Purpose Malignant clear cell renal carcinoma (ccRCC) is an aggressive tumor highly resistant to chemotherapy and radiation. Current therapeutic approaches to management of ccRCC have not significantly improved patient survival, therefore novel therapies are needed. Activated NFκB and STAT3 expression is associated with ccRCC pathogenesis. The dietary polyphenol curcumin is a well-documented antitumor agent and a known inhibitor of NFκB and STAT3 activation. Given the lack of effective therapies that block ccRCC progression, our objective was to examine whether curcumin could suppress the growth and migration of ccRCC cells, and whether this suppression was mediated via inhibition of NFκB and STAT3 activity. Methods Human ccRCC cell lines (769-p, 786-o, Caki-1, ACHN and A-498 cells) were exposed to curcumin to assess the impact of curcumin on ccRCC cell viability. Colony formation assay was used to assess the effect of curcumin on ccRCC cell renewal capability. Effect of curcumin on apoptosis was determined by annexin V binding and mitochondrial membrane depolarization assays. The anti-migratory effect of curcumin on ccRCC cells was assessed using the wound healing assay. Effect of curcumin on NFκB and STAT3 phosphorylation in 769-p cells was determined by western blot analysis. Results In ccRCC cells, curcumin decreased cell proliferation and cell viability, abolished clonogenic property, induced apoptosis and blocked cellular migration. The growth suppressive and pro-apoptotic effects of curcumin were accompanied by decreased phosphorylation of NFκB and STAT3. Conclusions The ability of curcumin to induce apoptosis and inhibit migration of ccRCC cells justifies additional mechanistic and preclinical studies that examine the effect of curcumin or other NFκB and STAT3 inhibitors as potential suppressors of ccRCC tumorigenesis.

Background: We recently reported that estrogen receptor alpha (ER alpha), even in absence of estrogen (E2), plays a critical role in lactotroph homeostasis. The anti-estrogen ICI 182780 ( ICI), but not tamoxifen or raloxifene, rapidly promoted the degradation of ER alpha, and inhibited cell proliferation. However, all three ER antagonists suppressed PRL release, suggesting that receptor occupation is sufficient to inhibit prl gene expression whereas receptor degradation is required to suppress lactotroph proliferation. In this study our objective was to determine whether ER alpha degradation versus occupation, differentially modulates the biological outcome of anti-estrogens.Principal Findings: Using the rat lactotroph cell line, GH3 cells, we report that ICI induced proteosome mediated degradation of ER alpha. In contrast, an ER alpha specific antagonist, MPP, that does not promote degradation of ER alpha, did not inhibit cell proliferation. Further, ICI, but not MPP, abolished anchorage independent growth of GH3 cells. Yet, both ICI and MPP were equally effective in suppressing prl expression and release, as well as ERE-mediated transcriptional activity.Conclusion: Taken together, our results demonstrate that in lactotrophs, ER alpha degradation results in decreased cell proliferation, whereas ER alpha occupation by an antagonist that does not promote degradation of ER alpha is sufficient to inhibit prl expression.

Medulloblastoma (MB) is the most common malignant brain tumor in children. Bcl-2 and MMP-9 promote the pathogenesis and progression of MB. The expression of both bcl-2 and MMP-9 is regulated by the transcription factor NF-kappaB. Curcumin, a natural food additive, has a potent anti-proliferative effect, presumably mediated through NF-kappaB suppression. The tumor-suppressing effects of curcumin are well documented, however, its effect on MB is unknown. Our objectives were to: a) examine the effect of curcumin on MB cell proliferation and apoptosis; b) characterize the mechanism that mediates the effect of curcumin; c) examine the effects of curcumin on MB cell migration. We report that curcumin inhibited cell proliferation and blocked clonogenicity of MB cells. Furthermore, curcumin down-regulated bcl-2 and bcl(x)l, leading to caspase-mediated cell death. Finally, curcumin blocked migration of MB cells. Thus, we propose developing curcumin as a novel therapeutic agent for MB.

Examination plays a role to judge learner's learning behavior and achievement in evaluation. In most cases, good grade means good learner. Teachers do not realize what learners know and how much they understand. Learners with poor grades are becoming giving up them easily. Modern evaluation, diagnoses students with learning ability not grade. There are two assumptions. First, the difficulty level of materials is suitable for the students. Second, the difficulty level of question matches the teaching material. The main purpose is diagnosing the student's ability. This research calculates the student's ability from online-test system with Item Response Theory (IRT). We integrate K-means to cluster learner's ability which is calculated from item response theory. Teachers can modify the learning material adaptively and teach students in accordance with their aptitude in their courses.

Both estrogen (E2) and EGF regulate lactotrophs, and we recently demonstrated that EGF phosphorylates S118 on estrogen receptor-alpha (ERalpha) and requires ERalpha to stimulate prolactin (PRL) release. However, the interactions between ligand-occupied ERalpha and activated ErbB1 and its impact on lactotroph function are unknown. Using rat GH3 lactotrophs, we found that both E2 and EGF independently stimulated proliferation and PRL gene expression. Furthermore, their combination resulted in an enhanced stimulatory effect on both cell proliferation and PRL gene expression. Inhibitors of ER as well as ErbB1 blocked the combined effects of E2 and EGF. Pretreatment with UO126 abolished the combined effects, demonstrating Erk1/2 requirement. Although bidirectionality in ER-ErbB1 cross-talk is a well-accepted paradigm, interestingly in lactotrophs, ErbB1 kinase inhibitor failed to block the effect of E2 on proliferation and stimulation of PRL gene expression, suggesting that ER does not require ErbB1 to mediate its effects. Furthermore, E2 did not affect the ability of EGF to induce c-Fos expression or modulate AP-1 activity. However, both E2 and EGF combine to enhance S118 phosphorylation of ERalpha, leading to enhanced E2-mediated estrogen response element transactivation. Taken together, our results suggest that, in lactotrophs, activated ErbB1 phosphorylates ERalpha to enhance the stimulatory effect of E2, thereby providing the molecular basis by which EGF amplifies the response of E2.

Prolactinomas are the most prevalent functional pituitary adenomas. Dopamine D2 receptor (D2R) agonists, such as bromocriptine are the first line of therapy; however, drug intolerance/resistance to D2R agonists exists. Apart from D2R agonists, there is no established medical therapy for prolactinomas; therefore, identifying novel therapeutics is warranted. Curcumin, a commonly used food additive in South Asian cooking, inhibits proliferation of several tumor cell lines; however, its effect on pituitary tumor cell proliferation has not been determined. Our objectives were to: 1) determine whether curcumin inhibits proliferation of pituitary tumor cell lines; 2) identify the signaling intermediaries that mediate the effect of curcumin; 3) examine whether curcumin inhibited pituitary hormone production and release; and 4) examine whether curcumin could enhance the growth-inhibitory effect of bromocriptine. Using rat lactotroph cell lines, GH3 and MMQ cells, we report that curcumin had a robust dose and time-dependent inhibitory effect on GH3 and MMQ cell proliferation. Inhibitory effects of curcumin persisted, even on removal of curcumin, and curcumin also blocked colony formation ability of pituitary tumor cells. The growth-inhibitory effect of curcumin was accompanied by decreased expression of cyclin D3 and ser 780 phosphorylation of retinoblastoma protein. In addition, curcumin also induced apoptosis in both GH3 and MMQ cells. Furthermore, curcumin suppresses intracellular levels and release of both prolactin and GH. Finally, we show that low concentrations of curcumin enhanced the growth-inhibitory effect of bromocriptine on MMQ cell proliferation. Taken together we demonstrate that curcumin inhibits pituitary tumor cell proliferation, induces apoptosis, and decreases hormone production and release, and thus, we propose developing curcumin as a novel therapeutic tool in the management of prolactinomas.

Epidermal growth factor (EGF) is a potent regulator of cell function in many cell types. EGF-receptor (EGFR/ErbB1)-activated Erk1/2 has been reported to activate estrogen receptor (ER) in an estrogen (E2)-independent manner. In the pituitary lactotrophs, both EGF and E2 stimulate prolactin (PRL) release, but the nature of interactions between ErbB and ERα signaling is unknown. Our objectives were to 1) characterize EGF-induced PRL release, 2) determine whether this effect requires ERα, and 3) determine the molecular basis for cross talk between ErbB and ERα signaling pathways. Using GH3 cells, a rat lactotroph cell line, we report that EGF stimulates PRL gene expression and release in a dose- and time-dependent manner. EGF caused a rapid and robust activation of Erk1/2 via ErbB1 and induced phosphorylation of S118 on ERα in an Erk1/2-dependent manner. The global antiestrogen ICI 182780 and the ERα-specific antagonist 1,3-bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylet hoxy)phenol]-1H-pyrazole dihydrochloride (MPP), but not the ERβ-specific antagonist 4-[2-Phenyl-5,7-bis(trifluoromethyl) pyrazolo[1,5-a]pyrimidin-3-yl]phenol (PHTPP), blocked the EGF-induced PRL release, indicating an ERα requirement. This was further supported by using ERα knockdown by small interfering RNA. Because the antiestrogens did not block EGF-induced Mek-1 or Erk1/2 phosphorylation, ERα is placed downstream from the ErbB1-activated Erk1/2. These results provide the first evidence that ErbB1-induced PRL release is ERα dependent.Epidermal growth factor-stimulated prolactin release in lactotrophs is dependent upon estrogen receptor α.