Sp1 and the 'hallmarks of cancer'

Integrated Bioinformatics Investigation of Novel Biomarkers of Uterine Leiomyosarcoma Diagnosis and Outcome

Uterine leiomyosarcomas (uLMS) have a poor prognosis and a high percentage of recurrent disease. Bioinformatics has become an integral element in rare cancer studies by overcoming the inability to collect a large enough study population. This study aimed to investigate and highlight crucial genes, pathways, miRNAs, and transcriptional factors (TF) on uLMS samples from five Gene Expression Omnibus datasets and The Cancer Genome Atlas Sarcoma study. Forty-one common differentially expressed genes (DEGs) were enriched and annotated by the DAVID software. With protein-protein interaction (PPI) network analysis, we selected ten hub genes that were validated with the TNMplotter web tool. We used the USCS Xena browser for survival analysis. We also predicted TF-gene and miRNA-gene regulatory networks along with potential drug molecules. TYMS and TK1 correlated with overall survival in uLMS patients. Finally, our results propose further validation of hub genes (TYMS and TK1), miR-26b-5p, and Sp1 as biomarkers of pathogenesis, prognosis, and differentiation of uLMS. Regarding the aggressive behavior and poor prognosis of uLMS, with the lack of standard therapeutic regimens, in our opinion, the results of our study provide enough evidence for further investigation of the molecular basis of uLMS occurrence and its implication in the diagnosis and therapy of this rare gynecological malignancy.

Combination of Oncolytic Measles Virus and Ursolic Acid Synergistically Induces Oncolysis of Hepatocellular Carcinoma Cells

Hepatocellular carcinoma (HCC) remains a difficult-to-treat cancer due to late diagnosis and limited curative treatment options. Developing more effective therapeutic strategies is essential for the management of HCC. Oncolytic virotherapy is a novel treatment modality for cancers, and its combination with small molecules merits further exploration. In this study, we combined oncolytic measles virus (MV) with the natural triterpenoid compound ursolic acid (UA) and evaluated their combination effect against HCC cells, including those harboring hepatitis B virus (HBV) or hepatitis C virus (HCV) replication. We found that the combination of MV and UA synergistically induced more cell death in Huh-7 HCC cells through enhanced apoptosis. In addition, increased oxidative stress and loss of mitochondrial potential were observed in the treated cells, indicating dysregulation of the mitochondria-dependent pathway. Similar synergistic cytotoxic effects were also found in HCC cells harboring HBV or HCV genomes. These findings underscore the potential of oncolytic MV and UA combination for further development as a treatment strategy for HCC.

Signaling pathways in cancer metabolism: mechanisms and therapeutic targets

A wide spectrum of metabolites (mainly, the three major nutrients and their derivatives) can be sensed by specific sensors, then trigger a series of signal transduction pathways and affect the expression levels of genes in epigenetics, which is called metabolite sensing. Life body regulates metabolism, immunity, and inflammation by metabolite sensing, coordinating the pathophysiology of the host to achieve balance with the external environment. Metabolic reprogramming in cancers cause different phenotypic characteristics of cancer cell from normal cell, including cell proliferation, migration, invasion, angiogenesis, etc. Metabolic disorders in cancer cells further create a microenvironment including many kinds of oncometabolites that are conducive to the growth of cancer, thus forming a vicious circle. At the same time, exogenous metabolites can also affect the biological behavior of tumors. Here, we discuss the metabolite sensing mechanisms of the three major nutrients and their derivatives, as well as their abnormalities in the development of various cancers, and discuss the potential therapeutic targets based on metabolite-sensing signaling pathways to prevent the progression of cancer.

Restoration of coronary microvascular function by OGA overexpression in a high-fat diet with low-dose streptozotocin-induced type 2 diabetic mice

Sustained hyperglycemia results in excess protein O-GlcNAcylation, leading to vascular complications in diabetes. This study aims to investigate the role of O-GlcNAcylation in the progression of coronary microvascular disease (CMD) in inducible type 2 diabetic (T2D) mice generated by a high-fat diet with a single injection of low-dose streptozotocin. Inducible T2D mice exhibited an increase in protein O-GlcNAcylation in cardiac endothelial cells (CECs) and decreases in coronary flow velocity reserve (CFVR, an indicator of coronary microvascular function) and capillary density accompanied by increased endothelial apoptosis in the heart. Endothelial-specific O-GlcNAcase (OGA) overexpression significantly lowered protein O-GlcNAcylation in CECs, increased CFVR and capillary density, and decreased endothelial apoptosis in T2D mice. OGA overexpression also improved cardiac contractility in T2D mice. OGA gene transduction augmented angiogenic capacity in high-glucose treated CECs. PCR array analysis revealed that seven out of 92 genes show significant differences among control, T2D, and T2D + OGA mice, and Sp1 might be a great target for future study, the level of which was significantly increased by OGA in T2D mice. Our data suggest that reducing protein O-GlcNAcylation in CECs has a beneficial effect on coronary microvascular function, and OGA is a promising therapeutic target for CMD in diabetic patients.

Upregulated Expression of ErbB1 in Diffuse Large B-Cell Lymphoma as a Predictor of Poor Overall Survival Outcome

We examined the transcript-level expression of ErbB family protein tyrosine kinases, including ERBB1, in primary malignant lymphoma cells from 498 adult patients with diffuse large B-cell lymphoma (DLBCL). ERBB1 expression in DLBCL cells was significantly higher than in normal B-lineage lymphoid cells. An upregulated expression of ERBB1 mRNA in DLBCL cells was correlated with an amplified expression of mRNAs for transcription factors that recognized ERBB1 gene promoter sites. Notably, amplified ERBB1 expression in DLBCL and its subtypes were associated with significantly worse overall survival (OS). Our results encourage the further evaluation of the prognostic significance of high-level ERBB1 mRNA expression and the clinical potential of ERBB1-targeting therapeutics as personalized medicines in high-risk DLBCL.

The role of KLF transcription factor in the regulation of cancer progression

Kruppel-like factors (KLFs) are a family of zinc finger transcription factors that have been found to play an essential role in the development of various human tissues, including epithelial, teeth, and nerves. In addition to regulating normal physiological processes, KLFs have been implicated in promoting the onset of several cancers, such as gastric cancer, lung cancer, breast cancer, liver cancer, and colon cancer. To inhibit cancer progression, various existing medicines have been used to modulate the expression of KLFs, and anti-microRNA treatments have also emerged as a potential strategy for many cancers. Investigating the possibility of targeting KLFs in cancer therapy is urgently needed, as the roles of KLFs in cancer have not received enough attention in recent years. This review summarizes the factors that regulate KLF expression and function at both the transcriptional and posttranscriptional levels, which could aid in understanding the mechanisms of KLFs in cancer progression. We hope that this review will contribute to the development of more effective anti-cancer medicines targeting KLFs in the future.

Suppression of USP7 negatively regulates the stability of ETS proto-oncogene 2 protein

Ubiquitin-specific protease 7 (USP7) is one of the deubiquitinating enzymes (DUBs) that remove mono or polyubiquitin chains from target proteins. Depending on cancer types, USP7 has two opposing roles: oncogene or tumor suppressor. Moreover, it also known that USP7 functions in the cell cycle, apoptosis, DNA repair, chromatin remodeling, and epigenetic regulation through deubiquitination of several substrates including p53, mouse double minute 2 homolog (MDM2), Myc, and phosphatase and tensin homolog (PTEN). The [P/A/E]-X-X-S and K-X-X-X-K motifs of target proteins are necessary elements for the binding of USP7. In a previous study, we identified a novel substrate of USP7 through bioinformatics analysis using the binding motifs for USP7, and suggested that it can be an effective tool for finding new substrates for USP7. In the current study, gene ontology (GO) analysis revealed that putative target proteins having the [P/A/E]-X-X-S and K-X-X-K motifs are involved in transcriptional regulation. Moreover, through protein-protein interaction (PPI) analysis, we discovered that USP7 binds to the AVMS motif of ETS proto-oncogene 2 (ETS2) and deubiquitinates M1-, K11-, K27-, and K29-linked polyubiquitination of ETS2. Furthermore, we determined that suppression of USP7 decreases the protein stability of ETS2 and inhibits the transcriptional activity of ETS2 by disrupting the binding between the GGAA/T core motif and ETS2. Therefore, we propose that USP7 can be a novel target in cancers related to the dysregulation of ETS2.

SP1 transcriptionally regulates UBE2N expression to promote lung adenocarcinoma progression

Lung adenocarcinoma (LUAD) is the main cause of cancer-related death worldwide. Understanding the mechanisms of LUAD progression may provide insights into targeted therapy approaches for this malignancy. Ubiquitin-conjugating enzyme 2 N (UBE2N) has been demonstrated to play key roles in the progression of various cancers. However, the functions and mechanisms underlying UBE2N expression in LUAD are still unclear. In this study, we found that UBE2N is highly expressed in LUAD and patients with high UBE2N expression in their tumors have poor clinical outcomes. Moreover, we showed that UBE2N interference significantly inhibited LUAD progression in vitro and in vivo. At the molecular level, we demonstrated that the UBE2N is a bona fide target of transcription factor SP1. SP1 directly bound to the promoter of UBE2N and upregulated its expression in LUAD cells, which in turn contributed to the progression of LUAD. Furthermore, we found that there is a strong positive correlation between the expression of SP1 and UBE2N in LUAD samples. Importantly, LUAD patients with concomitantly high expression of SP1 and UBE2N were significantly associated with poor clinical outcomes. In conclusion, our study demonstrated that the SP1-UBE2N signaling axis might play a key role in the malignant progression of LUAD, which provides new targets and strategies for the treatment of LUAD.

Targeting the chromatin effector Pygo2 promotes cytotoxic T cell responses and overcomes immunotherapy resistance in prostate cancer

The noninflamed microenvironment in prostate cancer represents a barrier to immunotherapy. Genetic alterations underlying cancer cell-intrinsic oncogenic signaling are increasingly appreciated for their role in shaping the immune landscape. Recently, we identified Pygopus 2 (PYGO2) as the driver oncogene for the amplicon at 1q21.3 in prostate cancer. Here, using transgenic mouse models of metastatic prostate adenocarcinoma, we found that Pygo2 deletion decelerated tumor progression, diminished metastases, and extended survival. Pygo2 loss augmented the activation and infiltration of cytotoxic T lymphocytes (CTLs) and sensitized tumor cells to T cell killing. Mechanistically, Pygo2 orchestrated a p53/Sp1/Kit/Ido1 signaling network to foster a microenvironment hostile to CTLs. Genetic or pharmacological inhibition of Pygo2 enhanced the antitumor efficacy of immunotherapies using immune checkpoint blockade (ICB), adoptive cell transfer, or agents inhibiting myeloid-derived suppressor cells. In human prostate cancer samples, Pygo2 expression was inversely correlated with the infiltration of CD8+ T cells. Analysis of the ICB clinical data showed association between high PYGO2 level and worse outcome. Together, our results highlight a potential path to improve immunotherapy using Pygo2-targeted therapy for advanced prostate cancer.

Specificity Proteins (Sp) and Cancer

The specificity protein (Sp) transcription factors (TFs) Sp1, Sp2, Sp3 and Sp4 exhibit structural and functional similarities in cancer cells and extensive studies of Sp1 show that it is a negative prognostic factor for patients with multiple tumor types. In this review, the role of Sp1, Sp3 and Sp4 in the development of cancer and their regulation of pro-oncogenic factors and pathways is reviewed. In addition, interactions with non-coding RNAs and the development of agents that target Sp transcription factors are also discussed. Studies on normal cell transformation into cancer cell lines show that this transformation process is accompanied by increased levels of Sp1 in most cell models, and in the transformation of muscle cells into rhabdomyosarcoma, both Sp1 and Sp3, but not Sp4, are increased. The pro-oncogenic functions of Sp1, Sp3 and Sp4 in cancer cell lines were studied in knockdown studies where silencing of each individual Sp TF decreased cancer growth, invasion and induced apoptosis. Silencing of an individual Sp TF was not compensated for by the other two and it was concluded that Sp1, Sp3 and Sp4 are examples of non-oncogene addicted genes. This conclusion was strengthened by the results of Sp TF interactions with non-coding microRNAs and long non-coding RNAs where Sp1 contributed to pro-oncogenic functions of Sp/non-coding RNAs. There are now many examples of anticancer agents and pharmaceuticals that induce downregulation/degradation of Sp1, Sp3 and Sp4, yet clinical applications of drugs specifically targeting Sp TFs are not being used. The application of agents targeting Sp TFs in combination therapies should be considered for their potential to enhance treatment efficacy and decrease toxic side effects.

TRIM56 acts through the IQGAP1-CDC42 signaling axis to promote glioma cell migration and invasion

Diffuse invasion is an important factor leading to treatment resistance and a poor prognosis in gliomas. Herein, we found that expression of the tripartite motif containing 56 (TRIM56), a RING-finger domain containing E3 ubiquitin ligase, was markedly higher in glioma than in normal brain tissue, and was significantly correlated with malignant phenotypes and a poor prognosis. In vitro and in vivo experimental studies revealed that TRIM56 promoted the migration and invasion of glioma cells. Mechanistically, TRIM56 was transcriptionally regulated by SP1 and promoted the K48-K63-linked poly-ubiquitination transition of IQGAP1 at Lys-1230 by interacting with it, which in turn promoted CDC42 activation. This mechanism was confirmed to mediate glioma migration and invasion. In conclusion, our study provides insights into the mechanisms through which TRIM56 promotes glioma motility, i.e., by regulating IQGAP1 ubiquitination to promote CDC42 activation, which might be clinically targeted for the treatment of glioma.

Clinicopathological and prognostic value of lncRNA TPT1-AS1 in cancer: a systematic review study and meta-analysis

INTRODUCTION

Aberrant expression of lncRNAs in cancer cells can impact their key phenotypes. We aimed to summarize available evidence on clinicopathological and prognostic value of lncRNA TPT1-AS1 in cancer.

METHODS

A systematic search was performed on Medline and Embase databases using relevant key terms covering lncRNA TPT1-AS1, cancer, and clinical outcomes. The effect size estimates and their 95 % confidence interval (CI) were pooled using random-effects models. Meta- analyses were conducted using STATA 16.0 software.

RESULTS

Seventeen articles met our eligibility criteria. Tumor tissue compared to normal tissue showed increased level of lncRNA TPT1-AS1 expression (pooled standardized mean difference (95 % CI): 0.65 (0.52-0.79)). Overexpression of this lncRNA was a significant predictor for poor prognosis (Pooled log-rank test P-value < 0.001); in patients with high-level of lncRNA TPT1-AS1, the risk of death at five years was 1.40 times greater than their counterparts. The pooled Odds ratios for association lncRNA TPT1-AS1 with tumor stage, tumor size, and lymph node metastasis were 1.94 (95 % CI: 0.90-4.19, 8 studies, I² = 79.6 %), 2.33 (95 % CI: 1.31-4.14, 5 studies, I² = 40.0 %), and 1.89 (95 % CI: 1.08-3.36, 5 studies, I² = 61.7 %), respectively. Regarding the identified potential mechanisms, lncRNA TPT1-AS1 plays a role in cancer growth mainly by sponging miRNAs and regulating their downstream targets or controlling the expression of key cell cycle regulators.

CONCLUSION

In cancer patients, elevated expression of lncRNA TPT1-AS1 might be associated with a shorter Overall Survival, advanced stages, larger tumor size, and lymph node metastasis.

Genetic Analysis of HIBM Myopathy-Specific GNE V727M Hotspot Mutation Identifies a Novel COL6A3 Allied Gene Signature That Is Also Deregulated in Multiple Neuromuscular Diseases and Myopathies

The GNE-associated V727M mutation is one of the most prevalent ethnic founder mutations in the Asian HIBM cohort; however, its role in inducing disease phenotype remains largely elusive. In this study, the function of this hotspot mutation was profoundly investigated. For this, V727M mutation-specific altered expression profile and potential networks were explored. The relevant muscular disorder-specific in vivo studies and patient data were further analyzed, and the key altered molecular pathways were identified. Our study found that the GNEV727M mutation resulted in a deregulated lincRNA profile, the majority of which (91%) were associated with a down-regulation trend. Further, in silico analysis of associated targets showed their active role in regulating Wnt, TGF-β, and apoptotic signaling. Interestingly, COL6a3 was found as a key target of these lincRNAs. Further, GSEA analysis showed HIBM patients with variable COL6A3 transcript levels have significant alteration in many critical pathways, including epithelial-mesenchymal-transition, myogenesis, and apoptotic signaling. Interestingly, 12 of the COL6A3 coexpressed genes also showed a similar altered expression profile in HIBM. A similar altered trend in COL6A3 and coexpressed genes were found in in vivo HIBM disease models as well as in multiple other skeletal disorders. Thus, the COL6A3-specific 13 gene signature seems to be altered in multiple muscular disorders. Such deregulation could play a pivotal role in regulating many critical processes such as extracellular matrix organization, cell adhesion, and skeletal muscle development. Thus, investigating this novel COL6A3-specific 13 gene signature provides valuable information for understanding the molecular cause of HIBM and may also pave the way for better diagnosis and effective therapeutic strategies for many muscular disorders.

Circ0005654 as a new biomarker of thyroid cancer interacting with SP1 to influence the prognosis: A case-control study

Circular RNAs (CircRNAs) have been reported to play key roles in the progression of various cancers, including thyroid cancer (TC). Transcription factor 1 (SP1) promotes the development of thyroid cancer. This study aims at investigating the expression level of Circ0005654 in combination with Transcription factor1 (SP1) in patients with TC for diagnostic and therapeutic purposes. A total of 76 patients with thyroid cancer underwent radical surgery. Intraoperatively, thyroid cancer tissues and paired adjacent tissues and the corresponding clinicopathological data were collected. The expression of SP1 and β-catenin in thyroid cancer and adjacent tissues was determined by immunohistochemistry (IHC) while the Circ0005654 expression level was measured by semiquantitative real-time polymerase chain reaction (sqRT-PCR). Then, we compared the variability of Circ0005654, SP1, and Wnt/β-catenin expression in cancerous and adjacent tissues and determined the relationship between the correlation analysis and the clinicopathological features of the thyroid cancer patients. The diagnostic value of Circ0005654 in thyroid cancer tissues was analyzed with the help of the receiver operating characteristic (ROC) curve, counting the 3-year postoperative survival rate, and analyzing the effect of Circ0005654 and SP1 protein levels on the 3-year survival rate of the patients. sqRT-PCR showed that the expression level of Circ0005654 in thyroid cancer tissue was significantly higher than that of adjacent tissues. The area under the ROC of Circ0005654 was 0.9553, 95% confidence interval: (0.9211-0.9895) with a cutoff value of 0.7895, a sensitivity of 92.11%, and a specificity of 86.84%. The IHC results showed that the expression level of SP1, β-catenin, and Wnt was higher in cancer tissues than in adjacent tissues; Circ0005654, SP1, Wnt/β-catenin expression levels were associated with tumor diameter, lymph node metastasis, TNM stage, and envelope invasion (all P < .05). According to the Circ0005654 expression level in thyroid cancer tissue, the 3-year survival rate of the high expression group was 77.5% and 94.4% in the low expression group with a statistically significant difference; the 3-year survival rate of SP1 positive and negative patients was 78.6% and 100%, respectively, with the data being significantly different. Circ0005654 may serve as a potential biomarker for thyroid cancer diagnosis and may be involved in the development of thyroid cancer.

Circ_0000253 promotes the progression of osteosarcoma via the miR-1236-3p/SP1 axis

OBJECTIVE

Circular RNAs (circRNAs) play important roles in modulating tumour progression. This study investigated the role of circ_0000253 in osteosarcoma (OS).

METHODS

We downloaded the chip dataset GSE140256 from the Gene Expression Omnibus database and the circRNAs differentially expressed in OS tissue and normal tissue samples were analysed. Quantitative real-time PCR (qRT-PCR) was carried out to examine circ_0000253 expression in OS tissues and cells. Cell counting kit-8, BrdU and flow cytometry assays were performed to verify the effects of circ_0000253 on OS cell growth and apoptosis. Bioinformatics analysis was conducted to predict, and RNA immunoprecipitation assay and dual-luciferase reporter gene assay were performed to verify the targeted relationships of miR-1236-3p with circ_0000253 and Sp1 transcription factor (SP1) mRNA 3'UTR. The effects of miR-1236-3p and circ_0000253 on SP1 expression in OS cells were detected through Western blot.

KEY FINDINGS

Circ_0000253 was upregulated in OS tissues and cell lines. Circ_0000253 overexpression facilitated OS cell growth and suppressed apoptosis, whereas knocking down circ_0000253 inhibited OS cell growth and facilitated apoptosis. Circ_0000253 targeted miR-1236-3p directly and negatively modulated its expression. SP1 was miR-1236-3p's target gene and positively regulated by circ_0000253.

CONCLUSION

Circ_0000253 promotes OS cell proliferation and suppresses cell apoptosis via regulating the miR-1236-3p/SP1 molecular axis.

Genome-scale CRISPR-Cas9 knockout screening in nasopharyngeal carcinoma for radiosensitive and radioresistant genes

BACKGROUND

Genome-scale CRISPR-Cas9 knockout screening may provide new insights into the mechanism underlying clinical radioresistance in nasopharyngeal carcinoma (NPC), which is remain largely unknown. Our objective was to screen the functional genes associated with radiosensitivity and radioresistance in NPC, laying a foundation for further research on its functional mechanismand.

METHODS

CRISPR-Cas9 library lentivirus screening in radiation-treated NPC cells was combined with second-generation sequence technology to identify functional genes, which were further validated in radioresistant NPC cells and patient tissues.

RESULTS

Eleven radiosensitive and radioresistant genes were screened. Among these genes, the expression of FBLN5, FAM3C, MUS81, and DNAJC17 were significantly lower and TOMM20, CDKN2AIP, SNX22, and SP1 were higher in the radioresistant NPC cells (C666-1R, 5-8FR) (p < 0.05). CALD1 was highly expressed in C666-1R. Furthermore, we found knockout of FBLN5, FAM3C, MUS81 and DNAJC17 promoted the proliferation of NPC cells, while CDKN2AIP and SP1 had the opposed results (p < 0.05). This result was verified in NPC patient tissues. Meanwhile, KEGG analysis showed that the Fanconi anemia pathway and the TGF-β signaling pathway possibly contributed to radiosensitivity or radioresistance in NPC.

CONCLUSIONS

Nine genes involved in the radiosensitivity or radioresistance of NPC: four genes for radiosensitivity (FBLN5, FAM3C, MUS81, and DNAJC17), two genes for radioresistance (CDKN2AIP, SP1), two potential radioresistant genes (TOMM20, SNX22), and a potential radiosensitive gene (CALD1). Genome-scale CRISPR-Cas9 knockout screening for radiosensitive and radioresistant genes in NPC may provide new insights into the mechanisms underlying clinical radioresistance to improve the efficacy of radiotherapy for NPC.

Assessing the effects of aging on the liver endothelial cell landscape using single-cell RNA sequencing

Endothelial cell (EC) function declines with age and contributes to the development of many vascular-related disease processes. Currently, the effects of aging on the molecular regulatory mechanisms of liver ECs have not been fully elucidated. Here, we employed single-cell RNA sequencing to map the transcriptome of ECs and analyzed their relationship with aging. We identified 8 different EC subtypes, interestingly, 2 of which were specially expressed in aged mice ECs namely aged capillary ECs (Aged ECs) and pro-inflammation capillary ECs (Proinfla.ECs). Double immunostaining for an EC marker (Cd31) and a marker of these specialized EC phenotypes confirmed the single-cell RNA sequencing data. Gene ontology analysis revealed that Aged ECs and Proinfla.ECs were associated with inflammatory response. Then we found that liver proliferating capillary ECs (Prolife.ECs) were most affected by senescence. Single-cell transcript analysis suggests that Prolife.ECs and angiogenic capillary ECs may form a poor microenvironment that promotes angiogenesis and tumorigenesis. Pseudo-temporal trajectories revealed that Prolife.ECs have different differentiation pathways in young and aged mice. In aged mice, Prolife.ECs could specifically differentiate into an unstable state, which was mainly composed of angiogenic capillary ECs. Intercellular communication revealed inflammatory activation in old group. Overall, this work compared the single-cell RNA profiles of liver ECs in young and aged mice. These findings provide a new insight into liver aging and its molecular mechanisms, and further exploration of Aged ECs and Proinfla.ECs may help to elucidate the molecular mechanisms associated with senescence.

Sp1 Controls the Basal Level of Interleukin-34 Transcription

Interleukin-34 (IL-34) is a cytokine that plays important roles at steady state and in diseases. The induced or inhibited expression of IL-34 by stimuli has been deeply investigated. However, the regulation of IL-34 basal expression is largely unknown. The aim of this study is to investigate whether IL-34 expression is regulated by a general transcription factor Specificity Protein 1 (Sp1) at transcription level. By using bioinformatic software, four putative Sp1-binding sites overlapping GC boxes were found in the core promoter region of IL-34. Alignment of the core promoter sequences of mammalian IL-34 showed GC box-C (-62/-57) and D (-11/-6) were conserved in some mammals. Luciferase assay results showed that only deletion of GC box-C (-62/-57) significantly reduced luciferase activities of IL-34 core promoter in SH-SY5Y cells. By using electrophoretic mobility shift assay (EMSA), it was found that Sp1 specifically interacted with GC box-C sequence CCCGCC (-62/-57) in the core promoter of IL-34. By using chromatin immunoprecipitation (ChIP), it was discovered that Sp1 bound to the core promoter of IL-34 in living cells. In addition, silencing of Sp1 expression by its specific siRNA reduced IL-34 mRNA and protein levels significantly in SH-SY5Y cells. Likewise, IL-34 expression was inhibited in a dose-dependent manner by a Sp1 inhibitor Plicamycin. Furthermore, silencing of Sp1 also downregulated mRNA and protein expression of IL-34 in GES-1 and 293T cell lines, suggesting that IL-34 transcription regulated by Sp1 was not cell-type specific. Taken together, these results indicate that Sp1 controls the basal level of IL-34 transcription.

p53 inhibits CTR1-mediated cisplatin absorption by suppressing SP1 nuclear translocation in osteosarcoma

Background

Osteosarcoma (OS) is a malignant bone tumor mainly affecting children and young adolescents. Cisplatin is a first-line chemotherapy drug for OS, however, drug resistance severely limits the survival of OS. Nevertheless, cellular factors in cisplatin resistance for OS remain obscure. In this study, the function and potential mechanism of p53 in cisplatin absorption were explored in OS cells.

Methods

The CRISPR-Cas9 gene editing technology was performed to obtain p53 gene knock-out U2OS cells. The p53 over-expression 143B cell line was established by lentivirus-mediated virus infection. Moreover, the functions of p53 and CTR1 in cisplatin absorption were assessed by inductively coupled plasma mass spectrometry (ICP-MS) through CTR1 over-expression and knock-down. Further, the DNA binding activity of SP1 on CTR1 gene promoter was determined by dual-luciferase assay and chromatin immunoprecipitation (ChIP) assay. The functional regulation of p53 on SP1 was studied by nucleocytoplasmic separation assay and electrophoretic mobility shift assay (EMSA). The interaction between p53 and SP1 was verified by Co-Immunoprecipitation assay.

Results

Under cisplatin treatment, p53 knock-out promoted CTR1 expression and cisplatin uptake, while p53 overexpression inhibited CTR1 expression and cisplatin uptake. Moreover, p53 regulated CTR1 level not by binding to CTR1 promoter directly but by suppressing the nuclear translocation of transcription factor specificity protein 1 (SP1). It was verified that SP1 is directly bound with CTR1 promoter. SP1 overexpression stimulated CTR1 expression, and SP1 knock-down attenuated CTR1 expression.

Conclusion

The p53 might function as a negative regulator in CTR1 mediated cisplatin absorption, and the p53-SP1-CTR1 axis is a target for cisplatin resistance.

Circ_0047835 Combines with miR-144-3p to Promote the Proliferation, Invasion, Migration, and Fibrosis of TGF-β1-Treated Human Tenon's Capsule Fibroblasts by Upregulating SP1

PURPOSE

Glaucoma is the leading cause of blindness worldwide with complex pathogenesis. Circular RNAs (circRNAs) play critical roles in various diseases, including glaucoma. The purpose of this study was to investigate the role of circ_0047835 and underlying mechanisms in the development of fibrosis after glaucoma filtration surgery.

METHODS

Human Tenon's capsule fibroblasts (HTFs) were stimulated using transforming growth factor-β1 (TGF-β1) to mimic a cellular model of glaucoma in vitro. Cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8) assay and 5-ethynyl-2'-deoxyuridine (EdU) assay. Cell invasion and migration were detected by transwell assay and wound healing assay, respectively. Western blot assay was used to measure protein levels. The expression levels of circ_0047835, microRNA-144-3p (miR-144-3p) and specific protein 1 (SP1) mRNA were determined by real-time quantitative polymerase chain reaction (RT-qPCR). The interaction between miR-144-3p and circ_0047835 or SP1 was confirmed by dual-luciferase reporter assay and RNA Immunoprecipitation (RIP) assay.

RESULTS

Circ_0047835 expression was elevated in glaucoma tissues and TGF-β1-treated HTFs. Circ_0047835 or SP1 knockdown suppressed the proliferation, migration, invasion, and fibrosis of TGF-β1-treated HTFs. MiR-144-3p was a target of circ_0047835, and miR-144-3p inhibition reversed the effects of circ_0047835 knockdown in TGF-β1-treated HTFs. Moreover, SP1 was identified as a target of miR-144-3p, and miR-144-3p overexpression weakened TGF-β1-induced proliferation, migration, invasion, and fibrosis by targeting SP1 in HTFs. Furthermore, circ_0047835 combined with miR-144-3p to regulate SP1 expression.

CONCLUSION

Circ_0047835 might contribute to fibrosis progression after glaucoma surgery by regulating the miR-144-3p/SP1 axis.

Cuproptosis-associated CDKN2A is targeted by plicamycin to regulate the microenvironment in patients with head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC), the most common malignancy of the head and neck, has an overall 5-year survival rate of <50%. Genes associated with cuproptosis, a newly identified copper-dependent form of cell death, are aberrantly expressed in various tumours. However, their role in HNSCC remains unknown. In this study, bioinformatic analysis revealed that the cuproptosis-related gene CDKN2A was correlated with the malignant behaviour of HNSCC. Kaplan-Meier (KM) curves showed that patients with high CDKN2A expression had a better prognosis. Multiomic analysis revealed that CDKN2A may be associated with cell cycle and immune cell infiltration in the tumour microenvironment and is important for maintaining systemic homeostasis in the body. Furthermore, molecular docking and molecular dynamics simulations suggested strong binding between plicamycin and CDKN2A. And plicamycin inhibits the progression of HNSCC in cellular assays. In conclusion, this study elucidated a potential mechanism of action of the cuproptosis-associated gene CDKN2A in HNSCC and revealed that plicamycin targets CDKN2A to improve the prognosis of patients.

UCHL1 regulated by Sp1 ameliorates cochlear hair cell senescence and oxidative damage

Age-related hearing loss (ARHL) is the most common cause of hearing loss in the elderly. Ubiquitin carboxyl-terminal hydrolase L1 (UCHL1) is a deubiquitinating enzyme involved in several types of human disease. The present study aimed to investigate the effect of UCHL1 on a hydrogen peroxide (H₂O₂)-induced ARHL model in cochlear hair cells and uncover its underlying mechanism. Reverse transcription-quantitative (RT-q)PCR and western blot analysis were used to assess UCHL1 expression in HEI-OC1 cells exposed to H₂O₂. Following UCHL1 overexpression in H₂O₂-induced HEI-OC1 cells, cell activity was assessed by Cell Counting Kit-8 assay. The content of oxidative stress-associated markers including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and reactive oxygen species (ROS ) was measured using corresponding commercial kits. Cell apoptosis was evaluated by TUNEL assay and western blot analysis. Cell senescence was assessed by senescence-associated β-galactosidase staining and western blot analysis. RT-qPCR and western blot analysis were applied to measure mRNA and protein expression levels, respectively, of specificity protein 1 (Sp1) in H₂O₂-treated HEI-OC1 cells. In addition, the association between UCHL1 and Sp1 was verified by luciferase reporter and chromatin immunoprecipitation (ChIP) assay. The mRNA and protein expression levels of UCHL1 were also determined in Sp1-overexpressing cells by RT-qPCR and western blot analysis, respectively. Following Sp1 overexpression in UCHL1-overexpressing H₂O₂-treated HEI-OC1 cells, cell activity, oxidative stress, apoptosis and senescence were assessed. Finally, the expression levels of NF-κB signaling-related proteins p-NF-κB p65 and NF-κB p65 were detected using western blot analysis. The results showed that UCHL1 was downregulated in H₂O₂-treated HEI-OC1 cells. In addition, UCHL1 overexpression enhanced cell viability and promoted oxidative damage, apoptosis and senescence in H₂O₂-induced HEI-OC1 cells. Furthermore, Sp1 was upregulated in H₂O₂-treated HEI-OC1 cells. Additionally, luciferase reporter and ChIP assays demonstrated that Sp1 interacted with the UCHL1 promoter to inhibit UCHL1 transcription. Sp1 overexpression reversed the effect of UCHL1 overexpression on cell viability, oxidative stress, apoptosis, senescence and activation of the NF-κB signaling pathway in H₂O_2-exposed HEI-OC1 cells. Collectively, the results suggested that UCHL1 transcriptional suppression by Sp1 protected cochlear hair cells from H₂O₂-triggered senescence and oxidative damage.

The role and application of transcriptional repressors in cancer treatment

Gene expression is modulated through the integration of many regulatory elements and their associated transcription factors (TFs). TFs bind to specific DNA sequences and either activate or repress transcriptional activity. Through decades of research, it has been established that aberrant expression or functional abnormalities of TFs can lead to uncontrolled cell division and the development of cancer. Initial studies on transcriptional regulation in cancer have focused on TFs as transcriptional activators. However, recent studies have demonstrated several different mechanisms of transcriptional repression in cancer, which could be potential therapeutic targets for the development of specific anti-cancer agents. In the first section of this review, "Emerging roles of transcriptional repressors in cancer development," we summarize the current understanding of transcriptional repressors and their involvement in the molecular processes of cancer progression. In the subsequent section, "Therapeutic applications," we provide an updated overview of the available therapeutic targets for drug discovery and discuss the new frontier of such applications.

Systematic analysis of the BET family in adrenocortical carcinoma: The expression, prognosis, gene regulation network, and regulation targets

BACKGROUND

Bromodomain and extracellular terminal (BET) family (including BRD2, BRD3, and BRD4) is considered to be a major driver of cancer cell growth and a new target for cancer therapy. Currently, more than 30 targeted inhibitors have shown significant inhibitory effects against various tumors in preclinical and clinical trials. However, the expression levels, gene regulatory networks, prognostic value, and target prediction of BRD2, BRD3, and BRD4 in adrenocortical carcinoma (ACC) have not been fully elucidated. Therefore, this study aimed to systematically analyze the expression, gene regulatory network, prognostic value, and target prediction of BRD2, BRD3, and BRD4 in patients with ACC, and elucidated the association between BET family expression and ACC. We also provided useful information on BRD2, BRD3, and BRD4 and potential new targets for the clinical treatment of ACC.

METHODS

We systematically analyzed the expression, prognosis, gene regulatory network, and regulatory targets of BRD2, BRD3, and BRD4 in ACC using multiple online databases, including cBioPortal, TRRUST, GeneMANIA, GEPIA, Metascape, UALCAN, LinkedOmics, and TIMER.

RESULTS

The expression levels of BRD3 and BRD4 were significantly upregulated in ACC patients at different cancer stages. Moreover, the expression of BRD4 was significantly correlated with the pathological stage of ACC. ACC patients with low BRD2, BRD3, and BRD4 expressions had longer survival than patients with high BRD2, BRD3, and BRD4 expressions. The expression of BRD2, BRD3, and BRD4 was altered by 5%, 5%, and 12% in 75 ACC patients, respectively. The frequency of gene alterations in the 50 most frequently altered BRD2, BRD3, and BRD4 neighboring genes in these ACC patients were ≥25.00%, ≥25.00%, and ≥44.44%, respectively. BRD2, BRD3, and BRD4 and their neighboring genes form a complex network of interactions mainly through co-expression, physical interactions, and shared protein domains. Molecular functions related to BRD2, BRD3, and BRD4 and their neighboring genes mainly include protein-macromolecule adaptor activity, cell adhesion molecule binding, and aromatase activity. Chemokine signaling pathway, thiamine metabolism, and olfactory transduction were found to be enriched as per the KEGG pathway analysis. SP1, NPM1, STAT3, and TP53 are key transcription factors for BRD2, BRD4, and their neighboring genes. MiR-142-3P, miR-484, and miR-519C were the main miRNA targets of BRD2, BRD3, BRD4, and their neighboring genes. We analyzed the mRNA sequencing data from 79 patients with ACC and found that ZSCAN12, DHX16, PRPF4B, EHMT1, CDK5RAP2, POMT1, WIZ, ZNF543, and AKAP8 were the top nine genes whose expression were positively associated with BRD2, BRD3, and BRD4 expression. The expression level of BRD2, BRD3, and BRD4 positively correlated with B cell and dendritic cell infiltration levels. BRD4-targeted drug PFI-1 and (BRD2, BRD3, and BRD4)-targeted drug I-BET-151 may have good inhibitory effects on the SW13 cell line.

CONCLUSIONS

The findings of this study provide a partial basis for the role of BRD2, BRD3, and BRD4 in the occurrence and development of ACC. In addition, this study also provides new potential therapeutic targets for ACC, which can serve as a reference for future basic and clinical research.

Preclinical and Clinical Applications of Metabolomics and Proteomics in Glioblastoma Research

Glioblastoma (GB) is a primary malignancy of the central nervous system that is classified by the WHO as a grade IV astrocytoma. Despite decades of research, several aspects about the biology of GB are still unclear. Its pathogenesis and resistance mechanisms are poorly understood, and methods to optimize patient diagnosis and prognosis remain a bottle neck owing to the heterogeneity of the malignancy. The field of omics has recently gained traction, as it can aid in understanding the dynamic spatiotemporal regulatory network of enzymes and metabolites that allows cancer cells to adjust to their surroundings to promote tumor development. In combination with other omics techniques, proteomic and metabolomic investigations, which are a potent means for examining a variety of metabolic enzymes as well as intermediate metabolites, might offer crucial information in this area. Therefore, this review intends to stress the major contribution these tools have made in GB clinical and preclinical research and highlights the crucial impacts made by the integrative "omics" approach in reducing some of the therapeutic challenges associated with GB research and treatment. Thus, our study can purvey the use of these powerful tools in research by serving as a hub that particularly summarizes studies employing metabolomics and proteomics in the realm of GB diagnosis, treatment, and prognosis.

HIV- 1 lentivirus tethering to the genome is associated with transcription factor binding sites found in genes that favour virus survival

Lentiviral vectors (LV) are attractive for permanent and effective gene therapy. However, integration into the host genome can cause insertional mutagenesis highlighting the importance of understanding of LV integration. Insertion site (IS) tethering is believed to involve cellular proteins such as PSIP1/LEDGF/p75, which binds to the virus pre-integration complexes (PICs) helping to target the virus genome. Transcription factors (TF) that bind both the vector LTR and host genome are also suspected influential to this. To determine the role of TF in the tethering process, we mapped predicted transcription factor binding sites (pTFBS) near to IS chosen by HIV-1 LV using a narrow 20 bp window in infected human induced pluripotent stem cells (iPSCs) and their hepatocyte-like cell (HLC) derivatives. We then aligned the pTFBS with these sequences found in the LTRs of native and self-inactivated LTRs. We found significant enrichment of these sequences for pTFBS essential to HIV-1 life cycle and virus survival. These same sites also appear in HIV-1 patient IS and in mice infected with HIV-1 based LV. This in silco data analysis suggests pTFBS present in the virus LTR and IS sites selected by HIV-1 LV are important to virus survival and propagation.

MicroRNAs-mediated regulation of glucose transporter (GLUT) expression in glioblastoma

Current knowledge about the role of microRNAs (miRNAs) in tumor glucose metabolism is growing, and a number of studies regularly confirm the impact miRNAs can have on glucose metabolism reprogramming in tumors. However, there remains a lack of understanding of the broader perspective on the role of miRNAs in energy reprogramming in glioblastoma. An important role in the metabolism of glucose is played by carrier proteins that ensure its transmembrane movement. Carrier proteins in mammalian cells are glucose transporters (GLUTs). In total, 12 types of GLUTs are distinguished, differing in localization, affinity for glucose and ability to regulate. The fact of increased consumption of glucose in tumors compared to non-proliferating normal tissues is known. Tumor cells need glucose to ensure their survival and growth, so the type of transport proteins like GLUT are critical for them. Previous studies have shown that GLUT-1 and GLUT-3 may play an important role in the development of some types of malignant tumors, including glioblastoma. In addition, there is evidence of how GLUT-1 and GLUT-3 expression is regulated by miRNAs in glioblastoma. Thus, the aim of this study is to highlight the role of specific miRNAs in modulating GLUT levels in order to take into account the use of miRNAs expression modulators as a useful strategy to increase the sensitivity of glioblastoma to current therapies.

ERBB1/EGFR and JAK3 Tyrosine Kinases as Potential Therapeutic Targets in High-Risk Multiple Myeloma

Our main objective was to identify abundantly expressed tyrosine kinases in multiple myeloma (MM) as potential therapeutic targets. We first compared the transcriptomes of malignant plasma cells from newly diagnosed MM patients who were risk-categorized based on the patient-specific EMC-92/SKY-92 gene expression signature values vs. normal plasma cells from healthy volunteers using archived datasets from the HOVON65/GMMG-HD4 randomized Phase 3 study evaluating the clinical efficacy of bortezomib induction/maintenance versus classic cytotoxic drugs and thalidomide maintenance. In particular, ERBB1/EGFR was significantly overexpressed in MM cells in comparison to normal control plasma cells, and it was differentially overexpressed in MM cells from high-risk patients. Amplified expression of EGFR/ERBB1 mRNA in MM cells was positively correlated with increased expression levels of mRNAs for several DNA binding proteins and transcription factors with known upregulating activity on EGFR/ERBB1 gene expression. MM patients with the highest ERBB1/EGFR expression level had significantly shorter PFS and OS times than patients with the lowest ERBB1/EGFR expression level. High expression levels of EGFR/ERBB1 were associated with significantly increased hazard ratios for unfavorable PFS and OS outcomes in both univariate and multivariate Cox proportional hazards models. The impact of high EGFR/ERBB1 expression on the PFS and OS outcomes remained significant even after accounting for the prognostic effects of other covariates. These results regarding the prognostic effect of EGFR/ERBB1 expression were validated using the MMRF-CoMMpass RNAseq dataset generated in patients treated with more recently applied drug combinations included in contemporary induction regimens. Our findings provide new insights regarding the molecular mechanism and potential clinical significance of upregulated EGFR/ERBB1 expression in MM.

Single-cell RNA-sequencing identifies anti-cancer immune phenotypes in the early lung metastatic niche during breast cancer

Microenvironmental changes in the early metastatic niche may be exploited to identify therapeutic targets to inhibit secondary tumor formation and improve disease outcomes. We dissected the developing lung metastatic niche in a model of metastatic, triple-negative breast cancer using single-cell RNA-sequencing. Lungs were extracted from mice at 7-, 14-, or 21 days after tumor inoculation corresponding to the pre-metastatic, micro-metastatic, and metastatic niche, respectively. The progression of the metastatic niche was marked by an increase in neutrophil infiltration (5% of cells at day 0 to 81% of cells at day 21) and signaling pathways corresponding to the hallmarks of cancer. Importantly, the pre-metastatic and early metastatic niche were composed of immune cells with an anti-cancer phenotype not traditionally associated with metastatic disease. As expected, the metastatic niche exhibited pro-cancer phenotypes. The transition from anti-cancer to pro-cancer phenotypes was directly associated with neutrophil and monocyte behaviors at these time points. Predicted metabolic, transcription factor, and receptor-ligand signaling suggested that changes in the neutrophils likely induced the transitions in the other immune cells. Conditioned medium generated by cells extracted from the pre-metastatic niche successfully inhibited tumor cell proliferation and migration in vitro and the in vivo depletion of pre-metastatic neutrophils and monocytes worsened survival outcomes, thus validating the anti-cancer phenotype of the developing niche. Genes associated with the early anti-cancer response could act as biomarkers that could serve as targets for the treatment of early metastatic disease. Such therapies have the potential to revolutionize clinical outcomes in metastatic breast cancer.

PPA1, an energy metabolism initiator, plays an important role in the progression of malignant tumors

Inorganic pyrophosphatase (PPA1) encoded by PPA1 gene belongs to Soluble Pyrophosphatases (PPase) family and is expressed widely in various tissues of Homo sapiens, as well as significantly in a variety of malignancies. The hydrolysis of inorganic pyrophosphate (PPi) to produce orthophosphate (Pi) not only dissipates the negative effects of PPi accumulation, but the energy released by this process also serves as a substitute for ATP. PPA1 is highly expressed in a variety of tumors and is involved in proliferation, invasion, and metastasis during tumor development, through the JNK/p53, Wnt/β-catenin, and PI3K/AKT/GSK-3β signaling pathways. Because of its remarkable role in tumor development, PPA1 may serve as a biological target for adjuvant therapy of tumor malignancies. Further, PPA1 is a potential biomarker to predict survival in patients with cancer, where the assessment of its transcriptional regulation can provide an in-depth understanding. Herein, we describe the signaling pathways through which PPA1 regulates malignant tumor progression and provide new insights to establish PPA1 as a biomarker for tumor diagnosis.

E2F7 enhances hepatocellular carcinoma growth by preserving the SP1/SOX4/Anillin axis via repressing miRNA-383-5p transcription

E2F family participates in most human malignancies by activating the transcription of the cell cycle-related genes. Whereas, as a specifical atypical member of this family, E2F7 was described as a repressor against its downstream genes and exerted oscillatory and controversial functions in cancers. Our previous study identified a molecular interaction promoting hepatocellular carcinoma (HCC) growth induced by SOX4 and Anillin. Meanwhile, we preliminarily identified SP1 as the upstream activator of SOX4. Intriguingly, we observed that the repressive E2F7 presents a remarkable high expression in HCC, and is positively correlated and involved in the same pathway with the potentially SP1/SOX4/Anillin axis. However, their exact interaction or mechanism controlling tumor progress between these genes has not been illustrated. Thus, we focused on this point in this study and attempted to improve the potential regulating axis in HCC cell proliferation and tumor growth for promoting tumor prevention and control. The expression profile of E2F7 in HCC tissues and tumor cells was detected along with the related candidate genes, through real-time quantitative polymerase chain reaction assay, the Western blot analysis, and the immunohistochemistry assay, combined with bioinformatics analysis of the HCC information from the the Cancer Genome Altas and Gene Expression Omnibus data sets. The correlation between E2F7 and HCC patients' clinicopathologic features was explored. Gain-of and loss-of-function assays were conducted both in vitro and in vivo along with the rescue experiment, for revealing the relative genes' functions in HCC progress. The ChIP and the dual-luciferase reporter assays were performed to verify the transcriptional regulating profile between E2F7 and SP1/SOX4/Anillin axis. E2F7 was upregulated in HCC and significantly correlated with SP1/SOX4/Anillin axis. High E2F7 expression is associated with dismal clinicopathologic features and poor survival of the patients. E2F7 depletion potently impaired SP1/SOX4/Anillin expression and significantly inhibited HCC growth. Furthermore, intensive exploration demonstrated that E2F7 preserves high SP1 levels by abrogating miR-383-5p in a transcriptional way. Atypical E2F7 is an important repressive transcription factor commonly upregulated in the HCC environment. E2F7 facilitates HCC growth by repressing miR-383-5p transcription and sequentially promoting SP1/SOX4/Anillin axis. Our findings provide us with probable targets for HCC prevention and therapeutic treatment.

Phosphorylation-mediated interaction between human E26 transcription factor 1 and specific protein 1 is required for tumor cell migration

Transcription factors, human E26 transcription factor 1 (Ets1) and specific protein 1 (Sp1), are known to induce gene expression in tumorigenicity. High Ets1 expression is often associated with colorectal tumorigenesis. In this study, we discover that metastasis and clone formation in SW480 cells mainly depend on the direct interaction between Ets1 and Sp1 instead of high Ets1 expression. The interaction domains are further addressed to be the segment at Sp1(626-708) and the segment at Ets1(244-331). In addition, the phosphorylation inhibition of Ets1 at Tyr283 by either downregulation of Src kinase or Src family inhibitor treatment decreases the interaction between Sp1 and Ets1 and suppresses SW480 migration. Either administration or overexpression of the peptides harboring the interaction segment strongly inhibits the colony formation and migration of SW480 cells. Our findings suggest that the interaction between Ets1 and Sp1 rather than Ets1 alone promotes transformation in SW480 cells and provide new insight into the Ets1 and Sp1 interaction as an antitumour target in SW480 cells.

Impact of ROS-Dependent Lipid Metabolism on Psoriasis Pathophysiology

Psoriasis is the most common autoimmune disease, yet its pathophysiology is not fully understood. It is now believed that psoriasis is caused by the increased activation of immune cells, especially Th1 lymphocytes. However, in psoriasis, immune cells interfere with the metabolism of keratinocytes, leading to their increased activation. Therefore, the pathophysiology of psoriasis is currently associated with the overproduction of ROS, which are involved in the activation of immune cells and keratinocytes as well as the modulation of various signaling pathways within them. Nevertheless, ROS modulate the immune system by also boosting the increasing generation of various lipid mediators, such as products of lipid peroxidation as well as endocannabinoids and prostaglandins. In psoriasis, the excessive generation of ROS and lipid mediators is observed in different immune cells, such as granulocytes, dendritic cells, and lymphocytes. All of the above may be activated by ROS and lipid mediators, which leads to inflammation. Nevertheless, ROS and lipid mediators regulate lymphocyte differentiation in favor of Th1 and may also interact directly with keratinocytes, which is also observed in psoriasis. Thus, the analysis of the influence of oxidative stress and its consequences for metabolic changes, including lipidomic ones, in psoriasis may be of diagnostic and therapeutic importance.

Histone deacetylases modulate resistance to the therapy in lung cancer

The acetylation status of histones located in both oncogenes and tumor suppressor genes modulate cancer hallmarks. In lung cancer, changes in the acetylation status are associated with increased cell proliferation, tumor growth, migration, invasion, and metastasis. Histone deacetylases (HDACs) are a group of enzymes that take part in the elimination of acetyl groups from histones. Thus, HDACs regulate the acetylation status of histones. Although several therapies are available to treat lung cancer, many of these fail because of the development of tumor resistance. One mechanism of tumor resistance is the aberrant expression of HDACs. Specific anti-cancer therapies modulate HDACs expression, resulting in chromatin remodeling and epigenetic modification of the expression of a variety of genes. Thus, HDACs are promising therapeutic targets to improve the response to anti-cancer treatments. Besides, natural compounds such as phytochemicals have potent antioxidant and chemopreventive activities. Some of these compounds modulate the deregulated activity of HDACs (e.g. curcumin, apigenin, EGCG, resveratrol, and quercetin). These phytochemicals have been shown to inhibit some of the cancer hallmarks through HDAC modulation. The present review discusses the epigenetic mechanisms by which HDACs contribute to carcinogenesis and resistance of lung cancer cells to anticancer therapies.

ATXN2-Mediated PI3K/AKT Activation Confers Gastric Cancer Chemoresistance and Attenuates CD8+ T Cell Cytotoxicity

As one of the primary therapeutic choices, chemotherapy is widely adopted for progressive gastric cancer (GC), but the development of chemoresistance has limited chemotherapy efficacy and partly contributes to poor prognosis. Immunotherapy is increasingly being applied in the clinical treatment of GC and is also benefitting patients. To ascertain whether ATXN2 affects chemotherapy efficacy in GC cells and its role in GC immune escape, we performed high-throughput sequencing to clarify genes differentially expressed between 5-FU-resistant and 5-FU-sensitive GC cells and then conducted qRT–PCR to assess ATXN2 expression in GC tissues. Furthermore, the influence of ATXN2 on resistance was studied in vitro and in vivo, ATXN2 and other protein expression levels were detected using Western blotting and immunohistochemistry (IHC), and the direct association of SP1 and ATXN2 was confirmed through luciferase reporter gene analysis. We found elevated ATXN2 in GC tumors and a negative correlation between ATXN2 levels and the prognosis of GC. Furthermore, by activating the PI3K/AKT pathway, ATXN2 was found to promote chemoresistance in GC, facilitating BCL2L1 expression. In GC cells, ATXN2 further stimulated PD-L1 expression and provided better immunotherapy efficacy. Finally, we demonstrated that SP1 transcriptionally regulated the expression of ATXN2 and prompted GC chemoresistance and immune escape. In conclusion, our study reveals the important roles of the SP1/ATXN2/PI3K-AKT/BCL2L1 signalling pathway in GC chemoresistance and of the SP1/ATXN2/PI3K-AKT/PD-L1 signalling pathway in GC immunotherapy. Our findings provide new theories and experimental references for overcoming chemotherapy resistance in GC and enhancing the efficacy of immunotherapy for GC.

Betulinic acid: A natural promising anticancer drug, current situation, and future perspectives

Natural products serve as the single most productive source for the discovery of drugs and pharmaceutical leads. Among the various chemicals derived from microbes, plants, and animals, phytochemicals have emerged as potential candidates for the development of anticancer drugs due to their structural diversities, complexities, and pleiotropic effects. Herein, we discuss betulinic acid (BA), a ubiquitously distributed lupane structured pentacyclic triterpenoid, scrutinized as a promising natural agent for the prevention, suppression, and management of various human malignancies. Ease of availability, common occurrences, cell-specific cytotoxicity, and astonishing selectivity are the important factors that contribute to the development of BA as an anticancer agent. The current review delineates the mechanistic framework of BA-mediated cancer suppression through the modulation of multiple signaling pathways and also summarizes the key outcomes of BA in preclinical investigations.

SP and KLF Transcription Factors in Cancer Metabolism

Tumor development and progression depend on reprogramming of signaling pathways that regulate cell metabolism. Alterations to various metabolic pathways such as glycolysis, oxidative phosphorylation, lipid metabolism, and hexosamine biosynthesis pathway are crucial to sustain increased redox, bioenergetic, and biosynthesis demands of a tumor cell. Transcription factors (oncogenes and tumor suppressors) play crucial roles in modulating these alterations, and their functions are tethered to major metabolic pathways under homeostatic conditions and disease initiation and advancement. Specificity proteins (SPs) and Krüppel-like factors (KLFs) are closely related transcription factors characterized by three highly conserved zinc fingers domains that interact with DNA. Studies have demonstrated that SP and KLF transcription factors are expressed in various tissues and regulate diverse processes such as proliferation, differentiation, apoptosis, inflammation, and tumorigenesis. This review highlights the role of SP and KLF transcription factors in the metabolism of various cancers and their impact on tumorigenesis. A better understanding of the role and underlying mechanisms governing the metabolic changes during tumorigenesis could provide new therapeutic opportunities for cancer treatment.

A conserved long-distance telomeric silencing mechanism suppresses mTOR signaling in aging human fibroblasts

Telomeres are repetitive nucleotide sequences at the ends of each chromosome. It has been hypothesized that telomere attrition evolved as a tumor suppressor mechanism in large long-lived species. Long telomeres can silence genes millions of bases away through a looping mechanism called telomere position effect over long distances (TPE-OLD). The function of this silencing mechanism is unknown. We determined a set of 2322 genes with high positional conservation across replicatively aging species that includes known and candidate TPE-OLD genes that may mitigate potentially harmful effects of replicative aging. Notably, we identified PPP2R2C as a tumor suppressor gene, whose up-regulation by TPE-OLD in aged human fibroblasts leads to dephosphorylation of p70S6 kinase and mammalian target of rapamycin suppression. A mechanistic link between telomeres and a tumor suppressor mechanism supports the hypothesis that replicative aging fulfills a tumor suppressor function and motivates previously unknown antitumor and antiaging strategies.

Transcription factor Sp1 regulates mitotic chromosome assembly and segregation

Aneuploidy is a pervasive feature of cancer cells that results from chromosome missegregation. Several transcription factors have been associated with aneuploidy; however, no studies to date have demonstrated that mammalian transcription factors directly regulate chromosome segregation during mitosis. Here, we demonstrate that the ubiquitously expressed transcription factor specificity protein 1 (Sp1), which we have previously linked to aneuploidy, has a mitosis-specific role regulating chromosome segregation. We find that Sp1 localizes to mitotic centromeres and auxin-induced rapid Sp1 degradation at mitotic onset results in chromosome segregation errors and aberrant mitotic progression. Furthermore, rapid Sp1 degradation results in anomalous mitotic chromosome assembly characterized by loss of condensin complex I localization to mitotic chromosomes and chromosome condensation defects. Consistent with these defects, Sp1 degradation results in reduced chromosome passenger complex activity and histone H3 serine 10 phosphorylation during mitosis, which is essential for condensin complex I recruitment and chromosome condensation. Together, these data provide the first evidence of a mammalian transcription factor acting specifically during mitosis to regulate chromosome segregation.

Regulation of alternative polyadenylation by the C2H2-zinc-finger protein Sp1

Alternative polyadenylation (APA) enhances gene regulatory potential by increasing the diversity of mRNA transcripts. 3' UTR shortening through APA correlates with enhanced cellular proliferation and is a widespread phenomenon in tumor cells. Here, we show that the ubiquitously expressed transcription factor Sp1 binds RNA in vivo and is a common repressor of distal poly(A) site usage. RNA sequencing identified 2,344 genes (36% of the total mapped mRNA transcripts) with lengthened 3' UTRs upon Sp1 depletion. Sp1 preferentially binds the 3' UTRs of such lengthened transcripts and inhibits cleavage at distal sites by interacting with the subunits of the core cleavage and polyadenylation (CPA) machinery. The 3' UTR lengths of Sp1 target genes in breast cancer patient RNA-seq data correlate with Sp1 expression levels, implicating Sp1-mediated APA regulation in modulating tumorigenic properties. Taken together, our findings provide insights into the mechanism for dynamic APA regulation by unraveling a previously unknown function of the DNA-binding transcription factor Sp1.

SP1-Induced Upregulation of lncRNA LINC00659 Promotes Tumour Progression in Gastric Cancer by Regulating miR-370/AQP3 Axis

Growing evidence demonstrates that long noncoding RNAs (lncRNAs) play critical roles in various human tumors. LncRNA LINC00659 (LINC00659) is a newly identified lncRNA and its roles in tumors remain largely unclear. In this study, we elucidated the potential functions and molecular mechanisms of LINC00659 on the biological behaviors of gastric cancer (GC), and also explored its clinical significance. We firstly demonstrated that LINC00659 levels were distinctly up-regulated in both GC specimens and cells using bioinformatics analysis and RT-PCR. The results of ChIP assays and luciferase reporter assays confirmed that upregulation of LINC00659 was activated by SP1 in GC. Clinical assays revealed that higher levels of LINC00659 were associated with TNM stage, lymphatic metastasis, and poorer prognosis. Moreover, LINC00659 was confirmed to be an independent prognostic marker for the patients with GC using multivariate assays. Lost-of-function assays indicated that knockdown of LINC00659 suppressed the proliferation, metastasis, and EMT progress of GC cells in vitro. Mechanistic investigation indicated that LINC00659 served as a competing endogenous RNA (ceRNA) for miR-370, thereby resulting in the upregulation of leading to the depression of its endogenous target gene AQP3. Overall, our present study revealed that the LINC00659/miR-370/AQP3 axis contributes to GC progression, which may provide clues for the exploration of cancer biomarkers and therapeutic targets for GC.

miR-335-5p regulates the proliferation, migration and phenotypic switching of vascular smooth muscle cells in aortic dissection by directly regulating SP1

Uncontrolled proliferation, migration and phenotypic switching of vascular smooth muscle cells (VSMCs) are important steps in the development and progression of aortic dissection (AD). The function and potential mechanism of miR-335-5p in the pathogenesis of AD are explored in this study. Specifically, the biological function of miR-335-5p is explored in vitro through CCK-8, Transwell, immunofluorescence, EdU, wound-healing, RT-qPCR and western blotting assays. In addition, an AD model induced by angiotensin II is used to investigate the function of miR-335-5p in vivo. A dual-luciferase assay is performed to verify the targeting relationship between miR-335-5p and specificity protein 1 (SP1). Experiments involving the loss of SP1 function are performed to demonstrate the function of SP1 in the miR-335-5p-mediated regulation of human aortic-VSMCs (HA-VSMCs). AD tissues and platelet-derived growth factor BB (PDGF-BB)-stimulated HA-VSMCs show significant downregulation of miR-335-5p expression and upregulated SP1 expression. Overexpression of miR-335-5p effectively suppresses cell proliferation, migration and synthetic phenotype markers and enhances contractile phenotype markers induced by PDGF-BB treatment. Additionally, SP1 is identified as a target gene downstream of miR-335-5p, and its expression is negatively correlated with miR-335-5p in AD. Upregulation of SP1 partially reverses the inhibitory effect of miR-335-5p on HA-VSMCs, whereas the downregulation of SP1 has the opposite effect. Furthermore, Ad-miR-335-5p clearly suppresses aorta dilatation and vascular media degeneration in the AD model. Our results suggest that miR-335-5p inhibits HA-VSMC proliferation, migration and phenotypic switching by negatively regulating SP1, and indicate that miR-335-5p may be a potential therapeutic target in AD.

Transcription factor Creb3l1 maintains proteostasis in neuroendocrine cells

OBJECTIVES

Dynamic changes to neuropeptide hormone synthesis and secretion by hypothalamic neuroendocrine cells is essential to ensure metabolic homeostasis. The specialised molecular mechanisms that allow neuroendocrine cells to synthesise and secrete vast quantities of neuropeptides remain ill defined. The objective of this study was to identify novel genes and pathways controlled by transcription factor and endoplasmic reticulum stress sensor Creb3l1 which is robustly activated in hypothalamic magnocellular neurones in response to increased demand for protein synthesis.

METHODS

We adopted a multiomic strategy to investigate specific roles of Creb3l1 in rat magnocellular neurones. We first performed chromatin immunoprecipitation followed by genome sequencing (ChIP-seq) to identify Creb3l1 genomic targets and then integrated this data with RNA sequencing data from physiologically stimulated and Creb3l1 knockdown magnocellular neurones.

RESULTS

The data converged on Creb3l1 targets that code for ribosomal proteins and endoplasmic reticulum proteins crucial for the maintenance of cellular proteostasis. We validated genes that compose the PERK arm of the unfolded protein response pathway including Eif2ak3, Eif2s1, Atf4 and Ddit3 as direct Creb3l1 targets. Importantly, knockdown of Creb3l1 in the hypothalamus led to a dramatic depletion in neuropeptide synthesis and secretion. The physiological outcomes from studies of paraventricular and supraoptic nuclei Creb3l1 knockdown animals were changes to food and water consumption.

CONCLUSION

Collectively, our data identify Creb3l1 as a comprehensive controller of the PERK signalling pathway in magnocellular neurones in response to physiological stimulation. The broad regulation of neuropeptide synthesis and secretion by Creb3l1 presents a new therapeutic strategy for metabolic diseases.

Sp1 induced gene TIMP1 is related to immune cell infiltration in glioblastoma

Tumor immune microenvironment exerts a profound effect on the population of infiltrating immune cells. Tissue inhibitor of matrix metalloproteinase 1 (TIMP1) is frequently overexpressed in a variety of cells, particularly during inflammation and tissue injury. However, its function in cancer and immunity remains enigmatic. In this study, we find that TIMP1 is substantially up-regulated during tumorigenesis through analyzing cancer bioinformatics databases, which is further confirmed by IHC tissue microarrays of clinical samples. The TIMP1 level is significantly increased in lymphocytes infiltrating the tumors and correlated with cancer progression, particularly in GBM. Notably, we find that the transcriptional factor Sp1 binds to the promoter of TIMP1 and triggers its expression in GBM. Together, our findings suggest that the Sp1-TIMP1 axis can be a potent biomarker for evaluating immune cell infiltration at the tumor sites and therefore, the malignant progression of GBM.

Sp1 is overexpressed and associated with progression and poor prognosis in bladder urothelial carcinoma patients

BACKGROUND

Specificity protein 1 (Sp1) is a transcription factor that exerts key functions in the carcinogenesis and progression of various types of cancer. However, its expression and prognostic value in bladder urothelial carcinoma (BUC) have yet to be completely elucidated.

METHODS

The present study performed reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to examine Sp1 mRNA expression in 12 pairs of urothelial carcinoma and adjacent normal bladder tissues. Immunohistochemistry (IHC) was performed in 113 paraffin-embedded urothelial carcinoma tissues to detect the expression of Sp1. Kaplan-Meier plots and Cox proportional hazards regression model were used to analyze the correlation between Sp1 expression and patient prognosis.

RESULTS

The mRNA expression of Sp1 was elevated in the urothelial carcinoma by RT-qPCR compared with their paired normal bladder tissues. Among 113 cases of patients with urothelial carcinoma, there were 39 low histological grade and 74 high histological grade, 61 unifocal tumor and 52 multifocal tumor, 78 cases in Ta, T1, and T2 stages, and 35 cases in T3 and T4 stages. The enhanced expression of Sp1 mRNA was observed in tumors with a high histological grade, and invasive and metastatic samples. Immunohistochemistry revealed that Sp1 high expression was significantly correlated with the histological grade, tumor stage, vascular invasion, lymph node metastasis and distant metastasis (P < 0.05). Kaplan-Meier analysis demonstrated that elevated Sp1 expression in cancer tissue was correlated with a significantly poor overall survival (OS) and disease-free survival (DFS) compared with samples with low Sp1 expression (P < 0.05). Multivariate analyses by Cox's proportional hazard model also revealed that the expression of Sp1 was an independent prognostic factor in urothelial carcinoma.

CONCLUSION

Sp1 expression is significantly elevated in urothelial carcinoma and may be used to identify a subset of patients with aggressive behaviors and poor clinical outcomes. Sp1 is a potential novel independent prognostic biomarker for patients with urothelial carcinoma following surgery.

High Expression of UPK3A Promotes the Progression of Gastric Cancer Cells by Inactivating p53 Pathway

Background

Gastric cancer is a common gastrointestinal tract cancer and is a considerable health burden worldwide. TCGA analysis found Uroplakin 3A (UPK3A) was upregulated in gastric cancer tissues. Our study was designed to investigate the underlying mechanism of Uroplakin 3A (UPK3A) in gastric cancer.

Methods

Data from TCGA database were used to assess the expression, and Kaplan-Meier plotter analysis was used to assess the prognosis value of UPK3A. Furthermore, there are effects of UPK3A silencing on the activity, proliferation, migration, and invasion of human gastric cancer cells (SNU-216 and HGC-27) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, wound healing, and Transwell assays. In addition, the expression of UPK3A, p53, KLF4, ZMAT3, MDM2, and SP1 was detected by qRT-PCR and Western blot assay.

Results

UPK3A was markedly upregulated in gastric cancer tissues compared to that in normal tissues, and patients with high UPK3A level showed poor prognosis. UPK3A was highly expressed in human gastric cancer cell lines compared to that in a normal human gastric epithelial cell line. Silencing of UPK3A inhibited the proliferation, migration, and invasion of gastric cancer cells. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that UPK3A was involved in the p53 signaling pathway. UPK3A suppressed the activation of p53 signaling pathway, and treatment with Pifithrin-α (an inhibitor of the p53 signaling pathway) or silencing of p53 significantly reversed the effect of UPK3A silencing on the expression of p53, KLF4, ZMAT3, MDM2, and SP1.

Conclusion

Our findings showed that UPK3A promotes the progression of gastric cancer by regulating the p53 signaling pathway and could be a potential therapeutic target for gastric cancer.

Inflammatory-Dependent Bidirectional Effect of Bile Acids on NLRP3 Inflammasome and Its Role in Ameliorating CPT-11-Induced Colitis

Irinotecan (CPT-11) in combination with 5-fluorouracil and leucovorin is a first-line chemotherapy regimen for the treatment of colorectal cancer; however, its clinical application is limited by the dose-limiting gastrointestinal toxicity of colitis. In our previous studies, several bile acids (BAs) were found significantly elevated in the colon of the CPT-11-induced rat colitis model. On the other hand, NLRP3 inflammasome has been reported to play important roles in mediating colitis. Interestingly, BA was stated to activate the NLRP3 inflammasome in some studies, while in some other reports, it showed an inhibitory effect. We assumed that the inflammatory status in different circumstances might have contributed to the controversial findings. In this study, we first discovered, under non-inflammatory conditions, that supplementing BA could activate the NLRP3 inflammasome in THP-1-differentiated macrophages and promote inflammation. In lipopolysaccharide (LPS)-induced inflammatory macrophages, however, BA inhibited the NLRP3 inflammasome and reduced inflammation. Further experiments demonstrated that Takeda G protein-coupled receptor 5 (TGR5) is essential in mediating the inhibitory effect of BA, while phospho-SP1 (p-SP1) is key to the activation. Furthermore, we applied the above findings to ameliorate CPT-11-caused colitis in rats by inhibiting SP1 with mithramycin A (MitA) or activating TGR5 using oleanolic acid (OA). Our findings may shed light on the discovery of effective interventions for reducing dose-limiting chemotherapy-induced colitis.

Potential Role of Silencing Ribonucleic Acid for Esophageal Cancer Treatment

INTRODUCTION

Esophageal cancer is an aggressive malignancy with high mortality. Optimal treatment of esophageal cancer remains an elusive goal. Ribonucleic acid (RNA) interference is a novel potential targeted approach to treat esophageal cancer. Targeting oncogenes that can alter critical cellular functions with silencing RNA molecules is a promising approach. The silencing of specific oncogenes in esophageal cancer cells in the experimental setting has been shown to decrease the expression of oncogenic proteins. This has resulted in cell apoptosis, reduction in cell proliferation, reduced invasion, migration, epithelial-mesenchymal transition, decrease in tumor angiogenesis and metastasis, and overcoming drug resistance. The Hedgehog (Hh) signaling pathway has been shown to be involved in esophageal adenocarcinoma formation in a reflux animal model. In addition to Hh, we will focus on other targets with clinical potential in the treatment of esophageal cancer.

MATERIALS AND METHODS

We searched for articles published from 2005 to August 2020 that studied the siRNA effects on inhibiting esophageal cancer formation in experimental settings. We used combinations of the following terms for searching: "esophageal cancer," "RNA interference," "small interfering RNA," "siRNA," "silencing RNA," "Smoothened (Smo)," "Gli," "Bcl-2," "Bcl-XL," "Bcl-W,″ "Mcl-1," "Bfl-1," "STAT3,"and "Hypoxia inducible factor (HIF)". A total of 21 relevant articles were found.

RESULTS AND CONCLUSIONS

Several proto-oncogenes/oncogenes including Hh pathway mediators, glioma-associated oncogene homolog 1 (Gli-1), Smoothened (Smo), and antiapoptotic Bcl-2 have potential as targets for silencing RNA in the treatment of esophageal cancer.