Isatin-Schiff base-copper (II) complex induces cell death in p53-positive tumors

MDM2 up-regulates the energy metabolism in NSCLC in a p53-independent manner

Although an E3 ligase MDM2 is the major negative regulator of the p53 tumor suppressor, a growing body of evidence suggests its p53-independent oncogenic properties. In particular, MDM2 has been shown to regulate serine metabolism independently of p53 status in several types of neoplasia, including NSCLC. Using the GSEA approach and publicly available molecular data on NSCLC tumors, our bioinformatics data suggest that MDM2 affects a number of metabolic genes, particularly those encoding components of the electron transport chain (ETC). To experimentally elucidate the role of MDM2 in respiration and energy metabolism of NSCLC cell models, we established NSCLC cell lines (WT p53+ A549 and p53-null H1299) overexpressing wild-type MDM2, or its catalytically deficient (C464A) mutant (MUT), or the control vector. Using TMRE staining and SeaHorse energy profiling, we demonstrated that wild-type MDM2, but not its catalytically inactive mutant, significantly increased mitochondrial membrane potential (MMP), glycolysis, respiration, and ATP production in a p53-independent manner. Further, we compared MDM2-associated effects of two natural compounds that, according to our docking experiment data, bind MDM2 with affinities similar to nutlin-3A, ganoderic acid A and berberine. Despite the fact that both nutlin-3A and berberine stabilized the MDM2 protein, they displayed differential effects on energy metabolism. Taken together, our data argue that MDM2 affects energy metabolism likely in a p53-independent manner. These results also highlight another pharmacological dimension of using MDM2-targeting compounds as potent inhibitors of glycolysis and respiration in tumor cells.

p53: The Multifaceted Roles of Covalent Modifications in Cancer

The p53 protein has attracted huge research interest over several decades due to its role as one of the most important tumor suppressors in mammals, which orchestrates a synchronous response from normal cells in the body to various forms of stress. The diverse cellular activities of the p53 protein are regulated mainly via its post-translational modifications (PTMs). PTMs affect p53 on several levels: at the level of the assembly of tetrameric complexes on DNA to transactivate its target genes, at the level of the assembly of tetrameric complexes on DNA to transactivate its target genes; at the level of proteolysis in the absence of stress; and on the contrary, at the level of augmented protein stability in response to stress signals. Disruptions in these regulatory mechanisms can lead to deviations from normal cellular function, boosting tumor initiation and progression. Conversely, targeted interventions in these pathways could prove beneficial for the development of antitumor therapies. Advancing our understanding of p53 modifiers and the proteins involved in its regulation equips researchers with an expanded toolkit for studying cellular processes and for developing biologically active molecules that influence p53-mediated responses.

Lipoxygenases at the Intersection of Infection and Carcinogenesis

The persisting presence of opportunistic pathogens like Pseudomonas aeruginosa poses a significant threat to many immunocompromised cancer patients with pulmonary infections. This review highlights the complexity of interactions in the host's defensive eicosanoid signaling network and its hijacking by pathogenic bacteria to their own advantage. Human lipoxygenases (ALOXs) and their mouse counterparts are integral elements of the innate immune system, mostly operating in the pro-inflammatory mode. Taking into account the indispensable role of inflammation in carcinogenesis, lipoxygenases have counteracting roles in this process. In addition to describing the structure-function of lipoxygenases in this review, we discuss their roles in such critical processes as cancer cell signaling, metastases, death of cancer and immune cells through ferroptosis, as well as the roles of ALOXs in carcinogenesis promoted by pathogenic infections. Finally, we discuss perspectives of novel oncotherapeutic approaches to harness lipoxygenase signaling in tumors.

Aminoquinoline-based Re(I) tricarbonyl complexes: Insights into their antiproliferative activity and mechanisms of action

In an effort to develop new potent anticancer agents, two Schiff base rhenium(I) tricarbonyl complexes, containing the ubiquitous aminoquinoline scaffold, were synthesized. Both aminoquinoline ligands and Re(I) complexes showed adequate stability over a 48-h incubation period. Furthermore, the cytotoxic activity of the precursor ligands and rhenium(I) complexes were evaluated against the hormone-dependent MCF-7 and hormone-independent triple negative MDA-MB-231 breast cancer cell lines. Inclusion of the [Re(CO)3Cl]+ entity significantly enhanced the cytotoxicity of the aminoquinoline Schiff base ligands against the tested cancer cell lines. Remarkably, the incorporation of the Schiff-base iminoquinolyl entity notably enhanced the cytotoxic activity of the Re(I) complexes, in comparison with the iminopyridyl entity. Notably, the quinolyl-substituted complex showed up to three-fold higher activity than cisplatin against breast cancer cell lines, underpinning the significance of the quinoline pharmacophore in rational drug design. In addition, the most active Re(I) complex showed better selectivity towards the breast cancer cells over non-tumorigenic FG-0 cells. Western blotting revealed that the complexes increased levels of γH2AX, a key DNA damage response protein. Moreover, apoptosis was confirmed in both cell lines due to the detection of cleaved PARP. The complexes show favourable binding affinities towards both calf thymus DNA (CT-DNA), and bovine serum albumin (BSA), and the order of their interactions align with their cytotoxic effects. The in silico molecular simulations of the complexes were also performed with CT-DNA and BSA targets.

At the Crossroads of the cGAS-cGAMP-STING Pathway and the DNA Damage Response: Implications for Cancer Progression and Treatment

The evolutionary conserved DNA-sensing cGAS-STING innate immunity pathway represents one of the most important cytosolic DNA-sensing systems that is activated in response to viral invasion and/or damage to the integrity of the nuclear envelope. The key outcome of this pathway is the production of interferon, which subsequently stimulates the transcription of hundreds of genes. In oncology, the situation is complex because this pathway may serve either anti- or pro-oncogenic roles, depending on context. The prevailing understanding is that when the innate immune response is activated by sensing cytosolic DNA, such as DNA released from ruptured micronuclei, it results in the production of interferon, which attracts cytotoxic cells to destroy tumors. However, in tumor cells that have adjusted to significant chromosomal instability, particularly in relapsed, treatment-resistant cancers, the cGAS-STING pathway often supports cancer progression, fostering the epithelial-to-mesenchymal transition (EMT). Here, we review this intricate pathway in terms of its association with cancer progression, giving special attention to pancreatic ductal adenocarcinoma and gliomas. As the development of new cGAS-STING-modulating small molecules and immunotherapies such as oncolytic viruses involves serious challenges, we highlight several recent fundamental discoveries, such as the proton-channeling function of STING. These discoveries may serve as guiding lights for potential pharmacological advancements.

Flaviviruses in AntiTumor Therapy

Oncolytic viruses offer a promising approach to tumor treatment. These viruses not only have a direct lytic effect on tumor cells but can also modify the tumor microenvironment and activate antitumor immunity. Due to their high pathogenicity, flaviviruses have often been overlooked as potential antitumor agents. However, with recent advancements in genetic engineering techniques, an extensive history with vaccine strains, and the development of new attenuated vaccine strains, there has been a renewed interest in the Flavivirus genus. Flaviviruses can be genetically modified to express transgenes at acceptable levels, and the stability of such constructs has been greatly improving over the years. The key advantages of flaviviruses include their reproduction cycle occurring entirely within the cytoplasm (avoiding genome integration) and their ability to cross the blood-brain barrier, facilitating the systemic delivery of oncolytics against brain tumors. So far, the direct lytic effects and immunomodulatory activities of many flaviviruses have been widely studied in experimental animal models across various types of tumors. In this review, we delve into the findings of these studies and contemplate the promising potential of flaviviruses in oncolytic therapies.

Non-Immunoglobulin Synthetic Binding Proteins for Oncology

Extensive application of technologies like phage display in screening peptide and protein combinatorial libraries has not only facilitated creation of new recombinant antibodies but has also significantly enriched repertoire of the protein binders that have polypeptide scaffolds without homology to immunoglobulins. These innovative synthetic binding protein (SBP) platforms have grown in number and now encompass monobodies/adnectins, DARPins, lipocalins/anticalins, and a variety of miniproteins such as affibodies and knottins, among others. They serve as versatile modules for developing complex affinity tools that hold promise in both diagnostic and therapeutic settings. An optimal scaffold typically has low molecular weight, minimal immunogenicity, and demonstrates resistance against various challenging conditions, including proteolysis - making it potentially suitable for peroral administration. Retaining functionality under reducing intracellular milieu is also advantageous. However, paramount to its functionality is the scaffold's ability to tolerate mutations across numerous positions, allowing for the formation of a sufficiently large target binding region. This is achieved through the library construction, screening, and subsequent expression in an appropriate system. Scaffolds that exhibit high thermodynamic stability are especially coveted by the developers of new SBPs. These are steadily making their way into clinical settings, notably as antagonists of oncoproteins in signaling pathways. This review surveys the diverse landscape of SBPs, placing particular emphasis on the inhibitors targeting the oncoprotein KRAS, and highlights groundbreaking opportunities for SBPs in oncology.

Strategies for Engineering of Extracellular Vesicles

Extracellular vesicles (EVs) are membrane vesicles released by cells into the extracellular space. EVs mediate cell-to-cell communication through local and systemic transportation of biomolecules such as DNA, RNA, transcription factors, cytokines, chemokines, enzymes, lipids, and organelles within the human body. EVs gained a particular interest from cancer biology scientists because of their role in the modulation of the tumor microenvironment through delivering bioactive molecules. In this respect, EVs represent an attractive therapeutic target and a means for drug delivery. The advantages of EVs include their biocompatibility, small size, and low immunogenicity. However, there are several limitations that restrict the widespread use of EVs in therapy, namely, their low specificity and payload capacity. Thus, in order to enhance the therapeutic efficacy and delivery specificity, the surface and composition of extracellular vesicles should be modified accordingly. In this review, we describe various approaches to engineering EVs, and further discuss their advantages and disadvantages to promote the application of EVs in clinical practice.

p53 Affects Zeb1 Interactome of Breast Cancer Stem Cells

P53 is a critical tumor suppressor that protects the integrity of genome and prevents cells from malignant transformation, including metastases. One of the driving forces behind the onset of metastases is the epithelial to mesenchymal transition (EMT) program. Zeb1 is one of the key transcription factors that govern EMT (TF-EMT). Therefore, the interaction and mutual influence of p53 and Zeb1 plays a critical role in carcinogenesis. Another important feature of tumors is their heterogeneity mediated by the presence of so-called cancer stem cells (CSCs). To this end, we have developed a novel fluorescent reporter-based approach to enrich the population of CSCs in MCF7 cells with inducible expression of Zeb1. Using these engineered cell lines, we studied the effect of p53 on Zeb1 interactomes isolated from both CSCs and regular cancer cells. By employing co-immunoprecipitations followed by mass spectrometry, we found that the composition of Zeb1 interactome was affected not only by the p53 status but also by the level of Oct4/Sox2 expression, indicating that stemness likely affects the specificity of Zeb1 interactions. This study, together with other proteomic studies of TF-EMT interactomes, provides a framework for future molecular analyses of biological functions of Zeb1 at all stages of oncogenesis.

Metal-Based Anticancer Complexes and p53: How Much Do We Know?

P53 plays a key role in protecting the human genome from DNA-related mutations; however, it is one of the most frequently mutated genes in cancer. The P53 family members p63 and p73 were also shown to play important roles in cancer development and progression. Currently, there are various organic molecules from different structural classes of compounds that could reactivate the function of wild-type p53, degrade or inhibit mutant p53, etc. It was shown that: (1) the function of the wild-type p53 protein was dependent on the presence of Zn atoms, and (2) Zn supplementation restored the altered conformation of the mutant p53 protein. This prompted us to question whether the dependence of p53 on Zn and other metals might be used as a cancer vulnerability. This review article focuses on the role of different metals in the structure and function of p53, as well as discusses the effects of metal complexes based on Zn, Cu, Fe, Ru, Au, Ag, Pd, Pt, Ir, V, Mo, Bi and Sn on the p53 protein and p53-associated signaling.

Methyltransferase Set7/9 as a Multifaceted Regulator of ROS Response

Reactive oxygen species (ROS) induce multiple signaling cascades in the cell and hence play an important role in the regulation of the cell's fate. ROS can cause irreversible damage to DNA and proteins resulting in cell death. Therefore, finely tuned regulatory mechanisms exist in evolutionarily diverse organisms that are aimed at the neutralization of ROS and its consequences with respect to cellular damage. The SET domain-containing lysine methyltransferase Set7/9 (KMT7, SETD7, SET7, SET9) post-translationally modifies several histones and non-histone proteins via monomethylation of the target lysines in a sequence-specific manner. In cellulo, the Set7/9-directed covalent modification of its substrates affects gene expression, cell cycle, energy metabolism, apoptosis, ROS, and DNA damage response. However, the in vivo role of Set7/9 remains enigmatic. In this review, we summarize the currently available information regarding the role of methyltransferase Set7/9 in the regulation of ROS-inducible molecular cascades in response to oxidative stress. We also highlight the in vivo importance of Set7/9 in ROS-related diseases.

BRCA Mutations-The Achilles Heel of Breast, Ovarian and Other Epithelial Cancers

Two related tumor suppressor genes, BRCA1 and BRCA2, attract a lot of attention from both fundamental and clinical points of view. Oncogenic hereditary mutations in these genes are firmly linked to the early onset of breast and ovarian cancers. However, the molecular mechanisms that drive extensive mutagenesis in these genes are not known. In this review, we hypothesize that one of the potential mechanisms behind this phenomenon can be mediated by Alu mobile genomic elements. Linking mutations in the BRCA1 and BRCA2 genes to the general mechanisms of genome stability and DNA repair is critical to ensure the rationalized choice of anti-cancer therapy. Accordingly, we review the literature available on the mechanisms of DNA damage repair where these proteins are involved, and how the inactivating mutations in these genes (BRCAness) can be exploited in anti-cancer therapy. We also discuss a hypothesis explaining why breast and ovarian epithelial tissues are preferentially susceptible to mutations in BRCA genes. Finally, we discuss prospective novel therapeutic approaches for treating BRCAness cancers.

Proteomics revealed the crosstalk between copper stress and cuproptosis, and explored the feasibility of curcumin as anticancer copper ionophore

As an essential micronutrient element in organisms, copper controls a host of fundamental cellular functions. Recently, copper-dependent cell growth and proliferation have been defined as "cuproplasia". Conversely, "cuproptosis" represents copper-dependent cell death, in a nonapoptotic manner. So far, a series of copper ionophores have been developed to kill cancer cells. However, the biological response mechanism of copper uptake has not been systematically analyzed. Based on quantitative proteomics, we revealed the crosstalk between copper stress and cuproptosis in cancer cells, and also explored the feasibility of curcumin as anticancer copper ionophore. Copper stress not only couples with cuproptosis, but also leads to reactive oxygen species (ROS) stress, oxidative damage and cell cycle arrest. In cancer cells, a feedback cytoprotection mechanism involving cuproptosis mediators was discovered. During copper treatment, the activation of glutamine transporters and the loss of Fe-S cluster proteins are the facilitators and results of cuproptosis, respectively. Through copper depletion, glutathione (GSH) blocks the cuproptosis process, rescues the activation of glutamine transporters, and prevents the loss of Fe-S cluster proteins, except for protecting cancer cells from apoptosis, protein degradation and oxidative damage. In addition, the copper ionophore curcumin can control the metabolisms of lipids, RNA, NADH and NADPH in colorectal cancer cells, and also up-regulates positive cuproptosis mediators. This work not only established the crosstalk between copper stress and cuproptosis, but also discolored the suppression and acceleration of cuproptosis by GSH and curcumin, respectively. Our results are significant for understanding cuproptosis process and developing novel anticancer reagents based on cuproptosis.

Design, synthesis, and biological evaluation of new celecoxib analogs as apoptosis inducers and cyclooxygenase-2 inhibitors

Series of new celecoxib analogs were synthesized to assess their anticancer activity against the MCF-7 cell line. Four compounds, 3a, 3c, 5b, and 5c, showed 1.4-9.2-fold more potent anticancer activity than celecoxib. The antiproliferative activity of the most potent compounds, 3c, 5b, and 5c, seems to be associated well with their ability to induce apoptosis in MCF-7 cells (18-24-fold). This evidence was supported by an increase in the expression of the tumor suppressor gene p53 (4-6-fold), the elevation in the Bax/BCL-2 ratio, and a significant increase in the level of active caspase-7 (4-7-fold). Moreover, compounds 3c and 5c showed significant cyclooxygenase-2 (COX-2) inhibitory activity. They were also docked into the crystal structure of the COX-2 enzyme (PDB ID: 3LN1) to understand their mode of binding.

The combined prognostic model of copper-dependent to predict the prognosis of pancreatic cancer

Purpose: To assess the prognostic value of copper-dependent genes, copper-dependent-related genes (CDRG), and CDRG-associated immune-infiltrating cells (CIC) for pancreatic cancer.

Methods: CDRG were obtained by single-cell analysis of the GSE156405 dataset in the Gene Expression Omnibus (GEO) database. In a ratio of 7:3, we randomly divided the Cancer Genome Atlas (TCGA) cohort into a training cohort and a test cohort. Tumor samples from the GSE62452 dataset were used as the validation cohort. CIBERSORT was used to obtain the immune cell infiltration. We identified the prognostic CDRG and CIC by Cox regression and the least absolute selection operator (LASSO) method. The clinical significance of these prognostic models was assessed using survival analysis, immunological microenvironment analysis, and drug sensitivity analysis.

Results: 536 CDRG were obtained by single-cell sequencing analysis. We discovered that elevated LIPT1 expression was associated with a worse prognosis in pancreatic cancer patients. EPS8, CASC8, TATDN1, NT5E, and LDHA comprised the CDRG-based prognostic model. High infiltration of Macrophages.M2 in pancreatic cancer patients results in poor survival. The combined prognostic model showed great predictive performance, with the area under the curve (AUC) values being basically between 0.7 and 0.9 in all three cohorts.

Conclusion: We found a cohort of CDRG and CIC in patients with pancreatic cancer. The combined prognostic model provided new insights into the prognosis and treatment of pancreatic cancer.

PNC-27, a Chimeric p53-Penetratin Peptide Binds to HDM-2 in a p53 Peptide-like Structure, Induces Selective Membrane-Pore Formation and Leads to Cancer Cell Lysis

PNC-27, a 32-residue peptide that contains an HDM-2 binding domain and a cell-penetrating peptide (CPP) leader sequence kills cancer, but not normal, cells by binding to HDM-2 associated with the plasma membrane and induces the formation of pores causing tumor cell lysis and necrosis. Conformational energy calculations on the structure of PNC-27 bound to HDM-2 suggest that 1:1 complexes form between PNC-27 and HDM-2 with the leader sequence pointing away from the complex. Immuno-scanning electron microscopy was carried out with cancer cells treated with PNC-27 and decorated with an anti-PNC-27 antibody coupled to 6 nm gold particles and an anti-HDM-2 antibody linked to 15 nm gold particles. We found multiple 6 nm- and 15 nm-labeled gold particles in approximately 1:1 ratios in layered ring-shaped structures in the pores near the cell surface suggesting that these complexes are important to the pore structure. No pores formed in the control, PNC-27-treated untransformed fibroblasts. Based on the theoretical and immuno-EM studies, we propose that the pores are lined by PNC-27 bound to HDM-2 at the membrane surface with the PNC-27 leader sequence lining the pores or by PNC-27 bound to HDM-2.

Copper in tumors and the use of copper-based compounds in cancer treatment

Copper homeostasis is strictly regulated by protein transporters and chaperones, to allow its correct distribution and avoid uncontrolled redox reactions. Several studies address copper as involved in cancer development and spreading (epithelial to mesenchymal transition, angiogenesis). However, being endogenous and displaying a tremendous potential to generate free radicals, copper is a perfect candidate, once opportunely complexed, to be used as a drug in cancer therapy with low adverse effects. Copper ions can be modulated by the organic counterpart, after complexed to their metalcore, either in redox potential or geometry and consequently reactivity. During the last four decades, many copper complexes were studied regarding their reactivity toward cancer cells, and many of them could be a drug choice for phase II and III in cancer therapy. Also, there is promising evidence of using ⁶⁴Cu in nanoparticles as radiopharmaceuticals for both positron emission tomography (PET) imaging and treatment of hypoxic tumors. However, few compounds have gone beyond testing in animal models, and none of them got the status of a drug for cancer chemotherapy. The main challenge is their solubility in physiological buffers and their different and non-predictable mechanism of action. Moreover, it is difficult to rationalize a structure-based activity for drug design and delivery. In this review, we describe the role of copper in cancer, the effects of copper-complexes on tumor cell death mechanisms, and point to the new copper complexes applicable as drugs, suggesting that they may represent at least one component of a multi-action combination in cancer therapy.

The radioenhancement potential of Schiff base derived copper (II) compounds against lung carcinoma in vitro

For the last years, copper complexes have been intensively implicated in biomedical research as components of cancer treatment. Herewith, we provide highlights of the synthesis, physical measurements, structural characterization of the newly developed Cu(II) chelates of Schiff Bases, Cu(Picolinyl-L-Tryptopahanate)2, Cu(Picolinyl-L-Tyrosinate)2, Cu(Isonicotinyl-L-Tyrosinate)2, Cu(Picolinyl-L-Phenylalaninate)2, Cu(Nicotinyl-L-Phenylalaninate)2, Cu(Isonicotinyl-L-Phenylalaninate)2, and their radioenhancement capacity at kV and MV ranges of irradiation of human lung carcinoma epithelial cells in vitro. The methods of cell growth, viability and proliferation were used. All compounds exerted very potent radioenhancer capacities in the irradiated lung carcinoma cells at both kV and MV ranges in a 100 μM concentration. At a concentration of 10 μM, only Cu(Picolinyl-L-Tyrosinate)2, Cu(Isonicotinyl-L-Tyrosinate)2, Cu(Picolinyl-L-Phenylalaninate)2 possessed radioenhancer properties at kV and MV ranges. Cu(Picolinyl-L-Tryptophanate)2 showed radioenhancer properties only at kV range. Cu(Nicotinyl-L-Phenylalaninate)2 and Cu(Isonicotinyl-L-Phenylalaninate)2 showed remarkable radioenhancer activity only at MV range. All compounds acted in dose-dependent manner at both tested energy ranges. These copper (II) compounds, in combination with 1 Gy irradiation at either 120 kV or 6 MV, are more efficient at delaying cell growth of lung cancer cells and at reducing cell viability in vitro than the irradiation administered alone. Thus, we have demonstrated that the studied copper compounds have a good potential for radioenhancement.

Discovery of Oxazol-2-amine Derivatives as Potent Novel FLT3 Inhibitors

Internal tandem duplication (ITD) of FMS-like tyrosine kinase 3 (FLT3) is the most common mutation in patients with acute myeloid leukemia (AML). FLT3-ITD⁺ induces constitutive activation of FLT3, causing an abnormally rapid proliferation of cancer cells. In this study, we identified novel FLT3 inhibitors and investigated 5-(4-fluorophenyl)-N-phenyloxazol-2-amine (compound 7; 7c) as candidates for the treatment of AML. The results showed that 7c inhibited the activities of FLT3 and mutated FLT3 in a cell-free kinase assay and Molm-13 and MV4-11 cells, as well as the proliferation of FLT3-ITD⁺ AML cells, increasing apoptosis. The anti-leukemic activity of 7c was confirmed by in vivo tumor growth inhibition in MV4-11 xenograft mice. Besides, 7c suppressed the expression of DNA damage repair genes. Combination treatment with 7c and olaparib (a poly (ADP-ribose) polymerase [PARP] inhibitor) synergistically inhibited cell proliferation in Molm-13 and MV4-11 cells. Our findings demonstrated that 7c is a therapeutic candidate targeting FLT3 for AML treatment and suggested that combination treatment with 7c and a PARP inhibitor may be an effective therapy regimen for FLT3-mutated AML.

Enhancement of Cisplatin Cytotoxicity by Cu(II)-Mn(II) Schiff Base Tetradentate Complex in Human Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (SCC) is one of the most predominant tumors worldwide and the present treatment policies are not enough to provide a specific solution. We aimed to assess the cytotoxic effect of Cu(II)–Mn(II) Schiff base tetradentate complex alone or in combination with cisplatin against squamous cell carcinoma cell line (SCCs) in vitro. Oral-derived gingival mesenchymal stem cells (GMSCs) were used as control. The cell viability was assessed by MTT assay. IC50 values were calculated. Evaluation of apoptosis and DNA damage were performed. In addition, the expression of pro-apoptotic and anti-apoptotic genes and proteins were tested. IC50 values indicated less toxicity of the Schiff base complex on GMSCs compared to cisplatin. Schiff base complex treatment resulted in up-regulation of p53 and Bax genes expression and down-regulation of Bcl2 gene expression in SCCs paralleled with increased protein expression of caspase-3 and Bax and down-regulation of Bcl-2 protein. Annexin V-FITC apoptosis kit showed a higher apoptotic effect induced by a Schiff base complex compared to the cisplatin-treated group. These effects were markedly increased on the combination of Schiff base and cisplatin. The present study established that Cu(II)–Mn(II) Schiff base tetradentate complex might induce a cytotoxic effect on SCCs cells via induction of the apoptotic pathway. Moreover, this Schiff base complex augments the anticancer effect of cisplatin.

Cancer predictive studies

The identification of individual or clusters of predictive genetic alterations might help in defining the outcome of cancer treatment, allowing for the stratification of patients into distinct cohorts for selective therapeutic protocols. Neuroblastoma (NB) is the most common extracranial childhood tumour, clinically defined in five distinct stages (1–4 & 4S), where stages 3–4 define chemotherapy-resistant, highly aggressive disease phases. NB is a model for geneticists and molecular biologists to classify genetic abnormalities and identify causative disease genes. Despite highly intensive basic research, improvements on clinical outcome have been predominantly observed for less aggressive cancers, that is stages 1,2 and 4S. Therefore, stages 3–4 NB are still complicated at the therapeutic level and require more intense fundamental research. Using neuroblastoma as a model system, here we herein outline how cancer prediction studies can help at steering preclinical and clinical research toward the identification and exploitation of specific genetic landscape. This might result in maximising the therapeutic success and minimizing harmful effects in cancer patients.

Apatinib sensitizes chemoresistant NSCLC cells to doxetaxel via regulating autophagy and enhances the therapeutic efficacy in advanced and refractory/recurrent NSCLC

The prognosis of advanced non-small cell lung cancer (NSCLC) is poor; therefore, identifying novel treatment strategies for patients with NSCLC is important. The present study aimed to investigate the efficacy of apatinib plus docetaxel vs. docetaxel alone, as well as their effects on regulating autophagy markers in patients with advanced NSCLC. Furthermore, it was evaluated whether apatinib sensitized chemoresistant NSCLC cells to docetaxel via regulating autophagy. A total of 39 patients with advanced NSCLC were consecutively enrolled and treated with apatinib plus docetaxel (n=19) or docetaxel alone (n=20) for four treatment cycles. The treatment response, adverse events and expression levels of autophagy markers [(light chain 3 α (LC3A) and Beclin-1] were evaluated in tumor samples, which were obtained via biopsy, before treatment and after 2-cycle treatment. In addition, in a mechanistic in vitro experiment, apatinib, docetaxel, the autophagy activator rapamycin and the autophagy inhibitor 3-methyladenine (3-MA) were used to treat docetaxel-resistant A549 (A549/DTX) cells alone or in various combinations. The expression levels of LC3A, Beclin-1, poly (ADP) ribose polymerase (PARP) and phosphorylated (p)-AKT were detected via western blotting, while the cell apoptosis rate was detected with an Annexin V/PI assay. The overall remission rate (37 vs. 10%; P=0.047) and disease control rate (84 vs. 45%; P=0.011) were increased in the Apatinib plus docetaxel group compared with the Docetaxel group. Most of the adverse events were mild and tolerable, and there was no difference between the two groups except for total hypertension and hand-foot syndrome, which were higher in the Apatinib plus docetaxel group). Compared with the levels prior to treatment, Beclin-1 and LC3A remained unchanged post-treatment in the Apatinib plus docetaxel group, while they were increased in the Docetaxel group. Docetaxel increased LC3A, Beclin-1 and p-AKT expression levels, PARP cleavage and the cell apoptosis rate in A549/DTX cells, and rapamycin further enhanced, while 3-MA reduced these effects of docetaxel. Moreover, apatinib repressed LC3A, Beclin-1, p-AKT expression levels and promoted the cell apoptosis rate in A549/DTX cells and docetaxel-treated A549/DTX cells. In conclusion, apatinib synergize the effect of docetaxel in treating patients with advanced NSCLC and chemoresistant NSCLC cells via inhibiting autophagy.

Key Players in the Mutant p53 Team: Small Molecules, Gene Editing, Immunotherapy

The transcription factor p53 is a key tumor suppressor that is inactivated in almost all cancers due to either point mutations in the TP53 gene or overexpression of its negative regulators. The p53 protein is known as the “cellular gatekeeper” for its roles in facilitating DNA repair, cell cycle arrest or apoptosis upon DNA damage. Most p53 mutations are missense and result in either structural destabilization of the protein, causing its partial unfolding and deactivation under physiological conditions, or impairment of its DNA-binding properties. Tumor cells with p53 mutations are generally more immunogenic due to “hot spot” neoantigens that instigate the immune system response. In this review, we discuss the key therapeutic strategies targeting mutant p53 tumors, including classical approaches based on small molecule intervention and emerging technologies such as gene editing and T cell immunotherapy.

HMGA2 regulates circular RNA ASPH to promote tumor growth in lung adenocarcinoma

In this study, we identified a circular form of ASPH RNA (circASPH), expression of which was upregulated in lung adenocarcinoma and the human lung adenocarcinoma cell lines. We also found a positive correlation between circASPH level and the T and N stages of lung adenocarcinoma patients. Patients with higher levels of circASPH had a shorter overall survival. Moreover, we demonstrated that circASPH was directly regulated by HMGA2 and Twist1. The direct positive regulation of circASPH by Twist1 was dependent on the presence of HMGA2. Functional assays indicated that circASPH promoted the proliferation, migration, and invasion of lung adenocarcinoma cell lines in vitro. The promoting effect of tumor growth by circASPH was also observed in vivo. Mechanistically, circASPH was identified to act as a molecular sponge for miR-370 and abrogate miR-370-mediated inhibition of HMGA2. Finally, we demonstrated that the oncogenic function of circASPH was HMGA2-dependent. These findings reveal the oncogenic functions of the HMGA2-circASPH-HMGA2 axis and may be useful in developing circRNA-based therapeutic strategies for lung adenocarcinoma.

Therapeutic Editing of the TP53 Gene: Is CRISPR/Cas9 an Option?

The TP53 gene encodes the transcription factor and oncosuppressor p53 protein that regulates a multitude of intracellular metabolic pathways involved in DNA damage repair, cell cycle arrest, apoptosis, and senescence. In many cases, alterations (e.g., mutations of the TP53 gene) negatively affect these pathways resulting in tumor development. Recent advances in genome manipulation technologies, CRISPR/Cas9, in particular, brought us closer to therapeutic gene editing for the treatment of cancer and hereditary diseases. Genome-editing therapies for blood disorders, blindness, and cancer are currently being evaluated in clinical trials. Eventually CRISPR/Cas9 technology is expected to target TP53 as the most mutated gene in all types of cancers. A majority of TP53 mutations are missense which brings immense opportunities for the CRISPR/Cas9 system that has been successfully used for correcting single nucleotides in various models, both in vitro and in vivo. In this review, we highlight the recent clinical applications of CRISPR/Cas9 technology for therapeutic genome editing and discuss its perspectives for editing TP53 and regulating transcription of p53 pathway genes.

Knockdown of Kinase Family 15 Inhibits Cancer Cell Proliferation In vitro and its Clinical Relevance in Triple-Negative Breast Cancer

PURPOSE

Breast cancer is the most prevalent malignancy and the leading cause of death among women. Triple-negative breast cancer (TNBC) is a subtype of breast cancer and shows a distinctly aggressive nature with higher rates of relapse and shorter overall survival in the metastatic setting compared to other subtypes of breast cancer. This study aimed to assess the effect of KIF15 on various clinicopathological characteristics, survival analysis, and cell proliferation in triple-negative breast cancer, which has not been reported to our knowledge.

METHODS

A total of 165 patients with triple-negative breast cancer were enrolled and clinical data were obtained, Mann-Whitney U analysis was performed to assess the correlation between the expression of KIF15 and clinical pathological characteristics of TNBC patients. Survival analysis was performed by Kaplan-Meier analysis and Log-rank test. The expression levels of KIF15 in cancer tissues and adjacent tissues were evaluated via Sign test. Lentivirus was used to down-regulate the expression of KIF15 in TNBC cells. The cell proliferation, colony formation capacity and apoptosis were examined by MTT, Giemsa staining and flow cytometry assay, respectively.

RESULTS

Our results showed that, among the 165 TNBC patients, the expression of KIF15 was positive correlation with clinicopathological features of TNBC. In addition, KIF15 low-expression group showed higher disease-free survival than KIF15 highexpression group and univariate analysis showed that KIF15 high-expression group appeared higher mortality than KIF low-expression group (P ≤ 0.05). Meanwhile, the expression levels of KIF15 in cancer tissue notably up-regulated in comparison with adjacent tissue. In vitro, knockdown of KIF15 significantly promoted cell apoptosis and suppressed cell proliferation and colony formation of TNBC cells.

CONCLUSION

By utilizing survival analysis, we found that high-expression of KIF15 in the TNBC samples were associated with poorer overall survival, while the anti-tumor effect of KIF15 knockdown was also confirmed at the cellular level in vitro. Taken together, KIF15 can be applied as a potential diagnostic and therapeutic target in TNBC.

HOXA5 inhibits the proliferation and neoplasia of cervical cancer cells via downregulating the activity of the Wnt/β-catenin pathway and transactivating TP53

HOXA5 is considered a regulator involved in embryonic development and cellular differentiation and a tumor suppressor. Nevertheless, its biological role in cervical carcinoma is still unclear. In the present study, immunohistochemistry showed that HOXA5 expression gradually decreased as the degree of cervical lesions deepened. Ectopic expression of HOXA5 restrained cell proliferation, decreased cell viability, and inhibited tumor formation in vitro and in vivo. Furthermore, the expression of HOXA5 could arrest cell cycle from G0/G1 to S phase. RNA-seq revealed that p21 and cyclinD1 were involved in this process. Moreover, the gene set enrichment analysis and the TOP/FOP reporter assay both suggested that HOXA5 could restrain the activity of the Wnt/β-catenin pathway. Further study using dual-luciferase reporter assay and quantitative chromatin immunoprecipitation assay demonstrated that HOXA5 could directly bind to the TAAT motif within the promoter of TP53 by its HD domain and transactivate TP53, which can upregulate p21. Altogether, our data suggest that HOXA5 inhibits the proliferation and neoplasia via repression activity of the Wnt/β-catenin pathway and transactivating TP53 in cervical cancer.

Copper homeostasis as target of both consolidated and innovative strategies of anti-tumor therapy

BACKGROUND

Copper was reported to be involved in the onset and progression of cancer. Proteins in charge of copper uptake and distribution, as well as cuproenzymes, are altered in cancer. More recently, proteins involved in signaling cascades, regulating cell proliferation, and anti-apoptotic protein factors were found to interact with copper. Therefore, therapeutic strategies using copper complexing molecules have been proposed for cancer therapy and used in clinical trials.

OBJECTIVES

This review will focus on novel findings about the involvement of copper and cupro-proteins in cancer dissemination process, epithelium to mesenchymal transition and vascularization. Particularly, implication of well-established (e.g. lysil oxidase) or newly identified copper-binding proteins (e.g. MEMO1), as well as their interplay, will be discussed. Moreover, we will describe recently synthesized copper complexes, including plant-derived ones, and their efficacy in contrasting cancer development.

CONCLUSIONS

The research on the involvement of copper in cancer is still an open field. Further investigation is required to unveil the mechanisms involved in copper delivery to the novel copper-binding proteins, which may identify other possible gene and protein targets for cancer therapy.