Circulating prolactin levels and risk of epithelial ovarian cancer

Efficacy and safety profiles of mood stabilizers and antipsychotics for bipolar depression: a systematic review

The whole picture of psychotropics for bipolar depression (BPD) remains unclear. This review compares the differences in efficacy and safety profiles among common psychotropics for BPD. MEDLINE, EMBASE, and PsycINFO were searched for proper studies. The changes in the depressive rating scale, remission/response rates, nervous system adverse events (NSAEs), gastrointestinal adverse events (GIAEs), metabolic parameters, and prolactin were compared between medication and placebo or among medications with the Cohen's d or number needed to treat/harm. The search provided 10 psychotropics for comparison. Atypical antipsychotics (AAPs) were superior to lithium and lamotrigine at alleviating acute depressive symptoms. Lithium was more likely to induce dry mouth and nausea. Cariprazine and aripiprazole seemed to be associated with an increased risk of akathisia and upper GIAEs. Lurasidone was associated with an increased risk of developing akathisia and hyperprolactinemia. Olanzapine, olanzapine-fluoxetine combination (OFC), and quetiapine were associated with an increased risk of NSAEs, metabolic risk, dry mouth, and constipation. Cariprazine, lurasidone, OFC, or quetiapine was optimal monotherapy for BPD. Further studies are needed to assess the efficacy and safety of lamotrigine for treating BPD. Adverse events varied widely across different drug types due to variations in psychopharmacological mechanisms, dosages, titration, and ethnicities.

Connections between prolactin and ovarian cancer

Ovarian cancer (OC) is characterized by a high morbidity and mortality, highlighting a great need for a better understanding of biological mechanisms that affect OC progression and improving its early detection methods. This study investigates effects of prolactin (PRL) on ovarian cancer cells, analyzes PRL receptors (PRLR) in tissue micro arrays and relates PRLR expression to survival of ovarian cancer. A database, composed of transcript profiles from OC, was searched for PRLR expression and results were put in relation to survival. Expression of PRLR in OC tissue sections and OC cell lines SKOV3, OV2008 and OVSAHO was assessed using immunohistochemistry, western blots and quantitative real-time PCR. The biological function of PRLR was evaluated by proliferation, colony formation and wound healing assays. Levels of PRLR mRNA are related to survival; in epithelial OC a high PRLR mRNA expression is related to a shorter survival. Analysis of a tissue micro array consisting of 84 OC showed that 72% were positive for PRLR immuno-staining. PRLR staining tended to be higher in OC of high grade tumors compared to lower grades. PRLR mRNA and protein can further be detected in OC cell lines. Moreover, in vitro treatment with PRL significantly activated the JAK/STAT pathway. PRLR expression is associated with OC survivals. PRL and its receptor may play an onco-modulatory role and promote tumor aggressiveness in OC. Alternatively, increased PRLR levels may form a base for the development of PRLR antagonist or PRLR antagonist-drug conjugate to increase selective uptake of anti-cancer drugs.

Prolactin and Risk of Epithelial Ovarian Cancer

BACKGROUND

Prolactin is synthesized in the ovaries and may play a role in ovarian cancer etiology. One prior prospective study observed a suggestive positive association between prolactin levels and risk of ovarian cancer.

METHODS

We conducted a pooled case-control study of 703 cases and 864 matched controls nested within five prospective cohorts. We used unconditional logistic regression to calculate adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association between prolactin and ovarian cancer risk. We examined heterogeneity by menopausal status at blood collection, body mass index (BMI), age, and histotype.

RESULTS

Among women with known menopausal status, we observed a positive trend in the association between prolactin and ovarian cancer risk (P _trend = 0.045; OR, quartile 4 vs. 1 = 1.34; 95% CI = 0.97-1.85), but no significant association was observed for premenopausal or postmenopausal women individually (corresponding OR = 1.38; 95% CI = 0.74-2.58; P _trend = 0.32 and OR = 1.41; 95% CI = 0.93-2.13; P _trend = 0.08, respectively; P _{heterogeneity} = 0.91). In stratified analyses, we observed a positive association between prolactin and risk for women with BMI ≥ 25 kg/m², but not BMI < 25 kg/m² (corresponding OR = 2.68; 95% CI = 1.56-4.59; P _trend < 0.01 and OR = 0.90; 95% CI = 0.58-1.40; P _trend = 0.98, respectively; P _{heterogeneity} < 0.01). Associations did not vary by age, postmenopausal hormone therapy use, histotype, or time between blood draw and diagnosis.

CONCLUSIONS

We found a trend between higher prolactin levels and increased ovarian cancer risk, especially among women with a BMI ≥ 25 kg/m².

IMPACT

This work supports a previous study linking higher prolactin with ovarian carcinogenesis in a high adiposity setting. Future work is needed to understand the mechanism underlying this association.

Impact of oral contraceptives and breastfeeding on disease activity in a sample of Egyptian rheumatoid arthritis patients

Background

Women are more affected by rheumatoid arthritis (RA) than men and the incidence of RA in women increases around the age of menopause indicating that hormonal factors may have a role in disease pathogenesis and progression. Despite several studies on the role of sex hormones and oral contraceptives (OCs) in RA patients, the effect of combined oral contraceptives on RA disease activity is still controversial, and since few studies have been performed in Egypt on this issue so we aimed to study the effect of OCs, breastfeeding, and prolactin on disease activity and their relation to the titer of autoantibodies in female Egyptian RA patients.

Results

One hundred twenty married female RA patients were classified into three groups based on the OCs use (n = 40 each); current, past and non-users and according to lactation into three groups; lactating using OCs (n = 22), lactating not using OCs (n = 30), and non-lactating (n = 68). Our patients were using combined estrogen-progestin oral contraceptives. Clinical manifestations, disease activity, and laboratory findings were determined. The clinical manifestations including arthritis, and morning stiffness were significantly reduced in current users in comparison to past and non-users. Mean DAS28 was reduced significantly (p < 0.05) in current and past users of OCs. Also, using OCs during lactation reduced the clinical manifestations significantly. Lactating women who were not using OCs had significantly high DAS28 and ESR (p < 0.05) in comparison to lactating using OCs and non-lactating. On the other hand, using OCs reduced serum prolactin significantly. Lactating women not using OCs had significantly high serum prolactin (p < 0.05) and (p < 0.001) in comparison to lactating using OCs and non-lactating respectively which was correlated with DAS28 score.

Conclusion

Oral contraceptives may be considered in RA female patients not only as a suitable birth control method but also it has a controlling effect on disease activity even during lactation.

Message

Oral contraceptives ameliorate disease activity in RA patients

Breastfeeding and the risk of epithelial ovarian cancer among women with a BRCA1 or BRCA2 mutation

OBJECTIVE

BRCA mutation carriers face a high lifetime risk of developing ovarian cancer. The strong inverse association between breastfeeding and the risk of ovarian cancer is established in the general population but is less well studied among women with a germline BRCA1 or BRCA2 mutation.

METHOD

Thus, we conducted a matched case-control analysis to evaluate the association between breastfeeding history and the risk of developing ovarian cancer. After matching for year of birth, country of residence, BRCA gene and personal history of breast cancer, a total of 1650 cases and 2702 controls were included in the analysis. Conditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence intervals (CI) associated with various breastfeeding exposures.

RESULTS

A history of ever-breastfeeding was associated with a 23% reduction in risk (OR = 0.77; 95%CI 0.66-0.90; P = 0.001). The protective effect increased with breastfeeding from one month to seven months after which the association was relatively stable. Compared to women who never breastfed, breastfeeding for seven or more months was associated with a 32% reduction in risk (OR = 0.68; 95%CI 0.57-0.81; P < 0.0001) and did not vary by BRCA gene or age at diagnosis. The combination of breastfeeding and oral contraceptive use was strongly protective (0.47; 95%CI 0.37-0.58; P < 0.0001).

CONCLUSIONS

These findings support a protective effect of breastfeeding for at least seven months among women with a BRCA1 or BRCA2 mutation, that is independent of oral contraceptive use.

Human Cytomegalovirus Infection Induces High Expression of Prolactin and Prolactin Receptors in Ovarian Cancer

One of the potential biomarkers for ovarian cancer patients is high serum level of prolactin (PRL), which is a growth factor that may promote tumor cell growth. The prolactin receptor (PRLR) and human cytomegalovirus (HCMV) proteins are frequently detected in ovarian tumor tissue specimens, but the potential impact of HCMV infection on the PRL system have so far not been investigated. In this study, HCMV’s effects on PRL and PRLR expression were assessed in infected ovarian cancer cells (SKOV3) by PCR and Western blot techniques. The levels of both PRL and PRLR transcripts as well as the corresponding proteins were highly increased in HCMV-infected SKOV3 cells. Tissue specimens obtained from 10 patients with ovarian cancer demonstrated high expression of PRLR, HCMV-IE, and pp65 proteins. Extensive expression of PRLR was detected in all examined ovarian tumor tissue specimens except for one from a patient who had focal expression of PRLR and this patient was HCMV-negative in her tumor. In conclusion, PRL and PRLR were induced to high levels in HCMV-infected ovarian cancer cells and PRLR expression was extensively detected in HCMV-infected ovarian tissue specimens. Highly induced PRL and PRLR by HCMV infection may be of relevance for the oncomodulatory role of this virus in ovarian cancer.

Fallopian tube initiation of high grade serous ovarian cancer and ovarian metastasis: Mechanisms and therapeutic implications

Ovarian cancer is the most lethal gynecologic malignancy and the fifth leading cause of cancer-related death in women. Although outcomes have improved in recent years, there remains an unmet clinical need to understand the early pathogenesis of ovarian cancer in order to identify new diagnostic approaches and agents of chemoprevention and chemotherapy. While high grade serous ovarian cancer (HGSOC), the most abundant histotype, was initially thought to arise from the ovarian surface epithelium, there is an increasing body of evidence suggesting that HGSOC originates in the fallopian tube. With this new understanding of cell of origin, understanding of disease development requires analysis with a novel perspective. Currently, factors that drive the initiation and migration of dysplastic tubal epithelial cells from the fallopian tube to the ovary are not yet fully defined. These factors include common mutations to fallopian tube epithelial cells, as well as factors originating from both the fallopian tube and ovary which are capable of inducing transformation and dissemination in said cells. Here, we review these changes, their causative agents, and various potential means of intervention.

Hyperprolactinaemia

Hyperprolactinaemia is one of the most common problems in clinical endocrinology. It relates with various aetiologies (physiological, pharmacological, pathological), the clarification of which requires careful history taking and clinical assessment. Analytical issues (presence of macroprolactin or of the hook effect) need to be taken into account when interpreting the prolactin values. Medications and sellar/parasellar masses (prolactin secreting or acting through “stalk effect”) are the most common causes of pathological hyperprolactinaemia. Hypogonadism and galactorrhoea are well-recognized manifestations of prolactin excess, although its implications on bone health, metabolism and immune system are also expanding. Treatment mainly aims at restoration and maintenance of normal gonadal function/fertility, and prevention of osteoporosis; further specific management strategies depend on the underlying cause. In this review, we provide an update on the diagnostic and management approaches for the patient with hyperprolactinaemia and on the current data looking at the impact of high prolactin on metabolism, cardiovascular and immune systems.

Ovarian cancer risk factors by tumor aggressiveness: An analysis from the Ovarian Cancer Cohort Consortium

Ovarian cancer risk factors differ by histotype; however, within subtype, there is substantial variability in outcomes. We hypothesized that risk factor profiles may influence tumor aggressiveness, defined by time between diagnosis and death, independent of histology. Among 1.3 million women from 21 prospective cohorts, 4,584 invasive epithelial ovarian cancers were identified and classified as highly aggressive (death in <1 year, n = 864), very aggressive (death in 1 to < 3 years, n = 1,390), moderately aggressive (death in 3 to < 5 years, n = 639), and less aggressive (lived 5+ years, n = 1,691). Using competing risks Cox proportional hazards regression, we assessed heterogeneity of associations by tumor aggressiveness for all cases and among serous and endometrioid/clear cell tumors. Associations between parity (p_het = 0.01), family history of ovarian cancer (p_het = 0.02), body mass index (BMI; p_het ≤ 0.04) and smoking (p_het < 0.01) and ovarian cancer risk differed by aggressiveness. A first/single pregnancy, relative to nulliparity, was inversely associated with highly aggressive disease (HR: 0.72; 95% CI [0.58-0.88]), no association was observed for subsequent pregnancies (per pregnancy, 0.97 [0.92-1.02]). In contrast, first and subsequent pregnancies were similarly associated with less aggressive disease (0.87 for both). Family history of ovarian cancer was only associated with risk of less aggressive disease (1.94 [1.47-2.55]). High BMI (≥35 vs. 20 to < 25 kg/m² , 1.93 [1.46-2.56] and current smoking (vs. never, 1.30 [1.07-1.57]) were associated with increased risk of highly aggressive disease. Results were similar within histotypes. Ovarian cancer risk factors may be directly associated with subtypes defined by tumor aggressiveness, rather than through differential effects on histology. Studies to assess biological pathways are warranted.

Ovarian cancer risk factors by tumor aggressiveness: An analysis from the Ovarian Cancer Cohort Consortium

Ovarian cancer risk factors differ by histotype; however, within subtype, there is substantial variability in outcomes. We hypothesized that risk factor profiles may influence tumor aggressiveness, defined by time between diagnosis and death, independent of histology. Among 1.3 million women from 21 prospective cohorts, 4,584 invasive epithelial ovarian cancers were identified and classified as highly aggressive (death in <1 year, n = 864), very aggressive (death in 1 to < 3 years, n = 1,390), moderately aggressive (death in 3 to < 5 years, n = 639), and less aggressive (lived 5+ years, n = 1,691). Using competing risks Cox proportional hazards regression, we assessed heterogeneity of associations by tumor aggressiveness for all cases and among serous and endometrioid/clear cell tumors. Associations between parity (phet = 0.01), family history of ovarian cancer (phet = 0.02), body mass index (BMI; phet ≤ 0.04) and smoking (phet < 0.01) and ovarian cancer risk differed by aggressiveness. A first/single pregnancy, relative to nulliparity, was inversely associated with highly aggressive disease (HR: 0.72; 95% CI [0.58-0.88]), no association was observed for subsequent pregnancies (per pregnancy, 0.97 [0.92-1.02]). In contrast, first and subsequent pregnancies were similarly associated with less aggressive disease (0.87 for both). Family history of ovarian cancer was only associated with risk of less aggressive disease (1.94 [1.47-2.55]). High BMI (≥35 vs. 20 to < 25 kg/m2 , 1.93 [1.46-2.56] and current smoking (vs. never, 1.30 [1.07-1.57]) were associated with increased risk of highly aggressive disease. Results were similar within histotypes. Ovarian cancer risk factors may be directly associated with subtypes defined by tumor aggressiveness, rather than through differential effects on histology. Studies to assess biological pathways are warranted.

Ovarian cancer risk factors by tumor aggressiveness: An analysis from the Ovarian Cancer Cohort Consortium

Ovarian cancer risk factors differ by histotype; however, within subtype, there is substantial variability in outcomes. We hypothesized that risk factor profiles may influence tumor aggressiveness, defined by time between diagnosis and death, independent of histology. Among 1.3 million women from 21 prospective cohorts, 4,584 invasive epithelial ovarian cancers were identified and classified as highly aggressive (death in <1 year, n = 864), very aggressive (death in 1 to < 3 years, n = 1,390), moderately aggressive (death in 3 to < 5 years, n = 639), and less aggressive (lived 5+ years, n = 1,691). Using competing risks Cox proportional hazards regression, we assessed heterogeneity of associations by tumor aggressiveness for all cases and among serous and endometrioid/clear cell tumors. Associations between parity (p_het = 0.01), family history of ovarian cancer (p_het = 0.02), body mass index (BMI; p_het ≤ 0.04) and smoking (p_het < 0.01) and ovarian cancer risk differed by aggressiveness. A first/single pregnancy, relative to nulliparity, was inversely associated with highly aggressive disease (HR: 0.72; 95% CI [0.58-0.88]), no association was observed for subsequent pregnancies (per pregnancy, 0.97 [0.92-1.02]). In contrast, first and subsequent pregnancies were similarly associated with less aggressive disease (0.87 for both). Family history of ovarian cancer was only associated with risk of less aggressive disease (1.94 [1.47-2.55]). High BMI (≥35 vs. 20 to < 25 kg/m² , 1.93 [1.46-2.56] and current smoking (vs. never, 1.30 [1.07-1.57]) were associated with increased risk of highly aggressive disease. Results were similar within histotypes. Ovarian cancer risk factors may be directly associated with subtypes defined by tumor aggressiveness, rather than through differential effects on histology. Studies to assess biological pathways are warranted.

Giant prolactinoma, germline BRCA1 mutation, and depression: a case report

Background

Giant prolactinomas are very rare pituitary tumors that may exhibit an aggressive behavior and present with a life-threatening condition.

Case presentation

A 25-year-old white woman was admitted to our hospital with a headache, psychomotor retardation, reduced vision, and loss of autonomy in daily activities. Her past medical history was significant for having oligomenorrhea and a depressive syndrome since her mother’s death. She also had a breast cancer gene 1 (BRCA1) mutation and a family history of breast cancer. She had marked hyperprolactinemia (7615 ng/dL), central hypocortisolism, growth hormone deficiency, and a giant pituitary tumor (52 × 30 × 33 mm) which was shown in magnetic resonance imaging with obstructive hydrocephalus, requiring emergency surgery. Treatment with cabergoline led to a 99.8% reduction in serum prolactin levels and significant tumor shrinkage. Her depressive symptoms progressively improved and psychiatric drugs were withdrawn after 3 months of cabergoline treatment. Currently, she is being followed in Endocrinology, Neurosurgery, and Neurophthalmology out-patient clinics and in a breast cancer unit. Careful monitoring, support, and follow-up will be essential throughout this patient’s life.

Conclusions

This case is a rare presentation of a giant prolactinoma in a young woman, who presented a life-threatening event. She also had an unexpected association between diseases or symptoms that may have contributed to the delay in diagnosis. Given the concomitant presence of a giant prolactinoma, a BRCA1 mutation, and depressive symptoms, a possible association was hypothesized. The breast cancer risk in a BRCA1 mutation carrier and the possible interference of hyperprolactinemia and life events were also discussed. However this hypothesis requires further investigation.

Diagnostic markers for the detection of ovarian cancer in BRCA1 mutation carriers

Background

Screening for ovarian cancer (OC) in women at high risk consists of a combination of carbohydrate antigen 125 (CA125) and transvaginal ultrasound, despite their low sensitivity and specificity. This could be improved by the combination of several biomarkers, which has been shown in average risk patients but has not been investigated until now in female BRCA mutation carriers.

Methods

Using a multiplex, bead-based, immunoassay system, we analyzed the concentrations of leptin, prolactin, osteopontin, insulin-like growth factor II, macrophage inhibitory factor, CA125 and human epididymis antigen 4 in 26 healthy wild type women, 26 healthy BRCA1 mutation carriers, 28 wildtype OC patients and 26 OC patients with BRCA1 mutation.

Results

Using the ROC analysis, we found a high overall sensitivity of 94.3% in differentiating healthy controls from OC patients with comparable results in the wildtype subgroup (sensitivity 92.8%, AUC = 0.988; p = 5.2e-14) as well as in BRCA1 mutation carriers (sensitivity 95.2%, AUC = 0.978; p = 1.7e-15) at an overall specificity of 92.3%.

The used algorithm also allowed to identify healthy BRCA1 mutation carriers when compared to healthy wildtype women (sensitivity 88.4%, specificity 80.7%, AUC = 0.895; p = 6e-08), while this was less pronounced in patients with OC (sensitivity 66.7%, specificity 67.8%, AUC = 0.724; p = 0.00065).

Conclusion

We have developed an algorithm, which can differentiate between healthy women and OC patients and have for the first time shown, that such an algorithm can also be used in BRCA mutation carriers. To clarify a suggested benefit to the existing early detection program, large prospective trials with mainly early stage OC cases are warranted.

Parity History Determines a Systemic Inflammatory Response to Spread of Ovarian Cancer in Naturally Aged Mice

Aging intersects with reproductive senescence in women by promoting a systemic low-grade chronic inflammation that predisposes women to several diseases including ovarian cancer (OC). OC risk at menopause is significantly modified by parity records during prior fertile life. To date, the combined effects of age and parity on the systemic inflammation markers that are particularly relevant to OC initiation and progression at menopause remain largely unknown. Herein, we profiled a panel of circulating cytokines in multiparous versus virgin C57BL/6 female mice at peri-estropausal age and investigated how cytokine levels were modulated by intraperitoneal tumor induction in a syngeneic immunocompetent OC mouse model. Serum FSH, LH and TSH levels increased with age in both groups while prolactin (PRL) was lower in multiparous respect to virgin mice, a finding previously observed in parous women. Serum CCL2, IL-10, IL-5, IL-4, TNF-α, IL1-β and IL-12p70 levels increased with age irrespective of parity status, but were specifically reduced following OC tumor induction only in multiparous mice. Animals developed hemorrhagic ascites and tumor implants in the omental fat band and other intraperitoneal organs by 12 weeks after induction, with multiparous mice showing a significantly extended survival. We conclude that previous parity history counteracts aging-associated systemic inflammation possibly by reducing the immunosuppression that typically allows tumor spread. Results suggest a partial impairment of the M2 shift in tumor-associated macrophages as well as decreased stimulation of regulatory B-cells in aged mice. This long term, tumor-concurrent effect of parity on inflammation markers at menopause would be a contributing factor leading to decreased OC risk.

Antidepressant use and circulating prolactin levels

PURPOSE

To determine whether antidepressants (AD), specifically selective serotonin reuptake inhibitors (SSRIs), are linked to elevated prolactin levels among the general population.

METHODS

Circulating prolactin levels were available for 4593 healthy participants in the Nurses' Health Study (NHS) and NHS2, including 267 AD users. We fit generalized linear models to calculate and compare adjusted mean prolactin levels between AD users and non-users and further among SSRI users. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) for "elevated" prolactin levels (>11 ng/mL) comparing AD users to non-users. We evaluated AD use and change in prolactin levels among 610 NHS participants with two measurements an average of 11 years apart.

RESULTS

Adjusted geometric mean prolactin levels were similar among SSRI users (13.2 ng/mL, 95 % CI 12.2-14.4), users of other classes of ADs (12.7 ng/mL, 95 % CI 11.0-14.6), and non-users (13.1 ng/mL, 95 % CI 12.8-13.4). Neither AD use (OR 1.17, 95 % CI 0.89-1.53) nor SSRI use (OR 0.95, 95 % CI 0.66-1.38) was associated with elevated prolactin levels. Change in prolactin levels was similar across women who started, stopped, consistently used, or never used ADs.

CONCLUSIONS

This study does not support the hypothesis that AD use would influence breast cancer risk via altered prolactin levels. These results provide some evidence that use of ADs to treat depression or other conditions may not substantially increase prolactin levels in the majority of women.

Reproductive factors, adiposity, breastfeeding and their associations with ovarian cancer in an Asian cohort

PURPOSE

The aim of this study was to assess associations of breastfeeding, adiposity and reproductive risk factors with ovarian cancer risk in a Singaporean population. In addition to the main analysis, interaction effects of parity on other risk factors were examined.

METHODS

A retrospective cohort consisting of 28,201 women with 107 incident ovarian cancers in up to 17 years of follow-up from the Singapore Breast Cancer Screening Project (1994-1997) was studied. Hazard ratios (HRs) for risk factors were estimated using Cox proportional hazards models.

RESULTS

Body mass index and breastfeeding were found to have no statistical significant association with ovarian cancer risk. Gravidity was inversely associated with ovarian cancer risk [each pregnancy, adjusted HR 0.89, 95% confidence interval (CI) 0.81, 0.97], while results for parity were very similar (per delivery, HR 0.89, 95% CI 0.81, 0.98). Each additional year of ovulatory period was found to increase ovarian cancer risk by 2% (HR 1.02, 95% CI 1.00, 1.04). Each year increase in total duration of oral contraceptive use reduced ovarian cancer risk by 6% (HR 0.94, 95% CI 0.85, 1.02).

CONCLUSIONS

Parity, gravidity and shorter ovulatory period were associated with lower ovarian cancer risk. Breastfeeding and body mass index were not associated with ovarian cancer risk, while increased duration of oral contraceptive use resulted in borderline risk reduction. No significant evidence was found to suggest that parity had an interaction effect on any risk factor.

STAT3 activation is required for the antiapoptotic effects of prolactin in cervical cancer cells

BACKGROUND

Prolactin (PRL) has been implicated in the development of different types of cancer. However, signaling pathways might be activated depending on various forms of prolactin receptor (PRLR). JAK/STAT is an important pathway associated with PRL effects. The activation of JAK/STAT pathway might activate antiapoptotic genes that could importantly lead to progression of tumorigenesis. Recently, we have reported that PRL is associated with cell survival by inhibition of apoptosis and the precise activated signaling pathways for this process are still questioned. The purpose of this study was to evaluate the activation of different signaling pathways in response to PRL as well as to identify the induction of antiapoptotic genes.

METHODS

Cervical cancer cell lines HeLa, SiHa and C-33 A were stimulated with PRL (200 ng/mL) for 30 and 60 min and non stimulated cells were used to measure basal protein expression. Inhibition assays were performed by using Jak2 specific inhibitor AG490, either alone or in combination with PRL for 48 h. Western blot were carried out to evaluate protein induction of the different signaling pathways and antiapoptotic proteins. Significant effects were determined by using ANOVA test.

RESULTS

STAT3 was significantly activated in cervical cancer lines in comparison with non-tumorigenic keratinocytes HaCaT. No significant differences were found when analyzing MAPK and PI3K signaling pathways. An increase of antiapoptotic genes Bcl-xl, Bcl-2, survivin and Mcl-1 was observed after stimulus with PRL; however, after inhibition with AG490, the induction of antiapoptotic genes was decreased.

CONCLUSION

Our data suggests that STAT3 is an important signaling pathway activated by PRL in cervical cancer cells and it modulates the induction of antiapoptotic genes. Blocking STAT3 could represent a possible therapeutic strategy in cervical cancer.

Hyperprolactinemia: pathophysiology and therapeutic approach

Prolactin (PRL) is a hormone, mainly secreted by lactotroph cells of the anterior pituitary gland. Recent studies have shown it may also be produced by many extrapituitary cells. Its well-recognized PRL plays an important role in lactation during pregnancy, but it is involved in other biological functions such as angiogenesis, immunoregulation and osmoregulation. Hyperprolactinemia is a typical condition producing reproductive dysfunction in both sexes, resulting in hypogonadism, infertility and galactorrhea. It may be also asymptomatic. Lactotroph adenomas (prolactinoma) is one of the most common cause of PRL excess, representing approximately 40% of all pituitary tumors. Several other conditions should be excluded before a clear diagnosis of hyperprolactinemia is made. Hyperprolactinemia may be secondary to pharmacological or pathological interruption of hypothalamic-pituitary dopaminergic pathways or idiopathic. Stress, renal failure or hypothyroidism are other frequent conditions to exclude in patients with hyperprolactinemia. We will review biochemical characteristics and physiological functions of that hormone. Clinical and pharmacological approach to hyperprolactinemia will also be discussed.

Bioactive prolactin levels and risk of breast cancer: a nested case-control study

BACKGROUND

Prolactin is a lactogenic hormone associated with breast cancer risk in prospective studies, which used immunoassays. The immunoassay captures multiple isoforms and may not fully reflect the biologic activity of prolactin relevant to breast carcinogenesis.

METHODS

We considered plasma bioactive prolactin levels measured by the Nb2 lymphoma cell bioassay, which is sensitive to the somatolactogenic activity of prolactin and growth hormone, within a nested case-control study of invasive breast cancer in the Nurses' Health Studies (NHS/NHSII). We also considered associations with breast cancer risk factors.

RESULTS

We had bioassay measures on 1,329 cases and 1,329 controls. Bioassay levels were inversely associated with parity (4+ vs. 0 children = -18%, P = 0.01), body mass index (30+ vs. <22 kg/m(2) = -16%, P < 0.01), and age at menopause (53+ vs. 48 years = -18%, P = 0.03) and positively with family history of breast cancer (yes vs. no = 14%, P < 0.01). The relative risk (RR) comparing the top versus bottom quartile of bioassay levels was 1.19 [95% confidence intervals (CI), 0.94-1.51; Ptrend = 0.18]. The association was suggestively stronger for postmenopausal (RR = 1.36; 95% CI, 0.93-1.98; Ptrend = 0.12) versus premenopausal women (RR = 0.99; 95% CI, 0.71-1.37; Ptrend = 0.71). There was an association for cases diagnosed <4 years after blood draw (RR = 2.66; 95% CI, 1.45-4.89; Ptrend < 0.01), but not for cases diagnosed later. We did not observe differential associations by estrogen receptor status or other tumor characteristics.

CONCLUSIONS

Our results show similar associations for prolactin levels measured by bioassay and by immunoassay with both breast cancer risk factors and risk.

IMPACT

Future work examining risk prediction model of breast cancer can use the immunoassay to accurately characterize risk.

Prolactin signaling enhances colon cancer stemness by modulating Notch signaling in a Jak2-STAT3/ERK manner

Prolactin (PRL) is a secretory cytokine produced by various tissues. Binding to the cognate PRL receptor (PRLR), it activates intracellular signaling via janus kinase (JAK), extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription (STAT) proteins. PRL regulates diverse activities under normal and abnormal conditions, including malignancies. Previous clinical data suggest serum PRL levels are elevated in colorectal cancer (CRC) patients. In this study, we first determined the expression of PRL and PRLR in colon cancer tissue and cell lines. Higher levels of PRLR expression were observed in the cancer cells and cell lines compared with normal colonic epithelial cells. Incubation of colon cancer cells with PRL-induced JAK2, STAT3 and ERK1/2 phosphorylation and increased expression of Jagged 1, which is a Notch-1 receptor ligand. Notch signaling regulates CRC stem cell population. We observed increased accumulation of the cleaved/active form of Notch-1 receptor (Notch intracellular domain) and increased expression of Notch responsive genes HEY1, HES1 and stem cell marker genes DCLK1, LGR5, ALDH1 and CD44. Finally, inhibiting PRL induced JAK2-STAT3 and JAK2-ERK1/2 using AG490 and PD98059, respectively, leads to complete abrogation of Notch signaling, suggesting a role for this pathway in regulating CRC stem cells. Together, our results demonstrate that cytokine signaling induced by PRL is active in colorectal cancers and may provide a novel target for therapeutic intervention.