A novel bispecific antibody targeting CD3 and prolactin receptor (PRLR) against PRLR-expression breast cancer.

BACKGROUND: Prolactin receptor (PRLR) is highly expressed in a subset of human breast cancer and prostate cancer, which makes it a potential target for cancer treatment. In clinical trials, the blockade of PRLR was shown to be safe but with poor efficacy. It is therefore urgent to develop new therapies against PRLR target. Bispecific antibodies (BsAbs) could guide immune cells toward tumor cells, and produced remarkable effects in some cancers. METHODS: In this study, a bispecific antibody targeting both tumor antigen PRLR and T cell surface CD3 antigen (PRLR-DbsAb) was constructed by split intein mediated protein transsplicing (BAPTS) system for the first time. Its binding activity was determined by Biacore and Flow cytometry, and target-dependent T cell mediated cytotoxicity was detected using LDH release assay. ELISA was utilized to study the secretion of cytokines by immune cells. Subcutaneous tumor mouse models were used to analyze the in vivo anti-tumor effects of PRLR-DbsAb. RESULTS: PRLR-DbsAb in vitro could recruit and activate T cells to promote the release of Th1 cytokines IFN- γ and TNF- α, which could kill PRLR expressed breast cancer cells. In xenograft models with breast cancer cell line T47D, NOD/SCID mice intraperitoneally injected with PRLR-DbsAb exhibited significant inhibition of tumor growth and a longer survival compared to mice treated with PRLR monoclonal antibody (PRLR mAb). CONCLUSIONS: Both in vitro and in vivo experiments showed PRLR-DbsAb had a potential therapy of cancer treatment potential therapy for cancer. Immunotherapy may be a promising treatment against the tumor target of PRLR.

Prolactin receptor expression as a novel prognostic biomarker for triple negative breast cancer patients.

Prolactin receptor (PRLR) is a novel emerging prognostic biomarker in different cancers, especially in breast cancer. However, there is limited information about the association of PRLR expression and triple-negative breast cancers (TNBC) prognosis. In this study, 80 TNBC patients were evaluated for PRLR expression by immunohistochemistry. The correlation of PRLR expression with clinicopathological features, patient recurrence, and survival was investigated. PRLR expression was considered positive if >10% of tumor cells were stained. The Fisher's exact test was used to analyze PRLR expression relation with the clinicopathological parameters. Survival distribution was estimated by the Kaplan-Meier method. Positive immunoreactivity for PRLR was observed in 50 out of 80 (62%) specimens. Although expression of PRLR was associated with TNBC patients' stage, no-correlation was observed between its expression and tumor size, grade, lymph node status, and Ki-67 expression. In addition, patients with positive expression of PRLR exhibited lower recurrence (P = 0.0027) and higher overall survival (P = 0.0285) in comparison with negative expression group. In multivariate analyses, positive expression of PRLR was an independent prognostic marker for lower recurrence (P < 0.001) and higher overall survival (P < 0.001). Therefore, PRLR plays a crucial role in TNBC and has to be considered as an independent prognostic biomarker for TNBC patients.

Prolactin signaling drives tumorigenesis in human high grade serous ovarian cancer cells and in a spontaneous fallopian tube derived model.

The pathways responsible for tumorigenesis of high grade serous ovarian cancer (HGSOC) from the fallopian tube epithelium (FTE) are still poorly understood. A human prolactin (PRL) like gene, Prl2c2 was amplified >100 fold in a spontaneous model of FTE-derived ovarian cancer (MOEhigh - murine oviductal epithelium high passage). Prl2c2 stable knockdown in MOEhigh cells demonstrated a significant reduction in cell proliferation, 2-dimensional foci, anchorage independent growth, and blocked tumor formation. The overall survival of ovarian cancer patients from transcriptome analysis of 1868 samples was lower when abundant PRL and prolactin receptors (PRL-R) were expressed. A HGSOC cell line (OVCAR3) and a tumorigenic human FTE cell line (FT33-Tag-Myc) were treated with recombinant PRL and a significant increase in cellular proliferation was detected. A CRISPR/Cas9 mediated PRL-R deletion in OVCAR3 and FT33-Tag-Myc cells demonstrated significant reduction in cell proliferation and eliminated tumor growth using the OVCAR3 model. PRL was found to phosphorylate STAT5, m-TOR and ERK in ovarian cancer cells. This study identified Prl2c2 as a driver of tumorigenesis in a spontaneous model and confirmed that prolactin signaling supports tumorigenesis in high grade serous ovarian cancer.

Prolactin regulates liver growth during postnatal development in mice.

The liver grows during the early postnatal period first at slower and then at faster rates than the body to achieve the adult liver-to-body weight ratio (LBW), a constant reflecting liver health. The hormone prolactin (PRL) stimulates adult liver growth and regeneration, and its levels are high in the circulation of newborn infants, but whether PRL plays a role in neonatal liver growth is unknown. Here, we show that the liver produces PRL and upregulates the PRL receptor in mice during the first 2 wk after birth, when liver growth lags behind body growth. At postnatal week 4, the production of PRL by the liver ceases coinciding with the elevation of circulating PRL and the faster liver growth that catches up with body growth. PRL receptor null mice ( Prlr-/-) show a significant decrease in the LBW at 1, 4, 6, and 10 postnatal weeks and reduced liver expression of proliferation [cyclin D1 ( Ccnd1)] and angiogenesis [platelet/endothelial cell adhesion molecule 1 ( Pecam1)] markers relative to Prlr+/+ mice. However, the LBW increases in Prlr-/- mice at postnatal week 2 concurring with the enhanced liver expression of Igf-1 and the liver upregulation and downregulation of suppressor of cytokine signaling 2 ( Socs2) and Socs3, respectively. These findings indicate that PRL acts locally and systemically to restrict and stimulate postnatal liver growth. PRL inhibits liver and body growth by attenuating growth hormone-induced Igf-1 liver expression via Socs2 and Socs3-related mechanisms.

Vasoinhibins, N-terminal mouse prolactin fragments, participate in mammary gland involution.

Vasoinhibins are a family of peptides that act on endothelial cells to suppress angiogenesis and promote apoptosis-mediated vascular regression. Vasoinhibins include the N-terminal fragments from prolactin (PRL), GH, and placental lactogen. One of the vasoinhibins, the N-terminal PRL fragment of 16 kDa, is generated by the lysosomal representative protease cathepsin D (Cath D). Because the normal growth and involution of the mammary gland (MG) are profoundly affected by the expansion and regression of blood vessels and also because PRL stimulates the growth and differentiation of MG, we proposed that intact PRL produced during lactation contributes to MG angiogenesis and increased blood flow, whereas during involution, the N-terminal PRL fragment would have proapoptotic effects on mammary epithelial cells (MECs). Therefore, we investigated the production of the N-terminal PRL fragment and its direct effect on the MG. Mouse PRL (mPRL) was proteolytically cleaved by Cath D between amino acids 148 and 149. N-terminal PRL fragment and Cath D expression increased during MG involution. Furthermore, incubation of MG fragments and MCF7 with recombinant 16 kDa mPRL revealed a proapoptotic effect in MECs. Ectopic mPRL in MECs was cleaved to 16 kDa PRL by Cath D in the MG lysosomal fraction. The majority of PRL derived from pituitary gland was cleaved to 16 kDa PRL in culture medium. Therefore, N-terminal PRL fragment increases during the involution period, has a proapoptotic effect on MECs, and is mainly generated by secreted Cath D in the extracellular space of MG.

Prolactin receptor expression and breast cancer: relationships with tumor characteristics among pre- and post-menopausal women in a population-based case-control study from Poland.

Previous studies have found an association between elevated circulating prolactin levels and increased risk of breast cancer. Prolactin stimulates breast cancer cell proliferation, migration, and survival via binding to the cell-surface prolactin receptor. The association of prolactin receptor expression with breast tumorigenesis remains unclear as studies that have focused on this association have had limited sample size and/or information about tumor characteristics. Here, we examined the association of prolactin expression with tumor characteristics among 736 cases, from a large population-based case-control study of breast cancer conducted in Poland (2000-2003), with detailed risk factor and pathology data. Tumors were centrally reviewed and prepared as tissue microarrays for immunohistochemical analysis of prolactin receptor expression. Association of prolactin receptor expression across strata of tumor characteristics was evaluated using χ (2) analysis and logistic regression. Prolactin receptor expression did not vary by menopausal status; therefore, data from pre- and post-menopausal women were combined in the analyses. Approximately 83 % of breast cancers were categorized as strong prolactin receptor staining. Negative/low prolactin receptor expression was independently associated with poorly differentiated (p = 1.2 × 10(-08)) and larger tumors (p = 0.0005). These associations were independent of estrogen receptor expression. This is the largest study to date in which the association of prolactin receptor expression with tumor characteristics has been evaluated. These data provide new avenues from which to explore the associations of the prolactin/prolactin receptor signaling network with breast tumorigenesis.

Fibroblast growth factor, estrogen, and prolactin receptor features in different grades of prostatic adenocarcinoma in elderly men.

The objective was to characterize and associate the receptor reactivities of fibroblastic growth factor (FGF)-2, FGF-7, FGF-8, epidermal growth factor (EGF), α-actin and vimentin in relation to the androgen receptor (AR), α and ß estrogen receptors (ERα and ERß), and prolactin receptor in the prostate of elderly men showing low- and high-grade adenocarcinoma. Thirty prostatic samples were taken from 60- to 90-year-old patients without prostatic lesions and with low-grade cancer and high-grade cancer, from the University Hospital, School of Medicine, the State University of Campinas. The results showed that increased FGF-2, FGF-7, and FGF-8 receptor reactivities and decreased AR reactivity were verified in both high- and low-grade cancer. However, the FGF-8 receptor showed greater involvement at the beginning of the malignancy alterations. Increased EGF receptor (EGFR) reactivity and diminished α-actin immunohistochemistry were identified in both cancer groups. Also, increased ERα, PR, and vimentin receptors were verified in both cancer groups. To conclude, the ERα involvement in the reactive stroma activation led to a microenvironment, which was favorable to cancer progression, due to maximizing stromal imbalance. The prolactin could be related to cancer progression due to its interaction with ERα action, indicating that this hormone could be a relevant target to prevent the estrogenic effects in the prostatic lesions. Both FGF receptor (FGFR)-2 and FGFR-8 play a fundamental role in the early stages of prostate cancer, suggesting that these molecules could be a promising therapeutic target. The differential localization of the fibroblastic factors between the prostatic epithelium and stroma of elderly men, who presented prostate cancer, could indicate a favorable distinction for tumoral progression.

The prolactin receptor transactivation domain is associated with steroid hormone receptor expression and malignant progression of breast cancer.

The polypeptide hormone prolactin (PRL) stimulates breast epithelial cell growth, differentiation, and motility through its cognate receptor, PRLr. PRLr is expressed in most breast cancers; however, its exact role remains elusive. Our laboratory previously described a novel mode of PRLr signaling in which Stat5a-mediated transcription is regulated through ligand-induced phosphorylation of the PRLr transactivation domain (TAD). Herein, we used a PRLr transactivation-deficient mutant (PRLrYDmut) to identify novel TAD-specific target genes. Microarray analysis identified 120 PRL-induced genes up-regulated by wild type but not PRLrYDmut. Compared with control, PRLr expression significantly induced expression of approximately 4700 PRL-induced genes, whereas PRLrYDmut ablated induction of all but 19 of these genes. Ingenuity pathway analysis found that the PRLr TAD most profoundly affected networks involving cancer and proliferation. In support of this, PRLrYDmut expression reduced anchorage-dependent and anchorage-independent growth. In addition, pathway analysis identified a link between the PRLr TAD and the estrogen and progesterone receptors (ERα/PR). Although neither ERα nor PR was identified as a PRL target gene, a TAD mutation significantly impaired ERα/PR expression and estrogen responsiveness. TMA analysis revealed a marked increase in nuclear, but not cytoplasmic, PRLr TAD phosphorylation as a function of neoplastic progression. We propose that PRLr TAD phosphorylation contributes to breast cancer pathogenesis, in part through regulation of ERα and PR, and has potential utility as a biomarker in this disease.

Prolactin regulation of the prostate gland: a female player in a male game.

Prolactin is best known for its actions on the mammary gland. However, circulating prolactin is also detected in males and its receptor (PRLR) is expressed in the prostate, suggesting that the prostate is a target of prolactin. Germline knockout of prolactin or its receptor has failed to reveal a key role for prolactin signaling in mouse prostate physiology. However, several studies involving rodent models and human prostate cell lines and specimens have supported the contribution of the canonical PRLR-Jak2-Stat5a/b pathway to prostate cancer tumorigenesis and progression. Increased expression of prolactin in the prostate itself (rather than changes in circulating prolactin levels) and crosstalk with androgen receptor (AR) signaling are potential mechanisms for increased Stat5a/b signaling in prostate cancer. In the mouse prostate, prolactin overexpression results in disorganized expansion of the basal/stem cell compartment, which has been proposed to house putative prostate tumor-initiating cells. These findings provide new insight into the molecular and cellular targets by which locally produced prolactin could contribute to prostate cancer initiation and progression. A number of pharmacological inhibitors targeting various levels of the PRLR-Jak2-Stat5a/b pathway have been developed and are entering clinical trials for advanced prostate cancer.

Luteal and placental function in the bitch: spatio-temporal changes in prolactin receptor (PRLr) expression at dioestrus, pregnancy and normal and induced parturition.

BACKGROUND: Endocrine mechanisms governing canine reproductive function remain still obscure. Progesterone (P4) of luteal origin is required for maintenance of pregnancy. Corpora lutea (CL) are gonadotrop-independent during the first third of dioestrus; afterwards prolactin (PRL) is the primary luteotropic factor. Interestingly, the increasing PRL levels are accompanied by decreasing P4 concentrations, thus luteal regression/luteolysis occurs in spite of an increased availability of gonadotropic support. PRL acts through its receptor (PRLr), the expression of which has not yet been thoroughly investigated at the molecular and cellular level in the dog. METHODS: The expression of PRLr was assessed in CL of non-pregnant dogs during the course of dioestrus (days 5, 15, 25, 35, 45, 65 post ovulation; p.o.) as well as in CL, the utero/placental compartments (Ut/Pl) and interplacental free polar zones (interplacental sites) from pregnant dogs during the pre-implantation, post-implantation and mid-gestation period of pregnancy and during the normal and antigestagen-induced luteolysis. Expression of PRLr was tested by Real Time PCR, immunohistochemistry and in situ hybridization. RESULTS: In non-pregnant CL the PRLr expression was significantly upregulated at day 15 p.o. and decreased significantly afterwards, towards the end of dioestrus. CL of pregnancy showed elevated PRLr expression until mid gestation while prepartal downregulation was observed. Interestingly, placental but not interplacental expression of PRLr was strongly time-related; a significant upregulation was observed towards mid-gestation. Within the CL PRLr was localized to the luteal cells; in the Ut/Pl it was localized to the fetal trophoblast and epithelial cells of glandular chambers. Moreover, in mid-pregnant animals treated with an antigestagen, both the luteal and placental, but not the uterine PRLr were significantly downregulated. CONCLUSIONS: The data presented suggest that the luteal provision of P4 in both pregnant and non-pregnant dogs may be regulated at the PRLr level. Furthermore, a role of PRL not only in maintaining the canine CL function but also in regulating the placental function is strongly suggested. A possible functional interrelationship between luteal P4 and placental and luteal PRLr expression also with respect to the prepartal luteolysis is implied.

Bovine luteal prolactin receptor expression: potential involvement in regulation of progesterone during the estrous cycle and pregnancy.

In the present study, we performed quantitative reverse-transcription PCR (qPCR) to examine changes in gene expression of prolactin receptor (long form: l-PRLR; short form: s-PRLR) and 20α-hydroxysteroid dehydrogenase (20α-HSD; EC 1.1.1.149) in the bovine corpus luteum (CL) throughout the estrous cycle and pregnancy. Western blotting was used to determine protein abundance. Bovine CL were collected and luteal stages (n = 6/stage) were classified by macroscopic observation as early (d 1 to 4 after ovulation), mid (d 5 to 10), late (d 11 to 17), and regressing (d 18 to 20). A CL of pregnancy (n = 6) was determined by the presence of conceptus (d 28 to term). The mRNA for both forms of PRLR were expressed at all the luteal stages. Expression of s-PRLR and l-PRLR mRNA was less (P < 0.01) during early and regressing luteal stages compared with mid and late stages. Expression of s-PRLR mRNA in CL of pregnancy was greater (P < 0.01) than early, mid, and regressing CL and did not differ from late luteal stage expression. A greater (P < 0.01) expression of l-PRLR mRNA was observed in pregnant vs. early and regressing CL. In addition, qPCR showed the presence of 20α-HSD mRNA during all luteal stages of the estrous cycle, with the greatest (P < 0.01) expression observed in the regressing luteal stage. Western blotting revealed protein abundance of both PRLR isoforms during all luteal stages and pregnancy, with a predominance of the s-PRLR protein. Densitometry analysis indicated that protein abundances of s-PRLR were greater (P < 0.05) than l-PRLR during early, mid, and late luteal stages and did not differ during the regressing luteal stage. Protein abundances of 20α-HSD were least (P < 0.05) during the early luteal stage. In conclusion, results of the current study suggest a possible involvement of PRLR, especially s-PRLR, in the regulation of progesterone secretion and metabolism during the bovine estrous cycle and pregnancy.

Prolactin receptor is a negative prognostic factor in patients with squamous cell carcinoma of the head and neck.

BACKGROUND: The influence of human prolactin (hPRL) on the development of breast and other types of cancer is well established. Little information, however, exists on the effects of hPRL on squamous cell carcinomas of the head and neck (SCCHNs). METHODS: In this study, we evaluated prolactin receptor (PRLR) expression in SCCHN cell lines and assessed by immunohistochemistry the expression in 89 patients with SCCHNs. The PRLR expression was correlated with clinicopathological characteristics as well as clinical outcome. The effect of hPRL treatment on tumour cell growth was evaluated in vitro. RESULTS: Immunoreactivity for PRLR was observed in 85 out of 89 (95%) tumours. Multivariate COX regression analysis confirmed high levels of PRLR expression (>25% of tumour cells) to be an independent prognostic factor with respect to overall survival (HR=3.70, 95% CI: 1.14-12.01; P=0.029) and disease-free survival (P=0.017). Growth of PRLR-positive cancer cells increased in response to hPRL treatment. CONCLUSION: Our data indicate that hPRL is an important growth factor for SCCHN. Because of PRLR expression in a vast majority of tumour specimens and its negative impact on overall survival, the receptor represents a novel prognosticator and a promising drug target for patients with SCCHNs.

Dynamic gene expression of GH/PRL-family hormone receptors in gill and kidney during freshwater-acclimation of Mozambique tilapia.

In teleosts, prolactin (PRL) and growth hormone (GH) act at key osmoregulatory tissues to regulate hydromineral balance. This study was aimed at characterizing patterns of expression for genes encoding receptors for the GH/PRL-family of hormones in the gill and kidney of Mozambique tilapia (Oreochromis mossambicus) during freshwater (FW)-acclimation. Transfer of seawater (SW)-acclimated tilapia to FW elicited rapid and sustained increases in plasma levels and pituitary gene expression of PRL177 and PRL188; plasma hormone and pituitary mRNA levels of GH were unchanged. In the gill, PRL receptor 1 (PRLR1) mRNA increased markedly after transfer to FW by 6h, while increases in GH receptor (GHR) mRNA were observed 48 h and 14 d after the transfer. By contrast, neither PRLR2 nor the somatolactin receptor (SLR) was responsive to FW transfer. Paralleling these endocrine responses were marked increases in branchial gene expression of a Na+/Cl- cotransporter and a Na+/H+ exchanger, indicators of FW-type mitochondrion-rich cells (MRCs), at 24 and 48 h after FW transfer, respectively. Expression of Na+/K+/2Cl- cotransporter, an indicator of SW-type MRCs, was sharply down-regulated by 6h after transfer to FW. In kidney, PRLR1, PRLR2 and SLR mRNA levels were unchanged, while GHR mRNA was up-regulated from 6h after FW transfer to all points thereafter. Collectively, these results suggest that the modulation of the gene expression for PRL and GH receptors in osmoregulatory tissues represents an important aspect of FW-acclimation of tilapia.

Clinicopathological significance of prolactin receptor expression in colorectal carcinoma and corresponding metastases.

The role of human prolactin and its receptor, the prolactin receptor, in colorectal cancer is largely unknown. Our study aimed to assess the prevalence of prolactin receptor expression, its association with clinicopathological variables, as well as its prognostic value, comparing results of primary tissues with those of corresponding metastases. In all, 373 primary colorectal cancer and 171 corresponding metastases were evaluated for prolactin receptor expression by immunohistochemistry using a tissue microarray technique. Immunoreactivity was semiquantitatively scored as either focal (<10% of tumor cells positive), moderate (10-50%), or extensive (>50%). Prolactin receptor expression was related to clinicopathological parameters as well as patient outcome. To substantiate our findings, prolactin receptor expression was additionally assessed in HT-29 and SW-480 colorectal cancer cell lines using western blot. Prolactin receptor expression was observed in 360 out of 373 (97%) primary tumors, with 21 (6%) cases showing focal, 55 (15%) moderate, and 284 (76%) extensive expression, respectively. Extensive prolactin receptor expression was significantly associated with tumor size (P=0.002) and grade (P<0.001) as well as histological subtype (P<0.001). Somer's D coefficients for concordance of primary tumors with corresponding lymph node and distant metastases were D=0.719 (P<0.001) and D=0.535 (P=0.001), respectively. Extensive prolactin receptor expression was significantly associated with disease progression (P=0.03) and cancer-specific survival (P=0.04) in patients with high-grade cancers. In conclusion, prolactin receptor expression is common in colorectal cancer, with high concordance between primary tumors and corresponding metastases. In view of evolving targeted therapy concepts in colorectal cancer, widespread prolactin receptor expression may offer a therapeutic perspective in affected patients.

Long term increased expression of the short form 1b prolactin receptor in PC-3 human prostate cancer cells decreases cell growth and migration, and causes multiple changes in gene expression consistent with reduced invasive capacity.

BACKGROUND: We have shown that treatment of human prostate cancer cells with the selective prolactin (PRL) receptor modulator, S179D PRL, inhibits growth in vitro, and the initiation and growth of xenografts in vivo. S179D PRL treatment also upregulates expression of the short form 1b (SF1b) PRL receptor, activation of which upregulates expression of the cell cycle-regulating protein, p21. METHODS: We examined the consequences of long term increased expression and activation of SF1b, at levels comparable to those resulting from treatment with S179D PRL, by creating PC-3-derived stable cell lines expressing a constitutively active form of SF1b, DeltaS2 SF1b. RESULTS: Increased expression of DeltaS2 SF1b decreased growth and migration of the cells. This was accompanied by an increase in cell-matrix interactions, and cell-cell aggregation when cells were plated on basement membrane components. Real-time PCR evaluated the expression of genes related to invasive capacity. Of particular interest was decreased expression of the protease, urokinase-type plaminogen activator, and its receptor, uPAR, and increased expression of its inhibitors, PAI-1 and 2. Also decreased in cells with increased expression of DeltaS2 SF1b was expression of basic fibroblast growth factor and vascular endothelial growth factor. CONCLUSION: We conclude that at least part of the beneficial effects of S179D PRL is the result of increased expression of SF1b, and that the effects of increased expression and activation of SF1b continue to be of potential benefit in the long term.

[Interaction of signal cascades induced by cAMP and prolactin in bovine oocyte-cumulus complexes].

Prolactin (PRL) is one of the pituitary hormones participating in the control of mammalian folliculo- and oogenesis. In the present study, the joint effect of PRL (50 ng/ml) and dibutyryl cAMP (dbcAMP, 1 mM) on oocyte maturation and the morphologic-functional state of surrounding cumulus cells was investigated in vitro. It has been shown that PRL totally suppresses the braking impact of dbcAMP on meiosis reinitiation and the completion of oocyte nuclear maturation. Furthermore, PRL partly inhibited cumulus expansion induced by dbcAMP, although it exerted the opposite effect in the control medium. In the presence of PRL, the inhibitory impact of dbcAMP on the proliferative activity of cumulus cells and on the PRL-elicited braking of destructive processes in the cells has been found. In cumulus cells, mRNA expression of PRL receptor long isoform was revealed by the RT-PCR method. The data obtained suggest an interaction of signal cascades induced by PRL and cAMP in bovine oocyte-cumulus complexes, with the coupling site of these cascades in oocytes being apparently different from that in cumulus cells.

Hyperprolactinemia and immunohistochemical expression of intracellular prolactin and prolactin receptor in primary central nervous system tumors and their relationship with cellular replication.

The role of prolactin (PRL) in the CNS remains uncertain. We evaluated the presence of hyperprolactinemia, intracellular prolactin (ICP), and prolactin receptor (PRL-R) in primary CNS tumors, and their relationship with cellular replication with a prospective cross-sectional study of 82 consecutive patients with primary CNS tumors admitted for neurosurgical resection between October 2003 and September 2005. Patients submitted to a questionnaire, and venous blood samples were obtained for measurement of serum PRL and TSH. Immunohistochemical analyses were performed to evaluate the presence of ICP, PRL-R, and Ki-67. Serum PRL levels ranged from 2 to 70 ng/ml, and hyperprolactinemia was detected in 25 cases (30.5%). ICP was detected in 18 patients (21.9%), in whom PRL ranged from 2 to 32 ng/ml. A positive correlation was found between PRL levels and the presence of ICP (Student's t test, P = 0.022). The PRL-R was observed immunohistochemically in 32 cases (39%). The frequencies of hyperprolactinemia, ICP, and PRL-R were similar across the several histological types of CNS tumors. Ki-67 index was similar in all groups. Hyperprolactinemia and intracellular presence of PRL and PRL-R were common findings in this population, suggesting a role for PRL in CNS tumor genesis.

[Preliminary study on the mechanisms of acupuncture in promoting embryo implantation in rats].

OBJECTIVE: To observe the influence of acupuncture on embryo implantation in rat model of embryo implantation dysfunction, and to primarily explore its possible mechanisms. METHODS: Pregnant rats were randomly allocated into the control group, the model group and the acupuncture group. The pregnancy rate and average number of blastocyst were observed, the serum levels of estrodiol (E2), progesterone (P4) and prolactin (PRL) were detected by RIA, and the protein and mRNA expression of progesterone receptor (PR) and prolactin receptor (PRLR) in endometrial tissue of implantation site were determined using immunohistochemical assay and RT-PCR respectively. RESULTS: The pregnancy rate and average number of blastocyst were significantly higher in the acupuncture group than those in the control group respectively (P <0.01). The serum levels of P4 and PRL as well as the protein and mRNA expression levels of PR and PRLR in the model group were significantly lower than those in the other two groups (P<0.05). CONCLUSION: Acupuncture can promote embryo implantation in rats to a certain degree, and its mechanism might be related with the effects of acupuncture in mediating the sexual hormone levels and the receptor expression of rats.

Tungstate administration improves the sexual and reproductive function in female rats with streptozotocin-induced diabetes.

BACKGROUND: Diabetes induces great alterations in female reproductive function. We analyzed the effects of tungstate, an anti-diabetic agent, on the reproductive function of healthy and diabetic female rats. METHODS: Healthy and streptozotocin-induced diabetic rats were treated with sodium tungstate (2 mg/ml in their drinking water) for 12 weeks. Markers of reproductive function and diabetes were measured in serum, and in uterus and ovaries by Western blot or RT-PCR. Reproductive function was also assessed by mating. RESULTS: Diabetic rats showed great impairment of libido, which was accompanied by a total loss of fertility (P < 0.05) and a decrease in the serum levels of FSH (P < 0.05) and LH (P < 0.05) compared with healthy rats. Tungstate treatment of diabetic rats partially recovered libido while fertility rate increased to 66.6%. This improvement was accompanied by a recovery of serum FSH (to a level higher than healthy rats) and LH. Moreover, tungstate treatment normalized ovarian expression of GLUT 3 hexose transporter, and estrogen, progesterone and FSH receptors, whereas only GLUT 3 and FSH receptors were normalized in the uterus. CONCLUSIONS: Our results indicate that the alterations in female reproduction in diabetes were partially reversed after tungstate treatment by a mechanism(s) involving the normalization of serum FSH and LH levels, and ovarian and uterine expression of FSH receptors and GLUT3.

Development of a real-time (Q) PCR assay to measure variation in expression of prolactin receptor mRNA in the hypothalamus and pituitary gland during late embryogenesis in turkeys and chickens.

Changes in levels of PRLR mRNA in the pituitary gland and hypothalamus of chickens and turkeys from embryonic day (ED) 15 and ED21 to 1 day post-hatch, respectively, were measured by real-time PCR. In both species, PRLR mRNA increased from low levels during the last week of ED to reach maxima at the peri-hatch period. Similarly, circulating levels of PRL also increased during this interval and were highly correlated with levels of the PRLR mRNA in both the pituitary gland and hypothalamus. This suggests that PRL was up-regulating its receptor. In support of this, stimulation of the turkey pituitary gland with VIP on ED24 resulted in a 4- and 3-fold increase in PRL and PRLR, respectively. Since VIP had no direct effect on the levels of PRLR transcript in the hypothalamus, it is likely that VIP is acting indirectly through increased PRL to up-regulate the number of receptors.