[Clinical characteristics and surgical management outcomes of glaucoma secondary to congenital ectropion uveae: a preliminary analysis of penetrating Schlemm's canaloplasty]

Objective: To investigate the clinical characteristics and treatment outcomes of glaucoma secondary to congenital ectropion uveae (CEU) using penetrating Schlemm's canaloplasty. Methods: This was a retrospective case series study. Medical records of patients diagnosed with glaucoma secondary to CEU and undergoing penetrating Schlemm's canaloplasty at the Eye Hospital of Wenzhou Medical University between August 2020 and December 2021 were collected. Clinical characteristics including the extent and location of iris ectropion, type of glaucoma, were analyzed. Follow-up visits were conducted at 1, 3, 6 months, and 1 year postoperatively. Visual acuity, intraocular pressure (IOP), anterior segment and fundus condition, filtering bleb morphology, use of IOP-lowering medications, ultrasound biomicroscopy results, and other indicators were analyzed to summarize surgical outcomes. Results: Six cases (6 eyes) of glaucoma secondary to CEU were included, all unilateral, with 3 left eyes and 3 right eyes; median age was 10.0 (5.3, 28.8) years; including 3 males and 3 females. Preoperative IOP was (31.7±10.0) mmHg (1 mmHg=0.133 kPa), and the preoperative number of IOP-lowering medications used was 2.0 (2.0, 3.2). The extent of iris ectropion in the 6 cases ranged from 270 ° to 360 °, with peripheral anterior synechiae corresponding to the location of iris ectropion, and angle closure with the degree of synechiae extending beyond Schwalbe's line. No surgical complications occurred in any of the 6 cases postoperatively. At 1 month postoperatively, the IOP was (16.4±3.2) mmHg, with a median of 0.0 (0.0, 1.5) medications used. At 3 months postoperatively, the IOP was (14.8±6.0) mmHg, with a median of 0.0 (0.0, 2.2) medications used. At 6 months postoperatively, the IOP was (18.1±6.1) mmHg, with a median of 0.0 (0.0, 0.5) medications used. Among them, 5 patients had a follow-up period of 1 year postoperatively, all achieving controlled IOP without the use of IOP-lowering medications, with an average IOP of (15.5±3.1) mmHg. No obvious filtering bleb formation was observed at the surgical site in all patients. Conclusions: Glaucoma secondary to CEU manifests primarily as closed-angle glaucoma, with a correspondence between the closure range of anterior iris adhesions in the angle and the extent of iris ectropion. Penetrating Schlemm's canaloplasty demonstrates favorable and stable efficacy for its treatment.

Smart exosomes enhance PDAC targeted therapy

Exosomes continue to attract interest as a promising nanocarrier drug delivery technology. They are naturally derived nanoscale extracellular vesicles with innate properties well suited to shuttle proteins, lipids, and nucleic acids between cells. Nonetheless, their clinical utility is currently limited by several major challenges, such as their inability to target tumor cells and a high proportion of clearance by the mononuclear phagocyte system (MPS) of the liver and spleen. To overcome these limitations, we developed "Smart Exosomes" that co-display RGD and CD47p110-130 through CD9 engineering (ExoSmart). The resultant ExoSmart demonstrates enhanced binding capacity to αvβ3 on pancreatic ductal adenocarcinoma (PDAC) cells, resulting in amplified cellular uptake in in vitro and in vivo models and increased chemotherapeutic efficacies. Simultaneously, ExoSmart significantly reduced liver and spleen clearance of exosomes by inhibiting macrophage phagocytosis via CD47p110-130 interaction with signal regulatory proteins (SIRPα) on macrophages. These studies demonstrate that an engineered exosome drug delivery system increases PDAC therapeutic efficacy by enhancing active PDAC targeting and prolonging circulation times, and their findings hold tremendous translational potential for cancer therapy while providing a concrete foundation for future work utilizing novel peptide-engineered exosome strategies.

FASN negatively regulates p65 expression by reducing its stability via Thr254 phosphorylation and isomerization by Pin1

FASN, the sole cytosolic enzyme responsible for de novo palmitate synthesis in mammalian cells, has been associated with poor prognosis in cancer and shown to cause drug and radiation resistance by upregulating DNA damage repair via suppression of p65 expression. Targeting FASN by repurposing proton pump inhibitors has generated impressive outcomes in triple-negative breast cancer patients. While p65 regulation of DNA damage repair was thought to be due to its suppression of poly(ADP-ribose) polymerase 1 gene transcription, the mechanism of FASN regulation of p65 expression was unknown. In this study, we show that FASN regulates p65 stability by controlling its phosphorylation at Thr254, which recruits the peptidyl-prolyl cis/trans isomerase Pin1 that is known to stabilize many proteins in the nucleus. This regulation is mediated by palmitate, the FASN catalytic product, not by FASN protein per se. This finding of FASN regulation of p65 stability via phosphorylation of Thr254 and isomerization by Pin1 implicates that FASN and its catalytic product palmitate may play an important role in regulating protein stability in general and p65 more specifically.

[Mid-term analysis of prospective cohort study of rivaroxaban in preventing CRT in breast cancer]

Objective: To explore the efficacy and safety of Rivaroxaban in preventing catheter related thrombosis (CRT) in patients with breast cancer who are undergoing central venous catheter chemotherapy, and provide basis for making standardized prevention and treatment strategies. Methods: In this research, a prospective cohort study was adopted, and breast cancer patients who received central venous catheter chemotherapy in Sanhuan Cancer Hospital during September 2020 to March 2022 were selected as a treatment group to take the rivaroxaban anticoagulation therapy with 10 mg.po.qd for one month. The control group got no preventive anticoagulation therapy. Vascular ultrasound examination was taken to confirm the occurrence of CRT, and a chi-square test was done for comparison the disparity between the groups. Logistic regression was applied to analyze the univariate and multivariate factors for the formation of CRT. Results: In the research, a total of 235 patients were selected, and there were a total of 19 035 days of catheterization with 81 days of catheterization on average. While in the control group, the incidence of CRT was 28.0% (33/118), the incidence of CRT in the treatment group was 20.5% (24/117), the difference was no significant (P=0.183). Subgroup analysis results showed that the peripherally inserted central catheter (PICC) was performed in 165 cases with the CRT incidence of 18.2% (30/165) and thrombosis was mostly seen around axillary vein, accounting for 63.3%. Subclavian vein catheterization was performed in 63 cases with the CRT incidence of 39.7% (25/63), and thrombosis was mostly seen around subclavian vein, accounting for 88.0% (22/25). Implantable venous access port was implanted in 7 cases around subclavian vein and internal jugular vein with the CRT incidence of 28.6% (2/7). The patients who developed CRT within 30 days after catheterization accounted for 54.4% (31/57), 22.8% (13/57) in a period during 30 days and 60 days) and 22.8% (13/57) in a period during 60 days and 180 days). The diagnosed CRT patients had been treated with rivaroxaban 15 mg.bid.po for 3 months. During the 3 months, 100.0% of the thrombosis waned, 71.9% (41/57) of the thrombosis waned within 30 days, 19.3% (11/57) in a period during 30 and 60days and 8.8% (5/57) in a period during 60 days and 90 days. Univariate and multivariate analysis indicated that the risk of CRT in subclavian vein catheterization was higher than that in PICC, respectively (OR=2.898, 95% CI:1.386-6.056 P=0.005), and the type of catheterization was an independent factor for the formation of thrombosis. Safety analysis result showed that in the prevention of CRT, rivaroxaban treatment did not induce drug-related bleeding, liver function damage, bone marrow suppression or any other side effects. While CRT diagnosed patients were treated with anticoagulation, they kept the central venous catheter, and the infusion was smooth. These patients all finished the anti-tumor treatment as planned, and no abnormalities like new thrombosis or pulmonary embolism were observed. Conclusions: In the mid-term analysis, the proportion of Rivaroxaban in preventing anticoagulant CRT decreases, but it don't reach statistical significance. The sample size should be further increased for observation. Rivaroxaban is proved effective and very safe in the treatment of CRT, and does not affect the concurrent chemotherapy. Medical personnel should carry out the policy of "early prevention, early detection and early treatment" for CRT so as to improve the patients' quality of life.

Small Molecule Inhibitors Targeting the "Undruggable" Survivin: The Past, Present, and Future from a Medicinal Chemist's Perspective

Survivin, a homodimeric protein and a member of the IAP family, plays a vital function in cell survival and cycle progression by interacting with various proteins and complexes. Its expression is upregulated in cancers but not detectable in normal tissues. Thus, it has been regarded and validated as an ideal cancer target. However, survivin is "undruggable" due to its lack of enzymatic activities or active sites for small molecules to bind/inhibit. Academic and industrial laboratories have explored different strategies to overcome this hurdle over the past two decades, with some compounds advanced into clinical testing. These strategies include inhibiting survivin expression, its interaction with binding partners and homodimerization. Here, we provide comprehensive analyses of these strategies and perspective on different small molecule survivin inhibitors to help drug discovery targeting "undruggable" proteins in general and survivin specifically with a true survivin inhibitor that will prevail in the foreseeable future.

[Hsp90 participates in the necroptosis of mouse neural cells induced by aluminum through the RIP1/RIP3/MLKL pathway]

Objective: To investigate whether heat shock protein 90 (HSP90) participates in the necroptosis of C57BL/6 mouse neurons and spatial memory impairment induced by Aluminum maltol [Al (mal) (3)] through RIP1/RIP3/MLKL pathway. Methods: In March 2022, Thirty-two C57 mice were randomly divided into control group, Low dose group, a medium dose group, and a high-dose group, with 8 mice in each group, and injected intraperitoneally with physiological saline, 20, 40, and 80, respectivelyμmol/kgAl (mal) (3) was administered, it was injected 5 days a week and discontinued 2 days for 60 days. Morris water maze test was used to test the spatial learning and memory ability of mice. Nissl staining was used to observe the pathological changes of brain tissue. The protein expression levels of RIP1, RIP3, MLKL and HSP90 in hippocampus were determined by Western blotting. Results: In the water maze experiment, compared with the control group, the number of mice crossing the platform decreased in each dose group, the difference was statistically significant (H=9.50, P=0.023), and the number of mice crossing the platform was statistically significant among each dose group (P <0.05). Compared with the control group, the number of hippocampal nerve cells in each dose group decreased, the arrangement was disordered, and the Nissellite bodies decreased. Western blotting results showed that compared with the control group, the expression level of RIP1 protein in the hippocampus of mice in high-dose group was higher, and the difference was statistically significant (P <0.05). The expression levels of RIP3, MLKL and HSP90 in hippocampal tissue of mice in medium and high dose groups were increased, and the differences were statistically significant (P<0.05). After siRNA intervention decreased the expression of HSP90 protein, the expressions of HSP90, RIP1, RIP3 and MLKL in Al (mal) (3) groups were increased, and the differences were statistically significant (P<0.05) . Conclusion: Through RIP1/RIP3/MLKL pathway, HSP90 is involved in neuronal programmed necrosis and spatial memory impairment induced by maltol aluminum in C57 mice.

Proline Isomerization: From the Chemistry and Biology to Therapeutic Opportunities

Proline isomerization, the process of interconversion between the cis- and trans-forms of proline, is an important and unique post-translational modification that can affect protein folding and conformations, and ultimately regulate protein functions and biological pathways. Although impactful, the importance and prevalence of proline isomerization as a regulation mechanism in biological systems have not been fully understood or recognized. Aiming to fill gaps and bring new awareness, we attempt to provide a wholistic review on proline isomerization that firstly covers what proline isomerization is and the basic chemistry behind it. In this section, we vividly show that the cause of the unique ability of proline to adopt both cis- and trans-conformations in significant abundance is rooted from the steric hindrance of these two forms being similar, which is different from that in linear residues. We then discuss how proline isomerization was discovered historically followed by an introduction to all three types of proline isomerases and how proline isomerization plays a role in various cellular responses, such as cell cycle regulation, DNA damage repair, T-cell activation, and ion channel gating. We then explore various human diseases that have been linked to the dysregulation of proline isomerization. Finally, we wrap up with the current stage of various inhibitors developed to target proline isomerases as a strategy for therapeutic development.

Reversible promoter demethylation of PDGFD confers gemcitabine resistance through STAT3 activation and RRM1 upregulation

Drug resistance is a major problem in cancer treatment with traditional or targeted therapeutics. Gemcitabine is approved for several human cancers and the first line treatment for locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC). However, gemcitabine resistance frequently occurs and is a major problem in successful treatments of these cancers and the mechanism of gemcitabine resistance remains largely unknown. In this study, we identified 65 genes that had reversible methylation changes in their promoters in gemcitabine resistant PDAC cells using whole genome Reduced Representation Bisulfite Sequencing analyses. One of these genes, PDGFD, was further studied in detail for its reversible epigenetic regulation in expression and shown to contribute to gemcitabine resistance in vitro and in vivo via stimulating STAT3 signaling in both autocrine and paracrine manners to upregulate RRM1 expression. Analyses of TCGA datasets showed that PDGFD positively associates with poor outcome of PDAC patients. Together, we conclude that the reversible epigenetic upregulation plays an important role in gemcitabine resistance development and targeting PDGFD signaling alleviates gemcitabine resistance for PDAC treatment.

APC Loss Prevents Doxorubicin-Induced Cell Death by Increasing Drug Efflux and a Chemoresistant Cell Population in Breast Cancer

Chemoresistance is a major health concern affecting cancer patients. Resistance is multifactorial, with one mechanism being the increased expression of ABC transporters (such as MDR1 and MRP1), which are drug efflux transporters capable of preventing intracellular accumulation of drugs and cell death. Our lab showed that the loss of Adenomatous Polyposis Coli (APC) caused an intrinsic resistance to doxorubicin (DOX), potentially through an enhanced tumor-initiating cell (TIC) population and the increased activation of STAT3 mediating the expression of MDR1 in the absence of WNT being activated. Here, in primary mouse mammary tumor cells, the loss of APC decreased the accumulation of DOX while increasing the protein levels of MDR1 and MRP1. We demonstrated decreased APC mRNA and protein levels in breast cancer patients compared with normal tissue. Using patient samples and a panel of human breast cancer cell lines, we found no significant trend between APC and either MDR1 or MRP1. Since the protein expression patterns did not show a correlation between the ABC transporters and the expression of APC, we evaluated the drug transporter activity. In mouse mammary tumor cells, the pharmacological inhibition or genetic silencing of MDR1 or MRP1, respectively, decreased the TIC population and increased DOX-induced apoptosis, supporting the use of ABC transporter inhibitors as therapeutic targets in APC-deficient tumors.

eIF3d: a driver of non-canonical cap-dependent translation of specific mRNAs and a trigger of biological/pathological processes

eIF3d, a known RNA binding subunit of the eIF3 complex, is a 66-68-kDa protein with an RNA-binding motif and a cap-binding domain. Compared with other eIF3 subunits, eIF3d is relatively understudied. However, recent progress in studying eIF3d has revealed a number of intriguing findings on its role in maintaining eIF3 complex integrity, global protein synthesis, and in biological and pathological processes. It has also been reported that eIF3d has non-canonical functions in regulating translation of a subset of mRNAs by binding to 5'-UTRs or interacting with other proteins independent of the eIF3 complex and additional functions in regulating protein stability. The non-canonical regulation of mRNA translation or protein stability may contribute to the role of eIF3d in biological processes such as metabolic stress adaptation and in disease onset and progression including SARS-CoV-2 infection, tumorigenesis and acquired immune deficiency syndrome. In this review, we critically evaluate the recent studies on these aspects of eIF3d and assess prospects in understanding the function of eIF3d in regulating protein synthesis, and in biological and pathological processes.

[Clinical characteristics of 37 antiphospholipid syndrome patients complicated by autoimmune hemolytic anemia]

Objective: We sought to investigate the clinical characteristics and risk factors of antiphospholipid syndrome (APS) complicated by autoimmune hemolytic anemia (AIHA). Methods: Retrospective anaysis.Three hundred fifteen consecutive patients with APS were enrolled at the Department of Rheumatology of Peking Union Medical College Hospital between May 2017 to May 2021, and their clinical manifestations[including initial symptoms, time interval between APS onset and diagnosis, systemic lupus erythematosus(SLE), thrombotic events, obstetric morbidity, and extra-criteria manifestations] and laboratory test results[including blood routine, antiphospholipid antibodies(aPLs), blood lipid profile, homocysteine, anti-nuclear antibody profile, immunoglobulin levels, and complement levels] were collected. Then, univariate and multivariate logistic regression analyses were performed. Clinical features and risk factors were analyzed using univariable and multivariable logistic regression analysis. Results: Among 315 APS patients, 37 cases (11.7%) were complicated by AIHA, and AIHA was the first manifestation or co-occurrence. The median time interval between APS onset and diagnosis was 12 months. The proportion of SLE in APS patients combined with AIHA was higher than that in APS patients without AIHA[62.2%(23/37) vs. 19.4%(54/278), P<0.001]. There was no significant difference in the proportions of thrombosis and pregnancy morbidity between the two groups. In terms of extra-criteria manifestations, APS patients with AIHA had a significantly (P<0.05) greater risk of thrombocytopenia (OR=6.19, 95%CI 2.81-13.65) and higher proportions of hypocomplementemia, a positive lupus anticoagulant (LA) result, double aPLs positivity[i.e., any two of the following antibodies were positive: LA, anticardilolipin antibody(aCL), and anti-β2 glycoprotein Ⅰ(β2GPⅠ)], and triple aPLs positivity (i.e., LA, aCL, and anti-β2GPⅠ antibodies were all positive). Multivariate logistic regression analysis showed that SLE (OR=3.46,95%CI 1.60-7.48), thrombocytopenia (OR=2.56,95%CI 1.15-5.67), and hypocomplementemia (OR=4.29,95%CI 2.03-9.04) were independent risk factors for the complication of APS. In the primary APS subgroup, multivariate logistic regression analysis showed that livedo reticularis (OR=10.51,95%CI 1.06-103.78), thrombocytopenia (OR=3.77, 95%CI 1.23-11.57), and hypocomplementemia (OR=5.92,95%CI 1.95-17.95) were independent risk factors for the complication of APS. Conclusions: AIHA is not rare in APS patients; moreover, it occurs more frequently in APS secondary to SLE and is more likely to present with a variety of extra-criteria manifestations. Patients with AIHA should be promptly tested for antiphospholipid antibody profiles and alerted to the possibility of thrombotic events.

[Present situation of myopia among primary and junior high school students in Yinzhou District, Ningbo City, Zhejiang Province]

Objective: To determine the situation of myopia among primary and junior high school students from 2019 to 2021 in Yinzhou District, Ningbo City, Zhejiang Province. Methods: Cross-sectional study. Department of Ophthalmology, The Affiliated People's Hospital of Ningbo University, carried out a cross-sectional study by reviewing the results of five times visual acuity screens among primary and junior high school students from 2019 to 2021 in Yinzhou District, Ningbo City, Zhejiang Province. The myopia rate, High myopia rate and spherical equivalent refraction were calculated according to the uncorrected distance visual acuity and non-cycloplegic subjective refraction. Chi-square test and analysis of variance were used to analysis the difference of myopia among term, sex and eye. Results: The visual acuity screen had been completed five times from 2019 to 2021 in Yinzhou District, with a total of 458 654 people, of which 454 812 people met the inclusion criteria. The myopia rate of each screen is 56.6%(50 443/89 122),52.5%(48 463/92 311),63.7%(57 968/91 002),53.2%(48 351/90 886),64.4%(58 920/91 491). The rate of Myopia increased gradually with promoting to high grade, and it was obviously in low grade,up to 17.6%. Conclusion: The myopia rate of primary and junior high school students was raising volatility from 2019 to 2021 in Yinzhou District, Ningbo City, Zhejiang Province.

[Effect analysis of the modified wire-loop snare technique in retrieving severely tilted inferior vena cava filters]

Objective: To examine the application effect of the modified wire-loop snare technique in retrieving severely tilted inferior vena cava filters (IVCF). Methods: The clinical data of 18 patients (12 males and 6 females, aged (62.1±13.1) years (range: 29 to 78 years)) who underwent the modified wire-loop snare technique to retrieve IVCF at the Affiliated Hospital of Qingdao University, Qingdao Eighth People's Hospital, and Jimo District Hospital of Traditional Chinese Medicine from November 2017 to April 2022 were retrospectively analyzed. The applied filters included drum-type filters (OptEase in 7 cases, Aegisy in 2 cases) and conical filters (Celect in 6 cases and Denali in 3 cases). Preoperative CT angiography and intraoperative digital subtraction angiography showed that the filter was severely tilted and the hook was covered by hyperplastic intima of the vena cave vein. A modified wire-loop snare technique was used to retrieve drum-type filters and conical filters via femoral and jugular vein approaches, respectively. After successful puncture, the long sheath was placed, the 4 F (1 F≈0.33 mm) vertebral catheter and a snare were inserted through the long sheath, and the 5 F pigtail catheter was inserted simultaneously to guide a 0.035 inch soft guide-wire (260 cm in length) to pass through the top of the filter and turning back. The tip of the soft guide-wire was snared by the vertebral catheter and pulled out of the sheath. The 4 F vertebral catheter was inserted following the tip of the guide-wire to form a wire-loop using the vertebral catheter and the pigtail catheter. After fixing the tip and tail of the soft guide-wire in vitro, the long sheath was pushed forward to cut the hyperplastic intima and the hook was pulled away from the vena cava wall to retrieve the filter under the support of two catheters. Results: The filters were successfully retrieved in 17 cases, the operation time was (25.5±8.7) minutes (range: 15 to 45 minutes), no complication occured. The hook of one filter (Celect) penetrated out of the vena vava wall and the wire-loop could not pull the hook back into the vena cava. Then the filter was removed by laparotomy. Conclusion: The modified wire-loop snare technique could retrieve the severely tilted retrivable drum-type filters and conical filters, even when serve adhesion exists between the filter and the vena cava wall.

Therapeutic Activity of the Lansoprazole Metabolite 5-Hydroxy Lansoprazole Sulfide in Triple-Negative Breast Cancer by Inhibiting the Enoyl Reductase of Fatty Acid Synthase

Fatty acid synthase (FASN), a sole cytosolic enzyme responsible for de-novo lipid synthesis, is overexpressed in cancer but not in normal non-lipogenic tissues. FASN has been targeted, albeit no such inhibitor has been approved. Proton pump inhibitors (PPIs), approved for digestive disorders, were found to inhibit FASN with anticancer activities in attempting to repurpose Food and Drug Administration-approved drugs. Indeed, PPI usage benefited breast cancer patients and increased their response rate. Due to structural similarity, we thought that their metabolites might extend anticancer effects of PPIs by inhibiting FASN. Here, we tested this hypothesis and found that 5-hydroxy lansoprazole sulfide (5HLS), the end lansoprazole metabolite, was more active than lansoprazole in inhibiting FASN function and regulation of NHEJ repair of oxidative DNA damage via PARP1. Surprisingly, 5HLS inhibits the enoyl reductase, whereas lansoprazole inhibits the thioesterase of FASN. Thus, PPI metabolites may contribute to the lasting anticancer effects of PPIs by inhibiting FASN.

A novel survivin dimerization inhibitor without a labile hydrazone linker induces spontaneous apoptosis and synergizes with docetaxel in prostate cancer cells

Survivin, a member of the inhibitor of apoptosis protein family, exists as a homodimer and is aberrantly upregulated in a wide spectrum of cancers. It was thought to be an ideal target due to its lack of expression in most adult normal tissues and importance in cancer cell survival. However, it has been challenging to target survivin due to its "undruggable" nature. We previously attempted to target its dimerization domain with a hypothesis that inhibiting survivin dimerization would promote its degradation in proteasome, which led to identification of a lead small-molecule inhibitor, LQZ-7F. LQZ-7F consists of a flat tetracyclic aromatic core with labile hydrazone linking a 1,2,5-oxadiazole moiety. In this study, we tested the hypothesis that LQZ-7F could be developed as a prodrug because the labile hydrazone linker could be hydrolyzed, releasing the tetracyclic aromatic core. To this end, we synthesized the tetracyclic aromatic core (LQZ-7F1) using reported procedure and tested LQZ-7F1 for its biological activities. Here we show that LQZ-7F1 has a significantly improved potency with submicromolar IC_50's and induces spontaneous apoptosis in prostate cancer cells. It also more effectively inhibits survivin dimerization and induces survivin degradation in a proteasome-dependent manner than LQZ-7F. We also show that the combination of LQZ-7F1 and docetaxel have strong synergism in inhibiting prostate cancer cell survival. Together, we conclude that the hydrazone linker with the oxadiazole tail is dispensable for survivin inhibition and the survivin dimerization inhibitor, LQZ-7F, may be developed as a prodrug for prostate cancer treatment and to overcome docetaxel resistance.

Translation initiation factor eIF3a regulates glucose metabolism and cell proliferation via promoting small GTPase Rheb synthesis and AMPK activation

Eukaryotic translation initiation factor 3 subunit A (eIF3a), the largest subunit of the eIF3 complex, has been shown to be overexpressed in malignant cancer cells, potentially making it a proto-oncogene. eIF3a overexpression can drive cancer cell proliferation but contributes to better prognosis. While its contribution to prognosis was previously shown to be due to its function in suppressing synthesis of DNA damage repair proteins, it remains unclear how eIF3a regulates cancer cell proliferation. In this study, we show using genetic approaches that eIF3a controls cell proliferation by regulating glucose metabolism via the phosphorylation and activation of AMP-activated protein kinase alpha (AMPKα) at Thr¹⁷² in its kinase activation loop. We demonstrate that eIF3a regulates AMPK activation mainly by controlling synthesis of the small GTPase Rheb, largely independent of the well-known AMPK upstream liver kinase B1 and Ca²⁺/calmodulin-dependent protein kinase kinase 2, and also independent of mammalian target of rapamycin signaling and glucose levels. Our findings suggest that glucose metabolism in and proliferation of cancer cells may be translationally regulated via a novel eIF3a–Rheb–AMPK signaling axis.

[Clinical analysis of chronic eosinophilic pneumonia in 9 cases]

Objective: To investigate the clinical features, treatment and prognosis of chronic eosinophilic pneumonia. Methods: Nine patients with chronic eosinophilic pneumonia diagnosed in Shandong Provincial Qianfoshan Hospital from January 2014 to December 2020 were enrolled and followed up. The data of clinically proven chronic eosinophilic pneumonia were reviewed. Results: The 9 cases included one male and eight females, aged from 16 to 71 years (median 47 years). Among them, 5 cases were complicated with asthma, 1 case was complicated with allergic rhinitis, and 1 case had an allergic history of pollen. All the patients had cough, expectoration, chest tightness and wheezing, and a few had fatigue (3/9), fever (1/9) and chest pain (1/9). Single or multiple patchy high-density shadows (9/9), mediastinal lymphadenopathy (7/9), air bronchogram (2/9), and reticular shadow (1/9) were observed in chest CT. Peripheral eosinophils (EOS) and serum total IgE increased to varying degrees in the 9 patients. Meanwhile, the bronchoscopy of 5 cases showed elevated percentage of eosinophils in alveolar lavage fluid, and the lung biopsy of remaining 4 cases showed EOS infiltration in lung alveolar and interstitium. After receiving glucocorticoid therapy for 0.5 to 1 month, the clinical symptoms of all 9 patients had been improved and lung lesions on CT scans had been obviously absorbed. Four cases relapsed during follow-up. Conclusions: For patients especially women who have a history of allergy, elevated blood eosinophils and serum total IgE with pulmonary high-density shadow or consolidation, chronic eosinophilic pneumonia should be considered, and bronchoscopy or percutaneous lung biopsy is indicated for a definite diagnosis. Glucocorticoid therapy is effective, but the rate of recurrence is high.

Oral oligofructose challenge reduces expression of glucose transport-1 and 5'-adenosine monophosphate-activated protein kinase in lamellar wall of Holstein heifer claw

The laminar tissue of bovine laminitis may undergo energy failure. The expression of glucose transport protein-1 (GLUT-1) and 5'-adenosine monophosphate-activated protein kinase (AMPK) affects the energy metabolism of digital laminar tissue. This study aimed to determine the expression of glucose uptake and AMPK in laminar wall corium of Holstein heifer claw by oral administration of oligofructose. A total of twelve clinically healthy Holstein heifers were selected and divided into two groups, including control (CON, n = 6) and experimental (OF, n = 6) groups. The heifers of OF group were given 17 g/kg BW oligofructose dissolved in water (20 mL/kg BW) and the heifers of CON group were given water only (20 mL/kg BW). The laminar tissues were collected after euthanasia. The amount of protein and transcript expression of AMPK and GLUT-1 were determined by western blot and quantitative reverse transcription-polymerase chain reaction (qRT-PCR), respectively. Expressions of phosphoenolpyruvate carboxy-kinase (PEPCK), receptor-c coactivator1-α (PGC-1α) and peroxisome proliferator-activated receptor-γ (PPAR-γ) were determined by qRT-PCR. The heifers of OF group showed no significant change in the expression and concentration of AMPK. The phosphor-(Thr172) AMPK and GLUT-1 were significantly decreased, while the gene contents of PPAR-γ and PGC-1α were significantly increased. The activation of AMPK and GLUT-1 in digital laminar tissues of heifers was inhibited, which may contribute to digital laminar tissue damage.

Characteristics and long-term ablation outcomes of supraventricular arrhythmias in hypertrophic cardiomyopathy: a 10-year, single-center experience

Background

A variety of supraventricular arrhythmias (SVAs) may occur in patients with hypertrophic cardiomyopathy (HCM). The characteristics and long-term ablation outcomes of different types of SVAs in HCM have not been comprehensively investigated.

Methods

We retrospectively enrolled 101 consecutive symptomatic HCM patients with suspected arrhythmia from May 2010 to October 2020. The clinical features and ablation outcomes of patients with SVAs were further analyzed.

Results

Seventy-eight patients had SVAs, consisting of 50 (64.1%) atrial fibrillation (AF), 16 (20.5%) atrial flutter (AFL), 15 (19.2%) atrioventricular reentrant tachycardia (AVRT), 11 (14.1%) atrial arrhythmia (AT), and 3 (3.8%) atrioventricular nodal reentrant tachycardia (AVNRT). Thirty-four patients underwent catheter ablation including 14 for AF, 9 for AVRT, 6 for AFL, 3 for AVNRT, 1 for both AF and AFL, and 1 for both AF and AVRT. They were followed up for a median (interquartile range) of 58.5 (82.9) months. There were no recurrences for patients with non-AF SVAs. For patients with AF, the 1- and 7-year AF-free survival were 87.5% and 49.5%, respectively. A ROC analysis revealed that a greater left ventricular end-diastolic dimension (LVEDD) was associated with higher recurrence of AF with an optimum cutoff value of 47mm (c-statistic = 0.91, p=0.011, sensitivity = 1.00, specificity = 0.82). In Kaplan-Meier analysis, patients with LVEDD ≥47mm had worse AF-free survival (log-rank p=0.014).

Conclusions

AF is the most common SVA in HCM, with AFL, AVRT, AT, and AVNRT ranking the second to the last according to the prevalence. The long-term catheter ablation outcome for non-AF SVAs in HCM is satisfying. A greater LVEDD predicts AF recurrence after catheter ablation in patients with HCM.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): National Natural Science Foundation of China Figure 1Figure 2

Minimally invasive co-injection of modular micro-muscular and micro-vascular tissues improves in situ skeletal muscle regeneration

Various conventional treatment strategies for volumetric muscle loss (VML) are often hampered by the extreme donor site morbidity, the limited availability of quality muscle flaps, and complicated, as well as invasive surgical procedures. The conventional biomaterial-based scaffolding systems carrying myoblasts have been extensively investigated towards improving the regeneration of the injured muscle tissues, as well as their injectable forms. However, the applicability of such designed systems has been restricted due to the lack of available vascular networks. Considering these facts, here we present the development of a unique set of two minimally invasively injectable modular microtissues, consisting of mouse myoblast (C2C12)-laden poly(lactic-co-glycolic acid) porous microspheres (PLGA PMs), or the micro-muscles, and human umbilical vein endothelial cell (HUVEC)-laden poly(ethylene glycol) hollow microrods (PEG HMs), or the microvessels. Besides systematic in vitro investigations, the myogenic performance of these modular composite microtissues, when co-injected, was explored in vivo using a mouse VML model, which confirmed improved in situ muscle regeneration and remolding. Together, we believe that the construction of these injectable modular microtissues and their combination for minimally invasive therapy provides a promising method for in situ tissue healing.

Inhibiting Fatty Acid Synthase with Omeprazole to Improve Efficacy of Neoadjuvant Chemotherapy in patients with Operable TNBC

PURPOSE

Fatty acid synthase (FASN) is overexpressed in 70% of operable triple negative breast cancer (TNBC) and is associated with poor prognosis. Proton pump inhibitors selectively inhibit FASN activity and induce apoptosis in TNBC cell lines.

EXPERIMENTAL DESIGN

Patients with operable TNBC were enrolled in this single arm Phase II study. Patients began omeprazole (OMP) 80 mg PO BID for 4-7 days prior to neoadjuvant anthracycline- taxane based chemotherapy (AC-T) and continued until surgery. The primary endpoint was pathologic complete response (pCR) in patients with baseline FASN overexpression (FASN+). Secondary endpoints included pCR in all surgery patients, change in FASN expression, enzyme activity, and downstream protein expression after OMP monotherapy; safety, and limited OMP pharmacokinetics.

RESULTS

Forty-two patients were recruited with a median age of 51y (28-72). Most patients had {greater than or equal to}cT2 (33, 79%) and {greater than or equal to}N1 (22, 52%) disease. FASN overexpression prior to AC-T was identified in 29/34 (85%) evaluable samples. The pCR rate was 72.4% (95% CI 52.8, 87.3) in FASN+ patients and 74.4% (95% CI 57.9, 87.0) in all surgery patients. Peak OMP concentration was significantly higher than the IC₅₀ for FASN inhibition observed in preclinical testing; FASN expression decreased with OMP monotherapy (mean change 0.12 (SD 0.25) ; p = 0.02). OMP was well tolerated with no {greater than or equal to} grade 3 toxicities.

CONCLUSIONS

FASN is commonly expressed in early TNBC. OMP can be safely administered in doses that inhibit FASN. The addition of OMP to neoadjuvant AC-T yields a promising pCR rate that needs further confirmation in randomized studies.

The effect of eIF3a on anthracycline-based chemotherapy resistance by regulating DSB DNA repair

BACKGROUND

Anthracycline are inhibitors of topoisomerase II leading to DNA double strand breaks, and it is widely used for treatment of breast cancer. eIF3a is the largest subunit of eukaryotic translation initiation factor 3 (eIF3) and highly expressed in breast cancer. In this study, we investigated the role of eIF3a in DSB DNA repair and the response of breast cancer patients to anthracycline-based chemotherapy.

METHODS

MTT assay was used to detect anthracycline sensitivity in cell lines. Real-time reverse transcriptase PCR, western blotting and immunofluorescence were performed to assess changes in gene expression levels. Cometassay and end-joining activity assay were conducted to explore the effect of eIF3a in NHEJ repair. Luciferase reporter assay was performed to detect LIG4 5'UTR activity. Immunohistochemistry was used to detect eIF3a, LIG4 and DNA-PKcs expression levels in breast cancer tissues.

RESULTS

The results showed that eIF3a increased cellular response to anthracyclines by regulating DSB repair activity via influencing the expression of LIG4 and DNA-PKcs at translational level. Breast cancer patients with high level of eIF3a or low level of LIG4 or low level of DNA-PKcs had better anthracycline-based chemotherapy prognosis compared. Moreover, Combined expressions of eIF3a, LIG4 and DNA-PKcs could be better to predict PFS in breast cancer patients with anthracycline-based chemotherapy.

CONCLUSION

Our findings suggest that eIF3a effects anthracycline-based chemotherapy response by regulating DSB DNA repair.

Proton pump inhibitors suppress DNA damage repair and sensitize treatment resistance in breast cancer by targeting fatty acid synthase

Human fatty acid synthase (FASN) is the sole cytosolic enzyme responsible for de novo lipid synthesis. FASN is essential for cancer cell survival and contributes to drug and radiation resistance by up-regulating DNA damage repair but not required for most non-lipogenic tissues. Thus, FASN is an attractive target for drug discovery. However, despite decades of effort in targeting FASN, no FASN inhibitors have been approved due to poor pharmacokinetics or toxicities. Here, we show that the FDA-approved proton pump inhibitors (PPIs) effectively inhibit FASN and suppress breast cancer cell survival. PPI inhibition of FASN leads to suppression of non-homologous end joining repair of DNA damages by reducing FASN-mediated PARP1 expression, resulting in apoptosis from oxidative DNA damages and sensitization of cellular resistance to doxorubicin and ionizing radiation. Mining electronic medical records of 6754 breast cancer patients showed that PPI usage significantly increased overall survival and reduced disease recurrence of these patients. Hence, PPIs may be repurposed as anticancer drugs for breast cancer treatments by targeting FASN to overcome drug and radiation resistance.

eIF3i regulation of protein synthesis, cell proliferation, cell cycle progression, and tumorigenesis

eIF3i, a 36-kDa protein, is a putative subunit of the eIF3 complex important for translation initiation of mRNAs. It is a WD40 domain-containing protein with seven WD40 repeats that forms a β-propeller structure with an important function in pre-initiation complex formation and mRNA translation initiation. In addition to participating in the eIF3 complex formation for global translational control, eIF3i may bind to specific mRNAs and regulate their translation individually. Furthermore, eIF3i has been shown to bind to TGF-β type II receptor and participate in TGF-β signaling. It may also participate in and regulate other signaling pathways including Wnt/β-catenin pathway via translational regulation of COX-2 synthesis. These multiple canonical and noncanonical functions of eIF3i in translational control and in regulating signal transduction pathways may be responsible for its role in cell differentiation, cell cycle regulation, proliferation, and tumorigenesis. In this review, we will critically evaluate recent progresses and assess future prospects in studying eIF3i.

Abstract PO-009: Genetically engineered exosomes enable active pancreatic cancer targeting and evading mononuclear phagocytic system

Introduction: Exosomes are emerging as promising nanocarriers for genes and drugs; however, major challenges exist including the absence of active tumor targeting and a high proportion of clearance by mononuclear phagocytic system (MPS) in liver and spleen. To overcome these obstacles currently preventing the effective application of nanodelivery technology in the field of cancer biology, we generate a novel exosome that recognizes both pancreatic ductal adenocarcinoma (PDAC) specific cell surface marker avb3 and the signal regulatory protein (SIRPa) on macrophages. Using this novel exosome, we have achieved active PDAC targeting and MPS evasion. Methods: We engineered the CD9, an exosome marker, to display a HA tagged RGD peptide at the E174 site of CD9 (CD9-HA-RGD). We overexpressed CD9-HA-RGD and a Flag tagged CD47 (CD47-Flag) in HEK 293 cells. CD47, a “don’t eat me” protein signal, mediates inhibition of phagocytosis through interacting with SIRPa on macrophages. Exosomes overexpressing CD9-HA-RGD and CD47-Flag were harvested from HEK 293 cell culture media by ultracentrifugation followed by purification with size exclusion chromatography (SEC). Exosomes displaying RGD and CD47 (Exo-RGD/CD47) were characterized in vitro using ELISA, western blot (WB), flow cytometry (FCM), PDAC cell uptake, and macrophage phagocytosis assays. Exo-RGD/CD47 was also evaluated in vivo in patient-derived PDAC cell line (PDCL5) orthotopic xenograft mouse model. Results: RGD and CD47 were demonstrated to be successfully displayed on exosome surface by analysis of HA and Flag expression using ELISA and FCM. Engineered Exo-RGD/CD47 exosomes achieved enhanced cell binding and increased uptake capacities in an avb3 expression dependent manner in PDAC cells. This was confirmed using excess RDG peptide in a competition assay. Control exosomes demonstrated low uptake efficiency by PDAC cells. Exo-RGD/CD47 resulted in 71.5% reduction of macrophage phagocytosis when compared to control exosomes as evaluated by THP1 cells phagocytosis assay. Using DiR stained exosomes, we demonstrated that Exo-RGD/CD47 systemic delivery significantly reduced liver accumulation up to 80.6% and 65.8% after 1h and 6h after injection, respectively, as compared to control group (p&lt;0.05). Similarly, Exo-RGD/CD47 delivery resulted in 70.1% reduction of splenic accumulation as compared to control at 6h after application (p&lt;0.05). Exo-RGD/CD47 systemic delivery also showed significant tumor accumulation in the PDCL5 xenograft tumor model as compared to control (p&lt;0.05). Conclusions: These data demonstrate that CD9 is an editable exosome biomarker by which peptides can be effectively displayed on the surface of an exosome. Displaying RGD and CD47 on the exosome surface results in a novel exosome that enables active PDAC targeting and evasion of phagocytosis by MPS. These findings suggest the newly designed exosome may have a better translational potential in PDAC diagnosis and therapy than traditional exosomes.

Citation Format: Shi-He Liu, Justin Creeden, F. Charles Brunicardi, JianTing Zhang. Genetically engineered exosomes enable active pancreatic cancer targeting and evading mononuclear phagocytic system [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2020 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2020;80(22 Suppl):Abstract nr PO-009.

Biodegradable Quantum Composites for Synergistic Photothermal Therapy and Copper-Enhanced Chemotherapy

In recent times, the combination therapy has garnered enormous interest owing to its great potential in clinical research. It has been reported that disulfiram, a clinical antialcoholism drug, could be degraded to diethyldithiocarbamate (DDTC) in vivo and subsequently result in the copper-DDTC complex (Cu(DDTC)₂) toward ablating cancer cells. In addition, the ultrasmall copper sulfide nanodots (CuS NDs) have shown great potential in cancer treatment because of their excellent photothermal and photodynamic therapeutic efficiencies. Herein, by taking advantage of the interactions between CuS and DDTC, a new multifunctional nanoplatform based on DDTC-loaded CuS (CuS-DDTC) NDs is successfully fabricated, leading to the achievement of the synergistic effect of photothermal and copper enhanced chemotherapy. All experimental results verified promising synergistic therapeutic effects. Moreover, in vivo biocompatibility and metabolism experiments displayed that the CuS-DDTC NDs could be quickly excreted from the body with no apparent toxicity signs. Together, our findings indicated the superior synergistic therapeutic effect of photothermal and copper-enhanced chemotherapy, providing a promising anticancer strategy based on the CuS-DDTC NDs drug delivery system.

eIF3a Regulation of NHEJ Repair Protein Synthesis and Cellular Response to Ionizing Radiation

Translation initiation in protein synthesis regulated by eukaryotic initiation factors (eIFs) is a crucial step in controlling gene expression. eIF3a has been shown to regulate protein synthesis and cellular response to treatments by anticancer agents including cisplatin by regulating nucleotide excision repair. In this study, we tested the hypothesis that eIF3a regulates the synthesis of proteins important for the repair of double-strand DNA breaks induced by ionizing radiation (IR). We found that eIF3a upregulation sensitized cellular response to IR while its downregulation caused resistance to IR. eIF3a increases IR-induced DNA damages and decreases non-homologous end joining (NHEJ) activity by suppressing the synthesis of NHEJ repair proteins. Furthermore, analysis of existing patient database shows that eIF3a expression associates with better overall survival of breast, gastric, lung, and ovarian cancer patients. These findings together suggest that eIF3a plays an important role in cellular response to DNA-damaging treatments by regulating the synthesis of DNA repair proteins and, thus, eIIF3a likely contributes to the outcome of cancer patients treated with DNA-damaging strategies including IR.

Near-Infrared-Activated Lysosome Pathway Death Induced by ROS Generated from Layered Double Hydroxide-Copper Sulfide Nanocomposites

The overdeveloped lysosomes in cancer cells are gaining increasing attention toward more precise and effective organelle-targeted cancer therapy. It is suggested that rod/plate-like nanomaterials with an appropriate size exhibited a greater quantity and longer-term lysosomal enrichment, as the shape plays a notable role in the nanomaterial transmembrane process and subcellular behaviors. Herein, a biodegradable platform based on layered double hydroxide-copper sulfide nanocomposites (LDH-CuS NCs) is successfully prepared via in situ growth of CuS nanodots on LDH nanoplates. The as-prepared LDH-CuS NCs exhibited not only high photothermal conversion and near-infrared (NIR)-induced chemodynamic and photodynamic therapeutic efficacies, but also could achieve real-time in vivo photoacoustic imaging (PAI) of the entire tumor. LDH-CuS NCs accumulated in lysosomes would then generate extensive subcellular reactive oxygen species (ROS) in situ, leading to lysosomal membrane permeabilization (LMP) pathway-associated cell death both in vitro and in vivo.

Repurposing metformin, simvastatin and digoxin as a combination for targeted therapy for pancreatic ductal adenocarcinoma

Patients with pancreatic adenocarcinoma (PDAC) have a 5-year survival rate of 8%, the lowest of any cancer in the United States. Traditional chemotherapeutic regimens, such as gemcitabine- and fluorouracil-based regimens, often only prolong survival by months. Effective precision targeted therapy is therefore urgently needed to substantially improve survival. In an effort to expedite approval and delivery of targeted therapy to patients, we utilized a platform to develop a novel combination of FDA approved drugs that would target pancreaticoduodenal homeobox1 (PDX1) and baculoviral inhibitor of apoptosis repeat-containing 5 (BIRC5) utilizing super-promoters of the target genes to interrogate an FDA approved drug library. We identified and selected metformin, simvastatin and digoxin (C3) as a novel combination of FDA approved drugs, which were shown to effectively target PDX1 and BIRC5 in human PDAC tumors in mice with no toxicity.

Synthesis and Identification of a Novel Lead Targeting Survivin Dimerization for Proteasome-Dependent Degradation

Survivin, a homodimeric member of the Inhibitor of Apoptosis Protein (IAP) family, is required for cancer cell survival and overexpressed in almost all solid tumors. However, targeting survivin has been challenging due to its "undruggable" nature. Recently, we used a novel approach to target the dimerization interface and identified inhibitors of two scaffolds that can directly bind to and inhibit survivin dimerization. One of the scaffolds, represented by the compound LQZ-7, contains an undesirable labile hydrazone linker and a potentially nonfunctional furazanopyrazine ring that we attempted to eliminate in this study. We found one compound, 7I, that is more active than the parent compound, LQZ-7, and when given orally effectively inhibits xenograft tumor growth and induces survivin loss in tumors. These findings indicate that 7I with a stable linker and a quinoxaline ring can be used as a lead for further optimization of this novel class of survivin inhibitors.

Inhibiting fatty acid synthase in operable triple negative breast cancer

584

Background: Fatty acid synthase (FASN) is overexpressed in 70% of newly diagnosed triple negative breast cancer (TNBC) and is associated with poor prognosis. In vitro, FASN overexpression induces drug resistance to DNA damaging agents. Proton pump inhibitors (PPI) selectively inhibit FASN activity and induce apoptosis in breast cancer cell lines with minimal effect on non-malignant cells. We report the results of a single arm phase II study of high dose omeprazole (OMP) in combination with anthracycline- taxane (AC-T) based neoadjuvant chemotherapy. Methods: Patients (pts) with operable TNBC independent of baseline FASN expression; and no prior PPI use within 12 months were enrolled. Pts began OMP 80 mg PO BID for 4-7 days prior to AC-T; carboplatin was allowed per physician discretion. OMP was continued until surgery. Paired biopsy samples were obtained before and after OMP monotherapy. The primary endpoint was pathologic complete response (pCR), defined as no residual invasive disease in breast or axilla, in pts with baseline FASN expression (FASN+) assessed using immunohistochemistry. Relevant secondary endpoints included pCR in the intent to treat population, change in FASN expression, enzyme activity and downstream target gene expression after OMP monotherapy; safety and limited OMP pharmacokinetics. We targeted a pCR rate of 60% in FASN+ pts (null pCR ~ 40%) with 80% power and alpha of 0.10. Results: A total of 42 pts were recruited from 5 US sites. Median age was 51y (28-72). Most pts had >cT2 (33, 79%) and ≥N1 (22, 52%) disease. 14 (33%) were African American. FASN expression prior to AC-T was identified in 28 (85%) samples available for analysis. The pCR rate was 71.4% (95% CI 51.3 to 86.8) in FASN+ pts and 71.8 %( 95% CI 55.1 to 85.0) in all enrolled pts. Fifteen pts (36%) received carboplatin with AC-T; pCR in this subset was 73%. Peak OMP concentration was significantly higher than IC50 observed during preclinical testing; FASN positivity significantly decreased with OMP monotherapy from 0.53(SD 0.25) at baseline to 0.38(SD 0.30; p = 0.02). OMP was well tolerated with no known grade (G) 3 or 4 toxicities. Chemotherapy toxicity was similar to prior studies using AC-T with G3 or 4 neutropenia (19%), febrile neutropenia (7%) and peripheral neuropathy (7%) being the most common. Conclusions: Consistent with previous studies, FASN is frequently expressed in early stage TNBC. OMP can be safely administered in doses that inhibit FASN. The addition of high dose OMP to neoadjuvant AC-T yields a promising pCR rate without adding toxicity. Funded by the Breast Cancer Research Foundation. Clinical trial information: NCT02595372 .

Single-nucleotide polymorphisms in a short basic motif in the ABC transporter ABCG2 disable its trafficking out of endoplasmic reticulum and reduce cell resistance to anticancer drugs

ATP-binding cassette (ABC) subfamily G member 2 (ABCG2) belongs to the ABC transporter superfamily and has been implicated in multidrug resistance of cancers. Although the structure and function of ABCG2 have been extensively studied, little is known about its biogenesis and the regulation thereof. In this study, using mutagenesis and several biochemical analyses, we show that the positive charges in the vicinity of the RKR motif downstream of the ABC signature drive trafficking of nascent ABCG2 out of the endoplasmic reticulum (ER) onto plasma membranes. Substitutions of and naturally occurring single-nucleotide polymorphisms within these positively charged residues disabled the trafficking of ABCG2 out of the ER. A representative ABCG2 variant in which the RKR motif had been altered underwent increased ER stress-associated degradation. We also found that unlike WT ABCG2, genetic ABCG2 RKR variants have disrupted normal maturation and do not reduce accumulation of the anticancer drug mitoxantrone and no longer confer resistance to the drug. We conclude that the positive charges downstream of the ABC signature motif critically regulate ABCG2 trafficking and maturation. We propose that single-nucleotide polymorphisms of these residues reduce ABCG2 expression via ER stress-associated degradation pathway and may contribute to reduced cancer drug resistance, improving the success of cancer chemotherapy.

CC-115, a Dual Mammalian Target of Rapamycin/DNA-Dependent Protein Kinase Inhibitor in Clinical Trial, Is a Substrate of ATP-Binding Cassette G2, a Risk Factor for CC-115 Resistance

CC-115, a triazole-containing compound, is a dual mammalian target of rapamycin (mTOR)/DNA-dependent protein kinase (DNA-PK) inhibitor currently in clinical trials. To develop this compound further, we investigated factors that may affect cellular response to CC-115. Previously, fatty acid synthase (FASN) was shown to upregulate DNA-PK activity and contribute to drug resistance; therefore, we hypothesized that FASN may affect cellular response to CC-115. Instead, however, we showed that CC-115 is a substrate of ATP-binding cassette G2 (ABCG2), a member of the ATP-binding cassette transporter superfamily, and that expression of ABCG2, not FASN, affects the potency of CC-115. ABCG2 overexpression significantly increases resistance to CC-115. Inhibiting ABCG2 function, using small-molecule inhibitors, sensitizes cancer cells to CC-115. We also found that CC-115 may be a substrate of ABCB1, another known ABC protein that contributes to drug resistance. These findings suggest that expression of ABC transporters, including ABCB1 and ABCG2, may affect the outcome in clinical trials testing CC-115. Additionally, the data indicate that ABC transporters may be used as markers for future precision use of CC-115. SIGNIFICANCE STATEMENT: In this article, we report our findings on the potential mechanism of resistance to CC-115, a dual inhibitor of mTOR and DNA-PK currently in clinical trials. We show that CC-115 is a substrate of ABCG2 and can be recognized by ABCB1, which contributes to CC-115 resistance. These findings provide novel information and potential guidance on future clinical testing of CC-115.

[Prevalence and risk factors of perivascular space in the population of Shunyi Study]

Objective: To investigate the prevalence on imaging, topographic distribution and risk factors of perivascular space (PVS) in community population. Methods: This study was based on the population of Shunyi Study in China from June 2013 to September 2016. One thousand two hundred and thirty-two stroke free participants older than 35 years, who completed cerebral MRI, were included. Cardiovascular risk factors were assessed by interview, physical examination and blood sample tests. PVS were evaluated on high-resolution 3-dimensional-T1WI, T2WI and FLAIR sequences. On T1WI, PVS were detected according to 3D imaging criteria. The number and anatomic location of large PVS (≥3 mm) were recorded. And severity of PVS was then semiquantitatively graded in both white matter (WM) and basal ganglia (BG). Associations between risk factors and PVS were analyzed by multinominal Logistic regression models and adjusted for age, gender and relevant confounders. Results: Perivascular spaces were observed in the BG or WM in every subject, aged (55±10) years and 37.3% male. Large PVS were detected in 19.0% (460/1 232) of participants. Severity of PVS was found to be strongly associated with age in both basal ganglia (severe versus mild: OR=1.81; 95%CI 1.45-2.27, P<0.01) and white matter (OR=1.39; 95%CI 1.13-1.71, P<0.01), and the proportion of subjects with hypercholesterolemia decreased with the severity of PVS in BG (OR=0.58, P=0.01) . The present of large PVS was found to be associated with age(present versus absent: OR=1.03, 95%CI 1.02-1.05, P<0.01) and ApoE ε4 carrier genotype(OR=1.53, 95%CI 1.01-2.23, P=0.04). Conclusions: Perivascular spaces are always detected in the BG or WM in elderly people, and large PVS are also prevalent in community-based population. The risk factors are different due to distribution and size, and may depend on anatomic or pathologic characteristics.

Dual Functional Modification of Alkaline Amino Acids Induces the Self-Assembly of Cylinder-Like Tobacco Mosaic Virus Coat Proteins into Gear-Like Architectures

Herein, the assembly of 3D uniform gear-like architectures is demonstrated with a tobacco mosaic virus (TMV) disk as a building block. In this context, the intrinsic behavior of the TMV disk that promotes its assembly into nanotubes is altered by a synergistic effect of dual functional modifications at the 53rd arginine mutation and the introduction of lysine groups in the periphery at 1st and 158th positions of the TMV disk, which results in the formation of 3D gear-like superstructures. Therein, the 53rd arginine moiety significantly strengthens the linkage between TMV disks in the alkaline environment through hydrogen bond interactions. The charge of lysine-modified lateral surfaces is partially neutralized in the alkaline solution, which induces the TMV disk to form a gear-like architecture to maintain its structural stability by exploiting the electrostatic repulsion between neighboring TMV disks. This study not only provides explicit evidence regarding the molecular-level understanding of how the modification of site-specific amino acid affects the assembly of resultant superstructures but also encourages the fabrication of functional protein-based nanoarchitectures.

Saturation cavity ring-down spectrometry using a dynamical relaxation model

We propose a new simple approximate solution to the two-state rate equation model for analyzing decay signals of saturation cavity ring-down spectrometry in the adiabatic and low-saturation regime. It helps obtain baseline-immune Doppler-free spectra for hyperfine transitions and linear absorption coefficients of a gas in the saturation regime. To demonstrate it, a baseline-immune Lamb dip spectrum of the R1A2 transitions in the 2v₂ + v₃ band of methane was recorded. The line position was determined to be 6 076.108 457 7(11) cm^-1, the relative uncertainty being 1.8 × 10^-10.

Discovery of New Lines in the R9 Multiplet of the 2v_{3} Band of ^{12}CH_{4}

We present the first results for resolving methane (CH_{4}) line transition frequencies down to the kilohertz level for overlapping lines using comb-linked cavity ring-down spectroscopy, while most available laboratory measurements, having resolution at the megahertz level, cannot separate merged lines. To demonstrate the technique, Lamb-dip spectra and linear-absorption spectra were used to identify overlapped lines of vibration-rotation spectra in the R9 multiplet of the 2v_{3} band. Three new weak lines were found for the first time. The experimental methods are extensible to other important bands of CH_{4} and many other gas-phase molecules, and should provide a more detailed understanding of molecular structure and line parameters for future high-precision studies.

Temperature-scanning saturation cavity ring-down spectrometry for Doppler-free spectroscopy

Saturation cavity ring-down spectroscopy (SCRDS) is a powerful Doppler-free spectroscopy means for measuring absolute frequencies of transitions at the ultra-low uncertainties. We report in this paper a simple way to implement it by temperature scanning the cavity length, which circumvents the need for a complex optical cavity-length stabilization system based upon a piezoelectric actuator (PZT). To demonstrate this approach, the absolute frequencies of the two transitions, R6F1 of the 2v₃ and Q9A1 of the 2v₂ + v₃ bands, of ¹²CH₄, are determined to be 182 185 269.362(20) MHz and 182 187 617.543(39) MHz. The accuracy of measurements is improved by about 3-4 orders of magnitude when compared to those obtained with conventional spectroscopic methods.

Novel synthetic bisindolylmaleimide alkaloids inhibit STAT3 activation by binding to the SH2 domain and suppress breast xenograft tumor growth

Signal transducer and activator of transcription 3 (STAT3) is constitutively activated in malignant tumors and plays important roles in multiple aspects of cancer aggressiveness. Thus, targeting STAT3 promises to be an attractive strategy for treatment of advanced metastatic tumors. Bisindolylmaleimide alkaloid (BMA) has been shown to have anti-cancer activities and was thought to suppress tumor cell growth by inhibiting protein kinase C. In this study, we show that a newly synthesized BMA analogue, BMA097, is effective in suppressing tumor cell and xenograft growth and in inducing spontaneous apoptosis. We also provide evidence that BMA097 binds directly to the SH2 domain of STAT3 and inhibits STAT3 phosphorylation and activation, leading to reduced expression of STAT3 downstream target genes. Structure activity relationship analysis revealed that the hydroxymethyl group in the 2,5-dihydropyrrole-2,5-dione prohibits STAT3-inhibitory activity of BMA analogues. Together, we conclude that the synthetic BMA analogues may be developed as anticancer drugs by targeting and binding to the SH2 domain of STAT3 and inhibiting the STAT3 signaling pathway.

[Effect of hyperandrogenism on obstetric complications of singleton pregnancy from in vitro fertilization in women with polycystic ovary syndrome]

Objective: To compare the difference in risks of obstetric complications of singleton pregnancy between women with hyperandrogenic polycystic ovary syndrome (PCOS) and women with normoandrogenic PCOS. Methods: Prospective cohort study. This study was a secondary analysis of data collected during a multicenter randomized controlled clinical trial. Women who got clinical singleton pregnancy were grouped according to whether they were diagnosed with hyperandrogenism at baseline. There were 118 women with hyperandrogenism and 366 women without hyperandrogenism. The incidences of obstetric complications and birth weight were compared between the two groups. Results: Women with hyperandrogenic PCOS had a significantly higher risk of preterm delivery than women with normoandrogenic PCOS [12.7% (15/118) versus 3.6% (13/366); OR=3.94, 95%CI: 1.82-8.56]. After adjustment of age, duration of infertility, body mass index, and fresh or frozen embryo transfer group, hyperandrogenism was still associated with an increased risk of preterm delivery (OR=3.67, 95%CI: 1.67-8.07). Compared with women with normoandrogenic PCOS, women with hyperandrogenic PCOS had similar risks of pregnancy loss, gestational diabetes mellitus, pre-eclampsia, placenta previa, and postpartum hemorrhage (all P>0.05). Birth weight as well as the risks of being small for gestational age and large for gestational age were also comparable between the two groups (all P>0.05). Conclusion: In women with PCOS and singleton pregnancy, those with preconceptional hyperandrogenism have a higher risk of preterm delivery than those without hyperandrogenism.

[Characterization and uncertainty evaluation of aqueous reference materials for cholesterol]

Objective: Characterization and evaluation of the uncertainty of the reference materials of cholesterol in aqueous solution. Methods: The certified reference material GBW09203b was weighed accurately and dissolved into methyl cyclodextrin aqueous solution to prepare six kinds of candidate reference materials of cholesterol according to the concentration. The materials were tested for homogeneity and stability using routine methods and were evaluated the uncertainty derived from the inhomogeneity and instability. The uncertainty due to measurement was derived from the purity of the raw material, the weighing and the density measurement. The certified values and expanded uncertainties were calculated according to the ISO Guide. The expanded uncertainty of the certified value was the combination of standard uncertainty of measurement, inhomogeneity and instability. The coverage factor, k, was determined from the Student's t-distribution corresponding to the calculated effective degrees of freedom and 95% level of confidence. Results: It showed that the six candidate reference materials were homogeneous and were tested to be stable for at least 1 year at -70 ℃ and -20 ℃ using the isochronous stability study. The relative uncertainties due to the inhomogeneity were 0.14%, 0.11%, 0.13%, 0.47%, 0.39% and 0.11%. The relative uncertainty due to the instability was 0.25% at -70 ℃. The uncertainties of measurement were 0.06%, 0.05%, 0.05%, 0.05%, 0.05% and 0.05%.The certified values (reference value ± expanded uncertainty, mmol/L) were as follows: (0.651±0.004), (1.310 ±0.007), (2.574±0.015), (5.210±0.055), (7.710±0.072), (10.242±0.056) mmol/L. Conclusions: Six kinds of certified reference materials for cholesterol in aqueous solution have been prepared, which were homogeneity, stable and reliable. It showed that the uncertainty of measurement was very small compared with the uncertainty due to inhomogeneity and instability.

eIF3a: A new anticancer drug target in the eIF family

eIF3a is the largest subunit of eIF3, which is a key player in all steps of translation initiation. During the past years, eIF3a is recognized as a proto-oncogene, which is an important discovery in this field. It is widely reported to be correlated with cancer occurrence, metastasis, prognosis, and therapeutic response. Recently, the mechanisms of eIF3a action in the carcinogenesis are unveiled gradually. A number of cellular, physiological, and pathological processes involving eIF3a are identified. Most importantly, it is emerging as a new potential drug target in the eIF family, and some small molecule inhibitors are being developed. Thus, we perform a critical review of recent advances in understanding eIF3a physiological and pathological functions, with specific focus on its role in cancer and anticancer drug targets.