BrdU Incorporation Assay to Analyze the Entry into S Phase

Comprehensive analysis of cellular metrics: From proliferation to mitochondrial membrane potential and cell death in a single sample

Changes in cell number during in vitro experiments and pharmacological screenings primarily depend on two factors: cell death and proliferation. The dynamics of these processes determine whether cell populations expand and accumulate or, conversely, decrease over time. Understanding the biological mechanisms governing these changes is crucial for deciphering the mode of action of any pharmacological or genetic treatment in fundamental research and pre-clinical trials. In this context, we introduce a robust and efficient flow cytometry-based methodology that enables comprehensive analysis of key cellular parameters that indicate changes in cell numbers. This approach encompasses the assessment of cell count along with critical maintenance parameters including proliferation, cell cycle dynamics, apoptosis, cell permeability, and mitochondrial depolarization. These parameters are intricately linked, offering a detailed view of the cellular state. The described methodology is versatile and adaptable for analyzing various cell types, whether at steady state or in response to treatments. To develop this workflow, we integrated and optimised multiple flow cytometry-based stainings such as annexin V, propidium iodide, bromodeoxyuridine, CellTrace Violet, and JC-1 into a unified protocol. This article offers a detailed, step-by-step guide to the entire method, covering aspects such as timing, sample preparation techniques, and the reagents used. Additionally, it includes examples of the data that can be obtained with this technique and illustrates its multiparametric visualization. Collectively, this methodology facilitates the rapid acquisition of up to eight different parameters from a single sample in one experiment.

TFF3 facilitates dormancy of anti-estrogen treated ER+ mammary carcinoma

BACKGROUND

Tumor dormancy is a substantial clinical obstacle in treatment of estrogen receptor positive mammary carcinoma (ER+MC), contributing to drug resistance, metastatic outgrowth, relapse, and consequent mortality.

METHODS

Preclinical models mimicking clinical anti-estrogen-induced ER+MC dormancy were generated in vivo. Function and a mechanism-based combination treatment were determined in the generated dormancy-like models in vitro, ex vivo, and in vivo.

RESULTS

The dormancy models display molecular features of dormancy and tumor mass and cellular dormancy with associated clinical dormancy behavior. Both serum and cancer tissue expression of Trefoil factor 3 (TFF3) are identified as prognostic indicators of dormant ER+MC with TFF3 functioning as an epigenetically regulated driver of dormancy-associated behaviors. BCL2-dependent pro-survival functions of TFF3 coupled with enhanced attributes of stemness designates TFF3 as an actionable target. Moreover, combination screening of a TFF3 small-molecule-inhibitor (AMPC) with compounds used clinically to treat anti-estrogen-resistant ER+MC identifies strong synergism between AMPC and CDK4/6 inhibitors in the dormancy-like models. The combination results in concomitant suppression of CCND1 expression and CDK4/6 kinase activity to decrease RB phosphorylation, with reduced BCL2 expression, leading to both ER + MC cell cycle arrest and apoptosis. The combined TFF3-CDK4/6 inhibition impedes metastatic outgrowth and ameliorates host animal survival in the dormancy-like models, producing a complete response in a percentage of animals.

CONCLUSIONS

Hence, in vivo models of anti-estrogen induced dormancy of ER+MC generated herein, identify TFF3 as a driver of this process. The combined inhibition of TFF3 and CDK4/6 may potentially alleviate the clinical challenges posed by anti-estrogen-induced dormancy in ER+MC.

Rho-Associated Protein Kinase Activity Is Required for Tissue Homeostasis in the Xenopus laevis Ciliated Epithelium

Lung epithelial development relies on the proper balance of cell proliferation and differentiation to maintain homeostasis. When this balance is disturbed, it can lead to diseases like cancer, where cells undergo hyperproliferation and then can undergo migration and metastasis. Lung cancer is one of the deadliest cancers, and even though there are a variety of therapeutic approaches, there are cases where treatment remains elusive. The rho-associated protein kinase (ROCK) has been thought to be an ideal molecular target due to its role in activating oncogenic signaling pathways. However, in a variety of cases, inhibition of ROCK has been shown to have the opposite outcome. Here, we show that ROCK inhibition with y-27632 causes abnormal epithelial tissue development in Xenopus laevis embryonic skin, which is an ideal model for studying lung cancer development. We found that treatment with y-27632 caused an increase in proliferation and the formation of ciliated epithelial outgrowths along the tail edge. Our results suggest that, in certain cases, ROCK inhibition can disturb tissue homeostasis. We anticipate that these findings could provide insight into possible mechanisms to overcome instances when ROCK inhibition results in heightened proliferation. Also, these findings are significant because y-27632 is a common pharmacological inhibitor used to study ROCK signaling, so it is important to know that in certain in vivo developmental models and conditions, this treatment can enhance proliferation rather than lead to cell cycle suppression.

Morroniside induces cardiomyocyte cell cycle activity and promotes cardiac repair after myocardial infarction in adult rats

Introduction: Acute myocardial infarction (AMI) is characterized by the loss of cardiomyocytes, which impairs cardiac function and eventually leads to heart failure. The induction of cardiomyocyte cell cycle activity provides a new treatment strategy for the repair of heart damage. Our previous study demonstrated that morroniside exerts cardioprotective effects. This study investigated the effects and underlying mechanisms of action of morroniside on cardiomyocyte cell cycle activity and cardiac repair following AMI. Methods: Neonatal rat cardiomyocytes (NRCMs) were isolated and exposed to oxygen-glucose deprivation (OGD) in vitro. A rat model of AMI was established by ligation of the left anterior descending coronary artery (LAD) in vivo. Immunofluorescence staining was performed to detect newly generated cardiomyocytes. Western blotting was performed to assess the expression of cell cycle-related proteins. Electrocardiography (ECG) was used to examine pathological Q waves. Masson's trichrome and wheat germ agglutinin (WGA) staining assessed myocardial fibrosis and hypertrophy. Results: The results showed that morroniside induced cardiomyocyte cell cycle activity and increased the levels of cell cycle proteins, including cyclin D1, CDK4, cyclin A2, and cyclin B1, both in vitro and in vivo. Moreover, morroniside reduced myocardial fibrosis and remodeling. Discussion: In conclusion, our study demonstrated that morroniside stimulates cardiomyocyte cell cycle activity and cardiac repair in adult rats, and that these effects may be related to the upregulation of cell cycle proteins.

Heterogeneous Cellular Response of Primary and Metastatic Human Gastric Adenocarcinoma Cell Lines to Magnoflorine and Its Additive Interaction with Docetaxel

Gastric cancer is the most common cancer and remains the leading cause of cancer death worldwide. In this study, the anticancer action of magnoflorine isolated via counter-current chromatography from the methanolic extract of Berberis vulgaris root against gastric cancer in models of primary ACC-201 and AGS and metastatic MKN-74 and NCI-N87 cell lines was analyzed. Cell viability and proliferation were tested through the use of MTT and BrdU tests, respectively. Cell cycle progression and apoptosis were evaluated using flow cytometry. The interaction of magnoflorine and docetaxel has been examined through isobolographic analysis. Moreover, potential toxicity was verified in zebrafish in an in vivo model. Gastric cancer cell lines revealed different responses to magnoflorine treatment with regard to viability/proliferation, apoptosis induction and cell cycle inhibition without any undesirable changes in the development of larval zebrafish at the tested concentrations. What is more, magnoflorine in combination with docetaxel produced an additive pharmacological interaction in all studied gastric cancer cell lines, which may suggest a complementary mechanism of action of both compounds. Taken together, these findings provide a foundation for the possibility of magnoflorine as a potential therapeutic approach for gastric cancer and merits further investigation, which may pave the way for clinical uses of magnoflorine.

Electrospun Fibers Loaded with Pirfenidone: An Innovative Approach for Scar Modulation in Complex Wounds

Hypertrophic scars (HTSs) are pathological structures resulting from chronic inflammation during the wound healing process, particularly in complex injuries like burns. The aim of this work is to propose Biofiber PF (biodegradable fiber loaded with Pirfenidone 1.5 w/w), an electrospun advanced dressing, as a solution for HTSs treatment in complex wounds. Biofiber has a 3-day antifibrotic action to modulate the fibrotic process and enhance physiological healing. Its electrospun structure consists of regular well-interconnected Poly-L-lactide-co-poly-ε-caprolactone (PLA-PCL) fibers (size 2.83 ± 0.46 µm) loaded with Pirfenidone (PF, 1.5% w/w), an antifibrotic agent. The textured matrix promotes the exudate balance through mild hydrophobic wettability behavior (109.3 ± 2.3°), and an appropriate equilibrium between the absorbency % (610.2 ± 171.54%) and the moisture vapor transmission rate (0.027 ± 0.036 g/min). Through its finer mechanical properties, Biofiber PF is conformable to the wound area, promoting movement and tissue oxygenation. These features also enhance the excellent elongation (>500%) and tenacity, both in dry and wet conditions. The ancillary antifibrotic action of PF on hypertrophic scar fibroblast (HSF) for 3 days downregulates the cell proliferation over time and modulates the gene expression of transforming growth factor β1 (TGF-β1) and α-smooth muscle actin (α-SMA) at 48-72 h. After 6 days of treatment, a decrement of α-SMA protein levels was detected, proving the potential of biofiber as a valid therapeutic treatment for HTSs in an established wound healing process.