Search

T cell receptor (TCR) engagement causes a global cellular response that entrains signaling pathways, cell cycle regulation, and cell death. The molecular regulation of mRNA translation in these processes is poorly understood. Using a whole-genome CRISPR screen for regulators of CD95 (FAS/APO-1)-mediated T cell death, we identified AMBRA1, a protein previously studied for its roles in autophagy, E3 ubiquitin ligase activity, and cyclin regulation. T cells lacking AMBRA1 resisted FAS-mediated cell death by down-regulating FAS expression at the translational level. We show that AMBRA1 is a vital regulator of ribosome protein biosynthesis and ribosome loading on select mRNAs, whereby it plays a key role in balancing TCR signaling with cell cycle regulation pathways. We also found that AMBRA1 itself is translationally controlled by TCR stimulation via the CD28-PI3K-mTORC1-EIF4F pathway. Together, these findings shed light on the molecular control of translation after T cell activation and implicate AMBRA1 as a translational regulator governing TCR signaling, cell cycle progression, and T cell death., Competing Interests: Competing interests statement:The authors declare no competing interest.

Background: Early prediction of treatment response is crucial for the optimal treatment of advanced breast cancer. We aimed to explore whether monitoring early changes in plasma human epidermal growth factor receptor 2 (HER2) levels using digital PCR (dPCR) could predict the treatment response in advanced breast cancer., Methods: This was a multicenter, prospective, noninterventional clinical study of patients with advanced breast cancer. All enrolled patients underwent blood testing to measure the HER2 levels by digital PCR before treatment initiation and once every 3 weeks during the study. The primary endpoints were a the diagnostic value of dPCR for detecting HER2 status in the blood and b the relevance of potential changes in the plasma HER2 level at 3 weeks from baseline for predicting treatment response., Results: Overall, 85 patients were enrolled between October 9, 2018, and January 23, 2020. dPCR had a specificity of 91.67% (95% CI: 80.61% to 97.43%) for detecting HER2 amplification, and the area under the receiver operating characteristic (ROC) curve was 0.84 (p < 0.01). A clinically relevant specificity threshold of approximately 90%, which was equivalent to a ≥15% decrease in the plasma HER2 ratio at 3 weeks from baseline, showed a positive predictive value of 97.37% (95% CI: 77.11% to 98.65%) in terms of predicting clinical benefit. Patients whose plasma HER2 ratio was reduced by ≥15% had a longer median progression-free survival (PFS) than those whose ratio was reduced by <15% (9.20 months vs. 4.50 months, p < 0.01)., Conclusions: Early changes in the plasma HER2 ratio may predict the treatment response in patients with advanced breast cancer and could facilitate optimal treatment selection., (© 2022 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Background: Extensive-stage small cell lung cancer (ES-SCLC) is deemed as a fatal malignancy with a poor prognosis. Although immunotherapy has gradually played an important role in the treatment of ES-SCLC since 2018, ES-SCLC treatment data and patient outcome before 2018, when chemotherapy served as a fundamental therapeutic strategy, is still meaningful as a summary of the situation regarding previous medical treatment and is a baseline for comparative data. In addition, the prognostic factors of ES-SCLC have failed to reach a consensus until now. Therefore, this study aimed to evaluate survival and identify the prognostic factors in an ES-SCLC population., Methods: We retrospectively collected the detailed medical records of 358 patients with ES-SCLC from January 1, 2011 to December 31, 2018 in a Chinese top-level cancer hospital. The prognostic factors were evaluated by Cox univariate and multivariate analysis., Results: The median overall survival (OS) of ES-SCLC patients (N = 358) was 14.0 months, the one- and two-year OS rates were 56.2% and 21.7%, respectively. Moreover, we identified two demographic characters (age ≥ 70, smoking index ≥ 400), one tumor burden factor (bone multimetastasis), two tumor biomarkers (cyfra211, CA125) and two laboratory indexes (decreased Na, PLR < 76) as independent prognostic factors for OS in this patient population. Progression-free survival (PFS) data of 238 patients was obtained for further analysis, and the median PFS was 6.2 months, and six-month and one-year PFS rates were 51.7% and 14.3%, respectively. Elevated cyfra211, decreased Hb and Na were identified as independent prognostic factors for PFS., Conclusions: This study provides real-world evidence of the survival and prognosis of ES-SCLC patients which will enable better evaluation and clinical decision-making in the future., (© 2021 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.)

Mg 2+ is required at micromolar concentrations as a cofactor for ATP, enzymatic reactions, and other biological processes. We show that decreased extracellular Mg 2+ reduced intracellular Mg 2+ levels and impaired the Ca 2+ flux, activation marker up-regulation, and proliferation after T cell receptor (TCR) stimulation. Reduced Mg 2+ specifically impairs TCR signal transduction by IL-2-inducible T cell kinase (ITK) due to a requirement for a regulatory Mg 2+ in the catalytic pocket of ITK. We also show that altered catalytic efficiency by millimolar changes in free basal Mg 2+ is an unrecognized but conserved feature of other serine/threonine and tyrosine kinases, suggesting a Mg 2+ regulatory paradigm of kinase function. Finally, a reduced serum Mg 2+ concentration in mice causes an impaired CD8 + T cell response to influenza A virus infection, reduces T cell activation, and exacerbates morbidity. Thus, Mg 2+ directly regulates the active site of specific kinases during T cell responses, and maintaining a high serum Mg 2+ concentration is important for antiviral immunity in otherwise healthy animals., (This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply.)

The pen shell, Atrina pectinata, is an economically valuable species that is widely distributed along the coastal waters of temperate and tropical areas, mainly growing in the Indian and Pacific Oceans. Eight novel microsatellite loci from the genome of A. pectinata were developed using fast isolation by amplified fragment length polymorphism of sequence containing repeats. The loci were screened in 30 wild individuals. The results showed that the number of alleles per locus and the polymorphism information content ranged from 2-6 and from 0.233-0.447, respectively. Observed and expected heterozygosities varied from 0.2069-0.7931 and 0.1887-0.5124, respectively. No significant deviations from Hardy-Weinberg equilibrium were detected. These microsatellite loci will be useful for further population studies of genetic diversity, population structure assessment, and conservation of A. pectinata.

Metastatic breast cancers are hard to treat and almost always fatal. Chloroquine diphosphate, a derivative of quinine, has long been used as a potent and commonly used medicine against different human diseases. We therefore investigated the effects of chloroquine diphosphate on a highly metastatic mouse mammary carcinoma cell line. In vitro treatment of 4T1 mouse breast cancer cells with chloroquine diphosphate resulted in significant inhibition of cellular proliferation and viability, and induction of apoptosis in 4T1 cells in a time- and dose-dependent manner. Further analysis indicated that induction of apoptosis was associated with the loss of mitochondrial membrane potential, release of cytochrome c, and activation of caspase-9 and caspase-3, and cleavage of poly(ADP-ribose) polymerase. The effect of chloroquine diphosphate was then examined using a mice model in which 4T1 cells were implanted subcutaneously. Chloroquine diphosphate (25mg/kg and 50mg/kg, respectively) significantly inhibited the growth of the implanted 4T1 tumor cells and induced apoptosis in the tumor microenvironment. Moreover, the metastasis of tumor cells to the lungs was inhibited significantly and the survival of the mice enhanced. These data suggested that chloroquine diphosphate might have chemotherapeutic efficacy against breast cancer including inhibition of metastasis., (Copyright © 2010 Elsevier Masson SAS. All rights reserved.)

Spliceosome-mediated RNA trans-splicing has emerged as an exciting mode of RNA therapy. Here we describe a novel trans-splicing strategy, which targets highly abundant pre-mRNAs, to produce therapeutic proteins in vivo. First, we used a pre-trans-splicing molecule (PTM) that mediated trans-splicing of human apolipoprotein A-I (hapoA-I) into the highly abundant mouse albumin exon 1. Hydrodynamic tail vein injection of the hapoA-I PTM plasmid in mice followed by analysis of the chimeric transcripts and protein, confirmed accurate and efficient trans-splicing into albumin pre-mRNA and production of hapoA-I protein. The versatility of this approach was demonstrated by producing functional human papillomavirus type-16 E7 (HPV16-E7) single-chain antibody in C57BL/6 mice and functional factor VIII (FVIII) and phenotypic correction in hemophilia A mice. Altogether, these studies demonstrate that trans-splicing to highly abundant albumin transcripts can be used as a general platform to produce therapeutic proteins in vivo.

The sign of Leser-Trélat (LT) is defined as the sudden eruption of multiple seborrhoeic keratoses (SKs), or increase in the number and size of existing SKs, associated with an underlying malignancy. A 75-year-old man was admitted to our hospital with dyspnoea and multiple verrucous papules that had been developing gradually over the previous 30 years. During the 3 months before presentation, the number of SKs on his chest and back had increased rapidly. A diagnosis of nasopharyngeal carcinoma was made based on results of computed tomography, endoscopy and biopsy examinations. The patient is receiving radiotherapy at present. To our knowledge, this is the first case of the Leser-Trélat sign associated with nasopharyngeal carcinoma.

Barbigerone is a naturally occurring isoflavone with antioxidant activity. In present study, we investigated the antitumor activity of barbigerone against murine lung cancer cells LL/2 and the possible mechanism in vitro. Our results showed that barbigerone inhibited LL/2 cells proliferation in a concentration- and time-dependent manner and caused apoptotic death of LL/2 cells. Barbigerone-induced apoptosis was characterized by enhanced mitochondrial cytochrome c release, activation of caspase-3,-9, but not caspase-8. Exposure of LL/2 cells to barbigerone resulted in upregulation of Bcl-2-associated protein (Bax) and down-regulation of Bcl-2. In addition, proliferation inhibitory effect of barbigerone was associated with decreased level of phosphorylated p42/44 mitogen-activated protein kinase (p42/44 MAPK) and phosphorylated Akt. Moreover, barbigerone exhibit less toxicity to non-cancer cells than tumor cells. In conclusion, our results indicated that barbigerone can inhibit murine lung cancer cell proliferation by inducing apoptosis via mitochondrial apoptotic pathway and by decreasing phosphorylated p42/44 MAPK and Akt. Its potential to be a candidate of anti-cancer agent is worth being further investigated., (2009 S. Karger AG, Basel.)

Pharmacophore models of Polo-like kinase-1 (PLK1) inhibitors have been established by using the HipHop and HypoGen algorithms implemented in the Catalyst software package. The best quantitative pharmacophore model, Hypo1, which has the highest correlation coefficient (0.9895), consists of one hydrogen bond acceptor, one hydrogen bond donor, one hydrophobic feature, and one hydrophobic aliphatic feature. Hypo1 was further validated by test set and cross validation method. Then Hypo1 was used as a 3D query to screen several databases including Specs, NCI, Maybridge, and Chinese Nature Product Database (CNPD). The hit compounds were subsequently subjected to filtering by Lipinski's rule of five and docking study to refine the retrieved hits and as a result to reduce the rate of false positive. Finally, a total of 20 compounds were selected and have been shifted to in vitro and in vivo studies. As far as we know, this is the first report on the pharmacophore modeling even the first publicly reported virtual screening study of PLK1 inhibitors.

The purpose of this study was to investigate the effects of chloroquine diphosphate on the proliferation and apoptosis of human leukemic K562 cells, and to elucidate its possible mechanism of activity. The inhibitory effect of chloroquine diphosphate with different concentrations on K562 cell proliferation was detected by MTT method. Apoptosis was measured by flow cytometry (FCM); morphological analysis of apoptosis was performed after staining with propidium iodide (PI) under fluorescence microscope; cell apoptosis was assessed by the DNA ladder shown agarose gel electrophoresis. After treatment with chloroquine diphosphate, K562 cells were stained by Rhodamine 123 to detect changes in mitochondrial transmembrane potential (DeltaPsim) by FCM. The results showed that the cell viability decreased in dose-dependent manner, following chloroquine diphosphate treatment at different concentrations (1.5625, 3.125, 6.25, 12.5, 25, 50 and 100 micromol/L) for 24, 48 and 72 hours. By FCM analysis, the significant increases of sub-G(1) were observed. DNA ladder was detected and apoptotic nuclei were observed. DeltaPsim decreased in K562 cells after chloroquine diphosphate treatment. It is concluded that the chloroquine diphosphate can inhibit the proliferation of K562 cells and induce cell apoptosis, which may relate to down-regulation of mitochondrial transmembrane potential (DeltaPsim).

Aurora-A has been identified as one of the most attractive targets for cancer therapy and a considerable number of Aurora-A inhibitors have been reported recently. In order to clarify the essential structure-activity relationship for the known Aurora-A inhibitors as well as identify new lead compounds against Aurora-A, 3D pharmacophore models were developed based on the known inhibitors. The best hypothesis, Hypo1, was used to screen molecular structural databases, including Specs and China Natural Products Database for potential lead compounds. The hit compounds were subsequently subjected to filtering by Lipinski's rules and docking study to refine the retrieved hits and as a result to reduce the rate of false positive. Finally, 39 compounds were purchased for further in vitro assay against several human tumour cell lines including A549, MCF-7, HepG2 and PC-3, in which Aurora-A is overexpressed. Two compounds show very low micromolar inhibition potency against some of these tumour cells. And they have been selected for further investigation.

Chloroquine is an antimalarial drug that has been used in the treatment and prophylaxis of malaria since the 1950s. The present study was undertaken to examine the effects of chloroquine on Bcap-37 human breast cancer cells' growth, cell cycle modulation, apoptosis induction, and associated molecular alterations in vitro. The chloroquine treatment decreased the viability of Bcap-37 cells in a concentration- and time-dependent manner, which correlated with G(2)/M phase cell cycle arrest. The chloroquine-mediated cell cycle arrest was associated with a decrease in protein levels/activity of polo-like kinase 1 (Plk1), phosphorylated cell division cycle 25C (Cdc25C), phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2), phosphorylated Akt. The chloroquine-treated Bcap-37 cells exhibited a marked decrease in the level of mitochondrial transmembrane potential (DeltaPsim), which was accompanied by the activation of caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP). Exposure of Bcap-37 cells to chloroquine also resulted in the induction of spindle abnormalities. In conclusion, the findings in this study suggested that chloroquine might have potential anticancer efficacy, which could be attributed, in part, to its proliferation inhibition and apoptosis induction of cancer cells through modulation of apoptosis and cell cycle-related proteins expressions, down-regulation of mitochondrial transmembrane potential (DeltaPsim), and induction of spindle abnormalities., (Copyright 2008 S. Karger AG, Basel.)

Using the cultured chicken embryonic chondrocytes as a model, the effects of simulated microgravity on the microtubular system of the cellular skeleton, extracellular matrix, alkaline phosphatase activity, intracellular free calcium concentration and mitochondrial ATP synthase activity with its oligomycin inhibition rate were studied with a clinostat. The microtubular content was measured by a flow cytometer. The decrease of microtubular content showed the impairment of the cellular skeleton system. Observation on the extracellular matrix by the scanning electron microscopy showed that it decreased significantly after rotating, and the fibers in the extracellular matrix were more tiny and disorderly than that of the control group. It can be concluded that the simulated microgravity can affect the secreting and assembly of the extracellular matrix. In contrast to the control, there was a time course decrease in alkaline phosphatase activity of chondrocytes, a marker of matrix mineralization. Meanwhile a significant drop in the intracellular calcium concentration happened at the beginning of rotation. These results indicate that simulated microgravity can suppress matrix calcification of cultured chondrocytes, and intracellular free calcium may be involved in the regulation of matrix calcification as the second signal transmitter. No significant changes happened in the mitochondrial ATP synthase activity and its oligomycin inhibition rate. Perhaps the energy metabolism wasn't affected by the simulated microgravity. The possible mechanisms about them were discussed., (c2003 COSPAR. Published by Elsevier Ltd. All rights reserved.)