[Cancer metabolism: a novel perspective on precision diagnosis and treatment for liver cancer]

Metabolic reprogramming has been identified as a hallmark of cancer. Liver is an essential hub in the body for the metabolism of three major nutrients including glucose, lipids and amino acids. Hepatocellular carcinoma(HCC) usually presents a variety of changes in characteristic metabolism, such as increased aerobic glycolysis, enhanced de novo lipid synthesis, glutamine depletion, and oxidative metabolism imbalance, which can provide energy and bio-macromolecular raw materials for rapidly growing and proliferating tumor cells. The process of tumor metabolic reprogramming is regulated by multiple factors, such as alterations in metabolic enzyme activity, abnormal gene expression, and signaling pathway disturbance. Advances in high-throughout metabolomics technology have provided a powerful platform for discovering the novel biomarkers and metabolic targets of HCC. Therefore, in-depth study of the metabolic characteristics and regulatory mechanisms of HCC is critical for the development of novel antimetabolites.

Syngas-Free Highly Regioselective Rhodium-Catalyzed Transfer Hydroformylation of Alkynes to α,β-Unsaturated Aldehydes

The hydroformylation of alkynes is a fundamental and important reaction in both academic research and industry. Conventional methods focus on the conversion of alkynes, CO, and H₂ into α,β-unsaturated aldehydes, but they often suffer from problems associated with operation, regioselectivity, and chemoselectivity. Herein, we disclose an operationally simple, mild, and syngas-free rhodium-catalyzed reaction for the hydroformylation of alkynes via formyl and hydride transfer from an alkyl aldehyde. This synthetic method uses inexpensive and easy-to-handle n-butyraldehyde to overcome the challenge posed by the use of syngas in traditional approaches and employs a commercially available catalyst and ligand to transform a broad range of internal alkynes, especially alkynyl-containing complex molecules, into versatile stereodefined α,β-unsaturated aldehydes with excellent chemo-, regio-, and stereoselectivity.

Evaluation of self-collected vaginal specimens for the detection of high-risk human papillomavirus infection and the prediction of high-grade cervical intraepithelial lesions in a high-burden, low-resource setting

OBJECTIVES

To compare the performance of self-collected vaginal (V) specimens with clinician-collected cervical (C) specimens for detection of high-risk human papillomavirus (hrHPV) and cervical disease using the Cepheid Xpert HPV, Roche Cobas 4800 HPV and Hologic Aptima HPV assays.

METHODS

Women aged 30-59 years (n = 1005) were recruited at two clinics in Papua New Guinea, and they provided specimens for testing at point-of-care using the Xpert HPV Test, and for subsequent testing using the Cobas HPV (n = 981) and Aptima HPV (n = 983) assays. Liquid-based cytology was performed on C specimens to predict underlying high-grade squamous intraepithelial lesions (HSIL). V specimen results of each assay were evaluated against a constructed reference standard and for detection of HSIL or worse.

RESULTS

There was substantial (κ >0.6) agreement in hrHPV detection between V and C specimens across all three assays. The sensitivity, specificity, and positive and negative predictive values of Xpert HPV using self-collected V specimens for the detection of HPV type 16 according to the constructed reference standard were 92.1%, 93.1%, 63.6% and 98.9%, respectively; compared with 90.4%, 94.3%, 67.8% and 98.7% for Cobas 4800 HPV; and 63.2%, 97.2%, 75.0% and 95.3% for Aptima HPV. Similar results were observed for all hrHPV types (combined) and for HPV types 18/45, on all three assays. The detection of any hrHPV using self-collected specimens had high sensitivity (86%-92%), specificity (87%-94%) and negative predictive value (>98%) on all assays for HSIL positivity.

CONCLUSIONS

Xpert HPV, using self-collected vaginal specimens, has sufficient accuracy for use in point-of-care 'test-and-treat' cervical screening strategies in high-burden, low-resource settings.

Iridium-Catalyzed Annulation Reactions of Thiophenes with Carboxylic Acids: Direct Evidence for a Heck-type Pathway

The functionalization of thiophenes is a fundamental and important reaction. Herein, we disclose iridium-catalyzed one-pot annulation reactions of (benzo)thiophenes with (hetero)aromatic or α,β-unsaturated carboxylic acids, which afford thiophene-fused coumarin-type frameworks. Dearomatization reactions of 2-substituted thiophenes with α,β-unsaturated carboxylic acids deliver various thiophene-containing spirocyclic products. The occurrence of two interconnected reactions provides direct evidence for a Heck-type pathway. The mechanistic scenario described herein is distinctly different from the S_E Ar and concerted metalation-protodemetalation (CMD) pathways encountered in the well-described oxidative C-H/C-H cross-coupling reactions of thiophenes with other heteroarenes.

Antitumor activity of chitosan from mayfly with comparison to commercially available low, medium and high molecular weight chitosans

Insects' cuticles have a potential to be evaluated as a chitin source. Especially adults of aquatic insects like mayflies (order Ephemeroptera) swarm in enormous numbers in artificially lit areas while mating in spring and then die by leaving huge amounts of dead insects' bodies. Here in this study, mayfly corpses were harvested and used for production of low MW chitosan. Dried mayfly bodies had 10.21% chitin content; mayfly chitin was converted into chitosan with efficiency rate of 78.43% (deacetylation degree, 84.3%; MW, 3.69 kDa). Cytotoxicity and anti-proliferative activity of mayfly and commercially available shrimp chitosans (low, medium, and high MW) were determined on L929 fibroblast and three different cancer types including HeLa, A549, and WiDr. Apoptosis and necrosis stimulating potential of mayfly and commercial chitosans were also evaluated on A549 and WiDr cells using acridine orange and propidium iodide dual staining to observe morphological changes in nuclei and thus to reveal the predominant cell death mechanism. The effects of chitosans have varied depending on cell types, concentration, and chitosan derivatives. Mayfly and low MW chitosans had a cytotoxic effect at a concentration of 500 μg mL^-1 on non-cancer cells. At concentrations below this value (250 μg mL^-1), mayfly and commercial chitosans except high MW one exhibited strong inhibitory activity on cancer cells especially A549 and WiDr cells. Mayfly chitosan induced early and late apoptosis in A549 cells, but late apoptosis and necrosis in WiDr cells. This study suggests that dead bodies of mayflies can be used for production of low MW chitosan with anti-proliferative activity.

Rhodium-catalyzed oxidative C–H/C–H cross-coupling of aniline with heteroarene: N-nitroso group enabled mild conditions

A rhodium(iii)-catalyzed oxidative ortho-heteroarylation of N-nitrosoaniline with heteroarene has been developed for the synthesis of (2-aminophenyl)heteroaryls under mild conditions.

Iridium-catalyzed oxidative Ar–H/Ar–H cross-coupling of primary benzamides with thiophenes

Described herein is an iridium(iii)-catalyzed oxidative Ar–H/Ar–H cross-coupling of primary benzamides with thiophenes for the synthesis of (2-thienyl)benzamides.

Rhodium(III)-Catalyzed Oxidative Cross-Coupling of Unreactive C(sp3)-H Bonds with C(sp2)-H Bonds

The development of the oxidative cross-coupling of unreactive C(sp³)-H bonds with (hetero)arene C(sp²)-H bonds is considerably appealing, yet conceptually and practically challenging. Here, we disclose the rhodium-catalyzed oxidative heteroarylation of unactivated C(sp³)-H bonds with heteroarene C(sp²)-H bonds. This method provides a step-economic route to β-heteroarylated 2-ethylpyridine derivatives, which exhibits relatively broad substrate scope, high tolerance level of sensitive functional groups, and high selectivity. The protocol can also be extended to the coupling reaction between 8-methylquinoline derivatives and heteroarenes.