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A significant volume of clinical and epidemiological data provides support to the concept that insulin and the insulin receptor (INSR) have an important role in breast cancer. Tumor suppressor p53 is the most frequently mutated molecule in human cancer. The present study was aimed at evaluating the hypothesis that p53 governs the expression and activation of the INSR gene in breast cancer cells. In addition, the study was designed to investigate the mechanism of action of p53 in the context of INSR gene regulation. The availability of MCF7 breast cancer-derived cell lines with specific disruption of either the insulin-like growth factor-1 receptor (IGF1R) or INSR allowed us to address the impact of the IGF1R and INSR pathways on p53 expression. Data indicate that the INSR gene constitutes a target for p53 action. Wild-type p53 stimulated INSR promoter activity in control cells while disruption of endogenous IGF1R or INSR led to inhibition of promoter activity by p53. Mutant p53 strongly stimulated INSR promoter. Furthermore, p53 directly binds to the INSR promoter in cells with a disrupted IGF1R. Combined, our results identified complex functional and physical interactions between p53 and the INSR pathway. The implications of the p53-INSR interplay in breast cancer needs to be further investigated.

Tumor protein 53 (p53) regulates fundamental pathways of cellular growth and differentiation. Aberrant p53 expression in glioblastoma multiforme, a terminal brain cancer, has been associated with worse patient outcomes and decreased chemosensitivity. Therefore, correctly identifying p53 status in glioblastoma is of great clinical significance. p53 immunohistochemistry is used to detect pathological presence of the TP53 gene product. Here, we examined the relationship between p53 immunoreactivity and TP53 mutation status by DNA Sanger sequencing in adult glioblastoma. Of 41 histologically confirmed samples, 27 (66%) were immunopositive for a p53 mutation via immunohistochemistry. Utilizing gene sequencing, we identified only eight samples (20%) with TP53 functional mutations and one sample with a silent mutation. Therefore, a ≥10% p53 immunohistochemistry threshold for predicting TP53 functional mutation status in glioma is insufficient. Implementing this ≥10% threshold, we demonstrated a remarkably low positive-predictive value (30%). Furthermore, the sensitivity and specificity with ≥10% p53 immunohistochemistry to predict TP53 functional mutation status were 100% and 42%, respectively. Our data suggests that unless reliable sequencing methodology is available for confirming TP53 status, raising the immunoreactivity threshold would increase positive and negative predictive values as well as the specificity without changing the sensitivity of the immunohistochemistry assay.

Accumulating evidence has indicated that microRNAs play a critical role in the pathogenesis of human cancers. microRNA-34a (miR-34a) has been shown to be a key regulator of tumor suppression by targeting several cancer-related signals, including the interleukin-6 receptor (IL-6R)/Signal Transducers and Activator of Transcription 3 (STAT3) signaling pathway. Previously, we determined that miR-34a expression was frequently reduced in high-grade serous carcinoma (HGSC), the major subtype of epithelial ovarian cancer (EOC). Considering that the IL-6R/STAT3 signaling pathway is upregulated and believed to be a potential therapeutic target in EOC, we investigated the biological significance of reduced miR-34a expression in HGSC with regard to IL-6R signaling. Additionally, we evaluated the viability of miR-34a as a therapeutic application for HGSC both in vitro and in vivo. Accordingly, we found that the ectopic expression of miR-34a significantly reduced tumor proliferation and invasion through downregulation of IL-6R expression, suggesting that reduced miR-34a expression might play an important role in the malignant potential of HGSC through upregulation of the IL-6R/STAT3 signaling pathway. Moreover, we demonstrated that replacement of miR-34a reduced tumorigenicity of HGSC in vivo. Therefore, this study may provide the rationale for miR-34a replacement as a promising therapeutic strategy for HGSC.

// Marcus Bauer 1 , Eva Johanna Kantelhardt 2, 3 , Thorsten Stiewe 4, 5, 6 , Andrea Nist 4 , Marco Mernberger 4 , Katharina Politt 4 , Volker Hanf 7 , Tilmann Lantzsch 8 , Christoph Uleer 9 , Susanne Peschel 10 , Jutta John 11 , Jorg Buchmann 12 , Edith Weigert 13 , Karl-Friedrich Burrig 14 , Claudia Wickenhauser 1 , Christoph Thomssen 2 , Frank Bartel 1, * and Martina Vetter 2, * 1 Institute of Pathology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany 2 Department of Gynaecology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany 3 Institute of Medical Epidemiology, Biostatistics and Informatics, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany 4 Institute of Molecular Oncology, Universities of Giessen and Marburg Lung Center, German Center for Lung Research (DZL), Marburg, Germany 5 Genomics Core Facility, Philipps-University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research (DZL), Marburg, Germany 6 Universities of Giessen and Marburg Lung Center, German Center for Lung Research (DZL), Marburg, Germany 7 Department of Gynaecology, Hospital Fuerth, Fuerth, Germany 8 Department of Gynaecology, Hospital St. Elisabeth and St. Barbara, Halle (Saale), Germany 9 Onkologische Praxis Uleer, Hildesheim, Germany 10 Department of Gynaecology, St. Bernward Hospital, Hildesheim, Germany 11 Department of Gynaecology, Helios Hospital Hildesheim, Hildesheim, Germany 12 Institute of Pathology, Hospital Martha-Maria, Halle (Saale), Germany 13 Institute of Pathology, Hospital Fuerth, Fuerth, Germany 14 Institute of Pathology Hildesheim, Hildesheim, Germany * Co-senior authors and contributed equally to this work Correspondence to: Frank Bartel, email: frank.bartel@medizin.uni-halle.de Keywords: p53; mutation; tumor suppression; breast cancer; single nucleotide polymorphism Received: September 18, 2018 Accepted: February 15, 2019 Published: March 08, 2019 ABSTRACT Background: Genetic factors play a substantial role in breast cancer etiology. Genes encoding proteins that have key functions in the DNA damage response, such as p53 and its inhibitors MDM2 and MDMX, are most likely candidates to harbor allelic variants that influence breast cancer susceptibility. The aim of our study was to comprehensively analyze the impact of SNPs in the TP53 , MDM2 , and MDMX genes in conjunction with TP53 mutational status regarding the onset and progression of breast cancer. Methods: In specimen from 815 breast cancer patients, five SNPs within the selected genes were analyzed: TP53 – Arg72Pro (rs1042522), MDM2 – SNP285 (rs2279744), SNP309 (rs117039649); MDMX – SNP31826 (rs1563828), and SNP34091 (rs4245739). Classification of the tumors was evaluated by histomorphology. Subtyping according hormone receptor status, HER2-status and proliferation rate enabled provision of the clinico-pathological surrogate of intrinsic subtypes. Results: The homozygous C-allele of MDM2 SNP285 was significantly associated with a younger age-at-diagnosis of 44.2 years, in contrast to G/G- and G/C-patients (62.4, 62.7 yrs., respectively; p = 0.0007; log-Rank-test). In contrast, there was no difference regarding the age-at-diagnosis for patients with the respective genotypes of MDM2 SNP309 ( p = 0.799; log-Rank-test). In patients with estrogen receptor (ER)-positive and TP53 -mutated tumors, however, the T/T-genotype of the MDM2 SNP309 was significantly associated with an earlier average age-at-diagnosis compared with T/G+G/G-patients (53.5 vs. 68.2 yrs; p = 0.002; log-Rank-test). In the triple-negative subgroup, the G/G-patients had an average age-at-diagnosis of 51 years compared with 63 years for SNP309T carriers ( p = 0.004; log-Rank-test) indicating a susceptibility of the G/G genotype for the development of triple negative breast cancer. Patients with the A/A-genotype of MDMX SNP31826 with ER-negative tumors were diagnosed 11 years earlier compared with patients and ER-positive tumors (53.2 vs. 64.4 yrs; p = 0.025, log-Rank-test). Furthermore, in luminal B-like patients (HER2-independent) the C/C-genotype of MDMX SNP34091 was significantly correlated with a decreased event-free survival compared with the A/A-genotype ( p < 0.001; log-Rank-test). Conclusions: We showed that SNPs in the MDM2 and MDMX genes affect at least in part the onset and progression of breast cancer dependent on the ER-status. Our findings provide further evidence for the distinct etiological pathways in ER-negative and ER-positive breast cancers.

// Sara Ibrahim Omar 1 and Jack Tuszynski 1, 2, 3 1 Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada 2 Department of Physics, Faculty of Science, University of Alberta, Edmonton, Alberta, Canada 3 Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy Correspondence to: Jack Tuszynski, email: jackt@ualberta.ca Keywords: p53; methylene quinuclidinone; R175H mutant p53; R273H mutant p53; mechanism of action Received: July 11, 2018 Accepted: November 26, 2018 Published: December 14, 2018 ABSTRACT One of the most important tumor suppressor proteins in eukaryotic cells is the transcription factor called p53. The importance of this protein in cells comes from the fact that it regulates a wide variety of cellular processes including the cell cycle, metabolism, DNA repair, senescence and apoptosis. In cancer cells, p53 is a major target as the most mutated protein, which has led to the search for potential activators of the mutant protein. Currently, the only mutated-p53 activator in clinical trials is a small molecule called APR-246. There is evidence that the active metabolite of APR-246 binds covalently to mutant p53 and restores its wild-type (wt) activity. In this work, we created atomistic in silico models of the wt, mutant and drugged mutant p53 proteins each in complex with DNA. Using molecular dynamics simulations we generated equilibrated models of the complexes. Detailed analysis revealed that the binding of the APR-246 active metabolite to the mutant proteins alters their interaction with DNA. In particular, the binding of the molecule at loop L1 of the protein allows the loop to anchor the protein to DNA similarly to wt p53. Several important p53-DNA interactions lost due to mutation were also restored in the drugged mutants. These findings, not only provide a possible mechanism of action of this drug, but also criteria to use in virtual screening campaigns for other p53 activators.

Cancer is a global public health concern that is characterized by the uncontrolled growth of tumor cells. It is regarded as the subsequent cause of death after cardiovascular disease. The most common types of cancer include breast, colorectal, lung, and prostate. The risk factors attributed to the development of common types of cancer are tobacco smoking, excessive alcohol consumption, dietary factors, ultraviolet radiation (UV), and lack of physical activities. Two major cellular apoptotic pathways targeted in cancer therapies are intrinsic and extrinsic. These two pathways are regulated by different types of proteins, the multidomain pro-apoptotic proteins (Bak, Bax, and Bok), BH3-only pro-apoptotic proteins (Bid, Bim, Bad, Noxa, and Puma), and the anti-apoptotic proteins (Mcl-1, Bfl-1, Bcl-XL, Bcl-2, Bcl-w, and Bcl-B). Other significant molecules/factors that are known to execute cellular apoptotic pathways include bioactive compounds, and reactive oxygen species (ROS). Proteolytic caspases are known to play a vital role in the initiation of apoptotic activities in cancerous cells. Based on their functions, they are categorized into initiators and executioners. Nanotechnology has produced novel outcomes in modern medicine. The green synthesis of nanoparticles has demonstrated prospective improvements in cancer therapies in combination with the existing therapies including photodynamic therapy. This review aims at highlighting the association between pro-apoptotic and anti-apoptotic proteins, and their significance in cancer therapy.

// Dawid Walerych 1 , Magdalena Pruszko 1 , Lukasz Zyla 2 , Michalina Wezyk 1 , Katarzyna Gaweda-Walerych 1 and Alicja Zylicz 2 1 Mossakowski Medical Research Centre, Polish Academy of Sciences, 02-106 Warsaw, Poland 2 International Institute of Molecular and Cell Biology in Warsaw, 02-109 Warsaw, Poland Correspondence to: Dawid Walerych, email: dwalerych@imdik.pan.pl Keywords: p53; oligomerization; FRET; dominant-negative; gain-of-function Received: February 05, 2018 Accepted: July 21, 2018 Published: August 10, 2018 ABSTRACT Human p53 protein acts as a transcription factor predominantly in a tetrameric form. Single residue changes, caused by hot-spot mutations of the TP53 gene in human cancer, transform wild-type (wt) p53 tumor suppressor proteins into potent oncoproteins - with gain-of-function, tumor-promoting activity. Oligomerization of p53 allows for a direct interplay between wt and mutant p53 proteins if both are present in the same cells – where a mutant p53’s dominant-negative effect known to inactivate wt p53, co-exists with an opposite mechanism – a “dominant-positive” suppression of the mutant p53’s gain-of-function activity by wt p53. In this study we determine the oligomerization efficiency of wt and mutant p53 in living cells using FRET-based assays and describe wt p53 to be more efficient than mutant p53 in entering p53 oligomers. The biased p53 oligomerization helps to interpret earlier reports of a low efficiency of the wt p53 inactivation via the dominant-negative effect, while it also implies that the “dominant-positive” effect may be more pronounced. Indeed, we show that at similar wt:mutant p53 concentrations in cells – the mutant p53 gain-of-function stimulation of gene transcription and cell migration is more efficiently inhibited than the wt p53’s tumor-suppressive transactivation and suppression of cell migration. These results suggest that the frequent mutant p53 accumulation in human tumor cells does not only directly strengthen its gain-of-function activity, but also protects the oncogenic p53 mutants from the functional dominance of wt p53.

Autophagy is important in regulating the balance between cell death and survival, with the tumor suppressor p53 as one of the key components in this interplay. We have previously utilized an in vitro model of the most common form of childhood cancer, B cell precursor acute lymphoblastic leukemia (BCP-ALL), to show that activation of the cAMP signaling pathway inhibits p53-mediated apoptosis in response to DNA damage in both cell lines and primary leukemic cells. The present study reveals that cAMP-mediated survival of BCP-ALL cells exposed to DNA damaging agents, involves a critical and p53-independent enhancement of autophagy. Although autophagy generally is regarded as a survival mechanism, DNA damage-induced apoptosis has been linked both to enhanced and reduced levels of autophagy. Here we show that exposure of BCP-ALL cells to irradiation or cytotoxic drugs triggers autophagy and cell death in a p53-dependent manner. Stimulation of the cAMP signaling pathway further augments autophagy and inhibits the DNA damage-induced cell death concomitant with reduced nuclear levels of p53. Knocking-down the levels of p53 reduced the irradiation-induced autophagy and cell death, but had no effect on the cAMP-mediated autophagy. Moreover, prevention of autophagy by bafilomycin A1 or by the ULK-inhibitor MRT68921, diminished the protecting effect of cAMP signaling on DNA damage-induced cell death. Having previously proposed a role of the cAMP signaling pathway in development and treatment of BCP-ALLs, we here suggest that inhibitors of autophagy may improve current DNA damage-based therapy of BCP-ALL - independent of p53.

// Danielly C. Ferraz da Costa 1, 2 , Nathali P.C. Campos 2, 3 , Ronimara A. Santos 1 , Francisca Hildemagna Guedes-da-Silva 2, 3 , Mafalda Maria D.C. Martins-Dinis 2, 3 , Leticia Zanphorlin 4 , Carlos Ramos 4 , Luciana P. Rangel 2, 5 and Jerson L. Silva 2, 3 1 Departamento de Nutricao Basica e Experimental, Instituto de Nutricao, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20550-013, RJ, Brazil 2 Instituto Nacional de Ciencia e Tecnologia de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil 3 Programa de Biologia Estrutural, Instituto de Bioquimica Medica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil 4 Instituto de Quimica, Universidade de Campinas, Campinas 13083-970, SP, Brazil 5 Departamento de Analises Clinicas e Toxicologicas, Faculdade de Farmacia, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil Correspondence to: Jerson L. Silva, email: jerson@bioqmed.ufrj.br Keywords: amyloid aggregation; p53; cancer; aggregation; resveratrol Received: June 22, 2017 Accepted: June 04, 2018 Published: June 26, 2018 ABSTRACT One potential target for cancer therapeutics is the tumor suppressor p53, which is mutated in more than 50% of malignant tumors. Loss of function (LoF), dominant negative (DN) and gain of function (GoF) mutations in p53 are associated with amyloid aggregation. We tested the potential of resveratrol, a naturally occurring polyphenol, to interact and prevent the aggregation of wild-type and mutant p53 in vitro using fluorescence spectroscopy techniques and in human breast cancer cells (MDA-MB-231, HCC-70 and MCF-7) using immunofluorescence co-localization assays. Based on our data, an interaction occurs between resveratrol and the wild-type p53 core domain (p53C). In addition, resveratrol and its derivatives pterostilbene and piceatannol inhibit mutant p53C aggregation in vitro . Additionally, resveratrol reduces mutant p53 protein aggregation in MDA-MB-231 and HCC-70 cells but not in the wild-type p53 cell line MCF-7. To verify the effects of resveratrol on tumorigenicity, cell proliferation and cell migration assays were performed using MDA-MB-231 cells. Resveratrol significantly reduced the proliferative and migratory capabilities of these cells. Our study provides evidence that resveratrol directly modulates p53, enhancing our understanding of the mechanisms involved in p53 aggregation and its potential as a therapeutic strategy for cancer treatment.

Irinotecan (CPT-11) and oxaliplatin (L-OHP) are among the most frequently used drugs against colorectal tumors. Therefore, it is important to define the molecular mechanisms that these agents modulate in colon cancer cells. Here we demonstrate that CPT-11 stalls such cells in the G₂/M phase of the cell cycle, induces an accumulation of the tumor suppressor p53, the replicative stress/DNA damage marker γH2AX, phosphorylation of the checkpoint kinases ATM and ATR, and an ATR-dependent accumulation of the pro-survival molecule survivin. L-OHP reduces the number of cells in S-phase, stalls cell cycle progression, transiently triggers an accumulation of low levels of γH2AX and phosphorylated checkpoint kinases, and L-OHP suppresses survivin expression at the mRNA and protein levels. Compared to CPT-11, L-OHP is a stronger inducer of caspases and p53-dependent apoptosis. Overexpression and RNAi against survivin reveal that this factor critically antagonizes caspase-dependent apoptosis in cells treated with CPT-11 and L-OHP. We additionally show that L-OHP suppresses survivin through p53 and its downstream target p21, which stalls cell cycle progression as a cyclin-dependent kinase inhibitor (CDKi). These data shed new light on the regulation of survivin by two clinically significant drugs and its biological and predictive relevance in drug-exposed cancer cells. CA extern

Heat shock protein 90 (HSP90) inhibitors suppressed MDM4 functions which mediated p53 ubiquitination, and blocked a chaperon function which influenced expression of the client proteins. We examined cytotoxic effects of the inhibitors, 17-allylamino-17-demetheoxygeldanamycin (17-AAG) and 17-dimethylaminoethylamino-17-demethoxy-geldanamycin (17-DMAG), on mesothelioma and investigated combinatory effects of the inhibitors and adenoviruses expressing the wild-type p53 gene (Ad-p53). A majority of mesothelioma lacks p14 and p16 expression, which leads to defective p53 pathway despite bearing the wild-type p53 genotype. The HSP90 inhibitors up-regulated endogenous wild-type p53 expression and induced cell death. Furthermore, the inhibitors increased the endogenous p53 levels that were induced by cisplatin. Nevertheless, the HSP90 inhibitors suppressed Ad-p53-induced exogenous p53 expression primarily at a posttranscriptional level and inhibited the Ad-p53-mediated cell death. HSP90 inhibitors suppressed ubiquitination processes which were involved in p53 degradation, but a proteasome inhibitor, MG-132, prevented the HSP90 inhibitors-induced p53 down-regulation. In contrast, an inhibitor for HSP70 with a chaperon function, pifithrin-μ, did not produce the p53 down-regulation. The HSP90 inhibitors did not suppress expression of Ad receptor molecules but rather increased expression of green fluorescence protein transduced by the same Ad vector. These data collectively indicated that an HSP90 inhibitor possessed a divalent action on p53 expression, as an activator for endogenous wild-type p53 through inhibited ubiquitination and a negative regulator of exogenously over-expressed p53 through the proteasome pathway.

// Larisa Y. Romanova 1, 2 , Frederick Mushinski 1, * and Alexander L. Kovalchuk 2 1 The Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA 2 The Virology and Cellular Immunology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Rockville, Maryland, USA * Deceased Correspondence to: Alexander L. Kovalchuk, email: kovalcha@niaid.nih.gov Keywords: RPA phosphorylation; p53; transcriptional activation; homologous recombination Received: January 24, 2018 Accepted: March 21, 2018 Published: May 22, 2018 ABSTRACT The inhibitory effect of p53 on homologous recombination (HR) is exerted through sequestration of replication protein A (RPA). Release of the p53/RPA complex in response to replication stress is crucially dependent on the phosphorylation status of both proteins and is required for efficient DNA repair by HR. Phosphorylation of RPA within its RPA2 subunit by cyclin-dependent kinases (CDK) is an early event in the replication stress response. Here we investigated the role of transcriptional activation of the p53 downstream target, p21 Waf1 , on RPA2 phosphorylation, the stability of the p53/RPA complex and HR in cells undergoing replication arrest induced by camptothecin (CPT). We show that in CPT-treated cells, activation of p53 and p21 Waf1 impedes RPA2 phosphorylation, while their depletion by siRNA stimulates it. The p53/RPA complex is more stable in wild-type cells than in cells depleted of p21 Waf1 . We used nocodazole-synchronized cells treated with CPT at the entrance to S phase to assess rates of HR. Regardless of their p53 or p21 Waf1 status, the cells proceed through S phase at a similar rate and enter G2. While HR is low in wild-type cells and high in p53-depleted cells, only partial inhibition of HR is observed in the p21 Waf1 -depleted cells. This correlates with the extent of RPA sequestration by p53. Thus, in CPT-treated cells, p53-induced transcriptional activation of p21 Waf1 regulates RPA2 phosphorylation, the stability of the p53/RPA complex and HR.

// Igor Bado 1 , Eric Pham 2 , Benjamin Soibam 3 , Fotis Nikolos 1 , Jan-Ake Gustafsson 1, 4 and Christoforos Thomas 1 1 Department of Biology and Biochemistry, Center for Nuclear Receptors and Cell Signaling, University of Houston, Houston, Texas, USA 2 Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA 3 Department of Computer Science and Engineering Technology, University of Houston-Downtown, Huston, Texas, USA 4 Center for Innovative Medicine, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden Correspondence to: Christoforos Thomas, email: thomaschristoforos@gmail.com Keywords: estrogen receptor β; p53; breast cancer; DNA damage response; therapy response Received: September 27, 2017 Accepted: March 21, 2018 Published: April 27, 2018 ABSTRACT Estrogen receptor α (ERα)-positive breast cancers tend to develop resistance to both endocrine therapy and chemotherapy. Despite recent progress in defining molecular pathways that confer endocrine resistance, the mechanisms that regulate chemotherapy response in luminal tumors remain largely elusive. Luminal tumors often express wild-type p53 that is a major determinant of the cellular DNA damage response. Similar to p53, the second ER subtype, ERβ, has been reported to inhibit breast tumorigenesis by acting alone or in collaboration with p53. However, a synergistic mechanism of action has not been described. Here, we suggest that ERβ relies on p53 to elicit its tumor repressive actions in ERα-positive breast cancer cells. Upregulation of ERβ and treatment with ERβ agonists potentiates the tumor suppressor function of p53 resulting in decreased survival. This effect requires molecular interaction between the two proteins that disrupts the inhibitory action of ERα on p53 leading to increased transcriptional activity of p53. In addition, we show that the same interaction alters the chemosensitivity of endocrine-resistant cells including their response to tamoxifen therapy. Our results suggest a collaboration of ERβ and p53 tumor suppressor activity in breast cancer cells that indicates the importance of ligand-regulated ERβ as a tool to target p53 activity and improve the clinical management of resistant disease.

Cancer cells subjected to ionizing radiation may release signals which can influence nearby non-irradiated cells, termed bystander effects. The transmission of bystander effects among cancer cells involves the activation of inflammatory cytokines, death ligands, and reactive oxygen/nitrogen species. In addition to bystander effects, two other forms of non-target effects (NTEs) have been identified in radiotherapy, as one is called cohort effects and the other is called abscopal effects. Cohort effects represent the phenomenon where irradiated cells can produce signals that reduce the survival of neighboring cells within an irradiated volume. The effects suggest the importance of cellular communication under irradiation with non-uniform dose distribution. In contrast, abscopal effects describe the NTEs that typically occur in non-irradiated cells distant from an irradiated target. These effects can be mediated primarily by immune cells such as T cells. Clinical trials have shown that application of radiation along with immunotherapy may enhance abscopal effects and improve therapeutic efficacy on non-target lesions outside an irradiated field. According to NTEs, cell viability is reduced not only by direct irradiation effects, but also due to signals emitted from nearby irradiated cells. A clinical consideration of NTEs could have a revolutionary impact on current radiotherapy via the establishment of more efficient and less toxic radiobiological models for treatment planning compared to conventional models. Thus, we will review the most updated findings about these effects and outline their mechanisms and potential applications in cancer treatment with a special focus on the brain, lung, and breast cancers.

To better understand the breast cancer progression and therapeutic resistance is crucial deepen the molecular mechanisms related to regulation of cells behavior in the tumor microenvironment. Inappropriate expression or activation of transcription factors in tumor breast microenvironment can lead to the malignant behavior of breast cancer cells. Bcl6 is a transcriptional factor that may play a role in the pathogenesis of breast cancer. Moreover, cells surrounding tumor cells, including macrophages and mast cells play an important role during tumor progression enhancing angiogenesis. We have demonstrated: 1) An increase of the BCL6 translocation and Bcl6 positive cells in G3 degree of disease; 2) A reduction of the expression of p53 in G3 breast cancer samples as compared to G1/G2 specimens; 3) Macrophages CD68+ and CD163+ in interstitial and periglandular position, increase in G3 specimens as compared to G1/G2 and control samples; 4) Tryptase-positive mast cells in periglandular position are more numerous in G3 tumor specimens as compared to G1/G2 and control samples. Overall, these data confirm the important role played by epigenetic events, including BCL6 translocation, p53 expression, and microenvironment components, including macrophage and mast cell infiltration and microvascular density involved in the regulation of breast cancer progression.

// Yuhei Kogata 1 , Tomohito Tanaka 1 , Yoshihiro J. Ono 1 , Masami Hayashi 1 , Yoshito Terai 1 and Masahide Ohmichi 1 1 Department of Obstetrics and Gynecology, Osaka Medical College, Takatsuki, Japan Correspondence to: Tomohito Tanaka, email: gyn123@osaka-med.ac.jp Keywords: endometrial cancer; foretinib; p53; apoptosis Received: September 08, 2017 Accepted: April 06, 2018 Published: April 27, 2018 ABSTRACT Objective: Foretinib (GSK1363089 or XL880), which is an oral multikinase inhibitor developed to primarily target the hepatocyte growth factor (HGF)/Met signaling pathway, has shown anti-tumor effects against some cancers in preclinical and clinical studies. Results: HGF/Met signaling in endometrial cancer cell lines was stimulated in an autocrine manner, and was essential for cell survival. Inhibiting the HGF/Met signaling with foretinib induced p53-dependent apoptosis in endometrial cancer cell lines in vitro . Foretinib also showed significant anti-cancer effects in vivo in experiments using cell tumor xenografts. p53 mutations were observed in 37 (10.8%) of 344 endometrial cancer specimens. Conclusion: The HGF/Met-MAPK/PI3K pathway in endometrial cancer is activated by HGF in an autocrine manner. Foretinib induces an anti-cancer effect through the anti-phosphorylation of Met, which results in the induction of p53-dependent apoptosis; foretinib was found to exert greater anti-cancer activity in endometrial cancer specimens with wild-type p53 than in specimens with p53 mutations. Our immunochemical analysis revealed that foretinib-induced p53-dependent apoptosis can be expected to have therapeutic potential in approximately 90% of endometrial cancer patients. Methods: We evaluated the HGF/Met signaling pathway in endometrial cancer cell lines and assessed the anti-cancer effects of foretinib using in vitro and in vivo experimental models. Furthermore, endometrial cancer specimens were subjected to an immunohistochemical analysis.

// Nobuhiro Saito 1, 2 , Yoshihiro Shirai 1, 2, * , Tadashi Uwagawa 1, 3 , Takashi Horiuchi 1, 2 , Hiroshi Sugano 1, 2 , Koichiro Haruki 1 , Hiroaki Shiba 1 , Toya Ohashi 2 and Katsuhiko Yanaga 1 1 Department of Surgery, The Jikei University School of Medicine, Tokyo, Japan 2 Division of Gene Therapy, Research Center for Medical Science, The Jikei University School of Medicine, Tokyo, Japan 3 Division of Clinical Oncology and Hematology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan * This author contributed equally to this work Correspondence to: Nobuhiro Saito, email: h24dr-saito@jikei.ac.jp Keywords: IMiDs; pancreatic cancer; gemcitabine/nab-paclitaxel; NF-κB; p53 Received: December 29, 2017 Accepted: February 25, 2018 Epub: March 02, 2018 Published: March 20, 2018 ABSTRACT Background: Chemotherapy with gemcitabine and nab-paclitaxel (gemcitabine/nab-paclitaxel) is recommended for unresectable pancreatic cancer. However, the therapeutic efficacy is attenuated by the antitumor agent-induced activation of nuclear factor-κB (NF-κB). Thalidomide inhibits NF-κB activation, therefore, we hypothesized that pomalidomide, a third-generation IMiD, would also inhibit NF-κB activation and enhance the antitumor effects of gemcitabine/nab-paclitaxel. Methods: In vitro , we assessed NF-κB activity and apoptosis in response to pomalidomide alone, gemcitabine/nab-paclitaxel, or combination of pomalidomide and gemcitabine/nab-paclitaxel in human pancreatic cancer cell lines (PANC-1 and MIA PaCa-2). In vivo , we established orthotopic model and the animals were treated with oral pomalidomide and injection of gemcitabine/nab-paclitaxel. Results: In pomalidomide and gemcitabine/nab-paclitaxel group, gemcitabine/nab-paclitaxel-induced NF-κB activation was inhibited and apoptosis was enhanced in comparison with those in the other groups both in vitro and in vivo . Especially, this study revealed for the first time that pomalidomide enhances p53 on pancreatic cancer cells. The tumor growth in the pomalidomide and gemcitabine/nab-paclitaxel group was significantly slower than that in the gemcitabine/nab-paclitaxel group. Moreover, pomalidomide induced G0/G1 cell cycle arrest and suppressed angiogenesis. Conclusions: Pomalidomide enhanced the antitumor effect of gemcitabine/nab-paclitaxel by inhibition of NF-κB activation. This combination regimen would be a novel strategy for treating pancreatic cancer.

// Toshimichi Tanaka 1 , Masahiko Watanabe 1 and Keishi Yamashita 1, 2 1 Department of Surgery, Kitasato University School of Medicine, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan 2 Division of Advanced Surgical Oncology, Department of Research and Development Center for New Medical Frontiers, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan Correspondence to: Keishi Yamashita, email: keishi23@med.kitasato-u.ac.jp Keywords: p53; mutation; gain of function; non-canonical function; carcinogenesis Received: February 10, 2017 Accepted: February 10, 2018 Published: March 23, 2018 ABSTRACT In normal tissue, p53 protein has a wide range of functions involving cell homeostasis; its mutation, however, permits a carcinogenic acquisition of function. TP53 gene mutation is a major genomic aberration in various human cancers and is a critical event in the multi-step carcinogenesis process. TP53 mutation is clinically relevant for the molecular classification of carcinogenesis, as most recently described rigorously by the Cancer Genome Atlas Research Network. TP53 gene mutation has been considered to work as a tumor suppressor gene through the loss of its transcriptional activity, which is designated as a canonical function. However, in cancer patients with mutant TP53 , mutated p53 protein is frequently overexpressed, suggesting the activation of an oncogenic process through a gain of function (GOF). As part of this GOF, molecular mechanisms explaining the non-canonical function of TP53 gene abnormality have been reported, in which mutant p53 unconventionally binds with various critical molecules suppressing oncogenic properties, such as p63 and p73. Moreover, mutant TP53 gene-targeted therapy has been rigorously developed, and promising clinical trials have been started. In this study, we summarize the novel aspects of mutant p53 and describe its prominent therapeutic potentials in human cancer.

Ovarian cancer (OC) has the highest rate of mortality among gynecological malignancy. Chemokine receptor CXCR2 in OC is associated with poor outcomes. However, the mechanisms by which CXCR2 regulates OC proliferation remain poorly understood. We generated CXCR2-positive cells from parental p53 wild-type (WT), mutant and null OC cells, and assessed the roles of CXCR2 on proliferation of OC cells in p53-dependent and independent manner. CXCR2 promoted cell growth rate: p53WT > mutant = null cells. Nutlin-3, a p53 stabilizer, inhibited cell proliferation in p53WT cells, but had little effect in p53-mutant or null cells, indicating p53-dependence of CXCR2-mediated proliferation. CXCR2 decreased p53 protein, a regulator of p21, and downregulated p21 promoter activity only in p53WT cells. The p53 responsive element (RE) of p21 promoter played a critical role in this CXCR2-mediated p21 downregulation. Moreover, CXCR2-positive cells activated more Akt than CXCR2-negative cells followed by enhanced murine double minute (Mdm2). Silencing Mdm2 or Akt1 upregulated p21 expression, whereas Akt1 overexpression downregulated p21 at the promoter and protein levels in p53WT cells. Cell cycle analysis revealed that CXCR2 decreased p21 gene in p53-null cells. Interestingly, romidepsin (histone deacetylase inhibitor)-induced p21 upregulation did not involve the p53 RE in the p21 promoter in p53-null cells. Romidepsin decreased the protein levels of Akt1 and Mdm2, leading to induction of p21 in p53-null cells. CXCR2 reduced romidepsin-induced p21 upregulation by activating Akt-induced Mdm2. Taken together, CXCR2 enhances cell proliferation by suppressing p21 through Akt-Mdm2 signaling in p53-dependent and independent manner.

// Ning Kon 1,* , Donglai Wang 1,* , Tongyuan Li 1 , Le Jiang 1 , Li Qiang 2,3,** and Wei Gu 1,3 1 Institute for Cancer Genetics, College of Physicians and Surgeons of Columbia University, New York, New York, USA 2 Naomi Berrie Diabetes Center, Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, New York, USA 3 Department of Pathology and Cell Biology, College of Physicians and Surgeons of Columbia University, New York, New York, USA * These two authors contributed equally to this work ** This author is listed as a co-corresponding author Correspondence to: Wei Gu, email: // Keywords : p53; Mdmx; Mdm4; metabolism; adipose tissues Received : September 26, 2017 Accepted : December 08, 2017 Published : January 02, 2018 Abstract Although cell-cycle arrest, senescence and apoptosis remain as major canonical activities of p53 in tumor suppression, the emerging role of p53 in metabolism has been a topic of great interest. Nevertheless, it is not completely understood how p53-mediated metabolic activities are regulated in vivo and whether this part of the activities has an independent role beyond tumor suppression. Mdmx (also called Mdm4), like Mdm2, acts as a major suppressor of p53 but the embryonic lethality of mdmx-null mice creates difficulties to evaluate its physiological significance in metabolism. Here, we report that the embryonic lethality caused by the deficiency of mdmx , in contrast to the case for mdm2 , is fully rescued in the background of p53 3KR/3KR , an acetylation-defective mutant unable to induce cell-cycle arrest, senescence and apoptosis. p53 3KR/3KR /mdmx -/- mice are healthy but skinny without obvious developmental defects. p53 3KR/3KR /mdmx -/- mice are resistant to fat accumulation in adipose tissues upon high fat diet. Notably, the levels of p53 protein are only slightly increased and can be further induced upon DNA damage in p53 3KR/3KR /mdmx -/- mice, suggesting that Mdmx is only partially required for p53 degradation in vivo . Further analyses indicate that the anti-obesity phenotypes in p53 3KR/3KR /mdmx -/- mice are caused by activation of lipid oxidation and thermogenic programs in adipose tissues. These results demonstrate the specific effects of the p53/Mdmx axis in lipid metabolism and adipose tissue remodeling and reveal a surprising role of Mdmx inhibition in anti-obesity effects beyond, commonly expected, tumor suppression. Thus, our study has significant implications regarding Mdmx inhibitors in the treatment of obesity related diseases.

In the present study, we examined the activity of p53 protein in Jurkat cells treated with high mobility group box-1 protein (HMGB1), thereafter we investigated the mechanism of extracellular HMGB1 mediated p53 expression in immune dysfunction of T lymphocytes. mRNA expression of p53, mdm2, and p21 was determined by Real-time reverse transcription-polymerase chain reaction(RT-PCR). The apoptotic rate of Jurkat cells was analyzed by flow cytometry. Expressions of bcl-2, bax, caspase-3, phosphorylated (p) extracellular signal-regulated kinase (ERK)1/2, ERK1/2, p-p38 mitogen-activated protein kinase (MAPK), p38 MAPK, and p-c-jun amino-terminal kinase (JNK)1/2 and JNK1/2 were simultaneously determined by Western blotting. After treatment with HMGB1 (100 ng/ml or 1000 ng/ml), the proliferative activity of Jurkat cells was significantly decreased, and a low and medium concentration of HMGB1 induced an up-regulation of p53 mRNA, p-p53 and p53 protein expression. Meanwhile, levels of mdm2 and p21 were elevated by incubated with HMGB1 (100 ng/ml) for 24 or 48 hours. Moreover, the proliferation of Jurkat cells in response to HMGB1 (100 ng/ml) in the vector group was significantly depressed. The bax and caspase-3 levels in p53 shRNA-expressed cells treated with HMGB1 (100 ng/ml) was markedly decreased, whereas expression of bcl-2 was obviously enhanced. Among ERK1/2, p38 MAPK and JNK1/2 signaling, only p38 MAPK pathway could be significantly activated by treatment with HMGB1, and the specific inhibitor of p38 MAPK was used, p53 and p-p53 expression induced by HMGB1 were significantly down-regulated. Taken together, our data strongly indicated that HMGB1 might enhance p53 expression, which was associated with both the proliferative activity as well as apoptosis of T cells.

// De-Hua Wei 1 , Yan Wang 1 and Hui-Rong Shi 2 1 Department of Gynecology, Puyang People's Hospital Affiliated to Xinxiang Medical University, Henan 457000, China 2 Department of Gynecology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China Correspondence to: De-Hua Wei, email: weidh_dh@21cn.com Keywords: ovarian cancer; metformin; p53; D-loop region; chemosensitivity Received: July 05, 2017 Accepted: November 03, 2017 Published: December 02, 2017 ABSTRACT Objective: This study aims to investigate the association of p53 and D-loop gene with drug resistance and sensitization induced by metformin in ovarian cancer. Results: Metformin suppresses cells in a time-dependent manner, but the inhibition does not change with the dose of metformin. This suggests that within a certain range of concentration in the body, metformin has a constant inhibitory effect on cells; and the long-term use of metformin yields a better effect. Conclusions: Metformin enhances the sensitivity of drug-resistant ovarian cancer cells to chemotherapy. Methods: The third passage cells of 17 cancerous ovarian tissues, which were successfully passaged five times, were used as the study objects; and the SKOV3 cell line was used as the positive control. After three adaptations, cells were cultured for 72 hours in an orthogonal experiment using drugs that were used for adaptation. Then, the inhibitory rate on cells in the experimental group was observed by CCK8 assay, in order to study the sensitization effect of metformin in different chemotherapies of ovarian cancer.

// Guanxiong Ding 1, 2, * , Shenghua Liu 1, 2, * , Qiang Ding 1, 2 and Chenchen Feng 1, 2 1 Department of Urology, Huashan Hospital, Fudan University, Shanghai 200040, PR China 2 Fudan Institute of Urology, Fudan University, Shanghai 200040, PR China * These authors contributed equally to this work Correspondence to: Chenchen Feng, email: drfengchenchen@163.com Keywords: adrenocortical carcinoma; HSD17B4; tumor suppressor; p53 Received: January 25, 2017 Accepted: November 07, 2017 Published: December 01, 2017 ABSTRACT Aim: Adrenocortical carcinoma (ACC) is characterized with excessive hormone production. We therefore investigated expression of hormone-related genes in ACC. Results: We queried status of 14 key genes directly involved in adrenal hormone production and found HSD17B4 expression was upregulated in 39% of ACC cases on top of all queried genes. Overexpression of HSD17B4 was significantly associate with a normo-hormonal phenotype. Constitutive HSD17B4 expression was higher in ACC cell line NCI-H295R than in adrenocortical small cell carcinoma cell line SW13. NCI-H295R cells with HSD17B4-knockdown (KD) demonstrated significantly inhibited proliferation, increased apoptosis, and increased cell cycle arrest. Enrichment analysis for mRNA expression in ACC samples with or without HSD17B4 overexpression showed significant change in p53 pathway. Replenish of HSD17B4 in SW13 cells and knockdown of HSD17B4 in H295R cells confirmed alterations in MDM4, ATR, and IE24 with alterations more contrasting in H295R cells. HSD17B4-KD inhibited cell invasion, migration and anchorage independent growth of NCI-H295R cells, but not of SW13 cells. Materials and Methods: Clinical and genetic data of ACC samples were reproduced from the ACC dataset of The Cancer Genome Atlas (TCGA) database using cBioPortal. Genes participating in adrenal hormone production were queried. Association between gene status and hormone release were studied and in vitro assays using RNA interference were carried out. Conclusions: Overexpression of HSD17B4 exerted tumor suppressive function in adrenocortical carcinoma and was not related to hormone excess. Crosstalk between HSD17B4 and p53 warrants further investigation.

Castration-resistant prostate cancer (CRPC) frequently develops after initial standard radiation and androgen deprivation therapy, leaving patients with limited further treatment options. Androgen receptor (AR) is a transcription factor that plays a key role in the initiation and progression of prostate cancer. p53, a major tumor suppressor that is rarely mutated in early-stages of prostate cancer, is often deregulated during prostate cancer progression. Here, we report an unusual co-amplification of MDM2 and MDMX, two crucial negative regulators of p53, in CRPC datasets. We demonstrate that combinatorial inhibition of MDM2 and MDMX, with nutlin-3 and NSC207895 respectively, has a profound inhibitory effect on cell proliferation of androgen-responsive, wild-type TP53 gene carrying prostate cancer cells LNCaP and 22Rv1. We further show that the combinatorial inhibition of MDM2 and MDMX not only activates p53, but also decreases cellular levels of AR and represses its function. Additionally, co-expression of MDM2 and MDMX stabilizes AR. Together, our results indicate that combinatorial inhibition of MDM2 and MDMX may offer a novel compelling strategy for prostate cancer therapy.

Cervical cancer, the third most commonly occurring cancer, is the second leading cause of cancer related mortality among women. Aberrant ubiquitination and proteasome activity, both human papillomavirus and tumor derived, have been shown to contribute to tumor angiogenesis, proliferation, and invasion in many cancers, including cervical cancer. Thus, small molecule proteasome inhibitors are a potential and strategic treatment option for cervical cancer. In this study, novel proteasome inhibitor delanzomib (CEP-18770) exhibited potent pro-apoptotic and cytotoxic effects on a panel of cervical cancer cell lines by blocking proteasomal activity. Delanzomib also significantly sensitized cervical cancer cells to treatment of doxorubicin (Dox), a traditional chemotherapeutic agent. Furthermore, proteasome inhibition revealed stabilization of p53 and p53 transcriptional targets and induction of p38/JNK phosphorylation. Additionally, delanzomib worked synergistically with Dox to further upregulate p53 and its downstream targets and enhanced Dox-induced p38 phosphorylation. Our study strongly supports the 26S proteasome as a potential therapeutic target in cervical cancer and proteasome inhibition by delanzomib may be a potential treatment strategy for cervical cancer patients.

Twist1 is a master regulator of epithelial mesenchymal transition and carcinoma metastasis. Twist1 has also been associated with increased malignancy of human glioma. However, the impact of inhibiting Twist1 on tumorigenicity has not been characterized in glioma models in the context of different oncogenic transformation paradigms. Here we used an orthotopic mouse glioma model of transplanted transformed neural progenitor cells (NPCs) to demonstrate the effects of Twist1 loss of function on tumorigenicity. Decreased tumorigenicity was observed after shRNA mediated Twist knockdown in HPV E6/7 Ha-RasV12 transformed NPCs and Cre mediated Twist1 deletion in Twist1 fl/fl NPCs transformed by p53 knockdown and Ha-RasV12 expression. By contrast, Twist1 deletion had no effect on tumorigenicity of NPCs transformed by co-expression of Akt and Ha-RasV12. We demonstrated a dramatic off-target effect of Twist1 deletion with constitutive Cre expression, which was completely reversed when Twist1 deletion was achieved by transient administration of recombinant Cre protein. Together these findings demonstrate that the function of Twist1 in these models is highly dependent on specific oncogenic contexts of NPC transformation. Therefore, the driver mutational context in which Twist1 functions may need to be taken into account when evaluating mechanisms of action and developing therapeutic approaches to target Twist1 in human gliomas.

// Yan Shu 1 , Ligang Ren 1 , Bo Xie 1 , Zhen Liang 2 and Jing Chen 1 1 Department of Urology, Tongde Hospital of Zhejiang Province, Hangzhou 310012, China 2 Department of Urology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China Correspondence to: Jing Chen, email: tdjingchen@163.com Keywords: prostate cancer, doxorubicin, miR-204, SIRT1, p53 Received: August 09, 2017 Accepted: September 24, 2017 Published: October 23, 2017 ABSTRACT Chemotherapy is important for adjuvant treatment of prostate cancer. However, some cancer cells exhibited low sensitivity to chemotherapeutic agents. We are supposed to sensitize these prostate cancer cells to chemotherapeutic agents such as doxorubicin. Previous reports have suggested that microRNAs (miRNAs) regulate chemosensitivity in various cancers. In the present study, we observed that expression level of miR-204 was decreased in prostate cancer cell lines and patients’ tumors. Furthermore, we found that restore of miR-204 dramatically enhanced the cytotoxicity of doxorubicin (DOX) against prostate cancer cell lines C4-2 and LNCaP carrying wild type (WT) p53. Mechanically, miR-204 in prostate cancer cells targets SIRT1 which is a histone deacetylase, and thus decreasing deacetylation of p53. As the results, acetylated p53 induced by DOX upregulates the expression of Noxa and Puma followed by induction of mitochondrial apoptosis. These data demonstrate that restore of miR-204 in prostate cancer cells enhances the mitochondrial apoptosis induced by doxorubicin by targeting the SIRT1/p53 pathway.

// Zhun Wang 1 , Shuanghe Peng 1 , Ning Jiang 1 , Aixiang Wang 1 , Shuguang Liu 1 , Hui Xie 1 , Linpei Guo 1 , Qiliang Cai 1 and Yuanjie Niu 1 1 Departments of Urology, Tianjin Institute of Urology, The second Hospital of Tianjin Medical University, Tianjin, 300211, China Correspondence to: Yuanjie Niu, email: yuanjieniu2014@163.com Keywords: renal cell carcinoma, p53, prognosis, meta-analysis Received: May 04, 2017 Accepted: September 21, 2017 Published: October 19, 2017 ABSTRACT Background: The prognostic value of p53 expression in renal cell carcinoma (RCC) had been investigated in previous studies; however, the results remain inconsistent. This study was performed to investigate the prognostic and clinicopathological significance of p53 protein expression in RCC. Materials and Methods: Literature was identified from PubMed, Embase, Web of Science, and Cochrane database, which investigated the relationships between p53 expression and outcomes. Hazard ratios (HRs) for survival outcomes and odds ratios (ORs) for clinical parameters associated with p53 were extracted from eligible studies. Heterogeneity was assessed using the I2 value. The fixed-effects model was used if there was no evidence of heterogeneity; otherwise, the random-effects model was used. Publication bias was evaluated using Begg's funnel plots and Egger's regression test. Results: A total of 2,013 patients from 22 studies were included in the meta-analysis. The results showed that p53 positive expression is associated with poor overall survival (OS) (HR = 2.17, 95% confidence [CI]: 1.51–3.13) and cancer-specific survival (CSS) (HR = 1.59, 95% CI: 1.19–2.12) in RCC. In addition, p53 positive expression was closely correlated with TNM stage (III/IV vs. I/II: OR = 2.51, 95% CI: 1.05–6.00), Fuhrman grade (III/IV vs. I/II: OR = 1.80, 95% CI: 1.24–2.63), and distant metastasis (M1 vs. M0: OR = 1.70, 95% CI: 1.16–2.49), but not related to lymph node involvement (N1 vs. N0: OR = 1.32, 95% CI: 0.80–2.18), primary tumor stage (pT3/pT4 vs. pT1/pT2: OR = 1.16, 95% CI: 0.88–1.53), and sex ( n = 2, male vs. female, OR = 1.09, 95% CI: 0.70–1.68). Conclusions: This study suggests that p53 positive expression is correlated with poor prognosis and advanced clinicopathological features in patients with RCC, which indicates that p53 is a potentially effective therapeutic target.

// Bo Cao 1 , Ziling Fang 1,2 , Peng Liao 1 , Xiang Zhou 1,3 , Jianping Xiong 2 , Shelya Zeng 1 and Hua Lu 1 1 Department of Biochemistry & Molecular Biology, Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA, USA 2 The First Affiliated Hospital of Nanchang University, Nanchang, People’s Republic of China 3 Fudan University Shanghai Cancer Center and the Institutes of Biomedical Sciences, Fudan University, Shanghai, People’s Republic of China Correspondence to: Hua Lu, email: // Keywords : RPL22/eL22, p53, MDM2, RPL11/uL5, RPL5/uL18 Received : July 25, 2017 Accepted : September 08, 2017 Published : October 06, 2017 Abstract Several ribosomal proteins (RPs) in response to various ribosomal stressors have been shown to play a critical role in p53-dependent regulation of cell cycle arrest, apoptosis and tumor suppression. Here, we report ribosomal protein L22 (RPL22/eL22) as a novel p53 activator highly mutated (mostly deletion mutation) in various types of human cancers, but not essential for ribosomal biogenesis in normal cells. Ectopic expression of RPL22/eL22 suppressed the colony formation of cancer cells in a p53-dependent manner, whereas knockdown of RPL22/eL22 significantly compromised p53 activation by Actinomycin D, rescuing p53-induced G1/G0 cell cycle arrest. Interestingly, human tumors with RPL22/eL22 deletion appeared to sustain wild type p53. Mechanistically, RPL22/eL22 bound to MDM2 acidic domain and inhibited MDM2-mediated p53 ubiquitination and degradation, hence extending the half-life of p53. Ribosome-profiling analysis revealed that induction of ribosomal stress by Actinomycin D leads to the increase of ribosome-free RPL22/eL22 pool. Also, RPL22/eL22 formed a complex with MDM2/RPL5/uL18/RPL11/uL5 and synergized with RPL11/uL5 to activate p53. Furthermore, the N terminus of RPL22/eL22 bound to MDM2, while the C terminus interacted with RPL5/uL18/RPL11/uL5; both of these two fragments activated p53 by inhibiting MDM2. Our study indicates that RPL22/eL22 highly mutated in human cancers plays an anti-cancer role likely through regulation of the MDM2-p53 feedback loop, and also suggests that targeting the RPL22/eL22-MDM2-p53 pathway could be a potential strategy for future development of anti-cancer therapy.

// Hsuan-Wen Chiu 1 , Yu-Chin Su 1 and Jiann-Ruey Hong 1, 2 1 Department of Biotechnology and Bioindustry, Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan 2 Department of Biotechnology and Bioindustry, National Cheng Kung University, Tainan 701, Taiwan Correspondence to: Jiann-Ruey Hong, email: jrhong@mail.ncku.edu.tw Keywords: B2 protein, cell death, p53, autophagy, lung cancer cell Received: July 27, 2017 Accepted: September 21, 2017 Published: October 06, 2017 ABSTRACT The betanodavirus B2 protein targets the mitochondria and acts as a “death factor”, but its effect on lung cancer cells is unknown. We examined the effect of the B2 protein on triggering apoptosis or necroptosis via P53-dependent and P53-independent pathways and increased in suppression of autophagy. The B2 protein targets the mitochondria of A549 (P53 +/+ ) and H1299 (P53 —/— ) lung cancer cells due to a specific signal sequence ( 41 RTFVISAHAA 50 ). This triggers generation of reactive oxygen species within the mitochondria, and a minor stress response in A549 cells, but a strong stress response in H1299 cells. We examined the molecular mechanism of this cell death pathway, and found that B2 protein induces the P53/Bax-mediated apoptotic pathway in A549 cells, and that a P53 specific inhibitor (pifithrin-α) switches this response to RIP3-mediated necroptosis. On the other hand, B2 induces RIP3-mediated necroptosis pathway in H1299 cells, and a necroptosis inhibitor (necrostatin-1) switches this response to the apoptotic pathway. Both types of cell death signals inhibited autophagy via a tightly increased balance of beclin-1 and Bcl-2. Thus, B2 protein triggers P53-dependent apoptosis in A549 cells and ROS/RIP3-mediated necroptosis in H1299 cells, and crosstalk of these pathways limits initiation of autophagy. These findings provide new insights into the possible control and treatment of lung cancer.

Caffeine, theophylline, and theobromine are the most well-known members of methylxanthines. Caffeine-induced serine/arginine-rich splicing factor 2, SRSF2, and SRSF3 are required for the alternative splicing of a subset of cancer-associated genes. However, it remains to be investigated whether and how theophylline and theobromine as well as caffeine exert their antitumor effects through mediating the alternative splicing process. Here, we reveal that theophylline down-regulated SRSF3 expression and switched p53 from alpha into a beta isoform as caffeine did in HeLa and MCF-7 cells via the reverse-transcriptase polymerase chain reaction and Western blot analysis. Further functional studies show that theophylline induced cellular apoptosis, senescence, and decreased colony formation. Interestingly, theophylline had a suppressive effect on cellular proliferation, whereas caffeine enhanced cellular proliferation rates via the 5-bromo-2-deoxyuridine analysis. Theophylline and caffeine had no effect on MCF-10A cells, which is a normal breast cell line. Our results provide an insight that theophylline as well as caffeine could be repurposed as antitumor leading compounds via the downregulation of splicing factor SRSF3 and its target genes.

// Jiahui Du 1 , Peng Yang 1 , Fanhua Kong 2 and Haiyan Liu 3 1 Department of Thoracic Surgery, Linyi People’s Hospital, Linyi, Shandong 276000, China 2 Department of Thoracic Surgery, Taian City Central Hospital, Taian, Shandong 271000, China 3 Department of Nursing, Linyi People’s Hospital, Linyi 276000, China Correspondence to: Haiyan Liu, email: HaiyanLiulinyi123@163.com Keywords: lung cancer; translationally controlled tumor protein; apoptosis; P53 Abbreviations: lTCTP: translationally controlled tumor protein; ActD: actinomycin D; KD: knockdown Received: May 24, 2017 Accepted: July 29, 2017 Published: October 10, 2017 ABSTRACT Translationally controlled tumor protein (TCTP) is an evolutionally highly conserved protein which has been implicated as a biomarker for cancer cell reversion although the mechanism is not very clear. This makes it a potential target for cancer therapy. P53 tumor suppressor protein is important in regulating cell growth, it can induce either growth arrest or programmed cell death (apoptosis). TCTP and P53 has been reported that can regulate the protein level of each other. Here we proved that TCTP is a malignancy state keeper in lung cancer and lower level of TCTP protein made cells more sensitive to stressful condition. No obvious difference has been observed from wildtype and the TCTP knockdown lung cancer cells (A549) when located in the normal circumstances. While under the stressful condition, the existence of higher protein level of TCTP can protect cells from apoptosis. TCTP and P53 formed a feedback signal pathway and through it to regulate the downstream Akt signal pathways to make the lung cancer cells keep a higher metabolism level and protect cancer cells from apoptosis induced by outside stress.

// Jinyu Zheng 1, * , Enhui Cui 2, * , Haikou Yang 2 , Mao Li 2 , Jing Zhou 2 , Ming Yan 2 , Jian Sun 2 and De-Rong Tang 3 1 Department of Neurosurgery, The Affiliated Huai’an Hospital of Xuzhou Medical College, Huai’an, China 2 Department of Anesthesiology, Huai’an Maternity and Child Healthcare Hospital, Yangzhou University Medical School, Huai’an, China 3 Department of Thoracic Surgery, Huai’an First People’s Hospital, Nanjing Medical University, Huai’an, China * Co-first authors Correspondence to: Jian Sun, email: sunjianmzys@163.com De-Rong Tang, email: tangderonglw@163.com Keywords: oxygen glucose deprivation/re-oxygenation, cyclophilin-D, compound 19, programmed necrosis, P53 Received: July 25, 2017 Accepted: August 28, 2017 Published: October 06, 2017 ABSTRACT Oxygen and glucose deprivation (OGD) with re-oxygenation (OGDR) is applied to neuronal cells to mimic ischemia-reperfusion injuries. Activation of cyclophilin D (Cyp-D)-dependent programmed necrosis pathway mediates OGDR-induced neuronal cell damages. Here, we tested the potential effect of Compound 19 (C19), a novel Cyp-D inhibitor, in this process. In both established neuronal cell lines (Neuro-2a and NB41A3 cells) and the primary murine CA1 hippocampal neurons, pretreatment with C19 largely attenuated OGDR-induced cell viability reduction and cell death. Significantly, C19 was ineffective in Cyp-D-silenced Neuro-2a cells. OGDR induced mitochondria-dependent programmed necrosis in neuronal cells. OGDR induced p53 translocation to mitochondria and association with Cyp-D, causing mitochondrial depolarization, cytochrome C release and reactive oxygen species production. Such effects were largely attenuated with pre-treatment of C19. Importantly, C19 was significantly more efficient than other known Cyp-D inhibitors in protecting neuronal cells from OGDR. These results suggest that targeting Cyp-D by C19 protects neuronal cells from OGDR.

Cisplatin (cis-Diamminedichloroplatinum II) has been widely and effectively used in chemotherapy against tumors. Nephrotoxicity due to cisplatin is one of the most common clinical causes of acute kidney injury (AKI), which has a poor prognosis and high mortality. The signaling mechanisms underlying cisplatin-induced AKI are not completely understood. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a tumor suppressor that negatively regulates the cell-survival pathway and is considered a double-edged sword in organ damage. In this study, we examined the effect that inhibiting PTEN activity in experimental models of cisplatin-induced AKI had on the degrees of AKI. Compared with vehicle mice, mice treated with bpV(pic) (specific inhibitor of PTEN) had exacerbated renal damage due to cisplatin-induced AKI. Furthermore, inhibition of PTEN activity increased cell apoptosis in the kidneys of mice induced by cisplatin. More inflammatory cytokines were activated after cisplatin treatment in mice of the bpV(pic)-treated group compared with vehicle mice, and these inflammatory cytokines may be partially derived from bone marrow cells. In addition, inhibiting PTEN activity decreased the phosphorylation of p53 in the pathogenesis of cisplatin-induced AKI. In summary, our study has demonstrated that inhibiting PTEN activity aggravates cisplatin-induced AKI via apoptosis, inflammatory reaction, and p53 signaling pathway. These results indicated that PTEN may serve as a novel therapeutic target for cisplatin-induced AKI.

// A-Rum Yoon 1 , JinWoo Hong 1 and Chae-Ok Yun 1 1 Department of Bioengineering, College of Engineering, Hanyang University, Seongdong-gu, Seoul 04763, Korea Correspondence to: Chae-Ok Yun, email: chaeok@hanyang.ac.kr Keywords: oncolytic adenovirus, decorin, p53, mitochondrial apoptosis Received: January 17, 2017 Accepted: August 23, 2017 Published: September 08, 2017 ABSTRACT Decorin (DCN) is a small leucine-rich proteoglycan that plays an important role in the regulation of apoptosis, proliferation, intercellular contact, and cell migration. Here we have investigated the detailed mechanism of apoptotic cell death induced by DCN expression. A marked increase in cytotoxicity was observed for both DCN-expressing replication-incompetent (dE1/DCN) and -competent (dB/DCN) adenoviruses (Ads) compared to the corresponding control Ads. FACS and TUNEL assays revealed that the expression of DCN induced apoptotic cell death. Specifically, the expression and stability of p53 were increased by DCN. In addition, western blot data showed that DCN expression activated mitochondrial apoptosis by increasing the expression level of p53. Similarly, DCN-expressing oncolytic Ads induced a greater antitumor effect in a murine xenograft model compared with control Ads. Tissue staining and western blot data from in vivo experiments demonstrated significantly higher levels of apoptosis in tumor tissues from mice treated with DCN-expressing Ads compared to those treated with control Ads. Collectively, these data support that cell killing effect is enhanced with Ad-mediated DCN expression via the induction of p53-mediated mitochondrial apoptosis, which could be a valuable benefit for antitumor efficacy.

// Venkat R. Katkoori 1 , Upender Manne 2 , Lakshmi S. Chaturvedi 3 , Marc D. Basson 3 , Pam Haan 1 , Daniel Coffey 4 and Harvey L. Bumpers 1 1 Department of Surgery, Michigan State University, College of Human Medicine, Lansing, MI, USA 2 Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA 3 Department of Surgery, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, ND, USA 4 Capital Colorectal Surgery, Lansing, MI, USA Correspondence to: Harvey L. Bumpers, email: harvey.bumpers@hc.msu.edu Keywords: p53, codon 72 polymorphism, p38MAPK, EMT, CREB Received: May 23, 2017 Accepted: August 16, 2017 Published: August 29, 2017 ABSTRACT Background: The codon 72 polymorphism in p53 has been implicated in colorectal cancer (CRC) risk, prognosis and CRC health disparities. We examined the functional consequence of this polymorphism in CRC. Experimental Design: Plasmids (pCMV6) that express different phenotypes of p53 [p53 wild type (wt) at codon 72 (R72 wt ), R72 wt with mutation at codon 273 cysteine (R72 273Cys ), p53 mutation at codon 72 (P72 wt ) and P72 wt with mutation at codon 273 (P72 273Cys )] were constructed. The CRC cell line Caco2, which does not express p53 for in vitro studies, was used as host. CRC xenografts were established in severe combined immunodeficient (SCID) mice using established cell lines. CRC surgical specimens, corresponding normal colon, and tumor xenografts were sequenced for codon 72 polymorphism of p53. Proteins signaling mechanisms were evaluated to assess the functional consequence of P72 phenotype of p53. Results: This study demonstrated a significantly increased survival of cells expressing P72 wt , mutant phenotype, versus R72 wt phenotype. WB analyses revealed that P72 wt induced activation of p38 and RAF/MEK/ extracellular signal-regulated kinase (ERK) MAP kinases. Activation of CREB was found to be higher in tumors that exhibit P72 phenotype. Metastatic lesions of CRC expressed more phospho-CREB than non-metastatic lesions. The expression of P72 wt promoted CRC metastasis. Conclusions: P72 contributes to the aggressiveness of CRC. Because P72 is over-expressed in CRC, specifically in African-American patients, this suggests a role for P72 in cancer health disparities. This work was supported by NIH/NCI Workforce Diversity Grant R21-CA171251 & U54CA118948.

// Toshihiro Uchihashi 1, * , Kaori Ota 2, * , Yusuke Yabuno 1, * , Shouichi Ohno 2 , Kohshiro Fukushima 2 , Yoko Naito 2 , Mikihiko Kogo 1 , Norikazu Yabuta 2, ** and Hiroshi Nojima 2 1 First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University, Osaka 565-0871, Japan 2 Department of Molecular Genetics, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan * These authors have contributed equally to this work ** Corresponding author for cell biological experiments Correspondence to: Norikazu Yabuta, email: nyabuta@biken.osaka-u.ac.jp Hiroshi Nojima, email: snj-0212@biken.osaka-u.ac.jp Keywords: cyclin G1, p53, DU145, SAS, adenovirus Received: December 14, 2016 Accepted: May 03, 2017 Published: August 24, 2017 ABSTRACT We previously reported that an ELAS1 peptide containing 29 amino acids induces apoptotic death in U2OS human osteosarcoma cells following DNA double-strand break insults. Here, we show that ELAS1 also caused apoptosis in prostate adenocarcinoma DU145 cells and tongue squamous-cell carcinoma SAS cells. ELAS1 appears to be safe because it induced apoptosis only in cancer cells, not in normal KD cells. Because the effect of ELAS1 is dependent on increased stability of p53 and enhanced phosphorylation of p53-S46, we exogenously expressed wild-type p53 protein to fully promote ELAS1-mediated induction of apoptosis in SAS cells. Interestingly, simultaneous expression of Myc-ELAS1 and FLAG-p53 mediated by an internal ribosome entry site efficiently induced apoptosis in SAS cells. Moreover, we prepared a recombinant adenovirus that simultaneously expressed Myc-ELAS1 and FLAG-p53. This adenovirus also killed SAS cells, as determined by a cell viability assay, in the presence of camptothecin, an inducer of DNA double-strand breaks. Moreover, nude mice harboring Myc-ELAS1-expressing SAS cells lived longer than mice harboring Myc-vector-expressing SAS cells, suggesting the usefulness of ELAS1 in vivo . Notably, Cy5-tagged ELAS1-t, which contained only ten amino acids, also efficiently induced apoptosis in both DU145 and SAS cells, suggesting the usefulness of ELAS1-t as a peptide. Taken together, our results suggest that ELAS1 is therapeutically useful as a peptide drug.

// Jianxin Diao 1,* , Haiye Li 1,* , Wei Huang 1,* , Wenxiao Ma 2 , Huan Dai 1 , Yawei Liu 3 , Ming Wang 4 , He Yu Hua 1 , Jinying Ou 1 , Xiaomin Sun 1 , Xuegang Sun 1 and Yungao Yang 1 1 School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China 2 Gao Ming People’s Hospital, Foshan, Guangdong, China 3 Nanfang Hospital, Southern Medical University, Guangdong,Guangzhou, China 4 Zhujiang Hospital of Southern Medical University, Guangdong, Guangzhou, China * These authors have contributed equally to this work Correspondence to: Yungao Yang, email: // Xuegang Sun, email: // Xiaomin Sun, email: // Keywords : San huang yin chi decoction, acute on chronic liver failure, APE1/Ref-1, apoptosis, p53, Pathology Section Received : November 15, 2016 Accepted : January 24, 2017 Published :August 04, 2017 Abstract Background & Aims: San huang yin chi decoction(SHYCD) is derived from the yin chen hao decoction, a well-known and canonical Chinese medicine formula from the “Treatise on Febrile Diseases”. Over the past decade, SHYCD has been used to treat and prevent the liver cirrhosis and liver failure. In the present study, we investigated the effects of SHYCD for acute on chronic liver failure(ACLF) and explored its potential mechanism. an ACLF rat model, which induced by carbon tetrachloride (CCl4) combined with D-galactosamine (D-GalN) and lipopolysaccharide(LPS), was used and confirmed by B-ultrasound analysis. Rats were randomly divided into control group, model group, SHYCD-H group, SHYCD-M group, SHYCD-L group, AGNHW group. Compared with the ACLF model group, High, medium, and low doses of SHYCD reduced ALT, AST, TBIL, NH3, IL-1β, IL-6, and TNFα expression levels in the serum, Shorten PT and INR time,and increased Fbg content in the whole blood, increased survival rate of the rats, improved liver pathological changes. APE1 / Ref-1 was mainly expressed in the nucleus, but the nucleus and cytoplasm were co-expressed after hepatocyte injury. SHYCD significantly downregulated APE1/Ref-1 expression in the cytoplasm. Increased APE1/Ref-1, Bcl-2, reduced p53, caspase-3, Bax, and Cyt-c in the total protein. Base on the results, we conclused that High, medium, and low doses of SHYCD could be applied in prevention and treatment of ACLF, and dose-dependent. The possible mechanism is to promote the APE1 / Ref-1 from the cytoplasm to the nuclear transfer, regulation of p53 apoptosis signal pathway prevention and treatment of ACLF.

// Soichiro Takase 1, 2, * , Satoshi Kano 3, * , Yuichiro Tada 4, * , Daisuke Kawakita 5 , Tomotaka Shimura 2, 6 , Hideaki Hirai 2 , Kiyoaki Tsukahara 1 , Akira Shimizu 1 , Yorihisa Imanishi 7 , Hiroyuki Ozawa 7 , Kenji Okami 8 , Yuichiro Sato 9 , Yukiko Sato 10 , Chihiro Fushimi 4 , Takuro Okada 1 , Hiroki Sato 1 , Kuninori Otsuka 7 , Yoshihiro Watanabe 7 , Akihiro Sakai 8 , Koji Ebisumoto 8 , Takafumi Togashi 9 , Yushi Ueki 9 , Hisayuki Ota 9 , Toyoyuki Hanazawa 11 , Hideaki Chazono 11 , Robert Yoshiyuki Osamura 12 and Toshitaka Nagao 2 1 Department of Otolaryngology Head and Neck Surgery, Tokyo Medical University, Tokyo, Japan 2 Department of Anatomic Pathology, Tokyo Medical University, Tokyo, Japan 3 Department of Otolaryngology-Head and Neck Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan 4 Department of Head and Neck Oncology and Surgery, International University of Health and Welfare Mita Hospital, Tokyo, Japan 5 Department of Otolaryngology Head and Neck Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan 6 Department of Otorhinolaryngology, Showa University School of Medicine, Tokyo, Japan 7 Department of Otorhinolaryngology-Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan 8 Department of Otolaryngology Head and Neck Surgery, Tokai University School of Medicine, Isehara, Japan 9 Department of Head and Neck Surgery, Niigata Cancer Center Hospital, Niigata, Japan 10 Department of Pathology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan 11 Department of Otolaryngology, Head and Neck Surgery, Chiba University Graduate School of Medicine, Chiba, Japan 12 Diagnostic Pathology Center, International University of Health and Welfare Mita Hospital, Tokyo, Japan * These authors contributed equally to this work Correspondence to: Toshitaka Nagao, email: nagao-t@tokyo-med.ac.jp Keywords: salivary duct carcinoma, androgen receptor, p53, CK5/6, HER2 Received: June 22, 2017 Accepted: July 26, 2017 Published: August 02, 2017 ABSTRACT Salivary duct carcinoma (SDC) is an uncommon, aggressive malignant neoplasm histologically resembling high-grade mammary ductal carcinoma. SDC can arise de novo or ex pleomorphic adenoma. To clarify the correlation of biomarker immunoprofile with clinicopathological findings and clinical outcome of SDC, we conducted immunohistochemistry for EGFR, HER2, HER3, AR, CK5/6, p53, and Ki-67, along with HER2 fluorescence in situ hybridization in 151 SDCs. SDCs ex pleomorphic adenoma more commonly overexpressed EGFR, HER2, HER3, and Ki-67 than de novo SDCs ( P = 0.015, < 0.001, 0.045, and 0.02, respectively). In multivariate analysis, AR− and CK5/6+ were associated with shorter progression-free survival ( P = 0.027 and 0.004, respectively). Moreover, patients with p53-extreme negative/positive demonstrated poorer overall survival ( P = 0.007). On assessing the revised classification by the combination of biomarker expression, the percentages of each subtype were as follows: ‘apocrine A’ (AR+/HER2−/Ki-67-low) (24%), ‘apocrine B’ (AR+/HER2−/Ki-67-high) (18%), ‘apocrine HER2’ (AR+/HER2+) (35%), ‘HER2-enriched’ (AR−/HER2+) (12%), and ‘double negative’ (AR−/HER2−) (11%). ‘Double negative’ was further subclassified into ‘basal-like’ (EGFR and/or CK5/6+) (7%) and ‘unclassified’ (3%). Consequently, patients with ‘apocrine A’ showed a better progression-free survival than those with any other subtypes. Our revised immunoprofiling classification was valuable for predicting the survival and might be useful in personalized therapy for patients with SDC.

// Xu Zhou 1, * , Weining Wu 1, * , Ailiang Zeng 1 , Er Nie 1 , Xin Jin 1 , Tianfu Yu 1 , Tongle Zhi 1 , Kuan Jiang 1 , Yingyi Wang 1 , Junxia Zhang 1 and Yongping You 1 1 Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210000, China * These authors have contributed equally to this work Correspondence to: Yongping You, email: yypl9@njmu.edu.cn Keywords: glioblastoma, proliferation, TMZ resistance, microRNA, p53 Abbreviations: GBM, glioblastoma multiforme; miRNAs, microRNAs; TMZ, temozolomide; CCK-8, Cell Counting Kit-8; EdU, 5-ethynyl-2′-deoxyuridine Received: February 18, 2017 Accepted: July 29, 2017 Published: August 24, 2017 ABSTRACT Glioblastoma multiforme is the most common primary malignancy in the brain and confers a uniformly poor prognosis. MicroRNAs have been shown to activate or inhibit tumorigenesis. Abnormalities in the p53 signaling pathway are found in various cancers and correlate with tumor formation. We examined the expression of microRNA-141-3p (miR-141-3p) in glioma of different grades by analysis of expression profiling databases and clinical specimens. Cell proliferation and flow cytometry assays were performed to evaluate the promotion of miR-141-3p in proliferation, cell cycle, apoptosis, and temozolomide resistance of glioblastoma cells in vitro . Bioinformatics analyses, luciferase reporter assays, and immunoblotting showed that p53 is a target gene of miR-141-3p. A significant inverse correlation was observed between expression of miR-141-3p and p53 in glioma and normal brain tissues (R 2 =0.506, P

Diffuse large B-cell lymphoma (DLBCL) is one of the leading causes of cancer-related mortality, and responds badly to existing treatment. Thus, it is of urgent need to identify novel prognostic markers and therapeutic targets of DLBCL. Recent studies have shown that long non-coding RNAs (lncRNAs) play an important role in the development of cancer. By using the next generation HiSeq sequencing assay, we determined lncRNAs exhibiting differential expression between DLBCL patients and healthy controls. Then, RT-qPCR was performed for identification in clinical samples and cell materials, and lncRNA PANDA was verified to be down-regulated in DLBCL patients and have considerable diagnostic potential. In addition, decreased serum PANDA level was correlated to poorer clinical outcome and lower overall survival in DLBCL patients. Subsequently, we determined the experimental role of lncRNA PANDA in DLBCL progression. Luciferase reporter assay and chromatin immunoprecipitation assay suggested that lncRNA PANDA was induced by p53 and p53 interacts with the promoter region of PANDA. Cell functional assay further indicated that PANDA functioned as a tumor suppressor gene through the suppression of cell growth by a G0/G1 cell cycle arrest in DLBCL. More importantly, Cignal Signal Transduction Reporter Array and western blot assay showed that lncRNA PANDA inactivated the MAPK/ERK signaling pathway. In conclusion, our integrated approach demonstrates that PANDA in DLBCL confers a tumor suppressive function through inhibiting cell proliferation and silencing MAPK/ERK signaling pathway. Thus, PANDA may be a promising therapeutic target for patients with DLBCL.