P21 and p27: roles in carcinogenesis and drug resistance

A comprehensive update on the potential of curcumin to enhance chemosensitivity in colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers and a major cause of cancer-related mortality worldwide. The efficacy of chemotherapy agents in CRC treatment is often limited due to toxic side effects, heterogeneity of cancer cells, and the possibility of chemoresistance which promotes cancer cell survival through several mechanisms. Combining chemotherapy agents with natural compounds like curcumin, a polyphenol compound from the Curcuma longa plant, has been reported to overcome chemoresistance and increase the sensitivity of cancer cells to chemotherapeutics. Curcumin, alone or in combination with chemotherapy agents, has been demonstrated to prevent chemoresistance by modulating various signaling pathways, reducing the expression of drug resistance-related genes. The purpose of this article is to provide a comprehensive update on studies that have investigated the ability of curcumin to enhance the efficacy of chemotherapy agents used in CRC. It is hoped that it can serve as a template for future research on the efficacy of curcumin, or other natural compounds, combined with chemotherapy agents to maximize the effectiveness of therapy and reduce the side effects that occur in CRC or other cancers.

Cytokines from SARS-CoV-2 Spike-Activated Macrophages Hinder Proliferation and Cause Cell Dysfunction in Endothelial Cells

Endothelial dysfunction plays a central role in the severity of COVID-19, since the respiratory, thrombotic and myocardial complications of the disease are closely linked to vascular endothelial damage. To address this issue, we evaluate here the effect of conditioned media from spike S1-activated macrophages (CM_S1) on the proliferation of human umbilical endothelial cells (HUVECs), focusing on the specific role of interleukin-1-beta (IL-1β), interleukin-6 (IL-6), interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α). Results obtained demonstrate that the incubation with CM_S1 for 72 h hinders endothelial cell proliferation and induces signs of cytotoxicity. Comparable results are obtained upon exposure to IFN-γ + TNF-α, which are thus postulated to play a pivotal role in the effects observed. These events are associated with an increase in p21 protein and a decrease in Rb phosphorylation, as well as with the activation of IRF-1 and NF-kB transcription factors. Overall, these findings further sustain the pivotal role of a hypersecretion of inflammatory cytokines as a trigger for endothelial activation and injury in the immune-mediated effects of COVID-19.

Sustained ERK signaling promotes G2 cell cycle exit and primes cells for whole-genome duplication

Whole-genome duplication (WGD) is a frequent event in cancer evolution that fuels chromosomal instability. WGD can result from mitotic errors or endoreduplication, yet the molecular mechanisms that drive WGD remain unclear. Here, we use live single-cell analysis to characterize cell-cycle dynamics upon aberrant Ras-ERK signaling. We find that sustained ERK signaling in human cells leads to reactivation of the APC/C in G2, resulting in tetraploid G0-like cells that are primed for WGD. This process is independent of DNA damage or p53 but dependent on p21. Transcriptomics analysis and live-cell imaging showed that constitutive ERK activity promotes p21 expression, which is necessary and sufficient to inhibit CDK activity and which prematurely activates the anaphase-promoting complex (APC/C). Finally, either loss of p53 or reduced ERK signaling allowed for endoreduplication, completing a WGD event. Thus, sustained ERK signaling-induced G2 cell cycle exit represents an alternative path to WGD.

Cell cycle machinery in oncology: A comprehensive review of therapeutic targets

The cell cycle is tightly regulated to ensure controlled cell proliferation. Dysregulation of the cell cycle machinery is a hallmark of cancer that leads to unchecked growth. This review comprehensively analyzes key molecular regulators of the cell cycle and how they contribute to carcinogenesis when mutated or overexpressed. It focuses on cyclins, cyclin-dependent kinases (CDKs), CDK inhibitors, checkpoint kinases, and mitotic regulators as therapeutic targets. Promising strategies include CDK4/6 inhibitors like palbociclib, ribociclib, and abemaciclib for breast cancer treatment. Other possible targets include the anaphase-promoting complex/cyclosome (APC/C), Skp2, p21, and aurora kinase inhibitors. However, challenges with resistance have limited clinical successes so far. Future efforts should focus on combinatorial therapies, next-generation inhibitors, and biomarkers for patient selection. Targeting the cell cycle holds promise but further optimization is necessary to fully exploit it as an anti-cancer strategy across diverse malignancies.

Non-coding RNA transcripts, incredible modulators of cisplatin chemo-resistance in bladder cancer through operating a broad spectrum of cellular processes and signaling mechanism

Bladder cancer (BC) is a highly frequent neoplasm in correlation with significant rate of morbidity, mortality, and cost. The onset of BC is predominantly triggered by environmental and/or occupational exposures to carcinogens, such as tobacco. There are two distinct pathways by which BC can be developed, including non-muscle-invasive papillary tumors (NMIBC) and non-papillary (or solid) muscle-invasive tumors (MIBC). The Cancer Genome Atlas project has further recognized key genetic drivers of MIBC along with its subtypes with particular properties and therapeutic responses; nonetheless, NMIBC is the predominant BC presentation among the suffering individuals. Radical cystoprostatectomy, radiotherapy, and chemotherapy have been verified to be the common therapeutic interventions in metastatic tumors, among which chemotherapeutics are more conventionally utilized. Although multiple chemo drugs have been broadly administered for BC treatment, cisplatin is reportedly the most effective chemo drug against the corresponding malignancy. Notwithstanding, tumor recurrence is usually occurred following the consumption of cisplatin regimens, particularly due to the progression of chemo-resistant trait. In this framework, non-coding RNAs (ncRNAs), as abundant RNA transcripts arise from the human genome, are introduced to serve as crucial contributors to tumor expansion and cisplatin chemo-resistance in bladder neoplasm. In the current review, we first investigated the best-known ncRNAs, i.e. microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), correlated with cisplatin chemo-resistance in BC cells and tissues. We noticed that these ncRNAs could mediate the BC-related cisplatin-resistant phenotype through diverse cellular processes and signaling mechanisms, reviewed here. Eventually, diagnostic and prognostic potential of ncRNAs, as well as their therapeutic capabilities were highlighted in regard to BC management.

Effect of Rosmarinic Acid on Cell Proliferation, Oxidative Stress, and Apoptosis Pathways in an Animal Model of Induced Glioblastoma Multiforme

BACKGROUND

In brain tumors, the complexity of the pathophysiological processes such as oxidative stress, cell proliferation, angiogenesis, and apoptosis have seriously challenged the definitive treatment. Rosmarinic acid (RA), as a polyphenolic compound, has been found to prevent tumor progression in some aggressive cancers. This study was designed to evaluate the anticancer effects of RA on brain tumors.

METHOD

Rats were divided into six groups. Implantation of C6 glioma cells was carried out in the caudate nucleus of the right hemisphere. RA at doses of 5, 10, and 20 mg/kg (i.p.) was administered to the treatment groups for seven days. Tumor volume (by MRI imaging), locomotor ability, survival time, histological alterations (by H & E staining), expression of p53 and p21 mRNAs (by RT-PCR), activities of antioxidant enzymes (superoxide dismutase [SOD] and catalase [CAT] by assay kits), expression of caspase-3 and VEGF (by immunohistochemical analysis), and TUNEL-positive cells (by tunnel staining) were analyzed.

RESULTS

The results indicated that the RA at a dose of 20 mg/kg reduced the tumor volume, prolonged survival time, increased p53 and p21 mRNAs, attenuated SOD and CAT activities in tumor tissue, elevated caspase-3, and increased the number of TUNEL-positive cells. Furthermore, histological analysis revealed less invasion of tumor cells into the normal parenchyma in rats treated with RA (20 mg/kg).

CONCLUSION

These findings provide evidence that the ability of RA to reduce tumor volume could be related to factors that modulate oxidative stress (SOD and CAT enzymes), cell proliferation (p53 and p21), and apoptosis (caspase-3).

Horizontal gene transfer of a functional cki homolog in the human pathogen Schistosoma mansoni

Schistosomes are parasitic flatworms responsible for the neglected tropical disease schistosomiasis, causing devastating morbidity and mortality in the developing world. The parasites are protected by a skin-like tegument, and maintenance of this tegument is controlled by a schistosome ortholog of the tumor suppressor TP53. To understand mechanistically how p53-1 controls tegument production, we identified a cyclin dependent kinase inhibitor homolog (cki) that was co-expressed with p53-1. RNA interference of cki resulted in a hyperproliferation phenotype, that, in combination with p53-1 RNA interference yielded abundant tumor-like growths, indicating that cki and p53-1 are bona fide tumor suppressors in Schistosoma mansoni. Interestingly, cki homologs are widely present throughout parasitic flatworms but evidently absent from their free-living ancestors, suggesting this cki homolog came from an ancient horizontal gene transfer event. This in turn implies that the evolution of parasitism in flatworms may have been aided by a highly unusual means of metazoan genetic inheritance.

Deciphering anoikis resistance and identifying prognostic biomarkers in clear cell renal cell carcinoma epithelial cells

This study tackles the persistent prognostic and management challenges of clear cell renal cell carcinoma (ccRCC), despite advancements in multimodal therapies. Focusing on anoikis, a critical form of programmed cell death in tumor progression and metastasis, we investigated its resistance in cancer evolution. Using single-cell RNA sequencing from seven ccRCC patients, we assessed the impact of anoikis-related genes (ARGs) and identified differentially expressed genes (DEGs) in Anoikis-related epithelial subclusters (ARESs). Additionally, six ccRCC RNA microarray datasets from the GEO database were analyzed for robust DEGs. A novel risk prognostic model was developed through LASSO and multivariate Cox regression, validated using BEST, ULCAN, and RT-PCR. The study included functional enrichment, immune infiltration analysis in the tumor microenvironment (TME), and drug sensitivity assessments, leading to a predictive nomogram integrating clinical parameters. Results highlighted dynamic ARG expression patterns and enhanced intercellular interactions in ARESs, with significant KEGG pathway enrichment in MYC + Epithelial subclusters indicating enhanced anoikis resistance. Additionally, all ARESs were identified in the spatial context, and their locational relationships were explored. Three key prognostic genes-TIMP1, PECAM1, and CDKN1A-were identified, with the high-risk group showing greater immune infiltration and anoikis resistance, linked to poorer prognosis. This study offers a novel ccRCC risk signature, providing innovative approaches for patient management, prognosis, and personalized treatment.

Pectinose induces cell cycle arrest in luminal A and triple-negative breast cancer cells by promoting autophagy through activation of the p38 MAPK signaling pathway

Breast cancer patients often have a poor prognosis largely due to lack of effective targeted therapy. It is now well established that monosaccharide enhances growth retardation and chemotherapy sensitivity in tumor cells. However, Pectinose whether has capability to restrict the proliferation of tumor cells remain unclear. Here, we report that Pectinose induced cytotoxicity is modulated by autophagy and p38 MAPK signaling pathway in breast cancer cell lines. The proliferation of cells was dramatically inhibited by Pectinose exposure in a dose-dependent manner, which was relevant to cell cycle arrest, as demonstrated by G2/M cell cycle restriction and ectopic expression of Cyclin A, Cyclin B, p21and p27. Mechanistically, we further identified that Pectinose is positively associated with autophagy and the activation of the p38 MAPK signaling in breast cancer. In contrast, 3-Ma or SB203580, the inhibitor of autophagy or p38 MAPK, reversed the efficacy of Pectinose suppressing on breast cancer cell lines proliferation and cell cycle process. Additionally, Pectinose in vivo treatment could significantly inhibit xenograft growth of breast cancer cells. Taken together, our findings were the first to reveal that Pectinose triggered cell cycle arrest by inducing autophagy through the activation of p38 MAPK signaling pathway in breast cancer cells,especially in luminal A and triple-negative breast cancer.

D-arabinose induces cell cycle arrest by promoting autophagy via p38 MAPK signaling pathway in breast cancer

Breast cancer patients often have a poor prognosis largely due to lack of effective targeted therapy. It is now well established that monosaccharide enhances growth retardation and chemotherapy sensitivity in tumor cells. We investigated whether D-arabinose has capability to restrict the proliferation of tumor cells and its mechanism. Here, we report that D-arabinose induced cytotoxicity is modulated by autophagy and p38 MAPK signaling pathway in breast cancer cell lines. The proliferation of cells was evaluated by CCK-8 and Colony formation assay. The distribution of cells in cell cycle phases was analyzed by flow cytometry. Cell cycle, autophagy and MAPK signaling related proteins were detected by western blotting. Mouse xenograft model was used to evaluate the efficacy of D-arabinose in vivo. The proliferation of cells was dramatically inhibited by D-arabinose exposure in a dose-dependent manner, which was relevant to cell cycle arrest, as demonstrated by G2/M cell cycle restriction and ectopic expression of cell cycle related proteins. Mechanistically, we further identified that D-arabinose is positively associated with autophagy and the activation of the p38 MAPK signaling in breast cancer. In contrast, 3-Ma or SB203580, the inhibitor of autophagy or p38 MAPK, reversed the efficacy of D-arabinose. Additionally, D-arabinose in vivo treatment could significantly inhibit xenograft growth of breast cancer cells. Our findings were the first to reveal that D-arabinose triggered cell cycle arrest by inducing autophagy through the activation of p38 MAPK signaling pathway in breast cancer cells.

PD-L1 intrinsically promotes the proliferation of breast cancer cells through the SKP2-p27/p21 axis

BACKGROUND

PD-L1 intrinsically promotes tumor progression through multiple mechanisms, which potentially leads to resistance to anti-PD-1/PD-L1 therapies. The intrinsic effect of PD-L1 on breast cancer (BC) cell proliferation has not been fully elucidated.

METHODS

we used proteomics, gene expression knockdown (KD), quantitative immunofluorescence (qIF), western blots, functional assays including colony-forming assay (CFA) and real-time cell analyzer (RTCA), and in vivo data using immunohistochemistry in breast cancer patients.

RESULTS

PD-L1 promoted BC cell proliferation by accelerating cell cycle entry at the G1-to-S phase transition. Global proteomic analysis of the differentially expressed nuclear proteins indicated the involvement of several proliferation-related molecules, including p21CIP1/WAF1. Western blotting and qIF demonstrated the higher expression of SKP2 and the lower expression of p21CIP1/WAF1 and p27Kip1 in PD-L1 expressing (PD-L1pos) cells as compared to PD-L1 KD (PD-L1KD) cells. Xenograft-derived cells and the TCGA BC dataset confirmed this relationship in vivo. Functionally, CFA and RTCA demonstrated the central role of SKP2 in promoting PD-L1-mediated proliferation. Finally, immunohistochemistry in 74 breast cancer patients confirmed PD-L1 and SKP-p21/p27 axis relationship, as it showed a highly statistically significant correlation between SKP2 and PD-L1 expression (p < 0.001), and both correlated significantly with the proliferation marker Ki-67 (p < 0.001). On the other hand, there was a statistically significant inverse relationship between PD-L1 and p21CIP1/WAF1 expression (p = 0.005). Importantly, double negativity for p21CIP1/WAF1 and p27Kip1 correlated significantly with PD-L1 (p < 0.001), SKP2 (p = 0.002), and Ki-67 (p = 0.002).

CONCLUSIONS

we have demonstrated the role of the SKP2-p27/p21 axis in intrinsic PD-L1-enhanced cell cycle progression. Inhibitors of SKP2 expression can alleviate resistance to ICPIs.

Statins in Chronic Liver Disease: Review of the Literature and Future Role

Chronic liver disease (CLD) is a major contributor to global mortality, morbidity, and healthcare burden. Progress in pharmacotherapeutic for CLD management is lagging given its impact on the global population. While statins are indicated for the management of dyslipidemia and cardiovascular disease, their role in CLD prevention and treatment is emerging. Beyond their lipid-lowering effects, their liver-related mechanisms of action are multifactorial and include anti-inflammatory, antiproliferative, and immune-protective effects. In this review, we highlight what is known about the clinical benefits of statins in viral and nonviral etiologies of CLD and hepatocellular carcinoma (HCC), and explore key mechanisms and pathways targeted by statins. While their benefits may span the spectrum of CLD and potentially HCC treatment, their role in CLD chemoprevention is likely to have the largest impact. As emerging data suggest that genetic variants may impact their benefits, the role of statins in precision hepatology will need to be further explored.

ACAT1 promotes proliferation and metastasis of bladder cancer via AKT/GSK3β/c-Myc signaling pathway

Acetyl-CoA acetyltransferase 1 (ACAT1) plays a significant role in the regulation of gene expression and tumorigenesis. However, the biological role of ACAT1 in bladder cancer (BLCA) has yet to be elucidated. This research aimed to elucidate the bioinformatics features and biological functions of ACAT1 in BLCA. Here, we demonstrate that ACAT1 is elevated in BLCA tissues and is correlated with specific clinicopathological features and an unfavorable prognosis for survival in BLCA patients. ACAT1 was identified as an independent risk factor in BLCA. Phenotypically, both in vitro and in vivo, ACAT1 knockdown suppressed BLCA cell proliferation and migration, while ACAT1 overexpression had the opposite effect. Mechanistic assays revealed that ACAT1 enhances BLCA cell proliferation and metastasis through the AKT/GSK3β/c-Myc signaling pathway by modulating the cell cycle and EMT. Taken together, the results of our study reveal that ACAT1 is an oncogenic driver in BLCA that enhances tumor proliferation and metastasis, indicating its potential as a diagnostic and therapeutic target for this disease.

O-GlcNAcylation of E3 ubiquitin ligase SKP2 promotes hepatocellular carcinoma proliferation

O-linked-β-N-acetylglucosamine (O-GlcNAc) modification (O-GlcNAcylation) and ubiquitination are critical posttranslational modifications that regulate tumor development and progression. The continuous progression of the cell cycle is the fundamental cause of tumor proliferation. S-phase kinase-associated protein 2 (SKP2), an important E3 ubiquitin ligase, assumes a pivotal function in the regulation of the cell cycle. However, it is still unclear whether SKP2 is an effector of O-GlcNAcylation that affects tumor progression. In this study, we found that SKP2 interacted with O-GlcNAc transferase (OGT) and was highly O-GlcNAcylated in hepatocellular carcinoma (HCC). Mechanistically, the O-GlcNAcylation at Ser34 stabilized SKP2 by reducing its ubiquitination and degradation mediated by APC-CDH1. Moreover, the O-GlcNAcylation of SKP2 enhanced its binding ability with SKP1, thereby enhancing its ubiquitin ligase function. Consequently, SKP2 facilitated the transition from the G1-S phase of the cell cycle by promoting the ubiquitin degradation of cell cycle-dependent kinase inhibitors p27 and p21. Additionally, targeting the O-GlcNAcylation of SKP2 significantly suppressed the proliferation of HCC. Altogether, our findings reveal that O-GlcNAcylation, a novel posttranslational modification of SKP2, plays a crucial role in promoting HCC proliferation, and targeting the O-GlcNAcylation of SKP2 may become a new therapeutic strategy to impede the progression of HCC.

Thioredoxin (Trx): A redox target and modulator of cellular senescence and aging-related diseases

Thioredoxin (Trx) is a compact redox-regulatory protein that modulates cellular redox state by reducing oxidized proteins. Trx exhibits dual functionality as an antioxidant and a cofactor for diverse enzymes and transcription factors, thereby exerting influence over their activity and function. Trx has emerged as a pivotal biomarker for various diseases, particularly those associated with oxidative stress, inflammation, and aging. Recent clinical investigations have underscored the significance of Trx in disease diagnosis, treatment, and mechanistic elucidation. Despite its paramount importance, the intricate interplay between Trx and cellular senescence-a condition characterized by irreversible growth arrest induced by multiple aging stimuli-remains inadequately understood. In this review, our objective is to present a comprehensive and up-to-date overview of the structure and function of Trx, its involvement in redox signaling pathways and cellular senescence, its association with aging and age-related diseases, as well as its potential as a therapeutic target. Our review aims to elucidate the novel and extensive role of Trx in senescence while highlighting its implications for aging and age-related diseases.

The effects of low ambient temperature on steroidogenesis and mitochondrial functions in the testes of wild ground squirrels (Spermophilus dauricus)

Seasonal reproduction is a widely used breeding strategy in wildlife, especially vertebrates inhabiting temperate regions. Generally, ambient temperature is considered a significant factor influencing the reproductive status of animals. In the present study, wild ground squirrels (Spermophilus dauricus), typical seasonal breeders, were used as an animal model to investigate the mechanism behind the impact of low ambient temperature on testicular function. To simulate the winter environment of wild ground squirrels, we lowered the temperature gradient in the rearing environment to 4 °C. At sampling, the body surface temperature of the squirrels reared under normal ambient temperature (22 °C, NAT group) and the low ambient temperature (4 °C, LAT group) were 31.5 °C and 22.8 °C, respectively. Subsequently, we conducted immunohistochemical assays, qPCR, and enzyme-linked immunosorbent assays (ELISA) to examine the variations in testicular functions, as well as the dynamics and functions of mitochondria, in the squirrels of NAT and LAT groups. As a result, the levels of positive immunostaining for PCNA, P21, and P27 were significantly lower in the testes of LAT group, while the levels of immunostaining for Cleaved Caspase-3 and TUNEL were significantly higher. In addition, the low-temperature treatment reduced the expression level of steroidogenesis-related genes, including LHR, FSHR, GATA-4, P450scc, and P450arom, and decreased the testosterone concentration. Moreover, markers of mitochondrial fission and fusion, DRP1 and MFN2, respectively, were increased in the testes of LAT group. Additionally, the mRNA level of SOD1 was notably higher in the testes of LAT group. In conclusion, the low ambient temperature inhibited spermatogenesis, steroidogenesis, as well as mitochondrial dynamics and functions in the testes of wild ground squirrels.

Establishment and Characterization of Immortalized Human Dermal Papilla Cells Expressing Human Papillomavirus 16 E6/E7

Primary human dermal papilla cells (HDPCs) are often preferred in studies on hair growth and regeneration. However, primary HDPCs are limited by their reduced proliferative capacity, decreased hair induction potential, and extended doubling times at higher passages. To overcome these limitations, pTARGET vectors containing human papillomavirus16 (HPV16) E6/E7 oncogenes were transfected into HDPCs and selected using G-148 to generate immortalized cells here. HPV16 E6/E7 oncogenes were efficiently transfected into primary HDPCs. Immortalized HDPC showed higher proliferative activity than primary HDPC, confirming an increased proliferation rate. Expression of p53 and pRb proteins was downregulated by E6 and E7, respectively. E6/E7 expressing HDPC cells revealed that cyclin-dependent kinase (CDK) inhibitor p21 expression was decreased, while cell cycle-related genes and proteins (CDK2 and cyclin E) and E2F family genes were upregulated. Immortalized HDPCs maintained their responsiveness to Wnt/β-catenin pathway and hair follicle formation capability, as indicated by their aggregative properties and stemness. E6/E7 immortalized HDPCs may facilitate in vitro hair growth and regeneration studies.

Tocotrienol isoforms: The molecular mechanisms underlying their effects in cancer therapy and their implementation in clinical trials

Tocotrienols are found in a variety of natural sources, like rice bran, annatto seeds and palm oil, and have been shown to have several health-promoting properties, particularly against chronic diseases such as cancer. The incidence of cancer is rapidly increasing around the world, not only a result of continued aging and population growth, but also due to the adoption of aspects of the Western lifestyle, such as high-fat diets and low-physical activity. The literature provides strong evidence that tocotrienols are able to inhibit the growth of various cancers, including breast, lung, ovarian, prostate, liver, brain, colon, myeloma and pancreatic cancers. These findings, along with the reported safety profile of tocotrienols in healthy human volunteers, encourage further research into these compounds' potential use in cancer prevention and treatment. The current review provided detailed information about the molecular mechanisms of action of different tocotrienol isoforms in various cancer models and evaluated the potential therapeutic effects of different vitamin E analogues on important cancer hallmarks, such as cellular proliferation, apoptosis, angiogenesis and metastasis. MEDLINE/PubMed and Scopus databases were used to identify recently published articles that investigated the anticancer effects of vitamin E derivatives in various types of cancer in vitro and in vivo along with clinical evidence of adjuvant chemopreventive benefits. Following an overview of pre-clinical studies, we describe several completed and ongoing clinical trials that are paving the way for the successful implementation of tocotrienols in cancer chemotherapy.

Targeting EBV-encoded products: Implications for drug development in EBV-associated diseases

Epstein-Barr virus, a human gamma-herpesvirus, has a close connection to the pathogenesis of cancers and other diseases, which are a burden for public health worldwide. So far, several drugs or biomolecules have been discovered that can target EBV-encoded products for treatment, such as Silvestrol, affinity toxin, roscovitine, H20, H31, curcumin, thymoquinone, and ribosomal protein L22. These drugs activate or inhibit the function of some biomolecules, affecting subsequent signalling pathways by acting on the products of EBV. These drugs usually target LMP1, LMP2; EBNA1, EBNA2, EBNA3; EBER1, EBER2; Bam-HI A rightward transcript and BHRF1. Additionally, some promising findings in the fields of vaccines, immunological, and cellular therapies have been established. In this review, we mainly summarise the function of drugs mentioned above and unique mechanisms, hoping that we can help giving insight to the design of drugs for the treatment of EBV-associated diseases.

Structure-Function Analysis of p57KIP2 in the Human Pancreatic Beta Cell Reveals a Bipartite Nuclear Localization Signal

Mutations in CDKN1C, encoding p57KIP2, a canonical cell cycle inhibitor, underlie multiple pediatric endocrine syndromes. Despite this central role in disease, little is known about the structure and function of p57KIP2 in the human pancreatic beta cell. Since p57KIP2 is predominantly nuclear in human beta cells, we hypothesized that disease-causing mutations in its nuclear localization sequence (NLS) may correlate with abnormal phenotypes. We prepared RIP1 insulin promoter-driven adenoviruses encoding deletions of multiple disease-associated but unexplored regions of p57KIP2 and performed a comprehensive structure-function analysis of CDKN1C/p57KIP2. Real-time polymerase chain reaction and immunoblot analyses confirmed p57KIP2 overexpression, construct size, and beta cell specificity. By immunocytochemistry, wild-type (WT) p57KIP2 displayed nuclear localization. In contrast, deletion of a putative NLS at amino acids 278-281 failed to access the nucleus. Unexpectedly, we identified a second downstream NLS at amino acids 312-316. Further analysis showed that each individual NLS is required for nuclear localization, but neither alone is sufficient. In summary, p57KIP2 contains a classical bipartite NLS characterized by 2 clusters of positively charged amino acids separated by a proline-rich linker region. Variants in the sequences encoding these 2 NLS sequences account for functional p57KIP2 loss and beta cell expansion seen in human disease.

Homospisulosine induced apoptosis in cervical carcinoma cells is associated with phosphorylation of Bcl-2 and up-regulation of p27/Kip1

Spisulosine (1-deoxysphinganine) is a sphingoid amino alcohol isolated from the sea clams that showed potent antiproliferative activity against a broad spectrum of solid tumors but failed in clinical trials due to neurotoxicity. However, its structural similarity to other bioactive sphingoids, interesting mode of action, and appreciable potency against cancer cells make it a suitable lead for future anticancer drug development. The present study was conducted to elucidate mechanisms of the antiproliferative/cytotoxic effects of newly synthesized spisulosine analog homospisulosine (KP7). The evaluation was performed on cervical carcinoma cells, representing an in vitro model of one of the most common cancer types and a significant worldwide cause of women's cancer mortality. Treatment with homospisulosine (2.0 μM) for 24, 48, and 72 h significantly inhibited the growth of HeLa cells in vitro and induced apoptosis detectable by DNA fragmentation, externalization of phosphatidylserine, dissipation of mitochondrial membrane potential, activation of caspase-3 and cleavage of PARP. In addition, treating HeLa cells with spisulosine increased p27 and Bcl-2 on protein levels and phosphorylation of Bcl-2 on Ser70 residue. These results support the potential for spisulosine analogs represented here by homospisulosine for future therapeutic development.

Podoplanin Drives Amoeboid Invasion in Canine and Human Mucosal Melanoma

Mucosal melanoma metastasizes at an early stage of the disease in human and dog. We revealed that overexpression of podoplanin in tumor invasion fronts (IF) was related to poor prognosis of dogs with mucosal melanoma. Moreover, podoplanin expressed in canine mucosal melanoma cells promotes proliferation and aggressive amoeboid invasion by activating Rho-associated kinase (ROCK)-myosin light chain 2 (MLC2) signaling. PDPN-ROCK-MLC2 signaling plays a role in cell-cycle arrest and cellular senescence escape as a mechanism for regulating proliferation. Podoplanin induces amoeboid invasion in the IFs of mouse xenografted tumor tissues, similar to canine mucosal melanoma clinical samples. We further identified that podoplanin expression was related to poor prognosis of human patients with mucosal melanoma, and human mucosal melanoma with podoplanin-high expression enriched gene signatures related to amoeboid invasion, similar to canine mucosal melanoma. Overall, we propose that podoplanin promotes canine and human mucosal melanoma metastasis by inducing aggressive amoeboid invasion and naturally occurring canine mucosal melanoma can be a novel research model for podoplanin expressing human mucosal melanoma.

IMPLICATIONS

Podoplanin could be a new therapeutic target to restrict the metastatic dissemination of canine and human mucosal melanoma.

Size-Specific Modulation of a Multienzyme Glucosome Assembly during the Cell Cycle

Enzymes in glucose metabolism have been subjected to numerous studies, revealing the importance of their biological roles during the cell cycle. However, due to the lack of viable experimental strategies for measuring enzymatic activities particularly in living human cells, it has been challenging to address whether their enzymatic activities and thus anticipated glucose flux are directly associated with cell cycle progression. It has remained largely elusive how human cells regulate glucose metabolism at a subcellular level to meet the metabolic demands during the cell cycle. Meanwhile, we have characterized that rate-determining enzymes in glucose metabolism are spatially organized into three different sizes of multienzyme metabolic assemblies, termed glucosomes, to regulate the glucose flux between energy metabolism and building block biosynthesis. In this work, we first determined using cell synchronization and flow cytometric techniques that enhanced green fluorescent protein-tagged phosphofructokinase is adequate as an intracellular biomarker to evaluate the state of glucose metabolism during the cell cycle. We then applied fluorescence single-cell imaging strategies and discovered that the percentage of Hs578T cells showing small-sized glucosomes is drastically changed during the cell cycle, whereas the percentage of cells with medium-sized glucosomes is significantly elevated only in the G1 phase, but the percentage of cells showing large-sized glucosomes is barely or minimally altered along the cell cycle. Should we consider our previous localization-function studies that showed assembly size-dependent metabolic roles of glucosomes, this work strongly suggests that glucosome sizes are modulated during the cell cycle to regulate glucose flux between glycolysis and building block biosynthesis. Therefore, we propose the size-specific modulation of glucosomes as a behind-the-scenes mechanism that may explain functional association of glucose metabolism with the cell cycle and, thereby, their metabolic significance in human cell biology.

G1 Dynamics at the Crossroads of Pluripotency and Cancer

G1 cell cycle phase dynamics are regulated by intricate networks involving cyclins, cyclin-dependent kinases (CDKs), and CDK inhibitors, which control G1 progression and ensure proper cell cycle transitions. Moreover, adequate origin licensing in G1 phase, the first committed step of DNA replication in the subsequent S phase, is essential to maintain genome integrity. In this review, we highlight the intriguing parallels and disparities in G1 dynamics between stem cells and cancer cells, focusing on their regulatory mechanisms and functional outcomes. Notably, SOX2, OCT4, KLF4, and the pluripotency reprogramming facilitator c-MYC, known for their role in establishing and maintaining stem cell pluripotency, are also aberrantly expressed in certain cancer cells. In this review, we discuss recent advances in understanding the regulatory role of these pluripotency factors in G1 dynamics in the context of stem cells and cancer cells, which may offer new insights into the interconnections between pluripotency and tumorigenesis.

Apoptotic Potential and Antitumor Efficacy of Trilliumoside A: A New Steroidal Saponin Isolated from Rhizomes of Trillium govanianum

Natural product-derived molecules exhibit potential as anticancer agents. Trilliumoside A, a new steroidal saponin, was obtained from rhizomes of Trillium govanianum, and its anticancer activity was investigated in the presented study. Trilliumoside A was investigated in a panel of cell lines, and it exhibited promising cytotoxic activity on the A549 cells (human lung cancer cells) with an IC50 of 1.83 μM. The mechanism of cell death induced by Trilliumoside A in A549 cells and its anticancer potential in murine tumor models (EAC and EAT) were presented in the current research. Trilliumoside A was found to induce apoptosis in A549 cells by increasing the expression of various apoptotic proteins, such as Bax, Puma, cytochrome C, cleaved PARP, and cleaved caspase 3. Additionally, Trilliumoside A regulates the expression of p53, CDK2, and Cyclin A by decreasing the mitochondrial membrane potential, elevating reactive oxygen species, and stopping the growth of A549 cells in the synthesis phase (S) of the cell cycle. Trilliumoside A showed a considerable reduction in the tumor volume, the amount of ascitic fluid, and the total cell number without affecting the body weight of animals. Our results demonstrate that Trilliumoside A inhibits the proliferation of human lung cancer cells by inducing DNA damage, arresting the cell cycle, and activating the mitochondrial signaling pathway. The study demonstrated the potential of Trilliumoside A as a potential anticancer agent.

MiRNA-related metastasis in oral cancer: moving and shaking

Across the world, oral cancer is a prevalent tumor. Over the years, both its mortality and incidence have grown. Oral cancer metastasis is a complex process involving cell invasion, migration, proliferation, and egress from cancer tissue either by lymphatic vessels or blood vessels. MicroRNAs (miRNAs) are essential short non-coding RNAs, which can act either as tumor suppressors or as oncogenes to control cancer development. Cancer metastasis is a multi-step process, in which miRNAs can inhibit or stimulate metastasis at all stages, including epithelial-mesenchymal transition, migration, invasion, and colonization, by targeting critical genes in these pathways. On the other hand, long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), two different types of non-coding RNAs, can regulate cancer metastasis by affecting gene expression through cross-talk with miRNAs. We reviewed the scientific literature (Google Scholar, Scopus, and PubMed) for the period 2000-2023 to find reports concerning miRNAs and lncRNA/circRNA-miRNA-mRNA networks, which control the spread of oral cancer cells by affecting invasion, migration, and metastasis. According to these reports, miRNAs are involved in the regulation of metastasis pathways either by directly or indirectly targeting genes associated with metastasis. Moreover, circRNAs and lncRNAs can induce or suppress oral cancer metastasis by acting as competing endogenous RNAs to inhibit the effect of miRNA suppression on specific mRNAs. Overall, non-coding RNAs (especially miRNAs) could help to create innovative therapeutic methods for the control of oral cancer metastases.

Metabolic clogging of mannose triggers dNTP loss and genomic instability in human cancer cells

Mannose has anticancer activity that inhibits cell proliferation and enhances the efficacy of chemotherapy. How mannose exerts its anticancer activity, however, remains poorly understood. Here, using genetically engineered human cancer cells that permit the precise control of mannose metabolic flux, we demonstrate that the large influx of mannose exceeding its metabolic capacity induced metabolic remodeling, leading to the generation of slow-cycling cells with limited deoxyribonucleoside triphosphates (dNTPs). This metabolic remodeling impaired dormant origin firing required to rescue stalled forks by cisplatin, thus exacerbating replication stress. Importantly, pharmacological inhibition of de novo dNTP biosynthesis was sufficient to retard cell cycle progression, sensitize cells to cisplatin, and inhibit dormant origin firing, suggesting dNTP loss-induced genomic instability as a central mechanism for the anticancer activity of mannose.

miRNAs as potential game-changers in head and neck cancer: Future clinical and medicinal uses

Head and neck cancers (HNCs) are a group of heterogeneous tumors formed most frequently from epithelial cells of the larynx, lips, oropharynx, nasopharynx, and mouth. Numerous epigenetic components, including miRNAs, have been demonstrated to have an impact on HNCs characteristics like progression, angiogenesis, initiation, and resistance to therapeutic interventions. The miRNAs may control the production of numerous genes linked to HNCs pathogenesis. The roles that miRNAs play in angiogenesis, invasion, metastasis, cell cycle, proliferation, and apoptosis are responsible for this impact. The miRNAs also have an impact on crucial HNCs-related mechanistic networks like the WNT/β-catenin signaling, PTEN/Akt/mTOR pathway, TGFβ, and KRAS mutations. miRNAs may affect how the HNCs respond to treatments like radiation and chemotherapy in addition to pathophysiology. This review aims to demonstrate the relationship between miRNAs and HNCs with a particular emphasis on how miRNAs impact HNCs signaling networks.

A nonsteroidal anti-inflammatory drug, zaltoprofen, inhibits the growth of extraskeletal chondrosarcoma cells by inducing PPARγ, p21, p27, and p53

Peroxisome proliferator-activated receptor gamma (PPARγ) is a nuclear receptor and master transcription factor of adipogenesis-related genes, and has been reported as an antitumor target for chondrosarcomas. Herein, we show that the nonsteroidal anti-inflammatory drug, zaltoprofen, induces the expression of PPARγ at the mRNA and protein levels, following the induction of PPARγ-activating factors, such as Krox20, C/EBPβ, and C/EBPα, in human extraskeletal chondrosarcoma H-EMC-SS cells. Upregulation of the cell cycle checkpoint proteins, p21, p27, and p53, was observed upon treatment of H-EMC-SS cells with zaltoprofen, which probably resulted in the inhibition of proliferation of these cells observed in vitro. Zaltoprofen treatment inhibited tumor growth, induced tumor cell apoptosis, and was well tolerated in a mouse model of extraskeletal myxoid chondrosarcoma. Our results provide mechanistic insights into the therapeutic effect of zaltoprofen that should promote further studies on the rational use of this drug for the effective treatment of sarcomas.

CDK4/6 inhibitor resistance in estrogen receptor positive breast cancer, a 2023 perspective

CDK4/6 inhibitors have become game-changers in the treatment of estrogen receptor-positive (ER+) breast cancer, and in combination with endocrine therapy are the standard of care first-line treatment for ER+/HER2-negative advanced breast cancer. Although CDK4/6 inhibitors prolong survival for these patients, resistance is inevitable and there is currently no clear standard next-line treatment. There is an urgent unmet need to dissect the mechanisms which drive intrinsic and acquired resistance to CDK4/6 inhibitors and endocrine therapy to guide the subsequent therapeutic decisions. We will review the insights gained from preclinical studies and clinical cohorts into the diverse mechanisms of CDK4/6 inhibitor action and resistance, and highlight potential therapeutic strategies in the context of CDK4/6 inhibitor resistance.

Recombinant human p53 adenovirus injection combined with Bortezomib inhibits proliferation and promotes apoptosis in multiple myeloma

BACKGROUND

Multiple myeloma (MM) is a B-cell malignancy characterized by abnormal proliferation of clonal plasma cells in the bone marrow, the incidence of which has further increased in recent years. In multiple myeloma, wild-type functional p53 is often inactivated or dysregulated. Therefore, this study aimed to investigate the role of p53 knockdown or overexpression in multiple myeloma and the therapeutic effect of recombinant adenovirus-p53 (rAd-p53) in combination with Bortezomib.

METHODS

SiRNA p53 and rAd-p53 were used to knock down and overexpress p53. RT-qPCR was used to detect gene expression, and western blotting (WB) was used to detect protein expression levels. We also constructed wild-type multiple myeloma cell line-MM1S cell xenograft tumor models and explored the effects of siRNA-p53, rAd-p53, and Bortezomib on multiple myeloma in vivo and in vitro. H&E staining and KI67 immunohistochemical staining were used to assess the anti-myeloma effects of recombinant adenovirus and Bortezomib in vivo.

RESULTS

The designed siRNA p53 effectively led to the knockdown of the p53 gene, while rAd-p53 could significantly achieve p53 overexpression. p53 gene inhibited MM1S cell proliferation and promoted apoptosis of wild-type multiple myeloma cell line MM1S. P53 gene inhibited tumor proliferation in vitro by promoting p21 expression and reducing cell cycle protein B1 expression of MM1S. P53 gene overexpression could inhibit tumor growth in vivo. Injection of rAd-p53 in tumor models inhibited tumor development through p21- and cyclin B1-mediated cell proliferation and apoptosis regulation.

CONCLUSIONS

We found that overexpression of p53 inhibits MM tumor cell survival and proliferation in vivo and in vitro. Furthermore, the combination of rAd-p53 and Bortezomib significantly improved the efficacy, which provides a new possibility for more effective treatment of MM.

Piperine-Chlorogenic Acid Hybrid Inhibits the Proliferation of the SK-MEL-147 Melanoma Cells by Modulating Mitotic Kinases

Melanoma is considered the most aggressive form of skin cancer, showing high metastatic potential and persistent high mortality rates despite the introduction of immunotherapy and targeted therapies. Thus, it is important to identify new drug candidates for melanoma. The design of hybrid molecules, with different pharmacophore fragments combined in the same scaffold, is an interesting strategy for obtaining new multi-target and more effective anticancer drugs. We designed nine hybrid compounds bearing piperine and chlorogenic acid pharmacophoric groups and evaluated their antitumoral potential on melanoma cells with distinct mutational profiles SK-MEL-147, CHL-1 and WM1366. We identified the compound named PQM-277 (3a) to be the most cytotoxic one, inhibiting mitosis progression and promoting an accumulation of cells in pro-metaphase and metaphase by altering the expression of genes that govern G2/M transition and mitosis onset. Compound 3a downregulated FOXM1, CCNB1, CDK1, AURKA, AURKB, and PLK1, and upregulated CDKN1A. Molecular docking showed that 3a could interact with the CUL1-RBX1 complex, which activity is necessary to trigger molecular events essential for FOXM1 transactivation and, in turn, G2/M gene expression. In addition, compound 3a effectively induced apoptosis by increasing BAX/BCL2 ratio. Our findings demonstrate that 3a is an important antitumor candidate prototype and support further investigations to evaluate its potential for melanoma treatment, especially for refractory cases to BRAF/MEK inhibitors.

Therapeutic effects of hAMSCs secretome on proliferation of MDA-MB-231 breast cancer cells by the cell cycle arrest in G1/S phase

BACKGROUND

Cancer refers to a disease resulting from the uncontrolled division and growth of abnormal cells. Among different cancer types, breast cancer is considered as one of the most commonly diagnosed cancers. Herein, we explored the therapeutic effects of human amniotic mesenchymal stromal cells (hAMSCs) secretome on breast cancer cells (MDA-MB-231) through analyzing cell cycle progression.

METHODS

We employed a co-culture system using 6-well Transwell plates and after 72 h, the cell cycle progression was evaluated in the hAMSCs-treated MDA-MB-231 cells through analyzing the expressions of RB, CDK4/6, cyclin D, CDK2, cyclin E, p16^/INK4a, p21^/WAF1/CIP1, and p27^/KIP1 using quantitative real-time PCR (qRT-PCR) and western blot method. Cell proliferation, apoptosis, and cell cycle progression were checked using an MTT assay, DAPI staining, and flow cytometry.

RESULTS

Our results indicated that elevation of RB, p21^/WAF1/CIP1, and p27^/KIP1 and suppression of RB hyperphosphorylation, p16^/INK4a, cyclin E, cyclin D1, CDK2, and CDK4/6 may contribute to inhibiting the proliferation of hAMSCs-treated MDA-MB-231 cells through cell cycle arrest in G1/S phase followed by apoptosis.

CONCLUSION

hAMSCs secretome may be an effective approach on breast cancer therapy through the inhibition of cell cycle progression.

NEDD4L inhibits glycolysis and proliferation of cancer cells in oral squamous cell carcinoma by inducing ENO1 ubiquitination and degradation

Glycolysis contributes to cell metabolism and facilitates cell proliferation of oral squamous cell carcinoma (OSCC), the most common type of oral cancer. Understanding the regulatory mechanisms involved in the glycolysis of OSCC cells may provide important therapeutic inspirations. Immunohistochemistry was used to examine protein localization patterns in human OSCC tissues and Western blot was conducted to gauge protein level. Lentivirus transduction was used to overexpress or silence genes of interest. Cell proliferation was assessed by Cell Counting Kit (CCK)-8 assay while glycolysis was examined via measurement of extracellular acidification rate, oxygen consumption rate, and lactate and ATP production. In vivo cancer development was evaluated with a mouse tumor growth model. OSCC tissues displayed reduced expression of NEDD4L compared with normal tissues. NEDD4L expression positively correlated with 5-year patient survival rate, indicating that NEDD4L may be a prognosis marker for OSCC. NEDD4L overexpression suppressed proliferation, cell cycle transition, and glycolysis in OSCC cells, and inhibited in vivo tumor growth. UbiBrowser identified ENO1, an enzyme that catalyzes glycolysis, as a substrate of NEDD4L. Overexpression of NEDD4L resulted in the ubiquitination and subsequent degradation of ENO1 whereas overexpression of ENO1 reversed the functional effects of NEDD4L overexpression, restoring proliferation, cell cycle transition, and glycolysis in OSCC cells. NEDD4L elicits tumor-suppressive functions via inhibition of OSCC cell proliferation, cell cycle transition, and glycolysis by stimulating ENO1 ubiquitination and degradation. Our results unraveled a signaling axis important for OSCC cell survival and metabolism, which can serve as a potential therapeutic target.

SCF-SKP2 E3 ubiquitin ligase links mTORC1/ER stress/ISR with YAP activation in murine renal cystogenesis

The Hippo pathway nuclear effector Yes-associated protein (YAP) potentiates the progression of polycystic kidney disease (PKD) arising from ciliopathies. The mechanisms underlying the increase in YAP expression and transcriptional activity in PKD remain obscure. We observed that in kidneys from mice with juvenile cystic kidney (jck) ciliopathy, the aberrant hyperactivity of mechanistic target of rapamycin complex 1 (mTORC1), driven by ERK1/2 and PI3K/AKT cascades, induced ER proteotoxic stress. To reduce this stress by reprogramming translation, the protein kinase R-like ER kinase-eukaryotic initiation factor 2α (PERK/eIF2α) arm of the integrated stress response (ISR) was activated. PERK-mediated phosphorylation of eIF2α drove the selective translation of activating transcription factor 4 (ATF4), potentiating YAP expression. In parallel, YAP underwent K63-linked polyubiquitination by SCF S-phase kinase-associated protein 2 (SKP2) E3 ubiquitin ligase, a Hippo-independent, nonproteolytic ubiquitination that enhances YAP nuclear trafficking and transcriptional activity in cancer cells. Defective ISR cellular adaptation to ER stress in eIF2α phosphorylation-deficient jck mice further augmented YAP-mediated transcriptional activity and renal cyst growth. Conversely, pharmacological tuning down of ER stress/ISR activity and SKP2 expression in jck mice by administration of tauroursodeoxycholic acid (TUDCA) or tolvaptan impeded these processes. Restoring ER homeostasis and/or interfering with the SKP2-YAP interaction represent potential therapeutic avenues for stemming the progression of renal cystogenesis.

The botanical drug PBI-05204, a supercritical CO2 extract of Nerium oleander, sensitizes alveolar and embryonal rhabdomyosarcoma to radiotherapy in vitro and in vivo

Treatment of rhabdomyosarcoma (RMS), the most common a soft tissue sarcoma in childhood, provides intensive multimodal therapy, with radiotherapy (RT) playing a critical role for local tumor control. However, since RMS efficiently activates mechanisms of resistance to therapies, despite improvements, the prognosis remains still largely unsatisfactory, mainly in RMS expressing chimeric oncoproteins PAX3/PAX7-FOXO1, and fusion-positive (FP)-RMS. Cardiac glycosides (CGs), plant-derived steroid-like compounds with a selective inhibitory activity of the Na+/K+-ATPase pump (NKA), have shown antitumor and radio-sensitizing properties. Herein, the therapeutic properties of PBI-05204, an extract from Nerium oleander containing the CG oleandrin already studied in phase I and II clinical trials for cancer patients, were investigated, in vitro and in vivo, against FN- and FP-RMS cancer models. PBI-05204 induced growth arrest in a concentration dependent manner, with FP-RMS being more sensitive than FN-RMS, by differently regulating cell cycle regulators and commonly upregulating cell cycle inhibitors p21Waf1/Cip1 and p27Cip1/Kip1. Furthermore, PBI-05204 concomitantly induced cell death on both RMS types and senescence in FN-RMS. Notably, PBI-05204 counteracted in vitro migration and invasion abilities and suppressed the formation of spheroids enriched in CD133+ cancer stem cells (CSCs). PBI-05204 sensitized both cell types to RT by improving the ability of RT to induce G2 growth arrest and counteracting the RT-induced activation of both Non‐Homologous End‐Joining and homologous recombination DSBs repair pathways. Finally, the antitumor and radio-sensitizing proprieties of PBI-05204 were confirmed in vivo. Notably, both in vitro and in vivo evidence confirmed the higher sensitivity to PBI-05204 of FP-RMS. Thus, PBI-05204 represents a valid radio-sensitizing agent for the treatment of RMS, including the intrinsically radio-resistant FP-RMS.

Ginsenoside Rh1 protects human endothelial cells against lipopolysaccharide-induced inflammatory injury through inhibiting TLR2/4-mediated STAT3, NF-κB, and ER stress signaling pathways

AIM

Endothelial cell (EC) dysfunction initiates atherosclerosis by inducing inflammatory cytokines and adhesion molecules. Herein, we investigated the role of ginsenoside Rh1 (Rh1) in lipopolysaccharide (LPS)-induced EC dysfunction.

MAIN METHODS

The inhibitory effect of Rh1 on LPS binding to toll-like receptor 2 (TLR2) or TLR4 was evaluated using an immunofluorescence (IF) assay. Annexin V and cleaved caspase-3-positive EC apoptosis were evaluated by flow cytometry and IF assay. Western blotting and quantitative reverse transcription-PCR were performed to clarify underlying molecular mechanisms. In vivo model, effect of Rh1 on EC dysfunction was evaluated by using en face IF assay on aortas isolated C57BL/6 mice.

KEY FINDING

LPS (500 ng/mL) activated inflammatory signaling pathways, including ERK1/2, STAT3, and NF-κB. Interestingly, Rh1 significantly abolished the binding of LPS to TLR2 and TLR4. Consistently, Rh1 inhibited LPS-induced NF-κB activation and its downstream molecules, including inflammatory cytokines and adhesion molecules. Furthermore, Rh1 alleviated LPS-induced downregulation of eNOS promoter activity. Notably, inactivation of eNOS by 50 μM L-NAME significantly increased NF-κB promoter activity. In addition, Rh1 abolished LPS-mediated cell cycle arrest and EC apoptosis by inhibiting endoplasmic reticulum stress via PERK/CHOP/ERO1-α signaling pathway. Consistent with in vitro experimental data, Rh1 effectively suppressed LPS-induced VCAM-1 and CHOP expression and rescuing LPS-destroyed tight junctions between ECs as indicated in ZO-1 expression on mice aorta.

SIGNIFICANCE

Rh1 suppresses LPS-induced EC inflammation and apoptosis by inhibiting STAT3/NF-κB and endoplasmic reticulum stress signaling pathways, mediated by blocking LPS binding-to TLR2 and TLR4. Consistently, Rh1 effectively reduced EC dysfunction in vivo model.

MED16 Promotes Tumour Progression and Tamoxifen Sensitivity by Modulating Autophagy through the mTOR Signalling Pathway in ER-Positive Breast Cancer

Recent studies have shown that the mediator complex (MED) plays a vital role in tumorigenesis and development, but the role of MED16 (mediator complex subunit 16) in breast cancer (BC) is not clear. Increasing evidence has shown that the mTOR pathway is important for tumour progression and therapy. In this study, we demonstrated that the mTOR signalling pathway is regulated by the expression level of MED16 in ER+ breast cancer. With the analysis of bioinformatics data and clinical specimens, we revealed an elevated expression of MED16 in luminal subtype tumours. We found that MED16 knockdown significantly inhibited cell proliferation and promoted G1 phase cell cycle arrest in ER+ BC cell lines. Downregulation of MED16 markedly reduced the sensitivity of ER+ BC cells to tamoxifen and increased the stemness and autophagy of ER+ BC cells. Bioinformatic analysis of similar genes to MED16 were mainly enriched in autophagy, endocrine therapy and mTOR signalling pathways, and the inhibition of mTOR-mediated autophagy restored sensitivity to tamoxifen by MED16 downregulation in ER+ BC cells. These results suggest an important role of MED16 in the regulation of tamoxifen sensitivity in ER+ BC cells, crosstalk between the mTOR signalling pathway-induced autophagy, and together, with the exploration of tamoxifen resistance, may indicate a new therapy option for endocrine therapy-resistant patients.

Comparative transcriptome analysis reveals physiological responses in liver tissues of Epinephelus coioides under acute hypoxia stress

Hypoxia is a common stressor for aquatic animals, including Epinephelus coioides, with a considerable impact on sustainable aquaculture. E. coioides is a widely consumed fish in China owing to its high nutritious value and taste. However, water hypoxia caused by high density culture process has become a great threat to E. coioides culture, and its response to hypoxia stress has not been discussed before. Therefore, the aim of this study was to examine the response of E. coioides to acute hypoxia using transcriptomic techniques. To this end, RNA sequencing was performed on the liver tissues of fish exposed to normoxic and hypoxic conditions for 1 h. The results presented 503 differentially expressed genes (DEGs) in the liver tissue of fish exposed to hypoxic condition compared with those in the normoxic group. Enrichment analysis using the Gene Ontology database showed that the DEGs were mainly enriched for functions related to cell apoptosis signaling pathways, insulin resistance, antioxidant enzymes, and glycolysis/gluconeogenesis signaling pathways. KEGG enrichment analysis showed that HIF-1, PI3K-AKT, IL-17, NF-kappa B, and MAPK signaling pathways were significantly enriched by the DEGs. The DEGs were mainly involved in immune response, inflammatory response, cell apoptosis regulation, energy metabolism, and substance metabolism. Additionally, the hypoxia response in E. coioides was mainly regulated via the PI3K-AKT-HIF-1 signaling axis. Overall, the findings of this study contribute to the understanding of hypoxia stress response in E. coioides, and provides target genes for breeding hypoxia-tolerant Epinephelus spp.

The Effects of Methanol Extracts of Hyssopus officinalis on Model of Induced Glioblastoma Multiforme (GBM) in Rats

Given the complexity of pathophysiological processes of brain tumors, ineffective therapies, and high mortality rate, new therapeutic options with less toxicity are necessary. Hyssopus officinalis (hyssop) is an aromatic plant with important biological activities. The aim of this study is to assess the anti-cancer effect of hyssop extract on damages of glioblastoma multiforme. In this study, total flavonoids, phenolic content, and quantification of phenolic compound of hyssop extracts were analyzed. In vitro antioxidant properties of hyssop extract were also examined. In addition, cell viability, apoptosis, and cell cycle were evaluated in C6 glioma cell culture. In vivo, the rats were divided randomly into four main groups: intact, control, vehicle, and treatment groups. 1 × 106 C6 rat glioma cells were implanted into the right caudate nucleus of the rat's brain. The treatment group received the methanol extract of hyssop (100 mg/kg) for 7 days. Evolution of locomotor activity, tumor volume, survival rate, activities of antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)), vascular endothelial growth factor (VEGF) expression, TUNEL-positive cells, p53 and p21 mRNA expression, and histological alterations were performed. The results showed that the methanol extract of hyssop increased the apoptosis and reduced the cell division of C6 glioma cells in cell culture. Moreover, methanol extract decreased the tumor volume and prolonged survival. Also, the activity of SOD and CAT enzymes was reduced in tumor tissue and enhanced in surrounding tissue. TUNEL-positive cells were increased in methanol extract of hyssop group. The expression of p53 and p21 mRNA was upregulated in the treatment group. Moreover, the histological analysis indicated a considerable decrease in invasion of tumor cells and inflammation in the hyssop-treated rats. According to the achieved results, it can be stated that hyssop has sufficient potential to inhibit damage of brain tumors, at least in part, by affecting the oxidative stress and cell proliferation pathways.

Expression of Cell Cycle Markers and Proliferation Factors during Human Eye Embryogenesis and Tumorigenesis

The expression pattern of the markers p19, Ki-67, MSX1, MSX2, PDL1, pRB, and CYCLINA2 was quantitatively and semiquantitatively analyzed in histologic sections of the developing and postnatal human eye at week 8, in retinoblastoma, and in various uveal melanomas post hoc studies by double immunofluorescence. The p19 immunoreactivity characterized retinal and/or choroidal cells in healthy and tumor tissues: expression was lower in the postnatal retina than in the developing retina and retinoblastoma, whereas it was high in epithelioid melanomas. Ki67 expression was high in the developing eye, retinoblastoma, and choroidal melanomas. MSX1 and MSX2 expression was similar in the developing eye and retinoblastoma, whereas it was absent in the postnatal eye. Their different expression was evident between epithelioid and myxoid melanomas. Similarly, PDL1 was absent in epithelioid melanomas, whereas it was highly expressed in developing and tumor tissues. Expression of pRB and CYCA2 was characteristic of developing and tumorous eye samples but not of the healthy postnatal eye. The observed expression differences of the analyzed markers correlate with the origin and stage of cell differentiation of the tissue samples. The fine balance of expression could play a role in both human eye development and ocular tumorigenesis. Therefore, understanding their relationship and interplay could open new avenues for potential therapeutic interventions and a better understanding of the mechanisms underlying the developmental plasticity of the eye and the development of neoplasms.

NSC305787, a pharmacological ezrin inhibitor, exhibits antineoplastic activity in pancreatic cancer cells

Pancreatic cancer is one of the most lethal human neoplasms, and despite advances in the understanding of the molecular complexity involved in the development and progression of this disease, little of this new information has been translated into improvements in therapy and prognosis. Ezrin (EZR) is a protein that regulates multiple cellular functions, including cell proliferation, survival, morphogenesis, adhesion, and motility. In pancreatic cancer, EZR is highly expressed and reflects an unfavorable prognosis, whereas EZR silencing ameliorates the malignant phenotype of pancreatic cancer cells. NSC305787 was identified as a pharmacological EZR inhibitor with favorable pharmacokinetics and antineoplastic activity. Here, we endeavored to investigate the impact of EZR expression on survival outcomes and its associations with molecular and biological characteristics in The Cancer Genome Atlas pancreatic adenocarcinoma cohort. We also assessed the potential antineoplastic effects of NSC305787 in pancreatic cancer cell lines. High EZR expression was an independent predictor of worse survival outcomes. Functional genomics analysis indicated that EZR contributes to multiple cancer-related pathways, including PI3K/AKT/mTOR signaling, NOTCH signaling, estrogen-mediated signaling, and apoptosis. In pancreatic cells, NSC305787 reduced cell viability, clonal growth, and migration. Our exploratory molecular studies identified that NSC305787 modulates the expression and activation of key regulators of the cell cycle, proliferation, DNA damage, and apoptosis, favoring a tumor-suppressive molecular network. In conclusion, EZR expression is an independent prognosis marker in pancreatic cancer. Our study identifies a novel molecular axis underlying the antineoplastic activity of NSC305787 and provides insights into the development of therapeutic strategies for pancreatic cancer.

O-GlcNAc tranferase regulates p21 protein levels and cell proliferation through the FoxM1-Skp2 axis in a p53-independent manner

The protein product of the CDKN1A gene, p21, has been extensively characterized as a negative regulator of the cell cycle. Nevertheless, it is clear that p21 has manifold complex and context-dependent roles that can be either tumor suppressive or oncogenic. Most well studied as a transcriptional target of the p53 tumor suppressor protein, there are other means by which p21 levels can be regulated. In this study, we show that pharmacological inhibition or siRNA-mediated reduction of O-GlcNAc transferase (OGT), the enzyme responsible for glycosylation of intracellular proteins, increases expression of p21 in both p53-dependent and p53-independent manners in nontransformed and cancer cells. In cells harboring WT p53, we demonstrate that inhibition of OGT leads to p53-mediated transactivation of CDKN1A, while in cells that do not express p53, inhibiting OGT leads to increased p21 protein stabilization. p21 is normally degraded by the ubiquitin-proteasome system following ubiquitination by, among others, the E3 ligase Skp-Cullin-F-box complex; however, in this case, we show that blocking OGT causes impairment of the Skp-Cullin-F-box ubiquitin complex as a result of disruption of the FoxM1 transcription factor–mediated induction of Skp2 expression. In either setting, we conclude that p21 levels induced by OGT inhibition correlate with cell cycle arrest and decreased cancer cell proliferation.

The role of phosphoinositide 3-kinases in immune-inflammatory responses: potential therapeutic targets for abdominal aortic aneurysm

The pathogenesis of abdominal aortic aneurysm (AAA) includes inflammatory responses, matrix metalloproteinases (MMPs) degradation, VSMC apoptosis, oxidative stress, and angiogenesis, among which the inflammatory response plays a key role. At present, surgery is the only curing treatment, and no effective drug can delay AAA progression in clinical practice. Therefore, searching for a signaling pathway related to the immune-inflammatory response is an essential direction for developing drugs targeting AAA. Recent studies have confirmed that the PI3K family plays an important role in many inflammatory diseases and is involved in regulating various cellular functions, especially in the immune-inflammatory response. This review focuses on the role of each isoform of PI3K in each stage of AAA immune-inflammatory response, making available explorations for a deeper understanding of the mechanism of inflammation and immune response during the formation and development of AAA.

l-Asparaginase synergizes with etoposide via the PI3K/Akt/mTOR pathway in Epstein-Barr virus-positive Burkitt lymphoma

Burkitt lymphoma (BL) is an aggressive Epstein-Barr virus (EBV)-driven B-cell lymphoma characterized by the translocation and rearrangement of the c-Myc proto-oncogene. High-intensity multidrug chemotherapy regimens have a limited effect on the survival of refractory or relapsed BL patients, mainly owing to the high EBV load and drug resistance. l-asparaginase ( l-Asp) and etoposide (VP-16) play a beneficial role in EBV-related lymphoproliferative diseases; however, their roles and mechanisms in BL remain unclear. In this study, we found that VP-16 inhibited BL cell proliferation and arrested the cell cycle at the G₂ /M phase. It also induced autophagy and activated the extrinsic and intrinsic apoptotic signaling pathways in BL cells. Mechanistically, VP-16 inhibited c-Myc expression and regulated the PI3K/Akt/mTOR signaling pathway. Notably, VP-16 also showed a specific synergistic effect with l-Asp to induce apoptosis in EBV-positive BL cells but not in EBV-negative BL cells. VP-16 combined with l-Asp further inhibited c-Myc expression and downregulated the PI3K/Akt/mTOR signaling pathway. Additionally, we found that VP-16 inhibited the expression of latent membrane protein 1 (LMP1), and in combination with l-Asp further decreased LMP1 expression in Raji cells. Our in vivo data also showed that the dual-drug combination significantly inhibited the growth of BL tumors and prolonged the survival of mice compared to VP-16 alone. In conclusion, this study provides new evidence that l-Asp may enhance the antitumor effect of VP-16 by inhibiting the PI3K/Akt/mTOR signaling pathway in EBV-positive BL cells.

Revisiting the Function of p21CDKN1A in DNA Repair: The Influence of Protein Interactions and Stability

The p21CDKN1A protein is an important player in the maintenance of genome stability through its function as a cyclin-dependent kinase inhibitor, leading to cell-cycle arrest after genotoxic damage. In the DNA damage response, p21 interacts with specific proteins to integrate cell-cycle arrest with processes such as transcription, apoptosis, DNA repair, and cell motility. By associating with Proliferating Cell Nuclear Antigen (PCNA), the master of DNA replication, p21 is able to inhibit DNA synthesis. However, to avoid conflicts with this process, p21 protein levels are finely regulated by pathways of proteasomal degradation during the S phase, and in all the phases of the cell cycle, after DNA damage. Several lines of evidence have indicated that p21 is required for the efficient repair of different types of genotoxic lesions and, more recently, that p21 regulates DNA replication fork speed. Therefore, whether p21 is an inhibitor, or rather a regulator, of DNA replication and repair needs to be re-evaluated in light of these findings. In this review, we will discuss the lines of evidence describing how p21 is involved in DNA repair and will focus on the influence of protein interactions and p21 stability on the efficiency of DNA repair mechanisms.

Targeting Cell Cycle Progression in HER2+ Breast Cancer: An Emerging Treatment Opportunity

The development of HER2-targeted therapies has dramatically improved patient survival and patient management and increased the quality of life in the HER2+ breast cancer patient population. Due to the activation of compensatory pathways, patients eventually suffer from resistance to HER2-directed therapies and develop a more aggressive disease phenotype. One of these mechanisms is the crosstalk between ER and HER2 signaling, especially the CDK4/6-Cyclin D-Rb signaling axis that is commonly active and has received attention for its potential role in regulating tumor progression. CDK 4/6 inhibitors interfere with the binding of cell-cycle-dependent kinases (CDKs) with their cognate partner cyclins, and forestall the progression of the cell cycle by preventing Rb phosphorylation and E2F release that consequentially leads to cancer cell senescence. CDK 4/6 inhibitors, namely, palbociclib, ribociclib, and abemaciclib, in combination with anti-estrogen therapies, have shown impressive outcomes in hormonal receptor-positive (HR+) disease and have received approval for this disease context. As an extension of this concept, preclinical/clinical studies incorporating CDK 4/6 inhibitors with HER2-targeted drugs have been evaluated and have shown potency in limiting tumor progression, restoring therapeutic sensitivity, and may improving the management of the disease. Currently, several clinical trials are examining the synergistic effects of CDK 4/6 inhibitors with optimized HER2-directed therapies for the (ER+/-) HER2+ population in the metastatic setting. In this review, we aim to interrogate the burden of HER2+ disease in light of recent treatment progress in the field and examine the clinical benefit of CDK 4/6 inhibitors as a replacement for traditional chemotherapy to improve outcomes in HER2+ breast cancer.

The Profile of MicroRNA Expression and Potential Role in the Regulation of Drug-Resistant Genes in Doxorubicin and Topotecan Resistant Ovarian Cancer Cell Lines

Epithelial ovarian cancer has the highest mortality among all gynecological malignancies. The main reasons for high mortality are late diagnosis and development of resistance to chemotherapy. Resistance to chemotherapeutic drugs can result from altered expression of drug-resistance genes regulated by miRNA. The main goal of our study was to detect differences in miRNA expression levels in two doxorubicin (DOX)- and two topotecan (TOP)-resistant variants of the A2780 drug-sensitive ovarian cancer cell line by miRNA microarray. The next aim was to recognize miRNAs as factors responsible for the regulation of drug-resistance genes. We observed altered expression of 28 miRNA that may be related to drug resistance. The upregulation of miR-125b-5p and miR-935 and downregulation of miR-218-5p was observed in both DOX-resistant cell lines. In both TOP-resistant cell lines, we noted the overexpression of miR-99a-5p, miR-100-5p, miR-125b-5p, and miR-125b-2-3p and decreased expression of miR-551b-3p, miR-551b-5p, and miR-383-5p. Analysis of the targets suggested that expression of important drug-resistant genes such as the collagen type I alpha 2 chain (COL1A2), protein Tyrosine Phosphatase Receptor Type K (PTPRK), receptor tyrosine kinase—EPHA7, Roundabout Guidance Receptor 2 (ROBO2), myristoylated alanine-rich C-kinase substrate (MARCK), and the ATP-binding cassette subfamily G member 2 (ABCG2) can be regulated by miRNA.

2-Pyridin-4-yl-methylene-beta-boswellic Acid-A Potential Candidate for Targeting O6-Methylguanine-DNA Methyltransferase Epi-transcriptional Reprogramming in KRAS G13D-Microsatellite Stable, G12V-Microsatellite Instable Mutant Colon Cancer

PMBA (2-Pyridin-4-yl-methylene-beta-boswellic acid), screened from among the 21 novel series of semisynthetic analogues of β-boswellic acid, is being presented as a lead compound for integrative management of KRAS mutant colorectal cancer (CRC), upon testing and analysis for its anticancerous activity on a panel of NCI-60 cancer cell lines and in vivo models of the disease. PMBA (1.7-29 μM) exhibited potent proliferation inhibition on the cell lines and showed sensitivity in microsatellite instability and microsatellite stable (GSE39582 and GSE92921) subsets of KRAS gene (Kirsten rat sarcoma viral oncogene homolog)-mutated colon cell lines, as revealed via flow cytometry analysis. A considerable decrease in mitogen-activated protein kinase pathway downstream effectors was observed in the treated cell lines via the western blot and STRING (Search tool for the retrieval of interacting genes/proteins) analysis. PMBA was further found to target KRAS at its guanosine diphosphate site. Treatment of the cell lines with PMBA showed significant reduction in MGMT promoter methylation but restored MGMT (O⁶-methylguanine-DNA methyltransferase) messenger ribonucleic acid expression via significant demethylation of the hypermethylated CpG (Cytosine phosphate guanine) sites in the MGMT promoter. A significant decrease in dimethylated H3K9 (Dimethylation of lysine 9 on histone 3) levels in the MGMT promoter in DNA hypo- and hypermethylated HCT-116^G13D and SW-620^G12V cells was observed after treatment. In the MNU (N-methyl-N-nitrosourea)-induced CRC in vivo model, PMBA instillation restricted and repressed polyp formation, suppressed tumor proliferation marker Ki67 (Marker of proliferation), ablated KRAS-associated cytokine signaling, and decreased mortality. Clinical trial data for the parent molecule revealed its effectiveness against the disease, oral bioavailability, and system tolerance. Comprehensively, PMBA represents a new class of KRAS inhibitors having a therapeutic window in the scope of a drug candidate. The findings suggest that the PMBA analogue could inhibit the growth of human CRC in vivo through downregulation of cancer-associated biomarkers as well as reactivate expression of the MGMT gene associated with increased H3K9 acetylation and H3K4 methylation with facilitated transcriptional activation, which might be important in silencing of genes associated with upregulation in the activity of KRAS.

Inhibitory effects on HepG2 cell proliferation and induction of cell cycle arrest by Chromolaena odorata leaf extract and fractions

Concern about the side effects of liver cancer treatment has driven studies on anticancer to find compounds from plants that can act as chemotherapy. The anticancer activity of Chromolaena odorata against colorectal cancer, lung cancer, leukemia, cervical cancer, breast cancer, and liver cancer has been proven. However, this plant’s mechanism that can inhibit liver cancer cell growth is still undetermined. This study aims to investigate the anticancer activity of C. odorata against HepG2 cells. Extraction of C. odorata leaves was done by maceration method using 80% ethanol and further fractionated. Total flavonoid and major compound of the crude extract were determined by aluminum chloride colorimetric assay and Liquid Chromatography-Mass Spectrometry method. The IC50 and proliferation analysis was performed by MTT assay. Cell cycle was analyzed by using flowcytometry. Total flavonoid of 1.95% and compounds such as 5,7,8,3ʹ,4ʹ-Pentamethoxyflavonone, 1-Carboethoxy-β-carboline, 3-Methylcanthin-2, 6- dion, Canthin-6-one were found in C. odorata. The proliferation of HepG2 was significantly lower after 72 hours of incubation with ½ IC50 of C. odorata fractions. HepG2 cells treated with C. odorata extract and fractions were accumulated in the G0-G1 phase. These results indicated that C. odorata leaves could inhibit the proliferation of HepG2 cells and induce cell cycle arrest.