Bench-to-bedside imaging in brain metastases: a road to precision oncology

Radiology has seen tremendous evolution in the last few decades. At the same time, oncology has made great strides in diagnosing and treating cancer. Distant metastases of neoplasms are being encountered more often in light of longer patient survival due to better therapeutic strategies and diagnostic methods. Brain metastasis (BM) is a dismal manifestation of systemic cancer. In the present scenario, magnetic resonance imaging (MRI), computed tomography (CT) and positron emission tomography (PET) are playing a big role in providing molecular information about cancer. Lately, molecular imaging has emerged as a stirring arena of dynamic imaging techniques that have enabled clinicians and scientists to noninvasively visualize and understand biological processes at the cellular and molecular levels. This knowledge has impacted etiopathogenesis, detection, personalized treatment, drug development, and our understanding of carcinogenesis. This article offers insight into the molecular biology underlying brain metastasis, its pathogenesis, imaging protocols, and algorithms. It also discusses disease-specific molecular imaging features, focusing on common tumors that spread to the brain, such as lung, breast, colorectal cancer, melanoma, and renal cell carcinoma. Additionally, it covers various targeted treatment options, criteria for assessing treatment response, and the role of artificial intelligence in diagnosing, managing, and predicting prognosis for patients with brain metastases.

Dimple Grinding Coupled with Optical Microscopy for Porosity Analysis of Metallic Coatings

Dimple grinding is one of the steps used in a common method of preparing samples for transmission electron microscopy (TEM); the TEM sample preparation process also involves ion beam sputtering after the dimpling stage. During dimpling, a spherical depression is machined into the sample, leaving a thicker rim to support and facilitate sample handling. In this paper, an alternative application for dimple grinding is developed; dimple grinding combined with optical microscopy is utilized to quantify internal porosity present within coatings. This technique essentially permits three dimensional porosity quantification across the coating thickness using a simple polishing method which provides analysis of areas larger than those observed during standard cross sectional microscopy. The application of this technique to nine electroless nickel-phosphorus (Ni-P) coatings deposited on Mg substrates is demonstrated. An analysis linking medium P content in the Ni-P coatings and high coating thickness to lower porosity is also performed. The lowest porosity was observed for medium P content coatings (5.2 wt% P), while the largest porosity occurred for the high P content coatings (10.0 wt% P). Porosity levels decreased continuously with increasing coating thickness (from 28 µm to 57 µm).

Landscaping tuberculosis multimorbidity: findings from a cross-sectional study in India

BACKGROUND

Multimorbidity, the concurrent presence of two or more chronic conditions is an emerging public health challenge. Till date, most of the research have focused on the presence and interaction of selected co-morbidities in tuberculosis (TB). There exist a critical knowledge gap on the magnitude of multimorbidity among TB patients and its impact on health outcomes.

METHODS

We undertook a cross-sectional study to assess the prevalence and patterns of multimorbidity among newly diagnosed TB patients in two states of India. A total of 323 patients were interviewed using a structured multimorbidity assessment questionnaire for primary care (MAQ-PC). MAQ-PC is already validated for Indian population and elicits 22 chronic conditions. We defined TB multimorbidity as the co-existence of TB with one or more chronic conditions and identified commonly occurring dyads (TB + single condition) and triads (TB + two conditions).

RESULTS

More than half (52%) of TB patients reported multimorbidity. Among dyads, depression, diabetes mellitus (DM), acid peptic disease (APD), hypertension, chronic alcoholism, arthritis and chronic back ache (CBA) were the most common co-occurring conditions while 'DM + arthritis', 'depression + APD', 'depression + DM' were the most commonly occurring triads among TB patients. Factors such as increasing age, low levels of education, alcohol abusers, drug-resistant TB and having health insurance were significantly associated with multimorbidity among TB patients.

CONCLUSIONS

Our findings suggest high prevalence of multimorbidity among newly diagnosed TB patients in India. The presence of concordant and discordant conditions with TB may increase the health complexity, thus necessitating appropriate care protocols. Given, the current situation, wherein TB and non-communicable diseases (NCD) services are delivered through collaborative framework between programmes, there is a need for addressing multimorbidity at the healthcare delivery level.

ROS production by mitochondria: function or dysfunction?

In eukaryotic cells, ATP generation is generally viewed as the primary function of mitochondria under normoxic conditions. Reactive oxygen species (ROS), in contrast, are regarded as the by-products of respiration, and are widely associated with dysfunction and disease. Important signaling functions have been demonstrated for mitochondrial ROS in recent years. Still, their chemical reactivity and capacity to elicit oxidative damage have reinforced the idea that ROS are the products of dysfunctional mitochondria that accumulate during disease. Several studies support a different model, however, by showing that: (1) limited oxygen availability results in mitochondria prioritizing ROS production over ATP, (2) ROS is an essential adaptive mitochondrial signal triggered by various important stressors, and (3) while mitochondria-independent ATP production can be easily engaged by most cells, there is no known replacement for ROS-driven redox signaling. Based on these observations and other evidence reviewed here, we highlight the role of ROS production as a major mitochondrial function involved in cellular adaptation and stress resistance. As such, we propose a rekindled view of ROS production as a primary mitochondrial function as essential to life as ATP production itself.

Oncometabolite lactate enhances breast cancer progression by orchestrating histone lactylation-dependent c-Myc expression

Due to the enhanced glycolytic rate, cancer cells generate lactate copiously, subsequently promoting the lactylation of histones. While previous studies have explored the impact of histone lactylation in modulating gene expression, the precise role of this epigenetic modification in regulating oncogenes is largely unchartered. In this study, using breast cancer cell lines and their mutants exhibiting lactate-deficient metabolome, we have identified that an enhanced rate of aerobic glycolysis supports c-Myc expression via promoter-level histone lactylation. Interestingly, c-Myc further transcriptionally upregulates serine/arginine splicing factor 10 (SRSF10) to drive alternative splicing of MDM4 and Bcl-x in breast cancer cells. Moreover, our results reveal that restricting the activity of critical glycolytic enzymes affects the c-Myc-SRSF10 axis to subside the proliferation of breast cancer cells. Our findings provide novel insights into the mechanisms by which aerobic glycolysis influences alternative splicing processes that collectively contribute to breast tumorigenesis. Furthermore, we also envisage that chemotherapeutic interventions attenuating glycolytic rate can restrict breast cancer progression by impeding the c-Myc-SRSF10 axis.

PKM2 dictates the poised chromatin state of PFKFB3 promoter to enhance breast cancer progression

The hypoxic milieu is a critical modulator of aerobic glycolysis, yet the regulatory mechanisms between the key glycolytic enzymes in hypoxic cancer cells are largely unchartered. In particular, the M2 isoform of pyruvate kinase (PKM2), the rate-limiting enzyme of glycolysis, is known to confer adaptive advantages under hypoxia. Herein, we report that non-canonical PKM2 mediates HIF-1α and p300 enrichment at PFKFB3 hypoxia-responsive elements (HREs), causing its upregulation. Consequently, the absence of PKM2 activates an opportunistic occupancy of HIF-2α, along with acquisition of a poised state by PFKFB3 HREs-associated chromatin. This poised nature restricts HIF-2α from inducing PFKFB3 while permitting the maintenance of its basal-level expression by harboring multiple histone modifications. In addition, the clinical relevance of the study has been investigated by demonstrating that Shikonin blocks the nuclear translocation of PKM2 to suppress PFKFB3 expression. Furthermore, TNBC patient-derived organoids and MCF7 cells-derived xenograft tumors in mice exhibited substantial growth inhibition upon shikonin treatment, highlighting the vitality of targeting PKM2. Conclusively, this work provides novel insights into the contributions of PKM2 in modulating hypoxic transcriptome and a previously unreported poised epigenetic strategy exhibited by the hypoxic breast cancer cells for ensuring the maintenance of PFKFB3 expression.

The Bivalent Bromodomain Inhibitor MT-1 Inhibits Prostate Cancer Growth

Bromodomains (BD) are epigenetic readers of histone acetylation involved in chromatin remodeling and transcriptional regulation of several genes including protooncogene cellular myelocytomatosis (c-Myc). c-Myc is difficult to target directly by agents due to its disordered alpha helical protein structure and predominant nuclear localization. The epigenetic targeting of c-Myc by BD inhibitors is an attractive therapeutic strategy for prostate cancer (PC) associated with increased c-Myc upregulation with advancing disease. MT-1 is a bivalent BD inhibitor that is 100-fold more potent than the first-in-class BD inhibitor JQ1. MT-1 decreased cell viability and causes cell cycle arrest in G0/G1 phase in castration-sensitive and resistant PC cell lines in a dose-dependent fashion. The inhibition of c-Myc function by MT-1 was molecularly corroborated by the de-repression of Protein Kinase D1 (PrKD) and increased phosphorylation of PrKD substrate proteins: threonine 120, serine 11, and serine 216 amino acid residues in β-Catenin, snail, and cell division cycle 25c (CDC25c) proteins, respectively. The treatment of 3D cell cultures derived from three unique clinically annotated heavily pretreated patient-derived PC xenografts (PDX) mice models with increasing doses of MT-1 demonstrated the lowest IC50 in tumors with c-Myc amplification and clinically resistant to Docetaxel, Cabazitaxel, Abiraterone, and Enzalutamide. An intraperitoneal injection of either MT-1 or in combination with 3jc48-3, an inhibitor of obligate heterodimerization with MYC-associated protein X (MAX), in mice implanted with orthotopic PC PDX, decreased tumor growth. This is the first pre-clinical study demonstrating potential utility of MT-1 in the treatment of PC with c-Myc dysregulation.

Imaging of Neck Nodes in Head and Neck Cancers - a Comprehensive Update

Cervical lymph node metastases from head and neck squamous cell cancers significantly reduce disease-free survival and worsen overall prognosis and, hence, deserve more aggressive management and follow-up. As per the eighth edition of the American Joint Committee on Cancer staging manual, extranodal extension, especially in human papillomavirus-negative cancers, has been incorporated in staging as it is important in deciding management and significantly impacts the outcome of head and neck squamous cell cancer. Lymph node imaging with various radiological modalities, including ultrasound, computed tomography and magnetic resonance imaging, has been widely used, not only to demonstrate nodal involvement but also for guided histopathological evaluation and therapeutic intervention. Computed tomography and magnetic resonance imaging, together with positron emission tomography, are used widely for the follow-up of treated patients. Finally, there is an emerging role for artificial intelligence in neck node imaging that has shown promising results, increasing the accuracy of detection of nodal involvement, especially normal-appearing nodes. The aim of this review is to provide a comprehensive overview of the diagnosis and management of involved neck nodes with a focus on sentinel node anatomy, pathogenesis, imaging correlates (including radiogenomics and artificial intelligence) and the role of image-guided interventions.

Hypoxia-induced loss of SRSF2-dependent DNA methylation promotes CTCF-mediated alternative splicing of VEGFA in breast cancer

Alternative splicing of vascular endothelial growth factor A (VEGFA) generates numerous isoforms with unique roles in tumor angiogenesis, and investigating the underlying mechanism during hypoxia necessitates diligent pursuance. Our research systematically demonstrated that the splicing factor SRSF2 causes the inclusion of exon-8b, leading to the formation of the anti-angiogenic VEGFA-165b isoform under normoxic conditions. Additionally, SRSF2 interacts with DNMT3A and maintains methylation on exon-8a, inhibiting CCCTC-binding factor (CTCF) recruitment and RNA polymerase II (pol II) occupancy, causing exon-8a exclusion and decreased expression of pro-angiogenic VEGFA-165a. Conversely, SRSF2 is downregulated by HIF1α-induced miR-222-3p under hypoxic conditions, which prevents exon-8b inclusion and reduces VEGFA-165b expression. Furthermore, reduced SRSF2 under hypoxia promotes hydroxymethylation on exon-8a, increasing CTCF recruitment, pol II occupancy, exon-8a inclusion, and VEGFA-165a expression. Overall, our findings unveil a specialized dual mechanism of VEGFA-165 alternative splicing, instrumented by the cross-talk between SRSF2 and CTCF, which promotes angiogenesis under hypoxic conditions.

Abstract 2475: Bromodomain inhibitor: MT1 and its potential role in modulation of prostate cancer progression

Bromodomains (BD) are epigenetic readers of histone acetylation involved in chromatin remodeling and transcriptional regulation of protooncogene cellular myelocytomatosis (c- Myc) and other genes. Because c-Myc cannot be directly targeted by small molecular inhibitors due to disordered alpha helical structure, epigenetic targeting of c-Myc by BD inhibitors is an attractive therapeutic strategy for diseases such as prostate cancer (PC) associated with increased c-Myc upregulation with advancing disease. We studied the efficacy of MT1, a novel bivalent BD inhibitor that is 100-fold more potent than the first in class BD inhibitor JQ1, at inhibiting PC growth. We tested the effect on viability by MT-1 on PC cell lines, 3D spheroids derived from clinically annotated drug resistant patient derived xenografts (PDX), mice PDX models and corroborated the molecular mechanism of MT1 down regulation of Myc leading to downstream Myc-dependent up regulation of Protein Kinase D1 (PrKD) substrate phosphorylation by western blot. MT-1 inhibited growth of PC in castration sensitive (LNCaP) and resistant PC cells (PC-3). MT-1 treatment upregulated PrKD expression and phosphorylation of known PrKD substrates: threonine 120 (Thr-120) residues in beta-catenin and the serine 216 in Cell Division Cycle 25 (CDC25C) in PC-3 cells. Moreover, MT-1 was effective in inhibition of 3D spheroids growth at IC 50 between 0.27-0.92µM in Abiraterone, Enzalutamide, Docetaxel, Cabazitaxel metastatic castrate resistant PCa patient-derived tumor 3D spheroids. Additionally, MT1 was effective in inhibiting the tumor growth in PDX mice model. A combined intra-peritoneal administration of MT-1 with another c-Myc inhibitor (3JC48-3), an obligate c-Myc and MYC-associated protein X (MAX) heterodimerization inhibitor, increased the efficacy of inhibiting the PDX growth in mice. This study provides strong pre-clinical in vitro and in vivo evidence for advancing MT- 1 as a novel c-Myc targeting drug in PC. The MT-1 drug development will likely be highly impactful as c-Myc is dysregulated in three fourths of men with advanced PC.

Citation Format: Sanjeev Shukla, Mohammed Al-Toubat, Allison H. Feibus, Ahmed Elshafei, Carlos Riveros, Nathalie Meurice, Justyna Gleba, Jonathan Chardon-Robles, Adam M. Kase, John A. Copland III, Joachim L. Petit, Teruko Osumi, K.C. Balaji. Bromodomain inhibitor: MT1 and its potential role in modulation of prostate cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2475.

Bovine cerebral theileriosis: first molecular report in cross bred cattle calf in India

Bovine tropical theileriosis caused by Theileria annulata, is a serious constraint to Indian dairy industry with more fatal infections in exotic cattle and substantial losses to cross-bred and indigenous zebu cattle. The present communication is to place on record the first report of molecular based confirmed case of cerebral theileriosis caused by T. annulata coupled with its morphological detection, clinical manifestations, haematological alterations and therapeutic management in a cross bred cattle calf from India. After preparation of peripheral thin blood smear from cross bred cattle calf at the site of collection and fixation with methanol, blood sample brought to Department of Veterinary Parasitology, College of Veterinary Science and A.H, Jabalpur and stained by standard protocol for Giemsa staining. Genomic DNA was isolated from the collected blood sample using QIAamp® DNA blood mini kit following the manufacturer's recommendations and PCR was performed. The cross bred cow calf revealed high rise in temperature (105.5°F), increased heart rate, labored breathing with seromucous nasal discharge, enlargement of prescapular lymph node and animal exhibited tonic clonic convulsions in response to any sudden noise. Giemsa stained thin blood smear revealed intraerythrocytic piroplasm and Koch'sblue bodies of T. annulata within the cytoplasm of lymphocytes. The species of Theileria was confirmed by molecular amplification of genomic DNA as T. annulata.

Measurement of the ν_{e}-Nucleus Charged-Current Double-Differential Cross Section at ⟨E_{ν}⟩=2.4 GeV Using NOvA

The inclusive electron neutrino charged-current cross section is measured in the NOvA near detector using 8.02×10^{20} protons-on-target in the NuMI beam. The sample of GeV electron neutrino interactions is the largest analyzed to date and is limited by ≃17% systematic rather than the ≃7.4% statistical uncertainties. The double-differential cross section in final-state electron energy and angle is presented for the first time, together with the single-differential dependence on Q^{2} (squared four-momentum transfer) and energy, in the range 1  GeV≤E_{ν}<6  GeV. Detailed comparisons are made to the predictions of the GENIE, GiBUU, NEUT, and NuWro neutrino event generators. The data do not strongly favor a model over the others consistently across all three cross sections measured, though some models have especially good or poor agreement in the single differential cross section vs Q^{2}.

Human Behavior-Inspired Linchpin-Directed Catalysis for Traceless Precision Labeling of Lysine in Native Proteins

The complex social ecosystem regulates the spectrum of human behavior. However, it becomes relatively easier to understand if we disintegrate the contributing factors, such as locality and interacting partners. Interestingly, it draws remarkable similarity with the behavior of a residue placed in a social setup of functional groups in a protein. Can it inspire principles for creating a unique environment for the precision engineering of proteins? We demonstrate that localization-regulated interacting partner(s) could render precise and traceless single-site modification of structurally diverse native proteins. The method targets a combination of high-frequency Lys residues through an array of reversible and irreversible reactions. However, excellent simultaneous control over chemoselectivity, site selectivity, and modularity ensures that the user-friendly protocol renders acyl group installation, including post-translational modifications (PTMs), on a single Lys. Besides, it offers a chemically orthogonal handle for the installation of probes. Also, a purification protocol integration delivers analytically pure single-site tagged protein bioconjugates. The precise labeling of a surface Lys residue ensures that the structure and enzymatic activities remain conserved post-bioconjugation. For example, the precise modification of insulin does not affect its uptake and downstream signaling pathway. Further, the method enables the synthesis of homogeneous antibody-fluorophore and antibody-drug conjugates (AFC and ADC; K183 and K249 labeling). The trastuzumab-rhodamine B conjugate displays excellent serum stability along with antigen-specific cellular imaging. Further, the trastuzumab-emtansine conjugate offers highly specific antiproliferative activity toward HER-2 positive SKBR-3 breast cancer cells. This work validates that disintegrate theory can create a comprehensive platform to enrich the chemical toolbox to meet the technological demands at the chemistry, biology, and medicine interface.

Traceless cysteine-linchpin enables precision engineering of lysine in native proteins

The maintenance of machinery requires its operational understanding and a toolbox for repair. The methods for the precision engineering of native proteins meet a similar requirement in biosystems. Its success hinges on the principles regulating chemical reactions with a protein. Here, we report a technology that delivers high-level control over reactivity, chemoselectivity, site-selectivity, modularity, dual-probe installation, and protein-selectivity. It utilizes cysteine-based chemoselective Linchpin-Directed site-selective Modification of lysine residue in a protein (LDM_C-K). The efficiency of the end-user-friendly protocol is evident in quantitative conversions within an hour. A chemically orthogonal C-S bond-formation and bond-dissociation are essential among multiple regulatory attributes. The method offers protein selectivity by targeting a single lysine residue of a single protein in a complex biomolecular mixture. The protocol renders analytically pure single-site probe-engineered protein bioconjugate. Also, it provides access to homogeneous antibody conjugates (AFC and ADC). The LDM_C-K-ADC exhibits highly selective anti-proliferative activity towards breast cancer cells.

Abstract 1622: Signaling of cyclin-dependent kinase 12 (CDK12) in prostate cancer cell lines

Cyclin-dependent kinase 12 (CDK12) belongs to the cyclin-dependent kinase (CDK) family of serine/threonine protein kinases. In contrast to CDKs which promote cell cycle progression, CDK12 is a transcriptional regulator of various cellular functions, most importantly cellular response to DNA damage and stress. Genomic alterations in CDK12 have been detected in up to 7% of patients with metastatic castration-resistant prostate cancer (CRPC). Phosphoproteomic studies have revealed that Protein Kinase D1 (PrKD1), another member of the serine/threonine kinase family, is the only kinase known to phosphorylate CDK12 at serine 681 (s681) and serine 685 (s685). While there is an increasing body of literature on CDK12 downstream signaling, there is almost no published data on upstream effectors or regulation of CDK12. Using site-directed mutagenesis, we generated CDK12 s681a and s681a+s685 mutants and transfected them into stable C4-2 and C4-2-PrKD1 cell lines to evaluate the interaction between CDK12 and PrKD1. Immunoprecipitation and immunoblotting revealed that endogenous CDK12 is stable in C4-2 cells with known levels of PrKD1 expression. However, stable transfection of C4-2-PrKD1 cells with wild-type CDK12 resulted in the degradation of nascent CDK12, whereas the non-phosphorylated mutants (s681 and s681+s685) remained stable. Our results suggest that PrKD1-mediated phosphorylation of s681and/or s685 residues affect CDK12 stability in C4-2-PrKD1 cells. We confirmed this finding by treating C4-2-PrKD1 cells with MG-132, a 26 S proteasome inhibitor, and repeating the experiment. Proteasomal inhibition rescued nascent transfected CDK12 levels even after PrKD1 phosphorylation. Our study demonstrates that CDK12 degradation might be mediated by PrKD1 phosphorylation at s681 and/or s685. Because PrKD1 and CKD12 are dysregulated across cancers, the results herein presented have potential implications for the treatment of not only prostate cancer but also other human malignancies.

Citation Format: Victor Chalfant, Carlos Riveros, Sanjeev Shukla, Teruko Osumi, K Balaji. Signaling of cyclin-dependent kinase 12 (CDK12) in prostate cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1622.

Abstract 3983: Dysregulated SerpinA6 levels and progression of prostate cancer

SerpinA6 is a major cortisol binding transport protein, which helps in cortisol tissue delivery particularly at inflammatory sites. Moreover, SerpinA6 has been reported to participate in stress response by releasing cortisol specifically at inflammatory sites upon cleavage by human neutrophil elastase between residues 344 and 345. In castrate resistant prostate cancer (CRPC) patients, reports suggest castration induces inflammation in the prostate, which increases glucocorticoids (GCs) levels and elevates pro-inflammatory cytokine IL-6 levels. We propose declining SerpinA6 levels in the prostate may play a role in prostate cancer disease progression. This could be due to increasing IL-6 levels after castration, which may inhibit or degrade SerpinA6. Deficient SerpinA6 may not be sufficient to keep steroids inactive, due to the increasing GCs. Our data suggests IL-6 treatment of androgen independent prostate cancer (PC-3) cells decreases SerpinA6 level and conversely increases glucocorticoid receptor (GR) expression in a dose (1-10ng/ml) and time (30-180 minutes) dependent fashion. Moreover, IL-6 dose dependent treatment in PC-3 cells decreases FOXO3a expression, a major apoptotic protein dysregulated in prostate cancer. Next, we determine the role of SerpinA6 (30µg/ml) and IL-6(5ng/ml) independently and in combination to PC-3 cells. We observed IL-6 and SerpinA6 co-treatment to PC-3 cells (charcoal stripped FBS media) for 6 hours reduced Neutrophil elastase levels significantly. Additionally we observed increased FOXO3a and SerpinA6 expression, whereas decreased GR and HNF3α levels. However, silencing IL-6 in PC-3 cells increased SerpinA6 expression. To further support our findings, silencing SerpinA6 in metastatic variant of PC-3 cells increased phosphor-Akt-(ser-473), glucocorticoid receptor and increased apoptotic protein FOXO3a expressions. Using dexamethasone (15µM), which is known to suppress PC-3 cell migration, we found increased expression of SerpinA6. Conversely, Mifepristone (15µM), which inhibits PC-3 cell growth, deceases SerpinA6 expression after 24 hours of treatment. In humans the normal range of circulatory SerpinA6 level are 19-45ug/ml. We treated normal prostate epithelial cells (RWPE1) and prostate cancer (PC-3) cells with human recombinant protein 18 and 36ug/ml of doses for 24 hours; RWPE1 cells represented a SerpinA6 dose dependent increase in cellular viability, whereas PC-3 cells demonstrated no change in the viability after a dose response treatment with SerpinA6 for 24 hours. These findings suggest the SerpinA6 context dependent role. We suggest that decreasing levels of SerpinA6 and FOXO3a expressions in the prostate cancer patients may have potential role in disease progression. Moreover, we need to have an effective agent, which could prevent the decreasing levels of SerpinA6 and FOXO3a in prostate to inhibit the progression of prostate cancer.

Citation Format: Carlos Riveros, Victor Chalfant, Jatinder Kumar, Sanjeev Shukla. Dysregulated SerpinA6 levels and progression of prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3983.

Improved loss-of-function CRISPR-Cas9 genome editing in human cells concomitant with inhibition of TGF-β signaling

Strategies to modulate cellular DNA repair pathways hold immense potential to enhance the efficiency of CRISPR-Cas9 genome editing platform. In the absence of a repair template, CRISPR-Cas9-induced DNA double-strand breaks are repaired by the endogenous cellular DNA repair pathways to generate loss-of-function edits. Here, we describe a reporter-based assay for expeditious measurement of loss-of-function editing by CRISPR-Cas9. An unbiased chemical screen performed using this assay enabled the identification of small molecules that promote loss-of-function editing. Iterative rounds of screens reveal Repsox, a TGF-β signaling inhibitor, as a CRISPR-Cas9 editing efficiency enhancer. Repsox invariably increased CRISPR-Cas9 editing in a panel of commonly used cell lines in biomedical research and primary cells. Furthermore, Repsox-mediated editing enhancement in primary human CD4⁺ T cells enabled the generation of HIV-1-resistant cells with high efficiency. This study demonstrates the potential of transiently targeting cellular pathways by small molecules to improve genome editing for research applications and is expected to benefit gene therapy efforts.

SARS-CoV-2 spike E156G/Δ157-158 mutations contribute to increased infectivity and immune escape

This study underscores the significance of NTD-specific SARS-CoV-2 spike mutations E156G/Δ157-158 in determining virion infectivity and neutralization by vaccine-elicited antibodies.

Breakthrough infections by emerging SARS-CoV-2 variants raise significant concerns. Here, we sequence-characterized the spike gene from breakthrough infections that corresponded to B.1.617 sublineage. Delineating the functional impact of spike mutations revealed that N-terminal domain (NTD)-specific E156G/Δ157-158 contributed to increased infectivity and reduced sensitivity to vaccine-induced antibodies. A six-nucleotide deletion (467–472) in the spike-coding region introduced this change in the NTD. We confirmed the presence of E156G/Δ157-158 from cases concurrently screened, in addition to other circulating spike (S1) mutations such as T19R, T95I, L452R, E484Q, and D614G. Notably, E156G/Δ157-158 was present in more than 90% of the sequences reported from the USA and UK in October 2021. The spike-pseudotyped viruses bearing a combination of E156G/Δ157-158 and L452R exhibited higher infectivity and reduced sensitivity to neutralization. Notwithstanding, the post-recovery plasma robustly neutralized viral particles bearing the mutant spike. When the spike harbored E156G/Δ157-158 along with L452R and E484Q, increased cell-to-cell fusion was also observed, suggesting a combinatorial effect of these mutations. Our study underscores the importance of non-RBD changes in determining infectivity and immune escape.

3JC48-3: Novel MYC inhibition in advanced prostate cancer

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Background: The proto-oncogene c-Myc is a transcription factor that is upregulated in several human cancers. Despite its key role, therapeutic targeting of c-Myc remains a challenge because of a disordered protein tertiary structure. The basic helical structure and zipper protein of c-Myc forms an obligate heterodimer with its partner MAX to function as a transcription factor. An attractive strategy is to inhibit MYC/MAX dimerization to decrease c-Myc transcriptional function. Several methods have been described to inhibit MYC/MAX dimerization including small molecular inhibitors and proteomimetics. Methods: We used NOD SCID gamma mice (NGS mice) that are immunodeficient, non-obese diabetic laboratory mice (Jackson Laboratories, Cat #J000077451) carrying patient-derived xenograft (PDX) following implantation of grade IV adenocarcinoma of the prostate from a patient into the flanks of each mouse. For maximum tolerable dose studies, we used C57BL/6 wild type mice (Jackson Laboratories, Cat #J000664). We performed a maximum dose tolerability study with the drug 3JC48-3 up to 100 mg/kg to determine limiting toxicity. We monitored the rate of growth for 2 weeks and measured the final volume of the tumors. Immunoprecipitation studies were performed using the prostate cancer cell line, PC-3, that were treated with the drug 3JC48-3 at different doses (0, 5, 10, and 20uM) for 24 hours and subsequently lysed. Results: We found 3JC48-3 decreases prostate cancer growth and viability in a dose-dependent fashion in vitro. We confirmed the inhibition of MYC/MAX dimerization by 3JC48-3 using immunoprecipitation experiments. Normal mice and mice with patient-derived prostate cancer xenografts (PDX) tolerated intraperitoneal injections of 3JC48-3 up to 100 mg/kg body weight without dose-limiting toxicity. Preliminary results in these PDX mouse models suggest that 3JC48-3 may be effective in decreasing the rate of tumor growth. Conclusions: Our study demonstrates that 3JC48-3 is a potent MYC/MAX heterodimerization inhibitor that decreases prostate cancer growth and viability in association with upregulation of both PrKD1 expression and kinase activity. In addition, 3JC48-3 is well tolerated in prostate cancer PDX mice models and may be a candidate drug for further preclinical development.

Combination therapy in metastatic castration sensitive prostate cancer: A Systematic review and network meta-analysis

Introduction

Studies directly comparing the different combination therapies offered to men with metastatic castration sensitive prostate cancer (mCSPC), are not available yet. This study was designed using the network meta-analysis (NMA) framework to provide a comparison of the different available options for the treatment of men with mCSPC.

Methods

A systematic search was performed and the prospective randomized controlled trials reporting the overall survival (OS) or failure-free survival (FFS) were selected for review. A total of 14 studies were included in the NMA.

Results

The addition of abiraterone, apalutamide, docetaxel, and docetaxel with zoledronic acid to the androgen deprivation therapy (ADT) demonstrated a significant improvement in the OS. In indirect comparison, abiraterone had a higher impact on the OS as compared to docetaxel (hazard ratio [HR]: 1.21, 95% confidence interval [CI]: 1.0-1.46) and docetaxel with zoledronic acid (HR: 1.31, 95% CI: 1.05-1.63) but not apalutamide. Furthermore, apalutamide was not different than docetaxel or docetaxel with zoledronic acid. There was a significant improvement in the FFS with the combination of abiraterone, apalutamide, docetaxel (HR: 0.61, 95% CI: 0.46-0.81), docetaxel with zoledronic acid (HR: 0.62, 95% CI: 0.43-0.9), and enzalutamide (HR: 0.39, 95% CI: 0.25-0.61) as compared to the ADT alone. Similar to the indirect comparison of OS, abiraterone outperformed docetaxel (HR: 1.66, 95% CI: 1.12-2.47), docetaxel with zoledronic acid (HR: 1.69, 95% CI: 1.06-2.68), and enzalutamide (HR: 1.06, 95% CI: 0.63-1.80), but not apalutamide in terms of impact on the FFS.

Conclusion

Overall, abiraterone demonstrated better OS and FFS outcomes as compared to all the other combination strategies in this NMA.

Epigenetic Regulation During Hypoxia and Its Implications in Cancer

Hypoxia is defined as a cellular stress condition caused by a decrease in oxygen below physiologically normal levels. Cells in the core of a rapidly growing solid tumor are faced with the challenge of inadequate supply of oxygen through the blood, owing to improper vasculature inside the tumor. This hypoxic microenvironment inside the tumor initiates a gene expression program that alters numerous signaling pathways, allowing the cancer cell to eventually evade adverse conditions and attain a more aggressive phenotype. A multitude of studies covering diverse aspects of gene regulation has tried to uncover the mechanisms involved in hypoxia-induced tumorigenesis. The role of epigenetics in executing widespread and dynamic changes in gene expression under hypoxia has been gaining an increasing amount of support in recent years. This chapter discusses, in detail, various epigenetic mechanisms driving the cellular response to hypoxia in cancer.

Assessment of front-line healthcare workers' Knowledge, Attitude and Practice after several months of COVID-19 pandemic

BACKGROUND

Frontline healthcare workers (F-HCWs) are at the forefront of medical care providers against the novel coronavirus 2019 (COVID-19) pandemic which has life-threatening potentials. Inadequate knowledge and incorrect attitudes among HCWs can directly influence practices and lead to delayed diagnosis, poor infection control practices, and spread of disease.

OBJECTIVES

The aim of this study was to assess the knowledge, attitude and practice (KAP) regarding the COVID-19 pandemic among the frontline healthcare workers (F-HCWs) working at a tertiary care hospital situated in eastern Uttar Pradesh and to identify the factors significantly associated with KAP.

METHODS

A cross-sectional study was conducted among 260 health care providers across eastern Uttar Pradesh including Basti city during December 2020. Data was collected using a self-primed pretested questionnaire from the FHCWs working at a tertiary care hospital of eastern Uttar Pradesh. In this survey, a convenience sampling method was adopted. 12 items on knowledge, 10 items on attitude, and 5 items on practices related to COVID-19. The other variables consisted of 4 items on socio-demographic attributes, p-value and 95% confidence intervals (CIs) were performed to assess the attitude and practices in relation to knowledge.

RESULTS

Of the total 260 study population, 228 were interviewed online, 32 were self-administered. Knowledge and attitude of the nursing staff were highest but practice score was best for residents. Among different age groups knowledge, attitude and practices scores were highest for 35-45, 45-60 and 25-35 age groups respectively. Respondents having 5-10 years of experience had the best knowledge and the attitude score was highest for HCWs having 10-20 years' experience but the practice score was higher for HCWs having more than 20 years' work experience. Overall knowledge score of respondents having strong correlation with attitude (p<0.05) and to the practice (p<0.05).

CONCLUSION

In this survey many F-HCWs reported adequate overall knowledge with a positive attitude and adopted appropriate practices. The F-HCWs with a higher level of education and more years of experience in health care facilities had better KAP towards COVID-19.

Unfolding the role of autophagy in the cancer metabolism

Autophagy is considered an indispensable process that scavenges toxins, recycles complex macromolecules, and sustains the essential cellular functions. In addition to its housekeeping role, autophagy plays a substantial role in many pathophysiological processes such as cancer. Certainly, it adapts cancer cells to thrive in the stress conditions such as hypoxia and starvation. Cancer cells indeed have also evolved by exploiting the autophagy process to fulfill energy requirements through the production of metabolic fuel sources and fundamentally altered metabolic pathways. Occasionally autophagy as a foe impedes tumorigenesis and promotes cell death. The complex role of autophagy in cancer makes it a potent therapeutic target and has been actively tested in clinical trials. Moreover, the versatility of autophagy has opened new avenues of effective combinatorial therapeutic strategies. Thereby, it is imperative to comprehend the specificity of autophagy in cancer-metabolism. This review summarizes the recent research and conceptual framework on the regulation of autophagy by various metabolic pathways, enzymes, and their cross-talk in the cancer milieu, including the implementation of altered metabolism and autophagy in clinically approved and experimental therapeutics.

Fate and transport in environmental quality

Changes in pollutant concentrations in environmental media occur both from pollutant transport in water or air and from local processes, such as adsorption, degradation, precipitation, straining, and so on. The terms "fate and transport" and "transport and fate" reflect the coupling of moving with the carrier media and biogeochemical processes describing local transformations or interactions. The Journal of Environmental Quality (JEQ) was one of the first to publish papers on fate and transport (F&T). This paper is a minireview written to commemorate the 50th anniversary of JEQ and show how the research interests, methodology, and public attention have been reflected in fate and transport publications in JEQ during the last 40 years. We report the statistics showing how the representation of different pollutant groups in papers changed with time. Major focus areas have included the effect of solution composition on F&T and concurrent F&T, the role of organic matter, and the relative role of different F&T pathways. The role of temporal and spatial heterogeneity has been studied at different scales. The value of long-term F&T studies and developments in modeling as the F&T research approach was amply demonstrated. Fate and transport studies have been an essential part of conservation measure evaluation and comparison and ecological risk assessment. For 50 years, JEQ has delivered new insights, methods, and applications related to F&T science. The importance of its service to society is recognized, and we look forward to new generations of F&T researchers presenting their contributions in JEQ.

Diosmetin Induces Modulation of Igf-1 and Il-6 Levels to Alter Rictor-Akt-PKCα Cascade in Inhibition of Prostate Cancer

Growth signals, which typically originate from the surrounding microenvironment, are important for cells. However, when stimulation by growth factors becomes excessive and exceeds their threshold limit, deleterious effects may ensue. In patients with cancer, maintenance of tumors depends, at least in part, on growth factor stimulation, which can also facilitate cancer progression into advanced stages. This is particularly important when the tumor grows beyond its tissue boundaries or when it invades and colonizes other tissues. These aforementioned malignant events are known to be partly supported by elevated cytokine levels. Among the currently known growth signals, insulin-like growth factor (IGF)-1 and IL-6 have been previously studied for their roles in prostate cancer. Both IGF-1 and IL-6 have been reported to activate the RAPTOR independent companion of MTOR complex 2 (Rictor)/AKT/protein kinase C α (PKCα) signaling pathway as one of their downstream mechanisms. At present, research efforts are mainly focused on the exploration of agents that alter growth factor (such as IGF-1) and cytokine (such as IL-6) signaling for their potential application as therapeutic agents, as both of these have been reported to modulate disease outcome. In the present study, IGF-1 and IL-6 served distinct roles in the androgen responsive LNCaP cell line and in the androgen refractory PC-3 cell line in a dose- and time-dependent manner. Increased phosphorylation of Rictor at the Thr-1135 residue, AKT at the Ser-473 residue and PKCα at the Ser-657 residue were observed after treatment with IGF-1 and IL-6. Subsequently, it was found that diosmetin, a natural plant aglycone, had the potential to modulate the downstream signaling cascade of Rictor/AKT/PKCα to inhibit the progression of prostate cancer. Treatment of LNCaP and PC-3 cells with diosmetin inhibited the phosphorylation of Rictor (Thr-1135), AKT (Ser-473) and PKCα (Ser-657) in a dose-dependent manner. Furthermore, the Bax/Bcl-2 expression ratio was increased in response to diosmetin treatment, which would result in increased apoptosis. Based on these observations, diosmetin may represent a novel therapeutic target for prostate cancer.

198 Immediate Post-Operative PDE5i Therapy Improves Early Erectile Function Outcomes after Robot-Assisted Radical Prostatectomy (RARP)

Aim

To assess whether the timing of post-operative Phosphodiesterase Inhibitor (PDE5i) therapy after Robot Assisted Radical Prostatectomy (RARP) is associated with a change in early erectile function, continence, or safety outcomes.

Method

Data was prospectively collected from a single surgeon in one tertiary centre and retrospectively evaluated. 158 patients were treated with PDE5i therapy post RARP over a two-year period.

Results

There were no significant differences in pre-operative characteristics between the therapy groups. Patients that had bilateral nerve sparing had a mean drop in Erectile Function (EF) score by 5.4 compared to 8.8 in the unilateral group. Additionally, 34.9% of bilateral nerve sparing patients returned to baseline compared to 12.1% of unilateral. Drop in EF scores and percentage return to baseline for unilateral nerve sparing was respectively 9 and 11.1% of immediate (day 1-2), 7 and 14.8% of early (day 3-14) and 9.7 and 9.5% of late (day &gt;14) therapy (p = 0.9 and p = 0.6). For bilateral nerve sparing this was respectively 3.5 and 42.9% immediate therapy, 5.5 and 35.5% early therapy and 7.3 and 25% late therapy (p = 0.017 and p = 0.045). Pad free and social continence was achieved in 54% and 37% of those receiving immediate therapy, 60% and 33% for early therapy and 26% and 54% for late therapy. There were no differences in compliance, complication, or readmission outcomes.

Conclusions

Immediate PDE5i therapy should be considered in patients following nerve sparing RARP in order to maximise functional outcomes, especially in those undergoing bilateral nerve spare.

734 Evaluation of A Webinar Based Surgical Teaching Course (EDUCATE) - A Prospective Cohort Study

Aim

Anecdotal evidence suggests Foundation Year (FY) doctors start surgical rotations with less confidence than medical rotations. The study aimed to determine the effect of a national webinar-based surgical teaching course on participants’ confidence, and to assess attitudes surrounding undergraduate surgical education.

Method

This prospective cohort study is reported with reference to STROBE guidelines and received ethical approval. A series of 15 free-access webinars was developed based on the Royal College of Surgeons Undergraduate Curriculum. An expert-validated questionnaire was used to collect data before and after the course. Inclusion criteria were UK-based medical students and FY doctors who attended at least one webinar. The primary outcome was confidence in completing common tasks during surgical rotations.

Results

Completed pre-course (484) and post-course (352) questionnaires yielded 92 paired samples (63% female). 85% were medical students, representing 29 UK universities, and 15% FY doctors. Mean confidence in assessing, investigating, and implementing initial management of surgical conditions was greater after the intervention (p ≤ 0.001). Mean confidence in managing on-call tasks and starting a surgical FY job was also higher post-course greater (p ≤ 0.001). These improvements correlated with webinar attendance (p ≤ 0.05). 27.1% of participants were satisfied with the quality of undergraduate surgical education. 22.9% agreed that surgical placements prepared them well to manage surgical tasks.

Conclusions

Medical students and FY doctors report low confidence and feel unprepared in managing surgical tasks. Additionally, they report poor satisfaction with undergraduate surgical education. This shortfall may be improved through delivery of a national, accessible, targeted online webinar series and curriculum.

ERK1/2-EGR1-SRSF10 Axis Mediated Alternative Splicing Plays a Critical Role in Head and Neck Cancer

Aberrant alternative splicing is recognized to promote cancer pathogenesis, but the underlying mechanism is yet to be clear. Here, in this study, we report the frequent upregulation of SRSF10 (serine and arginine-rich splicing factor 10), a member of an expanded family of SR splicing factors, in the head and neck cancer (HNC) patients sample in comparison to paired normal tissues. We observed that SRSF10 plays a crucial role in HNC tumorigenesis by affecting the pro-death, pro-survical splice variants of BCL2L1 (BCL2 Like 1: BCLx: Apoptosis Regulator) and the two splice variants of PKM (Pyruvate kinase M), PKM1 normal isoform to PKM2 cancer-specific isoform. SRSF10 is a unique splicing factor with a similar domain organization to that of SR proteins but functions differently as it acts as a sequence-specific splicing activator in its phosphorylated form. Although a body of research studied the role of SRSF10 in the splicing process, the regulatory mechanisms underlying SRSF10 upregulation in the tumor are not very clear. In this study, we aim to dissect the pathway that regulates the SRSF10 upregulation in HNC. Our results uncover the role of transcription factor EGR1 (Early Growth Response1) in elevating the SRSF10 expression; EGR1 binds to the promoter of SRSF10 and promotes TET1 binding leading to the CpG demethylation (hydroxymethylation) in the adjacent position of the EGR1 binding motif, which thereby instigate SRSF10 expression in HNC. Interestingly we also observed that the EGR1 level is in the sink with the ERK1/2 pathway, and therefore, inhibition of the ERK1/2 pathway leads to the decreased EGR1 and SRSF10 expression level. Together, this is the first report to the best of our knowledge where we characterize the ERK 1/2-EGR1-SRSF10 axis regulating the cancer-specific splicing, which plays a critical role in HNC and could be a therapeutic target for better management of HNC patients.

Immunotherapy for Alzheimer's Disease: Current Scenario and Future Perspectives

Alzheimer's disease (AD) is a global health concern owing to its complexity, which often poses a great challenge to the development of therapeutic approaches. No single theory has yet accounted for the various risk factors leading to the pathological and clinical manifestations of dementia-type AD. Therefore, treatment options targeting various molecules involved in the pathogenesis of the disease have been unsuccessful. However, the exploration of various immunotherapeutic avenues revitalizes hope after decades of disappointment. The hallmark of a good immunotherapeutic candidate is not only to remove amyloid plaques but also to slow cognitive decline. In line with this, both active and passive immunotherapy have shown success and limitations. Recent approval of aducanumab for the treatment of AD demonstrates how close passive immunotherapy is to being successful. However, several major bottlenecks still need to be resolved. This review outlines recent successes and challenges in the pursuit of an AD vaccine.

E2F1 and epigenetic modifiers orchestrate breast cancer progression by regulating oxygen-dependent ESRP1 expression

Epithelial splicing regulatory protein 1 (ESRP1) is an RNA binding protein that governs the alternative splicing events related to epithelial phenotypes. ESRP1 contributes significantly at different stages of cancer progression. ESRP1 expression is substantially elevated in carcinoma in situ compared to the normal epithelium, whereas it is drastically ablated in cancer cells within hypoxic niches, which promotes epithelial to mesenchymal transition (EMT). Although a considerable body of research sought to understand the EMT-associated ESRP1 downregulation, the regulatory mechanisms underlying ESRP1 upregulation in primary tumors remained largely uncharted. This study seeks to unveil the regulatory mechanisms that spatiotemporally fine-tune the ESRP1 expression during breast carcinogenesis. Our results reveal that an elevated expression of transcription factor E2F1 and increased CpG hydroxymethylation of the E2F1 binding motif conjointly induce ESRP1 expression in breast carcinoma. However, E2F1 fails to upregulate ESRP1 despite its abundance in oxygen-deprived breast cancer cells. Mechanistically, impelled by the hypoxia-driven reduction of tet methylcytosine dioxygenase 3 (TET3) activity, CpG sites across the E2F1 binding motif lose the hydroxymethylation marks while gaining the de novo methyltransferase-elicited methylation marks. These two oxygen-sensitive epigenetic events work in concert to repel E2F1 from the ESRP1 promoter, thereby diminishing ESRP1 expression under hypoxia. Furthermore, E2F1 skews the cancer spliceome by upregulating splicing factor SRSF7 in hypoxic breast cancer cells. Our findings provide previously unreported mechanistic insights into the plastic nature of ESRP1 expression and insinuate important implications in therapeutics targeting breast cancer progression.

Interplay within tumor microenvironment orchestrates neoplastic RNA metabolism and transcriptome diversity

The heterogeneous population of cancer cells within a tumor mass interacts intricately with the multifaceted aspects of the surrounding microenvironment. The reciprocal crosstalk between cancer cells and the tumor microenvironment (TME) shapes the cancer pathophysiome in a way that renders it uniquely suited for immune tolerance, angiogenesis, metastasis, and therapy resistance. This dynamic interaction involves a dramatic reconstruction of the transcriptomic landscape of tumors by altering the synthesis, modifications, stability, and processing of gene readouts. In this review, we categorically evaluate the influence of TME components, encompassing a myriad of resident and infiltrating cells, signaling molecules, extracellular vesicles, extracellular matrix, and blood vessels, in orchestrating the cancer-specific metabolism and diversity of both mRNA and noncoding RNA, including micro RNA, long noncoding RNA, circular RNA among others. We also highlight the transcriptomic adaptations in response to the physicochemical idiosyncrasies of TME, which include tumor hypoxia, extracellular acidosis, and osmotic stress. Finally, we provide a nuanced analysis of existing and prospective therapeutics targeting TME to ameliorate cancer-associated RNA metabolism, consequently thwarting the cancer progression. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing RNA Turnover and Surveillance > Regulation of RNA Stability RNA in Disease and Development > RNA in Disease.

Quantification of bioactive compounds in guava at different ripening stages

Guava (Psidium guajava L.) is one of the most important tropical fruits belonging to the genus Psidium and the Myrtaceae family and claim to have phenolic compounds that have been reported to possess strong antioxidant activity. This study was aimed to evaluate the bioactive constituents in guava cultivars at different ripening stages by HPLC. The five guava cultivars were selected at different ripening stages and the bioactive components were analysed by high-pressure liquid chromatography. The quantification of bioactive compounds revealed that the highest amount of bioactive compounds was found in cultivar Safeda at the unripe stage, while a minimum amount was found in ripe Apple Colour guava cultivar. The six bioactive compounds were quantified in the range of gallic acid (9.46-63.08 mg/100 g), quercetin (0.11-2.51 mg/100 g), myrcetin (0.09-0.034 mg/100 g), ascorbic acid (7.45-75.07 mg/100 g), apegenin (0.01-0.032 mg/100 g) and lycopene (0.34-0.92 mg/100 g). The exploratory evaluation of guava samples was performed through Principal Component Analysis (PCA), the bioactive compounds, lycopene, myricetin, and quercetin are dominant variables on this PC1 (61.52%) (Scores better than 0.7), thereby causing greater variability among these samples. The second principal component (PC2) represents 16.54% of the total variance and the ascorbic acid, gallic acid and apeginin (score better than 0.7), are the dominant variables on this PC.

31 Immediate Post-Operative Phosphodiesterase-5 Inhibitors (PDE5i) Therapy Improves Early Erectile Function Outcomes After Robot Assisted Radical Prostatectomy (RARP)

Introduction

To assess whether the timing of post-RARP PDE5i therapy affects early erectile function, continence, or safety outcomes.

Method

Data from 158 patients treated with PDE5is post-RARP was prospectively collected over two years from a single surgeon at one tertiary centre and retrospectively evaluated. Therapy was started: immediately (day 1-2) in 29%, early (day 3-14) in 37% and late (after day 14) post-op in 34%. EPIC-26 Erectile Function (EF) scores were collected pre-op and post-op after a median 43-day follow-up interval.

Results

Drop in EF scores and percentage return to baseline post unilateral nerve sparing (UNS) compared to bilateral nerve sparing (BNS) RARP was respectively 9 and 11.1% versus 3.5 and 42.9% of immediate therapy, 7 and 14.8% versus 5.5 and 35.5% of early and 9.7 and 9.5% versus 7.3 and 25% of late. Pad free and social continence was achieved in 54% and 37% of those receiving immediate therapy, 60% and 33% for early and 26% and 54% for late.

Conclusions

Immediate post RARP PDE5i therapy may protect EF and should be considered clinically, with more benefits for BNS than UNS patients. Immediate or early, rather than late, PDE5i therapy improved early continence in BNS patients.

429 National Evaluation of Confidence and Preparedness for Surgical Rotations in Medical Students and Foundation Year Doctors

Introduction

Limited published and anecdotal evidence suggests foundation year (FY) doctors start their surgical rotations with lower confidence than medical rotations. This may be due to insufficient undergraduate practical teaching related to common surgical rotations. This study aimed to evaluate the confidence and preparedness for surgical rotations of medical students and FY doctors.

Method

An expert-validated questionnaire was distributed nationally to UK medical students and FY doctors. The primary outcome was confidence in completing common tasks during surgical rotations.

Results

491 participants (84% medical students, 16% FYs) were recruited from 36 UK medical schools. 80% were likely to pursue a career in surgery however only 7% felt confident about starting a surgical FY job. 66% felt neutral or unsatisfied about the quality of medical school surgical teaching, and 80% indicated that placements did not prepare them well to manage common FY surgical tasks. The internal reliability of the questionnaire was high (=0.939).

Conclusions

Medical students and FY doctors lack confidence and preparation for surgical jobs. High-quality, practically grounded educational courses such as the National Surgical Teaching Society (NSTS) webinar curriculum could improve confidence and preparedness for surgical rotations. Further research evaluating the benefits of such courses is warranted.

Oxygen gradient and tumor heterogeneity: The chronicle of a toxic relationship

The commencement of cancer is attributed to one or a few cells that become rogue and attain the property of immortality. The inception of distinct cancer cell clones during the hyperplastic and dysplastic stages of cancer progression is the utimate consequence of the dysregulated cellular pathways and the proliferative potential itself. Furthermore, a critical factor that adds a layer of complexity to this pre-existent intra-tumoral heterogeneity (ITH) is the foundation of an oxygen gradient, that is established due to the improper architecture of the tumor vasculature. Therefore, as a resultant effect, the poorly oxygenated regions thus formed and characterized as hypoxic, promote the emergence of aggressive and treatment-resistant cancer cell clones. The extraordinary property of the hypoxic cancer cells to exist harmoniously with cancerous and non-cancerous cells in the tumor microenvironment (TME) further increases the intricacies of ITH. Here in this review, the pivotal influence of differential oxygen concentrations in shaping the ITH is thoroughly discussed. We also emphasize on the vitality of the interacting networks that govern the overall fate of oxygen gradient-dependent origin of tumor heterogeneity. Additionally, the implications of less-appreciated reverse Warburg effect, a symbiotic metabolic coupling, and the associated epigenetic regulation of rewiring of cancer metabolism in response to oxygen gradients, have been highlighted as critical influencers of ITH.

Tumor suppressor SMAR1 regulates PKM alternative splicing by HDAC6-mediated deacetylation of PTBP1

BACKGROUND

Highly proliferating cancer cells exhibit the Warburg effect by regulation of PKM alternative splicing and promoting the expression of PKM2. Majority of the alternative splicing events are known to occur in the nuclear matrix where various MARBPs actively participate in the alternative splicing events. SMAR1, being a MARBP and an important tumor suppressor, is known to regulate the splicing of various cancer-associated genes. This study focuses on the regulation of PKM alternative splicing and inhibition of the Warburg effect by SMAR1.

METHODS

Immunohistochemistry was performed in breast cancer patient samples to establish the correlation between SMAR1 and PKM isoform expression. Further, expression of PKM isoforms upon modulation in SMAR1 expression in breast cancer cell lines was quantified by qRT-PCR and western blot. The acetylation status of PTBP1 was estimated by immunoprecipitation along with its enrichment on PKM pre-mRNA by CLIP in SMAR1 knockdown conditions. The role of SMAR1 in tumor metabolism and tumorigenesis was explored by in vitro enzymatic assays and functional assays upon SMAR1 knockdown. Besides, in vivo tumor formation by injecting adeno-SMAR1-transduced MDA-MB-231 cells in NOD/SCID mice was performed.

RESULTS

The expression profile of SMAR1 and PKM isoforms in breast cancer patients revealed that SMAR1 has an inverse correlation with PKM2 and a positive correlation with PKM1. Further quantitative PKM isoform expression upon modulation in SMAR1 expression also reflects that SMAR1 promotes the expression of PKM1 over tumorigenic isoform PKM2. SMAR1 deacetylates PTBP1 via recruitment of HDAC6 resulting in reduced enrichment of PTBP1 on PKM pre-mRNA. SMAR1 inhibits the Warburg effect, tumorigenic potential of cancer cells, and in vivo tumor generation in a PKM2-dependent manner.

CONCLUSIONS

SMAR1 regulates PKM alternative splicing by causing HDAC6-dependent deacetylation of PTBP1, resulting in reduced enrichment of PTBP1 on PKM pre-mRNA. Additionally, SMAR1 suppresses glucose utilization and lactate production via repression of PKM2 expression. This suggests that tumor suppressor SMAR1 inhibits tumor cell metabolism and tumorigenic properties of cancer cells via regulation of PKM alternative splicing.

Impact of “national suicide prevention week” on digital awareness of suicide prevention : an insight from google trends

Introduction

Every year in the month of September, National Suicide Prevention Week is celebrated. The goal of suicide prevention week is to inform the public about suicide prevention, primarily the warning signs of suicide. However, the impact of this month on the general population is unknown. The Google trends show how frequent web searches have been performed for a particular search-term, which provide an approximation of the people’s interest.

Objectives

To evaluate public interest in suicide prevention by analyzing the google trends of “Suicide Prevention” search-term.

Methods

We estimated the interest in such topics by running the google trends data of the last decade by using the filter [Search Term:“Suicide Prevention”, Locations: “United States” and Time Ranges “ 2010 to 2020”].

Results

During this specific interval, people have searched “Suicide Prevention” most frequently during the month of September (month of National Suicide Prevention week). Conversely, in the other months, interest in “suicide prevention” fluctuated between little to none. The only other time people have shown interest in Suicide prevention, other than the month of September, was with suicide news in the media, such as the death of a celebrity by suicide, or suicide-related TV shows. [Figure]

Conclusions

Although it is not definitive, it gives some idea that National Suicide Prevention week has a considerable impact on population interest. Since we did not observe sufficient public interest in other months, there should be frequent and systematic efforts to spread suicide prevention awareness among the general population.

Development of near-infrared imaging agents for detection of junction adhesion molecule-A protein

•

Anti-junctional adhesion molecule-A (JAM-A) monoclonal antibodies (mAb) conjugated with near infra-red fluorescent dye, IR700 – as a JAM-A mAb/IR700 agent was developed.

•

An in vivo JAM-A mAb/IR700-specific near infra-red imaging of human-derived prostate and breast cancer xenograft is presented.

•

A single injection of the agent is diminished number of mitotic cells in cancerous tissue of mice bearing heterotopic tumors.

•

Since, our agent depicts the specific accumulation within the targeted tumors, this agent may be adapted to solid tumor targeted photoimmunotherapy.

Introduction

Prostate and breast cancer are the most prevalent primary malignant human tumors globally. Prostatectomy and breast conservative surgery remain the most common definitive treatment option for the >500,000 men and women newly diagnosed with localized prostate and breast cancer each year only in the US. Morphological examination is the mainstay of diagnosis but margin under-sampling of the excised cancer tissue may lead to local recurrence. In despite of the progress of non-invasive optical imaging, there is still a clinical need for targeted optical imaging probes that could rapidly and globally visualize cancerous tissues.

Methods

Elevated expression of junctional adhesion molecule-A (JAM-A) on tumor cells and its multiple pro-tumorigenic activity make the JAM-A a candidate for molecular imaging. Near-infrared imaging probe, which employed anti-JAM-A monoclonal antibody (mAb) phthalocyanine dye IR700 conjugates (JAM-A mAb/IR700), was synthesized and used to identify and visualize heterotopic human prostate and breast tumor mouse xenografts in vivo.

Results

The intravenously injected JAM-A mAb/IR700 conjugates enabled the non-invasive detection of prostate and breast cancerous tissue by fluorescence imaging. A single dose of JAM-A mAb/IR700 reduced number of mitotic cancer cells in vivo, indicating theranostic ability of this imaging agent. The JAM-A mAb/IR700 conjugates allowed us to image a specific receptor expression in prostate and breast tumors without post-image processing.

Conclusion

This agent demonstrates promise as a method to image the extent of prostate and breast cancer in vivo and could assist with real-time visualization of extracapsular extension of cancerous tissue.

Hypoxia-induced alternative splicing in human diseases: the pledge, the turn, and the prestige

Maintenance of oxygen homeostasis is an indispensable criterion for the existence of multicellular life-forms. Disruption of this homeostasis due to inadequate oxygenation of the respiring tissues leads to pathological hypoxia, which acts as a significant stressor in several pathophysiological conditions including cancer, cardiovascular defects, bacterial infections, and neurological disorders. Consequently, the hypoxic tissues develop necessary adaptations both at the tissue and cellular level. The cellular adaptations involve a dramatic alteration in gene expression, post-transcriptional and post-translational modification of gene products, bioenergetics, and metabolism. Among the key responses to oxygen-deprivation is the skewing of cellular alternative splicing program. Herein, we discuss the current concepts of oxygen tension-dependent alternative splicing relevant to various pathophysiological conditions. Following a brief description of cellular response to hypoxia and the pre-mRNA splicing mechanism, we outline the impressive number of hypoxia-elicited alternative splicing events associated with maladies like cancer, cardiovascular diseases, and neurological disorders. Furthermore, we discuss how manipulation of hypoxia-induced alternative splicing may pose promising strategies for novel translational diagnosis and therapeutic interventions.

Hypoxia-induced changes in intragenic DNA methylation correlate with alternative splicing in breast cancer

The tumor microenvironment is marked by gradients in the level of oxygen and nutrients, with oxygen levels reaching a minimum at the core of the tumor, a condition known as tumor hypoxia. Mediated by members of the HIF family of transcription factors, hypoxia leads to a more aggressive tumor phenotype by transactivation of several genes as well as reprogramming of pre-mRNA splicing. Intragenic DNA methylation, which is known to affect alternative splicing in cancer, could be one of several reasons behind the changes in splicing patterns under hypoxia. Here, we have tried to establish a correlation between intragenicDNA methylation and alternative usage of exons in tumor hypoxia. First, we have generated a customhypoxia signature consisting of 34 genes that are upregulated under hypoxia and are direct targets of HIF-1α. Using this gene expression signature, we have successfully stratified publicly available breast cancer patient samples into hypoxia positive and hypoxia negative groups followed by mining of differentially spliced isoforms between these groups. The Hypoxia Hallmark signature from MSigDB was also used independently to stratify the same tumor samples into hypoxic and normoxic.We found that 821 genes were showing differential splicing between samples stratified using a custom signature, whereas, 911 genes were showing differential splicing between samples stratified using the MSigDB signature. Finally, we performed multiple correlation tests between the methylation levels (β) of microarray probes located within 1 kilo base pairs of isoform-specific exons using those exons' expression levels in the same patient samples in which the methylation level was recorded. We found that the expression level of one of the exons ofDHX32 and BICD2 significantly correlated with the methylation levels, and we were also able to predict patient survival (p-value: 0.02 for DHX32 and 0.0024 for BICD2). Our findings provide new insights into the potential functional role of intragenic DNA methylation in modulating alternative splicing during hypoxia.

Hypoxia-induced TGF-β-RBFOX2-ESRP1 axis regulates human MENA alternative splicing and promotes EMT in breast cancer

Hypoxic microenvironment heralds epithelial-mesenchymal transition (EMT), invasion and metastasis in solid tumors. Deregulation of alternative splicing (AS) of several cancer-associated genes has been instrumental in hypoxia-induced EMT. Our study in breast cancer unveils a previously unreported mechanism underlying hypoxia-mediated AS of hMENA, a crucial cytoskeleton remodeler during EMT. We report that the hypoxia-driven depletion of splicing regulator ESRP1 leads to skipping of hMENA exon 11a producing a pro-metastatic isoform, hMENAΔ11a. The transcriptional repression of ESRP1 is mediated by SLUG, which gets stimulated via hypoxia-driven TGF-β signaling. Interestingly, RBFOX2, an otherwise RNA-binding protein, is also found to transcriptionally repress ESRP1 while interacting with SLUG. Similar to SLUG, RBFOX2 gets upregulated under hypoxia via TGF-β signaling. Notably, we found that the exosomal delivery of TGF-β contributes to the elevation of TGF-β signaling under hypoxia. Moreover, our results show that in addition to hMENA, hypoxia-induced TGF-β signaling contributes to global changes in AS of genes associated with EMT. Overall, our findings reveal a new paradigm of hypoxia-driven AS regulation of hMENA and insinuate important implications in therapeutics targeting EMT.

Role of class I histone deacetylases in the regulation of maspin expression in prostate cancer

Maspin repression is frequently observed in prostate cancer; however, the molecular mechanism(s) causing the loss is not completely understood. Here, we demonstrate that inhibition of class I histone deacetylases (HDACs) mediates re-expression of maspin which plays an essential role in suppressing proliferation and migration capability in prostate cancer cells. Human prostate cancer LNCaP and DU145 cells treated with HDAC inhibitors, sodium butyrate, and trichostatin A, resulted in maspin re-expression. Interestingly, an exploration into the molecular mechanisms demonstrates that maspin repression in prostate tumor and human prostate cancer cell lines occurs via epigenetic silencing through an increase in HDAC activity/expression, independent of promoter DNA hypermethylation. Furthermore, transcriptional activation of maspin was accompanied with the suppression of HDAC1 and HDAC8 with significant p53 enrichment at the maspin promoter associated with an increase in histone H3/H4 acetylation. Our results provide evidence of maspin induction as a critical epigenetic event altered by class I HDACs in the restoration of balance to delay proliferation and migration ability of prostate cancer cells.