721. Expression of IARS2 gene in colon cancer and effect of its knockdown on biological behavior of RKO cells.
作者: Ling Zhong.;Yi Zhang.;Jing-Yu Yang.;Liang-Fa Xiong.;Tao Shen.;Ya-Lian Sa.;Yi-Ming O'Yang.;Si-Hui Zhao.;Jia-Yong Chen.
来源: Int J Clin Exp Pathol. 2015年8卷10期12151-9页
To investigate the expression level of IARS2 gene in colon cancer tissues and various cell strains of the cancer; to explore cytologically the effect of IARS2 gene knockdown on proliferation, apoptosis and cell cycle of RKO cells in the cancer.
722. Characterization of various types of mast cells derived from model mice of familial gastrointestinal stromal tumors with KIT-Asp818Tyr mutation.
作者: Noriko Kajimoto.;Norihiro Nakai.;Mizuka Ohkouchi.;Yuka Hashikura.;Ning-Ning Liu-Kimura.;Koji Isozaki.;Seiichi Hirota.
来源: Int J Clin Exp Pathol. 2015年8卷10期11970-82页
Sporadic mast cell neoplasms and gastrointestinal stromal tumors (GISTs) often have various types of somatic gain-of-function mutations of the c-kit gene which encodes a receptor tyrosine kinase, KIT. Several types of germline gain-of-function mutations of the c-kit gene have been detected in families with multiple GISTs. All three types of model mice for the familial GISTs with germline c-kit gene mutations at exon 11, 13 or 17 show development of GIST, while they are different from each other in skin mast cell number. Skin mast cell number in the model mice with exon 17 mutation was unchanged compared to the corresponding wild-type mice. In the present study, we characterized various types of mast cells derived from the model mice with exon 17 mutation (KIT-Asp818Tyr) corresponding to human familial GIST case with human KIT-Asp820Tyr to clarify the role of the c-kit gene mutation in mast cells. Bone marrow-derived cultured mast cells (BMMCs) derived from wild-type mice, heterozygotes and homozygotes were used for the experiments. Immortalized BMMCs, designated as IMC-G4 cells, derived from BMMCs of a homozygote during long-term culture were also used. Ultrastructure, histamine contents, proliferation profiles and phosphorylation of various signaling molecules in those cells were examined. In IMC-G4 cells, presence of additional mutation(s) of the c-kit gene and effect of KIT inhibitors on both KIT autophosphorylation and cell proliferation were also analyzed. We demonstrated that KIT-Asp818Tyr did not affect ultrastructure and proliferation profiles but did histamine contents in BMMCs. IMC-G4 cells had an additional novel c-kit gene mutation of KIT-Tyr421Cys which is considered to induce neoplastic transformation of mouse mast cells and the mutation appeared to be resistant to a KIT inhibitor of imatinib but sensitive to another KIT inhibitor of nilotinib. IMC-G4 cells might be a useful mast cell line to investigate mast cell biology.
723. Whole exome sequencing reveals a C-terminal germline variant in CEBPA-associated acute myeloid leukemia: 45-year follow up of a large family.
作者: Anand Pathak.;Katja Seipel.;Alexander Pemov.;Ramita Dewan.;Christina Brown.;Sarangan Ravichandran.;Brian T Luke.;Michael Malasky.;Shalabh Suman.;Meredith Yeager.; .; .;Richard A Gatti.;Neil E Caporaso.;John J Mulvihill.;Lynn R Goldin.;Thomas Pabst.;Mary L McMaster.;Douglas R Stewart.
来源: Haematologica. 2016年101卷7期846-52页
Familial acute myeloid leukemia is rare and linked to germline mutations in RUNX1, GATA2 or CCAAT/enhancer binding protein-α (CEBPA). We re-evaluated a large family with acute myeloid leukemia originally seen at NIH in 1969. We used whole exome sequencing to study this family, and conducted in silico bioinformatics analysis, protein structural modeling and laboratory experiments to assess the impact of the identified CEBPA Q311P mutation. Unlike most previously identified germline mutations in CEBPA, which were N-terminal frameshift mutations, we identified a novel Q311P variant that was located in the C-terminal bZip domain of C/EBPα. Protein structural modeling suggested that the Q311P mutation alters the ability of the CEBPA dimer to bind DNA. Electrophoretic mobility shift assays showed that the Q311P mu-tant had attenuated binding to DNA, as predicted by the protein modeling. Consistent with these findings, we found that the Q311P mutation has reduced transactivation, consistent with a loss-of-function mutation. From 45 years of follow up, we observed incomplete penetrance (46%) of CEBPA Q311P. This study of a large multi-generational pedigree reveals that a germline mutation in the C-terminal bZip domain can alter the ability of C/EBP-α to bind DNA and reduces transactivation, leading to acute myeloid leukemia.
724. Use of a genetically engineered mouse model as a preclinical tool for HER2 breast cancer.
作者: Helen Creedon.;Lucy A Balderstone.;Morwenna Muir.;Jozef Balla.;Laura Gomez-Cuadrado.;Natasha Tracey.;Joseph Loane.;Teresa Klinowska.;William J Muller.;Valerie G Brunton.
来源: Dis Model Mech. 2016年9卷2期131-40页
Resistance to human epidermal growth factor receptor 2 (HER2)-targeted therapies presents a major clinical problem. Although preclinical studies have identified a number of possible mechanisms, clinical validation has been difficult. This is most likely to reflect the reliance on cell-line models that do not recapitulate the complexity and heterogeneity seen in human tumours. Here, we show the utility of a genetically engineered mouse model of HER2-driven breast cancer (MMTV-NIC) to define mechanisms of resistance to the pan-HER family inhibitor AZD8931. Genetic manipulation of MMTV-NIC mice demonstrated that loss of phosphatase and tensin homologue (PTEN) conferred de novo resistance to AZD8931, and a tumour fragment transplantation model was established to assess mechanisms of acquired resistance. Using this approach, 50% of tumours developed resistance to AZD8931. Analysis of the resistant tumours showed two distinct patterns of resistance: tumours in which reduced membranous HER2 expression was associated with an epithelial-to-mesenchymal transition (EMT) and resistant tumours that retained HER2 expression and an epithelial morphology. The plasticity of the EMT phenotype was demonstrated upon re-implantation of resistant tumours that then showed a mixed epithelial and mesenchymal phenotype. Further AZD8931 treatment resulted in the generation of secondary resistant tumours that again had either undergone EMT or retained their original epithelial morphology. The data provide a strong rationale for basing therapeutic decisions on the biology of the individual resistant tumour, which can be very different from that of the primary tumour and will be specific to individual patients.
725. Single-Nucleotide Polymorphism on Exon 17 of Insulin Receptor Gene Influences Insulin Resistance in PCOS: A Pilot Study on North Indian Women.
作者: Sukanya Gangopadhyay.;Nitin Agrawal.;Aruna Batra.;Bhaskar Charan Kabi.;Akash Gupta.
来源: Biochem Genet. 2016年54卷2期158-68页
Polycystic ovarian syndrome (PCOS), a major cause of infertility, is also strongly associated with insulin resistance. Defects in insulin receptor signaling are considered as one of the major molecular pathogeneses for insulin resistance. To investigate the possible mechanism of this signaling defect at genetic level, single-nucleotide polymorphism (SNP) [His 1085 C/T] at the exon 17 of insulin receptor gene (INSR) was studied in this pilot study. Polymerase chain reaction was performed on leucocytic DNA of women diagnosed with PCOS, selected from the outpatient department of Safdarjung Hospital, New Delhi, using suitable primer to amplify a region on INSR. An equal number of age-matched healthy women were selected as controls. SNP analysis was performed with restriction enzyme length polymorphism technique using Pm II enzyme. Serum insulin level was measured by ELISA kit and HOMA-IR was calculated mathematically. A higher frequency of the CC genotype was observed in PCOS women than in controls. Also, HOMA-IR, a tool for estimating insulin resistance, was significantly high in PCOS women with the CC genotype. C1008T SNP at exon 17 of INSR is associated with insulin resistance in Indian women with PCOS. Presence of CC genotype (C1085T) could be developed as a marker for insulin resistance and metabolic complications in PCOS women.
726. A novel, anisamide-targeted cyclodextrin nanoformulation for siRNA delivery to prostate cancer cells expressing the sigma-1 receptor.
作者: Kathleen A Fitzgerald.;Meenakshi Malhotra.;Matt Gooding.;Florence Sallas.;James C Evans.;Raphael Darcy.;Caitriona M O'Driscoll.
来源: Int J Pharm. 2016年499卷1-2期131-145页
Prostate cancer is a leading cause of cancer-related death in men and RNA interference (RNAi) has emerged as a potential therapeutic option. However, the absence of a safe and specific delivery vector remains a major obstacle to the clinical application of RNAi. Cyclodextrin derivatives are known to be efficient delivery systems with low toxicity in a variety of cell types. In this study, a cationic cyclodextrin derivative was synthesized to complex siRNA. The nanoparticle was then further modified by exploiting the ability of the β-cyclodextrin cavity to form an inclusion complex with the hydrophobic molecule adamantane. PEGylated adamantane derivatives were synthesized with and without the anisamide-targeting ligand on the terminal end of the PEG chain. Anisamide is known to bind specifically to the sigma receptor which is overexpressed on the surface of prostate cancer cells. The resulting nanocomplexes were slightly cationic and less than 300 nm in size. They successfully protected siRNA from serum-induced nuclease degradation and were non-toxic to prostate cancer cells. In addition, the targeted nanoparticles mediated high levels of siRNA cellular uptake and corresponding PLK1 gene knockdown in prostate cancer cells in vitro. To our knowledge, this is the first time that the ability of cyclodextrins to form inclusion complexes with adamantane derivatives has been exploited for the targeted delivery of siRNA to prostate cancer cells via the sigma receptor.
727. Loss of FAT1 during the progression from DCIS to IDC and predict poor clinical outcome in breast cancer.
作者: Li Wang.;Shuhua Lyu.;Shuling Wang.;Honghong Shen.;Fengting Niu.;Xia Liu.;Junjun Liu.;Yun Niu.
来源: Exp Mol Pathol. 2016年100卷1期177-83页
FAT1 and β-catenin are important tumor regulatory factors. The aim of this study was to detect the possible disparity in their expression from ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC) and to explore its correlation with clinicopathological factors. We used immunohistochemistry to detect protein expression of FAT1 and β-catenin in breast cancer tissues from 113 cases of DCIS and 149 cases of IDC. As compared with DCIS, expression of FAT1 and β-catenin were significantly decreased in IDC (P<0.05). In addition, our study also revealed a correlation between their expression and some clinicopathological factors. We found that FAT1 expression was associated with nuclear grade and comedonecrosis (P<0.05) in DCIS, whereas FAT1 expression showed significant variation with histological grade and LN status (P<0.05) in IDC. Similar associations were observed in the β-catenin subgroup. Furthermore, expressions of FAT1 and β-catenin were correlated with each other in DCIS and IDC (P<0.05). FAT1(-), β-catenin(-), or FAT1(-)/β-catenin(-) may indicate worse DFS and OS in breast cancer (P<0.05). This study suggests that loss of FAT1 and β-catenin are associated with breast cancer progression, aggressive behavior, and poor prognosis. FAT1 alone or together with β-catenin might be a valuable biomarker in predicting the prognosis of patients with breast cancer.
728. Family History of Cancer in Relation to Breast Cancer Subtypes in African American Women.
作者: Traci N Bethea.;Lynn Rosenberg.;Nelsy Castro-Webb.;Kathryn L Lunetta.;Lara E Sucheston-Campbell.;Edward A Ruiz-Narváez.;Marjory Charlot.;Song-Yi Park.;Elisa V Bandera.;Melissa A Troester.;Christine B Ambrosone.;Julie R Palmer.
来源: Cancer Epidemiol Biomarkers Prev. 2016年25卷2期366-73页
The evidence on the relation of family history of cancers other than breast cancer to breast cancer risk is conflicting, and most studies have not assessed specific breast cancer subtypes.
729. AT-101 simultaneously triggers apoptosis and a cytoprotective type of autophagy irrespective of expression levels and the subcellular localization of Bcl-xL and Bcl-2 in MCF7 cells.
作者: P Antonietti.;F Gessler.;H Düssmann.;C Reimertz.;M Mittelbronn.;J H M Prehn.;D Kögel.
来源: Biochim Biophys Acta. 2016年1863卷4期499-509页
The effects of autophagy on cell death are highly contextual and either beneficial or deleterious. One prime example for this dual function of autophagy is evidenced by the cell responses to the BH3 mimetic AT-101 that is known to induce either apoptotic or autophagy-dependent cell death in different settings. Based on previous reports, we hypothesized that the expression levels of pro-survival Bcl-2 family members may be key determinants for the respective death mode induced by AT-101. Here we investigated the role of autophagy in the response of MCF7 breast cancer cells to AT-101. AT-101 treatment induced a prominent conversion of LC3-I to LC3-II and apoptotic cell death characterized by the appearance of Annexin-positive/PI-negative early apoptotic cells and PARP cleavage. Inhibition of the autophagy pathway, either through application of 3-MA or by lentiviral knockdown of ATG5, strongly potentiated cell death, indicating a pro-survival function of autophagy. Overexpression of wild type Bcl-xL significantly diminished the net amount of AT-101-induced cell death, but failed to alter the death-enhancing effects of the ATG5 knockdown. This was also observed with the organelle-specific variants Bcl-xL-ActA and Bcl-2-ActA (mitochondrial) as well as Bcl-xL-cb5 and Bcl-2-cb5 (ER) which all reduced AT-101-induced cell death, but did not affect the death-enhancing effects of 3-MA. Collectively, our data indicate that in apoptosis-proficient MCF7 cells, AT-101 triggers Bcl-2- and Bcl-xL-dependent apoptosis and a cytoprotective autophagy response that is independent of the expression and subcellular localization of Bcl-xL and Bcl-2.
730. Effects of two organomodified clays intended to food contact materials on the genomic instability and gene expression of hepatoma cells.
作者: Sara Maisanaba.;María Jordá-Beneyto.;Ana M Cameán.;Ángeles Jos.
来源: Food Chem Toxicol. 2016年88卷57-64页
Globally, food industries have made significant progress in order to increase the shelf-life of food products and have fewer economic losses. In this sense, the use of organomodified clays destined to be incorporated in polymer matrices play a novel role, leading to improved materials named nanocomposites with enhanced technological profiles. Due to the presence of these clays into the package, the safety of the consumers is a main concern. Cloisite(®)30B and Clay1 are two organomodified clays containing quaternary ammonium salts as modifiers, that can be potentially used to reinforce packaging polymers. Available toxicity data about these clays, specifically genotoxicity, is still limited and inconclusive in some aspects. Thus, the purpose of this work was to evaluate both clays ability to induce genomic instability through the cytokinesis block micronucleus cytome assay (CBMN) and for the first time, their influence in the modulation of several genes involved in genotoxicity and cell death mechanisms. Overall, no genotoxicity response was obtained in any case at the conditions tested. On the other hand, significant expression changes were observed on the genes selected. Nevertheless, further studies are highly needed to elucidate and increase the knowledge about the molecular mechanisms of clays toxicity.
731. Glycomic analysis of gastric carcinoma cells discloses glycans as modulators of RON receptor tyrosine kinase activation in cancer.
作者: Stefan Mereiter.;Ana Magalhães.;Barbara Adamczyk.;Chunsheng Jin.;Andreia Almeida.;Lylia Drici.;Maria Ibáñez-Vea.;Catarina Gomes.;José A Ferreira.;Luis P Afonso.;Lúcio L Santos.;Martin R Larsen.;Daniel Kolarich.;Niclas G Karlsson.;Celso A Reis.
来源: Biochim Biophys Acta. 2016年1860卷8期1795-808页
Terminal α2-3 and α2-6 sialylation of glycans precludes further chain elongation, leading to the biosynthesis of cancer relevant epitopes such as sialyl-Lewis X (SLe(X)). SLe(X) overexpression is associated with tumor aggressive phenotype and patients' poor prognosis.
732. Ancestral-derived effects on the mutational landscape of laryngeal cancer.
作者: Meganathan P Ramakodi.;Rob J Kulathinal.;Yujin Chung.;Ilya Serebriiskii.;Jeffrey C Liu.;Camille C Ragin.
来源: Genomics. 2016年107卷2-3期76-82页
Laryngeal cancer disproportionately affects more African-Americans than European-Americans. Here, we analyze the genome-wide somatic point mutations from the tumors of 13 African-Americans and 57 European-Americans from TCGA to differentiate between environmental and ancestrally-inherited factors. The mean number of mutations was different between African-Americans (151.31) and European-Americans (277.63). Other differences in the overall mutational landscape between African-American and European-American were also found. The frequency of C>A, and C>G were significantly different between the two populations (p-value<0.05). Context nucleotide signatures for some mutation types significantly differ between these two populations. Thus, the context nucleotide signatures along with other factors could be related to the observed mutational landscape differences between two races. Finally, we show that mutated genes associated with these mutational differences differ between the two populations. Thus, at the molecular level, race appears to be a factor in the progression of laryngeal cancer with ancestral genomic signatures best explaining these differences.
733. Mitigation of arsenic-induced acquired cancer phenotype in prostate cancer stem cells by miR-143 restoration.
作者: Ntube N O Ngalame.;Ngome L Makia.;Michael P Waalkes.;Erik J Tokar.
来源: Toxicol Appl Pharmacol. 2016年312卷11-18页
Inorganic arsenic, an environmental contaminant and a human carcinogen is associated with prostate cancer. Emerging evidence suggests that cancer stem cells (CSCs) are the driving force of carcinogenesis. Chronic arsenic exposure malignantly transforms the human normal prostate stem/progenitor cell (SC) line, WPE-stem to arsenic-cancer SCs (As-CSCs), through unknown mechanisms. MicroRNAs (miRNAs) are small, non-coding RNAs that negatively regulate gene expression at the posttranscriptional level. In prior work, miR-143 was markedly downregulated in As-CSCs, suggesting a role in arsenic-induced malignant transformation. In the present study, we investigated whether loss of miR-143 expression is important in arsenic-induced transformation of prostate SCs. Restoration of miR-143 in As-CSCs was achieved by lentivirus-mediated miR-143 overexpression. Cells were assessed bi-weekly for up to 30weeks to examine mitigation of cancer phenotype. Secreted matrix metalloproteinase (MMP) activity was increased by arsenic-induced malignant transformation, but miR-143 restoration decreased secreted MMP-2 and MMP-9 enzyme activities compared with scramble controls. Increased cell proliferation and apoptotic resistance, two hallmarks of cancer, were decreased upon miR-143 restoration. Increased apoptosis was associated with decreased BCL2 and BCL-XL expression. miR-143 restoration dysregulated the expression of SC/CSC self-renewal genes including NOTCH-1, BMI-1, OCT4 and ABCG2. The anticancer effects of miR-143 overexpression appeared to be mediated by targeting and inhibiting LIMK1 protein, and the phosphorylation of cofilin, a LIMK1 substrate. These findings clearly show that miR-143 restoration mitigated multiple cancer characteristics in the As-CSCs, suggesting a potential role in arsenic-induced transformation of prostate SCs. Thus, miR-143 is a potential biomarker and therapeutic target for arsenic-induced prostate cancer.
734. Pathology and Genetics of Syndromic Gastric Polyps.
作者: Lodewijk A A Brosens.;Laura D Wood.;G Johan Offerhaus.;Christina A Arnold.;Dora Lam-Himlin.;Francis M Giardiello.;Elizabeth A Montgomery.
来源: Int J Surg Pathol. 2016年24卷3期185-99页
Gastric polyps are found in 1% to 4% of patients undergoing gastroscopy. The vast majority are sporadic, but some gastric polyps indicate an underlying syndrome. Gastric polyps can manifest in each of the gastrointestinal polyposis syndromes, including the recently described gastric adenocarcinoma and proximal polyposis of the stomach syndrome. In addition, gastric polyps occur in Lynch syndrome and in a few rare conditions that are not primarily gastrointestinal. While some of these syndromes are clearly associated with an increased risk of gastric cancer, others are not. Interestingly, even in disorders with a well-established risk of gastric cancer, the neoplastic potential and the precursor status of these gastric polyps are not always clear. Although rare, recognition of syndromic gastric polyps is important for individual patient management. These conditions also serve as important models to study gastric homeostasis and gastric tumorigenesis.
735. Fibromatosis of the Sigmoid Colon With CTNNB1 (β-Catenin) Gene Mutation, Arising at the Site of Ileocolic Anastomosis for Resection of Gastrointestinal Stromal Tumor.
作者: Khin Thway.;Sara Abou Sherif.;Angela M Riddell.;Satvinder Mudan.
来源: Int J Surg Pathol. 2016年24卷3期264-8页
We describe a case of intra-abdominal fibromatosis, which occurred in a 44-year-old woman who had a previous history of gastrointestinal stromal tumor (GIST) of the sigmoid mesocolon, which was treated with imatinib and resection. A mass was detected at the site of ileocolic anastomosis of the previous small bowel resection and sigmoid colectomy, nearly 3 years later. Clinically, this was suspected to represent recurrent GIST and was excised, but histology and mutational analysis showed desmoid-type fibromatosis with a mutation in codon 41 of exon 3 of the CTNNB1 (β-catenin) gene. The occurrence of fibromatosis at the site of excision of GIST is very rare, but its recognition is important as the treatment of the two neoplasms differs significantly. As imaging cannot reliably distinguish between these 2 entities, histological diagnosis is crucial for correct clinical management.
736. Wilms tumor protein 1 (WT1)-- not only a diagnostic but also a prognostic marker in high-grade serous ovarian carcinoma.
作者: Eliane Tabea Taube.;Carsten Denkert.;Jalid Sehouli.;Catarina Alisa Kunze.;Manfred Dietel.;Ioana Braicu.;Anne Letsch.;Silvia Darb-Esfahani.
来源: Gynecol Oncol. 2016年140卷3期494-502页
Wilms tumor protein 1 (WT1) expression is used in gynecological pathology as a diagnostic marker of serous differentiation, and is frequently co-expressed with ER-α. Early phase studies on WT1 vaccine in gynecological cancers are ongoing. In this study we aimed to determine the prognostic value of WT1 in high-grade serous ovarian carcinoma.
737. Downregulation of Nrf2 by the combination of TRAIL and Valproic acid induces apoptotic cell death of TRAIL-resistant papillary thyroid cancer cells via suppression of Bcl-xL.
作者: Hyun-Young Cha.;Bok-Soon Lee.;Jae Won Chang.;Ju Kyeong Park.;Jae Ho Han.;Yong-Sung Kim.;Yoo Seob Shin.;Hyung Kwon Byeon.;Chul-Ho Kim.
来源: Cancer Lett. 2016年372卷1期65-74页
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) represents an effective agent for the treatment of many cancers, though the majority of thyroid cancers are found to be resistant. Therefore it would be necessary to identify agents capable of increasing the sensitivity of these cancers to TRAIL-mediated cell death. Here, we examined the therapeutic effect and its underlying mechanism of combination treatment of TRAIL and histone deacetylase inhibitor, Valproic acid (VPA) in vitro using human papillary thyroid cancer (PTC) cells and in vivo using an orthotopic mouse model of PTC. TRAIL-VPA combination therapy synergistically induced apoptotic cell death in TRAIL-resistant PTC through caspase activation. In addition, downregulation of antioxidant transcription factor, Nrf2 by co-treatment of TRAIL-VPA induces cell death via suppression of Bcl-xL in vitro and in vivo; these effects were further enhanced following siRNA inhibition of these proteins in combination with TRAIL or TRAIL-VPA. Taken together, VPA sensitized TRAIL-resistant PTC cells to apoptotic cell death through involvement of Nrf2 and Bcl-xL. Thus, the combination of VPA and TRAIL may be a promising therapy for TRAIL-resistant PTC.
738. Aberrant DNA Methylation Is Associated with a Poor Outcome in Juvenile Myelomonocytic Leukemia.
作者: Hirotoshi Sakaguchi.;Hideki Muramatsu.;Yusuke Okuno.;Hideki Makishima.;Yinyan Xu.;Yoko Furukawa-Hibi.;Xinan Wang.;Atsushi Narita.;Kenichi Yoshida.;Yuichi Shiraishi.;Sayoko Doisaki.;Nao Yoshida.;Asahito Hama.;Yoshiyuki Takahashi.;Kiyofumi Yamada.;Satoru Miyano.;Seishi Ogawa.;Jaroslaw P Maciejewski.;Seiji Kojima.
来源: PLoS One. 2015年10卷12期e0145394页
Juvenile myelomonocytic leukemia (JMML), an overlap of myelodysplastic / myeloproliferative neoplasm, is an intractable pediatric myeloid neoplasm. Epigenetic regulation of transcription, particularly by CpG methylation, plays an important role in tumor progression, mainly by repressing tumor-suppressor genes. To clarify the clinical importance of aberrant DNA methylation, we studied the hypermethylation status of 16 target genes in the genomes of 92 patients with JMML by bisulfite conversion and the pryosequencing technique. Among 16 candidate genes, BMP4, CALCA, CDKN2A, and RARB exhibited significant hypermethylation in 72% (67/92) of patients. Based on the number of hypermethylated genes, patients were stratified into three cohorts based on an aberrant methylation score (AMS) of 0, 1-2, or 3-4. In the AMS 0 cohort, the 5-year overall survival (OS) and transplantation-free survival (TFS) were good (69% and 76%, respectively). In the AMS 1-2 cohort, the 5-year OS was comparable to that in the AMS 0 cohort (68%), whereas TFS was poor (6%). In the AMS 3-4 cohort, 5-year OS and TFS were markedly low (8% and 0%, respectively). Epigenetic analysis provides helpful information for clinicians to select treatment strategies for patients with JMML. For patients with AMS 3-4 in whom hematopoietic stem cell transplantation does not improve the prognosis, alternative therapies, including DNA methyltransferase inhibitors and new molecular-targeting agents, should be established as treatment options.
739. mir-129-5p Attenuates Irradiation-Induced Autophagy and Decreases Radioresistance of Breast Cancer Cells by Targeting HMGB1.
BACKGROUND This study aimed to determine the role of miR-129-5p in irradiation-induced autophagy in breast cancer cells and to investigate its downstream regulation in autophagy-related radiosensitivity. MATERIAL AND METHODS Relative miR-129-5p expression in breast cancer cell lines MCF-7, MDA-MB-231, BT474, and BT549, and in 1 non-tumorigenic breast epithelial cell line, MCF-10A, was compared. The effect of miR-129-5p on irradiation-induced autophagy and radiosensitivity of the cancer cells was explored. The regulative effect of miR-129-5p on HMGB1 and the functional role of this axis in autophagy and radiosensitivity were also studied. RESULTS Ectopic expression of miR-129-5p sensitized MDA-MD-231 cells to irradiation, while knockdown of miR-129-5p reduced radiosensitivity of MCF-7 cells. MiR-129-5p overexpression inhibited irradiation-induced autophagy. HMGB1 is a direct functional target of miR-129-5p in breast cancer cells. MiR-129-5p may suppress autophagy and decrease radioresistance of breast cancer cells by targeting HMGB1. CONCLUSIONS The miR-129-5p/HMGB1 axis can regulate irradiation-induced autophagy in breast cancer and might be an important pathway in regulating radiosensitivity of breast cancer cells.
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