A review of the efficacy of appetite stimulating medications in hospitalized adults.

BACKGROUND: The majority of evidence on efficacy of appetite-stimulating medications is limited to specific populations and the outpatient treatment setting. However, hospitalized adults remain at risk for poor appetite and inadequate intake. METHOD: The purpose of this review was to assess recent evidence on the efficacy of dronabinol, megestrol acetate, and mirtazapine (used to stimulate appetite) on promoting change in intake; somatic symptoms, such as appetite and nausea; and weight change during hospital stay. The population was limited to hospitalized adults or adults who demonstrated a need for appetite stimulation during hospitalization. RESULTS: Of the 382 articles screened, four met inclusion criteria (one randomized control trial, two retrospective cohort studies, and one retrospective case series). Based on the studies included, these appetite stimulants have limited efficacy on improving appetite and meal intake. There was no significant change in weight. CONCLUSION: Current data lack standardization, generalizability, and comparability, and higher quality evidence is needed before conclusions can be identified on the efficacy of dronabinol, megestrol acetate, and mirtazapine in the inpatient setting.

Propensity score-matching analysis comparing safety outcomes of appetite-stimulating medications in oncology patients.

PURPOSE: Anorexia and weight loss are common complications in the elderly, advanced cancer population. Appetite stimulants are commonly used therapies for oncology patients with weight loss, yet their safety comparison remains unknown. METHODS: This was a two-center, retrospective, study conducted in New York City at Mount Sinai Beth Israel and New York University Langone from January 2016 to July 2019 in adult patients with histologic evidence of malignancy who were taking either megestrol acetate or mirtazapine as an appetite-stimulating medication. Endpoints included safety concerns of mortality, QTc prolongation, venous thromboembolism, fall, somnolence, xerostomia, and hallucinations. Effectiveness of weight gain or maintenance of weight was not assessed. A propensity score-matching analysis was performed using a logistic regression analysis to assess the two comparable groups. RESULTS: The study included 350 patients (69.56 ± 13.31 years) with the most common malignancies being gastrointestinal, breast, and hematologic with metastasis present in over half the patients. Adverse events were commonly seen in the oncology population. After a propensity score-matched analysis, all safety outcomes associated with mirtazapine compared to megestrol acetate were similar; all-cause mortality (7%, n = 7 vs. 12%, n = 12, p = 0.23), QTc prolongation (31%, n = 31 vs. 31%, n = 31, p = 1.00), thromboembolism (11%, n = 11 vs. 11%, n = 11, p = 1.00), somnolence (29%, n = 30 vs. 22%, n = 23, p = 0.34), xerostomia (27%, n = 28 vs. 18%, n = 19, p = 0.24), and hallucinations (17%, n = 18 vs. 8%, n = 8, p = 0.06), respectfully. CONCLUSION: There were no safety differences seen when evaluating both agents.

Megestrol acetate is a specific inducer of CYP3A4 mediated by human pregnane X receptor.

PURPOSE: Megestrol acetate is a synthetic progestogen used to treat some cancers and cancer-associated cachexia, but its potential interactions with other drugs are not well known. This study aims to determine the regulation of drug metabolizing enzymes by megestrol acetate. METHODS: Primary human hepatocytes were treated and analyzed by PCR array to identify genes involved in drug metabolism that are impacted by megestrol acetate. P450 3A4 (CYP3A4) reporter gene assay and HPLC analyses of nifedipine metabolites were used to determine CYP3A4 gene expression and activities. Competitive ligand binding assay was used to determine the affinity of megestrol acetate toward human pregnane x receptor (hPXR). Electrophoretic mobility shift assay and mammalian two hybrid assay were used to determine the mechanism of megestrol to activate hPXR. RESULTS: The levels and activities of CYP3A4 were significantly induced (> 4-folds) by megestrol acetate in human hepatocytes and HepG2 cells. Megestrol treatment induced CYP3A4 through the activation of hPXR, a ligand-activated transcription factor that plays a role in drug metabolism and transport. Other tested nuclear receptors showed no response. The mechanism studies showed that megestrol activated hPXR by binding to the ligand binding domain (LBD) of hPXR and increasing the recruitment of the cofactors such as steroid receptor cofactor (SRC-1). CONCLUSION: The results suggest that megestrol acetate is a specific inducer of CYP3A4 mediated by hPXR and therefore has the potential to cause drug interactions, especially in the co-administration with drugs that are substrates of CYP3A4.

Megestrol acetate induced proliferation and differentiation of osteoblastic MC3T3-E1 cells: A drug repurposing approach.

AIMS: Drug repurposing or repositioning i.e.; identifying new indications for existing drugs have recently accelerated the process of drug discovery and development. Megestrol acetate (1) is a well-known progestin. It is commonly used as an appetite stimulant, and also in the treatment of breast, and endometrial cancers. The aim of this study is to investigate the effect of megestrol acetate (1) in osteoblast differentiation, and to determine the possible mechanism involved in megestrol acetate (1) induced osteoblast differentiation. MAIN METHODS: Cytotoxicity of different steroidal drugs was evaluated using MTT assay. Alkaline phosphatase (ALP) activity was also determined, and alizarin red S (ARS) staining was performed to measure extracellular mineralization. Osteogenic protein levels were determined using Western blot analysis. KEY FINDINGS: Results of the current study indicated that the megestrol acetate (1) enhanced the proliferation and differentiation of osteoblast cells at 1, 0.2, and 0.04 µM. This stimulatory effect of the megestrol acetate (1) was more prominent at 0.2 µM for cell proliferation, while the maximum cell differentiation (ALPase activity, and calcification) was observed at 0.04 µM. Western blot analysis also showed that megestrol acetate (1) altered the expression of bone morphogenic protein-2 (BMP2), p38, and pJNK proteins. Hence, only moderate doses of MGA (1) can enhance osteoblast proliferation and differentiation. SIGNIFICANCE: Our results identified that megestrol acetate (1) could be a potential lead for further research towards bone fragility related disorders.

Ten years of Croatian national guidelines for use of eicosapentaenoic acid and megestrol acetate in cancer cachexia syndrome - Evaluation of awareness and implementation among Croatian oncologists.

BACKGROUND & AIMS: Cancer cachexia (CC) syndrome and anorexia-cachexia syndrome are common terms used to describe changes in metabolism with increased inflammatory activity and can progressively develop through various stages such as pre-cachexia; cachexia; and refractory cachexia. Therefore in year 2007 Croatian guidelines for use of eicosapentaenoic acid and megestrol acetate in cancer cachexia syndrome were published. Aim of this study was to assess the awareness and implementation of Croatian guidelines for use of eicosapentaenoic acid (EPA) and megestrol acetate (MA) into clinical practice among Croatian oncologists approximately 10 years after the publication, but also to point out the importance of adequate recognition and treatment of CC. METHODS: Survey with questions was designed to assess the awareness and implementation of Croatian guidelines for use of EPA and MA into clinical practice and was distributed among all Croatian oncologists in secondary and tertiary hospital centers. Survey was conducted in January 2011 (40 months following release of the guidelines), February 2013 and June 2018, and were formed in a way of yes/no answers. Additional multiple choice questions that focus on the implementation of guidelines were added in June 2018. RESULTS: A total of 128 oncologists completed a questionnaire. There was no statistically significant difference in follow up period (2011-2018) of percentage of oncologists that are familiar with Croatian guidelines for use of EPA and MA in CC, percentage of oncologists in which Croatian national guidelines changed their approach in treating patients with CC syndrome and proportion of oncologists that are using MA, enteral nutrition formulas with EPA or their combination. Most of the oncologists 38% (N = 44) are using >2.2 g of EPA per day. Nutritional support is prescribed in 25-50% of patients by 42% (N = 48) of oncologists and most of the oncologists (35%, N = 41) start with nutritional support when a body mass loss is >5%. Oncologists mostly recommend patients to use nutritional support during 1 year or more (43%, N = 49) or two months to 1 year (42%, N = 48). Compliance of patients with malignant diseases for using nutritional support was mostly evaluated as medium (69%, N = 60). CONCLUSIONS: Results have shown that majority of oncologists who filled the questionnaire believe that the Croatian national guidelines for use of EPA and MA in CC syndrome changed their approach in treating patients with CC, but also that there are several targeted issues that can be significantly improved. The awareness of and adherence to national guidelines was maintained at high level even 11 years after the guidelines were published.

Megestrol acetate for cachexia-anorexia syndrome. A systematic review.

In 1993, megestrol acetate (MA) was approved by the US Food and Drug Administration for the treatment of anorexia, cachexia, or unexplained weight loss in patients with acquired immunodeficiency syndrome. The mechanism by which MA increases appetite is unknown, and its effectiveness for anorexia and cachexia in neoplastic, elderly, and acquired immunodeficiency syndrome patients is under investigation. This is an updated version of a Cochrane systematic review first published in 2005 and later updated in 2013 entitled 'Megestrol acetate for the treatment of anorexia-cachexia syndrome'. MA vs. placebo: in studies where MA was compared with placebo, the overall results showed that MA patients gained weight (mean difference, MD 2.25 kg, 95% CI [1.19, 3.3]) but did not gain quality of life (QOL) (standarized mean difference, SMD 0.5, 95% CI [-0.13, 1.13]), with more adverse events (relative risk, RR 1.46, 95% CI [1.05, 2.04]), but no difference in deaths (RR 1.26, 95% CI [0.70, 2.27]). MA vs. no treatment: MA patients gained weight (MD 1.45 kg, 95% CI [0.15, 2.75]) but did not gain QOL (standardized mean difference 3.89 95% CI [-14, 6.28]). There was no increase in adverse events (RR 0.90, 95% CI [0.39, 2.08]) or deaths (RR 1.01, 95% CI [0.42, 2.45]). MA vs. active drugs: MA patients gained weight (MD 2.5 kg, 95% CI [0.37, 4.64]) but did not gain QOL (MD 0.20 95% CI [-0.02, 0.43]) and did not report an increase in adverse events (RR 1.05 95% CI [0.95, 1.16]) or in deaths (RR 1.53, 95% CI [1.02, 2.29]) Different doses of MA: in studies where lower doses of MA were compared with higher doses of MA, we did not find differences either in weight gain (MD -0.94 kg, 95% CI [-3.33, 1.45]), QOL (MD 0.31 95% CI [-0.19, 0.81]), or adverse events (RR 1.34, 95% CI [0.65, 2.76]). Thus, we cannot reach a conclusion for an optimal dose of MA.

Randomized double-blind clinical trial of combined treatment with megestrol acetate plus celecoxib versus megestrol acetate alone in cachexia-anorexia syndrome induced by GI cancers.

PURPOSE: Previous studies reported promising efficacy for celecoxib in the treatment of cancer cachexia. We designed this study to test the hypothesis that combination therapy with megestrol acetate (MA) plus celecoxib is superior to MA alone. METHODS: Ninety eligible gastrointestinal cancer patients randomly received either MA 320 mg/day plus placebo (arm1) or MA 320 mg/day plus celecoxib 200 mg/day (arm2). Patients were evaluated at baseline, then 1 and 2 months after starting interventions. The primary outcome was body weight. Secondary outcomes were quality of life, grip strength, appetite score, performance status, plasma albumin, CRP, IL-6, and Glasgow Prognostic Score. RESULTS: Patients were comparable at baseline. Sixty patients were assessable for the first month and 33 patients for the second month. After 2 months, patients in arm1 (MA + placebo) and arm2 (MA + celecoxib) experienced 4.0 ± 3.4 and 2.2 ± 3.6Kg of weight gain respectively (P = 0.163). Changes relative to baseline were statistically significant in both arms of the study (P = 0.001). Regarding secondary outcomes, comparisons between groups did not show any statistically significant difference, but within-group changes were significant in both arms of the study. CONCLUSION: Since both MA alone and MA plus celecoxib are associated with improvement of cachexia in GI cancer patients, this study failed to show that adding celecoxib (200 mg/day) to megestrol (320 mg/day) could enhance anti-cachexic effects of megestrol.

Pterostilbene, a natural phenolic compound, synergizes the antineoplastic effects of megestrol acetate in endometrial cancer.

Endometrial cancer is the most common gynecologic cancer in the United States and its incidence and mortality has been rising over the past decade. Few treatment options are available for patients with advanced and recurring endometrial cancers. Novel therapies, which are frequently toxic, are difficult to establish in this patient population which tends to be older and plagued by comorbidities such as diabetes mellitus and hypertension. Therefore, novel, non-toxic therapies are urgently needed. Megestrol acetate is a frequently used drug in endometrial cancer patients. However, its response rate is only 20-30%. To enhance the activity of megestrol acetate in endometrial cancer patients, we explored the potential of combining natural supplements with megestrol acetate and found that the addition of the natural phenolic compound, pterostilbene, to megestrol acetate resulted in a synergistic inhibition of cancer cell growth in vitro and an enhanced reduction of tumor growth in a xenograft mouse model. In addition, dual treatment led to attenuation of signaling pathways, as well as cell cycle and survival pathways. Our results demonstrated for the first time that the anti-tumor activity of megestrol acetate can be enhanced by combining with pterostilbene, providing an insight into the potential application of pterostilbene and megestrol acetate combination for the treatment of endometrial cancer.

Pharmacy Report: Megestrol Acetate-Induced Adrenal Insufficiency.

A man aged 65 years with metastatic renal cell carcinoma presented for evaluation after a recent fall. A thorough workup of the case was performed and secondary adrenal insufficiency induced by the administration of megestrol acetate was determined to be the cause. Adrenal insufficiency is a serious disorder that is a potential adverse event of megestrol acetate, a medication used to help patients with cancer cachexia increase their appetite and gain weight. This association is not well recognized in clinical practice, so this case highlights the importance of distinguishing possible endocrine complications induced by the long-term administration or sudden discontinuation of megestrol acetate.

Megestrol acetate improves cardiac function in a model of cancer cachexia-induced cardiomyopathy by autophagic modulation.

BACKGROUND: Cachexia is a complex metabolic syndrome associated with cancer. One of the features of cachexia is the loss of muscle mass, characterized by an imbalance between protein synthesis and protein degradation. Muscle atrophy is caused by the hyperactivation of some of the main cellular catabolic pathways, including autophagy. Cachexia also affects the cardiac muscle. As a consequence of the atrophy of the heart, cardiac function is impaired and mortality is increased. Anti-cachectic therapy in patients with cancer cachexia is so far limited to nutritional support and anabolic steroids. The use of the appetite stimulant megestrol acetate (MA) has been discussed as a treatment for cachexia. METHODS: In this study the effects of MA were tested in cachectic tumour-bearing rats (Yoshida AH-130 ascites hepatoma). Rats were treated daily with 100 mg/kg of MA or placebo starting one day after tumour inoculation, and for a period of 16 days. Body weight and body composition were assessed at baseline and at the end of the study. Cardiac function was analysed by echocardiography at baseline and at day 11. Locomotor activity and food intake were assessed before tumour inoculation and at day 11. Autophagic markers were assessed in gastrocnemius muscle and heart by western blot analysis. RESULTS: Treatment with 100 mg/kg/day MA significantly attenuated the loss of body weight (-9 ± 12%, P < 0.05) and the wasting of lean and fat mass (-7.0 ± 6% and -22.4 ± 3 %, P < 0.001 and P < 0.05, respectively). Administration of 100 mg/kg/day MA significantly protected the heart from general atrophy (633.8 ± 30 mg vs. placebo 474 ± 13 mg, P < 0.001). Tumour-bearing rats displayed cardiac dysfunction, as indicated by the significant impairment of the left ventricular ejection fraction, the left ventricular fractional shortening, the stroke volume, the end dyastolic volume, and the end systolic volume. In contrast, MA significantly improved left ventricular ejection fraction, left ventricular fractional shortening, and left ventricular end systolic volume. Western blotting analysis showed an upregulation of the autophagic pathway in the gastrocnemius and hearts of the placebo-treated tumour-bearing rats. Treatment with MA, however, was able to modulate the autophagic markers (e.g. Beclin-1, p62, TRAF6, and LC3) in the gastrocnemius and in the hearts of tumour-bearing rats. Most importantly, 100 mg/kg/day MA reduced mortality [hazard ratio (HR): 0.44; 95%CI: 0.20-1.00; P = 0.0486]. CONCLUSIONS: Megestrol acetate improved survival and reduced wasting through a marked downregulation of autophagy, occurring in both skeletal and heart muscle, the latter effect leading to a significant improvement of cardiac function. Our data suggest that MA might represent a valuable strategy to counteract the development of cancer cachexia-induced cardiomyopathy.

New Biopolymer Nanoparticles Improve the Solubility of Lipophilic Megestrol Acetate.

As many substances are poorly soluble in water and thus possess decreased bioavailability, creating orally administered forms of these substances is a challenge. The objective of this study was to determine whether the solubility of megestrol acetate, a Biopharmaceutical Classification System (BCS) class II drug, can be improved by using a newly-synthesized surfactant (Rofam 70: a rapeseed methyl ester ethoxylate) and compare it with two references surfactants (Tween 80, Pluronic F68) at three different pH values. Spectrophotometry was used to compare the solubility profiles in the presence of three tested surfactants at pH 5.0, 7.4 and 9.0. Rapeseed methyl ester ethoxylate was found to improve the solubility of the BCS Class II drug and increase its bioavailability; It increased drug solubility more effectively than Pluronic F68. Its cytotoxicity results indicate its possible value as a surfactant in Medicine and Pharmacy.

Fenretinide: a novel treatment for endometrial cancer.

Resistance to progestin treatment is a major hurdle in the treatment of advanced and reoccurring endometrial cancer. Fenretinide is a synthetic retinoid that has been evaluated in clinical trials as a cancer therapeutic and chemo-preventive agent. Fenretinide has been established to be cytotoxic to many kinds of cancer cells. In the present study, we demonstrate that fenretinide decreased cell viability and induced apoptosis in Ishikawa cells, which are an endometrial cancer cell line, in dose dependent manner in-vitro. This effect was found to be independent of retinoic acid nuclear receptor signaling pathway. Further, we have shown that this induction of apoptosis by fenretinide may be caused by increased retinol uptake via STRA6. Silencing of STRA6 was shown to decrease apoptosis which was inhibited by knockdown of STRA6 expression in Ishikawa cells. Results of an in-vivo study demonstrated that intraperitoneal injections of fenretinide in endometrial cancer tumors (created using Ishikawa cells) in mice inhibited tumor growth effectively. Immunohistochemistry of mice tumors showed a decrease in Ki67 expression and an increase in cleaved caspase-3 staining after fenretinide treatment when compared to vehicle treated mice. Collectively, our results are the first to establish the efficacy of fenretinide as an antitumor agent for endometrial cancer both in-vitro and in-vivo, providing a valuable rationale for initiating more preclinical studies and clinical trials using fenretinide for the treatment of endometrial cancer.

Sterol regulatory element-binding protein-1/fatty acid synthase involvement in proliferation inhibition and apoptosis promotion induced by progesterone in endometrial cancer.

BACKGROUND: The number of endometrial cancer (EC) cases is escalating rapidly, with no evident improvements in survival rates. The downregulation of progesterone receptor, resulting in progestin resistance, is presently a major problem regarding the therapeutic aspect. On the basis of this, we can focus more on the downstream signaling pathways that are controlled by progesterone. Lipid biosynthesis mediated by sterol regulatory element-binding protein-1/fatty acid synthase (SREBP-1/FASN) is of utmost importance to the growth and the proliferation of EC cells, so we hypothesize that SREBP-1/FASN might be involved in suppressing the proliferation and promoting apoptosis in EC cells through the effects induced by progesterone. MATERIAL AND METHODS: The Cell Counting Kit-8 was used to analyze the growth inhibition ratio of Ishikawa cells upon treatment with megestrol acetate (MA; MA is a progesterone derivative, also known as 17α-acetoxy-6-dehydro-6-methylprogesterone) and to determine the 50% inhibitory concentration. Apoptosis ratio was analyzed by treatment of the cells with MA at 50% inhibitory concentration at different time intervals using Annexin V-FITC/propidium iodide. The protein and messenger RNA levels of SREBP-1 and FASN were compared between the experimental and control groups (MA-treated Ishikawa cells were considered to be the experimental group). RESULTS: The experimental group showed obvious growth inhibition that was time and concentration dependent. The apoptosis ratio was also significantly higher in the experimental group compared with the control group (P < 0.01). The protein and messenger RNA levels of SREBP-1 and FASN were significantly reduced by MA too. CONCLUSIONS: Sterol regulatory element-binding protein-1/FASN is involved in the proliferation suppression and apoptosis promotion brought about by MA in Ishikawa cells.

Successful treatment for subinvolution of placental sites in the bitch with low oral doses of progestagen.

Subinvolution of placental sites (SIPS) is the major cause of persistent sanguineous vaginal discharge after parturition in the bitch. Spontaneous remission is common but may take several months, and hence, medical therapy to end the discharge is often requested. In this retrospective study, we evaluated the effect of treatment for SIPS with low oral doses of a progestagen. Nine bitches with SIPS, but otherwise clinically healthy, were found in the computer database of the Department of Clinical Sciences of Companion Animals. Seven of these bitches were treated with low oral doses of a progestagen (megestrol acetate, 0.1 mg/kg body weight (bw) once daily for the 1st week, then 0.05 mg/kg bw once daily for the 2nd week). The other two bitches were untreated. Treatment results were evaluated by a telephone questionnaire. Progestagen treatment was successful in all of the treated dogs; sanguineous vaginal discharge stopped within the treatment period. One of the two untreated dogs remained symptomatic until the next oestrus, approximately 120 days after parturition, and the other remained symptomatic until 6 weeks before the start of the next pro-oestrus, 270 days after parturition. No side effects of the progestagen treatment were observed. Subsequent gestations, parturitions and puerperal periods of 5 mated bitches were uneventful. One bitch did not become pregnant after mating. In conclusion, the results of this study indicate that oral administration of low doses of progestagen for 2 weeks is effective in stopping persistent sanguineous vaginal discharge in bitches with SIPS, with neither side effects nor reduced subsequent fertility.

Low-dose megestrol acetate revisited: a viable adjunct to surgical sterilization in free roaming cats?

Approximately 2-3 million cats are euthanased in animal shelters across the United States annually. Preventing pregnancy in cats is a key step to reducing this number. While surgery is generally a safe and effective tool for curbing reproduction in cats, it is not a practical method to achieve the reduction in numbers required for an appreciable impact on the cat population as a whole. Low-dose megestrol acetate (MA) is a synthetic progestin that has been used for the management of reproduction in free roaming cat populations; however, there has been no regulatory oversight regarding the use of this product for this purpose. Additionally, there is a paucity of data regarding the safety and efficacy of the product for the management of reproduction in free roaming cats. The purpose of this review is: (1) to outline the need for a non-surgical contraceptive in cats; (2) to discuss the uses of MA in domestic cats; (3) to consider potential adverse effects of the drug, and (4) to discuss regulatory challenges associated with the use of MA in free roaming cat populations. In order to answer the questions posed in this review, more data will need to be collected in laboratory and field studies.

Different influence of ovine estrus synchronization treatments on caruncular early angiogenesis.

The present study compares two protocols for ovine estrus synchronization by assessing the caruncular angiogenic response to the establishment of pregnancy. The analysis consisted of the immunohistochemical evaluation of Vascular Endothelial Growth Factor (VEGF), Platelet Endothelial Cell Adhesion Molecule-1 (PECAM-1, CD31) and Von Willebrand Factor (vWF) in ovine caruncular stroma. A flock of thirty-eight adult ewes was divided in two groups and synchronized with either progestagens (Group P) or prostaglandin analogues (Group PG). Immunohistochemistry was performed in uterine samples obtained from pregnant ewes (P, n=15; PG, n=13) on days 15 post coitus (pc), 17pc and 21pc (day 0 =day of estrus). Each factor was assessed by total vascular density (TVD, total positive blood vessels/mm2), capillary vascular density (CVD, positive blood capillaries/mm2) and arteriolar vascular density (AVD, positive arterioles/mm2). Group P demonstrated higher VEGF-CVD (P=0.045) when compared to prostaglandin treated animals. Vascular CD31-expression decreased on days 15pc and 21pc (TVD, P=0.007 and CVD, P=0.014) in both groups. vWF analysis did not show significant differences between groups or days of study. These results demonstrate a different influence of progestagen-based and prostaglandin analogues-based synchronization treatments over VEGF vascular expression during caruncular development taking place in response to pregnancy establishment. In addition, observations pointed out in this study support the involvement of CD31 in the angiogenic stimulus that occurs during early maternal placentation in the ewe.

Altered claudin-4 expression in progesterone-treated endometrial adenocarcinoma cell line Ishikawa.

OBJECTIVE: To detect the expression change of claudin-4 in Ishikawa endometrial adenocarcinoma cell line in response to progesterone. To determine whether claudin-4 is involved in the anticancer effect of progesterone. METHODS: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine the 50% inhibitory concentration (IC50) of megestrol acetate (MA) in treating Ishikawa cells. After the Ishikawa cells were treated with MA at IC50, cell apoptosis was examined by flow cytometry and transmission electron microscopy. The messenger RNA and protein expression levels of claudin-4 were further quantified by real-time polymerase chain reaction and Western blot. The localization of claudin-4 was examined by immunofluorescent staining. RESULTS: The IC50 of MA on Ishikawa cells was 15 mg/L incubated for 72 hours. Apoptosis percentage was elevated from 0.07% ± 0.02% to 3.93% ± 0.81% after MA treatment. The expression of claudin-4 at both protein and messenger RNA levels was significantly decreased after the treatment of MA (P < 0.05). The localization of claudin-4 transferred from cytomembrane to cytoplasm and nucleus. CONCLUSION: Megestrol acetate can inhibit the growth of Ishikawa cells. It may work through decreasing claudin-4 expression and cell apoptosis. The localization change of claudin-4 may also be involved in the anticancer effect of progesterone.

[Regulation of claudin-4 gene expression in endometrial adenocarcinoma Ishikawa cell line by progesterone].

OBJECTIVE: To explore the regulation of claudin-4 expression in endometrial adenocarcinoma cell lines by progesterone. METHODS: Ishikawa cells were treated with various concentrations of megestrol acetate (MA: 2, 5, 10, 15, 20 mg/L). After cultured for 24, 48 and 72 hours, cells growth were measured by methyl thiazolyl tetrazolium (MTT). The group of Ishikawa cells incubated with MA at the 50% inhibitory concentration (IC(50)) was selected for cell apoptosis assay by using transmission electron microscopy and flow cytometry method. Real-time PCR and western blot were used for detecting the mRNA and protein expression levels of claudin-4. The localization of claudin-4 was examined by immunofluorescent staining. RESULTS: The inhibitory effects of megestrol acetate on the growth of Ishikawa cells were dose-dependent and time-dependent. IC(50) of MA on Ishikawa cells was 15 mg/L after incubated for 72 hours. After MA treatment, Ishikawa cells showed shrinkage, nuclear chromatin condensation, fractures of nuclear membrane and endoplasmic reticulum expansion, even round apoptotic bodies were found. The apoptosis rate of cells before MA treatment was (0.076 ± 0.024)%, and the rate was (3.934 ± 0.816)% by MA treated for 72 hours, in which there were signicant difference (P < 0.05). The relative quantification of claudin-4 mRNA and protein of the cells before MA treatment were 0.64 ± 0.20 and 0.94 ± 0.18, while they were 0.47 ± 0.15 and 0.62 ± 0.15 after MA treated. The expression of claudin-4 was significantly decreased after MA treatment (P < 0.05). The localization of claudin-4 transferred from cytomembrane to cytoplasm and nucleus after MA treatment. CONCLUSIONS: MA could inhibite the growth of Ishikawa cells, in which the mechanism may be decrease the expression of claudin-4 and the apoptosis of cells. The distribution change of claudin-4 may be related to the anti-cancer effect of progesterone.

Indinavir inhibits the expression of cytoplasmic aromatase and nuclear SREBP in the hippocampus of reperfusion injury-induced ischemic rats.

Ischemic brain injury due to insults, such as stroke, is a leading cause of severe neurological and neurobehavioral deficits and death. Neurodegeneration can be prevented by local aromatase expression, and estrogen synthesis can be neuroprotective in ischemia/reperfusion. Therefore, aromatase, the enzyme that transforms androgens to estrogens, may be a potential target for the study of reperfusion injury after brain ischemia. We investigated the expression of aromatase and sterol regulatory element binding protein (SREBP) using Western blotting in the rat hippocampus after transient global ischemia plus hypotension. After 10 min of ischemia, aromatase and SREBP expression was observed in cytosolic extracts after 1, 4 and 10 weeks of reperfusion. Previous immunoblot analysis demonstrated that the highest aromatase expression appeared in damaged hippocampi after 1 week. In this study, SREBP expression was increased at 1 week in the nuclear extracts of damaged hippocampi. The aromatase inhibitor megestrol acetate (20 mg/kg/day; 21 days) and the SREBP inhibitor indinavir (15 mg/kg/day; 30 days) suppressed aromatase levels in ischemic hippocampi. Our findings indicate that ischemia, as well as chronic neurodegenerative processes, leads to an increase in cytoplasmic aromatase and nuclear SREBP. Thus, it is possible to hypothesize that an interaction between this enzyme gene and the transcription factor exists.