Epithelial to mesenchymal transition (EMT) and extracellular matrix degradation are critical for the initiation and progression of tumor invasion. We have recently identified Krüppel-like factor 8 (KLF8) as a critical inducer of EMT and invasion. KLF8 induces EMT primarily by repressing E-cadherin transcription. However, how KLF8 promotes invasion is unknown. Here we report a novel KLF8-to-MMP9 signaling that promotes human breast cancer invasion. To identify the potential KLF8 regulation of MMPs in breast cancer, we established two inducible cell lines that allow either KLF8 overexpression in MCF-10A or knockdown in MDA-MB-231 cells. KLF8 overexpression induced a strong increase in MMP9 expression and activity as determined by quantitative real-time PCR and zymography. This induction was well correlated with the MMP inhibitor-sensitive Matrigel invasion. Conversely, KLF8 knockdown caused the opposite changes that could be partially prevented by MMP9 overexpression. Promoter-reporter assays and chromatin and oligonucleotide precipitations determined that KLF8 directly bound and activated the human MMP9 gene promoter. Three-dimensional (3D) glandular culture showed that KLF8 expression disrupted the normal acinus formation which could be prevented by the MMP inhibitor, whereas KLF8 knockdown corrected the abnormal 3D architecture which could be protected by MMP9 overexpression. KLF8 knockdown promoted MDA-MB-231 cell aggregation in suspension culture which could be prevented by MMP9 overexpression. KLF8 knockdown inhibited the lung metastasis of MDA-MB-231 cells in nude mice. Immunohistochemical staining strongly correlated the co-expression of KLF8 and MMP9 with the patient tumor invasion, metastasis and poor survival. Taken together, this work identified the KLF8 activation of MMP9 as a novel and critical signaling mechanism underlying human breast cancer invasion and metastasis.

SummaryMicroglia are well known to play a critical role in maintaining brain homeostasis. However, their role in epileptogenesis has yet to be determined. Here, we demonstrate that elevated mTOR signaling in mouse microglia leads to phenotypic changes, including an amoeboid-like morphology, increased proliferation, and robust phagocytosis activity, but without a significant induction of pro-inflammatory cytokines. We further provide evidence that these noninflammatory changes in microglia disrupt homeostasis of the CNS, leading to reduced synapse density, marked microglial infiltration into hippo-campal pyramidal layers, moderate neuronal degeneration, and massive proliferation of astrocytes. Moreover, the mice thus affected develop severe early-onset spontaneous recurrent seizures (SRSs). Therefore, we have revealed an epileptogenic mechanism that is independent of the microglial inflammatory response. Our data suggest that microglia could be an opportune target for epilepsy prevention.

Aim Clomiphene citrate (CC) and anastrozole (AZ) have been used off label to increase testosterone (T) in hypogonadal infertile men (HIM). Both medications have been shown to increase T with different effects on estradiol (E2) and T-to-E2 ratios. There are no reported randomized trials comparing CC and AZ to improve T levels in HIM. We aimed to establish equivalence of CC vs. AZ with respect to improvement in T levels in HIM. Methods We randomized 26 HIM (T less than 350 ng/dL and normal luteinizing hormone [LH]). Patients were randomized to CC (25 mg/day) or AZ (1 mg/day) for 12 weeks. Hormones assayed were total T, free T, E2, LH, follicle stimulating hormone (FSH), and sex hormone binding globulin (SHBG). Patient-reported outcomes were the International Index of Erectile Function, Erection Hardness Scale, and the Androgen Deficiency in the Aging Male questionnaires. Blood tests and questionnaires were recorded at baseline, 6 and 12 weeks. Semen analyses were performed at baseline and 12 weeks. Results T increased significantly from baseline in both groups at 6 and 12 weeks. There was a significantly larger increase in T and mean increase from baseline in CC vs. AZ (571 vs. 408 ng/dL, respectively). Whereas E-2 levels increased in the CC group, they decreased in the AZ group. Though both groups demonstrated an increase in T-to-E-2 ratio from baseline, statistic significance at 6 and 12 weeks was only achieved with AZ. Neither group demonstrated significant changes in seminal parameters or patient-reported outcomes. Conclusions We failed to demonstrate equivalence of CC vs. AZ. CC resulted in significantly higher T levels than AZ. AZ resulted in a significantly larger increase in T/E-2 ratio than CC. No significant differences between CC and AZ on seminal parameters or patient-reported outcomes were demonstrated.

Background and Purpose-Increased activation of excitatory amino acid (EAA) receptors is considered a major cause of neuronal damage. Possible sources and mechanisms of ischemia-induced EAA release were investigated pharmacologically with microdialysis probes placed bilaterally in rat striatum. Methods-Forebrain ischemia was induced by bilateral carotid artery occlusion and controlled hypotension in halothaneanesthetized rats. During 30 minutes of ischemia, microdialysate concentrations of glutamate and aspartate were measured in the presence of a nontransportable blocker of the astrocytic glutamate transporter GLT-1, dihydrokinate (DHK), or an anion channel blocker, 4,4Ј-dinitrostilben-2,2Ј-disulfonic acid (DNDS), administered separately or together through the dialysis probe. Results-In control striata during ischemia, glutamate and aspartate concentrations increased 44Ϯ13 (meanϮSEM) times and 19Ϯ5 times baseline, respectively, and returned to baseline values on reperfusion. DHK (1 mmol/L in perfusate; nϭ8) significantly attenuated EAA increases compared with control (glutamate peak, 9.6Ϯ1.7 versus control, 15.4Ϯ2.6 pmol/L). EAA levels were similarly decreased by 10 mmol/L DHK. DNDS (1 mmol/L; nϭ5) also suppressed EAA peak increases (glutamate peak, 5.8Ϯ1.1 versus control, 10.1Ϯ0.7 pmol/L). At a higher concentration, DNDS (10 mmol/L; nϭ7) further reduced glutamate and aspartate release and also inhibited ischemia-induced taurine release.