Pirin Inhibits FAS-Mediated Apoptosis to Support Colorectal Cancer Survival.

Resistance to immunotherapy in colorectal cancer (CRC) is associated with obstruction of FAS (Apo-1 or CD95)-dependent apoptosis, a hallmark of cancer. Here it is demonstrated that the upregulation of pirin (PIR) protein in colon cancers promotes tumorigenesis. Knockout or inhibition of PIR dramatically increases FAS expression, FAS-dependent apoptosis and attenuates colorectal tumor formation in mice. Specifically, NFκB2 is a direct transcriptional activator of FAS and robustly suppressed by PIR in dual mechanisms. One is the disruption of NFκB2 complex (p52-RELB) association with FAS promoter, the other is the inhibition of NIK-mediated NFκB2 activation and nuclear translocation, leading to the inability of active NFκB2 complex toward the transcription of FAS. Furthermore, PIR interacts with FAS and recruits it in cytosol, preventing its membrane translocation and assembling. Importantly, knockdown or knockout of PIR dramatically sensitizes cells to FAS mAb- or active CD8+ T cells-triggered cell death. Taken together, a PIR-NIK-NFκB2-FAS survival pathway is established, which plays a key role in supporting CRC survival.

ELP3 stabilizes c-myc to promote tumorigenesis.

ELP3, the catalytic subunit of Elongator complex, is an acetyltransferase and associated with tumor progression. However, the detail of ELP3 oncogenic function remains largely unclear. Here, we found that ELP3 stabilizes c-Myc to promote tumorigenesis in an acetyltransferase-independent manner. Mechanically, ELP3 competes with the E3-ligase FBXW7ß for c-Myc binding, resulting in the inhibition of FBXW7ß-mediated ubiquitination and proteasomal degradation of c-Myc. ELP3-knockdown diminishes glycolysis and glutaminolysis and dramatically retards cell proliferation and xenograft growth by downregulating c-Myc, and such effects are rescued by reconstitution of c-Myc expression. Moreover, ELP3 and c-Myc were overexpressed with a positive correlation in colorectal cancer and hepatocellular carcinoma. Taken together, we elucidate a new function of ELP3 in promoting tumorigenesis by stabilizing c-Myc, suggesting that inhibition of ELP3 is a potential strategy for the therapy of c-Myc-driven carcinomas.

ZEB1 Transcriptionally Activates PHGDH to Facilitate Carcinogenesis and Progression of HCC.

BACKGROUND & AIMS: Phosphoglycerate dehydrogenase (PHGDH), the rate-limiting enzyme of the de novo serine synthesis pathway (SSP), has been implicated in the carcinogenesis and metastasis of hepatocellular carcinoma (HCC) because of its excessive expression and promotion of SSP. In previous experiments we found that SSP flux was diminished by knockdown of zinc finger E-box binding homeobox 1 (ZEB1), a stimulator of HCC metastasis, but the underlying mechanism remains largely unknown. Here, we aimed to determine how SSP flux is regulated by ZEB1 and the contribution of such regulation to carcinogenesis and progression of HCC. METHODS: We used genetic mice with Zeb1 knockout in liver specifically to determine whether Zeb1 deficiency impacts HCC induced by the carcinogen diethylnitrosamine plus CCl4. We explored the regulatory mechanism of ZEB1 in SSP flux using uniformly-labeled [13C]-glucose tracing analyses, liquid chromatography-mass spectrometry, real-time quantitative polymerase chain reaction, luciferase report assay, and chromatin immunoprecipitation assay. We determined the contribution of the ZEB1-PHGDH regulatory axis to carcinogenesis and metastasis of HCC by cell counting assay, methyl thiazolyl tetrazolium (MTT) assay, scratch wound assay, Transwell assay, and soft agar assay in vitro, orthotopic xenograft, bioluminescence, and H&E assays in vivo. We investigated the clinical relevance of ZEB1 and PHGDH by analyzing publicly available data sets and 48 pairs of HCC clinical specimens. RESULTS: We identified that ZEB1 activates PHGDH transcription by binding to a nonclassic binding site within its promoter region. Up-regulated PHGDH augments SSP flux to enable HCC cells to be more invasive, proliferative, and resistant to reactive oxygen species and sorafenib. Orthotopic xenograft and bioluminescence assays have shown that ZEB1 deficiency significantly impairs the tumorigenesis and metastasis of HCC, and such impairments can be rescued to a large extent by exogenous expression of PHGDH. These results were confirmed by the observation that conditional knockout of ZEB1 in mouse liver dramatically impedes carcinogenesis and progression of HCC induced by diethylnitrosamine/CCl4, as well as PHGDH expression. In addition, analysis of The Cancer Genome Atlas database and clinical HCC samples showed that the ZEB1-PHGDH regulatory axis predicts poor prognosis of HCC. CONCLUSIONS: ZEB1 plays a crucial role in stimulating carcinogenesis and progression of HCC by activating PHGDH transcription and subsequent SSP flux, deepening our knowledge of ZEB1 as a transcriptional factor in fostering the development of HCC via reprogramming the metabolic pathway.

c-Src facilitates tumorigenesis by phosphorylating and activating G6PD.

Glucose-6-phosphate dehydrogenase (G6PD) is the first and rate-limiting enzyme in pentose phosphate pathway (PPP), excessive activation of which has been considered to be involved in tumorigenesis. Here, we show that tyrosine kinase c-Src interacts with and phosphorylates G6PD at Tyr 112. This phosphorylation enhances catalytic activity of G6PD by dramatically decreasing its Km value and increasing its Kcat value for substrate glucose-6-phosphate. Activated G6PD therefore augments the PPP flux for NADPH and ribose-5-phosphate production which is required for detoxification of intracellular reactive oxygen species (ROS) and biosynthesis of cancer cells, and eventually contributes to tumorigenesis. Consistently, c-Src activation is closely correlated with tyrosine phosphorylation and activity of G6PD in clinical colorectal cancer samples. We thus uncover another aspect of c-Src in promoting cell proliferation and tumorigenesis, deepening our understanding of c-Src as a proto-oncogene.

A follow-up study in children with status epilepticus during sleep: From clinical spectrum to outcome.

PURPOSE: To evaluate the correlation between clinical spectrum and therapeutic outcomes and neuropsychological deficits in children with status epilepticus during sleep (SES). METHODS: The clinical spectrum of patients with SES was defined as follows: status epilepticus of benign childhood epilepsy with centro-temporal spikes (SEBECTs), atypical benign focal epilepsy during childhood (ABFEC), non-idiopathic focal epilepsy (NIFE), and Landau-Kleffner syndrome (LKS). SES cases were divided into 4 groups according to neuropsychological findings before treatment: developmental delay/intellectual disability (DD/ID), cognitive impairment (CI), attention deficit and/or hyperactivity behaviors (AHD), and normal group (NG). The therapeutic outcomes were classified into 3 groups: satisfactory response, recurrence, and seizure control. RESULTS: A total of 39 cases (24 males and 15 females) were recruited, including 3 cases with SEBECTs, 26 with ABFEC, 8 with NIFE [2 with focal cortical dysplasia (FCD)], and 2 with LKS. There were 7 patients in the DD/ID group, 8 in the CI group, 19 in the AHD group, and 5 in the NG group. Neuropsychological outcomes were significantly different among clinical spectrum (P < 0.001), and neuropsychological deficits frequently occurred in the ABFEC group or in the NIFE group. Besides, 18 patients in the satisfactory group had satisfactory response to medicine or surgery (2 out of 18 cases with FCD), whereas recurrence was observed at least one session within one year in 16 cases in the recurrence group, and no improvement in spike-wave index and cognition/behavior was noted in 5 patients in the seizure control group, although seizure could be controlled. There were significant differences in therapeutic outcomes among clinical spectrum (P = 0.041), with the worst outcomes in the NIFE group (only 1 out of 8 with satisfactory good response). CONCLUSIONS: It is important to categorize patients with SES into epilepsy syndromes, including SEBECTs, ABFPEC, NIFE, and LKS; the clinical spectrum may be a significant determinant to influence the outcomes of SES, including neuropsychological deficits and therapeutic outcomes.

c-Src Promotes Tumorigenesis and Tumor Progression by Activating PFKFB3.

Reprogramming of glucose metabolism is a key event in tumorigenesis and progression. Here, we show that active c-Src stimulates glycolysis by phosphorylating (Tyr194) and activating PFKFB3, a key enzyme that boosts glycolysis by producing fructose-2,6-bisphosphate and activating PFK1. Increased glycolysis intermediates replenish non-oxidative pentose phosphate pathway (PPP) and serine pathway for biosynthesis of cancer cells. PFKFB3 knockout (KO) cells and their counterpart reconstituted with PFKFB3-Y194F show comparably impaired abilities for proliferation, migration, and xenograft formation. Furthermore, PFKFB3-Y194F knockin mice show impaired glycolysis and, mating of these mice with APCmin/+ mice attenuates spontaneous colon cancer formation in APCmin/+ mice. In summary, we identify a specific mechanism by which c-Src mediates glucose metabolism to meet cancer cells' requirements for maximal biosynthesis and proliferation. The PFKFB3-Tyr194 phosphorylation level highly correlates with c-Src activity in clinical tumor samples, indicating its potential as an evaluation for tumor prognosis.

Acquired epileptiform opercular syndrome evaluated with real-time transcranial Doppler ultrasound-video-electroencephalogram before and after treatment: a case report.

BACKGROUND: Acquired epileptiform opercular syndrome (AEOS) with electrical status epilepticus during sleep (ESES) may be recurrent and intractable. The real-time transcranial Doppler ultrasound-sleep-deprived video electroencephalogram (TCD-SDvEEG) can be used to observe the relationships among hemodynamic, electrophysiological, and clinical factors in a patient during therapy. This study reported the case of a healthy 5-year-old boy with AEOS. CASE PRESENTATION: The patient had initial seizures during sleep at the age of 1 year, with the left mouth pouting, left eye blinking and drooling for several seconds, and, sometimes, the left upper-limb flexion and head version to the left, lasting for 1-2 min. The combined antiepileptic drug regimens, including valproate, lamotrigine, and clonazepam, failed in the present case. Therefore, the add-on high-dose methylprednisolone therapy was provided. Also, the serial TCD-SDvEEG was used to monitor the dynamic changes before and after add-on steroid treatment. The results showed less than 15% variation in the range of blood flow fluctuation with spikes during non-rapid eye movement sleep after treatment. This was similar to the outcomes in healthy children and also accorded with the clinical improvements such as seizure control, drooling control, and language ability melioration. However, 95% of spike-wave index (SWI) was still maintained. The improvements in cerebral hemodynamics and clinical manifestations were faster and earlier than the SWI progression. CONCLUSIONS: The real-time TCD-SDvEEG was highly sensitive in detecting therapeutic changes. The findings might facilitate the understanding of the mechanisms underlying neurovascular coupling in patients with AEOS accompanied by ESES.

[Overnight sleep structure of children with epilepsia].

OBJECTIVE: To evaluate the effect of epilepsy on sleep in children. METHODS: Whole night polysomnography was performed in 48 epileptic children and 12 healthy controls. The 48 epileptic children were divided into focal seizure and generalized seizure groups and into waking seizure and sleeping seizure groups according to the time of occurrence of the seizures. Various parameters of sleep structure were analyzed. RESULTS: The sleep efficiency of epileptic children was significantly lower than that of the healthy controls (85.4 +/- 8.6% vs 90.9 +/- 5.8%; P < 0.05). The total recording time (TRT) of sleep was significantly longer and the sleep efficiency was significantly lower in the focal seizure group compared to the control group (P < 0.05). The percentage of stage 1 non-rapid-eye-movement sleep (S1 sleep) increased and the percentage of rapid-eye-movement (REM) sleep decreased in the generalized seizure group compared to the control group (P < 0.05). The percentage of S1 sleep increased and both the percentage of REM sleep and the sleep efficiency decreased in the sleeping seizure group as compared with the control group (P < 0.05). There were no significant differences in the parameters of sleep structure between the waking seizure and the control group. Among the sleeping seizure group, the children with generalized seizure showed significantly lower REM sleep percentage and sleep efficiency, and those with focal seizure had significantly longer TRT and higher S1 sleep percentage as compared with the controls. CONCLUSIONS: Epilepsy affects sleep structure of patients, and different types of seizure have different influences on sleep structure. Children with generalized seizure have prolonged light sleep and shortened REM sleep. When generalized seizures occur during waking, the increase of light sleep is more pronounced. While generalized seizures occur during sleeping, REM sleep reduction is more prominent. Children with focal seizures have decreased sleep efficiency. When focal seizures occur during waking, the sleep structure of patients is normal. However, when seizures occur during sleeping light sleep increases and sleep efficiency decreases.