Doxorubicin downregulates cell cycle regulatory hub genes in breast cancer cells.

Breast cancer (BC) is the leading commonly diagnosed cancer in the world, with complex mechanisms underlying its development. There is an urgent need to enlighten key genes as potential therapeutic targets crucial to advancing BC treatment. This study sought to investigate the influence of doxorubicin (DOX) on identified key genes consistent across numerous BC datasets obtained through bioinformatic analysis. To date, a meta-analysis of publicly available coding datasets for expression profiling by array from the Gene Expression Omnibus (GEO) has been carried out. Differentially Expressed Genes (DEGs) identified using GEO2R revealed a total of 23 common DEGs, including nine upregulated genes and 14 downregulated genes among the datasets of three platforms (GPL570, GPL6244, and GPL17586), and the commonly upregulated DEGs, showed significant enrichment in the cell cycle in KEGG analysis. The top nine genes, NUSAP1, CENPF, TPX2, PRC1, ANLN, BUB1B, AURKA, CCNB2, and CDK-1, with higher degree values and MCODE scores in the cytoscape program, were regarded as hub genes. The hub genes were activated in disease states commonly across all the subclasses of BC and correlated with the unfavorable overall survival of BC patients, as verified by the GEPIA and UALCAN databases. qRT-PCR confirmed that DOX treatment resulted in reduced expression of these genes in BC cell lines, which reinforces the evidence that DOX remains an effective drug for BC and suggests that developing modified formulations of doxorubicin to reduce toxicity and resistance, could enhance its efficacy as an effective therapeutic option for BC.

Deregulation of miR-375 Inhibits HOXA5 and Promotes Migration, Invasion, and Cell Proliferation in Breast Cancer.

Breast cancer (BC) is a highly aggressive tumour and one of the women's leading causes of cancer-related deaths in worldwide. MiR-375 overexpressed in BC cells, and its biological relevance is largely unknown. Here in, we explored the function of miR-375 in BC. MicroRNA-375 targets were predicted by online target prediction tools and found that HOXA5 is one of the potential targets. MTT assay was employed to assess the effect of miR-375 on cell proliferation, where migration and invasion transwell assays were applied to detect cell migratory and invasive ability. Besides, relative expression of miR-375 and HOXA5 was measured in BC and HEK-293 cells, and its downstream gene target expressions were evaluated by qRT-PCR and western blot. In this study, we found that miR-375 expression was higher in BC cell lines than in the HEK-293 cell line, whereas HOXA5 expression was significantly lower. Our study showed that exogenous inhibition of miR-375 promoted HOXA5 expression; on the contrary, miR-375 mimics down-regulated HOXA5 expression level. Knockdown of miR-375 expression in BC cells reduces cell proliferation, migration, and invasion by inverse correlation expression of HOXA5. Our findings associated that miR-375 accelerated apoptosis evasion, proliferation, migration, and invasion by targeting HOXA5. In addition, nucleolin interferes in miR-375 biogenesis while silencing of nucleolin significantly reduced miR-375 expression and increased HOXA5 expression in BC. Thus, miR-375/HOXA5 axis may represent a potential therapeutic target for BC treatment.

Dysregulation of miRISC Regulatory Network Promotes Hepatocellular Carcinoma by Targeting PI3K/Akt Signaling Pathway.

Hepatocellular carcinoma (HCC) remains the third leading malignancy worldwide, causing high mortality in adults and children. The neuropathology-associated gene AEG-1 functions as a scaffold protein to correctly assemble the RNA-induced silencing complex (RISC) and optimize or increase its activity. The overexpression of oncogenic miRNAs periodically degrades the target tumor suppressor genes. Oncogenic miR-221 plays a seminal role in the carcinogenesis of HCC. Hence, the exact molecular and biological functions of the oncogene clusters miR-221/AEG-1 axis have not yet been examined widely in HCC. Here, we explored the expression of both miR-221 and AEG-1 and their target/associate genes by qRT-PCR and western blot. In addition, the role of the miR-221/AEG-1 axis was studied in the HCC by flow cytometry analysis. The expression level of the AEG-1 did not change in the miR-221 mimic, and miR-221-transfected HCC cells, on the other hand, decreased the miR-221 expression in AEG-1 siRNA-transfected HCC cells. The miR-221/AEG-1 axis silencing induces apoptosis and G2/M phase arrest and inhibits cellular proliferation and angiogenesis by upregulating p57, p53, RB, and PTEN and downregulating LSF, LC3A, Bcl-2, OPN, MMP9, PI3K, and Akt in HCC cells.

The absence of cellular glucose triggers oncogene AEG-1 that instigates VEGFC in HCC: A possible genetic root cause of angiogenesis.

BACKGROUND AND OBJECTIVE: Astrocyte Elevated Gene-1 (AEG-1) is the master and multi-regulator of the various transcriptional factor primarily regulating chemoresistance, angiogenesis, metastasis, and invasion under the pathological condition, including liver cancer. This study was focused on investigating the process of tumor angiogenesis in liver carcinoma by studying the role of AEG-1 under GD/2DG conditions. METHOD AND RESULTS: The PCR and western blot analysis revealed that glucose depletion (GD) induces the overexpression of AEG-1. Further, it leads to the constant expression of VEGFC through the activation of HIF-1α/CCR7 via the stimulations of PI3K/Akt signaling pathways. GLUT2 is the major transporter of a glucose molecule that is highly participating under GD through the expression of AEG-1 and constantly expresses glucokinase (GCK). The obtained data suggest that AEG-1 act as an angiogenesis and glycolysis regulator by modulating the expression of GCK through HIF-1α and GLUT2. 2-deoxy-D-glucose (2DG) is a glycolysis inhibitor that induces impaired glycolysis and cellular apoptosis by cellular oxidative stress. The administration of 2DG has led to the chemoresistance of AEG-1. CONCLUSION: The total findings of the study judged that disruption of cellular energy metabolism induced by the absence of glucose or the presence of mutant glucose moiety (2DG) promotes the overexpression of AEG-1. The GD/2DG activates the VEGFC by inducing the HIF-1α and CCR7. Moreover, AEG-1 induces the expression of OPN, which regulates metastasis, angiogenesis, and actively participates in protective autophagy by promoting LC3 a/b.

Corrigendum: Dysregulation of miR-375/AEG-1 Axis by Human Papillomavirus 16/18-E6/E7 Promotes Cellular Proliferation, Migration, and Invasion in Cervical Cancer.

[This corrects the article DOI: 10.3389/fonc.2019.00847.].

AEG-1/miR-221 Axis Cooperatively Regulates the Progression of Hepatocellular Carcinoma by Targeting PTEN/PI3K/AKT Signaling Pathway.

Hepatocellular carcinoma (HCC) is the third leading malignancy worldwide, causing mortality in children and adults. AEG-1 is functioned as a scaffold protein for the proper assembly of RNA-induced silencing complex (RISC) to optimize or increase its activity. The increased activity of oncogenic miRNAs leads to the degradation of target tumor suppressor genes. miR-221 is an oncogenic miRNA, that plays a seminal role in carcinogenesis regulation of HCC. However, the molecular mechanism and biological functions of the miR-221/AEG-1 axis have not been investigated extensively in HCC. Here, the expression of miR-221/AEG-1 and their target/associate genes was analyzed by qRT-PCR and Western blot. The role of the miR-221/AEG-1 axis in HCC was evaluated by proliferation assay, migration assay, invasion assay, and flow cytometry analysis. The expression level of miR-221 decreased in AEG-1 siRNA transfected HCC cells. On the other hand, there were no significant expression changes of AEG-1 in miR-221 mimic and miR-221 inhibitor transfected HCC cells and inhibition of miR-221/AEG-1 axis decreased cell proliferation, invasion, migration, and angiogenesis and induced apoptosis, cell cycle arrest by upregulating p57, p53, PTEN, and RB and downregulating LSF, MMP9, OPN, Bcl-2, PI3K, AKT, and LC3A in HCC cells. Furthermore, these findings suggest that the miR-221/AEG-1 axis plays a seminal oncogenic role by modulating PTEN/PI3K/AKT signaling pathway in HCC. In conclusion, the miR-221/AEG-1 axis may serve as a potential target for therapeutics, diagnostics, and prognostics of HCC.

Dysregulation of miR-375/AEG-1 Axis by Human Papillomavirus 16/18-E6/E7 Promotes Cellular Proliferation, Migration, and Invasion in Cervical Cancer.

Cervical Cancer (CC) is a highly aggressive tumor and is one of the leading causes of cancer-related deaths in women. miR-375 was shown to be significantly down-regulated in cervical cancer cells. However, the precise biological functions of miR-375 and the molecular mechanisms underlying its action in CC are largely unknown. miR-375 targets were predicted by bioinformatics target prediction tools and validated using luciferase reporter assay. Herein, we investigated the functional significance of miR-375 and its target gene in CC to identify potential new therapeutic targets. We found that miR-375 expression was significantly downregulated in CC, and astrocyte elevated gene-1 (AEG-1) was identified as a target of miR-375. Our results also showed that ectopic expression of miR-375 suppressed CC cell proliferation, migration, invasion and angiogenesis, and increased the 5-fluorouracil-induced apoptosis and cell cycle arrest in vitro. In contrast, inhibition of miR-375 expression significantly enhanced these functions. Furthermore, HPV - 16 E6/E7 and HPV - 18 E6/E7 significantly down-regulates miR-375 expression in CC. HPV 16/18-E6/E7/miR-375/AEG-1 axis plays an important role in the regulation of cell proliferation, migration, and invasion in CC. Therefore, targeting miR-375/AEG-1 mediated axis could serve as a potential therapeutic target for CC.

Knockdown of human telomerase reverse transcriptase induces apoptosis in cervical cancer cell line.

Background & objectives: : Human telomerase reverse transcriptase (hTERT) is the catalytic subunit of telomerase enzyme that maintains telomere ends by the addition of telomeric repeats to the ends of chromosomal DNA, and that may generate immortal cancer cells. Hence, the activity of telomerase is raised in cancer cells including cervical cancer. The present study aimed to validate the unique siRNA loaded chitosan coated poly-lactic-co-glycolic acid (PLGA) nanoparticle targeting hTERT mRNA to knock down the expression of hTERT in HeLa cells. Methods: : The siRNA loaded chitosan coated polylactic-co-glycolic acid (PLGA) nanoparticles were synthesized by double emulsion solvent diffusion method. The characterization of nano-formulation was done to determine efficient siRNA delivery. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot were performed to evaluate silencing efficiency of nano-formulation. Results: :Size, zeta potential and encapsulation efficiency of nanoparticles were 249.2 nm, 12.4 mV and 80.5 per cent, respectively. Sustained release of siRNA from prepared nanoparticle was studied for 72 h by ultraviolet method. Staining assays were performed to confirm senescence and apoptosis. Silencing of hTERT mRNA and protein expression were analyzed in HeLa cells by RT-PCR and Western blot. Interpretation & conclusions: : The findings showed that biodegradable chitosan coated PLGA nanoparticles possessed an ability for efficient and successful siRNA delivery. The siRNA-loaded PLGA nanoparticles induced apoptosis in HeLa cells. Further studies need to be done with animal model.

Parthenolide induces apoptosis and autophagy through the suppression of PI3K/Akt signaling pathway in cervical cancer.

OBJECTIVE: To investigate the effect of parthenolide on apoptosis and autophagy and to study the role of the PI3K/Akt signaling pathway in cervical cancer. RESULTS: Parthenolide inhibits HeLa cell viability in a dose dependent-manner and was confirmed by MTT assay. Parthenolide (6 µM) induces mitochondrial-mediated apoptosis and autophagy by activation of caspase-3, upregulation of Bax, Beclin-1, ATG5, ATG3 and down-regulation of Bcl-2 and mTOR. Parthenolide also inhibits PI3K and Akt expression through activation of PTEN expression. Moreover, parthenolide induces generation of reactive oxygen species that leads to the loss of mitochondrial membrane potential. CONCLUSION: Parthenolide induces apoptosis and autophagy-mediated growth inhibition in HeLa cells by suppressing the PI3K/Akt signaling pathway and mitochondrial membrane depolarization and ROS generation. Parthenolide may be a potential therapeutic agent for the treatment of cervical cancer.