KDM4B Histone Demethylase Inhibition Attenuates Tumorigenicity of Malignant Melanoma Cells by Overriding the p53-Mediated Tumor Suppressor Pathway.

Despite significant advances in the treatment of cutaneous melanoma (hereafter melanoma), the prognosis remains less favorable due to therapeutic resistance, which is presumably linked to epigenetic dysregulation. We hypothesized that the histone lysine demethylase KDM4B could play a pivotal role in controlling therapy-resistant melanoma. To validate our hypothesis, we retrieved RNA sequencing data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) program and observed upregulation of KDM4B in both primary and metastatic melanoma, which was associated with poor survival. To explore its role, we used murine B16, human SK-MEL-5, and G-361 melanoma cells as in vitro models of melanoma. We found that KDM4B inhibition using NCGC00244536 increased global levels of H3K9me3 and downregulated the expressions of cell cycle progression-related genes Cdk1, Cdk4, Ccnb1, and Ccnd1. Moreover, genetic ablation of KDM4B or its chemical inhibition using NCGC00244536 reduced p53 production by upregulating MDM2, which enhances the proteolytic degradation of p53. Interestingly, despite the reduction of p53, these interventions augmented apoptosis and senescence-induced cell death by activating pathways downstream of p53, as evidenced by reduced levels of pro-survival Bcl-2 and Bcl-xL proteins and increased production of pro-apoptotic cleaved caspase-3, caspase-7, Bax, and the senescence inducer Cdkn1a. Compared to the FDA-approved anti-melanoma agent dacarbazine, NCGC00244536 exhibited more pronounced cytotoxic and antiproliferative effects in melanoma cells. Importantly, NCGC00244536 demonstrated minimal cytotoxicity to low Kdm4b-expressing mouse embryonic fibroblasts. In conclusion, our findings suggest that KDM4B inhibition can override the antitumor effect of p53, and potentially serve as a therapeutic strategy for melanoma.

Repurposing propofol for breast cancer therapy through promoting apoptosis and arresting cell cycle.

Breast cancer is the most prevalent cancer among women worldwide, characterized by a high mortality rate and propensity for metastasis. Although surgery is the standard treatment for breast cancer, there is still no effective method to inhibit tumor metastasis and improve the prognosis of patients with breast cancer after surgery. Propofol, one of the most widely used intravenous anesthetics in surgery, has exhibited a positive association with improved survival outcomes in patients with breast cancer post­surgery. However, the underlying molecular mechanism remains to be elucidated. The present study revealed that triple negative breast cancer cells, MDA­MB­231 and 4T1, exposed to propofol exhibited a significant decrease in cell viability. Notably, propofol exhibited minimal cytotoxic effects on HUVECs under the same conditions. Furthermore, propofol significantly inhibited the migration and invasion ability of MDA­MB­231 and 4T1 cells. Propofol promoted apoptosis in 4T1 cells through upregulation of Bax and cleaved caspase 3, while downregulating B­cell lymphoma­extra large. Concomitantly, propofol induced cell cycle arrest of 4T1 cells by downregulating cyclin E2 and phosphorylated cell division cycle 6. Furthermore, propofol exhibited excellent anticancer efficacy in a 4T1 breast cancer allograft mouse model. The present study sheds light on the potential of propofol as an old medicine with a novel use for breast cancer treatment.

Laser-responsive erastin-loaded chondroitin sulfate nanomedicine targeting CD44 and system xc- in liver cancer: A non-ferroptotic approach.

Erastin, a ferroptosis-inducing system xc- inhibitor, faces clinical challenges due to suboptimal physicochemical and pharmacokinetic properties, as well as relatively low potency and off-target toxicity. Addressing these, we developed ECINs, a novel laser-responsive erastin-loaded nanomedicine utilizing indocyanine green (ICG)-grafted chondroitin sulfate A (CSA) derivatives. Our aim was to improve erastin's tumor targeting via CSA-CD44 interactions and enhance its antitumor efficacy through ICG's photothermal and photodynamic effects in the laser-on state while minimizing off-target effects in the laser-off state. ECINs, with their nanoscale size of 186.7 ± 1.1 nm and high erastin encapsulation efficiency of 93.0 ± 0.8%, showed excellent colloidal stability and sustained drug release up to 120 h. In vitro, ECINs demonstrated a mechanism of cancer cell inhibition via G1-phase cell cycle arrest, indicating a non-ferroptotic action. In vivo biodistribution studies in SK-HEP-1 xenograft mice revealed that ECINs significantly enhanced tumor distribution of erastin (1.9-fold greater than free erastin) while substantially reducing off-target accumulation in the lungs and spleen by 203-fold and 19.1-fold, respectively. Combined with laser irradiation, ECINs significantly decreased tumor size (2.6-fold, compared to free erastin; 2.4-fold, compared to ECINs without laser irradiation) with minimal systemic toxicity. This study highlights ECINs as a dual-modality approach for liver cancer treatment, demonstrating significant efficacy against tumors overexpressing CD44 and system xc-.

Effective Synthesis of C20-epi-Isothiocyanato-Salinomycin and Its Thiourea Derivatives as Potential Anticancer Agents.

Salinomycin, a naturally occurring polyether ionophore antibiotic isolated from Streptomyces albus, has been demonstrated potent cytotoxic activity against a variety of cancer cell lines. In particular, it exhibits selective targeting of cancer stem cells. However, systemic toxicity, drug resistance and low bioavailability of the drug significantly limit its potential applications. In this study, the C20-epi-isothiocyanate of salinomycin was designed and synthesized, and then reacted with amines as a versatile synthon to assemble a series of salinomycin thiourea derivatives, which improved the druggability of salinomycin. The antiproliferative activities of the compounds were evaluated in vitro against A549, HepG2, Hela, 4T1, and MCF-7 cancer cell lines using the CCK-8 assay. The pharmacological results showed that some salinomycin thiourea derivatives exhibited excellent inhibitory activity against at least one of the tested tumor cells and high selectivity. Further mechanistic studies showed that compound 9f, containing a 3,5-difluorobenzyl moiety, could directly induce apoptosis, probably by increasing caspase-9 protein expression and cell cycle arrest in G1 phase in a concentration dependent manner.

Targeting SERCA2 in Anti-Tumor Drug Discovery.

SERCA2, a P-type ATPase located on the endoplasmic reticulum of cells, plays an important role in maintaining calcium balance within cells by transporting calcium from the cytoplasm to the endoplasmic reticulum against its concentration gradient. A multitude of studies have demonstrated that the expression of SERCA2 is abnormal in a wide variety of tumor cells. Consequently, research exploring compounds that target SERCA2 may offer a promising avenue for the development of novel anti-tumor drugs. This review has summarized the anti-tumor compounds targeting SERCA2, including thapsigargin, dihydroartemisinin, curcumin, galangin, etc. These compounds interact with SERCA2 on the endoplasmic reticulum membrane, disrupting intracellular calcium ion homeostasis, leading to tumor cell apoptosis, autophagy and cell cycle arrest, ultimately producing anti-tumor effects. Additionally, several potential research directions for compounds targeting SERCA2 as clinical anti-cancer drugs have been proposed in the review. In summary, SERCA2 is a promising anti-tumor target for drug discovery and development.

Unrevealing Lithium Repositioning in the Hallmarks of Cancer: Effects of Lithium Salts (LiCl and Li2CO3) in an In Vitro Cervical Cancer Model.

Lithium, a natural element, has been employed as a mental stabilizer in psychiatric treatments; however, some reports indicate it has an anticancer effect, prompting the consideration of repurposing lithium for cancer treatment. The potential anticancer use of lithium may depend on its form (salt type) and the type of cancer cells targeted. Little is known about the effects of Li2CO3 or LiCl on cancer cells, so we focused on exploring their effects on proliferation, apoptosis, migration, and cell cycle as part of the hallmarks of cancer. Firstly, we established the IC50 values on HeLa, SiHa, and HaCaT cells with LiCl and Li2CO3 and determined by crystal violet that cell proliferation was time-dependent in the three cell lines (IC50 values for LiCl were 23.43 mM for SiHa, 23.14 mM for HeLa, and 15.10 mM for HaCaT cells, while the IC50 values for Li2CO3 were 20.57 mM for SiHa, 11.52 mM for HeLa, and 10.52 mM for HaCaT cells.) Our findings indicate that Li2CO3 and LiCl induce DNA fragmentation and caspase-independent apoptosis, as shown by TUNEL, Western Blot, and Annexin V/IP assay by flow cytometry. Also, cell cycle analysis showed that LiCl and Li2CO3 arrested the cervical cancer cells at the G1 phase. Moreover, lithium salts displayed an anti-migratory effect on the three cell lines observed by the wound-healing assay. All these findings imply the viable anticancer effect of lithium salts by targeting several of the hallmarks of cancer.

In vitro, bioassay guided identification of anticancer compounds from Vitex negundo Linn. Leaf using T98 glioma cells.

Gliomas, the most devastating of brain tumours, pose immense therapeutic challenges due to the adverse effects of standard chemotherapeutic drugs. Seeking alternatives, natural products have emerged as promising sources for cancer treatment. Vitex negundo, a significant medicinal plant in traditional medicine, offers potential remedies for various ailments. In this study, fractionation via column chromatography we isolated fraction #25 from leaves of Vitex negundo. Employing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, wound healing assay, flow cytometry for cell cycle analysis, and HRLC-MS for compound identification, we investigated its effects on glioma cells. Results indicate that fraction #25 significantly reduces glioma cell viability and proliferation, inhibits cell migration in a dose-dependent manner, and arrests the cell cycle at G1 phase. Compound analysis reveals the presence of potent antiproliferative agents, including 7-hydroxy-3,4,5,6,8-pentamethoxyflavone, Virol-B, Momordin Ia, and Oryzalexin A. These findings underscore the potential of Vitex negundo as a source of anticancer compounds against glioma cells.

Stable laminar shear stress induces G1 cell cycle arrest and autophagy in urothelial carcinoma by a torque sensor-coupled cone-and-plate device.

The microenvironments of urinary systems play crucial roles in the development and metastasis of cancers due to their generation of complex temporal and spatial fluidic profiles. Because of their versatility in creating desired biomimetic flow, cone-and-plate bioreactors offer great potential for bladder cancer research. In this study, we construct a biocompatible cone-and-plate device coupled with a torque sensor, enabling the application and real-time monitoring of stable shear stress up to 50 dyne/cm². Under a stable shear stress stimulation at 12 dyne/cm2, bladder cancer cell BFTC-905 is arrested at the G1 phase with decreased cell proliferation after 24-hour treatment. This effect is associated with increased cyclin-dependent kinase inhibitors p21 and p27, inhibiting cyclin D1/CDK4 complex with dephosphorylation of serine 608 on the retinoblastoma protein. Consequently, an increase in cyclin D3 and decreases in cyclin A2 and cyclin E2 are observed. Moreover, we demonstrate that the shear stress stimulation upregulates the expression of autophagy-related proteins Beclin-1, LC3B-I and LC3B-II, while caspase cleavages are not activated under the same condition. The design of this system and its application shed new light on flow-induced phenomena in the study of urothelial carcinomas.

N-formylmethionine-leucyl-phenylalanine protects against irradiation-induced damage to hematopoiesis and intestines.

BACKGROUND: Ionizing radiation (IR), including radiotherapy, can exert lasting harm on living organisms. While liposaccharide (LPS) offers resistance to radiation damage, it also induces toxic responses. Thankfully, an LPS analogue called N-formylmethionine-leucyl-phenylalanine (fMLP) holds the potential to mitigate this toxicity, offering hope for radiation protection. METHODS: Survival of C57BL/6 mice exposed to IR after administration with fMLP/LPS/WR-2721 or saline was recorded. Cell viability and apoptosis assay of bone marrow (BMC), spleen and small intestinal epithelial (HIECs) cells were tested by Cell Counting Kit-8 (CCK-8) and flow cytometry assay. Tissue damage was evaluated by Hematoxilin and Eosin (H&E), Ki-67, and TUNEL staining. RNA sequencing was performed to reveal potential mechanisms of fMLP-mediated radiation protection. Flow cytometry and western blot were performed to verify the radiation protection mechanism of fMLP on the cell cycle. RESULTS: The survival rates of C57BL/6 mice exposed to ionizing radiation after administering fMLP increased. fMLP demonstrated low toxicity in vitro and in vivo, maintaining cell viability and mitigating radiation-induced apoptosis. Moreover, it protected against tissue damage in the hematopoietic and intestinal system. RNA sequencing shed light on fMLP's potential mechanism, suggesting its role in modulating innate immunity and cell cycling. This was evidenced by its ability to reverse radiation-induced G2/M phase arrests in HIECs. CONCLUSION: fMLP serves as a promising radioprotective agent, preserving cells and radiosensitive tissues from IR. Through its influence on the cell cycle, particularly reversing radiation-induced arrest in G2/M phases, fMLP offers protection against IR's detrimental effects.

Sophocarpine inhibits the progression of glioblastoma via PTEN/PI3K/Akt signaling pathway.

Glioblastoma multiforme (GBM) is the most fatal primary brain tumor which lacks effective treatment drugs. Alkaloids are known as a class of potential anti-tumor agents. Sophocarpine, a tetracyclic quinazoline alkaloid derived from Sophora alopecuroides L., possesses several pharmacological effects including anti-tumor effects in some malignancies. However, the effect and mechanism of sophocarpine on GBM remains to be explored. In this study, based on in vitro experiments, we found that sophocarpine significantly inhibited the viability, proliferation and migration of GBM cells including U251 and C6 cells in a dose- and time-dependent manner. Besides, sophocarpine arrested GBM cell cycle in G0/G1 phase and induced their apoptosis. Subsequently, we found that sophocarpine upregulated the expression of PTEN, a GBM tumor suppressor, and downregulated PI3K/Akt signaling in GBM cells. Moreover, inactivating of PTEN with bpV(phen) trihydrate partially restored the anti-GBM effects of sophocarpine via PI3K/Akt signaling. Finally, sophocarpine significantly inhibited the growth of tumor both in subcutaneous and orthotopic U251 xenograft GBM model in nude mice via PTEN/PI3K/Akt axis. Taken together, these results suggested that sophocarpine impeded GBM progression via PTEN/PI3K/Akt axis both in vitro and in vivo, providing with a promising therapy for treating GBM.

Deoxyelephantopin induces apoptosis and cell cycle arrest in GL261 glioblastoma cells.

Glioblastoma multiforme (GBM) is a highly malignant central nervous system tumor with a poor prognosis. Developing new therapeutic drugs is crucial. This study evaluates deoxyelephantopin (DET), a major component of *Elephantopus scaber* L., for its potential anti-GBM effects. The effects of DET on GBM cell lines were investigated using the MTT assay and Annexin-V kit to assess cell death and apoptosis. Western blot analysis examined apoptosis and cell cycle-related proteins. ELISA kits measured VEGF and TGF-ß levels. In vivo, NOD SCID mice were injected with GL-261 cells and treated with DET to evaluate tumor growth and survival. DET inhibited GBM cell growth in a time- and dose-dependent manner. MTT and Annexin-V assays confirmed cell death and apoptosis. Western blot analysis showed DET downregulated Bcl-2 and increased caspase-3, Bax, and cytochrome c levels. ELISA results indicated that DET suppressed VEGF and TGF-ß expression. DET treatment also decreased phosphorylation of AKT and STAT-3, CDK4, cyclin D2, MMP2, and MMP9 levels. In vivo, DET significantly inhibited tumor growth and improved survival rates in mice. DET exhibits significant in vitro and in vivo anticancer effects, making it a promising candidate for further research and potential clinical application against GBM.

Eslicarbazepine induces apoptosis and cell cycle arrest in C6 glioma cells in vitro and suppresses tumor growth in an intracranial rat model.

BACKGROUND: Glioblastoma multiforme (GBM) is the most malignant brain tumor, with a poor prognosis and life expectancy of 14-16 months after diagnosis. The standard treatment for GBM consists of surgery, radiotherapy, and chemotherapy with temozolomide. Most patients become resistant to treatment after some time, and the tumor recurs. Therefore, there is a need for new drugs to manage GBM. Eslicarbazepine (ESL) is a well-known antiepileptic drug belonging to the dibenzazepine group with anticancer potentials. In this study, for the first time, we evaluated the potential effects of ESL on C6 cell growth, both in vitro and in vivo, and examined its molecular effects. METHODS: To determine the effect of ESL on the c6 cell line, cell viability, proliferation, and migration were evaluated by MTT assay, colony formation, and wound healing assay. Also, apoptosis and cell cycle were examined by flow cytometry, qRT-PCR, and western blotting. In addition, an intracranial model in Wistar rats was used to investigate the effect of ESL in vivo, and the tumor size was measured using both Caliper and MRI. RESULTS: The obtained results are extremely consistent and highly encouraging. C6 cell viability, proliferation, and migration were significantly suppressed in ESL-treated C6 cells (p < 0.001), as determined by cell-based assays. ESL treatment led to significant enhancement of apoptosis (p < 0.01), as determined by flow cytometry, and upregulation of genes involved in cell apoptosis, such as the Bax/Bcl2 ratio at RNA (p < 0.05) and protein levels (5.37-fold). Flow cytometric analysis of ESL-treated cells revealed G2/M phase cell cycle arrest. ESL-treated cells demonstrated 2.49-fold upregulation of p21 alongside, 0.22-fold downregulation of cyclin B1, and 0.34-fold downregulation of cyclin-dependent kinase-1 at the protein level. Administration of ESL (30 mg/kg) to male rats bearing C6 intracranial tumors also suppressed the tumor volume and weight (p < 0.01). CONCLUSIONS: Based on these novel findings, ESL has the potential for further experimental and clinical studies in glioblastoma.

Unlocking daidzein's healing power: Present applications and future possibilities in phytomedicine.

BACKGROUND: Cancer is one of the leading causes of death and a great threat to people around the world. Cancer treatment modalities include surgery, radiotherapy, chemotherapy, radiochemotherapy, hormone therapy, and immunotherapy. The best approach is to use a combination of several types. Among the treatment methods mentioned above, chemotherapy is frequently used, but its activity is hampered by the development of drug resistance and many side effects. In this regard, the use of medicinal plants has been discussed, and in recent decades, the use of isolated phytochemicals came into the focus of interest. By critically evaluating the available evidence and emphasizing the unique perspective offered by this review, we provide insights into the potential of daidzein as a promising therapeutic agent, as well as outline future research directions to optimize its efficacy in clinical settings. PURPOSE: To summarized the therapeutic potential of daidzein, an isoflavone phytoestrogen in the management of several human diseases with the focuses on the current status and future prospects as a therapeutic agent. METHODS: Several search engines, including PubMed, GoogleScholar, and ScienceDirect, were used, with the search terms "daidzein", "daidzein therapeutic potential", or individual effects. The study included all peer-reviewed articles. However, the most recent publications were given priority. RESULTS: Daidzein showed protective effects against malignant diseases such as breast cancer, prostate cancer but also non-malignant diseases such as diabetes, osteoporosis, and cardiovascular diseases. Daidzein activates multiple signaling pathways leading to cell cycle arrest and apoptosis as well as antioxidant and anti-metastatic effects in malignant cells. Moreover, the anticancer effects against different cancer cells were more prominent and discussed in detail. CONCLUSIONS: In short, daidzein represents a promising compound for drug development. The comprehensive potential anticancer activities of daidzein through various molecular mechanisms and its therapeutic/clinical status required further detail studies.

HAND2-AS1 plays a tumor-suppressive role in hepatoblastoma through the negative regulation of CDK1.

Objective: Hepatoblastoma (HB) is the most commonly seen pediatric liver malignancy. The preliminary experiment of our research group found that cyclin dependent kinase 1 (CDK1) was upregulated in HB. By in silico analysis, long noncoding RNA (lncRNA) HAND2 antisense RNA 1 (HAND2-AS1) was determined as the research object. Herein, HAND2-AS1 expression in HB and its effect and mechanism on HB were extensively investigated. Methods: CDK1-related lncRNAs were searched using the microarray data from the Gene Expression Omnibus (GEO) database and Gene Expression Profiling Interactive Analysis (GEPIA) online database. qRT-PCR, Western blot, and immunohistochemistry were performed to determine the mRNA expression and protein levels of target genes. MTT, flow cytometry and DAPI staining assays were conducted to measure proliferation activity, cell cycle progression, and apoptosis of HB cells. The interaction between lncRNA and protein was determined by RNA pull-down and FISH assays. Luciferase assay was applied to identify whether HAND2-AS1 stimulates the transcription of CDK1. CDK1 mRNA stability was detected through actinomycin D assay. Aycloheximide assay was used to detect the CDK1 protein stability. Results: HAND2-AS1 was downregulated in HB tissues and cells. HAND2-AS1 overexpression impeded HB cells proliferation activity and cycle progression while inducing cell apoptosis of HB cells, while knockdown of HAND2-AS1 emerged the opposite effect. HAND2-AS1 negatively correlated with CDK1. HAND2-AS1 downregulated CDK1 expression by affecting the transcriptional activity, mRNA and protein stability of CDK1. Furthermore, HAND2-AS1 impeded HB cell proliferation and cycle progression while inducing cell apoptosis by downregulating CDK1. Conclusion: Our research highlights that HAND2-AS1 can exert a tumor-suppressive effect on HB through the negative regulation of CDK1, and the HAND2-AS1/CDK1 is expected to be a diagnostic molecular marker and therapeutic target for HB in clinical practice.

Antitumor effect of polyphyllin I (PPI) on colorectal cancer: Evidence from patient-derived organoids and Notch signaling suppression.

Colorectal cancer (CRC) is a malignant tumor with a high incidence, ranking first among gastrointestinal malignancies. We investigated the impact of polyphyllin I (PPI), a natural compound found in Paris polyphylla, on CRC. PPI has been documented to exhibit anticancer activity against various tumors. This study aimed to assess the effects of PPI on colorectal cancer and explore its potential mechanisms. Our research demonstrated that PPI inhibited proliferation, promoted apoptosis, and induced G2 cell-cycle arrest in a dose-dependent manner. Additionally, our results indicated that PPI suppressed Notch signaling by downregulating the Notch1 receptor, its ligand Jagged1, and the downstream target Hes1 expression. Furthermore, we confirmed the antitumor effect of PPI on patient-derived organoids. In conclusion, our study indicates that PPI impedes the growth of colon cancer by suppressing the Notch signaling pathway.

Hyperglycemia-independent neonatal streptozotocin-induced retinopathy (NSIR) in rats.

Introduction: Chemicals, such as MNU (N-methyl-N-nitrosourea) and NaIO3 (sodium iodate), are widely used to induce retinal degeneration in rodents. Streptozotocin (STZ) is an analog of N-acetyl glucosamine in which an MNU moiety is linked to a hexose and has a special toxic effect on insulin-producing pancreatic ß-cells. It is commonly used to induce hyperglycemia to model diabetes. While intracerebroventricular injection of STZ can produce Alzheimer's disease independent of hyperglycemia, most retinal studies using STZ focus on the effects of hyperglycemia on the retina, but whether STZ has any impact on retinal cells independent of hyperglycemia is unknown. We aimed to investigate the role of cytotoxicity of STZ in rat retina. Methods: Intravitreal or subcutaneous injection of STZ was performed on newborn rats. Electroretinogram (ERG) and H&E staining investigated retinal function and morphological changes. Retinal cell types, cell death, proliferation, inflammation, and angiogenesis were studied by immunostaining. RNA sequencing was performed to examine the transcriptome changes of retinal cells after intravitreal injection of STZ. Results: Intravitreal (5 µg or 10 µg) or subcutaneous (30 mg/kg) injection of STZ at the early stage of newborn rats couldn't induce hyperglycemia but caused NSIR (Neonatal STZ-induced retinopathy), including reduced ERG amplitudes, retinal rosettes and apoptosis, cell cycle arrest, microglial activation, and delayed retinal angiogenesis. STZ did not affect the early-born retinal cell types but significantly reduced the late-born ones. Short-term and long-term hyperglycemia had no significant effects on the NSIR phenotypes. RNA sequencing revealed that STZ induces oxidative stress and activates the p53 pathway of retinal cells. Locally or systemically, STZ injection after P8 couldn't induce SINR when all retinal progenitors exit the cell cycle. Conclusion: NSIR in rats is independent of hyperglycemia but due to STZ's direct cytotoxic effects on retinal progenitor cells. NSIR is a typical reaction to STZ-induced retinal oxidative stress and DNA damage. This significant finding suggests that NSIR may be a valuable model for studying retinal progenitor DNA damage-related diseases, potentially leading to new insights and treatments.

Mutant P53 modulation by cryptolepine through cell cycle arrest and apoptosis in triple negative breast cancer.

BACKGROUND: Triple Negative Breast cancer is an aggressive breast cancer subtype. It has a more aggressive clinical course, an earlier age of onset, a larger propensity for metastasis, and worse clinical outcomes as evidenced by a higher risk of recurrence and a shorter survival rate. Currently, the primary options for TNBC treatment are surgery, radiation, and chemotherapy. These treatments however remain ineffective due to recurrence. However, given that p53 mutations have been identified in more than 60-88 % of TNBC, translating p53 into the clinical situation is particularly important in TNBC. In this study, we screened and evaluated the therapeutic potential of cryptolepine (CRP) in TNBC in-vitro models being an anti-malarial drug it could be repurposed as an anti-cancer therapeutic targeting TNBC. Moreover, the cytotoxicity activity of cryptolepine to TNBC cells and a detailed anti-tumor mechanism in mutant P53 has not been reported before. METHODS: MTT assays were used to examine the cytotoxicity and cell viability activity of Cryptolepine in TNBC, non-TNBC T47D and MCF-7 and non-malignant MCF10A cells. Scratch wound and clonogenic assay was used to evaluate the cryptolepine's effect on migration and colony forming ability of TNBC cells. Flow cytometry, MMP and DAPI was used to assess cell cycle arrest and cell apoptosis mechanism. The expression of proteins was detected by western blots. The differential expression of RNAs was evaluated by RT-PCR and the interaction between P53 and drug was evaluated computationally using in-silico approach and in-vitro using ChIP assay. RESULTS: In this study, we found that cryptolepine has more preferential cytotoxicity in TNBC than non-TNBC cells. Notably, our studies revealed the mechanism by which cryptolepine induces intrinsic apoptosis and inhibit migration, colony formation ability, induce cell cycle arrest by inducing conformational change in the mutant P53 thereby increasing its DNA binding ability, hence activating its tumor suppressing potential significantly. CONCLUSION: Our study revealed that CRP significantly reduced the proliferation, migration and colony forming ability of TNBC cells lines. Moreover, it was revealed that CRP induces cell cycle arrest and apoptosis by activating mutant P53 and enhancing its DNA binding ability to induce its tumor suppressing ability.

Lupiwighteone as an Antitumor Agent Reverses Multidrug Resistance in K562/ADR Cells by Regulating Cellular Prion Protein-Oct4 Axis.

INTRODUCTION: One of the many reasons for cancer treatment failure and recurrence is acquired Multidrug Resistance (MDR). Overcoming cancer drug resistance has been the focus of researchers' studies. Cellular prion protein (PrPC) is a glycophosphatidylinositol-anchored cell-surface glycoprotein that has been implicated in tumor behavior, including proliferation, apoptosis, invasion, metastasis, and chemoresistance. >Method: Lupiwighteone (Lup), a natural isoflavone found in the root of Glycyrrhiza glabra, has anticancer activity against prostate cancer cells, neuroblastoma cells, and human breast cancer cells. However, its pharmacological effects and mechanisms in drug-resistant cancer cells have not been reported. In this study, we used an adriamycin- resistant leukemia K562 cell model, and for the first time, we investigated the reversal effect of Lup on its MDR and the potential mechanism. RESULT: The results indicated that Lup could induce apoptosis through the mitochondrial pathway while upregulating the expression of related apoptotic proteins, such as Bax, Cyto C, Caspase-3, and PARP1. Autophagy is commonly recognized as a protective mechanism that mediates MDR during treatment. We found that Lup induced cellular autophagy while upregulating the expression of related autophagy proteins such as Beclin 1 and LC3 II. CONCLUSION: In addition, when Lup was combined with adriamycin, Lup decreased the IC50 of K562/ADR cells; moreover, Lup can downregulate the expression of drug-resistant proteins, suggesting that Lup can reverse drug resistance. Further studies have shown that Lup can downregulate the expression of PrPC-PI3K-Akt axis proteins and PrPC-Oct4 axis proteins. This study demonstrated that Lup has the potential to inhibit the proliferation of K562/ADR cells by targeting PrPC, and further study of the signaling pathway associated with PrPC may provide the experimental basis for the treatment of drug-resistant leukemia.

Artesunate induces HO-1-mediated cell cycle arrest and senescence to protect against ocular fibrosis.

Recent research found artesunate could inhibit ocular fibrosis; however, the underlying mechanisms are not fully known. Since the ocular fibroblast is the main effector cell in fibrosis, we hypothesized that artesunate may exert its protective effects by inhibiting the fibroblasts proliferation. TGF-ß1-induced ocular fibroblasts and glaucoma filtration surgery (GFS)-treated rabbits were used as ocular fibrotic models. Firstly, we analyzed fibrosis levels by assessing the expression of fibrotic marker proteins, and used Ki67 immunofluorescence, EdU staining, flow cytometry to determine cell cycle status, and SA-ß-gal staining to assess cellular senescence levels. Then to predict target genes and pathways of artesunate, we analyzed the differentially expressed genes and enriched pathways through RNA-seq. Western blot and immunohistochemistry were used to detect the pathway-related proteins. Additionally, we validated the dependence of artesunate's effects on HO-1 expression through HO-1 siRNA. Moreover, DCFDA and MitoSOX fluorescence staining were used to examine ROS level. We found artesunate significantly inhibits the expression of fibrosis-related proteins, induces cell cycle arrest and cellular senescence. Knocking down HO-1 in fibroblasts with siRNA reverses these regulatory effects of artesunate. Mechanistic studies show that artesunate significantly inhibits the activation of the Cyclin D1/CDK4-pRB pathway, induces an increase in cellular and mitochondrial ROS levels and activates the Nrf2/HO-1 pathway. In conclusion, the present study identifies that artesunate induces HO-1 expression through ROS to activate the antioxidant Nrf2/HO-1 pathway, subsequently inhibits the cell cycle regulation pathway Cyclin D1/CDK4-pRB in an HO-1-dependent way, induces cell cycle arrest and senescence, and thereby resists periorbital fibrosis.

Mouse models to investigate in situ cell fate decisions induced by p53.

Investigating how transcription factors control complex cellular processes requires tools that enable responses to be visualised at the single-cell level and their cell fate to be followed over time. For example, the tumour suppressor p53 (also called TP53 in humans and TRP53 in mice) can initiate diverse cellular responses by transcriptional activation of its target genes: Puma to induce apoptotic cell death and p21 to induce cell cycle arrest/cell senescence. However, it is not known how these processes are regulated and initiated in different cell types. Also, the context-dependent interaction partners and binding loci of p53 remain largely elusive. To be able to examine these questions, we here developed knock-in mice expressing triple-FLAG-tagged p53 to facilitate p53 pull-down and two p53 response reporter mice, knocking tdTomato and GFP into the Puma/Bbc3 and p21 gene loci, respectively. By crossing these reporter mice into a p53-deficient background, we show that the new reporters reliably inform on p53-dependent and p53-independent initiation of both apoptotic or cell cycle arrest/senescence programs, respectively, in vitro and in vivo.