Transgelin-2, a novel cancer stem cell-related biomarker, is a diagnostic and therapeutic target for biliary tract cancer

BACKGROUND

Biliary tract cancer (BTC) is a relatively rare but aggressive gastrointestinal cancer with a high mortality rate. Cancer stem cell (CSC) populations play crucial roles in tumor biology and are responsible for the low response to anti-cancer treatment and the high recurrence rate. This study investigated the role of Transgelin-2 (TAGLN2), overexpressed in CSC in BTC cells, and analyzed its expression in patient tissues and serum to identify potential new targets for BTC.

METHODS

TAGLN2 expression was suppressed by small-interfering or short hairpin RNAs, and its effects on tumor biology were assessed in several BTC cell lines. Furthermore, the effects of TAGLN2 silencing on gemcitabine-resistant BTC cells, differentially expressed genes, proteins, and sensitivity to therapeutics or radiation were assessed. TAGLN2 expression was also assessed using western blotting and immunohistochemistry in samples obtained from patients with BTC to validate its clinical application.

RESULTS

Suppression of TAGLN2 in BTC cell lines decreased cell proliferation, migration, invasion, and tumor size, in addition to a reduction in CSC features, including clonogenicity, radioresistance, and chemoresistance. TAGLN2 was highly expressed in BTC tissues, especially in cancer-associated fibroblasts in the stroma. Patients with a low stromal immunohistochemical index had prolonged disease-free survival compared to those with a high stromal immunohistochemical index (11.5 vs. 7.4 months, P = 0.013). TAGLN2 expression was higher in the plasma of patients with BTC than that in those with benign diseases. TAGLN2 had a higher area under the curve (0.901) than CA19-9, a validated tumor biomarker (0.799; P < 0.001).

CONCLUSION

TAGLN2 plays a critical role in promoting BTC cell growth and motility and is involved in regulating BTC stemness. Silencing TAGLN2 expression enhanced cell sensitivity to radiation and chemotherapeutic drugs. The expression of TAGLN2 in patient tissue and plasma suggests its potential to serve as a secretory biomarker for BTC. Overall, targeting TAGLN2 could be an appropriate therapeutic strategy against advanced cancer following chemotherapy failure.

Phenotypic characteristics of circulating tumor cells and predictive impact for efficacy of chemotherapy in patients with pancreatic cancer: a prospective study

Objective

Early chemoresistance and tumor mass progression are associated with poor prognosis in pancreatic ductal adenocarcinoma (PDAC). Circulating tumor cells (CTCs) have been studied as potential predictors of treatment response and prognosis in PDAC; however, this approach has yet to be applied in clinical practice. The aim of our study was to investigate the phenotypic characteristics of CTCs and determine their predictive value for PDAC progression.

Methods

We prospectively enrolled 40 patients who were pathologically diagnosed with PDAC and collected blood samples at diagnosis, 2 months after diagnosis, and during disease progression or recurrence. We used a microfabricated filter-based enrichment system to retrieve and analyze CTCs, which were classified using immunofluorescence staining (CD45, EpCAM, and vimentin).

Results

Our study included 20 women and 20 men (median age, 66 years). Overall, 45% of the patients (18/40) had disseminated disease, and 77.5% (31/40) received chemotherapy. Multivariate analysis revealed that the total CTC count and carbohydrate antigen 19-9 level at 2 months after diagnosis were associated with disease progression (P<0.05). Linear mixed model analysis revealed that the total CTC count and vimentin-positive CTCs were significantly correlated with treatment response during chemotherapy (P=0.024 and 0.017, respectively). Kaplan-Meier analysis showed that total CTC positivity at 2 months was significantly associated with poor progression-free survival (P=0.038).

Conclusion

Our study's findings suggest that CTCs can serve as predictive biomarkers of clinical outcomes in patients with PDAC receiving palliative chemotherapy. In particular, the total CTC count and vimentin-positive CTCs showed changes associated with the chemotherapy response.

A phase I/II study of ivaltinostat combined with gemcitabine and erlotinib in patients with untreated locally advanced or metastatic pancreatic adenocarcinoma

This phase I/II study evaluated the safety and efficacy of a new histone deacetylase (HDAC) inhibitor, ivaltinostat, in combination with gemcitabine and erlotinib for advanced pancreatic ductal adenocarcinoma (PDAC). Patients diagnosed with unresectable, histologically confirmed PDAC who had not undergone previous therapy were eligible. Phase I had a 3 + 3 dose escalation design to determine the maximum tolerable dose (MTD) of ivaltinostat (intravenously on days 1, 8 and 15) with gemcitabine (1000 mg/m2 intravenously on days 1, 8 and 15) and erlotinib (100 mg/day, orally) for a 28-day cycle. In phase II, patients received a six-cycle treatment with the MTD of ivaltinostat determined in phase I. The primary endpoint was the objective response rate (ORR). Secondary endpoints included overall survival (OS), disease control rate (DCR) and progression-free survival (PFS). The MTD of ivaltinostat for the phase II trial was determined to be 250 mg/m2 . In phase II, 24 patients were enrolled. The median OS and PFS were 8.6 (95% confidence interval [CI]: 5.3-11.2) and 5.3 months (95% CI: 3.7-5.8). Of the 16 patients evaluated for response, ORR and DCR were 25.0% and 93.8% with a median OS/PFS of 10.8 (95% CI: 8.3-16.7)/5.8 (95% CI: 4.6-6.7) months. Correlative studies showed that mutation burden detected by cfDNA and specific blood markers such as TIMP1, pro-MMP10, PECAM1, proMMP-2 and IGFBP1 were associated with clinical outcomes. Although the result of a small study, a combination of ivaltinostat, gemcitabine and erlotinib appeared to be a potential treatment option for advanced PDAC.

GLRX3, a novel cancer stem cell-related secretory biomarker of pancreatic ductal adenocarcinoma

Background

Cancer stem cells (CSCs) are implicated in carcinogenesis, cancer progression, and recurrence. Several biomarkers have been described for pancreatic ductal adenocarcinoma (PDAC) CSCs; however, their function and mechanism remain unclear.

Method

In this study, secretome analysis was performed in pancreatic CSC-enriched spheres and control adherent cells for biomarker discovery. Glutaredoxin3 (GLRX3), a novel candidate upregulated in spheres, was evaluated for its function and clinical implication.

Results

PDAC CSC populations, cell lines, patient tissues, and blood samples demonstrated GLRX3 overexpression. In contrast, GLRX3 silencing decreased the in vitro proliferation, migration, clonogenicity, and sphere formation of cells. GLRX3 knockdown also reduced tumor formation and growth in vivo. GLRX3 was found to regulate Met/PI3K/AKT signaling and stemness-related molecules. ELISA results indicated GLRX3 overexpression in the serum of patients with PDAC compared to that in healthy controls. The sensitivity and specificity of GLRX3 for PDAC diagnosis were 80.0 and 100%, respectively. When GLRX3 and CA19–9 were combined, sensitivity was significantly increased to 98.3% compared to that with GLRX3 or CA19–9 alone. High GLRX3 expression was also associated with poor disease-free survival in patients receiving curative surgery.

Conclusion

Overall, these results indicate GLRX3 as a novel diagnostic marker and therapeutic target for PDAC targeting CSCs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08898-y.

Identification of Circulating Serum miRNAs as Novel Biomarkers in Pancreatic Cancer Using a Penalized Algorithm

Pancreatic cancer (PC) is difficult to detect in the early stages; thus, identifying specific and sensitive biomarkers for PC diagnosis is crucial, especially in the case of early-stage tumors. Circulating microRNAs are promising non-invasive biomarkers. Therefore, we aimed to identify non-invasive miRNA biomarkers and build a model for PC diagnosis. For the training model, blood serum samples from 63 PC patients and 63 control subjects were used. We selected 39 miRNA markers using a smoothly clipped absolute deviation-based penalized support vector machine and built a PC diagnosis model. From the double cross-validation, the average test AUC was 0.98. We validated the diagnosis model using independent samples from 25 PC patients and 81 patients with intrahepatic cholangiocarcinoma (ICC) and compared the results with those obtained from the diagnosis using carbohydrate antigen 19-9. For the markers miR-155-5p, miR-4284, miR-346, miR-7145-5p, miR-5100, miR-661, miR-22-3p, miR-4486, let-7b-5p, and miR-4703-5p, we conducted quantitative reverse transcription PCR using samples from 17 independent PC patients, 8 ICC patients, and 8 healthy individuals. Differential expression was observed in samples from PC patients. The diagnosis model based on the identified markers showed high sensitivity and specificity for PC detection and is potentially useful for early PC diagnosis.

Search for Sub-eV Sterile Neutrinos at RENO

We report a search result for a light sterile neutrino oscillation with roughly 2200 live days of data in the RENO experiment. The search is performed by electron antineutrino (ν[over ¯]_{e}) disappearance taking place between six 2.8 GW_{th} reactors and two identical detectors located at 294 m (near) and 1383 m (far) from the center of the reactor array. A spectral comparison between near and far detectors can explore reactor ν[over ¯]_{e} oscillations to a light sterile neutrino. An observed spectral difference is found to be consistent with that of the three-flavor oscillation model. This yields limits on sin^{2}2θ_{14} in the 10^{-4}≲|Δm_{41}^{2}|≲0.5  eV^{2} region, free from reactor ν[over ¯]_{e} flux and spectrum uncertainties. The RENO result provides the most stringent limits on sterile neutrino mixing at |Δm_{41}^{2}|≲0.002  eV^{2} using the ν[over ¯]_{e} disappearance channel.

Iroquois Homeobox 1 Acts as a True Tumor Suppressor in Multiple Organs by Regulating Cell Cycle Progression

Iroquois homeobox 1 (IRX1) belongs to the Iroquois homeobox family known to play an important role during embryonic development. Interestingly, however, recent studies have suggested that IRX1 also acts as a tumor suppressor. Here, we use homozygous knockout mutants of zebrafish to demonstrate that the IRX1 gene is a true tumor suppressor gene and mechanism of the tumor suppression is mediated by repressing cell cycle progression. In this study, we found that knockout of zebrafish Irx1 gene induced hyperplasia and tumorigenesis in the multiple organs where the gene was expressed. On the other hands, overexpression of the IRX1 gene in human tumor cell lines showed delayed cell proliferation of the tumor cells. These results suggest that the IRX1 gene is truly involved in tumor suppression. In an attempt to identify the genes regulated by the transcription factor IRX1, we performed microarray assay using the cRNA obtained from the knockout mutants. Our result indicated that the highest fold change of the differential genes fell into the gene category of cell cycle regulation, suggesting that the significant canonical pathway of IRX1 in antitumorigenesis is done by regulating cell cycle. Experiment with cell cycle blockers treated to IRX1 overexpressing tumor cells showed that the IRX1 overexpression actually delayed the cell cycle. Furthermore, Western blot analysis with cyclin antibodies showed that IRX1 overexpression induced decrease of cyclin production in the cancer cells. In conclusion, our in vivo and in vitro studies revealed that IRX1 gene functionally acts as a true tumor suppressor, inhibiting tumor cell growth by regulating cell cycle.

Abstract 4687: Gastric cancer stem cell-related marker LINGO2 is associated with cancer phenotype and poor patient survival

The expression of leucine-rich repeat and immunoglobulin-like domain-containing nogo receptor-interacting protein 2 (LINGO2), has been reported in Parkinson’s disease; however, its role in other diseases is unknown. Gastric cancer is the second leading cause of cancer death. Cancer stem cells (CSC) are a subpopulation of cancer cells that contribute to the initiation and invasion of cancer. We identified LINGO2 as a CSC-associated protein in gastric cancers both in vitro and in patient-derived tissues. We studied the effect of LINGO2 on cell motility, stemness, and tumorigenicity using cells sorted based on LINGO2 expression and LINGO2-silenced cells. Tissue microarray analysis showed that LINGO2 expression was significantly elevated in advanced gastric cancers. The overall survival of patients expressing high LINGO2 was significantly shorter than that of patients with low LINGO2. Cells expressing high LINGO2 showed elevated cell motility and tumorigenicity while LINGO2 silencing reversed these properties. Silencing LINGO2 reduced AKT/MEK/ERK phosphorylation and decreased EMT-associated markers - N-cadherin and Vimentin and stemness-associated markers - OCT4 and IHH. These indicate the involvement of LINGO2 in gastric cancer initiation and progression by altering cell motility, stemness, and tumorigenicity, suggesting LINGO2 as a putative target for gastric cancer treatment.

Citation Format: Soo Been Park, Jung Hyun Jo, Chanyang Kim, Hee Seung Lee, Dawoon E. Jung, Si Young Song. Gastric cancer stem cell-related marker LINGO2 is associated with cancer phenotype and poor patient survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4687.

Fuel-Composition Dependent Reactor Antineutrino Yield at RENO

We report a fuel-dependent reactor electron antineutrino (ν[over ¯]_{e}) yield using six 2.8 GW_{th} reactors in the Hanbit nuclear power plant complex, Yonggwang, Korea. The analysis uses 850 666 ν[over ¯]_{e} candidate events with a background fraction of 2.0% acquired through inverse beta decay (IBD) interactions in the near detector for 1807.9 live days from August 2011 to February 2018. Based on multiple fuel cycles, we observe a fuel ^{235}U dependent variation of measured IBD yields with a slope of (1.51±0.23)×10^{-43}  cm^{2}/fission and measure a total average IBD yield of (5.84±0.13)×10^{-43}  cm^{2}/fission. The hypothesis of no fuel-dependent IBD yield is ruled out at 6.6σ. The observed IBD yield variation over ^{235}U isotope fraction does not show significant deviation from the Huber-Mueller (HM) prediction at 1.3 σ. The measured fuel-dependent variation determines IBD yields of (6.15±0.19)×10^{-43} and (4.18±0.26)×10^{-43}  cm^{2}/fission for two dominant fuel isotopes ^{235}U and ^{239}Pu, respectively. The measured IBD yield per ^{235}U fission shows the largest deficit relative to the HM prediction. Reevaluation of the ^{235}U IBD yield per fission may mostly solve the reactor antineutrino anomaly (RAA) while ^{239}Pu is not completely ruled out as a possible contributor to the anomaly. We also report a 2.9 σ correlation between the fractional change of the 5 MeV excess and the reactor fuel isotope fraction of ^{235}U.

Identification of potential biomarkers for diagnosis of pancreatic and biliary tract cancers by sequencing of serum microRNAs

BACKGROUND

Pancreatic and biliary tract cancer (PC and BTC, respectively) are difficult to diagnose because of their clinical characteristics; however, recent studies suggest that serum microRNAs (miRNAs) might be the key to developing more efficient diagnostic methods for these cancers.

METHODS

We analysed the genome-wide expression of serum miRNAs in PC and BTC patients to identify novel biomarker candidates using high-throughput sequencing and experimentally validated miRNAs on clinical samples.

RESULTS

Statistical and classification analysis of the serum miRNA-expression profiles of 55 patient samples showed distinguishable patterns between cancer patients and healthy controls; however, we were unable to distinguish the two cancers. We found that three of the highest performing miRNAs were capable of distinguishing cancer patients from controls, with an accuracy of 92.7%. Additionally, dysregulation of these three cancer-specific miRNAs was demonstrated in an independent sample group by quantitative reverse transcription polymerase chain reaction.

CONCLUSIONS

These results suggested three candidate serum miRNAs (mir-744-5p, mir-409-3p, and mir-128-3p) as potential biomarkers for PC and BTC diagnosis.

Novel Gastric Cancer Stem Cell-Related Marker LINGO2 Is Associated with Cancer Cell Phenotype and Patient Outcome

The expression of leucine-rich repeat and immunoglobulin-like domain-containing nogo receptor-interacting protein 2 (LINGO2) has been reported in Parkinson’s disease; however, its role in other diseases is unknown. Gastric cancer is the second leading cause of cancer death. Cancer stem cells (CSC) are a subpopulation of cancer cells that contribute to the initiation and invasion of cancer. We identified LINGO2 as a CSC-associated protein in gastric cancers both in vitro and in patient-derived tissues. We studied the effect of LINGO2 on cell motility, stemness, tumorigenicity, and angiogenic capacity using cells sorted based on LINGO2 expression and LINGO2-silenced cells. Tissue microarray analysis showed that LINGO2 expression was significantly elevated in advanced gastric cancers. The overall survival of patients expressing high LINGO2 was significantly shorter than that of patients with low LINGO2. Cells expressing high LINGO2 showed elevated cell motility, angiogenic capacity, and tumorigenicity, while LINGO2 silencing reversed these properties. Silencing LINGO2 reduced kinase B (AKT)/extracellular signal-regulated kinase (ERK)/ERK kinase (MEK) phosphorylation and decreased epithelial-mesenchymal transition (EMT)-associated markers—N-Cadherin and Vimentin and stemness-associated markers— POU class 5 homeobox 1 (OCT4) and Indian hedgehog (IHH), and markedly decreased the CD44⁺ population. These indicate the involvement of LINGO2 in gastric cancer initiation and progression by altering cell motility, stemness, and tumorigenicity, suggesting LINGO2 as a putative target for gastric cancer treatment.

Measurement of Reactor Antineutrino Oscillation Amplitude and Frequency at RENO

The RENO experiment reports more precisely measured values of θ_{13} and |Δm_{ee}^{2}| using ∼2200 live days of data. The amplitude and frequency of reactor electron antineutrino (ν[over ¯]_{e}) oscillation are measured by comparing the prompt signal spectra obtained from two identical near and far detectors. In the period between August 2011 and February 2018, the far (near) detector observed 103 212 (850 666) ν[over ¯]_{e} candidate events with a background fraction of 4.8% (2.0%). A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the measured number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.0896±0.0048(stat)±0.0047(syst) and |Δm_{ee}^{2}|=[2.68±0.12(stat)±0.07(syst)]×10^{-3}  eV^{2}.

Abstract 4480: Irx1 gene knockout in zebrafish induces to multiorgan tumorigenesis through cell cycle aberration

The Iroquois homeobox 1 (IRX1) belongs to Iroquois homeobox family and plays an important role during embryonic development. Recent studies have suggested that IRX1 acts as a tumor suppressor in gastric cancer and head and neck carcinoma. The zebrafish allows easy genetic modification at a lower cost, thus being a valuable model for cancer biology. For functional annotation we established homozygous knockout mutants of Irx1a and Irx1b and followed to evaluate long-term phenotypes. Homozygous knockout zebrafish for either Irx1a or Irx1b are vital and survived long enough to see long-term phenotypes. However, majority of the homozygotes for both Irx1a /b were severely malformed, could not survive longer than 6 month, and were not fertile. Surprisingly, hyperplasia and tumorigenesis developed in homozygous Irx1a mutants in multiple organs, including bile duct, intestine, kidney, ovary, and testis where irx1 genes are expressed in adults when evaluated by in situ hybridization. Bile duct hyperplasia or tumor was the most common phenotype, occurring in half and two thirds at 6 and 12 months, respectively. Irx1b mutants also developed similar tumorigenesis but showed less prevalent phenotypes than Irx1a mutants, suggesting functional preservation and redundancy. Analysis of differential genes (Wild type vs. Irx1a/b knockout) by cRNA microarray (Agilent Zebrafish v3 GE 4X44 Microarrays) revealed 687 up- and 963 downregulated genes by Irx1a/b knockout. Significant canonical pathways were cyclins and cell cycle regulation, mitotic roles of polo-like kinase, FXR/RXR activation, estrogen-mediated S-phase entry, and cell cycle control of chromosomal replication, suggesting aberrant cell cycle regulation as an important mechanism of tumorigenesis. Real-time RT PCR validated the differential expression of cell cycle-related genes, especially genes involved in G2/M phase progression. Differential genes included CCND1, ARAF, CDKN2C, and FGFR1 among the upregulated genes, and ANAPC7, CCNA2, CCNB1, 2, HAUS1, 3, 6, CDC7, CDC20, CDCA8, FBXO5, 32, 43 and PLK3 among the downregulated genes. Overexpression by transfection decreased cell proliferation in cholangiocarcinoma cells (SNU-1196 and HuCCT1) without altering sensitivity to H2O2-induced apoptosis on annexin V flow cytometry. Western blot revealed decreased expression of CCND1, CCNE, CCNA1, CCNB1 by IRX1 expression. Flow cytometry using propidium iodide and Alexa647-anti-pHH3 showed decreased mitotic fraction by IRX1 expression. On cell cycle synchronization and release using hydroxyuria and nocodazole showed slight delay in G1-S progression and marked delay in G2-M progression and entry into G1. In conclusion, this study identified Irx1 gene as an important tumor-suppressor gene at various organs, and knockout or Irx1 leads to tumorigenesis by altering cell cycle regulation, especially at G2/M phase.

Citation Format: Inhye Jung, Dawoon E. Jung, DoHee Kim, Dong Hee Kim, Yong Yoon Chung, Seung Woo Park. Irx1 gene knockout in zebrafish induces to multiorgan tumorigenesis through cell cycle aberration [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4480.

Abstract 4337: Identification of novel fusion gene, PUM1-TRAF3, as potent biomarker in bile duct cancer

Background: Gene fusion occurs when a part of one gene fuses with a part of another gene by genome rearrangement and may possess oncogenic properties. Bile duct cancer (BDC) are one of the most lethal malignancy, but lack of proper diagnostic or prognostic markers. Our aim was to investigate BDC specific fusion genes found in patient's specimens and its clinical significance. Method : We extracted total RNA from five BDC tissues and normal tissues from the same patients. RNA sequencing was performed and the result data was analyzed using ChimeraScan, Jaffa or FusionCatcher softwares to detect gene fusion. The expression of the detected novel fusion gene was confirmed by ddPCR using tissues from the operated BDC patients and its clinical significance was analyzed with medical information of the patients. Result : We found 52 BDC specific fusion genes by RNA sequencing and we identified novel BDC specific fusion gene, PUM1-TRAF3 by bioinformatics analysis. Total 55 patients with BDC who underwent curative surgery were evaluated to investigate clinical significance of PUM1-TRAF3. There were 28 patients (50.1%) who expressed PUM1-TRAF3 by ddPCR. Patients with PUM1-TRAF3 presented higher rate of female gender (57.1 vs. 25.9, p=0.019), advanced stage (25% vs. 3.7%, p=0.025) and recurrence rate (64.7 vs. 48.1%, p=0.080) compared to patients without PUM1-TRAF3. Disease free survival (DFS) was 12.1 vs. 29.8 (p=0.078) and overall survival was 26.1 vs. 36.6 (p=0.239) between the patients with PUM1-TRAF3 and without PUM1-TRAF3. In multivariated analysis by cox-regression, expression of PUM1-TRAF3 (HR 2.86, p=0.023), advanced stage (HR 2.69, p=0.041), higher CA19-9 (HR 1.00, p=0.011) and positive resection margin (HR 4.57, p=0.002) were significantly associated with short DFS.Conclusion : In this study, we identified novel BDC-specific fusion gene, PUM1-TRAF3. Expression of PUM1-TRAF3 was confirmed in patient's tissues and associated with short DFS in operated BDC patients. PUM1-TRAF3 can be a potent biomarker in BDC.

Citation Format: Dawoon E. Jung, Kahee Kim, Chanyang Kim, Soo Been Park, Jung Hyun Jo, Hee Seung Lee, Si Young Song. Identification of novel fusion gene, PUM1-TRAF3, as potent biomarker in bile duct cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4337.

In Vivo Study of Natural Killer (NK) Cell Cytotoxicity Against Cholangiocarcinoma in a Nude Mouse Model

BACKGROUND/AIM

Natural killer (NK) cells are one of the lymphocytes clinically used for various cancer types. Cytotoxicity of NK cells to cholangiocarcinoma (CC), however, has not yet been studied. Nor NK cell therapy against CC has been clinically applied. In this study, relevance of NK cell therapy for anti-tumor efficacy against CC was pre-clinically investigated.

MATERIALS AND METHODS

Human HuCCT-1 cells, an intrahepatic CC cell line, were xenografted into nude mice. The HuCCT-1 tumor-bearing nude mice then received multiple infusions of ex vivo-expanded human NK cells (SMT01) and in vivo cytotoxic activity of the NK cells against the CC cells was evaluated.

RESULTS

SMT01 infusion resulted in significant inhibition of the CC tumor growth. Body weight of the mice administrated with chemotherapy was found to be maintained at the lowest level among all treatment groups while all the SMT01 infusion groups well maintained their body weight.

CONCLUSION

The present in vivo study demonstrates that NK cells contain cytolytic activity against cholangiocarcinoma and show beneficial effect of NK cell therapy in relevance to quality of life. Further investigation of the NK cell-based immunotherapy can be useful to determine cancer therapeutics for the specific tumor.

Combined use of CEMIP and CA 19-9 enhances diagnostic accuracy for pancreatic cancer

Carbohydrate antigen (CA) 19-9 is the only diagnostic marker used in pancreatic cancer despite its limitations. Here, we aimed to identify the diagnostic role of CEMIP (also called KIAA1199) combined with CA 19-9 in patients with pancreatic cancer. A retrospective analysis of prospectively collected patient samples was performed to determine the benefit of diagnostic markers in the diagnosis of pancreatic cancer. We investigated CEMIP and CA 19-9 levels in 324 patients with pancreatic cancer and 49 normal controls using serum enzyme-linked immunosorbent assay. Median CA 19-9 and CEMIP levels were 410.5 U/ml (40.8-3342.5) and 0.67 ng/ml (0.40-1.08), respectively, in patients with pancreatic cancer. The AUROC for CA 19-9 and CEMIP were 0.847 (95% confidence interval [CI]: 0.806-0.888) and 0.760 (95% CI: 0.689-0.831), respectively. Combination of CA 19-9 with CEMIP showed markedly improved AUROC over CA 19-9 alone in pancreatic cancer diagnosis (0.94 vs. 0.89; P < 0.0001). CEMIP showed a diagnostic yield of 86.1% (68/79) in CA 19-9 negative pancreatic cancer. Combined use with CEMIP showed significantly improved diagnostic value compared with CA 19-9 alone in pancreatic cancer. Especially, CEMIP may be a complementary marker in pancreatic cancer patients with normal CA 19-9 levels.

Impaired Lymphocytes Development and Xenotransplantation of Gastrointestinal Tumor Cells in Prkdc-Null SCID Zebrafish Model

Severe combined immunodeficiency (SCID) mice have widely been used as hosts for human tumor cell xenograft study. This animal model, however, is labor intensive. As zebrafish is largely emerging as a promising model system for studying human diseases including cancer, developing efficient immunocompromised strains for tumor xenograft study are also demanded in zebrafish. Here, we have created the Prkdc-null SCID zebrafish model which provides the stable immune-deficient background required for xenotransplantation of tumor cell. In this study, the two transcription activator-like effector nucleases that specifically target the exon3 of the zebrafish Prkdc gene were used to induce a frame shift mutation, causing a complete knockout of the gene function. The SCID zebrafish showed susceptibility to spontaneous infection, a well-known phenotype found in the SCID mutation. Further characterization revealed that the SCID zebrafish contained no functional T and B lymphocytes which reflected the phenotypes identified in the mice SCID model. Intraperitoneal injection of human cancer cells into the adult SCID zebrafish clearly showed tumor cell growth forming into a solid mass. Our present data show the suitability of using the SCID zebrafish strain for xenotransplantation experiments, and in vivo monitoring of the tumor cell growth in the zebrafish demonstrates use of the animal model as a new platform of tumor xenograft study.

Regulation of SIRT3 signal related metabolic reprogramming in gastric cancer by Helicobacter pylori oncoprotein CagA

Injection of the Helicobacter pylori cytotoxin-associated gene A (CagA) is closely associated with the development of chronic gastritis and gastric cancer. Individuals infected with H. pylori possessing the CagA protein produce more reactive oxygen species (ROS) and show an increased risk of developing gastric cancer. Sirtuins (SIRTs) are nicotinamide adenine dinucleotide (NAD⁺)-dependent deacetylases and mitochondrial SIRT3 is known to be a tumor suppressor via its ability to suppress ROS and hypoxia inducible factor 1α (HIF-1α). However, it is unclear whether increased ROS production by H. pylori is regulated by SIRT3 followed by HIF-1α regulation and whether intracellular CagA acts as a regulator thereof. In this study, we investigated correlations among SIRT3, ROS, and HIF-1α in H. pylori-infected gastric epithelial cells. We observed that SIRT3-deficient AGS cells induce HIF-1α protein stabilization and augmented transcriptional activity under hypoxic conditions. In CagA⁺H. pylori infected cells, CagA protein localized to mitochondria where it subsequently suppressed SIRT3 proteins. CagA⁺H. pylori infection also increased HIF-1α activity through the ROS production induced by the downregulated SIRT3 activity, which is similar to the hypoxic condition in gastric epithelial cells. In contrast, overexpression of SIRT3 inhibited the HIF-1α protein stabilization and attenuated the increase in HIF-1α transcriptional activity under hypoxic conditions. Moreover, CagA⁺H. pylori attenuated HIF-1α stability and decreased transcriptional activity in SIRT3-overexpressing gastric epithelial cells. Taken together, these findings provide valuable insights into the potential role of SIRT3 in CagA⁺H. pylori-mediated gastric carcinogenesis and a possible target for cancer prevention via inhibition of HIF-1α.

The DNA aptamer binds stemness-enriched cancer cells in pancreatic cancer

Pancreatic cancer remains one of the most common and lethal cancers. Most patients (80%) present with inoperable advanced pancreatic cancer at initial diagnosis, and their early diagnosis is a significant unmet challenge. Recent studies indicate that cancer, including pancreatic cancer, is initiated and propagated by cancer stem cells (CSCs). CSCs are responsible not only for the pathogenesis of cancer but also for the heterogeneity, malignant degree, anticancer therapy resistance, and recurrence of tumors. Therefore, the identification of CSCs may be a crucial stepping stone for overcoming this disastrous pancreatic cancer. Here, we investigated pancreatic CSC-associated aptamers as a novel tool for diagnosis and therapeutic agents. Aptamers that bind to stemness-enriched cancer cells in pancreatic cancer were developed by modified Cell-SELEX method. Positive selection was performed by the sphere cells generated by pancreatic cancer cell line, HPAC, and then the aptamer pool was negatively selected by pancreatic normal cell line, HPDE. Aptamers 1 and 146 showing high specificity upon the K_D values with 22.18 and 22.62 nM were selected. These 2 aptamers were validated by binding to HPAC sphere cells and to HPDE cells, and both aptamers showed specificity to HPAC sphere cells only. Aptamer-positive cells showed high expression levels of CSC-associated genes compared with the aptamer-negative cells by FACS analysis. The colocalization of CD44, CD24, ESA, and CD133 was also observed in the aptamer-positive cells by confocal microscopy. In the present study, these 2 pancreatic CSC-associated aptamers may be potential candidates for novel diagnostic markers, CSC-targeting drug delivery, or circulating tumor cell detection.

Abstract 101: Identification of pancreatobilliary cancer specific fusion genes in patient tissues

Gene fusion occurs when a part of one gene fuses with or attaches to a part of another gene by genome rearrangement and the result in gene fusion may possess oncogenic properties; fused gene may be translated into a unique protein that may promotes cancer properties. Pancreatic cancer and bile duct cancer are one of the most lethal cancer types with low 5-year survival rates, but lack of proper diagnostic or prognostic markers. Our aim was to investigate pancreatobilliary- specific fusion genes found in patient's specimens. We used TRIzol to extract total RNA from seven pancreatic cancer tissues and normal tissues from the same patients, and five bile duct cancer tissues and normal tissues from the same patients. Total RNA was assessed for RNA sequencing and the result data was analyzed using ChimeraScan to detect gene fusion. To identify the cancer somatic fusion gene, the fusion occurred in normal tissues and previously reported fusion genes found in normal tissues were excluded and the fusion occurred in coding region was included. As a result, we found 87 pancreatic cancer tissue specific- and 52 bile duct cancer tissue specific- fusion genes. We then selected fusion genes that either one of the gene has been reported to express in cancer tissues. We confirmed the expression of selected fusion genes by RT-PCR in cancer and normal tissues as well as in cancer cell lines. As a result we observed novel pancreatobilliary cancer specific fusion genes. These findings indicate the presence of novel fusion genes as well as its possible application for the early diagnosis or prognosis of pancreatic and bile duct cancer.

Citation Format: Kahee Kim, Dawoon E. Jung, Mi-kyoung Seo, Sang Woo Kim, Si Young Song. Identification of pancreatobilliary cancer specific fusion genes in patient tissues. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 101.

Abstract 1955: Computational correlation among microRNAs and mRNAs specifically expressed in pancreatic cancer stem cells

The objective of this study was to analyze and identify pancreatic cancer stem cell-specific microRNAs (miRNAs) and messenger RNAs (mRNAs) and investigate their correlations to cancer stem cell biology. More, pancreatic cancer stem cell-specific miRNAs in cancer patients’ serum were analyzed to determine as a diagnostic application. We used sphere cultivation methods to enrich the stem cell population from the pancreatic cancer cell line, Capan-1 with the normal pancreatic cell line, YGIC-6, and analyzed the overall miRNA and mRNA expressions using with microarray analysis. Total RNA from normal and patient's serum was extracted and the expression individual miRNAs in serum was analyzed by real-time PCR. Fifty two miRNAs including mir-26a, miR-99a, miR-106a, mir-125b, miR-192 and mir-429 were differentially expressed in the pancreatic cancer stem cells. From the miRNA analysis, 170 miRNAs were differentially expressed in the normal cell line YGIC-6, 126 miRNAs in the cancer cell line Capan-1 and 12 miRNAs in both the normal and cancer cell line originated stem cell populations. Examining both the miRNA and mRNA profiles, 52 miRNAs and 111 stem cell-associated mRNAs were highly correlated (both p values&lt;0.01) that were differentially expressed in the pancreatic cancer stem cells. These miRNAs and mRNAs were further investigated with cross-correlation analysis, which showed a number of highly correlated miRNAs and mRNAs that are either directly or indirectly linked based on the target prediction software. The correlation degree is shown on the heatmap, and individual miRNAs with their highly correlated individual mRNAs were analyzed to predict possible mechanisms for miRNAs in pancreatic cancer stem cells. To examine miRNAs level in serum, total RNA was extracted from normal and cancer patient's serum and the expression level of individual miRNAs were analyzed. The expression level (Ct value) of mir-106a, mir-125b and mir-429 was differentially expressed in cancer patient's serum than normal and mir-99a was differentially expressed in cancer patients with poor prognosis. Differentially expressed miRNAs in pancreatic cancer stem cells provide insights into possible linkages between individual miRNAs and stem cell-associated target mRNAs in cancer stem cells and have broad implications in our understanding of cancer stem cells and cancer stem cell-targeted cancer therapy. Expression level of miRNAs in serum was differed in normal and cancer patient suggests miRNAs as a diagnostic and prognostic marker.

Citation Format: Dawoon E. Jung, Hyungseok Choi, Jee Yeon Heo, Hee Seung Lee, Kyong Joo Lee, Si Young Song. Computational correlation among microRNAs and mRNAs specifically expressed in pancreatic cancer stem cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1955.

Abstract 1427: Embigin is overexpressed in pancreatic ductal adenocarcinoma and regulates cell motility through epithelial to mesenchymal transition via the TGF-β pathway

Embigin is a member of the immunoglobulin superfamily and encodes a transmembrane glycoprotein. Strong expression of Embigin has been observed in the mouse endoderm during early postimplantation embryogenesis and in the gut and visceral endoderm at the somite stage. There have been reports of Embigin involvement in neuromuscular junction formation and plasticity; however, the molecular functions of Embigin in other organs are unknown. Pancreatic cancer is an extremely aggressive malignancy, and it is necessary to understand the biology of pancreatic cancer to better detect and treat this disease. Our aim was to investigate the possible role of Embigin in pancreatic cancer. In pancreatic ductal adenocarcinoma tissues, Embigin expression was higher than that in normal pancreatic tissues. Immunohistochemical analysis revealed expression of Embigin in pancreatic cancer cells, as well as expression of monocarboxylate transporter 2 (MCT2) in cancer tissues. To gain further insight, we transfected BxPC-3 and HPAC pancreatic cancer cells with siRNA or shRNA targeting Embigin and observed reductions in cell proliferation, migration, invasion, wound healing, and reduced levels of matrix metalloproteinases-2 and -9. Silencing of Embigin increased intracellular L-lactate concentration by 1.5-fold and decreased MCT2 levels at the plasma membrane. Furthermore, Embigin silencing led to a reduced expression of PI3K, GSK3-β, and Snail/Slug. Upon treating BxPC-3 cells with transforming growth factor-β (TGF-β), we observed elevated expression of Snail/Slug, Embigin, and Vimentin; meanwhile, when treating cells with SB-216763, a GSK3-β inhibitor, we noted decreases in GSK3-β, Snail/Slug, and Embigin expression, suggesting that the TGF-β signaling cascade, comprising PI3K, GSK3-β, Snail/Slug, and Embigin signals, mediates epithelial to mesenchymal transition (EMT) in pancreatic cancer cells. These findings indicate the involvement of Embigin in EMT in pancreatic cancer progression and suggest Embigin as a putative target for the detection and/or treatment of pancreatic cancer.

Citation Format: Dawoon E. Jung, Jeong Mi Kim, Chanyang Kim, Si Young Song. Embigin is overexpressed in pancreatic ductal adenocarcinoma and regulates cell motility through epithelial to mesenchymal transition via the TGF-β pathway. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1427. doi:10.1158/1538-7445.AM2015-1427

Embigin is overexpressed in pancreatic ductal adenocarcinoma and regulates cell motility through epithelial to mesenchymal transition via the TGF-β pathway

Embigin is a member of the immunoglobulin superfamily and encodes a transmembrane glycoprotein. There have been reports of Embigin involvement in neuromuscular junction formation and plasticity; however, the molecular functions of Embigin in other organs are unknown. Our aim was to investigate the possible role of Embigin in pancreatic cancer. In pancreatic ductal adenocarcinoma tissues, Embigin expression was higher than that in normal pancreatic tissues. Immunohistochemical analysis revealed expression of Embigin in pancreatic cancer cells, as well as expression of monocarboxylate transporter 2 (MCT2) in cancer tissues. To gain further insight, we transfected BxPC-3 and HPAC pancreatic cancer cells with siRNA or shRNA targeting Embigin and observed reductions in cell proliferation, migration, invasion, wound healing, and reduced levels of matrix metalloproteinases-2 and -9. Silencing of Embigin increased intracellular L-lactate concentration by 1.5-fold and decreased MCT2 levels at the plasma membrane. Furthermore, Embigin silencing led to a reduced expression of PI3K, GSK3-β, and Snail/Slug. Upon treating BxPC-3 cells with transforming growth factor-β (TGF-β), we observed elevated expression of Snail/Slug, Embigin, and Vimentin; meanwhile, when treating cells with SB-216763, a GSK3-β inhibitor, we noted decreases in GSK3-β, Snail/Slug, and Embigin expression, suggesting that the TGF-β signaling cascade, comprising PI3K, GSK3-β, Snail/Slug, and Embigin signals, mediates epithelial to mesenchymal transition (EMT) in pancreatic cancer cells. These findings indicate the involvement of Embigin in EMT in pancreatic cancer progression and suggest Embigin as a putative target for the detection and/or treatment of pancreatic cancer.

Glioma is formed by active Akt1 alone and promoted by active Rac1 in transgenic zebrafish

BACKGROUND

Ongoing characterization of glioma has revealed that Akt signaling plays a crucial role in gliomagenesis. In mouse models, however, Akt alone was not sufficient to induce glioma.

METHODS

We established transgenic zebrafish that overexpressed dominant-active (DA) human Akt1 or Rac1(G12V) (DARac1) at ptf1a domain and investigated transgenic phenotypes and mechanisms leading to gliomagenesis.

RESULTS

Transgene expressions were spatiotemporally restricted without any developmental abnormality of embryos and persisted at cerebellum and medulla in adult zebrafish. DAAkt1 alone induced glioma (with visible bumps at the head), with incidences of 36.6% and 49% at 6 and 9 months, respectively. Histologically, gliomas showed various histologic grades, increased proliferation, and frequent invasion into the fourth ventricle. Preferential location of small tumors at periventricular area and coexpression of Her4 suggested that tumors originated from Ptf1a- and Her4-positive progenitor cells at ventricular zone. Gliomagenesis was principally mediated by activation of survival pathway through upregulation of survivin genes. Although DARac1 alone was incapable of gliomagenesis, when coexpressed with DAAkt1, gliomagenesis was accelerated, showing higher tumor incidences (62.0% and 73.3% at 6 and 9 months, respectively), advanced histologic grade, invasiveness, and shortened survival. DARac1 upregulated survivin2, cyclin D1, β-catenin, and snail1a but downregulated E-cadherin, indicating that DARac1 promotes gliomagenesis by enhancing proliferation, survival, and epithelial-to-mesenchymal transition. On pharmacologic tests, only Akt1/2 inhibitor effectively suppressed gliomagenesis, inhibited cellular proliferation, and induced apoptosis in established gliomas.

CONCLUSIONS

The zebrafish model reinforces the pivotal role of Akt signaling in gliomagenesis and suggests Rac1 as an important protein involved in progression.

Aberrant Hedgehog ligands induce progressive pancreatic fibrosis by paracrine activation of myofibroblasts and ductular cells in transgenic zebrafish

Hedgehog (Hh) signaling is frequently up-regulated in fibrogenic pancreatic diseases including chronic pancreatitis and pancreatic cancer. Although recent series suggest exclusive paracrine activation of stromal cells by Hh ligands from epithelial components, debates still exist on how Hh signaling works in pathologic conditions. To explore how Hh signaling affects the pancreas, we investigated transgenic phenotypes in zebrafish that over-express either Indian Hh or Sonic Hh along with green fluorescence protein (GFP) to enable real-time observation, or GFP alone as control, at the ptf1a domain. Transgenic embryos and zebrafish were serially followed for transgenic phenotypes, and investigated using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), in situ hybridization, and immunohistochemistry. Over-expression of Ihh or Shh reveals virtually identical phenotypes. Hh induces morphologic changes in a developing pancreas without derangement in acinar differentiation. In older zebrafish, Hh induces progressive pancreatic fibrosis intermingled with proliferating ductular structures, which is accompanied by the destruction of the acinar structures. Both myofibroblasts and ductular are activated and proliferated by paracrine Hh signaling, showing restricted expression of Hh downstream components including Patched1 (Ptc1), Smoothened (Smo), and Gli1/2 in those Hh-responsive cells. Hh ligands induce matrix metalloproteinases (MMPs), especially MMP9 in all Hh-responsive cells, and transform growth factor-ß1 (TGFß1) only in ductular cells. Aberrant Hh over-expression, however, does not induce pancreatic tumors. On treatment with inhibitors, embryonic phenotypes are reversed by either cyclopamine or Hedgehog Primary Inhibitor-4 (HPI-4). Pancreatic fibrosis is only prevented by HPI-4. Our study provides strong evidence of Hh signaling which induces pancreatic fibrosis through paracrine activation of Hh-responsive cells in vivo. Induction of MMPs and TGFß1 by Hh signaling expands on the current understanding of how Hh signaling affects fibrosis and tumorigenesis. These transgenic models will be a valuable platform in exploring the mechanism of fibrogenic pancreatic diseases which are induced by Hh signaling activation.

Abstract 3023: MicroRNA expression profile in pancreatic cancer stem cells

MicroRNA(or miRNA) regulates various biological process including development, differentiation, proliferation, maintenance and apoptosis. Recently, existence of cancer stem cells was reported in some solid malignancies, including breast, brain, prostate, liver and pancreas cancers. Pancreatic ductal adenocarcinoma remains an extremely aggressive malignancy that is virtually therapy-resistant. Thus better understanding on cancer stem cell biology will not only help us to develop diagnostic marker for early diagnosis but also to treat against chemoresistant pancreatic cancer. Lately, evidences of miRNA involvement in cancer stem cells have been reported. Several miRNAs including let-7, mir-200, and mir-181 shows regulatory functions in cancer stem cells of different organs, however, miRNAs in other cancers including pancreas has not yet been reported. In this present study, we analyzed pancreatic cancer stem cell specific miRNAs and further investigated their functional role in cancer stem cells.

To analyze the differentially expressed miRNAs, we used sphere cultivation methods to enrich stem cell population and analyzed overall miRNA expression with miRNA microarray. Then correlation of miRNA expression and mRNA expression was analyzed by using linear model Yijkg=µ+Ai+Dj+Vk+Gg+AGig+VGkg+εijkg where A, D, V, and G represent the additive effect of the ith array, jth dye, kth biological group, and gth gene, respectively; AG represents the combinatorial effect of the ith array with the gth gene; εijkg describes the random error associated with each measurement; and VG for the combinatorial effect of the kth biological group with the gth gene. All additive effects were estimated via least squares and an F-test was performed on the modeled data to select differentially expressed genes. The candidate miRNA expression was confirmed by qRT-PCR.

As a result, number of miRNAs showed differential expression in sphere and are considered to have functional role in cancer stem cells by directly or indirectly targeting mRNAs. Further, correlation analysis suggested possible linkage between miRNA clusters with stem cell associated mRNAs.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3023.

Pancreatic adenocarcinoma up-regulated factor (PAUF), a novel up-regulated secretory protein in pancreatic ductal adenocarcinoma

The identification of novel tumor-specific proteins or antigens is of great importance for diagnostic and therapeutic applications in pancreatic cancer. Using oligonucleotide microarrays, we identified a broad spectrum of differentially expressed pancreatic cancer-related genes. Of these, we selected an overexpressed expressed sequence taq and cloned a 721-bp full-length cDNA with an open reading frame of 196 amino acids. This novel gene was localized on the Homo sapiens 16p13.3 chromosomal locus, and its nucleotide sequence matched the Homo sapiens similar to common salivary protein 1 (LOC124220). We named the gene pancreatic adenocarcinoma up-regulated factor. The pancreatic adenocarcinoma up-regulated factor was secreted into the culture medium of pancreatic adenocarcinoma up-regulated factor-overexpressing Chinese hamster ovary cells, had an apparent molecular mass of approximately 25 kDa, and was N-glycosylated. The induction of pancreatic adenocarcinoma up-regulated factor in Chinese hamster ovary cells increased cell proliferation, migration, and invasion ability in vitro. Subcutaneous injection of mice with Chinese hamster ovary/pancreatic adenocarcinoma up-regulated factor cells resulted in 3.8-fold greater tumor sizes compared to Chinese hamster ovary/mock cells. Reverse transcription-polymerase chain reaction and western blotting with antirecombinant human pancreatic adenocarcinoma up-regulated factor antibodies confirmed that pancreatic adenocarcinoma up-regulated factor was highly expressed in six of eight pancreatic cancer cell lines. Immunohistochemical staining of human pancreatic cancer tissues also showed pancreatic adenocarcinoma up-regulated factor overexpression in the cytoplasm of cancer cells. Transfection with pancreatic adenocarcinoma up-regulated factor-specific small-interfering RNA reduced cancer cell migration and invasion in vitro. Treatment with antirecombinant human pancreatic adenocarcinoma up-regulated factor in vitro and in vivo reduced proliferation, migration, invasion, and tumorigenic ability. Collectively, our results suggest that pancreatic adenocarcinoma up-regulated factor is a novel secretory protein involved in pancreatic cancer progression and might be a potential target for the treatment of pancreatic cancer.

Efficacy and prognosis of a short course of prednisolone therapy for pediatric epilepsy

PURPOSE

To evaluate the efficacy and safety of adjunctive prednisolone therapy in children with cryptogenic epileptic encephalopathy, other than infantile spasms, and to determine its prognosis.

METHODS

Prednisolone, 2mg/kg per day for 6 weeks, tapered for a further 2 weeks, was given in combination with previously prescribed antiepileptic drugs. A retrospective assessment of 41 children thus treated included measurements of seizure frequency, electroencephalographic findings, global assessments of cognitive function, and adverse drug events. Long-term patient prognoses over a mean follow-up period of 3 years and 5 months (range, 14-90 months) were also examined.

RESULTS

Of 41 patients, 32 had Lennox-Gastaut syndrome, 4 had Doose syndrome, 1 had Otahara syndrome, 2 had Landau-Kleffner syndrome, and 2 had other unspecified generalized epilepsies. After prednisolone therapy, 73% (30/41) of patients showed a reduction in seizure frequency of >50%, and 59% (24/41) became seizure free. However, only seven patients (four with Lennox-Gastaut syndrome, two with Doose syndrome, and one with unspecified generalized epilepsy) who became seizure free remained free of seizures at the time of the final follow-up. Electroencephalographic findings and global assessments of cognitive function correlated well with seizure outcomes. No significant demographic factors influenced the efficacy of prednisolone or patient prognoses after prednisolone tapering. Most adverse events were transient, or were tolerated well with conservative management, with maintenance of the medication.

CONCLUSION

Prednisolone therapy may be a safe and effective adjunct in patients with cryptogenic epileptic encephalopathies, but the high relapse rate is of concern.