Tumor Spheroids of an Aggressive Form of Central Neurocytoma Have Transit-Amplifying Progenitor Characteristics with Enhanced EGFR and Tumor Stem Cell Signaling

Central neurocytoma (CN) has been known as a benign neuronal tumor. In rare cases, CN undergoes malignant transformation to glioblastomas (GBM). Here we examined its cellular origin by characterizing differentiation potential and gene expression of CN-spheroids. First, we demonstrate that both CN tissue and cultured primary cells recapitulate the hierarchal cellular composition of subventricular zone (SVZ), which is comprised of neural stem cells (NSCs), transit amplifying progenitors (TAPs), and neuroblasts. We then derived spheroids from CN which displayed EGFR+/ MASH+ TAP and BLBP+ radial glial cell (RGC) characteristic, and mitotic neurogenesis and gliogenesis by single spheroids were observed with cycling multipotential cells. CN-spheroids expressed increased levels of pluripotency and tumor stem cell genes such as KLF4 and TPD5L1, when compared to their differentiated cells and human NSCs. Importantly, Gene Set Enrichment Analysis showed that gene sets of GBM-Spheroids, EGFR Signaling, and Packaging of Telomere Ends are enriched in CN-spheroids in comparison with their differentiated cells. We speculate that CN tumor stem cells have TAP and RGC characteristics, and upregulation of EGFR signaling as well as downregulation of eph-ephrin signaling have critical roles in tumorigenesis of CN. And their ephemeral nature of TAPs destined to neuroblasts, might reflect benign nature of CN.

Tumor Spheroids of an Aggressive Form of Central Neurocytoma Have Transit-Amplifying Progenitor Characteristics with Enhanced EGFR and Tumor Stem Cell Signaling

Central neurocytoma (CN) has been known as a benign neuronal tumor. In rare cases, CN undergoes malignant transformation to glioblastomas (GBM). Here we examined its cellular origin by characterizing differentiation potential and gene expression of CN-spheroids. First, we demonstrate that both CN tissue and cultured primary cells recapitulate the hierarchal cellular composition of subventricular zone (SVZ), which is comprised of neural stem cells (NSCs), transit amplifying progenitors (TAPs), and neuroblasts. We then derived spheroids from CN which displayed EGFR+/ MASH+ TAP and BLBP+ radial glial cell (RGC) characteristic, and mitotic neurogenesis and gliogenesis by single spheroids were observed with cycling multipotential cells. CN-spheroids expressed increased levels of pluripotency and tumor stem cell genes such as KLF4 and TPD5L1, when compared to their differentiated cells and human NSCs. Importantly, Gene Set Enrichment Analysis showed that gene sets of GBM-Spheroids, EGFR Signaling, and Packaging of Telomere Ends are enriched in CN-spheroids in comparison with their differentiated cells. We speculate that CN tumor stem cells have TAP and RGC characteristics, and upregulation of EGFR signaling as well as downregulation of eph-ephrin signaling have critical roles in tumorigenesis of CN. And their ephemeral nature of TAPs destined to neuroblasts, might reflect benign nature of CN.

Expression of µ-Opioid Receptor in CA1 Hippocampal Astrocytes

µ-opioid receptor (MOR) is a class of opioid receptors with a high affinity for enkephalins and beta-endorphin. In hippocampus, activation of MOR is known to enhance the neuronal excitability of pyramidal neurons, which has been mainly attributed to a disinhibition of pyramidal neurons via activating Gαi subunit to suppress the presynaptic release of GABA in hippocampal interneurons. In contrast, the potential role of MOR in hippocampal astrocytes, the most abundant cell type in the brain, has remained unexplored. Here, we determine the cellular and subcellular distribution of MOR in different cell types of the hippocampus by utilizing MOR-mCherry mice and two different antibodies against MOR. Consistent with previous findings, we demonstrate that MOR expression in the CA1 pyramidal layer is co-localized with axon terminals from GABAergic inhibitory neurons but not with soma of pyramidal neurons. More importantly, we demonstrate that MOR is highly expressed in CA1 hippocampal astrocytes. The ultrastructural analysis further demonstrates that the astrocytic MOR is localized in soma and processes, but not in microdomains near synapses. Lastly, we demonstrate that astrocytes in ventral tegmental area and nucleus accumbens also express MOR. Our results provide the unprecedented evidence for the presence of MOR in astrocytes, implicating potential roles of astrocytic MOR in addictive behaviors.

A Case of von Hippel-Lindau Disease with Colorectal Adenocarcinoma, Renal Cell Carcinoma and Hemangioblastomas / Journal of the Korean Cancer Association, 대한암학회지

von Hippel-Lindau (VHL) disease is an autosomal dominant inherited tumor syndrome associated with mutations of the VHL tumor suppressor gene located on chromosome 3p25. The loss of functional VHL protein contributes to tumorigenesis. This condition is characterized by development of benign and malignant tumors in the central nervous system (CNS) and the internal organs, including kidney, adrenal gland, and pancreas. We herein describe the case of a 74-year-old man carrying the VHL gene mutation who was affected by simultaneous colorectal adenocarcinoma, renal clear cell carcinoma, and hemangioblastomas of CNS.

Ca2+ Entry is Required for Mechanical Stimulation-induced ATP Release from Astrocyte

Astrocytes and neurons are inseparable partners in the brain. Neurotransmitters released from neurons activate corresponding G protein-coupled receptors (GPCR) expressed in astrocytes, resulting in release of gliotransmitters such as glutamate, D-serine, and ATP. These gliotransmitters in turn influence neuronal excitability and synaptic activities. Among these gliotransmitters, ATP regulates the level of network excitability and is critically involved in sleep homeostasis and astrocytic Ca2+ oscillations. ATP is known to be released from astrocytes by Ca2+-dependent manner. However, the precise source of Ca2+, whether it is Ca2+ entry from outside of cell or from the intracellular store, is still not clear yet. Here, we performed sniffer patch to detect ATP release from astrocyte by using various stimulation. We found that ATP was not released from astrocyte when Ca2+ was released from intracellular stores by activation of Galpha(q)-coupled GPCR including PAR1, P2YR, and B2R. More importantly, mechanical stimulation (MS)-induced ATP release from astrocyte was eliminated when external Ca2+ was omitted. Our results suggest that Ca2+ entry, but not release from intracellular Ca2+ store, is critical for MS-induced ATP release from astrocyte.

Exponential Rise in Prostate-Specific Antigen (PSA) during Anti-Androgen Withdrawal Predicts PSA Flare after Docetaxel Chemotherapy in Patients with Castration-Resistant Prostate Cancer

PURPOSE: To investigate the relationship between rising patterns of prostate-specific antigen (PSA) before chemotherapy and PSA flare during the early phase of chemotherapy in patients with castration-resistant prostate cancer (CRPC). MATERIALS AND METHODS: This study included 55 patients with CRPC who received chemotherapy and in whom pre-treatment or post-treatment PSA levels could be serially obtained. The baseline parameters included age, performance, Gleason score, PSA level, and disease extent. PSA doubling time was calculated using the different intervals: the conventional interval from the second hormone manipulation following the nadir until anti-androgen withdrawal (PSADT1), the interval from the initial rise after anti-androgen withdrawal to the start of chemotherapy (PSADT2), and the interval from the nadir until the start of chemotherapy (PSADT3). The PSA growth patterns were analyzed using the ratio of PSADT2 to PSADT1. RESULTS: There were two growth patterns of PSA doubling time: 22 patients (40.0%) had a steady pattern with a more prolonged PSADT2 than PSADT1, while 33 (60.0%) had an accelerating pattern with a shorter PSADT2 than PSADT1. During three cycles of chemotherapy, PSA flare occurred in 11 patients (20.0%); of these patients, 3 were among 33 (9.1%) patients with an accelerating PSA growth pattern and 8 were among 22 patients (36.4%) with a steady PSA growth pattern (p=0.019). Multivariate analysis showed that only PSA growth pattern was an independent predictor of PSA flare (p=0.034). CONCLUSION: An exponential rise in PSA during anti-androgen withdrawal is a significant predictor for PSA flare during chemotherapy in CRPC patients.

Familial Prostate Cancer in Three Brothers

We treated a family of 3 brothers with prostate cancer, which is the first report of familial prostate cancer in Korea. Prostate cancer was diagnosed in the first brother with a prostate-specific antigen (PSA) level of 12.70 ng/ml of at the age of 68 years. He underwent a radical retropubic prostatectomy (RRP); the cancer was pathologically staged to T2cN1Mo. He received adjuvant hormonal therapy postoperatively. Three years later, prostate cancer was diagnosed in the third brother at the age of 61 years with a high PSA level of 4.45 ng/ml. He underwent RRP, which revealed the pathological stage to be T2cN0M0. Three months later, the second brother, who had visited our hospital for lower urinary tract symptoms and for a PSA screening test was diagnosed with prostate cancer at the age of 60 years (PSA level of 3.96 ng/ml). He also underwent RRP, and his cancer was staged pathologically as T2cN0M0.

Management of BCG Failures in Non-Muscle-Invasive Bladder Cancer

PURPOSE: Bacillus Calmette-Guerin (BCG) intravesical therapy is the standard treatment in high-risk patients with non-muscle-invasive bladder cancer, but a significant number of patients experience recurrence after BCG therapy. Although several treatment options are available for recurrence after BCG therapy, the optimal treatment strategy is still controversial. We reviewed current and promising treatment options after BCG failure. MATERIALS AND METHODS: search of published literature using PubMed and meeting abstracts was performed. RESULTS: BCG failures are further subdefined as BCG refractory, BCG resistant, BCG relapsing, and BCG intolerance. Several predictors for BCG response have been studied, but prediction or stratification before therapy seems to be difficult in clinical practice. Novel biomarkers associated with immunologic mechanisms appear to be promising to predict BCG failure. Radical cystectomy is the standard treatment for BCG-refractory disease, but the timing of cystectomy is controversial. BCG maintenance or combination with interferon-alpha is a promising therapy for BCG resistance or relapse. Some salvage therapies or device-assisted instillations have been also promising, but the efficacy and safety of these novel therapies should be confirmed by large prospective studies before their clinical use in BCG failure. CONCLUSIONS: Patients with BCG failure are not a homogeneous group and need to be stratified. Radical cystectomy should be performed without delay in patients with BCG-refractory status, but salvage intravesical therapies may be an alternative in cases without true refractory status. Although BCG and interferon intravesical therapy is promising, more efficient salvage therapy after BCG failure is required.

Single Institutional Experience of Bladder-Preserving Trimodality Treatment for Muscle-Invasive Bladder Cancer

The authors designed this study to determine the clinical effectiveness of trimodality treatment, i.e., transurethral resection of a bladder tumor (TURBT) and concurrent chemoradiotherapy (CRT). Twenty patients with a muscle-invasive bladder cancer were treated by TURBT followed by concurrent cisplatin (75 mg/m(2) day), administered on weeks 1 and 4 of radiotherapy. According to residual tumor status after TURBT, patients were classified into patients with a complete TURBT group and incomplete TURBT group. Response to treatment was evaluated by restaging TURBT at 4 weeks after completing CRT (post-CRT). Fifteen patients (75%) achieved complete remission (CR) at restaging; 10 patients (50%) remained continuously free of tumor recurrence. Disease-specific and overall survivals were 51.1% and 38.6% at 5 yr post-CRT, respectively. Of 16 patients in the complete TURBT group, 14 patients (87.5%) achieved CR, which was significantly different from that observed in the incomplete TURBT group, in which only 1 (25%) of 4 patients achieved CR (p=0.032). Five- year disease-specific and overall survivals were 71.6% and 53.5%, respectively. Ten patients (90.9%) maintained their own bladder among the 11 surviving patients. Trimodality treatment was found to be an effective treatment in patients who underwent complete TURBT for a muscle-invasive bladder cancer.

Epidermal Growth Factor Receptor as Predicting Factor on Biochemical Recurrence after Radical Prostatectomy: A Prospective Study / 대한비뇨기과학회지

PURPOSE: We investigated epidermal growth factor receptor(EGFR) expression in prostate cancer(PCa) and their potential role as predicting factor on biochemical recurrence(BCR). MATERIALS AND METHODS: Between February 2005 and February 2007, EGFR expression were prospectively evaluated in a consecutive series of 88 PCa patients with the following characteristics: 66 patients treated with retropubic radical prostatectomy(RRP); 22 patients treated with neoadjuvant hormonal therapy followed by RRP. The relationship between EGFR expression and several clinicopathologic parameters were evaluated. The probability of BCR-free survival was determined using the Kaplan-Meier method. RESULTS: EGFR expression, was evaluated by immunohistochemistry, was found in 31 of 88(35.2%) patients. 8 of 31 EGFR-positive patients(25.8%) had BCR, whereas only 5 of 57 EGFR-negative patients(8.8%) had BCR (p=0.031) during a median follow-up of 21 months. Among several variables, high serum prostate-specific antigen values(>or=20), extraprostatic extension, seminal vesicle invasion, and EGFR expression were the significant predictors of BCR on univariate analysis. But, multivariate analysis showed that no variable was significant predictor of BCR. EGFR-negative patients had a significantly longer mean BCR-free survival time than EGFR-positive patients(p=0.027). CONCLUSIONS: EGFR expression could be an potential predicting factor on BCR following RRP.