The cell proliferation antigen Ki-67 organises heterochromatin

PDCD11 Stabilizes C-MYC Oncoprotein by Hindering C-MYC-SKP2 Negative Feedback Loop to Facilitate Progression of p53-Mutant Breast and Colon Malignancies

C-MYC is a proto-oncoprotein whose dysregulation triggers tumorigenesis and tumor progression in ≈70% of cancer cases. It is presently demonstrated that aberrantly upregulated MYC is caused by the overexpressed and "extra-nucleolar" PDCD11 in p53-mutant breast and colon cancer cells, which is highly correlated to tumor progression, metastasis, and recurrence. In the nucleoplasm, PDCD11 binds to the TAD of C-MYC to prevent SKP2, a transcriptional target of C-MYC as well as one of the major E3 ligase components targeting C-MYC, from interacting with and ubiquitinating C-MYC in feedback. The ensuing stabilized C-MYC activates downstream signaling to facilitate the cellular G1/S transition, proliferation, and migration. PDCD11 silencing restores SKP2-mediated C-MYC degradation, thereby remarkably suppressing tumor growth and metastasis in nude mice. These findings highlight PDCD11 as a novel C-MYC partner and thereby offer a potential therapeutic rationale to challenge PDCD11-mediated "pro-stabilization" effect on C-MYC, a widely considered "undruggable" target, to combat C-MYC-driven malignancies with p53 mutation.

HMGA1 as a prognostic biomarker for gliomas: expression patterns, survival correlations, and clinical insights from a Pakistani cohort

PURPOSE

High-Mobility Group A1 (HMGA1) is a chromatin-associated protein involved in regulating key cellular processes, including DNA transcription, replication, recombination, and repair. It is highly expressed during embryogenesis and reactivated in various cancers, where it contributes to tumor progression and metastasis. We investigated the prognostic significance of HMGA1 gene expression in gliomas by comparing its expression in normal brain tissue and different glioma grades.

METHODS

Real-time quantitative PCR (qPCR) was performed on 75 glioma samples obtained from Aga Khan University Hospital (Pakistan), along with 10 Normal Adjacent Tissue (NAT) samples. The correlation between HMGA1 expression and prognosis was evaluated using Kaplan-Meier (KM) plotter in glioma patients. Statistical analyses were conducted using the R platform and further validated through the online database Chinese Glioma Genome Atlas (CGGA) using online tools.

RESULTS

HMGA1 expression was significantly upregulated in gliomas compared to NAT (p < 0.001) and increased with tumor grade (p = 0.015). High HMGA1 expression correlated with Ki-67 levels and was associated with worse survival (p = 0.0014). Patients with elevated HMGA1 had a 3.5-fold higher mortality risk (95% CI: 1.5-7.9, p = 0.003). ROC analysis yielded an AUC of 0.752, indicating its potential prognostic value.

CONCLUSION

HMGA1 overexpression is associated with poor prognosis in gliomas, suggesting its potential as a prognostic marker. However, further validation is needed to confirm its clinical utility.

Palmitic acid induces cardiomyocyte apoptosis by enhancing the KLF4/cMLCK signaling pathway

Hyperlipidemia and myocardial apoptosis caused by myocardial ischemia are the main causes of high mortality rates in cardiovascular diseases. Previous studies have indicated that Krüppel-like factor 4 (KLF4) is involved in the induction of cardiac myocyte apoptosis under various stress conditions. In current study, we discovered that KLF4 also participates in palmitic acid (PA)-induced cardiac myocyte apoptosis. However, the specific mechanisms by which KLF4 regulates cardiac myocyte apoptosis remain unclear. Cardiac myosin light-chain kinase (cMLCK) is a crucial enzyme involved in regulating cardiac myocyte contraction and is closely associated with the regulation of apoptosis. Here, we employed the lipotoxicity in vitro and in vivo models to explore the potential synergistic role of KLF4 and cMLCK in cardiac myocyte apoptosis. Our findings demonstrate that under the influence of PA, upregulation of KLF4 expression accompanied by downregulation of cMLCK expression leads to cardiomyocyte apoptosis and cell proliferation inhibition. Selective knockdown and overexpression of KLF4 in cardiomyocytes further confirmed the involvement of KLF4 in PA-induced cardiomyocyte apoptosis. Likewise, overexpression of cMLCK alleviated PA-induced cardiac myocyte apoptosis. Our study reveals the pro-apoptotic effect of KLF4 and elucidates the specific mechanism by which the KLF4/cMLCK signaling pathway is involved in PA-induced cardiac myocyte apoptosis, providing new therapeutic targets for cardiovascular disease treatment.

Biodegradable Mg-1%Ca alloy inhibits the growth of cervical cancer

The traditional treatment for cervical cancer involves aggressive surgery combined with radiotherapy and chemotherapy. Nevertheless, these treatments have certain limitations and side effects, thus breakthroughs and advances are required in cervical cancer therapy. Magnesium alloy is a promising antitumor biomaterial with excellent biocompatibility and biodegradability. However, the potential effects of magnesium alloy on cervical tumors have not been extensively explored. Recent studies have demonstrated that adding a small amount of calcium to the magnesium matrix can reduce grain size and corrosion rate while providing good biocompatibility. We conductedin vivoandin vitroexperiments to test the antitumor properties of Mg-1%Ca alloys. The results indicated that the Mg-1%Ca alloy released Mg2+and OH-more slowly, inhibited the proliferation of SiHa and HeLa cells, induced apoptosis in tumor cells, disrupted the cytoskeleton, and inhibited cell migration and invasion. At the molecular level, Mg-1%Ca alloy significantly activated the mitochondrial apoptosis pathway and inhibited the MAPK/ERK signaling pathway. In the future, Mg-1%Ca may be employed in the treatment of cervical cancer as a novel adjuvant therapeutic material with anticancer function to prevent the occurrence and progression of cancer proliferation and metastasis.

Human Retinal Organoid Model of Ocular Toxoplasmosis

The health burden of ocular toxoplasmosis is substantial, and there is an unmet need for safe and curative anti-microbial drugs. One major barrier to research on new therapeutics is the lack of in vitro human-based models beyond two-dimensional cultured cells and tissue explants. We aimed to address this research gap by establishing a human retinal organoid model of ocular toxoplasmosis. Retinal organoids, generated from human induced pluripotent stem cells and grown to two stages of organization, were incubated with a suspension of live or heat-killed GT-1 strain T. gondii tachyzoites, or medium without tachyzoites. Both developing (1 month post-isolation) and matured (6 months post-isolation) organoids were susceptible to infection. Spread of live parasites from the margin to the entire organoid over 1 week was indicated by immunolabelling for T. gondii surface antigen 1. This progression was accompanied by changes in the levels of selected tachyzoite transcripts-SAG1, GRA6, and ROP16-and human cytokine transcripts-CCL2, CXCL8, CXCL10, and IL6-in infected versus control conditions. Our human retinal organoid model of ocular toxoplasmosis offers the opportunity for many future lines of study, including tachyzoite interactions with retinal cell populations and leukocyte subsets, parasite stage progression, and disease processes of different T. gondii strains, as well as drug testing.

Novel Ti6Al4V Surface Treatment for Subperiosteal Dental Implants: Evaluation of Osteoblast-like Cell Proliferation and Osteogenic Response

Nowadays, custom-made subperiosteal implants are emerging as a solution in all those cases where there is lack of healthy bone tissue to support endosseous implants. The development of innovative techniques has allowed the production of grids that precisely match the patient's anatomy. Elucidating the impact of laser-melted Ti6Al4V grids on both hard and soft tissues with which they come into contact is, therefore, mandatory. In this study, we analyzed the effects of five different surface treatments on a human osteoblast-like cell line (MG-63). In particular, the cell proliferation and osteogenic response were evaluated. Taken together, our data demonstrate that in our in vitro setting, the new surface treatment developed by Al Ti color could enhance osteogenesis and improve the stabilization of the implant to the residual bone by stimulating the best osteogenic response in MG-63 cells. Although further studies are required to validate our data in an in vivo model, our results provide the basis for future advances in implantology for the long-term maintenance of osseointegration.

Ultrasound-based artificial intelligence model for prediction of Ki-67 proliferation index in soft tissue tumors

RATIONALE AND OBJECTIVES

To investigate the value of deep learning (DL) combined with radiomics and clinical and imaging features in predicting the Ki-67 proliferation index of soft tissue tumors (STTs).

MATERIALS AND METHODS

In this retrospective study, a total of 394 patients with STTs admitted from January 2021 to December 2023 in two separate hospitals were collected. Hospital-1 was the training cohort (323 cases, of which 89 and 234 were high and low Ki-67, respectively) and Hospital-2 was the external validation cohort (71 cases, of which 23 and 48 were high and low Ki-67, respectively). Clinical and ultrasound characteristics including age, sex, tumor size, morphology, margins, internal echoes and blood flow were assessed. Risk factors with significant correlations were screened by univariate and multivariate logistic regression analyses. After extracting the radiomics and DL features, the feature fusion model is constructed by Support Vector Machine. The prediction results obtained from separate clinical features, radiomics features and DL features were combined to construct decision fusion models. Finally, the DeLong test was used to compare whether the AUCs between the models were significantly different.

RESULTS

The three feature fusion models and three decision fusion models constructed demonstrated excellent diagnostic performance in predicting Ki-67 expression levels in STTs. Among them, the feature fusion model based on clinical, radiomics, and DL performed the best with an AUC of 0.911 (95% CI: 0.886-0.935) in the training cohort and 0.923 (95% CI: 0.873-0.972) in the validation cohort, and proved to be well-calibrated and clinically useful. The DeLong test showed that the decision fusion models based on clinical, radiomics and DL performed significantly worse than the three feature fusion models on the validation set. There was no statistical difference in diagnostic performance between the other models.

CONCLUSION

The ultrasound-based fusion model of clinical, radiomics, and DL features showed good performance in predicting Ki-67 expression levels in STTs.

The role of MKI67 in the regulation of 60S pre-ribosome nucleolar export, transcripts, energy supply, and apoptosis

MKI67 (Ki67) is expressed exclusively in proliferating cells in human tissues, rendering it as a valuable diagnostic marker for cancer. However, the function of this protein in cells remains unclear. In this study, we present the findings on the regulatory functions of MKI67 in conjunction with its partner proteins GNL2 and MDN1, which are involved in pre-ribosome processing, as well as the regulatory functions in its absence. In proliferating HEK293T cells, MKI67 binds contiguously to the chromatin in conjunction with GNL2 and MDN1, localizing most densely to the nucleolar periphery to regulate 60S pre-ribosome export. On the other hand, RNA-seq analysis reveals that these three proteins can independently regulate many target transcripts, but they often share their target transcripts, yet often regulate them at different expression levels. MDN1 depletion strongly downregulates RNA gene transcripts involved in ribosome biogenesis and splicing. In contrast, MKI67 depletion strongly upregulates transcripts of protein-coding genes, including synapse-specific proteins and the mitosis-related protein NEK7. Furthermore, MKI67 depletion coordinately up- or down-regulates the levels of transcripts of several pathways, thereby enabling MKI67-depleted cells to adapt to less active metabolic states. The underlying mechanism by which MKI67 depletion upregulates transcripts appears to involve attenuation of transcript levels in cooperation with mRNA degradation systems, as evidenced by analysis of NEK7 and UNC13A translations. In conclusion, the present results indicate that MKI67 contributes to proliferation via nucleolar export of 60S pre-ribosome particles and high energy supply. Conversely, its absence leads the cells to adapt to the senescent and differentiated conditions.

Molecular differences between young and mature stria vascularis from organotypic explants and transcriptomics

The stria vascularis (SV) is an essential component of the inner ear that regulates the ionic environment required for hearing. SV degeneration disrupts cochlear homeostasis, leading to irreversible hearing loss, yet a comprehensive understanding of the SV, and consequently therapeutic availability for SV degeneration, is lacking. We developed a whole-tissue explant model from neonatal and mature mice to create a platform for advancing SV research. We validated our model by demonstrating that the proliferative behavior of the SV in vitro mimics SV in vivo. We also provided evidence for pharmacological experimentation by investigating the role of Wnt/β-catenin signaling in SV proliferation. Finally, we performed single-cell RNA sequencing from in vivo neonatal and mature mouse SV and surrounding tissue and revealed key genes and pathways that may play a role in SV proliferation and maintenance. Together, our results contribute new insights into investigating biological solutions for SV-associated hearing loss.

Targeted Inhibition of CHD1L by OTI-611 Reprograms Chemotherapy and Targeted Therapy-Induced Cell Cycle Arrest and Suppresses Proliferation to Produce Synergistic Antitumor Effects in Breast and Colorectal Cancer

The second and third most frequently diagnosed cancers worldwide are breast (2.3 million new cases) and colorectal (1.9 million new cases), respectively. Although advances in cancer therapies and early detection have improved the overall survival of patients, patients still develop resistance or cancer recurrence. Thus, the development of novel therapies that can affect multiple mechanisms of drug resistance and cell survival is ideal for the treatment of advanced and metastatic cancers. CHD1L is a novel oncogenic protein involved in regulating chromatin remodeling, DNA damage repair, epithelial-mesenchymal transition (EMT), and programmed cell death via PARthanatos. Herein, we assess in real-time how the CHD1L inhibitor (CHD1Li) OTI-611 modulates cell cycle progression in Colo678, SUM149PT, and SW620 cell lines. By utilizing a cell cycle reporter, we tracked the real-time cell cycle progression of cancer cells treated with OTI-611 alone and in combination with standard-of-care (SOC) therapies. Our results indicate that OTI-611 causes G1 phase cell cycle arrest through a CHD1L-mediated mechanism that regulates Cyclin D1 expression and localization. As a result of this mechanism, OTI-611 can reprogram the cell cycle effects of other antitumor agents to modulate and arrest cells in G1 when used in combination, including agents commonly known to arrest cells in the G2/M phase. Therefore, we conclude that OTI-611-induced G1 arrest represents a critical component of its unique mechanism of action, contributing significantly to its anticancer activity.

Synergism between TLR4 and B. infantis in the development of the premature intestine

BACKGROUND

Intestinal microbiota has a role in early life maturation including maturation of intestinal immune function. However, the interaction of the TLR4 with colonizing bacteria in intestinal development is incompletely understood.

METHODS

An established human immature small intestinal cell line, human fetal intestinal organoids, and wild-type (WT) and TLR4 gene knockout (TLR4 -/-) neonatal mice were used to test the synergism between the innate immune receptor TLR4 and postbiotics from Bifidobacteria longum subsp. infantis (B. infantis) in development of the premature intestine.

RESULTS

TLR4-mediated postbiotics induced immature enterocyte proliferation and filamentous actin (F-actin) maturation both at the mRNA and protein levels. Proliferation of mRNA levels increased in wild-type mice but not in TLR4 -/- mice fed by postbiotics, both in the ileum and colon. Postbiotics can also change tight junction distribution in WT neonatal colon but not in TLR4 -/- mice.

CONCLUSIONS

Our data suggest a novel regulation of intestinal development by a synergistic role of the innate immune receptor TLR4 and early life colonizing bacteria, such as B. infantis. This study should provide new insights into the mechanisms of intestinal maturation as well as opportunities to target novel approaches to NEC prevention and treatment.

IMPACT

The innate immune system and postbiotics affect immature intestinal development. The innate immune receptor TLR4 prevention of NEC. Mechanism of prevention of NEC. This is the first time this has been demonstrated in human fetal intestine. In vitro process for future clinical studies for prevention of NEC.

An injectable shape-adaptive hydrogel system for subconjunctival injuries: In situ and permanently releases rapamycin to prevent fibrosis via promoting autophagy

Subconjunctival fibrosis (SCF) is a common and refractory eye disease that is a serious threat to vision. The severe side effects of existing drugs and low drug bioavailability due to the ocular barrier are major challenges in SCF treatment. Hence, there is an urgent need to explore safer and more effective strategies for administering anti-SCF drugs. Herein, an injectable and adaptable hydrogel system containing the antifibrotic drug rapamycin was fabricated to address this complex need. This system possesses moderate mechanical properties, self-healing and shape-adaptive capabilities, injectability, and biosafety. It is designed to promote autophagy by modulating the PI3K/AKT/mTOR/WIPI2 pathway, thereby inhibiting SCF. In vivo experiments utilizing a rat subconjunctival injury model indicated that in situ administration of this hydrogel system effectively inhibited SCF. This system constitutes a promising method for promoting autophagy to protect against SCF, which will foster its widespread application for other fibrotic diseases.

Diffusion-weighted MRI of advanced gastric cancer: correlations of the apparent diffusion coefficient with Borrmann classification, proliferation and aggressiveness

OBJECTIVES

This study aimed to compare apparent diffusion coefficient (ADC) values derived from diffusion-weighted imaging (DWI) of different Borrmann types of advanced gastric cancer (AGC) and correlate these ADC values with Ki-67 expression and serum CEA levels in AGC.

METHODS

A total of 84 patients with AGC who underwent DWI of the upper abdomen before tumor resection in our hospital between June 2014 and July 2018 were included in the present study. DWI was obtained with a single-shot echo planar imaging sequence in the axial plane (b values: 0, 100, 700 and 1000 s/mm2). Mean ADC values were calculated from tumor regions. Postoperatively, specimens were used to determine Borrmann type (1-4). Then, ADC values for AGCs categorized by Borrmann type were compared by one-way analysis of variance with Bonferroni correction for multiple comparisons. Subsequently, associations between ADC values and Ki-67 expression and serum CEA levels were evaluated by Spearman's correlation analysis.

RESULTS

The mean ADC value for Borrmann type 3 AGC was significantly lower compared to the mean ADC value for Borrmann type 2 AGC (p < 0.01). There were significant negative correlations between ADC values and Ki-67 scores (r = -0.639, p < 0.001), and between ADC values and serum CEA levels (r = -0.575, p < 0.001).

CONCLUSIONS

DWI can help characterize Borrmann types of AGC. ADC values may reflect Ki-67 expression and serum CEA levels in patients with AGC, and have utility as a non-invasive indicator for evaluating the aggressiveness and prognosis of AGC.

Viral encephalitis and seizures cause rapid depletion of neuronal progenitor cells and alter neurogenesis in the adult mouse dentate gyrus

Infections impacting the central nervous system (CNS) constitute a substantial predisposing factor for the emergence of epileptic seizures. Given that epilepsy conventionally correlates with hippocampal sclerosis and neuronal degeneration, a potentially innovative avenue for therapeutic intervention involves fostering adult neurogenesis, a process primarily occurring within the subgranular zone of the dentate gyrus (DG) through the differentiation of neural stem cells (NSC). While experimental seizures induced by chemoconvulsants or electrical stimulation transiently enhance neurogenesis, the effects of encephalitis and the resultant virus-induced seizures remain inadequately understood. Thus, this study employed the Theiler's Murine Encephalomyelitis Virus (TMEV) model of virus-induced seizures in adult C57BL/6J mice to investigate the impact of infection-induced seizures on neurogenesis at three distinct time points [3, 7, and 14 days post-infection (dpi)]. Immunohistochemical analysis revealed a reduction in the overall number of proliferating cells post-infection. More notably, the specific cell types exhibiting proliferation diverged between TMEV and control (CTR) mice: (1) Neuronal progenitors (doublecortin, DCX+) were almost entirely absent at 3 dpi in the dorsal DG. They resumed proliferation at 14 dpi, but, did not recover to CTR levels, and displayed aberrant migration patterns. (2) The number of proliferating NSCs significantly decreased within the dorsal DG of TMEV mice at 14 dpi compared to CTR, while (3) a heightened population of proliferating astrocytes was observed. Most observed changes were not different between seizing and non-seizing infected mice. In summary, our findings demonstrate that viral infection rapidly depletes neuronal progenitor cells and causes aberrant migration of the remaining ones, potentially contributing to hyperexcitability. Additionally, the increased differentiation toward glial cell fates in infected mice emerges as a possible additional pro-epileptogenic mechanism.

Procyanidin B2 targeted CCR7 expression to inhibit the senescence-associated secretory phenotype through the NF-κB pathway to promote osteogenic differentiation of periodontal ligament stem cells in periodontitis

Periodontitis is recognized as a chronic inflammatory disease, with aging emerging as a significant risk factor. Cellular senescence plays a crucial role in the biological process of aging. The senescence-associated secretory phenotype (SASP) is characterized by a series of pro-inflammatory factors, chemokines, and proteases, which are hallmark characteristics of senescent cells. These factors collectively alter the local environment, impacting the function of periodontal ligament stem cells (PDLSCs). Procyanidin B2 (PB2), the main dimer of oligomeric procyanidins, possesses antioxidant, anti-inflammatory, and anti-cancer properties. The molecular mechanisms through which PB2 exerts its protective effects against periodontitis remain incompletely understood. Therefore, this research aimed to investigate the effects and underlying mechanisms of PB2 on the osteogenic differentiation of PDLSCs within an inflammatory environment. To simulate a chronic inflammatory condition, PDLSCs were stimulated with Porphyromonas gingivalis Lipopolysaccharide (Pg. LPS). The findings indicated that PB2 significantly alleviated the inflammatory responses, enhanced the activity of antioxidant enzymes, and upregulated the osteogenic differentiation of PDLSCs stimulated by Pg. LPS. RNA sequencing (RNA-Seq) revealed that Pg. LPS influenced the cell cycle, cellular senescence, and NF-κB signaling pathways. In contrast, PB2 treatment reduced the number of senescent cells and diminished the expression of senescence-associated proteins and genes. Western blot analysis verified that PB2 also decreased the levels of CCR7 and suppressed the NF-κB signaling pathways. In conclusion, PB2 targeted CCR7 expression to inhibit the SASP through NF-κB signaling pathway, demonstrating its anti-inflammatory and osteogenic properties, positioning PB2 as a promising therapeutic option for the adjuvant treatment of periodontitis.

COL8A2 activation enhances function of corneal endothelial cells through HIPPO signaling/mitochondria pathway

Corneal endothelial cells (CECs) are essential for maintaining corneal transparency and hydration through their barrier and pump functions. The COL8A2 gene encodes a component of the extracellular matrix of the cornea, which is crucial for the normal functioning of these cells. Mutations in COL8A2 are linked to corneal dystrophies, emphasizing the gene's importance in corneal health. The purpose of this research is to explore the effects of COL8A2 activation within CECs, to understand its contribution to cellular behavior and health. COL8A2 CRISPR/dCas9 activation system (aCOL8A2) was used to activate the COL8A2. In rats, wound healing and mitochondrial function were assessed after COL8A2 activation. As a result, aCOL8A2 promoted wound healing of rat corneal endothelium by increasing mitochondrial membrane potential. In cultured human CECs, proteomic analysis was performed to screen and identify the differential protein profiles between control and aCOL8A2 cells. Western blot was used to validate the differential proteins from both cells. Mitochondrial function and intracellular distribution were assessed by measuring ATP production and mitochondrial membrane potential. In cultured human CECs, aCOL8A2 increased COL8A2 and phospho-YAP levels. Transendothelial electrical resistance (TEER) was increased and actin cytoskeleton was attenuated by aCOL8A2. Gene ontology analysis revealed that the proteins were mainly involved in the regulation of folate biosynthesis, ECM-receptor interaction, cell differentiation, NADP activity and cytoskeleton. ATP production was increased, mitochondrial membrane potential was polarized and mitochondrial distribution was widespread in the aCOL8A2 group. In conclusion, aCOL8A2 induces a regulatory cascade affecting mitochondrial positioning and efficiency, mediated by alterations in the cytoskeletal architecture and the YAP signaling pathway. This sequence of events serves to bolster the functional capacities of corneal endothelial cells, including their pump and barrier functions, essential for corneal health and transparency.

Proliferating CLL cells express high levels of CXCR4 and CD5

Chronic lymphocytic leukemia (CLL) is an incurable progressive malignancy of CD5+ B cells with a birth rate between 0.1% and 1% of the entire clone per day. However, the phenotype and functional characteristics of proliferating CLL cells remain incompletely understood. Here, we stained peripheral blood CLL cells for ki67 and DNA content and found that CLL cells in G1-phase have a CXCR4loCD5hi phenotype, while CLL cells in S/G2/M-phase express high levels of both CXCR4 and CD5. Induction of proliferation in vitro using CD40L stimulation results in high ki67 levels in CXCR4loCD5hi cells with CXCR4 expression increasing as CLL cells progress through S and G2/M-phases, while CXCR4hiCD5lo CLL cells remained quiescent. Dye dilution experiments revealed an accumulation of Ki67hi-divided cells in the CXCR4hiCD5hi fraction. In Eµ-TCL1 transgenic mice, the CXCR4hiCD5hi fraction expressed high levels of ki67 and was expanded in enlarged spleens of diseased animals. Human peripheral blood CXCR4hiCD5hi CLL cells express increased levels of IgM and the chemokine receptors CCR7 and CXCR5 and migrate efficiently toward CCL21. We found higher levels of CXCR4 in patients with progressive disease and the CXCR4hiCD5hi fraction was expanded upon clinical relapse. Thus, this study defines the phenotype and functional characteristics of dividing CLL cells identifying a novel subclonal population that underlies CLL pathogenesis and may drive clinical outcomes.

ImmunoCellCycle-ID - a high-precision immunofluorescence-based method for cell cycle identification

The cell cycle is a fundamental process essential for cell proliferation, differentiation and development. It consists of four major phases: G1, S, G2 and M. These phases collectively drive the reproductive cycle and are meticulously regulated by various proteins that play crucial roles in both the prevention and progression of cancer. Traditional methods for studying these functions, such as flow cytometry, require a substantial number of cells to ensure accuracy. In this study, we have developed a user-friendly immunofluorescence-based method for identifying cell cycle stages, providing single-cell resolution and precise identification of G1, early/mid S, late S, early/mid G2, late G2, and each sub-stage of the M phase using fluorescence microscopy called ImmunoCellCycle-ID. This method provides high-precision cell cycle identification and can serve as an alternative to, or in combination with, traditional flow cytometry to dissect detailed sub-stages of the cell cycle in a variety of cell lines.

Identification of apelin/APJ signaling dysregulation in a human iPSC-derived granulosa cell model of Turner syndrome

The interaction between germ cells and somatic cells in the ovaries plays a crucial role in establishing the follicle reserve in mammals. Turner syndrome (TS) predominantly affects females who have a partial or complete loss of one X chromosome. Our understanding of the role that granulosa cells (GCs) play in TS disease progression and pathogenesis remains limited. In this study, we achieved GC differentiation efficiency of up to 80% from iPSCs. When attempting to replicate the differentiation process of embryonic granulosa cells, we observed the downregulation of specific genes-GATA4, FOXL2, AMHR2, CYP19A1, and FSH-in Turner syndrome-derived granulosa cells (TS-GCs). Additionally, we identified dysregulation of the cell cycle in TS-GCs. To uncover the endogenous defects in TS-GCs, we compared global transcriptome patterns between iPSC-derived granulosa cells from healthy individuals and those with Turner syndrome. The apelin/APJ pathway exhibited differential signaling between the healthy and TS groups. Supplementation with apelin ligands and activation of apelin/APJ downstream signaling via Akt/PKB restored cell cycle progression and marker gene expression. We hypothesize that during early embryonic development, failures in apelin/APJ signaling in GCs of Turner syndrome patients lead to abnormalities in ovarian development, ultimately resulting in early oocyte loss and infertility.

Acidic Pepsin Affects Laryngeal Carcinoma Cell Growth and Invasion Through Glycolysis

OBJECTIVE

The pathogenic mechanism underlying the effects of acidic pepsin in laryngeal cancer remains unclear. This study investigated whether acidic pepsin influences Glut-1 expression and glycolytic activity in laryngeal carcinoma cells and whether it plays a role in the growth and migration of these cells through glycolysis.

STUDY DESIGN

In vitro study.

SETTING

A university-affiliated hospital.

METHODS

Laryngeal carcinoma TU 212 and TU 686 cells were treated with acidic pepsin and 2-deoxy-d-glucose (2-DG), then transfected with Glut-1 small interfering RNA (siRNA). Glucose uptake was detected by a radioimmunoassay counter, lactate secretion was detected by a lactic acid kit, and Glut-1 expression was detected by western blotting. Cell viability, migration and invasion, and clonal formation were assessed using the Cell Counting Kit-8, Transwell chamber, and clonal formation assays, respectively.

RESULTS

Acidic pepsin significantly increased Glut-1 expression in laryngeal carcinoma cells compared with the control group (P < .01). It also significantly enhanced 18F-fluorodeoxyglucose (Cin/Cout) uptake, lactate secretion, cell viability, migration, invasion, and clonal formation in laryngeal carcinoma cells compared with the control group (P < .01). The glycolytic inhibitor 2-DG and Glut-1 siRNA significantly reversed the effects of acidic pepsin on laryngeal carcinoma cells (P < .01).

CONCLUSION

Acidic pepsin enhances the growth and migration of laryngeal carcinoma cells by upregulating Glut-1, thus promoting glycolysis.

Cytocompatibility of electrospun poly-L-lactic acid membranes for Bruch's membrane regeneration using human embryonic stem cell-derived retinal pigment epithelial cells

Cell replacement therapy is under development for dry age-related macular degeneration (AMD). A thin membrane resembling the Bruch's membrane is required to form a cell-on-membrane construct with retinal pigment epithelial (RPE) cells. These cells have been differentiated from human embryonic stem cells (hESCs) in vitro. A carrier membrane is required for cell implantation, which is biocompatible for cell growth and has dimensions and physical properties resembling the Bruch's membrane. Here a nanofiber electrospun poly-L-lactic acid (PLLA) membrane is tested for capacity to support cell growth and maturation. The requirements for laminin coating of the membrane are identified here. A porous electrospun nanofibrous PLLA membrane of ∼50 nm fiber diameter was developed as a prototype support for functional RPE cells grown as a monolayer. The need for laminin coating applied to the membrane following treatment with poly-L-ornithine (PLO), was identified in terms of cell growth and survival. Test membranes were compared in terms of hydrophilicity after laminin coating, mechanical properties of surface roughness and Young's modulus, porosity and ability to promote the attachment and proliferation of hESC-RPE cells in culture for up to 8 weeks. Over this time, RPE cell proliferation, morphology, and marker and gene expression, were monitored. The functional capacity of cell monolayers was identified in terms of transepithelial electrical resistance (TEER), phagocytosis of cells, as well as expression of the cytokines, vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF). PLLA polymer fibers are naturally hydrophobic, so their hydrophilicity was improved by pretreatment with PLO for subsequent coating with the bioactive protein laminin. They were then assessed for amount of laminin adsorbed, contact angle and uniformity of coating using scanning electron microscopy (SEM). Pretreatment with 100% PLO gave the best result over 10% PLO treatment or no treatment prior to laminin adsorption with significantly greater surface stiffness and modulus. By 6 weeks after cell plating, the coated membranes could support a mature RPE monolayer showing a dense apical microvillus structure and pigmented 3D polygonal cell morphology. After 8 weeks, PLO (100%)-Lam coated membranes exhibited the highest cell number, cell proliferation, and RPE barrier function measured as TEER. RPE cells showed the higher levels of specific surface marker and gene expression. Microphthalmia-associated transcription factor expression was highly upregulated indicating maturation of cells. Functionality of cells was indicated by expression of VEGF and PEDF genes as well as phagocytic capacity. In conclusion, electrospun PLLA membranes coated with PLO-Lam have the physical and biological properties to support the distribution and migration of hESC-RPE cells throughout the whole structure. They represent a good membrane candidate for preparation of hESC-RPE cells as a monolayer for implantation into the subretinal space of AMD patients.

Synergistic celecoxib and dimethyl-celecoxib combinations block cervix cancer growth through multiple mechanisms

OBJECTIVE

The synergistic inhibitory effect of celecoxib (CXB) and dimethyl-celecoxib (DMC) plus paclitaxel (PA) or cisplatin (CP) on human cervix HeLa and SiHa cells was assessed at multiple cellular levels in order to elucidate the biochemical mechanisms triggered by the synergistic drug combinations.

METHODS

The effect of CXB (5 μM)/CP (2 μM) or CXB (5 μM)/PA (15 μM) and DMC (15 μM)/CP (5 μM) or DMC (15 μM)/PA (20 μM) for 24 h was assayed on cancer cell proliferation, energy metabolism, mitophagy, ROS production, glycoprotein-P activity, DNA stability and apoptosis/necrosis.

RESULTS

Drug combinations synergistically decreased HeLa and SiHa cell proliferation (>75%) and arrested cellular cycle by decreasing S and G2/M phases as well as the Ki67 content (HeLa) by 7.5-30 times. Cell viability was preserved (>90%) and no apparent effects on non-cancer cell growth were observed. Mitochondrial and glycolytic protein contents (44-95%) and ΔΨm (45-50%) in HeLa cells and oxidative phosphorylation and glycolysis fluxes (70-90%) in HeLa and SiHa cells were severely decreased, which in turn promoted a drastic fall in the ATP supply (85-88%). High levels of mitophagy proteins in HeLa cells and active mitochondrial digestion in HeLa and SiHa cells was observed. Mitochondrial fission and microtubule proteins were also affected. Intracellular ROS content (2-2.3-fold) and ROS production was stimulated (2.3-4 times), whereas content and activity of glycoprotein-P (45-85%) were diminished. DNA fragmentation was not observed and apoptosis/necrosis was not detected suggesting that cell death could be mainly associated to mitophagy induction.

CONCLUSIONS

CXB or DMC combination with canonical chemotherapy may be a promising chemotherapy strategy against cervical cancer growth, because it can selectively block multiple cell processes including inhibition of energy pathways and in consequence ATP-dependent processes such as cell proliferation, glycoprotein-P activity, ROS production and mitophagy, with no apparent effects on non-cancer cells.

Systematic discovery of DNA-binding tandem repeat proteins

Tandem repeat proteins (TRPs) are widely distributed and bind to a wide variety of ligands. DNA-binding TRPs such as zinc finger (ZNF) and transcription activator-like effector (TALE) play important roles in biology and biotechnology. In this study, we first conducted an extensive analysis of TRPs in public databases, and found that the enormous diversity of TRPs is largely unexplored. We then focused our efforts on identifying novel TRPs possessing DNA-binding capabilities. We established a protein language model for DNA-binding protein prediction (PLM-DBPPred), and predicted a large number of DNA-binding TRPs. A subset was then selected for experimental screening, leading to the identification of 11 novel DNA-binding TRPs, with six showing sequence specificity. Notably, members of the STAR (Short TALE-like Repeat proteins) family can be programmed to target specific 9 bp DNA sequences with high affinity. Leveraging this property, we generated artificial transcription factors using reprogrammed STAR proteins and achieved targeted activation of endogenous gene sets. Furthermore, the members of novel families such as MOON (Marine Organism-Originated DNA binding protein) and pTERF (prokaryotic mTERF-like protein) exhibit unique features and distinct DNA-binding characteristics, revealing interesting biological clues. Our study expands the diversity of DNA-binding TRPs, and demonstrates that a systematic approach greatly enhances the discovery of new biological insights and tools.

Breast milk induces the differentiation of monocytes into macrophages, promoting human cytomegalovirus infection

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus found in human breast milk that is frequently transmitted from HCMV-seropositive mothers to their infants during the postnatal period. Despite extensive research, the mechanisms underlying HCMV transmission from breast milk and the anatomical location at which virus transfer takes place remain unclear. Breast milk contains many uniquely differentiated macrophages that undergo specific morphological and functional modifications in the mammary gland during lactation. Although the existence of permissive HCMV infection in differentiated macrophages has been well-described, the role of breast milk in this process remains unknown. Herein, we report that exposure of isolated peripheral blood monocytes to breast milk induces their differentiation into macrophages that exhibit an M2 phenotype (CD14highCD163highCD68highCD206high) and promotes a productive and sustained HCMV infection. We also found that breast milk triggers macrophage proliferation and thus sustains a unique population of proliferating, long-lived, and HCMV-susceptible macrophages that are capable of ongoing production of infectious virions. These results suggest a mechanism that explains chronic HCMV shedding into the breast milk of postpartum seropositive mothers. We also found that HCMV virions released from breast milk-induced macrophages generate a productive infection in primary infant tonsil epithelial cells. Collectively, our results suggest that breast milk may facilitate HCMV transmission from mother to infant via the oropharyngeal mucosa.

IMPORTANCE

While human cytomegalovirus (HCMV) is frequently detected in the breast milk of HCMV-seropositive women and is often transmitted to infants via breastfeeding, the mechanisms by which this transmission occurs remain unclear. In this study, we modeled HCMV transmission at the oropharyngeal mucosa. We treated human monocytes with breast milk to mimic the lactating mammary gland microenvironment. We found that monocytes differentiated into macrophages with an M2 phenotype, which were highly permissive for HCMV. We also discovered that breast milk induces macrophage proliferation. Thus, exposure to breast milk increased the number of HCMV-susceptible macrophages and supported high levels of infectious HCMV. We found that HCMV virions released from breast milk-induced macrophages could infect primary infant tonsil epithelial cells. Collectively, these findings reveal the dual role of breast milk that induces the differentiation and proliferation of macrophages in the mammary gland and thus facilitates mother-to-child HCMV transmission at the oropharyngeal mucosa.

A liquid-like coat mediates chromosome clustering during mitotic exit

The individualization of chromosomes during early mitosis and their clustering upon exit from cell division are two key transitions that ensure efficient segregation of eukaryotic chromosomes. Both processes are regulated by the surfactant-like protein Ki-67, but how Ki-67 achieves these diametric functions has remained unknown. Here, we report that Ki-67 radically switches from a chromosome repellent to a chromosome attractant during anaphase in human cells. We show that Ki-67 dephosphorylation during mitotic exit and the simultaneous exposure of a conserved basic patch induce the RNA-dependent formation of a liquid-like condensed phase on the chromosome surface. Experiments and coarse-grained simulations support a model in which the coalescence of chromosome surfaces, driven by co-condensation of Ki-67 and RNA, promotes clustering of chromosomes. Our study reveals how the switch of Ki-67 from a surfactant to a liquid-like condensed phase can generate mechanical forces during genome segregation that are required for re-establishing nuclear-cytoplasmic compartmentalization after mitosis.

Construction of a 5-Gene super-enhancer-related signature for osteosarcoma prognosis and the regulatory role of TNFRSF11B in osteosarcoma

Osteosarcoma, one of the most common primary malignancies in children and adolescents, has the primary characteristics of a poor prognosis and high rate of metastasis. This study used super-enhancer-related genes derived from two different cell lines to construct five novel super-enhancer-related gene prognostic models for patients with osteosarcoma. The training and testing datasets were used to confirm the prognostic models of the five super-enhancer-related genes, which resulted in an impartial predictive element for osteosarcoma. The immunotherapy and prediction of the response to anticancer drugs have shown that the risk signature of the five super-enhancer-related genes positively correlate with chemosensitivity. Furthermore, functional analysis of the risk signature genes revealed a significant relationship between gene groups and the malignant characteristics of tumours. TNF Receptor Superfamily Member 11b (TNFRSF11B) was selected for functional verification. Silencing of TNFRSF11B suppressed the proliferation, migration, and invasion of osteosarcoma cells in vitro and suppressed osteosarcoma growth in vivo. Moreover, transcriptome sequencing was performed on MG-63 cells to study the regulatory mechanism of TNFRSF11B in osteosarcoma cells, and it was discovered that TNFRSF11B is involved in the development of osteosarcoma via the phosphoinositide 3-kinase signalling pathway. Following the identification of TNFRSF11B as a key gene, we selected an inhibitor that specifically targeted this gene and performed molecular docking simulations. In addition, risedronic acid inhibited osteosarcoma growth at both cellular and molecular levels. In conclusion, the super-enhancer-related gene signature is a viable therapeutic tool for osteosarcoma prognosis and treatment.

Flow cytometric analysis for Ki67 assessment in formalin-fixed paraffin-embedded breast cancer tissue

BACKGROUND

Pathologists commonly employ the Ki67 immunohistochemistry labelling index (LI) when deciding appropriate therapeutic strategies for patients with breast cancer. However, despite several attempts at standardizing the Ki67 LI, inter-observer and inter-laboratory bias remain problematic. We developed a flow cytometric assay that employed tissue dissociation, enzymatic treatment and a gating process to analyse Ki67 in formalin-fixed paraffin-embedded (FFPE) breast cancer tissue.

RESULTS

We demonstrated that mechanical homogenizations combined with thrombin treatment can be used to recover efficiently intact single-cell nuclei from FFPE breast cancer tissue. Ki67 in the recovered cell nuclei retained reactivity against the MIB-1 antibody, which has been widely used in clinical settings. Additionally, since the method did not alter the nucleoskeletal structure of tissues, the nuclei of cancer cells can be enriched in data analysis based on differences in size and complexity of nuclei of lymphocytes and normal mammary cells. In a clinical study using the developed protocol, Ki67 positivity was correlated with the Ki67 LI obtained by hot spot analysis by a pathologist in Japan (rho = 0.756, P < 0.0001). The number of cancer cell nuclei subjected to the analysis in our assay was more than twice the number routinely checked by pathologists in clinical settings.

CONCLUSIONS

The findings of this study showed the application of this new flow cytometry method could potentially be used to standardize Ki67 assessments in breast cancer.

Ki67 deficiency impedes chromatin accessibility and BCR gene rearrangement

The proliferation marker Ki67 has been attributed critical functions in maintaining mitotic chromosome morphology and heterochromatin organization during the cell cycle, indicating a potential role in developmental processes requiring rigid cell-cycle control. Here, we discovered that despite normal fecundity and organogenesis, germline deficiency in Ki67 resulted in substantial defects specifically in peripheral B and T lymphocytes. This was not due to impaired cell proliferation but rather to early lymphopoiesis at specific stages where antigen-receptor gene rearrangements occurred. We identified that Ki67 was required for normal global chromatin accessibility involving regulatory regions of genes critical for checkpoint stages in B cell lymphopoiesis. In line with this, mRNA expression of Rag1 was diminished and gene rearrangement was less efficient in the absence of Ki67. Transgenes encoding productively rearranged immunoglobulin heavy and light chains complemented Ki67 deficiency, completely rescuing early B cell development. Collectively, these results identify a unique contribution from Ki67 to somatic antigen-receptor gene rearrangement during lymphopoiesis.

ISWI chromatin remodeling complexes recruit NSD2 and H3K36me2 in pericentromeric heterochromatin

Histone H3 lysine36 dimethylation (H3K36me2) is generally distributed in the gene body and euchromatic intergenic regions. However, we found that H3K36me2 is enriched in pericentromeric heterochromatin in some mouse cell lines. We here revealed the mechanism of heterochromatin targeting of H3K36me2. Among several H3K36 methyltransferases, NSD2 was responsible for inducing heterochromatic H3K36me2. Depletion and overexpression analyses of NSD2-associating proteins revealed that NSD2 recruitment to heterochromatin was mediated through the imitation switch (ISWI) chromatin remodeling complexes, such as BAZ1B-SMARCA5 (WICH), which directly binds to AT-rich DNA via a BAZ1B domain-containing AT-hook-like motifs. The abundance and stoichiometry of NSD2, SMARCA5, and BAZ1B could determine the localization of H3K36me2 in different cell types. In mouse embryos, H3K36me2 heterochromatin localization was observed at the two- to four-cell stages, suggesting its physiological relevance.

Teicoplanin-Decorated Reduced Graphene Oxide Incorporated Silk Protein Hybrid Hydrogel for Accelerating Infectious Diabetic Wound Healing and Preventing Diabetic Foot Osteomyelitis

Developing hybrid hydrogel dressings with anti-inflammatory, antioxidant, angiogenetic, and antibiofilm activities with higher bone tissue penetrability to accelerate diabetic wound healing and prevent diabetic foot osteomyelitis (DFO) is highly desirable in managing diabetic wounds. Herein, the glycopeptide teicoplanin is used for the first time as a green reductant to chemically reduce graphene oxide (GO). The resulting teicoplanin-decorated reduced graphene oxide (rGO) is incorporated into a mixture of silk proteins (SP) and crosslinked with genipin to yield a physicochemically crosslinked rGO-SP hybrid hydrogel. This hybrid hydrogel exhibits high porosity, self-healing, shear-induced thinning, increased cell proliferation and migration, and mechanical properties suitable for tissue engineering. Moreover, the hybrid hydrogel eradicates bacterial biofilms with a high penetrability index in agar and hydroxyapatite disks covered with biofilms, mimicking bone tissue. In vivo, the hybrid hydrogel accelerates the healing of noninfected wounds in a diabetic rat and infected wounds in a diabetic mouse by upregulating anti-inflammatory cytokines and downregulating matrix metalloproteinase-9, promoting M2 macrophage polarization and angiogenesis. The implantation of hybrid hydrogel into the infected site of mouse tibia improves bone regeneration. Hence, the rGO-SP hybrid hydrogel can be a promising wound dressing for treating infectious diabetic wounds, providing a further advantage in preventing DFO.

Early and Late Effects of Low-Dose X-ray Exposure in Human Fibroblasts: DNA Repair Foci, Proliferation, Autophagy, and Senescence

The effects of low-dose radiation exposure remain a controversial topic in radiation biology. This study compares early (0.5, 4, 24, 48, and 72 h) and late (5, 10, and 15 cell passages) post-irradiation changes in γH2AX, 53BP1, pATM, and p-p53 (Ser-15) foci, proliferation, autophagy, and senescence in primary fibroblasts exposed to 100 and 2000 mGy X-ray radiation. The results show that exposure to 100 mGy significantly increased γH2AX, 53BP1, and pATM foci only at 0.5 and 4 h post irradiation. There were no changes in p-p53 (Ser-15) foci, proliferation, autophagy, or senescence up to 15 passages post irradiation at the low dose.

Circular RNAs in tuberculosis and lung cancer

This review signifies the role of circular RNAs (circRNAs) in tuberculosis (TB) and lung cancer (LC), focusing on pathogenesis, diagnosis, and treatment. CircRNAs, a newly discovered type of non-coding RNA, have emerged as key regulators of gene expression and promising biomarkers in various bodily fluids due to their stability. The current review discusses circRNA biogenesis, highlighting their RNase-R resistance due to their loop forming structure, making them effective biomarkers. It details their roles in gene regulation, including splicing, transcription control, and miRNA interactions, and their impact on cellular processes and diseases. For LC, the review identifies circRNA dysregulation affecting cell growth, motility, and survival, and their potential as therapeutic targets and biomarkers. In TB, it addresses circRNAs' influence on host anti-TB immune responses, proposing their use as early diagnostic markers. The paper also explores the interplay between TB and LC, emphasizing circRNAs as dual biosignatures, and the necessity for differential diagnosis. It concludes that no single circRNA biomarker is universally applicable for both TB and LC. Ultimately, the review highlights the pivotal role of circRNAs in TB and LC, encouraging further research in biomarker identification and therapeutic development concomitant for both diseases.

The role of rRNA in maintaining genome stability

Over the past few decades, unbiased approaches such as genetic screening and protein affinity purification have unveiled numerous proteins involved in DNA double-strand break (DSB) repair and maintaining genome stability. However, despite our knowledge of these protein factors, the underlying molecular mechanisms governing key cellular events during DSB repair remain elusive. Recent evidence has shed light on the role of non-protein factors, such as RNA, in several pivotal steps of DSB repair. In this review, we provide a comprehensive summary of these recent findings, highlighting the significance of ribosomal RNA (rRNA) as a critical mediator of DNA damage response, meiosis, and mitosis. Moreover, we discuss potential mechanisms through which rRNA may influence genome integrity.

Oncogenic Cell Tagging and Single-Cell Transcriptomics Reveal Cell Type-Specific and Time-Resolved Responses to Vhl Inactivation in the Kidney

Defining the initial events in oncogenesis and the cellular responses they entrain, even in advance of morphologic abnormality, is a fundamental challenge in understanding cancer initiation. As a paradigm to address this, we longitudinally studied the changes induced by loss of the tumor suppressor gene von Hippel Lindau (VHL), which ultimately drives clear cell renal cell carcinoma. Vhl inactivation was directly coupled to expression of a tdTomato reporter within a single allele, allowing accurate visualization of affected cells in their native context and retrieval from the kidney for single-cell RNA sequencing. This strategy uncovered cell type-specific responses to Vhl inactivation, defined a proximal tubular cell class with oncogenic potential, and revealed longer term adaptive changes in the renal epithelium and the interstitium. Oncogenic cell tagging also revealed markedly heterogeneous cellular effects including time-limited proliferation and elimination of specific cell types. Overall, this study reports an experimental strategy for understanding oncogenic processes in which cells bearing genetic alterations can be generated in their native context, marked, and analyzed over time. The observed effects of loss of Vhl in kidney cells provide insights into VHL tumor suppressor action and development of renal cell carcinoma.

SIGNIFICANCE

Single-cell analysis of heterogeneous and dynamic responses to Vhl inactivation in the kidney suggests that early events shape the cell type specificity of oncogenesis, providing a focus for mechanistic understanding and therapeutic targeting.

Micropeptide AF127577.4-ORF hidden in a lncRNA diminishes glioblastoma cell proliferation via the modulation of ERK2/METTL3 interaction

Micropeptides hidden in long non-coding RNAs (lncRNAs) have been uncovered to program various cell-biological changes associated with malignant transformation-glioblastoma (GBM) cascade. Here, we identified and characterized a novel hidden micropeptide implicated in GBM. We screened potential candidate lncRNAs by establishing a workflow involving ribosome-bound lncRNAs, publicly available MS/MS data, and prognosis-related lncRNAs. Micropeptide expression was detected by western blot (WB), immunofluorescence (IF), and immunohistochemistry (IHC). Cell proliferation rate was assessed by calcein/PI staining and EdU assay. Proteins interacted with the micropeptide were analyzed by proteomics after co-immunoprecipitation (Co-IP). We discovered that lncRNA AF127577.4 indeed encoded an endogenous micropeptide, named AF127577.4-ORF. AF127577.4-ORF was associated with GBM clinical grade. In vitro, AF127577.4-ORF could suppress GBM cell proliferation. Moreover, AF127577.4-ORF reduced m6A methylation level of GBM cells. Mechanistically, AF127577.4-ORF diminished ERK2 interaction with m6A reader methyltransferase like 3 (METTL3) and downregulated phosphorylated ERK (p-ERK) level. The ERK inhibitor reduced p-ERK level and downregulated METTL3 protein expression. AF127577.4-ORF weakened the stability of METTL3 protein by ERK. Also, AF127577.4-ORF suppressed GBM cell proliferation via METTL3. Our study identifies a novel micropeptide AF127577.4-ORF hidden in a lncRNA, with a potent anti-proliferating function in GBM by diminishing METTL3 protein stability by reducing the ERK2/METTL3 interaction. This micropeptide may be beneficial for development of therapeutic strategies against GBM.

Immunohistochemical Expression Levels of Epidermal Growth Factor Receptor, Cyclooxygenase-2, and Ki-67 in Canine Cutaneous Squamous Cell Carcinomas

Squamous cell carcinoma (SCC) stands as the second most prevalent skin cancer in dogs, primarily attributed to UV radiation exposure. Affected areas typically include regions with sparse hair and pale or depigmented skin. The significance of spontaneous canine cutaneous SCC as a model for its human counterpart is underscored by its resemblance. This study assesses the expression of key markers-Epidermal Growth Factor Receptor (EGFR), Cyclooxygenase-2 (Cox-2), and Ki-67-in canine cutaneous SCC. Our objective is to investigate the association between their expression levels and classical clinicopathological parameters, unraveling the intricate relationships among these molecular markers. In our retrospective analysis of 37 cases, EGFR overexpression manifested in 43.2% of cases, while Cox-2 exhibited overexpression in 97.3%. The EGFR, Cox-2 overexpression, and Ki-67 proliferation indices, estimated through immunohistochemistry, displayed a significant association with the histological grade, but only EGFR labeling is associated with the presence of lymphovascular emboli. The Ki-67 labeling index expression exhibited an association with EGFR and Cox-2. These findings propose that EGFR, Cox-2, and Ki-67 hold promise as valuable markers in canine SCC. EGFR, Cox-2, and Ki-67 may serve as indicators of disease progression, offering insights into the malignancy of a lesion. The implications extend to the potential therapeutic targeting of EGFR and Cox-2 in managing canine SCC. Further exploration of these insights is warranted due to their translational relevance and the development of targeted interventions in the context of canine SCC.

Biological Effects of PMMA and Composite Resins on Human Gingival Fibroblasts: An In Vitro Comparative Study

The use of temporary resin for provisional restorations is a fundamental step to maintain the position of prepared teeth, to protect the pulpal vitality and the periodontal health as well as the occlusion. The present study aimed at evaluating the biological effects of two resins used in dentistry for temporary restorations, Coldpac (Yates Motloid) and ProTemp 4™ (3M ESPE ™), and their eluates, in an in vitro model of human gingival fibroblasts (hGFs). The activation of the inflammatory pathway NFκB p65/NLRP3/IL-1β induced by the self-curing resin disks was evaluated by real-time PCR, Western blotting and immunofluorescence analysis. The hGFs adhesion on resin disks was investigated by means of inverted light microscopy and scanning electron microscopy (SEM). Our results suggest that hGF cells cultured in adhesion and with eluate derived from ProTemp 4™ (3M ESPE ™) resin evidenced a downregulation in the expression of the inflammatory mediators such as NFκB p65, NLRP3 and IL-1β compared to the cells cultured with Coldpac (Yates Motloid) after 24 h and 1 week of culture. Furthermore, the cells cultured with ProTemp 4™ (3M ESPE ™) after 24 h and 1 week of culture reported a higher cell viability compared to the cells cultured with Coldpac (Yates Motloid), established by MTS cell analysis. Similar results were obtained when hGFs were placed in culture with the eluate derived from ProTemp 4™ (3M ESPE ™) resin which showed a higher cell viability compared to the cells cultured with eluate derived from Coldpac (Yates Motloid). These results highlighted the lower pro-inflammatory action and improved cell biocompatibility of ProTemp 4™ (3M ESPE ™), suggesting a better performance in terms of cells-material interaction.

Ki-67 is necessary during DNA replication for fork protection and genome stability

BACKGROUND

The proliferation antigen Ki-67 has been widely used in clinical settings for cancer staging for many years, but investigations on its biological functions have lagged. Recently, Ki-67 has been shown to regulate both the composition of the chromosome periphery and chromosome behaviour in mitosis as well as to play a role in heterochromatin organisation and gene transcription. However, how the different roles for Ki-67 across the cell cycle are regulated and coordinated remain poorly understood. The progress towards understanding Ki-67 function have been limited by the tools available to deplete the protein, coupled to its abundance and fluctuation during the cell cycle.

RESULTS

Here, we use a doxycycline-inducible E3 ligase together with an auxin-inducible degron tag to achieve a rapid, acute and homogeneous degradation of Ki-67 in HCT116 cells. This system, coupled with APEX2 proteomics and phospho-proteomics approaches, allows us to show that Ki-67 plays a role during DNA replication. In its absence, DNA replication is severely delayed, the replication machinery is unloaded, causing DNA damage that is not sensed by the canonical pathways and dependent on HUWE1 ligase. This leads to defects in replication and sister chromatids cohesion, but it also triggers an interferon response mediated by the cGAS/STING pathway in all the cell lines tested.

CONCLUSIONS

We unveil a new function of Ki-67 in DNA replication and genome maintenance that is independent of its previously known role in mitosis and gene regulation.

Traditional Clinicopathological Biomarkers Still Determine Disease-Free and Overall Survival in Invasive Breast Cancer Patients: A Pilot Study

Background: Molecular classification, tumor diameter, Ki67 expression, and brachytherapy administration still act as the most potent potential predictors of breast cancer recurrence and overall survival. Methods: Over the period of 23 months, we included in the study 92 invasive breast cancer (IBrC) patients initially diagnosed at the Clinical Ward of Breast Cancer and Reconstructive Surgery, Oncology Center in Bydgoszcz, Poland. The probability of disease-free survival (DFS) and overall survival (OS) in relation to potential prognostic factors for the patients were determined using a Kaplan-Meier analysis, and univariate and multivariate Cox regression analyses evaluated the predictive factors of IBrC patients. The investigation of the potential prognostic model's accuracy was analyzed using the ROC curve. Results: Patients with tumor size < 2 cm, Ki67 expression < 20%, luminal-A molecular subtype, and extra-dose brachytherapy boost administration displayed the most favorable prognosis according to breast cancer disease-free survival and overall survival. The estimated 5 year probability of DFS and OS rates in women with tumor diameter < 2 cm were 89% and 90%, respectively. In tumor diameter > 2 cm, the estimated 5 year probability of DFS was 73% and OS was 76%. Interestingly, the tumor diameter of 1.6 cm with a specificity of 60.5% and a sensitivity of 75% occurred as the best threshold point to differentiate patients with cancer recurrence from those without cancer progression. Conclusions: Our study provides essential information on the clinicopathological profile and future outcomes of early stage IBrC patients. Furthermore, the tumor diameter cut-off value of 1.6 cm discriminating between disease recurrence and those without disease progression patients represents an innovative direction for further research.

N-Nitrosodimethylamine investigations in Muta™Mouse define point-of-departure values and demonstrate less-than-additive somatic mutant frequency accumulations

The N-nitrosamine, N-nitrosodimethylamine (NDMA), is an environmental mutagen and rodent carcinogen. Small levels of NDMA have been identified as an impurity in some commonly used drugs, resulting in several product recalls. In this study, NDMA was evaluated in an OECD TG-488 compliant Muta™Mouse gene mutation assay (28-day oral dosing across seven daily doses of 0.02-4 mg/kg/day) using an integrated design that assessed mutation at the transgenic lacZ locus in various tissues and at the endogenous Pig-a gene-locus, along with micronucleus frequencies in peripheral blood. Liver pathology was determined together with NDMA exposure in blood and liver. The additivity of mutation induction was assessed by including two acute single-dose treatment groups (i.e. 5 and 10 mg/kg dose on Day 1), which represented the same total dose as two of the repeat dose treatment groups. NDMA did not induce statistically significant increases in mean lacZ mutant frequency (MF) in bone marrow, spleen, bladder, or stomach, nor in peripheral blood (Pig-a mutation or micronucleus induction) when tested up to 4 mg/kg/day. There were dose-dependent increases in mean lacZ MF in the liver, lung, and kidney following 28-day repeat dosing or in the liver and kidney after a single dose (10 mg/kg). No observed genotoxic effect levels (NOGEL) were determined for the positive repeat dose-response relationships. Mutagenicity did not exhibit simple additivity in the liver since there was a reduction in MF following NDMA repeat dosing compared with acute dosing for the same total dose. Benchmark dose modelling was used to estimate point of departure doses for NDMA mutagenicity in Muta™Mouse and rank order target organ tissue sensitivity (liver > kidney or lung). The BMD50 value for liver was 0.32 mg/kg/day following repeat dosing (confidence interval 0.21-0.46 mg/kg/day). In addition, liver toxicity was observed at doses of ≥ 1.1 mg/kg/day NDMA and correlated with systemic and target organ exposure. The integration of these results and their implications for risk assessment are discussed.

Osmolar Modulation Drives Reversible Cell Cycle Exit and Human Pluripotent Cell Differentiation via NF-κВ and WNT Signaling

Terminally differentiated cells are commonly regarded as the most stable cell state in adult organisms, characterized by growth arrest while fulfilling their specialized functions. A better understanding of the mechanisms involved in promoting cell cycle exit will improve the ability to differentiate pluripotent cells into mature tissues for both pharmacological and therapeutic use. Here, it demonstrates that a hyperosmolar environment enforces a protective p53-independent quiescent state in immature hepatoma cells and in pluripotent stem cell-derived models of human hepatocytes and endothelial cells. Prolonged culture in hyperosmolar conditions stimulates changes in gene expression promoting functional cell maturation. Interestingly, hyperosmolar conditions do not only trigger growth arrest and cellular maturation but are also necessary to maintain this maturated state, as switching back to plasma osmolarity reverses the changes in expression of maturation and proliferative markers. Transcriptome analysis revealed sequential stages of osmolarity-regulated growth arrest followed by cell maturation, mediated by activation of NF-κВ, and repression of WNT signaling, respectively. This study reveals that a modulated increase in osmolarity serves as a biochemical signal to promote long-term growth arrest and cellular maturation into different lineages, providing a practical method to generate differentiated hiPSCs that resemble their mature counterpart more closely.

Construction of brain metastasis prediction model in limited stage small cell lung cancer patients without prophylactic cranial irradiation

INTRODUCTION

Small cell lung cancer (SCLC) is a highly aggressive lung cancer variant known for its elevated risk of brain metastases (BM). While earlier meta-analyses supported the use of prophylactic cranial irradiation (PCI) to reduce BM incidence and enhance overall survival, modern MRI capabilities raise questions about PCI's universal benefit for limited-stage SCLC (LS-SCLC) patients. As a response, we have created a predictive model for BM, aiming to identify low-risk individuals who may not require PCI.

METHODS

A total of 194 LS-SCLC patients without PCI treated between 2009 and 2021 were included. We conducted both univariate and multivariate analyses to pinpoint the factors associated with the development of BM. A nomogram for predicting the 2- and 3-year probabilities of BM was then constructed.

RESULTS

Univariate and multivariate analyses revealed several significant independent risk factors for the development of BM. These factors include TNM stage, the number of chemotherapy (ChT) cycles, Ki-67 expression level, pretreatment serum lactate dehydrogenase (LDH) levels, and haemoglobin (HGB) levels. These findings underscore their respective roles as independent predictors of BM. Based on the results of the final multivariable analysis, a nomogram model was created. In the training cohort, the nomogram yielded an area under the receiver operating characteristic curve (AUC) of 0.870 at 2 years and 0.828 at 3 years. In the validation cohort, the AUC values were 0.897 at 2 years and 0.789 at 3 years. The calibration curve demonstrated good agreement between the predicted and observed probabilities of BM.

CONCLUSIONS

A novel nomogram has been developed to forecast the likelihood of BM in patients diagnosed with LS-SCLC. This tool holds the potential to assist healthcare professionals in formulating more informed and tailored treatment plans.

Correlation of MR-Based Metabolomics and Molecular Profiling in the Tumor Microenvironment of Temozolomide-Treated Orthotopic GL261 Glioblastoma in Mice

The tumor microenvironment in glioblastoma (GB) is considered to be "cold", i.e., the fraction of cytotoxic T cells, for instance, is low. Instead, macrophages are the major immune cell population in GB, which stem either from tissue response (resident microglia) or recruitment of macrophages from the periphery, thereby undergoing tumor-dependent "imprinting" mechanisms by which macrophages can adapt a tumor-supportive phenotype. In this regard, it is important to describe the nature of macrophages associated with GB, in particular under therapy conditions using the gold standard chemotherapy drug temozolomide (TMZ). Here, we explored the suitability of combining information from in vivo magnetic resonance spectroscopic (MRS) approaches (metabolomics) with in vitro molecular analyses to assess therapy response and characterize macrophage populations in mouse GB using an isogenic GL261 model. For macrophage profiling, expression levels of matrix metalloproteinases (MMPs) and A disintegrin and metalloproteinases (ADAMs) were determined, since their gene products affect macrophage-tumor cell communication by extensive cleavage of immunomodulatory membrane proteins, such as PD-L1. In tumor mice with an overall therapy response, expression of genes encoding the proteases ADAM8, ADAM10, and ADAM17 was increased and might contribute to the immunosuppressive phenotype of GB and immune cells. In tumors responding to therapy, expression levels of ADAM8 were upregulated by TMZ, and higher levels of PD-L1 were correlated significantly. Using a CRISPR/Cas9 knockout of ADAM8 in GL261 cells, we demonstrated that soluble PD-L1 (sPD-L1) is only generated in the presence of ADAM8. Moreover, primary macrophages from WT and ADAM8-deficient mice showed ADAM8-dependent release of sPD-L1, independent of the macrophage polarization state. Since ADAM8 expression is induced in responding tumors and PD-L1 shedding is likely to decrease the anti-tumor activities of T-cells, we conclude that immunotherapy resistance is caused, at least in part, by the increased presence of proteases, such as ADAM8.

Distinct states of nucleolar stress induced by anticancer drugs

Ribosome biogenesis is a vital and highly energy-consuming cellular function occurring primarily in the nucleolus. Cancer cells have an elevated demand for ribosomes to sustain continuous proliferation. This study evaluated the impact of existing anticancer drugs on the nucleolus by screening a library of anticancer compounds for drugs that induce nucleolar stress. For a readout, a novel parameter termed 'nucleolar normality score' was developed that measures the ratio of the fibrillar center and granular component proteins in the nucleolus and nucleoplasm. Multiple classes of drugs were found to induce nucleolar stress, including DNA intercalators, inhibitors of mTOR/PI3K, heat shock proteins, proteasome, and cyclin-dependent kinases (CDKs). Each class of drugs induced morphologically and molecularly distinct states of nucleolar stress accompanied by changes in nucleolar biophysical properties. In-depth characterization focused on the nucleolar stress induced by inhibition of transcriptional CDKs, particularly CDK9, the main CDK that regulates RNA Pol II. Multiple CDK substrates were identified in the nucleolus, including RNA Pol I- recruiting protein Treacle, which was phosphorylated by CDK9 in vitro. These results revealed a concerted regulation of RNA Pol I and Pol II by transcriptional CDKs. Our findings exposed many classes of chemotherapy compounds that are capable of inducing nucleolar stress, and we recommend considering this in anticancer drug development.

The nucleolar protein GNL3 prevents resection of stalled replication forks

Faithful DNA replication requires specific proteins that protect replication forks and so prevent the formation of DNA lesions that may damage the genome. Identification of new proteins involved in this process is essential to understand how DNA lesions accumulate in cancer cells and how they tolerate them. Here, we show that human GNL3/nucleostemin, a GTP-binding protein localized mostly in the nucleolus and highly expressed in cancer cells, prevents nuclease-dependent resection of nascent DNA in response to replication stress. We demonstrate that inhibiting origin firing reduces resection. This suggests that the heightened replication origin activation observed upon GNL3 depletion largely drives the observed DNA resection probably due to the exhaustion of the available RPA pool. We show that GNL3 and DNA replication initiation factor ORC2 interact in the nucleolus and that the concentration of GNL3 in the nucleolus is required to limit DNA resection. We propose that the control of origin firing by GNL3 through the sequestration of ORC2 in the nucleolus is critical to prevent nascent DNA resection in response to replication stress.

The anaphase-promoting complex controls a ubiquitination-phosphoprotein axis in chromatin during neurodevelopment

Mutations in the degradative ubiquitin ligase anaphase-promoting complex (APC) alter neurodevelopment by impairing proteasomal protein clearance, but our understanding of their molecular and cellular pathogenesis remains limited. Here, we employ the proteomic-based discovery of APC substrates in APC mutant mouse brain and human cell lines and identify the chromosome-passenger complex (CPC), topoisomerase 2a (Top2a), and Ki-67 as major chromatin factors targeted by the APC during neuronal differentiation. These substrates accumulate in phosphorylated form, suggesting that they fail to be eliminated after mitosis during terminal differentiation. The accumulation of the CPC kinase Aurora B within constitutive heterochromatin and hyperphosphorylation of its target histone 3 are corrected in the mutant brain by pharmacologic Aurora B inhibition. Surprisingly, the reduction of Ki-67, but not H3S10ph, rescued the function of constitutive heterochromatin in APC mutant neurons. These results expand our understanding of how ubiquitin signaling regulates chromatin during neurodevelopment and identify potential therapeutic targets in APC-related disorders.

Vitexin suppresses the proliferation, angiogenesis and stemness of endometrial cancer through the PI3K/AKT pathway

CONTEXT

Endometrial cancer is a common gynecologic malignancy. Vitexin is an active flavonoid compound with an antitumor function.

OBJECTIVE

This study elucidated the role of vitexin in endometrial cancer development and clarified the potential mechanism.

MATERIALS AND METHODS

The toxicity of vitexin (0-80 μM) treatment for 24 h on HEC-1B and Ishikawa cells was tested utilizing the CCK-8 assay. Endometrial cancer cells were divided into vitexin 0, 5, 10, and 20 μM groups. Cell proliferation, angiogenesis and stemness in vitro after treatment with vitexin (0, 5, 10, 20 μM) for 24 h were evaluated using the EdU staining assay, tube formation assay and sphere formation assay, respectively. Twelve BALB/c mice were grouped into control and vitexin (80 mg/kg) groups to monitor tumour growth for 30 days.

RESULTS

Vitexin suppressed cell viability of HEC-1B (IC₅₀ = 9.89 μM) and Ishikawa (IC₅₀ = 12.35 μM) cells. The proliferation (55.3% and 80% for HEC-1B; 44.7% and 75% for Ishikawa), angiogenesis (54.3% and 78.4% for HEC-1B; 47.1% and 68.2% for Ishikawa) and stemness capacity (57.2% and 87.3% for HEC-1B; 53.4% and 78.4% for Ishikawa) of endometrial cancer cells were inhibited by 10 and 20 μM vitexin. Furthermore, the inhibitory effects of vitexin on endometrial cancer were reversed by PI3K/AKT agonist 740Y-P (20 μM). Moreover, the xenograft tumour experiment lasting for 30 days proved that vitexin (80 mg/kg) blocked tumour growth of endometrial cancer in vivo.

DISCUSSION AND CONCLUSIONS

Vitexin has therapeutic potential on endometrial cancer, which supports further clinical trials.

Regulation of phosphosignaling pathways involved in transcription of cell cycle target genes by TRH receptor activation in GH1 cells

Thyrotropin-releasing hormone (TRH) is known to activate several cellular signaling pathway, but the activation of the TRH receptor (TRH-R) has not been reported to regulate gene transcription. The aim of this study was to identify phosphosignaling pathways and phosphoprotein complexes associated with gene transcription in GH1 pituitary cells treated with TRH or its analog, taltirelin (TAL), using label-free bottom-up mass spectrometry-based proteomics. Our detailed analysis provided insight into the mechanism through which TRH-R activation may regulate the transcription of genes related to the cell cycle and proliferation. It involves control of the signaling pathways for β-catenin/Tcf, Notch/RBPJ, p53/p21/Rbl2/E2F, Myc, and YY1/Rb1/E2F through phosphorylation and dephosphorylation of their key components. In many instances, the phosphorylation patterns of differentially phosphorylated phosphoproteins in TRH- or TAL-treated cells were identical or displayed a similar trend in phosphorylation. However, some phosphoproteins, especially components of the Wnt/β-catenin/Tcf and YY1/Rb1/E2F pathways, exhibited different phosphorylation patterns in TRH- and TAL-treated cells. This supports the notion that TRH and TAL may act, at least in part, as biased agonists. Additionally, the deficiency of β-arrestin2 resulted in a reduced number of alterations in phosphorylation, highlighting the critical role of β-arrestin2 in the signal transduction from TRH-R in the plasma membrane to transcription factors in the nucleus.

OMA1 and YME1L as a Diagnostic Panel in Hepatocellular Carcinoma

Identifying new hepatocellular carcinoma (HCC)-driven signaling molecules and discovering their molecular mechanisms are crucial for efficient and better outcomes. Recently, OMA1 and YME1L, the inner mitochondrial proteases, were displayed to be associated with tumor progression in various cancers; however, their role in HCC has not yet been studied. Therefore, we evaluated the possible role of OMA1/YME1L in HCC staging and discussed their potential role in cellular apoptosis and proliferation. Our study was performed using four groups of male albino rats: a normal control and three diethyl nitrosamine-treated groups for 8, 16, and 24 weeks. The OMA1 and YME1L, matrix-metalloproteinase-9 (MMP-9), and cyclin D1 content were measured in liver tissues, while alpha-fetoprotein (AFP) level was assessed in serum. Additionally, Ki-67 expression was evaluated by immunohistochemistry. The relative hepatic expression of Bax, and tissue inhibitor matrix metalloproteinase (TIMP-3) was measured. Herein, we confirmed for the first time that OMA1 is down-regulated while YME1L is up-regulated in HCC in the three studied stages with subsequent inhibition of apoptosis and cell cycle progression. Furthermore, these proteases have a possible role in metastasis. These newly recognized results suggested OMA1 and YME1L as possible diagnostic tools and therapeutic targets for HCC management.

The In Vivo and In Vitro Effects of Terminalia bellirica (Gaertn.) Roxb. Fruit Extract on Testosterone-Induced Hair Loss

Due to the continuous increase in patients with androgenetic alopecia (AGA) and psychological disorders such as depression and anxiety, the demand for hair loss treatment and effective hair growth materials has increased. Terminalia bellirica (Gaertn.) Roxb. (TBE) reportedly exerts anti-inflammatory, hepatoprotective, and antidiabetic effects, among others, but its effects on testosterone (TS)-inhibited hair growth remains unclear. In this study, we evaluated the effects of TBE on TS-induced hair growth regression in human follicle dermal papilla cells (HFDPCs) and C57BL/6 mice. Oral administration of TBE increased TS-induced hair growth retardation. Interestingly, effects were greater when compared with finasteride, a commercial hair loss treatment product. Histological analyses revealed that oral TBE administration increased hair follicles in the dorsal skin of C57BL/6 mice. Additionally, western blotting and immunofluorescence showed that oral TBE administration recovered the TS-induced inhibition of cyclin D1, proliferating cell nuclear antigen (PCNA), and Ki67 expression in vivo. Using in vitro proliferation assays, TBE promoted HFDPC growth, which was suppressed by TS treatment. Thus, TBE may be a promising nutraceutical for hair health as it promoted hair growth in AGA-like in vitro and in vivo models.