Topoisomerase 2-alpha Research Articles

Abstract PO1-01-02: Final analysis of neoadjuvant chemotherapy with pegylated liposomal doxorubicin/cyclophosphamide followed by taxanes with full-course trastuzumab/pertuzumab for HER2-positive breast cancer: a single-arm, phase II study

Abstract Background: The optimal neoadjuvant treatment regimen for HER2-positive breast cancer remains unclear, especially regarding the use of anthracycline. We conducted a prospective phase II study to evaluate sequential neoadjuvant chemotherapy with pegylated liposomal doxorubicin (PLD)/cyclophosphamide followed by taxanes in the presence of full-course trastuzumab/pertuzumab in HER2-positive early breast cancer patients. Methods: In this single-arm, open-label, multicenter, phase II study, eligible patients with confirmed HER2-positive early breast cancer were recruited from four independent hospitals. Patients received four cycles of PLD (35 mg/m2) and cyclophosphamide (600 mg/m2), followed by four cycles of taxanes (docetaxel, 100 mg/m2 or nab-paclitaxel, 260 mg/m2), concomitant with eight cycles of trastuzumab (8 mg/kg loading dose, then 6 mg/kg) and pertuzumab (840 mg loading dose, then 420 mg) every 3 weeks. The primary endpoint was total pathological complete response (ypT0/is ypN0, tpCR). Secondary endpoints included breast pCR (bpCR), objective response rate (ORR), disease control rate, the proportion of patients requiring breast-conserving surgery, and safety. For biomarkers analysis, tumor tissues were collected at baseline and evaluated for Topoisomerase 2 Alpha (TOP2A) expression assessed prospectively with immunohistochemistry (IHC) assay by independent pathologists. Results: Between May 27, 2020 and May 11, 2022, 78 eligible patients were treated and underwent surgery, of whom 42 (53.8%) patients underwent breast-conserving surgery. After neoadjuvant therapy, 47 (60.3%, 95% CI, 48.5%-71.2%) patients achieved a tpCR in the breast and axilla. The bpCR was observed in 49 (62.8%) patients. ORRs were 76.9% (95% CI, 66.0%-85.7%) and 93.6% (95% CI, 85.7%-97.9%) after 4-cycle and 8-cycle neoadjuvant therapy, respectively. All (100%) patients achieved disease control since the end of the first cycle. No correlations between clinicopathological variables and pathological response were observed. Grade 3 or worse AEs occurred in 35 (44.9%) patients. Nine (11.5%) patients experienced asymptomatic LVEF reduction (≥10% from baseline), but all with a minimum value of >55%. No treatment-related surgical delay or death occurred. For biomarkers analysis, the status of TOP2A was not found to be associated with pCR or 4th-cycle ORR. Conclusions: This dual HER2-blockade plus polychemotherapy as sequential neoadjuvant regimen demonstrates promising anti-tumor activity and acceptable tolerability for patients with HER2-positive breast cancer. Citation Format: Yaping Yang, Liang Jin, Yudong li, Fengxia Gan, Nanyan Rao, Jun Zhang, Ruifa Feng, Zhenzhen Liu, Qiang Liu. Final analysis of neoadjuvant chemotherapy with pegylated liposomal doxorubicin/cyclophosphamide followed by taxanes with full-course trastuzumab/pertuzumab for HER2-positive breast cancer: a single-arm, phase II study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-01-02.

Insights into the structure–function relationship of missense mutations in the human TOP2A protein in ovarian cancer

Topoisomerase 2-alpha (TOP2A) is a nuclear protein that is responsible for the maintenance of the topological state of DNA. TOP2A is highly upregulated in ovarian cancer, and its copy number is an important prognosis factor. A large number of single-nucleotide polymorphism (SNP), insertion, and deletion mutations have been reported in TOP2A. Thus, a structural and functional study of missense SNPs was carried out to screen potentially damaging mutations. The 193 non-synonymous SNPs in the coding region of TOP2A in the dbSNP database were selected for in silico analysis. The deleterious SNPs were screened using sorting intolerant from tolerant (SIFT), PolyPhen-2, SNAP2, and SNPs&Go, and we obtained four possibly damaging SNPs at the end (Y481C, N7741, E922K, and R1514W). Mutants Y481C and E922K were predicted to be highly deleterious and showed decreased protein stability compared with native proteins, as predicted by I-Mutant 3. We used the SWISS-MODEL to model the structure of these two mutants, and the structural attributes of modeled mutants were studied using Hope Project, solvent accessibility-based protein–protein interface identification and recognition (SPPIDER), SRide, and HBAT, which predicted small variations from the native protein. Molecular dynamics simulation demonstrated a decrease in root mean square deviation (RMSD) and the radius of gyration of two mutants, which is relative to the native protein. The molecular docking of TOP2A with etoposide suggests that mutations may lead to resistance to TOP2A-targeted chemotherapy. In addition, the relative expression analysis performed by qRT-PCR also reveals that there is a three-fold increase in the expression levels of the TOP2A protein in ovarian adenoma cancer cell lines. Our analysis reveals that Y481C and E922K are highly damaging variants of TOP2A, which alter the protein dynamics and may be implicated in causing ovarian cancer.

HMGB2 is a potential diagnostic marker and therapeutic target for liver fibrosis and cirrhosis.

High mobility group proteins 1 and 2 (HMGB1 and HMGB2) are 80% conserved in amino acid sequence. The function of HMGB1 in inflammation and fibrosis has been extensively characterized. However, an unaddressed central question is the role of HMGB2 on liver fibrosis. In this study, we provided convincing evidence that the HMGB2 expression was significantly upregulated in human liver fibrosis and cirrhosis, as well as in several mouse liver fibrosis models. The carbon tetrachloride (CCl4) induced liver fibrosis mouse model was used. AAV8-Hmgb2 was utilized to overexpress Hmgb2 in the liver, while Hmgb2-/- mice were used for loss of function experiments. The HMGB2 inhibitor inflachromene and liposome-shHMGB2 (lipo-shHMGB2) were employed for therapeutic intervention. The serum HMGB2 levels were also markedly elevated in patients with liver fibrosis and cirrhosis. Deletion of Hmgb2 in Hmgb2-/- mice or inhibition of HMGB2 in mice using a small molecule ICM slowed the progression of CCl4-induced liver fibrosis despite constant HMGB1 expression. In contrast, AAV8-mediated overexpression of Hmgb2 enchanced CCl4-incuded liver fibrosis. Primary hepatic stellate cells (HSCs) isolated from Hmgb2-/- mice showed significantly impaired transdifferentiation and diminished activation of α-SMA, despite a modest induction of HMGB1 protein. RNA-seq analysis revealed the induction of top 45 CCl4-activated genes in multiple signaling pathways including integrin signaling and inflammation. The activation of these genes by CCl4 were abolished in Hmgb2-/- mice or in ICM-treated mice. These included C-X3-C motif chemokine receptor 1 (Cx3cr1) associated with inflammation, cyclin B (Ccnb) associated with cell cycle, DNA topoisomerase 2-alpha (Top2a) associated with intracellular component, and fibrillin (Fbn) and fibromodulin (Fmod) associated with extracellular matrix. We conclude that HMGB2 is indispensable for stellate cell activation. Therefore, HMGB2 may serve as a potential therapeutic target to prevent HSC activation during chronic liver injury. The blood HMGB2 level may also serve as a potential diagnostic marker to detect early stage of liver fibrosis and cirrhosis in humans.

Circular RNA Ubiquitin-associated Protein 2 Silencing Suppresses Bladder Cancer Progression by Downregulating DNA Topoisomerase 2-alpha Through Sponging miR-496

BackgroundCircular RNAs (circRNAs) have been uncovered to be implicated in the malignant development of bladder cancer (BC). ObjectiveHerein, this work aimed to investigate the role and mechanism of circRNA ubiquitin-associated protein 2 (circUBAP2) in BC progression. Design, setting, and participantsQuantitative real-time polymerase chain reaction and Western blotting were used for the detection of genes and proteins. Outcome measurements and statistical analysisIn vitro functional experiments were conducted using colony formation, 5-ethynyl-2′-deoxyuridine (EdU), Transwell, wound healing, and flow cytometry assays, respectively. A glycolysis analysis was conducted by assessing glucose uptake and lactate production. A murine xenograft model was established to perform in vivo experiments. The binding interaction between miR-496 and circUBAP2 or DNA topoisomerase 2-alpha (TOP2A) was verified using a dual-luciferase reporter assay. Results and limitationsCircUBAP2 was highly expressed in BC patients, and high circUBAP2 expression showed a shorter survival rate. Functionally, knockdown of circUBAP2 could suppress BC cell growth, migration, invasion, and aerobic glycolysis in vitro, as well as impede BC growth in nude mice. Mechanistically, circUBAP2 acted as a sponge for miR-496, which targeted TOP2A. Moreover, circUBAP2 could indirectly regulate TOP2A expression through sequestering miR-496. Furthermore, a series of rescue experiments showed that miR-496 inhibition reversed the anticancer action of circUBAP2 knockdown on BC cells. Moreover, miR-496 could attenuate BC cell malignant phenotypes and aerobic glycolysis, which were abolished by TOP2A overexpression. ConclusionsSilencing of circUBAP2 could suppress BC growth, invasion, migration, and aerobic glycolysis by the miR-496/TOP2A axis, suggesting a promising target for the molecular targeted therapies of BC. Patient summaryCircular RNA ubiquitin-associated protein 2 (circUBAP2) was found to be associated with poor prognosis in bladder cancer (BC). Knockdown of circUBAP2 might suppress BC growth, invasion, migration, and aerobic glycolysis, indicating that it may be a new target for the development of molecular targeted therapy for BC.

Evaluation of indirect-ELISA using eluted antigens from Trichinella spiralis muscle larvae for diagnosis of swine trichinellosis

Trichinellosis is caused by Trichinella spiralis muscle larvae (TsML), which is transmitted to human when they eat infected raw or undercooked meat. T. spiralis infection is detected by an enzyme-linked immunosorbent assay (ELISA) using excretory–secretory antigens (ESAg); however, the preparation of ESAg is challenging, and yields are low, which hampers screening efforts. In this study, crude somatic antigens (CSAg) of TsML with molecular weights (MWs) of 43, 79 and 101 kDa have been identified in swine trichinellosis sera with less cross-reaction with uninfected sera and other parasitic infected sera. After that, the CSAg at MWs of 43, 79 and 101 kDa (TsCSAg-43, TsCSAg-79, and TsCSAg-101, respectively) were isolated from sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The eluted antigens were analyzed by IgG-ELISA for sensitivity and specificity, and specific antigens from the three regions were identified by two-dimensional polyacrylamide gel electrophoresis (2-DE) and liquid chromatography-tandem mass spectrometry (LC-MS-MS). The sensitivity of IgG-ELISA using the three eluted antigens was 100% with specificities of 97.77%, 95.54%, 90.63% and for TsCSAg-43, TsCSAg-79, and TsCSAg-101, respectively. The LC-MS-MS results of immunomics showed that 18/20 spots of the antigens with MWs of 43, 79, and 101 kDa represent 11 different proteins identified. TsCSAg-43 showed the highest specificity, indicating that the specific proteins identified, including 45 kDa antigen–trichina [fragment], DNA topoisomerase 2-alpha antigen targeted by protective antibodies, and a conserved hypothetical protein (gi339234223), should be developed and produced in large volumes for further immunodiagnostic studies.

Clinical Utility of Reflex Testing with Cancer Biomarkers to Improve Diagnostic Accuracy of Primary Human Papillomavirus Screening.

Human papillomavirus (HPV) testing is the cornerstone of cervical cancer screening, with outstanding sensitivity but only moderate specificity. We evaluated whether reflex testing for cancer biomarkers improves the sensitivity/specificity balance of screening. Cervical samples from women in Cape Town, South Africa, ages 30-65 years, were collected and tested with Xpert HPV and with real-time PCR to detect mRNA for cyclin-dependent kinase inhibitor 2A (CDKN2A), topoisomerase 2 alpha (TOP2A), and Ki67 (MKi67). Women with histologically confirmed cervical intraepithelial neoplasia grade 2 or worse (CIN2+; 85 women without and 166 with HIV) and women with no cervical disease (331 without and 257 with HIV) were included. When used as reflex tests after a positive HPV result, biomarkers discriminated well between women with and without CIN2+. The inclusion of both CDKN2A and MKi67 had the best performance, with area under the curve (AUC) of 0.9171 and 0.8734 in women without and with HIV, respectively. Although excellent, these performance parameters did not improve on an approach utilizing only HPV testing with more stringent cycle threshold cutoffs and HPV genotype selection, which achieved AUC of 0.9059 and 0.8705 in women without and with HIV, respectively. Biomarkers can be used as triage after positive HPV results but do not outperform an approach utilizing higher viral load cutoffs on selected high-risk genotypes. A screening approach using HPV testing alone can be more easily implemented at the point of care.

Synthesis, spectroscopic characterization, molecular docking and in vitro cytotoxicity investigations on 8-Amino-6-Methoxy Quinolinium Picrate: a novel breast cancer drug

Density Functional Theory (DFT) studies of the 8-Amino-6-Methoxy Quinolinium Picrate (8A6MQP) molecule have been carried out with extensive and accurate investigations of detailed vibrational and spectroscopic investigations as well as validated experimentally. The 8A6MQP sample was synthesized and characterized using FT-IR, FT-Raman, FT-NMR and UV-Vis spectroscopic techniques. Subsequently, the optimized molecular structure and harmonic resonance frequencies of the molecule were computed based on DFT/B3LYP method with a 6-311G++(d,p) basis set using the Gaussian 09 program. The experimental and calculated vibrational wavenumbers were assigned. The absorption spectrum of the molecule was computed in the liquid phase (ethanol), which exhibits n to л* electronic transition and compared with the observed UV-Vis spectrum. Frontier molecular orbital analysis shows the molecular reactivity and kinetic stability of the molecule. The Mulliken atomic charge distribution and molecular electrostatic potential surface analysis of the molecule validate the reactive site of the molecule. The natural bond orbital analysis proves the bioactivity of the molecule. Molecular docking analysis indicates that the 8A6MQP molecule inhibits the action of DNA topoisomerase 2-alpha protein, which is associated with breast cancer. In addition, the in vitro cytotoxicity analysis of the 8A6MQP molecule against human cervical cancer cell lines (ME180) and human breast cancer cell lines (MDA MB 231) were determined by MTT assay, which evidences that the title molecule exhibits higher inhibition against the breast cancer cell lines compared to that of cervical cancer cell lines. Hence, the present study paves the way for the development of novel drugs in the treatment of breast cancer. Communicated by Ramaswamy H. Sarma

Prognostic Value and Significant Pathway Exploration Associated with TOP2A Involved in Papillary Thyroid Cancer.

BackgroundTopoisomerase 2-alpha (TOP2A) has been identified as a hub gene that played an important role in the initiation and progression of thyroid carcinoma (THCA). However, the exact function of TOP2A in papillary thyroid cancer (PTC) remained elusive. The current study aimed to evaluate the TOP2A expression, prognosis significance and key signaling pathways involved in PTC.MethodsWe firstly evaluated the expression of TOP2A in PTC via UALCAN, cBioportal, HPA and LinkdedOmics databases. Genetic alteration of TOP2A in PTC was then explored in cBioportal. Prognostic impacts of TOP2A expression on disease-free survival (DFS) of PTC patients were subsequently evaluated using Kaplan–Meier plotter and Gepia databases. Taking gender, age, cancer stage, T, N and M stages into consideration, we compared survival difference between TOP2A high and low expression groups. KEGG pathway analysis in WebGestalt and GSEA analysis were further performed to reveal the potential TOP2A-associated signaling pathways involved in PTC. Finally, the upstream microRNAs of TOP2A were assessed using DIANA, TargetScan, miRDB and miRWALK database, followed by mechanism exploration of upstream microRNAs.Results1) The mRNA and protein of TOP2A were highly expressed in PTC tissue compared with normal thyroid tissue. TOP2A expression was associated with patient’s age, N stage and cancer stage (all P<0.05). TOP2A protein was mainly localized to nucleoplasm. 2) Most of samples occurred the missense substitution, and mutation site was located at K1199E. Nucleotide mutations were mainly presented as G>A (35.29%). 3) TOP2A high expression significantly influenced the DFS of PTC patients (P=0.015). Restricted survival analysis showed that TOP2A high expression caused poorer DFS of female patients (P=0.003) and those with age <60 years old (P=0.002), early clinical stage (P=0.012), N0 stage (P=0.002) or M0 stage (P=0.040). 4) Pathway analysis suggested that TOP2A positively participated in the cell cycle, oocyte meiosis and p53 signaling pathways (all P<0.05) involved in thyroid cancer.ConclusionThe expression of TOP2A was higher in PTC tissue, which resulted in a worse DFS of patients with PTC. TOP2A might act as an effective therapeutic target for PTC treatment.

Simultaneous analysis of cellular glycoproteome and phosphoproteome in cervical carcinoma by one-pot specific enrichment

Cervical carcinoma is a kind of common gynecological cancer, the physiopathology of which is consanguineously connected with protein glycosylation and phosphorylation. Here, the magnetic binary metal oxide composites with the functionalization of hydrophilic tripeptide is designed and synthesized for simultaneous enrichment of glycopeptide and phosphopeptide in HeLa cells. Multiple kinds of metal sites realize more comprehensive enrichment of phosphopeptides compared with single metal, and ultra-hydrophilic property of glutathione further endows the composites with excellent affinity towards glycopeptides. The composites exhibited low detection limit (0.5 fmol/μL) and high selectivity (digests of β-casein and BSA, 1:500, m/m) for phosphopeptides, also showed good enrichment efficiency for glycopeptide including detection limit (0.1 fmol/μL) and selectivity (digests of HRP and BSA, 1:50, m/m). Meanwhile, the composites still possess outstanding enrichment capability towards phosphopeptide and glycopeptide after stored for two months or six consecutive times reuse. Eventually, 1177 phosphopeptides and 438 glycopeptides are identified simultaneously from 100 μg HeLa cell digests. As anticipated, potential biomarkers, such as heat shock protein beta-1, DNA topoisomerase 2-alpha, proliferation marker protein Ki-67 and 60 kDa heat shock protein are detected, suggesting its promising application in discovery and screening of cervical carcinoma.

The unique molecular targets associated antioxidant and antifibrotic activity of curcumin in in vitro model of acute lung injury: A proteomic approach.

Bleomycin (BLM) injury is associated with the severity of acute lung injury (ALI) leading to fibrosis, a high-morbidity, and high-mortality respiratory disease of unknown etiology. BLM-induced ALI is marked by the activation of a potent fibrogenic cytokine transcription growth factor beta-1 (TGFβ-1), which is considered a critical cytokine in the progression of alveolar injury. Previously, our work demonstrated that a diet-derived compound curcumin (diferuloylmethane), represents its antioxidative and antifibrotic application in TGF-β1-mediated BLM-induced alveolar basal epithelial cells. However, curcumin-specific protein targets, as well as its mechanism using mass spectrometry-based proteomic approach, remain elusive. To elucidate the underlying mechanism, a quantitative proteomics approach and bioinformatics analysis were employed to identify the protein targets of curcumin in BLM or TGF-β1-treated cells. With subsequent in vitro experiments, curcumin-related pathways and cellular processes were predicted and validated. The current study discusses two separate proteomics experiments using BLM and TGF-β1-treated cells with the proteomics approach, various unique target proteins were identified, and proteomic analysis revealed that curcumin reversed the expressions of unique proteins like DNA topoisomerase 2-alpha (TOP2A), kinesin-like protein (KIF11), centromere protein F (CENPF), and so on BLM or TGF-β1 injury. For the first time, the current study reveals that curcumin restores TGF-β1 induced peroxisomes like PEX-13, PEX-14, PEX-19, and ACOX1. This was verified by subsequent in vitro assays. This study generated molecular evidence to deepen our understanding of the therapeutic role of curcumin at the proteomic level and may be useful to identify molecular targets for future drug discovery.

Analysis of m6A RNA Methylation-Related Genes in Liver Hepatocellular Carcinoma and Their Correlation with Survival.

N6-methyladenosine (m6A) modification on RNA plays an important role in tumorigenesis and metastasis, which could change gene expression and even function at multiple levels such as RNA splicing, stability, translocation, and translation. In this study, we aim to conduct a comprehensive analysis on m6A RNA methylation-related genes, including m6A RNA methylation regulators and m6A RNA methylation-modified genes, in liver hepatocellular carcinoma, and their relationship with survival and clinical features. Data, which consist of the expression of widely reported m6A RNA methylation-related genes in liver hepatocellular carcinoma from The Cancer Genome Atlas (TCGA), were analyzed by one-way ANOVA, Univariate Cox regression, a protein–protein interaction network, gene enrichment analysis, feature screening, a risk prognostic model, correlation analysis, and consensus clustering analysis. In total, 405 of the m6A RNA methylation-related genes were found based on one-way ANOVA. Among them, DNA topoisomerase 2-alpha (TOP2A), exodeoxyribonuclease 1 (EXO1), ser-ine/threonine-protein kinase Nek2 (NEK2), baculoviral IAP repeat-containing protein 5 (BIRC5), hyaluronan mediated motility receptor (HMMR), structural maintenance of chromosomes protein 4 (SMC4), bloom syndrome protein (BLM), ca-sein kinase I isoform epsilon (CSNK1E), cytoskeleton-associated protein 5 (CKAP5), and inner centromere protein (INCENP), which were m6A RNA methylation-modified genes, were recognized as the hub genes based on the protein–protein interaction analysis. The risk prognostic model showed that gender, AJCC stage, grade, T, and N were significantly different between the subgroup with the high and low risk groups. The AUC, the evaluation parameter of the prediction model which was built by RandomForest, was 0.7. Furthermore, two subgroups were divided by consensus clustering analysis, in which stage, grade, and T differed. We identified the important genes expressed significantly among two clusters, including uridine-cytidine kinase 2 (UCK2), filensin (BFSP1), tubulin-specific chaperone D (TBCD), histone-lysine N-methyltransferase PRDM16 (PRDM16), phosphorylase b ki-nase regulatory subunit alpha (PHKA2), serine/threonine-protein kinase BRSK2 (BRSK2), Arf-GAP with coiled-coil (ACAP3), general transcription factor 3C polypep-tide 2 (GTF3C2), and guanine nucleotide exchange factor MSS4 (RABIF). In our study, the m6A RNA methylation-related genes in liver hepatocellular carcinoma were analyzed systematically, including the expression, interaction, function, and prognostic values, which provided an important theoretical basis for m6A RNA methylation in liver cancer. The nine important m6A-related genes could be prognostic markers in the survival time of patients.

DGCR5 is activated by PAX5 and promotes pancreatic cancer via targeting miR-3163/TOP2A and activating Wnt/β-catenin pathway.

Long noncoding RNA DiGeorge syndrome critical region gene 5 (DGCR5) has been shown to be highly associated with cancer development. However, the biological role and molecular mechanism of DGCR5 in pancreatic cancer (PC) remains largely unknown. This study aimed to explore the role of DGCR5 in PC. It was revealed that DGCR5 was highly expressed in PC tissues compared with adjacent normal tissues and was associated with poor prognosis in PC patients. Furthermore, DGCR5 depletion inhibited the proliferation, migration and invasion by increasing apoptosis and inducing G0/G1 cell cycle arrest in vitro. Moreover, xenograft assay validated that DGCR5 promotes PC tumor growth in vivo. Mechanistically, DGCR5 was found to act as a ceRNA by sponging miR-3163 to regulate DNA topoisomerase 2-alpha (TOP2A) and inhibit Wnt/β-catenin pathway. In addition, it was found that DGCR5 downregulation could enhance the sensitivity of PC cells to gemcitabine, and ChIP assay showed that PAX5 (Paired Box 5) could bind to the promoter region of DGCR5 and increase its transcription. The results of the present study indicated that DGCR5 may be a potential diagnostic biomarker and therapeutic target for PC.

PROGNOSTIC VALUE OF TOPOISOMERASE 2-ALPHA AND B-MYB IN EARLY BREAST CANCER TREATED WITH ADJUVANT CHEMOTHERAPY.

SUMMARYBreast cancer is the most common malignancy in females. Despite its well-established prognostic factors, our prognostic ability at an individual patient level remains limited. In this study, the immunohistochemical expression of B-Myb and DNA topoisomerase 2-alpha (Topo2a) was analyzed in primary tumors to identify patients with a higher risk of disease recurrence after adjuvant chemotherapy for early invasive breast cancer. We analyzed a cohort of 215 early invasive breast cancer patients having undergone surgery from 2002 to 2003 at the Zagreb University Hospital Centre, including 153 patients treated with adjuvant chemotherapy. All of them were followed-up prospectively for at least ten years according to routine institutional practice. Statistically significant correlations were found between B-Myb and Topo2a expression levels and particular well-established prognostic factors. B-Myb expression was lower in estrogen receptor (ER)-positive tumors (p=0.0773), whereas larger tumors and those with positive lymphovascular invasion displayed a statistically significantly higher B-Myb expression (p=0.0409 and p=0.0196). Higher tumor grade indicated higher Topo2a values (p=0.0102 and p=0.0069). The subgroup with the expression of both proteins above the median value had an almost statistically significantly (p=0.0613) inferior prognosis compared to the rest of the cohort. Study results showed the B-Myb and Topo2a expression to have a prognostic value in breast cancer patients after adjuvant chemotherapy, which should be additionally explored in future studies in a larger patient cohort.

Licorice Ameliorates Cisplatin-Induced Hepatotoxicity Through Antiapoptosis, Antioxidative Stress, Anti-Inflammation, and Acceleration of Metabolism.

Cisplatin (CP) is one of the most effective antitumor drugs in the clinic, but has serious adverse reactions, and its hepatotoxicity has not been fully investigated. Licorice (GC), a traditional herbal medicine, has been commonly used as a detoxifier for poisons and drugs, and may be an effective drug for CP-induced hepatotoxicity. However, its mechanism and the effector molecules remain ambiguous. Therefore, in this study, a network pharmacology and proteomics-based approach was established, and a panoramic view of the detoxification of GC on CP-induced hepatotoxicity was provided. The experimental results indicated that GC can recover functional indices and pathological liver injury, inhibit hepatocyte apoptosis, upregulate B-cell lymphoma/leukemia 2 (Bcl-2) and superoxide dismutase (SOD) levels, and downregulate cellular tumor antigen p53 (p53), caspase-3, malondialdehyde high mobility group protein B1 (HMGB1), tumor necrosis factor alpha (TNF-α), and interleukin 1β (IL-1β) levels. Proteomics indicated that GC regulates phosphatidylcholine translocator ABCB1 (ABCB1B), canalicular multispecific organic anion transporter 1 (ABCC2), cytochrome P450 4A2 (CYP4A2), cytochrome P450 1A1 (CYP1A1), cytochrome P450 1A2 (CYP1A2), estrogen receptor (ESR1), and DNA topoisomerase 2-alpha (TOP2A), inhibits oxidative stress, apoptosis, and inflammatory responses, and accelerates drug metabolism. In this study, we provide the investigation of the efficacy of GC against CP-induced hepatotoxicity, and offer a promising alternative for the clinic.

LncRNA FAM230B Promotes Gastric Cancer Growth and Metastasis by Regulating the miR-27a-5p/TOP2A Axis.

Long non-coding RNAs serve as key components of competing endogenous RNA (ceRNA) networks that underlie tumorigenesis. We investigated the pathogenic roles of lncRNA FAM230B and its molecular mechanism in gastric cancer (GC). The levels of FAM230B expression in five gastric cancer cell lines and in human gastric mucosal cells were compared by quantitative RT-PCR. To analyze the function of FAM230B in GC, we overexpressed FAM230B in AGS cells, silenced FAM230B in MGC-803 cells, and tested the effect of FAM230B on tumor growth in nude mice. The interaction between miR-27a-5p and FAM230B was predicted by a bioinformatics analysis and then verified with a dual-luciferase reporter assay. We also further investigated the role and mechanism of FAM230B by forcing overexpression of miR-27a-5p in MGC-803 gastric cancer cells. We found that FAM230B was highly expressed in gastric cancer cell lines and mainly located in the cytoplasm. FAM230B overexpression promoted the proliferation, migration, and invasion of AGS cells and repressed their apoptosis; it also facilitated tumor growth in vivo. In contrast, FAM230B knockdown suppressed the proliferation, migration, and invasion of MGC0803 cells, but enhanced their apoptosis and inhibited tumor growth in vivo. MiR-27a-5p expression was suppressed by FAM230B overexpression in AGS cells. MiR-27a-5p inhibited the proliferation, migration, and invasion of gastric cancer cells, and promoted the apoptosis of gastric cancer cells by reducing TOP2A (topoisomerase 2 alpha) expression. Our study showed that lncRNA FAM230B might function to promote GC. FAM230B functioned as a ceRNA by sponging miR-27a-5p and enhancing TOP2A expression.

Identification of sumoylated targets in proliferating mouse spermatogonia and human testicular seminomas.

Spermatogenesis is regulated by a complex network of posttranslation modifications. Sumoylation (a modification by small ubiquitin-like modifiers, or SUMO proteins) was identified as an important cellular event in different cell types. SUMO proteins are highly expressed in the testis, and their role during spermatogenesis has begun to be elucidated. Given the important role of sumoylation in the regulation of mitosis and cancer progression in other tissues, the aim of the current study was to identify the targets of SUMO in proliferating mouse spermatogonia and human seminoma tissues and to initially examine the level of sumoylation in relation to the proliferative activity of the tissues. Using freshly purified spermatogonia and C18-4 spermatogonia cell line, mass spectrometry analysis identified several SUMO targets implicated into the proliferation of spermatogonia (such as heat shock protein 60 [HSP60] and prohibitin). Tissue array and western blot approaches showed that SUMO expression is a prominent feature of human seminomas and that the proliferative activity of the tumor tissues was positively correlated with the level of SUMO expression. Downregulation of sumoylation with si-RNA was not sufficient to significantly affect the proliferation of C18-4 spermatogonia; however, SUMO overexpression increased the proliferation rate of the cells. These data suggest that cells are more sensitive to an elevated level of SUMO, and that this situation may lead to an upregulated cellular proliferation and, possibly, cancer. Mass spectrometry analysis identified around a hundred SUMO targets in seminoma samples. Notably, many of the identified proteins (such as proliferating cell nuclear antigen [PCNA], DNA topoisomerase 2-alpha [Top2A], prohibitin, 14-3-3 protein, and others) were implicated in oncogenic transformation and cancer progression.

Array expression meta-analysis of cancer stem cell genes identifies upregulation of PODXL especially in DCC low expression meningiomas.

BackgroundMeningiomas are the most common intracranial tumors, with a subset of cases bearing a progressive phenotype. The DCC netrin 1 receptor (DCC) is a candidate gene for early meningioma progression. Cancer stem cell (CSC) genes are emerging as cancer therapeutic targets, as their expression is frequently associated with aggressive tumor phenotypes. The main objective of the study was to identify deregulated CSC genes in meningiomas.Materials and methodsInterrogating two expression data repositories, significantly differentially expressed genes (DEGs) were determined using DCC low vs. DCC high expression groups and WHO grade I (GI) vs. grade II + grade III (GII + GIII) comparison groups. Human stem cell (SC) genes were compiled from two published data sets and were extracted from the DEG lists. Biofunctional analysis was performed to assess associations between genes or molecules.ResultsIn the DCC low vs. DCC high expression groups, we assessed seven studies representing each between seven and 58 samples. The type I transmembrane protein podocalyxin like (PODXL) was markedly upregulated in DCC low expression meningiomas in six studies. Other CSC genes repeatedly deregulated included, e.g., BMP/retinoic acid inducible neural specific 1 (BRINP1), prominin 1 (PROM1), solute carrier family 24 member 3 (SLC24A3), rRho GTPase activating protein 28 (ARHGAP28), Kruppel like factor 5 (KLF5), and leucine rich repeat containing G protein-coupled receptor 4 (LGR4). In the GI vs. GII + GIII comparison groups, we assessed six studies representing each between nine and 68 samples. DNA topoisomerase 2-alpha (TOP2A) was markedly upregulated in GII + GIII meningiomas in four studies. Other CSC genes repeatedly deregulated included, e.g., ARHGAP28 and PODXL. Network analysis revealed associations of molecules with, e.g., cellular development and movement; nervous system development and function; and cancer.ConclusionsThis meta-analysis on meningiomas identified a comprehensive list of deregulated CSC genes across different array expression studies. Especially, PODXL is of interest for functional assessment in progressive meningiomas.

New insights into diagnosis and therapeutic options for proliferative hepatoblastoma.

The highly proliferating C2A subtype is characterized by topoisomerase 2-alpha gene up-regulation and FA pathway activation, and the HB therapeutic arsenal could include bortezomib for the treatment of patients with the most aggressive tumors. (Hepatology 2018;68:89-102).

Racial Disparities in the Molecular Landscape of Cancer.

African Americans (AA) have the highest incidence and mortality of any racial/ethnic group in the US for most cancer types. Heterogeneity in the molecular biology of cancer, as a contributing factor to this disparity, is poorly understood. To address this gap in knowledge, we explored the molecular landscape of colorectal cancer (CRC), non-small cell lung cancer (NSCLC) and high-grade glioma (HGG) from 271 AA and 636 Caucasian (CC) cases. DNA from formalin-fixed paraffin-embedded tumors was sequenced using next-generation sequencing. Additionally, we evaluated protein expression using immunohistochemistry. The Exome Aggregation Consortium Database was evaluated for known ethnicity associations. Considering only pathogenic or presumed pathogenic mutations, as determined by the American College of Medical Genetics and Genomics guidelines, and using Bonferroni and Benjamini-Hochberg corrections for multiple comparisons, we found that CRC tumors from AA patients harbored significantly more mutations of phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) than those from CC patients. CRC tumors in AA patients also appeared to harbor more mutations of mitogen-activated protein kinase kinase 1 (MAP2K1/MEK1), MPL proto-oncogene (MPL), thrombo-poietin receptor, and neurofibromin 1 (NF1) than those from CC patients. In contrast, CRCs from AA patients were likely to carry fewer mutations of ataxia-telangiectasia mutated (ATM), as well as of proto-oncogene B-Raf (BRAF), including the V600E variant, than those from CC patients. Rates of immunohistochemical positivity for epidermal growth factor receptor (EGFR) and DNA topoisomerase 2-alpha (TOP2A) tended to be higher in CRCs from AA patients than in CC patients. In NSCLC adenocarcinoma, BRAF variants appeared to be more frequent in the AA than in the CC cohort, whereas in squamous cell lung carcinoma, programmed death-ligand 1 (PD-L1) expression tended to be lower in the AA than in CC group. Moreover, HGG tumors from AA patients showed a trend toward harboring more mutations of protein tyrosine phosphatase non-receptor 11 (PTPN11), than HGG tumors from the CC cohort. In contrast, mutations of phosphatase and tensin homolog (PTEN) and tumor protein 53 (TP53) appeared to be higher in HGG tumors in CC patients than in their AA counterparts. Our data revealed significant differences and trends in molecular signatures of the three cancer types in AA and CC cohorts. These findings imply that there may be differences in carcinogenesis between AA and CC patients and that race may be a factor that should be considered regarding cancer incidence and outcome.

Overexpression of Topoisomerase 2-Alpha Confers a Poor Prognosis in Pancreatic Adenocarcinoma Identified by Co-Expression Analysis.

Pancreatic ductal adenocarcinoma (PDAC) is the fourth most common cause of human cancer-related death in the developed countries. Its progression and prognosis are influenced by a complex network of gene interactions. The purpose of this study is to explore key genes associated with pancreatic ductal adenocarcinoma and to predict the possible mechanisms. A weighted gene co-expression network was constructed to identify gene modules associated with the progression of PDAC. In the significant module (R 2=0.30), a total of 20 network hub genes were identified, 6 of which were also hub nodes in the protein-protein interaction network of the module genes. In validation, TOP2A has a higher correlation than other hub genes. Also, in the test set (n=118), TOP2A was more highly expressed in PDAC than normal pancreas samples (P<0.001). What is more, gene set enrichment analysis demonstrated that eight gene sets (n=118), "nucleotide excision repair," "P53 signaling pathway," "proteasome," "mismatch repair," "homologous recombination," "DNA replication," "cell cycle," and "base excision repair," were enriched (FDR<0.05). In gene ontology analysis, TOP2A in the enriched set was associated with cell cycle and cell division. Furthermore, survival analysis indicated that higher expression of TOP2A resulted in the lower overall survival time as well as disease-free survival time. TOP2A was identified in association with the progression and prognosis of PDAC probably by regulating cell cycle and p53 signaling pathway.