An overview of targeted cancer therapy

Seven New Cytotoxic and Antimicrobial Xanthoquinodins from Jugulospora vestita

During the course of a screening for novel biologically active secondary metabolites produced by the Sordariomycetes (Ascomycota, Fungi), the ex-type strain of Jugulospora vestita was found to produce seven novel xanthone-anthraquinone heterodimers, xanthoquinodin A11 (1) and xanthoquinodins B10–15 (2–7), together with the already known compound xanthoquinodin B4 (8). The structures of the xanthoquinodins were determined by analysis of the nuclear magnetic resonance (NMR) spectroscopic and mass spectrometric data. Moreover, the absolute configurations of these metabolites were established by analysis of the ¹H−¹H coupling constants, nuclear Overhauser effect spectroscopy (NOESY) correlations, and Electronic Circular Dichroism (ECD) spectroscopic data. Antifungal and antibacterial activities as well as cytotoxicity of all compounds were tested. Xanthoquinodin B11 showed fungicidal activities against Mucor hiemalis [minimum inhibitory concentration (MIC) 2.1 µg/mL], Rhodotorula glutinis (MIC 2.1 µg/mL), and Pichia anomala (MIC 8.3 µg/mL). All the compounds 1–8 displayed anti-Gram-positive bacteria activity (MIC 0.2–8.3 µg/mL). In addition, all these eight compounds showed cytotoxicity against KB 3.1, L929, A549, SK-OV-3, PC-3, A431, and MCF-7 mammalian cell lines. The six novel compounds (1–3, 5–7), together with xanthoquinodin B4, were also found in the screening of other strains belonging to Jugulospora rotula, revealing the potential chemotaxonomic significance of the compound class for the genus.

Analytical Challenges in Development of Chemoresistance Predictors for Precision Oncology

Chemoresistance, i.e., tumor insensitivity to chemotherapy, shortens life expectancy of cancer patients. Despite the availability of new treatment options, initial systemic regimens for solid tumors are dominated by a set of standard chemotherapy drugs, and alternative therapies are used only when a patient has demonstrated chemoresistance clinically. Chemoresistance predictors use laboratory parameters measured on tissue samples to predict the patient's response to chemotherapy and help to avoid application of chemotherapy to chemoresistant patients. Despite thousands of publications on putative chemoresistance predictors, there are only about a dozen predictors that are sufficiently accurate for precision oncology. One of the major reasons for inaccuracy of predictors is inaccuracy of analytical methods utilized to measure their laboratory parameters: an inaccurate method leads to an inaccurate predictor. The goal of this study was to identify analytical challenges in chemoresistance-predictor development and suggest ways to overcome them. Here we describe principles of chemoresistance predictor development via correlating a clinical parameter, which manifests disease state, with a laboratory parameter. We further classify predictors based on the nature of laboratory parameters and analyze advantages and limitations of different predictors using the reliability of analytical methods utilized for measuring laboratory parameters as a criterion. Our eventual focus is on predictors with known mechanisms of reactions involved in drug resistance (drug extrusion, drug degradation, and DNA damage repair) and using rate constants of these reactions to establish accurate and robust laboratory parameters. Many aspects and conclusions of our analysis are applicable to all types of disease biomarkers built upon the correlation of clinical and laboratory parameters.

The study of EGFR-ligand complex electron property relationship with biological activity

The present investigation grounded on estimation of electron properties of the structures of EGFR proteins-ligand complexes using our laboratory-developed methodology AlteQ approach, which describes the molecular electron density of the complex in space for a certain point in three-dimensional coordinates. Briefly, the system embodies molecular electron density as a sum of Slater's type atomic increments of the molecular system. Further, using this methodology, we calculated different electron characteristics of selected EGFR protein-ligand complexes and established the relationship between different electron properties with their experimental pharmacological activity value (pIC₅₀). The study suggested that EGFR inhibitory activity has higher correlation with intermolecular contacts of H with pi-system of aromatic ring between protein and ligands. Therefore, this created model has impact to identify and design potential ligands against EGFR in anticancer drug discovery.Communicated by Ramaswamy H. Sarma.

Ferroptosis: An emerging approach for targeting cancer stem cells and drug resistance

Resistance to chemotherapeutic agents remains a major challenge in the fierce battle against cancer. Cancer stem cells (CSCs) are a small population of cells in tumors that possesses the ability to self-renew, initiate tumors, and cause resistance to conventional anticancer agents. Targeting this population of cells was proven as a promising approach to eliminate cancer recurrence and improve the clinical outcome. CSCs are less susceptible to death by classical anticancer agents inducing apoptosis. CSCs can be eradicated by ferroptosis, which is a non-apoptotic-regulated mechanism of cell death. The induction of ferroptosis is an attractive strategy to eliminate tumors due to its ability to selectively target aggressive CSCs. The current review critically explored the crosstalk and regulatory pathways controlling ferroptosis, which can selectively induce CSCs death. In addition, successful chemotherapeutic agents that achieve better therapeutic outcomes through the induction of ferroptosis in CSCs were discussed to highlight their promising clinical impact.

Combinational treatment of 5-fluorouracil and casticin induces apoptosis in mouse leukemia WEHI-3 cells in vitro

Leukemia is one of the major diseases causing cancer-related deaths in the young population, and its cure rate is unsatisfying with side effects on patients. Fluorouracil (5-FU) is currently used as an anticancer drug for leukemia patients. Casticin, a natural polymethoxyflavone, exerts anticancer activity against many human cancer cell lines in vitro, but no other reports show 5-FU combined with casticin increased the mouse leukemia cell apoptosis in vitro. Herein, the antileukemia activity of 5-FU combined with casticin in WEHI-3 mouse leukemia cells was investigated in vitro. Treatment of two-drug combination had a higher decrease in cell viability and a higher increase in apoptotic cell death, the level of DNA condensation, and the length of comet tail than that of 5-FU or casticin treatment alone in WEHI-3 cells. In addition, the two-drug combination has a greater production rate of reactive oxygen species but a lower level of Ca²⁺ release and mitochondrial membrane potential (ΔΨ_m ) than that of 5-FU alone. Combined drugs also induced higher caspase-3 and caspase-8 activities than that of casticin alone and higher caspase-9 activity than that of 5-FU or casticin alone at 48 hours treatment. Furthermore, 5-FU combined with casticin has a higher expression of Cu/Zn superoxide dismutase (SOD [Cu/Zn]) and lower catalase than that of 5-FU or casticin treatment alone. The combined treatment has higher levels of Bax, Endo G, and cytochrome C of proapoptotic proteins than that of casticin alone and induced lower levels of B-cell lymphoma 2 (BCL-2) and BCL-X of antiapoptotic proteins than that of 5-FU or casticin only. Furthermore, the combined treatment had a higher expression of cleaved poly (ADP-ribose) polymerase (PARP) than that of casticin only. Based on these findings, we may suggest that 5-FU combined with casticin treatment increased apoptotic cell death in WEHI-3 mouse leukemia cells that may undergo mitochondria and caspases signaling pathways in vitro.

Cholangiocarcinoma 2020: the next horizon in mechanisms and management

Cholangiocarcinoma (CCA) includes a cluster of highly heterogeneous biliary malignant tumours that can arise at any point of the biliary tree. Their incidence is increasing globally, currently accounting for ~15% of all primary liver cancers and ~3% of gastrointestinal malignancies. The silent presentation of these tumours combined with their highly aggressive nature and refractoriness to chemotherapy contribute to their alarming mortality, representing ~2% of all cancer-related deaths worldwide yearly. The current diagnosis of CCA by non-invasive approaches is not accurate enough, and histological confirmation is necessary. Furthermore, the high heterogeneity of CCAs at the genomic, epigenetic and molecular levels severely compromises the efficacy of the available therapies. In the past decade, increasing efforts have been made to understand the complexity of these tumours and to develop new diagnostic tools and therapies that might help to improve patient outcomes. In this expert Consensus Statement, which is endorsed by the European Network for the Study of Cholangiocarcinoma, we aim to summarize and critically discuss the latest advances in CCA, mostly focusing on classification, cells of origin, genetic and epigenetic abnormalities, molecular alterations, biomarker discovery and treatments. Furthermore, the horizon of CCA for the next decade from 2020 onwards is highlighted.

CircRNA hsa_circ_0002577 accelerates endometrial cancer progression through activating IGF1R/PI3K/Akt pathway

Background

Endometrial cancer (EC) is a common gynecologic malignancy worldwide. This study investigated the regulatory effects of circular RNA (circRNA) hsa_circ_0002577 on the tumorigenesis of EC.

Methods

Tumor samples and adjacent normal tissues were obtained from 84 EC patients. Recombinant lentiviral vectors expressing hsa_circ_0002577 (Lv-circRNA), short hairpin RNAs against hsa_circ_0002577 (sh-circRNA), miR-625-5p mimics, miR-625-5p inhibitor, lentiviral vectors expressing insulin-like growth factor 1 receptor (IGF1R) and their corresponding controls were transfected into EC cells as designated. A mouse xenograft model was established in BALB/c mice by inoculating Ishikawa cells transfected with sh-circRNA or control sequence.

Results

Hsa_circ_0002577 was upregulated in EC tissue samples and cells as compared to normal controls. EC patients with higher expression of hsa_circ_0002577 showed poorer overall survival and more advanced tumor stage. EC cells transfected with Lv-circRNA showed promoted proliferation, migration, and invasion, whereas the delivery of sh-circRNA exerted an opposite effect. Further analyses showed that hsa_circ_0002577 acted as a miR-625-5p sponge in EC cells. IGF1R was a potential downstream target of miR-625-5p. The expression of IGF1R in EC tissues was significantly higher than that in matched controls. Hsa_circ_0002577 accelerated EC development by inducing IGF1R expression and activating PI3K/Akt signaling pathway. Also, the knockdown of hsa_circ_0002577 delayed tumor growth and metastasis in the inoculated mice.

Conclusion

Our study showed that circRNA hsa_circ_002577 accelerated EC progression by acting as a miR-625-5p sponge, upregulating IGF1R and activating the PI3K/Akt pathway, suggesting the potential therapeutic use of hsa_circ_002577 in EC treatment.

Trial registration

Not Applicable.

Field-controlled magnetoelectric core-shell CoFe2O4@BaTiO3 nanoparticles as effective drug carriers and drug release in vitro

The targeted drug release at tumor cells while sparing normal cells is a huge challenge. Core-shell magnetoelectric (ME) nanoparticles have addressed this problem using shape-dependent magneto-electric attributes. The colloidally stable, core-shell cobalt ferrite@barium titanate (CFO@BTO) ME nanoparticles (NPs) used for in vitro study were synthesized using sonochemical method. The structural characteristics and core-shell morphology were analyzed by X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) respectively. Further magnetic and exchange coupling between two phases of ME nanostructures were studied at room temperature. Colloidal stability was studied in different suspension solutions (Water, SBB, PBS, and DMEM) using dynamic light scattering. Subsequently, the synthesized nanoparticles were functionalized with anticancer drugs including doxorubicin and methotrexate up to 80% via (EDC) chemistry. In vitro cytotoxicity studies carried out on human hepatocellular carcinoma (HepG2) and human malignant melanoma (HT144), cells validated the magneto-electric property of CFO@BTO nano-carriers in the presence of external magnetic field (5 mT), with significantly enhanced cytotoxicity when compared to free drugs and without field replicates. The resulted IC₅₀ values ranging from 5.3-7.3 μg/ml compared to 30.1-43.1 μg/ml in the absence of a magnetic field also confirmed the involved physical attributes of magnetoelectric nanostructures. The fluorescent microscopy results also indicated the increased apoptosis in magnetic field-assisted samples. Finally, hemolysis assay indicated the suitability of CFO@BTO nano-carriers for intravenous applications at IC₅₀ concentration.

PIWIL1 promotes gastric cancer via a piRNA-independent mechanism

Targeted cancer therapy aims to achieve specific elimination of cancerous but not normal cells. Recently, PIWI proteins, a subfamily of the PAZ-PIWI domain (PPD) protein family, have emerged as promising candidates for targeted cancer therapy. PPD proteins are essential for small noncoding RNA pathways. The Argonaute subfamily partners with microRNA and small interfering RNA, whereas the PIWI subfamily partners with PIWI-interacting RNA (piRNA). Both PIWI proteins and piRNA are mostly expressed in the germline and best known for their function in transposon silencing, with no detectable function in mammalian somatic tissues. However, PIWI proteins become aberrantly expressed in multiple types of somatic cancers, thus gaining interest in targeted therapy. Despite this, little is known about the regulatory mechanism of PIWI proteins in cancer. Here we report that one of the four PIWI proteins in humans, PIWIL1, is highly expressed in gastric cancer tissues and cell lines. Knocking out the PIWIL1 gene (PIWIL1-KO) drastically reduces gastric cancer cell proliferation, migration, metastasis, and tumorigenesis. RNA deep sequencing of gastric cancer cell line SNU-1 reveals that KO significantly changes the transcriptome, causing the up-regulation of most of its associated transcripts. Surprisingly, few bona fide piRNAs exist in gastric cancer cells. Furthermore, abolishing the piRNA-binding activity of PIWIL1 does not affect its oncogenic function. Thus, PIWIL1 function in gastric cancer cells is independent of piRNA. This piRNA-independent regulation involves interaction with the UPF1-mediated nonsense-mediated mRNA decay (NMD) mechanism. Altogether, our findings reveal a piRNA-independent function of PIWIL1 in promoting gastric cancer.

Novel 2-indolinone thiazole hybrids as sunitinib analogues: Design, synthesis, and potent VEGFR-2 inhibition with potential anti-renal cancer activity

Novel 2-indolinone thiazole hybrids were designed and synthesized as VEGFR-2 inhibitors based on sunitinib, an FDA-approved anticancer drug. The proposed structures of the prepared 2-indolinone thiazole hybrids were confirmed based on their spectral data and CHN analyses. The target compounds were screened in vitro for their anti-VEGFR-2 activity. All tested compounds exhibited a potent submicromolar inhibition of VEGFR-2 kinase with IC₅₀ values ranging from 0.067 to 0.422 μM, relative to sunitinib reference drug (IC₅₀ = 0.075 ± 0.002 μM). Compounds 5, 15a, 15b, 17, 19c displayed excellent VEGFR-2 inhibitory activity, comparable or nearly equipotent to sunitinib. Compound 13b stood out as the most potent against VEGFR-2 showing IC₅₀ value of 0.067 ± 0.002 μM, lower than that of sunitinib. In addition, the most potent derivatives were assessed for their anticancer activity against two renal cancer cell lines. Compound 13b (IC₅₀ = 3.9 ± 0.13 μM) was more potent than sunitinib (IC₅₀ = 4.93 ± 0.16 μM) against CAKI-1 cell line. Moreover, thiazole 15b displayed excellent anticancer activity against CAKI-1 cell line (IC₅₀ = 3.31 ± 0.11 μM), superior to that of sunitinib (IC₅₀ = 4.93 ± 0.16 μM). Thiazole 15b was also equipotent to sunitinib (IC₅₀ = 1.23 ± 0.04 μM) against A498 cell line. Besides, compound 15b revealed a safety profile much better than that of sunitinib against normal human renal cells. Furthermore, a docking study revealed a proper fitting of the most active compounds into the ATP binding site of VEGFR-2, rationalizing their potent anti-VEGFR-2 activity.

β-radiating radionuclides in cancer treatment, novel insight into promising approach

Targeted radionuclide therapy, known as molecular radiotherapy is a novel therapeutic module in cancer medicine. β-radiating radionuclides have definite impact on target cells via interference in cell cycle and particular signalings that can lead to tumor regression with minimal off-target effects on the surrounding tissues. Radionuclides play a remarkable role not only in apoptosis induction and cell cycle arrest, but also in the amelioration of other characteristics of cancer cells. Recently, application of novel β-radiating radionuclides in cancer therapy has been emerged as a promising therapeutic modality. Several investigations are ongoing to understand the underlying molecular mechanisms of β-radiating elements in cancer medicine. Based on the radiation dose, exposure time and type of the β-radiating element, different results could be achieved in cancer cells. It has been shown that β-radiating radioisotopes block cancer cell proliferation by inducing apoptosis and cell cycle arrest. However, physical characteristics of the β-radiating element (half-life, tissue penetration range, and maximum energy) and treatment protocol determine whether tumor cells undergo cell cycle arrest, apoptosis or both and to which extent. In this review, we highlighted novel therapeutic effects of β-radiating radionuclides on cancer cells, particularly apoptosis induction and cell cycle arrest.

Monoclonal Antibody Against ROR1 Induces Apoptosis in Human Bladder Carcinoma Cells

BACKGROUND

Receptor tyrosine kinase-like Orphan Receptor 1 (ROR1) is one of the promising cell surface antigens for targeting cancer cells. The aim of this study was to evaluate ROR1 cell surface expression in bladder cancer cells using a murine anti-ROR1 monoclonal antibody (mAb) called 5F1-B10 as well as investigate its potential in apoptosis induction.

METHODS

Expression of ROR1 in two human bladder cell lines, 5637 and EJ138, as well as a non-cancerous human cell line, Human Fetal Foreskin Fibroblast (HFFF), was examined by flow cytometry and immunocytochemistry. Immunohistochemical staining of cancer and normal bladder tissues was also performed.

RESULTS

The flow cytometry results showed that 5F1-B10 mAb could recognize ROR1 molecules in 86.1% and 45.6% of 5637 and EJ138 cells, respectively. The expression level of ROR1 was 5.49% in HFFF cells. The immunocytochemistry and immunohistochemistry staining results also confirmed the presence of ROR1 on the surface of both bladder cancer cells and tissues, respectively. The obtained data from apoptosis assay demonstrated that 5F1-B10 mAb could induce apoptosis in both 5637 and EJ138 cell lines.

CONCLUSION

Taken together, our finding indicates the role of ROR1 in bladder cancer cell survival and suggests this receptor might be a promising target for developing novel therapeutic agents against bladder carcinoma.

ASR488, a novel small molecule, activates an mRNA binding protein, CPEB1, and inhibits the growth of bladder cancer

Due to a lack of mechanistic insights, muscle-invasive bladder cancer (MIBC) remains incurable and is one of the most lethal types of cancer in the United States. The present study investigated changes in the molecular signatures of MIBC cells (TCCSUP and HT1376) after treatment with a novel small molecule, ASR488, to gain knowledge of the mechanisms that inhibited MIBC cell growth. ASR488 treatment initiated apoptotic signaling in MIBC cells. Pathway enrichment analysis was used to analyze the changes in function of differentially expressed genes. Gene Ontology analysis, as well as Kyoto Encyclopedia of Genes and Genomes analysis, was also performed. These analyses along with reactome pathway enrichment analyses indicated that the genes upregulated in the ASR488-treated cells are involved in focal adhesion, neurotrophin signaling, p53 signaling, endoplasmic reticulum functioning in terms of protein processing, and pathways related to bladder cancer. The genes downregulated in ASR488-treated MIBC cells were mainly involved in DNA replication, mismatch repair, RNA degradation, nucleotide excision repair and TGFβ signaling (P<0.05). Furthermore, reverse transcription-quantitative PCR analysis revealed an increase in transcripts of the most upregulated genes in ASR 488-treated MIBC cells: CPEB1 (36-fold), IL11 (30-fold), SFN (20.12-fold) and CYP4F11 (15.8-fold). In conclusion, the analysis of biological functions of the most differentially expressed genes revealed possible mechanisms that may be associated with the aggressiveness of MIBC.

Human fibronectin extra domain B as a biomarker for targeted therapy in cancer

The extracellular matrix protein fibronectin contains a domain that is rarely found in healthy adults and is almost exclusively expressed by newly formed blood vessels in tumours, particularly in solid tumours, different types of lymphoma and some leukaemias. This domain, called the extra domain B (ED‐B), thus has broad therapeutic potential. The antibody L19 has been developed to specifically target ED‐B and has shown therapeutic potential when combined with cytokines, such as IL‐2. In this review article, we discuss the preclinical research and clinical trials that highlight the potential of ED‐B targeting for the imaging and treatment of various types of cancer. ED‐B‐centred studies also highlight how proper patient stratification is of utmost importance for the successful implementation of novel antibody‐based targeted therapies.

Fragmentation pattern of certain isatin–indole antiproliferative conjugates with application to identify their in vitro metabolic profiles in rat liver microsomes by liquid chromatography tandem mass spectrometry

The fragmentation pattern of certain isatin-based compounds was carried out using collision-induced dissociation inside the triple quadrupole mass analyzer. These data were used as a clue for the identification of metabolites of the recently reported isatin-based antiproliferative agent, namely, N′-[5-bromo-1-methyl-2-oxo-1,2-dihydro-3H-indol-3-ylidene]-5-methoxy-1H-indole-2-carbohydrazide (1) in rat liver microsomes (RLMs) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Prediction of the vulnerable sites for metabolic pathways in compound 1 was performed by WhichP450 module of StarDrop software. In vitro metabolites for compound 1 were identified with the aid of rat liver microsomes. The in silico data were utilized as a guide for the practical work. Compound 1 was metabolized into three (hydroxylated, reduced and O-demethylated) metabolites in RLMs in the presence of NADPH. The chemical structures of those metabolites were elucidated, and the metabolic pathways were proposed by comparing the fragmentation pattern of the isatin–indole conjugates 1–7. The data presented in this paper provided useful information on the effect of different substituents on the ionization/fragmentation processes and can be used in the characterization of isatin derivatives. In silico toxicity assessments for the title compounds 1–7 and for the metabolites of compound 1 were conducted utilizing the deductive estimation of risk from existing knowledge (DEREK) module of StarDrop software.

The Effect of Polyphenolics in Extracts from Natural Materials on Metabolic Activity of Metastatic Melanoma WM-266-4 Cells

The importance of natural crops in medicine and pharmacy is growing. Beside bioactive compounds used directly as therapeutic agents, there are also raw materials used for drug synthesis or as a basic model for new biologically active compounds. In this paper, the optimum conditions for material extraction of Curcuma longa, Lycium barbarum, Equisetum arvense, Vitis vinifera, and Rosmarinus officinalis were investigated to achieve high antioxidant levels. The main aim of this study was to verify the correlation between the content of antioxidants, proanthocyanidins and total phenolic substances for certain extracts from the raw materials (Curcuma longa, Lycium barbarum, Equisetum arvense, Vitis vinifera and Rosmarinus officinalis) and the reduction of the metabolic activity of skin cancer cells.

Citrus lemon essential oil nanoemulsion (CLEO-NE), a safe cell-depended apoptosis inducer in human A549 lung cancer cells with anti-angiogenic activity

Aims: Citrus lemon essential oil (CLEO) has been introduced as a strong antioxidant mixture. However, it is not efficient enough due to its hydrophobic nature. Nanoemulsions improve the drugs' bio-compatibility in aqueous conditions.Methods: The CLEO nanoemulsion (CLEO-NE) was formulated by ultrasound-based-emulsification and they were characterised. The anti-angiogenic and antioxidant activities were studied by the chicken chorioallantoic membrane (CAM) and antioxidant (ABTS and DPPH) assays, respectively. Finally, the apoptotic property of CLEO-NE on both HFF and A549 was evaluated by [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay and real time-PCR (measuring Cas-3 gene expression).Results: The 30.2-nm CLEO-NE droplets significantly increased Cas-3 in A549 cells and decreased angiogenesis in chick embryo chorioallantoic membrane (p < 0.01).Conclusion: In conclusion, CLEO-NE has the potential to be used as a safe cell-depended anticancer agent for human lung cancer. However, further genes and cell lines have to be studied to clarify its targeted-anticancer activity.

LncRNA NR2F1-AS1 Regulates miR-371a-3p/TOB1 Axis to Suppress Proliferation of Colorectal Cancer Cells

A recent study reported the oncogenic function of lncRNA NR2F1-AS1 in liver cancer. Interestingly, by analyzing TCGA data set, downregulation of NR2F1-AS1 in colorectal cancer (CRC) was observed. This observation triggered interest to analyze the functions of NR2F1-AS1 in CRC. It was observed that NR2F1-AS1 was downregulated in CRC and predicted poor survival. NR2F1-AS1 can directly interact with miR-371a-3p but their overexpression failed to affect the expression of each other. However, NR2F1-AS1 overexpression led to the upregulation of TOB1, a target of miR-371a-3p. Cell proliferation analysis revealed reduced proliferation rate of CRC cells after NR2F1-AS1 and TOB1 overexpression. MiR-371a-3p overexpression played an opposite role and reduced the effects of NR2F1-AS1 and TOB1 overexpression. In conclusion, NR2F1-AS1 regulates miR-371a-3p/TOB1 axis to suppress proliferation of CRC cells.

Production of recombinant lethal factor of Bacillus anthracis in Bacillus subtilis

Cancer is considered as a disease with high rates of mortality and morbidity. The limitations and side effects of common treatments have prompted the need for innovative cancer therapies. Furthermore, selectivity and targeting of cancer cells are crucial factors to successful treatment of cancer. One of these methods is the use of bacterial toxins including Bacillus anthracis toxin to aid cancer therapy. This toxin is composed of three polypeptides: protective factor (PA), lethal factor (LF), and edema factor (EF). PA can bind to various surface receptors of all types of human cells and it internalizes the lethal factor and edema factor subunits of the toxin in the cytosol. In the present study, we cloned and expressed the lef gene of B. anthracis as the lethal part of the toxin in Bacillus subtilis WB600 by a shuttle expression vector PHT4. The rLF made in B. subtilis is efficiently secreted by the host into the culture medium which facilitates downstream processing. The rLF can be used to study cancer treatment. Abbreviations: EF: edema factor; LF: lethal factor; PA: protective factor; rLF: recombinant lethal factor; rPAm: recombinant protective factor mutants; uPA: urokinase-type plasminogen activator; uPAR: urokinase-type plasminogen activator receptor.

Epigenetic Modulators as Potential Multi-targeted Drugs Against Hedgehog Pathway for Treatment of Cancer

The Sonic hedgehog signalling is known to play a crucial role in regulating embryonic development, cancer stem cell maintenance and tissue patterning. Dysregulated hedgehog signalling has been reported to affect tumorigenesis and drug response in various human malignancies. Epigenetic therapy relying on DNA methyltransferase and Histone deacetylase inhibitors are being proposed as potential drug candidates considering their efficiency in preventing development of cancer progenitor cells, killing drug resistant cells and also dictating "on/off" switch of tumor suppressor genes and oncogenes. In this docking approach, epigenetic modulators were virtually screened for their efficiency in inhibiting key regulators of SHH pathway viz., sonic hedgehog, Smoothened and Gli using polypharmacological approach. The control drugs and epigenetic modulators were docked with PDB protein structures using AutoDock vina and further checked for their drug-likeness properties. Further molecular dynamics simulation using VMD and NAMD, and MMP/GBSA energy calculation were employed for verifying the stability and entropy of the ligand-receptor complex. EPZ-6438 and GSK 343 (EZH2 inhibitors), CHR 3996 and Mocetinostat (HDAC inhibitors), GSK 126 (HKMT inhibitor) and UNC 1215 (L3MBTL3 antagonist) exhibited multiple-targeted approach in modulating HH signalling. This is the first study to report these epigenetic drugs as potential multi-targeted hedgehog pathway inhibitors. Thus, epigenetic polypharmacology approach can be explored as a better alternative to challenges of acute long term toxicity and drug resistance occurring due to traditional single targeted chemotherapy in the future.

Synthesis, Biological Evaluation and In Silico Studies of Certain Oxindole-Indole Conjugates as Anticancer CDK Inhibitors

On account of their overexpression in a wide range of human malignancies, cyclin-dependent kinases (CDKs) are among the most validated cancer targets, and their inhibition has been featured as a valuable strategy for anticancer drug discovery. In this study, a hybrid pharmacophore approach was adopted to develop two series of oxindole-indole conjugates (6a-i and 9a-f) and carbocycle-indole conjugates (11a,b) as efficient antitumor agents with potential inhibitory action toward CDK4. All oxindole-indole conjugates, except 6i, 9b, and 9c efficiently affected the growth of the human breast cancer MCF-7 (IC₅₀: 0.39 ± 0.05-21.40 ± 1.58 μM) and/or MDA-MB-231 (IC₅₀: 1.03 ± 0.04-22.54 ± 1.67 μM) cell lines, whereas bioisosteric replacement of the oxindole nucleus with indane or tetralin rings (compounds 11a,b) diminished the anti-proliferative activity. In addition, hybrids 6e and 6f displayed effective cell cycle disturbance and proapoptotic capabilities in MCF-7 cells. Furthermore, the efficient anti-proliferative agents towards MCF-7 and/or MDA-MB-231 cell lines (6a-h, 9a, and 9e) were investigated for their potential inhibitory action toward CDK4. Hybrids 6a and 6e displayed good CDK4 inhibitory activity with IC₅₀s equal 1.82 and 1.26 µM, respectively. The molecular docking study revealed that oxindole moiety is implicated in two H-bonding interactions via both (NH) and (C=O) groups with the key amino acids Glu94 and Val96, respectively, whereas the indole framework is stably accommodated in a hydrophobic sub-pocket establishing hydrophobic interactions with the amino acid residues of Ile12, Val20, and Gln98 lining this sub-pocket. Collectively, these results highlighted hybrids 6a and 6e as good leads for further optimization as promising antitumor drugs toward breast malignancy and CDK inhibitors.

Fullerene Derivatives as Lung Cancer Cell Inhibitors: Investigation of Potential Descriptors Using QSAR Approaches

Background

Nanotechnology-based strategies in the treatment of cancer have potential advantages because of the favorable delivery of nanoparticles into tumors through porous vasculature.

Materials and Methods

In the current study, we synthesized a series of water-soluble fullerene derivatives and observed their anti-tumor effects on human lung carcinoma A549 cell lines. The quantitative structure–activity relationship (QSAR) modeling was employed to investigate the relationship between anticancer effects and descriptors relevant to peculiarities of molecular structures of fullerene derivatives.

Results

In the QSAR regression model, the evaluation results revealed that the determination coefficient r² and leave-one-out cross-validation q² for the recommended QSAR model were 0.9966 and 0.9246, respectively, indicating the reliability of the results. The molecular modeling showed that the lack of chlorine atom and a lower number of aliphatic single bonds in saturated hydrocarbon chains may be positively correlated with the lung cancer cytotoxicity of fullerene derivatives. Synthesized water-soluble fullerene derivatives have potential functional groups to inhibit the proliferation of lung cancer cells.

Conclusion

The guidelines obtained from the QSAR model might strongly facilitate the rational design of potential fullerene-based drug candidates for lung cancer therapy in the future.

Redox cycling of copper by coumarin-di(2-picolyl)amine hybrid molecule leads to ROS-mediated modulation of redox scavengers, DNA damage and cell death in diethylnitrosamine induced hepatocellular carcinoma

Targeted therapy is a new strategy for cancer treatment that targets chemical entities specific to cancer cells than normal ones. One of the features associated with malignancy is the elevated copper which plays an integral role in angiogenesis. Work is in progress in our lab to identify new copper chelators to target elevated copper under targeted therapy for the killing of cancer cells. Recently, a coumarin-based copper chelator, di(2-picolyl)amine-3(bromoacetyl)coumarin hybrid molecule (ligand-L) has been synthesized by us, and also studied its copper-dependent macromolecular damage response in copper overloaded lymphocytes. The present study investigates the anticancer activity of ligand-L and its mode of action in rat model of diethylnitrosamine (DEN) induced hepatocellular carcinoma. It has been found that liver tissue has a marked increase in copper levels in DEN induced hepatocellular carcinoma. Ex vivo results showed that ligand-L inhibited cell viability, induced reactive oxygen species (ROS) generation, DNA damage, loss of mitochondrial membrane potential and caspase-3 activation in isolated hepatocellular carcinoma cells (HCC). All these effects induced by ligand-L were abrogated by neocuproine and N-acetylcysteine (ROS scavenger). Further, ligand-L treatment of animals bearing hepatocellular carcinoma results in an increment in the cellular redox scavengers, lipid peroxidation and DNA breakage in malignant hepatocytes. In vivo studies using ligand-L also showed that ligand-L possesses anticancer properties as evidenced by improvement in liver marker enzymes and liver surface morphology, and reduced alpha-fetoprotein in the treated group compared to untreated cancer-induced group. Overall, this study suggests that copper-ligand-L interaction leads to ROS generation which caused DNA damage and apoptosis in malignant cells. This study provides enough support to establish ligand-L as a clinically relevant lead molecule for the treatment of different malignancies.

Anti-neoplastic and immunomodulatory potency of co-treatment based on bovine lactoferrin and/or muramyl dipeptide in tumor-bearing mice

The current study investigates anti-neoplastic and immunomodulatory activities of co-treatment based on bovine lactoferrin (bLF) and/or muramyl dipeptide (MDP) with or without cisplatin (Cis) in tumor-bearing mice. In the present study, bLF (100 mg/kg; orally) and MDP (0.5 mg/kg; subcutaneously) was administered alone or together. MDP or bLF was co-treated with Cis (1 mg/kg; intraperitoneally) in mice-bearing Ehrlich solid carcinoma. Tumor size, tumor mass proliferation, apoptosis using immunohistochemistry, the alteration in spleen cell proliferation, phenotype using flow cytometry and white blood cells total and differential counts were detected. Treatment with Cis or (bLF and MDP) significantly reduced tumor size, upregulated the pro-apoptotic p53 expression and downregulated the anti-apoptotic Bcl-2 and proliferative marker PCNA expression compared to non-treated tumor-bearing animals. Moreover, co-treatment of MDP and Cis significantly potentiated the reduction of the tumor size, downregulated the Bcl-2 and PCNA expression and upregulated the p53 expression compared to Cis-treated animals. While bLF and Cis co-treatment positively controlled PCNA and p53 expression compared to tumor-bearing animals, it significantly potentiated the reduction of the tumor size and downregulated the Bcl-2 expression compared to Cis-treated animals. Co-treatment of (bLF and MDP), (bLF and Cis) or (MDP and Cis) increased the spleen cell proliferation and altered the immunological profile of the CD3+CD4+, CD3+CD8+, CD3+CD4+CD69+, CD3+CD8+CD69+ and CD11b+Ly6G+ cells to achieve better immune response against tumor. In conclusion, co-treatments based on bLF and/or MDP are promising therapies against cancer, through their potency to control proliferation, enhance apoptosis and improve the immune status against tumor cells.

Systematic profiling of staralog response to acquired drug resistant kinase gatekeeper mutations in targeted cancer therapy

Kinase-targeted therapy has been widely used as a lifesaving strategy for cancer patients. However, many patients treated with targeted cancer drugs are clinically observed to rapidly develop acquired resistance. Kinase gatekeeper mutation is one of the most chief factors contributing to the resistance, which modulates the accessibility of kinase's ATP-binding pocket. Previously, the pan-kinase inhibitor Staurosporine and its analogs (termed as Staralogs) have been reported to exhibit wild-type sparing selectivity for some kinase gatekeeper mutants, such as EGFR T790M, Her2 T798M and cSrc T338M. Here, we describe an integrative approach to systematically profile the molecular response of 15 representative Staralogs to 17 kinase gatekeeper mutations in targeted cancer therapy. With the profile we are able to divide gatekeeper mutations into three classes (i.e. classes I, II and III) and to divide Staralogs into two groups (i.e. groups 1 and 2) using heuristic clustering. The class I and II mutations confer consistent sensitivity and resistance for all Staralogs, respectively, while the class III mutations address divergent effects on different Staralogs. The mutations to Ile residue can generally reduce Staralog affinity by inducing unfavorable steric hindrance, whereas the mutations to Met and Leu residues would improve Staralog affinity by establishing favorable S···π interaction, van der Waals packing and/or hydrophobic contact. The group 1 and 2 Staralogs are primarily determined by carbonyl or hydroxyl substitution state at the position 7 of Staralog core, where points to kinase gatekeeper residue and can thus be directly influenced by gatekeeper mutation.

Synthesis and Bioactivity Assessment of Novel Spiro Pyrazole-Oxindole Congeners Exhibiting Potent and Selective in vitro Anticancer Effects

The present work aims to design and synthesize novel series of spiro pyrazole-3,3’-oxindoles analogues and investigate their bioactivity as antioxidant and antimicrobial agents, as well as antiproliferative potency against selected human cancerous cell lines (i.e., breast, MCF-7; colon, HCT-116 and liver, HepG-2) relative to healthy noncancerous control skin fibroblast cells (BJ-1). The mechanism of their cytotoxic activity has been also examined by immunoassaying the levels of key anti- and proapoptotic protein markers. The analytical and spectral data of the all synthesized target congeners were compatible with their structures. Synthesized compounds showed diverse moderate to powerful antimicrobial and antioxidant activities. Results of MTT assay revealed that seven synthesized compounds (i.e., 11a, 11b, 12a, 12b, 13b, 13c and 13h) particularly exhibited significant cytotoxicity against the three cancerous cell lines under investigation. Ranges of IC₅₀ values obtained were 5.7–21.3 and 5.8–37.4 µg/mL against HCT-116 and MCF-7, respectively; which is 3.8 and 6.5-fold (based on the least IC₅₀ values) more significant relative to the reference chemotherapeutic drug doxorubicin. In HepG-2 cells, the analogue 13h exhibited the highest cytotoxicity with IC₅₀ value of 19.2µg/mL relative to doxorubicin (IC₅₀ = 21.6µg/mL). The observed cytotoxicity was specific to cancerous cells, as evidenced by the minimal toxicity in the noncancerous control skin-fibroblast cells. ELISA results indicated that the observed antiproliferative effect against examined cancer cell lines is mediated via engaging the activation of apoptosis as illustrated by the significant increase in proapoptotic protein markers (p53, bax and caspase-3) and reduction in the antiapoptotic marker bcl-2. Taken together, results of the present study emphasize the potential of spiro pyrazole-oxindole analogues as valuable candidate anticancer agents against human cancer cells.

Disparity between Inter-Patient Molecular Heterogeneity and Repertoires of Target Drugs Used for Different Types of Cancer in Clinical Oncology

Inter-patient molecular heterogeneity is the major declared driver of an expanding variety of anticancer drugs and personalizing their prescriptions. Here, we compared interpatient molecular heterogeneities of tumors and repertoires of drugs or their molecular targets currently in use in clinical oncology. We estimated molecular heterogeneity using genomic (whole exome sequencing) and transcriptomic (RNA sequencing) data for 4890 tumors taken from The Cancer Genome Atlas database. For thirteen major cancer types, we compared heterogeneities at the levels of mutations and gene expression with the repertoires of targeted therapeutics and their molecular targets accepted by the current guidelines in oncology. Totally, 85 drugs were investigated, collectively covering 82 individual molecular targets. For the first time, we showed that the repertoires of molecular targets of accepted drugs did not correlate with molecular heterogeneities of different cancer types. On the other hand, we found that the clinical recommendations for the available cancer drugs were strongly congruent with the gene expression but not gene mutation patterns. We detected the best match among the drugs usage recommendations and molecular patterns for the kidney, stomach, bladder, ovarian and endometrial cancers. In contrast, brain tumors, prostate and colorectal cancers showed the lowest match. These findings provide a theoretical basis for reconsidering usage of targeted therapeutics and intensifying drug repurposing efforts.

Applied precision cancer medicine in metastatic biliary tract cancer

INTRODUCTION

Advanced therapy-refractory biliary tract cancer (BTC) has poor prognosis and constitutes a major challenge for adequate treatment strategies. By mapping the molecular profiles of advanced BTC patients, precision cancer medicine may provide targeted therapies for these patients.

OBJECTIVE

In this analysis, we aimed to show the potential of PCM in metastatic BTC.

METHODS

In this single-center, real-world retrospective analysis of our PCM platform, we describe the molecular profiling of 30 patients diagnosed with different types of metastatic BTC. Tumor samples of the patients were examined using a 161-gene next-generation sequencing panel, immunohistochemistry (IHC), and fluorescence in situ hybridization for chromosomal translocations.

RESULTS

In total, we identified 35 molecular aberrations in 30 patients. The predominant mutations were KRAS (n = 8), TP53 (n = 7), IDH2 (n = 4), and IDH1 (n = 3) that accounted for the majority of all molecular alterations (62.86%). BRAF mutations were observed in two patients. Less frequent alterations were noted in ARID1A, CTNNB1, ESR1, FBXW7, FGFR2, MET, NOTCH2, PIK3CA, PTCH1, SMAD4, and SRC1, each in one case. FGFR fusion gene was detected in one patient. No mutations were detected in eight patients. IHC revealed EGFR and p-mTOR expression in 28 patients. Applying these results to our patients, targeted therapy was recommended for 60% of the patients (n = 18). One patient achieved stable disease.

CONCLUSIONS

PCM is a feasible treatment approach and may provide molecular-guided therapy recommendations for metastatic BTC.

Bacteria and cancer: Different sides of the same coin

Conventional cancer therapies such as chemotherapy, radiation therapy, and immunotherapy due to the complexity of cancer have been unsuccessful in the complete eradication of tumor cells. Thus, there is a need for new therapeutic strategies toward cancer. Recently, the therapeutic role of bacteria in different fields of medicine and pharmaceutical research has attracted attention in recent decades. Although several bacteria are notorious as cancer-causing agents, recent research revealed intriguing results suggesting the bacterial potential in cancer therapy. Thus, bacterial cancer therapy is an alternative anticancer approach that has promising results on tumor cells in-vivo. Moreover, with the aid of genetic engineering, some natural or genetically modified bacterial strains can directly target hypoxic regions of tumors and secrete therapeutic molecules leading to cancer cell death. Additionally, stimulation of immune cells by bacteria, bacterial cancer DNA vaccine and antitumor bacterial metabolites are other therapeutic applications of bacteria in cancer therapy. The present study is a comprehensive review of different aspects of bacterial cancer therapy alone and in combination with conventional methods, for improving cancer therapy.

Mitochondrial characteristics contribute to proliferation and migration potency of MDA-MB-231 cancer cells and their response to cisplatin treatment

AIM

Despite recent advances in therapeutic strategies, cancer is still a leading cause of mortality worldwide. Mitochondrial dysfunction is implicated in cancer initiation and metastasis, and even in chemo- and radio-resistance. However, the precise role of mitochondria in cancer is crosstalk and controversial. This study is trying to find out the effect of transferring normal mitochondria into the highly aggressive and proliferative MDA-MB-231 cancer cells, and to evaluate the effect of the transfer with/without a combination therapy with cisplatin.

MATERIALS AND METHODS

Normal mitochondria were isolated from human umbilical cord derived-mesenchymal stem cells. The mitochondria were transferred into the MDA-MB-231 cells, and also into cells with mitochondrial dysfunction induced by rhodamine red 6 (R6G). Cell proliferation and sensitivity of the cells to cisplatin were measured by cell counting after the mitochondria transfer. Also, apoptosis was evaluated by DAPI staining and in situ cell death detection (TdT-mediated dUTP nickend labeling; TUNEL) methods. Migration capability of the cells was studied by transwell assay.

KEY FINDINGS

Transfer of normal mitochondria into MDA-MB-231 cells increased cell proliferation. However, the transfer of mitochondria enhanced cisplatin-induced apoptosis in MDA-MB-231 cells in which mitochondria were already disrupted. Introduction of normal cell-derived mitochondria into the MDA-MB-231 cells increased their invasive, but decreased the migration potency of the cells in the group with mitochondrial dysfunction (MDA + RG6 + Cisplatin).

CONCLUSION

The introduction of healthy mitochondria to highly aggressive and proliferative cells would be considered as a new therapeutic modality for some types of cancer.

Nanoparticles carrying fingolimod and methotrexate enables targeted induction of apoptosis and immobilization of invasive thyroid cancer

Metastatic tumors are the main cause of cancer-related death, as the invading cancer cells disrupt normal functions of distant organs and are nearly impossible to eradicate by traditional cancer therapeutics. This is of special concern when the cancer has created multiple metastases and extensive surgery would be too dangerous to execute. Therefore, combination chemotherapy is often the selected treatment form. However, drug cocktails often have severe adverse effects on healthy cells, whereby the development of targeted drug delivery could minimize side-effects of drugs and increase the efficacy of the combination therapy. In this study, we utilized the folate antagonist methotrexate (MTX) as targeting ligand conjugated onto mesoporous silica nanoparticles (MSNs) for selective eradication of folate receptor-expressing invasive thyroid cancer cells. The MSNs was subsequently loaded with the drug fingolimod (FTY720), which has previously been shown to efficiently inhibit proliferation and invasion of aggressive thyroid cancer cells. To assess the efficiency of our carrier system, comprehensive in vitro methods were employed; including flow cytometry, confocal microscopy, viability assays, invasion assay, and label-free imaging techniques. The in vitro results show that MTX-conjugated and FTY720-loaded MSNs potently attenuated both the proliferation and invasion of the cancerous thyroid cells while keeping the off-target effects in normal thyroid cells reasonably low. For a more physiologically relevant in vivo approach we utilized the chick chorioallantoic membrane (CAM) assay, showing decreased invasive behavior of the thyroid derived xenografts and an increased necrotic phenotype compared to tumors that received the free drug cocktail. Thus, the developed multidrug-loaded MSNs effectively induced apoptosis and immobilization of invasive thyroid cancer cells, and could potentially be used as a carrier system for targeted drug delivery for the treatment of diverse forms of aggressive cancers that expresses folate receptors.

Nanoparticles for multimodal antivascular therapeutics: Dual drug release, photothermal and photodynamic therapy

The poor delivery of nanoparticles to target cancer cells hinders their success in the clinical setting. In this work, an alternative target readily available for circulating nanoparticles has been selected to eliminate the need for nanoparticle penetration in the tissue: the tumor blood vessels. A tumor endothelium-targeted nanoparticle (employing an RGD-containing peptide) capable of co-delivering two anti-vascular drugs (one anti-angiogenic drug and one vascular disruption agent) is here presented. Furthermore, the nanodevice presents two additional anti-vascular capabilities upon activation by Near-Infrared light: provoking local hyperthermia (by gold nanorods in the system) and generating toxic reactive oxygen species (by the presence of a photosensitizer). RGD-targeting is shown to increase uptake by HUVEC cells, and while the nanoparticles are shown not to be toxic for these cells, upon Near-Infrared irradiation their almost complete killing is achieved. The combination of all four therapeutic modalities is then evaluated in an ex ovo fibrosarcoma xenograft model, which shows a significant reduction in the number of blood vessels irrigating the xenografts when the nanoparticles are present, as well as the destruction of the existing blood vessels upon irradiation. These results suggest that the combination of different anti-vascular therapeutic strategies in a single nanocarrier appears promising and should be further explored in the future. STATEMENT OF SIGNIFICANCE MVR2019: The combination of antivascular drugs with different mechanisms of action (such as antiangiogenic drugs and vascular disruption agents) has been recently proposed as a promising approach to maximize the therapeutic potential of anti-vascular therapeutics. Given the capacity of nanoparticles to co-deliver different drugs in optimizable ratios, nanomedicine appears to have a huge potential for the development of this kind of multimodal antivascular. To showcase this, an multimodal anti-vascular nanodevice for cancer therapy is here presented. This tumor endothelium-targeted nanosystem is capable of co-delivering two anti-vascular drugs (anti-angiogenic and vascular disruption agent) while also providing two additional therapeutic modalities that can be activated by Near-Infrared light: provoking local hyperthermia (photothermal therapy) and generating toxic reactive oxygen species (photodynamic therapy).

Molecular Pathway Analysis of Mutation Data for Biomarkers Discovery and Scoring of Target Cancer Drugs

DNA mutations govern cancer development. Cancer mutation profiles vary dramatically among the individuals. In some cases, they may serve as the predictors of disease progression and response to therapies. However, the biomarker potential of cancer mutations can be dramatically (several orders of magnitude) enhanced by applying molecular pathway-based approach. We developed Oncobox system for calculation of pathway instability (PI) values for the molecular pathways that are aggregated mutation frequencies of the pathway members normalized on gene lengths and on number of genes in the pathway. PI scores can be effective biomarkers in different types of comparisons, for example, as the cancer type biomarkers and as the predictors of tumor response to target therapies. The latter option is implemented using mutation drug score (MDS) values, which algorithmically rank the drugs capacity of interfering with the mutated molecular pathways. Here, describe the mathematical basis and algorithms for PI and MDS values calculation, validation and implementation. The example analysis is provided encompassing 5956 human tumor mutation profiles of 15 cancer types from The Cancer Genome Atlas (TCGA) project, that totally make 2,316,670 mutations in 19,872 genes and 1748 molecular pathways, thus enabling ranking of 128 clinically approved target drugs. Our results evidence that the Oncobox PI and MDS approaches are highly useful for basic and applied aspects of molecular oncology and pharmacology research.

Thiazole-containing compounds as therapeutic targets for cancer therapy

In the last few decades, considerable progress has been made in anticancer agents development, and several new anticancer agents of natural and synthetic origin have been produced. Among heterocyclic compounds, thiazole, a 5-membered unique heterocyclic motif containing sulphur and nitrogen atoms, serves as an essential core scaffold in several medicinally important compounds. Thiazole nucleus is a fundamental part of some clinically applied anticancer drugs, such as dasatinib, dabrafenib, ixabepilone, patellamide A, and epothilone. Recently, thiazole-containing compounds have been successfully developed as possible inhibitors of several biological targets, including enzyme-linked receptor(s) located on the cell membrane, (i.e., polymerase inhibitors) and the cell cycle (i.e., microtubular inhibitors). Moreover, these compounds have been proven to exhibit high effectiveness, potent anticancer activity, and less toxicity. This review presents current research on thiazoles and elucidates their biological importance in anticancer drug discovery. The findings may aid researchers in the rational design of more potent and bio-target specific anticancer drug molecules.

Targeting innate sensing in the tumor microenvironment to improve immunotherapy

The innate immune sensing pathways play critical roles in the defense against pathogen infection, but their roles in cancer immunosurveillance and cancer therapies are less defined. We propose that defective innate immune sensing inside the tumor microenvironment might limit T-cell responses to immunotherapy. A recent mechanistic understanding of conventional therapies revealed that both innate immune sensing and T-cell responses are essential for optimal antitumor efficacy. T-cell-based immunotherapy, particularly immune checkpoint blockade, has achieved great success in reactivating antitumor immune responses to lead to tumor regression, but only in a small fraction of patients. Therefore, incorporating conventional therapy that can increase innate sensing and immunotherapy should lead to promising strategies for cancer patients. Here, we review the innate sensing pathways related to cancer initiation/progression and therapies, summarize the recent key findings in innate immune sensing related to conventional therapies, evaluate current combination strategies, and highlight the potential issues of combinational therapies in terms of antitumor efficacy and toxicities.

A Chemical Approach to Overcome Tyrosine Kinase Inhibitors Resistance: Learning from Chronic Myeloid Leukemia

BACKGROUND

The possibilities of treatment for oncological diseases are growing enormously in the last decades. Unfortunately, these developments have led to the onset of resistances with regards to the new treatments. This is particularly true if we face with the therapeutic field of Tyrosine Kinase Inhibitors (TKIs). This review gives an overview of possible TKI resistances that can occur during the treatment of an oncologic diesease and available strategies that can be adopted, taking cues from a successful example such as CML.

METHODS

We performed a literature search for peer-reviewed articles using different databases, such as PubMed and Scopus, and exploiting different keywords and different logical operators.

RESULTS

68 papers were included in the review. Twenty-four papers give an overview of the causes of TKIs resistances in the wide oncologic field. The remaining papers deal CML, deeply analysing the TKIs Resistances present in this pathology and the strategies adopted to overcome them.

CONCLUSION

The aim of this review is to furnish an overview and a methodological guideline for the approach and the overcoming of TKIs Resistances.

Sphingosine-1-phosphate promotes PDGF-dependent endothelial progenitor cell angiogenesis in human chondrosarcoma cells

The malignant bone tumors that are categorized as chondrosarcomas display a high potential for metastasis in late-stage disease. Higher-grade chondrosarcomas contain higher levels of expression of platelet-derived growth factor (PDGF) and its receptor. The phosphorylation of sphingosine by sphingosine kinase enzymes SphK1 and SphK2 generates sphingosine-1-phosphate (S1P), which inhibits human chondrosarcoma cell migration, while SphK1 overexpression suppresses lung metastasis of chondrosarcoma. We sought to determine whether S1P mediates levels of PDGF-A expression and angiogenesis in chondrosarcoma. Surprisingly, our investigations found that treatment of chondrosarcoma cells with S1P and transfecting them with SphK1 cDNA increased PDGF-A expression and induced angiogenesis of endothelial progenitor cells (EPCs). Ras, Raf, MEK, ERK and AP-1 inhibitors and their small interfering RNAs (siRNAs) inhibited S1P-induced PDGF-A expression and EPC angiogenesis. Our results indicate that S1P promotes the expression of PDGF-A in chondrosarcoma via the Ras/Raf/MEK/ERK/AP-1 signaling cascade and stimulates EPC angiogenesis.

Targeted Diphtheria Toxin-Based Therapy: A Review Article

Cancer remains one of the leading causes of death worldwide. Conventional therapeutic strategies usually offer limited specificity, resulting in severe side effects and toxicity to normal tissues. Targeted cancer therapy, on the other hand, can improve the therapeutic potential of anti-cancer agents and decrease unwanted side effects. Targeted applications of cytolethal bacterial toxins have been found to be especially useful for the specific eradication of cancer cells. Targeting is either mediated by peptides or by protein-targeting moieties, such as antibodies, antibody fragments, cell-penetrating peptides (CPPs), growth factors, or cytokines. Together with a toxin domain, these molecules are more commonly referred to as immunotoxins. Targeting can also be achieved through gene delivery and cell-specific expression of a toxin. Of the available cytolethal toxins, diphtheria toxin (DT) is one of the most frequently used for these strategies. Of the many DT-based therapeutic strategies investigated to date, two immunotoxins, Ontak^TM and Tagraxofusp^TM, have gained FDA approval for clinical application. Despite some success with immunotoxins, suicide-gene therapy strategies, whereby controlled tumor-specific expression of DT is used for the eradication of malignant cells, are gaining prominence. The first part of this review focuses on DT-based immunotoxins, and it then discusses recent developments in tumor-specific expression of DT.

Paronychia and Periungual Granulation as a Novel Side Effect of Ibrutinib: A Case Report

Ibrutinib is an oral covalent inhibitor of the Bruton's tyrosine kinase pathway and is approved for the treatment of B-cell malignancies including chronic lymphocytic leukaemia, mantle cell lymphoma, and Waldenström's macroglobulinaemia. It is generally a drug of choice for high-risk patients with indolent lymphomas. The safety profile of ibrutinib appears to be tolerable, with well-known side effects such as infections and haematologic complications. Additionally, dermatological adverse reactions with ibrutinib therapy have been reported to encompass maculopapular rash and hair/nail abnormalities. Here, we present a case of ibrutinib-induced paronychia and periungual granulation in a 40-year-old woman. To the best of our knowledge, this is the third description of ibrutinib-induced paronychia and periungual granulation.

The potency of chitosan-based Pinus merkusii bark extract nanoparticles as anti-cancer on HeLa cell lines

BACKGROUND AND AIM

Cervical cancer accounts for the fourth as a cause of death from cancer in women worldwide, with more than 85% of events and deaths occurring in developing countries. The main problems of chemotherapy are the lack of selectivity and drug resistance. This study aimed to investigate the signal transduction of chitosan-based Pinus merkusii bark extract nanoparticles (Nano-PMBE) as an anticancer on HeLa cell line.

MATERIALS AND METHODS

Nano-PMBE was prepared based on the ionic gelation method. Its anticancer activities in HeLa cells were investigated through cytotoxicity test, cell cycle, and apoptosis analysis. The expression of p53 and caspase-9 was also observed.

RESULTS

The results showed that Nano-PMBE has a size of 394.3 nm. Meanwhile, the Nano-PMBE was cytotoxic to HeLa cells (IC50 of 384.10 µg/ml), caused G0/G1 phase arrest and cell apoptosis in HeLa cells. Besides, the expression of p53 and caspase-9 has increased.

CONCLUSION

The results showed a notable anticancer effect of Nano-PMBE by arresting the cell cycle and inducing apoptosis in HeLa cells, suggesting that it might have therapeutic potential for cervical cancer. Further research is needed to find out more about the anticancer mechanism of Nano-PMBE in HeLa cells to in vivo and clinical studies.

Proteasome Inhibitors Suppress ErbB Family Expression through HSP90-Mediated Lysosomal Degradation

Although dual EGFR/HER2 tyrosine kinase inhibitor lapatinib has provided effective clinical benefits for HER2-positive breast cancer patients, acquired resistance to this drug remains a major concern. Thus, the development of alternative therapeutic strategies is urgently needed for patients who failed lapatinib treatment. Proteasome inhibitors have been reported to possess high anti-tumor activity to breast cancer cells. Therefore, this study aims to examine whether and how proteasome inhibitor bortezomib can overcome lapatinib resistance. Treatments with several proteasome inhibitors, including Bortezomib, MG132, and proteasome inhibitor I (PSI), as well as the viabilities of both HER2-positive breast cancer cell lines and their lapatinib-resistant clones, were inhibited. Importantly, the expressions of ErbB family were downregulated at both transcriptional and translational levels. Also, our results further indicated that proteasome inhibitors decreased ErbB family expression through lysosomal degradation pathway in a heat shock protein 90 (HSP90)-dependent manner. In this study, our data supported a potential approach to overcome the acquired resistance of HER2-overexpressing breast cancer patients to lapatinib using proteasome inhibitors.

CMKLR1-targeting peptide tracers for PET/MR imaging of breast cancer

Background: Molecular targeting remains to be a promising approach in oncology. Overexpression of G protein-coupled receptors (GPCRs) in human cancer is offering a powerful opportunity for tumor-selective imaging and treatment employing nuclear medicine. We utilized novel chemerin-based peptide conjugates for chemokine-like receptor 1 (CMKLR1) targeting in a breast cancer xenograft model. Methods: By conjugation with the chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), we obtained a family of five highly specific, high-affinity tracers for hybrid positron emission tomography/magnetic resonance (PET/MR) imaging. A xenograft model with target-positive DU4475 and negative A549 tumors in immunodeficient nude mice enabled CMKLR1-specific imaging in vivo. We acquired small animal PET/MR images, assessed biodistribution by ex vivo measurements and investigated the tracer specificity by blocking experiments. Results: Five CMKLR1-targeting peptide tracers demonstrated high biological activity and affinity in vitro with EC₅₀ and IC₅₀ values below 2 nM. Our target-positive (DU4475) and target-negative (A549) xenograft model could be validated by ex vivo analysis of CMKLR1 expression and binding. After preliminary PET imaging, the three most promising tracers [⁶⁸Ga]Ga-DOTA-AHX-CG34, [⁶⁸Ga]Ga-DOTA-KCap-CG34 and [⁶⁸Ga]Ga-DOTA-ADX-CG34 with best tumor uptake were further analyzed. Hybrid PET/MR imaging along with concomitant biodistribution studies revealed distinct CMKLR1-specific uptake (5.1% IA/g, 3.3% IA/g and 6.2% IA/g 1 h post-injection) of our targeted tracers in DU4475 tumor tissue. In addition, tumor uptake was blocked by excess of unlabeled peptide (6.4-fold, 5.5-fold and 3.4-fold 1 h post-injection), further confirming CMKLR1 specificity. Out of five tracers, we identified these three tracers with moderate, balanced hydrophilicity to be the most potent in receptor-mediated tumor targeting. Conclusion: We demonstrated the applicability of ⁶⁸Ga-labeled peptide tracers by visualizing CMKLR1-positive breast cancer xenografts in PET/MR imaging, paving the way for developing them into theranostics for tumor treatment.

Biomedical and bioimaging applications of 2D pnictogens and transition metal dichalcogenides

Multifunctional platforms will play a key role and gain more prominence in the field of personalized healthcare worldwide in the near future due to the ever-increasing number of patients suffering from cancer. Along with the development of efficient techniques for cancer treatment, a considerable effort should be devoted toward the exploration of an emerging class of materials with unique properties that might be beneficial in this context. Currently, 2D post-carbon materials, such as pnictogens (phosphorene, antimonene), transition metal dichalcogenides, and boron nitride, have become popular due to their efficient photothermal behavior, drug-loading capability, and low toxicity. This review underlines the recent progresses made in the abovementioned 2D materials for photothermal/photodynamic cancer therapies and their applicability in bioimaging applications.

Antiproliferative activity and possible mechanism of action of certain 5-methoxyindole tethered C-5 functionalized isatins

Background

Cancer is one of the most dreaded human diseases, that has become an ever-increasing health problem and is a prime cause of death globally. The potential antiproliferative activity of certain indole-isatin molecular hybrids 5a-w was evaluated in vitro against three human cancer cell lines.

Methods

Standard protocols were adopted to examine the antiproliferative potential and mechanisms of compounds 5a-w. Western blot analysis was carried out on compound 5o.

Results

Compounds 5a-w demonstrated in vitro antiproliferative activity in the range of 22.6-97.8%, with compounds 5o and 5w being the most active antiproliferative compounds   with IC₅₀ values of 1.69 and 1.91 µM, which is fivefold and fourfold more potent than sunitinib (IC₅₀=8.11 µM), respectively. Compound 5o was selected for in-depth pharmacological testing to understand its possible mechanism of antiproliferative activity. It caused a lengthening of the G1 phase and a reduction in the S and G2/M phases of the cell cycle and had an IC₅₀ value of 10.4 μM with the resistant NCI-H69AR cancer cell line. Moreover, compound 5o significantly decreased the amount of phosphorylated Rb protein in a dose-dependent fashion, which was confirmed via Western blot analysis.

Conclusion

The current investigation highlighted the potential antiproliferative activity of compounds 5a-w as well as the antiproliferative profile of compound 5o. These compounds can be harnessed as new lead antiproliferatives in the preclinical studies of cancer chemotherapy.

Microvesicle-Mediated Delivery of Minicircle DNA Results in Effective Gene-Directed Enzyme Prodrug Cancer Therapy

An emerging approach for cancer treatment employs the use of extracellular vesicles, specifically exosomes and microvesicles, as delivery vehicles. We previously demonstrated that microvesicles can functionally deliver plasmid DNA to cells and showed that plasmid size and sequence, in part, determine the delivery efficiency. In this study, delivery vehicles comprised of microvesicles loaded with engineered minicircle (MC) DNA that encodes prodrug converting enzymes developed as a cancer therapy in mammary carcinoma models. We demonstrated that MCs can be loaded into shed microvesicles with greater efficiency than their parental plasmid counterparts and that microvesicle-mediated MC delivery led to significantly higher and more prolonged transgene expression in recipient cells than microvesicles loaded with the parental plasmid. Microvesicles loaded with MCs encoding a thymidine kinase (TK)/nitroreductase (NTR) fusion protein produced prolonged TK-NTR expression in mammary carcinoma cells. In vivo delivery of TK-NTR and administration of prodrugs led to the effective killing of both targeted cells and surrounding tumor cells via TK-NTR-mediated conversion of codelivered prodrugs into active cytotoxic agents. In vivo evaluation of the bystander effect in mouse models demonstrated that for effective therapy, at least 1% of tumor cells need to be delivered with TK-NTR-encoding MCs. These results suggest that MC delivery via microvesicles can mediate gene transfer to an extent that enables effective prodrug conversion and tumor cell death such that it comprises a promising approach to cancer therapy.