A 60 kDa prolactin variant secreted by cervical cancer cells modulates apoptosis and cytokine production (original) (raw)
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High expression of prolactin receptor is associated with cell survival in cervical cancer cells
Cancer cell international, 2013
Background: The altered expression of prolactin (PRL) and its receptor (PRLR) has been implicated in breast and other types of cancer. There are few studies that have focused on the analysis of PRL/PRLR in cervical cancer where the development of neoplastic lesions is influenced by the variation of the hormonal status. The aim of this study was to evaluate the expression of PRL/PRLR and the effect of PRL treatment on cell proliferation and apoptosis in cervical cancer cell lines.
Clinical and Experimental Immunology, 2004
SUMMARY The cytokine hormone prolactin (PRL) has been shown previously to modulate native cellular responses and maturation of antigen-presenting cells. Here we have addressed its effect on the antigen-specific response of cytotoxic T lymphocytes (CTL). CTL were generated from HLA-A2 lymphocytes after three rounds of stimulation with autologous dendritic cells loaded with HLA-A2-restricted carcinoembrionic antigen (CEA) Cap-1 (YLSGANLNL) peptide. Selected cultures were expanded on cytokine-supplemented feeder-layers, enriched for CD8+ lymphocytes and analysed for PRL-receptor (PRL-R) expression and PRL responsiveness. Resting CD8+ lymphocytes were negative for PRL-R, whereas antigen-activated CD8+ lymphocytes derived from long-term cultures were highly positive. Results of a 51Cr release assay showed CTL killing of CEA-loaded, but not unloaded, T2 cell line and the CEA-positive gastric carcinoma cell line KATO, but not of the CEA-negative T leukaemia cell line Jurkat. Interferon (IF...
Experimental Biology and Medicine, 1995
Studies were undertaken to identify intracellular mediators of prolactin inhibition of giucocorticoid-induced apoptosis in Nb2 lymphoma cells. A short-term assay was implemented that quantitates fragmented DNA released from the genome by reaction with diphenylamine. Induction and inhibition of internucleosomal DNA cleavage (indicative of apoptosis) was verified by agarose gel electrophoresis of extracted cellular DNA. Synchronized Nb2 cells (GdG,) exhibited increased DNA fragmentation after 4-hr incubation with dexamethasone (DEX) (2S100 nM) which was inhibited by ovine prolactin (oPRL) (0.1-1 ng/ml), the giucocorticoid receptor antagonist, RUM6 (500 nM), and the nuclease inhibitor, aurintricarboxylic acid (100 ILM). Signals previously implicated in prolactin induction of mitogenesis in Nb2 cells were investigated for their role in prolactin inhibition of apoptosls including: protein kinase C activation, arachidonic acid metabolism, poiyamine production, tyrosine phosphorylation, and extracellular calcium. Protein kinase C agonists, phorbol-12-myristate-13acetate, and 1,2-dioctanoyl-sn-glyceroi, f the calcium ionophore, A231 87 (200 nM), did not mimic oPRL inhibition of DEX-induced DNA fragmentation. Protein kinase C inhibitors, gossypol and quercetin, did not block prolactin action. Arachidonic acid did not mimic prolactin protection against DEX-induced DNA fragmentation. Inhibitors of arachidonic acid metabolism, 5,8,11 , I 4-eicosatetraynoic acid, nordihydroguaiaretic acid, and indomethacin did not block prolactin action. The polyamine, spermine, inhibited DEX-induced DNA fragmentation at 1.5 to 2.5 mM. However, inhibition of polyamine synthesis with a-dlfluoromethyl ornithine or methyiglyoxal bis(guany1hydrazone) did not inhibit prolactin action. Prolactin action was not blocked by inhibitors of tyrosine kinase activation, genistein and tyrphostin-47. On the other hand, pervanadate, a potent tyrosine phosphatase Inhibitor, consistently inhibited DEX-induced DNA fragmentation. Prolactin action and DEX-Induced apoptosls both occurred in calcium-free PBS. In summary, protein kinase C activation and eicosanoid production do not appear to mediate this prolactin action. Although spermine could block DNA fragmentation, blockade of the poiyamine cascade did not inhibit prolactin action, suggesting that poiyamines do not mediate this prolactin effect. While inhibitors of tyrosine kinase activation did not block prolactin action, tyrosine phosphatase inhibition in the presence of basal tyrosine kinase activity mimicked prolactin action, suggesting tyrosine phosphorylation participation in the anti-apoptotic effect. Extracellular calcium was not required for prolactin or DEX action. [P.S.E.B.M. 1995 he Nb2 lymphoma cell line is a pre-T-cell line derived from a lymph node tumor in an estro-T gen-treated male rat (1). Nb2 cells proliferate in response to prolactin (PRL) and other lactogenic hormones which act through the mutant, intermediate form of the prolactin receptor present in these cells (2, 3). Other Nb2 cell mitogens include cytokines, interleukin-2 (IL-2) and IL-7 (4, 5). The high sensitivity of the Nb2 cell to prolactin-induced mitogenesis have made it a model system for studying prolactin mechanism of action.
Prolactin acts as a potent survival factor for human breast cancer cell lines
British journal of cancer, 2004
Human breast cancer is the leading cause of cancer death in women from Western societies, and a large study of the epidemiology demonstrated strong associations between human prolactin and risk of breast cancer. Using established models of apoptosis of human breast cancer cell lines, we assessed the role of prolactin in breast cancer cell growth and survival. We showed that prolactin had no effect on the metabolic activity or total cell number of any cell lines. We confirmed endogenous prolactin production by these cells and that the levels varied. In the presence of a prolactin-neutralising antibody, each of the cell lines responded with the induction of apoptosis as opposed to growth inhibition. The sensitivity of the cell lines to the physiological inducer of apoptosis, C2-ceramide, appeared relative to the levels of endogenous prolactin that they contained. We then showed that exogenously added prolactin acted as a potent survival factor against apoptosis in all the cell lines e...
The role of prolactin in human breast cancer Review
Biochemia Medica
Much of the literature on human breast cancer and prolactin (PRL) appears to be contradictory. PRL has been first recognizedas a hormone that plays an important role in breast cancer initiation and development in rodents, and, at least partly, in humans. Bioactive PRL is synthesized by human breast cancer cells in culture and acts in an autocrine/paracrine stimulatory loop within breast tissue. The actions of this ligand are mediated by PRL receptor (PRLR) isoforms found on, or secreted by, humanbreast epithelium. The PRL/PRLR complex associates with,and activates, several signaling pathways that are shared withother members of the cytokine receptor superfamily. Proximal PRLR signaling is initiated by three tyrosine kinases, namely Jak2, Src, and Tec. Some recent literature data have indicated a functional role forPRL within the nucleus where it acts in a complex with cyclophilin B as a transcriptional inducer. Several epidemiological studies have indicated that PRL mayalso function as a progression factor for human breast cancer. PRL might be an important local growth promoter involved in the pathogenesis of human breast cancer. Hyperprolactinemia could be an indicator of disease progression and poor prognosis and clinical approaches to controlling this disease need to incorporate antagonists of PRL/PRLR interaction or PRL receptor-associated signaltransduction.
Oncology Reports
Estrogens and estrogen receptors (ERs), such as ERα and ERβ, prolactin (PRL) and prolactin receptor (PRLR) have been reported to be involved in the physiopathology of uterine cervical cancer (UCC). The 60 kDa PRL is an isoform of PRL, which is produced by UCC-derived cells. The present study aimed to evaluate the expression of hormonal receptors in different degrees of cervical lesions, and to determine whether 60 kDa PRL and 17β-estradiol (E2) modulated cell survival and metabolism in UCC cells, and in HaCaT cells transduced with human papillomavirus (HPV) 16 and 18 E6/E7 oncogenes. ERα, ERβ, PRLR, Ki67 and B-cell lymphoma 2 expression levels were analyzed in biopsies of precursor lesions and UCC using immunohistochemistry. In addition, HeLa, SiHa and C33A cells, and transduced HaCaT cells, were stimulated with 60 kDa PRL, E2 or a combination of both. Proliferation was evaluated using the xCELLigence platform, apoptosis was analyzed by flow cytometry and cell metabolism was determined using the MTT assay. The results revealed that ERα, ERβ, PRLR and Ki67 expression levels were increased during the progression of cancer. In vitro, 60 kDa PRL alone significantly increased proliferation of SiHa cells. Furthermore, E2 alone or in combination with 60 kDa PRL increased the sensitivity of SiHa cells to cisplatin and increased the percentage of apoptosis; in HaCaT cells, these treatment strategies had the opposite effect on cisplatin sensitivity. Treatment with E2 increased mitochondrial activity in HeLa and SiHa cells, and in HaCaT cells transduced with HPV 16 E6/E7 and HPV 18 E6 oncogenes. PRL had a similar effect on HeLa cells, and on HaCaT cells transduced with HPV 18 E6 and HPV 16 E7. The co-expression of these receptors demonstrated the hormonal dependence of UCC. In addition, E2 and the 60 kDa PRL significantly impacted the metabolism, but not the survival, of cells.
Growth Factors, 2008
Macrophages play a crucial role in host immunosurveillance against pathogens and malignancies. The enhanced productions of pro-inflammatory cytokines are central to the regulatory role of macrophages and induction of robust immune response. The excessive inflammatory response of macrophages can result into pathological conditions in host. We have previously reported that prolactin (PRL) induces the production of nitric oxide (NO) and tumor necrosis factor (TNF)-a in murine peritoneal macrophages. It was suggested that protein tyrosine kinases (PTKs), mitogenactivated protein kinases (MAPKs) and Ca 11 signaling were involved in the NO production by macrophages on PRL treatment. In this manuscript, we investigated the role of PTKs [Janus kinase (JAK) 2 and phosphoinositide 3-kinase (PI3K)] and c-Jun N-terminal kinase (JNK) MAPK in PRLinduced activation of murine peritoneal macrophages. It is reported that PRL-induced activation of macrophages in vitro is dependent on JAK/signal transducers and activators of transcription (STAT) and JNK MAPK-signaling pathways. It is observed that pre-treatment of macrophages with JNK inhibitor, SP600125; tyrosine kinase inhibitor, genistein; PI3K inhibitor, Wortmannin and JAK2 inhibitor, AG490 inhibited the phosphorylation of JNK MAPK. Further, pre-treatment of macrophages with SP600125 inhibited the PRL-induced production of IFN-g and TNF-a. AG490, inhibitor of JAK2, down-regulated transcription factors c-jun and STAT1 and inhibited the PRL-induced IFN-g, TNF-a, IL-1b and IL-12p40 production in macrophages.
Modulation of prolactin expression in human T lymphocytes by cytokines
Journal of Neuroimmunology, 2005
Besides its pivotal role in reproduction, the polypeptide hormone prolactin (PRL) has immunomodulatory properties. Whereas the bulk of circulating PRL is produced by the pituitary, PRL is also produced by the decidua, the myometrium, the mammary gland and leukocytes. Extrapituitary PRL expression is regulated differently from that in the pituitary, due to the use of an alternative promoter. Here we show for the first time that in T lymphocytes PRL expression is subject to regulation by cytokines. We established that both IL-2 and IL-4 reduced PRL mRNA levels in T lymphocytes to 25 and 28% of control values, respectively. PRL mRNA expression was inhibited to a lesser extent by IL-1h, which decreased PRL mRNA levels to 58% of control values. D
The Journal of Immunology, 2011
Monocytes attracted by tumor-induced chronic inflammation differentiate to APCs, the type of which depends on cues in the local tumor milieu. In this work, we studied the influence of human cervical cancer cells on monocyte differentiation and showed that the majority of cancer cells either hampered monocyte to dendritic cell differentiation or skewed their differentiation toward M2-like macrophages. Blocking studies revealed that M2 differentiation was caused by tumor-produced PGE 2 and IL-6. TGF-b, IL-10, VEGF, and macrophage colony-stimulating factor did not play a role. Notably, these CD14 + CD163 + M2 macrophages were also detected in situ. Activation of cancer cell-induced M2-like macrophages by several TLR-agonists revealed that compared with dendritic cells, these M2 macrophages displayed a tolerogenic phenotype reflected by a lower expression of costimulatory molecules, an altered balance in IL-12p70 and IL-10 production, and a poor capacity to stimulate T cell proliferation and IFN-g production. Notably, upon cognate interaction with Th1 cells, these tumor-induced M2 macrophages could be switched to activated M1-like macrophages that expressed high levels of costimulatory molecules, produced high amounts of IL-12 and low amounts of IL-10, and acquired the lymphoid homing marker CCR7. The effects of the interaction between M2 macrophages and Th1 cells could partially be mimicked by activation of these APCs via CD40 in the presence of IFN-g. Our data on the presence, induction, and plasticity of tumor-induced tolerogenic APCs in cervical cancer suggest that tumor-infiltrated Th1 cells can stimulate a tumor-rejecting environment by switching M2 macrophages to classical proinflammatory M1 macrophages.
Clinical Immunology, 2005
We investigate the immunomodulator role of prolactin (PRL) on CD4+ and B cell activation from healthy subjects in comparison with hyperprolactinemic patients. Peripheral blood mononuclear cells, CD4+ or B cells, purified, were cultured under different conditions, as follows: with mitogen, without stimulus, with different concentrations of human PRL, with unspecific mitogen plus PRL, or with antibodies against PRL. The results revealed that PRL is produced by lymphocytes, the expression of CD69 and CD154 molecules, and interleukin secretions depend partially on the autocrine PRL, this is supported by the findings that secretions of IL-2, IFNγ, and co-stimulatory molecule expression were markedly reduced when autocrine PRL was blocked with anti-PRL antibodies. Furthermore, PRL activity was only observed during the first 2 h after activation. In contrast, B cell culture did not show any alteration by adding or blocking PRL in the expression of CD40 and CD86 in both groups: healthy subject and hyperprolactinemic patients.