cell-cell adhesion, extracellular-matrix degradation, and migration/invasion. Here we evaluated the expression of related biomarker proteins (cyclin D1, metalloproteinases MMP-2 and MMP-9, and E-cadherin) in human androgen-dependent (LNCaP) and independent (PC3) prostate cancer cells. Reverse transcriptase (RT)-polymerase chain reaction (PCR), gelatin zymography, Western blotting, confocal immunofluorescence microscopy, and assays on cell proliferation, adhesion, wound-healing, migration and random homing were performed. VIP increased cell proliferation and cyclin D1 expression whereas it decreased cell adhesion and E-cadherin expression in LNCaP and PC3 cells. VIP enhanced the gelatinolytic activity of MMP-2 and MMP-9. Semiquantitative RT-PCR assays showed that VIP stimulated mRNA levels of these MMPs and suppressed mRNA levels of its inhibitory protein RECK. VIP promoted cell invasion and migration, and the responses were faster according to the most aggressive status in cancer progression (androgen-independence). The involvement of nuclear factor-kappaB (NF-kappaB) was demonstrated since the anti-inflammatory agent curcumin blocked VIP effects on the above biomarkers in both cell lines. Taken together, these results and the presence of kappaB sites on gene promoter of cyclin D1, MMPs and, possibly, E-cadherin suggest that VIP may act as a cytokine in an early metastatic stage of human prostate cancer through the NF-kappaB/MMPs-RECK/E-cadherin system. Our findings may help to define novel targets and agents with potential usefulness in prostate cancer therapy.
    The Prostate 03/2009; 69(7):774-86. · 3.84 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We analyzed the cross-talk between receptors for vasoactive intestinal peptide (VIP) and the human epidermal growth factor family of tyrosine kinase receptors (HER) in oestrogen-dependent (T47D) and oestrogen-independent (MDA-MB-468) human breast cancer cells. VIP treatment slowly increased the expression levels of EGFR but it rapidly augmented phosphorylation of EGFR and HER2 in both cell lines. This pattern of HERs transactivation was blocked by the specific VIP antagonist JV-1-53, supporting the direct involvement of VIP receptors in formation of P-EGFR and P-HER2. VIP-induced transactivation was also abolished by H89 (protein kinase A inhibitor), PP2 (Src inhibitor) or TAPI-1 (inhibitor of matrix metalloproteases), following a differential pattern. These results shed a new light on the specific signalling pathways involved in EGFR/HER2 transactivation by VPAC receptors and suggest the potential usefulness of VIP receptor antagonists together with current antibodies against EGFR/HER2 and/or tyrosine kinase inhibitors for breast cancer therapy.
    Molecular and Cellular Endocrinology 01/2009; 302(1):41-8. · 4.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Previous studies have shown that vasoactive intestinal peptide (VIP) and its receptors (VPAC(1) and VPAC(2) receptors) are involved in promotion and growth of many human tumours including breast cancer. Here we investigated whether VIP regulates the expression of the main angiogenic factor, vascular endothelial cell growth factor (VEGF) in human oestrogen-dependent (T47D) and oestrogen-independent (MDA-MB-4687) breast cancer cells. Semiquantitative and quantitative real-time RT-PCRs were used at mRNA level whereas enzyme immunoanalysis was performed at protein level. Both cancer cell lines expressed VIP and VPAC(1) (but not VPAC(2)) receptors that were functional as shown by VIP stimulation of adenylate cyclase activity. VIP induced VEGF expression at both mRNA and protein levels following a time-dependent pattern. The responses were faster in T47D than in MDA-MB-468 cells. The observed VIP regulation of VEGF expression appears to be modulated at least by the cAMP/protein kinase A (PKA) and the phosphoinositide 3-kinase (PI3-K) signalling systems as shown by studies of adenylate cyclase stimulation and using specific kinase inhibitors such as H89 and wortmannin. These actions suggest a proangiogenic potential of VIP in breast cancer.
    Regulatory Peptides 01/2008; 144(1-3):101-8. · 2.06 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Receptors for vasoactive intestinal peptide (VIP) and the human epidermal growth factor family of tyrosine kinase receptors (HER) are potent promoters of cell proliferation, survival, migration, adhesion and differentiation in prostate cancer cell lines. In this study, we analyzed the cross-talk between both classes of receptors through the regulation of HER2 transactivation and expression by VIP. Three growth-hormone-releasing hormone analogs endowed with antagonistic activity for VIP receptors (JV-1-51, -52, and -53) abrogated the autocrine/paracrine stimuli of VIP on androgen-independent PC3 cells in the absence or the presence of 10% fetal bovine serum. Semiquantitative and real-time quantitative RT-PCR together with Western blotting showed increased expression levels of both mRNA and proteins for HER2 and HER3 in PC3 and androgen-dependent LNCaP prostate cancer cells as compared to non-neoplastic RWPE-1 cells. VIP (100 nM) stimulated the expression levels of both HER2 and HER3 in PC3 cells in a time-dependent manner. Whereas these effects were relatively slow, VIP rapidly (0.5 min) increased HER2 tyrosine phosphorylation. This pattern of HER transactivation was blocked by H89, a protein kinase A (PKA) inhibitor, as well as by the specific VIP antagonist JV-1-53, indicating the involvement of VIP receptors and PKA activity in phosphorylated HER2 formation. These findings support the merit of further studies on the potential usefulness of VIP receptor antagonists and both HER2 antibodies and tyrosine kinase inhibitors for prostate cancer therapy.
    International Journal of Oncology 12/2007; 31(5):1223-30. · 2.66 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We show that vasoactive intestinal peptide (VIP) exerts trophic and proangiogenic activities in experimental prostate cancer in vivo. Nude mice were subcutaneously injected with Matrigel impregnated with LNCaP prostate cancer cells. Cell treatment with 100 nM VIP for 1h before xenograft resulted in increased tumor growth after 8 and, more remarkably, 15 days of injection. The same occurred with the mRNA expression of the main angiogenic factor, vascular endothelial growth factor (VEGF), as shown by real-time RT-PCR quantification. The proangiogenic activity of VIP was further established by showing increases of hemoglobin levels, Masson trichromic staining, and immunohistochemical CD34 staining in tumors excised 15 days after subcutaneous injection of VIP-treated cells as compared to control conditions. All these parameters indicate that VIP increases vessel formation. This xenograft model is a useful tool to study in vivo the effects of VIP-related peptides in tumor growth and development of blood supply as well as their therapeutical potential in prostate cancer.
    Peptides 10/2007; 28(9):1896-901. · 2.52 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The effect of vasoactive intestinal peptide (VIP) on cyclooxygenase-2 (COX-2) expression was analyzed in human prostate non-neoplastic (RWPE-1) as well as cancer androgen-dependent (LNCaP) and independent (PC3) cells. The three cell lines expressed VIP mRNA and VIP peptide, as measured by RT-PCR and immunochemistry, which supports an autocrine/paracrine action of VIP in the prostate gland. VIP levels were progressively higher from non-neoplastic to androgen-dependent and independent cells. Real-time RT-PCR and Western-blotting showed that VIP stimulated both COX-2 mRNA and protein expression in a faster manner as prostate cancer stage progressed (i.e. RWPE1<LNCaP<PC3 cells). Furthermore, VIP induced higher levels of COX-2 protein expression in cancer cells as compared with non-neoplastic cells. The anti-inflammatory agent curcumin blocked VIP-induced COX-2 expression in all cell lines studied supporting the involvement of nuclear factor-kappaB (NFkappaB) in such a response. In fact, VIP increased the translocation of the NFkappaB p50 subunit to the nucleus and the binding of the active form to its target gene promoter, as measured by Western-blotting and ELISA, respectively. VIP provoked faster responses according to the most aggressive status in cancer progression (androgen-independent situation). These results together with the existence of two NFkappaB sites in the COX-2 gene promoter together suggest that COX-2 may be a target for VIP in prostate cancer progression. On the other hand, VIP could be a proinflammatory cytokine acting through the NFkappaB/COX-2 system.
    Molecular and Cellular Endocrinology 05/2007; 270(1-2):8-16. · 4.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Vascular endothelial growth factor (VEGF) is a main factor promoting neovascularization (angiogenesis) of solid tumours as prostate carcinoma. Hypoxia stimulates VEGF gene expression by activating the hypoxia-inducible factor-1 (HIF-1alpha). In the present study, the hypoxia-mimicking agent Ni(2+) induced vasoactive intestinal peptide (VIP) expression at both mRNA and peptide levels but it did not modify the expression of VIP receptors (VPAC(1), VPAC(2) and PAC(1) receptors) in androgen-dependent human LNCaP prostate cancer cells. VIP increased the mRNA levels of VPAC(1) and PAC(1) receptors whereas it decreased VPAC(2) receptor mRNA level. These features support that hypoxia up-regulation of VIP gene expression in prostatic carcinoma may lead to VIP regulation of the expression of its receptors by means of autocrine/paracrine mechanisms. Either VIP or hypoxia mimetics with Ni(2+) increased VEGF expression whereas both conditions together resulted in an additive response. It suggests two independent mechanisms for the observed pro-angiogenic activities of VIP and hypoxia. VIP did not stimulate HIF-1alpha mRNA expression but increased the translocation of HIF-1alpha from the cytosolic compartment to the cell nucleus. Moreover, VIP was unable to modify the expression of the HIF-1alpha inhibitor FIH-1 discarding the possibility of an indirect effect of VIP on HIF-1 transactivation.
    Molecular and Cellular Endocrinology 05/2006; 249(1-2):116-22. · 4.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP) bind similarly to VPAC1 and VPAC2 receptors, whereas PACAP binds with higher affinity than VIP to PAC1 receptors. Here we demonstrate by different approaches the expression of the three subclasses of PACAP/VIP receptors in human normal and malignant breast tissue. At the mRNA level, reverse transcription-polymerase chain reaction experiments showed VPAC1 and VPAC2 receptors as well as various isoforms (null, hip/hop) of PAC1 receptors due to alternative splicing. At the protein level, Western blot experiments revealed the three subclasses of receptor although no conclusive differences could be established when comparing control, peritumoral and tumoral tissue samples. Immunohistochemistry showed the distribution of these receptors: they were located at epithelial cells in normal and cancer conditions but also in leukocytes at the stromal level in carcinomatous tissue. A weaker immunostaining of PAC1 receptors in normal tissue and a strong density of the three PACAP/VIP receptor subclasses in cancer tissue may be related to differential expression patterns during breast tumor progression but more samples need to be studied to validate this hypothesis. PAC1, VPAC1 and VPAC2 receptors were functional, as shown by their coupling to adenylate cyclase stimulation: VIP, PACAP-27 and PACAP-38 behaved similarly at this level, whereas both VPAC receptors acted alike as shown by means of specific peptide agonists and antagonists. The present results together with the known presence of PACAP and VIP in the mammary gland support a paracrine/autocrine involvement of both peptides at this level in physiological and pathological conditions, i.e. during malignant transformation.
    Gynecological Endocrinology 07/2005; 20(6):327-33. · 1.30 Impact Factor

Publication Stats

694 Citations
243.87 Total Impact Points

Institutions

  • 1984–2014
    • University of Alcalá
      • Department of Physiology, Biochemistry and Molecular Biology
      Cómpluto, Madrid, Spain
  • 2006
    • Hospital Príncipe De Asturias
      Madrid, Madrid, Spain
  • 1987
    • Hospital Universitario Henares
      Madrid, Madrid, Spain
  • 1984–1987
    • Facultad de Medicina
      Madrid, Madrid, Spain