Surfactant-based supramolecular dye assembly: A highly selective and economically viable platform for quantification of heparin antidote

Herein, we have employed a supramolecular assembly of a cationic dye, LDS-698 and a common surfactant sodium dodecyl sulfate (SDS) as a turn-on fluorescent sensor for protamine (Pr) detection. Addition of cationic Pr to the solution of dye-surfactant complex brings negatively charged SDS molecules together through strong electrostatic interaction, assisting aggregation of SDS way before its critical micellar concentration (CMC). These aggregates encapsulate the dye molecules within their hydrophobic region, arresting non-radiative decay channels of the excited dye. Thus, the LDS-698•SDS assembly displays substantial enhancement in fluorescence intensity that follows a nice linear trend with Pr concentration, providing limit of detection (LOD) for Pr as low as 3.84(±0.11) nM in buffer, 124.4(±6.7) nM in 1% human serum and 28.3(±0.5) nM in 100% human urine. Furthermore, high selectivity, low background signal, large stokes shift, and emission in the biologically favorable deep-red region make the studied assembly a promising platform for Pr sensing. As of our knowledge it is the first ever Pr sensory platform, using a very common surfactant (SDS), which is economically affordable and very easily available in the market. This innovative approach can replace the expensive, exotic and specialized chemicals considered for the purpose and thus showcase its potential in practical applications.

Quantifying Y chromosome loss in primary and metastatic prostate cancer by chromosome painting

Somatic Y chromosome loss in hematopoietic cells is associated with higher mortality in men. However, the status of the Y chromosome in cancer tissue is not fully known due to technical limitations, such as difficulties in labelling and sequencing DNA from the Y chromosome. We have developed a system to quantify Y chromosome gain or loss in patient-derived prostate cancer organoids. Using our system, we observed Y chromosome loss in 4 of the 13 (31%) patient-derived metastatic castration-resistant prostate cancer (mCRPC) organoids; interestingly, loss of Yq (long arm of the Y chromosome) was seen in 38% of patient-derived organoids. Additionally, potential associations were observed between mCRPC and Y chromosome nullisomy. The prevalence of Y chromosome loss was similar in primary and metastatic tissue, suggesting that Y chromosome loss is an early event in prostate cancer evolution and may not a result of drug resistance or organoid derivation. This study reports quantification of Y chromosome loss and gain in primary and metastatic prostate cancer tissue and lays the groundwork for further studies investigating the clinical relevance of Y chromosome loss or gain in mCRPC.

SLCO1B3 and SLCO2B1 genotypes, androgen deprivation therapy, and prostate cancer outcomes: a prospective cohort study and meta-analysis

Solute carrier organic anion (SLCO) transporters (OATP transporters) are involved in cellular uptake of drugs and hormones. Germline variants in SLCO1B3 and SLCO2B1 have been implicated in prostate cancer progression and therapy response, including to androgen deprivation and statin medications, but results have appeared heterogeneous. We conducted a cohort study of five single-nucleotide polymorphisms (SNPs) in SLCO1B3 and SLCO2B1 with prior evidence among 3208 men with prostate cancer who participated in the Health Professionals Follow-up Study or the Physicians' Health Study, following participants prospectively after diagnosis over 32 years (median, 14 years) for development of metastases and cancer-specific death (lethal disease, 382 events). Results were suggestive of, but not conclusive for, associations between some SNPs and lethal disease and differences by androgen deprivation and statin use. All candidate SNPs were associated with SLCO mRNA expression in tumor-adjacent prostate tissue. We also conducted a systematic review and harmonized estimates for a dose-response meta-analysis of all available data, including 9 further studies, for a total of 5598 patients and 1473 clinical events. The A allele of the exonic SNP rs12422149 (14% prevalence), which leads to lower cellular testosterone precursor uptake via SLCO2B1, was associated with lower rates of prostate cancer progression (hazard ratio per A allele, 0.80; 95% confidence interval, 0.69-0.93), with little heterogeneity between studies (I2, 0.27). Collectively, the totality of evidence suggests a strong association between inherited genetic variation in SLCO2B1 and prostate cancer prognosis, with potential clinical use in risk stratification related to androgen deprivation therapy.

Quinaldine Red as a fluorescent probe for determining the melting temperature (Tm) of proteins: a simple, rapid and high-throughput assay

Proteins play an important role in biological systems and several proteins are used in diagnosis, therapy, food industry etc. Thus, knowledge about the physical properties of the proteins is of utmost importance, which will aid in understanding their function and subsequent applications. The melting temperature (Tm) of a protein is one of the essential parameters which gives information about the stability of a protein under different conditions. In the present study, we have demonstrated a method for determining the Tm of proteins using the supramolecular interaction between Quinaldine Red (QR) and proteins. Using this method, we have determined the Tm of 5 proteins and compared our results with established protocols. Our results showed good agreement with the other methods and published values. The method developed in this study is inexpensive, quick, and devoid of complex instruments and pre/post-treatment of the samples. In addition, this method can be adopted for high throughput in multi-plate mode. Thus, this study projects a new methodology for Tm determination of various proteins with user friendly operation.

Trajectory tracking control of a pneumatically actuated continuum manipulator in the presence of obstacles by using terminal sliding mode control

This paper proposes an efficient trajectory planning and dynamic tracking controller scheme for a pneumatic continuum manipulator under the effect of material hysteresis. First of all, generalized governing nonlinear dynamic equations in the form of partial differential equations for pneumatic continuum manipulator dynamics are developed by using discrete Cosserat-rod theory, where the manipulator material hysteresis is modeled by using a fractional order Bouc-Wen model. Then, the trajectory planning for the end-effector of a continuum manipulator is proposed, which accounts for the static obstacles in the workspace and the Jacobian singularity. Subsequently, an adaptive terminal sliding mode controller for the joint space control combined with a simple PI controller for task space control is proposed. The proposed controller guarantees exponential convergence of the manipulator tip positional error in finite time, even in the existence of external disturbances and model uncertainties, without any need for prior knowledge of their upper bounds. Finally, the proposed controller is applied to a two-segment continuum manipulator, the trunk of Robotino-XT, through numerical simulations and the performance gain over two controllers proposed in the literature for similar pneumatic continuum manipulators is demonstrated.

In house synthesized novel distyryl-BODIPY dye and polymer assembly as deep-red emitting probe for protamine detection

In this contribution, we designed and synthesized a deep-red emitting distyryl-BODIPY dye (dye 3) which is non-fluorescent in aqueous solution due to the formation of non-emissive aggregates. However, in presence of an amphiphilic polymer (polystyrene sulfonate, PSS), the aggregated dye molecules de-aggregate and form dye 3-PSS complex, which significantly modulates the optical features of the bound dye. Interestingly, the dye 3-PSS complex shows turn-on fluorescence response in deep-red region in presence of protamine (Pr) due to the formation of dye 3-PSS-Pr ternary complex. Such enhancement follows a linear trend in the dynamic range of 0-8.75 μM of Pr which has been utilized to determine Pr with limit of detection (LOD) of 15.04(±0.5) nM in phosphate buffer. Furthermore, excellent selectivity of the dye 3-PSS system towards Pr allows us to determine Pr even in complex biological matrix like 1% human serum. Thus, dye 3-PSS system can be applied as a very effective tool for the detection and quantification of Pr in deep-red region, overcoming several limitations encountered with the probes in the shorter wavelength region. This is the first report on BODIPY dye based supramolecular assembly for sensing and quantification of protamine.

Polymer-mediated tuning of the monomer-aggregate equilibrium of a coumarin derivative for ratiometric sensing of protamine

Amongst the various existing methods of analyte quantification, fluorescent-based methods, especially the ratiometric methods, continue to gain significant attention due to their high reproducibility, low environmental influence, and self-calibrating behavior. This paper presents the modulation in a monomer-aggregate equilibrium of coumarin-7 (C7) dye at pH ∼ 3, under the influence of a multi-anionic polymer, poly(styrene sulfonate) (PSS), leading to a significant modification in the ratiometric optical signal of the dye. At pH ∼ 3, cationic C7 formed aggregates in the presence of PSS via a strong electrostatic interaction, resulting in the development of a new emission peak at 650 nm at the expense of the monomer emission at 513 nm. Such contradicting changes in fluorescence intensities at two different wavelengths gave rise to a ratiometric signal, which was found to be highly sensitive towards external stimuli such as pH, and ionic strength. The stability of the C7-PSS complex was found to decrease as the pH of the solution was increased beyond 5, which indicated the decline in the electrostatic attraction between C7 and PSS due to the deprotonation of the C7 dye. Furthermore, an increase in the monomeric peak and a concomitant decrease of the aggregate peak with added salt in the solution (at pH ∼ 3) clearly justified the presence of an electrostatic attraction between C7 and PSS for the complex formation. This was further validated by the excited-state lifetime measurement of the C7-PSS complex, which showed a systematic increase in lifetime contribution from the monomeric species at the expense of aggregated species, as the concentration of NaCl increased in the solution. Thus, protamine (Pr), being a highly positively charged polypeptide, largely affected the monomer-aggregate equilibrium of the C7-PSS system, leading to a phenomenal change in the ratiometric signal, which was utilized to quantify with LOD as low as ∼2.8 nM in buffer for the bio-analyte Pr. Moreover, the ratiometric response of the C7-PSS assembly demonstrated excellent selectivity towards Pr, facilitating its practical relevance for the quantification of Pr in a 1% human serum matrix. Therefore, the studied C7-PSS can be utilized as a potential candidate for the quantification of the protamine even in complex biological media.

Optimal design of a helical coil support for dewars in fuel cell applications

Fuel cells are gaining popularity because of their efficient energy production without causing environmental pollution. Recently, DRDO has developed a fuel cell-based air-independent propulsion (AIP) system. In this system, the hydrogen is produced onboard while oxygen is carried in liquefied form (LOX) from the land in specially designed insulated storage vessels called dewars. Such vessels are needed because LOX has a low boiling point (NBP ~ 90 K) and heat of vaporization (~ 213 kJ/kg), due to which it boils off easily even when there is a small amount of heat inleak from the ambient. A typical dewar consists of two vessels separated by insulation. Support members are used to hold the two vessels together. Heat inleak through the supports and the insulation of the dewar causes the boiling of LOX. The vessels are subjected to dynamic loads during the voyage due to the filling and consumption of LOX. Therefore, the support system should be designed to withstand the dynamic loads experienced by the dewar. While the support system should have enough mechanical strength to withstand the loads it is subjected to, it should also restrict the heat inleak from the ambient to minimize the LOX boil-off. To meet this requirement, we need to optimize the support system design. Design optimization of support systems is especially critical in submarines to reduce the snorkeling frequency. Even though the dewars are available commercially for various applications, their design methodologies are not available in the open literature. Cylindrical rods are generally used as support members. In earlier studies, the authors have shown that helical coils give better thermal performance than tension rods as dewar supports. These two support systems involve different design criteria. It is important to evolve an optimal design of the support system to maximize the mechanical strength of the support while minimizing the heat inleak through the support. In this paper, we present a design methodology for optimizing helical support. We have proposed a modified optimization technique derived from the classical genetic algorithm (GA) for this purpose. The modification has been done by ensuring the design feasibility of the coil at each step of the algorithm. The proposed optimization technique has been tested on a LOX dewar, and an optimal design of the helical coil support has been obtained.

Aggregation Assisted Turn-On Response of ANS Dye towards Protamine

Protamine, a polycationic peptide, plays major role in human pharmacotherapy especially as an antidote of heparin to reverse its anticoagulant activity but overdose of protamine (Pr) causes serious health issues....

Increased MYBL2 expression in aggressive hormone-sensitive prostate cancer

Loss of the histone demethylase KDM5D (lysine-specific demethylase 5D) leads to in vitro resistance of prostate cancer cells to androgen deprivation therapy (ADT) with and without docetaxel. We aimed to define downstream drivers of the KDM5D effect. Using chromatin immunoprecipitation sequencing (ChIP-seq) of the LNCaP cell line (androgen-sensitive human prostate adenocarcinoma) with and without silenced KDM5D, MYBL2-binding sites were analyzed. Associations between MYBL2 mRNA expression and clinical outcomes were assessed in cohorts of men with localized and metastatic hormone-sensitive prostate cancer. In vitro assays with silencing and overexpression of MYBL2 and KDM5D in androgen receptor (AR)-positive hormone-sensitive prostate cancer cell lines, LNCaP and LAPC4, were used to assess their influence on cellular proliferation, apoptosis, and cell cycle distribution, as well as sensitivity to androgen deprivation, docetaxel, and cabazitaxel. We found that silencing KDM5D increased histone H3 lysine K4 (H3K4) trimethylation and increased MYBL2 expression. KDM5D and MYBL2 were negatively correlated with some but not all clinical samples. Higher MYBL2 expression was associated with a higher rate of relapse in localized disease and poorer overall survival in men with metastatic disease in the CHAARTED trial. Lower MYBL2 levels enhanced LNCaP and LAPC4 sensitivity to androgen deprivation and taxanes. In vitro, modifications of KDM5D and MYBL2 altered cell cycle distribution and apoptosis in a cell line-specific manner. These results show that the transcription factor MYBL2 impacts in vitro hormone-sensitive prostate cancer sensitivity to androgen deprivation and taxanes, and lower levels are associated with better clinical outcomes in men with hormone-sensitive prostate cancer.

Fluorogenic gemcitabine based light up sensor for serum albumin detection in complex biological matrices

Herein we report fluorogenic derivative of gemcitabine (GEM-DNS), synthesized from gemcitabine hydrochloride and dansyl chloride in a single step. Owing to its large stoke shift of ∼200 nm and intriguing photophysical properties, the said dye has been utilized to estimate albumin concentration in complex bio-media such as human urine and blood serum. High sensitivity and selectivity towards albumin make the aforementioned dye a powerful diagnostic tool to detect ailments such as liver cirrhosis, diabetes, hypertension etc.

Red emitting fluorogenic dye as an efficient turn-on probe for milk allergen

Development of simple, fast and non-destructive technique such as fluorescence based method for the quantification of milk allergens in various dairy products is a highly rewarding task. In this contribution, a red emitting fluorogenic dye, quinaldine red (QR) is reported for the detection and quantification of a milk allergen, beta lactoglobulin (β-LG) in milk and whey matrices, utilizing its high selectivity and sensitivity towards β-LG. Detail spectroscopic investigation reveals that binding of QR to the hydrophobic calyx site of β-LG protein substantially reduces the torsional agility and propensity of TICT state formation of QR, rendering the dye highly fluorescent in nature. This enables estimation of β-LG with LOD 52.1(±0.9) nM in buffer solution and 0.21(±0.01) μM in 5 % bovine milk matrix respectively. Additionally, high selectivity and sensitivity, excellent repeatability, quick response, and emission in the biologically favorable red spectral region make QR based fluorometric quantification of β-LG a highly attractive choice. Finally, the estimated β-LG concentrations in milk and whey matrices from fluorometric titration and densitometry methods are found to match excellently with each other, suggesting potential of QR as an efficient turn-on fluorescent probe for the quantification of β-LG (milk allergen) in various dairy products.

Molecular Imaging of Neuroendocrine Prostate Cancer by Targeting Delta-Like Ligand 3

Treatment-induced neuroendocrine prostate cancer (NEPC) is a lethal subtype of castration-resistant prostate cancer. Using the 89Zr-labeled delta-like ligand 3 (DLL3) targeting antibody SC16 (89Zr-desferrioxamine [DFO]-SC16), we have developed a PET agent to noninvasively identify the presence of DLL3-positive NEPC lesions. Methods: Quantitative polymerase chain reaction and immunohistochemistry were used to compare relative levels of androgen receptor (AR)-regulated markers and the NEPC marker DLL3 in a panel of prostate cancer cell lines. PET imaging with 89Zr-DFO-SC16, 68Ga-PSMA-11, and 68Ga-DOTATATE was performed on H660 NEPC-xenografted male nude mice. 89Zr-DFO-SC16 uptake was corroborated by biodistribution studies. Results: In vitro studies demonstrated that H660 NEPC cells are positive for DLL3 and negative for AR, prostate-specific antigen, and prostate-specific membrane antigen (PSMA) at both the transcriptional and the translational levels. PET imaging and biodistribution studies confirmed that 89Zr-DFO-SC16 uptake is restricted to H660 xenografts, with background uptake in non-NEPC lesions (both AR-dependent and AR-independent). Conversely, H660 xenografts cannot be detected with imaging agents targeting PSMA (68Ga-PSMA-11) or somatostatin receptor subtype 2 (68Ga-DOTATATE). Conclusion: These studies demonstrated that H660 NEPC cells selectively express DLL3 on their cell surface and can be noninvasively identified with 89Zr-DFO-SC16.

The Impact of PIK3R1 Mutations and Insulin-PI3K-Glycolytic Pathway Regulation in Prostate Cancer

PURPOSE

Oncogenic alterations of the PI3K/AKT pathway occur in >40% of patients with metastatic castration-resistant prostate cancer, predominantly via PTEN loss. The significance of other PI3K pathway components in prostate cancer is largely unknown.

EXPERIMENTAL DESIGN

Patients in this study underwent tumor sequencing using the MSK-IMPACT clinical assay to capture single-nucleotide variants, insertions, and deletions; copy-number alterations; and structural rearrangements, or were profiled through The Cancer Genome Atlas. The association between PIK3R1 alteration/expression and survival was evaluated using univariable and multivariable Cox proportional-hazards regression models. We used the siRNA-based knockdown of PIK3R1 for functional studies. FDG-PET/CT examinations were performed with a hybrid positron emission tomography (PET)/CT scanner for some prostate cancer patients in the MSK-IMPACT cohort.

RESULTS

Analyzing 1,417 human prostate cancers, we found a significant enrichment of PIK3R1 alterations in metastatic cancers compared with primary cancers. PIK3R1 alterations or reduced mRNA expression tended to be associated with worse clinical outcomes in prostate cancer, particularly in primary disease, as well as in breast, gastric, and several other cancers. In prostate cancer cell lines, PIK3R1 knockdown resulted in increased cell proliferation and AKT activity, including insulin-stimulated AKT activity. In cell lines and organoids, PIK3R1 loss/mutation was associated with increased sensitivity to AKT inhibitors. PIK3R1-altered patient prostate tumors had increased uptake of the glucose analogue 18F-fluorodeoxyglucose in PET imaging, suggesting increased glycolysis.

CONCLUSIONS

Our findings describe a novel genomic feature in metastatic prostate cancer and suggest that PIK3R1 alteration may be a key event for insulin-PI3K-glycolytic pathway regulation in prostate cancer.

Waste derived approach towards wealthy fluorescent N-doped graphene quantum dots for cell imaging and H2O2 sensing applications

Herein, we report the synthesis of a highly fluorescent nitrogen doped graphene quantum dots (N-GQDs) from waste precursors such as melamine sponge and arjuna bark via a microwave treatment and its functional and morphological characterization using various spectroscopy techniques such as optical, FTIR, XPS and TEM. The as-prepared aqueous N-GQD (dia. 2-3 nm) was used for the bio-imaging application using breast carcinoma cell line (MDA-MB-231) as a model, and the locations of all cells in the cytoplasm as well as nuclei were observed to stain brightly in blue fluorescent color successfully. In addition to that, the aqueous N-GQD showed fluorescence quenching behavior in the presence of hydrogen peroxide, which was exploited to sense H₂O₂, a probable toxin generated in the diseased cells. Importantly, the cell cytotoxicity was measured and found to be non-toxic (70% survival) to the MDA-MB-231 cells even at very high concentration (∼1.8 mg/ml) of the synthesized N-GQD. This study revealing excellent biocompatibility and imaging of the model cancer cells, and sensing of H₂O₂ by fluorescent quenching, indicates potential in-vivo cell culture applications of the prepared fluorescent N-GQD.

Grading of HCC Biopsy Images using Nucleus and Texture Features

Hepatocellular carcinoma (HCC) is one of the most critical health problems in the world. For proper treatment, it is important to identify the grade of cancer morbidity from HCC biopsy image. The diagnostic work is not only time-consuming but also subjective. The same biopsy image may be diagnosed as of different grades by different doctors, due to lack of experience or difference in opinion. In this work, we proposed an automatic grading system with classification accuracy matching to an experienced doctor, to help augment the diagnosis process. First, we proposed a segmentation method to isolate all nucleus-like objects present in a biopsy image. Non-target objects (here the target is a single HCC nucleus) present in the biopsy image are isolated too in the segmentation process. To eliminate such non-target objects, we proposed clustering of segmented images and a novel method to filter out target objects. Next, we proposed a two track neural network, where input consists of 2 different images. It combines a single segmented nucleus and a random cropped texture patch of the biopsy image to which the nucleus belongs. At this classifier output, we grade the single nucleus. Finally, a majority voting method is used to identify the grade of the whole biopsy image. We achieved an accuracy of 99.03% for nucleus image grading and 99.66% accuracy for grading biopsy images.

Prognostic and therapeutic significance of COP9 signalosome subunit CSN5 in prostate cancer

Chromosome 8q gain is associated with poor clinical outcomes in prostate cancer, but the underlying biological mechanisms remain to be clarified. CSN5, a putative androgen receptor (AR) partner that is located on chromosome 8q, is the key subunit of the COP9 signalosome, which deactivates ubiquitin ligases. Deregulation of CSN5 could affect diverse cellular functions that contribute to tumor development, but there has been no comprehensive study of its function in prostate cancer. The clinical significance of CSN5 amplification/overexpression was evaluated in 16 prostate cancer clinical cohorts. Its oncogenic activity was assessed by genetic and pharmacologic perturbations of CSN5 activity in prostate cancer cell lines. The molecular mechanisms of CSN5 function were assessed, as was the efficacy of the CSN5 inhibitor CSN5i-3 in vitro and in vivo. Finally, the transcription cofactor activity of CSN5 in prostate cancer cells was determined. The prognostic significance of CSN5 amplification and overexpression in prostate cancer was independent of MYC amplification. Inhibition of CSN5 inhibited its oncogenic function by targeting AR signaling, DNA repair, multiple oncogenic pathways, and spliceosome regulation. Furthermore, inhibition of CSN5 repressed metabolic pathways, including oxidative phosphorylation and glycolysis in AR-negative prostate cancer cells. Targeting CSN5 with CSN5i-3 showed potent antitumor activity in vitro and in vivo. Importantly, CSN5i-3 synergizes with PARP inhibitors to inhibit prostate cancer cell growth. CSN5 functions as a transcription cofactor to cooperate with multiple transcription factors in prostate cancer. Inhibiting CSN5 strongly attenuates prostate cancer progression and could enhance PARP inhibition efficacy in the treatment of prostate cancer.

Carbon nano-dot for cancer studies as dual nano-sensor for imaging intracellular temperature or pH variation

Cellular temperature and pH govern many cellular physiologies, especially of cancer cells. Besides, attaining higher cellular temperature plays key role in therapeutic efficacy of hyperthermia treatment of cancer. This requires bio-compatible, non-toxic and sensitive probe with dual sensing ability to detect temperature and pH variations. In this regard, fluorescence based nano-sensors for cancer studies play an important role. Therefore, a facile green synthesis of orange carbon nano-dots (CND) with high quantum yield of 90% was achieved and its application as dual nano-sensor for imaging intracellular temperature and pH was explored. CND was synthesized from readily available, bio-compatible citric acid and rhodamine 6G hydrazide using solvent-free and simple heating technique requiring purification by dialysis. Although the particle size of 19 nm (which is quite large for CND) was observed yet CND exhibits no surface defects leading to decrease in photoluminescence (PL). On the contrary, very high fluorescence was observed along with good photo-stability. Temperature and pH dependent fluorescence studies show linearity in fluorescence intensity which was replicated in breast cancer cells. In addition, molecular nature of PL of CND was established using pH dependent fluorescence study. Together, the current investigation showed synthesis of highly fluorescent orange CND, which acts as a sensitive bio-imaging probe: an optical nano-thermal or nano-pH sensor for cancer-related studies.

Host-Assisted Aggregation-Induced Emission of a Tetraphenylethylene Derivative and Its Responses toward External Stimuli

Aggregation-induced emission (AIE) of fluorogenic dyes offers many opportunities as smart materials, fluorescence sensing of analytes, bioimaging, molecular electronics, and many others. AIE dyes (called AIEgens) produce emission through aggregation, which are more advantageous than conventional emission of monomeric fluorophores, as the latter is unduly susceptible toward various quenching processes. Here, we report AIE enhancement of a polyanionic sulfonato-tetraphenylethylene (SuTPE) derivative, achieved through supramolecularly assisted dye aggregation, as SuTPE interacts with a multicationic amino-β-cyclodextrin (AβCD) host. Aggregation of the dye is induced mainly because of strong electrostatic interaction of SuTPE with AβCD, causing a significant extent of charge neutralization for the polyanionic dyes, helping their assemblage at the multicationic host portal. Job's plot studies suggest preferential formation of 2:1 dye-to-host stoichiometric complexes in the present system. Ionic-strength-dependent studies nicely support the involvement of electrostatic interaction in the present system through salt-induced disintegration of the SuTPE-AβCD complexes. The AIE enhancement for the SuTPE-AβCD system is very sensitive to the external stimuli, such as pH and temperature, suggesting its prospects in various stimuli-responsive applications. Furthermore, the SuTPE-AβCD system can suitably quantify an important bioanalyte, ATP, following a competitive binding strategy, suggesting its potential application as a supramolecular biosensor.

A BODIPY-O-glycoside based near-infrared fluorescent sensor for serum albumin

Highly sensitive and selective near-infrared fluorescent bioprobes for serum albumin detection and quantification are in high demand for biomedical applications. Herein, we report a near-infrared emitting BODIPY-O-glycoside dye as a turn-on emission sensor for serum albumin. To the best of our knowledge, this is the first report of NIR-emitting BODIPY dyes for serum albumin sensing. Despite the various outstanding photophysical properties of the BODIPY dyes, their insolubility in water/biological media restricts their real biomedical applications. To overcome this issue, highly stable unadulterated BODIPY-O-glycoside nanoparticles (BDP-Glu-NPs) were prepared in aqueous solution by self-assembly of amphiphilic BODIPY-O-glycoside dyes. The BDP-Glu-NPs were characterized by spectroscopic, NMR, DLS and TEM studies. The ability of the BDP-Glu-NPs for the detection and quantification of serum albumin was demonstrated. It showed a 150-fold fluorescence enhancement in the presence of serum albumin, with excellent selectivity over other amino acids, porphyrin, proteins and various inorganic salts. Detection of human serum albumin (HSA) in urine samples showed that the bioprobe is applicable to a clinically significant range of the analytes with very low detection limit. These results suggested that the BDP-Glu-NPs can act as potential bioprobe to quantify albumin in biochemical and clinical samples.

Stimuli Responsive Confinement of a Molecular Rotor Based BODIPY Dye inside a Cucurbit[7]uril Nanocavity

Present study reports the interaction of a molecular rotor based BODIPY dye, 8-anilino-BODIPY (ABP), with a versatile macrocyclic molecule, cucurbit[7]uril (CB7), investigated through various techniques such as ground-state absorption, steady-state fluorescence, time-resolve emission, proton NMR, and quantum chemical studies. Although BODIPY dyes have widespread applications due to their intriguing photochemical properties, studies on their noncovalent interactions with different macrocyclic hosts, especially regarding their supramolecularly induced modulations in photophysical properties are very limited. The investigated BODIPY dye, especially its protonated ABPH⁺ form (pH ∼ 1), shows a large fluorescence enhancement on its interaction with the CB7 host, due to large reduction in the structural flexibility for the bound dye, causing a suppression in its nonradiative de-excitation process in the excited state. Unlike ABPH⁺, the neutral ABP form (pH ∼ 7) shows considerably weaker interaction with CB7. For ABPH⁺-CB7 system, observed photophysical results indicate formation of both 1:1 and 1:2 dye-to-host complexes. Plausible geometries of these complexes are obtained from quantum chemical studies which are substantiated nicely from ¹H NMR results. The response of the ABPH⁺-CB7 system toward changing temperature of the solution have also been investigated elaborately to understand the potential of the system in different stimuli-responsive sensor applications.

Abstract 2498: Identification and characterization of the PIK3R1-mutant subtype in PI3K-addicted prostate cancer

Metastatic castration-resistant metastatic prostate cancer (mCRPC) is incurable. Recent comprehensive genomic characterization of localized and metastatic prostate cancer has identified a long tail of oncogenic driver mutations and demonstrated recurrent alteration of genes involved in phosphoinositide 3-kinase (PI3K) signaling in ~40% mCRPC cases. Alterations in the PI3K-signaling pathway in cancer have led to a surge in the development of PI3K/Akt inhibitors and many of these targeted therapies are currently in clinical trials and show great promise for the treatment of PI3K-addicted tumors. Therefore, in precision oncology, the identification of advanced prostate cancers with high PI3K activity is critical for treatment selection and eligibility into clinical trials of PI3K/Akt inhibitors.

We analyzed panel sequencing data from 2965 prostate cancer patients (1770 localized and 1195 mCRPC cases) from the Memorial Sloan Kettering Cancer Center clinical sequencing cohort (MSK-IMPACT). The MSK-IMPACT panel sequencing includes all protein-coding mutations, copy number alterations, selected promoter mutations and structural rearrangements of 341, 410 and 468 cancer-associated genes (all panels included). Among the PI3K-AKT-mTOR pathway components (19 genes in MSK-IMPACT panel) we identified a significant enrichment of PIK3R1 (regulatory subunit that codes for p85α protein and modulates the catalytic activity of PI3K-pathway) alterations in mCRPC patients compared to localized prostate cancer (5% mCRPC vs 2% localized cases; p<0.0001). Copy number analysis identified more frequent deletion of the PIK3R1 chromosomal region in mCRPC compared to localized disease (Chromosome 5q13.1; 25% vs 15% p< 0.0001). We also observed that loss of PIK3R1 mRNA is associated with shorter biochemical recurrence-free survival of patients in primary prostate cancer cohorts (low vs high quartile; TCGA; HR: 2.8 and Taylor et al, HR: 2.6) indicating that PIK3R1 inactivation may act as a driver of aggressive prostate cancer. Experimentally we showed that RNAi mediated knockdown of PIK3R1 was sufficient to induce Akt-activation and increase cell growth in human prostate cancer cell line (LAPC4 and 22RV1) models. Most importantly we showed that Akt-inhibitors ipatasertib and MS2206 strongly reduced the viability of prostate cancer cells (LAPC4 and 22RV1) with PIK3R1 knockdown or PIK3R1 mutated mCRPC derived organoid (MSKPCa3) compared to PIK3R1 wild type cells irrespective of their PTEN status.

In summary, our study identified an association between PIK3R1 alterations and lethal prostate cancer and demonstrated that men with mCRPC who harbor defective PIK3R1 may benefit from Akt inhibitors. Further in-depth studies are warranted to uncover the biological and phenotypic characterization of PIK3R1-altered prostate cancer.

Citation Format: Goutam Chakraborty, Subhiksha Nandakumar, Rahim Hirani, Sai Harisha Rajanala, Bastien Nguyen, Romina Ghale, Ying Z. Mazzu, Lina E. Jehane, Gwo-Shu Mary Lee, Lorelei A. Mucci, Nikolaus Schultz, Philip W. Kantoff. Identification and characterization of the PIK3R1-mutant subtype in PI3K-addicted prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2498.

Abstract 979: Bcl-2 inhibitor enhances anti-androgen therapy induced regression of castration sensitive prostate cancer

Prostate cancer (PC) is the second most common cause of cancer-related deaths in males in the United States (U.S.). In the United States, an estimated 191,930 new cases will be diagnosed in 2020, resulting in 33,330 deaths, representing 10.4% of all cancer-related deaths in men in the U.S. Over the past decade, preclinical studies have demonstrated that androgen receptor (AR) signaling is a principal driver of prostate cancer, and androgen deprivation therapy (ADT) has been a mainstay in the treatment of PC. Although most PCs are initially sensitive to ADT, the duration of response is variable, and relapse invariably occurs in the transition to metastatic castration-resistant prostate cancer (mCRPC) the most lethal form of the disease. A significant proportion of mCRPCs exhibit alteration (amplification and mutation) of the AR gene. Notably, localized castration sensitive prostate cancer (CSPC) rarely demonstrates alterations of AR. This observation indicates that the alteration of AR likely results from exposure to systemic therapies rather than acting as a driver from primary CSPC to more aggressive disease. For mCRPC patients, many initially respond to second-line AR inhibitors (eg. enzalutamide and abiraterone) or docetaxel-based chemotherapy, however durable responses are rare. Therefore, it is vital to investigate additional therapeutic strategies to delay or prevent the transition of CSPC to mCRPC.

Earlier studies showed that the survival of malignant cells after anti-cancer therapies could be due to increase expression in anti-apoptotic proteins, such as the Bcl-2 family of proteins. In our current study, we observed that treatment with androgen inhibits but AR inhibitors (eg enzalutamide, apalutamide) restore Bcl2 expression in human CSPC cell lines indicating possible direct negative-regulation of the Bcl2 by the AR-signaling pathway. Experimentally we also showed that overexpression of BCL2 in human CSPC cells acts as an early mediator of ADT resistance in CSPC. Cell growth assays showed an overall strong additive effect on growth inhibition with enzalutamide in-combination with the Bcl-2 inhibitor (venetoclax) on human CSPC cells. Our in-vivo isograft tumor growth results were consistent with the in-vitro data where we observed a significant decrease in tumor volume and an increase of overall survival when mice treated with enzalutamide and venetoclax in combination as compared to either of the drugs when treated alone. Our current study for the first time develops a rationale for combining ADT with Bcl2 targeted therapies for CSPC. We believe this combination will show great potential for future clinical trials of high-risk CSPC patients and may block or delay the ADT-induced shift from CSPC to mCRPC.

Citation Format: Rahim Hirani, Subhiksha Nandakumar, Teja Kalidindi, Deborah Fidele, Harisha Rajanala, Ying Mazzu, Yuki Yoshikawa, Lina Jehane, Gwo-Shu Mary Lee, Elisa de Stanchina, Adam Sowalsky, Michael J. Morris, Heiko Schoder, Naga Vara Kishore Pillarsetty, Lorelei A. Mucci, Daniel Danila, Goutam Chakraborty, Philip W. Kantoff. Bcl-2 inhibitor enhances anti-androgen therapy induced regression of castration sensitive prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 979.

Significance of targeting the antiapoptotic pathway in castration-sensitive prostate cancer

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Background: Prostate cancer (PC) is a major health problem for men in the U.S. and is the second most common cause of cancer-related deaths in males. Although most PCs are initially sensitive to androgen-deprivation therapy (ADT), the duration of response is variable, and eventually, the cancer becomes resistant to ADT and progresses to metastatic castration-resistant prostate cancer (mCRPC). For mCRPC patients, many initially respond to second-line ARIs (eg. enzalutamide and abiraterone) or docetaxel-based chemotherapy however durable responses are rare. Therefore, it is vital to investigate additional therapeutic strategies to delay or prevent the transition of castration-sensitive prostate cancer (CSPC) to mCRPC. Methods: We treated castration-sensitive human PC cells with various anti-androgen inhibitors to investigate the direct association between Bcl2 expression and AR-pathway. We used a lentiviral-based over-expression method to develop BCL2 over-expressed experimental PC cell line systems and subjected them to various in -vitro and in vivo studies. We studied the combinational effect of Bcl2 and AR inhibitor on the in vitro growth of hormone-sensitive human PC cells and in vivo mice model. Results: We observed that treatment with androgen inhibits but ARIs (eg enzalutamide, apalutamide) restore Bcl2 expression in human CSPC cell lines indicating there is possible direct negative-regulation of the Bcl2 by the AR-signaling pathway. BCL2 over-expressed LNCaP cells show deregulation of the AR pathway, induces PSMA expression, and exhibit relative resistance to enzalutamide indicating that over-expression of BCL2 induces castration resistance in hormone-sensitive PC cells. Our cell growth inhibition assay showed an overall strong additive effect on growth inhibition with enzalutamide and the pharmacological Bcl2 inhibitor (venetoclax) combination on LNCaP cells and 22Rv1 cells. We also observed a negative association between BCL2 and AR pathway in clinical PC cohorts (Localized and mCRPC). In the isograft mice model, we showed the combination of enzalutamide and venetoclax significantly reduces subcutaneous prostate tumor growth and increases overall survival (~2 weeks) compare to control groups of mice. Moreover, using Isogenic cell lines (control and BCL2 over-expressed LNCaP) we showed higher uptake of [68Ga]-PSMA-11 in BCL2 over-expressed prostate tumors compared to control tumors in immunodeficient mice indicating that BCL2 over-expressed PC can monitor non-invasively by PSMA-PET imaging. Conclusions: Our current study develops a rationale for combining ADT with Bcl2-inhibitors for CSPC. We believe this combinatorial therapeutic approach will show great potential for future clinical trials of high-risk hormone-sensitive PC patients and may block the ADT-induced shift of CSPC to mCRPC.

Gastric pull-up by the retrosternal route for esophageal replacement: Feasibility in a limited-resource scenario

OBJECTIVES

The authors herein report the results of esophageal replacement by gastric pull-up technique through the retrosternal route as an option for esophageal replacement in a resource-constrained setup.

METHOD

Prospectively collected data upon twenty-two consecutive patients (male:female = 17:5) with mean age 24.9 months (7 months-12 years) and mean weight 7.9 kg (4.2-32 kg) who underwent retrosternal gastric pull-up for esophageal atresia (n = 18; 16 atresia with distal fistula & 2 pure atresia) and corrosive injuries to the esophagus (n = 4) over the past 8 years are presented. The management protocol and surgical technique have been described. Observations parameters included indication for esophageal replacement, age at surgery, sex of the child and other demographic details, clinical and operative findings, post-operative outcomes and follow-up details.

RESULTS

Retrosternal gastric pull-up could be performed in all cases with no mortality or graft loss. Of 22, 20 cases were extubated on-table and 2 cases were extubated within 48 hours of surgery. Mean operative duration was 265 min (range: 175 min to 310 min) and blood loss was 115.3 ml (range: 80-400 ml). Dense vascular adhesions in the region of the esophageal hiatus were encountered in patients with abdominal esophagostomy (n = 4) which were probably related to the local dissection at the time of previous surgery. Minor anastomotic leak was observed in 8 of 22 patients which settled spontaneously over 21 days mean period (range: 18 to 31 days). Antegrade dilatation was required in 3 of 8 cases with minor leak. None of them required revision of anastomosis. Mean follow-up duration is 63 months (range: 11 months - 94 months). Weight gain after surgery was close to or beyond the 25th centile. Symptoms of dumping syndrome or GER were not observed in our cohort.

CONCLUSION

Our data have demonstrated the safety and feasibility of esophageal replacement by gastric transposition through the retrosternal route in a resource-limited setup. No significant difference has been observed from the results and complications reported in literature for the same procedure.

TYPE OF STUDY

Prospective observational study / treatment study.

LEVEL OF EVIDENCE

Level III.

A simple strategy to reduce the salivary gland and kidney uptake of PSMA-targeting small molecule radiopharmaceuticals

PURPOSE

Peptide-based prostate-specific membrane antigen (PSMA) targeted radionuclide therapy (TRT) agent [¹⁷⁷Lu]-PSMA-617 has emerged as leading TRT candidate for treatment of castration-resistant prostate cancer (mCRPC). [¹⁷⁷Lu]-PSMA-617 and other small molecule-based PSMA ligands have shown efficacy in reducing the tumor burden in mCRPC patients but irradiation to the salivary gland and kidneys is a concern and dose-limiting factor. Therefore, methods to reduce non-target organ toxicity are needed to safely treat patients and preserve their quality of life. Herein, we report that addition of cold PSMA ligand PSMA-11 can aid in reducing the uptake of [¹⁷⁷Lu]-PSMA-617 in the salivary glands and kidneys.

METHODS

Groups of athymic nude mice (n = 4) bearing PC3-PIP (PSMA+) tumor xenografts were administered with [¹⁷⁷Lu]-PSMA-617 along with 0, 5, 100, 500, 1000, and 2000 pmoles of PSMA-11 and biodistribution studies were performed at 1 h.

RESULTS

Biodistribution studies at 1 h post-administration revealed that [¹⁷⁷Lu]-PSMA-617 uptake in PC3-PIP tumors was 21.71 ± 6.13, 18.7 ± 2.03, 26.44 ± 2.94, 16.21 ± 3.5, 13.52 ± 3.68, and 12.03 ± 1.96 %ID/g when 0, 5, 100, 500, 1000, and 2000 pmoles of PSMA-11 were added, respectively. Corresponding uptake values in kidney were 123.14 ± 52.52, 132.31 ± 47.4, 84.29 ± 78.25, 2.12 ± 1.88, 1.16 ± 0.36, and 0.64 ± 0.23 %ID/g, respectively. Corresponding salivary gland uptake values were 0.48 ± 0.11, 0.45 ± 0.15, 0.38 ± 0.3, 0.08 ± 0.03, 0.09 ± 0.07, and 0.05 ± 0.02 % ID/g, respectively.

CONCLUSION

The uptake of [¹⁷⁷Lu]-PSMA-617 in the salivary gland and kidney can be substantially reduced without significantly impacting tumor uptake by adding cold PSMA-11.

Professors and Practitioners: Assessing the Impact of COVID-19 in the State of Oklahoma with and Without Residents of Long-Term Care Facilities

OBJECTIVES

Our analysis, which began as a request from the Oklahoma Governor for useable analysis for state decision making, seeks to predict statewide COVID-19 spread through a variety of lenses, including with and without long-term care facilities (LTCFs), accounting for rural/urban differences, and considering the impact of state government regulations of the citizenry on disease spread.

METHODS

We utilize a deterministic susceptible exposed infectious resistant (SEIR) model designed to fit observed fatalities, hospitalizations, and ICU beds for the state of Oklahoma with a particular focus on the role of the rural/urban nature of the state and the impact that COVID-19 cases in LTCFs played in the outbreak.

RESULTS

The model provides a reasonable fit for the observed data on new cases, deaths, and hospitalizations. Moreover, removing LTCF cases from the analysis sharpens the analysis of the population in general, showing a more gradual increase in cases at the start of the pandemic and a steeper increase when the second surge occurred.

CONCLUSIONS

We anticipate that this procedure could be helpful to policymakers in other states or municipalities now and in the future.

Red-fluorescent graphene quantum dots from guava leaf as a turn-off probe for sensing aqueous Hg(ii)

In this work, we have prepared red-fluorescent graphene quantum dots and utilized as a highly selective and sensitive fluorescence turn-off probe for detection of the toxic metal ion Hg²⁺ from guava leaf extract.

Attenuation of SRC Kinase Activity Augments PARP Inhibitor-mediated Synthetic Lethality in BRCA2-altered Prostate Tumors

PURPOSE

Alterations in DNA damage repair (DDR) pathway genes occur in 20%-25% of men with metastatic castration-resistant prostate cancer (mCRPC). Although PARP inhibitors (PARPis) have been shown to benefit men with mCRPC harboring DDR defects due to mutations in BRCA1/2 and ATM, additional treatments are necessary because the effects are not durable.

EXPERIMENTAL DESIGN

We performed transcriptomic analysis of publicly available mCRPC cases, comparing BRCA2 null with BRCA2 wild-type. We generated BRCA2-null prostate cancer cells using CRISPR/Cas9 and treated these cells with PARPis and SRC inhibitors. We also assessed the antiproliferative effects of combination treatment in 3D prostate cancer organoids.

RESULTS

We observed significant enrichment of the SRC signaling pathway in BRCA2-altered mCRPC. BRCA2-null prostate cancer cell lines had increased SRC phosphorylation and higher sensitivity to SRC inhibitors (e.g., dasatinib, bosutinib, and saracatinib) relative to wild-type cells. Combination treatment with PARPis and SRC inhibitors was antiproliferative and had a synergistic effect in BRCA2-null prostate cancer cells, mCRPC organoids, and Trp53/Rb1-null prostate cancer cells. Inhibition of SRC signaling by dasatinib augmented DNA damage in BRCA2-null prostate cancer cells. Moreover, SRC knockdown increased PARPi sensitivity in BRCA2-null prostate cancer cells.

CONCLUSIONS

This work suggests that SRC activation may be a potential mechanism of PARPi resistance and that treatment with SRC inhibitors may overcome this resistance. Our preclinical study demonstrates that combining PARPis and SRC inhibitors may be a promising therapeutic strategy for patients with BRCA2-null mCRPC.

Abstract 6219: Combined inhibition of androgen signaling and apoptosis pathways in hormone sensitive prostate cancer

In the United States, where prostate cancer (PC) screening is common, over 90% of patients present initially with localized or locally advanced disease. Over the past decade, research has confirmed that PC tumor cells' response to the presence of androgen (testosterone) is a principal driver of PC. Men with PC who recur after surgery or radiation frequently undergo androgen deprivation therapy (ADT), wherein androgen exposure is chemically diminished. However, it is frequently followed by resistance, androgen-independent growth, and eventually the development of metastatic castration-resistant prostate cancer (mCRPC), the most lethal form of the disease. For those cancers that become mCRPC, many respond to other forms of ADT or chemotherapy. Therefore, it is vital to investigate additional therapeutic strategy to delay or prevent the transition of hormone sensitive cancer to mCRPC.

In response to stress signals from anti-cancer therapies, malignant cells may express pro-apoptotic activator proteins, such as the expression of the Bcl2 family of proteins. The block in apoptosis (Bcl2 family) that keeps cancer cells alive in response to anti-cancer agents is therefore an attractive candidate for targeted therapies. Previous studies have documented that overexpression of Bcl2 family proteins are associated with therapeutic resistance of PC, disease recurrence and shortened survival in CRPC. However, association between androgen signaling pathways and Bcl2 family proteins is not clearly understood. In our current study we observed that treatment with androgen inhibits the expression of Bcl2 family proteins (Bcl2, Bcl-w, Bcl-xL) in hormone sensitive human PC LNCaP cell lines. Importantly, we also observed that treatment with the androgen receptor (AR) inhibitor enzalutamide restores their (Bcl2, Bcl-w, Bcl-xL) expression even when treated with a very low concentration. This data indicates that there is direct negative-regulation of the Bcl2 family of proteins by the AR-signaling pathway. We also observed that there is synergistic effect of enzalutamide and the Bcl2-inhibitor venetoclax on growth inhibition of LNCaP cells. Our current study develops a rationale for combining enzalutamide or other androgen signaling agent inhibitors with Bcl2 targeted therapies for hormone sensitive prostate cancer. We believe this combinatorial therapeutic approach will show great potential for future clinical trials of high-risk hormone sensitive PC patients and may block the ADT-induced shift of hormone sensitive PC to mCRPC.

Citation Format: Goutam Chakraborty, Rahim Hirani, Lina E. Jehane, Ying Z. Mazzu, Yuki Yoshikawa, Sai Harisha Rajanala, Gwo-Shu M. Lee, Philip W. Kantoff. Combined inhibition of androgen signaling and apoptosis pathways in hormone sensitive prostate cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6219.

Abstract 1650: Non-invasive imaging tool to predict BRCA2 silencing in the context of prostate cancer

Background: We recently demonstrated that biallelic as well as monoallelic loss of the DNA damage response (DDR) gene BRCA2 in prostate cancer (PC) cell lines and mCRPC organoids leads to an aggressive form of PC and early androgen deprivation therapy (ADT) resistance (Chakraborty et al.). Clinical studies have established that DDR deficiency is generally associated with a poor prognosis. Very recently, immunohistochemical analysis of mCRPC patient samples by Paschalis et al. revealed that defects in DDR genes (in particular BRCA2 and ATM) are associated with increased prostate-specific membrane antigen (PSMA; folate hydrolase, FOLH1) expression on the cell membrane. PSMA expression can be measured non-invasively in pre-clinical models and human subjects using one of the several positron emission tomography (PET) imaging agents such as [68Ga]-PSMA11 or [124I]-MSK-PSMA11 that are being evaluated in pre-clinical and/or clinical setting. Therefore, we hypothesized that upregulation of PSMA expression can be a marker for BRCA2 loss and this increased expression can be quantified using PET agents both in vitro and in vivo.

Experimental design: We investigated the effect of BRCA2 deletion on PSMA expression in the castration sensitive human PC cell line LNCaP at the transcriptional and translational level and quantified the changes using saturation binding assays with [124I]-MSK-PSMA11. Using CRISPR-Cas9 and RNAi-based methods, we silenced BRCA2 in the castration sensitive cell line LNCaP and evaluated its effect on PSMA at the transcriptional and translational level. We carried out saturation binding assay using [124I]-MSK-PSMA11 to measure changes in cell surface PSMA receptor density.

Results: BRCA2 knockout was achieved successfully using CRISPR-Cas9 based methods. Immunoblotting analysis revealed that BRCA2 loss resulted in a significant increase in PSMA levels when compared to control LNCaP cell line. Immunohistochemical analysis confirmed this obervation. Cell binding assays demonstrated that BRCA2 null LNCaP cell lines have about 5-6 fold higher uptake of the PET tracer [124I]-MSK-PSMA11. We will be conducting in vivo studies to demonstrate that BRCA2 deletion leads to a significant increase in PSMA signal in mice xenograft models.

Conclusions: Our results indicate that BRCA2 silencing leads to significant upregulation of PSMA expression in PC cell lines, which can be imaged using a PSMA targeted PET tracer. These studies were partly supported by DOD-PCRP-Grant # W81XWH-19-1-0536 and PCF Young Investigator Award to Goutam Chakraborty. References: Chakraborty G et al. Clin Can Res 2019 DOI:10.1158/1078-0432.CCR-19-1570; Paschalis A et al. Eur Urol. 2019 Oct; 76(4): 469-478.

Citation Format: Teja Kalidindi, Sang Gyu Lee, Heiko Schoder, Lina E. Jehanae, Rahim Hirani, Goutam Chakraborty, Philip W. Kantoff, Naga Vara Kishore Pillarsetty. Non-invasive imaging tool to predict BRCA2 silencing in the context of prostate cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1650.

Ribonucleotide reductase small subunit M2 is a master driver of aggressive prostate cancer

Although there are molecularly distinct subtypes of prostate cancer, no molecular classification system is used clinically. The ribonucleotide reductase small subunit M2 (RRM2) gene plays an oncogenic role in many cancers. Our previous study elucidated comprehensive molecular mechanisms of RRM2 in prostate cancer (PC). Given the potent functions of RRM2, we set out to determine whether the RRM2 signature can be used to identify aggressive subtypes of PC. We applied gene ontology and pathway analysis in RNA‐seq datasets from PC cells overexpressing RRM2. We refined the RRM2 signature by integrating it with two molecular classification systems (PCS and PAM50 subtypes) that define aggressive PC subtypes (PCS1 and luminal B) and correlated signatures with clinical outcomes in six published cohorts comprising 4000 cases of PC. Increased expression of genes in the RRM2 signature was significantly correlated with recurrence, high Gleason score, and lethality of PC. Patients with high RRM2 levels showed higher PCS1 score, suggesting the aggressive PC feature. Consistently, RRM2‐regulated genes were highly enriched in the PCS1 signature from multiple PC cohorts. A simplified RRM2 signature (12 genes) was identified by intersecting the RRM2 signature, PCS1 signature, and the PAM50 classifier. Intriguingly, inhibition of RRM2 specifically targets PCS1 and luminal B genes. Furthermore, 11 genes in the RRM2 signature were correlated with enzalutamide resistance by using a single‐cell RNA‐seq dataset from PC circulating tumor cells. Finally, high expression of RRM2 was associated with an immunosuppressive tumor‐immune microenvironment in both primary prostate cancer and metastatic prostate cancer using CIBERSORT analysis and LM22, a validated leukocyte gene signature matrix. These data demonstrate that RRM2 is a driver of aggressive prostate cancer subtypes and contributes to immune escape, suggesting that RRM2 inhibition may be of clinical benefit for patients with PC.

Novel approach towards the synthesis of highly efficient flame retardant electrode and oil/organic solvent absorber

We have developed a facile one pot process to synthesize an ultra-light functionalized spongy graphene (FSG). This is the first approach to use carbon based flame retardant spongy material as an electrode to build completely flame retardant supercapacitor (FRS) also as an oil/organic solvent absorber. The fully FRS concept has created by the compilation of as-prepared FSG with flame retardant separator and electrolyte. As-prepared FSG contained high amount of phosphorus and nitrogen functional groups, which makes it potent flame retardant electrochemical material, to use it as an efficient FR electrode. Flame test of FSG revealed that it doesn't catch fire for ∼1500 s. Also, FSG was able to sustain flame retardancy at a temperature as high as 1500 °C for continuous exposure of ∼300 s. FSG used as an electrode for symmetric capacitor possessing maximum specific capacitance of 494.3 F g^-1 at a current density 1 A g^-1. Corresponding high energy density and power density values are 55.6 Wh kg^-1 and 1799 W kg^-1. It shows cycling stability of 86.1% after 5000 cycles at current density of 10 A g^-1. The electrochemical property of FSG was also confirmed using three electrode system. Flame retardant FSG material was also used for the absorption and recovery of oil and organic solvents. FSG has high oil and organic solvent sorption capacity in the range of 40-70 g/g, also can be reused for minimum 10 cycles. Such approach has great significance for multifunctional graphene based nanocomposites will open the new window for large-scale applications.

Fraction genome altered (FGA) to regulate both cell autonomous and non-cell autonomous functions in prostate cancer and its effect on prostate cancer aggressiveness

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Background: Our ability to distinguish lethal from non-lethal forms of prostate cancer (PC) is limited. Given prostate tumors’ genetic heterogeneity, is it unlikely that a single somatic variant is prognostic. Herein we investigated fraction of genome altered (FGA; percentage of copy number altered chromosome regions out of measured regions; cBioportal) and tumor mutational count (TMC; number of mutational events per case) harbored by the primary tumor as two tumor-specific factors posited to influence disease aggressiveness or responsiveness to certain therapeutic agents. Methods: We used the TCGA data (n= 490 primary PC) and MSKCC-IMPACT (n=717, Zehir et al 2017) PC datasets to analyze the correlation between FGA and TMC in PC. GSEA was performed with transcriptomes used to identify signaling pathways associated with these two measures. We then categorized 490 primary PC patients from TCGA dataset into 4 groups based on FGA and TMC levels (based on the median values) to assess associations with outcomes. Results: Primary PC patients who harbor FGAhighTMClow exhibited shorter disease-free survival (High Risk). We observed attenuation of the androgen signaling pathway and induction of cell proliferation pathways associated with this aggressive form of disease. We used results from CIBERSORT algorithm and deep learning methods of TCGA data and observed that quantities of tumor infiltrating lymphocytes was higher in the FGAhighTMClow group (p=0.038). However, we also observed significantly reduced immune effector signaling-pathway signaling in this high-risk FGAhighTMClow group suggesting the presence of immune-suppressive networks in primary disease associated with a high risk of progression. Conclusions: A greater understanding of molecular features of aggressive primary PC (FGA/TMC) will be important in developing management strategies. Based on our preliminary analyses, we hypothesize that patients whose primary PC harbors FGAhighTMClow have a higher likelihood of aggressive disease due to their impact on PC cell proliferation and dedifferentiation (cell autonomous), and subdued immune responses (non-cell-autonomous).

The impact of the expression of the transcription factor MYBL2 on outcomes of patients with localized and advanced prostate cancer

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Background: Patients with metastatic hormone-sensitive prostate cancer (mHSPC) have a variable response to ADT and some benefit from the addition of docetaxel or an androgen signaling pathway inhibitor. We found that loss of the epigenetic regulator KDM5D is associated with more aggressive prostate cancer (PC). We sought to determine whether MYBL2 which is regulated by KDM5D mediates this effect. MYBL2 is a transcription factor which controls key genes (e.g. FOXM1) and increases cell cycle progression and survival. Methods: AR expressing hormone-sensitive cell lines, LNCaP and LAPC4 were used. Motif analysis and CHiPseq of LNCaP with and without siKDM5D was performed and impact of modulation of KDM5D and MYBL2 in both cells on cell survival was assessed. Gene expression profiling (GEP) data assessed MYBL2’s association with KDM5D levels in localized disease (publicly available data) and mHSPC (Decipher whole Affymetrix platform on CHAARTED samples). Results: Silencing KDM5D increased H3K4me3 and increased MYBL2 expression. GEP showed a strong negative correlation between KDM5D and MYBL2 in patients with localized PC (-0.66; TCGA) but not from primary prostate cancer tissue with mHSPC (-0.03; CHAARTED). Cells with low KDM5D and high MYBL2 were androgen independent and more resistant to docetaxel. In TCGA, patients with high MYBL2 had a higher rate of relapse from localized disease. In patients with metastatic disease (CHAARTED) low MYBL2 was associated with a better overall survival (OS) on multivariable analysis when treated with ADT or ADT + docetaxel. Conclusions: Low MYBL2 is associated with a longer OS with ADT alone and ADT and docetaxel independent of clinical variables. Patients with high MYBL2 expression had better OS with ADT plus docetaxel compared with patients with high MYBL2 treated with ADT alone.[Table: see text]

Checkpoint kinase inhibition in prostate cancer cells resistant to poly ADP-ribose polymerase inhibitors

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Background: Poly ADP-ribose polymerase inhibitors (PARPi) have shown promise in the treatment of metastatic castration-resistant prostate cancer patients with DNA damage response defects . The phase 3 PROfound trial showed olaparib delayed the time to radiographic progression or death as compared with abiraterone or enzalutamide. In addition to olaparib, three other PARPi are in Phase 3 trials in prostate cancer (PC): rucaparib, talazoparib, and niraparib. Despite responses, resistance is common and treatment options for PARPi-resistant patients are limited. In this study, we observed de novo activation of checkpoint kinases (CHEK) in talazoparib-resistant (TR) PC cells. Therefore, we hypothesized that targeting CHEK may mitigate resistance to PARPi in PC. Methods: We developed TR human prostate cancer PC3 (low BRCA2 protein due to heterozygous deletion of BRCA2) cells. We performed phosphoproteomic analysis to identify possible mechanisms of talazoparib resistance in PC3 cells and validated the results with Western blot. Results: TR-PC3 cells proliferated slower and had a significant increase in the phosphorylation of CHEK2 compared to parental (p) PC3. Treatment with a CHEK2-selective inhibitor, CCT241533, did not affect cell growth in TR-PC3 cells. Conversely, treatment with a CHEK 1/2 inhibitor, prexasertib, led to significant cell growth inhibition in TR-PC3 at a much lower IG 50% concentration compared to pPC3. RNAi-mediated knockdown validated the superior efficacy of combined CHEK1 and CHEK2 inhibition since this combination produced the greatest cell growth inhibition seen in both TR-PC3 and de novo PARPi-resistant p22RV1. Treatment of pPC-3 and p22RV1 with combinations of talazoparib and prexasertib showed greater cell growth inhibition compared to either drug alone. Conclusions: Resistance to PARPi in PC cells with deletion of BRCA2 may potentially be overcome with CHEK inhibition. Moreover, our preliminary data suggested that the effect of PARPi and CHEK inhibitors on PARPi/CHEK inhibitor-naïve PC cells was greatest when used together, indicating that patients with PC may experience greatest anti-tumor activity of the two drugs when they are used in combination.

Does the degree of substitution on the cyclodextrin hosts impact their affinity towards guest binding?

The degree of substitution on βCD rims by sulfobutylether groups significantly modulates the binding affinity of the SBE_nβCD hosts for the studied cationic guest molecule.

Significance of BRCA2 and RB1 Co-loss in Aggressive Prostate Cancer Progression

PURPOSE

Previous sequencing studies revealed that alterations of genes associated with DNA damage response (DDR) are enriched in men with metastatic castration-resistant prostate cancer (mCRPC). BRCA2, a DDR and cancer susceptibility gene, is frequently deleted (homozygous and heterozygous) in men with aggressive prostate cancer. Here we show that patients with prostate cancer who have lost a copy of BRCA2 frequently lose a copy of tumor suppressor gene RB1; importantly, for the first time, we demonstrate that co-loss of both genes in early prostate cancer is sufficient to induce a distinct biology that is likely associated with worse prognosis.

EXPERIMENTAL DESIGN

We prospectively investigated underlying molecular mechanisms and genomic consequences of co-loss of BRCA2 and RB1 in prostate cancer. We used CRISPR-Cas9 and RNAi-based methods to eliminate these two genes in prostate cancer cell lines and subjected them to in vitro studies and transcriptomic analyses. We developed a 3-color FISH assay to detect genomic deletions of BRCA2 and RB1 in prostate cancer cells and patient-derived mCRPC organoids.

RESULTS

In human prostate cancer cell lines (LNCaP and LAPC4), loss of BRCA2 leads to the castration-resistant phenotype. Co-loss of BRCA2-RB1 in human prostate cancer cells induces an epithelial-to-mesenchymal transition, which is associated with invasiveness and a more aggressive disease phenotype. Importantly, PARP inhibitors attenuate cell growth in human mCRPC-derived organoids and human CRPC cells harboring single-copy loss of both genes.

CONCLUSIONS

Our findings suggest that early identification of this aggressive form of prostate cancer offers potential for improved outcomes with early introduction of PARP inhibitor-based therapy.See related commentary by Mandigo and Knudsen, p. 1784.

Pancreas as a Content in Congenital Diaphragmatic Hernia: A Rarity

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Total Intestinal Atresia: Revisiting the Pathogenesis of Congenital Atresias

Despite various theories to explain the pathogenesis of atresias, the exact mechanism is still controversial. Currently, atresias are believed to result from vascular accidents and less likely due to the failure of recanalization. We report a case which challenges this belief. A 1-day-old neonate was explored for suspected jejunal atresia. Apart from Type III jejunal atresia, 15 cm from DJ junction, there was surprisingly no distal lumen in the intestine from jejunum till rectum. Multiple enterotomies revealed the whole of the remaining jejunum, ileum, and large colon to be a solid cord-like structure. No distal luminal contents or histopathological evidence of ischemic damage was seen, thus suggesting the probable etiology to be a failure of recanalization of the gut cord rather than a late vascular accident. Such rare cases provide insights into possible embryogenetic mechanisms which can then aid in formulating preventive measures.

The Polycomb Repressor Complex 1 Drives Double-Negative Prostate Cancer Metastasis by Coordinating Stemness and Immune Suppression

The mechanisms that enable immune evasion at metastatic sites are poorly understood. We show that the Polycomb Repressor Complex 1 (PRC1) drives colonization of the bones and visceral organs in double-negative prostate cancer (DNPC). In vivo genetic screening identifies CCL2 as the top prometastatic gene induced by PRC1. CCL2 governs self-renewal and induces the recruitment of M2-like tumor-associated macrophages and regulatory T cells, thus coordinating metastasis initiation with immune suppression and neoangiogenesis. A catalytic inhibitor of PRC1 cooperates with immune checkpoint therapy to reverse these processes and suppress metastasis in genetically engineered mouse transplantation models of DNPC. These results reveal that PRC1 coordinates stemness with immune evasion and neoangiogenesis and point to the potential clinical utility of targeting PRC1 in DNPC.