The risks of medical treatment of prolactinoma

Identification and structural elucidation of an oxidation product generated during stability studies of Cabergoline drug product

Cabergoline is a dopamine agonist with applications as anti-Parkinson drug and prolactin inhibitor. The cabergoline drug product Laktostop® 50 µg/mL is used in veterinary medicine for lactation suppression in cats and dogs e.g. during false pregnancy. Recently, during ongoing HPLC stability testing of Laktostop® 50 µg/mL a new oxidation product of Cabergoline was identified. A synthesis starting from Cabergoline was developed, followed by full characterization of the unknown impurity. Preliminary HPLC and LC-MS analyses indicated the unknown impurity as mono-oxygenated product of Cabergoline (Cabergoline N-oxide) that is presumably formed with oxygen by a radical mechanism. Thus, Cabergoline was treated with oxidizing agents such as m-chloroperoxybenzoic acid to afford the desired Cabergoline-N-oxide as a byproduct. After isolation by column chromatography, NMR and LC-MS-MS studies provided evidence that oxidation occurred at the N-allyl nitrogen of Cabergoline to form Cabergoline-N-oxide. © 1905 Elsevier Science. All rights reserved.

Comparative efficacy of metformin combined with cabergoline versus metformin alone in patients with PCOS and hyperprolactinemia: A systematic review and meta-analysis of randomized controlled trials

Isntroduction. Polycystic ovary syndrome (PCOS) is a multifaceted endocrine-gynecological condition affecting a substantial number of women during their reproductive years. Metformin (MET) has been shown to improve ovarian function in PCOS-related conditions, while cabergoline is recognized for its powerful and sustained ability to reduce prolactin levels. This study investigates the potential impact of combining cabergoline with metformin while comparing it with metformin alone in the treatment of PCOS alongside hyperprolactinemia.

METHOD

To gather data, we searched PubMed, Google Scholar, ScienceDirect, and Cochrane Central. Eligible studies were randomized controlled trials involving patients with PCOS and hyperprolactinemia. Outcome measures included changes in the levels of prolactin, testosterone, DHEAS, BMI and menstrual irregularities. RevMan version 5.4 was used to analyze outcomes.

RESULT

This study incorporated three Randomized Controlled Trials (RCTs) involving 405 participants in total. Patients receiving a combination of metformin and cabergoline experienced significant reductions in prolactin and testosterone levels (p= <0.0001 and p=<0.0001, respectively). Conversely, alterations in DHEAS levels and BMI did not reach statistical significance (p = 0.19 and p = 0.71, respectively). Notably, women solely prescribed metformin exhibited significantly higher rates of menstrual irregularities compared to those receiving both metformin and cabergoline (p=<0.0001).

CONCLUSION

Our analysis underscores the synergistic effect achieved by pairing metformin and cabergoline in patients with PCOS and hyperprolactinemia. However, we encountered only a restricted number of studies meeting our criteria. It is imperative to consistently assess the combined effects of metformin and cabergoline to gain deeper insights into their effectiveness in addressing PCOS and hyperprolactinemia.

Curcumin affects autophagy of prolactinoma cells by upregulating miR-206 to exert antitumor effects

We explored the effects of curcumin on the aberrant biological behaviors of prolactinoma cells and the downstream pathways through which curcumin exerts its antitumor effects. We used quantitative reverse transcription-polymerase chain reaction assays to measure miR-206 expression levels in peripheral blood samples from patients with prolactinoma before and after curcumin treatment. We also investigated the proliferation level, viability, and invasion ability of groups of cells treated with different concentrations of curcumin using 3-(4,5)-dimethylthiahiazo (-z-y1)-3-di-phenytetrazoliumromide (MTT) assays, cell cloning assays, and Transwell assays, respectively. Furthermore, we determined the levels of autophagy-related proteins and protein kinase B/mammalian target of the rapamycin (Akt/mTOR) signaling pathway-related proteins in each group of treated cells by western blot. Curcumin treatment upregulated miR-206 expression levels in the peripheral blood of patients with prolactinoma and in GH3 cells. Knockdown of miR-206 expression enhanced the proliferation and invasive ability of GH3 cells, while curcumin treatment effectively inhibited the aberrant biological behavior of GH3 cells enhanced by miR-206 knockdown. miR-206 knockdown also activated the Akt/mTOR signaling pathway and inhibited autophagy in GH3 cells, and these changes were effectively reversed by curcumin treatment. Thus, curcumin inhibited the Akt/mTOR signaling pathway and promoted cell autophagy by miR-206 upregulation, resulting in antitumor effects that inhibited prolactinoma cell proliferation and invasion.

Transcriptomic Profiling of Lactotroph Pituitary Neuroendocrine Tumors via RNA Sequencing and Ingenuity Pathway Analysis

INTRODUCTION

Lactotroph pituitary neuroendocrine tumors (PitNETs) are common pituitary tumors, but their underlying molecular mechanisms remain unclear. This study aimed to investigate the transcriptomic landscape of lactotroph PitNETs and identify potential molecular mechanisms and therapeutic targets through RNA sequencing and ingenuity pathway analysis (IPA).

METHODS

Lactotroph PitNET tissues from five surgical cases without dopamine agonist treatment underwent RNA sequencing. Normal pituitary tissues from 3 patients served as controls. Differentially expressed genes (DEGs) were identified, and the functional pathways and gene networks were explored by IPA.

RESULTS

Transcriptome analysis revealed that lactotroph PitNETs had gene expression patterns that were distinct from normal pituitary tissues. We identified 1,172 upregulated DEGs, including nine long intergenic noncoding RNAs (lincRNAs) belonging to the top 30 DEGs. IPA of the upregulated DEGs showed that the estrogen receptor signaling, oxidative phosphorylation signaling, and EIF signaling were activated. In gene network analysis, key upstream regulators, such as EGR1, PRKACA, PITX2, CREB1, and JUND, may play critical roles in lactotroph PitNETs.

CONCLUSION

This study provides a comprehensive transcriptomic profile of lactotroph PitNETs and highlights the potential involvement of lincRNAs and specific signaling pathways in tumor pathogenesis. The identified upstream regulators may be potential therapeutic targets for future investigations.

Alternations of Blood Pressure Following Surgical or Drug Therapy for Prolactinomas

Several subtypes of pituitary neuroendocrine tumors (PitNETs), such as acromegaly and Cushing's disease, can result in hypertension. However, whether prolactinoma is associated with this complication remains unknown. Moreover, the effect of treatment with surgery or drugs on blood pressure (BP) is unknown. Herein, a retrospective study reviewed 162 patients with prolactinoma who underwent transsphenoidal surgery between January 2005 and December 2022. BP measurements were performed 1 day before and 5 days after surgery. Accordingly, patients' medical characteristics were recorded. In addition, in situ rat and xenograft nude-mice prolactinoma models have been used to mimic prolactinoma. In vivo BP and serum prolactin (PRL) levels were measured after cabergoline (CAB) administration in both rats and mice. Our data suggest that surgery can effectively decrease BP in prolactinoma patients with or without hypertension. The BP-lowering effect was significantly associated with several variables, including age, sex, disease duration, tumor size, invasion, dopamine agonists (DAs)-resistance, recurrence, and preoperative PRL levels. Moreover, in situ and xenograft prolactinomas induced BP elevation, which was alleviated by CAB treatment without and with a statistical difference in rats and mice, respectively. Thus, surgery or CAB can decrease BP in prolactinoma, indicating that pre- and postoperative BP management becomes essential.

Prognostic factors for surgical treatment of prolactin-secreting pituitary adenomas

Introduction

Usually, prolactinomas are treated with dopamine agonists (DA). Surgery is considered an option when the patient cannot bear or does not respond positively to DA therapy.

Aim

This study aims to determine the early and late outcomes of surgery, with particular emphasis on developing prognostic factors for surgical treatment and analyzing risk factors affecting the recurrence of hyperprolactinemia and prolactinoma.

Material and methods

This retrospective study was conducted at the Feofaniya Clinical Hospital of the State Administration of Affairs (Kyiv, Ukraine), evaluating 109 patients' records from 2009 to 2019. The main patients' inclusion criteria were: serum prolactin (PRL) level of more than 100 ng/ml, presence of pituitary adenoma (PA) on MRI, histologically approved PA by microscopy. According to the size of the prolactin-secreting PA (PSPAs) the selected 109 patients were divided into two groups: micro- (≤10 mm, n = 75) and macroadenoma group (10-40 mm, n = 34).

Results

1 month after the operation, PRL levels decreased by 87% (p < 0.001), 12 months-by 93% (p < 0.001). After receiving surgery and DA therapy for 12 months 77.1% of patients achieved biochemical remission. Out of the total number of patients observed, 15.6% (n = 17) had a Knosp score greater than 3. Additionally, in the macroadenoma group, the percentage of patients with a Knosp score greater than 3 was 41,2%, which was significantly higher as compared to the microadenoma group (4%, p < 0.001). In patients with microadenomas a weak reverse correlation between patients' age (r = -0.258, p < 0.026) and positive with tumor size (r = 0.251, p < 0.030) was revealed. In the macroadenoma group significant association was found only between preoperative serum PRL level and tumor size (r = 0.412, p < 0.016). The preoperative PRL can be used as a diagnostic marker for lack of early biochemical remission in patients with PSPAs with diagnostic accuracy 66.9%.

Conclusions

This study found that primary transsphenoidal surgery is an effective treatment in reaching PRL level control in patients with both micro- and macroprolactinomas. The correct and thorough selection of candidates for surgery is crucial to achieve postoperative serum PRL normalization in the vast majority of patients.

Aflibercept suppresses ovarian hyperstimulation syndrome: an experimental study in rats

OBJECTIVE

In this study, we aimed to determine the impact of the antiangiogenic medications, namely, aflibercept and cabergoline in the prevention and treatment of ovarian hyperstimulation syndrome in a rat model.

METHODS

A total of 36 female Wistar rats were randomly allocated to one of the five groups, including disease-free and ovarian hyperstimulation syndrome controls: Group no OHSS (control, n=6) received saline only intraperitoneally (i.p.); group just OHSS (ovarian hyperstimulation syndrome only, n=6) received 10 IU pregnant mare serum gonadotropin and 30 IU human chorionic gonadotropin subcutaneously to produce ovarian hyperstimulation syndrome; group cabergoline+OHSS (cabergoline+ovarian hyperstimulation syndrome, n=8) received 100 μg/kg oral cabergoline; group aflibercept (12.5 mg/kg)+OHSS (aflibercept+ovarian hyperstimulation syndrome, n=8) received 12.5 mg/kg i.p. aflibercept; and group aflibercept (25 mg/kg)+OHSS (aflibercept+ovarian hyperstimulation syndrome, n=8) received 25 mg/kg i.p. aflibercept. The groups were compared for ovarian weight, immunohistochemical vascular endothelial growth factor expression, spectrophotometric vascular permeability evaluated with methylene blue solution in peritoneal lavage, and body weight growth.

RESULTS

Vascular endothelial growth factor immunoexpression was substantially greater in the just OHSS group (22.00±10.20%) than in the aflibercept (12.5 mg/kg)+OHSS (7.87±6.13%) and aflibercept (25 mg/kg)+OHSS (5.63±4.53%) groups (p=0.008 and p=0.005, respectively). Post-hoc tests indicated that cabergoline, 12.5 mg/kg aflibercept, and 25 mg/kg aflibercept decreased vascular permeability compared to the untreated ovarian hyperstimulation syndrome group (p=0.003, p=0.003, and p=0.001, respectively). JOH group had the heaviest ovaries, whereas aflibercept (25 mg/kg)+OHSS group had the lightest. In terms of body weight gain, cabergoline+OHSS group was substantially greater than the aflibercept (12.5 mg/kg)+OHSS and aflibercept (25 mg/kg)+OHSS groups (p=0.006 and p=0.007, respectively).

CONCLUSION

Aflibercept, an antiangiogenic medication, decreased ovarian hyperstimulation syndrome by lowering the vascular permeability and vascular endothelial growth factor expression.

Current and Perspective Approaches to the Treatment of Prolactinomas

Background

Along with the presence of the 2011 Endocrine Society Clinical Practice Guidelines and numerous large-scale studies on the treatment of hyperprolactinemia of different origin, there are some unresolved questions, ambiguous and sometimes contradictory points of view regarding the management of patients with prolactinomas. This overview is devoted to the analysis of the results of modern clinical studies and the approaches towards the management of hyperprolactinemia caused by prolactinoma.

Materials and methods

A systematic research of the literature for the appropriate keywords published mainly for the last 10 years was done; also, a reference list of each selected article was analysed. We included to our review the articles reporting controversial issues or new data on the treatment of hyperprolactinemia.

Results

The review describes various problems arising during the treatment of prolactinoma. The presence of primary and secondary dopamine agonist resistance in each case requires an individual approach, and sometimes may include the use of the antineoplastic agent t emozolomide. The side effects of dopamine agonists are discussed, with quite rare ones, including valvulopathy, pathological psychological conditions and cerebrospinal rhinorrhea. The controversial issue of the duration and doses of the drug used to achieve a lasting effect in the treatment of prolactinomas is considered. There are some points connected with the frequency of relapses. Thus, recurrence is correlated to the duration of treatment with dopamine agonists, prolactin levels at diagnosis, and the initial tumor size. Metformin, somatostatin analogues, selective estrogen receptor modulators, tyrosine kinase inhibitors, inhibitors of the mammalian target of rapamycin, epidermal growth factor receptor antagonists are investigated nowadays as potential alternative methods of drug treatment of prolactinomas.

Conclusion

Drug therapy with dopamine agonists makes it possible to achieve the desired results in the vast majority of patients. However, despite the proven safety of this group of medicines, the risk of side effects should still be taken into account. The therapy regimen should be determined by the clinical course of prolactinoma and the patient's response to treatment. Other options of treatment should be considered in patients intolerant to medical therapy, with contraindication or resistance to dopamine agonists, in the case of a malignant tumor. The presence of refractory to any of the applied methods of treatment and aggressive prolactinomas leads to the search for new drugs.

De Novo Psychiatric Disorders in a Woman With Giant Prolactinoma Treated With Cabergoline

Dopamine agonists are the first-line treatment of prolactinomas. The risk of developing de novo psychiatric symptoms during dopamine agonist therapy is low. Herein, we report the case of a 42-year-old woman with a giant prolactinoma who developed a psychiatric disorder after 1 day of cabergoline therapy initiation. She presented with amenorrhea, galactorrhea, headaches, and disturbed vision. Biological investigations revealed hyperprolactinemia (2975 ng/ml) with gonadotropin deficiency. Pituitary MRI showed a giant pituitary adenoma. The patient was treated with cabergoline at the dose of 1 mg twice weekly. One day after the treatment initiation, she developed acute delirium with temporospatial disorientation and compulsive medication use. These symptoms disappeared 1 week after the reduction of the dose of cabergoline. Patients with hyperprolactinemia receiving an initial high dose of cabergoline may develop changes in mood and behavior regardless of prior psychiatric history.

The Role of Aromatase Inhibitors in Male Prolactinoma

BACKGROUND

dopamine agonists are the recommended treatment for male prolactinomas, but some patients may develop dopamine-agonist-resistant hyperprolactinemia, leading to persistent hypogonadism that requires treatment with testosterone. However, testosterone replacement therapy may be associated with a decrease in the efficacy of dopamine agonists due to the aromatization of testosterone to estradiol, which can stimulate the proliferation and hyperplasia of lactotroph cells in the pituitary, inducing resistance to dopamine agonists.

OBJECTIVE

this paper systematically reviewed the role of aromatase inhibitors for men with prolactinoma and dopamine-agonist-resistant or persistent hypogonadism following treatment.

METHOD

we performed a systematic review of all studies (according to PRISMA guidelines), assessing the role of aromatase inhibitors, including anastrozole and letrozole, for male prolactinoma. An English-language search for relevant studies was conducted on PubMed from its inception to 1 December 2022. The reference lists of the relevant studies were also reviewed.

RESULTS

our systematic review identified six articles (nine patients), including five case reports and a single case series, on the use of aromatase inhibitors for male prolactinomas. Reducing estrogen levels with an aromatase inhibitor improved sensitivity to dopamine agonists, as the addition of anastrozole or letrozole improves the control of prolactin levels and may lead to the shrinkage of tumors.

CONCLUSION

aromatase inhibitors are of potential value to patients with dopamine-agonist-resistant prolactinoma, or when hypogonadism persists while using high-dose dopamine agonists.

How best to monitor the specific side effects of medical treatments of Cushing's disease

The first-line treatment of Cushing's disease is transsphenoidal surgery. Medical treatment of Cushing's disease can be considered in several situations: as a presurgical treatment in patients with severe comorbidities, when surgery fails, or while waiting for the maximal efficacy of radiation techniques. Several modalities of medical treatment are possible, from adrenal-targeting drugs (steroidogenesis inhibitors) to pituitary-targeting drugs (somatostatin receptor ligand pasireotide or the dopamine agonist cabergoline), or even drugs that antagonize the glucocorticoid receptor (mifepristone). Given the morbidities associated with hypercortisolism, and the fact that medical treatment can be delivered on a long-term basis, it is important to obtain eucortisolism and to monitor the drug effectively. The efficacy of these drugs will not be detailed in this review, nor their roles in the therapeutic algorithm of Cushing's disease. This review will rather focus specifically on adverse events associated with these drugs (ketoconazole, levoketoconazole, metyrapone, osilodrostat, pasireotide, cabergoline and mifepristone), and the way in which to monitor and treat them, based on retrospective studies and the most recently published prospective studies.

Management of prolactinomas in children and adolescents; which factors define the response to treatment?

PURPOSE

Prevalence, presentation and clinical outcome of prolactinomas vary in children and adults. In this study, we evaluated the clinical features and outcome of children and adolescents with prolactinoma to identify the differences from that of adults, and thus to establish the management strategies for this age group.

METHODS

Patients with prolactinoma diagnosed before 18 years of age from a single center in the last 20-years were included. Clinical and laboratory data, radiological findings and treatment outcome were evaluated retrospectively.

RESULTS

Twenty-eight patients (23 female; 82.1%) with prolactinoma were included. Median age at diagnosis was 15.2 years (12.6-17.7 years) in girls, 12.9 years (12.0-16.7 years) in boys. First line treatment was cabergoline in 82% of patients and normal prolactin level was achieved with maximum dose of 2 mg/week in 78%. Surgery was required in 28% of patients. Adenomas < 13.5 mm responded conventional doses of CAB. Adenomas > 30 mm were drug resistant or required surgery. Adenomas between 13.5 mm and 30 mm with invasion/extension were more likely to have drug resistance. CAB had to be continued following surgery in all patients. One macroprolactinoma had an increase in size which was accompanied with increasing prolactin level.

CONCLUSIONS

All microprolactinomas responded well to DA treatment. However, all adenomas larger than 30 mm was resistant to CAB or required surgery. Probability of drug resistance and requirement of second line therapy were higher in adenomas between 13.5 mm and 30 mm with invasion/extension. Doses over 2 mg/week of CAB in drug-resistant patients may not provide additional benefit. The frequency of follow-up MRI could be determined based on prolactin levels and emergence of new neurological symptoms.

First-line surgery in prolactinomas: lessons from a long-term follow-up study in a tertiary referral center

CONTEXT

Although consensus guidelines recommend dopamine agonists (DAs) as the first-line approach in prolactinomas, some patients may opt instead for upfront surgery, with the goal of minimizing the need for continuation of DAs over the long term. While this approach can be recommended in selected patients with a microprolactinoma, the indication for upfront surgery in macroprolactinomas remains controversial, with limited long-term data in large cohorts. We aimed at elucidating whether first-line surgery is equally safe and effective for patients with micro- or macroprolactinomas not extending beyond the median carotid line (i.e., Knosp grade ≤ 1).

METHODOLOGY

Retrospective study of patients with prolactinomas Knosp grade ≤ 1 treated with upfront surgery. The primary endpoint was patients' dependence on DAs at last follow-up. The secondary endpoint was postoperative complications. Independent risk factors for long-term dependence on DAs were analyzed.

RESULTS

A microadenoma was noted in 45 patients (52%) and a macroadenoma in 41 (48%), with 17 (20%) harboring a Knosp grade 1 prolactinoma. Median follow-up was 80 months. First-line surgery resulted in long-term remission in 31 patients (72%) with a microprolactinoma and in 18 patients (45%) with a macroprolactinoma (p = 0.02). DA therapy was ultimately required in 11 patients (24%) with microadenomas vs. 20 (49%) with macroadenomas (p = 0.03). As for the latter, DA was required in 13 patients (76%) with Knosp grade 1 macroadenomas vs. 7 patients (29%) with Knosp grade 0 macroadenomas (p = 0.004). There was no mortality, and morbidity was minimal. Knosp grade 1 prolactinomas (OR 7.3, 95% CI 1.4-37.7, p = 0.02) but not adenoma size (i.e., macroprolactinomas) were an independent predictor of long-term dependence on DAs.

CONCLUSIONS

First-line surgery in patients with microprolactinomas or macroprolactinomas Knosp grade 0 resulted in a good chance of non-dependency on DA therapy. However, in patients with prolactinomas Knosp grade 1, first-line surgery cannot be recommended, as adjuvant DA therapy after surgery is required in the majority of them over the long term.

The Role of MicroRNAs in Therapeutic Resistance of Malignant Primary Brain Tumors

Brain tumors in children and adults are challenging tumors to treat. Malignant primary brain tumors (MPBTs) such as glioblastoma have very poor outcomes, emphasizing the need to better understand their pathogenesis. Developing novel strategies to slow down or even stop the growth of brain tumors remains one of the major clinical challenges. Modern treatment strategies for MPBTs are based on open surgery, chemotherapy, and radiation therapy. However, none of these treatments, alone or in combination, are considered effective in controlling tumor progression. MicroRNAs (miRNAs) are 18-22 nucleotide long endogenous non-coding RNAs that regulate gene expression at the post-transcriptional level by interacting with 3'-untranslated regions (3'-UTR) of mRNA-targets. It has been proven that miRNAs play a significant role in various biological processes, including the cell cycle, apoptosis, proliferation, differentiation, etc. Over the last decade, there has been an emergence of a large number of studies devoted to the role of miRNAs in the oncogenesis of brain tumors and the development of resistance to radio- and chemotherapy. Wherein, among the variety of molecules secreted by tumor cells into the external environment, extracellular vesicles (EVs) (exosomes and microvesicles) play a special role. Various elements were found in the EVs, including miRNAs, which can be transported as part of these EVs both between neighboring cells and between remotely located cells of different tissues using biological fluids. Some of these miRNAs in EVs can contribute to the development of resistance to radio- and chemotherapy in MPBTs, including multidrug resistance (MDR). This comprehensive review examines the role of miRNAs in the resistance of MPBTs (e.g., high-grade meningiomas, medulloblastoma (MB), pituitary adenomas (PAs) with aggressive behavior, and glioblastoma) to chemoradiotherapy and pharmacological treatment. It is believed that miRNAs are future therapeutic targets in MPBTs and such the role of miRNAs needs to be critically evaluated to focus on solving the problems of resistance to therapy this kind of human tumors.