Molecular Insights into the Specific Targeting of c-MYC G-Quadruplex by Thiazole Peptides.

Stabilization of a G-quadruplex (G4) in the promotor of the c-MYC proto-oncogene leads to inhibition of gene expression, and it thus represents a potentially attractive new strategy for cancer treatment. However, most G4 stabilizers show little selectivity among the many G4s present in the cellular complement of DNA and RNA. Intriguingly, a crescent-shaped cell-penetrating thiazole peptide, TH3, preferentially stabilizes the c-MYC G4 over other promotor G4s, but the mechanisms leading to this selective binding remain obscure. To investigate these mechanisms at the atomic level, we performed an in silico comparative investigation of the binding of TH3 and its analogue TH1 to the G4s from the promotors of c-MYC, c-KIT1, c-KIT2, and BCL2. Molecular docking and molecular dynamics simulations, combined with in-depth analyses of non-covalent interactions and bulk and per-nucleotide binding free energies, revealed that both TH3 and TH1 can induce the formation of a sandwich-like framework through stacking with both the top and bottom G-tetrads of the c-MYC G4 and the adjacent terminal capping nucleotides. This framework produces enhanced binding affinities for c-MYC G4 relative to other promotor G4s, with TH3 exhibiting an outstanding binding priority. Van der Waals interactions were identified to be the key factor in complex formation in all cases. Collectively, our findings fully agree with available experimental data. Therefore, the identified mechanisms leading to specific binding of TH3 towards c-MYC G4 provide valuable information to guide the development of new selective G4 stabilizers.

PtdIns4P exchange at endoplasmic reticulum-autolysosome contacts is essential for autophagy and neuronal homeostasis.

Inter-organelle contacts enable crosstalk among organelles, facilitating the exchange of materials and coordination of cellular events. In this study, we demonstrated that, upon starvation, autolysosomes recruit Pi4KIIα (Phosphatidylinositol 4-kinase II α) to generate phosphatidylinositol-4-phosphate (PtdIns4P) on their surface and establish endoplasmic reticulum (ER)-autolysosome contacts through PtdIns4P binding proteins Osbp (Oxysterol binding protein) and cert (ceramide transfer protein). We found that the Sac1 (Sac1 phosphatase), Osbp, and cert proteins are required for the reduction of PtdIns4P on autolysosomes. Loss of any of these proteins leads to defective macroautophagy/autophagy and neurodegeneration. Osbp, cert, and Sac1 are required for ER-Golgi contacts in fed cells. Our data establishes a new mode of organelle contact formation - the ER-Golgi contact machinery can be reused by ER-autolysosome contacts by re-locating PtdIns4P from the Golgi apparatus to autolysosomes when faced with starvation.Abbreviations: Atg1: Autophagy-related 1; Atg8: Autophagy-related 8; Atg9: Autophagy-related 9; Atg12: Autophagy-related 12; cert: ceramide transfer protein; Cp1/CathL: cysteine proteinase-1; CTL: control; ER: endoplasmic reticulum; ERMCS: ER-mitochondria contact site; fwd: four wheel drive; GM130: Golgi matrix protein 130 kD; Osbp: Oxysterol binding protein; PG: phagophore; PtdIns4K: phosphatidylinositol 4-kinase; Pi4KIIα: Phosphatidylinositol 4-kinase II α; Pi4KIIIα: Phosphatidylinositol 4-kinase III α; PtdIns4P: phosphatidylinositol-4-phosphate; PR: photoreceptor cell; RT: room temperature; Sac1: Sac1 phosphatase; Stv: starvation; Syx17: Syntaxin 17; TEM: transmission electron microscopy; VAP: VAMP-associated protein.

The landscape of aging.

Aging is characterized by a progressive deterioration of physiological integrity, leading to impaired functional ability and ultimately increased susceptibility to death. It is a major risk factor for chronic human diseases, including cardiovascular disease, diabetes, neurological degeneration, and cancer. Therefore, the growing emphasis on "healthy aging" raises a series of important questions in life and social sciences. In recent years, there has been unprecedented progress in aging research, particularly the discovery that the rate of aging is at least partly controlled by evolutionarily conserved genetic pathways and biological processes. In an attempt to bring full-fledged understanding to both the aging process and age-associated diseases, we review the descriptive, conceptual, and interventive aspects of the landscape of aging composed of a number of layers at the cellular, tissue, organ, organ system, and organismal levels.

Molecular Mechanisms of Alveolar Epithelial Stem Cell Senescence and Senescence-Associated Differentiation Disorders in Pulmonary Fibrosis.

Pulmonary senescence is accelerated by unresolved DNA damage response, underpinning susceptibility to pulmonary fibrosis. Recently it was reported that the SARS-Cov-2 viral infection induces acute pulmonary epithelial senescence followed by fibrosis, although the mechanism remains unclear. Here, we examine roles of alveolar epithelial stem cell senescence and senescence-associated differentiation disorders in pulmonary fibrosis, exploring the mechanisms mediating and preventing pulmonary fibrogenic crisis. Notably, the TGF-ß signalling pathway mediates alveolar epithelial stem cell senescence by mechanisms involving suppression of the telomerase reverse transcriptase gene in pulmonary fibrosis. Alternatively, telomere uncapping caused by stress-induced telomeric shelterin protein TPP1 degradation mediates DNA damage response, pulmonary senescence and fibrosis. However, targeted intervention of cellular senescence disrupts pulmonary remodelling and fibrosis by clearing senescent cells using senolytics or preventing senescence using telomere dysfunction inhibitor (TELODIN). Studies indicate that the development of senescence-associated differentiation disorders is reprogrammable and reversible by inhibiting stem cell replicative senescence in pulmonary fibrosis, providing a framework for targeted intervention of the molecular mechanisms of alveolar stem cell senescence and pulmonary fibrosis. Abbreviations: DPS, developmental programmed senescence; IPF, idiopathic pulmonary fibrosis; OIS, oncogene-induced replicative senescence; SADD, senescence-associated differentiation disorder; SALI, senescence-associated low-grade inflammation; SIPS, stress-induced premature senescence; TERC, telomerase RNA component; TERT, telomerase reverse transcriptase; TIFs, telomere dysfunction-induced foci; TIS, therapy-induced senescence; VIS, virus-induced senescence.

Molecular mechanism of anionic stabilizer for telomere G-quadruplex.

Telomere DNA assumes a high-order G-quadruplex (G4) structure, stabilization of which prevents telomere lengthening by telomerase in cancer. Through applying combined molecular simulation methods, an investigation on the selective binding mechanism of anionic phthalocyanine 3,4',4'',4'''-tetrasulfonic acid (APC) and human hybrid (3 + 1) G4s was firstly performed at the atomic level. Compared to the groove binding mode of APC and the hybrid type I (hybrid-I) telomere G4, APC preferred to bind to the hybrid type II (hybrid-II) telomere G4 via end-stacking interactions, which showed much more favorable binding free energies. Analyses of the non-covalent interaction and binding free energy decomposition revealed a decisive role of van der Waals interaction in the binding of APC and telomere hybrid G4s. And the binding of APC and hybrid-II G4 that showed the highest binding affinity adopted the end-stacking binding mode to form the most extensive van der Waals interactions. These findings add new knowledge to the design of selective stabilizers targeting telomere G4 in cancer.

Pulmonary Alveolar Stem Cell Senescence, Apoptosis, and Differentiation by p53-Dependent and -Independent Mechanisms in Telomerase-Deficient Mice.

Pulmonary premature ageing and fibrogenesis as in idiopathic pulmonary fibrosis (IPF) occur with the DNA damage response in lungs deficient of telomerase. The molecular mechanism mediating pulmonary alveolar cell fates remains to be investigated. The present study shows that naturally occurring ageing is associated with the DNA damage response (DDR) and activation of the p53 signalling pathway. Telomerase deficiency induced by telomerase RNA component (TERC) knockout (KO) accelerates not only replicative senescence but also altered differentiation and apoptosis of the pulmonary alveolar stem cells (AEC2) in association with increased innate immune natural killer (NK) cells in TERC KO mice. TERC KO results in increased senescence-associated heterochromatin foci (SAHF) marker HP1γ, p21, p16, and apoptosis-associated cleaved caspase-3 in AEC2. However, additional deficiency of the tumour suppressor p53 in the Trp53-/- allele of the late generation of TERC KO mice attenuates the increased senescent and apoptotic markers significantly. Moreover, p53 deficiency has no significant effect on the increased gene expression of T1α (a marker of terminal differentiated AEC1) in AEC2 of the late generation of TERC KO mice. These findings demonstrate that, in natural ageing or premature ageing accelerated by telomere shortening, pulmonary senescence and IPF develop with alveolar stem cell p53-dependent premature replicative senescence, apoptosis, and p53-independent differentiation, resulting in pulmonary senescence-associated low-grade inflammation (SALI). Our studies indicate a natural ageing-associated molecular mechanism of telomerase deficiency-induced telomere DDR and SALI in pulmonary ageing and IPF.

Identification of peptidomimetic telomere dysfunction inhibitor (TELODIN) through telomere dysfunction-induced foci (TIF) assay.

Telomere dysfunction-induced focus (TIF) assay allows efficient profiling of telomere dysfunctions in cells and tissues. Here, we describe the use of the TIF assay to screen synthetic peptides from E3 ubiquitin ligase FBW7, a tumor suppressor gene product, to prevent TIFs caused by environmental radiation stress. We demonstrate peptidomimetic telomere dysfunction inhibitor as a potentially intervening therapeutic drug candidate in aging-related diseases. This work demonstrates a novel utility of the TIF assay protocol in identifying telomere dysfunction inhibitors. For complete details on the use and execution of this protocol, please refer to Wang et al (2020).

Mechanisms of cancer stem cell senescence: Current understanding and future perspectives.

Cancer stem cells (CSCs) are a small population of heterogeneous tumor cells with the capacity of self-renewal and aberrant differentiation for immortality and divergent lineages of cancer cells. In contrast to bulky tumor cells, CSCs remain less differentiated and resistant to therapy even when targeted with tissue-specific antigenic markers. This makes CSCs responsible for not only tumor initiation, development, but also tumor recurrence. Emerging evidence suggests that CSCs can undergo cell senescence, a non-proliferative state of cells in response to stress. While cell senescence attenuates tumor cell proliferation, it is commonly regarded as a tumor suppressive mechanism. However, mounting research indicates that CSC senescence also provides these cells with the capacity to evade cytotoxic effects from cancer therapy, exacerbating cancer relapse and metastasis. Recent studies demonstrate that senescence drives reprogramming of cancer cell toward stemness and promotes CSC generation. In this review, we highlight the origin, heterogeneity and senescence regulatory mechanisms of CSCs, the complex relationship between CSC senescence and tumor therapy, and the recent beneficial effects of senotherapy on eliminating senescent tumor cells.

Antidiabetic activities of glycoprotein from pea (Pisum sativum L.) in STZ-induced diabetic mice.

Polysaccharides have hypoglycemic activity and pea protein has high nutritional value. The purified pea glycoprotein PGP2 has been shown to inhibit the activity of α-glucosidase and α-amylase in previous studies. To study the mechanism of PGP2-induced blood glucose lowering in vivo, this paper established a diabetic mouse model by intraperitoneal injection of STZ and high-fat diet, and evaluated the blood-glucose-lowering activity of the pea component PGP2 at different doses. The results showed that intragastric administration of PGP2 could effectively reduce diabetic weight loss and polyphagia symptoms, reduce fasting blood glucose levels in mice, and improve oral glucose tolerance levels in mice. PGP2 could promote insulin secretion and had a protective effect on mouse organs. After intragastric administration of PGP2 in mice, the serum levels of total cholesterol, triglycerides and low-density lipoprotein decreased. PGP2 up-regulated the gene expression of insulin receptor substrates IRS-1 and IRS-2 in liver tissues, thereby reducing insulin resistance. Based on the above experimental results, PGP2 had good hypoglycemic activity and was expected to be developed as a natural medicine for the treatment of type II diabetes.

Pulmonary alveolar stem cells undergo senescence, apoptosis and differentiation by p53-dependent and -independent mechanisms in telomerase deficient mice.

Pulmonary senescence and fibrosis occur with deoxyribonucleic acid (DNA) damage response in the lungs deficient of telomerase. The molecular mechanism mediating pulmonary alveolar cell fates remains to be investigated. The present study shows that pulmonary alveolar epithelial type 2 cells (AEC2) (alveolar stem cells) undergo not only replicative senescence, but also apoptosis and differentiation in association with increased innate immune natural killer (NK) cells in telomerase knockout (KO) mice. Telomerase ribonucleic acid (RNA) component (TERC) deficiency results in increased senescence-associated heterochromatin foci marker HP1γ, p21, p16 and apoptosis-associated cleaved caspase-3 in AEC2. However, p53 deficiency in the Trp53-/- allele of the late generation of TERC KO mice attenuates the increased senescent and apoptotic markers significantly. Moreover, p53 deficiency has no significant effect on the increased gene expression of T1α (a marker of terminal differentiated alveolar epithelial type 1 cells [AEC1]) in AEC2 of the late generation of TERC KO mice. Collectively, our findings suggest that pulmonary senescence takes place in deficiency of telomerase RNA component with the alveolar stem cells undergoing p53-dependent senescence and apoptosis as well as p53-independent differentiation.

Insight Derived from Molecular Dynamics Simulation into the Selectivity Mechanism Targeting c-MYC G-Quadruplex.

Stabilizing G-quadruplex (G4) structures formed in the c-MYC oncogene promoter represents a fundamental strategy for cancer therapy. However, most G4 stabilizers lack selectivity over various G4s in the genomes. By investigating the binding characteristics of a conjugated imidazole/carbazole (IZCZ-3) molecule with the G4s of c-MYC, c-KIT, and telomere through molecular docking and molecular dynamics simulations, the present study demonstrates that though the binding affinities between IZCZ-3 and the monomeric G4s are inconsistent with the experimental data, the dimeric c-MYC and c-KIT G4s can be targeted by IZCZ-3 through forming concomitant π-π stacking interactions with the intermolecular assembly producing significant contributions to the binding affinity. In the intermolecular dimeric G4-IZCZ-3 binding complexes, IZCZ-3 prefers the c-MYC G4 that has two exposed G-tetrads per monomer over the single G-tetrad-exposed c-KIT G4 by creating more aggregation effects. Taking the aggregation effects into account, the binding affinity order of IZCZ-3 follows c-MYC G4 > c-KIT G4 > telomeric G4, agreeing well with the experimental observation. Thus, the selectivity of IZCZ-3 for c-MYC G4 probably comes from its role in stabilizing the sandwichlike intermolecular aggregates, providing a framework for the development of selective stabilizers targeting c-MYC G4.

Antimicrobial activity and mechanism of peptide CM4 against Pseudomonas aeruginosa.

Antibacterial peptide CM4 (ABP-CM4) is a small cationic peptide with broad-spectrum activities against bacteria, fungi and tumor cells and may possibly be used as an antimicrobial agent. In this study, a C-terminal amidated antibacterial peptide ABP-CM4 (ABP-CM4N) with the strongest antibacterial activity was obtained through screening the antibacterial activities of ABP-CM4 with different modifications. The minimal inhibitory concentration of ABP-CM4N was 8 µM against P. aeruginosa (ATCC 27853) which was lower than that of ABP-CM4 (16 µM). The strengthened antimicrobial activity of ABP-CM4N may be associated with the increased membrane binding capacity, being two times that of ABP-CM4 (p < 0.001). The antibacterial mechanism of ABP-CM4N to Pseudomonas aeruginosa was examined by means of cell membrane integrity analysiss, the intracellular ultrastructure change observation and E. coli genomic DNA binding assay. It was found that ABP-CM4N had the same antimicrobial mechanism as ABP-CM4, and the aim of the antimicrobial mechanism was mainly to destroy the cell membrane which caused nucleic acid or protein leakage, and secondly to interact with E. coli genomic DNA after penetrating the cell membrane. Furthermore, in vitro ABP-CM4N showed a better bacteriostatic activity in meats, with the treated samples showing two to three times less positive colonies than ABP-CM4.

[Occurrence and Prediction Model of Disinfection By-Products in Tap Water].

Disinfection by-products (DBPs) are defined as important parameters that can deteriorate drinking water quality. The investigation was performed at a laboratory located on a campus in H City of the Zhejiang province. The purpose of the work was to obtain knowledge on the occurrence of DBPs in tap water and boiled water taken from the same pipe, to establish a statistical model to predict DBPs information in tap water based on physicochemical parameters, and to evaluate carcinogenic and non-carcinogenic risks caused by DBPs on a predictional level. The results showed three categories of trihalomethanes (THMs), haloacetonnitrile (HANs), and haloacetic acids (HAAs), including 10 species of disinfection by-products detected in drinking water. The detection rate of target DBPs in tap water was 100% and the concentrations varied in the ranges of 10.12-28.39, 0.98-5.19, and 2.65-7.83 µg·L-1, respectively. In boiled water, bromochloracetonitrile (BCAN) was not detected; the detection rates of tribromomethane(TBM), trichloroacetonitrile (TCAN), and dibromoacetonitrile (DBAN) were 46.43%, 82.14%, and 92.86%, respectively, while the detection rate for other DBPs was 100%. The concentrations of THMs, HANs, and HAAs were in the ranges of 0.60-12.58, 0.02-0.52, and 2.42-5.86 µg·L-1, respectively. After heating, the concentrations of THMs and HANs decreased by 84.22% and 91.45%, respectively. No obvious decrease was found for HAAs. The pH value and specific ultraviolet absorbance (SUVA) had positive correlation with DBPs, whereas residual chlorine and ammonia nitrogen had negative correlation with DBPs. Based on the correlation between the physicochemical parameters and DBPs, a multiple linear regression prediction model of THMs was established, with deviation less than 10.00%, which can be used for the prediction of THMs in tap water. Based on the EPA recommended health risk assessment model, the carcinogenic and non-carcinogenic risks of chlorine disinfection by-products through oral intake were calculated. It was found that the carcinogenic risks caused by the disinfection by-products in the tap and boiled water were (17.24-84.63)×10-6 and (25.49-258.82)×10-7, respectively, and the non-carcinogenic risks were (4.17-50.32)×10-2 and (6.52-107.74)×10-3, respectively. The carcinogenic risk caused mainly by THMs and bromodicloromethane (BDCM) contributed the highest cancer risk in tap water, while for boiled water, trichloromethane (TCM) was found to contribute the highest cancer and non-carcinogenic risk. In boiled water, the reduction of THMs was up to 94.38%, and the cancer risk was reduced by 79.00%.

Characterization and antitumor activities of polysaccharides obtained from ginger (Zingiber officinale) by different extraction methods.

Three different extraction technologies including hot water extraction (HWE), enzyme assisted extraction (EAE) and ultrasonic cell grinder extraction (UCGE) were employed to extract crude ginger polysaccharides (GPs) under their respective best parameters, then crude GPs were purified by DEAE cellulose-52 and Sephadex G-200 size-exclusion chromatography in that order. Five GPs fractions (HGP, EGP1, EGP2, UGP1, and UGP2, respectively) were obtained. The differences of five GPs in chemical composition, characterization and antitumor activities were further compared. The molecular weights were different in five GPs, varying from 11.81 to 1831.75 kDa. Mannose and glucose as the main monosaccharide and the glycosidic linkage of →4)-α-D-Glc(1→ and -α-Manp-(1→ existed in both five GPs. While EGP2 and UGP1 possessed specific structure of →6)-ß-D-Galp-(1→ and UGP1 contained more sulfate group. Moreover, UGP1 exhibited strong inhibitory effect on three tumor cells especially the colon cancer. The inhibition rates of UGP1 on H1975, HCT116 and MCF-7 were 23.339 ± 2.285%, 56.843 ± 2.405% and 21.061 ± 1.920% respectively. The study indicated GPs extracted by UCGE could reserve more active structure and inhibit colon cancer more significantly.

Molecular insight into the selective binding between human telomere G-quadruplex and a negatively charged stabilizer.

The single-strand human telomere overhang forms intramolecular high-order structures named G-quadruplex (G4) under physiological conditions. Telomere G4 stabilization prevents telomere lengthening by telomerase in cancer cells representing a promising strategy in cancer therapy. Using molecular docking and molecular dynamics (MD) simulations, specific binding of the anionic phthalocyanine 3,4',4'',4'''-tetrasulfonic acid (APC) to the human hybrid (3 + 1) G4s was investigated at the atomic level. We found that APC preferred the end-stacking binding with the telomere hybrid type II (hybrid-II) G4 as compared to the groove binding with the hybrid type I (hybrid-I) G4 remarkable stabilizing effect and more favourable binding free energies. Analysis of non-covalent interaction and decomposition of the binding free energy revealed that van der Waals interaction played a leading role in the binding of APC and telomere hybrid G4s. These findings provide evidence for the first time to shed light on the designs of selective telomere G4 stabilizers.

Identification of new hypoxia-regulated epithelial-mesenchymal transition marker genes labeled by H3K4 acetylation.

Hypoxia-induced epithelial-mesenchymal transition (EMT) involves the interplay between chromatin modifiers histone deacetylase 3 (HDAC3) and WDR5. The histone mark histone 3 lysine 4 acetylation (H3K4Ac) is observed in the promoter regions of various EMT marker genes (eg, CDH1 and VIM). To further define the genome-wide location of H3K4Ac, a chromatin immunoprecipitation followed by massively parallel DNA sequencing (ChIP-seq) analysis was performed using a head and neck squamous cell carcinoma (HNSCC) FaDu cell line under normoxia and hypoxia. H3K4Ac was found to be located mainly around the transcription start site. Coupled with analysis of gene expression by RNA sequencing and using a HDAC3 knockdown cell line, 10 new genes (BMI1, GLI1, SMO, FOXF1, SIRT2, etc) that were labeled by H3K4Ac and regulated by HDAC3 were identified. Overexpression or knockdown of GLI1/SMO increased or repressed the in vitro migration and invasion activity in OECM-1/FaDu cells, respectively. In HNSCC patients, coexpression of GLI1 and SMO in primary tumors correlated with metastasis. Our results identify new EMT marker genes that may play a significant role in hypoxia-induced EMT and metastasis and further provide diagnostic and prognostic implications.

Role of telomerase in the tumour microenvironment.

Telomeres are specialized genomic structures that protect chromosomal ends to maintain genomic stability. Telomeric length is primarily regulated by the telomerase complex, essentially consisting of an RNA template (TERC), an enzymatic subunit (telomerase reverse transcriptase, TERT). In humans, telomerase activity is repressed during embryonic differentiation and is absent in most somatic cells. However, it is upregulated or reactivated in 80%-90% of the primary tumours in humans. The human TERT (hTERT) plays a pivotal role in cellular immortality and tumourigenesis. However, the molecular mechanisms of telomerase functioning in cancer have not been fully understood beyond the telomere maintenance. Several research groups, including ours, have demonstrated that hTERT possesses vital functions independent of its telomere maintenance, including angiogenesis, inflammation, cancer cell stemness, and epithelial-mesenchymal transformation (EMT). All these telomere-independent activities of hTERT may contribute to the regulation of the dynamics and homeostasis of the tumour microenvironment (TME), thereby promoting tumour growth and development. Cancer progression and metastasis largely depend upon the interactions between cancer cells and their microenvironment. In this review, the involvement of TERT in the tumour microenvironment and the underlying implications in cancer therapeutics have been summarized.

[Disinfection By-products and the Relevant Health Risk in the Water Supply System in H City of Zhejiang Province].

The occurrence of 18 types of disinfection by-products (DBPs) in two waterworks and the corresponding water supply networks of H City in Zhejiang Province was determined by gas chromatography coupled with electron capture detector (GC-ECD). The correlation between DBPs and organic precursors, and health risks caused by DBPs, were discussed. Results showed that the disinfection by-products detected in drinking water in H City mainly include trihalomethanes (THMs), haloacetic acid (HAAs), haloacetonitrile (HANs) and trichloronitromethane (HNMs), with highest concentrations of THMs followed by HAAs. In the finish water of CX Waterworks and tap water supplied by CX Water works, concentrations of THMs ranged from 7.70 to 32.73µg·L-1and 9.00 to 51.42µg·L-1, respectively, and those of HAAs 3.05 to 21.30µg·L-1 and 6.00 to 26.79µg·L-1, respectively. The THMs in finished water and tap water of TH Waterworks were in the range 8.65-38.76µg·L-1 and 12.09-42.04µg·L-1, respectively, and those of HAAs were 2.42-14.79µg·L-1 and 2.80-33.40µg·L-1, respectively. The DBPs in the finished and tap water of the two waterworks were at lower levels than the limitations regulated by the Sanitary Standard for Drinking Water (GB 5749-2006). The index of dissolved organic carbon (DOC) and UV254 were adopted to describe the organic compounds, and it was found that trichloromethane (TCM) was significantly negatively correlated with DOC and UV254in tap water. Based on the EPA recommended health risk assessment model, the carcinogenic and non-carcinogenic risks of chlorine disinfection by-products in the oral intake route were calculated. It was found that the carcinogenic risks caused by the disinfection by-products in the finished water and tap water of H City were 5.94×10-6-4.76×10-5 and 5.94×10-6-5.56×10-5, respectively, while the non-carcinogenic risks were 0.91×10-2-4.20×10-2 and 1.26×10-2-4.72×10-2, respectively. The carcinogenic risk is mainly from THMs:bromodichloromethane (BDCM) contributes the highest cancer risk, and the non-carcinogenic risk is mainly from TCM.

Undo the brake of tumour immune tolerance with antibodies, peptide mimetics and small molecule compounds targeting PD-1/PD-L1 checkpoint at different locations for acceleration of cytotoxic immunity to cancer cells.

Recent clinical success of immunotherapy that inhibits the negative immune regulatory pathway programmed cell death protein-1/PD-1 ligand 1 (PD-1/PD-L1) has initiated a new era in the treatment of metastatic cancer. However, greater challenges remain to treat all cancers. The molecular architecture in the immune synapse constituting positive engagements for immune activation and negative checkpoints against immune hyperactivity is regulated dynamically by interaction between proteostasis and tumour microenvironment. This article reviews recent progresses in our understandings of the cellular and molecular mechanisms of the negative checkpoint PD-1/PD-L1 behaviours in immune tolerance of tumourigenesis and metastasis. We provide an overview on PD-L1 gene expression regulation, protein turnover, intra- and extracellular trafficking, exosome-mediated inter-cellular transport, molecular interface peptide mimetics, inhibitory chemical compounds such as metformin, and antibody dynamics. We summarise PD-L1 post-translational modifications including glycosylation, palmitoylation, phosphorylation and ubiquitination, reflecting future research directions and opportunities in identifying tumour-specific signalling targets, their regulatory molecules and pathways for intervention into various types of cancers.

PEST-containing nuclear protein mediates the proliferation, migration, and invasion of human neuroblastoma cells through MAPK and PI3K/AKT/mTOR signaling pathways.

BACKGROUND: PEST-containing nuclear protein (PCNP), a novel nuclear protein, is involved in cell proliferation and tumorigenesis. However, the precise mechanism of action of PCNP in the process of tumor growth has not yet been fully elucidated. METHODS: ShRNA knockdown and overexpression of PCNP were performed in human neuroblastoma cells. Tumorigenic and metastatic effects of PCNP were examined by tumor growth, migration, and invasion assays in vitro, as well as xenograft tumor assay in vivo. RESULTS: PCNP over-expression decreased the proliferation, migration, and invasion of human neuroblastoma cells and down-regulation of PCNP showed reverse effects. PCNP over-expression increased protein expressions of cleaved caspase-3, cleaved caspase-8, cleaved caspase-9, and cleaved poly adenosine diphosphate-ribose polymerase, as well as ratios of B-cell lymphoma-2 (Bcl-2)-associated X protein/Bcl-2 and Bcl-2-associated death promoter/B-cell lymphoma-extra large in human neuroblastoma cells, however PCNP knockdown exhibited reverse trends. PCNP over-expression increased phosphorylations of extracellular signal-regulated protein kinase 1/2, p38, c-Jun N-terminal kinase, as well as decreased phosphorylations of phosphatidylinositol 3-kinase (PI3K), Akt, and mammalian target of rapamycin (mTOR), nevertheless PCNP knockdown exhibited opposite effects. Furthermore, PCNP over-expression significantly reduced the growth of human neuroblastoma xenograft tumors by down-regulating angiogenesis, whereas PCNP knockdown markedly promoted the growth of human neuroblastoma xenograft tumors through up-regulation of angiogenesis. CONCLUSIONS: PCNP mediates the proliferation, migration, and invasion of human neuroblastoma cells through mitogen-activated protein kinase and PI3K/AKT/mTOR signaling pathways, implying that PCNP is a therapeutic target for patients with neuroblastoma.