Circadian Rhythm Is Disrupted by ZNF704 in Breast Carcinogenesis

Circular RNA HSDL2 promotes breast cancer progression via miR-7978 ZNF704 axis and regulating hippo signaling pathway

Circular RNAs (circRNAs) are a new group of endogenous RNAs recently found to be involved in the development of various diseases, including their confirmed involvement in the progression of several types of cancers. Unluckily, the abnormal expression and functions of circRNAs in breast cancer shall be further investigated. This work aims to elucidate the action and molecular mechanism of circHSDL2 in the malignant progression of breast cancer. Differential expression profiles of circRNAs in breast cancer tissues relative to normal breast tissues and in the exosomes of breast cancer patients compared to healthy women were analyzed from databases to identify potentially functional circRNAs. CircHSDL2 was selected for further investigation. Cell proliferation, migration and invasion assays were done to assess the effect of circHSDL2 overexpression on breast cancer cells. Bioinformatics test and dual-luciferase reporter experiments were done to explore the interaction between circHSDL2 and miRNA. Downstream target genes were further investigated through proteomics analysis and Western blotting. The influence of circHSDL2 on breast cancer in vivo was evaluated through xenograft experiments in nude mice. Functional analysis demonstrated circHSDL2 overexpression promoted the division, movement, and invasion of breast cancer cells both in vivo and in vitro. Mechanistically, circHSDL2 acted as a sponge for miR-7978 to affect ZNF704 expression and thereby regulate the Hippo pathway in breast cancer cells. In conclusion, circHSDL2 regulates the Hippo pathway through the miR-7978/ZNF704 axis to facilitate the malignancy of breast cancer. This may be a potential biomarker and treatment target.

The contribution of circadian clock to the biological processes

All organisms have various circadian, behavioral, and physiological 24-h periodic rhythms, which are controlled by the circadian clock. The circadian clock controls various behavioral and physiological rhythms. In mammals, the primary circadian clock is present in the suprachiasmatic nucleus of the hypothalamus. The rhythm of the circadian clock is controlled by the interaction between negative and positive feedback loops, consisting of crucial clock regulators (including Bmal1 and Clock), three cycles (mPer1, mPer2, and mPer3), and two cryptochromes (Cry1 and Cry2). The development of early mammalian embryos is an ordered and complex biological process that includes stages from fertilized eggs to blastocysts and undergoes important morphological changes, such as blastocyst formation, cell multiplication, and compaction. The circadian clock affects the onset and timing of embryonic development. The circadian clock affects many biological processes, including eating time, immune function, sleep, energy metabolism, and endocrinology, therefore, it is also crucial for overall health, growth and development after birth. This review summarized the effects of the circadian clock in the body's physiological activities. A new strategy is proposed for the prevention of malformations or diseases by regulating the circadian clock or changing circadian rhythms.

E3 ubiquitin ligase UBR5 modulates circadian rhythm by facilitating the ubiquitination and degradation of the key clock transcription factor BMAL1

The circadian clock is the inner rhythm of life activities and is controlled by a self-sustained and endogenous molecular clock, which maintains a ~ 24 h internal oscillation. As the core element of the circadian clock, BMAL1 is susceptible to degradation through the ubiquitin-proteasome system (UPS). Nevertheless, scant information is available regarding the UPS enzymes that intricately modulate both the stability and transcriptional activity of BMAL1, affecting the cellular circadian rhythm. In this work, we identify and validate UBR5 as a new E3 ubiquitin ligase that interacts with BMAL1 by using affinity purification, mass spectrometry, and biochemical experiments. UBR5 overexpression induced BMAL1 ubiquitination, leading to diminished stability and reduced protein level of BMAL1, thereby attenuating its transcriptional activity. Consistent with this, UBR5 knockdown increases the BMAL1 protein. Domain mapping discloses that the C-terminus of BMAL1 interacts with the N-terminal domains of UBR5. Similarly, cell-line-based experiments discover that HYD, the UBR5 homolog in Drosophila, could interact with and downregulate CYCLE, the BMAL1 homolog in Drosophila. PER2-luciferase bioluminescence real-time reporting assay in a mammalian cell line and behavioral experiments in Drosophila reveal that UBR5 or hyd knockdown significantly reduces the period of the circadian clock. Therefore, our work discovers a new ubiquitin ligase UBR5 that regulates BMAL1 stability and circadian rhythm and elucidates the underlying molecular mechanism. This work provides an additional layer of complexity to the regulatory network of the circadian clock at the post-translational modification level, offering potential insights into the modulation of the dysregulated circadian rhythm.

Zinc finger protein 468 up-regulation of TFAM contributes to the malignant growth and cisplatin resistance of breast cancer cells

BACKGROUND

Because of the progress on the diagnosis and treatment for patients with breast cancer (BC), the overall survival of the patients has been improved. However, a number of BC patients cannot benefit from the existing therapeutic strategies as the essential molecular events triggering the development of BC are not well understood. Previous studies have shown that abnormal expression of zinc finger proteins is involved in the development of various malignancies, whereas it remains largely unclear on their significance during the progression of BC. In this study, we aimed to explore the clinical relevance, cellular function and underlying mechanisms of zinc finger protein 468 (ZNF468) in BC.

METHODS

The clinical relevance of ZNF468 and TFAM was analyzed based on TCGA database. Overexpression or knockdown of ZNF468 and TFAM were performed by transfecting the cells with overexpression plasmids and siRNAs, respectively. Overexpression and knockdown efficacy was checked by immunoblotting. CCK-8, colony formation, transwell and apoptosis experiments were conducted to check the cellular function of ZNF468 and TFAM. The content of mtDNA was measured by the indicated assay kit. The effects of cisplatin on BC cells were detected by CCK-8 and colony formation assays. The regulation of ZNF468 on TFAM was analyzed by RT-qPCR, immunoblotting, dual luciferase activity and ChIP-qPCR assays.

RESULTS

ZNF468 was overexpressed in BC patients and inversely correlated with their prognosis. Based on overexpression and knockdown assays, we found that ectopic expression of ZNF468 was essential for the proliferation, growth and migration of BC cells. The expression of ZNF468 also negatively regulated the sensitivity of BC cells to the treatment of cisplatin. Mechanistically, ZNF468 potentiated the transcription activity of TFAM gene via direct binding on its promoter. Lastly, we demonstrated that ZNF468 up-regulation of TFAM was important for the growth, migration and cisplatin resistance in BC cells.

CONCLUSION

Our study indicates that ZNF468 promotes BC cell growth and migration via transcriptional activation of TFAM. ZNF468/TFAM axis can serve as the diagnostic and therapeutic target, as well as the predictor of cisplatin effectiveness in BC patients.

Molecular mechanisms of artificial light at night affecting circadian rhythm disturbance

Artificial light at night (ALAN) pollution has been regarded as a global environmental concern. More than 80% of the global population is exposed to light pollution. Exacerbating this issue, artificially lit outdoor areas are growing by 2.2% per year, while continuously lit areas have brightened by 2.2% each year due to rapid population growth and expanding urbanization. Furthermore, the increasing prevalence of night shift work and smart device usage contributes to the inescapable influence of ALAN. Studies have shown that ALAN can disrupt endogenous biological clocks, resulting in a disturbance of the circadian rhythm, which ultimately affects various physiological functions. Up until now, scholars have studied various disease mechanisms caused by ALAN that may be related to the response of the circadian system to light. This review outlines the molecular mechanisms by which ALAN causes circadian rhythm abnormalities in sleep disorders, endocrine diseases, cardiovascular disease, cancer, immune impairment, depression, anxiety and cognitive impairments.

Circadian Regulator-Mediated Molecular Subtypes Depict the Features of Tumor Microenvironment and Indicate Prognosis in Head and Neck Squamous Cell Carcinoma

Introduction

Circadian rhythm is involved in multiple biological activities and implicated in cancer development. However, the role of circadian rhythm in head and neck squamous cell carcinoma (HNSCC) has not been fully interpreted yet. Herein, the present study set out to explore the significance of circadian regulator genes (CRGs) in HNSCC.

Materials and Methods

The molecular landscape and clinical significance of 13 CRGs in HNSCC were explored based on The Cancer Genome Atlas (TCGA). The biological functions of PER3, a key CRG, were validated by cellular experiments. The correlation of CRGs with microenvironment, pathway activities, and prognosis was determined by bioinformatic algorithms. A novel circadian score was introduced to evaluate the circadian modification pattern of each patient and further validated in an independent cohort from the Gene Expression Omnibus (GEO) dataset.

Results

CRGs presented high heterogeneity in HNSCC at both genomic and transcriptomic levels. Specifically, PER3 indicated a better prognosis and inhibited HNSCC cell proliferation. Moreover, HNSCC tissues displayed three circadian regulator patterns with distinct clinical outcomes, transcriptomic characteristics, and microenvironment features. Circadian score was an independent risk factor and exhibited excellent predictive efficiency in both the training cohort from the TCGA database and the validation cohort from the GEO database.

Conclusions

CRGs played an indispensable role in HNSCC development. An in-depth exploration of circadian rhythm would improve the understanding of HNSCC carcinogenesis and confer novel insights for future clinical practices.

Nuclear complement C3b promotes paclitaxel resistance by assembling the SIN3A/HDAC1/2 complex in non-small cell lung cancer

In addition to the classical role as a serum effector system of innate immunity, accumulating evidence suggests that intracellular complement components have indispensable functions in immune defense, T cell homeostasis, and tumor cell proliferation and metastasis. Here, we revealed that complement component 3 (C3) is remarkably upregulated in paclitaxel (PTX)-resistant non-small cell lung cancer (NSCLC) cells and that knockdown of C3 promoted PTX-induced cell apoptosis, sensitizing resistant cells to PTX therapy. Ectopic C3 decreased PTX-induced apoptosis and induced resistance to PTX treatment in original NSCLC cells. Interestingly, C3b, the activated fragment of C3, was found to translocate into the nucleus and physically associate with the HDAC1/2-containing SIN3A complex to repress the expression of GADD45A, which plays an important role in cell growth inhibition and apoptosis induction. Importantly, C3 downregulated GADD45A by enhancing the binding of the SIN3A complex with the promoter of GADD45A, thus decreasing the H3Ac level to compress chromatin around the GADD45A locus. Subsequently, ectopic GADD45A promoted PTX-induced cell apoptosis, sensitizing resistant cells to PTX therapy, and insufficiency of GADD45A in original cancer cells induced resistance to PTX treatment. These findings identify a previously unknown nucleus location and oncogenic property for C3 in chemotherapy and provide a potential therapeutic opportunity to overcome PTX resistance.

HMGN1 enhances CRISPR-directed dual-function A-to-G and C-to-G base editing

C-to-G base editors have been successfully constructed recently, but limited work has been done on concurrent C-to-G and A-to-G base editing. In addition, there is also limited data on how chromatin-associated factors affect the base editing. Here, we test a series of chromatin-associated factors, and chromosomal protein HMGN1 was found to enhance the efficiency of both C-to-G and A-to-G base editing. By fusing HMGN1, GBE and ABE to Cas9, we develop a CRISPR-based dual-function A-to-G and C-to-G base editor (GGBE) which is capable of converting simultaneous A and C to G conversion with substantial editing efficiency. Accordingly, the HMGN1 role shown in this work and the resulting GGBE tool further broaden the genome manipulation capacity of CRISPR-directed base editors.

Elevated ZNF704 expression is associated with poor prognosis of uveal melanoma and promotes cancer cell growth by regulating AKT/mTOR signaling

BACKGROUND

Uveal melanoma (UM) is the most common intraocular malignancy in adults, with a poor survival prognosis. To date, limited understanding of UM's molecular mechanisms constitutes an obstacle to developing effective therapy. In this study, we examined key regulators mediating UM progression and their clinical relevance.

METHODS

Transcriptomics of UM patients and cells were analyzed via RNA sequencing and bioinformatic analysis. Zinc finger protein 704 (ZNF704) was identified as prognosis-related biomarker for UM based on clinical characteristics and RNA-seq data from The Cancer Genome Atlas (TCGA). Gene expression was knocked down by specific shRNAs/siRNAs and overexpressed by transfection with plasmids inserted with investigated gene cDNA. Cell proliferation, viability and invasion abilities were determined by CCK8, colony formation and transwell assays, respectively. For cell cycle and apoptosis, cells were PI or PI/Annexin V-APC stained and analyzed by flow cytometry. Standard immunoblotting and quantitative RT-PCR were employed to assess the mRNA and protein abundance. To determine tumor growth in vivo, 4-week-old BALB/c-nu immune-deficient nude mice were inoculated with tumor cells.

RESULTS

Analysis of differential expressed genes (DEGs) and survival analysis identified ZNF704 as a novel biomarker of UM. Prognostic analysis indicated ZNF704 as an independent predictor of UM overall survival. Expression of ZNF704 is elevated in UM tissues relative to adjacent normal choroid tissues. Knockdown of ZNF704 suppressed the growth and migration of UM cells and vice versa. In addition, expression of ZNF704 arrest UM cells at G0/G1 phase and inhibit cell apoptosis. RNA sequencing analysis indicated that SORBS3 were dysregulated after ZNF704 downregulation. Gene Set Enrichment Analysis (GSEA) revealed that upon ZNF704 knowndown, genes related with PI3K/AKT/mTOR, EMT and metastasis are enriched. Mechanistically, ZNF704 activates AKT/mTOR/glycolysis signaling pathway in UM cells. Moreover, expression of SORBS3 is downregulated by ZNF704 and knockdown of SORBS3 restored tumor cell viability in ZNF704 silenced cells.

CONCLUSIONS

ZNF704 predicts poor prognosis of UM and exhibit pro-oncogenic effect in UM progression in vivo and in vitro, mediated through AKT/mTOR signaling pathway and suppression of SORBS3 expression.

Pioneer Factor Improves CRISPR-Based C-To-G and C-To-T Base Editing

Base editing events in eukaryote require a compatible chromatin environment, but there is little research on how chromatin factors contribute to the editing efficiency or window. By engineering BEs (base editors) fused with various pioneer factors, the authors found that SOX2 substantially increased the editing efficiency for GBE and CBE. While SoxN-GBE (SOX2-NH3-GBE) improved the editing efficiency at overall cytosines of the protospacer, SoxM-GBE/CBE (SOX2-Middle-GBE/CBE) enabled the higher base editing at PAM-proximal cytosines. By separating functional domains of SOX2, the SadN-GBE (SOX2 activation domain-NH3-GBE) is constructed for higher editing efficiency and SadM-CBE for broader editing window to date. With the DNase I assay, it is also proved the increased editing efficiency is most likely associated with the induction of chromatin accessibility by SAD. Finally, SadM-CBE is employed to introduce a stop codon in the proto-oncogene MYC, at a locus rarely edited by previous editors with high efficiency. In this work, a new class of pioneer-BEs is constructed by fusion of pioneer factor or its functional domains, which exhibits higher editing efficiency or broader editing window in eukaryote.

Obesity, cancer risk, and time-restricted eating

Obesity and the associated metabolic syndrome is considered a pandemic whose prevalence is steadily increasing in many countries worldwide. It is a complex, dynamic, and multifactorial disorder that presages the development of several metabolic, cardiovascular, and neurodegenerative diseases, and increases the risk of cancer. In patients with newly diagnosed cancer, obesity worsens prognosis, increasing the risk of recurrence and decreasing survival. The multiple negative effects of obesity on cancer outcomes are substantial, and of great clinical importance. Strategies for weight control have potential utility for both prevention efforts and enhancing cancer outcomes. Presently, time-restricted eating (TRE) is a popular dietary intervention that involves limiting the consumption of calories to a specific window of time without any proscribed caloric restriction or alteration in dietary composition. As such, TRE is a sustainable long-term behavioral modification, when compared to other dietary interventions, and has shown many health benefits in animals and humans. The preliminary data regarding the effects of time-restricted feeding on cancer development and growth in animal models are promising but studies in humans are lacking. Interestingly, several short-term randomized clinical trials of TRE have shown favorable effects to reduce cancer risk factors; however, long-term trials of TRE have yet to investigate reductions in cancer incidence or outcomes in the general population. Few studies have been conducted in cancer populations, but a number are underway to examine the effect of TRE on cancer biology and recurrence. Given the simplicity, feasibility, and favorable metabolic improvements elicited by TRE in obese men and women, TRE may be useful in obese cancer patients and cancer survivors; however, the clinical implementation of TRE in the cancer setting will require greater in-depth investigation.

Nuclear Receptor Coregulators in Hormone-Dependent Cancers

Nuclear receptors (NRs) function collectively as a transcriptional signaling network that mediates gene regulatory actions to either maintain cellular homeostasis in response to hormonal, dietary and other environmental factors, or act as orphan receptors with no known ligand. NR complexes are large and interact with multiple protein partners, collectively termed coregulators. Coregulators are essential for regulating NR activity and can dictate whether a target gene is activated or repressed by a variety of mechanisms including the regulation of chromatin accessibility. Altered expression of coregulators contributes to a variety of hormone-dependent cancers including breast and prostate cancers. Therefore, understanding the mechanisms by which coregulators interact with and modulate the activity of NRs provides opportunities to develop better prognostic and diagnostic approaches, as well as novel therapeutic targets. This review aims to gather and summarize recent studies, techniques and bioinformatics methods used to identify distorted NR coregulator interactions that contribute as cancer drivers in hormone-dependent cancers.

U2 small nuclear RNA auxiliary factor 2, transcriptionally activated by the transcription factor Dp-1/E2F transcription factor 1 complex, enhances the growth and aerobic glycolysis of leiomyosarcoma cells

The dysregulation of U2 Small Nuclear RNA Auxiliary Factor 2 (U2AF2) is associated with malignant behaviors of multiple types of tumors. In this study, we explored the association between U2AF2 dysregulation and the survival of patients with primary leiomyosarcoma, the regulatory effect of U2AF2 on cell growth/aerobic glycolysis, and the mechanisms of U2AF2 dysregulation at the transcriptional level. Gene expression and survival time of patients with primary leiomyosarcoma were extracted from TCGA-Sarcoma (SARC). Leiomyosarcoma cell lines SK-LMS-1 and SK-UT-1 were utilized to construct in vitro and in vivo models. Results showed that the higher U2AF2 expression group had significantly shorter progression-free survival (HR: 2.049, 95%CI: 1.136-3.697, p = 0.011) and disease-specific survival (4.656, 95%CI: 2.141-10.13, p < 0.001) compared to the lower U2AF2 expression group. U2AF2 knockdown suppressed leiomyosarcoma cell growth and aerobic glycolysis (decreased glucose uptake, lactate production, and extracellular acidification rate) in vitro. Tumors derived from SK-LMS-1 cells with U2AF2 knockdown grew significantly slower, with lower GLUT1, PGK1, and PGAM1 protein expression than the control groups. TFDP1 and E2F1 could interact with each other in leiomyosarcoma cells. Both TFDP1 and E2F1 could bind to the promoter of U2AF2 and exert a synergistic activating effect on U2AF2 transcription. In conclusion, this study revealed that U2AF2 upregulation is associated with poor survival of leiomyosarcoma. Its upregulation enhances proliferation and aerobic glycolysis of leiomyosarcoma cells in vitro and in vivo. TFDP1 and E2F1 can form a complex, which binds to the U2AF2 gene promoter and synergistically activates its transcription.

The Circadian Clock and Cancer: Links between Circadian Disruption and Disease Pathology

There is growing evidence that disruption of our 24-hour clock increases our risk for acquiring several diseases and disorders. One of these diseases is cancer. While the mechanistic links between circadian clock disruption and cancer initiation or progression are an active area of study, significantly more work needs to be done to understand the molecular substrates involved. Of particular complexity remains the functions of the clock in individual cells during the process of transformation (cancer initiation) vs. the functions of the clock in tumor-surrounding stroma in the process of tumor progression or metastasis. Indeed, the nexus of cellular circadian dynamics, metabolism, and carcinogenesis is drawing more attention, and many new studies are now highlighting the critical role of circadian rhythms and clock proteins in cancer prevention. In this brief review, we cover some of the basic mechanisms reported to link circadian disruption and cancer at the level of gene expression and metabolism. We also review some of the human studies addressing circadian disruption and cancer incidence as well as some controlled laboratory studies connecting the two in pre-clinical models. Finally, we discuss the tremendous opportunity to use circadian approaches for future prevention and treatment in the context of cancer in specific organs.

Identification of ZNF704 as a Novel Oncogene and an Independent Prognostic Marker in Chondrosarcoma

Purpose

The transcription factor zinc finger protein 704 (ZNF704) is implicated in tumorigenesis. However, the underlying role of ZNF704 in the pathogenesis of chondrosarcoma remains not well delineated. This study investigates the expression level, prognostic significance and potential biological function of ZNF704 in human chondrosarcoma.

Materials and Methods

The mRNA and protein levels of ZNF704 in fresh chondrosarcomas and the paired adjacent non-tumor tissues were evaluated using real-time PCR and immunoblotting, respectively. The protein expression of ZNF704 in chondrosarcoma specimens was detected by immunohistochemistry, and the associations among its expression level, clinicopathological characteristics and prognosis were further investigated. Cell viability, colony formation and apoptosis assay were determined in chondrosarcoma cells and a xenograft model with ZNF704 knockdown.

Results

The expression levels of ZNF704 mRNA and protein in chondrosarcoma tissues were significantly higher than those in the paired adjacent non-tumor tissues and benign cartilage tumors. Clinicopathological analysis revealed that ZNF704 was expressed at higher levels in chondrosarcoma patients with higher histological grade and advanced MSTS stage. We also found that high expression of ZNF704 significantly correlated with a worse overall survival of chondrosarcoma patients. Multivariate Cox regression analysis indicated that ZNF704 was an independent prognostic marker in chondrosarcoma patients. Our in vitro studies demonstrated that knockdown of ZNF704 markedly inhibited chondrosarcoma cell viability, colony formation and induced apoptosis. In a nude mouse xenograft model, ZNF704 knockdown slowed down chondrosarcoma growth by inducing apoptosis in vivo.

Conclusion

These findings suggest that ZNF704 may act as a potent oncogene implicated in chondrosarcoma development, and serve as a independent prognostic marker, highlight the potential of ZNF704 as a novel biomarker and therapeutic target for chondrosarcoma.