The CNS microenvironment promotes leukemia cell survival by disrupting tumor suppression and cell cycle regulation in pediatric T-cell acute lymphoblastic leukemia

A major obstacle in improving survival in pediatric T-cell acute lymphoblastic leukemia is understanding how to predict and treat leukemia relapse in the CNS. Leukemia cells are capable of infiltrating and residing within the CNS, primarily the leptomeninges, where they interact with the microenvironment and remain sheltered from systemic treatment. These cells can survive in the CNS, by hijacking the microenvironment and disrupting normal functions, thus promoting malignant transformation. While the protective effects of the bone marrow niche have been widely studied, the mechanisms behind leukemia infiltration into the CNS and the role of the CNS niche in leukemia cell survival remain unknown. We identified a dysregulated gene expression profile in CNS infiltrated T-ALL and CNS relapse, promoting cell survival, chemoresistance, and disease progression. Furthermore, we discovered that interactions between leukemia cells and human meningeal cells induced epigenetic alterations, such as changes in histone modifications, including H3K36me3 levels. These findings are a step towards understanding the molecular mechanisms promoting leukemia cell survival in the CNS microenvironment. Our results highlight genetic and epigenetic alterations induced by interactions between leukemia cells and the CNS niche, which could potentially be utilized as biomarkers to predict CNS infiltration and CNS relapse.

Characterization of KLHL14 anti-oncogenic action in malignant mesothelioma

Malignant mesothelioma (MM) is a very aggressive neoplasia with a short life expectancy and limited therapeutic options. Thus, the identification of novel molecular targets is a matter of great urgency. Kelch-like (KLHL) proteins play an important role in a number of physiological and pathological cell-regulatory processes. Among this family, the function of KLHL14 is still very poorly characterized. KLHL14 was originally identified as a gene involved in regulating the epithelial-mesenchymal transition (EMT) process. Here, we demonstrate that KLHL14 not only prevents EMT but also plays an anti-oncogenic role in MM. Indeed, KLHL14 depletion enhanced proliferation, motility, invasion and colony formation in MM cells. Importantly, we also demonstrated that KLHL14 mechanism of action is dependent on Transforming Growth Factor β (TGF-β). In fact, TGF-β promotes de novo synthesis, increases protein stability and induces nuclear-cytoplasmic shuttling of KLHL14. Collectively, this research is an important step further to decipher KLHLs mechanism of action and further contributes to the understanding of the molecular mechanisms regulating MM.

NT157 exhibits antineoplastic effects by targeting IRS and STAT3/5 signaling in multiple myeloma

Multiple myeloma (MM) is a prevalent hematological malignancy with high recurrence and no definitive cure. The current study revisits the role of the IGF1/IGF1R axis in MM, introducing a novel inhibitor, NT157. The IGF1/IGF1R pathway is pivotal in MM, influencing cell survival, proliferation, and migration and impacting patient survival outcomes. NT157 targets intracellular proteins such as IRS and STAT proteins and demonstrates antineoplastic potential in hematological malignancies and solid tumors. In the present study, we assessed IGF1R signaling-related gene expression in MM patients and healthy donors, unveiling significant distinctions. MM cell lines displayed varying expression patterns of IGF1R-related proteins. A gene dependence analysis indicated the importance of targeting receptor and intracellular elements over autocrine IGF1. NT157 exhibited inhibitory effects on MM cell viability, clonal growth, cell cycle progression, and survival. Moreover, NT157 reduced IRS2 expression and STAT3, STAT5, and RPS6 activation and modulated oncogenes and tumor suppressors, fostering a tumor-suppressive molecular profile. In summary, our study demonstrates that the IGF1/IGF1R/IRS signaling axis is differentially activated in MM cells and the NT157's capacity to modulate crucial molecular targets, promoting antiproliferative effects and apoptosis in MM cells. NT157 may offer a multifaceted approach to enhance MM therapy.

Berberine chloride suppresses pancreatic adenocarcinoma proliferation and growth by targeting inflammation-related genes: an in silico analysis with in vitro and vivo validation

PURPOSE

Targeting inflammatory crosstalk between tumors and their microenvironment has emerged as a crucial method for suppressing pancreatic adenocarcinoma (PAAD) progression. Berberine (BBR) is a natural pentacyclic isoquinoline alkaloid known for its anti-inflammatory and antitumor pharmacological effects; however, the mechanism underlying PAAD suppression remains unclear. We aim to investigate the effects of BBR on PAAD progression and their underlying mechanisms.

METHODS

The prognostic value of inflammation-related genes in PAAD was assessed using bioinformatics analyses, then the pharmacological effects and potential mechanisms of BBR on PAAD will be investigated in silico, in vitro, and in vivo.

RESULTS

Fifty-eight prognostic inflammation-related genes were identified in PAAD, which were shown to have good sensitivity and specificity using a novel inflammation-related gene risk-prognosis prediction model. Among these, four candidate genes (CAPS3, PTGS2, ICAM1, and CXCR4) were predicted as targets of BBR in PAAD in silico. Molecular docking simulations showed that the four key targets docked well with BBR. Further BBR treatment suppressed cell proliferation, colony formation, and induced cell cycle arrest in vitro. Moreover, BBR exhibited a significant tumor-suppressive effect in murine subcutaneous xenografts without macroscopic hepatic and renal toxicities. In addition, BBR downregulated CAPS3, PTGS2, ICAM1, and CXCR4 protein expression.

CONCLUSION

This study not only elucidated the prognostic value of inflammation-related genes in PAAD but also demonstrated the potential of BBR to inhibit PAAD by targeting these genes.

A glimpse into let-7e roles in human disorders; friend or foe?

MicroRNAs (miRNAs) have been linked to abnormal expression and regulation in a number of diseases, including cancer. Recent studies have concentrated on miRNA Let-7e's significance in precision medicine for cancer screening and diagnosis as well as its prognostic and therapeutic potential. Differential let-7e levels in bodily fluids have the possibility to enable early detection of cancer utilizing less-invasive techniques, reducing biopsy-related risks. Although Let-7e miRNAs have been described as tumor suppressors, it is crucial to note that there exists proof to support their oncogenic activity in vitro and in in vivo. Let-7e's significance in chemo- and radiation treatment decisions has also been demonstrated. Let-7e can also prevent the synthesis of proinflammatory cytokines in a number of degenerative disorders, including musculoskeletal and neurological conditions. For the first time, an overview of the significance of let-7e in the prevention, detection, and therapy of cancer and other conditions has been given in the current review. Additionally, we focused on the specific molecular processes that underlie the actions of let-7e, more particularly, on malignant cells.

Tumor-isolated Cutibacterium acnes as an effective tumor suppressive living drug

The two major challenges in cancer treatment are reducing the side effects and minimizing the cost of cancer treatment. A better therapy to treat cancer remains to be developed despite the presence of many therapeutic options. Here, we present bacterial therapy for treating cancer using tumor-isolated Cutibacterium acnes, which is safe to use, has minimal side effects compared to chemotherapeutic drugs, and most importantly, targets the tumor microenvironment due to the bacterium's anaerobic nature. It activates the immune system, and the immune cells effectively penetrate through the tumor tissue and form an immunologic hub inside, explicitly targeting the tumor and destroying the cells. This bacterial therapy is a new cost-effective innovative treatment.

Role of long pentraxin PTX3 in cancer

Cancer has become a leading cause of death and disease burden worldwide, closely related to rapid socioeconomic development. However, the fundamental reason is the lack of comprehensive understanding of the mechanism of cancer, accurate identification of preclinical cancer, and effective treatment of the disease. Therefore, it is particularly urgent to study specific mechanisms of cancer and develop effective prediction and treatment methods. Long Pentraxin PTX3 is a soluble pattern recognition molecule produced by various cells in inflammatory sites, which plays a role as a promoter or suppressor of cancer in multiple tumors through participating in innate immune response, neovascularization, energy metabolism, invasion, and metastasis mechanisms. Based on this, this article mainly reviews the role of PTX3 in various cancers.

The E3 ubiquitin ligase CHIP drives monoubiquitylation-mediated nuclear import of the tumor suppressor PTEN

Monoubiquitylation is a principal mechanism driving nuclear translocation of the protein PTEN (phosphatase and tensin homolog deleted on chromosome ten). In this study, we describe a novel mechanism wherein the protein CHIP (C-terminus of Hsc70-interacting protein) mediates PTEN monoubiquitylation, leading to its nuclear import. Western blot analysis revealed a rise in both nuclear and total cellular PTEN levels under monoubiquitylation-promoting conditions, an effect that was abrogated by silencing CHIP expression. We established time-point kinetics of CHIP-mediated nuclear translocation of PTEN using immunocytochemistry and identified a role of karyopherin α1 (KPNA1) in facilitating nuclear transport of monoubiquitylated PTEN. We further established a direct interaction between CHIP and PTEN inside the nucleus, with CHIP participating in either polyubiquitylation or monoubiquitylation of nuclear PTEN. Finally, we showed that oxidative stress enhanced CHIP-mediated nuclear import of PTEN, which resulted in increased apoptosis, and decreased cell viability and proliferation, whereas CHIP knockdown counteracted these effects. To the best of our knowledge, this is the first report elucidating non-canonical roles for CHIP on PTEN, which we establish here as a nuclear interacting partner of CHIP.

Violation of molecular structure of intracellular water as a possible cause of carcinogenesis and its suppression by microwave radiation(hypothesis)

The manuscript discusses a possible hypothesis about the transformation of healthy cells into cancer cells as a result of modification of the molecular structure of intracellular water from normal hexagonal to abnormal cubic phase (which may be caused by radiation, chemical, viral, mechanical and microbiological factors) and the possibility of returning to its original state under the influence of microwave radiation. The authors are not aware of any relevant experimental and theoretical support for this hypothesis in other literature.Our hypothesis is based on a completely unexpected experimental fact that we have received. It turned out that the radio spectra of cancer-affected tissues and the cubic phase of water are identical which confirms that these tissues really contain a cubic phase of water. It should be expected that the use of radiation of "therapeutic" frequencies may lead to regression of tumor growth. This assumption is based on another experimental fact confirming the possibility of the transition of the molecular structure of water from the cubic phase to the hexagonal phase (which is contained in healthy tissues) when irradiated with therapeutic frequencies.The conducted experiments demonstrate the real possibilities of structural-phase and spectral mutual transformations of the water medium under the influence of extremely low intensity flows of microwaves at "therapeutic" frequencies of 1000 MHz and 985 MHz or "pathologic" frequencies of 990 MHz and 51 GHz. The aim of this study was to experimentally verify a possible causal relationship between the violation of the molecular structure of intracellular water in healthy tissues and carcinogenesis.

Self-assembled porphyrin-based photosensitizer nanomicelles for enhanced photodynamic therapy

Preparation of a supermacromolecular photosensitizer that can stay in the tumor site and exhibits high photoconversion efficiency is useful for improving the efficacy of tumor photodynamic therapy (PDT). In this paper, we prepared tetratroxaminobenzene porphyrin (TAPP) loaded biodegradable silk nanospheres (NSs) and characterized their morphology, optical properties and the singlet oxygen-generating capacity. On this basis, the effect of in vitro photodynamic killing efficacy by as-prepared nanometer micelles was evaluated and the tumor retention ability and tumor killing effect of the nanometer micelles were verified by the co-culture of photosensitizer micelle and tumor cells. The results show that tumor cells were killed well under 660 nm laser irradiation even at a lower concentration of as-prepared TAPP NSs. In addition, due to the excellent safety of as-prepared nanomicelle, they exhibit great potential applications in improved tumor PDT.

In vivo anti-tumor activity of Lignosus rhinocerus TM02® using a MCF7-xenograft NCr nude mice model

ETHNOPHARMACOLOGICAL RELEVANCE

Lignosus rhinocerus (Cooke) Ryvarden (also known as Tiger Milk mushroom, TMM), is a basidiomycete belonging to the Polyporaceae family. It has been documented to be used by traditional Chinese physicians and indigenous people in Southeast Asia to treat a variety of illnesses, such as gastritis, arthritis, and respiratory conditions, as well as to restore patients' physical well-being. TMM has also been used in folk medicine to treat cancer. For example, people from the indigenous Kensiu tribe of northeast Kedah (Malaysia) apply shredded TMM sclerotium mixed with water directly onto breast skin to treat breast cancer, while Chinese practitioners from Hong Kong, China prescribe TMM sclerotium as a treatment for liver cancer. L. rhinocerus has previously been demonstrated to possess selective anti-proliferative properties in vitro, however pre-clinical in vivo research has not yet been conducted.

AIM OF STUDY

This study aimed to examine the anti-tumor activities of L. rhinocerus TM02®, using two different sample preparations [cold water extract (CWE) and fraction] via various routes of administration (oral and intraperitoneal) on an MCF7-xenograft nude mouse model. This study also investigated the inhibitory effect of TM02® CWE and its fractions against COX-2 in vitro using LPS-induced RAW264.7 macrophages, on the basis of the relationship between COX-2 and metastasis, apoptosis resistance, as well as the proliferation of cancer cells.

MATERIALS AND METHODS

The first preparation, L. rhinocerus TM02® sclerotium powder (TSP) was dissolved in cold water to obtain the cold water extract (CWE). It was further fractionated based on its molecular weight to obtain the high (HMW), medium (MMW) and low (LMW) molecular weight fractions. The second preparation, known as the TM02® rhinoprolycan fraction (TRF), was obtained by combining the HMW and MMW fractions. TSP was given orally to mimic the daily consumption of a supplement; TRF was administered intraperitoneally to mimic typical tumorous cancer treatment with a rapid and more thorough absorption through the peritoneal cavity. Another experiment was conducted to examine changes in COX-2 activity in LPS-induced RAW264.7 macrophages after a 1-h pre-treatment with CWE, HMW, and MMW.

RESULTS

Our results revealed that intraperitoneal TRF-injection (90 μg/g BW) for 20 days reduced initial tumor volume by ∼64.3% (n = 5). The percentage of apoptotic cells was marginally higher in TRF-treated mice vs. control, suggesting that induction of apoptosis as one of the factors that led to tumor shrinkage. TSP (500 μg/g BW) oral treatment (n = 5) for 63 days (inclusive of pre-treatment prior to tumor inoculation) effectively inhibited tumor growth. Four of the five tumors totally regressed, demonstrating the effectiveness of TSP ingestion in suppressing tumor growth. Although no significant changes were found in mouse serum cytokines (TNF-α, IL-5, IL-6 and CCL2), some increasing and decreasing trends were observed. This may suggest the immunomodulatory potential of these treatments that can directly or indirectly affect tumor growth. Pre-treatment with CWE, HMW and MMW significantly reduced COX-2 activity in RAW264.7 macrophages upon 24 h LPS-stimulation, suggesting the potential of L. rhinocerus TM02® extract and fractions in regulating M1/M2 polarization.

CONCLUSION

Based on the findings of our investigation, both the rhinoprolycan fraction and crude sclerotial powder from L. rhinocerus TM02® demonstrated tumor suppressive effects, indicating that they contain substances with strong anticancer potential. The antitumor effects of L. rhinocerus TM02® in our study highlights the potential for further explorations into its mechanism of action and future development as a prophylactic or adjunct therapeutic against tumorous cancer.

Lactate oxidase/catalase-displaying nanoparticles efficiently consume lactate in the tumor microenvironment to effectively suppress tumor growth

The aggressive proliferation of tumor cells often requires increased glucose uptake and excessive anaerobic glycolysis, leading to the massive production and secretion of lactate to form a unique tumor microenvironment (TME). Therefore, regulating appropriate lactate levels in the TME would be a promising approach to control tumor cell proliferation and immune suppression. To effectively consume lactate in the TME, lactate oxidase (LOX) and catalase (CAT) were displayed onto Aquifex aeolicus lumazine synthase protein nanoparticles (AaLS) to form either AaLS/LOX or AaLS/LOX/CAT. These complexes successfully consumed lactate produced by CT26 murine colon carcinoma cells under both normoxic and hypoxic conditions. Specifically, AaLS/LOX generated a large amount of H₂O₂ with complete lactate consumption to induce drastic necrotic cell death regardless of culture condition. However, AaLS/LOX/CAT generated residual H₂O₂, leading to necrotic cell death only under hypoxic condition similar to the TME. While the local administration of AaLS/LOX to the tumor site resulted in mice death, that of AaLS/LOX/CAT significantly suppressed tumor growth without any severe side effects. AaLS/LOX/CAT effectively consumed lactate to produce adequate amounts of H₂O₂ which sufficiently suppress tumor growth and adequately modulate the TME, transforming environments that are favorable to tumor suppressive neutrophils but adverse to tumor-supportive tumor-associated macrophages. Collectively, these findings showed that the modular functionalization of protein nanoparticles with multiple metabolic enzymes may offer the opportunity to develop new enzyme complex-based therapeutic tools that can modulate the TME by controlling cancer metabolism.

Zinc finger myeloid Nervy DEAF-1 type (ZMYND) domain containing proteins exert molecular interactions to implicate in carcinogenesis

Morphogenesis and organogenesis in the low organisms have been found to be modulated by a number of proteins, and one of such factor, deformed epidermal auto-regulatory factor-1 (DEAF-1) has been initially identified in Drosophila. The mammalian homologue of DEAF-1 and structurally related proteins have been identified, and they formed a family with over 20 members. The factors regulate gene expression through association with co-repressors, recognition of genomic marker, to exert histone modification by catalyze addition of some chemical groups to certain amino acid residues on histone and non-histone proteins, and degradation host proteins, so as to regulate cell cycle progression and execution of cell death. The formation of fused genes during chromosomal translocation, exemplified with myeloid transforming gene on chromosome 8 (MTG8)/eight-to-twenty one translocation (ETO) /ZMYND2, MTG receptor 1 (MTGR1)/ZMYND3, MTG on chromosome 16/MTGR2/ZMYND4 and BS69/ZMYND11 contributes to malignant transformation. Other anomaly like copy number variation (CNV) of BS69/ZMYND11 and promoter hyper methylation of BLU/ZMYND10 has been noted in malignancies. It has been reported that when fusing with Runt-related transcription factor 1 (RUNX1), the binding of MTG8/ZMYND2 with co-repressors is disturbed, and silencing of BLU/ZMYND10 abrogates its ability to inhibition of cell cycle and promotion of apoptotic death. Further characterization of the implication of ZMYND proteins in carcinogenesis would enhance understanding of the mechanisms of occurrence and early diagnosis of tumors, and effective antitumor efficacy.

The complexity of p53-mediated metabolic regulation in tumor suppression

Although the classic activities of p53 including induction of cell-cycle arrest, senescence, and apoptosis are well accepted as critical barriers to cancer development, accumulating evidence suggests that loss of these classic activities is not sufficient to abrogate the tumor suppression activity of p53. Numerous studies suggest that metabolic regulation contributes to tumor suppression, but the mechanisms by which it does so are not completely understood. Cancer cells rewire cellular metabolism to meet the energetic and substrate demands of tumor development. It is well established that p53 suppresses glycolysis and promotes mitochondrial oxidative phosphorylation through a number of downstream targets against the Warburg effect. The role of p53-mediated metabolic regulation in tumor suppression is complexed by its function to promote both cell survival and cell death under different physiological settings. Indeed, p53 can regulate both pro-oxidant and antioxidant target genes for complete opposite effects. In this review, we will summarize the roles of p53 in the regulation of glucose, lipid, amino acid, nucleotide, iron metabolism, and ROS production. We will highlight the mechanisms underlying p53-mediated ferroptosis, AKT/mTOR signaling as well as autophagy and discuss the complexity of p53-metabolic regulation in tumor development.

A common pathway to cancer: Oncogenic mutations abolish p53 oscillations

The tumor suppressor p53 oscillates in response to DNA double-strand breaks, a behavior that has been suggested to be essential to its anti-cancer function. Nearly all human cancers have genetic alterations in the p53 pathway; a number of these alterations have been shown to be oncogenic by experiment. These alterations include somatic mutations and copy number variations as well as germline polymorphisms. Intriguingly, they exhibit a mixed pattern of interactions in tumors, such as co-occurrence, mutual exclusivity, and paradoxically, mutual antagonism. Using a differential equation model of p53-Mdm2 dynamics, we employ Hopf bifurcation analysis to show that these alterations have a common mode of action, to abolish the oscillatory competence of p53, thereby, we suggest, impairing its tumor suppressive function. In this analysis, diverse genetic alterations, widely associated with human cancers clinically, have a unified mechanistic explanation of their role in oncogenesis.

Directing ricin-based immunotoxins with targeting affibodies and KDEL signal peptide to cancer cells effectively induces apoptosis and tumor suppression

The plant toxin ricin, especially its cytotoxic A chain (RTA), can be genetically engineered with targeting ligands to develop specific anti-cancer recombinant immunotoxins (RITs). Here, we used affibody molecules targeting two cancer biomarkers, the receptors HER2 and EGFR, along with the KDEL signal peptide to construct two cancer-specific ricin-based RITs, HER2Afb-RTA-KDEL and EGFRAfb-RTA-KDEL. The affibodies successfully provided target-specificity and subsequent receptor-mediated endocytosis and the KDEL signal peptide routed the RITs through the retrograde transport pathway, effectively delivering RTA to the cytosol as well as avoiding the alternate recycling pathway that typical cancer cells frequently have. The in vivo efficacy of RITs was enhanced by introducing the albumin binding domain (AlBD) to construct AlBD/HER2Afb/RTA-KDEL. Systemic administration of AlBD-containing RITs to tumor-bearing mice significantly suppressed tumor growth without any noticeable side-effects. Collectively, combining target-selective affibody molecules, a cytotoxic RTA, and an intracellularly designating peptide, we successfully developed cancer-specific and efficacious ricin-based RITs. This approach can be applied to develop novel protein-based “magic bullets” to effectively suppress tumors that are resistant to conventional anti-cancer drugs.

Oncogenic gain of function due to p53 amyloids by aberrant alteration of cell cycle and proliferation

Transcription factor p53 has been shown to aggregate into cytoplasmic/nuclear inclusions, compromising its native tumor suppressive functions. Recently, p53 is shown to form amyloids, which play a role in conferring cancerous properties to cells leading to tumorigenesis. However, the exact pathways involved in p53 amyloid-mediated cellular transformations are unknown. Here, using an in cellulo model of full-length p53 amyloid formation, we demonstrate the mechanism of loss of p53 tumor-suppressive function with concomitant oncogenic gain-of functions. Global gene expression profiling of cells suggests that p53 amyloid formation dysregulates the genes associated with cell cycle, proliferation, apoptosis, senescence along with major signaling pathways. This is further supported by the proteome analysis, showing a significant alteration in levels of p53 target proteins and enhanced metabolism, which enables the survival of cells. Our data indicate that specifically targeting the key molecules in pathways affected by p53 amyloid formation such as cyclin-dependent kinase-1, leads to loss of oncogenic phenotype and induces apoptosis of cells. Overall, our work establishes the mechanism of the transformation of cells due to p53 amyloids leading to cancer pathogenesis.

Innovative mouse models for the tumor suppressor activity of Protocadherin-10 isoforms

Background

Nonclustered mouse protocadherin genes (Pcdh) encode proteins with a typical single ectodomain and a cytoplasmic domain with conserved motifs completely different from those of classic cadherins. Alternative splice isoforms differ in the size of these cytoplasmic domains. In view of the compelling evidence for gene silencing of protocadherins in human tumors, we started investigations on Pcdh functions in mouse cancer models.

Methods

For Pcdh10, we generated two mouse lines: one with floxed exon 1, leading to complete Pcdh10 ablation upon Cre action, and one with floxed exons 2 and 3, leading to ablation of only the long isoforms of Pcdh10. In a mouse medulloblastoma model, we used GFAP-Cre action to locally ablate Pcdh10 in combination with Trp53 and Rb1 ablation. From auricular tumors, that also arose, we obtained tumor-derived cell lines, which were analyzed for malignancy in vitro and in vivo. By lentiviral transduction, we re-expressed Pcdh10 cDNAs. RNA-Seq analyses were performed on these cell families.

Results

Surprisingly, not only medulloblastomas were generated in our model but also tumors of tagged auricles (pinnae). For both tumor types, ablation of either all or only long isoforms of Pcdh10 aggravated the disease. We argued that the perichondrial stem cell compartment is at the origin of the pinnal tumors. Immunohistochemical analysis of these tumors revealed different subtypes. We obtained several pinnal-tumor derived (PTD) cell lines and analyzed these for anchorage-independent growth, invasion into collagen matrices, tumorigenicity in athymic mice. Re-expression of either the short or a long isoform of Pcdh10 in two PTD lines counteracted malignancy in all assays. RNA-Seq analyses of these two PTD lines and their respective Pcdh10-rescued cell lines allowed to identify many interesting differentially expressed genes, which were largely different in the two cell families.

Conclusions

A new mouse model was generated allowing for the first time to examine the remarkable tumor suppression activity of protocadherin-10 in vivo. Despite lacking several conserved motifs, the short isoform of Pcdh10 was fully active as tumor suppressor. Our model contributes to scrutinizing the complex molecular mechanisms of tumor initiation and progression upon PCDH10 silencing in many human cancers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09381-y.

Histone deacetylase inhibitors inhibit cervical cancer growth through Parkin acetylation-mediated mitophagy

Parkin, an E3 ubiquitin ligase, plays a role in maintaining mitochondrial homeostasis through targeting damaged mitochondria for mitophagy. Accumulating evidence suggests that the acetylation modification of the key mitophagy machinery influences mitophagy level, but the underlying mechanism is poorly understood. Here, our study demonstrated that inhibition of histone deacetylase (HDAC) by treatment of HDACis activates mitophagy through mediating Parkin acetylation, leading to inhibition of cervical cancer cell proliferation. Bioinformatics analysis shows that Parkin expression is inversely correlated with HDAC2 expression in human cervical cancer, indicating the low acetylation level of Parkin. Using mass spectrometry, Parkin is identified to interact with two upstream molecules, acetylase acetyl-CoA acetyltransferase 1 (ACAT1) and deacetylase HDAC2. Under treatment of suberoylanilide hydroxamic acid (SAHA), Parkin is acetylated at lysine residues 129, 220 and 349, located in different domains of Parkin protein. In in vitro experiments, combined mutation of Parkin largely attenuate the interaction of Parkin with PTEN induced putative kinase 1 (PINK1) and the function of Parkin in mitophagy induction and tumor suppression. In tumor xenografts, the expression of mutant Parkin impairs the tumor suppressive effect of Parkin and decreases the anticancer activity of SAHA. Our results reveal an acetylation-dependent regulatory mechanism governing Parkin in mitophagy and cervical carcinogenesis, which offers a new mitophagy modulation strategy for cancer therapy.

Metabolic installation of macrophage-recruiting glycan ligand on tumor cell surface for in vivo tumor suppression

Synthetic probes that could direct immune cells against tumors are potential immunotherapeutics. We herein report in vivo tumor suppression via an intravenously injected abiotic sialic acid (TCCSia) that could be metabolically incorporated into tumor cell surface to yield of a high affinity ligand (TCCSiaα2,3-Gal) of Siglec-1 specifically expressed on macrophages. We observed marked suppression of pulmonary metastasis and subcutaneous tumor growth of B16F10 melanoma cells in mice with TCCSia, suggesting the utility of abiotic sialic acid to modulate tumor immunity via recruiting Siglec+ immune cells.

Multiple subcellular localizations and functions of protein kinase Cδ in liver cancer

Protein kinase Cδ (PKCδ) is a member of the PKC family, and its implications have been reported in various biological and cancerous processes, including cell proliferation, cell death, tumor suppression, and tumor progression. In liver cancer cells, accumulating reports show the bi-functional regulation of PKCδ in cell death and survival. PKCδ function is defined by various factors, such as phosphorylation, catalytic domain cleavage, and subcellular localization. PKCδ has multiple intracellular distribution patterns, ranging from the cytosol to the nucleus. We recently found a unique extracellular localization of PKCδ in liver cancer and its growth factor-like function in liver cancer cells. In this review, we first discuss the structural features of PKCδ and then focus on the functional diversity of PKCδ based on its subcellular localization, such as the nucleus, cell surface, and extracellular space. These findings improve our knowledge of PKCδ involvement in the progression of liver cancer.

Epigenetic-Mediated Regulation of Gene Expression for Biological Control and Cancer: Cell and Tissue Structure, Function, and Phenotype

Epigenetic gene regulatory mechanisms play a central role in the biological control of cell and tissue structure, function, and phenotype. Identification of epigenetic dysregulation in cancer provides mechanistic into tumor initiation and progression and may prove valuable for a variety of clinical applications. We present an overview of epigenetically driven mechanisms that are obligatory for physiological regulation and parameters of epigenetic control that are modified in tumor cells. The interrelationship between nuclear structure and function is not mutually exclusive but synergistic. We explore concepts influencing the maintenance of chromatin structures, including phase separation, recognition signals, factors that mediate enhancer-promoter looping, and insulation and how these are altered during the cell cycle and in cancer. Understanding how these processes are altered in cancer provides a potential for advancing capabilities for the diagnosis and identification of novel therapeutic targets.

Epigenetic-Mediated Regulation of Gene Expression for Biological Control and Cancer: Fidelity of Mechanisms Governing the Cell Cycle

The cell cycle is governed by stringent epigenetic mechanisms that, in response to intrinsic and extrinsic regulatory cues, support fidelity of DNA replication and cell division. We will focus on (1) the complex and interdependent processes that are obligatory for control of proliferation and compromised in cancer, (2) epigenetic and topological domains that are associated with distinct phases of the cell cycle that may be altered in cancer initiation and progression, and (3) the requirement for mitotic bookmarking to maintain intranuclear localization of transcriptional regulatory machinery to reinforce cell identity throughout the cell cycle to prevent malignant transformation.

Photoreactive-proton-generating hyaluronidase/albumin nanoparticles-loaded PEG-hydrogel enhances antitumor efficacy and disruption of the hyaluronic acid extracellular matrix in AsPC-1 tumors

Depletion of tumor extracellular matrix (ECM) is viewed as a promising approach to enhance the antitumor efficacy of chemotherapeutic-loaded nanoparticles. Hyaluronidase (HAase) destroys hyaluronic acid-based tumor ECM, but it is active solely at acidic pHs of around 5.0 and is much less active at physiological pH. Herein, we report the development of our novel UV-light-reactive proton-generating and hyaluronidase-loaded albumin nanoparticles (o-NBA/HAase-HSA-NPs). The method to prepare the nanoparticles was based on pH-jump chemistry using o-nitrobenzaldehyde (o-NBA) in an attempt to address the clinical limitation of HAase. When in suspension/PEG-hydrogel and irradiated with UV light, the prepared o-NBA/HAase-HSA-NPs clearly reduced the pH of the surrounding medium to as low as 5.0 by producing protons and were better able to break down HA-based tumor cell spheroids (AsPC-1) and HA-hydrogel/microgels, presumably due to the enhanced HA activity at a more optimal pH. Moreover, when formulated as an intratumor-injectable PEG hydrogel, the o-NBA/HAase-HSA-NPs displayed significantly enhanced tumor suppression when combined with intravenous paclitaxel-loaded HSA-NPs (PTX-HSA-NPs) in AsPC-1 tumor-bearing mice: The tumor volume in mice administered UV-activated o-NBA/HAase-HSA-NPs and PTX-HSA-NPs was 198.2 ​± ​30.0 ​mm³, whereas those administered PBS or non-UV-activated o-NBA/HAase-HSA-NPs and PTX-HSA-NPs had tumor volumes of 1230.2 ​± ​256.2 and 295.4 ​± ​17.1 ​mm³, respectively. These results clearly demonstrated that when administered with paclitaxel NPs, our photoreactive o-NBA/HAase-HSA-NPs were able to reduce pH and degrade HA-based ECM, and thereby significantly suppress tumor growth. Consequently, we propose our o-NBA/HAase-HSA-NPs may be a prototype for development of future nanoparticle-based HA-ECM-depleting tumor-ablating agents.

Synergistic effects of autophagy/mitophagy inhibitors and magnolol promote apoptosis and antitumor efficacy

Mitochondria as a signaling platform play crucial roles in deciding cell fate. Many classic anticancer agents are known to trigger cell death through induction of mitochondrial damage. Mitophagy, one selective autophagy, is the key mitochondrial quality control that effectively removes damaged mitochondria. However, the precise roles of mitophagy in tumorigenesis and anticancer agent treatment remain largely unclear. Here, we examined the functional implication of mitophagy in the anticancer properties of magnolol, a natural product isolated from herbal Magnolia officinalis. First, we found that magnolol induces mitochondrial depolarization, causes excessive mitochondrial fragmentation, and increases mitochondrial reactive oxygen species (mtROS). Second, magnolol induces PTEN-induced putative kinase protein 1 (PINK1)‒Parkin-mediated mitophagy through regulating two positive feedforward amplification loops. Third, magnolol triggers cancer cell death and inhibits neuroblastoma tumor growth via the intrinsic apoptosis pathway. Moreover, magnolol prolongs the survival time of tumor-bearing mice. Finally, inhibition of mitophagy by PINK1/Parkin knockdown or using inhibitors targeting different autophagy/mitophagy stages significantly promotes magnolol-induced cell death and enhances magnolol's anticancer efficacy, both in vitro and in vivo. Altogether, our study demonstrates that magnolol can induce autophagy/mitophagy and apoptosis, whereas blockage of autophagy/mitophagy remarkably enhances the anticancer efficacy of magnolol, suggesting that targeting mitophagy may be a promising strategy to overcome chemoresistance and improve anticancer therapy.

Installation of high-affinity Siglec-1 ligand on tumor surface for macrophage-engaged tumor suppression

Siglecs that binds cell surface sialoglycans are a family of immunomodulatory receptors, of which, Siglec-7 expressed on natural killer (NK) cells promotes tumor immunoevation while the role of Siglec-1 expressed on macrophages on tumor development remains largely unexplored. Herein, we selectively introduced high affinity sialoside ligands of Siglec-1 and Siglec-7 to tumor cell surface via in vivo Strain-promoted Azide-Alkyne cyclization of ^TCCSiaα2,3-Lactose or ^FITCSiaα2,6-Lactose with 9-azido sialic acid (^AzSia) metabolically installed on tumor cell surface. We found that ^TCCSiaα2,3-Lactose conjugated on tumor surface moderately inhibited tumor growth while ^FITCSiaα2,6-Lactose promote tumor growth. These results suggest high-affinity ligand of Siglec-1 dispalyed on tumors surface provide a new perspective for tumor immunotherapy.

The tumor suppression theory of aging

Despite continued increases in human life expectancy, the factors determining the rate of human biological aging remain unknown. Without understanding the molecular mechanisms underlying aging, efforts to prevent aging are unlikely to succeed. The tumor suppression theory of aging introduced here proposes somatic mutation as the proximal cause of aging, but postulates that oncogenic transformation and clonal expansion, not functional impairment, are the relevant consequences of somatic mutation. Obesity and caloric restriction accelerate and decelerate aging due to their effect on cell proliferation, during which most mutations arise. Most phenotypes of aging are merely tumor-suppressive mechanisms that evolved to limit malignant growth, the dominant age-related cause of death in early and middle life. Cancer limits life span for most long-lived mammals, a phenomenon known as Peto's paradox. Its conservation across species demonstrates that mutation is a fundamental but hard limit on mammalian longevity. Cell senescence and apoptosis and differentiation induced by oncogenes, telomere shortening or DNA damage evolved as a second line of defense to limit the tumorigenic potential of clonally expanding cells, but accumulating senescent cells, senescence-associated secretory phenotypes and stem cell exhaustion eventually cause tissue dysfunction and the majority, if not most, phenotypes of aging.

The complexities of PKCα signaling in cancer

Protein kinase C α (PKCα) is a ubiquitously expressed member of the PKC family of serine/threonine kinases with diverse functions in normal and neoplastic cells. Early studies identified anti-proliferative and differentiation-inducing functions for PKCα in some normal tissues (e.g., regenerating epithelia) and pro-proliferative effects in others (e.g., cells of the hematopoietic system, smooth muscle cells). Additional well documented roles of PKCα signaling in normal cells include regulation of the cytoskeleton, cell adhesion, and cell migration, and PKCα can function as a survival factor in many contexts. While a majority of tumors lose expression of PKCα, others display aberrant overexpression of the enzyme. Cancer-related mutations in PKCα are uncommon, but rare examples of driver mutations have been detected in certain cancer types (e. g., choroid gliomas). Here we review the role of PKCα in various cancers, describe mechanisms by which PKCα affects cancer-related cell functions, and discuss how the diverse functions of PKCα contribute to tumor suppressive and tumor promoting activities of the enzyme. We end the discussion by addressing mutations and expression of PKCα in tumors and the clinical relevance of these findings.

Metabolic regulation of cell competition

Cell Competition is a selective process by which viable cells are eliminated from developing or adult tissues by interactions with their neighbors. In many cases, the eliminated cells (losers) display reduced fitness, yet they would be able to sustain tissue growth or maintenance in a homotypic environment, and are only eliminated when confronted with surrounding wild type cells (winners). In addition, cells with oncogenic mutations that do not show reduced fitness can also be eliminated from tissues when surrounded by wild type cells. Depending on the context, transformed cells can also become supercompetitors and eliminate surrounding wild type cells, thereby promoting tumor formation. Several factors have been shown to play essential roles in Cell Competition, including genes relevant in developmental growth, tumor formation and epithelial apico-basal polarity. Recent discoveries, however, suggest that energy metabolism plays a central role in very different models of cell competition. Here we review the involvement of mitochondrial dynamics and metabolism, autophagy and nutritional status in cell competition and discuss the possible implications of this emerging field.

The human VRK1 chromatin kinase in cancer biology

VRK1 is a nuclear Ser-Thr chromatin kinase that does not mutate in cancer, and is overexpressed in many types of tumors and associated with a poor prognosis. Chromatin VRK1 phosphorylates several transcription factors, including p53, histones and proteins implicated in DNA damage response pathways. In the context of cell proliferation, VRK1 regulates entry in cell cycle, chromatin condensation in G2/M, Golgi fragmentation, Cajal body dynamics and nuclear envelope assembly in mitosis. This kinase also controls the initial chromatin relaxation associated with histone acetylation, and the non-homologous-end joining (NHEJ) DNA repair pathway, which involves sequential steps such as γH2AX, NBS1 and 53BP1 foci formation, all phosphorylated by VRK1, in response to ionizing radiation or chemotherapy. In addition, VRK1 can be an alternative target for therapies based on synthetic lethality strategies. Therefore, VRK1 roles on proliferation have a pro-tumorigenic effect. Functions regulating chromatin stability and DNA damage responses have a protective anti-tumor role in normal cells, but in tumor cells can also facilitate resistance to genotoxic treatments.

p21WAF1/CIP1 promotes p53 protein degradation by facilitating p53-Wip1 and p53-Mdm2 interaction

Downregulation of the p53 tumor suppressor in cancers is frequently accompanied by the upregulation of Wip1 (a phosphatase) and Mdm2 (an E3 ubiquitin ligase). Mdm2 binds and ubiquitinates p53, promoting its degradation by the proteasome. As the p53/Mdm2 interaction is alleviated by the phosphorylation of the serine-15 (S15) residue of p53, Wip1, which can directly dephosphorylate phospho-S15, facilitates the Mdm2-mediated degradation of p53. Here, we found that p21^WAF1/CIP1, previously shown to bind p53 and Mdm2, reduces the cellular levels of p53 protein by decreasing its stability. This is accompanied by a decrease in p53-S15 phosphorylation levels. In agreement, p21 promotes the p53/Wip1 interaction. Additionally, p21 interacts with Wip1, forming a trimeric complex of p53, p21, and Wip1. Studies using a p21 deletion mutant that cannot bind p53 revealed that the p53/p21 complex is more efficient than p53 alone in facilitating the binding of p53 to Wip1 and Mdm2. These findings indicate that p21 is a novel negative regulator of p53 stability and therefore, may be used as a target to restore p53 activity by preventing the action of Wip1 and Mdm2 on p53.

Purification and Characterization of a Novel Fibrinolytic Enzyme from Cipangopaludina Cahayensis

Background:

Cipangopaludina cahayensis contains active fibrinolytic proteins and has been considered a potential anti-cancer agent. However, its anti-cancer characteristics and functions have yet to be elucidated

Objectives:

To study the fibrinolytic activity and anticancer activity of crude protein extracts from Cipangopaludina cahayensis.

Materials and Methods:

Crude proteases were separated and extracted from the Cipangopaludina cahayensis through homogenization, desalting, ammonium sulfate fractionation, dialysis, and ion exchange chromatography. The fibrinolytic activity of extracted proteins was assessed using the fiber plate method. Total protein concentrations of the crude proteases were determined via BCA assay. Molecular weights (MWs) were determined through SDS-PAGE electrophoresis.

Results:

The crude extract had a MW of ~ 50 kDa, and the highest protein concentration was 3.026 mg.mL^-1. The optimum pH for fibrinolytic activity was 7.0. Cell culture assays demonstrated that the addition of the crude enzyme extracts to the human ovary cancer cell line Ovcar-3 resulted in significant growth defects.

Conclusions:

Our data showed that crude proteins purified from Cipangopaludina cahayensis are novel fibrinolytic proteases and have potential anti-cancer propertie

Two sides of the same coin: Insights into the myoepithelial cells in carcinoma ex pleomorphic adenoma development

The myoepithelial cell seems to play an important role as a tumor suppressor in the development of carcinoma ex pleomorphic adenoma. Nevertheless, interesting aspects concerning the other side of the coin, i.e., the contribution of the myoepithelial cell to cell proliferation, were brought to light. Here we highlighted the studies in which myoepithelial cells were presented as tumor suppressors and promoters in the context of PA malignant transformation. In conclusion, even if in a paracrine way, divergent signals can alter the suppressor role of the myoepithelial cell and induce it to compose a microenvironment propitious to the tumor progression of the malignant cells. This would cause myoepithelial cells to succumb and malignant epithelial cells to initiate progression beyond the basal membrane.

Anticancer Actions of Azurin and Its Derived Peptide p28

Cancers are a great threat to humans. In cancer therapy, surgical removal of the tumor combined with radiotherapy and chemotherapy is the most routine treatment procedure and usually the most effective. However, radiotherapy and chemotherapy drugs that kill cancer cells efficiently also kill normal cells, thus exhibiting large side effects. Cancer-targeted drugs, which aim to specifically recognize proteins or signaling pathways associated with tumor proliferation and migration, have achieved marked progress in recent years. Azurin is a copper-containing redox protein secreted by Pseudomonas aeruginosa. Azurin and its derived peptide p28 preferentially enter a variety of cancer cells and induce apoptosis or cell cycle arrest. Mechanistic studies revealed that azurin and p28 target the p53 and receptor tyrosine kinase signaling pathways as well as other pathways. Two phase I trials of p28 have been carried out, with findings that p28 is safe and exhibits anticancer activity in both adult and pediatric patients. In this review paper, we provide an up-to-date summary of progress on the anticancer mechanisms and therapeutic strategies for azurin and p28.

A comprehensive review of tumor proliferative and suppressive role of semaphorins and therapeutic approaches

Semaphorins have been traditionally known as axon guidance proteins that negatively regulate axonal growth. However, in the past couple of decades, their versatile role in so many other biological processes has come to prominence as well. One such example is their role in cancer. In this review article, the focus was on the tumor proliferative and tumor suppressive role of all 20 semaphorin family members under the 7 semaphorin classes found in vertebrates and invertebrates as well as the ongoing and emerging therapeutic approaches to combat semaphorin-mediated cancers. Except sema6C, 19 of the 20 non-viral semaphorin family members have been discovered to be associated with cancer in one way or another. Eleven semaphorin family members have been discovered to be tumor proliferative and 8 to be tumor suppressive. Six therapeutic avenues and their safety profiles have been discussed which are currently at use or at the various stages of development. Finally, perspectives on which approach is the best for treating cancers associated with semaphorins have been given.

Simultaneous impact of atorvastatin and mesenchymal stem cells for glioblastoma multiform suppression in rat glioblastoma multiform model

Glioblastoma multiform (GBM) is known as an aggressive glial neoplasm. Recently incorporation of mesenchymal stem cells with anti-tumor drugs have been used due to lack of immunological responses and their easy accessibility. In this study, we have investigated the anti-proliferative and apoptotic activity of atorvastatin (Ator) in combination of mesenchymal stem cells (MSCs) on GBM cells in vitro and in vivo. The MSCs isolated from rats and characterized for their multi-potency features. The anti-proliferative and migration inhibition of Ator and MSCs were evaluated by MTT and scratch migration assays. The annexin/PI percentage and cell cycle arrest of treated C6 cells were evaluated until 72 h incubation. The animal model was established via injection of C6 cells in the brain of rats and subsequent injection of Ator each 3 days and single injection of MSCs until 12 days. The growth rate, migrational phenotype and cell cycle progression of C6 cells decreased and inhibited by the interplay of different factors in the presence of Ator and MSCs. The effect of Ator and MSCs on animal models displayed a significant reduction in tumor size and weight. Furthermore, histopathology evaluation proved low hypercellularity and mitosis index as well as mild invasive tumor cells for perivascular cuffing without pseudopalisading necrosis and small delicate vessels in Ator + MSCs condition. In summary, Ator and MSCs delivery to GBM model provides an effective strategy for targeted therapy of brain tumor.

Comparative eye and liver differentially expressed genes reveal monochromatic vision and cancer resistance in the shortfin mako shark (Isurus oxyrinchus)

The shortfin mako, Isurus oxyrinchus is an oceanic pelagic shark found worldwide in tropical and subtropical waters. However, the understanding of its biology at molecular level is still incipient. We sequenced the messenger RNA isolated from eye and liver tissues. De novo transcriptome yielded a total of 705,940 transcripts. A total of 3774 genes were differentially expressed (DEGs), with 1612 in the eye and 2162 in the liver. Most DEGs in the eye were related to structural and signaling functions, including nonocular and ocular opsin genes, whereas nine out of ten most overexpressed genes in the liver were related to tumor suppression, wound healing, and human diseases. Furthermore, DEGs findings provide insights on the monochromatic shark vision and a repertory of cancer-related genes, which may be insightful to elucidate shark resistance to cancer. Therefore, our results provide valuable sequence resources for future functional and population studies.

Topically applicated curcumin/gelatin-blended nanofibrous mat inhibits pancreatic adenocarcinoma by increasing ROS production and endoplasmic reticulum stress mediated apoptosis

BACKGROUND

Pancreatic adenocarcinoma (PDAC) is one of the most fatal malignancies. Surgical resection supplemented by chemotherapy remains the major therapeutic regimen, but with unavoidable resistance and systemic toxic reaction. Curcumin is a known safe natural compound that can effectively eliminate pancreatic adenocarcinoma cells in vitro, making it a promising candidate for substitution in subsequent chemotherapy. However, due to its extremely low bioavailability caused by its insolubility and circular elimination, curcumin had an unexpectedly modest therapeutic effect in clinical trials.

RESULTS

Here, we electrospun curcumin/gelatin-blended nanofibrous mat to largely improve curcumin's bioavailability by local controlled-release. With characterization by scanning electron microscopy, fluorescence microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and high-performance liquid chromatography, it was revealed that curcumin was uniformly dispersed in the fiber of the mats with nanoscopic dimensions and could be continuously released into the surrounding medium for days. The cancer inhibitory effects of nano-curcumin and underlying mechanisms were further explored by assays using pancreatic adenocarcinoma cell and experiments using xenograft model. The results showed the released nano-curcumin could effectively inhibit pancreatic adenocarcinoma cell proliferation not only in vitro, but more importantly in vivo. This cytotoxic effect of nano-curcumin against pancreatic adenocarcinoma was achieved through provoking the production of intracellular reactive oxygen species and activating endoplasmic reticulum stress, which leads to enhanced cell apoptosis via decreased phosphorylation of signal transducer and activator of transcription 3.

CONCLUSIONS

Clinically, curcumin/gelatin-blended nanofibrous mat could be a promising, secure, efficient and affordable substitutional agent for the elimination of residual cancer cells after tumor resection. Moreover, our strategy to obtain curcumin released from nanofibrous mat may provide a universally applicable approach for the study of the therapeutic effects and molecular mechanisms of other potential medicines with low bioavailability.

Tuning the pharmacokinetics and efficacy of irinotecan (IRI) loaded gelatin nanoparticles through folate conjugation

Gelatin based nanocarriers have major limitation of shorter circulation half-life (t_1/2). Present study addressed this issue by conjugating gelatin with folate followed by nanoprecipitation in presence of polysorbate 80 to form folate attached gelatin nanoparticles (GNP-F). The folic acid was conjugated with gelatin through the formation of amide linkage with a maximum conjugation yield of ~69%. Cryo-SEM analysis indicated that unconjugated gelatin nanoparticles (GNP) and GNP-F were spherical of nearly identical size of ~200 nm. The irinotecan (IRI)-loading efficiency estimated for IRI-GNP and IRI-GNP-F was 6.6 ± 0.42% and 11.2 ± 0.73% respectively and both formulations showed faster release of IRI at acidic pH (~5) than at physiological pH (~7). Further IRI-GNP-F demonstrated significantly higher cytotoxicity in folate receptor (FR)-positive HeLa cells than the unconjugated IRI-GNP nanoparticles confirming active targeting. Subsequently the antitumor activity of above formulations in FR-positive fibrosarcoma (syngeneic) tumor-bearing mice followed the order of IRI-GNP-F > IRI-GNP > free IRI. The pharmacokinetic evaluation of IRI-GNP and IRI-GNP-F revealed that encapsulation of IRI within GNP without folate improved its plasma maximum concentration (C_max). However, folate conjugation of GNP remarkably improved the t_1/2 of IRI. Taken together, folate as a targeting ligand modulates the pharmacokinetic property of IRI loaded GNP to favor active verses passive targeting.

In vitro and in vivo growth inhibition of human cervical cancer cells via human papillomavirus E6/E7 mRNAs' cleavage by CRISPR/Cas13a system

Sustained infection of high-risk human papillomavirus (HR-HPVs), especially HPV16 and HPV18, is a major cause of cervical cancer. E6 and E7 oncoproteins, encoded by the HPV genome, are critical for transformation and maintenance of malignant phenotypes of cervical cancer. Here, we used an emerging programmable clustered regularly interspaced short palindromic repeat (CRISPR)/Cas13a system to cleave HPV 16/18 E6/E7 messenger RNAs (mRNAs). The results showed that customized CRISPR/Cas13a system effectively and specifically knocked down HPV 16/18 E6/E7 mRNAs, inducing growth inhibition and apoptosis in HPV16-positive SiHa and HPV18-positive HeLa Cell lines, but not in HPV-negative C33A cell line. Simultaneously, we detected downregulation of E6/E7 oncoproteins and upregulation of tumor suppressor P53 and RB proteins. In addition, we used subcutaneous xenograft tumor growth assays to find that the weight and volume of tumors in the SiHa-16E6CR1 group knocked down by the CRISPR/Cas13a system were significantly lower than those in the SiHa-VECTOR group lacking crRNA. Our study demonstrated that targeting HPV E6/E7 mRNAs by the CRISPR/Cas13a system may be a candidate therapeutic strategy for HPV-related cervical cancer.

The more the merrier: how homo-oligomerization alters the interactome and function of ribonucleotide reductase

Stereotyped as a nexus of dNTP synthesis, the dual-subunit enzyme - ribonucleotide reductase (RNR) - is coming into view as a paradigm of oligomerization and moonlighting behavior. In the present issue of 'omics', we discuss what makes the larger subunit of this enzyme (RNR-α) so interesting, highlighting its emerging cellular interactome based on its unique oligomeric dynamism that dictates its compartment-specific occupations. Linking the history of the field with the multivariable nature of this exceedingly sophisticated enzyme, we further discuss implications of new data pertaining to DNA-damage response, S-phase checkpoints, and ultimately tumor suppression. We hereby hope to provide ideas for those interested in these fields and exemplify conceptual frameworks and tools that are useful to study RNR's broader roles in biology.

PEGylated lipid bilayer coated mesoporous silica nanoparticles co-delivery of paclitaxel and curcumin leads to increased tumor site drug accumulation and reduced tumor burden

Homogeneous PEGylated lipid bilayer coated highly ordered MSNs (PLMSNs) which were systematically optimized and characterized to co-encapsulate paclitaxel (Tax) and curcumin (Cur) were verified to manifest prolonged and enhanced cytotoxic effect against canine breast cancer cells in our previous study. In this article, we took further study of the pharmacokinetic property, cellular uptake, subcellular localization, in vivo distribution and tumor accumulation ability, and treatment efficacy of the drug delivery system. The results revealed that the delivery system could significantly increase the AUC of two drugs, and the anti-tumor effect showed that both intravenous and intratumoral administration group better controlled the tumor weight than that of other groups (P < .05), and the anti-tumor rates were 58.4% and 58.3% respectively. Cell uptake and localization study showed that PLMSNs could effectively carry drugs into cancer cells with sustained release characteristics. The subcellular localization of PLMSNs was mainly in lysosomes and mitochondria. In vivo fluorescence tracing results showed that PLMSNs could be effectively accumulated in the tumor site. The results revealed that the delivery system could effectively reduce the clinical dosage of drugs and reduce its toxic side effects, effectively carry drugs into cancer cells, and exhibit good targeting characteristics for breast cancer.

YY1 inhibits the migration and invasion of pancreatic ductal adenocarcinoma by downregulating the FER/STAT3/MMP2 signaling pathway

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis and a high mortality rate. The transcription factor YY1 acts as an inhibitor of many types of tumors. We found that YY1 knockdown promoted the invasion and migration of PANC-1 and BxPC-3 cells; FER knockdown partially restored the promotion of pancreatic cancer caused by YY1 knockdown. In vivo experiments yielded the same results. According to luciferase reporter gene, electrophoretic mobility shift (EMSA) and chromatin immunoprecipitation (ChIP) assays, YY1 directly binds to the FER promoter region. Moreover, higher level FER expression results in a worse TNM stage and prognosis for patients with PDAC. Furthermore, by downregulating FER, YY1 inhibits the formation of the STAT3-MMP2 complex, thereby suppressing expression of MMP2 and ultimately inhibiting the migration and invasion of pancreatic cancer. Our study demonstrates that the YY1/FER/STAT3/MMP2 axis is associated with the progression of pancreatic cancer and may provide a new therapeutic target for the treatment of pancreatic cancer.

Upregulation of RUNX1 Suppresses Proliferation and Migration through Repressing VEGFA Expression in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, and occurs in people with chronic liver diseases. Current treatment methods include surgery, transplant, and chemotherapy. Our study demonstrates runt-related transcription factor 1 (RUNX1) as a novel molecule in the initiation and development of HCC, and the role of its interaction with vascular endothelial growth factor A (VEGFA) in HCC. We showed the suppressive role of RUNX1 in the proliferation and migration of hepatocytes. In addition, the repressor RUNX1 functioned as a transcription factor on the promoter of VEGFA to inhibit the expression of VEGFA. Study in the HCC cells demonstrated that the suppression of HCC proliferation and migration was masked in the presence of overexpressed VEGFA. Introduction of RUNX1 into HCC mice model significantly limited the tumor growth. In summary, our study demonstrated that RUNX1 functions as a repressor in the HCC and this suppressive function was dependent on its effect on VEGFA.

Interference with the bromodomain epigenome readers drives p21 expression and tumor senescence

Head and neck cancer (HNSCC) are one of the most common solid malignancies of the world, being responsible for over 350,000 deaths every year. Much of the complications in managing and treating HNSCC advent from the complex genetic and epigenetic landscape of the disease. Emerging information has shown promising results in targeting BRD4, an epigenetic regulator bromodomain that functions as a scaffold for transcription factors at promoters and super-enhancers. Here we show that by disrupting the interaction between BRD4 and histones using the bromodomain inhibitor JQ1, HNSCC cells undergo cell growth arrest followed by cellular senescence. Mechanistically, JQ1 negatively impacted the phosphorylation levels of SIRT1 along with the acetylation levels of mutant p53 (active). In vivo administration of JQ1 resulted in disruption of HNSCC growth along with the activation of cellular senescence, observed by the accumulation of DNA double-strand breaks, p16^ink4, accumulation of senescence-associated beta-galactosidase, and loss of phosphorylated Sirt1^ser47. Furthermore, we also demonstrate that JQ1 was efficient in reducing the population of cancer stem cells from HNSCC xenografts.

Role of long non-coding RNAs in lymphoma: A systematic review and clinical perspectives

Long non-coding RNAs (lncRNAs), are over 200 nucleotides in length, and they rarely act as templates for protein synthesis. Mounting studies have shown that lncRNAs play a crucial regulatory role in various processes that sustain life, such as epigenetic regulation, cell cycle control, splicing, and post-transcriptional regulation. LncRNAs were aberrantly expressed in most hematological malignancies including lymphoma, participating in tumor suppression or promoting oncogenesis and modulating key genes in different pathways. The specific expression patterns of lncRNAs in lymphoma make them good candidates to be used as diagnostic biomarkers or as therapeutic targets. LncRNAs can be targeted by multiple approaches including nucleic acid therapeutics, CRISPR/Cas genome editing techniques, small molecule inhibitors, and gene therapy. Efforts are made to develop therapeutic strategies aimed at targeting lncRNAs, but there are still some avenues to be covered before they can be applied to the clinical treatment of lymphoma.

Loss of ALDH1L1 folate enzyme confers a selective metabolic advantage for tumor progression

ALDH1L1 (cytosolic 10-formyltetrahydrofolate dehydrogenase) is the enzyme in folate metabolism commonly downregulated in human cancers. One of the mechanisms of the enzyme downregulation is methylation of the promoter of the ALDH1L1 gene. Recent studies underscored ALDH1L1 as a candidate tumor suppressor and potential marker of aggressive cancers. In agreement with the ALDH1L1 loss in cancer, its re-expression leads to inhibition of proliferation and to apoptosis, but also affects migration and invasion of cancer cells through a specific folate-dependent mechanism involved in invasive phenotype. A growing body of literature evaluated the prognostic value of ALDH1L1 expression for cancer disease, the regulatory role of the enzyme in cellular proliferation, and associated metabolic and signaling cellular responses. Overall, there is a strong indication that the ALDH1L1 silencing provides metabolic advantage for tumor progression at a later stage when unlimited proliferation and enhanced motility become critical processes for the tumor expansion. Whether the ALDH1L1 loss is involved in tumor initiation is still an open question.

Re-evaluation of the linear no-threshold (LNT) model using new paradigms and modern molecular studies

The linear no-threshold (LNT) model is currently used to estimate low dose radiation (LDR) induced health risks. This model lacks safety thresholds and postulates that health risks caused by ionizing radiation is directly proportional to dose. Therefore even the smallest radiation dose has the potential to cause an increase in cancer risk. Advances in LDR biology and cell molecular techniques demonstrate that the LNT model does not appropriately reflect the biology or the health effects at the low dose range. The main pitfall of the LNT model is due to the extrapolation of mutation and DNA damage studies that were conducted at high radiation doses delivered at a high dose-rate. These studies formed the basis of several outdated paradigms that are either incorrect or do not hold for LDR doses. Thus, the goal of this review is to summarize the modern cellular and molecular literature in LDR biology and provide new paradigms that better represent the biological effects in the low dose range. We demonstrate that LDR activates a variety of cellular defense mechanisms including DNA repair systems, programmed cell death (apoptosis), cell cycle arrest, senescence, adaptive memory, bystander effects, epigenetics, immune stimulation, and tumor suppression. The evidence presented in this review reveals that there are minimal health risks (cancer) with LDR exposure, and that a dose higher than some threshold value is necessary to achieve the harmful effects classically observed with high doses of radiation. Knowledge gained from this review can help the radiation protection community in making informed decisions regarding radiation policy and limits.

Specific delivery of delta-5-desaturase siRNA via RNA nanoparticles supplemented with dihomo-γ-linolenic acid for colon cancer suppression

We have previously demonstrated that DGLA treatment along with Delta-5-Desaturase (D5D) siRNA in various types of cancer cells enhances the formation of 8-HOA from COX-2-catalyzed DGLA peroxidation, which in turn inhibits cancer cell growth and migration. However, delivery of naked siRNA remains a formidable challenge due to its "off-target" effect. In this study, we employed RNA nanotechnology for specific delivery of D5D-siRNA to xenograft colon tumors using 3WJ RNA nanoparticles. When a targeting module, i.e., the EpCAM aptamer, was incorporated, the 3WJ pRNA nanoparticles were able specifically deliver D5D siRNA to human colon cancer HCA-7 cells both in vitro and in vivo, resulting in significant downregulation of D5D expression. Co-treatment with DGLA in combination with 3WJ-EpCAM-siRNA induced a higher DGLA/AA ratio and enhanced formation of 8-HOA at a threshold level, and in HCA-7 tumor-bearing mice, induced significant tumor suppression. We further confirmed that 8-HOA formation, promoted by COX-2-catalyzed DGLA peroxidation, inhibited HDAC and consequently induced apoptosis in tumor cells. Therefore, the 3WJ RNA nanoparticle system holds great promise as a suitable therapeutic delivery platform for colon cancer therapy.

Tumor suppression by the EGR1, DMP1, ARF, p53, and PTEN Network

Recent studies have indicated that EGR1 is a direct regulator of tumor suppressors including TGFβ1, PTEN, and p53. The Myb-like transcription factor Dmp1 is a physiological regulator of the Arf-p53 pathway through transactivation of the Arf promoter and physical interaction of p53. The Dmp1 promoter has binding sites for Egr proteins, and Egr1 is a target for Dmp1. Crosstalks between p53 and PTEN have been reported. The Egr1-Dmp1-Arf-p53-Pten pathway displays multiple modes of interaction with each other, suggesting the existence of a functional network of tumor suppressors that maintain normal cell growth and prevent the emergence of incipient cancer cells.