bluuebunny/crossref_metadata_2025_split huggingface dataset:
Digoxin exposure and prostate cancer mortality: A matched cohort study.
Authors: Flahavan Evelyn , Bennett Kathleen , Sharp Linda , Barron Thomas Ian 
Published: March 2020

e13096 Background: Digoxin (DIG) exposure has been associated with reduced prostate cancer (PC) incidence in epidemiological studies. Preclinical data suggests that this anti-cancer effect is mediated through the inhibition of hypoxia-inducible factor 1-α by DIG. This retrospective cohort study examines associations between DIG exposure and mortality in men with PC. Methods: Men diagnosed with PC during 2001–2006 were identified from National Cancer Registry Ireland records and linked prescription claims data. Propensity scores for DIG exposure in the 90 days prior to PC diagnosis were estimated. DIG exposed and unexposed men were matched (1:1) within a calliper of 0.2 standard deviations of the propensity score logit, using greedy matching without replacement. Standardized differences were used to assess covariate balance (z-score <0.1) between matched cohorts. Hazard ratios (HR) for associations between DIG exposure and all-cause (ACM) or PC-specific (PCM) mortality were estimated using Cox proportional hazards models adjusted for age, comorbidity, tumour stage and grade. Categorical exposure-response analyses were carried out using tertiles of exposure (low, intermediate, high) in the 90 days pre-diagnosis. Results: 5734 PC cases were identified from the linked database. 395 cases received DIG in the 90 days pre-diagnosis, of which 391 were matched to unexposed controls. Matched covariate balance was acceptable. In adjusted analyses, DIG exposure was not associated with ACM (HR 1.06, 95% CI 0.88-1.27) but was associated with a small but non-significant reduction in the risk of PCM (HR 0.89, 95% CI 0.68-1.17). In the exposure-response analysis, DIG exposure in the highest tertile, but not in the intermediate or lower tertiles, was associated with a reduced risk of PCM approaching statistical significance (HR 0.69, 95% CI 0.47-1.01, p=0.059). Men in the high DIG exposure group received a supply of DIG for 98% of their eligible follow up in the year post diagnosis. Post diagnostic DIG exposure in the intermediate and lower tertiles was 94% and 80% respectively. Conclusions: DIG exposure was associated with a non-significant decrease in PCM. Stratification by exposure suggests the presence of an exposure-response relationship.
Phase I study of panobinostat (LBH589) and letrozole in post-menopausal women with metastatic breast cancer.
Authors: Tan Winston , Allred Jacob B , Moreno-Aspitia Alvaro , Northfelt Donald W. , Ingle James N. , Perez Edith A. 
Published: March 2020

e13501 Background: Loss of estrogen receptor alpha gene expression has been associated with insensitivity to endocrine therapy in human breast cancer patients. Histone deacetylase (HDAC) inhibitors have recently been found to restore sensitivity to the estrogen receptor by modulation of the estrogen and progesterone receptors. This had been shown with both aromatase and tamoxifen refractory and in triple negative cell lines . We performed a Phase I study of the combination of LBH589 (panobinostat) and letrozole to evaluate safety and tolerability in patients with metastatic breast cancer prior to the performance of a phase II trial. Methods: We enrolled postmenopausal women with metastatic breast cancer, ECOG PS 0 or 1, ANC>1500/mm3, platelets>100,000/mm3, normal total bilirubin, and ALT/AST adequate laboratory tests were eligible. Letrozole dose was 2.5 mg/day orally. Dose of LBH589: Level 1, 20 mg orally three times weekly; Level 2, 30 mg orally three times a week. Results: 12 patients (dose level 1:6 patients, dose level 2: 6 patients) have been enrolled. 43 cycles of treatment have been given to these12 patients. Initial cohort of 3 patients at the 20 mg dose level had no dose limiting toxicity (DLT). At the 30 mg dose level 3/6 patients had DLT (thrombocytopenia grade 1: 2 pts; grade 3:1 pt; grade 4: 1 pt; and diarrhea grade 3: 1 pt. One pt at the 30 mg dose level has a confirmed partial response and remains on study after 6 cycles of treatment. Subsequent cohort of 3 patients had 1 dose DLT with doubling of the creatinine. The main DLT was thrombocytopenia in 3/6 pts at the 30 mg dose level. Conclusions: The recommended dose for phase II testing of LBH589 is 20 mg orally 3 times per week in combination with standard dose letrozole.
Automated quantitative analyses (AQUA) of cyclic-AMP-response-element-binding protein (CREB), phosphorylated CREB (pCREB), and ataxia-telangiectasia-mutated protein kinase (ATM) protein expression in patients (pts) undergoing thoracic radiation for locally advanced non-small cell lung cancer (NSCLC).
Authors: Chao Bo H. , Traynor Anne M. , Yang David T , Zhang Chong , Pier Thomas , Kim KyungMann , Rehrauer William M. , Cannon Donald Maurice , Cannon George M. , Bye Tyler , Tibbetts Randal S. 
Published: March 2020

e13537 Background: Increased protein expression of CREB, a DNA damage-regulated transcription factor, has been associated with poor survival in advanced NSCLC. We have demonstrated that exposure of cancer cell lines to low dose ionizing radiation (IR) increased pCREB on a Ser133 residue. However, exposure to high dose IR correlated with pCREB on Ser121 by ATM, a master regulator of the cellular DNA damage response. This unusual bimodal response of CREB to IR, reflected by activation at low doses and attenuation at high doses, suggested that CREB may control cell fate decisions in response to DNA damage. We hypothesized that patterns of protein expression of CREB, pCREB Ser133, and ATM would predict treatment response in pts who have undergone radiotherapy for locally advanced NSCLC. Methods: Diagnostic tumor specimens were obtained from pts who underwent thoracic radiation in a clinical trial for locally advanced NSCLC. Protein expression of CREB, pCREB Ser133, and ATM was assessed by AQUA. Wilcoxon rank sum test was used to assess differences in protein expression. Univariate regression was conducted to evaluate protein expression and clinical outcomes. Kruskal Wallis test was used to assess protein expression and pneumonitis. Results: Sufficient tumor tissue was available for 35 of 79 pts enrolled. Best responses in 6 months included 12% CR, 73% PR, 9% SD, and 6% PD. Pre-treatment protein expression per AQUA analyses of CREB, pCREB Ser133, and ATM were not statistically associated with time to in-field progression, time to out-of-field progression, time to distant metastasis, best response, pneumonitis, or overall survival. Unexpectedly, increased expression of pCREB Ser133 was associated with durable anti-tumor response to radiation at a median duration of 14.6 months (p=0.03). Conclusions: Protein expression per AQUA of CREB, pCREB Ser133, and ATM did not confirm our hypotheses, possibly related to our limited sample size. Further analysis of the role of CREB in response to IR in cancer pts is ongoing.
Effect of short hairpin RNA targeting of fibroblast activation protein on tumor growth and angiogenesis in a 4T1 murine breast cancer model.
Authors: Cai Fan , Peng Feng , Wang Chunting , Li Zhiyong , Xian Shuang , Wei Yuquan 
Published: March 2020

e13538 Background: Fibroblast activation protein(FAP) is an increased abnormal signal protein in the TME and has  both dipeptidyl peptidase and endopeptidase activity. FAP has been recognized to influence cancer growth and invasion, through its non- enzyme function or proteolytic activities in concert with other moleculars such as CD26, uPAR, β1-integrin, and MMP-1. Since FAP is over expression in epithelial cancers and absent from normal adult tissues, it has long been suggested to be a target of antitumor therapy. Methods: 21 BALB/C female mice implanted with 4T1 breast cancer were enrolled and randomly divided into three groups (n=7 per group) .The experiment group(E-group) was administered with shRNA targeting of FAP every 48 hours in 2 weeks by local administration, and the two control groups with HK or 5%GS. Tumor volumes and weights were monitored. Expression of FAP was detected by RT-PCR and immunohistochemistry staining. Collagen fiber, microvessel density and cell apoptosis were investigated. Results: The expression of FAP was reduced about 50% by shRNA targeting of FAP; the tumor volume and weight of the E-group showed significant reduction of 40% compared with the controls (p=0.001). Knockdown of FAP increased accumulation of disorganized collagen fibers; the MVD in control groups was about 4 times at least compared to the E-group (p<0.001) and apoptosis cells markedly increased 3 fold (p=0.0015). Conclusions: Knockdown of FAP by shRNA interference mediated inhibition of breast cancer growth, amelioration of the tumor microenvironment including increased accumulation of disorganized collagen, suppressed angiogenesis, and promotion of apoptosis. FAP contributes to the formation of TME and is a stimulative factor of breast cancer growth. Target of FAP may be a potential supplemental therapeutic method for breast cancer.
SYK expression in metastatic retinoblastoma.
Authors: Brennan Rachel Christine , Wilson Matthew W. , Dyer Michael A. , Bahrami Armita 
Published: March 2020

e13544 Background: Retinoblastoma is an aggressive childhood cancer of the retina. While more than 90% of patients are cured when tumor is confined to the globe, for up to half of children in developing countries with advanced tumor at diagnosis, retinoblastoma remains a lethal disease. Recent whole-genome sequencing demonstrated that the retinoblastoma genome is relatively stable (Zhang et al). However, RB1 loss is associated with epigenetic deregulation of several cancer pathways. Significantly, the proto-oncogene SYK, spleen tyrosine kinase, which has no role in normal eye development, is upregulated in retinoblastoma and required for tumor cell survival (Zhang et al). Immunohistochemical (IHC) studies showed that SYK is ubiquitously overexpressed in intraocular retinoblastoma, whereas it is absent in normal retina. The purpose of this study is to investigate whether SYK overexpression persists in metastatic retinoblastoma. Methods: From 1962-2011, seven metastatic retinoblastoma tumor specimens (excluding bone marrow or cerebrospinal fluid) from six retinoblastoma patients were retrieved from the Pathology Archives in our institution. Morphology and supportive IHC, to include immunopositivity for synaptophysin and immunonegativity for cytokeratins, confirmed the diagnosis of metastatic retinoblastoma in each case. IHC for SYK was performed according to the previously published technique (Zhang et al). Results: Tumors occurred in two male and four female patients with seven metastatic retinoblastoma samples in scalp, lymph node, neck, ovary and bone (femur). By IHC, all seven metastatic retinoblastoma tumor samples were positive for SYK. Conclusions: This is the first report of SYK overexpression in metastatic retinoblastoma. Drugs targeting SYK are already in clinical trials for adults with leukemia and rheumatoid arthritis, and preclinical efficacy in vitro and in vivo has been established. Moving from bench to bedside with this epigenetically targeted agent warrants further investigation.
Reactivation of p53 mutant protein by PRIMA-1 and induction of apoptosis in pancreatic cancer cells.
Authors: Izetti Patricia , Hautefeuille Agnes , Abujamra Ana Lucia , Farias Caroline Brunetto de , Roesler Rafael , Macedo Gabriel de Souza , Alemar Barbara , Lenz Guido , Osvaldt Alessandro Bersch , Hainaut Pierre , Ashton-Prolla Patricia 
Published: March 2020

e13546 Background: Inactivating TP53 mutations are common events in different types of cancers, including pancreatic adenocarcinoma, where it occurs in as much as 70% of cases. Accumulation of mutant p53 provides a molecular target that may be reactivated into a conformation capable of arresting tumor growth. The small molecule PRIMA-1 (p53 reactivation and induction of massive apoptosis) has been shown to selectively induce apoptosis in tumor cells by reactivating some p53 mutants, but no previous studies have investigated its effects in pancreatic cancer. Methods: PANC-1 (mutant TP53 R273H) and CAPAN-2 (wild-type TP53) pancreatic cell lines were used as in vitro models. We tested the effects of PRIMA-1 on cell viability (MTT assay), apoptosis (morphology, AnnexinV/FITC-FACS), cell cycle (BrdU incorporation) and expression of p53 regulated proteins by western blotting. As control of p53-dependent effects, PANC-1 cell lines were transfected with siRNA against TP53 (sip53). Results: PRIMA-1 selectively induced apoptosis in PANC-1 cells compared to CAPAN-2 cells and this effect was concomitant with an increase in the levels of MDM2, Bax and cleaved caspase-3 as detected by western blot analysis. Treatment with PRIMA-1 for 24h induced a 50% reduction in DNA synthesis whereas G2/M arrest was detected after 12h of treatment. p53 silencing in PANC-1 decreased the cytotoxicity of PRIMA-1, characterizing a p53-dependent effect. Finally, N-acetylcysteine completely blocked PRIMA-1-induced growth suppression and apoptosis, suggesting that PRIMA-1 exerts its effect at least in part via restoring redox-dependent effects to mutant p53. Conclusions: Our data indicate that PRIMA-1 induces apoptosis in TP53 mutant pancreatic cancer cells by promoting the re-activation of p53 and subsequent of proapoptotic signaling pathways, suggesting a possible mechanism for effective targeting of pancreatic cancer.
Genomics and proteomics-based discovery of novel cancer biomarkers and molecular targets for cell-permeable peptide/small molecule-based drugs.
Authors: Daigo Yataro , Takano Atsushi , Nakamura Yusuke 
Published: March 2020

e13552 Background: Identification of cancer-specific oncoproteins is an effective approach to develop new diagnostics and therapeutics. Methods: We have established a strategy as follows to identify new oncoproteins, which can be applied as biomarkers and drug development; i) To identify genes overexpressed in 120 clinical lung cancers using the cDNA microarray representing 27,648 genes, ii) To verify the genes for their low expression in 23 normal tissues by northern-blotting, iii) To validate the clinicopathological significance of their protein expression by tissue microarray covering 262 cases of non-small cell lung cancers (NSCLCs), iv) To verify whether they are essential for the growth of cancer cells by siRNAs, v) To do immunoprecipitation assays and mass-spectrometric analysis to identify their interacting proteins in cancer cells, and screening of cell-permeable peptides that could inhibit the protein-protein interaction that is essential for carcinogenesis. Results: We identified 35 oncoproteins to be upregulated in the majority of lung cancers, and further selected CDCA5 (cell division cycle associated 5) as a good candidate. Tumor tissue microarray analysis of 262 NSCLC patients revealed that CDCA5 positivity was an independent prognostic factor. Suppression of CDCA5 expression with siRNAs inhibited the growth of lung cancer cells; concordantly, induction of exogenous expression of CDCA5 conferred growth-promoting activity in mammalian cells. We also found that extracellular signal-regulated kinase (ERK) kinase interacted with and phosphorylated CDCA5 at Serine 209 in vivo. Functional inhibition of the interaction between CDCA5 and ERK kinase by a cell-permeable peptide corresponding to a 20-amino-acid sequence part of CDCA5, which included the Serine 209 phosphorylation site by ERK, significantly reduced phosphorylation of CDCA5 and resulted in growth suppression of lung cancer cells. Conclusions: CDCA5 positivity should be useful as a novel prognostic biomarker in the clinic. Selective suppression of the ERK-CDCA5 pathway by cell-permeable peptide or small molecule-based drugs could be a promising strategy for cancer therapy.
Immunohistochemical expression of phospho-mTOR protein in breast carcinoma tissues and correlation with clinicopathologic parameters.
Authors: Michalaki Vasiliki , Frangou-Plemenou M , Kondi-Pafiti Agathi , Gennatas Konstantinos 
Published: March 2020

e13556 Background: The mammalian target of rapamycin (m-TOR) kinase plays a central role in coordinating cell growth in response to mitogens, amino acid and energy sufficiency. The pathway leading to mTOR activation by these factors, is important for the regulation of protein synthesis and cell survival with implications in carcinogenesis. For these reasons, mTOR is currently under investigation as a potential target for anti-cancer therapy. The aim of this study was to determine the phospho-mTOR (p-mTOR) kinase expression in breast cancer tissues and the relationships with clinicopathological parameters of the breast tumors. Methods: We investigated the status of p-mTOR, in 140 breast carcinomas by immunohistochemistry. Western blot analysis was performed to verify the expression levels of p-mTOR. The relationship of protein expression with clinicopathological data and the correlations of protein expression levels were explored. Multiple logistic regression analyses with stepwise method was used in order to find independent factors associated wth p-mTOR. Results: 47.1% of the patients were p-mTOR positive. In univariate analyses a greater proportion of p-mTOR positive patients was found in those having progesterone receptors, in those hving higher grades of differentiation. When multiple analysis was conducted the only factor that was independently associated with p-mTOR kinase was the tumors grade of differentiation adjusted for age. Subjects with moderate grade of differentiation had greater likelihood for being p-mTOR positive compared to those with low grade of differentiation with odds ratio equal to 3.869 (95% CI: 1.35-11.04, p=0.012). Conclusions: The kinase p-mTOR was found in the neoplastic cells of almost half of the patients were enrolled. Overexpression of p-mTOR was correlated with well-to-moderately differentiated tumors (p<0.001) Our results indicate that dysregulation of the p-mTOR pathway may have an important role in the development of breast carcinoma, but not necessarily in the progression of the disease.
The roles of hypoxia, PTEN, and Rad51 in mediating metastatic prostate cancer cells' responses to PARP inhibitor and topoisomerase 1 inhibitor.
Authors: Zhang Jingsong , Wu Minghui , Wang Xue 
Published: March 2020

e13564 Background: With the recent success of poly (ADP-ribose) polymerase inhibitor (PARPi) in the treatment of BRCA1 or BRCA2 mutated cancers, there is increasing interest to explore synthetic lethality in cancers with defective DNA repair pathways. Rad51 is an essential protein in the homologous recombination repair (HRR) of DNA double strand breaks. Previous studies with non metastatic prostate cancer (mCaP) cells have reported low Rad51 levels in cells with loss of PTEN or under hypoxia, which then led to their sensitivity to PARPi. Given intra tumor hypoxia and loss of PTEN is common in mCaP, we test PAPRi, ABT888 and DNA damaging topoisomerase I inhibitor, CPT11, either alone or in combination in mCaP preclinical models. Methods: mCaP cell lines with functional PTEN (DU145) and loss of PTEN (PC3) were grew under normoxia (21% O2) or hypoxia (0.2% O2). DNA damage, HRR, apoptosis were assessed with comet assay, western blot, immunofluorescence and flowcytometry. The regulation of RAD51 was studied with quantitative RT-PCR and RAD51 promoter reporter assay. PC3 xenograft was used for in vivo study. Results: Despite of its low levels of expression under hypoxia, up regulation of Rad51 was observed soon after treating hypoxic PC3 and Du145 cells with ABT888 or SN38, an active metabolite of CPT11. Such Rad51 up regulation led to less DNA damage and apoptosis under hypoxia compared to normoxia. Inhibiting RAD51 expression with siRNA overcame PC3 and Du145’s resistance to SN38. Furthermore, ABT888 enhanced the activities of SN38 as detected by clonogenic assay and flowcytometry under both normoxia and hypoxia. Consistent with the in vitro data, ABT888 by itself had limited anti-tumor activities despite the loss of PTEN in PC3 xenografts. The anti-tumor activity of single agent CPT11 was significantly improved with the ABT888 and CPT11 combination (P<0.008). Conclusions: neither loss of PTEN nor hypoxia sensitized mCaP cells to PARPi or DNA damaging drugs. Such resistance under hypoxia was at least partly due to up regulation of Rad51. Combining ABT888 with CPT11 overcame the resistance to CPT11 under hypoxia and enhanced its anti-tumor activities both in vitro and in vivo.
Effect of a combination of epigenetic agents on the malignant phenotype in models of T-cell lymphoma.
Authors: Marchi Enrica , Kalac Matko , Bongero Danielle , McIntosh Christine , Fogli Laura K , Scotto Luigi , Rossi Maura , Zinzani Pier Luigi , Pileri Stefano A , Piccaluga Pier Paolo , O'Connor Owen 
Published: March 2020

e13569 Background: CHOP and CHOP-like chemotherapy are the most used regimens for the treatment of peripheral T-cell lymphomas (PTCLs) despite sub-optimal results. Histone deacetylase inhibitors (HDACIs) have shown class activity in PTCLs. The interaction between the HDACIs (depsipeptide (R), belinostat (B), vorinostat (V) and panobinostat (P)) and a DNMT inhibitor (decitabine (D) was investigated in vitro, in vivo and at the molecular level in T-cell lymphoma and leukemia cell lines (H9, HH, P12, PF-382). Methods: For cytotoxicity assays, luminescence cell viability assay was used (CellTiter-Glo). Drug:drug interactions were analyzed with relative risk ratios (RRR) based on the GraphPad software (RRR<1 defining synergism). Apoptosis was assessed by Yo-Pro-1 and propidium iodine followed by FACSCalibur acquisition. Gene expression profiling was analyzed using Illumina Human HT-12 v4 Expression BeadChip microarrays and Gene Spring Software for the analysis. Results: The IC50s for B, R, V, P, D and 5-Azacytidine alone were assessed at 24, 48 and 72 hours. In cytotoxicity assays the combination of D plus B, R, V or P at 72 hours showed synergism in all the cell lines (RRRs 0.0007-0.9). All the cell lines were treated with D, B or R for 72 hours and all the combinations showed significantly more apoptosis than the single drug exposures and controls (RRR < 1). In vivo, HH SCID beige mice were treated i.p. for 3 cycles with the vehicle solution, D or B or their combination at increasing dose. The combination cohort showed statistically significant tumor growth inhibition compared to all the other cohorts. Gene expression analysis revealed differentially expressed genes and modulated pathways for each of the single agent treatment and the combination. The effects of the two drugs were largely different (only 39 genes modified in common). Most of the effects induced by the single agent were maintained in the combination group. Interestingly, 944 genes were modulated uniquely by the combination treatment. Conclusions: The combination of a DNMTI and HDACIs is strongly synergistic in vitro, in vivo and at the molecular level in model of T-cell lymphoma and these data will constitute the basis for a phase I-II clinical trials.