Obesity and risk of fracture in postmenopausal women: a meta-analysis of cohort studies.

BACKGROUND: Obesity is associated with an increased risk of fracture in adults, but is unclear in postmenopausal women. We aim to determine the association of obesity with the risk of fracture in postmenopausal women. METHODS: PubMed, EMBASE, Cochrane Library and Web of Science were searched up to 11 April 2022 for cohort studies. And the included studies regarding the relationship between obesity with all cause of fracture in postmenopausal women were included in our meta-analysis. Data were screened and extracted independently by two reviewers. The relative risks (RR) were estimated using a random-effects model. Between-study heterogeneity was assessed using Cochran's Q and I2 statistics. RESULTS: Eight cohort studies comprising 671,532 postmenopausal women and 40,172 fractures were included. Overall, the pooling analysis shows that obesity in postmenopausal women is associated with an increased risk of all-cause fracture (relative ratio (RR) = 1.18; 95% confidence interval (CI):1.09-1.28, I2 = 86.3%, p = .000). Sub-analyses for each site of fracture indicate that obesity was associated with an increased risk of vertebral fracture in postmenopausal women (RR = 1.154, 95% CI: 1.020-1.305, I2 = 94.5%, p = .023), but reduced the risk of pelvic fracture (RR = 0.575, 95% CI:0.470-0.702, I2 = 0.0%, p = .000). There is no statistically significant difference in the risk of hip and humerus fractures associated with obesity in postmenopausal women. CONCLUSION: Obesity is associated with an increased risk of all-cause and vertebral fractures in postmenopausal women, but is a protective factor for pelvic fractures. Our findings suggest that postmenopausal women who regulate their weight might lower their risk of fractures.Registration: (PROSPERO: CRD42022324973)KEY MESSAGESObesity is associated with an increased risk of all-cause and vertebral fractures in postmenopausal women.Obesity maybe a protective factor for pelvic fractures in postmenopausal women.Postmenopausal women should regulate their weight to prevent fractures.

Deubiquitination complex platform: A plausible mechanism for regulating the substrate specificity of deubiquitinating enzymes

Deubiquitinating enzymes (DUBs) or deubiquitinases facilitate the escape of multiple proteins from ubiquitin‒proteasome degradation and are critical for regulating protein expression levels in vivo. Therefore, dissecting the underlying mechanism of DUB recognition is needed to advance the development of drugs related to DUB signaling pathways. To data, extensive studies on the ubiquitin chain specificity of DUBs have been reported, but substrate protein recognition is still not clearly understood. As a breakthrough, the scaffolding role may be significant to substrate protein selectivity. From this perspective, we systematically characterized the scaffolding proteins and complexes contributing to DUB substrate selectivity. Furthermore, we proposed a deubiquitination complex platform (DCP) as a potentially generic mechanism for DUB substrate recognition based on known examples, which might fill the gaps in the understanding of DUB substrate specificity.

The dichotomous role of immunoproteasome in cancer: Friend or foe?

Immunoproteasome is a variant of proteasome with structural differences in 20S subunits optimizing them for the production of antigenic peptides with higher binding affinity to major histocompatibility complex (MHC)-I molecules. Apart from this primary function in antigen presentation, immunoproteasome is also responsible for the degradation of proteins, both unfolded proteins for the maintenance of protein homeostasis and tumor suppressor proteins contributing to tumor progression. The altered expression of immunoproteasome is frequently observed in cancers; however, its expression levels and effects vary among different cancer types exhibiting antagonistic roles in tumor development. This review focuses on the dichotomous role of immunoproteasome in different cancer types, as well as summarizes the current progression in immunoproteasome activators and inhibitors. Specifically targeting immunoproteasome may be a beneficial therapeutic intervention in cancer treatment and understanding the role of immunoproteasome in cancers will provide a significant therapeutic insight for the prevention and treatment of cancers.

AKT inhibitor Hu7691 induces differentiation of neuroblastoma cells

While neuroblastoma accounts for 15% of childhood tumor-related deaths, treatments against neuroblastoma remain scarce and mainly consist of cytotoxic chemotherapeutic drugs. Currently, maintenance therapy of differentiation induction is the standard of care for neuroblastoma patients in clinical, especially high-risk patients. However, differentiation therapy is not used as a first-line treatment for neuroblastoma due to low efficacy, unclear mechanism, and few drug options. Through compound library screening, we accidently found the potential differentiation-inducing effect of AKT inhibitor Hu7691. The protein kinase B (AKT) pathway is an important signaling pathway for regulating tumorigenesis and neural differentiation, yet the relation between the AKT pathway and neuroblastoma differentiation remains unclear. Here, we reveal the anti-proliferation and neurogenesis effect of Hu7691 on multiple neuroblastoma cell lines. Further evidence including neurites outgrowth, cell cycle arrest, and differentiation mRNA marker clarified the differentiation-inducing effect of Hu7691. Meanwhile, with the introduction of other AKT inhibitors, it is now clear that multiple AKT inhibitors can induce neuroblastoma differentiation. Furthermore, silencing AKT was found to have the effect of inducing neuroblastoma differentiation. Finally, confirmation of the therapeutic effects of Hu7691 is dependent on inducing differentiation in vivo, suggesting that Hu7691 is a potential molecule against neuroblastoma. Through this study, we not only define the key role of AKT in the progression of neuroblastoma differentiation but also provide potential drugs and key targets for the application of differentiation therapies for neuroblastoma clinically.

Disulfiram enhances the antitumor activity of cisplatin by inhibiting the Fanconi anemia repair pathway / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

A series of chemotherapeutic drugs that induce DNA damage, such as cisplatin (DDP), are standard clinical treatments for ovarian cancer, testicular cancer, and other diseases that lack effective targeted drug therapy. Drug resistance is one of the main factors limiting their application. Sensitizers can overcome the drug resistance of tumor cells, thereby enhancing the antitumor activity of chemotherapeutic drugs. In this study, we aimed to identify marketable drugs that could be potential chemotherapy sensitizers and explore the underlying mechanisms. We found that the alcohol withdrawal drug disulfiram (DSF) could significantly enhance the antitumor activity of DDP. JC-1 staining, propidium iodide (PI) staining, and western blotting confirmed that the combination of DSF and DDP could enhance the apoptosis of tumor cells. Subsequent RNA sequencing combined with Gene Set Enrichment Analysis (GSEA) pathway enrichment analysis and cell biology studies such as immunofluorescence suggested an underlying mechanism: DSF makes cells more vulnerable to DNA damage by inhibiting the Fanconi anemia (FA) repair pathway, exerting a sensitizing effect to DNA damaging agents including platinum chemotherapy drugs. Thus, our study illustrated the potential mechanism of action of DSF in enhancing the antitumor effect of DDP. This might provide an effective and safe solution for combating DDP resistance in clinical treatment.

Endoplasmic reticulum-mitochondria miscommunication is an early and causal trigger of hepatic insulin resistance and steatosis.

BACKGROUND & AIMS: Hepatic insulin resistance in obesity and type 2 diabetes was recently associated with endoplasmic reticulum (ER)-mitochondria miscommunication. These contact sites (mitochondria-associated membranes: MAMs) are highly dynamic and involved in many functions; however, whether MAM dysfunction plays a causal role in hepatic insulin resistance and steatosis is not clear. Thus, we aimed to determine whether and how organelle miscommunication plays a role in the onset and progression of hepatic metabolic impairment. METHODS: We analyzed hepatic ER-mitochondria interactions and calcium exchange in a time-dependent and reversible manner in mice with diet-induced obesity. Additionally, we used recombinant adenovirus to express a specific organelle spacer or linker in mouse livers, to determine the causal impact of MAM dysfunction on hepatic metabolic alterations. RESULTS: Disruption of ER-mitochondria interactions and calcium exchange is an early event preceding hepatic insulin resistance and steatosis in mice with diet-induced obesity. Interestingly, an 8-week reversal diet concomitantly reversed hepatic organelle miscommunication and insulin resistance in obese mice. Mechanistically, disrupting structural and functional ER-mitochondria interactions through the hepatic overexpression of the organelle spacer FATE1 was sufficient to impair hepatic insulin action and glucose homeostasis. In addition, FATE1-mediated organelle miscommunication disrupted lipid-related mitochondrial oxidative metabolism and induced hepatic steatosis. Conversely, reinforcement of ER-mitochondria interactions through hepatic expression of a synthetic linker prevented diet-induced glucose intolerance after 4 weeks' overnutrition. Importantly, ER-mitochondria miscommunication was confirmed in the liver of obese patients with type 2 diabetes, and correlated with glycemia, HbA1c and HOMA-IR index. CONCLUSIONS: ER-mitochondria miscommunication is an early causal trigger of hepatic insulin resistance and steatosis, and can be reversed by switching to a healthy diet. Thus, targeting MAMs could help to restore metabolic homeostasis. LAY SUMMARY: The literature suggests that interactions between the endoplasmic reticulum and mitochondria could play a role in hepatic insulin resistance and steatosis during chronic obesity. In the present study, we reappraised the time-dependent regulation of hepatic endoplasmic reticulum-mitochondria interactions and calcium exchange, investigating reversibility and causality, in mice with diet-induced obesity. We also assessed the relevance of our findings to humans. We show that organelle miscommunication is an early causal trigger of hepatic insulin resistance and steatosis that can be improved by nutritional strategies.

WSB1 regulates c-Myc expression through β-catenin signaling and forms a feedforward circuit

The dysregulation of transcription factors is widely associated with tumorigenesis. As the most well-defined transcription factor in multiple types of cancer, c-Myc can transform cells by transactivating various downstream genes. Given that there is no effective way to directly inhibit c-Myc, c-Myc targeting strategies hold great potential for cancer therapy. In this study, we found that WSB1, which has a highly positive correlation with c-Myc in 10 cancer cell lines and clinical samples, is a direct target gene of c-Myc, and can positively regulate c-Myc expression, which forms a feedforward circuit promoting cancer development. RNA sequencing results from Bel-7402 cells confirmed that WSB1 promoted c-Myc expression through the β-catenin pathway. Mechanistically, WSB1 affected β-catenin destruction complex-PPP2CA assembly and E3 ubiquitin ligase adaptor β-TRCP recruitment, which inhibited the ubiquitination of β-catenin and transactivated c-Myc. Of interest, the effect of WSB1 on c-Myc was independent of its E3 ligase activity. Moreover, overexpressing WSB1 in the Bel-7402 xenograft model could further strengthen the tumor-driven effect of c-Myc overexpression. Thus, our findings revealed a novel mechanism involved in tumorigenesis in which the WSB1/c-Myc feedforward circuit played an essential role, highlighting a potential c-Myc intervention strategy in cancer treatment.

Loss and gain of function of Grp75 or mitofusin 2 distinctly alter cholesterol metabolism, but all promote triglyceride accumulation in hepatocytes.

In the liver, contact sites between the endoplasmic reticulum (ER) and mitochondria (named MAMs) may be crucial hubs for the regulation of lipid metabolism, thus contributing to the exacerbation or prevention of fatty liver. We hypothesized that tether proteins located at MAMs could play a key role in preventing triglyceride accumulation in hepatocytes and nonalcoholic fatty liver disease (NAFLD) occurrence. To test this, we explored the role of two key partners in building MAM integrity and functionality, the glucose-regulated protein 75 (Grp75) and mitofusin 2 (Mfn2), which liver contents are altered in obesity and NAFLD. Grp75 or Mfn2 expression was either silenced using siRNA or overexpressed with adenoviruses in Huh7 cells. Silencing of Grp75 and Mfn2 resulted in decreased ER-mitochondria interactions, mitochondrial network fusion state and mitochondrial oxidative capacity, while overexpression of the two proteins induced mirror impacts on these parameters. Furthermore, Grp75 or Mfn2 silencing decreased cellular cholesterol content and enhanced triglyceride secretion in ApoB100 lipoproteins, while their overexpression led to reverse effects. Cellular phosphatidylcholine/phosphatidylethanolamine ratio was decreased only upon overexpression of the proteins, potentially contributing to altered ApoB100 assembly and secretion. Despite the opposite differences, both silencing and overexpression of Grp75 or Mfn2 induced triglyceride storage, although a fatty acid challenge was required to express the alteration upon protein silencing. Among the mechanisms potentially involved in this phenotype, ER stress was closely associated with altered triglyceride metabolism after Grp75 or Mfn2 overexpression, while blunted mitochondrial FA oxidation capacity may be the main defect causing triglyceride accumulation upon Grp75 or Mfn2 silencing. Further studies are required to decipher the link between modulation of Grp75 or Mfn2 expression, change in MAM integrity and alteration of cholesterol content of the cell. In conclusion, Grp75 or Mfn2 silencing and overexpression in Huh7 cells contribute to altering MAM integrity and cholesterol storage in opposite directions, but all promote triglyceride accumulation through distinct cellular pathways. This study also highlights that besides Mfn2, Grp75 could play a central role in hepatic lipid and cholesterol metabolism in obesity and NAFLD.

Advances in the optimization of the linker in proteolysis-targeting chimeras (PROTAC) / 药学学报

With high selectivity and potency, target protein degradation technology has recently emerged as a strategy for drug discovery and design. Proteolysis-targeting chimeras (PROTAC) function as inducers for the degradation of target proteins and are a research focus in drug development. Current research on PROTAC mainly revolves around the rational design of PROTAC molecules, the discovery of new E3 ubiquitin ligase ligands and improvement in drug targeting. In this review, we focus on the PROTAC linker and its effects on the generation of the E3 enzyme-PROTAC-target protein ternary complex from three standpoints: length, binding site and chemical properties. We discuss the influences of the linker on the efficacy and the selectivity of PROTAC molecules.

Cyclin-dependent kinases-based synthetic lethality: Evidence, concept, and strategy

Synthetic lethality is a proven effective antitumor strategy that has attracted great attention. Large-scale screening has revealed many synthetic lethal genetic phenotypes, and relevant small-molecule drugs have also been implemented in clinical practice. Increasing evidence suggests that CDKs, constituting a kinase family predominantly involved in cell cycle control, are synthetic lethal factors when combined with certain oncogenes, such as

Phosphorylation regulates cullin-based ubiquitination in tumorigenesis

Cullin-RING ligases (CRLs) recognize and interact with substrates for ubiquitination and degradation, and can be targeted for disease treatment when the abnormal expression of substrates involves pathologic processes. Phosphorylation, either of substrates or receptors of CRLs, can alter their interaction. Phosphorylation-dependent ubiquitination and proteasome degradation influence various cellular processes and can contribute to the occurrence of various diseases, most often tumorigenesis. These processes have the potential to be used for tumor intervention through the regulation of the activities of related kinases, along with the regulation of the stability of specific oncoproteins and tumor suppressors. This review describes the mechanisms and biological functions of crosstalk between phosphorylation and ubiquitination, and most importantly its influence on tumorigenesis, to provide new directions and strategies for tumor therapy.

ZDHHC12-mediated claudin-3 -palmitoylation determines ovarian cancer progression

The membrane protein claudin-3 (CLDN3) is critical for the formation and maintenance of tight junction and its high expression has been implicated in dictating malignant progression in various cancers. However, the post-translational modification of CLDN3 and its biological function remains poorly understood. Here, we report that CLDN3 is positively correlated with ovarian cancer progression both and Of interest, CLDN3 undergoes -palmitoylation on three juxtamembrane cysteine residues, which contribute to the accurate plasma membrane localization and protein stability of CLDN3 Moreover, the deprivation of -palmitoylation in CLDN3 significantly abolishes its tumorigenic promotion effect in ovarian cancer cells. By utilizing the co-immunoprecipitation assay, we further identify ZDHHC12 as a CLDN3-targating palmitoyltransferase from 23 ZDHHC family proteins. Furthermore, the knockdown of ZDHHC12 also significantly inhibits CLDN3 accurate membrane localization, protein stability and ovarian cancer cells tumorigenesis Thus, our work reveals -palmitoylation as a novel regulatory mechanism that modulates CLDN3 function, which implies that targeting ZDHHC12-mediated CLDN3 -palmitoylation might be a potential strategy for ovarian cancer therapy.

Regulation of Mitochondria-Associated Membranes (MAMs) by NO/sGC/PKG Participates in the Control of Hepatic Insulin Response.

Under physiological conditions, nitric oxide (NO) produced by the endothelial NO synthase (eNOS) upregulates hepatic insulin sensitivity. Recently, contact sites between the endoplasmic reticulum and mitochondria named mitochondria-associated membranes (MAMs) emerged as a crucial hub for insulin signaling in the liver. As mitochondria are targets of NO, we explored whether NO regulates hepatic insulin sensitivity by targeting MAMs. In Huh7 cells, primary rat hepatocytes and mouse livers, enhancing NO concentration increased MAMs, whereas inhibiting eNOS decreased them. In vitro, those effects were prevented by inhibiting protein kinase G (PKG) and mimicked by activating soluble guanylate cyclase (sGC) and PKG. In agreement with the regulation of MAMs, increasing NO concentration improved insulin signaling, both in vitro and in vivo, while eNOS inhibition disrupted this response. Finally, inhibition of insulin signaling by wortmannin did not affect the impact of NO on MAMs, while experimental MAM disruption, using either targeted silencing of cyclophilin D or the overexpression of the organelle spacer fetal and adult testis-expressed 1 (FATE-1), significantly blunted the effects of NO on both MAMs and insulin response. Therefore, under physiological conditions, NO participates to the regulation of MAM integrity through the sGC/PKG pathway and concomitantly improves hepatic insulin sensitivity. Altogether, our data suggest that the induction of MAMs participate in the impact of NO on hepatocyte insulin response.

Advances in hyperprogressive disease of PD-1/PD-L1 antibody drugs and rational drug therapy / 药学学报

With the significant breakthrough that programmed cell death 1 (PD-1)/programmed cell death 1 ligand 1 (PD-L1) antibody drugs achieved promising clinical outcomes across various tumor types, immunotherapy targeting immune checkpoint has been considered a promising way to treat cancer. However, most recently studies suggest that the hyperprogressive disease occurred frequently during the therapy of using PD-1/PD-L1 antibody drugs and has become an urgent problem to be solved. In this review, we summarize the progress and potential reasons of hyperprogressive disease caused by PD-1/PD-L1 blockade, and further discuss its application based on the rational use of biomarkers for searching the benefit patients.

Targeting slug-mediated non-canonical activation of c-Met to overcome chemo-resistance in metastatic ovarian cancer cells

Metastasis-associated drug resistance accounts for high mortality in ovarian cancer and remains to be a major barrier for effective treatment. In this study, SKOV3/T4, a metastatic subpopulation of ovarian cancer SKOV3 cells, was enriched to explore potential interventions against metastatic-associated drug resistance. Quantitative genomic and functional analyses were performed and found that slug was significantly increased in the SKOV3/T4 subpopulation and contributed to the high resistance of SKOV3/T4. Further studies showed that slug activated c-Met in a ligand-independent manner due to elevated levels of fibronectin and provoked integrin V function, which was confirmed by the significant correlation of slug and p-Met levels in 121 ovarian cancer patient samples. Intriguingly, c-Met inhibitor(s) exhibited greatly enhanced anti-cancer effects in slug-positive ovarian cancer models both and . Additionally, IHC analyses revealed that slug levels were highly correlated with reduced survival of ovarian cancer patients. Taken together, this study not only uncovers the critical roles of slug in drug resistance in ovarian cancer but also highlights a promising therapeutic strategy by targeting the noncanonical activation of c-Met in slug-positive ovarian cancer patients with poor prognosis.

Disruption of Mitochondria-Associated Endoplasmic Reticulum Membrane (MAM) Integrity Contributes to Muscle Insulin Resistance in Mice and Humans.

Modifications of the interactions between endoplasmic reticulum (ER) and mitochondria, defined as mitochondria-associated membranes (MAMs), were recently shown to be involved in the control of hepatic insulin action and glucose homeostasis, but with conflicting results. Whereas skeletal muscle is the primary site of insulin-mediated glucose uptake and the main target for alterations in insulin-resistant states, the relevance of MAM integrity in muscle insulin resistance is unknown. Deciphering the importance of MAMs on muscle insulin signaling could help to clarify this controversy. Here, we show in skeletal muscle of different mice models of obesity and type 2 diabetes (T2D) a marked disruption of ER-mitochondria interactions as an early event preceding mitochondrial dysfunction and insulin resistance. Furthermore, in human myotubes, palmitate-induced insulin resistance is associated with a reduction of structural and functional ER-mitochondria interactions. Importantly, experimental increase of ER-mitochondria contacts in human myotubes prevents palmitate-induced alterations of insulin signaling and action, whereas disruption of MAM integrity alters the action of the hormone. Lastly, we found an association between altered insulin signaling and ER-mitochondria interactions in human myotubes from obese subjects with or without T2D compared with healthy lean subjects. Collectively, our data reveal a new role of MAM integrity in insulin action of skeletal muscle and highlight MAM disruption as an essential subcellular alteration associated with muscle insulin resistance in mice and humans. Therefore, reduced ER-mitochondria coupling could be a common alteration of several insulin-sensitive tissues playing a key role in altered glucose homeostasis in the context of obesity and T2D.

Effects of RNA interference of FABP5 on subcutaneous tumor of human hepatocellular carcinoma cell line HepG2 transplanted in nude mice / 中国病理生理杂志

AIM:To investigate the effect of recombinant lentiviral vector for RNA interference (RNAi) on the expression of fatty acid-binding protein 5 (FABP5) gene in hepatocellular carcinoma HepG2 cells and tumor formation in nude mice.METHODS:RNAi lentiviral vector was used in the experiment.Human hepatocellular carcinoma HepG2 cells were divided into 3 groups:the HepG2 cells in experimental group were transfected with the recombinant lentivirirus vector LV-shRNA-FABP5, the cells in negative control group were transfected with a control lentiviral vector LV-shRNA-NC, and the cells in normal control group were without any treatment.The nude mice were randomly divided into 3 groups.The growth of the transplanted tumor cells in the nude mice was observed.The tumor growth curve, volume and weight were de-termined 4 weeks after the cell inoculation.The expression of FABP5 was detected by real-time PCR, Western blot and im-munohistochemical staining.RESULTS:Transfection of the lentiviral vector FABP5-shRNA obviously reduced FABP5 ex-pression in the HepG2 cells.Tumor formation was all positive in the 3 groups of the nude mice inoculated with the tumor cells.Compared with normal control group and negative control group, the tumor growth slowed significantly in experimental group with smaller volume and weight.FABP5 expression in the transplanted tumor tissues was significantly down-regulated at mRNA and protein levels in experimental group as compared with normal control group and negative control group. CONCLUSION:RNAi-induced down-regulation of FABP5 effectively inhibits the growth of transplanted hepatocellular carcinoma, suggesting that FABP5 gene may be an effective target for gene therapy in treating liver cancer.

Mitochondria-associated endoplasmic reticulum membrane (MAM) integrity is required for insulin signaling and is implicated in hepatic insulin resistance.

Mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) are functional domains between both organelles involved in Ca(2+) exchange, through the voltage-dependent anion channel (VDAC)-1/glucose-regulated protein 75 (Grp75)/inositol 1,4,5-triphosphate receptor (IP3R)-1 complex, and regulating energy metabolism. Whereas mitochondrial dysfunction, ER stress, and altered Ca(2+) homeostasis are associated with altered insulin signaling, the implication of MAM dysfunctions in insulin resistance is unknown. Here we validated an approach based on in situ proximity ligation assay to detect and quantify VDAC1/IP3R1 and Grp75/IP3R1 interactions at the MAM interface. We demonstrated that MAM integrity is required for insulin signaling and that induction of MAM prevented palmitate-induced alterations of insulin signaling in HuH7 cells. Disruption of MAM integrity by genetic or pharmacological inhibition of the mitochondrial MAM protein, cyclophilin D (CypD), altered insulin signaling in mouse and human primary hepatocytes and treatment of CypD knockout mice with metformin improved both insulin sensitivity and MAM integrity. Furthermore, ER-mitochondria interactions are altered in liver of both ob/ob and diet-induced insulin-resistant mice and improved by rosiglitazone treatment in the latter. Finally, increasing organelle contacts by overexpressing CypD enhanced insulin action in primary hepatocytes of diabetic mice. Collectively, our data reveal a new role of MAM integrity in hepatic insulin action and resistance, providing a novel target for the modulation of insulin action.

Detection and significance of the main nutritional ingredients of tree shrew’ s milk / 中国比较医学杂志

Objective To explore the basic ingredients of the tree shrew’ s( Tupaia belangeri) milk and compare with the dairy ingredients of other milks.Methods We select ten seed tree shrews after delivery ( 1 ~21 ) d with lactation mother tree shrews, and use artificial passive breastfeeding method let the young tree shrews suck breast milk,we took the milk from the young tree shrews in the stomach, directly using aseptic operation with a syringe immediately, once every two days, for consecutive three to five times, and a total of 18 mL milk was taken from each seed tree shrew.Then the milk was detected according to the national standard method for component testing.Results The total solid content of the tree shrew’ s milk was 43.63%, including 26.01%of fat, 10.41%of protein, 0.45% of lactose and 0.99%of ash content.Compared with cow's milk, the tree shrew’ s milk contained 3.36 times of total solid contents, 1.24 times of ash, 2.74 times of protein, 6.67 times of fat, and 0.09 times of lactose.Compare with baby formula milk, the tree shrew’ s milk contained 1.44 times of total solid contents, 0.20 times of ash, 0.58 times of protein, 1.53 times of fat, and 0.06 times of lactose.The trace mineral composition of the tree shrew’ s milk showed that the calcium, phosphorus, potassium, sodium, magnesium, and iron contents were 1.83 times, 2.73 times, 1.25 times, 1.93 times, 1.28 times, and 1.48 times higher than those in the cow's milk, and were 0.66 times, 0.85 times, 0.34 times, 0.26 times, 0.85 times, 0.24 times lower than those in baby formula milk.Conclusions The main nutrients of tree shrew’ s milk is of high fat, high protein and low sugar, and it can provide a basis for tree shrews artificial brood and breeding work.

Effects of RNA interference targeting CDC25a gene on proliferation of human liver cancer HepG2 cells / 中国病理生理杂志

[ ABSTRACT] AIM:To investigate the effect of silencing cell division cycle 25a ( CDC25a) gene on the prolifera-tion of human hepatoma HepG2 cells.METHODS:CDC25a gene in human hepatoma HepG2 cells was silenced by RNA interference.Real-time PCR was applied to detect the expression of CDC25a, cyclin E and CDK2 at mRNA levels in the HepG2 cells.Western blotting was applied to detect the expression of CDC25a at protein level.In addition, MTT assay, Giemsa staining and flow cytometry were used to measure the proliferation of human hepatoma HepG2 cells.RESULTS:The expression of CDC25a at mRNA and protein levels in RNA silence group was lower than those in negative control group and normal control group (P<0.05).The mRNA expression of cyclin E and CDK2 in silence group was lower than that in negative control group and normal control group (P<0.05).The cell proliferation in silence group was lower than that in negative control group and normal control group ( P<0.05) .The results of flow cytometry revealed that the cells in silence group were blocked in G1 phase.CONCLUSION:Infection of LV-CDC25a-RNAi recombinant to the HepG2 cells effec-tively inhibits the CDC25a gene expression and the proliferation of human hepatoma cells, and arrests the cells in G1 phase, suggesting that CDC25a gene may be a key target for the treatment of liver cancer.