Study on the Mechanism of Astragalus Polysaccharides on Cervical Cancer Based on Network Pharmacology.

BACKGROUND: Astragalus polysaccharides (APS) is a natural phytochemical which has been extensively utilized for anti-tumor therapy over the past few years. However, its impact on cervical cancer (CC) has rarely been studied. OBJECTIVE: To clarify the exact mechanism of anti-cancer effects of Astragalus polysaccharides (APS) on Cervical Cancer (CC), we screened differentially expressed genes (DEGs) from The Cancer Genome Atlas (TCGA) to construct the cancer network. METHODS: Then we performed functional enrichment analysis with gene ontology (GO) and KEGG pathway analyses, constructed protein-protein interaction (PPI) network, and performed molecular docking (MD) analysis to identify the key gene for docking with APS. Further, we observed the effects of APS on cell proliferation, cell cycle, and apoptosis experiments in HeLa cells. qRT-PCR and western blot were used to detect the expression of target genes. RESULTS: A total of 793 DEGs were screened using criteria, which included 541 genes that were upregulated and 251 genes that were down-regulated. Using topological attributes for identifying critical targets, molecular docking (MD), and survival analyses, this study predicted the APS targets: POLO-like kinase 1(PLK1), Cyclin-cell division 20(CDC20), and Cyclin-dependent kinase 1 (CDK1), which regulated HeLa cells. The results of cell proliferation, cell cycle, and apoptosis experiments concluded that APS inhibited the development of HeLa cells in a concentrationdependent manner. Also, qRT-PCR and western blot experiments demonstrated that APS could significantly down-regulate the expression of PLK1, CDC20, and CDK1 in the CC cells. CONCLUSION: The result revealed that APS might have a therapeutic potential in treating CC and might permit intervention with treatments targeting PLK1, CDC20, and CDK1.

The relationship between MHC-peptide interaction and resistance to virus in chickens.

INTRODUCTION: The MHC-peptide interaction has a subtle influence on host resistance to virus. This paper aims to study the relationship between MHC-peptide interaction and MHC-related virus-resistance. METHODS: By 3D homology modeling, the structure of chicken BF2 molecule BF2*0201 (PDB code: 4d0d) was studied and compared with the known structures of BF2 molecule BF2*0401 (PDB code: 4e0r) to elucidate the characteristics of BF2*0201-binding antigenic peptides. RESULTS: The results show that due to the amino acid difference between the two binding groove of 4e0r and 4d0d, the size of the binding groove of the two are 1130 ų and1380 ų respectively, indicating the amino acid species that 4e0r binding peptide has lower selectivity than 4d0d; and because of large side chain conformation of Arg (especially Arg111) of 4e0r replaced by small side chain Tyr111 of 4d0d, the volume of central part of the binding groove of 4d0d is obviously larger than that of 4e0r, indicating that the restrictive of binding antigenic peptides for 4d0d is narrower than that of 4e0r; and on account of the chargeability of the binding groove of the two are different, namely the binding groove chargeability of 4e0r (strong positive polarity) and 4d0d (weak negative polarity). CONCLUSION: There are generally more peptides presented by the BF2 of B2 haplotype than by that of B4 haplotype, leading to more resistance of B2 than that of B4 to virus.

Study on the contrast of the MHC-peptide interaction of B2/B21 haplotype and MHC-related virus resistance in chickens.

INTRODUCTION: Three-dimensional (3D) structures of MHC class I exert some influence by the MHC-peptide interaction over host resistance to the virus. The thesis aims at studying the connection between MHC-peptide interaction of B2/B21 haplotype and MHC-related resistance to the virus. METHODS: The structure of chicken MHC class I BF2*0201 from B2 haplotype was studied and contrasted with that of BF2*2101 from B21 haplotype by using DNAMAN and PyMol software. RESULTS: The amino acid difference resulted in the difference in size and changeability of the binding groove of the two, resulting in different choices on the binding polypeptide. 3bew's (the crystal structure of BF2*2101 bound to peptide RV10) small side chain His111 replaces the short side chain Tyr111 of 4cvx (the crystal structure of BF2*0201 bound to peptide YL9), and the very small amino acid of Ser69 and Ser97 make the middle of the 3bew's binding groove become apparently broad and bound restrictive of amino acid smaller. Moreover, due to the specific amino acids-Arg9, Asp24, and Asp73 of 4cvx and Arg9, Asp24, and His111 of 3bew, the effect of the polypeptide and the binding groove differ between the two, and 3bew tends to bind polypeptides with negatively charged amino acids, but the large space in the middle can also accommodate other amino acids. Contrasted with the binding groove characteristic of 4cvx, it can be said that the selectivity of 3bew is higher than that of 4cvx in the amino acid type of the binding polypeptide, so the B21 haplotype has more host resistance to the virus than that of the B2 haplotype in chicken. CONCLUSION: There are usually various kinds of peptides presented by the BF2*2101 molecules of B21 haplotypes, resulting in resistance to pathogenic microorganisms, such as Rous sarcoma virus and/or Marek's disease virus. These findings may have an important theoretical foundation for screening of virus antigen, vaccine design, and genetic resistance breeding.

MicroRNA-373-3p inhibits the growth of cervical cancer by targeting AKT1 both in vitro and in vivo.

OBJECTIVE: In this study, we aimed to investigate the function of microRNA-373-3p (miR-373-3p) in the pathogenesis of cervical cancer. METHODS: Human and mouse cervical cancer cell lines were transfected with miR-373-3p mimic and inhibitor. Cell proliferation and viability were evaluated with Cell Counting Kit-8 (CCK-8) assay and Lactate Dehydrogenase (LDH) assay, respectively. The AKT1-targeting role of miR-373-3p was analyzed by qPCR and Western blot. Finally, a mouse xenograft cervical tumor model was adopted to study the in vivo effect of miR-373-3p on tumor growth and the expression of AKT1. RESULTS: Over-expression of miR-373-3p significantly reduced the proliferation of cervical carcinoma cell line in vitro. In addition, miR-373-3p overexpression also inhibited cervical cancer growth in tumor-bearing mice. Mechanistically, we found that AKT1 gene can be targeted by miR-373-3p. MiR-373-3p mimic decreased the mRNA and protein expression of AKT1, while the miR-373-3p inhibitor increased the level of AKT1 in cervical cancer cells. AKT1 overexpression rescued the proliferation of cervical cancer cells transfected with miR-373-3p. CONCLUSION: MiR-373-3p can serve as a novel anti-tumor microRNA in cervical cancer by targeting AKT1.

MicroRNA-497 regulates cisplatin chemosensitivity of cervical cancer by targeting transketolase.

Cervical cancer is one of the most lethal malignancies amongst women, partially because it is unresponsive to many chemotherapeutic drugs. The mechanism underlying cisplatin (DDP) resistance in cervical cancer remains largely elusive. In this study, by detecting the 12 most reported down-regulated miRNAs in chemotherapy-sensitive and -resistant cervical cancer cells, we found that miR-497 was significantly reduced in chemotherapy-resistant HeLa/DDP cells and contributed to DDP chemosensitivity. Transketolase (TKT), a thiamine-dependent enzyme that plays a role in the channeling of excess glucose phosphates to glycolysis in the pentose phosphate pathway, was identified as a direct target of miR-497. TKT expression in clinical specimens was characterized by immunohistochemistry and the result showed that TKT was highly expressed in 81.1% (60/74) of samples examined. Data from Oncomine databases revealed that TKT was significantly up-regulated in cervical cancer tissues compared to normal controls. Gain-of-function and loss-of-function studies showed that the miR-497/TKT axis was a critical modulator in DDP chemosensitivity as demonstrated by cell viability and apoptosis assays. Mechanistically, DDP chemosensitivity induced by the miR-497/TKT axis was associated with glutathione (GSH) depletion and reactive oxygen species (ROS) generation, and GSH treatment effectively abrogated miR-497/TKT-mediated chemosensitivity. In conclusion, these findings suggest that a deregulated miR-497/TKT axis has important implications in the cervical cancer cellular response to DDP, and thus targeting this axis may be a promising way to improve chemosensitivity in cervical cancer.

HPV E6/p53 mediated down-regulation of miR-34a inhibits Warburg effect through targeting LDHA in cervical cancer.

MicroRNAs (miRNA) play crucial roles in regulating cell proliferation, differentiation and developmental timing. Aberrantly expressed miRNAs have recently emerged as key regulators of metabolism. However, little is known about its role in tumor metabolism of cervical cancer. In this study, we determined the oncogenic effects of miRNAs on Warburg effect, a metabolic phenotype that allows cancer cells to utilize glucose even under aerobic conditions. A gain-of-function study was performed in 12 down-regulated miRNAs that frequently reported in cervical cancer. We found that miR-34a plays a suppressive role in Warburg effect as evidenced by decreased lactate production and glucose consumption. Knockdown of oncoprotein E6 expression of human papillomavirus in SiHa and HeLa cells by siRNAs lead to an increased protein level of p53, decreased level of miR-34a, as well as reduced Warburg effect. Subsequently, lactate dehydrogenase A (LDHA), which catalyzes the last key step in glycolysis, was identified as a direct target of miR-34a. Silencing of LDHA or introduction of miR-34a significantly attenuated colony formation ability and invasive capacity of SiHa and HeLa cells, and these effects were fully compromised by reintroduction of LDHA. In conclusion, our findings demonstrated that deregulated miR-34a/LDHA axis induced by HPV E6/p53 signaling facilitates tumor growth and invasion through regulating Warburg effect in cervical cancer, and provided new insights into the mechanism by which miR-34a contributes to the development and progression of cervical cancer.

Comparison of telbivudine versus lamivudine in interrupting perinatal transmission of hepatitis B virus.

BACKGROUND: Infection with hepatitis B virus (HBV) during pregnancy may lead to perinatal transmission. OBJECTIVES: To compare the efficacy and safety of telbivudine versus lamivudine in interrupting perinatal transmission of hepatitis B virus. STUDY DESIGN: All pregnant women enrolled in this study were positive for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg). Test patients underwent antiviral therapy with telbivudine or lamivudine while control patients received hepatitis B immune globulin (HBIG) injection. RESULTS: Patients in the telbivudine group had significantly lower HBV DNA and HBeAg levels and higher HBV DNA negative conversion rates compared to those in the lamivudine group before delivery. HBV DNA negative conversion rates in patients with abnormal alanine aminotransferase (ALT) levels were significantly higher than those in patients with normal ALT levels in the telbivudine and lamivudine groups before delivery. The intrauterine HBV infection rate and the percentage of immunization failure were both 0% in the telbivudine and lamivudine groups (χ(2)=0, 0; P=1, 1 respectively), compared to both 5% in the HBIG group (χ(2)=11.83, 7.86; P=0.002, 0.009 respectively). The side effects of three groups in mother and child were all unobvious. CONCLUSIONS: Telbivudine and lamivudine can reduce HBV DNA levels in pregnant women, interrupt the vertical transmission of HBV and be used safely in mothers and children.

[Relationship between the expression of HBV DNA, HBV cccDNA in human ovary tissues and the HBV intrauterine infection].

OBJECTIVE: To investigate the relationship between hepatitis B virus (HBV) deoxyribonucleic acid (DNA) and HBV covalently closed circular DNA (cccDNA) in the ovary and HBV intrauterine infection. METHODS: HBV DNA and HBV cccDNA were assayed in the ovaries of 33 pregnant women who were positive for HBV DNA, tested by Fluorescent quantitative polymerase chain reaction (FQ-PCR). The level of HBV mark (HBVM) and the content of HBV DNA in peripheral blood of infants were measured by chemoluminescence and FQ-PCR methods respectively. RESULTS: The overall positive rate for both HBV DNA and HBV cccDNA in ovarian samples was 51.52% (17/33). The rate on intrauterine infection among infants was 12.12% (4/33) and all the 4 infected infants were delivered from mothers with normal hepatic function. When HBV DNA and HBV cccDNA were both positive, the rate of intrauterine infection in infants was significantly higher than those who were with both negative results (P < 0.05). Levels of HBV cccDNA and the rate of positive samples were significantly higher in mothers with infants who appeared to have had intrauterine infection than those did not (P < 0.01 and < 0.05, respectively). CONCLUSION: HBV infection could be discovered in the human ovary and might be transmitted to the filial generation via ovum.