Ovarian cancer is the number one cause of death from gynecologic malignancy. A defective p53 pathway is a hallmark of ovarian carcinoma. The p53 mutation correlates significantly with resistance to platinum-based chemotherapy, early relapse and shortened overall survival in ovarian cancer patients. PUMA (p53 upregulated modulator of apoptosis), a BH3-only Bcl-2 family protein, was recently identified as a transcriptional target of p53 and a potent apoptosis inducer in various cancer cells. In this study, we showed that the induction of PUMA by cisplatin was abolished in p53-deficient SKOV3 cells. Elevated expression of PUMA-induced apoptosis and sensitized A2780s and SKOV3 ovarian cancer cells to cisplatin, and the combination of PUMA and low-dose cisplatin, significantly suppressed xenograft tumor growth in vivo through enhanced induction of apoptosis compared with treatment with PUMA or cisplatin alone. The effects of PUMA were mediated by enhanced caspase activation and release of cytochrome c and Smac (second mitochondria-derived activator of caspase) into the cytosol. Furthermore, PUMA chemosensitized intrinsically resistant SKOV3 cells to cisplatin through downregulation of B-cell lymphoma-extra large (Bcl-xL) and myeloid cell leukemia sequence 1 (Mcl-1). PUMA-mediated Bcl-xL downregulation mainly happened at the transcription level, whereas PUMA-induced Mcl-1 downregulation was associated with caspase-dependent cleavage and proteasome-mediated degradation. To our knowledge, these data suggest a new mechanism by which overexpression of PUMA enhances sensitivity of SKOV3 cells to cisplatin by lowering the threshold set simultaneously by Bcl-xL and Mcl-1. Taken together, our findings indicate that PUMA is an important modulator of therapeutic responses of ovarian cancer cells and is potentially useful as a chemosensitizer in ovarian cancer therapy.
Microtubule-associated proteins (MAPs) have been considered to play significant roles in the tumor evolution of non-small cell lung cancer (NSCLC). Nevertheless, mRNA transcription levels and prognostic value of distinct MAPs in patients with NSCLC remain to be clarified.In this study, the Oncomine database, Gene Expression Profiling Interactive Analysis (GEPIA) database, and Human Protein Atlas were utilized to analyze the relationship between mRNA/protein expression of different MAPs and clinical characteristics in NSCLC patients, including tumor type and pathological stage. The correlation between the transcription level of MAPs and overall survival (OS) of NSCLC patients was analyzed by Kaplan-Meier plotter. Besides, 50 frequently altered neighbor genes of the MAPs were screened out, and a network has been constructed via the cBioPortal and Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) dataset. Meanwhile, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis on the expression data of MAPs and their 50 frequently altered neighbor genes in NSCLC tissues. Furthermore, The Cancer Immunome Atlas (TCIA) was utilized to analyze the relationship between MAP expression and the response to immunotherapy. Finally, we used reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to verify the expression of MAPs in 20 patients with NSCLC.The present study discovered that the mRNA transcription levels of MAP7/7D2 were enriched in NSCLC tissues, while those of the MAP2/4/6/7D3 were lower in NSCLC specimens than those in control specimens. The mRNA transcription level of MAP6 was significantly associated with the advanced stage of NSCLC. Besides, survival analysis indicated that higher mRNA expressions of MAP2/4/6/7/7D3 were correlated considerably with favorable OS of NSCLC patients, whereas increased mRNA expression levels of MAP1A/1S were associated with poor OS. Moreover, the expression of MAP1A/1B/1S/4/6/7D1/7D3 was significantly correlated with immunophenoscore (IPS) in NSCLC patients.Our analysis indicated that MAP1A/1S could serve as potential personalized therapeutic targets for patients with NSCLC, and the enriched MAP2/4/6/7/7D3 expression could serve as a biomarker for favorable prognosis in NSCLC. Besides, the expression of MAP1A/1B/1S/4/6/7D1/7D3 was closely related to the response to immunotherapy. Taken together, MAP expression has potential application value in the clinical treatment and prognosis assessment of NSCLC patients, and further verifiable experiments can be conducted to verify our results.
Background: Glioblastoma multiforme (GBM) is one of the most common and lethal types of human primary brain tumours. SARI (Suppressor of AP-1 regulated by interferon) functions as a tumour suppressor in various cancers. However, the role of SARI in regulating the tumour microenvironment remains unknown.Methods: An intracranial glioma model in nude mice, which we monitored by magnetic resonance imaging (MRI) and 3D micro-CT, were eastablished to exaim the function of SARI in glioma growth and metastasis. The underlying mechanisms of SARI function were determined by flow cytometry, immunofluerence staining, and in vitro assay. Glioma tissue microarray was employed to investigate the expression and predictive role of SARI.Findings: SARI inhibits glioma tumour growth and metastasis by inhibiting the recruitment of MDSCs in intracranial and subcutaneous glioma. Ectopic expression of SARI efficiently inhibited intracranial and subcutaneous glioma growth as evidenced by MRI and 3D micro-CT. Mechanistically, SARI inhibits the recruitment of CXCR4+ MDSCs into the glioma microenvironment by inhibiting HIF1-α expression and SDF-1α transcription. Notably, the attenuation of SDF-1α/CXCR4 signalling could revert the effect of SARI on the inhibition of glioma progression. Furthermore, tissue microarray staining indicated that SARI expression inversely correlates with poor clinical outcomes in glioma patients.Interprepation: SARI is a novel regulator of tumour microenvironment and a potential therapeutic and predictive target protein in glioma patients.Funding: This study was supported by the National Natural Science Foundation of China Program grant (no. 81772939) and the National Key R＆D Program of China grant (no. 2017YFA0105702).Declaration of Interest: All authors declare that there are no conflicts of interestEthical Approval: All the animal experiments were approved approved in accordance with institution guidelines by the Ethics Committee of West China Hospital, Sichuan University. The tissue samples obtained from 50 glioma patients (age: from 55 to 75 years old; grade: WHO I-IV) were recruited to perform biopsy at West China hospital (Chengdu, China) and the study was approved by the Ethics Committee of West China Hospital.
The binding of vascular endothelial growth factor (VEGF) to its receptors stimulates tumor growth; therefore, modulation of VEGF would be a viable approach for antiangiogenic therapy. We constructed a series of soluble decoy receptors containing different VEGF receptor 1 (FLT1) and VEGF receptor 2 (KDR) extracellular domains fused with the Fc region of human immunoglobulin (Ig) and evaluated their antiangiogenic effects and antitumor effects. Results of in vitro binding and cell proliferation assays revealed that decoy receptor FP3 had the highest affinity to VEGF-A and -B. Compared with bevacizumab, FP3 more effectively inhibited human umbilical vein endothelial cell (HUVEC) migration and vessel sprouting from rat aortic rings. FP3 significantly reduced phosphorylation of AKT and ERK1/2, critical proteins in the VEGF-mediated survival pathway in endothelial cells. Moreover, FP3 inhibited tumor growth in human hepatocellular carcinoma (HepG2), breast cancer (MCF-7), and colorectal cancer (LoVo) tumor models, and reduced microvessel density in tumor tissues. The FP3-mediated inhibition of tumor growth was significantly higher than that of bevacizumab at the same dose. FP3 also demonstrated synergistic antitumor effects when combined with 5-fluorouracil (5-FU). Taken together, FP3 shows a high affinity for VEGF and produced antiangiogenic effects, suggesting its potential for treating angiogenesis-related diseases such as cancer. The binding of vascular endothelial growth factor (VEGF) to its receptors stimulates tumor growth; therefore, modulation of VEGF would be a viable approach for antiangiogenic therapy. We constructed a series of soluble decoy receptors containing different VEGF receptor 1 (FLT1) and VEGF receptor 2 (KDR) extracellular domains fused with the Fc region of human immunoglobulin (Ig) and evaluated their antiangiogenic effects and antitumor effects. Results of in vitro binding and cell proliferation assays revealed that decoy receptor FP3 had the highest affinity to VEGF-A and -B. Compared with bevacizumab, FP3 more effectively inhibited human umbilical vein endothelial cell (HUVEC) migration and vessel sprouting from rat aortic rings. FP3 significantly reduced phosphorylation of AKT and ERK1/2, critical proteins in the VEGF-mediated survival pathway in endothelial cells. Moreover, FP3 inhibited tumor growth in human hepatocellular carcinoma (HepG2), breast cancer (MCF-7), and colorectal cancer (LoVo) tumor models, and reduced microvessel density in tumor tissues. The FP3-mediated inhibition of tumor growth was significantly higher than that of bevacizumab at the same dose. FP3 also demonstrated synergistic antitumor effects when combined with 5-fluorouracil (5-FU). Taken together, FP3 shows a high affinity for VEGF and produced antiangiogenic effects, suggesting its potential for treating angiogenesis-related diseases such as cancer.
After online publication of the article 1 , the authors noticed one inadvertent mistake in Fig. 5a that needs to be corrected.In detail, the pathological picture of PBS group in Fig. 5a is inadvertently duplicated as the image of PBS group in Fig. 7b in the main text.This duplication is a result of errors in figure assembly, and the correct Fig. 5 is provided as follows.The key findings of the article are not affected by these corrections.www.nature.
Mucopolysaccharidosis type I-Hurler (MPS I-H) is a neurodegenerative lysosomal storage disorder (LSD) caused by inherited defects of the α-L-iduronidase (IDUA) gene. Current treatments are ineffective for treating central nervous system (CNS) manifestations because lysosomal enzymes do not effectively cross the blood-brain barrier (BBB). To enable BBB transport of the enzyme, we engineered a modified IDUA protein by adding a brain-targeting peptide from melanotransferrin. We demonstrated that fusion of melanotransferrin peptide (MTfp) at the N terminus of human IDUA (hIDUA) was enzymatically active and could efficiently cross the BBB in vitro. Then, liver-directed gene therapy using the adeno-associated virus 8 (AAV8) vector, which encoded the modified hIDUA cDNA driven by a liver-specific expression cassette was evaluated in an adult MPS I-H mouse model. The results showed that intravenous (i.v.) infusion of AAV8 resulted in sustained supraphysiological levels of IDUA activity and normalized glycosaminoglycan (GAG) accumulation in peripheral tissues. Addition of MTfp to the hIDUA N terminus allowed efficient BBB transcytosis and IDUA activity restoration in the brain, resulting in significant improvements in brain pathology and neurobehavioral deficits. Our results provide a novel strategy to develop minimally invasive therapies for treatment of MPS I-H and other neurodegenerative LSDs.
Abstract Transcription factors are known to mediate the conversion of somatic cells to induced pluripotent stem cells (iPSCs). Transcription factor TFAP2C plays important roles in the regulation of embryonic development and carcinogenesis; however, the roles of Tfap2c in regulating somatic cell reprogramming are not well understood. Here we demonstrate Tfap2c is induced during the generation of iPSCs from mouse fibroblasts and acts as a facilitator for iPSCs formation. Mechanistically, the c-Myc -dependent apoptosis, which is a roadblock to reprogramming, can be significantly mitigated by Tfap2c overexpression. Meanwhile, Tfap2c can greatly promote mesenchymal-to-epithelial transition (MET) at initiation stage of OSKM-induced reprogramming. Further analysis of gene expression and targets of Tfap2c during reprogramming by RNA-sequencing (RNA-seq) and ChIP-qPCR indicates that TFAP2C can promote epithelial gene expression by binding to their promoters directly. Finally, knockdown of E-cadherin ( Cdh1 ), an important downstream target of TFAP2C and a critical regulator of MET antagonizes Tfap2c -mediated reprogramming. Taken together, we conclude that Tfap2c serves as a strong activator for somatic cell reprogramming through promoting the MET and inhibiting c-Myc -dependent apoptosis.
Vascular endothelial growth factor receptor (VEGFR) or vascular endothelial growth factor (VEGF) inhibitors have shown only modest clinical activity for most tumor types when used as single agents.However, present evidence indicates that these antiangiogenic drugs can cause transient "normalization" of the tumor vasculature, thereby improving the delivery of systemic chemotherapy.We examined temporal changes in tumor vascular function in response to the novel VEGFR2 inhibitor, SKLB1002.Established tumor-bearing animals were evaluated at serial time points for treatment-associated changes in tumor vascular architecture and function.As a result, blocking VEGF signaling by SKLB1002 produced a morphologically and functionally "normalized" vascular network.Consistent with our observations, a 2.2 fold increase in intratumoral doxorubicin levels was determined with SKLB1002 pretreatment compared with administration of doxorubicin alone.Finally, combined SKLB1002 and doxorubicin exhibited significant antitumor (49% of control size) and antimetastatic effects (12% of control metastatic nodules) in vivo.Our results showed SKLB1002 induced vascular normalization and enhanced anticancer drug delivery, which were associated with the observed synergistic effect in vivo.
Polo-like kinase 1 (Plk1) is a key cell cycle regulator that is frequently overexpressed in human hepatocellular carcinomas. Blockade of the Plk1 pathway has been reported to be capable of inducing anti-tumor effect. Here, plasmids containing U6 promoter-driven shRNAs against human Plk1 were constructed and transfected in human hepatocellular carcinoma cell line HepG2. ShRNA targeting Plk1 almost completely reduced Plk1 expression in HepG2 hepatocellular carcinoma cells, as confirmed by RT-PCR and Western blot. As a consequence, HepG2 cells exhibited reduced proliferation and enhanced apoptosis in vitro. Most importantly, Treatment with Plk shRNA-DOTAP:Chol complex significantly suppressed the growth of HepG2 xenografts, accompanied with phenotypic changes in tumor cells, including proliferation inhibition and apoptosis induction. Our study suggested that shRNA-mediated silencing of Plk1 might be a novel therapeutic approach against human hepatocellular carcinoma by inhibiting tumor cells proliferation and inducing apoptosis.
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