61 research outputs found

    Lovastatin enhances adenovirus-mediated TRAIL induced apoptosis by depleting cholesterol of lipid rafts and affecting CAR and death receptor expression of prostate cancer cells

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    Oncolytic adenovirus and apoptosis inducer TRAIL are promising cancer therapies. Their antitumor efficacy, when used as single agents, is limited. Oncolytic adenoviruses have low infection activity, and cancer cells develop resistance to TRAIL-induced apoptosis. Here, we explored combining prostate-restricted replication competent adenovirus-mediated TRAIL (PRRA-TRAIL) with lovastatin, a commonly used cholesterol-lowering drug, as a potential therapy for advanced prostate cancer (PCa). Lovastatin significantly enhanced the efficacy of PRRA-TRAIL by promoting the in vivo tumor suppression, and the in vitro cell killing and apoptosis induction, via integration of multiple molecular mechanisms. Lovastatin enhanced PRRA replication and virus-delivered transgene expression by increasing the expression levels of CAR and integrins, which are critical for adenovirus 5 binding and internalization. Lovastatin enhanced TRAIL-induced apoptosis by increasing death receptor DR4 expression. These multiple effects of lovastatin on CAR, integrins and DR4 expression were closely associated with cholesterol-depletion in lipid rafts. These studies, for the first time, show correlations between cholesterol/lipid rafts, oncolytic adenovirus infection efficiency and the antitumor efficacy of TRAIL at the cellular level. This work enhances our understanding of the molecular mechanisms that support use of lovastatin, in combination with PRRA-TRAIL, as a candidate strategy to treat human refractory prostate cancer in the future

    Down-Regulation of EBV-LMP1 Radio-Sensitizes Nasal Pharyngeal Carcinoma Cells via NF-κB Regulated ATM Expression

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    BACKGROUND:The latent membrane protein 1 (LMP1) encoded by EBV is expressed in the majority of EBV-associated human malignancies and has been suggested to be one of the major oncogenic factors in EBV-mediated carcinogenesis. In previous studies we experimentally demonstrated that down-regulation of LMP1 expression by DNAzymes could increase radiosensitivity both in cells and in a xenograft NPC model in mice. RESULTS:In this study we explored the molecular mechanisms underlying the radiosensitization caused by the down-regulation of LMP1 in nasopharyngeal carcinoma. It was confirmed that LMP1 could up-regulate ATM expression in NPCs. Bioinformatic analysis of the ATM ptomoter region revealed three tentative binding sites for NF-κB. By using a specific inhibitor of NF-κB signaling and the dominant negative mutant of IkappaB, it was shown that the ATM expression in CNE1-LMP1 cells could be efficiently suppressed. Inhibition of LMP1 expression by the DNAzyme led to attenuation of the NF-κB DNA binding activity. We further showed that the silence of ATM expression by ATM-targeted siRNA could enhance the radiosensitivity in LMP1 positive NPC cells. CONCLUSIONS:Together, our results indicate that ATM expression can be regulated by LMP1 via the NF-κB pathways through direct promoter binding, which resulted in the change of radiosensitivity in NPCs

    Emerging mechanisms of the unfolded protein response in therapeutic resistance: from chemotherapy to Immunotherapy

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    Abstract The accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) causes ER stress and activates the unfolded protein response (UPR). As an adaptive cellular response to hostile microenvironments, such as hypoxia, nutrient deprivation, oxidative stress, and chemotherapeutic drugs, the UPR is activated in diverse cancer types and functions as a dynamic tumour promoter in cancer development; this role of the UPR indicates that regulation of the UPR can be utilized as a target for tumour treatment. T-cell exhaustion mainly refers to effector T cells losing their effector functions and expressing inhibitory receptors, leading to tumour immune evasion and the loss of tumour control. Emerging evidence suggests that the UPR plays a crucial role in T-cell exhaustion, immune evasion, and resistance to immunotherapy. In this review, we summarize the molecular basis of UPR activation, the effect of the UPR on immune evasion, the emerging mechanisms of the UPR in chemotherapy and immunotherapy resistance, and agents that target the UPR for tumour therapeutics. An understanding of the role of the UPR in immune evasion and therapeutic resistance will be helpful to identify new therapeutic modalities for cancer treatment. Video Abstrac

    Blastocoele expansion: an important parameter for predicting clinical success pregnancy after frozen-warmed blastocysts transfer

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    Abstract Objective To assess the predictive value of each individual morphological parameter: blastocoele expansion degree, inner cell mass (ICM), and trophectoderm (TE) grades on the clinical pregnancy outcome in frozen–warmed embryo transfer (FET) cycles. Methods This is a retrospective cohort study, including 1154 FET cycles receiving vitrified-warmed one or two blastocysts transfer from August 2011 through to May 2018. The correlation between blastocyst morphology parameters and clinical outcome after FET was assessed. Results In the subgroup analysis based on clinical pregnancy, the patients who achieved clinical pregnancy had a significantly higher degree of blastocyst expansion (3.69 ± 0.68 vs. 3.53 ± 0.78, P = 0.000) and had a thicker endometrium (9.65 ± 1.63 vs. 9.28 ± 1.64) compared with those with non-clinical pregnancy. The logistic regression analysis showed that among the three blastocyst morphology parameters, only the blastocoele expansion degree was significantly correlated with the clinical pregnancy outcome and had ability to predict the outcome after FET cycles with one or two vitrified-warmed blastocysts transferred. Both ICM and TE stages were not associated with pregnancy outcomes. Conclusions The blastocoele expansion degree may be essential for successful pregnancy and should be given priority when selecting frozen blastocyst for transfer

    Association of follicle-stimulating hormone receptor polymorphisms with ovarian response in Chinese women: a prospective clinical study.

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    BACKGROUND: Follicular stimulating hormone (FSH) is a glycoprotein and widely used for the treatment of infertility; FSH action is mediated by FSH receptor (FSHR), SNPs of which determine the ovarian response. Two polymorphisms of the FSHR gene were identified, which caused a change of threonine (T) to alanine (A) at position 307 and asparagine (N) to serine(S) at position 680. Both polymorphic sites give rise to three discrete variants of the FSHR: TT, TA, and AA for position 307; NN, NS, and SS for position 680. METHODOLOGY/PRINCIPAL FINDINGS: 450 Chinese women were recruited in an assisted reproductive technology program from October 2011 to March 2012. FSHR polymorphisms at the positions 307 and 680 were examined by PCR-RFLP. Serum FSH and estradiol level, FSH amount, ovarian response and pregnancy rate were recorded during treatment. The basal FSH levels were higher in AA [7.38 ± 2.07 vs 6.34 ± 1.75, 6.63 ± 1.94, P<0.05, 95% CI (6.75, 8.01)] and SS [7.51 ± 2.01 vs 6.31 ± 1.75, 6.66 ± 1.96, P<0.05, 95% CI (6.88, 8.15)] compared to other genotypes respectively; the days for ovulation induction was slightly longer in AA and SS. Women with AA and SS have higher rates of poor response compared to carriers of other genotypes (P<0.05). Furthermore, there is a nearly complete linkage between these two polymorphisms in Chinese women (D'=0.95, r(2)=0.84). CONCLUSIONS/SIGNIFICANCE: In Chinese women receiving ART, the subjects with AA and SS genotypes have higher basal FSH levels, and these genotypes are associated with an increased risk of poor response. Our data suggested that the personalized FSH therapy may be applied according to patient's genetic background in clinical settings. The linkage suggested that the polymorphisms of Thr307Ala and Asn680Ser may be used as TAG-SNP markers for analysis of potential genotyping in ART

    The expression profiles of signature genes from CD103+LAG3+ tumour-infiltrating lymphocyte subsets predict breast cancer survival

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    Abstract Background Tumour-infiltrating lymphocytes (TILs), including T and B cells, have been demonstrated to be associated with tumour progression. However, the different subpopulations of TILs and their roles in breast cancer remain poorly understood. Large-scale analysis using multiomics data could uncover potential mechanisms and provide promising biomarkers for predicting immunotherapy response. Methods Single-cell transcriptome data for breast cancer samples were analysed to identify unique TIL subsets. Based on the expression profiles of marker genes in these subsets, a TIL-related prognostic model was developed by univariate and multivariate Cox analyses and LASSO regression for the TCGA training cohort containing 1089 breast cancer patients. Multiplex immunohistochemistry was used to confirm the presence of TIL subsets in breast cancer samples. The model was validated with a large-scale transcriptomic dataset for 3619 breast cancer patients, including the METABRIC cohort, six chemotherapy transcriptomic cohorts, and two immunotherapy transcriptomic cohorts. Results We identified two TIL subsets with high expression of CD103 and LAG3 (CD103+LAG3+), including a CD8+ T-cell subset and a B-cell subset. Based on the expression profiles of marker genes in these two subpopulations, we further developed a CD103+LAG3+ TIL-related prognostic model (CLTRP) based on CXCL13 and BIRC3 genes for predicting the prognosis of breast cancer patients. CLTRP-low patients had a better prognosis than CLTRP-high patients. The comprehensive results showed that a low CLTRP score was associated with a high TP53 mutation rate, high infiltration of CD8 T cells, helper T cells, and CD4 T cells, high sensitivity to chemotherapeutic drugs, and a good response to immunotherapy. In contrast, a high CLTRP score was correlated with a low TP53 mutation rate, high infiltration of M0 and M2 macrophages, low sensitivity to chemotherapeutic drugs, and a poor response to immunotherapy. Conclusions Our present study showed that the CLTRP score is a promising biomarker for distinguishing prognosis, drug sensitivity, molecular and immune characteristics, and immunotherapy outcomes in breast cancer patients. The CLTRP could serve as a valuable tool for clinical decision making regarding immunotherapy
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