Inhibition of E2F1 activity and cell cycle progression by arsenic via retinoblastoma protein

Single-cell sequencing revealed metabolic reprogramming and its transcription factor regulatory network in prostate cancer

BACKGROUND/AIMS

Prostate cancer is the most frequently diagnosed cancer among men in the United States and is the second leading cause of cancer-related deaths in men. The incidence of prostate cancer is gradually rising due to factors such as aging demographics and changes in dietary habits. The objective of this study is to investigate the metabolic reprogramming changes occurring in prostate cancer and identify potential therapeutic targets.

METHODS

In this study, we utilized single-cell sequencing to comprehensively characterize the alterations in metabolism and the regulatory role of transcription factors in various subtypes of prostate cancer.

RESULTS

In comparison to benign prostate tissue, prostate cancer displayed substantial metabolic variations, notably exhibiting heightened activity in fatty acid metabolism and cholesterol metabolism. This metabolic reprogramming not only influenced cellular energy utilization but also potentially impacted the activity of the androgen receptor (AR) pathway through the synthesis of endogenous steroid hormones. Through our analysis of transcription factor activity, we identified the crucial role of SREBPs, which are transcription factors associated with lipid metabolism, in prostate cancer. Encouragingly, the inhibitor Betulin effectively suppresses prostate cancer growth, highlighting its potential as a therapeutic agent for prostate cancer treatment.

Mechanistic update of Trisenox in blood cancer

Acute promyelocytic leukemia (APL)/blood cancer is M3 type of acute myeloid leukemia (AML) formed inside bone marrow through chromosomal translocation mutation usually between chromosome 15 & 17. It accounts around 10% cases of AML worldwide. Trisenox (TX/ATO) is used in chemotherapy for treatment of all age group of APL patients with highest efficacy and survival rate for longer period. High concentration of TX inhibits growth of APL cells by diverse mechanism however, it cures only PML-RARα fusion gene/oncogene containing APL patients. TX resistant APL patients (different oncogenic make up) have been reported from worldwide. This review summarizes updated mechanism of TX action via PML nuclear bodies formation, proteasomal degradation, autophagy, p53 activation, telomerase activity, heteromerization of pRb & E2F, and regulation of signaling mechanism in APL cells. We have also provided important information of combination therapy of TX with other molecules mechanism of action in acute leukemia cells. It provides updated information of TX action for researcher which may help finding new target for further research in APL pathophysiology or new TX resistant APL patients drug designing.

Upregulation of miR-20a-5p as the Potential MicroRNA Marker in Red Blood Cell Storage Lesion

Background

Packed red blood cells (PRBCs) can be preserved for 42 days, and stored PRBCs have slow, dangerous changes over time during storage. miRNA is approximately 22 nucleotides long, a small single-stranded noncoding RNA molecule. miRNA guides by pairing bases with their downstream target mRNA to regulate negative expression. They are essential in many life processes, including cell differentiation, proliferation, and apoptosis. Therefore, miRNA alterations may represent possible biomarkers of PRBC storage lesions. This study is aimed at validating the miR-20a-5p in PRBC storage. Study Design and Methods. A total of 20 PRBC samples were divided into day 1 and day 20 storage groups. Total miRNA was extracted and quantified by probe-based RT-qPCR assays to explore the potential role of miRNAs in PRBC storage lesions.

Results

Upregulated miR-20a-5p in PRBC storage on day 20 compared to day 1. MiR-20a-5p promoted cell survival, which may affect the downstream regulation and decrease PRBC viability in prolonged storage.

Conclusion

On this basis, this detection may help to assess the quality of stored PRBCs.

N-linked glycosylation is essential for anti-tumor activities of KIAA1324 in gastric cancer

KIAA1324 is a transmembrane protein largely reported as a tumor suppressor and favorable prognosis marker in various cancers, including gastric cancer. In this study, we report the role of N-linked glycosylation in KIAA1324 as a functional post-translational modification (PTM). Loss of N-linked glycosylation eliminated the potential of KIAA1324 to suppress cancer cell proliferation and migration. Furthermore, we demonstrated that KIAA1324 undergoes fucosylation, a modification of the N-glycan mediated by fucosyltransferase, and inhibition of fucosylation also significantly suppressed KIAA1324-induced cell growth inhibition and apoptosis of gastric cancer cells. In addition, KIAA1324-mediated apoptosis and tumor regression were inhibited by the loss of N-linked glycosylation. RNA sequencing (RNAseq) analysis revealed that genes most relevant to the apoptosis and cell cycle arrest pathways were modulated by KIAA1324 with the N-linked glycosylation, and Gene Regulatory Network (GRN) analysis suggested novel targets of KIAA1324 for anti-tumor effects in the transcription level. The N-linked glycosylation blockade decreased protein stability through rapid proteasomal degradation. The non-glycosylated mutant also showed altered localization and lost apoptotic activity that inhibits the interaction between GRP78 and caspase 7. These data demonstrate that N-linked glycosylation of KIAA1324 is essential for the suppressive role of KIAA1324 protein in gastric cancer progression and indicates that KIAA1324 may have anti-tumor effects by targeting cancer-related genes with N-linked glycosylation. In conclusion, our study suggests the PTM of KIAA1324 including N-linked glycosylation and fucosylation is a necessary factor to consider for cancer prognosis and therapy improvement.

Microneedle Patch Delivery of PROTACs for Anti-Cancer Therapy

Proteolysis-targeting chimera (PROTAC) is an emerging technique for degrading disease-related proteins. However, the current PROTACs suffer from inadequate solubility and lack of organ targeting, which has hampered their druggability. Herein, we report direct and sustained delivery of PROTACs using microneedle patches to the diseased tissues. In this study, we use an estrogen receptor alpha (ERα)-degrading PROTAC, ERD308, to treat ER-positive breast cancer. A pH-sensitive micelle, MPEG-poly(β-amino ester) (MPEG-PAE), is used to encapsulate ERD308 along with an FDA-approved CDK4/6 inhibitor, Palbociclib (Pal), before loading into biodegradable microneedle patches. These patches enable prolonged drug release into deep tumors, maintaining therapeutic levels for at least 4 days, with an excellent drug retention rate of over 87% in tumors. ERD308 released from the microneedle patches can sufficiently degrade ERα in MCF7 cells. Co-administration of ERD308 and Palbociclib exhibits excellent efficacy by over 80% tumor reduction as well as a good safety profile. Our work demonstrates the feasibility and proof-of-concept therapeutic potential of using microneedle patches to directly deliver PROTACs into tumors.

The potential of Lycium barbarum miR166a in kidney cancer treatment

Predator species of animal can absorb plant microRNA that can regulate target gene expression and physiological function across species. The herb Lycium barbarum, a traditional Chinese medicine, has a wide range of antitumor effects. However, there are no reports on the effects of microRNA derived from it on the cross-border regulation of renal cell carcinoma (RCC). We performed in vitro and in vivo experiments to explore the role and mechanism of the L. barbarum-derived microRNA miR166a (Lb-miR166a) in cross-border regulation of RCC. Our mRNA sequencing analysis showed that Lb-miR166a regulates the expression of various genes in tumor cells, including 1232 upregulated genes and 581 downregulated genes, which were enriched to 1094 Gene Ontology entries and 43 Kyoto Encyclopedia of Genes and Genomes pathways. In vitro cell experiments confirmed that Lb-miR166a can inhibit the proliferation of RCC cells, promote the apoptosis of tumor cells, and inhibit the invasion and metastasis of tumor cells by regulating the expression of related genes. Furthermore, our in vivo tumor-bearing experiment showed that subcutaneous tumor formation volume decreased in Lb-miR166a mice, along with the number of liver metastases. This study elucidates the role and mechanism of Lb-miR166a in RCC treatment (Fig. 1). Our results further mechanistically confirm the antitumor properties of L. barbarum. Our study may contribute to the clinical development of a targeted drug for RCC treatment.

Glucocorticoid receptor hypersensitivity enhances inflammatory signaling and inhibits cell cycle progression in porcine PBMCs

The consequences of glucocorticoid receptor (GR) hypersensitivity during infection have so far received little attention. We previously discovered that a natural gain-of-function Ala610Val substitution in the porcine GR aggravates response of pigs to lipopolysaccharide (LPS)-induced endotoxemia, which can be alleviated by dexamethasone (DEX) pretreatment. In this work, we investigated the relevant molecular basis of these phenotypes by transcriptomic profiling of porcine peripheral blood mononuclear cells (PBMCs) carrying different GR genotypes, in unstimulated conditions or in response to DEX and/or LPS in vitro. The Val allele differentially regulated abunda+nt genes in an additive-genetic manner. A subset of more than 200 genes was consistently affected by the substitution across treatments. This was associated with upregulation of genes related i.a. to endo-lysosomal system, lipid and protein catabolism, and immune terms including platelet activation, and antigen presentation, while downregulated genes were mainly involved in cell cycle regulation. Most importantly, the set of genes constitutively upregulated by Val includes members of the TLR4/LPS signaling pathway, such as LY96. Consequently, when exposing PBMCs to LPS treatment, the Val variant upregulated a panel of additional genes related to TLR4 and several other pattern recognition receptors, as well as cell death and lymphocyte signaling, ultimately amplifying the inflammatory responses. In contrast, when stimulated by DEX treatment, the Val allele orchestrated several genes involved in anti-inflammatory responses during infection. This study provides novel insights into the impact of GR hypersensitivity on the fate and function of immune cells, which may be useful for endotoxemia therapy.

Aspirin Mediates Its Antitumoral Effect Through Inhibiting PTTG1 in Pituitary Adenoma

CONTEXT

DNA demethylation and inhibitory effects of aspirin on pituitary cell proliferation have been demonstrated.

OBJECTIVE

Our aim was to clarify the molecular mechanisms behind the aspirin-related effects in pituitary cells.

METHODS

DNA methylome and whole transcriptome profile were investigated in RC-4B/C and GH3 pituitary cell lines upon aspirin treatment. Effects of aspirin and a demethylation agent, decitabine, were further tested in vitro. PTTG1 expression in 41 human PitNET samples and whole genome gene and protein expression data of 76 PitNET and 34 control samples (available in Gene Expression Omnibus) were evaluated.

RESULTS

Aspirin induced global DNA demethylation and consequential transcriptome changes. Overexpression of Tet enzymes and their cofactor Uhrf2 were identified behind the increase of 5-hydroxymethylcytosine (5hmC). Besides cell cycle, proliferation, and migration effects that were validated by functional experiments, aspirin increased Tp53 activity through p53 acetylation and decreased E2f1 activity. Among the p53 controlled genes, Pttg1 and its interacting partners were downregulated upon aspirin treatment by inhibiting Pttg1 promoter activity. 5hmC positively correlated with Tet1-3 and Tp53 expression, and negatively correlated with Pttg1 expression, which was reinforced by the effect of decitabine. Additionally, high overlap (20.15%) was found between aspirin-regulated genes and dysregulated genes in PitNET tissue samples.

CONCLUSION

A novel regulatory network has been revealed, in which aspirin regulated global demethylation, Tp53 activity, and Pttg1 expression along with decreased cell proliferation and migration. 5hmC, a novel tissue biomarker in PitNET, indicated aspirin antitumoral effect in vitro as well. Our findings suggest the potential beneficial effect of aspirin in PitNET.

Unique Transcriptomic Changes Underlie Hormonal Interactions During Mammary Histomorphogenesis in Female Pigs

Successful lactation and the risk for developing breast cancer depend on growth and differentiation of the mammary gland (MG) epithelium that is regulated by ovarian steroids (17β-estradiol [E] and progesterone [P]) and pituitary-derived prolactin (PRL). Given that the MG of pigs share histomorphogenic features present in the normal human breast, we sought to define the transcriptional responses within the MG of pigs following exposure to all combinations of these hormones. Hormone-ablated female pigs were administered combinations of E, medroxyprogesterone 17-acetate (source of P), and either haloperidol (to induce PRL) or 2-bromo-α-ergocryptine. We subsequently monitored phenotypic changes in the MG including mitosis, receptors for E and P (ESR1 and PGR), level of phosphorylated STAT5 (pSTAT5), and the frequency of terminal ductal lobular unit (TDLU) subtypes; these changes were then associated with all transcriptomic changes. Estrogen altered the expression of approximately 20% of all genes that were mostly associated with mitosis, whereas PRL stimulated elements of fatty acid metabolism and an inflammatory response. Several outcomes, including increased pSTAT5, highlighted the ability of E to enhance PRL action. Regression of transcriptomic changes against several MG phenotypes revealed 1669 genes correlated with proliferation, among which 29 were E inducible. Additional gene expression signatures were associated with TDLU formation and the frequency of ESR1 or PGR. These data provide a link between the hormone-regulated genome and phenome of the MG in a species having a complex histoarchitecture like that in the human breast, and highlight an underexplored synergy between the actions of E and PRL during MG development.

Effects of HMGA2 gene silencing on cell cycle and apoptosis in the metastatic renal carcinoma cell line ACHN

Objective

To explore the role of high mobility group AT-hook 2 (HMGA2) in the regulation of the cell cycle and apoptosis.

Methods

The renal carcinoma cell line ACHN was transiently transfected with small interfering RNA to knock down the expression of the HMGA2 gene. Cell cycle analysis was undertaken using flow cytometry. The mRNA and protein levels of HMGA2, E2F transcription factor 1 (E2F1), cyclin D1, cyclin dependent kinase 6 (CDK6), B-cell lymphoma-2 (Bcl-2), caspase-3 and caspase-9 were analysed using reverse transcription quantitative real-time polymerase chain reaction and Western blot analysis.

Results

The mRNA and protein levels of HMGA2 were significantly higher in renal carcinoma cell lines compared with the human renal proximal tubular epithelial cell line HKC. After HMGA2 gene-specific silencing, more cells entered the G₀/G₁ phase, while fewer cells entered the G₂/M phase; and the cells exhibited early and late apoptosis. HMGA2 gene-specific silencing significantly reduced the mRNA and protein levels of E2F1, cyclin D1, CDK6 and Bcl-2; and increased the mRNA and protein levels of caspase-3 and caspase-9.

Conclusion

The HMGA2 gene may be involved in the tumorigenesis and development of renal cancer, thus inhibiting HMGA2 gene expression might provide a potential therapeutic target in the future.

MiR-423-5p activated by E2F1 promotes neovascularization in diabetic retinopathy by targeting HIPK2

BACKGROUND

Diabetic retinopathy (DR) is a diabetic complication and the primary cause of blindness in the world. However, the treatments of DR are challenging given its complicated pathogenesis. Here, we investigated the molecular mechanisms of DR by focusing on the function of E2F1/miR-423-5p/HIPK2/HIF1α/VEGF axis.

METHODS

Cultured retinal endothelial cells (hRMECs, hRECs) were treated with 25 mM glucose to mimic the high glucose-induced DR in vitro. Streptozotocin (STZ) was injected into mice to induce DR in mice. qRT-PCR, western blotting, immunohistochemistry, and ELISA were employed to measure levels of E2F1, miR-423-5p, HIPK2, HIF1α, and VEGF. H&E staining was utilized to examine retinal neovascularization. CCK-8 assay, transwell assay, and vascular tube formation assay were used to assess the cell viability, migration, and angiogenesis. Dual luciferase assay was performed to validate interactions between E2F1 and miR-423-5p, miR-423-5p and HIPK2.

RESULTS

HG treatment increased the cell viability, migration, and angiogenesis accompanied by upregulation of E2F1, miR-423-5p, HIF1α, and VEGF levels, but reduction in HIPK2 expression. Knockdown of E2F1 or miR-423-5p suppressed the HG-induced increases in cell viability, migration, and angiogenesis. E2F1 transcriptionally activated miR-423-5p expression and miR-423-5p mimics blocked the effects of E2F1 knockdown on angiogenesis. Moreover, miR-423-5p directly targeted HIPK2 to disinhibit HIF1α/VEGF signaling. Knockdown of HIPK2 reversed the effects of miR-423-5p inhibitor on cell viability, migration, and angiogenesis. Knockdown of E2F1 suppressed neovascularization during DR in vivo.

CONCLUSIONS

E2F1 activates miR-423-5p transcription during DR to promote angiogenesis via suppressing HIPK2 expression to disinhibit HIF1α/VEGF signaling. Strategies targeting E2F1/miR-423-5p/HIPK2 axis could be potentially used for DR treatment.

Targeting cyclin-dependent kinase 4/6 as a therapeutic approach for mucosal melanoma

Mucosal melanoma is a rare but devastating subtype of melanoma which typically has a worse prognosis than other melanoma subtypes. Large-scale next-generation sequencing studies, including our recent research, have also proved that the molecular landscape and potential oncogenic drivers of mucosal melanoma remain distinct from that of cutaneous melanoma. Recently, a number of selective cyclin-dependent kinase 4 (CDK4)/6 inhibitors have been approved for clinical application in breast cancer or entered phase III clinical trial in other solid tumors. Additionally, we have revealed that the dysregulation of cell cycle progression, caused by CDK4 amplification, is a key genetic feature in half of mucosal melanoma and targeting of CDK4 in selected mucosal melanoma patients is a potentially promising direction for precision cancer treatment by using molecular-characterized mucosal melanoma patient-derived-xenograft models. This review summarizes the current literature regarding CDK4/6 dysregulation in mucosal melanoma, preclinical and clinical studies of CDK4/6 inhibitors and potential combinational strategies in treating mucosal melanoma.

Arsenic co-carcinogenesis: Inhibition of DNA repair and interaction with zinc finger proteins

Arsenic is widely present in the environment and is associated with various population health risks including cancers. Arsenic exposure at environmentally relevant levels enhances the mutagenic effect of other carcinogens such as ultraviolet radiation. Investigation on the molecular mechanisms could inform the prevention and intervention strategies of arsenic carcinogenesis and co-carcinogenesis. Arsenic inhibition of DNA repair has been demonstrated to be an important mechanism, and certain DNA repair proteins have been identified to be extremely sensitive to arsenic exposure. This review will summarize the recent advances in understanding the mechanisms of arsenic carcinogenesis and co-carcinogenesis, including DNA damage induction and ROS generation, particularly how arsenic inhibits DNA repair through an integrated molecular mechanism which includes its interactions with sensitive zinc finger DNA repair proteins.

Novel chemotherapeutic agent FX-9 activates NF-κB signaling and induces G1 phase arrest by activating CDKN1A in a human prostate cancer cell line

Background

The aminoisoquinoline FX-9 shows pro-apoptotic and antimitotic effects against lymphoblastic leukemia cells and prostate adenocarcinoma cells. In contrast, decreased cytotoxic effects against non-neoplastic blood cells, chondrocytes, and fibroblasts were observed. However, the actual FX-9 molecular mode of action is currently not fully understood.

Methods

In this study, microarray gene expression analysis comparing FX-9 exposed and unexposed prostate cancer cells (PC-3 representing castration-resistant prostate cancer), followed by pathway analysis and gene annotation to functional processes were performed. Immunocytochemistry staining was performed with selected targets.

Results

Expression analysis revealed 0.83% of 21,448 differential expressed genes (DEGs) after 6-h exposure of FX-9 and 0.68% DEGs after 12-h exposure thereof. Functional annotation showed that FX-9 primarily caused an activation of inflammatory response by non-canonical nuclear factor-kappa B (NF-κB) signaling. The 6-h samples showed activation of the cell cycle inhibitor CDKN1A which might be involved in the secondary response in 12-h samples. This secondary response predominantly consisted of cell cycle-related changes, with further activation of CDKN1A and inhibition of the transcription factor E2F1, including downstream target genes, resulting in G1-phase arrest. Matching our previous observations on cellular level senescence signaling pathways were also found enriched. To verify these results immunocytochemical staining of p21 Waf1/Cip1 (CDKN1A), E2F1 (E2F1), PAI-1 (SERPNE1), and NFkB2/NFkB p 100 (NFKB2) was performed. Increased expression of p21 Waf1/Cip1 and NFkB2/NFkB p 100 after 24-h exposure to FX-9 was shown. E2F1 and PAI-1 showed no increased expression.

Conclusions

FX-9 induced G1-phase arrest of PC-3 cells through activation of the cell cycle inhibitor CDKN1A, which was initiated by an inflammatory response of noncanonical NF-κB signaling.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08836-y.

Arsenic trioxide reduces the expression of E2F1, cyclin E, and phosphorylation of PI3K signaling molecules in acute leukemia cells

Arsenic trioxide (ATO) has been used for the treatment of acute promyelocytic leukemia (APL). Although ATO modulates cell cycle progression and apoptosis in APL cells, its exact mechanism of action remains elusive. In this research, we investigated its effects on E2F1, cyclin E, p53, pRb, and PI3K signaling molecules by western blotting, immunocytochemistry and/or confocal imaging. We found that ATO inhibited the proliferation of APL cells through down-regulation of E2F1 and cyclin E expression, and stimulation of pRb. It also reduced the interaction of pRb and E2F1with binding to the E2F1 promoter, by stimulating pRb association. ATO also effected the phosphorylation of pRb at S608 and T373 residues and association of E2F1, pRb, and p53, simultaneously. However, in p53-knockdown NB4 cells, ATO did not significantly reduce E2F1 and cyclin E expression. Our findings demonstrate that ATO inhibits APL cell growth through reduced expression of E2F1, cyclin E, and stimulation of pRb. It also effected both interaction and association of E2F1, pRb, and p53 by phosphorylation of pRb at T373 and S608 residues and reduced phosphorylation of PI3K signaling molecules. This novel mode of action of ATO in APL cells may be useful for designing new APL drugs.

Umbelliferone Ameliorates Benign Prostatic Hyperplasia by Inhibiting Cell Proliferation and G1/S Phase Cell Cycle Progression through Regulation of STAT3/E2F1 Axis

Umbelliferone (UMB), also known as 7-hydroxycoumarin, is a derivative of coumarin, which is widely found in many plants such as carrots, coriander, and garden angelica. Although many studies have already revealed the various pharmacological properties of UMB, its effect on benign prostatic hyperplasia (BPH) remains unclear. Therefore, the present study aimed to elucidate the underlying mechanism of the anti-proliferative effect of UMB in a human benign prostatic hyperplasia cell line (BPH-1), as well as its ameliorative effect on BPH in testosterone propionate (TP)-induced rats. The results showed that UMB exerts an anti-proliferative effect in BPH-1 cells by modulating the signal transducer and activator of transcription 3 (STAT3)/E2F transcription factor 1 (E2F1) axis. UMB treatment not only inhibited androgen/androgen receptor (AR) signaling-related markers, but also downregulated the overexpression of G1/S phase cell cycle-related markers. In TP-induced rats, UMB administration demonstrated an anti-BPH effect by significantly reducing prostate size, weight, and epithelial thickness. In addition, UMB suppressed cell proliferation by reducing the expression of proliferating cell nuclear antigen (PCNA) and p-STAT3 (Tyr 705) in prostate tissue following TP injection. These findings suggest that UMB has pharmacological effects against BPH.

Gypenoside LI arrests the cell cycle of breast cancer in G0/G1 phase by down-regulating E2F1

ETHNOPHARMACOLOGICAL RELEVANCE

Gynostemma pentaphyllum (Thunb.) Makino, a traditional medicine in China, has been widely used for the treatment of various diseases. Gypenoside LI (Gyp LI) is a major constituent from steamed G. pentaphyllum. Previous studies have shown that gypnenoside LI possess inhibitory effect on the growth of many cancer cells. However, its pharmacological effect in breast cancer and the mechanism have not been reported yet.

AIM OF THE STUDY

To investigate the anti-breast cancer activity of gypenoside LI and underlying mechanisms of gypenoside LI in MDA-MB-231 and MCF-7 cells.

MATERIAL/METHODS

The cytotoxicity of gypenoside LI was determined by MTT, colony-formation and three-dimensional spheroid assay. The migration, cell apoptosis and the cell cycle were investigated through cell morphology observation, flow cytometry analysis and key proteins detection. The anticancer mechanisms of gypenoside LI were detected by RNA sequencing (RNA-seq) and Gene Set Enrichment Analysis (GSEA) transcriptome analysis.

RESULTS

Gypenoside LI inhibited cell proliferation, migration, induced cell apoptosis and cell cycle arrest. Gypenoside LI arrested cell cycle at G0/G1 phase by regulating E2F1. It also inhibited tumor proliferation by regulating the expression of ERCC6L. Interestingly, we found that E2F1 siRNA also down-regulated the expression of ERCC6L. Gypenoside LI showed potential anti-breast cancer cells activity, especially on triple-negative breast cancer cells.

CONCLUSIONS

These data indicate that gypenoside LI could inhibit human breast cancer cells through inhibiting proliferation and migration, inducing apoptosis, arresting cell cycle at G0/G1 phase by regulating E2F1. It could be used as potential multi-target chemopreventive agents for cancer.

Overexpression of CCNE1 confers a poorer prognosis in triple-negative breast cancer identified by bioinformatic analysis

Background

Triple-negative breast cancer (TNBC) is a major subtype of breast cancer. Due to the lack of effective therapeutic targets, the prognosis is poor. In order to find an effective target, despite many efforts, the molecular mechanisms of TNBC are still not well understood which remain to be a profound clinical challenge.

Methods

To identify the candidate genes in the carcinogenesis and progression of TNBC, microarray datasets GSE36693 and GSE65216 were downloaded from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) were identified, and functional and pathway enrichment analyses were performed using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases via DAVID. We constructed the protein-protein interaction network (PPI) and performed the module analysis using STRING and Cytoscape. Then, we reanalyzed the selected DEG genes, and the survival analysis was performed using cBioportal.

Results

A total of 140 DEGs were identified, consisting of 69 upregulated genes and 71 downregulated genes. Three hub genes were upregulated among the selected genes from PPI, and biological process analysis uncovered the fact that these genes were mainly enriched in p53 pathway and the pathways in cancer. Survival analysis showed that only CCNE1 may be involved in the carcinogenesis, invasion, or recurrence of TNBC. The expression levels of CCNE1 were significantly higher in TNBC cells than non-TNBC cells that were detected by qRT-PCR (P < 0.05).

Conclusion

CCNE1 could confer a poorer prognosis in TNBC identified by bioinformatic analysis and plays key roles in the progression of TNBC which may contribute potential targets for the diagnosis, treatment, and prognosis assessment of TNBC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02200-x.

Transcriptional E2F1/2/3/6 as potential prognostic biomarkers in cutaneous melanoma

Although the abnormal expression of members of the E2F family has been reported to participate in carcinogenesis in many human types of cancer, the bioinformatics role of the E2F family in melanoma is unknown. This research was designed to detect the expression, methylation, prognostic value and potential effects of the E2F family in melanoma. We investigated E2F family mRNA expression from the Oncomine and GEPIA databases and their methylation status in the MethHC database. Meanwhile, we detected the relative E2F family expression levels by qPCR and immunohistochemistry. Kaplan-Meier Plotter was used to draw survival analysis charts, and gene functional enrichment analyses were applied through cBioPortal database analysis. E2F1/2/3/4/5/6 mRNA and proteins were clearly upregulated in cutaneous melanoma patients, and high expression levels of E2F1/2/3/6 were statistically related to high methylation levels. Increased mRNA expression of E2F1/2/3/6 was related to lower overall survival rates (OS) and disease-free survival (DFS) in cutaneous melanoma cases. Meanwhile, E2F1/2/3/6 carried out these effects through regulating multiple signaling pathways, including the MAPK, PI3K-Akt and p53 signaling pathways. Taking together, our findings suggest that E2F1/2/3/6 could act as potential targets for precision therapy in cutaneous melanoma patients.

ERINA Is an Estrogen-Responsive LncRNA That Drives Breast Cancer through the E2F1/RB1 Pathway

Resistance to therapeutic drugs is a major challenge in the treatment of cancers, including breast cancer. Long noncoding RNAs (lncRNA) are known to have diverse physiologic and pathophysiologic functions, including in cancer. In searching for lncRNA responsible for cancer drug resistance, we identified an intergenic lncRNA ERINA (estrogen inducible lncRNA) as a novel lncRNA highly expressed in multiple cancer types, especially in estrogen receptor-positive (ER⁺) breast cancers. Expression of ERINA was inversely correlated with survival of patients with ER⁺ breast cancer and sensitivity to CDK inhibitor in breast cancer cell lines. Functional characterization established ERINA as an oncogenic lncRNA, as knockdown of ERINA in breast cancer cells inhibited cell-cycle progression and tumor cell proliferation in vitro and xenograft tumor growth in vivo. In contrast, overexpression of ERINA promoted cell growth and cell-cycle progression. ERINA promoted cell-cycle progression by interacting with the E2F transcription factor 1 (E2F1), which prevents the binding of E2F1 to the tumor suppressor retinoblastoma protein 1 (RB1). ERINA also functioned as an estrogen and ER-responsive gene, and an intronic ER-binding site was identified as an enhancer that mediates the transactivation of ERINA. In summary, ERINA is an estrogen-responsive oncogenic lncRNA that may serve as a novel biomarker and potential therapeutic target in breast cancer. SIGNIFICANCE: These findings identify ERINA as an estrogen-responsive, oncogenic lncRNA, whose elevated expression may contribute to drug resistance and poor survival of patients with ER⁺ breast cancer.

An updated review of the H19 lncRNA in human cancer: molecular mechanism and diagnostic and therapeutic importance

Accumulating evidence has reported that H19 long non-coding RNA (lncRNA) expression level is deregulated in human cancer. It has been also demonstrated that de-regulated levels of H19 could affect cancer biology by various mechanisms including microRNA (miRNA) production (like miR-675), miRNA sponging and epigenetic modifications. Furthermore, lncRNA could act as a potential diagnosis and prognosis biomarkers and also a candidate therapeutic approach for different human cancers. In this narrative review, we shed light on the molecular mechanism of H19 in cancer development and pathogenesis. Moreover, we discussed the expression pattern and diagnostic and therapeutic importance of H19 as a potential biomarker in a range of human malignancies from breast to osteosarcoma cancer.

Comparison of the therapeutic effects of lobaplatin and carboplatin on retinoblastoma in vitro and in vivo

Retinoblastoma (RB) is one of the most aggressive malignancies affecting infants and children. Platinum drugs are commonly used in the treatment of RB; however, their efficacy is often compromised by drug resistance and severe toxicity. The present study aimed to investigate and compare the toxicity and antitumor activity of the third-generation platinum drugs, carboplatin and lobaplatin, in vitro and in vivo. The Y79 RB cell line was treated with carboplatin or lobaplatin in vitro and then used to establish xenografts in immunodeficient nude mice in vivo; the effects of pharmacological doses of these drugs were then assessed. High concentrations of carboplatin and lobaplatin markedly inhibited Y79 RB cell proliferation in vitro. In addition, the lobaplatin group exhibited higher proportions of early-stage apoptotic cells than the carboplatin group, while no significant differences in the proportions of cells in the S phase were observed between the 2 groups, as shown by flow cytometry. Significant changes in the E2F1/Cdc25a/Cdk2 pathway in the RB cells were detected by RNA-seq following carboplatin or lobaplatin intervention. RT-qPCR, immunofluorescence and immunohistochemical analyses in vivo and in vitro demonstrated that the trends of drug-induced inhibition of tumor pathological changes may have been regulated through the E2F1/Cdc25a/Cdk2 pathway, and that lobaplatin was more effective than carboplatin in controlling tumors in vivo. On the whole, the findings of the present study demonstrate that lobaplatin is associated with lower cytotoxicity and exerts more prominent therapeutic effects than carboplatin on Y79 RB cells in vitro and in mice in vivo.

Circular RNA circ-CSPP1 regulates CCNE2 to facilitate hepatocellular carcinoma cell growth via sponging miR-577

Objective

Circ-centro-some/spindle pole-associated protein (CSPP1) has been confirmed to be characterized in diverse human malignancies and its ectopic expression may regulate tumor progression and development. However, in hepatocellular carcinoma (HCC), its biological role, clinical significance and molecular mechanism are still unclear.

Methods

Circ-CSPP1 expression and its prognostic values in HCC tissues were detected by qRT-PCR or in situ hybridization (ISH), and enriched by using Rnase R. The functional experiments (Circ-CSPP1 was overexpressed or knocked down) were performed in HCC cells. The HCC cell growth was analyzed by CCK-8 assay, transwell, wound healing and colony formation assays. The interation between circ-CSPP1 and miR-577/miR-577 and cyclin E2 (CCNE2) were determined by dual luciferase assay or RNA binding protein immunoprecipitation (RIP) assay. The RNA fluorescence in situ hybridization (FISH) assay was used to detect the subcellular distribution. Finally, an in vivo nude mouse tumor model was constructed.

Results

In HCC patients and cells, circ-CSPP1 was aberrantly expressed, and its upregulation predicted poor prognosis, and closely correlated with tumor size and TNM stage. Circ-CSPP1 resisted RnaseR digestion, indicating it is a circular RNA structure. Moreover, overexpression of circ-CSPP1 promoted HCC cell viability, colony formation, migration, and invasion in vitro. Knockdown of circ-CSPP1 showed contrary results. Circ-CSPP1 acts as a miR-577 sponge and positively regulated the target of miR-577, CCNE2. Besides, miR-577 inhibitor rescued the suppressive effects of circ-CSPP1 knockdown on HCC cell growth, whereas was completely reversed by silencing of CCNE2. Finally, the in vivo experiments confirmed that circ-CSPP1 knockdown regulated xenograft tumor volume and downregulated CCNE2, p-Rb, E2F1 and c-myc expression.

Conclusion

These findings revealed that circ-CSPP1 contributed to HCC progression by positively regulating CCNE2 via miR-577, thus established its potential as new a prognostic and therapeutic marker for HCC patients.

Role of RB1 in human embryonic stem cell-derived retinal organoids

Three-dimensional (3D) organoid models derived from human pluripotent stem cells provide a platform for studying human development and understanding disease mechanisms. Most studies that examine biallelic inactivation of the cell cycle regulator Retinoblastoma 1 (RB1) and the link to retinoblastoma is in mice, however, less is known regarding the pathophysiological role of RB1 during human retinal development. To study the role of RB1 in early human retinal development and tumor formation, we generated retinal organoids from CRISPR/Cas9-derived RB1-null human embryonic stem cells (hESCs). We showed that RB is abundantly expressed in retinal progenitor cells in retinal organoids and loss of RB1 promotes S-phase entry. Furthermore, loss of RB1 resulted in widespread apoptosis and reduced the number of photoreceptor, ganglion, and bipolar cells. Interestingly, RB1 mutation in retinal organoids did not result in retinoblastoma formation in vitro or in the vitreous body of NOD/SCID immunodeficient mice. Together, our work identifies a crucial function for RB1 in human retinal development and suggests that RB1 deletion alone is not sufficient for tumor development, at least in human retinal organoids.

Erythrocyte Membrane-Coated Arsenic Trioxide-Loaded Sodium Alginate Nanoparticles for Tumor Therapy

Arsenic trioxide (ATO) has a significant effect on the treatment of acute promyelocytic leukemia (APL) and advanced primary liver cancer, but it still faces severe side effects. Considering these problems, red blood cell membrane-camouflaged ATO-loaded sodium alginate nanoparticles (RBCM-SA-ATO-NPs, RSANs) were developed to relieve the toxicity of ATO while maintaining its efficacy. ATO-loaded sodium alginate nanoparticles (SA-ATO-NPs, SANs) were prepared by the ion crosslinking method, and then RBCM was extruded onto the surface to obtain RSANs. The average particle size of RSANs was found to be 163.2 nm with a complete shell-core bilayer structure, and the average encapsulation efficiency was 14.31%. Compared with SANs, RAW 264.7 macrophages reduced the phagocytosis of RSANs by 51%, and the in vitro cumulative release rate of RSANs was 95% at 84 h, which revealed a prominent sustained release. Furthermore, it demonstrated that RSANs had lower cytotoxicity as compared to normal 293 cells and exhibited anti-tumor effects on both NB4 cells and 7721 cells. In vivo studies further showed that ATO could cause mild lesions of main organs while RSANs could reduce the toxicity and improve the anti-tumor effects. In brief, the developed RSANs system provides a promising alternative for ATO treatment safely and effectively.

PIR promotes tumorigenesis of breast cancer by upregulating cell cycle activator E2F1

Pirin (PIR) protein belongs to the superfamily of cupin and is highly conserved between eukaryotic and prokaryotic organisms. It has been reported that PIR is upregulated in various tumors and involved in tumorigenesis. However, its biological functions particularly in promoting tumorigenesis are, to date, poorly characterized. Here we report that knockdown of PIR in MCF7 and MDA-MB-231 cell lines causes a dramatic decrease in cell proliferation and xenograft tumor growth in mice. Mechanistically, the cell cycle activator E2F1 and its target genes cdk4, cdk6, cycE, cycD and DDR1 are remarkably downregulated in PIR depleted cells, leading to G1/S phase arrest. Luciferase reporter assay and chromatin immunoprecipitation assay indicate that PIR can activate E2F1 transcription by binding to its promoter region. Consistent with the observation in PIR knockdown cells, PIR inhibitors markedly inhibit the proliferation of both cell lines. Furthermore, knockdown of PIR significantly decreases the abilities of MCF7 cells for mobility and invasion in vitro and their metastasis in mice, which may be attributed to the decrease of DDR1. In conclusion, PIR stimulates tumorigenesis and progression by activating E2F1 and its target genes. Our finding thus suggests PIR as a potential druggable target for the therapy of cancers with high expression level of PIR.

The circRNA circAGFG1 acts as a sponge of miR-195-5p to promote triple-negative breast cancer progression through regulating CCNE1 expression

Background

In recent years, circular RNAs (circRNAs), a new star of non-coding RNA, have been emerged as vital regulators and gained much attention for involvement of initiation and progression of diverse kinds of human diseases, especially cancer. However, regulatory role, clinical significance and underlying mechanisms of circRNAs in triple-negative breast cancer (TNBC) still remain largely unknown.

Methods

Here, the expression profile of circRNAs in 4 pairs of TNBC tissues and adjacent non-tumor tissues was analyzed by RNA-sequencing. Quantitative real-time PCR and in situ hybridization were used to determine the level and prognostic values of circAGFG1 in two TNBC cohorts. Then, functional experiments in vitro and in vivo were performed to investigate the effects of circAGFG1 on tumor growth and metastasis in TNBC. Mechanistically, fluorescent in situ hybridization, dual luciferase reporter assay, RNA pull-down and RNA immunoprecipitation experiments were performed to confirm the interaction between circAGFG1 and miR-195-5p in TNBC.

Results

We found that circAGFG1 was evidently up-regulated in TNBC, and its level was correlated with clinical stage, pathological grade and poor prognosis of patients with TNBC. The results indicated that circAGFG1 could promote TNBC cell proliferation, mobility and invasion as well as tumorigenesis and metastasis in vivo. Mechanistic analysis showed that circAGFG1 may act as a ceRNA (competing endogenous RNA) of miR-195-5p to relieve the repressive effect of miR-195-5p on its target cyclin E1 (CCNE1).

Conclusions

Our findings suggest that circAGFG1 promotes TNBC progression through circAGFG1/miR-195-5p/CCNE1 axis and it may serve as a new diagnostic marker or target for treatment of TNBC patients.

Electronic supplementary material

The online version of this article (10.1186/s12943-018-0933-7) contains supplementary material, which is available to authorized users.

Long noncoding RNA DLX6-AS1 accelerates the glioma carcinogenesis by competing endogenous sponging miR-197-5p to relieve E2F1

Long noncoding RNAs (lncRNAs) participate in numerous of human cancer tumorigenesis. Nevertheless, the in-depth molecular mechanism that lncRNAs regulate the gliomagenesis is still ambiguous. In this research, our study invests energy in the biologic roles of lncRNA DLX6-AS1 on the glioma tumorigenesis. Here, we demonstrated that DLX6-AS1 expression was both high-expressed in the glioma cells and tissue, and the overexpression of DLX6-AS1 was clinically correlated with the poor outcome of glioma patients. In the cellular functional assays, silenced DLX6-AS1 expression by siRNAs inhibited the proliferation, invasion and tumor growth in vitro and in vivo, while the enhanced DLX6-AS1 expression by plasmids promotes them. The bioinformatics predictive tools, luciferase reporter assay and correlation analysis found that miR-197-5p could both target the 3'-UTR of DLX6-AS1 as well as E2F1 gene, constructing DLX6-AS1-miR-197-5p-E2F1 axis. Moreover, receiver operating characteristic (ROC) curve analysis revealed that lncRNA DLX6-AS1 has valuable diagnostic value clinical diagnose for the glioma patients (AUC = 0.736). Overall, our finding supports that DLX6-AS1 accelerates the glioma carcinogenesis by competing endogenous sponging miR-197-5p to relieve E2F1, acting as a novel therapeutic target for glioma.

Mechanistic insights into anticancer properties of oligomeric proanthocyanidins from grape seeds in colorectal cancer

Although the anticancer properties of oligomeric proanthocyanidins (OPCs) from grape seeds have been well recognized, the molecular mechanisms by which they exert anticancer effects are poorly understood. In this study, through comprehensive RNA-sequencing-based gene expression profiling in multiple colorectal cancer cell lines, we for the first time illuminate the genome-wide effects of OPCs from grape seeds in colorectal cancer. Our data revealed that OPCs affect several key cancer-associated genes. In particular, genes involved in cell cycle and DNA replication were most significantly and consistently altered by OPCs across multiple cell lines. Intriguingly, our in vivo experiments showed that OPCs were significantly more potent at decreasing xenograft tumor growth compared with the unfractionated grape seed extract (GSE) that includes the larger polymers of proanthocyanidins. These findings were further confirmed in colorectal cancer patient-derived organoids, wherein OPCs more potently inhibited the formation of organoids compared with GSE. Furthermore, we validated alteration of cell cycle and DNA replication-associated genes in cancer cell lines, mice xenografts as well as patient-derived organoids. Overall, this study provides an unbiased and comprehensive look at the mechanisms by which OPCs exert anticancer properties in colorectal cancer.

Preparation and characterization of erythrocyte membrane cloaked PLGA/arsenic trioxide nanoparticles and evaluation of their in vitro anti-tumor effect

Arsenic trioxide (ATO) is used for acute promyelocytic leukemia (APL) that is resistant to all-trans-retinoic acid, but its direct intravenous injection sometimes induces severe toxic side effects. Here, we developed a delivery system of red blood cell membrane (RBCM) cloaked poly (lactic-co-glycolic) acid (PLGA)-ATO nanoparticles (RPANs) to reduce the toxicity. PLGA was used to entrap the ATO, and the PLGA-ATO nanoparticles (PANs) were prepared by the emulsification method. Then RBCMs were employed to cloak the PANs using ultrasonication, to develop the RPANs delivery system. The prepared RPANs had a uniform size of around 233.6 nm with an obvious core–shell structure, as observed by TEM. The completeness of the membrane proteins was confirmed by SDS-PAGE and an in vitro release time of 65 h was determined for the RPANs. The RPANs also exhibited low cytotoxicity against the 293k kidney cell line (84.6% cell viability rate), which suggested that the ATO toxicity was reduced by RBCM cloaking. Moreover, the anti-tumor effects of the RPANs against the HL60 cell line were comparable to those of ATO solution. Our study demonstrated that the RPANs system has anti-tumor potential and could be developed into a safe and sustained release delivery system for ATO.

Arsenic trioxide (ATO) is used for acute promyelocytic leukemia (APL) that is resistant to all-trans-retinoic acid, but its direct intravenous injection sometimes induces severe toxic side effects.