Cyclins and cell cycle checkpoints

Effect of long-stranded non-coding RNA-BANCR on the progression of thyroid papillary carcinoma and its mechanism

OBJECTIVE

This study aims to investigate the role of BRAF-activated long non-coding RNA (BANCR) in papillary thyroid carcinoma (PTC) progression and its association with clinical and molecular characteristics.

METHODS

Sixteen PTC patients were stratified into four groups (PTC, HT, HT-LNM, and PTC-LNM) based on cervical lymph node metastasis and concurrent Hashimoto's thyroiditis (HT) to explore BANCR expression and its relationship with immune-related factors and tumor microenvironment (TME). Functional assays, including Transwell invasion, colony formation, and CCK8 were performed to evaluate the biological effects of BANCR in PTC cell lines. Bioinformatics analysis further identified BANCR-related pathways and clinical relevance.

RESULTS

BANCR expression was significantly reduced in PTC tissues compared to normal thyroid tissues and was inversely correlated with tumor grade, lymph node metastasis, and T stage. Overexpression of BANCR in PTC cell lines inhibited proliferation, invasion and migration. Bioinformatics analysis demonstrated significant associations between BANCR and immune cell infiltration, immune-related genes, and stromal scores.

CONCLUSIONS

BANCR acts as a tumor suppressor in PTC, suppressing tumor growth and metastasis. These findings provide insights into BANCR's potential as a prognostic marker and therapeutic target in PTC.

SERCA2 dysfunction accelerates angiotensin II-induced aortic aneurysm and atherosclerosis by induction of oxidative stress in aortic smooth muscle cells

BACKGROUND AND AIM

Our previous research indicates that sarcoplasmic/endoplasmic reticulum calcium ATPase 2 (SERCA2) dysfunction facilitates the phenotypic transformation of aortic smooth muscle cells (ASMCs) and intensifies aortic aneurysm through the regulation of calcium-dependent pathways and endoplasmic reticulum stress. Our hypothesis is that additional mechanisms are involved in aortic aneurysm and atherosclerosis induced by SERCA2 dysfunction from the perspective of ASMC phenotypic transformation.

METHODS & RESULTS

In SERCA2 dysfunctional mice and their control littermates, ASMCs were isolated to analyze protein expression and cell functions, and angiotensin II was infused into these mice that were backcrossed into LDL receptor deficient background to induce aortic aneurysm and atherosclerosis. In ASMCs from SERCA2 dysfunctional mice, the cell cycle was accelerated, and proliferation and migration were enhanced, which could be reversed by SERCA agonist CDN1163 or calcium chelator BAPTA-AM. In ASMCs, SERCA2 dysfunction increased reactive oxygen species (ROS) production, activating extracellular signal-regulated kinases 1 and 2 (ERK1/2) and angiotensin II/angiotensin II type 1 receptor (AT1R) pathways. Both ERK1/2 and angiotensin II/AT1R activations are implicated in SERCA2 dysfunction-induced ASMC phenotypic transformation and ROS production. The redox modulator Tempol suppressed ERK1/2 and angiotensin II/AT1R pathways, inhibiting ASMC phenotypic transformation and alleviating angiotensin II-induced aortic aneurysm and atherosclerosis.

CONCLUSION

SERCA2 dysfunction accelerates aortic aneurysm and atherosclerosis by inducing oxidative stress in ASMCs, with activations of ERK1/2 and angiotensin II/AT1R involved in ASMC phenotypic transformation. Inhibition of oxidative stress in ASMCs is beneficial in alleviating angiotensin II-induced aortic aneurysm and atherosclerosis caused by SERCA2 dysfunction.

The role of cell cycle-related genes in the tumorigenesis of adrenal and thyroid neuroendocrine tumors

The molecular mechanisms underlying adrenal and thyroid neuroendocrine tumors, including their tumorigenesis, progression, and metastasis, involve unique pathways regulating cell cycle progression. To better understand these mechanisms and pathways, extensive in-depth research on cell cycle-related genes is necessary. This review aims to describe and interpret current single-cell RNA sequencing studies on neuroblastoma, medullary thyroid cancer, and pheochromocytoma tumors. Our review summarizes differentially expressed cell cycle-related genes with distinct functions, highlighting their potential as therapeutic targets and components of panels used to determine tumor type or aggressiveness. Although some insights have been gained, there is still limited information on these topics, and further research is required to explore the regulatory mechanisms of these tumors.

Castration-resistant prostate cancer is resensitized to androgen deprivation by autophagy-dependent apoptosis induced by blocking SKP2

Resistance to androgen receptor (AR)-targeted therapies for prostate cancer (PCa) is characteristic of an aggressive subtype called castration-resistant prostate cancer (CRPC) and is often associated with tumor relapse. Both relapse and poor prognosis in patients with CRPC are associated with increased abundance of the E3 ubiquitin ligase SKP2. Therefore, we investigated the therapeutic potential of combined inhibition of AR and SKP2 for CRPC. We found that combined targeting of AR and SKP2 with small-molecule inhibitors decreased proliferation in two CRPC cell lines in culture and in xenografts in humanized mice. Furthermore, combined therapy in mice markedly decreased the growth of Pten/Trp53 double-knockout tumors, a particularly invasive model of CRPC, whereas disruption of either AR or SKP2 alone only modestly suppressed their growth. Mechanistically, the inhibition of SKP2 in CRPC cells induced autophagy-dependent apoptosis and promoted luminal-associated phenotypes, which promoted responsiveness to AR-targeted therapy. These effects were further enhanced by coinhibition of AR and were not induced by the AR inhibitor alone. Our findings indicate that targeting both AR and SKP2 signaling pathways is necessary to treat CRPC.

Exploring the Complexity of Pan-Cancer: Gene Convergences and in silico Analyses

Cancer is a complex and multifaceted group of diseases characterized by highly intricate mechanisms of tumorigenesis and tumor progression, which complicates diagnosis, prognosis, and treatment. In recent years, targeted therapies have gained prominence by focusing on specific mutations and molecular features unique to each tumor type, offering more effective and personalized treatment options. However, it is equally critical to explore the genetic commonalities across different types of cancer, which has led to the rise of pan-cancer studies. These approaches help identify shared therapeutic targets across various tumor types, enabling the development of broader and potentially more widely applicable treatment strategies. This review aims to provide a comprehensive overview of key concepts related to tumors, including tumorigenesis processes, the tumor microenvironment, and the role of extracellular vesicles in tumor biology. Additionally, we explore the molecular interactions and mechanisms driving tumor progression, with a particular focus on the pan-cancer perspective. To achieve this, we conducted an in silico analysis using publicly available datasets, which facilitated the identification of both common and divergent genetic and molecular patterns across different tumor types. By integrating these diverse areas, this review offers a clearer and deeper understanding of the factors influencing tumorigenesis and highlights potential therapeutic targets.

Unlocking the role of miR-17: Driving G1-S cell cycle transition in oral tongue cancer through integrated bioinformatics and laboratory analyses

OBJECTIVE

This study aims to identify miRNA-mediated regulation of the cell cycle in oral tongue cancer.

METHODS

Comprehensive computational analysis was performed on the GEO dataset "GSE168227". DIANA Tool-mir path v.3, STRING, Cytoscape 3.6.0, Enrichr, and TargetScan Human 7.2 were utilized to identify and analyze miRNAs and their targets in oral tongue cancer. The identified miRNA and its target genes were further analyzed in oral tongue cancer patients using qPCR and immunohistochemistry (IHC).

RESULTS

Computational analysis revealed miR-17 as a differentially expressed miRNA in oral tongue cancer. Database analysis indicated potential binding sites of miR-17 for CDKN1A and CCND1 mRNA at 3'-UTR. In oral tongue cancer samples, miR-17, CDKN1A, and CCND1expression were upregulated compared to controls. IHC demonstrated overexpression of p21 and Cyclin D1 across various tumor grades, with predominant cytoplasmic expression of p21 observed in oral tongue cancer samples.

CONCLUSION

The findings suggest that miR-17 may regulate the G1-S transition of the cell cycle in oral tongue cancer. Further validation and functional studies are warranted to confirm their role as biomarkers.

Ulp1 Regulates Cell Proliferation Through INO1 in Pichia pastoris

BACKGROUND/OBJECTIVES

Ulp1 is a vital regulator of the cell cycle, with its absence leading to G2/M phase arrest in Saccharomyces cerevisiae. This study aims to investigate the role of Ulp1 in cell cycle regulation in Pichia pastoris and to elucidate its mechanisms of action, particularly through the modulation of the gene INO1.

METHODS

We generated Ulp1 knockout strains in Pichia pastoris using the FLP-FRT system and performed RNA sequencing (RNA-seq) to analyze gene expression changes. We assessed cell proliferation in Ulp1 knockout and INO1 overexpressing strains, as well as the effects of inositol supplementation.

RESULTS

Our findings revealed significant downregulation of INO1 and other genes in Ulp1 knockout strains. Importantly, overexpression of INO1 restored cell proliferation, indicating that Ulp1 regulates this process via INO1. Notably, supplementation with exogenous inositol did not rescue cell proliferation, suggesting that the enzymatic activity of INO1 is not required for Ulp1's regulatory function.

CONCLUSIONS

This study demonstrates that Ulp1 modulates cell proliferation in Pichia pastoris through INO1, independent of its enzymatic activity. These insights enhance our understanding of Ulp1's role in cell cycle regulation and open new avenues for exploring the molecular mechanisms governing yeast cell division. Further investigations are warranted to delineate the intricate regulatory pathways involved in this process.

Inhibition of DNA Topoisomerase Ι by Flavonoids and Polyacetylenes Isolated from Bidens pilosa L

Human DNA topoisomerase I (Topo I) is an essential enzyme in regulating DNA supercoiling during transcription and replication, and it is an important therapeutic target for anti-tumor agents. Bidens pilosa L. is a medicinal herb that is used as a folk medicine for cancers in China. A new flavonoid (1) and a new polyacetylene (20), along with eighteen flavonoids (2-19) and nine polyacetylenes (21-29), were isolated and identified from the methanol extract of the whole plant of B. pilosa, and some of the compounds (4, 5, 6 and 7) exhibited potent cytotoxicity against a panel of five human cancer cell lines. The DNA relaxation assay revealed that some flavonoids and polyacetylenes exerted inhibitory activities on human DNA Topo I, among them compounds 1, 2, 5, 6, 7, 8, 15, 19, 20, 22, and 24 were the most active ones, with IC50 values of 393.5, 328.98, 145.57, 239.27, 224.38, 189.84, 89.91, 47.5, 301.32, 178.03, and 218.27 μM, respectively. The structure-activity analysis of flavonoids was performed according to the results from the Topo I inhibition assay. The DNA content analysis revealed that 5, 6, and 7 potently arrested cell cycle at the G1/S and G2/M phases in human colon cancer cell DLD-1 depending on the concentration of the inhibitors. The levels of protein expression related to the G1/S and G2/M cell cycle checkpoints were in accordance with the results from the DNA content analysis. These findings suggest that flavonoids are one of the key active ingredients accounting for the anti-tumor effect of B. pilosa.

MDM2: current research status and prospects of tumor treatment

Mousedouble minute 2 (MDM2) is one of the molecules activated by p53 and plays an important role in the regulation of p53. MDM2 is generally believed to function as a negative regulator of p53 by facilitating its ubiquitination and subsequent degradation. Consequently, blocked p53 activity often fails in damaged cells to undergo cell cycle arrest or apoptosis. Given that around 50% of human cancers involve the inactivation of p53 through genetic mutations, and directly targeting p53 through drug development has limited feasibility, targeting molecular regulation related to p53 has great potential and has become a research hotspot. For example, developing drugs that target the interaction between p53 and MDM2. Such drugs aim to reactivate p53 by targeting either MDM2 binding or p53 phosphorylation. Researchers have identified various compounds that can serve as inhibitors, either by directly binding to MDM2 or by modifying p53 through phosphorylation. Furthermore, a significant correlation exists between the expression of MDM2 in tumors and the effectiveness of immunotherapy, predominantly in the context of immune checkpoint inhibition. This review presents a comprehensive overview of the molecular characteristics of MDM2 and the current state of research on MDM2-targeting inhibitors. It includes a review of the impact of MDM2 targeting on the efficacy of immunotherapy, providing guidance and direction for the development of drugs targeting the p53-MDM2 interaction and optimization of immunotherapy.

Orally Bioavailable Proteolysis-Targeting Chimeras: An Innovative Approach in the Golden Era of Discovering Small-Molecule Cancer Drugs

Proteolysis-targeting chimeras (PROTACs) are an emerging therapeutic modality that show promise to open a target space not accessible to conventional small molecules via a degradation-based mechanism. PROTAC degraders, due to their bifunctional nature, which is categorized as 'beyond the Rule of Five', have gained attention as a distinctive therapeutic approach for oral administration in clinical settings. However, the development of PROTACs with adequate oral bioavailability remains a significant hurdle, largely due to their large size and less than ideal physical and chemical properties. This review encapsulates the latest advancements in orally delivered PROTACs that have entered clinical evaluation as well as developments highlighted in recent scholarly articles. The insights and methodologies elaborated upon in this review could be instrumental in supporting the discovery and refinement of novel PROTAC degraders aimed at the treatment of various human cancers.

Hippo cooperates with p53 to maintain foregut homeostasis and suppress the malignant transformation of foregut basal progenitor cells

Basal progenitor cells serve as a stem cell pool to maintain the homeostasis of the epithelium of the foregut, including the esophagus and the forestomach. Aberrant genetic regulation in these cells can lead to carcinogenesis, such as squamous cell carcinoma (SCC). However, the underlying molecular mechanisms regulating the function of basal progenitor cells remain largely unknown. Here, we use mouse models to reveal that Hippo signaling is required for maintaining the homeostasis of the foregut epithelium and cooperates with p53 to repress the initiation of foregut SCC. Deletion of Mst1/2 in mice leads to epithelial overgrowth in both the esophagus and forestomach. Further molecular studies find that Mst1/2-deficiency promotes epithelial growth by enhancing basal cell proliferation in a Yes-associated protein (Yap)-dependent manner. Moreover, Mst1/2 deficiency accelerates the onset of foregut SCC in a carcinogen-induced foregut SCC mouse model, depending on Yap. Significantly, a combined deletion of Mst1/2 and p53 in basal progenitor cells sufficiently drives the initiation of foregut SCC. Therefore, our studies shed light on the collaborative role of Hippo signaling and p53 in maintaining squamous epithelial homeostasis while suppressing malignant transformation of basal stem cells within the foregut.

Power-law behavior of transcriptional bursting regulated by enhancer-promoter communication

Revealing how transcriptional bursting kinetics are genomically encoded is challenging because genome structures are stochastic at the organization level and are suggestively linked to gene transcription. To address this challenge, we develop a generic theoretical framework that integrates chromatin dynamics, enhancer-promoter (E-P) communication, and gene-state switching to study transcriptional bursting. The theory predicts that power law can be a general rule to quantitatively describe bursting modulations by E-P spatial communication. Specifically, burst frequency and burst size are up-regulated by E-P communication strength, following power laws with positive exponents. Analysis of the scaling exponents further reveals that burst frequency is preferentially regulated. Bursting kinetics are down-regulated by E-P genomic distance with negative power-law exponents, and this negative modulation desensitizes at large distances. The mutual information between burst frequency (or burst size) and E-P spatial distance further reveals essential characteristics of the information transfer from E-P communication to transcriptional bursting kinetics. These findings, which are in agreement with experimental observations, not only reveal fundamental principles of E-P communication in transcriptional bursting but also are essential for understanding cellular decision-making.

Human Intestinal Organoids and Microphysiological Systems for Modeling Radiotoxicity and Assessing Radioprotective Agents

Radiotherapy is a commonly employed treatment for colorectal cancer, yet its radiotoxicity-related impact on healthy tissues raises significant health concerns. This highlights the need to use radioprotective agents to mitigate these side effects. This review presents the current landscape of human translational radiobiology, outlining the limitations of existing models and proposing engineering solutions. We delve into radiotherapy principles, encompassing mechanisms of radiation-induced cell death and its influence on normal and cancerous colorectal cells. Furthermore, we explore the engineering aspects of microphysiological systems to represent radiotherapy-induced gastrointestinal toxicity and how to include the gut microbiota to study its role in treatment failure and success. This review ultimately highlights the main challenges and future pathways in translational research for pelvic radiotherapy-induced toxicity. This is achieved by developing a humanized in vitro model that mimics radiotherapy treatment conditions. An in vitro model should provide in-depth analyses of host-gut microbiota interactions and a deeper understanding of the underlying biological mechanisms of radioprotective food supplements. Additionally, it would be of great value if these models could produce high-throughput data using patient-derived samples to address the lack of human representability to complete clinical trials and improve patients' quality of life.

4D nucleome equation predicts gene expression controlled by long-range enhancer-promoter interaction

Recent experimental evidence strongly supports that three-dimensional (3D) long-range enhancer-promoter (E-P) interactions have important influences on gene-expression dynamics, but it is unclear how the interaction information is translated into gene expression over time (4D). To address this question, we developed a general theoretical framework (named as a 4D nucleome equation), which integrates E-P interactions on chromatin and biochemical reactions of gene transcription. With this equation, we first present the distribution of mRNA counts as a function of the E-P genomic distance and then reveal a power-law scaling of the expression level in this distance. Interestingly, we find that long-range E-P interactions can induce bimodal and trimodal mRNA distributions. The 4D nucleome equation also allows for model selection and parameter inference. When this equation is applied to the mouse embryonic stem cell smRNA-FISH data and the E-P genomic-distance data, the predicted E-P contact probability and mRNA distribution are in good agreement with experimental results. Further statistical inference indicates that the E-P interactions prefer to modulate the mRNA level by controlling promoter activation and transcription initiation rates. Our model and results provide quantitative insights into both spatiotemporal gene-expression determinants (i.e., long-range E-P interactions) and cellular fates during development.

Silver Nanoparticles (AgNPs) as Enhancers of Everolimus and Radiotherapy Sensitivity on Clear Cell Renal Cell Carcinoma

Nanomedicine's advent has promised to revolutionize different biomedical fields, including oncology. Silver Nanoparticles (AgNPs) showed promising results in different tumor models. Clear cell Renal Cell Carcinoma (ccRCC) is especially challenging due to its late diagnosis, poor prognosis and treatment resistance. Therefore, defining new therapeutic targets and regimens could improve patient management. This study intends to evaluate AgNPs' effect in ccRCC cells and explore their potential combinatory effect with Everolimus and Radiotherapy. AgNPs were synthesized, and their effect was evaluated regarding their entering pathway, cellular proliferation capacity, ROS production, mitochondrial membrane depolarization, cell cycle analysis and apoptosis assessment. AgNPs were combined with Everolimus or used to sensitize cells to radiotherapy. AgNPs are cytotoxic to 786-O cells, a ccRCC cell line, entering through endocytosis, increasing ROS, depolarizing mitochondrial membrane, and blocking the cell cycle, leading to a reduction of proliferation capacity and apoptosis. Combined with Everolimus, AgNPs reduce cell viability and inhibit proliferation capacity. Moreover, 786-O is intrinsically resistant to radiation, but after AgNPs' administration, radiation induces cytotoxicity through mitochondrial membrane depolarization and S phase blockage. These results demonstrate AgNPs' cytotoxic potential against ccRCC and seem promising regarding the combination with Everolimus and sensitization to radiotherapy, which can, in the future, benefit ccRCC patients' management.

Affimer-mediated locking of p21-activated kinase 5 in an intermediate activation state results in kinase inhibition

Kinases are important therapeutic targets, and their inhibitors are classified according to their mechanism of action, which range from blocking ATP binding to covalent inhibition. Here, a mechanism of inhibition is highlighted by capturing p21-activated kinase 5 (PAK5) in an intermediate state of activation using an Affimer reagent that binds in the P+1 pocket. PAK5 was identified from a non-hypothesis-driven high-content imaging RNAi screen in urothelial cancer cells. Silencing of PAK5 resulted in reduced cell number, G1/S arrest, and enlargement of cells, suggesting it to be important in urothelial cancer cell line survival and proliferation. Affimer reagents were isolated to identify mechanisms of inhibition. The Affimer PAK5-Af17 recapitulated the phenotype seen with siRNA. Co-crystallization revealed that PAK5-Af17 bound in the P+1 pocket of PAK5, locking the kinase into a partial activation state. This mechanism of inhibition indicates that another class of kinase inhibitors is possible.

Nutrient-Based Approaches for Melanoma: Prevention and Therapeutic Insights

Melanoma, a prevalent and lethal form of skin cancer, remains a formidable challenge in terms of prevention and treatment. While significant progress has been made in understanding its pathogenesis and treatment, the quest for effective prevention strategies and therapeutic approaches remains ongoing. Considering the increased advancements in understanding the dynamic interplay between nutrients and melanoma, we aim to offer a refreshed perspective on nutrient-based approaches for melanoma prevention and adjunctive therapy. In contrast to other studies, we have innovatively provided a detailed exposition of the nutrients' influences on melanoma prognosis and treatment. This review firstly examines various nutrients, including antioxidants (namely vitamins A, D, C, and E; selenium; and caffeine), polyunsaturated fatty acids, and flavonoids, for their effects and underlying mechanisms in reducing melanoma risk. Among these nutrients, caffeine shows the most promising potential, as it is supported by multiple cohort studies for its protective effect against melanoma. In contrast, there is a certain degree of inconsistency in the research of other nutrients, possibly due to inherent differences between animal studies and epidemiological research, as well as variations in the definition of nutrient intake. To comprehensively investigate the impact of nutrients on melanoma progression and therapeutic approaches, the following sections will explore how nutrients influence immune responses and other physiological processes. While there is robust support from cell and animal studies regarding the immunomodulatory attributes of vitamins D and zinc, the anti-angiogenic potential of polyphenols, and the cell growth-inhibitory effects of flavonoids, the limited availability of human-based research substantially constrains their practical relevance in clinical contexts. As for utilizing nutrients in adjuvant melanoma treatments, multiple approaches have garnered clinical research support, including the utilization of vitamin D to decrease the postoperative recurrence rates among melanoma patients and the adoption of a high-fiber diet to enhance the effectiveness of immunotherapy. In general, the effects of most nutrients on reducing the risk of melanoma are not entirely clear. However, several nutrients, including vitamin D and dietary fiber, have demonstrated their potential to improve the melanoma prognosis and enhance the treatment outcomes, making them particularly deserving of clinical attention. A personalized and interdisciplinary approach, involving dermatologists, oncologists, nutritionists, and researchers, holds the promise of optimizing melanoma treatment strategies.

PI3K/AKT inhibitor BEZ-235 targets CCND2 and induces G1 arrest in breast implant-associated anaplastic large cell lymphoma

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a mature, CD30-positive T-cell lymphoma lacking expression of the anaplastic lymphoma kinase (ALK). In contrast to ALK-positive ALCL, BIA-ALCL cells express cyclin D2 (CCND2) which controls cyclin dependent kinases 4 and 6 (CDK4/6). DNA methylation and expression analyses performed with cell lines and primary cells suggest that the expression of CCND2 in BIA-ALCL cell lines conforms to the physiological status of differentiated T-cells, and that it is not the consequence of genomic alterations as observed in other hematopoietic tumors. Using cell line model systems we show that treatment with the CDK4/6 inhibitor palbociclib effects dephosphorylation of the retinoblastoma protein (RB) and causes cell cycle arrest in G1 in BIA-ALCL. Moreover, we show that the PI3K/AKT inhibitor BEZ-235 induces dephosphorylation of the mTORC1 target S6 and of GSK3β, indicators for translational inhibition and proteasomal degradation. Consequently, CCND2 protein levels declined after stimulation with BEZ-235, RB was dephosphorylated and the cell cycle was arrested in G1. Taken together, our data imply potential application of CDK4/6 inhibitors and PI3K/AKT inhibitors for the therapy of BIA-ALCL.

The Therapeutic Potential of CDK4/6 Inhibitors, Novel Cancer Drugs, in Kidney Diseases

Inflammation is a crucial pathological feature in cancers and kidney diseases, playing a significant role in disease progression. Cyclin-dependent kinases CDK4 and CDK6 not only contribute to cell cycle progression but also participate in cell metabolism, immunogenicity and anti-tumor immune responses. Recently, CDK4/6 inhibitors have gained approval for investigational treatment of breast cancer and various other tumors. Kidney diseases and cancers commonly exhibit characteristic pathological features, such as the involvement of inflammatory cells and persistent chronic inflammation. Remarkably, CDK4/6 inhibitors have demonstrated impressive efficacy in treating non-cancerous conditions, including certain kidney diseases. Current studies have identified the renoprotective effect of CDK4/6 inhibitors, presenting a novel idea and potential direction for treating kidney diseases in the future. In this review, we briefly reviewed the cell cycle in mammals and the role of CDK4/6 in regulating it. We then provided an introduction to CDK4/6 inhibitors and their use in cancer treatment. Additionally, we emphasized the importance of these inhibitors in the treatment of kidney diseases. Collectively, growing evidence demonstrates that targeting CDK4 and CDK6 through CDK4/6 inhibitors might have therapeutic benefits in various cancers and kidney diseases and should be further explored in the future.

Artichoke as a melanoma growth inhibitor

Melanoma is the most lethal malignancy in skin cancers. About 97,610 new cases of melanoma are projected to occur in the United States (US) in 2023. Artichoke is a very popular plant widely consumed in the US due to its nutrition. In recent years, it has been shown that artichoke shows powerful anti-cancer effects on cancers such as breast cancer, colon cancer, liver cancer, and leukemia. However, there is little known about its effect on melanoma. This study was designed to investigate if artichoke extract (AE) has any direct effect on the growth of melanoma. Clonogenic survival assay, cell proliferation, and caspase-3 activity kits were used to evaluate the effects AE has on cell survival, proliferation, and apoptosis of the widely studied melanoma cell line HTB-72. We further investigated the possible molecular mechanisms using RT-PCR and immunohistochemical staining. The percentage of colonies of HTB-72 melanoma cells decreased significantly after treated with AE. This was paralleled with the decrease in the optic density (OD) value of cancer cells after treatment with AE. This was further supported by the decreased expression of PCNA mRNA after treated with AE. Furthermore, the cellular caspase-3 activity increased after treated with AE. The anti-proliferative effect of AE on melanoma cells correlated with increased p21, p27, and decreased CDK4. The pro-apoptotic effect of AE on melanoma cells correlated with decreased survivin. Artichoke inhibits growth of melanoma by inhibition of proliferation and promotion of apoptosis. Such a study might be helpful to develop a new promising treatment for melanoma.

Tasmanian devil cathelicidins exhibit anticancer activity against Devil Facial Tumour Disease (DFTD) cells

The Tasmanian devil (Sarcophilus harrisii) is endangered due to the spread of Devil Facial Tumour Disease (DFTD), a contagious cancer with no current treatment options. Here we test whether seven recently characterized Tasmanian devil cathelicidins are involved in cancer regulation. We measured DFTD cell viability in vitro following incubation with each of the seven peptides and describe the effect of each on gene expression in treated cells. Four cathelicidins (Saha-CATH3, 4, 5 and 6) were toxic to DFTD cells and caused general signs of cellular stress. The most toxic peptide (Saha-CATH5) also suppressed the ERBB and YAP1/TAZ signaling pathways, both of which have been identified as important drivers of cancer proliferation. Three cathelicidins induced inflammatory pathways in DFTD cells that may potentially recruit immune cells in vivo. This study suggests that devil cathelicidins have some anti-cancer and inflammatory functions and should be explored further to determine whether they have potential as treatment leads.

Essential amino acid starvation induces cell cycle arrest, autophagy, and inhibits osteogenic differentiation in murine osteoblast

This study investigates the effects of essential amino acid (EAA) starvation on murine osteoblasts cells and the underlying mechanisms. We performed and observed the cell proliferation, autophagy, and osteogenic differentiation under deprivation of EAA in vitro. The results showed that EAA starvation resulted in cell cycle arrest via phosphorylation of the MAPK signaling pathway, leading to inhibition of cell proliferation and osteogenic differentiation. Additionally, the LKB1-AMPK signaling pathway was also found to be phosphorylated, inducing autophagy. These findings highlight the significant role of EAA in regulating cellular processes. Furthermore, this study contributes to our understanding of the effects of nutrient deprivation on cellular physiology and may aid in the development of novel therapeutic strategies for diseases associated with amino acid metabolism.

MDM2 Implications for Potential Molecular Pathogenic Therapies of Soft-Tissue Tumors

Murine double minute 2 (MDM2, gene name MDM2) is an oncogene that mainly codes for a protein that acts as an E3 ubiquitin ligase, which targets the tumor suppressor protein p53 for degradation. Overexpression of MDM2 regulates the p53 protein levels by binding to it and promoting its degradation by the 26S proteasome. This leads to the inhibition of p53's ability to regulate cell cycle progression and apoptosis, allowing for uncontrolled cell growth, and can contribute to the development of soft-tissue tumors. The application of cellular stress leads to changes in the binding of MDM2 to p53, which prevents MDM2 from degrading p53. This results in an increase in p53 levels, which triggers either cell cycle arrest or apoptosis. Inhibiting the function of MDM2 has been identified as a potential therapeutic strategy for treating these types of tumors. By blocking the activity of MDM2, p53 function can be restored, potentially leading to tumor cell death and inhibiting the growth of tumors. However, further research is needed to fully understand the implications of MDM2 inhibition for the treatment of soft-tissue tumors and to determine the safety and efficacy of these therapies in clinical trials. An overview of key milestones and potential uses of MDM2 research is presented in this review.

A polyethylene glycol-conjugate of deoxycytidine analog, DFP-14927, produces potential antitumor effects on pancreatic tumor-xenograft murine models via inducing G2/M arrest

A deoxycytidine analog is a potential agent for the treatment of several cancers, which includes poorly prognostic pancreatic cancer. We previously developed deoxycytidine analog DFP-10917, and long-term/low-dose infusions of this analog has produced antitumor effects in leukemia cancer- and ovarian cancer-xenograft models. DFP-10917 is now undergoing clinical Phase III study in the United States for the treatment of patients with relapsed or refractory acute myeloid leukemia. PEG-drug conjugation has become a promising technique to improve the pharmacokinetic and pharmacodynamic properties of anti-cancer drugs. In the present study, we synthesized a novel PEG-drug conjugate of DFP-10917, referred to hereafter as DFP-14927, using a 4-armed CTPEG system to endow the DFP-10917 drug with favorable long-circulating properties that maximize its utility and antitumor efficacy. Intravenous injection of the synthesized DFP-14927 returned encouraging antitumor effects in a Panc-1 human pancreatic tumor- and a BxPC-3 human pancreatic tumor-xenograft models. These effects were comparable to that of free DFP-10917 as well as to that of gemcitabine, which is considered a standard in the treatment of pancreatic cancer. In vitro studies revealed that DFP-14927 inhibits cell division on human pancreatic cancer cell lines via arrest of the G2/M phase in the cell cycle, which is consistent with the effects of free DFP-10917. Intravenous administration of the newly synthesized DFP-14927 has induced G2/M arrest in human pancreatic tumor-xenograft murine models, which represents an improvement in the pharmacokinetics of DFP-10917. DFP-14927 could be an alternative for patients who cannot accept prolonged or continuous infusions of DFP-10917.

RNAi screen in the Drosophila wing of genes encoding proteins related to cytoskeleton organization and cell division

Cell division and cytoskeleton organization are fundamental processes participating in the development of Drosophila imaginal discs. In this manuscript we describe the phenotypes in the adult fly wing generated by knockdowns of 85% of Drosophila genes encoding proteins likely related to the regulation of cell division and cytoskeleton organization. We also compile a molecular classification of these proteins into classes that describe their expected or known main biochemical characteristics, as well as mRNA expression in the wing disc and likely protein subcellular localization for a subset of these genes. Finally, we analyze in more detail one protein family of cytoskeleton genes (Arp2/3 complex), and define the consequences of interfering with cell division for wing growth and patterning.

Cell Cycle Dynamics during Stomatal Development: Window of MUTE Action and Ramification of Its Loss-of-Function on an Uncommitted Precursor

Plants develop in the absence of cell migration. As such, cell division and differentiation need to be coordinated for functional tissue formation. Cellular valves on the plant epidermis, stomata, are generated through a stereotypical sequence of cell division and differentiation events. In Arabidopsis, three master regulatory transcription factors, SPEECHLESS (SPCH), MUTE and FAMA, sequentially drive initiation, proliferation and differentiation of stomata. Among them, MUTE switches the cell cycle mode from proliferative asymmetric division to terminal symmetric division and orchestrates the execution of the single symmetric division event. However, it remains unclear to what extent MUTE regulates the expression of cell cycle genes through the symmetric division and whether MUTE accumulation itself is gated by the cell cycle. Here, we show that MUTE directly upregulates the expression of cell cycle components throughout the terminal cell cycle phases of a stomatal precursor, not only core cell cycle engines but also check-point regulators. Time-lapse live imaging using the multicolor Plant Cell Cycle Indicator revealed that MUTE accumulates up to the early G2 phase, whereas its successor and direct target, FAMA, accumulate at late G2 through terminal mitosis. In the absence of MUTE, meristemoids fail to differentiate and their G1 phase elongates as they reiterate asymmetric divisions. Together, our work provides the framework of cell cycle and master regulatory transcription factors to coordinate a single symmetric cell division and suggests a mechanism for the eventual cell cycle arrest of an uncommitted stem-cell-like precursor at the G1 phase.

Single Cell Analysis of Human Thyroid Reveals the Transcriptional Signatures of Aging

The thyroid gland plays a critical role in the maintenance of whole-body metabolism. However, aging frequently impairs homeostatic maintenance by thyroid hormones due to increased prevalence of subclinical hypothyroidism associated with mitochondrial dysfunction, inflammation, and fibrosis. To understand the specific aging-related changes of endocrine function in thyroid epithelial cells, we performed single-cell RNA sequencing (RNA-seq) of 54 726 cells derived from pathologically normal thyroid tissues from 7 patients who underwent thyroidectomy. Thyroid endocrine epithelial cells were clustered into 5 distinct subpopulations, and a subset of cells was found to be particularly vulnerable with aging, showing functional deterioration associated with the expression of metallothionein (MT) and major histocompatibility complex class II genes. We further validated that increased expression of MT family genes are highly correlated with thyroid gland aging in bulk RNAseq datasets. This study provides evidence that aging induces specific transcriptomic changes across multiple cell populations in the human thyroid gland.

Synthesis and Antiproliferative Activity against Cancer Cells of Indole-Aryl-Amide Derivatives

Indoles constitute a large family of heterocyclic compounds widely occurring in nature which are present in a number of bioactive natural and synthetic compounds, including anticancer agents or atypical opioid agonists. As a result, exponential increases in the development of novel methods for the synthesis of indole-containing compounds have been reported in the literature. A series of indole-aryl amide derivatives 1-7 containing tryptamine or an indolylacetic acid nucleus were designed, synthesized, and evaluated as opioid ligands. These new indole derivatives showed negligible to very low affinity for μ- and δ-opioid receptor (OR). On the other hand, compounds 2, 5 and 7 showed Ki values in the low μM range for κ-OR. Since indoles are well known for their anticancer potential, their effect against a panel of tumor cell lines was tested. The target compounds were evaluated for their in vitro cytotoxicity in HT29, HeLa, IGROV-1, MCF7, PC-3, and Jurkat J6 cells. Some of the synthesized compounds showed good activity against the selected tumor cell lines, with the exception of IGROV1. In particular, compound 5 showed a noteworthy selectivity towards HT29 cells, a malignant colonic cell line, without affecting healthy human intestinal cells. Further studies revealed that 5 caused the cell cycle arrest in the G1 phase and promoted apoptosis in HT29 cells.

FOXA1 is a transcriptional activator of Odf2/Cenexin and regulates primary ciliation

Primary cilia are sensory organelles essential for embryonic and postnatal development, and tissue homeostasis in adulthood. They are generated in a cell cycle-dependent manner and found on most cells of the body. Although cilia formation is intensively investigated virtually nothing is known about the transcriptional regulation of primary ciliation. We used here Odf2/Cenexin, encoding a protein of the mother centriole and the basal body that is mandatory for primary cilia formation, as the target gene for the identification of transcriptional activators. We identified a consensus binding site for Fox transcription factors (TFs) in its promoter region and focused here on the Fox family. We found transcriptional activation of Odf2 neither by FOXO TFs nor by the core TF for multiciliation, FOXJ1. However, we identified FOXA1 as a transcriptional activator of Odf2 by reporter gene assays and qRT-PCR, and showed by qWB that Foxa1 knockdown caused a decrease in ODF2 and CP110 proteins. We verified the binding sequence of FOXA1 in the Odf2 promoter by ChIP. Finally, we demonstrated that knockdown of FOXA1 affected primary cilia formation. We, thus, showed for the first time, that FOXA1 regulates primary ciliation by transcriptional activation of ciliary genes.

Target Mechanisms of the Cyanotoxin Cylindrospermopsin in Immortalized Human Airway Epithelial Cells

Cylindrospermopsin (CYN) is a cyanobacterial toxin that occurs in aquatic environments worldwide. It is known for its delayed effects in animals and humans such as inhibition of protein synthesis or genotoxicity. The molecular targets and the cell physiological mechanisms of CYN, however, are not well studied. As inhalation of CYN-containing aerosols has been identified as a relevant route of CYN uptake, we analyzed the effects of CYN on protein expression in cultures of immortalized human bronchial epithelial cells (16HBE14o^-) using a proteomic approach. Proteins whose expression levels were affected by CYN belonged to several functional clusters, mainly regulation of protein stability, cellular adhesion and integration in the extracellular matrix, cell proliferation, cell cycle regulation, and completion of cytokinesis. With a few exceptions of upregulated proteins (e.g., ITI inhibitor of serine endopeptidases and mRNA stabilizer PABPC1), CYN mediated the downregulation of many proteins. Among these, centrosomal protein 55 (CEP55) and osteonectin (SPARC) were significantly reduced in their abundance. Results of the detailed semi-quantitative Western blot analyses of SPARC, claudin-6, and CEP55 supported the findings from the proteomic study that epithelial cell adhesion, attenuation of cell proliferation, delayed completion of mitosis, as well as induction of genomic instability are major effects of CYN in eukaryotic cells.

Descriptive and functional analyses of four cyclin proteins in Trichomonas vaginalis

Trichomonas vaginalis is an early divergent protozoan parasite that causes trichomoniasis, the most common non-viral sexually transmitted infection. In metazoans, there is abundant and detailed research on the cell cycle and the components involved in the regulation mechanisms. Regulators such as the cyclin-dependent kinases (CDKs) and cyclins activate the highly regulated processes of cell division. While CDKs have important roles in the phosphorylation of specific substrates, cyclins are important activating-components of CDKs that allow orderly passage through the different stages of the cell cycle. Cell cycle cyclins are characterized by showing drastic changes in their concentration during the cell cycle progression. However, in protists such as T. vaginalis, some biological processes such as cell cycle regulation remain less well studied. In an attempt to gain insight into cell cycle regulation in T. vaginalis, as an initial approach we characterized four proteins with features of cyclins. The genes encoding these putative cyclins were cloned to produce the recombinant proteins TvCYC1, TvCYC2, TvCYC3, and TvCYC4. The functional activity of TvCYC2, TvCYC3, and TvCYC4 was assessed through their complementation of a yeast cln1,2,3Δ mutant strain; TvCYC1 was not able to complement this mutant. Furthermore, our results suggest that TvCYC1, TvCYC2, and TvCYC3, are able to interact with and activate the kinase activity of TvCRK1, a kinase previously characterized by our group. The present study represents the first characterization of cyclins potentially involved in cell cycle regulation in T. vaginalis.

Alterations in hepatic mitotic and cell cycle transcriptional networks during the metabolic switch in broiler chicks

During embryonic life, chicks mainly derive energy from hepatic oxidation of yolk lipids. After hatch, chicks must rely on carbohydrate-rich feed to obtain energy. This requires an abrupt and intensive switch of metabolic processes, particularly in the liver. We recently identified a number of transcriptional and post-transcriptional regulatory networks that work concordantly to tune metabolic processes during the metabolic switch. Here, we used delayed feeding post-hatch (48 h) to impede the metabolic switch in broilers. We used RNA-seq to identify hepatic transcriptome differences between late stage embryos (E18) and two-day-old chicks (D2), which were either fed-from-hatch (FED) or not fed (DLY). Between FED and E18, 2,430 genes were differentially expressed (fold-change≥ 2; FDR p-value 0.05), of these 1,237 were downregulated in FED birds and 1,193 were upregulated. Between DLY and E18, 1979 genes were differentially expressed, of these 1,043 were downregulated and 936 were upregulated in DLY birds. Between DLY and FED, 880 genes were differentially expressed, of these 543 were downregulated and 337 were upregulated in DLY birds. We found that in addition to disturbances in a number of metabolic pathways, unfed chicks had a widespread suppression of gene networks associated with cell proliferation, cell cycle progression and mitosis. Expression patterns suggest that hepatocytes of delayed-fed birds have abnormal mitosis and increased polyploidization. This suggests that post-hatch feed consumption maintains the rate and integrity of liver growth immediately, which in turn, likely helps facilitate the appropriate programming of hepatic metabolic networks.

Genome-Wide Identification, Expression Profiling, and Characterization of Cyclin-like Genes Reveal Their Role in the Fertility of the Diamondback Moth

Simple Summary

Cyclin genes are known as cell cycle regulators and play a significant role in the fertility of different organisms, including mice and insects. Until now, no study has been performed on the complete identification of the cyclin genes in insects. Here, we identified 21 cyclin genes in the diamondback moth (DBM) genome through a comprehensive genome-wide analysis and evaluated the gene structure, genomic location, and evolutionary relationship. Cis-regulatory elements and potential miRNA targeting the cyclin genes were also assessed. By analyzing the transcriptomic and RT-qPCR based expression profiling at different stages and tissues, we found that the majority of the cyclin genes were significantly expressed in the reproductive tissues. Moreover, RNAi-mediated characterization of PxCyc B1 showed its role in female fertility. The current study provides a basis for further evaluation of the cyclin genes, which may be used as a potential target for pest management programs.

Abstract

Cyclin-like genes are primarily considered as cell cycle regulators and have shown to be crucial for insect growth, development, reproduction, and fertility. However, no research has been performed on the cyclin-like genes in the diamondback moth (Plutella xylostella). Here, we identified the 21 cyclin genes in the genome of P. xylostella and clustered them into four groups. Most cyclin genes showed a well-maintained gene structure and motif distribution within the same group. The putative promoter regions of cyclin genes contained several transcription binding factors related to reproduction, along with growth and development. Furthermore, 16 miRNAs were identified targeting the 13 cyclin genes. Transcriptome and quantitative real-time PCR (qRT-PCR)-based expression profiling of cyclin-like genes at different stages and tissues were evaluated, revealing that 16 out of 21 cyclin genes were highly expressed in reproductive tissues of adult females and males. The Cyclin B1 gene (PxCyc B1) was only expressed in the ovary of the adult female and selected for the subsequent analysis. RNAi-mediated suppression of PxCyc B1 interrupted the external genitalia and length of the ovariole of female adults. Furthermore, the egg-laying capacity and hatching rate were also significantly decreased by suppressing the PxCyc B1, indicating the importance of cyclin genes in the reproduction and fertility of P. xylostella. The current study explained the detailed genome-wide analysis of cyclin-like genes in P. xylostella, which provided a basis for subsequent research to assess the roles of cyclin genes in reproduction, and the cyclin gene may be considered an effective target site to control this pest.

ZFP281 drives a mesenchymal-like dormancy program in early disseminated breast cancer cells that prevents metastatic outgrowth in the lung

Increasing evidence shows that cancer cells can disseminate from early evolved primary lesions much earlier than the classical metastasis models predicted. Here, we reveal at a single-cell resolution that mesenchymal-like (M-like) and pluripotency-like programs coordinate dissemination and a long-lived dormancy program of early disseminated cancer cells (DCCs). The transcription factor ZFP281 induces a permissive state for heterogeneous M-like transcriptional programs, which associate with a dormancy signature and phenotype in vivo. Downregulation of ZFP281 leads to a loss of an invasive, M-like dormancy phenotype and a switch to lung metastatic outgrowth. We also show that FGF2 and TWIST1 induce ZFP281 expression to induce the M-like state, which is linked to CDH1 downregulation and upregulation of CDH11. We found that ZFP281 not only controls the early dissemination of cancer cells but also locks early DCCs in a dormant state by preventing the acquisition of an epithelial-like proliferative program and consequent metastases outgrowth.

Deficiency of nitrogen but not phosphorus triggers the life cycle transition of the dinoflagellate Scrippsiella acuminata from vegetative growth to resting cyst formation

Nitrogen (N) and phosphorus (P) are essential elements for algal growth. When N and P are deficient, dinoflagellates will take a series of measures to achieve population continuation including formation of resting cysts, an important ecological strategy of dinoflagellates that plays a key role in the initiation and termination of harmful algal blooms (HABs). How the deficiency of N and P affects algal growth and cyst formation has been investigated in some dinoflagellate species, but how it affects the life cycle transition in dinoflagellates has been poorly understood. In this study, we further explored the effect of N and P deficiency on the algal growth and resting cyst production in the cosmopolitan HABs-causing species Scrippsiella acuminata via refining the N and P concentration gradients. Further, we tracked the expression patterns of one CyclinB and one CDK1 genes of S. acuminata at different growth stages under three deficiency concentrations (1/1000 dilutions of N, P, and both N and P). The results suggest that N deficiency always triggered the cyst formation but P deficiency mainly inhibited the vegetative growth instead of inducing cyst formation. We also observed the highest cyst production when S. acuminata was cultured in the f/2-Si medium that was a one-thousandth dilution of N and P (N∼ 0.882 μM; P∼ 0.0362 μM). Our results for the expressions of CyclinB and CDK1 were well consistent with the results of algal growth and cyst formation at different deficiencies of N and P in terms of that higher expressions of these two genes were corresponding to higher rates of vegetative cell growth, while their expressions in resting cysts maintained to be moderate but significantly lower than that in fast-growing vegetative cells. Although we are still not sure whether the changing expressions of the two genes did regulate the transition of life cycle (i.e. cyst formation), or happened as parallels to the expressions of other truly regulating genes, our observations are surely inspirational for further investigations on the genetic regulation of life cycle transition in dinoflagellates. Our work will provide clues to probe the physiological and molecular mechanisms underlying the nutrient deficiency-induced alternation between life cycle stages in dinoflagellates.

Glucose-Functionalized Silver Nanoparticles as a Potential New Therapy Agent Targeting Hormone-Resistant Prostate Cancer cells

Purpose

Silver nanoparticles (AgNPs) have shown great potential as anticancer agents, namely in therapies’ resistant forms of cancer. The progression of prostate cancer (PCa) to resistant forms of the disease (castration-resistant PCa, CRPC) is associated with poor prognosis and life quality, with current limited therapeutic options. CRPC is characterized by a high glucose consumption, which poses as an opportunity to direct AgNPs to these cancer cells. Thus, this study explores the effect of glucose functionalization of AgNPs in PCa and CRPC cell lines (LNCaP, Du-145 and PC-3).

Methods

AgNPs were synthesized, further functionalized, and their physical and chemical composition was characterized both in water and in culture medium, through UV-visible spectrum, dynamic light scattering (DLS), transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR). Their effect was assessed in the cell lines regarding AgNPs’ entering pathway, cellular proliferation capacity, ROS production, mitochondrial membrane depolarization, cell cycle analysis and apoptosis evaluation.

Results

AgNPs displayed an average size of 61nm and moderate monodispersity with a slight increase after functionalization, and a round shape. These characteristics remained stable when redispersed in culture medium. Both AgNPs and G-AgNPs were cytotoxic only to CRPC cells and not to hormone-sensitive ones and their effect was higher after functionalization showing the potential of glucose to favor AgNPs’ uptake by cancer cells. Entering through endocytosis and being encapsulated in lysosomes, the NPs increased the ROS, inducing mitochondrial damage, and arresting cell cycle in S Phase, therefore blocking proliferation, and inducing apoptosis.

Conclusion

The nanoparticles synthesized in the present study revealed good characteristics and stability for administration to cancer cells. Their uptake through endocytosis leads to promising cytotoxic effects towards CRPC cells, revealing the potential of G-AgNPs as a future therapeutic approach to improve the management of patients with PCa resistant to hormone therapy or metastatic disease.

Mitosis, Focus on Calcium

The transformation of a single fertilised egg into an adult human consisting of tens of trillions of highly diverse cell types is a marvel of biology. The expansion is largely achieved by cell duplication through the process of mitosis. Mitosis is essential for normal growth, development, and tissue repair and is one of the most tightly regulated biological processes studied. This regulation is designed to ensure accurate segregation of chromosomes into each new daughter cell since errors in this process can lead to genetic imbalances, aneuploidy, that can lead to diseases including cancer. Understanding how mitosis operates and the molecular mechanisms that ensure its fidelity are therefore not only of significant intellectual value but provide unique insights into disease pathology. The purpose of this review is to revisit historical evidence that mitosis can be influenced by the ubiquitous second messenger calcium and to discuss this in the context of new findings revealing exciting new information about its role in cell division.

CircRNA-miRNA interactions in atherogenesis

Atherosclerosis is the major cause of coronary artery disease (CAD) which includes unstable angina, myocardial infarction, and heart failure. The onset of atherogenesis, a process of atherosclerotic lesion formation in the intima of arteries, is driven by lipid accumulation, a vicious cycle of reactive oxygen species (ROS)-induced oxidative stress and inflammatory reactions leading to endothelial cell (EC) dysfunction, vascular smooth muscle cell (VSMC) activation, and foam cell formation which further fuel plaque formation and destabilization. In recent years, there is a surge in the number of publications reporting the involvement of circular RNAs (circRNAs) in the pathogenesis of cardiovascular diseases, cancers, and metabolic syndromes. These studies have advanced our understanding on the biological functions of circRNAs. One of the most common mechanism of action of circRNAs reported is the sponging of microRNAs (miRNAs) by binding to the miRNAs response element (MRE), thereby indirectly increases the transcription of their target messenger RNAs (mRNAs). Individual networks of circRNA-miRNA-mRNA associated with atherogenesis have been extensively reported, however, there is a need to connect these findings for a complete overview. This review aims to provide an update on atherogenesis-related circRNAs and analyze the circRNA-miRNA-mRNA interactions in atherogenesis. The atherogenic mechanisms and clinical relevance of each atherogenesis-related circRNA were systematically discussed for better understanding of the knowledge gap in this area.

Thyroid receptor β might be responsible for breast cancer associated with Hashimoto's thyroiditis: a new insight into pathogenesis

Breast cancer is the most common cancer affecting females worldwide. Often it is observed that women suffering from Hashimoto's thyroiditis exhibit a greater propensity towards development of breast cancer. The exact mechanism for the same is unknown. However, multiple experimental evidences suggest a significant role of thyroid receptor β (TR-β) in regulating cell growth and proliferation and thus play a potent role as a tumor suppressor in several cancers, including breast cancer. Thyroid receptor β shows anti-proliferative action through mediators like β-catenin, RUNX2, PI3K/AKT, and cyclin regulation. The present review explores the link between these pathways and how they may be dysregulated due to Hashimoto's thyroiditis. Further, we propose a new mechanism for cancer prognosis associated with Hashimoto's thyroiditis, which may lead to the development of TR-β targeting as a novel therapeutic approach.

Radiobiological effects of wound fluid on breast cancer cell lines and human-derived tumor spheroids in 2D and microfluidic culture

Intraoperative radiotherapy (IORT) could abrogate cancer recurrences, but the underlying mechanisms are unclear. To clarify the effects of IORT-induced wound fluid on tumor progression, we treated breast cancer cell lines and human-derived tumor spheroids in 2D and microfluidic cell culture systems, respectively. The viability, migration, and invasion of the cells under treatment of IORT-induced wound fluid (WF-RT) and the cells under surgery-induced wound fluid (WF) were compared. Our findings showed that cell viability was increased in spheroids under both WF treatments, whereas viability of the cell lines depended on the type of cells and incubation times. Both WFs significantly increased sub-G1 and arrested the cells in G0/G1 phases associated with increased P16 and P21 expression levels. The expression level of Caspase 3 in both cell culture systems and for both WF-treated groups was significantly increased. Furthermore, our results revealed that although the migration was increased in both systems of WF-treated cells compared to cell culture media-treated cells, E-cadherin expression was significantly increased only in the WF-RT group. In conclusion, WF-RT could not effectively inhibit tumor progression in an ex vivo tumor-on-chip model. Moreover, our data suggest that a microfluidic system could be a suitable 3D system to mimic in vivo tumor conditions than 2D cell culture.

Therapeutics Targeting p53-MDM2 Interaction to Induce Cancer Cell Death

Named as the guardian of the genome, p53 is a tumor suppressor that regulates cell function, often through many different mechanisms such as DNA repair, apoptosis, cell cycle arrest, senescence, metabolism, and autophagy. One of the genes that p53 activates is MDM2, which forms a negative feedback loop since MDM2 induces the degradation of p53. When p53 activity is inhibited, damaged cells do not undergo cell cycle arrest or apoptosis. As 50% of human cancers inactivate p53 by mutation, current research focuses on reactivating p53 by developing drugs that target the p53-MDM2 interaction, which includes the binding of MDM2 and phosphorylation of p53. The objective of this article is to provide a short list and description of p53-MDM2 antagonists that may be excellent candidates for inducing cancer cell death. Relevant articles were searched for and identified using online databases such as PubMed and ScienceDirect. Increasing p53 levels, by targeting the p53-MDM2 interaction, can help p53 play its role as a tumor suppressor and induce cancer cell death. Researchers have identified different compounds that can act as inhibitors, either by directly binding to MDM2 or by modifying p53 with phosphorylation. The results associated with the drugs demonstrate the importance of targeting such interactions to inhibit cancer cell growth, which indicates that the use of the compounds may improve cancer therapeutics.

Contact guidance as a consequence of coupled morphological evolution and motility of adherent cells

Adherent cells seeded on substrates spread and evolve their morphology while simultaneously displaying motility. Phenomena such as contact guidance, viz. the alignment of cells on patterned substrates, are strongly linked to the coupling of morphological evolution with motility. Here, we employ a recently developed statistical thermodynamics framework for modelling the non-thermal fluctuating response of cells to probe this coupling. This thermodynamic framework is first extended via a Langevin style model to predict temporal responses of cells to unpatterned and patterned substrates. The Langevin model is then shown to not only predict the different experimentally observed temporal scales for morphological observables such as cell area and elongation but also the interplay of morphology with motility that ultimately leads to contact guidance.

5-Bromo-3,4-dihydroxybenzaldehyde Promotes Hair Growth through Activation of Wnt/β-Catenin and Autophagy Pathways and Inhibition of TGF-β Pathways in Dermal Papilla Cells

Various studies addressing the increasing problem of hair loss, using natural products with few side effects, have been conducted. 5-bromo-3,4-dihydroxybenzaldehyde (BDB) exhibited anti-inflammatory effects in mouse models of atopic dermatitis and inhibited UVB-induced oxidative stress in keratinocytes. Here, we investigated its stimulating effect and the underlying mechanism of action on hair growth using rat vibrissa follicles and dermal papilla cells (DPCs), required for the regulation of hair cycle and length. BDB increased the length of hair fibers in rat vibrissa follicles and the proliferation of DPCs, along with causing changes in the levels of cell cycle-related proteins. We investigated whether BDB could trigger anagen-activating signaling pathways, such as the Wnt/β-catenin pathway and autophagy in DPCs. BDB induces activation of the Wnt/β-catenin pathway through the phosphorylation of GSG3β and β-catenin. BDB increased the levels of autophagic vacuoles and autophagy regulatory proteins Atg7, Atg5, Atg16L, and LC3B. We also investigated whether BDB inhibits the TGF-β pathway, which promotes transition to the catagen phase. BDB inhibited the phosphorylation of Smad2 induced by TGF-β1. Thus, BDB can promote hair growth by modulating anagen signaling by activating Wnt/β-catenin and autophagy pathways and inhibiting the TGF-β pathway in DPCs.

Cyclin-Dependent Kinase Inhibitors and Their Therapeutic Potential in Colorectal Cancer Treatment

Cyclin-dependent kinases (CDKs) are key players in cell cycle regulation. So far, more than ten CDKs have been described. Their direct interaction with cyclins allow progression through G1 phase, transitions to S and G2 phase and finally through mitosis (M). While CDK activation is important in cell renewal, its aberrant expression can lead to the development of malignant tumor cells. Dysregulations in CDK pathways are often encountered in various types of cancer, including all gastrointestinal (GI) tract tumors. This prompted the development of CDK inhibitors as novel therapies for cancer. Currently, CDK inhibitors such as CDK4/6 inhibitors are used in pre-clinical studies for cancer treatment. In this review, we will focus on the therapeutic role of various CDK inhibitors in colorectal cancer, with a special focus on the CDK4/6 inhibitors.

Cell Cycle Dysregulation and Renal Fibrosis

Precise regulation of cell cycle is essential for tissue homeostasis and development, while cell cycle dysregulation is associated with many human diseases including renal fibrosis, a common process of various chronic kidney diseases progressing to end-stage renal disease. Under normal physiological conditions, most of the renal cells are post-mitotic quiescent cells arrested in the G0 phase of cell cycle and renal cells turnover is very low. Injuries induced by toxins, hypoxia, and metabolic disorders can stimulate renal cells to enter the cell cycle, which is essential for kidney regeneration and renal function restoration. However, more severe or repeated injuries will lead to maladaptive repair, manifesting as cell cycle arrest or overproliferation of renal cells, both of which are closely related to renal fibrosis. Thus, cell cycle dysregulation of renal cells is a potential therapeutic target for the treatment of renal fibrosis. In this review, we focus on cell cycle regulation of renal cells in healthy and diseased kidney, discussing the role of cell cycle dysregulation of renal cells in renal fibrosis. Better understanding of the function of cell cycle dysregulation in renal fibrosis is essential for the development of therapeutics to halt renal fibrosis progression or promote regression.

Cellular microRNA-127-3p suppresses oncogenic herpesvirus-induced transformation and tumorigenesis via down-regulation of SKP2

Kaposi's sarcoma-associated herpesvirus (KSHV) causes the endothelial tumor KS, a leading cause of morbidity and mortality in sub-Saharan Africa. KSHV-encoded microRNAs (miRNAs) are known to play an important role in viral oncogenesis; however, the role of host miRNAs in KS tumorigenesis remains largely unknown. Here, high-throughput small-RNA sequencing of the cellular transcriptome in a KS xenograft model revealed miR-127-3p as one of the most significantly down-regulated miRNAs, which we validated in KS patient tissues. We show that restoration of miR-127-3p suppresses KSHV-driven cellular transformation and proliferation and induces G1 cell cycle arrest by directly targeting the oncogene SKP2. This miR-127-3p-induced G1 arrest is rescued by disrupting the miR-127-3p target site in SKP2 messenger RNA (mRNA) using gene editing. Mechanistically, miR-127-3p-mediated SKP2 repression elevates cyclin-dependent kinase (CDK) inhibitor p21Cip1 and down-regulates cyclin E, cyclin A, and CDK2, leading to activation of the RB protein tumor suppressor pathway and suppression of the transcriptional activities of E2F and Myc, key oncoprotein transcription factors crucial for KSHV tumorigenesis. Consequently, metabolomics analysis during miR-127-3p-induced cell cycle arrest revealed significant depletion of dNTP pools, consistent with RB-mediated repression of key dNTP biosynthesis enzymes. Furthermore, miR-127-3p reconstitution in a KS xenograft mouse model suppresses KSHV-positive tumor growth by targeting SKP2 in vivo. These findings identify a previously unrecognized tumor suppressor function for miR-127-3p in KS and demonstrate that the miR-127-3p/SKP2 axis is a viable therapeutic strategy for KS.

Reviewing cancer's biology: an eclectic approach

BACKGROUND

Cancer refers to a group of some of the worldwide most diagnosed and deadliest pathophysiological conditions that conquered researchers' attention for decades and yet begs for more questions for a full comprehension of its complex cellular and molecular pathology.

MAIN BODY

The disease conditions are commonly characterized by unrestricted cell proliferation and dysfunctional replicative senescence pathways. In fact, the cell cycle operates under the rigorous control of complex signaling pathways involving cyclins and cyclin-dependent kinases assumed to be specific to each phase of the cycle. At each of these checkpoints, the cell is checked essentially for its DNA integrity. Genetic defects observed in these molecules (i.e., cyclins, cyclin-dependent kinases) are common features of cancer cells. Nevertheless, each cancer is different concerning its molecular and cellular etiology. These could range from the genetic defects mechanisms and/or the environmental conditions favoring epigenetically harbored homeostasis driving tumorigenesis alongside with the intratumoral heterogeneity with respect to the model that the tumor follows.

CONCLUSIONS

This review is not meant to be an exhaustive interpretation of carcinogenesis but to summarize some basic features of the molecular etiology of cancer and the intratumoral heterogeneity models that eventually bolster anticancer drug resistance for a more efficient design of drug targeting the pitfalls of the models.

Rational Design and Development of Novel CDK9 Inhibitors for the Treatment of Acute Myeloid Leukemia

CDK9 is an essential drug target correlated to the development of acute myeloid leukemia (AML). Starting from the hit compound 10, which was discovered through a screening of our in-house compound library, the structural modifications were carried out based on the bioisosterism and scaffold hopping strategies. Consequently, compound 37 displayed the optimal CDK9 inhibitory activity with an IC₅₀ value of 5.41 nM, which was nearly 1500-fold higher than compound 10. In addition, compound 37 exhibited significant antiproliferative activity in broad cancer cell lines. Further investigation of in vivo properties demonstrated that compound 37 could be orally administrated with an acceptable bioavailability (F = 33.7%). In MV-4-11 subcutaneous xenograft mouse model, compound 37 (7.5 mg/kg) could significantly suppress the tumor progression with a T/C value of 27.80%. Compound 37 represents a promising lead compound for the development of a novel class of CDK9 inhibitors for the treatment of acute myeloid leukemia.

FGF-2 induces a failure of cell cycle progression in cells harboring amplified K-Ras, revealing new insights into oncogene-induced senescence

Paradoxically, oncogenes that drive cell cycle progression may also trigger pathways leading to senescence, thereby inhibiting the growth of tumorigenic cells. Knowledge of how these pathways operate, and how tumor cells may evade these pathways, is important for understanding tumorigenesis. The Y1 cell line, which harbors an amplification of the proto-oncogene Ras, rapidly senesces in response to the mitogen fibroblast growth factor-2 (FGF-2). To gain a more complete picture of how FGF-2 promotes senescence, we employed a multi-omics approach to analyze histone modifications, mRNA and protein expression, and protein phosphorylation in Y1 cells treated with FGF-2. Compared to control cells treated with serum alone, FGF-2 caused a delayed accumulation of acetylation on histone H4 and higher levels of H3K27me3. Sequencing analysis revealed decreased expression of cell cycle-related genes with concomitant loss of H3K27ac. At the same time, FGF-2 promoted the expression of p21, various cytokines, and MAPK-related genes. Nuclear envelope proteins, particularly lamin B1, displayed increased phosphorylation in response to FGF-2. Proteome analysis suggested alterations in cellular metabolism, as evident by modulated expression of enzymes involved in purine biosynthesis, tRNA aminoacylation, and the TCA cycle. We propose that Y1 cells senesce due to an inability to progress through the cell cycle, which may stem from DNA damage or TGFb signaling. Altogether, the phenotype of Y1 cells is consistent with rapidly established oncogene-induced senescence, demonstrating the synergy between growth factors and oncogenes in driving senescence and bringing additional insight into this tumor suppressor mechanism.

Targeting microRNAs with thymoquinone: a new approach for cancer therapy

Cancer is a global disease involving transformation of normal cells into tumor types via numerous mechanisms, with mortality among all generations, in spite of the breakthroughs in chemotherapy, radiotherapy and/or surgery for cancer treatment. Since one in six deaths is due to cancer, it is one of the overriding priorities of world health. Recently, bioactive natural compounds have been widely recognized due to their therapeutic effects for treatment of various chronic disorders, notably cancer. Thymoquinone (TQ), the most valuable constituent of black cumin seeds, has shown anti-cancer characteristics in a wide range of animal models. The revolutionary findings have revealed TQ's ability to regulate microRNA (miRNA) expression, offering a promising approach for cancer therapy. MiRNAs are small noncoding RNAs that modulate gene expression by means of variation in features of mRNA. MiRNAs manage several biological processes including gene expression and cellular signaling pathways. Accordingly, miRNAs can be considered as hallmarks for cancer diagnosis, prognosis and therapy. The purpose of this study was to review the various molecular mechanisms by which TQ exerts its potential as an anti-cancer agent through modulating miRNAs.