HFIP-promoted halo-carbocyclizations of N- and O-tethered arene-alkene substrates to access all halo (X = Br, I, Cl)-functionalized tetrahydroquinoline and chroman cores.

A new method for the stereoselective metal-, additive- and oxidant-free Friedel-Crafts-type halo-carbocyclization of N- and O-tethered arene-olefin substrates is reported, involving reaction with a suitable electrophilic halogenating reagent (NXS/DCDMH) in hexafluoroisopropanol. All halo (X = Br, I, Cl)-functionalized tetrahydroquinolines and chromans were obtained in excellent yields and with high levels of diastereocontrol (dr = >99 : 1), and these products were successfully transformed into synthetically useful compounds such as dihydroquinolines and partial or full azahelicene compounds.

An Update on MR Spectroscopy in Cancer Management: Advances in Instrumentation, Acquisition, and Analysis.

MR spectroscopy (MRS) is a noninvasive imaging method enabling chemical and molecular profiling of tissues in a localized, multiplexed, and nonionizing manner. As metabolic reprogramming is a hallmark of cancer, MRS provides valuable metabolic and molecular information for cancer diagnosis, prognosis, treatment monitoring, and patient management. This review provides an update on the use of MRS for clinical cancer management. The first section includes an overview of the principles of MRS, current methods, and conventional metabolites of interest. The remainder of the review is focused on three key areas: advances in instrumentation, specifically ultrahigh-field-strength MRI scanners and hybrid systems; emerging methods for acquisition, including deuterium imaging, hyperpolarized carbon 13 MRI and MRS, chemical exchange saturation transfer, diffusion-weighted MRS, MR fingerprinting, and fast acquisition; and analysis aided by artificial intelligence. The review concludes with future recommendations to facilitate routine use of MRS in cancer management. Keywords: MR Spectroscopy, Spectroscopic Imaging, Molecular Imaging in Oncology, Metabolic Reprogramming, Clinical Cancer Management © RSNA, 2024.

A deep hybrid learning pipeline for accurate diagnosis of ovarian cancer based on nuclear morphology.

Nuclear morphological features are potent determining factors for clinical diagnostic approaches adopted by pathologists to analyze the malignant potential of cancer cells. Considering the structural alteration of the nucleus in cancer cells, various groups have developed machine learning techniques based on variation in nuclear morphometric information like nuclear shape, size, nucleus-cytoplasm ratio and various non-parametric methods like deep learning have also been tested for analyzing immunohistochemistry images of tissue samples for diagnosing various cancers. We aim to correlate the morphometric features of the nucleus along with the distribution of nuclear lamin proteins with classical machine learning to differentiate between normal and ovarian cancer tissues. It has already been elucidated that in ovarian cancer, the extent of alteration in nuclear shape and morphology can modulate genetic changes and thus can be utilized to predict the outcome of low to a high form of serous carcinoma. In this work, we have performed exhaustive imaging of ovarian cancer versus normal tissue and developed a dual pipeline architecture that combines the matrices of morphometric parameters with deep learning techniques of auto feature extraction from pre-processed images. This novel Deep Hybrid Learning model, though derived from classical machine learning algorithms and standard CNN, showed a training and validation AUC score of 0.99 whereas the test AUC score turned out to be 1.00. The improved feature engineering enabled us to differentiate between cancerous and non-cancerous samples successfully from this pilot study.

Histone Chaperone Nucleophosmin Regulates Transcription of Key Genes Involved in Oral Tumorigenesis.

Nucleophosmin (NPM1) is a multifunctional histone chaperone that can activate acetylation-dependent transcription from chromatin templates in vitro. p300-mediated acetylation of NPM1 has been shown to further enhance its transcription activation potential. Acetylated and total NPM1 pools are increased in oral squamous cell carcinoma. However, the role of NPM1 or its acetylated form (AcNPM1) in transcriptional regulation in cells and oral tumorigenesis is not fully elucidated. Using ChIP-seq analyses, we provide the first genome-wide profile of AcNPM1 and show that AcNPM1 is enriched at transcriptional regulatory elements. AcNPM1 co-occupies marks of active transcription at promoters and DNase I hypersensitive sites at enhancers. In addition, using a high-throughput protein interaction profiling approach, we show that NPM1 interacts with RNA Pol II, general transcription factors, mediator subunits, histone acetyltransferase complexes, and chromatin remodelers. NPM1 histone chaperone activity also contributes to its transcription activation potential. Further, NPM1 depletion leads to decreased AcNPM1 occupancy and reduced expression of genes required for proliferative, migratory and invasive potential of oral cancer cells. NPM1 depletion also abrogates the growth of orthotopic tumors in mice. Collectively, these results establish that AcNPM1 functions as a coactivator during during RNA polymerase II-driven transcription and regulates the expression of genes that promote oral tumorigenesis.

Butyrylation Meets Adipogenesis-Probed by a p300-Catalyzed Acylation-Specific Small Molecule Inhibitor: Implication in Anti-obesity Therapy.

The enzyme p300, besides having acetyltransferase activity, can also catalyze other acylation modifications, whose physiological implications are still being investigated. Here, we report that the level of histone butyrylation increases globally as well as locally in the promoters of pro-adipogenic genes during adipogenesis. To delineate the role of p300-catalyzed butyrylation from acetylation in adipogenesis, we identified a semisynthetic derivative (LTK-14A) of garcinol, which specifically inhibited histone butyrylation without affecting acetylation. Treatment of 3T3L1 cells with LTK-14A abolished adipogenesis with downregulation of pro-adipogenic genes along with inhibition of H4K5 butyrylation. Administering LTK-14A to high-fat diet-fed and genetically obese db/db mice led to attenuation/decrease in their weight gain. The reduced obesity could be partially attributed to the inhibition of H4K5 butyrylation in adipocytes and liver. This report therefore not only, for the first time, causally links histone butyrylation with adipogenesis but also presents a probable candidate for anti-obesity therapeutics.

Highly Selective and Catalytic C-N Bond Cleavage of Tertiary Sulfonamides: Scope and Mechanistic Insight.

A highly chemoselective C-N bond cleavage reaction of p-methoxybenzyl- (PMB), 3,4-dimethoxybenzyl- (DMB), or cinnamyl-substituted tertiary sulfonamides in the presence of catalytic Bi(OTf)3 is presented. A wide range of sulfonamide substrates smoothly furnished the corresponding C-N bond cleavage products in good to excellent yields. Great efforts have been made to obtain insights into the reaction mechanism based on a series of control experiments and mass spectroscopy.

Functional interplay between YY1 and CARM1 promotes oral carcinogenesis.

Coactivator associated arginine methyltransferase 1 (CARM1) has been functionally implicated in maintenance of pluripotency, cellular differentiation and tumorigenesis; where it plays regulatory roles by virtue of its ability to coactivate transcription as well as to modulate protein function as an arginine methyltransferase. Previous studies establish an oncogenic function of CARM1 in the context of colorectal and breast cancer, which correlate to its overexpressed condition. However, the mechanism behind its deregulated expression in the context of cancer has not been addressed before. In the present study we uncover an oncogenic function of CARM1 in the context of oral cancer, where it was found to be overexpressed. We also identify YY1 to be a positive regulator of CARM1 gene promoter, where silencing of YY1 in oral cancer cell line could lead to reduction in expression of CARM1. In this context, YY1 showed concomitant overexpression in oral cancer patient samples compared to adjacent normal tissue. Cell line based experiments as well as xenograft study revealed pro-neoplastic functions of YY1 in oral cancer. Transcriptomics analysis as well as qRT-PCR validation clearly indicated pro-proliferative, pro-angiogenic and pro-metastatic role of YY1 in oral cancer. We also show that YY1 is a substrate of CARM1 mediated arginine methylation, where the latter could coactivate YY1 mediated reporter gene activation in vivo. Taken together, CARM1 and YY1 were found to regulate each other in a positive feedback loop to facilitate oral cancer progression.

p53 mediated regulation of coactivator associated arginine methyltransferase 1 (CARM1) expression is critical for suppression of adipogenesis.

Coactivator-associated arginine methyltransferase 1 (CARM1/PRMT4) is a type I arginine methyltransferase that mediates transcriptional activation via methylation of histone H3 on R17, R26, and R42. CARM1 is also a coactivator of transcription of various transcription factors such as NF-kB, MEF2C, ß-catenin, p53, PPAR-gamma etc. CARM1 has been functionally implicated in maintenance of pluripotency, cellular differentiation, and tumorigenesis; where its expression status plays an important role. Although its expression has been shown to be regulated by a few miRNAs in different contexts at post-transcriptional level, transcriptional regulation of CARM1 gene is still unexplored. In this report we demonstrate that CARM1 is a p53 responsive gene, where p53 could suppress CARM1 promoter-driven luciferase expression. CARM1 gene expression was found to be repressed by p53 in 3T3L1 preadipocytes when activated with Nutlin-3a treatment. Ectopic overexpression of CARM1 could rescue inhibitory effect of p53 on adipogenesis, suggesting a role of p53-CARM1 axis of regulation operational in the context of adipocyte differentiation. p53 and CARM1 showed antagonistic regulatory influence on PPAR-gamma expression; which suggests that p53-mediated suppression of adipogenesis could be partly via repression of CARM1 expression. Taken together these observations provide convincing mechanistic explanation for p53 function in the context of adipocyte differentiation process.

Fe(OTf)3-catalysed Friedel-Crafts reaction of benzenoid arenes with α,ß-unsaturated carbonyl compounds: easy access to 1,1-diarylalkanes.

A simple and efficient method for the synthesis of 1,1-diarylalkanes via the Friedel-Crafts-type alkylation reaction of electron-rich arenes with cinnamic acid ester derivatives or chalcones is reported. Iron triflate has been found to be the best catalyst for the Friedel-Crafts-type alkylation reaction with α,ß-unsaturated carbonyl compounds. This reaction afforded ß,ß-diaryl carbonyl compounds in good yields (65-93%) and with excellent regioselectivities. Remarkably, this method is also compatible with a variety of indoles to provide 3-indolyl-aryl carbonyl compounds in excellent yields. Great efforts have been made to deduce a plausible reaction mechanism based on isotopic labelling experiments.