Therapeutic Cancer Drugs Research Articles

AB001. Development of tumour-targeted therapy for the treatment of adult and paediatric high-grade gliomas.

Brain cancer patients, especially those suffering from high-grade gliomas (HGGs) face a bleak future with very dismal long-term disease-free survival outcomes due to the limited treatment options currently available. Therefore, there is an unmet need for new therapeutic intervention that extends patients' progress-free survival and improves their quality of life. A significant hurdle is the inability of current chemotherapy agents to cross the blood-brain barrier (BBB). BBB acts as a protective shield that filters the blood to ensure nothing harmful makes it to the brain. This protection is usually good, but it becomes a problem if you want to deliver therapeutic cancer drugs through it. This barrier blocks 98% of drugs from entering the brain. Even the ones that cross BBB are unevenly distributed in the normal brain and tumour tissue, resulting in mediocre treatment and severe side effects. We are developing drug delivery systems that can cross the BBB and facilitate the specific accumulation of drugs in the tumour tissue. This will significantly improve the efficacy of anticancer drugs in treating various brain cancers and reduce systemic toxicity. Our group has explored and developed BBB crossing and tumour targeting near infra-red dyes, which can be covalently attached to Food and Drug Administration (FDA)-approved chemotherapy agents (drug-dye conjugates), thereby delivering it to the tumour tissue. We synthesized such drug-dye conjugates to target various aberrant pathways in HGG and tested these conjugates against patient-derived HGG cell lines. One such conjugate was tested on a mouse model of glioblastoma, an aggressive form of HGG, and shown to cross the BBB and specifically accumulate in tumour tissue, bringing forth tumour burden reduction. The results obtained from this work serve as proof of principle that enables tumour-specific drug delivery to treat HGG. This work also paves the way for treating other brain cancers and central nervous system (CNS) disorders like Parkinson's and Alzheimer's disease, for which no adequate therapy exists.

Effective combination of liposome-targeted chemotherapy and PD-L1 blockade of murine colon cancer.

Therapeutic cancer drug efficacy can be limited by insufficient tumor penetration, rapid clearance, systemic toxicity and (acquired) drug resistance. The poor therapeutic index due to inefficient drug penetration and rapid drug clearance and toxicity can be improved by using a liposomal platform. Drug resistance for instance against pemetrexed, can be reduced by combination with docetaxel. Here, we developed a specific liposomal formulation to simultaneously deliver docetaxel and pemetrexed to enhance efficacy and safety. Hydrophobic docetaxel and hydrophilic pemetrexed were co-encapsulated into pH-sensitive liposomes using a thin-film hydration method with high efficiency. The physicochemical properties, toxicity, and immunological effects of liposomes were examined in vitro. Biodistribution, anti-tumor efficacy, and systemic immune response were evaluated in vivo in combination with PD-L1 immune checkpoint therapy using two murine colon cancer models. In cellular experiments, the liposomes exhibited strong cytotoxicity and induced immunogenic cell death. In vivo, the treatment with the liposome-based drug combination inhibited tumor development and stimulated immune responses. Liposomal encapsulation significantly reduced systemic toxicity compared to the delivery of the free drug. Tumor control was strongly enhanced when combined with anti-PDL1 immunotherapy in immunocompetent mice carrying syngeneic MC38 or CT26 colon tumors. We showed that treatment with liposome-mediated chemotherapy of docetaxel and pemetrexed combined with anti-PD-L1 immunotherapy is a promising strategy for the treatment of colon cancers.

Associations between insurance status and the cancer clinical trial enrollment process.

85 Background: Most patients with cancer experience multi-leveled barriers to clinical trial participation, potentially including financial concerns due to the complexity surrounding trial-related insurance coverage. Our study sought to understand the association between insurance status and cancer clinical trial eligibility, offer, and enrollment. Methods: This retrospective cohort study included patients with breast or ovarian cancer receiving a therapeutic cancer drug at the University of Alabama at Birmingham between January 2017 and February 2020. Available clinical trials and eligibility criteria were abstracted from OnCore and ClinicalTrials.gov. Patient trial eligibility, offer from provider, demographics, and clinical characteristics were abstracted from electronic medical records. Patient trial enrollment was determined via OnCore. Odds of clinical trial eligibility, offer, and enrollment by insurance status (private, public [Medicaid, Medicare]) were estimated using logistic regression models. Models estimating odds of trial offer and enrollment contained only eligible patients. Models were adjusted for patient age at diagnosis, race and ethnicity, rural-urban residence, Area Deprivation Index, cancer type, and cancer stage (early, late). Results: A total of 513 patients with breast (71%) or ovarian (29%) cancer were included in our analyses. Median age at diagnosis was 60 (interquartile range: 49-67) years; the majority were White (69%) and had early stage cancer (65%). Half of patients had private insurance (54%), and 46% of patients had public insurance (38% Medicare, 8% Medicaid). Patients with private insurance more often had early stage cancer compared to patients with public insurance (73% vs 57%). Almost two-thirds of patients (65%) were eligible for clinical trial enrollment. Of eligible patients (n = 333), 68% were offered a trial and 47% enrolled onto a trial. In adjusted analyses, patients with public vs private insurance had similar odds of clinical trial eligibility (odds ratio [OR] 0.95, 95% confidence intervals [CI] 0.61-1.48), being offered to participate (OR 1.23, 95% CI 0.71-2.14), and clinical trial enrollment (OR 1.13, 95% CI 0.68-1.89). Conclusions: Our results suggest oncologists do not assess trial eligibility or offering a trial based on insurance status, and patients do not differentially participate based on their insurance coverage. Further research is needed to understand implications of trial participation (e.g., out-of-pocket and time costs) for patients covered by differing insurance.

Design, synthesis and bioactivity evaluation of favorable evodiamine derivative scaffold for developing cancer therapy

Natural product evodiamine is one of the most privileged scaffolds in drug discovery and is suitable for derivatization, which can be conducted quickly for structure optimization and structure-activity relationship research. In this work, a comprehensive SAR study on evodiamine scaffold with N14-3′-fluorophenyl substituted was completed, and compounds with high anti-tumor activity and good inhibitory effect on Top1 and Top2 were screened out. Tested evodiamine derivatives exhibited excellent broad-spectrum anti-tumor activity. Among them, compound 8b revealed 55.15% and 55.50% inhibition for Top1 and Top2 at 25 μM, as well as 0.16 and 0.13 μM IC50 value for MGC-803 and SGC-7901 cells, respectively; compound 9a revealed 70.50% and 71.81% inhibition for Top1 and Top2 at 25 μM, as well as 0.22 and 0.27 μM IC50 value for MGC-803 and SGC-7901 cells, respectively. The further biological evaluation showed that they could functionally induce apoptosis, significantly arrest the cell cycle at the G2/M phase, and markedly inhibit cell proliferation, migration and invasion. In addition, compound 9a performed a tumor inhibitory rate of 36.35% and showed no apparent toxicity in vivo. Overall, these optimized protocols will advance the progression of cancer chemotherapy and can be used to expand the options for screening therapeutic cancer drugs.

Ligustrazine alleviates cyclophosphamide-induced hepatotoxicity via the inhibition of Txnip/Trx/NF-κB pathway

AimsCyclophosphamide (CP) is a common therapeutic drug for cancer, but exposure to CP can cause acute hepatotoxicity. This study aimed to elucidate the protective effects of Ligustrazine (2, 3, 5, 6-tetramethylpyrazine, TMP) on hepatotoxicity induced by CP or its active metabolite 4-hydroperoxycyclophosphamide (4-HC). Main methodsWe presented a comprehensive investigation about the hepatoprotection of TMP on CP-induced mice and 4-HC-treated HSC-LX2 cells. Liver function was detected via enzyme-linked immunosorbent assay (ELISA). Hepatic histopathology analysis was performed via hematoxylin and eosin (H&E) and Masson staining. Survival of hepatocytes was detected by TUNEL assay. Related proteins in the thioredoxin (Trx)-interacting protein (Txnip)/Trx/Nuclear factor-kappa B (NF-κB) pathway were measured by western blotting. Key findingsThe results indicated that CP or 4-HC could increase the levels of alanine aminotransferase and aspartate aminotransferase, enhance inflammatory factors and oxidative indicators, and suppress the activity of oxidoreductases. Moreover, significant changes in liver histological structure, fibrosis, and cell death were observed through the activation of Txnip/Trx/NF-κB pathway. In contrast, administration of TMP significantly reversed these above changes. Furthermore, TMP intervention participated in the inhibition of NLRP3 inflammasome accompanied with pyroptosis, as well as upregulating Trx expression and downregulating p-NF-κB, while the protective effect of TMP was limited to the involvement of Txnip overexpression. SignificanceTMP treatment could significantly alleviate the hepatotoxicity process as evidenced by improving the structure and function of the liver, inhibiting oxidative stress and inflammation accompanied with pyroptosis, which was positively correlated with the inhibition of Txnip/Trx/NF-κB pathway.

Challenges and opportunities in the delivery of cancer therapeutics: update on recent progress.

Global cancer prevalence has continuously increased in the last decades despite substantial progress achieved for patient care. Cancer is no longer recognized as a singular disease but as a plurality of different ones, leading to the important choice of the drug administration route and promoting the development of novel drug-delivery systems (DDS). Due to their structural diversity, therapeutic cancer drugs present specific challenges in physicochemical properties that can adversely affect their efficacy and toxicity profile. These challenges are addressed by innovative DDS to improve bioavailability, pharmacokinetics and biodistribution profiles. Here, we define the drug delivery challenges related to oral, intravenous, subcutaneous or alternative routes of administration, and review innovative DDS, marketed or in development, that answer those challenges.

The Unique Pharmacometrics of Small Molecule Therapeutic Drug Tracer Imaging for Clinical Oncology.

Simple SummaryNew clinical radiology scans using trace amounts of therapeutic cancer drugs labeled with radioisotope injected into patients can provide oncologists with fundamentally unique insights about drug delivery to tumors. This new application of radiology aims to improve how cancer drugs are used, towards improving patient outcomes. The article reviews published clinical research in this important new field.Translational development of radiolabeled analogues or isotopologues of small molecule therapeutic drugs as clinical imaging biomarkers for optimizing patient outcomes in targeted cancer therapy aims to address an urgent and recurring clinical need in therapeutic cancer drug development: drug- and target-specific biomarker assays that can optimize patient selection, dosing strategy, and response assessment. Imaging the in vivo tumor pharmacokinetics and biomolecular pharmacodynamics of small molecule cancer drugs offers patient- and tumor-specific data which are not available from other pharmacometric modalities. This review article examines clinical research with a growing pharmacopoeia of investigational small molecule cancer drug tracers.

A High-Throughput Image Cytometry Method for the Formation, Morphometric, and Viability Analysis of Drug-Treated Mammospheres.

The nonadherent mammosphere assay has been commonly used to investigate cancer stem cell activities in breast cancers that have the ability to form tumorspheres and maintain tumor growth. The sphere formation step is critical, in that it enables the construction of the mammosphere models for downstream assays. The mammosphere assay has also been used to assess the effects of drug treatment on the tumorspheres formed from primary cancer cells or cell lines. Traditionally, the mammosphere formation has been evaluated by standard microscopy systems that required external software for additional analyses. However, this method can be time-consuming and low-throughput, thus impractical for high-throughput characterization of mammosphere models and screening for potential therapeutic cancer drugs. To overcome these challenges, we developed a plate-based high-throughput method to rapidly analyze mammospheres in whole wells using the Celigo Image Cytometer. The method is employed to characterize mammosphere formation and morphology for adherent and nonadherent propagation of four breast cancer cell lines (MCF7, MDA-MB-436, MDA-MB-231, and SKBR3). Next, the dose-dependent effects of four small molecule drugs (doxorubicin, paclitaxel, 8-quinolinol, and salinomycin) are characterized based on sphere formation and viability stained with calcein AM and propidium iodide. We observed growth and morphometric differences between adherent and nonadherent propagation of the four cell lines. Furthermore, drug treatments induced various effects on mammosphere formation, morphology, and viability. The proposed image cytometry method provides a useful tool suitable for high-throughput characterization and analysis of mammospheres, which can improve assay efficiency when investigating the formation capabilities and drug-induced cytotoxicity effects.

Sorafenib as an Inhibitor of RUVBL2.

RUVBL1 and RUVBL2 are highly conserved ATPases that belong to the AAA+ (ATPases Associated with various cellular Activities) superfamily and are involved in various complexes and cellular processes, several of which are closely linked to oncogenesis. The proteins were implicated in DNA damage signaling and repair, chromatin remodeling, telomerase activity, and in modulating the transcriptional activities of proto-oncogenes such as c-Myc and β-catenin. Moreover, both proteins were found to be overexpressed in several different types of cancers such as breast, lung, kidney, bladder, and leukemia. Given their various roles and strong involvement in carcinogenesis, the RUVBL proteins are considered to be novel targets for the discovery and development of therapeutic cancer drugs. Here, we describe the identification of sorafenib as a novel inhibitor of the ATPase activity of human RUVBL2. Enzyme kinetics and surface plasmon resonance experiments revealed that sorafenib is a weak, mixed non-competitive inhibitor of the protein’s ATPase activity. Size exclusion chromatography and small angle X-ray scattering data indicated that the interaction of sorafenib with RUVBL2 does not cause a significant effect on the solution conformation of the protein; however, the data suggested that the effect of sorafenib on RUVBL2 activity is mediated by the insertion domain in the protein. Sorafenib also inhibited the ATPase activity of the RUVBL1/2 complex. Hence, we propose that sorafenib could be further optimized to be a potent inhibitor of the RUVBL proteins.

Application of capsaicin as a potential new therapeutic drug in human cancers.

Capsaicin, the major active ingredient of chili pepper, may play a "dual role" in tumourigenesis, acting as a carcinogen or as a cancer preventive agent. The aim of this study was to investigate the anticancer mechanisms of capsaicin and the effects of capsaicin on traditional chemotherapeutic drugs and radiotherapy in various cancer types and the potential for clinical application in cancer therapy. We conducted extensive literature searches through PubMed to collect representative studies of capsaicin in different cancer types. These studies investigated the anticancer molecular mechanisms of capsaicin. We then searched for the effects of capsaicin on traditional chemotherapeutic drugs or radiotherapy. Finally, in terms of clinical application, we searched for the advances of capsaicin-loaded nanoparticles in malignant tumours. In most studies, capsaicin is a potential anti-tumour compound and the anti-cancer mechanisms are mainly related to anti-proliferation, induction of apoptosis and autophagy, anti-angiogenesis and anti-metastasis. It is worth noting that the biological functions of capsaicin are greatly affected by its concentration and the effective concentration in different malignant tumours varies considerably. Furthermore, capsaicin can affect the anti-cancer activity of conventional chemotherapeutic drugs or radiation therapy and more and more capsaicin-loaded nanoparticles have been developed to prolong the drug retention of capsaicin in the blood circulation and allow active targeting of specific cancer cells to enhance its accurate delivery and targeting specificity, suggesting that capsaicin may be used as a potential chemopreventive or a new auxiliary therapeutic drug for cancer. However, there is still a need for well-controlled studies to assess the safety and efficacy of capsaicin, and further preclinical and clinical trials are needed to elucidate its anti-tumour effects when combined with other standard drugs or radiotherapy. Capsaicin exhibits strong anti-cancer properties in various cancer types. The combination of capsaicin with conventional chemotherapy drugs or radiotherapy can improve the sensitivity, reduce the side effects and enhance the tolerance of patients to cancer treatment. The development of capsaicin-loaded nanoparticles may provide a very promising approach to chemotherapy for malignant tumours.

In vitro Cell Migration, Invasion, and Adhesion Assays: From Cell Imaging to Data Analysis.

Cell migration is a key procedure involved in many biological processes including embryological development, tissue formation, immune defense or inflammation, and cancer progression. How physical, chemical, and molecular aspects can affect cell motility is a challenge to understand migratory cells behavior. In vitro assays are excellent approaches to extrapolate to in vivo situations and study live cells behavior. Here we present four in vitro protocols that describe step-by-step cell migration, invasion and adhesion strategies and their corresponding image data quantification. These current protocols are based on two-dimensional wound healing assays (comparing traditional pipette tip-scratch assay vs. culture insert assay), 2D individual cell-tracking experiments by live cell imaging and three-dimensional spreading and transwell assays. All together, they cover different phenotypes and hallmarks of cell motility and adhesion, providing orthogonal information that can be used either individually or collectively in many different experimental setups. These optimized protocols will facilitate physiological and cellular characterization of these processes, which may be used for fast screening of specific therapeutic cancer drugs for migratory function, novel strategies in cancer diagnosis, and for assaying new molecules involved in adhesion and invasion metastatic properties of cancer cells.

Cytotoxicity of Conjugates of 188Re-Labeled Dendrimers and Monoclonal Antibodies Anti-ICO-25 (MUC1) and Anti-ICO-80 (CD5) Against SKOV-3 (Ovary Cancer) and Jurkat Tumor Cell Lines (T-Lymphoblstic Lymphoma)

Targeted radioimmunotherapy is a promising approach to radiotherapy. Tumor-specific compounds were synthesized using monoclonal antibodies anti-ICO-25 (MUC1) and anti-ICO-80 (CD5) labeled with the therapeutic radioisotope 188Re. The specificity of the conjugates was demonstrated in vitro using SKOV-3 (ovary cancer) and Jurkat tumor cell lines (T-lymphoblastic lymphoma), which are known to have membrane surface receptors specific for the corresponding antibodies. Short-term survival tests revealed 90-93% death of tumor cells, indicating the proposed conjugates were promising for targeted delivery of diagnostic and therapeutic cancer drugs.

Dickkopf‑3 upregulation mediates the cardioprotective effects of curcumin on chronic heart failure.

Curcumin, isolated from rhizome of turmeric, has been widely studied as a potential therapeutic drug for cancer. However, protective effects of curcumin on chronic heart failure (CHF) have not been fully studied. In the present study, the effects of curcumin on CHF and the underlying mechanisms were investigated. A total of 40 rabbits were randomized into 4 groups: Control rabbits fed with placebo (Con) or curcumin (Con-cur), CHF rabbits fed with placebo (CHF) or curcumin (CHF-cur). CHF was induced by volume and pressure overload. The effects of curcumin on cardiac function and left ventricular (LV) structure were assessed by echocardiography and histology. The effects of curcumin on CHF molecular biomarkers were detected by dihydroethidium and immunohistochemical staining. The effects of curcumin on Dickkopf-related protein 3 (DKK-3), p38 mitogen-activated protein kinase (p38), c-Jun N-terminal kinase (JNK) and apoptosis signal-regulating kinase 1 (ASK1) were assessed by immunohistochemical staining and western blot analysis. Cardiac dysfunction and LV remodeling were successfully produced by ten weeks volume overload and eight weeks pressure overload in the CHF group. Compared with the Con group, the CHF group demonstrated higher levels of CHF molecular biomarkers, a lower level of DKK-3 expression and alterations of p38, JNK and ASK1 protein expression. Curcumin alleviated all those abnormalities markedly in the CHF-cur group. In summary, curcumin may exert cardioprotective effects by up-regulating DKK-3, which in turn may inhibit p38 and JNK signaling pathways in an ASK1-dependent way. The present study demonstrated that Dickkopf-3 upregulation mediates the cardioprotective effects of curcumin on chronic heart failure for the first time.

Combination treatment of all-trans retinoic acid (ATRA) and γ-secretase inhibitor (DAPT) cause growth inhibition and apoptosis induction in the human gastric cancer cell line.

Current medication for gastric cancer patients has a low success rate with resistance and side effects. According to recent studies, γ-secretase inhibitors is used as therapeutic drugs in cancer. Moreover, all-trans retinoic acid (ATRA) is a natural compound proposed for the treatment/chemo-prevention of cancers. The aim of this study was to explore the effects of ATRA in combination with N-[N-(3,5-difluorophenacetyl-l-alanyl)]-S-phenylglycine t-butyl ester(DAPT) as γ-secretase inhibitor on viability and apoptosis of the AGS and MKN-45 derived from human gastric cancer. AGS and MKN-45 gastric cancer cell lines were treated with different concentrations of ATRA or DAPT alone or ATRA plus DAPT. The viability, death detection and apoptosis of cells was examined by MTT assay and Ethidium bromide/acridine orange staining. The distribution of cells in different phases of cell cycle was also evaluated through flow cytometry analyses. In addition, caspase 3/7 activity and the expression of caspase-3 and bcl-2 were examined. DAPT and ATRA alone decreased gastric cancer cells viability in a concentration dependent manner. The combination of DAPT and ATRA exhibited significant synergistic inhibitory effects. The greater percentage of cells were accumulated in G0/G1 phase of cell cycle in combination treatment. The combination of DAPT and ATRA effectively increased the proportion of apoptotic cells and the level of caspase 3/7 activities compared to single treatment. Moreover, augmented caspase-3 up-regulation and bcl-2 down-regulation were found following combined application of DAPT and ATRA. The combination of DAPT and ATRA led to more reduction in viability and apoptosis in respect to DAPT or ATRA alone in the investigated cell lines.

Rhus coriaria increases protein ubiquitination, proteasomal degradation and triggers non-canonical Beclin-1-independent autophagy and apoptotic cell death in colon cancer cells

Colorectal cancer is the fourth leading cause of cancer-related deaths worldwide. Here, we investigated the anticancer effect of Rhus coriaria extract (RCE) on HT-29 and Caco-2 human colorectal cancer cells. We found that RCE significantly inhibited the viability and colony growth of colon cancer cells. Moreover, RCE induced Beclin-1-independent autophagy and subsequent caspase-7-dependent apoptosis. Blocking of autophagy by chloroquine significantly reduced RCE-induced cell death, while blocking of apoptosis had no effect on RCE-induced cell death. Mechanistically, RCE inactivated the AKT/mTOR pathway by promoting the proteasome-dependent degradation of both proteins. Strikingly, we also found that RCE targeted Beclin-1, p53 and procaspase-3 to degradation. Proteasome inhibition by MG-132 not only restored these proteins to level comparable to control cells, but also reduced RCE-induced cell death and blocked the activation of autophagy and apoptosis. The proteasomal degradation of mTOR, which occurred only 3 hours post-RCE treatment was concomitant with an overall increase in the level of ubiquitinated proteins and translated stimulation of proteolysis by the proteasome. Our findings demonstrate that Rhus coriaria possesses strong anti-colon cancer activity through stimulation of proteolysis as well as induction of autophagic and apoptotic cell death, making it a potential and valuable source of novel therapeutic cancer drug.

Inhibition of the HDAC/Suv39/G9a pathway restores the expression of DNA damage-dependent major histocompatibility complex classI-related chainAandB in cancer cells.

Immunotherapy is expected to be promising as a next generation cancer therapy. Immunoreceptors are often activated constitutively in cancer cells, however, such levels of ligand expression are not effectively recognized by the native immune system due to tumor microenvironmental adaptation. Studies have demonstrated that natural-killer group 2, member D (NKG2D), a major activating immunoreceptor, responds to DNA damage. The upregulation of major histocompatibility complex class I-related chain A and B (MICA/B) (members of NKG2D ligands) expression after DNA damage is associated with NK cell-mediated killing of cancer cells. However, the regulation of DNA damage-induced MICA/B expression has not been fully elucidated in the context of the types of cancer cell lines. In the present study, we found that MICA/B expression varied between cancer cell lines after DNA damage. Screening in terms of chromatin remodeling identified that inhibitors related to chromatin relaxation via post-translational modification on histone H3K9, i.e. HDAC, Suv39 or G9a inhibition, restored DNA damage-dependent MICA/B expression in insensitive cells. In addition, we revealed that the restored MICA/B expression was dependent on ATR as well as E2F1, a transcription factor. We further revealed that low-dose treatment of an HDAC inhibitor was sufficient to restore MICA/B expression in insensitive cells. Finally, we demonstrated that HDAC inhibition restored DNA damage-dependent cytotoxic NK activity against insensitive cells. Thus, the present study revealed that DNA damage-dependent MICA/B expression in insensitive cancer cells can be restored by chromatin relaxation via the HDAC/Suv39/G9a pathway. Collectively, manipulation of chromatin status by therapeutic cancer drugs may potentiate the antitumor effect by enhancing immune activation following radiotherapy and DNA damage-associated chemotherapy.

Insights into the Roles of Midazolam in Cancer Therapy.

With its high worldwide mortality and morbidity, cancer has gained increasing attention and novel anticancer drugs have become the focus for cancer research. Recently, studies have shown that most anesthetic agents can influence the activity of tumor cells. Midazolam is a γ-aminobutyric acid A (GABAA) receptor agonist, used widely for preoperative sedation and as an adjuvant during neuraxial blockade. Some studies have indicated the potential for midazolam as a novel therapeutic cancer drug; however, the mechanism by which midazolam affects cancer cells needs to be clarified. This systematic review aims to summarize the progress in assessing the molecular mechanism of midazolam as an anticancer agent.

Rational design and structure-activity relationship studies of quercetin-amino acid hybrids targeting the anti-apoptotic protein Bcl-xL.

Anti-apoptotic proteins, like the Bcl-2 family proteins, present an important therapeutic cancer drug target. Their activity is orchestrated through neutralization upon interaction of pro-apoptotic protein counterparts that leads to immortality of cancer cells. Therefore, generating compounds targeting these proteins is of immense therapeutic importance. Herein, Induced Fit Docking (IFD) and Molecular Dynamics (MD) simulations were performed to rationally design quercetin analogues that bind in the BH3 site of the Bcl-xL protein. IFD calculations determined their binding cavity while Molecular Mechanics Poisson Boltzmann Surface Area (MM-PBSA) and Molecular Mechanics Generalised Born Surface Area (MM-GBSA) calculations provided an insight into the binding enthalpies of the analogues. The quercetin analogues were synthesized and their binding to Bcl-xL was verified with fluorescence spectroscopy. The binding affinity and the thermodynamic parameters between Bcl-xL and quercetin-glutamic acid were estimated through Isothermal Titration Calorimetry. 2D 1H-15N HSQC NMR chemical shift perturbation mapping was used to chart the binding site of the quercetin analogues in the Bcl-xL that overlapped with the predicted poses generated by both IFD and MD calculations. Furthermore, evaluation of the four conjugates against the prostate DU-145 and PC-3 cancer cell lines, revealed quercetin-glutamic acid and quercetin-alanine as the most potent conjugates bearing the higher cytostatic activity. This pinpoints that the chemical space of natural products can be tailored to exploit new hits for difficult tractable targets such as protein-protein interactions.

COSMIC: somatic cancer genetics at high-resolution.

COSMIC, the Catalogue of Somatic Mutations in Cancer (http://cancer.sanger.ac.uk) is a high-resolution resource for exploring targets and trends in the genetics of human cancer. Currently the broadest database of mutations in cancer, the information in COSMIC is curated by expert scientists, primarily by scrutinizing large numbers of scientific publications. Over 4 million coding mutations are described in v78 (September 2016), combining genome-wide sequencing results from 28 366 tumours with complete manual curation of 23 489 individual publications focused on 186 key genes and 286 key fusion pairs across all cancers. Molecular profiling of large tumour numbers has also allowed the annotation of more than 13 million non-coding mutations, 18 029 gene fusions, 187 429 genome rearrangements, 1 271 436 abnormal copy number segments, 9 175 462 abnormal expression variants and 7 879 142 differentially methylated CpG dinucleotides. COSMIC now details the genetics of drug resistance, novel somatic gene mutations which allow a tumour to evade therapeutic cancer drugs. Focusing initially on highly characterized drugs and genes, COSMIC v78 contains wide resistance mutation profiles across 20 drugs, detailing the recurrence of 301 unique resistance alleles across 1934 drug-resistant tumours. All information from the COSMIC database is available freely on the COSMIC website.

Small Molecular Inhibitors Targeting Chromatin Regulating Proteins for Cancer.

Chromatin-regulating proteins modulate nucleosome structure by either modifying histones covalently or disrupting DNA-protein interaction directly with ATP hydrolysis. Evidence has shown that chromatin-regulating proteins play critical roles in regulation of molecular processes using DNA as template, including gene expression, DNA replication, DNA damage repair, and chromosome integrity. In most of human malignancies, chromatin-regulating proteins have been shown as functional oncogenes. In some scenarios, chromatin-regulating proteins also could have tumor suppressive functions. Thereby, small molecular inhibitors targeting chromatin-regulating proteins could be used for cancer therapies. Numerous small molecular inhibitors against chromatin-regulating proteins are recently developed by academic and industrial groups. These compounds are evaluated for antitumor effects in vitro and in vivo. Some of them have shown great potential to become a therapeutic drug for cancer, and is currently evaluated in clinical trials. A few compounds have been approved for clinical use in cancer treatment. In this review, we will focus on the recent progress on the development of small inhibitors of chromatin-regulating proteins for cancer therapy.