Developmental exposure to corticosterone: behavioral changes and differential effects on leukemia inhibitory factor (LIF) and corticotropin-releasing hormone (CRH) gene expression in the mouse

Rationale Cytokines are found in both the peripheral and central nervous system. There has been increasing interest in their potential role in some of the behavioral features of depressive disorders. Leukemia inhibitory factor (LIF), a proinflammatory cytokine, produces stimulation of adrenocorticotropic hormone (ACTH) secretion in response to emotional and inflammatory stress and recently has been linked to depressive-type behavior. Both the hypothalamic–pituitary–adrenal axis and the immune system, including cytokine-mediated responses, appear to be susceptible to long-term programming during fetal and neonatal development. Objective The present study was designed to characterize the effects of perinatal exposure to corticostereone on behavior, hypothalamic LIF and corticotropin-releasing hormone (CRH) mRNA expression, and basal plasma corticosterone levels in adult female mice. Methods Corticosterone was added to the drinking water beginning the last week of gestation and continued until weaning. Behavior in the open field and forced swim tests, baseline plasma corticosterone levels, and hypothalamic LIF and CRH gene expression were evaluated in the adult offspring. Results Mice exposed to perinatal corticosterone showed increased immobility in the forced swim test and increased locomotor activity in the open field test. Although there were no differences between treatment groups in terms of basal plasma levels of corticosterone or hypothalamic CRH mRNA, LIF mRNA expression was increased in the hypothalamus. Conclusions These results show that perinatal exposure to glucocorticoids can produce long-term behavioral changes and upregulation of central LIF mRNA expression.     

Antidepressant Effects of Abscisic Acid Mediated by the Downregulation of Corticotrophin-Releasing Hormone Gene Expression in Rats

Background:

Corticotrophin-releasing hormone (CRH) is considered to be the central driving force of the hypothalamic-pituitary-adrenal axis, which plays a key role in the stress response and depression. Clinical reports have suggested that excess retinoic acid (RA) is associated with depression. Abscisic acid (ABA) and RA are direct derivatives of carotenoids and share a similar molecular structure. Here, we proposed that ABA also plays a role in the regulation of CRH activity sharing with the RA signaling pathway.

Methods:

[₃H]-ABA radioimmunoassay demonstrated that the hypothalamus of rats shows the highest concentration of ABA compared with the cortex and the hippocampus under basal conditions.

Results:

Under acute stress, ABA concentrations increased in the serum, but decreased in the hypothalamus and were accompanied by increased corticosterone in the serum and c-fos expression in the hypothalamus. Moreover, chronic ABA administration increased sucrose intake and decreased the mRNA expression of CRH and retinoic acid receptor alpha (RARα) in the hypothalamus of rats. Furthermore, ABA improved the symptom of chronic unpredictable mild stress in model rats, as indicated by increased sucrose intake, increased swimming in the forced swim test, and reduced mRNA expression of CRH and RARα in the rat hypothalamus. In vitro, CRH expression decreased after ABA treatment across different neural cells. In BE(2)-C cells, ABA inhibited a series of retinoid receptor expression, including RARα, a receptor that could facilitate CRH expression directly.

Conclusions:

These results suggest that ABA may play a role in the pathogenesis of depression by downregulating CRH mRNA expression shared with the RA signaling pathway.     

Role of the basolateral amygdala in mediating the effects of the fatty acid amide hydrolase inhibitor URB597 on HPA axis response to stress

The endocannabinoid system is an important regulator of neuroendocrine and behavioral adaptation in stress related disorders thus representing a novel potential therapeutic target. The aim of this study was to determine the effects of the fatty acid amide hydrolase (FAAH) inhibitor URB597 on stress mediators of HPA axis and to study the role of the basolateral amygdala (BLA) in responses to forced swim stress.Systemic administration of URB597 (0.1 and 0.3 mg/kg) reduced the forced swim stress-induced activation of HPA axis. More specifically, URB597 decreased stress-induced corticotropin-releasing hormone (CRH) mRNA expression in the paraventricular nucleus (PVN) of the hypothalamus, and pro-opiomelanocortin (POMC) mRNA expression dose-dependently in pituitary gland without affecting plasma corticosterone levels. URB597 treatment also attenuated stress-induced neuronal activation of the amygdala and PVN, and increased neuronal activation in the locus coeruleus (LC) and nucleus of solitary tract (NTS). Injection of the CB1 receptor antagonist AM251 (1 ng/side) in the BLA significantly attenuated URB597-mediated effects in the PVN and completely blocked those induced in the BLA.These results suggest that the BLA is a key structure involved in the anti-stress effects of URB597, and support the evidence that enhancement of endogenous cannabinoid signaling by inhibiting FAAH represents a potential therapeutic strategy for the management of stress-related disorders.     

Alterations in central neuropeptide expression, release, and receptor binding in rats bred for high anxiety: critical role of vasopressin.

To model aspects of trait anxiety/depression, Wistar rats were bred for extremes in either hyper (HAB)- or hypo(LAB)-anxiety as measured on the elevated plus-maze and in a variety of additional behavioral tests. Similar to psychiatric patients, HAB rats prefer passive stress-coping strategies, indicative of depression-like behavior, show hyper-reactivity of the hypothalamo-pituitary-adrenal axis, and a pathological response to the dexamethasone/corticotropin-releasing hormone (CRH) challenge test. Here we tested central mRNA expression, release patterns, and receptor binding of neuropeptides critically involved in the regulation of both anxiety-related behavior and the HPA axis. Thus, CRH, arginine-8-vasopressin (AVP), and oxytocin (OXT) were studied in brains of HAB and LAB males both under basal conditions and after exposure to a mild emotional stressor. In HAB rats, CRH mRNA was decreased in the bed nucleus of the stria terminalis only. While no significant difference in CRH1-receptor binding was found in any brain area, CRH2-receptor binding was elevated in the hypothalamic paraventricular nucleus (PVN), the ventromedial hypothalamus, and the central amygdala of HABs compared to LABs. AVP, but not OXT, mRNA expression as well as release of the neuropeptide, were higher in the PVN of HABs, whereas AVP V1a-receptor binding failed to show significant differences in any brain region studied. Remarkably, intra-PVN treatment of HABs with the AVP V1-receptor antagonist d (CH(2))(5) Tyr (Me) AVP resulted in a decrease in anxiety/depression-related behavior. The elevated expression and release of AVP within the PVN of HAB rats together with the behavioral effects of the AVP V1-receptor antagonist suggest a critical involvement of this neuropeptide in neuroendocrine and behavioral phenomena associated with trait anxiety/depression.     

Chronic administration of the delta opioid receptor agonist (+)BW373U86 and antidepressants on behavior in the forced swim test and BDNF mRNA expression in rats

Rationale Selective delta opioid receptor agonists have been shown to produce antidepressant-like behavioral effects and increase brain-derived neurotrophic factor (BDNF) mRNA expression when given acutely, but the chronic effects of delta agonists have been less well characterized.Objective The present study examined the effects of chronic exposure to the delta agonist (+)BW373U86 (BW) on antidepressant-like behavior in the forced swim test and on BDNF mRNA expression in comparison to chronic treatment with the antidepressants fluoxetine, desipramine, bupropion, and tranylcypromine.Methods Sprague–Dawley rats were treated chronic ally with one of the above treatments and were tested for antidepressant effects in the forced swim test, and assayed for BDNF mRNA expression by in situ hybridization.Results Acute administration of 10 mg/kg BW produced a significant antidepressant-like effect in the forced swim test, while chronic (8- or 21-day) BW administration did not produce a significant antidepressant-like effect. When 10 mg/kg BW was administered for 8 days, it produced a significant increase in BDNF mRNA expression in the frontal cortex, while having no effect on BDNF expression when given for 21 days. Chronic bupropion and desipramine significantly decreased BDNF expression in the dentate gyrus of the hippocampus, while fluoxetine had no effect in any brain region. Chronic tranylcypromine produced a significant increase in BDNF expression in the CA1 region of the hippocampus.Conclusions Chronic exposure to BW produces tolerance to most effects, although at differential rates. In addition, increased BDNF mRNA expression does not appear to be a common effect of chronic administration of various antidepressants.     

Reduction of hypothalamic vasopressinergic hyperdrive contributes to clinically relevant behavioral and neuroendocrine effects of chronic paroxetine treatment in a psychopathological rat model.

The neuroendocrine and behavioral effects of chronic paroxetine treatment were investigated in two rat lines selectively bred for high anxiety-related behavior (HAB) or low anxiety-related behavior (LAB) emotionality. In addition to a characteristic behavioral phenotype with markedly passive stress-coping strategies, HAB rats show a hypothalamic vasopressinergic hyperdrive that is causally related to hypothalamic-pituitary-adrenocortical dysregulation as demonstrated in the combined dexamethasone (DEX)/corticotropin-releasing hormone (CRH) test. A total of 8 weeks of chronic paroxetine treatment induced a more active coping strategy in the forced swim test in HAB rats only. In contrast, paroxetine-treated LAB rats did not change their swimming behavior. To investigate the neuroendocrine alterations linked to these behavioral changes, a combined DEX/CRH test was performed. In HAB rats, the paroxetine-induced behavioral changes towards more active coping strategies were accompanied by a normalization of the CRH-stimulated increase in corticotropin (ACTH) and corticosterone secretion. Concomitantly, the hypothalamic vasopressinergic hyperdrive was found to be reduced in HAB but not LAB rats, as indicated by a decrease in vasopressin mRNA expression, whereas vasopressin 1a receptor binding was unaffected. These findings provide the first evidence that the vasopressinergic system is likely to be critically involved in the behavioral and neuroendocrine effects of antidepressant drugs. This novel mechanism of action of paroxetine on vasopressin gene regulation renders vasopressinergic neuronal circuits a promising target for the development of more causal antidepressant treatment strategies.     

Impact of maternal deprivation on brain corticotropin-releasing hormone circuits: prevention of CRH receptor-2 mRNA changes by desipramine treatment.

Corticotropin-releasing hormone (CRH) acts within the brain and pituitary to coordinate the overall endocrinological and behavioral stress response. From postnatal day (PND) 4 to 14, the infant rat displays minimal adrenal response to mild stress. However, maternal deprivation alters the pituitary-adrenal system such that the infants become responsive to specific stimuli. We hypothesized that maternal deprivation would also affect CRH brain circuits. Since tricyclic antidepressants have been shown to decrease the adrenal response to stress in adult rats, we hypothesized that CRH-related changes induced by maternal deprivation would be prevented by this treatment. Thus, we investigated CRH-related molecules on animals that were maternally deprived on PND 13 compared with nondeprived animals. We found that maternal deprivation caused alterations in the gene expression of both CRH receptors (CRHr) 1 and 2 in specific brain regions, and that some of these effects were augmented by chronic isotonic saline injections. There was a significant increase in CRH, CRHr1, and r2 mRNA in the cortex. In amygdala, CRHr1 and r2 mRNAs were decreased. CRHr2 mRNA was also decreased in the ventromedial nucleus of the hypothalamus, whereas an increase was detected in the hippocampal pyramidal cells. One week of desipramine (DES) administration preceding the maternal deprivation event prevented all the deprivation-induced changes in CRHr2 mRNA, regardless of the direction of the original change. We also found that chronic injection treatments enhanced the adrenocortical response and improved the efficiency of negative feedback in maternal deprivation animals. These results demonstrate that maternal deprivation elicits modifications of CRH brain circuits in a site-specific manner, and that the regulation of CRHr2 gene expression is mediated by mechanisms different from those involved with the modulation of CRHr1 in the infant rat.     

Role of estrogen receptors in thyroid toxicity induced by mono (2-ethylhexyl) phthalate via endoplasmic reticulum stress: An in vitro mechanistic investigation

Mono(2-ethylhexyl) phthalate (MEHP) can influence the expression of estrogen receptors (ERs) and induce thyroid injury. The expression of ERs can be related to thyroid disease and abnormal expression of ERs has been associated with activation of endoplasmic reticulum stress. This study aimed to clarify the role of ERs in MEHP-induced thyroid damage via endoplasmic reticulum stress. We exposed Nthy-ori 3–1 cells to different doses of MEHP. We found that after the exposure, the cell viability and the expression levels of thyroid hormone metabolism-related proteins decreased, while the apoptosis level and the expression levels of ERs (ERα and GPR30) increased. Three endoplasmic reticulum stress-related signaling pathways were activated by MEHP. After ERα and GPR30 were knocked down, these three pathways were inhibited and the thyroid toxicity was alleviated. Taken together, our results indicate that MEHP can induce thyroid toxicity by upregulating the expression of ERs, further activating endoplasmic reticulum stress.     

Effects of imipramine and bupropion on the duration of immobility of ACTH-treated rats in the forced swim test: involvement of the expression of 5-HT2A receptor mRNA

We examined the effect of chronic administration of imipramine and bupropion, monoamine reuptake inhibitors, on the duration of immobility in the forced swim test and serotonin (5-HT)(2A) receptor function in the form of 5-HT(2A) receptor mRNA levels in rats chronically treated with adrenocorticotropic hormone (ACTH). The immobility-decreasing effect of bupropion without imipramine did not influence the chronic ACTH treatment. The effect on the expression of 5-HT(2A) receptor mRNA of chronic ACTH treatment was decreased by bupropion, but not imipramine. These results suggest that bupropion has the effect of reducing immobility time in the forced swim test in the tricyclic antidepressant-resistant depressive model induced by chronic ACTH treatment in rats, and that decreased 5-HT(2A) receptor mRNA levels may be involved in this phenomenon.     

Endocrine and gene expression changes following forced swim stress exposure during cocaine abstinence in mice

Rationale  Stress can reinstate previous cocaine-seeking long after drug is no longer present. However, little is known regarding the effect of chronic drug exposure and subsequent drug abstinence on responsivity to stress. Objective  To determine the effect of acute (24-h) and prolonged (14-day) drug-free periods in cocaine-experienced mice on behavioral, endocrine, and molecular outputs following stress exposure. Materials and methods  Mice were administered a cocaine binge (15mg/kg, every hour for 3h) for 2weeks. Following a 24-h or 14-day drug-free period, stress responsivity, along with levels of anxiety, were measured using the forced swim test and elevated zero maze, respectively. In addition, alterations in the levels of plasma corticosterone, corticotrophin-releasing factor (CRF) mRNA, brain-derived neurotrophic factor (BDNF) mRNA, and histone acetylation at their respective promoters were examined following stress exposure. Results  At both acute and prolonged abstinence time points, behavioral measures were essentially unaltered; however, cocaine-experienced mice exhibited an augmented corticosterone response to the forced swim stress compared to saline-treated mice. Stress exposure increased BDNF mRNA levels in the ventral tegmental area (VTA) and nucleus accumbens (NAc) only in cocaine-experienced mice following a prolonged, but not acute, drug-free period. Increased BDNF mRNA in the NAc was associated with an increase in acetylated histone 3 (AcH3) at the BDNF I promoter. CRF mRNA levels were increased in the amygdala (AMYG); however, this was not associated with alterations in histone acetylation at the promoter. Conclusion  These results demonstrate that drug history and prolonged abstinence can alter the endocrine and molecular responses to stress, which may facilitate the reinstatement of drug-seeking behaviors.     

Altered serotonergic neurotransmission but normal hypothalamic-pituitary-adrenocortical axis activity in mice chronically treated with the corticotropin-releasing hormone receptor type 1 antagonist NBI 30775.

Antagonists of the corticotropin-releasing hormone receptor type 1 (CRH-R1) are regarded as promising tools for the treatment of stress-related psychiatric disorders. Owing to the intricate relationship between CRH and serotonin (5-HT), we studied the effects of chronic oral treatment of C57Bl6/N mice with the CRH-R1 antagonist NBI 30775 (formerly known as R121919) on hippocampal serotonergic neurotransmission during basal (on 15th day of treatment) and stress (forced swimming; on 16th day of treatment) conditions by in vivo microdialysis. Given the important role of CRH in the regulation of hypothalamic-pituitary-adrenocortical (HPA) axis activity and behavior, the effects of NBI 30775 on dialysate-free corticosterone levels, and on home cage and forced swimming-related behavior were also assessed. Chronic administration of NBI 30775 (18.4+/-0.9 mg/kg/day) did not result in alterations in food consumption and body weight. NBI 30775 caused complex changes in hippocampal serotonergic neurotransmission. Whereas no effects on the diurnal rhythms of 5-HT and its metabolite 5-hydroxyindoleacetic acid were found, the responses of the neurotransmitter and its metabolite to 10 min of forced swim stress were reduced and prolonged, respectively. NBI 30775 did not change free corticosterone levels over the diurnal rhythm. Moreover, NBI 30775-treated mice showed a similar forced swim stress-induced increase in corticosterone as observed in the control group. No effects of NBI 30775 on home cage, and swim stress-related active behaviors (climbing, swimming) and immobility were found. Thus, whereas chronic antagonism of CRH-R1 did not compromise HPA axis performance and behavior, distinct changes in serotonergic neurotransmission developed. Owing to the important role of 5-HT in the pathophysiology of mood and anxiety disorders, the latter observation may contribute to the therapeutical efficacy of CRH-R1 antagonists in these illnesses.     

Bisphenol A induces corticotropin-releasing hormone expression in the placental cells JEG-3

Bisphenol A is utilized to make polycarbonate plastics and is an environmental pollutant. Recent research has indicated that it is an endocrine disruptor and may interfere with reproduction. Placental corticotrophin-releasing hormone (CRH) is a peptide hormone which is involved in fetal development. Increased plasma CRH is associated with elevated risk of premature delivery. In the present study, we demonstrated that bisphenol A increased CRH mRNA expression in the placental JEG-3 cells at or above 25μM. Reporter gene assay also demonstrated that bisphenol A could induce CRH gene transactivity. Since cyclic AMP response element (CRE) is a major regulatory element located in CRH promoter, the sequence-specific binding activity was investigated by using electrophoretic mobility shift assay. Our data indicated that bisphenol A increased the CRE binding activity. Western analysis further illustrated that PKA could be the signal triggering the CRE binding and CRH gene transactivation. In summary, the present study demonstrated that bisphenol A could induce CRH expression in placental cells and the underlying signal transduction pathway was also described.     

Chronic variable stress or chronic morphine facilitates immobility in a forced swim test: reversal by naloxone

The behaviors displayed in a forced swim test were investigated in rats previously exposed to a chronic variable stress treatment or chronic administration of morphine. In addition, to further explore the participation of an endogenous opiate mechanism in these behavioral effects, naloxone was either administered during the chronic treatment (prior to each stress or morphine exposure) or immediately prior to the forced swim test. Animals were submitted daily to a different stressor for 1 week or injected with morphine (10 mg/kg, IP) for 6 days, whereas controls were unmanipulated except for the injection process. On the day following the last stressor, control and stressed animals were administered saline or naloxone (2 mg/kg, IP) 15 min prior to the forced swim test. Morphine treated animals were similarly tested on the third day following the last morphine injection. In a separate group of rats, naloxone (2 mg/kg, IP) was administered daily 10 min prior to each stressor of the chronic stress regime or each daily morphine injection. A significant increase in the time spent in immobility was observed in stressed animals as well as in rats chronically treated with morphine. In both groups, this potentiated immobility was attenuated by naloxone pretreatment prior to the forced swim test or when given before each daily stressor or morphine injection. In addition, the concurrent exposure to stress or morphine along with naloxone administration enhanced struggling in the first 5 min of the forced swim test. Taken together, the results of these experiments support the conclusion that the increase in immobility seen following chronic variable stress or repeated morphine exposure is modulated by the activation of an endogenous opiate mechanism, given that this effect is attenuated by naloxone administration.     

Differential expression patterns of Wnt and beta-catenin/TCF target genes in the uterus of immature female rats exposed to 17alpha-ethynyl estradiol.

To characterize the effects of an estrogen receptor (ER) agonist on the gene expressions in the uterus, immature female rats were administered once orally with 17alpha-ethynyl estradiol (EE, 3 mug/kg), a potent ER agonist. We focused on four categories of sex steroid hormone receptor genes: well-known estrogen target genes, Wnt genes, and beta-catenin/T-cell factor (TCF) target genes. ERalpha, ERbeta, progesterone receptor, and androgen receptor mRNAs were all downregulated at 24 and/or 48 h after EE administration. Complement C3 and insulin-like growth factor 1 mRNAs were markedly induced after EE administration. Although the time courses of Wnt4, Wnt5a, and Wnt7a mRNA status varied until 12 h after EE administration, all of them were simultaneously downregulated at 24 and 48 h. The remarkable downregulation of Wnt7a mRNA in response to EE was considered to be important to understand the various uterine phenomena affected by ER agonists. In the beta-catenin/TCF target genes, the downregulation of anti-Mullerian hormone type 2 receptor and bone morphogenetic protein 4 mRNA after EE administration appeared to be closely related to the downregulation of Wnt7a. The upregulation of cyclin D1 and follistatin mRNA at the early phase after EE administration was considered to have been affected by the upregulation of Wnt4. These results indicate that an ER agonist influences not only the mRNA expression of sex steroid hormone receptor genes and well-known estrogen target genes but also Wnt genes (Wnt4, Wnt5a, Wnt7a) and beta-catenin/TCF target genes in the uterus of immature rats, indicating that their molecules are the potential players affected by estrogenic stimuli.     

Consequences of chronic social stress on behaviour and vasopressin gene expression in the PVN of DBA/2OlaHsd mice--influence of treatment with the CRHR1-antagonist R121919/NBI 30775

Accumulating evidence suggests that corticotropin-releasing hormone (CRH) neurocircuitry modulate the neuroendocrine and behavioural phenotypes in depression and anxiety. Thus, the administration of the selective CRH-receptor 1 (CRHR1)-antagonist R121919/NBI 30775 has proven its ability to act as an anxiolytic in rats. It is still unclear whether vasopressinergic neuronal circuits, which are known to be involved in the regulation of emotionality, are affected by R121919/NBI 30775. Using DBA/2OlaHsd mice, we investigated the effects of chronic social defeat and concomitant treatment with R121919/NBI 30775 on 1) the behavioural profile in the modified hole board test and 2) in-situ hybridization analysis-based expression of arginine vasopressin (AVP) and CRH mRNA in both the hypothalamic paraventricular nucleus and supraoptic nucleus. The results suggest that chronic social defeat leads to increased avoidance behaviour and reduction in directed exploration, general exploration, and locomotion. Chronic treatment with the CRHR1-antagonist was effective in reversing the directed exploration to control level. The dissection of the antagonist-treated group into responders and non-responders using the parameter time spent on board revealed further positive effects of R121919/NBI 30775 on avoidance behaviour and locomotion. Behavioural changes were accompanied by alterations in AVP gene expression in the paraventricular nucleus. Taken together, the anxiolytic action of the CRHR1 antagonist was found in a subgroup of animals only, and further studies have to be done to clarify the inter-individual biological differences in response patterns to this compound to optimise its application under clinical conditions.     

番石榴叶天然成分抑制3T3-L1细胞成脂分化的研究

目的观察番石榴叶天然成分槲皮素、槲皮素-3-O-(6″-芥子酸)-β-D-吡喃半乳糖苷(Quercetin-3-O-(6″-eru-coyl)-β-D-galactopyranoside,QEG)及槲皮素-3-O-(6″-阿魏酸)-β-D-吡喃半乳糖苷(Quercetin-3-O-(6″-feruloyl)-β-D-ga-lactopyranoside,QFG)对小鼠3T3-L1细胞成脂分化的影响。方法诱导3T3-L1细胞成脂分化,油红O染色法测定脂滴含量,实时定量PCR(Q-PCR)检测丝氨酸蛋白酶脂肪因子adipsin,CCTTA增强子结合蛋白α(C/EBPα)、过氧化物酶体增殖物激活受体γ(PPARγ)、雌激素受体α(ERα)和雌激素受体β(ERβ)mRNA表达,Western blot检测C/EBPα和PPARγ的蛋白表达。结果 QFG和槲皮素都能抑制3T3-L1细胞成脂分化,而QEG对此没有作用。QFG能够剂量依赖性地抑制成脂分化,并且降低adipsin、C/EBPα和PPARγmRNA及后两者蛋白表达,而对ERα和ERβmRNA的表达没有影响。结论 QFG抑制细胞成脂分化的能力比槲皮素强,其作用主要是通过抑制C/EBPα和PPARγ的表达而实现的,而且可能与雌激素受体途径无关。     

抗雌激素治疗对耐酪氨酸激酶抑制剂非小细胞肺癌细胞株抗增殖作用的机制探讨

目的 探讨氟维司群逆转吉非替尼耐药非小细胞肺癌细胞株耐药性的可能性及其机制.方法 分别用不同浓度的氟维司群和吉非替尼,单药以及联合对非小细胞肺癌细胞株H1975[含表皮生长因子受体(EGFR)L858R&T790m突变]、H1650(含EGFR Del E746-A750&PTEN De突变)、PC-9(含EGFR Del E746-A750突变)细胞进行干预后,采用MTT法检测细胞增殖变化,Western blot法检测EGFR、雌激素受体(ER)、磷酸化表皮生长因子受体(p-EGFR)的蛋白表达.结果①H1975、H1650、PC-9肺癌细胞中均有EGFR及ER表达;②吉非替尼及氟维司群联合用药较单药可明显抑制H1975、H1650、PC-9肺癌细胞的增殖(P<0.001);③H1975耐药细胞株内T790m突变型EGFR的磷酸化水平可以快速地被雌激素升高或被氟维司群抑制;④ 在酪氨酸激酶抑制剂(EGFR-TKI)获得性耐药的肺癌细胞株中雌激素、表皮生长因子(EGF)分别下调EGFR、ER的水平,氟维司群、吉非替尼分别上调EGFR、ER的水平.结论 采用EGFR的靶向治疗与抗雌激素治疗相结合的治疗方案提高EGFR和ER阳性的EGFR-TKI获得性耐药的NSCLC的治疗效果在理论上是可行的.