ATF3-CBS signaling axis coordinates ferroptosis and tumorigenesis in colorectal cancer.

The induction of ferroptosis is promising for cancer therapy. However, the mechanisms enabling cancer cells to evade ferroptosis, particularly in low-cystine environments, remain elusive. Our study delves into the intricate regulatory mechanisms of Activating transcription factor 3 (ATF3) on Cystathionine ß-synthase (CBS) under cystine deprivation stress, conferring resistance to ferroptosis in colorectal cancer (CRC) cells. Additionally, our findings establish a positively correlation between this signaling axis and CRC progression, suggesting its potential as a therapeutic target. Mechanistically, ATF3 positively regulates CBS to resist ferroptosis under cystine deprivation stress. In contrast, the suppression of CBS sensitizes CRC cells to ferroptosis through targeting the mitochondrial tricarboxylic acid (TCA) cycle. Notably, our study highlights that the ATF3-CBS signaling axis enhances ferroptosis-based CRC cancer therapy. Collectively, the findings reveal that the ATF3-CBS signaling axis is the primary feedback pathway in ferroptosis, and blocking this axis could be a potential therapeutic approach for colorectal cancer.

Toward Bicalutamide Analogues with High Structural Diversity Using Catalytic Asymmetric Oxohydroxylation.

A catalytic enantioselective synthesis of bicalutamide derivatives with promising potentials in prostate cancer treatment has been disclosed. The key intermediates, α-hydroxy-ß-keto esters, were efficiently constructed through cinchoninium-mediated asymmetric oxohydroxylation of easily accessible alkenes with potassium permanganate. Good yields and high levels of asymmetric induction are achieved. This method provides a new synthetic route to bicalutamide analogues with high structural diversity, which will beneficially support subsequent structure-activity relationship studies and boost prostate cancer drug development.

Surgical treatment of interstitial pregnancy without cornual resection: A case report.

RATIONALE: Interstitial pregnancy (IP) is a rare but extremely life-threatening form of ectopic pregnancy. The traditional surgical treatment for this anomaly is the resection of uterine cornua or fallopian tubes, which often damages their structural integrity, thereby compromising the reproductive potential for women who wish to preserve fertility. PATIENT CONCERNS: A 33-year-old female was admitted to our hospital with suspected ectopic pregnancy, following a 4-weeks history of positive pregnancy tests after uterine evacuation. The patient was hemodynamically stable on arrival. Ultrasound revealed an empty uterus with an eccentric gestational sac located at the fundus and surrounded by a thin myometrium, indicative of a suspected interstitial pregnancy. DIAGNOSIS AND INTERVENTION: After failed attempt at medical management with a single dose of intramuscular methotrexate, the patient was arranged for hysteroscopy-assisted laparoscopy. In surgery, the uterine cavity appeared empty, and a 2 × 2 cm bulge with increased vascularity at the right uterine courna was identified upon examination. The gestational sac was aspirated through the vagina from the right ostium of the uterine tube using a suction curette pointing at the right ostium. Sutures were not needed afterward, and the myometrial anatomy was left undisrupted. The diagnosis of IP was confirmed by the postoperative histological report. OUTCOMES: Perioperative blood loss was approximately 10 ml and the operative time was 40 minutes. The patient had an uneventful postoperative recovery and was discharged after 3 days. Subsequent follow-ups showed a significant reduction in the patient serum beta hCG to 48IU/L within 5 days postoperation, and a negative result after 7 days. LESSONS: This novel surgical technique is an alternative minimally-invasive approach for selected early diagnosed and hemodynamically stable IP patients. The technique represents a safe, quick, and simple approach combining the benefits of laparoscopy, such as allowing for immediate conversion of cornuectomy when uterus ruptures, and the benefits of suction curettage, such as shorter operative time and minimal blood loss. We believe patients with interstitial pregnancy who still have fertility wishes would benefit from this surgical technique to a larger extent in the future.

Inhibitors of thiol-mediated uptake.

Ellman's reagent has caused substantial confusion and concern as a probe for thiol-mediated uptake because it is the only established inhibitor available but works neither efficiently nor reliably. Here we use fluorescent cyclic oligochalcogenides that enter cells by thiol-mediated uptake to systematically screen for more potent inhibitors, including epidithiodiketopiperazines, benzopolysulfanes, disulfide-bridged γ-turned peptides, heteroaromatic sulfones and cyclic thiosulfonates, thiosulfinates and disulfides. With nanomolar activity, the best inhibitors identified are more than 5000 times better than Ellman's reagent. Different activities found with different reporters reveal thiol-mediated uptake as a complex multitarget process. Preliminary results on the inhibition of the cellular uptake of pseudo-lentivectors expressing SARS-CoV-2 spike protein do not exclude potential of efficient inhibitors of thiol-mediated uptake for the development of new antivirals.

Cell-Penetrating Dynamic-Covalent Benzopolysulfane Networks.

Cyclic oligochalcogenides (COCs) are emerging as promising systems to penetrate cells. Clearly better than and different to the reported diselenolanes and epidithiodiketopiperazines, we introduce the benzopolysulfanes (BPS), which show efficient delivery, insensitivity to inhibitors of endocytosis, and compatibility with substrates as large as proteins. This high activity coincides with high reactivity, selectively toward thiols, exceeding exchange rates of disulfides under tension. The result is a dynamic-covalent network of extreme sulfur species, including cyclic oligomers, from dimers to heptamers, with up to nineteen sulfurs in the ring. Selection from this unfolding adaptive network then yields the reactivities and selectivities needed to access new uptake pathways. Contrary to other COCs, BPS show high retention on thiol affinity columns. The identification of new modes of cell penetration is important because they promise new solutions to challenges in delivery and beyond.

Diselenolane-Mediated Cellular Uptake: Efficient Cytosolic Delivery of Probes, Peptides, Proteins, Artificial Metalloenzymes and Protein-Coated Quantum Dots.

Cyclic oligochalcogenides are emerging as powerful tools to penetrate cells. With disulfide ring tension maximized, selenium chemistry had to be explored next to enhance speed and selectivity of dynamic covalent exchange on the way into the cytosol. We show that diseleno lipoic acid (DiSeL) delivers a variety of relevant substrates. DiSeL-driven uptake of artificial metalloenzymes enables bioorthogonal fluorophore uncaging within cells. Binding of a bicyclic peptide, phalloidin, to actin fibers evinces targeted delivery to the cytosol. Automated tracking of diffusive compared to directed motility and immobility localizes 79 % of protein-coated quantum dots (QDs) in the cytosol, with little endosomal capture (0.06 %). These results suggest that diselenolanes might act as molecular walkers along disulfide tracks in locally denatured membrane proteins, surrounded by adaptive micellar membrane defects. Miniscule and versatile, DiSeL tags are also readily available, stable, soluble, and non-toxic.

Diselenolane-mediated cellular uptake.

The emerging power of thiol-mediated uptake with strained disulfides called for a move from sulfur to selenium. We report that according to results with fluorescent model substrates, cellular uptake with 1,2-diselenolanes exceeds uptake with 1,2-dithiolanes and epidithiodiketopiperazines with regard to efficiency as well as intracellular localization. The diselenide analog of lipoic acid performs best. This 1,2-diselenolane delivers fluorophores efficiently to the cytosol of HeLa Kyoto cells, without detectable endosomal capture as with 1,2-dithiolanes or dominant escape into the nucleus as with epidithiodiketopiperazines. Diselenolane-mediated cytosolic delivery is non-toxic (MTT assay), sensitive to temperature but insensitive to inhibitors of endocytosis (chlorpromazine, methyl-ß-cyclodextrin, wortmannin, cytochalasin B) and conventional thiol-mediated uptake (Ellman's reagent), and to serum. Selenophilicity, the extreme CSeSeC dihedral angle of 0° and the high but different acidity of primary and secondary selenols might all contribute to uptake. Thiol-exchange affinity chromatography is introduced as operational mimic of thiol-mediated uptake that provides, in combination with rate enhancement of DTT oxidation, direct experimental evidence for existence and nature of the involved selenosulfides.

Epidithiodiketopiperazines: Strain-Promoted Thiol-Mediated Cellular Uptake at the Highest Tension.

The disulfide dihedral angle in epidithiodiketopiperazines (ETPs) is near 0°. Application of this highest possible ring tension to strain-promoted thiol-mediated uptake results in efficient delivery to the cytosol and nucleus. Compared to the previous best asparagusic acid (AspA), ring-opening disulfide exchange with ETPs occurs more efficiently even with nonactivated thiols, and the resulting thiols exchange rapidly with nonactivated disulfides. ETP-mediated cellular uptake is more than 20 times more efficient compared to AspA, occurs without endosomal capture, depends on temperature, and is "unstoppable" by inhibitors of endocytosis and conventional thiol-mediated uptake, including siRNA against the transferrin receptor. These results suggest that ETP-mediated uptake not only maximizes delivery to the cytosol and nucleus but also opens the door to a new multitarget hopping mode of action.

Phase-Transfer and Ion-Pairing Catalysis of Pentanidiums and Bisguanidiniums.

Catalysts accelerate biological processes and organic reactions in a controlled and selective fashion. There are continuing efforts in asymmetric catalysis to develop efficient catalysts with broad reaction scope and industrial practicability. Among the various modes of asymmetric catalysis, phase-transfer catalysis has attracted intense interest due to its facile scale up and low catalyst loading. Chiral quaternary ammonium and phosphonium salts are well-studied classes of chiral phase-transfer catalysts, and they are typically composed of sp3-hybridized quaternary onium salts. In this Account, we describe our recent attempts to develop N-sp2-hybridized guanidinium-type salts as efficient phase-transfer catalysts as well as ion-pair catalysis based on N-sp2 hybridized bisguanidinium-type salts. The sp2-quaternized ammonium salts, pentanidiums, which contain five nitrogen atoms in conjugation, displayed remarkable phase-transfer catalytic efficiency. We have shown that pentanidium can catalyze Michael additions of tert-butyl glycinate-benzophenone Schiff bases with various α,ß-unsaturated acceptors, such as vinyl ketones, acrylates, and chalcones, in high enantioselectivities. The structurally amendable pentanidium phase-transfer catalysts supply diverse reactivity and selectivity to various other organic transformations, such as α-hydroxylation of 3-substituted-2-oxindoles, Michael addition of 3-alkyloxindoles with vinyl sulfone, and alkylation reactions of sulfenate anions and dihydrocoumarins. Pentanidium salts are applicable to enantioselective transformations on a preparative scale at low catalyst loading, allowing for the synthesis of a broad range of enantiopure compounds. From computational and experimental results, we also proposed that the halogenated pentanidium catalysts participated in halogen bonding and that this contributed to the excellent stereocontrol in alkylation reactions. Subsequently, we determined that chiral cations can direct functional anions besides basic anions in traditional Brønsted basic phase-transfer reactions, including metal-centered anions. We identified dicationic bisguanidinium as an excellent ion-pairing catalyst, first demonstrating that bisguanidinium formed an ion pair with permanganate and directed the anion in enantioselective dihydroxylation and oxohydroxylation of a,ß-unsaturated esters. This initial success led us to explore chiral cationic ion-pairing catalysis as a general mode of catalysis. This mode of catalysis is at the interphase between organocatalysis, phase-transfer catalysis and organometallic catalysis. We then identified bisguanidinium diphosphatobisperoxotungstate and bisguanidinium dinuclear oxodiperoxomolybdosulfate ion pairs as the active catalysts in enantioselective sulfoxidations using aqueous H2O2 as the oxidant. The structure of the bisguanidinium dinuclear oxodiperoxomolybdosulfate ion pair was elucidated using single-crystal X-ray analysis. Bisguanidinium-catalyzed sulfoxidations emerged as a practical methodology for the synthesis of enantioenriched sulfoxides including armodafinil and lansoprazole, which are commercial drugs. Finally, we are also able to show that pentanidium and bisguanidinium hypervalent silicates are intermediates in enantioselective alkylations using silylamide as a Brønsted probase.

Bisguanidinium dinuclear oxodiperoxomolybdosulfate ion pair-catalyzed enantioselective sulfoxidation.

Catalytic use of peroxomolybdate for asymmetric transformations has attracted increasing attention due to its catalytic properties and application in catalysis. Herein, we report chiral bisguanidinium dinuclear oxodiperoxomolybdosulfate [BG]2+[(µ-SO4)Mo2O2(µ-O2)2(O2)2]2- ion pair, as a catalyst for enantioselective sulfoxidation using aqueous H2O2 as the terminal oxidant. The ion pair catalyst is isolatable, stable and useful for the oxidation of a range of dialkyl sulfides. The practical utility was illustrated using a gram-scale synthesis of armodafinil, a commercial drug, with the catalyst generated in situ from 0.25 mol% of bisguanidinium and 2.5 mol% of Na2MoO4·2H2O. Structural characterization of this ion pair catalyst has been successfully achieved using single-crystal X-ray crystallography.

Pentanidium- and Bisguanidinium-Catalyzed Enantioselective Alkylations Using Silylamide as Brønsted Probase.

Most asymmetric phase transfer reactions are Brønsted base reactions, and the inorganic bases used greatly influenced the profile of the reaction. Alkoxide salts are able to activate substrates with high pKa values, but background reactions are often unavoidable. On the other hand, carbonate and phosphate salts are milder, but their low basicity limits the scope of their reactions. This presents a difficult situation whereby fragile substrates such as lactone will be hydrolyzed by a stronger base but will not be activated with a weaker one. Thus, a Brønsted probase strategy is devised, in which a strong base can be generated in situ from silylamide (probase) through the use of fluoride. In this approach, the strong base produced will be transient and not be in excess, thus reducing background and side reactions. We demonstrate this strategy using pentanidinium and bisguanidinium as catalysts; highly enantioselective phase transfer alkylation of several types of substrates including dihydrocoumarin (lactone) can be achieved. We found that the probase also acts as a silylation reagent, generating silyl enol ether or silyl ketene acetal, which are key intermediates in the reaction. We further propose that hypervalent silicates form ion-pairs with pentanidinium and bisguanidinium as intermediates in the reaction, and it is through these ion-pairs that the selective enantiofacial approach of the electrophile is determined.

Enantioselective Sulfoxidation Catalyzed by a Bisguanidinium Diphosphatobisperoxotungstate Ion Pair.

The first enantioselective tungstate-catalyzed oxidation reaction is presented. High enantioselectivities were achieved for a variety of drug-like phenyl and heterocyclic sulfides under mild conditions with H2 O2 , a cheap and environmentally friendly oxidant. Synthetic utility was demonstrated through the preparation of (S)-Lansoprazole, a commercial proton-pump inhibitor. The active ion-pair catalyst was identified to be bisguanidinium diphosphatobisperoxotungstate using Raman spectroscopy and computational studies.

Successful Treatment of a Recurrent Cesarean Scar Pregnancy by Transvaginal Cesarean Scar Pregnancy Lesion Resection: A Case Report.

Background: Cesarean scar pregnancy (CSP) is a type of ectopic pregnancy with the gestation sac located on a previous cesarean scar. Recurrent CSP (RCSP) is the occurrence of 2 or more consecutive CSPs. Until this case, there have been only 8 previous reported cases of RCSPs in the English-language literature. Case: A 30-year-old, Chinese woman was admitted to our hospital for RCSP. We had successfully terminated her first CSP by a series of treatments including uterine arterial embolization with local methotrexate injection, mifepristone, and misoprostol administration, as well as an ultrasound-guided suction curettage evacuation. However, this time we performed only a transvaginal CSP lesion resection, which achieved an improved outcome. Conclusion: This case highlights the likelihood of RCSP and the need for transvaginal CSP lesion resection to decrease the risk of RCSP in CSP patients who desire future pregnancy.

[Association of the H770H of PR gene polymorphism with susceptibility to endometriosis].

OBJECTIVE: To investigate the association of PR gene exon 5 region H770H (rs1042839) single nucleotide polymorphism (SNP) with the genetic susceptibility to endometriosis (EM) in southern Han Chinese women. METHODS: Totally 431 EM patients and 499 non-EM women were collected and separated into EM group and control group, that all cases were confirmed by operation and pathology. A case-control study was performed in EM and control groups to evaluate the association of these SNP with the susceptibility to EM by using a fluorescent quantitative PCR-based high resolution melting (HRM) method. RESULTS: The C and T of PR H770H allele frequencies among the EM and control groups were 97.9% (844/862), 2.1% (18/862) and 99.4% (992/998), 0.6% (6/998), respectively. The CC, CT and TT of PR H770H genotype frequencies among the EM and control groups were 95.8% (413/431), 4.2% (18/431), 0 and 98.8% (493/499), 1.2% (6/499), 0, respectively. There were statistical significances in the PR H770H alleles and genotypes distributions between the two groups (χ(2)=7.386, P=0.007; χ(2)=8.135, P=0.004). Carrying allele C reduced the risk of EM (OR=0.986, 95%CI: 0.976-0.996), while carrying allele T enhanced the risk of EM (OR=3.319, 95% CI: 1.323-8.325); carrying genotype CC reduced the risk of EM 0.970 time (OR=0.970, 95% CI: 0.949-0.991), whereas carrying genotype CT enhanced the risk of EM 3.473 times (OR=3.473, 95%CI: 1.391-8.671). CONCLUSION: There is significant association between the polymorphism of PR H770H and genetic susceptibility to EM in southern Han Chinese women.

Enantioselective Oxidation of Alkenes with Potassium Permanganate Catalyzed by Chiral Dicationic Bisguanidinium.

Chiral anion-controlled ion-pairing catalysis was demonstrated to be a wide-ranging strategy that can utilize a variety of cationic metal species. In a similar manner, we envision a complementary strategy using chiral cation in partnership with inorganic anionic metal salts. Herein, we report a chiral dicationic bisguanidinium-catalyzed asymmetric oxidation reaction of alkenes with potassium permanganate. Chiral induction is attributed to ion-pairing interaction between chiral cation and enolate anion. The success of the current permanganate oxidation reaction together with mechanistic insights should provide inspiration for expansion to other anionic metal salts and would open up new paradigms for asymmetric transition metal catalysis, phase-transfer catalysis, and ion-pairing catalysis.

Enantioselective Synthesis of Quaternary Carbon Stereocenters: Addition of 3-Substituted Oxindoles to Vinyl Sulfone Catalyzed by Pentanidiums.

A pentanidium-catalyzed highly enantioselective conjugate addition of 3-alkyloxindoles to phenyl vinyl sulfone has been demonstrated. This approach allows the construction of 3,3-dialkyl-substituted oxindole frameworks with high yield and excellent enantioselectivity (up to 99%) under simple phase-transfer conditions. A variety of oxindoles bearing all-carbon quaternary stereogenic centers were obtained in the presence of 0.25 mol% pentanidium. Meanwhile, practicality was illustrated by a gram-scale asymmetric synthesis of two 3,3-dialkyl-substituted oxindoles. The resulting adduct can be smoothly transformed to the natural product analogue in a short synthetic route.

Catalytic enantioselective alkylation of sulfenate anions to chiral heterocyclic sulfoxides using halogenated pentanidium salts.

We report halogenated pentanidiums as phase-transfer catalysts for the asymmetric alkylation of sulfenate anions to various sulfoxides with high enantioselectivities (up to 99% ee) and yields (up to 99%). This approach gives access to enantioenriched heterocyclic sulfoxides that might not be compatible with strong oxidants or organometallic reagents. Computational studies have revealed that the multiple noncovalent interactions such as halogen bonds and nonclassical hydrogen bonds are involved.

Breast feeding and immunoprophylaxis efficacy of mother-to-child transmission of hepatitis B virus.

OBJECTIVE: This study was designed to explore if hepatitis B virus (HBV) may be transmitted via breast milk through mother-to-child transmission (MTCT), and assay the immunoprophylaxis efficacy after passive-active immunization. METHOD: From year 2008 to 2012, 67,720 pregnant women were screened and 1186 HBsAg-carrier mothers and their infants aged 8-12 months were followed in multi-centers of China, among whom HBV markers (HBsAg, HBsAb, HBeAg, HBeAb and HBcAb) and HBV-DNA were measured. RESULTS: HBsAg positive rate of pregnant women was 6.7% (4533/67,720) and infants' immunoprophylaxis failure rate was 3.3% (39/1186). Immunoprophylaxis failure infants were all born to mothers of HBeAg positive and HBV-DNA >6 log10 copies/ml. Among infants of HBeAg positive mothers, HBV infection rate was 9.0% and HBsAg positive rate was 8.3% in breast-feeding group versus 9.2% in formula-feeding group, P=0.761. Occurrence of perinatal HBV infection was indicated in uterus or during delivery. Different feeding patterns had no effects on HBsAb conversion of infants with the implementation of immunization. CONCLUSIONS: HBsAg prevalence rate of pregnant women enrolled was 6.7% and immunoprophylaxis failure rate of infants was 3.3%, while the infection rate reached 9.0% in infants of HBeAg positive mothers. Breast feeding did not increase the occurrence of HBV MTCT.

[Association of P53 gene polymorphisms with susceptibility to endometriosis].

OBJECTIVE: To assess the association of a single nucleotide polymorphism(SNP) in tumor suppressor gene P53 with the risk of endometriosis (EM) in Han Chinese women. METHODS: For 460 EM patients, 113 patients with endometrial carcinoma and 530 matched unrelated controls, a rs1042522(C/G) SNP of the P53 gene was genotyped by polymerase chain reaction-single strand polymorphism (PCR-SSP) and DNA sequencing. RESULTS: A significant difference has been detected in the distribution of rs1042522 alleles and genotypes between the EM patients and controls (P< 0.01). Allele G has increased the risk of EM by 1.209 times, while allele C has reduced this risk by 0.837 times. Compared with GG genotype, GC and CC genotypes have both increased the risk for EM (OR=2.073, 95%CI: 1.521-2.820, and OR=1.930, 95%CI: 1.363-2.733, respectively). Significant differences were also detected in the distribution of rs1042522 alleles and genotypes between endometrial carcinoma patients and controls (P< 0.01). Allele G has increased the risk to endometrial carcinoma by 1.311 times, while allele C has reduced this risk by 0.757 times. Compared with GG genotypes, individuals with GC and CC genotypes are more likely to be affected with endometrial carcinoma (OR=2.778, 95%CI: 1.585-4.870, and OR=2.864, 95%CI: 1.557-5.263, respectively). CONCLUSION: Our study has suggested a significant association between the rs1042522(G/C) polymorphism and susceptibility to EM in Han Chinese women. The mechanism of EM is similar to carcinoma from genetics point of view.