Aurora Kinase A Is Overexpressed in Human Retinoblastoma and Correlates with Histopathologic High-Risk Factors: Implications for Targeted Therapy.

Retinoblastoma (RB) is an intraocular malignancy initiated by loss of RB1 function and/or dysregulation of MYCN oncogene. RB is primarily treated with chemotherapy; however, systemic toxicity and long-term adverse effects remain a significant challenge necessitating the identification of specific molecular targets. Aurora kinase A (AURKA), a critical cell cycle regulator, contributes to cancer pathogenesis, especially in RB1-deficient and MYCN-dysregulated tumors. The current immunohistochemistry study in patient specimens (n = 67) indicated that AURKA is overexpressed in RB, and this elevated expression correlates with one or more histopathologic high-risk factors, such as tumor involvement of the optic nerve, choroid, sclera, and/or anterior segment. More specifically, AURKA is ubiquitously expressed in most advanced-stage RB tumors that show a suboptimal response to chemotherapy. shRNA-mediated depletion/pharmacologic inhibition studies in cell lines, patient-derived cells, in vivo xenografts, and enucleated patient specimens confirmed that RB cells are highly sensitive to a lack of functional AURKA. In addition, AURKA and N-myc proto-oncogene protein (MYCN) associate with each other to regulate their levels in RB cells. Overall, these results demonstrate a previously unknown up-regulation of AURKA in RB, facilitated by its crosstalk with MYCN. The elevated levels of this kinase may indicate unfavorable prognosis in tumors refractory to chemotherapy. This study provides a rationale and confirms that therapeutic targeting of elevated AURKA in RB could be a potential treatment approach.

Identifying Treatment Resistance Related Pathways by Analyzing Serum Extracellular Vesicles of Patients With Resistant Versus Regressed Retinoblastoma.

Purpose: To identify the genes and pathways responsible for treatment resistance (TR) in retinoblastoma (RB) by analyzing serum small extracellular vesicles (sEVs) of patients with TR active RB (TR-RB) and completely regressed RB (CR-RB). Methods: Serum-derived sEVs were characterized by transmission electron microscopy and nanoparticle tracking analysis. sEV transcriptome profiles of two TR-RB and one CR-RB with good response (>20 years tumor free) were compared to their age-matched controls (n = 3). Gene expression data were analyzed by the R Bioconductor package. The CD9 protein and mRNA expression of CD9, CD63, and CD81 were studied in five RB tumors and two control retinae by immunohistochemistry and quantitative reverse transcription-polymerase chain reaction. Results: The isolated serum sEVs were round shaped and within the expected size (30-150 nm), and they had zeta potentials ranging from -10.8 to 15.9 mV. The mean ± SD concentrations of sEVs for two adults and four children were 1.1 × 1012 ± 0.1 and 5.8 × 1011 ± 1.7 particles/mL. Based on log2 fold change of ±2 and P < 0.05 criteria, there were 492 dysregulated genes in TR-RB and 184 in CR-RB. KAT2B, VWA1, CX3CL1, MLYCD, NR2F2, USP46-AS1, miR6724-4, and LINC01257 genes were specifically dysregulated in TR-RB. Negative regulation of apoptotic signaling, cell growth, and proton transport genes were greater than fivefold expressed only in TR-RB. CD9, CD63, and CD81 mRNA levels were high in RB tumors versus control retina, with increased and variable CD9 immunoreactivity in the invasive areas of the tumor. Conclusions: Serum sEVs could serve as a potential liquid biopsy source for understanding TR mechanisms in RB.

Lipid Metabolic Reprogramming in Embryonal Neoplasms with MYCN Amplification.

Tumor cells reprogram their metabolism, including glucose, glutamine, nucleotide, lipid, and amino acids to meet their enhanced energy demands, redox balance, and requirement of biosynthetic substrates for uncontrolled cell proliferation. Altered lipid metabolism in cancer provides lipids for rapid membrane biogenesis, generates the energy required for unrestricted cell proliferation, and some of the lipids act as signaling pathway mediators. In this review, we focus on the role of lipid metabolism in embryonal neoplasms with MYCN dysregulation. We specifically review lipid metabolic reactions in neuroblastoma, retinoblastoma, medulloblastoma, Wilms tumor, and rhabdomyosarcoma and the possibility of targeting lipid metabolism. Additionally, the regulation of lipid metabolism by the MYCN oncogene is discussed.

Quantitative background parenchymal enhancement and fibro-glandular density at breast MRI: Association with BRCA status.

OBJECTIVES: To investigate whether MRI-based measurements of fibro-glandular tissue volume, breast density (MRBD), and background parenchymal enhancement (BPE) could be used to stratify two cohorts of healthy women: BRCA carriers and women at population risk of breast cancer. METHODS: Pre-menopausal women aged 40-50 years old were scanned at 3 T, employing a standard breast protocol including a DCE-MRI (35 and 30 participants in high- and low-risk groups, respectively). The dynamic range of the DCE protocol was characterised and both breasts were masked and segmented with minimal user input to produce measurements of fibro-glandular tissue volume, MRBD, and voxelwise BPE. Statistical tests were performed to determine inter- and intra-user repeatability, evaluate the symmetry between metrics derived from left and right breasts, and investigate MRBD and BPE differences between the high- and low-risk cohorts. RESULTS: Intra- and inter-user reproducibility in estimates of fibro-glandular tissue volume, MRBD, and median BPE estimations were good, with coefficients of variation < 15%. Coefficients of variation between left and right breasts were also low (< 25%). There were no significant correlations between fibro-glandular tissue volume, MRBD, and BPE for either risk group. However, the high-risk group had higher BPE kurtosis, although linear regression analysis did not reveal significant associations between BPE kurtosis and breast cancer risk. CONCLUSIONS: This study found no significant differences or correlations in fibro-glandular tissue volume, MRBD, or BPE metrics between the two groups of women with different levels of breast cancer risk. However, the results support further investigation into the heterogeneity of parenchymal enhancement. KEY POINTS: • A semi-automated method enabled quantitative measurements of fibro-glandular tissue volume, breast density, and background parenchymal enhancement with minimal user intervention. • Background parenchymal enhancement was quantified over the entire parenchyma, segmented in pre-contrast images, thus avoiding region selection. • No significant differences and correlations in fibro-glandular tissue volume, breast density, and breast background parenchymal enhancement were found between two cohorts of women at high and low levels of breast cancer risk.

Beyond the learning curve: improving outcomes in Robotic myomectomy compared to laparoscopic myomectomy.

Uterine myomas are benign tumours frequently seen in women of reproductive age. Myomectomy remains a viable option for treating this condition in women who wish to preserve their uterus. We undertook this study to compare the peri-operative surgical outcomes of Robotic myomectomy (RM) with laparoscopic myomectomy (LM) in Indian patients of uterine myomas after the initial learning curve of RM was achieved. A retrospective chart review was performed for the patients who underwent RM or LM for the treatment of uterine myomas. A total of 177 patients, 116 in the RM group and 61 in the LM group, were included in the study. The mean age in the RM and LM group was 34.31 ± 5.40 years and 33.54 ± 4.96 years, respectively (p = 0.355). The mean total operative time was marginally more in RM group (127.37 ± 110.67 vs. 120.66 ± 44.27, p = 0.650) but the difference was not statistically significant. Patients in the RM group had significantly less blood loss (115.43 ± 79.43 vs. 340.98 ± 453.9 ml, p = < 0.0001), hospital stay (1.28 ± 0.49 vs. 1.92 ± 1.05 days, p = < 0.0001), requirement of blood transfusion (93.97 vs. 81.97%, p = 0.031) and requirement of intravenous (IV) analgesia (41.38 vs. 34.43%, p = 0.019) as compared to the patients in the LM group. The Robotic myomectomy significantly reduces blood loss, the duration of hospital stay, and requirement of blood transfusions and IV analgesia as compared to the laparoscopic myomectomy.

Comprehensive Analysis of Serum Small Extracellular Vesicles-Derived Coding and Non-Coding RNAs from Retinoblastoma Patients for Identifying Regulatory Interactions.

The present study employed nanoparticle tracking analysis, transmission electron microscopy, immunoblotting, RNA sequencing, and quantitative real-time PCR validation to characterize serum-derived small extracellular vesicles (sEVs) from RB patients and age-matched controls. Bioinformatics methods were used to analyze functions, and regulatory interactions between coding and non-coding (nc) sEVs RNAs. The results revealed that the isolated sEVs are round-shaped with a size < 150 nm, 5.3 × 1011 ± 8.1 particles/mL, and zeta potential of 11.1 to −15.8 mV, and expressed exosome markers CD9, CD81, and TSG101. A total of 6514 differentially expressed (DE) mRNAs, 123 DE miRNAs, and 3634 DE lncRNAs were detected. Both miRNA-mRNA and lncRNA-miRNA-mRNA network analysis revealed that the cell cycle-specific genes including CDKNI1A, CCND1, c-MYC, and HIF1A are regulated by hub ncRNAs MALAT1, AFAP1-AS1, miR145, 101, and 16-5p. Protein-protein interaction network analysis showed that eye-related DE mRNAs are involved in rod cell differentiation, cone cell development, and retinol metabolism. In conclusion, our study provides a comprehensive overview of the RB sEV RNAs and regulatory interactions between them.

Capacity of Candida species to produce acetaldehyde at various concentrations of alcohol.

Background: Along with tobacco use, alcohol consumption is one of the crucial factors for oral cancer. Acetaldehyde (ACH), a byproduct of alcohol, is reported as carcinogenic. One of the producers of ACH from alcohol is Candida species. The aim of the study was to quantify the ACH produced by Candida species at various concentrations of alcohol. Materials and Methods: Clinical isolates of Candida, namely Candida albicans, Candida krusei and Candida tropicalis and C. albicans ATCC 18,804, were subjected to various concentrations of alcohol. Alcohol dehydrogenase and ACH were estimated using spectrophotometry and headspace gas chromatography, respectively. Results: Out of all three clinical isolates, C. tropicalis produced more ACH (412.1 µM) at 10 mM alcohol concentration by 105colony-forming unit/ml followed by C. albicans (233 µM) and C. krusei (53.7 µM). C. albicans of clinical isolate and ATCC species (222 µM) did not show much difference. Conclusion: The study results conclude that Candida species are capable of producing carcinogenic levels of ACH on exposure to various concentrations of alcohol.

The Oncogene MYCN Modulates Glycolytic and Invasive Genes to Enhance Cell Viability and Migration in Human Retinoblastoma.

Retinoblastoma is usually initiated by biallelic RB1 gene inactivation. In addition, MYCN copy number alterations also contribute to RB pathogenesis. However, MYCN expression, its role in disease progression and correlation with RB histological risk factors are not well understood. We studied the expression of MYCN in enucleated RB patient specimens by immunohistochemistry. MYCN is overexpressed in RB compared to control retina. Our microarray gene expression analysis followed by qRT-PCR validation revealed that genes involved in glucose metabolism and migration are significantly downregulated in MYCN knockdown cells. Further, targeting MYCN in RB cells using small molecule compounds or shRNAs led to decreased cell survival and migration, increased apoptosis and cell cycle arrest, suggesting that MYCN inhibition can be a potential therapeutic strategy. We also noted that MYCN inhibition results in reduction in glucose uptake, lactate production, ROS levels and gelatinolytic activity of active-MMP9, explaining a possible mechanism of MYCN in RB. Taking clues from our findings, we tested a combination treatment of RB cells with carboplatin and MYCN inhibitors to find enhanced therapeutic efficacy compared to single drug treatment. Thus, MYCN inhibition can be a potential therapeutic strategy in combination with existing chemotherapy drugs to restrict tumor cell growth in RB.

Aurora Kinase B Inhibition: A Potential Therapeutic Strategy for Cancer.

Aurora kinase B (AURKB) is a mitotic serine/threonine protein kinase that belongs to the aurora kinase family along with aurora kinase A (AURKA) and aurora kinase C (AURKC). AURKB is a member of the chromosomal passenger protein complex and plays a role in cell cycle progression. Deregulation of AURKB is observed in several tumors and its overexpression is frequently linked to tumor cell invasion, metastasis and drug resistance. AURKB has emerged as an attractive drug target leading to the development of small molecule inhibitors. This review summarizes recent findings pertaining to the role of AURKB in tumor development, therapy related drug resistance, and its inhibition as a potential therapeutic strategy for cancer. We discuss AURKB inhibitors that are in preclinical and clinical development and combination studies of AURKB inhibition with other therapeutic strategies.

Aurora Kinase B Expression, Its Regulation and Therapeutic Targeting in Human Retinoblastoma.

Purpose: Aurora kinase B (AURKB) plays a pivotal role in the regulation of mitosis and is gaining prominence as a therapeutic target in cancers; however, the role of AURKB in retinoblastoma (RB) has not been studied. The purpose of this study was to determine if AURKB plays a role in RB, how its expression is regulated, and whether it could be specifically targeted. Methods: The protein expression of AURKB was determined using immunohistochemistry in human RB patient specimens and immunoblotting in cell lines. Pharmacological inhibition and shRNA-mediated knockdown were used to understand the role of AURKB in cell viability, apoptosis, and cell cycle distribution. Cell viability in response to AURKB inhibition was also assessed in enucleated RB specimens. Immunoblotting was employed to determine the protein levels of phospho-histone H3, p53, p21, and MYCN. Chromatin immunoprecipitation-qPCR was performed to verify the binding of MYCN on the promoter region of AURKB. Results: The expression of AURKB was found to be markedly elevated in human RB tissues, and the overexpression significantly correlated with optic nerve and anterior chamber invasion. Targeting AURKB with small-molecule inhibitors and shRNAs resulted in reduced cell survival and increased apoptosis and cell cycle arrest at the G2/M phase. More importantly, primary RB specimens showed decreased cell viability in response to pharmacological AURKB inhibition. Additional studies have demonstrated that the MYCN oncogene regulates the expression of AURKB in RB. Conclusions: AURKB is overexpressed in RB, and targeting it could serve as a novel therapeutic strategy to restrict tumor cell growth.

An automated approach for the optimised estimation of breast density with Dixon methods.

OBJECTIVE: To present and evaluate an automated method to correct scaling between Dixon water/fat images used in breast density (BD) assessments. METHODS: Dixon images were acquired in 14 subjects with different T1 weightings (flip angles, FA, 4°/16°). Our method corrects intensity differences between water (W) and fat (F) images via the application of a uniform scaling factor (SF), determined subject-by-subject. Based on the postulation that optimal SFs yield relatively featureless summed fat/scaled-water (F+WSF) images, each SF was chosen as that which generated the lowest 95th-percentile in the absolute spatial-gradient image-volume of F+WSF . Water-fraction maps were calculated for data acquired with low/high FAs, and BD (%) was the total percentage water within each breast volume. RESULTS: Corrected/uncorrected BD ranged from, respectively, 10.9-71.8%/8.9-66.7% for low-FA data to 8.1-74.3%/5.6-54.3% for high-FA data. Corrected metrics had an average absolute increase in BD of 6.4% for low-FA data and 18.4% for high-FA data. BD values estimated from low- and high-FA data were closer following SF-correction. CONCLUSION: Our results demonstrate need for scaling in such BD assessments, where our method brought high-FA and low-FA data into closer agreement. ADVANCES IN KNOWLEDGE: We demonstrated a feasible method to address a main source of inaccuracy in Dixon-based BD measurements.

Inhibition of Pyruvate Dehydrogenase Kinase as a Therapeutic Strategy against Cancer.

Cancer cells alter their metabolism to support the uninterrupted supply of biosynthetic molecules required for continuous proliferation. Glucose metabolism is frequently reprogrammed in several tumors in addition to fatty acid, amino acid and glutamine metabolism. Pyruvate Dehydrogenase Kinase (PDK) is a gatekeeper enzyme involved in altered glucose metabolism in tumors. There are four isoforms of PDK (1 to 4) in humans. PDK phosphorylates E1α subunit of pyruvate dehydrogenase complex (PDC) and inactivates it. PDC decarboxylates pyruvate to acetyl CoA, which is further metabolized in mitochondria. Overexpression of PDK was observed in several tumors and is frequently associated with chemotherapy related drug resistance, invasion and metastasis. Elevated expression of PDK leads to a shift in glucose metabolism towards glycolysis instead of oxidative phosphorylation. This review summarizes recent literature related to the role of PDKs in cancer and their inhibition as a strategy. In particular, we discuss the role of PDK in tumor progression, metabolic reprogramming in stem cells, and their regulation by miRNAs and lncRNAs, oncogenes and tumor suppressors. Further, we review strategies aimed at targeting PDK to halt tumor growth and progression.

A Novel Mutation in Helical Domain 2 of NOD2 in Sporadic Blau Syndrome.

We report a 12-year-old girl who presented with bilateral granulomatous anterior uveitis accompanied by boggy arthritis of knee and ankle joints, intermittent fever, and nodular skin rash. She was diagnosed with sporadic Blau syndrome (early-onset sarcoidosis) based on above clinical signs and presence of non-necrotising granuloma on iris biopsy. DNA sequencing revealed a previously unreported heterozygous mutation consisting of a G>A transition in exon 4 of the NOD2 gene. This resulted in a glutamic acid to lysine substitution in helical domain 2 of the nucleotide binding and oligomerization (NACHT) region, possibly reducing efficiency of auto-inhibition in NOD2 signaling. Interestingly, the ocular inflammation resolved completely following therapeutic vitrectomy in both eyes whereas the systemic symptoms of fever and arthritis continued to wax and wane while on treatment with oral methotrexate and corticosteroids.

Clinicopathological characteristics of desmoplastic ameloblastoma: A systematic review.

The aim of the present review was to systematically present the clinicopathological data of desmoplastic ameloblastoma (DA) from articles published in the literature. A comprehensive search of the databases (PubMed, Medline, SCOPUS, Web of Science, and Google Scholar) for published articles on DA was conducted. A total of 238 cases were identified and analyzed from 76 published papers. DA showed a slight male predilection (male: female=1.07:1) with a predominance in the fourth and fifth decades of life. Mandibular involvement (52.55%) was most commonly seen with a marked tendency for the anterior region (mandible: 40.9%, maxilla: 48.07%). The size of the lesion ranged from .5 cm to 20.4 cm, with the majority of cases measuring more than 3 cm in size (53.84%). Radiologically, most of the lesions presented mixed radiolucency and radiopacity (62%), and root resorption was observed in only seven cases. The majority of the lesions showed ill-defined margins upon radiographic examination (65.78%). Most of the cases were treated with resection (78.57%), and five of the 10 recurrent cases were treated by enucleation/curettage. DA is characterized by the unique presentation of clinicopathological parameters. It is not possible to comment on its aggressive/recurrent nature and best treatment modality due to inadequate follow-up data.

Acute myeloid leukemia cells require 6-phosphogluconate dehydrogenase for cell growth and NADPH-dependent metabolic reprogramming.

Acute myeloid leukemia (AML) cells are highly dependent on glycolytic pathways to generate metabolic energy and support cell growth, hinting at specific, targetable vulnerabilities as potential novel targets for drug development. Elevated levels of NADPH, a central metabolic factor involved in redox reactions, are common in myeloid leukemia cells, but the significance or biochemical basis underlying this increase is unknown. Using a small molecule analog that efficiently inhibits NADPH-producing enzymes, we found that AML cells require NADPH homeostasis for cell growth. We also found that inhibiting NADPH production through knockdown of 6-phosphogluconate dehydrogenase (6PGD) within the pentose phosphate pathway was sufficient to reduce cell growth and lactate production, a measure of metabolic reprogramming. Further, inhibition of 6PGD activity reduced NADH levels and enzymatic activity of the oxidized NADH-dependent sirtuin-1. Targeting 6PGD and NADPH production was sufficient to block growth of AML cell lines resistant to the chemotherapeutics daunorubicin and cytarabine. Importantly, stromal cell-mediated resistance to targeted inhibition of oncogenic FLT3 kinase activity by quizartinib was circumvented by 6PGD knockdown. Overall, these data suggest that the dependency of AML cells on NADPH to permit increased glycolytic flux creates a potential vulnerability of possible therapeutic benefit, since much of the enhanced production of NADPH is dependent on the activity of a single enzyme, 6PGD.

Functional Activity of Matrix Metalloproteinases 2 and 9 in Tears of Patients With Glaucoma.

Purpose: To evaluate the differential expression of tear matrix metalloproteinases (MMP) 2 and 9 in of patients with various forms of glaucoma. Methods: Tear samples were collected with a Schirmer's strip from 148 eyes of 113 patients (medically naïve patients with primary open-angle [POAG] or angle closure glaucoma [PACG] and those with pseudoexfoliation syndrome [PXF] or glaucoma [PXG]). These were compared to patients undergoing cataract surgery (controls) for this cross-sectional study. Functional activities of tear MMP-9 and MMP-2 were analyzed by gelatin zymography. Tenon's capsules (n = 15) were harvested from the inferior quadrant in those undergoing cataract surgery and protein expression of MMP-9 was analyzed by immunohistochemistry (IHC). Hydrogen peroxide (H2O2) stress-induced effects on in vitro activities of MMP-9 in human trabecular meshwork (HTM) cells were analyzed. Results: The MMP-9 activity in tears was increased significantly in POAG, (n = 27), PACG (n = 24), and PXF (n = 40) eyes compared to controls (n = 35), and was increased significantly in eyes with glaucoma compared to moderate/severe glaucoma (P < 0.001). The MMP-9 expression was significantly lower in PXG (n = 22) eyes. Immunohistochemistry of Tenon's capsule revealed increased expression of MMP-9 in primary glaucoma eyes. Increased MMP-9 activity was seen in in vitro by gelatin zymography and was confirmed by Western and immunofluorescent assay on HTM upon 800 and 1000 µM H2O2-induced stress for 2 to 3 hours with approximately 80% cell death. Conclusions: Increased tear MMP-9 activity in early glaucoma and pseudoexfoliation syndrome suggesting activation of extracellular matrix (ECM) degradation can be used as a tear-based predictive biomarker. Decreased expression in advanced stages suggests exhaustion of the degradation response.

Role of aquaporins in oral cancer.

Aquaporins (AQP) are the membrane proteins involved in the transport of water and some neutral solutes. Thirteen types of AQP are identified in various human tissues. The expression of AQP's has been studied in various tumors among one is oral cancer. These molecules are involved in cell proliferation, migration, and metastasis. AQP target inhibitors act directly or indirectly through focal adhesion kinase-mitogen-activated protein kinase signaling pathway and shown promising results along with anti-cancer drugs. However, further researches were required to verify the efficiency and safety of these AQPs-target inhibitors in clinical therapy.