Regulatory Effects of Zuogui Pill on Apoptosis of Follicles in Rats Injured by 60Co-γRays Based on PI3K/Akt/m TOR Signaling Pathway

[Objectives]To explore the protective effects of Zuogui Pill on ^(60)Co-γ-ray-induced premature aging of rats based on phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/Akt/mTOR)signaling pathway.[Methods]Sixty sexually mature female SD rats were irradiated with ^(60)Co-γ-ray(6.0 Gy,LD 40)for 24 h at one time.These rats were randomly divided into model group,Progynova group[0.18(g·kg)/d],Progynova[0.09(g·kg)/d]+Zuogui Pill high dose[23.625(g·kg)/d)]group,Zuogui Pill high dose[23.625(g·kg)/d)]group,Zuogui Pill medium dose[9.45(g·kg)/d)]group and Zuogui Pill low dose[4.725(g·kg)/d]group.The administration(once a day)lasted 21 d.The rat serum[follicle-stimulating hormone(FSH),luteinizing hormone(LH)and estradiol(E_(2))]were detected by Enzyme-linked immunosorbent assay(ELISA).The morphological changes of ovary were observed by hematoxylin-eosin(HE)staining.The apoptosis rate of granulosa cells was detected by terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick-end labeling(TUNEL).The protein expression of phosphorylated(p)-PI3K,p-Akt,p-mTOR,B-cell lymphoma-2(Bcl-2),and Bcl-2-associated X protein(Bax)in ovarian tissues were detected by Western blot.[Results]Compared with the normal group,the model group showed significant increase in the serum FSH(P<0.01),significant decrease in serum E_(2)(P<0.05),and decrease in the number of early follicles and luteum in the ovary(P<0.01).Besides,the apoptosis rate of granulosa cells increased significantly(P<0.01);the expression of p-PI3K,p-Akt,p-mTOR and Bcl-2 in ovarian tissue decreased significantly,while the expression of Bax increased significantly(P<0.01).Compared with the model group,the number of early follicles in the ovary increased and the apoptosis rate of granulosa cells decreased after intervention in each administration group.In addition,the protein expressions of p-PI3K,p-Akt,p-mTOR and Bcl-2 increased,while the expression of Bax decreased,especially in Progynova+Zuogui Pill high dose group,the differences were statistically significant(P<0.05,P<0.01).[Conclusions]Zuogui Pill may protect the radiation-injured ovary through activating the expression of PI3K/Akt/mTOR protein in ovarian tissue,increasing the amount of Bcl-2 protein and inhibiting the expression of Bax protein.

WJH 6^(th) Anniversary Special Issues(2): Hepatocellular carcinoma Mammalian target of rapamycin inhibition in hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is one of the leading causes of cancer-related death worldwide. It is associated with a poor prognosis and has limited treatment options. Sorafenib, a multi-targeted kinase inhibitor, is the only available systemic agent for treatment of HCC that improves overall survival for patients with advanced stage disease; unfortunately, an effective second-line agent for the treatment of progressive or sorafenib-resistant HCC has yet to be identified. This review focuses on components of the mammalian target of rapamycin(mTOR) pathway, its role in HCC pathogenesis, and dual mTOR inhibition as a therapeutic option with potential efficacy in advanced HCC. There are several important upstream and downstream signals in the mTOR pathway, and alternative tumor-promoting pathways are known to exist beyond mTORC1 inhibition in HCC. This review analyzes the relationships of the upstream and downstream regulators of mTORC1 and mTORC2 signaling; it also provides a comprehensive global picture of the interaction between mTORC1 and mTORC2 which demonstrates the pre-clinical relevance of the mTOR pathway in HCC pathogenesis and progression. Finally, it provides scientific rationale for dual mTORC1 and mTORC2 inhibition in the treatment of HCC. Clinical trials utilizing mTORC1 inhibitors and dual mTOR inhibitors in HCC are discussed as well. The mTOR pathway is comprised of two main components, mTORC1 and mTORC2; each has a unique role in the pathogenesis and progression of HCC. In phase Ⅲ studies, mTORC1 inhibitors demonstrate anti-tumor ac-tivity in advanced HCC, but dual mTOR(mTORC1 and mTORC2) inhibition has greater therapeutic potential in HCC treatment which warrants further clinical investigation.

CircMAN1A2 promotes vasculogenic mimicry of nasopharyngeal carcinoma cells through upregulating ERBB2 via sponging miR-940

Nasopharyngeal carcinoma(NPC)is the most prevalent human primary malignancy of the head and neck,and the presence of vasculogenic mimicry(VM)renders anti-angiogenic therapy ineffective and poorly prognostic.However,the underlying mechanisms are unclear.In the present study,we used miR-940 silencing and overexpression for in vitro NPC cell EdU staining,wound healing assay and 3D cell culture assay,and in vivo xenograft mouse model and VM formation to assess miR-940 function.We found that ectopic miR-940 expression reduced NPC cell proliferation,migration and VM,as well as tumorigenesis in vivo.By bioinformatic analysis,circMAN1A2 was identified as a circRNA that binds to miR-940.Mechanistically,we confirmed that circMAN1A2 acts as a sponge for miR-940,impairs the inhibitory effect of miR-940 on target ERBB2,and then activates the PI3K/AKT/mTOR signaling pathway using RNA-FISH,dual luciferase reporter gene and rescue analysis assays.In addition,upregulation of ERBB2 expression is associated with clinical staging and poor prognosis of NPC.Taken together,the present findings suggest that circMAN1A2 promotes VM formation and progression of NPC through miR-940/ERBB2 axis and further activates the PI3K/AKT/mTOR pathway.Therefore,circMAN1A2 may become a biomarker and therapeutic target for anti-angiogenic therapy in patients with nasopharyngeal carcinoma.

Novel nervous and multi-system regenerative therapeutic strategies for diabetes mellitus with mTOR

Throughout the globe,diabetes mellitus（DM） is increasing in incidence with limited therapies presently available to prevent or resolve the significant complications of this disorder.DM impacts multiple organs and affects all components of the central and peripheral nervous systems that can range from dementia to diabetic neuropathy.The mechanistic target of rapamycin（m TOR） is a promising agent for the development of novel regenerative strategies for the treatment of DM.m TOR and its related signaling pathways impact multiple metabolic parameters that include cellular metabolic homeostasis,insulin resistance,insulin secretion,stem cell proliferation and differentiation,pancreatic β-cell function,and programmed cell death with apoptosis and autophagy.m TOR is central element for the protein complexes m TOR Complex 1（m TORC1） and m TOR Complex 2（m TORC2） and is a critical component for a number of signaling pathways that involve phosphoinositide 3-kinase（PI 3-K）,protein kinase B（Akt）,AMP activated protein kinase（AMPK）,silent mating type information regulation 2 homolog 1（Saccharomyces cerevisiae）（SIRT1）,Wnt1 inducible signaling pathway protein 1（WISP1）,and growth factors.As a result,m TOR represents an exciting target to offer new clinical avenues for the treatment of DM and the complications of this disease.Future studies directed to elucidate the delicate balance m TOR holds over cellular metabolism and the impact of its broad signaling pathways should foster the translation of these targets into effective clinical regimens for DM.

Macrophage-derived exosomal miR-342-3p promotes the progression of renal cell carcinoma through the NEDD4L/CEP55 axis

Due to its difficulty in early diagnosis and lack of sensitivity to chemotherapy and radiotherapy,renal cell carcinoma(RCC)remains to be a frequent cause of cancer-related death.Here,we probed into new targets for its early diagnosis and treatment for RCC.microRNA(miRNA)data of M2-EVs and RCC were searched on the Gene Expression Omnibus database,followed by the prediction of the potential downstream target.Expression of target genes was measured via RT-qPCR and Western blot,respectively.M2 macrophage was obtained viaflow cytometry with M2-EVs extracted.The binding ability of miR-342-3p to NEDD4L and to CEP55 ubiquitination was studied with their roles in the physical abilities of RCC cells assayed.Subcutaneous tumor-bearing mouse models and lung metastasis models were prepared to observe in vivo role of target genes.M2-EVs induced RCC growth and metastasis.miR-342-3p showed high expression in both M2-EVs and RCC cells.M2-EVs carrying miR-342-3p promoted RCC cell abilities to proliferate,invade and migrate.In RCC cells,M2-EV-derived miR-342-3p could specifically bind to NEDD4L and consequently elevate CEP55 protein expression via suppressing NEDD4L,thereby exerting tumor-promoting effects.CEP55 could be degraded by ubiquitination under the function of NEDD4L,and miR-342-3p delivered by M2-EVs facilitated the RCC occurrence and development by activating the PI3K/AKT/mTOR signaling pathway.In conclusion,M2-EVs promote RCC growth and metastasis by delivering miR-342-3p to suppress NEDD4L and subsequently inhibit CEP55 ubiquitination and degradation via activation of the PI3K/AKT/mTOR signaling pathway,strongly driving the proliferative,migratory and invasive of RCC cells.

Advance in the Study of the Mechanisms Regulated by Sphingosine-1-Phosphate

Sphingosine-1-phosphate（S1P） is a bioactive lipid messenger in the cells that regulate gene expression and NF-κB signal pathway through unknown mechanisms.Recently,Cheng Luo,associate professor of DDDC in Shanghai Institute of Materia Medica,whose project was funded by the National Natural Science Foundation of China,joined in a research team led by Professor Sarah Spiegel of Virginia Commonwealth University.The team continuously made significant breakthroughs in understanding the regulation mechanism of Sphingosine-1- Phosphate.In September 2009,in a paper published on SCIENCE magazine（Science 2009, 325：1254-7）,they firstly demonstrated that S1P is a physiologically important regulator of histone deacetylases（HDACs）,HDACs are direct intracellular targets of S1P.Furthermore,they identified the mechanism that S1P regulates gene expression through regulating the activity of HDACs.In June 24th,2010,in another paper to be published on NATURE magazine（Nature 2010,June 24th,advance online publication,（doi：10.1038/ nature09128）） which reports the regulation of NF-κB signaling pathway by S1P.They demonstrate that S1P is the missing cofactor for TRAF2（tumour-necrosis factor receptor-associated factor 2） and indicate a new paradigm for the regulation of lysine-63- linked poly-ubiquitination.The study also highlight the key role of SphK1 and its product S1P in TNF-αsignalling and the canonical NF-κB activation pathway, and then play crucial role in inflammatory,antiapoptotic and immune processes.The identification of new mechanisms fay which S1P regulates gene expression and TNF and NF-κB signaling pathway will light up the road to develop novel inhibitors that might be useful for treatment of cancer and in- flammatory diseases.